Visible light irradiation of [60]fullerene causes killing and initiation of transformation in BALB/3T3 cells

Cell transformation in vitro is a model of carcinogenesis in vivo. Two-stag e transformation assay increases the sensitivity of cells to chemicals and permits detection of carcinogens acting as initiating agents. [60]Fullerene (Co) was cytotoxic in BALB/3T3 cells when it was irradiated by visible ligh t, but not without Light irradiation. Under conditions when C-60 was cytoto xic, it acted as an initiating agent for cell transformation, but it did no t act as a complete transforming agent. The initiating activity of visible- light-irradiated C60 was statistically significant in a modified two-stage transformation assay including a procedure for replating cells treated by C 60 and Light, but it was equivocal in the standard two-stage transformation assay.