DNA damage and repair following treatment of V-79 cells with sulfonated phthalocyanines.

Abstract

Abstract. Two gallium‐phthalocyanines were tested for their effects on cell survival, trypsinization, and DNA strand breaks in intact and permeable cells, measured by alkaline elution. Gallium‐tetrasulfophthalocyanine was not phototoxic to cells and caused no measurable DNA damage in intact cells, while a mixture of less sulfonated gallium‐sulfophthalocyanines, containing an average of 2.7 sulfonates per molecule, was very phototoxic and induced DNA strand breaks and/or alkali‐sensitive sites; however, both drugs were equally effective at inducing DNA strand breaks in permeable cells. The DNA damage was rapidly repaired in intact cells; this process was not inhibited by aphidicolin, an inhibitor of DNA polymerases alpha and delta, under conditions in which DNA replicative synthesis was inhibited by more than 90%.