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NMR Fine-Tuned for High-Content Metabolomics Screening
Last Updated on Monday, 28 November 2011 01:48 Written by admin Monday, 28 November 2011 01:48
Scientists report on the development of a nuclear magnetic resonance (NMR)-based method forscreening the metabolomic response of drug-treated mammalian cells to drug therapy. TheSanford-Burnham Medical Research Institute, and Rady Children’s Hospital investigators, say the highly sensitive, fast, and simple method is carried out in 96-well format, and could have particular utility as a method for high-throughput primary screens. The preparation technique takes just five minutes to metabolically inactivate and lyse hundreds of drug-treated samples, and a metabolomic screening of around 100 samples can be carried out in 24 hours.
Giovanni Paternostro, M.D., and colleagues describe their approach, analyze the results of validation studies on drug-treated cancer cell lines, and evaluate the technique for screening a kinase inhibitor library. Their work is described in Nature Communications in a paper titled “Metabolomic high-content nuclear magnetic resonance-based drug screening of a kinase inhibitor library.”
High-throughput screening (HTS) is widely used as a tool in drug discovery, but most screens monitor a single variable, which is often related to activity on a single target, the researchers explain. Although high-content screening (HCS) approaches that provide multivariate readouts are gaining ground, these techniques generally rely on automated digital microscopy.
The technique developed by the Sanford-Burnham researchers involves seeding cells into a 96-well plate and treating them with several drugs. The cells’ metabolism is then quenched using sodium dodecyl sulphate (SDS), and the cells lysed using ultrasonication, in an overall process that takes just five minutes. The entire content of the well, including endo- and exo-metabolome, is then transferred into an NMR tube for analysis.
The team needed to address the relative contribution of the intracellular metabolome to the NMR spectrum acquired on the well content, including both medium and the lysed cell metabolomes. To answer this they generated NMR spectra on the entire content of the well (i.e., both endo- and exo-metabolomes), and also on the exometabolome, the endometabolome, and the medium. They found that major NMR signals arose from the extracellular metabolites, but several signals arising from the intracellular metabolites were also detected, for example glutamate, choline, and phosphocholine. Importantly, they found that spectra acquired on samples containing both endo- and extracellular metabolomes included signals resulting exclusively from the endometabolome—such as phosphocholine and glycerophosphocholine—which didn’t overlap with other extracellular resonances.
The researchers evaluated the sensitivity of the approach for monitoring metabolic changes induced by 24 hours of drug treatment, on both suspension (CCRF-CEM human leukemia cells) and adherent mammalian carcinoma cell lines (human SKOV-3 ovarian cancer cells). The cell lines were treated using either dexamethasone (Dex), rapamycin (Rap) dichloroacetate (DCA), vincristine (Vin), and different doses of L-asparaginase. The resulting spectra, generated using three different 1H NMR pulse sequences, showed that, as expected, the response to drug treatment by the more resistant SKOV-3 cells was far less pronounced compared with the CCRF-CEM cells. Encouragingly, the NMR screening approach could also be applied to detecting metabolic changes in response to forms of intervention, such as the transfection of HeLa cells the microRNAs mir-121 and mir-16. These results indicated that mir-16 induced a greater degree of metabolomic change than mir-121.
Because the developed technique requires just a small amount of cells, the investigators suggest in might have utility in studying drug response directly in primary cells, and so avoid phenotypic changes that can be induced by growth in culture. They evaluated metabolomic changes in cells isolated from bone marrow specimens of an untreated AML patient, in response to treatment with Rap and L-asparaginase, at different doses. In order to specifically highlight metabolic changes in the cells themselves, the NRM spectra acquired on unconditioned medium were compared to those acquired on AML primary cells with and without drug administraton. The resulting spectra clearly showed distinct changes in the metabolome of the primary cells as a result of drug treatment. Further analyses indicated these changes were more pronounced in response to L-asparaginase than for Rap therapy.
The team then moved on to use the approach for carrying out screening of metabolomic response to a kinase inhibitor (KI) library. Multiple rounds of screening on KIs with well-characterized and less well-characterized effects on the metabolome confirmed the utility of the technique for identifying metabolic alterations resulting from inhibitor treatment. More specifically, four hits were validated from their action on the well-characterized lactate to pyruvate ratio parameter.
“We believe that this NMR-based assay might find an immediate relevant application for screening a large number of individual or combinatorial drug interventions, reducing the number of possible drugs to be studied in more detail,” the authors state. “In addition, it might find an immediate relevant application into clinical studies.”
They admit that the main drawback of NMR is the relatively limited number of compounds that can be detected. However, they stress, “although not comprehensive of all metabolites, the wealth of information obtained from the multivariate metabolic readout is of great advantage for drug screening purposes.” The method could therefore represent a valuable high-throughput primary screen, which could then be followed by secondary assays to analyze the exo- and endo-metabolomes of selected hits using combinations of different anaytical platforms.
“There are many other possible applications of this method, for example lactate production and substrate utilization in cancer versus noncancer cells, or gluconeogenesis from different substrates in hepatocytes, relevant to diabetes. Importantly, because the measurements are performed within a global metabolic profile, they can also provide a series of compounds with partially different mechanisms of actions, which can be explored for potential synergies.”
Source: http://www.genengnews.com/gen-news-highlights/nmr-fine-tuned-for-high-content-metabolomics-screening/81245988/
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Research at A&M and Scripps finds HIV-killing compound
Last Updated on Monday, 28 November 2011 01:35 Written by admin Monday, 28 November 2011 01:35
COLLEGE STATION - A powerful topical preventative for HIV, the virus that causes AIDS, could be a step closer to clinical trials, thanks to a newly discovered molecular compound that research at Texas A&M University and the Scripps Research Institute shows dissolves the virus on contact.
The ability of the synthetic compound known as “PD 404,182″ to break apart the AIDS-causing virus before it can infect cells was discovered by Zhilei Chen, assistant professor in the university’s Artie McFerrin Department of Chemical Engineering, and her team of researchers. Their findings appear in the November online edition of “Antimicrobial Agents and Chemotherapy,” a journal of the American Society for Microbiology.
“This is a virucidal small-molecule compound, meaning that it has the ability to kill a virus; in this case that virus is HIV,” Chen says.
“Basically, it acts by breaking the virus open. We found that when HIV comes in contact with this compound, it breaks open and loses its genetic material. In a sense, the virus ‘dissolves,’ and its RNA becomes exposed.
Since RNA is pretty unstable, once it is exposed it’s gone very quickly and the virus is rendered non-infectious.”
In other words, the compound works by quickly ripping open the virus before it can inject its genetic material into a human cell. What’s more – and perhaps even more important – the compound, Chen explains, achieves this by acting on something within the virus other than its viral envelope protein, meaning that the virus can’t alter its proteins to bolster its resistance – something that’s made HIV notoriously difficult to treat.
“We believe this compound is not working on the viral protein of the viruses but on something else common in all the viruses on which we tested it – some cellular material common in these viruses,” Chen notes. “Because this compound is acting on a component that is not encoded by the virus, it will be difficult for the virus to evolve resistance against this compound.”
While not a cure for HIV, the compound demonstrates significant potential for use as a preventative, specifically in the form of a topical gel that could be applied in the vaginal canal, Chen explains.
“We conducted a number of tests to demonstrate that this compound remains active in vaginal fluid and is not rendered ineffective,” Chen says. “In the form of a vaginal gel, the compound would serve as a barrier, acting almost instantaneously to destroy the virus before it could infect a cell, thereby preventing HIV transmission from one person to another.”
Surprisingly, Chen and her team did not set out to discover an HIV preventative. Instead, they were conducting screenings of molecules for use in potential drug therapies targeting hepatitis C virus, which causes the dangerous and often fatal disease of the liver. Employing a screening system developed by Chen, the team screened thousands of molecular compounds, in search of those that could block aspects of the HCV life cycle.
During the course of the screenings, the team made an interesting discovery
- not only was PD 404,182 an HCV inhibitor, it also worked on lentiviruses (the group’s negative control in its experimental procedures). Intrigued by that finding, Chen then tested PD 404,182 on HIV, which itself is a lentivirus and found the compound to be even more effective on HIV than on HCV.
“We believe PD 404,182 acts through a unique and important mechanism,” Chen notes. “Most of the known virucidal compounds interact with the virus membrane, but our compound does not appear to interact with the virus membrane. Instead, it bypasses interaction with the membrane and still compromises the structural integrity of the virus.”
The ability of the compound to avoid interaction with the virus membrane is important because human cells have similar membranes, Chen notes. If the compound were to disrupt the structure of the virus membrane, it could also disrupt and ultimately kill human cells. PD 404,182 doesn’t interact with these membranes and is therefore a more attractive option for clinical treatment, Chen says.
As is the case with any potential pharmaceutical, several key steps are still needed before it winds up on drug store shelves. In addition to several rounds of animal studies to ensure the compound is safe for humans, further collaborations with chemists are needed to continue to improve the efficiency of the compound. Chen says. What’s more, Chen also plans to further explore the mechanism by which PD 404,182 breaks apart HIV.
