Inhibition of DNA synthesis of melanoma cells by azelaic acid.

Azelaic acid was successfully used in the clinical treatment of 7 cases of lentigo maligna in that remission of the lesions was observed in all our patients. In order to elucidate mechanism(s) of the beneficial clinical effects, we studied the effect of azelaic acid on cultured melanoma cells. Cell numbers recovered from melanoma cell cultures grown for several days in the presence of 10 mM azelaic acid were 50-70% less than those recovered from control cultures or from cultures containing 10 mM adipic acid. This reduction of cell numbers was not due to a simple cytotoxic or cytolytic effect of azelaic acid but rather due to a dose-dependent inhibition of DNA synthesis. Interestingly, nontoxic concentrations of azelaic acid, which significantly reduced DNA synthesis of cultured melanoma cells, had no overt effect on the protein synthesis of these cells. It is conceivable that inhibition of DNA synthesis is one of the mechanisms by which azelaic acid prevents growth and proliferation of abnormal melanocytes.