MODULATION OF AROMATASE-ACTIVITY BY GROWTH-FACTORS IN AN ANDROGEN SENSITIVE HUMAN PROSTATE-CANCER CELL-LINE, LNCAP

The effects of steroids and peptide growth factors on aromatase activi ty in an androgen sensitive human prostate cancer cell line (LNCaP) we re investigated. Factors were selected based on their observed modulat ion of the enzyme in other tissues. Incubation with epidermal growth f actor and transforming growth factor-I decreased aromatase activity in LNCaP cells by 25-40%. Insulin like growth factor-1, dexamethasone, d ibutyryl cAMP and phorbol 12-myristate 13-acetate, all of which are mo dulators of aromatase in other tissues, had no significant effect on a romatase activity in LNCaP cells. In addition, the cAMP-dependent prot ein kinase and protein kinase C inhibitor 1-(5-isoquinolinylsulfonyl)- 2 methylpiperazine (H-7) had no effect on the enzyme activity. Factors affecting prostatic aromatase may be distinct from those for other kn own species.