This work is collaboration between Chen’s team, consisting of graduate students Ana Maria Chamoun and Rudo Simeon, postdoctoral associate Karuppiah Chockalingam, and Professor Philippe Gallay’s team at the Scripps Research Institute.
Source: http://www.kxxv.com/story/16095021/research-at-am-and-scripps-finds-hiv-killing-compound
Posted under Cell Analysis, Discoveries, Innovations and Patents, DNA Reasearch, HIV Research, New Drugs, North America, R & D, Reports, Research Projects, USA and Canada | Comments Off
Vaccine for ovarian, breast cancer shows promise
Last Updated on Wednesday, 9 November 2011 02:40 Written by admin Wednesday, 9 November 2011 02:40
(CBS) A new vaccine that targets ovarian and breast cancer has shown promise in early studies, giving scientists hope they may be closer to stopping the deadly diseases.
PICTURES: 25 breast cancer myths busted
Known as PANVAC, the vaccine triggers the immune system to attack tumor cells.
“With this vaccine, we can clearly generate immune responses that lead to clinical responses in some patients,” lead scientist Dr. James Gulley, director and deputy chief of the clinical trials group at the laboratory of tumor immunology and biology at the National Cancer Institute, said in a written statement.
For their research, published in the Nov. 8 issue of Clinical Cancer Research, scientists tested the vaccine on 26 patients, 12 of whom had breast cancer, 14 of whom ovarian. Most of the women had undergone prior chemotherapy treatment.
What did the scientists find? The vaccine caused women with breast cancer’s disease progression to stall for 2.5 months, and their median survival was 14 months. Four had stable disease, meaning the cancer didn’t grow nor shrink. Women with ovarian cancer reported a two month gap in disease progression, and survived for 15 months, and three had stable disease.
The cancer vaccine stalls cancer progression for only a couple of months? What’s the big deal?
“That time frame is not anything to write home about,” Gulley told WebMD. But he said that one of the women who had breast cancer currently shows evidence of cancer after undergoing the experimental vaccine – four years later.
“It gives us encouragement that we may be on to something here,” he said.
That 32-year-old woman was the youngest in the study, according to WebMD, but her cancer had spread to her liver and chest lymphnodes. At 18 months, there was no X-ray evidence of cancer. Gulley isn’t sure why her treatment was so successful, but the woman had only undergone chemotherapy once. That suggests her immune system might have been stronger than the other women’s.
But don’t expect the vaccine on the market anytime soon. This was only a small study, so more needs to be done.
Gulley said interest in a cancer vaccine is increasing among scientists, but said in the statement that “more studies in the appropriate patient populations are required” to ensure safety, and which patients would benefit most.
The National Cancer Institute has more on cancer vaccines in development.
Source: http://www.cbsnews.com/8301-504763_162-57321522-10391704/vaccine-for-ovarian-breast-cancer-shows-promise/
Posted under Cell Analysis, Discoveries, Innovations and Patents, Medicinal Chemistry, New Drugs, New Products, North America, R & D, Reports, USA and Canada | Comments Off
Study: Shark Chemical May Protect Humans Against Viruses
Last Updated on Tuesday, 20 September 2011 01:19 Written by admin Tuesday, 20 September 2011 01:19
A chemical derived from sharks could help protect humans against viral infections such as hepatitis, American research out Tuesday showed.
Scientists found that a chemical called squalamine demonstrated effective antiviral activity against a range of human viruses from yellow fever to hepatitis B, C and D, in both lab and animal experiments.
As the chemical has already been used in human clinical trials for the treatment of cancer and eye disorders, it means it could quickly be tested as a new drug treatment for viral diseases, researchers at Georgetown University Medical Center, Washington, said.
“To realize that squalamine potentially has broad antiviral properties is immensely exciting, especially since we already know so much from ongoing studies about its behavior in people,” lead researcher Professor Michael Zasloff, said.
“Squalamine appears to protect against viruses that attack the liver and blood tissues, and other similar compounds that we know exist in the shark likely protect against respiratory viral infections, and so on,” he added.
Zasloff believes the research, published in the “Proceedings of the National Academy of Sciences” journal, also explains the mystery of how sharks, which have a very primitive immune system, can so effectively fight the viruses that plague other living creatures.
He continued, “We may be able to harness the shark’s novel immune system to turn all of these antiviral compounds into agents that protect humans against a wide variety of viruses. That would be revolutionary. While many antibacterial agents exist, doctors have few antiviral drugs to help their patients, and few of those are broadly active.”
Source: http://www.foxnews.com/health/2011/09/20/study-shark-chemical-may-protect-humans-against-viruses/
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Canadian-made virus shows promise as cancer treatment
Last Updated on Wednesday, 31 August 2011 04:32 Written by admin Wednesday, 31 August 2011 04:32
An Ottawa-based research team has developed a virus that is showing promise as a new way of attacking and shrinking cancer tumours while leaving healthy tissue alone.
It’s early days in the still-experimental field of therapeutic cancer viruses, called oncolytic viruses. But this new study from researchers from the Ottawa Hospital Research Institute (OHRI) and the University of Ottawa advances the field a little further by showing that the virus is safe in most patients.
For the study, researchers recruited 23 advanced cancer patients whose cancer had spread to multiple organs. All had failed to respond to the usual treatments and all were in the final stages of the disease.
The patients agreed to receive a single infusion of an experimental virus into their blood, called JX-594.
JX-594 is a form of vaccinia virus that’s been used as a live vaccine against smallpox. The JX-594 virus has been genetically engineered to enhance its natural anti-cancer properties.
The doctors tried out five doses of the virus, and then took biopsies of the tumours eight to 10 days later.
The researchers found that seven of the eight patients in the highest dose groups had evidence that the virus was in place and replicating in their tumours — and not in normal tissues.
What’s more, six of eight patients in the two highest dose groups experienced a shrinking or stabilization of their tumours, while those in lower dose groups saw less of this effect.
None of the 23 patients experienced significant side effects from the virus injection, with the most common side effect being mild to moderate flu-like symptoms that lasted less than one day.
The study, which is published in the journal Nature, was designed primarily to test the safety of the virus, not to cure the patients. In fact, some of the patients later died of their disease.
But the observation that some patients saw their tumours shrink was a welcome discovery.
Dr. John Bell, one of the study’s co-authors and a researcher at OHRI says it’s exciting that the virus led to results after just one dose.
“Of course, we will need to do more trials to know if this virus can truly make a difference for patients,” he said in a statement.
Bell says the advantage of therapeutic viruses is that they can be sent through the blood, infect the cancer tumours and leave the healthy tissue alone. It’s possible that oncolytic viruses could one day offer an alternative to conventional chemotherapy and radiation treatment, which tend to destroy healthy cells as well as cancer cells.
“Oncolytic viruses are unique because they can attack tumours in multiple ways, they have very mild side effects compared to other treatments, and they can be easily customized for different kinds of cancer,” Bell said.
“We’re still in the early stages of testing these viruses in patients, but I believe that someday, viruses and other biological therapies could truly transform our approach for treating cancer.”
JX-594 was developed with Jennerex Inc., a biotherapeutics company co-founded by Dr. Bell in Ottawa and Dr. David Kirn in San Francisco.
The study was funded in part by Jennerex, as well as the Terry Fox Foundation, the Canadian Institutes of Health Research and the Ontario Institute for Cancer Research, and others.
Bell and his research team plan to do further tests on many more patients to show the treatment actually works and that the body doesn’t learn to resist the virus over time.
A Phase 2 trial is to start soon aimed at patients with end-stage liver cancer or colon cancer.
Dr. Don Morris, a professor of Medicine and Oncology at the University of Calgary says even if this treatment is shown to be effective in cancer patients, it would be years before it would be widely available.
“Truly, this is not a treatment that could be applied to community cancer patients out of a trial. We may be three, five or seven years away before this is mainstream. The caution is that this is new hope, but tempered hope,” he told CTV News.
Source: http://calgary.ctv.ca/servlet/an/local/CTVNews/20110831/cancer-tumour-virus-ottawa-110831/20110831/?hub=CalgaryHome
Posted under Cancer Research, Cell Analysis, Discoveries, Innovations and Patents, Medicinal Chemistry, North America, Oncology Research, Press Releases, R & D, Research Projects, USA and Canada | Comments Off
Genetic Link Predisposes to Mesothelioma
Last Updated on Monday, 29 August 2011 11:34 Written by admin Monday, 29 August 2011 11:34
An investigation led by scientists at the University of Hawaii Cancer Center, Honolulu, and Fox Chase Cancer Center, Philadelphia has identified germline mutations in the BAP1 gene that predispose individuals to malignant mesothelioma. The research, published online yesterday in Nature Genetics, describes two U.S. families with a high incidence of mesothelioma, as well as other cancers, associated with mutations of the gene BAP1 [1].
Scientists have discovered that individuals who carry a mutation in a gene called BRCA1-associated protein 1 (BAP1) are susceptible to developing two forms of cancer — mesothelioma and melanoma of the eye. When these individuals are exposed to asbestos or similar mineral fibers, their risk of developing mesothelioma, an aggressive cancer of the lining of the chest and abdomen, may be markedly increased.
