Overexpression of AMF1 sensitizes U2OS cells to UV irradiation-induced apoptosis. (A) U2OS/AMF1 and U2OS/β-Gal cells were exposed to UV irradiation (100 J/m2) at 70% confluence. Cells were harvested after 48 h of incubation, processed, and subjected to flow cytometric analysis. Boundaries for sub-G1, indicative of apoptosis, are marked on top of each graph. (B) Series of UV dosages were tested under the same conditions as in panel A. The percentage of cells with a sub-G1 DNA content is graphed. Data were derived from three separate experiments. Error bars, standard errors.