Prostate Cancer Research Today is a free monthly online journal that collates and summarizes the latest research about Prostate Cancer, including details on symptoms, genetics, screening, treatment, information.

Protein tyrosine phosphatase PTP1B is involved in neuroendocrine differentiation of prostate cancer.

Wu C, Zhang L, Bourne PA, Reeder JE, di Sant'Agnese PA, Yao JL, Na Y, Huang J

Department of Pathology, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA.

BACKGROUND: Prostate cancer (PC) contains a minor component of neuroendocrine (NE) cells that may stimulate androgen-independent growth of the tumor. The mechanism of neuroendocrine differentiation remains unknown. METHODS: The expression of PTP1B, a protein tyrosine phosphatase, was studied in LNCaP cells induced to show neuroendocrine phenotype by androgen withdrawal. Wild-type PTP1B and its dominant-negative mutant were transfected into LNCaP cells to study their effects on neuroendocrine differentiation. In vivo expression of PTP1B in human prostate cancer was studied by immunohistochemistry. RESULTS: Androgen withdrawal of LNCaP cells led to increased expression of PTP1B with a corresponding increase in its tyrosine phosphatase activity. Overexpression of PTP1B in LNCaP cells led to neuroendocrine differentiation while expression of its dominant-negative mutant inhibited neuroendocrine differentiation. Immunohistochemical study showed that PTP1B was exclusively expressed in neuroendocrine cells of human prostate cancer tissue. CONCLUSION: Our findings suggest that PTP1B plays an important role in neuroendocrine differentiation, and therefore, may possibly be involved in the progression of prostate cancer.

Published 3 July 2006 in Prostate, 66(11): 1125-35.
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