Like the liver and just a few other organs, the prostate gland has the ability to regenerate itself. In castrated mice, the prostate shrinks to a tenth of its original size. But giving the mice testosterone restores the prostate. HHMI investigator Owen Witte, at the University of California, Los Angeles, thinks some prostate cancers may be co-opting the gland's regenerative properties.

“The majority of cells in the gland require testosterone for their maintenance but there is a group of cells that can survive in the absence of testosterone and re-grow the whole organ,” explains Witte. He has created numerous prostate cancer cell lines and mouse models that can report what genes and proteins are activated when prostate cancers grow. With the help of these tools, he is studying what role stem cell-related proteins in the prostate might play in cancers. He has found one protein—dubbed prostate stem cell antigen—in higher levels in prostate cancers, a hint that cancers could be pirating the prostate regeneration system. By understanding how different molecules interact at different points during prostate cancer growth, Witte hopes his research will lead to treatments to stop the tumors at their earliest stages.

—S.W.

HHMI INVESTIGATOR