Fig. 13
Cellular Model of Ultraviolet Radiation Stress-Induced Senescence in NCI-H2170 Cells. The cells were treated for 3 days (twice a day, 20 min per session) without (0 J/cm2) and with a total dose of 8 J/cm2 of UVA light. A Flow Cytometry Gating for Single and Live Cells, Quarter 1: Forward Scatter Area vs. Forward Scatter Height; first gate that was used to exclude any doublets and clumps of multiple cells to eliminate skewed results, Quarter 2: Forward Scatter Area vs. Propidium iodide; gate that is used for live cells and gate out obvious debris (as dead cells often have varied areas and heights that can make data look sloppy), once the single cells of interest were the only cells in our analysis, Quarter 3: Control cells stained with propidium iodide show G1, S, and G2/M phase distributions. Quarter 4: The frequency of G1 senescent cells increased dramatically, and the frequencies of S and G2/M phases decreased significantly. Plots were made using ModFit. B Significantly decreased ZNF334 expression in senescent cells treated with UVA. qRT-PCR analysis was performed using RNA prepared from senescent NCI-H2170 cells treated with 8 J/cm2 of UVA light. GAPDH was used as a reference gene. Data are expressed using the 2−∆∆Ct method. Non-parametric Wilcoxon test was carried out to evaluate statistical differences between groups. Differences were considered significant when p < 0.05. C Significantly decreased TINAGL1 expression in senescent cells treated with UVA. qRT-PCR analysis was performed using RNA prepared from senescent NCI-H2170 cells treated with 8 J/cm2 of UVA light. GAPDH was used as a reference gene. Data are expressed using the 2−∆∆Ct method. Non-parametric Wilcoxon test was carried out to evaluate statistical differences between groups. Differences were considered significant at p < 0.05