Mesothelioma tumors are typically associated with asbestos and erionite exposure. Erionite is a naturally occurring mineral fiber similar to asbestos that is found in rock formations and volcanic ash. Deposits have been located in at least 12 states. However, unlike asbestos, erionite is not currently regulated by the U.S. Environmental Protection Agency as one of the six asbestos fibers [2]. Only a small percentage of people exposed to asbestos or erionite actually develop mesothelioma.
Mesothelioma is one of the deadliest forms of cancer, killing approximately 3,000 people each year in the United States, with half of those diagnosed dying within one year. Moreover, rates of new cases of mesothelioma in parts of the world, including Europe and China, have risen steadily over the past decade.
Michele Carbone, M.D., Ph.D., study co-leader and director of the University of Hawaii Cancer Center, said [3]:
This discovery is a first step in understanding the role of the BAP1 gene and its potential utility when screening for mutations in those at high risk. Identifying people at greatest risk for developing mesothelioma, especially those exposed to dangerous levels of asbestos and erionite worldwide, is a task made easier by virtue of this discovery.
Joseph R. Testa, Ph.D., study co-leader and Carol and Kenneth E. Weg chair in Human Genetics at Fox Chase Cancer Center, added [3]:
This is the first study to demonstrate that individual genetic makeup can greatly influence susceptibility to mesothelioma. People exposed to dangerous levels of asbestos or erionite, those with a strong family history of mesothelioma, or those who have been previously diagnosed with a rare tumor of the eye known as uveal melanoma, may benefit from this new discovery.
The researchers focused on two US mesothelioma families — one in Wisconsin and one in Louisiana — in which members were not exposed to asbestos or erionite. Family members developed a number of malignancies, including breast, ovarian, pancreatic and renal cancers, although mesothelioma predominated.
The scientists suspected that mutations in the BAP1 gene might underlie mesothelioma in people with a strong family history of the disease after noticing genetic changes in or near other stretches of DNA where the BAP1 gene is located. Looking more closely at two families with unusually high rates of mesothelioma, they saw that every person who had provided a sample and had developed mesothelioma or melanoma of the eye also carried mutations in the BAP1 gene. Further study led to sequencing the gene in 26 individuals who had developed mesothelioma but did not have a family history of the disease. Tumors from about 25 percent of this group carried mutations in the BAP1 gene, and in two cases the mutations were inherited. Both of the individuals with inherited mutations had previously developed melanoma of the eye.
The researchers hypothesize that when individuals with BAP1 mutations are exposed to asbestos, mesothelioma predominates over melanoma of the eye. Alternatively, the BAP1 mutation alone may be sufficient to cause mesothelioma, providing a cause for tumors that arise spontaneously without previous environmental exposure.
Source: http://www.highlighthealth.com/research/genetic-link-predisposes-to-mesothelioma/
Posted under Cancer Research, Cell Analysis, Discoveries, Innovations and Patents, DNA Reasearch, Genetics & Pharmacogenetics, North America, Oncology Research, Press Releases, Reports, USA and Canada | Comments Off
New tests screen for gum disease, oral cancer
Last Updated on Wednesday, 10 August 2011 11:10 Written by admin Wednesday, 10 August 2011 11:10
Future dental visits may involve more than a simple cleaning. Oral DNA testing may also help screen patients for gum disease or oral cancer.
Dr. Jessica Lawson of Urbandale Family Dentistry began offering the tests last spring. Two tests involve gum disease and a third for oral human papillomavirus, or HPV, assesses risks for oral cancer.
Researchers anticipate salivary testing may become the diagnostic tool of the future, in some instances even replacing blood work, said Lawson, one of the few dentists in the metro area offering the tests.
“It really supports what we’re doing with our patients. They know we have their best interest at heart. We’re looking to prevent, rather than treat and fix,” she said.
According to the manufacturer, OralDNA Labs, the periodontal tests have been available for nearly two years and the HPV test since January 2010.
Lawson’s staff educates all patients about testing, especially existing gum disease patients who don’t respond to frequent cleanings. Tests cost $150 each.
So far, 24 of her patients have undergone one of the gum disease tests. A handful had the HPV test, which can be a more difficult discussion since transmission is associated with sexual contact.
Testing is simple. Patients swish saline in their mouths for 30 seconds and spit it into a collection tube. The HPV test requires that patients gargle since the virus typically lives in the soft palate, esophagus and throat — similar to tissue in the cervix, where HPV is also present. Results are returned in seven to 10 days.
An estimated 50 to 60 percent of Americans have gum disease — some undiagnosed. Those patients usually have cleanings every three months. One test shows a patient’s genetic susceptibility to gum disease. It’s also a good test for new patients, Lawson said.
The other periodontal test shows what concentration of bacteria are present in the saliva and what antibiotic best treats it. The manufacturer recommends re-testing in six weeks.
Patient Amanda Rynning, 31, took that test a month ago to pinpoint the cause of tender, bleeding gums during flossing.
“I kind of questioned it a bit, but the more she talked about it and explained things, the more I felt comfortable taking the test,” she said.
The results allowed Lawson to customize Rynning’s antibiotic treatment and schedule a follow-up in a few weeks.
The test is also recommended for pregnant women to identify the presence of a specific oral bacteria associated with a higher rate of pre-term, low birth weight babies.
The HPV test targets two strains associated with squamous cell carcinoma of the head and neck, which affects 40,000 Americans every year.
As sexual activity is beginning at younger ages, the virus has become a hot topic, Lawson said.
“The prototype has changed for oral cancer. It used to be middle-aged to older men who were heavy tobacco users, abused alcohol and had other risk factors. Eighteen to 40-year-olds are now the high risk population for oral cancer due to increased sexual activity and skin-to-skin or mucous membrane transmission.”
Because there is no evidence Gardisil, an HPV vaccine, will protect against oral cancer, dentists may recommend exams every three months if needed. Lawson also can monitor with a VELscope, a fluorescent light that reflects light back at different wavelengths if tissue is damaged.
Caught early, the prognosis for oral cancer is good, Lawson said, adding that actor Michael Douglas was treated for the same condition. Initial symptoms include:
Earaches
Sore throat
Changes in voice box
Swollen, hard lymph nodes.
“We’re hoping with this test we’re monitoring things so at the first sign of symptoms we get them referred to the appropriate physicians,” she said.
Source: http://www.desmoinesregister.com/article/20110810/LIFE/308100026/-1/GALLERY_ARRAY/New-tests-screen-gum-disease-oral-cancer
Posted under Cell Analysis, Discoveries, Innovations and Patents, DNA Reasearch, North America, Oncology Research, R & D, Reports, USA and Canada | Comments Off
Urine Test May Help Detect, Stratify Prostate Cancer
Last Updated on Thursday, 4 August 2011 11:07 Written by admin Thursday, 4 August 2011 11:07
In men with elevated prostate specific antigen (PSA), an investigational urine test can detect and stratify prostate cancer, researchers reported.
The test is based on the detection of a gene fusion that is specific to prostate cancer, combined with another marker, according to Arul Chinnaiyan, MD, PhD, of the University of Michigan Medical School in Ann Arbor, and colleagues.
Stratifying patients by the combined marker identified groups with markedly different risks of cancer, high-grade cancer, and clinically significant cancer on biopsy, Chinnaiyan and colleagues reported online in Science Translational Medicine.
The noninvasive test could allow some men with elevated PSA to avoid a needle biopsy, the researchers noted.
“Many more men have elevated PSA than actually have cancer but it can be difficult to determine this without biopsy,” Chinnaiyan said in a statement. “The hope is that this test could be an intermediate step before getting a biopsy.”
The fusion at the heart of the test involves the genes transmembrane protease, serine 2 (TMPRSS2), and v-ets erythroblastosis virus E26 oncogene homolog (avian) (ERG).
The fusion appears in about half of all prostate cancers, Chinnaiyan and colleagues noted, but when it appears it is almost 100% specific for malignancy.
In a series of experiments, the researchers showed that the fusion gene was associated with indicators of clinically significant cancer at biopsy and prostatectomy.
The indicators included tumor size, high Gleason score at prostatectomy, and upgrading of Gleason grade at prostatectomy, they reported.
But because the fusion gene is not universally present, the researchers created a model that combined it and the prostate cancer antigen 3 (PCA3) gene.
In 1,065 men who underwent biopsy, the researchers used the model to stratify men into three groups – lowest, intermediate, and highest levels of the combined genes.
They found that the groups had distinctly different patterns of risk. Specifically:
- 363, 346, and 356 men were in the lowest, intermediate, and highest score groups, respectively – or 34%, 32% and 33%.
- Biopsy resulted in a cancer diagnosis in 21%, 43%, and 69% of men in the lowest, intermediate, and highest groups, respectively. The difference between the low and high groups was significant at P<0.001.
- 7%, 20%, and 40% of men in the lowest, intermediate, and highest groups were diagnosed with cancer that had a Gleason score of greater than 6. The difference between the low and high groups was again significant at P<0.001.
- Of the 966 men with enough information to determine the Epstein criteria for significance of cancer on biopsy, 15%, 33%, and 61% of men in the three groups, respectively, had Epstein-criteria-defined significant cancer.
The researchers cautioned that the test remains investigational. As well, they noted, most of the men studied so far have been Caucasian, so that additional study is needed to see if the results apply more broadly.
