Human prostatic cancer cell derivedgrowth factor stimulating fibroblasts and its mechanisms

Abstract

A human prostatic cell line JCA-1 has been shown to release into culture medium an activity that promotes the proliferation of murine fibroblast 3T3 cells. The presence of additional serum-free conditioned culture supernatant from JCA-1 cells accelerates the 3T3 growth rate as determined by cell counts, [3H]thymidine uptake into DNA and colony formation in soft agar gel. The growth activity was determined not to derive from culture medium components. Treatment of JCA-1 cells with RNA synthesis inhibitor actinomycin D abrogated the activity, indicating that protein synthesis is required for the presence of this activity from JCA-1 cells. The molecular mass of this prostatic cell derived growth factor (PRGF) was larger than 10,000 KDa, and its interaction with fibroblasts resulted in an approximate 27 percent increase in replicating cell cycle phases S and G2M with a reciprocal decrease of G1 cells. These data indicated a mechanism causing a more rapid entry of cells into replication. The interaction between prostatic cancer cells and related tissues and their relation to pathogenesis is reviewed.