EFFECTS OF IFN-BETA ON GROWTH OF HUMAN PROSTATIC JCA-1 CALLS

Addition of IFN-beta resulted in a dose-dependent reduction of growth, a drop in H-3 thymidine incorporation into DNA, and a concurrent 69 % and 15% increase in the S and G(2)/M phases, of the human prostatic JCA-1 cells. No correlation existed between the antimitogenicity of IF N and increases in the double-stranded RNA dependent protein kinase ac tivity. Although IFN elicited a large increase in 2-5A synthetase acti vity, activation of the 2-5A-dependent RNase L could not be demonstrat ed in JCA-1 cells rendered permeable to 2-5A, implying that the 2-5A p athway is not involved in the anti-proliferative effects of IFN. Analy sis of endogenous proteins phosphorylated in vitro show that some IFN- inducible phosphoproteins were dependent upon the presence of double-s tranded DNA. (C) 1994 Academic Press, Inc.