Exosomes and Prostate Cancer
Just as a dandelion sends forth its seeds, cells in our bodies release tiny, self-contained pods called extracellular vesicles (EVs). But unlike dandelion wisps that scatter in the wind, these EVs are sent in specific directions, as if the cell says, "Go out the back door," or "Go to the street." Once they're launched, EVs get busy. Each one carries an abbreviated, condensed version of the cell's proteins and genetic information and as an EV moves from one cell to another, it causes little changes in the cells it touches. "EV production is amplified in prostate cancer," says geneticist Stephen Gould, Ph.D., professor of biological chemistry, "sometimes as much as 10 times higher than in normal cells." The problem is that the contact between a cancer-made EV and a normal cell can be harmful. These EVs "have been shown to promote cancer growth and metastasis by delivering signals and molecules to neighboring cells." Basically, as the EVs transfer genetic material from the "mother ship" – the cancer cell that made them – they reprogram neighboring cells to create a friendlier environment where cancer is more likely to thrive. "For example, cancer cancerderived vesicles can cause endothelial cells to make new blood vessels to feed the tumor," notes Gould, "and can silence cells of the immune system that might otherwise attack and kill the tumor cells."
As the EVs transfer genetic
material from the "mother ship"
– the cancer cell that made them
– they reprogram nearby cells to
create a friendlier environment
where cancer can thrive.
With co-investigator William Isaacs, Ph.D., the William Thomas Gerrard, Mario Anthony Duhon and Jennifer and John Chalsty Professor of Urology, Gould is using his award from the Patrick C. Walsh Prostate Cancer Research Fund to characterize EVs made by prostate cancer cells. The scientists are identifying the specific proteins and RNA material released by the cells, and testing to see if they can affect the production of these vesicles. They also hope to find out the role EVs play in cell-to-cell communication; particularly, how they transmit RNA and other genetic material from prostate cancer cells to normal cells. Gould believes this work will produce several potential targets for new ways to treat prostate cancer.