April 30, 2009, 9:37 PM CT

Cancer-obesity link

A new link between body fat and cancer identified by a Michigan State University researcher underscores obesity's health risk and could lead to new cancer therapy and prevention strategies.

Jenifer Fenton, an MSU food science and human nutrition researcher with the Michigan Agricultural Experiment Station, identified the correlation between obesity and colon cancer, the third-leading killer of Americans, in part by examining tissue hormones.

Working with MSU/MAES physiologist Julia Busik and biologist Fay Hansen-Smith of Oakland University in Rochester, Mich., Fenton examined a key hormone found in fat tissue and thought to promote cancer. Her conclusions are published in a study today in the journal Carcinogenesis.

Leptin - a fat cell-derived hormone regulating body energy - is higher in obese individuals. Fenton's study is the first to demonstrate that, at higher levels, leptin induces premalignant colon cells to produce more of a growth factor that can increase blood supply to early cancer cells - promoting tumor growth and cancer progression.

"Adipose tissue, or fat, is recognized as a significant risk factor for diabetes and heart disease, but the role of adipose tissue in cancer risk is less understood," Fenton said. "Abdominal fat in particular seems to be linked to the greatest risk for cancer. As your waist-to-hip ratio increases, so does your risk for cancer, particularly breast, colon and endometrial cancers"......... Posted by: Andria      Read more         Source

April 30, 2009, 5:08 AM CT

A new weapon against brain cancer

An unlikely multidisciplinary scientific collaboration has discovered that an electronic nose developed for air quality monitoring on Space Shuttle Endeavour can also be used to detect odour differences in normal and malignant brain cells. The results of the pilot study open up new possibilities for neurosurgeons in the fight against brain cancer.

Neurosurgeons from the City of Hope Cancer Center, along with researchers from the Brain Mapping Foundation in West Hollywood and the Jet Propulsion Laboratory (JPL) in Pasadena, used NASA's electronic nose to investigate the role of cellular odours in cellular trafficking, brain cancer metastasis, stem cell migration, and the potential of the device to be used for intraoperative imaging.

The electronic nose, which is to be installed on the International Space Station in order to automatically monitor the station's air, can detect contaminants within a range of one to approximately 10,000 parts per million. In a series of experiments, the Brain Mapping Foundation used NASA's electronic nose to sniff brain cancer cells and cells in other organs. Their data demonstrates that the electronic nose can sense differences in odour from normal versus malignant cells. These experiments will help pave the way for more sophisticated biochemical analysis and experimentation......... Posted by: Andria      Read more         Source

April 29, 2009, 5:18 AM CT

Diagnostic advance in head and neck cancer

Pharmacy scientists at Oregon State University today announced the discovery of a genetic regulator that is expressed at higher levels in the most aggressive types of head and neck cancers, in work that may help to identify them earlier or even offer a new treatment at some point in the future.

This "transcriptional regulator" is called CTIP2, and in recent research has been demonstrated to be a master regulator that has important roles in a number of biological functions, ranging from the proper development of enamel on teeth to skin formation and the possible therapy of eczema or psoriasis.

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2671404.

In the newest study, published recently in PLoS ONE, a professional journal, researchers found for the first time that levels of CTIP2 were more than five times higher in the "poorly differentiated" tumor cells that caused the most deadly types of squamous cell carcinomas in the larynx, throat, tongue and other parts of the head. There was a high connection between greater CTIP2 expression and the aggressive nature of the cancer.

Head and neck squamous cell cancers are the sixth most common cancers in the world, the scientists said in their study, and a significant cause of mortality. In 2008, cancers of the oral cavity and pharynx alone accounted for 35,310 new cases in the United States and 7,590 deaths. They have been associated with such things as tobacco use and alcohol consumption......... Posted by: Andria      Read more         Source

April 27, 2009, 5:23 AM CT

Reducing prostate cancer and disease

Statins, drugs widely prescribed to lower cholesterol, may have protective effects on prostate health. This large Mayo Clinic cohort study looked at three different aspects of urological health -- prostate cancer, erectile dysfunction and prostate enlargement. Initial research results are being presented April 25-30, 2009, at the American Urological Association (AUA) meeting in Chicago.

