Fig. 3

HDAC4 enhances radioresistance of EC cells via downregulation of miR-146a. Radioresistant KYSE30 (KYSE30R) cells were treated with exogenous miR-146a mimic and expression vectors (oe-) containing the HDAC4 alone or in combination under 8 Gy X-ray irradiation. A miR-146a expression in radioresistant (n = 46) and radiosensitive ESCC (n = 36) tissues was determined using RT-qPCR, normalized to U6. B miR-146a expression in radioresistant KYSE30 cells and parental cells was determined using RT-qPCR, normalized to U6. C HDAC4 protein level in radioresistant KYSE30 cells was determined using Western blot analysis, normalized to GAPDH. D miR-146a expression in radioresistant KYSE30 cells was determined using RT-qPCR, normalized to U6. E Colony-formation ability of irradiated (8 Gy)/unirradiated (0 Gy) radioresistant KYSE30 cells was detected by colony formation assay. F Apoptosis of irradiated (8 Gy)/unirradiated (0 Gy) radioresistant KYSE30 cells was detected by flow cytometry based Annexin V-FITC/PI apoptosis assay. G Expression of cleaved-caspase3, cleaved-caspase8, pro caspase3 and pro caspase8 in irradiated (8 Gy)/unirradiated (0 Gy) radioresistant KYSE30 cells was measured using Western blot analysis, normalized to GAPDH. Values obtained from three independent experiments in triplicate were expressed as mean ± standard deviation. Values between two groups were analyzed by unpaired t-test, and values among three or more groups by one-way ANOVA followed by Tukey's post hoc test. * p < 0.05