Sca-1 expression identified stem cells in the proximal region of prostatic ducts with high capacity to reconstitute prostatic tissue
Review of: Patricia E Burger, Xiaozhong Xiong, Sandra Coetzee, Sarah N Salm, David Moscatelli, Ken Goto and E Lynette Wilson. PNAS, Proc Natl Acad Sci USA, May 17, 2005,vol. 102, no. 20 pp 7180 – 7185.
Stem cells and tumor cells have many common features, including self-renewal, multidrugresistance, telomerase expression and related to the prostate, androgen independence. Experimental studies demonstrated that androgens are not a prerequisite for survival of prostatic stem cells. Therefore, an understanding of prostate stem cell biology is important for new therapeutic approaches in androgen-independant prostate cancer (PCa). Furthermore, stem cells may also play a role in the development of benign prostatic hyperplasia. Isolation and characterization of prostatic stem cells will increase our understanding of the normal prostatic physiology, and hopefully also the mechanisms behind the development of prostatic hyperplasia and prostate cancer.
Burger and colleagues have previously shown a high density of prostatic stem cells in the proximal regions of the prostatic ducts. In the present paper, they identify a candidate population of prostatic stem cells in the proximal region of murine prostatic ducts that express high levels of Sca-1, in conjunction with alpha6 integrin and the anti-apoptotic factor Bcl-2, which are typical findings of stem cells. In addition, the isolated Sca-1 expressing cells were shown to regenerate abundant normal functional prostatic ducts in an in vivo transplantation assay, whereas cells that do not express this antigen formed very little tissue.
Further stratification of the phenotype of the stem cells may enable the development of rational therapies for treating prostate cancer and benign prostatic hyperplasia.