THE VAST MAJORITY OF PROSTATE CANCERS APPEAR TO BE LINKED TO A COMMON GENETIC process--a discovery that holds promise of curing cancer by reversing the process. The previously unsuspected relationship between tumors and one specific genetic process turned up in research at Johns Hopkins University.
Called gene switching, the process occurs when some members of a particular group of genes switch on while other members shut down. Gene switching is commonplace during the development of embryos, but the Hopkins scientists believe that their study, reported in the March issue of Nature Medicine, marks the first time that gene switching has been definitively linked to cancer.
When the Hopkins team compared gene activity in normal and malignant prostate cells, they found that a gene called pp32 was switched on in normal cells but usually switched off in cancer cells. Previous studies had revealed that pp32 helps prevent cells from turning malignant. Now it's clear that close relatives of this gene act like evil twins and encourage tumor growth, says Dr. Shrihari S. Kadkol, a pathologist. Moreover, adds Dr. Gary R. Pasternack, the molecular pathologist who leads the work, the same sort of gene-switching pattern has also been spotted in breast cancer patients.
If the findings are confirmed, they might lead to drugs that would treat prostate cancer by reversing the gene-switching process. Pasternack expects that uncovering the trigger for the switching eventually can lead to a method of restoring pp32's tumor-blocking role.