Source: http://www.medpagetoday.com/HematologyOncology/ProstateCancer/27884?pfc=101&spc=224
Posted under Cancer Research, Cell Analysis, Discoveries, Innovations and Patents, DNA Reasearch, Medicinal Chemistry, North America, Oncology Research, R & D, Reports, USA and Canada | Comments Off
Scientists Claim Leukemia Stem Cell Signature Independently Predicts Poor Survival in AML
Last Updated on Friday, 2 September 2011 11:39 Written by admin Tuesday, 2 August 2011 11:27
Research on samples from human acute myeloid leukemia (AML) patients has suggested that the a leukemia stem cell (LSC) gene expression profile can accurately be used to predict patient survival, even among AML patients with cytogenetically normal disease. An international team led by researchers at Ontario’s University Health Network and the University of Toronto’s Department of Molecular Genetics claim their findings support those from xenograft models suggesting that the disease is propagated by a population of rare LSCs.
Describing their findings in Nature Medicine, John E. Dick, M.D., Kolja Eppert, M.D., and colleagues report that the LSC gene signature is similar to that of hematopoietic stem cells (HSCs), and that both gene signatures were significant and independent predictors of patient survival. Moreover, the LSC gene signature could accurately predict poor survival in about 50% of AML patients with cytogenetically normal disease who would otherwise be classified as low risk on the basis of mutations in specific individual genes. Importantly, the LSC signature could be identified even in unsorted AML cell populations in which LSCs were very rare, suggesting that LSC-derived AML-blasts retain at least part of their progenitors’ expression profiles.
The researchers finally highlight the need to develop LSC biomarkers for use in patient evaluation, and claim that therapies targeting LSCs would improve survival outcomes. Their paper is titled “Stem cell gene expression programs influence clinical outcome in human leukemia.”
Xenograft studies indicate that some solid tumors and leukemias are organized as cellular hierarchies sustained by cancer stem cells (CSCs), the authors write. Although the clinical relevance of the CSC model in humans has, to date, remained uncertain, recent evidence from leukemia patients does support the notion that LSC properties may be prognostic: correlative studies have linked outcome with either the capacity for a sample to be xenografted or surface expression of LSC-linked markers.
Moreover, they continue, if CSCs are more prognostic than non-CSCs, the molecular machinery underpinning the properties of such stem cells is likely to likely to influence clinical outcome. “Indeed, LSCs have the core set of biological functions common to all stem cells, including self-renewal and the ability to produce differentiated, non-stem cell progeny.”
The University Health Network team set out to investigate the specific properties of CSCs in leukemia further by defining the gene expression signatures of both LSCs and hematopoietic stem cells (HSCs) from functionally validated, sorted fractions of primary human AML samples. Sixteen primary human AML samples were sorted into four cell populations on the basis of surface expression of the markers CD34 and CD38: previous studies have suggested LSCs are primarily CD34+CD38-. Each cell fraction was then assayed using an optimized xenotransplantation assay to identify LSC-enriched and LSC-depleted populations.
As expected, LSCs were found in the CD34+CD38? fraction in all but one of the informative cases. However, the cells were also found in at least one other fraction in the majority of AML samples, and in 50% of cases the majority of LSCs were found in the CD34+CD38+ fraction, “establishing heterogeneity between cell surface marker expression and LSC activity among individual samples,” the authors state. Overall, LSCs ranged in frequency from 1 in 1.6 × 103 cells, to 1 in 1.1 × 106, but were generally found at the highest frequency in the CD34+CD38? fraction. Importantly, the researchers note, “LSC-containing fractions that initiated leukemia generated a xenograft that acquired the marker phenotype of non-LSC fractions, confirming earlier reports that AML is hierarchically organized.”
Each functionally validated fraction was then subjected to global gene expression analysis to identify LSC-related (LSC-R) gene profiles. Bioinformatics analyses compared global gene expression patterns of 25 LSC-enriched fractions to 29 fractions without LSCs. The results threw up an initial LSC-R signature including 42 genes, which was validated by RT-PCR. This same gene signature was identified in AML samples with a variety of karyotypic alterations and French-American-British subtype.
Then, because LSCs and HSCs both have canonical stem cell functions including self-renewal and the ability to make non-stem cell, mature progeny, the team also generated HSC gene-expression profiles to see whether human LSCs share molecular mechanisms and gene-expression programs with HSCs.
A comparison of the resulting 121-gene HSC-related (HSC-R) profile with the LSC-R gene profile identified 44 leading-edge genes, termed the core enriched HSC-LSC genes (CE-HSC-LSC), which appeared to represent HSC genes that are also differentially expressed in LSCs. Of these, 18 are implicated in stem cell regulation, oncogenesis, or both, the authors note. However, protein interaction network analyses highlighted the enrichment of multiple pathways distinct from the progenitor network, including Notch and Jak-STAT signaling, which are implicated in stem cell regulation, “thereby supporting the stem cell nature of the HSC- and LSC-related gene profiles.”
Significantly, when the researchers compared their data with previously generated gene datasets from stem, progenitor, and mature cell populations, and from embryonic stem cells, they found that LSC gene expression correlated positively with primitive cell gene sets and negatively with gene sets derived from more differentiated cells and from ES cells. “Collectively, our data establishes that an HSC expression program and not a common lineage-committed progenitor or ES cell-expression pattern is preferentially expressed in LSCs compared with more mature non-LSC leukemic cells,” they conclude.
To test the clinical relevance of LSCs, the team then looked for a link between LSC-R and HSC-R gene signatures and clinical outcomes, in three large clinically annotated gene expression datasets derived from unsorted AML cells. They found that the LSC-R and HSC-R profiles were very similar among a cohort of 285 AML samples, and that the profiles were either positively or negatively correlated with cluster gene sets characterized by molecular markers indicative of poor prognosis or good prognosis.
They then analyzed the LSC-R, HSC-R, and CE-HSC-LSC signatures in new gene expression data generated on about a third of the AML samples that had been stratified in terms of poor or good prognostic risk groups on the basis of cytogenetic alterations. In this case higher expression of all three signatures distinguished poor prognostic risk subjects. “These findings demonstrate that AML samples associated with worse prognosis express stem cell-related genes more highly than less aggressive AML samples,” they note.
As a final test of clinical relevance, the researchers looked at a cohort of 160 cytogenetically normal AML subjects for whom gene expression and survival data were available. For this analysis they used the LSC-R or HSC-R gene signature to divide the subjects into two equal groups, based on the median expression of the respective signatures in bulk AML bone marrow cells.
Both signatures negatively correlated with overall survival and event-free survival with a high degree of significance. Moreover, there was a significant negative correlation between the occurrence of complete remission and high expression of the LSC-R signature, and an almost significant negative correlation between complete remission occurrence and the HSC-R signature. “Our data demonstrate that high expression of stem cell expression signatures directly predicts patient survival in cytogenetically normal AML and, therefore, that variation in stem cell expression programs among subject samples is highly correlated with heterogeneity in disease outcome,” the team writes.
Of particular interest, multivariate analyses showed that the LSC-R and HSC-R signatures predicted overall and event-free survival independently of known molecular prognostic factors in cytogenetically normal patients, such as molecular risk status and CEBPA mutation. In fact, after subdividing the AML samples that were informative for molecular risk status, they found that each stem cell signature identified subsets of subjects with poor survival in both high molecular risk (HMR) group and low molecular risk (LMR) groups. “Thus, the LSC-R and HSC-R signatures can be used to separate patients currently identified as low risk into groups who respond well to standard therapy and those who may benefit from more intensive therapy, including stem cell transplant.”
The researchers state their studies provide evidence supporting the hierarchical organization of AML according to the CSC model, and support the notion that LSCs are not just artifacts of experimental xenograft models. Moreover, they suggest a similar investigative approach could be used to assess both the identity and clinical relevance of LSCs and CSCs from other leukemias and solid tumors.
“Our findings warrant validation in a large cohort and a clinical trial to test the LSC-R signature in the LMR subgroup,” they continue. “If our results are confirmed, poor-risk patients might benefit from more aggressive therapy such as allogeneic transplant or alternative therapy.”
The authors admit that they found it rather counterintuitive that a stem cell signature could be detected in unsorted samples containing a very small population of LSCs, and in which the vast majority of cells are differentiated non-LSC blasts. This, they remark, suggests that stem cell expression programs persist in these blasts at a population level, even though no individual blast retains the full repertoire or expression level of stem cell genes.
Source: http://genengnews.com/gen-news-highlights/scientists-claim-leukemia-stem-cell-signature-independently-predicts-poor-survival-in-aml/81245599/
Posted under Cancer Research, Cell Analysis, Discoveries, Innovations and Patents, North America, Oncology Research, R & D, Reports, Research Projects, USA and Canada | Comments Off
Studies Show Natural Protein May Provide Benefits Against Stroke up to 12 Hours After Onset
Last Updated on Wednesday, 27 July 2011 04:38 Written by admin Wednesday, 27 July 2011 04:38
Scientists suggest that treating stoke patients with an endogenous immunomodulatory neuroprotectant protein, ?B-crystallin (Cryab), could help limit brain damage even if first administered 12 hours after the onset of stroke. Studies by a Stanford University School of Medicine team in a mouse model of stroke found that administering Cryab to animals 12 hours after stroke induction led to significantly reduced stroke volume and lower levels of inflammatory cytokines associated with stroke pathology than untreated mice.
