Establishment of an immortalized Copenhagen rat prostate epithelial cell line.

An immortal cell line of Copenhagen rat prostate epithelium was established after transfection of primaly cultured cells with SV4O DNA and designated EPYP-1. The established cells have continued to proliferate more than 70 population doublings, have not undergone senescence, and stain positively for SV40 T-antigen in their nuclei by immunohistochemistry. They grow in a monolayer with an epithelial morphology and exhibit positive staining for cytokeratin. EPYP-1 cells exhibited positive staining with anti-prostatic acid phosphatase antibody and expressed Integrin a6,B1 on their plasma membrane. They did not demonstrate Dil-Ac-LDL uptake as an endothelial marker. Both testosterone and dihydrotestosterone stimulated the growth of EPYP-1. Genetically EPYP-1 was aneuploid, however no tumors formed after subcutaneous and intra-prostatic injection of the cells in Copenhagen rats. This immortalized cell line of Copenhagen rat prostate epithelial origin may be suitable for studying early events in the conversion of cells to tumorigenicity.