VIDEO ALERT: Additional audio and video resources, including excerpts from an interview with Drs. St. Sauver, Karnes and Breau describing the research, are available on the Mayo Clinic News Blog,. These materials are also subject to embargo, but appears to be accessed in advance by journalists for incorporation into stories. The password for this post is password Statin049.

These Mayo Clinic study findings came from data in the Olmsted County Study of Urinary Health Status among Men, a large cohort study of men living in Olmsted County, Minn. This study has followed 2,447 men ages 40 to 79 from 1990 to the present to assess various urologic outcomes among aging men.

"A main advantages of this large cohort study is that the men have participated in this study for over 15 years. Because of this, we have the ability to look at associations between statin use, how long statins were used and multiple aspects of urologic function," says Jennifer St. Sauver, Ph.D., Mayo Clinic epidemiologist and study author......... Posted by: Andria      Read more         Source

April 27, 2009, 5:14 AM CT

How to improve immune response to cancer

A team of researchers at The Campbell Family Institute for Breast Cancer Research (CFIBCR) at Princess Margaret Hospital and international collaborators have discovered how to trigger an improved immune response to cancer that could be included in new clinical trials that use a patient's own cells to destroy tumours.

The findings, published online today in Nature Medicine (DOI: 10.1038/nm.1953), demonstrate the tantalizing potential of immunotherapy in cancer therapy, says principal investigator Dr. Pamela Ohashi, co-director, CFIBCR.

In the lab study, the researchers combined interleukin-7 (IL-7) a key component of the immune system with a viral vaccine to improve the ability of the cells of the immune system to attack tumours. The result was clear: The combination boosted immunity to tumours.

"We are extremely excited because our research has revealed the unexpected ways IL-7 works to break down barriers that naturally block the immune response to tumours. This is important because current vaccine approaches for immune treatment induce a response in just 1% to 3% of patients," says Dr. Ohashi, a senior scientist in signaling biology who holds a Canada Research Chair in Autoimmunity and Tumour Immunity. She is also a Professor, University of Toronto, in the Department of Medical Biophysics and Immunology. "......... Posted by: Andria      Read more         Source

April 21, 2009, 5:31 AM CT

Genetic Variants Predict Recurrence of Bladder Cancer

Researchers at The University of Texas M. D. Anderson Cancer Center have discovered genetic variations in the inflammation pathway that reduce the likelihood of recurrence and increase survival of patients with non-muscle invasive bladder cancer (NMIBC) who are treated with mainstream treatment.

Patients with risk-reducing genotypes were 84 percent less likely to have their disease recur after therapy with Bacillus Calmette-Guerin (BCG), the prevailing immunotherapy to prevent high-risk NMIBC patients from developing recurrence. The recurrence-free median survival time among these patients was 96.7 months compared with 47 months among those with the more typical genotype, the team reported at the 100th Annual Meeting of the American Association for Cancer Research.

"The future purpose of this kind of study is personalized cancer treatment," said senior author Xifeng Wu, M.D., Ph.D., a professor in the Department of Epidemiology at M. D. Anderson. "This genetic information is an essential step toward constructing a blueprint that will determine therapy response and follow-up strategy".

Currently, the primary therapy for NMIBC is transurethral resection - surgical removal of the tumor tissues from bladder - combined with chemotherapy or immunotherapy such as BCG injection. Overall, the recurrence rate is around 50 percent over four years......... Posted by: Andria      Read more         Source

April 16, 2009, 5:12 AM CT

A gel to treat esophageal cancer

Gastroenterologists at Rush University Medical Center are studying the safety and efficacy of a new system for delivering chemotherapy for patients with esophageal cancer, a rare, but deadly disease that attacks the throat. The unique drug treatment delivers a highly concentrated dose of chemotherapy injected directly on to the hard-to-reach tumors in the esophagus non-surgically. Scientists at Rush are trying to determine if the gel therapy can reduce the size of the malignant tumors.

Patients diagnosed with esophageal cancer are commonly diagnosed at very advanced stages and not only have to undergo chemoradiation treatment, but may also have an esophagectomy, which is a surgical procedure to remove a part of or the entire esophagus.

"Patients with esophageal cancer have very few therapy options and life expectancy can be less than two years from first diagnosis," said Dr. Sohrab Mobarhan, principal investigator of the study and clinical director of the Coleman Foundation Comprehensive Clinic for Gastrointestinal Cancers at Rush. "This also could potentially be a viable therapy option for patients who have inoperable tumors located in their esophagus." .

