A New Target for Treatment-Resistant Prostate Cancer

Despite the ongoing debate about prostate cancer screening and whether the benefits outweigh the risks, there is no debate that new treatment options are needed for men with advanced disease.  The University of Rochester Medical Center’s Dr. Edward Messing, chair of the Department of Urology and a world-renowned expert in the diagnosis and treatment of prostate cancer, says this stage of the disease is usually lethal.

Last month, in a high-profile scientific journal, our team reported a small, yet exciting step forward – we found a protein that controls cell growth in these late-stage tumors, which can be frustratingly aggressive and usually grow resistant to standard treatment.

The protein, called paxillin, appears to be a major player in prostate cancer, the second most common form of cancer in men. In the “team” of prostate cancer cells, paxillin is like the quarterback because it’s essential for the disease to execute its game plan – grow and spread throughout the body. We found that paxillin is ramped up in tissue from human tumors, much more so than in normal cells. And in mice with human prostate cancer cells, getting rid of paxillin caused the tumors to grow more slowly.

Though very early, the finding could be important for men with late-stage prostate cancer that no longer responds to hormone therapy, which starves tumors of the hormones that fuel their growth. The therapy usually keeps the cancer at bay for a year or two, but, according to the American Cancer Society, nearly all prostate cancers treated with hormone therapy become resistant over a period of months or years and the cancer makes an unwelcome comeback. Somehow, these tumors find a way to grow even when their main power source is choked off.

Paxillin controls cell growth even in the absence of hormones and provides a completely new treatment target for the disease. It’s an exciting development because once hormone therapy fails there aren’t many good options for men and their doctors to turn to.

Surprisingly, the finding stems from research in frogs. We were studying signals triggered by hormones in frog eggs when we came across paxillin. You never know where research will lead you.

To read more about paxillin in prostate cancer visit A New Route for Tackling Treatment-Resistant Prostate Cancer.

Aritro Sen, Ph.D. (at right), is a research assistant professor in the Division of Endocrinology and Metabolism and lead author of the new study. He conducted the work with senior author Stephen R. Hammes, M.D., Ph.D. (left), the Louis S. Wolk Distinguished Professor in Medicine and chief of the Division of Endocrinology and Metabolism at the Medical Center.