UC San Diego

Prostate cancer is the second most common cause of cancer death for U.S. men. While androgen deprivation therapy is effective for treating many patients, some patients’ prostate cancer nevertheless progress into a lethal form which does not depend on androgen. The mechanism behind androgen-independent prostate cancer remains unknown; however, previous data suggests cancer stem cells are a potential cause. To confirm the presence of cancer stem cells in prostate cancer and to explore the timing of prostate cancer stem cell detection, patient needle biopsy samples confirmed as containing prostate cancer were stained with six stem cell markers. Stem cell markers CD133, LGR5, ALDH7A1, CD44, Nanog and Oct4 were found to react with the exact structures used by pathologists to diagnose prostate cancer in H&E staining procedures. The six markers are positively expressed in all available patient needle biopsy samples with the exception of CD44. CD44 is not expressed in one of the samples. The expression of six stem cell markers confirms that the adenocarcinoma structures in prostate cancer are composed of stem cell-like cells. The stem cell nature of cancer cells in early prostate cancer provides insight to a new treatment, differentiation therapy, to target the disease.