Conversely, animals in which the Cryab gene had been knocked out demonstrated increased lesion size and diminished neurologic function after stroke than wild-type mice. The research team, led by Gary K. Steinberg, M.D., director of Stanford’s Institute for Neuro-Innovation and Translational Neurosciences, reports its findings in PNAS in a paper titled “Systemic augmentation of ?B-crystallin provides therapeutic benefit twelve hours post-stroke onset via immune modulation.”
Tissue plasminogen activator (tPA) is currently the only FDA-approved treatment for stroke, and must be given within 4.5 hours of stroke onset to be effective, the researchers note. tPA acts through the conversion of plasminogen into active plasmin, to cleave the blood clot, and exemplifies strategies that aim to alter the obstructive blood clot rather than actually protect the damaged brain.
Cryab, meanwhile, is a small heat shock protein (designated sHSP B5) that is constitutively expressed in the lens of the eye and muscle, and is induced in many types of brain injury. Previous studies have shown the protein has both anti-apoptotic and immunomodulatory properties; it is also the most abundant induced transcript in multiple sclerosis lesions and is highly expressed in areas of inflammation, the authors add.
Previous studies by a group led by co-author Lawrence Steinman, M.D., George A. Zimmermann professor of neurology and neurological sciences and pediatrics at Stanford, had found that Cryab reduces the severity of brain damage caused by multiple sclerosis, and that the protein can also limit the damage caused by reduced blood supply to heart tissue and to the retina. These findings, coupled with other research suggesting that Cryab has neuroprotective properties, led Drs. Steinberg, Steinman, and colleagues to evaluate the effects of Cryab deficiency on cerebral ischemia.
They found that Cryab-knockout animals demonstrated significantly larger lesions two days after an induced cerebral artery occlusion than wild-type mice. This increased damage in the Cryab-deficient animals persisted at seven days, indicating that Cryab deficiency affects both the early and delayed phases of ischemic damage. The Cryab-knockout mice also scored significantly worse in terms of functional assessment.
Interestingly, granulocyte and macrophage populations, and the subpopulation of monocytes, were significantly higher in the Cryab-deficient mice at the two-day post-stroke stage, but not at seven days. The numbers of lymphoid cells, however, were significantly increased in the knockout animals at seven days. More specifically, there were increased numbers of granulocytes and activated macrophages in the Cryab-deficient mice than in the wild-type controls at two days. There were also marked increases in the numbers of T cells in the brains of Cryab knockouts than wild-type mice at seven days and, in particular, increased levels of IL-17-producing ??-TCR+ (??-T) cells. The overall data suggested that “a deficiency of Cryab might lead to a more vigorous inflammatory response to stroke,” the authors note.
Because some research has previously suggested that Cryab expression is upregulated in neurons and astrocytes after cerebral ischemia, the researchers moved on to analyze levels of Cryab in the plasma of wild-type mice before stroke, and at various time points after the induction of stroke. This showed that Cryab levels were significantly increased at the 12 hour time point, and decreased gradually over the next seven days.
When they analyzed the plasma concentrations of Cryab in human patients with ischemic stroke, they found increased levels of the protein in younger patients within four hours of stroke symptom onset, but surprisingly not in older patients. In younger patients only, lesion volume also correlated with plasma Cryab levels, “perhaps indicating that the body’s endogenous response to stroke is age dependent,” the team suggests.
To test the notion that increased plasma Cryab after stroke is beneficial, Cryab-knockout mice were given intraperitoneal injections of recombinant Cryab protein, starting one hour before stroke onset and continuing at 12 hours, 24 hours, and then daily for seven days in total. Lesion sizes in the Cryab-treated knockout mice were significantly smaller than those of the knockout animals that weren’t given exogenous Cryab. Evaluation of splenocytes from PBS-treated wild-type mice, Cryab-deficient animals, and Cryab-treated Cryab-knockout animals showed that those of PBS-treated knockouts produced more proinflammatory IL-2, IL-17, and TNF than both PBS-treated wild-type mice and Cryab-treated Cryab-deficient mice. The animals receiving exogenous Cryab also produced more anti-inflammatory IL-10. “These data indicate that restoration of plasma Cryab by systemic treatment modulates the peripheral inflammatory response and is sufficient to decrease the lesion sizes in Cryab?/? mice to the levels of wild-type mice after stroke,” the researchers note.
They progressed to evaluate whether Cryab therapy could benefit wild-type mice after stroke onset. When Cryab was administered one hour before and 12 hours after stroke onset, the lesion size at two days was not different between PBS- and Cryab-treated wild-type mice groups. In contrast, when it was administered 1 hour before, 12 hours and 24 hours after, and then daily for seven days, the lesion sizes were significantly reduced in the Cryab-treated group compared with the PBS-treated group. “Moreover, starting the initial treatment even 12 hours after the stroke onset—making the treatment highly relevant if translated into the clinic—conferred neuroprotection in the Cryab-treated group,” the team claims. Analysis of splenocytes cytokines seven days after stroke in wild-type mice again showed that the Cryab-treated animals produced less proinflammatory IL-2, IL-17, IFN-?, IL-12p40, and IL-6, and more anti-inflammatory IL-10, than the PBS-treated animals.
“Our findings describe a therapeutic role for Cryab in stroke, and emphasize how it functions as an endogenous neuroprotectant by modulating the immune system,” the authors conclude. “Its presence as an endogenous protectant can be exploited by administering it in larger quantities as a therapeutic agent. Its benefit seen with starting the treatment 12 hours after stroke would represent a significant improvement over tPA if translated to the clinic.”
Source: http://genengnews.com/gen-news-highlights/studies-show-natural-protein-may-provide-benefits-against-stroke-up-to-12-hours-after-onset/81245471/
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A deadly new reason to avoid deer ticks
Last Updated on Monday, 11 July 2011 02:35 Written by admin Monday, 11 July 2011 02:35
Move over, Lyme disease: Another tick-borne illness is on the rise in various parts of the country, and this one can kill.
Known as babesiosis, the disease is caused by a microscopic parasite that attacks blood cells, causing flu-like symptoms that can make it difficult to accurately diagnose. Like Lyme disease, which is caused by bacteria, babesia microti parasites are carried by deer ticks.
First documented in Massachusetts in 1969, the once-obscure babesiosis has surfaced as a significant public health threat in parts of the Northeast and Upper Midwest over the last several years. A recent study in the journal Emerging Infectious Diseases, published by the U.S. Centers for Disease Control and Prevention, revealed that between 2001 and 2008 cases climbed from six to 119 in New York’s Lower Hudson Valley — a 20-fold regional increase.
And many cases may be escaping detection, experts say.
“I think it’s underreported. One of the reasons we’re seeing more about it is because people are becoming more aware,” said Dr. Peter Krause, a babesiosis researcher and senior research scientist at the Yale University School of Public Health. “The theory is that it’s spreading from east to west, as if you were dropping a pebble in a pond and it spread outward geographically.”
About 1,000 cases are reported annually in affected locales, Krause said, but many people with babesiosis have no symptoms and never know they’re harboring the parasite. For others, symptoms can include high fever, severe headache, fatigue, chills, and muscle aches and pains. It is treated with antimicrobial drugs, such as antibiotics.
People with compromised immune systems — including the elderly and those with cancer, HIV or no spleens — are especially at risk of potentially deadly complications such as organ failure. Between 10 percent and 20 percent of patients in those populations die as a result, Krause said.
The more prolific Lyme disease causes similar symptoms in early stage cases but is easier to diagnose by its telltale bullseye rash, said Dr. Barbara Herwaldt, a medical epidemiologist at the CDC who specializes in parasitic conditions.
Deer are pivotal to the life cycle of ticks carrying the babesia microti parasite by serving as a blood meal, shelter and a place to mate, Krause said. Ticks also feed on birds, who serve as carriers for Lyme disease, which affects the entire continental United States. Fortunately for humans, birds don’t carry babesia microti.
Krause noted that ticks need a moist climate to thrive, so dry states such as Arizona are not likely to see babesiosis cases caused by tick bites. But the disease can potentially spread to all states in an even sneakier way — through the blood supply.
Although a blood screening test is in trials, Krause said, donors are currently only asked if they have had babesiosis, and those who harbored it but never showed symptoms can pass it through their donated blood. And because most blood recipients are already physically compromised, babesiosis has about a 30 percent mortality rate in that group, he said.
“Getting babesiosis through the blood supply is a rare event and people shouldn’t panic,” he said. “I don’t think it will reach a crisis level, but it’s still a concern.”
To help prevent babesiosis, the CDC advises people with compromised immune systems or other vulnerabilities to avoid tick-infested wooded areas, particularly during warm months. The agency also recommends that everyone walk in the middle of trails and avoid bushy areas with lots of leaves or tall grasses and to use the repellent DEET and pre-treat clothes with an insect repellent containing permethrin before going outdoors.
The CDC also recommends doing full-body checks and showering within a few hours of being in the woods, as well as tossing used clothes in the dryer to kill any ticks that might be hiding there.
