Prostate cancer cells have three-way survival switch

Prostate cancer cells can use three different signaling pathways to inactivate a protein that causes cell death and resist hormone treatment to stay alive, a Wake Forest University Baptist Medical Centre study concludes.

By inactivating a protein called BAD, prostate cancer cells become resistant to treatment that lowers levels of male hormones, such as testosterone, that prostate cells normally need to survive. The finding, published in the July 28 issue of the Journal of Biological Chemistry, may help lead to more effective drug treatments for prostate cancer. “The normal response of prostate cells when male hormones are blocked is cell death. The cancer finds a way to resist the treatment, and we wanted to discover the mechanism,” senior researcher Dr. George Kulik, assistant professor of cancer biology, said in a prepared statement. In prostate cancer cells, BAD is shut down by three signaling pathways activated by vasoactive intestinal peptide, epidermal growth factor and phosphoinositide 3-kinase. It appears that each of these three molecules is separately capable of inactivating BAD, which means that prostate cancer cells have three redundant survival mechanisms, Kulik said. “Our findings suggest that BAD is an important switch in the development and growth of prostate cancer,” he said. Kulik and his colleagues hope to conduct research in animals in order to test their findings.(Source: Journal of Biological Chemistry: Wake Forest University Baptist Medical Centre: July 2006).