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Archive - Sep 17, 2012

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Underlying Mechanism of Taxane Chemotherapy for Prostate Cancer Treatment

The power of taxane-based chemotherapy drugs are misunderstood and potentially underestimated, according to researchers at Weill Cornell Medical College writing in the September 15, 2012 issue of Cancer Research. Most physicians and investigators believe that taxane chemotherapy (paclitaxel, docetaxel, and cabazitaxel) just does one thing -- stop a cancer cell from dividing -- but the team of Weill Cornell scientists have revealed it acts much more powerfully and broadly, especially against prostate cancer. "Taxanes are one of the best class of chemotherapy drugs that we can use to treat our cancer patients, but while they are effective against a wide range of tumors, they don't work in all of them, and often patients become resistant," says the study's senior investigator, Dr. Paraskevi Giannakakou, an associate professor of pharmacology in medicine and pharmacology and director of laboratory research for the Division of Hematology and Medical Oncology at Weill Cornell. "However, our new understanding of the precise action of taxanes in a cancer cell may help us overcome drug insensitivity or acquired resistance to the drugs and design therapies that can be used in combination with them to improve cancer control." In their report, the researchers stress that investigators must shift their attention away from taxane's function during cell division to the drugs' effects on halting the everyday movement of proteins and protein-to-protein communication within cancer cells -- and to understanding how and why a cancer cell can still survive.

Breath Analysis Could Aid Diagnosis of Pulmonary Nodules

A pilot study, published in the October 2012 issue of the International Association for the Study of Lung Cancer's (IASLC) Journal of Thoracic Oncology, showed that breath testing could be used to discriminate between benign and malignant pulmonary nodules. The study looked at 74 patients who were under investigation for pulmonary nodules and attended a referral clinic in Colorado between March 2009 and May 2010. Researchers from Israel and Colorado collected exhaled breath from each patient, analyzing the exhaled volatile organic compounds using gas chromatography with mass spectrometry and information from chemical nanoarrays, which have been developed by Professor Hossam Haick and his colleagues in the Technion-Israel Institute of Technology. The patients also underwent a bronchoscopy, wedge resection, and/or lobectomy, whichever was required for final diagnosis. Nodules that either regressed or remained stable over a 24-month period were considered benign. The two techniques accurately identified that 53 pulmonary nodules were malignant and 19 were benign. Furthermore, the nanoarrays method discriminated between adenocarcinoma and squamous cell carcinoma and between early versus advanced disease. This kind of testing could help solve some of the problems computed tomography screening has created. While low-dose CT screening has reduced the mortality rate by 20 percent, many people have to undergo invasive procedures only to find out their pulmonary nodules are not cancerous. The false positive rate is 96 percent. This testing could serve as a secondary screener for patients who were found to have pulmonary nodules after CT screening. Authors say, "the reported breath test in this study could have significant impact on reducing unnecessary investigation and reducing the risk of procedure-related morbidity and costs.

Chloride Channel Study Offers New Hope for Asthma Sufferers

A new study that identifies ways to reduce the factors that lead to an asthma attack gives hope to asthma sufferers. A University of California-San Francisco (UCSF) researcher and his colleagues believe they have found a way to help asthma sufferers by impeding the two most significant biological responses that lead to an asthma attack. Asthma, a respiratory disorder that causes shortness of breath, coughing, and chest discomfort, results from changes in the airways that lead to the lungs. It affects 18.7 million adults and 7.0 million children in the U.S., according to the Centers for Disease Control and Prevention. In a paper published online on September 17, 2012 in the PNAS, researchers from UCSF, Johns Hopkins University, and Duke University demonstrate that a specific calcium-activated chloride channel holds valuable clues to reducing two biological processes that contribute to the severity of asthma. These channels regulate airway secretions and smooth muscle contraction, the two major factors that lead to an asthma attack. "Maybe if we could inhibit both of these processes by blocking this one channel, then we could affect the two symptoms of asthma," said senior author Jason Rock, Ph.D., assistant professor in the UCSF Department of Anatomy. Normally, humans have few mucus-producing cells but asthma sufferers have an elevated number of these cells in the lining of the tubes that lead to the lungs. Asthmatics also have an abnormal amount of smooth muscle surrounding the airway tubes. Even the slightest stimulus can cause these to contract. "The overabundance of mucus plugging the airways combined with hyper-contractility of the smooth muscle – when the tubes get really small – make it difficult to move air in or out," Dr. Rock said. "A lot of people equate that with breathing through a straw." Dr.