Heterogeneous cell-cycle behavior in response to UVB irradiation by a population of single cancer cells visualized by time-lapse FUCCI imaging

HeLa cells expressing FUCCI were irradiated by 100 or 200 J/m 2 UVB. Modulation of the cell-cycle and apoptosis were observed by time-lapse confocal microscopy imaging every 30 min for 72 h.

Correlation between cell survival and factors including cell-cycle phase at the time of the irradiation of UVB, mitosis and the G 1 /S transition were analyzed using the Kaplan–Meier method along with the log rank test. Time-lapse FUCCI imaging of HeLa cells demonstrated that UVB irradiation induced cell-cycle arrest in S/G 2 /M phase in the majority of the cells. The cells irradiated by 100 or 200 J/m 2 UVB during G 0 /G 1 phase had a higher survival rate than the cells irradiated during S/G 2 /M phase.