Cytotoxic and mutagenic effects of carcinogenic aromatic amides and polycyclic hydrocarbons and ultraviolet irradiation in normally repairing and repair-deficient (xeroderma pigmentosum) diploid human skin fibroblasts.

The cloning ability of fibroblasts taken from a xeroderma pigmentosum patient proved 2.5-3.5 times more sensitive to the cytotoxic effect of active derivatives of carcinogens or to UV irradiation than that of normal cells. They also exhibited a corresponding 2.5- to 2.5-fold greater increase in the frequency of induced mutations to 8-azaguanine resistance per survivor, which might have been expected since these XP cells exhibit less than 20% of the DNA-repairing capacity of the normal cells following exposure to such DNA-damaging agents.