The authors of the study also advised clinicians to consider babesiosis in patients who have been exposed to ticks or received blood products and who show up for treatment with a fever and anemia resulting from the destruction of red blood cells.
Source: http://yourlife.usatoday.com/health/story/2011/07/A-deadly-new-reason-to-avoid-deer-ticks/49212700/1
Posted under Cell Analysis, Discoveries, Innovations and Patents, Medicinal Chemistry, North America, Press Releases, R & D, Reports, USA and Canada | Comments Off
Coffee buzz protects brain from Alzheimer’s
Last Updated on Thursday, 30 June 2011 11:00 Written by admin Thursday, 30 June 2011 11:00
For years we’ve been told that caffeinated coffee was bad for us. It’s unhealthy and addictive, doctors warned. But as vindication for all who stuck by their energizing elixir, a new study shows that guzzling caffeinated coffee may actually be good for our brains. In fact, it may help keep Alzheimer’s at bay.
The study, which was published early online in the Journal of Alzheimer’s Disease, was in mice whose DNA had been tweaked to contain a human Alzheimer’s gene. Just like humans with familial Alzheimer’s, these mice become increasingly forgetful as they age.
Amazingly, the equivalent of four to five cups of caffeinated coffee every few days led to much improved memories in the Alzheimer’s mice, says study co-author Gary Arendash, a scientist at the Florida Alzheimer’s Disease Research Center in Tampa.
Earlier research by Arendash and his colleagues showed that caffeine could at least partially block the production of beta amyloid, the sticky protein that clogs the brains of Alzheimer’s patients. They also found that a substance called granulocyte-colony stimulating factor, or GCSF, sparked the production of new axons, the communication cables that link nerve cells together, as well as new nerve cells themselves.
What’s really interesting is that caffeinated coffee — but not decaf — boosted the production of GCSF.
For the new study, Arendash and his colleagues “treated” healthy mice and Alzheimer’s mice with either caffeinated or decaffeinated coffee. Then the researchers ran a test to see if either beverage led to better memories.
The test they used mimics one that is given to humans to diagnose Alzheimer’s. In that test, people are given a bag of objects to look through (we’ll call that Bag A). And then they’re shown another bag of objects (Bag B). Later on, they’re asked to remember what was in Bag A.
Studies have shown that people with Alzheimer’s have a tough time remembering what was in Bag A because the distraction of looking through the objects from Bag B gets in the way of storing the contents of A in their long term memories. That’s generally not a problem for people with healthy brains.
The two part mouse test involved water mazes. The mice has to find — and remember — the location of a submerged platform in a tub of water that is deep enough that they need to swim till they find the platform.
After they find the platform in one tub, they’re moved to another tub where they have to find yet another platform. Mice with Alzheimer’s generally have a tough time remembering the location of the first platform when they’re placed in the original tub. But in Arendash’s study, Alzheimer’s mice that got caffeinated coffee had memories that were just as good as those of normal mice.
Lest you dismiss this study because it’s just in rodents, Arendash says he’s got new data in humans. That data is still being analyzed, he says, but so far it looks like caffeinated coffee has the same impact in people as it does in mice.
Source: http://bodyodd.msnbc.msn.com/_news/2011/06/28/6968218-coffee-buzz-protects-brain-from-alzheimers
Posted under Alzheimer's disease, Cell Analysis, Discoveries, Innovations and Patents, North America, R & D, Reports, Research Projects, USA and Canada | Comments Off
Hemophilia Is Target of Therapy on Genome
Last Updated on Monday, 27 June 2011 11:13 Written by admin Monday, 27 June 2011 11:13
Researchers using a new technique for editing the genome of living cells have shown that they can cure hemophilia in mice, at least in principle, with a couple of injections that carry out the “cut” and “paste” operations needed to insert a corrective gene.
This is the first time this genome-editing technique has succeeded in a live animal. Along with other applications, like two AIDS treatments in preliminary stages, the new technique could be the decisive improvement that gives credibility to the long-struggling field of gene therapy.
“This may well revolutionize the field, but it won’t do so overnight,” said Dr. Katherine A. High of the Children’s Hospital of Philadelphia, the research team leader. “Any novel kind of therapeutic takes time to develop.”
The essence of the technique is the molecular scissors custom-designed to cut the genome at a unique site. This allows the corrective gene to be inserted at the right place in a chromosome.
In previous forms of gene therapy, corrective genes have been inserted into the genome at random sites, for lack of the ability to control where they go. This approach means they are not under their natural control systems and, worse, may be inserted in the middle of some other gene that they disrupt.
“There’s a huge interest in this,” said Dr. Mark A. Kay, a gene therapist at the Stanford University School of Medicine. The genome editing approach “could be game-changing in some applications,” he said.
The technique depends on natural agents called zinc finger proteins whose role is to bind to specific sites on the genome and control adjacent genes. By mixing and matching the DNA of different natural zinc finger proteins, researchers can create artificial zinc fingers for any chosen target site on the genome.
In their genome-editing role, the zinc fingers are attached to a DNA-cutting enzyme derived from a bacterium. When a pair of zinc finger proteins line up on opposing strands of DNA, their DNA cutters face each other and scissor the DNA apart.
The zinc finger technique has been developed by Sangamo BioSciences and by academic researchers who belong to the Zinc Finger Consortium. “We are fairly inundated with requests,” said Philip D. Gregory, Sangamo’s chief scientific officer.
Sangamo designed the zinc finger pairs for Dr. High’s hemophilia project. But the fingers are designed to cut the human Factor 9 gene, not the mouse version, which has a different sequence of DNA units. So Dr. High genetically engineered a strain of hemophiliac mice that carry a mutated version of the human Factor 9 gene in place of their own.
After the cut-and-paste operation, the mice possessed a good working copy of human Factor 9, producing enough to make their blood clot much faster, and well enough to prevent hemophilia, Dr. High and her colleagues report in the journal Nature. To show that the new gene was stably incorporated into cells, they then cut out part of the mice’s livers. The liver regenerated from existing cells, retaining their ability to produce good copies of Factor 9.
Dr. High said it was too soon to try the technique in people, given that an adequate treatment for hemophilia already exists. She plans to test it next in dogs, which are a standard model for new hemophilia treatments. One of the possible problems with the technique is that the zinc fingers sometimes cut at sites other than the intended target site.
Dr. High said that besides hemophilia, the zinc finger technique could address many other liver-based genetic diseases.
Zinc fingers are being used in a different way in a treatment for AIDS, at present in early clinical trials. The fingers are used to disrupt a gene called CCR5, which makes the receptor used by the AIDS virus to gain access to cells. People with no CCR5 receptor are naturally immune to AIDS.
The hope is that patients will acquire the same immunity after their T cells are treated with zinc fingers and returned to the body.
“We are very hopeful that zinc finger technologies will have a spectacular impact on gene therapy and genetic medicine in general,” Dr. Gregory said.
Source: http://www.nytimes.com/2011/06/27/us/27therapy.html
Posted under Cell Analysis, Discoveries, Innovations and Patents, DNA Reasearch, HIV Research, North America, Research Projects, USA and Canada | Comments Off
Genentech to Appeal to F.D.A. for Breast Cancer Drug
Last Updated on Monday, 27 June 2011 11:10 Written by admin Monday, 27 June 2011 11:10
Genentech this week will step up its efforts to keep the drug Avastin available as a treatment for breast cancer, urging the Food and Drug Administration to give it one more chance to prove the medicine works.
At a hearing on Tuesday and Wednesday in suburban Washington, Genentech will ask the F.D.A. to reconsider its proposal last December to revoke the approval of Avastin for breast cancer on the grounds that new studies did not confirm that the drug helped patients.
Genentech’s approach seems intended to broaden the terms under which Avastin can remain available. The company is arguing that even if the F.D.A. reaffirms that data do not support Avastin’s effectiveness, the approval should be retained while Genentech does one more clinical trial. Avastin has remained available for breast cancer pending the appeal process.
Avastin was put on the market under an accelerated program begun in the early 1990s that allows drugs for serious diseases to be approved with less than the usual amount of evidence, subject to further studies. Dozens of drugs have been approved this way, and in at least a couple of cases approvals have been withdrawn. But this is the first time the F.D.A. will hold a hearing to consider a company’s appeal.
The debate over Avastin has evoked passions on both sides among those involved in women’s health issues. Some patient advocates argue that the F.D.A. needs to revoke the approval to maintain the integrity of the accelerated process and to ensure that cancer patients receive drugs that work.
But some breast cancer patients are expected to testify at the hearing that the drug should be kept available because it helps some women, even if not all.
“It’s so depressing to think that a federal agency can make a decision that can potentially cause me to die,” said Crystal Hanna, 35, a mother of two from Parkersburg, W.Va., who said Avastin has kept her cancer under control for almost a year.
The public comments sent to the F.D.A. before the hearing at its campus outside Washington, overwhelmingly support retaining the approval. Many of them, using virtually identical language, cite the case of Ms. Hanna, who drafted a comment for friends that circulated widely on the Internet.