The investigational drug, called OncoGel, is made of two major components, the ReGel drug delivery system, which is a gel made up of ingredients used in biodegradable stitches, and paxclitaxel, a well established, FDA-approved anti-cancer chemotherapy agent. Patients receive a one-time injection of OncoGel during an endoscopy......... Posted by: Andria      Read more         Source

April 13, 2009, 1:53 PM CT

Genetics alone is poor indicator for drug response

In certain respects, cells are less like machines and more like people. True, they have lots of components, but they also have lots of personality. For example, when specific groups of people are studied in aggregate (conservatives, liberals, atheists, evangelicals), they appear to be fairly uniform and predictable. But when looked at one person at a time, individuals often break the preconceptions.

Same with cells.

Scientists tend to identify characteristics of particular cells by looking at millions at a time. As a result, they'll find that, say, "group A" responds very well to a particular cancer therapy, whereas "group B" does not. They will then often compare group A to group B to find out why.

But often ignored is that not every cell in either group behaves in ways that the aggregate indicates. In a group of cells shown to be vulnerable to a particular cancer therapy, perhaps 10 percent resist it while 90 percent succumb. While scientists have offered various explanations for this, few have studied it.

Now a group of researchers in the lab of Harvard Medical School Professor of Systems Biology Peter Sorger have studied such "outlier" cells in the context of a new and highly touted cancer drug. They have observed that vastly disparate reactions occur within genetically homogeneous cell groups. These discrepancies result from protein levels that vary from cell to cell, even among cells that are identical genetic twins. What's more, these protein levels and their subsequent traits can be passed down to daughter cellsa heritability that has nothing to do with genetics......... Posted by: Andria      Read more         Source

April 13, 2009, 1:27 PM CT

When cancer cells can't let go

Like a climber scaling a rock face, a migrating cancer cell has to keep a tight grip on the surface but also let go at the right moment to move ahead. Chan et al. reveal that the focal adhesion kinase (FAK) coordinates these processes to permit forward movement. The study will be published online April 13 (www.jcb.org) and will appear in the April 20 print issue of the Journal of Cell Biology

Crawling cancer cells send out extensions called invadopodia. By releasing enzymes that dissolve the extracellular matrix (ECM), invadopodia clear a path for the cell to wriggle through. As they move, cancer cells get traction by temporarily attaching to the ECM through focal adhesions. FAK spurs focal adhesions to disengage, and it is more abundant in metastatic tumors. Whether FAK also regulates invadopodia was unknown.

When Chan et al. removed FAK, breast cancer cells were much less invasive. But to the team's surprise, the FAK-lacking cells sprouted extra invadopodia. The cells also sported large focal adhesions that were especially sticky. The protein Src serves as FAK's helper. FAK and Src work together to phosphorylate tyrosines in proteins such as paxillin, which then disassemble the focal adhesion. But the team observed that in cells missing FAK, the phosphorylated proteins accumulated in invadopodia. Src's localization reflects this difference. In control cells, Src accumulated in focal adhesions. In FAK's absence, Src headed to the invadopodia......... Posted by: Andria      Read more         Source

April 6, 2009, 10:14 PM CT

Breakthrough model for human cancer

AVEO Pharmaceuticals, Inc., a biopharmaceutical company leveraging breakthrough discoveries in cancer biology to discover, develop and commercialize targeted oncology therapies, today announced findings from its novel human-in-mouse (HIM) cancer model system, in which AVEO successfully created invasive human tumors from primary human breast tissue that develop over time in mice and mimic human tumor behaviors and response. The findings were published this week in the Early Edition of the Proceedings of the National Academy of Sciences

More than 95 percent of oncology drugs entering the clinic fail, due in large part to the lack of predictive animal models in the preclinical development phases. AVEO researchers have developed a sophisticated cancer biology platform that provides models of human cancer more relevant than traditional mouse models known as xenografts. In the AVEO HIM model, normal human breast tissue is engineered to express oncogenes and is then introduced into mice where it forms human breast tissue in the mouse mammary microenvironment. The tumors which then develop spontaneously acquire common and distinct mutations during tumor progression. This process results in human tumors in mice that reflect their human counterparts in that they differ slightly from one instance to another, exhibiting natural genetic variation akin to that seen in patients......... Posted by: Andria      Read more         Source