Figure 3
HIF-1 activation is required for RCC4-EV cells to confer resistance against lidocaine-induced cell death. (a and b) RCC4-EV cells were exposed to 4 mM lidocaine for 24 h with or without 100 µM YC-1. (a) Graphic depictions of caspase-3/7 activity (n = 5). (b) Cells were harvested and cell death percentages were analyzed by flow cytometry. (c and d) RCC4-VHL cells were exposed to 4 mM lidocaine and treated with 100 µM nPG, 100 µM DFX, or exposure to 1% O2 conditions for 24 h. Graphic depictions of caspase-3/7 activity (n = 5). (c) Cells were harvested and cell death percentages were analyzed by flow cytometry. (d) (e–g) RCC4-EV cells were transfected with small interfering RNA (siRNA) targeting HIF-1α (hif1a), HIF-2α (hif2a), or a negative control (scr). Expression of mRNA of HIF-1α, HIF-2α was measued by qRT-PCR. (e) Cells were exposed to 4 mM lidocaine for 24 h. Graphic depictions of caspase-3/7 activity (n = 5). (f) Cells were harvested and cell death percentages were analyzed by flow cytometry. (g) Data presented in (a–g) are expressed as mean ± standard deviation (SD). Differences between results were evaluated by two-way ANOVA followed by Dunnett’s test for multiple comparisons. *p < 0.05 compared to the control cell population at incubation time 0 h (no treatment). # p < 0.05 compared to the indicated experimental group.