Even if approval as a breast cancer treatment is ultimately rescinded, Avastin will retain approval to treat lung, colon, kidney and brain cancers. So doctors will be able to use it “off label” to treat breast cancer. But insurers might no longer pay for it for that use, putting the drug, which can cost $88,000 a year, out of reach for many women.
The Avastin issue has become caught up in the politics of overhauling health care, with some critics saying the decision not to pay for it represents rationing and others saying that Medicare should not pay for a drug that does not work. The F.D.A. maintains that it is not permitted to consider costs.
The ultimate decision will be made by the F.D.A. commissioner, Dr. Margaret A. Hamburg, who appears to have some latitude. The rules say that the F.D.A. “may” revoke the approval of a drug, but does not have to.
“Even where F.D.A. determines that confirmatory trials do not establish clinical benefit, withdrawal is not required and instead should be based on the public health considerations that motivate the accelerated approval statute,” Genentech argues in a summary of its arguments filed before the hearing.
But the F.D.A.’s drug division views the company’s request as a stalling tactic. “How many bites of the apple do you get?” Dr. Richard Pazdur, the director of the agency’s oncology drug division, said in an interview at a cancer conference early this month.
The agency, in a summary of its arguments, says that because it has already determined that the benefits of Avastin do not outweigh the risks, retaining the approval while the new study is conducted “would not be in the interest of the public health and would jeopardize the integrity of the accelerated approval program.”
Genentech and its parent company, Roche, could lose as much as $1 billion in annual sales if the breast cancer approval were revoked. Already Avastin sales for treatment of breast cancer have started declining. The drug is the world’s best-selling cancer drug, with sales last year of roughly $7 billion.
The F.D.A. approved the drug for advanced breast cancer in February 2008, after one clinical trial showed that combining Avastin with another drug, paclitaxel, delayed the median time before tumors worsened by 5.5 months, compared with using paclitaxel alone. But the women who got Avastin did not live significantly longer than those who got only paclitaxel, which is also known by the brand name Taxol.
Subsequent trials, in which Avastin was combined with different chemotherapy drugs, showed a much smaller delay in tumor progression, ranging from less than 1 month to 2.9 months. And again there was no improvement in survival for those receiving Avastin.
Based on those results and on the fact that Avastin has some life-threatening side effects, including bowel perforation and hemorrhaging, the F.D.A.’s cancer drug advisory committee voted 12 to 1 last July that the approval for the treatment of breast cancer be revoked.
The hearing this week will be before the same committee, which will make recommendations to the F.D.A. commissioner. Of the six voting committee members expected to attend, five voted to revoke the approval last July. The sixth was not at that earlier meeting. Since the data have not changed, Genentech, in the summary of its arguments, concedes it is not likely to change the committee’s mind about the benefits of Avastin.
Instead it will argue that the drug with which Avastin is combined matters. Therefore, the company should be given a chance to do another trial in which Avastin is combined with paclitaxel, as in the original trial that led to the drug’s approval.
Source: http://www.nytimes.com/2011/06/27/health/27drug.html
Posted under Cancer Research, Drug Development, FDA News, New Drugs, New Products, North America, Oncology Research, Press Releases, R & D, USA and Canada | Comments Off
Experimental Type 1 diabetes vaccine fails during second step of trial
Last Updated on Monday, 27 June 2011 11:07 Written by admin Monday, 27 June 2011 11:07
The quest for a vaccine to stop Type 1 diabetes in its tracks has hit a roadblock.
An experimental drug failed in the second step of a three-phase trial on 145 American and Canadian patients who had just been diagnosed with the disease.
The vaccine is based on an enzyme that is targeted by a diabetes patient’s immune system.
Researchers hoped the vaccine would train the immune system to not attack the enzyme – a process that destroys the pancreas’ insulin-producing cells.
But according to a study published by the medical journal The Lancet on Monday, patients who got the vaccine experienced no difference in the progression of the disease.
The vaccine was aimed at Type 1 diabetes, which used to be known as juvenile diabetes and affects less than 10% of people with the disease.
Most sufferers have what’s known as adult-onset or Type 2 diabetes.
New research shows vitamin D may ward off those at risk for Type 2 from actually developing the disease.
A study released over the weekend revealed that patients with the high levels of the vitamin were 25% less likely than those with the lowest amounts to get diabetes.
Scientists theorize that vitamin D may help the body produce more insulin or increase the body’s sensitivity to insulin.
Source: http://www.nydailynews.com/lifestyle/health/2011/06/27/2011-06-27_experimental_type_1_diabetes_vaccine_fails_during_second_step_of_trial.html?r=news/national
Posted under Clinical Trials, Discoveries, Innovations and Patents, Drug Development, New Products, North America, R & D, Reports, USA and Canada | Comments Off
Kidney improvement sustained by Abbott drug-study
Last Updated on Friday, 24 June 2011 11:18 Written by admin Friday, 24 June 2011 11:18
NEW YORK, June 24 (Reuters) – Diabetics with moderate to severe chronic kidney disease showed significant and sustained improvement in kidney function through 52 weeks of treatment with a novel drug being developed by Abbott Laboratories (ABT.N), according to data from a midstage clinical trial.
The oral drug, bardoxolone methyl, is the first medicine to demonstrate improvement in kidney function in patients with the deadly disease and could delay the need for expensive and inconvenient kidney dialysis, researchers said.
Current treatments, which are primarily blood pressure control medicines, have only been able to slow progression of chronic kidney disease.
“This is totally unique in my 20-plus years of treating patients with chronic kidney disease. There’s nothing out there that increases kidney function,” Dr. David Warnock, who presented the data at a European kidney meeting in Prague on Friday, said in a telephone interview.
“The important improvement we saw at the primary endpoint of week 24 is persisting and sustained throughout the entire 52 weeks of treatment,” Warnock added.
Bardoxolone showed statistically significant kidney improvement compared with placebo at all three doses tested — 150 milligrams, 75mg and 25mg — researchers said.
Based on the results of the 227-patient study, Abbott and its partner, privately-held Reata Pharmaceuticals, which discovered the drug, selected the 75mg dose for a recently initiated pivotal Phase III trial.
Bardoxolone is the first drug from a new class called antioxidant inflammatory modulators that work by suppressing inflammation, researchers said.
Patients in the midstage trial had Type 2 diabetes and moderate to severe chronic kidney disease, defined by an estimated glomerular filtration rate (eGFR) of 20 to 45. A person with normally functioning kidneys has an eGFR — a common measure of kidney function — of 100.
The Abbott drug raised eGFR by nearly 30 percent compared with placebo at the two higher doses. Those who got the 75 mg dose had an average eGFR improvement of 10.5, while 150mg patients saw a 9.5 eGFR improvement.
About 21 percent of placebo patients suffered a significant loss of kidney function (more than 25 percent) over the course of the 52 weeks, which is typical for the progressive disease, researchers said.
That compared with just 9 percent with significant kidney function loss for bardoxolone patients, meaning 91 percent experienced beneficial effects on kidney function, Warnock explained.
“What we have now today is a very promising data set that would suggest there is a possibility we can actually improve kidney function even in patients who have far advanced severe chronic kidney disease,” said Warnock, a professor of medicine in the division of nephrology at the University of Alabama in Birmingham.
“If this is confirmed as being clinically significant in terms of benefit to these patients, the prospects are very, very exciting,” he added.
The 1,600-subject Phase III trial will determine whether the new drug can delay progression to dialysis or cardiovascular death among very high risk kidney patients with diabetes.
The most common adverse side effect seen with bardoxolone methyl included muscle spasm, transient elevations in liver enzymes and nausea.
Most of the side effects seen in the first 24 weeks of treatment had moderated or subsided during the latter portion of the study, Warnock said.
“The adverse effect profile was something that we’re quite comfortable with, and we feel comfortable moving forward now with the definitive Phase III outcomes study,” he said.
An estimated 20 million Americans have chronic kidney disease; about 500,000 are on dialysis or in need of transplants, according to the National Kidney Foundation.
Diabetes is the most common cause of end stage renal disease, which progresses to a need for kidney dialysis and death.
“To keep patients off the dialysis machine will be a huge impact in terms of quality of life,” Warnock said.
In addition, end stage renal disease patients consume a huge portion of the Medicare budget compared to their numbers, he said.
“If we can keep people off dialysis, which costs about $75,000 a year, that would be just absolutely huge,” he said.
Results of the Phase II study presented in Prague are also being published in the New England Journal of Medicine. (Reporting by Bill Berkrot; editing by John Wallace)
Source: http://www.reuters.com/article/2011/06/24/abbott-kidney-idUSN1E75L0XM20110624
Posted under Drug Development, New Drugs, New Products, North America, R & D, Reports, USA and Canada | Comments Off
Pfizer’s Remoxy Fails to Win FDA Approval
Last Updated on Friday, 24 June 2011 11:13 Written by admin Friday, 24 June 2011 11:13
WASHINGTON — The latest attempt at an abuse-resistant formulation of oxycodone (Remoxy) failed to win approval from the FDA, according to a statement from Pfizer.
Late Thursday, the company said it had received a complete response letter from the FDA, which described the reasons for the FDA’s decision.
The FDA had turned down an earlier version of the drug in 2008, but Pfizer’s King Pharmaceuticals re-submitted the new drug application in January.
