Ectopic hormone production by a prostatic small cell carcinoma xenograft line.

The xenograft line, UCRU-PR-2, has been characterized further. Established from a primary human undifferentiated small cell carcinoma of the prostate, it has been maintained as a stable xenograft line in nude mice and is currently in passage 9. The tumor has maintained the features of small cell undifferentiated carcinoma but shows epithelial as well as neuroendocrine characteristics. In this paper, we describe synthesis and secretion of peptide hormones, ACTH, beta-endorphin and somatostatin in vivo and ACTH and beta-endorphin in vitro by the tumor, UCRU-PR-2. This suggests that the gene for proopiomelanocortin is expressed and that processing of the molecule occurs. This line may yield insights into the histogenesis of the subtypes of prostate cancer, and also aid studies of regulation of ectopic hormone production.