SELECTIVE FARNESOL TOXICITY AND TRANSLOCATION OF PROTEIN-KINASE-C IN NEOPLASTIC HELA-S3K AND NONNEOPLASTIC CF-3 CELLS

We have reported earlier that farnesol, a 15 carbon isoprenoid, has in hibitory effects on the growth and viability of a variety of cultured cells of neoplastic derivation but is considerably less cytotoxic to c ells derived from normal tissue (Cancer Lett., 79, 175-179). As part o f our search for the mechanism of this observation, we have studied th e effect of 20 mu M farnesol on the distribution of protein kinase C ( PKC) between cytosolic and membrane fractions of HeLa S3K cells and fi broblasts line CF-3. In HeLa cells farnesol caused translocation of PK C from membrane fraction to cytosol after 1 h of incubation and also p revented PMA-stimulated induction of PKC translocation from cytosol to membranes. Up to 6 h of incubation, there was no effect of farnesol o n PKC localization in CF-3 fibroblasts. The results point to possible involvement of PKC in the toxic effect of farnesol which occurs with s ome degree of selectivity depending on cell origin.