Salicylic Acid Inhibits Ultraviolet- and cis-Platinum-induced Human Immunodeficiency Virus Expression

Previous studies have shown that exposure of HeLa cells stably transfected with an HIV-long terminal repeat-chloramphenicol acetyltransferase (HTV-LTR-CAT) construct to many DNA-damaging agents (such as UV light) induces expression from the HIV LTR. By culturing the cells with salicylic acid we demonstrated dose-dependent repression of this UV-or cis-platinum (cfc-Pt)-induced HIV expression. While salicylic acid treatment, indomethacin treatment, UV exposure, or cis-Pt treatment alone decreased viability by up to 50%, equal numbers of viable cells were used for the CAT assays. Repression was evident if salicylic acid was administered 2 h before, at the same time as, or up to 6 h after exposure to the DNA-damaging agent The kinetics were similar for UV- and for cu-Pt-induced HIV expression, and induction was dependent on the UV dose or cis-Pt concentration added to the culture. pH changes of the media alone in the absence of salicylic acid did not affect HIV expression. Indomethacin (100 um) did not affect UV- or cu-Pt-induced HIV expression. These results suggest a role for the prostaglandins or the cyclo-oxygenase pathway or both in HIV induction mediated by DNA-damaging agents.