Enhanced expression of vimentin in motile prostate cell lines and in poorly differentiated and metastatic prostate carcinoma.

Abstract

BACKGROUND: The metastatic potential of a series of prostate cell lines was analysed by measuring motility and invasiveness, and further correlated to the expression of epithelial differentiation markers. METHODS: Invasion and motility were measured using in vitro assays. Immunohistochemistry of cell lines and tissues was used to identify expression of cytokeratins 8 and 1, 5, 10, 14, vimentin, prostate specific antigen, prostate specific membrane antigen, androgen receptor, desmoglein, E-cadherin, beta1 integrin, CD44, hmet, vinculin and actin. RESULTS: Expression of vimentin was the only marker to correlate with motility, no markers correlated to invasion. Lower vimentin expression was observed in cells with low motility (PNT2-C2) and high expression in cells with high motility (P4E6, PNT1a, PC-3). Vimentin expression was not detected in well differentiated tumours, moderately differentiated tumours contained vimentin positive cells (1/9 bone scan negative, 2/5 bone scan positive), but the majority of poorly differentiated cancers (4/11 bone scan negative, 9/14 bone scan positive) and bone metastases (7/8) had high vimentin expression in tumour cells. CONCLUSIONS: Motile prostate cancer cell lines express vimentin. In tissue sections, the presence of vimentin positive tumour cells correlated positively to poorly differentiated cancers and the presence of bone metastases.