Olivier Brandicourt, Pfizer president and general manager, said in the statement that the company was “working to understand and address the issues in the FDA Complete Response Letter. Pain is an important strategic disease area for Pfizer. We share the concern about misuse and abuse of opioid medicines and are committed to being part of the solution to address this important public health and safety issue.”
Pfizer was, however, successful with another abuse-resistant product — its short-acting oxycodone product, Oxecta, which was approved earlier in the week. An earlier formulation of that drug, too, had been turned down by an FDA advisory panel, but was okayed after the company removed the niacin from its recipe, which was meant to deter oral abuse.
The Oxecta only deters crushing, chewing, snorting, and injecting — not pill-popping.
Making drugs harder to abuse has been one key strategy for some companies in an attempt to control what the government has deemed an epidemic of prescription painkiller abuse.
Source: http://www.medpagetoday.com/PainManagement/PainManagement/27252
Posted under Drug Development, FDA News, New Drugs, New Products, North America, R & D, USA and Canada | Comments Off
Pfizer, Acura Say FDA Clears Painkiller Oxecta
Last Updated on Tuesday, 21 June 2011 11:02 Written by admin Tuesday, 21 June 2011 11:02
Pfizer Inc. and Acura Pharmaceuticals Inc. said Monday the Food and Drug Administration approved a powerful painkiller that is designed to be harder to abuse.
The FDA cleared marketing of Oxecta as an immediate-release treatment for moderate to severe pain. The drug is designed to discourage common methods of abuse like crushing or dissolving, and it contains a compound that irritates the nose if it is snorted.
Shares of Acura, based in Palatine, Ill., rose 78 cents, or 20.2 percent, to $4.65 in afternoon trading. Earlier in the day its shares surged as much as 75.7 percent. Pfizer stock was unchanged at $20.26.
Oxecta is similar to Purdue Pharma LP’s OxyContin, the top-selling painkiller in the U.S. Regulators and health officials have pushed hard to get alternatives on the market after reports showed millions of people were abusing OxyContin and other prescription painkillers.
Acura and King Pharmaceuticals developed Oxecta under the name Acurox. Pfizer of New York bought King for $3.6 billion, and Oxecta is the first of King’s drugs to be approved since the deal closed in March. A second approval could come Thursday, as Pfizer is waiting for the FDA to return a decision on the drug candidate Remoxy.
OxyContin is an extended-release painkiller, however, and Citi Investment Research analyst John Boris said those drugs represent a larger market. Boris said annual sales of Oxecta could rise as high as $100 million, but Remoxy sales could reach $500 million a year.
Unlike those drugs, Oxecta is designed to start working right away.
Boris said he does not believe Remoxy will be approved this week, as Pfizer has disclosed a manufacturing issue that could delay approval. Remoxy was developed by Durect Corp. and licensed by Pain Therapeutics Inc. Pfizer now holds a sublicense from Pain Therapeutics.
Source: http://abcnews.go.com/Business/wireStory?id=13883837
Posted under Drug Development, FDA News, North America, USA and Canada | Comments Off
UPDATE 1-Pfizer stop-smoking pill raises heart risk-FDA
Last Updated on Friday, 17 June 2011 11:13 Written by admin Friday, 17 June 2011 11:13
WASHINGTON, June 16 (Reuters) – Pfizer Inc’s (PFE.N) stop-smoking drug Chantix can lead to a small increase in cardiovascular problems such as heart attacks for patients who already have cardiovascular disease, U.S. drug regulators said on Thursday.
The Food and Drug Administration is changing the label for Chantix after reviewing the results of a clinical trial.
An independent randomized trial of 700 smokers with cardiovascular disease who were treated with Chantix or a placebo showed that Chantix was effective in helping paients quit smoking for as long as one year.
However, patients who took the pill were also slightly more likely to have a heart attack or other adverse cardiovascular event versus patients on a placebo.
Many smokers who try to quit do so to prevent the risk of heart attacks, which may now be associated with Chantix.
“The known benefits of Chantix should be weighed against its potential risks when deciding to use the drug in smokers with cardiovascular disease,” the FDA said in a statement.
The FDA said it is also requiring Pfizer to evaluate the cardiovascular safety of Chantix by conducting a large, combined analysis of randomized, placebo-controlled trials.
Pfizer’s non-nicotine pill has already come under fire for psychiatric side effects, which have crimped global sales and prompted the FDA to issue a restrictive “black box” warning label for the drug.
Investors had high hopes for the drug — called Champix in Europe — when Pfizer first launched its smoking-cessation aid in 2006, but reports of serious side effects have prevented strong sales growth.
Annual sales are now about $800 million, making the pill a moderate-sized product for the world’s biggest drug maker.
Chantix has been associated with agitation, depression and suicidal thoughts, and, in clinical trials, linked with nightmares. Psychiatric symptoms have occurred in people without a history of mental illness and have worsened in people who already had mental illness.
Source: http://www.reuters.com/article/2011/06/16/drugs-fda-chantix-idUSN1618502520110616
Posted under Cancer Research, FDA News, New Products, North America, Oncology Research, USA and Canada | Comments Off
Genome Maps Solve Medical Mystery For Calif. Twins
Last Updated on Thursday, 16 June 2011 10:51 Written by admin Thursday, 16 June 2011 10:51
Ever since scientists began to sequence the entire genomes of individuals —beginning with those of Nobelist James Watson and scientific entrepreneur J. Craig Venter in 2007 — skeptics have wondered just how useful this elegant and expensive trick would become.
A pair of 14-year-old twins, Alexis and Noah Beery, now provide a compelling answer, even if it’s not yet clear how generalizable their case is to others with genetic disorders.
Whole-genome sequencing has enabled doctors to provide the Beery twins with a simple, highly effective treatment for a rare condition called DRD, or dopa-responsive dystonia. The tale of their cure appears in this week’s issue of the journal Science Translational Medicine.
The twins were diagnosed with cerebral palsy at age two. But their mother, Retta Beery, didn’t think that was correct. For one thing, Alexis’s contorted posture and jerky movements always seemed to be better in the morning and increased as the day went on.
Turns out DRD is known for these diurnal variations, as Retta found out through dogged research. That led to a diagnosis of DRD when the twins were five. Since DRD was thought to be a deficiency of the neurotransmitter dopamine, low doses of a drug called L-dopa (also used for Parkinson’s disease) rather miraculously made the twins’ “cerebral palsy” go away within days.
But other symptoms persisted and worsened. At age 14, Noah had hand tremors, awkwardness and attentional problems. More alarmingly, Alexis had breathing problems due to spasms in her larynx. But when doctors probed for an explanation of these symptoms, the twins tested negative for known mutations of two genes known to be involved in DRD.
As it happens, the twins’ father, Joe Beery, works for a California biotech company that makes DNA sequencing machines. So the parents wondered if a deep dive into their twins’ DNA might explain the nature of their particular genetic defect.
Scientists at Baylor College of Medicine, a pioneer in whole-genome sequencing of individuals, thought it was worth a go. They sequenced the genomes of the twins, their older brother, their parents and their grandparents.
Comparing the results, the researchers found that the twins both inherited a gene variant from each parent that, together, led them to have low levels of not just dopamine but two other neurotransmitters, serotonin and noradrenalin.
The twins’ neurologist, Jennifer Friedman of Rady Children’s Hospital in San Diego, suggested giving the teenagers a supplement called 5-HTP that’s a precursor for serotonin.
Together with the L-dopa, the additional supplement has improved Alexis’s breathing point to the point that she’s now running track again. Noah’s handwriting and athletic performance have improved, and he’s better able to focus in school.
And there’s an intriguing bonus. Scientists think the gene mutation that the Beery twins inherited from their mother may be responsible for a pattern of a neuromuscular disease called fibromyalgia in her family. Fibromyalgia sometimes responds to anti-depressants called SSRIs that raise serotonin levels.
If that hypothesis pans out, it would suggest that rare genetic disorders such as DRD are just the most dramatic manifestation – in people who inherit a double dose of certain gene variants – of much more common disorders such as fibromyalgia among people who have a single copy of the mutation.
Study authors say the Beerys’ case shows how genomics will ultimately revolutionize medicine by making diagnosis more precise and pointing toward life-changing treatments. Other cases are beginning to pop up, such as a Wisconsin boy whose rare disease was diagnosed by whole-genome sequencing and subsequently treated with a bone marrow transplant. (His story appeared in a Pulitzer Prize-winning series by the Milwaukee Journal-Sentinel.)
Cost is still a big obstacle. At the time the Beery family’s genomes were sequenced, it cost around $100,000 per person. Dr. Richard Gibbs of Baylor says now, less than two years later, it would cost about half as much – less than $10,000 for the actual sequencing, plus the cost of computer processing of the results and validation.
The skeptics also point out that not all genetic insights from sequencing will lead to such cheap, simple and effective treatments as the Beery twins got.
Source: http://www.npr.org/blogs/health/2011/06/16/137204964/genome-maps-solve-medical-mystery-for-calif-twins
Posted under Cell Analysis, Discoveries, Innovations and Patents, DNA Reasearch, Genetics & Pharmacogenetics, Medicinal Chemistry, North America, Research Projects, USA and Canada | Comments Off
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