Establishment and Characterization of Three Androgen‐independent, Metastatic Carcinoma Cell Lines from 3,2′‐Dimethyl‐4‐aminobiphenyl‐induced Prostatic Tumors in F344 Rats

Three stable carcinoma cell lines, designated PLS10, PLS20 and PLS30, have been established from 3,2′‐dimethyl‐4‐aminobiphenyl plus testosterone‐induced carcinomas in the dorsolateral prostate of male F344 rats. The cells are keratin‐positive and grow as typical epithelial monolayers in culture. When injected into intact male nude mice, PLS10 and PLS30 cells form well‐differentiated adenocarcinomas with abundant connective tissue stroma, while PLS20 cells give rise to poorly differentiated adenocarcinomas. Growth of all PLS cell lines in nude mice is not affected by castration and the cells are immunohistochemically negative for androgen receptors. Tumor growth rates in nude mice were found to be PLS20 > PLS10 > PLS30, with significant in vitro stimulation by insulin/transferrin, but not epidermal growth factor, dexamethasone or basic fibroblast growth factor. Spontaneous lung metastases were observed in all cases. However, skeletal invasion including bone is essentially observed only with the PLS20 tumors. Gelatin zymography showed predominant secretion of the active form of gelatinase B (Mr 92,000 type IV collagenase) by all the cell lines. Karyotype analysis revealed PLS10, PLS30 and PLS20 to be diploid, hyperdiploid and hypertetraploid, respectively. The results demonstrate that the three PLS cell lines are androgen‐independent and metastatic in common, but have different histology, growth potential and invasiveness. They may therefore be useful models for understanding progression and metastasis of human prostatic carcinomas.