Reversible effects on cellular metabolism and proliferation by trisodium phosphonoformate

The antiviral compound trisodium phosphonoformate (PFA), which inhibits herpesvirus multiplication by 50% at a concentration of 10 muM, did not show any effects on macromolecular synthesis and cell proliferation in HeLa and human lung cells at this concentration. At the high concentration of 2 mM, PFA reduced DNA synthesis to 50% after 1 h of treatment, whereas no effects could be seen on RNA and protein synthesis. Treatment for 24 h with 1 mM PFA inhibited both DNA synthesis and cell proliferation to 50%. The inhibition of DNA synthesis and cell proliferation at 10 mM PFA was rapidly reversed by removing the drug from the cells.