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Archive - Jul 13, 2015

DNA-PKcs Protein Is a Master Regulator of the Pathways and Signals That Lead to the Development of Metastases in Prostate Cancer

Cancer is a disease of cell growth, but most tumors only become lethal once they metastasize or spread from their first location to sites throughout the body. For the first time, researchers at Thomas Jefferson University in Philadelphia report a single molecule that appears to be the central regulator driving metastasis in prostate cancer. The study, published in the July 13, 2015 issue of Cancer Cell, offers a target for the development of a drug that could prevent metastasis in prostate cancer, and possibly other cancers as well. The Cancer Cell article is titled “DNA-PKcs Mediated Transcriptional Regulation Drives Prostate Cancer Progression and Metastasis.” "Finding a way to halt or prevent cancer metastasis has proven elusive. We discovered that a molecule called DNA-PKcs (DNA-dependent protein kinase, catalytic subunit--see image) could give us a means of knocking out major pathways that control metastasis before it begins," says Karen Knudsen, Ph.D., Director of the Sidney Kimmel Cancer Center at Thomas Jefferson University in Philadelphia. Dr. Knudson is the Hilary Koprowski Professor and Chair of Cancer Biology, Professor of Urology, Radiation Oncology, and Medical Oncology at Jefferson. Metastasis is thought of as the last stage of cancer. The tumor undergoes a number of changes to its DNA - mutations - that make the cells more mobile, able to enter the bloodstream, and then also sticky enough to anchor down in a new location, such as the bone, the lungs, the liver, or other organs, where new tumors start to grow. Although these processes are fairly well characterized, there appeared to be many non-overlapping pathways that ultimately lead to these traits. Now, Dr. Knudsen and colleagues have shown that one molecule appears to be central to many of the processes required for a cancer to spread.

New Drug Approach Employing GABA-NAMs Relieves Depression in 24 Hours with Minimal Side-Effects; Animal Study Points to Possible Revolution in Treatment of Depression

A new study by researchers at University of Maryland School of Medicine has identified promising compounds that could successfully treat depression in less than 24 hours while minimizing side effects. Although they have not yet been tested in people, the compounds could offer significant advantages over current antidepressant medications. The research, led by Scott Thompson, Ph.D., Professor and Chair of the Department of Physiology at the University of Maryland School of Medicine (UM SOM), was published online on April 22, 2015 in the journal Neuropsychopharmacology. The article is titled “Rapid Antidepressant Action and Restoration of Excitatory Synaptic Strength After Chronic Stress by Negative Modulators of Alpha5-Containing GABAA Receptors. "Our results open up a whole new class of potential antidepressant medications," said Dr. Thompson. "We have evidence that these compounds can relieve the devastating symptoms of depression in less than one day, and can do so in a way that limits some of the key disadvantages of current approaches." Currently, most people with depression take medications that increase levels of the neurochemical serotonin in the brain. The most common of these drugs, such as Prozac and Lexapro, are selective serotonin re-uptake inhibitors, or SSRIs. Unfortunately, SSRIs are effective in only a third of patients with depression. In addition, even when these drugs work, they typically take between three and eight weeks to relieve symptoms. As a result, patients often suffer for months before finding a medicine that makes them feel better. This is not only emotionally excruciating; in the case of patients who are suicidal, it can be deadly. Better treatments for depression are clearly needed. Dr. Thompson and his team focused on another neurotransmitter besides serotonin, an inhibitory compound called GABA.

Male Black Widow Spiders Destroy Female’s Web to Deter Rivals; New Study Shows Home-Wrecking Behavior Could Protect Females from Harassment

Male black widow spiders destroy large sections of the female’s web during courtship and wrap it up in their own silk. New research recently published online in an open-access article in Animal Behaviour shows that this home-wrecking behavior deters rival males, by making the female’s web less attractive to them. The article is titled “Web Reduction by Courting Male Black Widows Renders Pheromone-Emitting Females' Webs Less Attractive to Rival Males.” Surprisingly, the females don’t seem to mind the destruction. The authors of the study, from Simon Fraser University in Canada, say the males’ behavior could protect the female from harassment, enabling her to get on with parenting. The western black widow spider – Latrodectus hesperus – is native to western North America. Female black widows (image) are approximately 15 mm long and black, with a distinctive red hourglass-shaped mark on the abdomen. The male is much smaller, and a lighter tan color with a striped abdomen. Black widows build messy webs, which they use to communicate via vibrations and pheromones. “The silk pheromones that female black widows produce are like scent-based personal ads,” said Dr. Catherine Scott, lead author of the study. “One whiff of the pheromone can tell a male about the age, mating history, and even hunger level of the female. These complex chemical messages are just one part of the spiders’ communication system, and web reduction is a fascinating behavior that allows a male to interfere with a female’s message.” Competition for females is fierce: as many as 40 male suitors may arrive at a female’s web in one night. Because of this, males have developed ways to fend off the competition, such as guarding females and applying mating plugs.