Overexpression of cyclin D1 is rare in human prostate carcinoma

BACKGROUND. Overexpression of cyclin D1 has been documented in a number of human cancers. Increased expression of cyclin D1 can contribute to cellular transformation and abnormal proliferation. METHODS. Quantitative RT-PCR and/or Western blot analysis were used to dete rmine the level of cyclin D1 expression in 96 human prostate tumors, 15 ben ign prostate hyperplasias, 4 prostate cancer cell lines, and 3 xenografts. RESULTS. Our results demonstrate that 4.2% of the prostate tumors examined overexpressed cyclin D1 trasnscripts. In the cell lines, expression was nor mal, with the exception that reduced levels of cyclin D1 transcript and pro tein were observed in the DU145 cell Line, as expected from cells with muta nt RB. Normal levels of cyclin D1 were found in all xenograft tumors and BP H specimens examined. CONCLUSIONS. These data show that overexpression of cyclin D1 occurs rarely in human prostate tumors. However, when overexpression of cyclin D1 does o ccur, it may identify a subset of tumors with a different molecular biology . (C) 1999 Wiley-Liss, Inc.