Growth modulation of human prostatic cancer cells by interleukin-1 and interleukin-1 receptor antagonist.

The effects of interleukin-1 (IL-1 alpha or IL 1 beta) on androgen-dependent LNCaP and androgen-independent JCA-1 human prostatic cancer cell proliferation were investigated. IL-1 alpha or IL-1 beta induced a dose dependent growth reduction by 50-80% as determined by cell cycle phase distribution, cell number and clonal growth in short and long term cultures. IL-1 negated the androgen growth effect on equal molar basis but the androgen receptors were not blocked by IL-1. The presence of intracellular IL-1 receptors was detected by flow cytometry and the IL-1 mediated growth reduction could be blocked with a 500 fold excess of the IL-1 receptor antagonist (hIL-1ra), revealing a growth control involving IL-1, HIL-1ra, androgen and their receptors.