Researchers Uncover How Cancer Cells Defy Death

Histological slide showing prostate
cancer; © NCI Visuals Online

The goal of the research was to uncover how prostate cancer cells become resistant to treatment that lowers levels of male hormones such as testosterone, which the cells normally need to survive. They found that a protein known as BAD is involved in three different survival strategies used by the cancer cells. "The normal response of prostate cells when male hormones are blocked is cell death," said George Kulik, Ph.D., D.V.M., assistant professor of cancer biology and senior researcher at Wake Forest University School of Medicine. "The cancer cells find a way to resist the treatment and we wanted to discover the mechanism."

The researchers evaluated three different pathways involved in cell signalling, the complex system of communication that governs cell actions. It had previously been shown that three pathways (activated by vasoactive intestinal peptide, epidermal growth factor or phosphoinositide 3-kinase) are known to be involved in cell survival. The goal of the researchers was to learn how these pathways are involved in the cancer cells resisting death. They found that all three signalling pathways work by inactivating a protein known as BAD that causes cell death.

Kulik said it appears that each of the three molecules is separately capable of inactivating BAD, which means that prostate cancer cells have three redundant survival mechanisms. "Our findings suggest that BAD is an important switch in the development and growth of prostate cancer," said Kulik. Next, the researchers hope to conduct animal studies to test their findings. "If our finding is confirmed in animals and in human tumours, there are important implications for therapy," said Kulik.

For example, scientists could develop a drug to prevent BAD from being inhibited. Or, they could use the findings to test current drugs designed to block the effects of PI3K, one of the molecules. This would involve monitoring the status of BAD to see if the drugs were having their intended effects.; Source: Wake Forest University Baptist Medical Center