Figure 3.

TiO₂ sensitizes normal cells to ultraviolet A irradiation leading to apoptotic cell death (A and B) Measurement of cell death by FACS analysis after propidium iodide staining. (A) Treatment of Chang cells with TiO₂ in combination with UVA irradiation caused cell death in proportion to the size of TiO₂ (TiO₂^P25–70, TiO₂^P25–130, TiO₂^P25–300), while treatment with TiO₂ alone did not induce cell death. (B) Treatment of WI-38 and MCF10A cells with TiO₂^P25–70 in combination with ultraviolet A irradiation caused cell death, while treatment with either TiO₂ or ultraviolet A alone did not induce cell death.

Abbreviations: UVA, ultraviolet A; WI-38, normal lung fibroblast cell line; MCF10A, normal breast epithelial cell line.