Fig. 2. CASC9 depletion inhibits the proliferation of SCC15 and CAL27 cells and promotes apoptosis.

a The verification of the knockdown efficiency of three siRNAs (si-1, si-2, si-3) targeting different sites of CASC9 in SCC15 and CAL27 cells showed that si-3 was the most effective siRNA for silencing CASC9 in both SCC15 and CAL27 cells. b The MTT assay revealed that the proliferation of CASC9-knockdown SCC15 and CAL27 cells was significantly increased. c Flow cytometric analysis revealed that the apoptosis index of CASC9-knockdown SCC15 and CAL27 cells increased significantly. d The TUNEL assay showed that the rate of TUNEL-positive cells in SCC15 and CAL27 cells increased significantly after the expression of CASC9 was silenced. e, f Western blotting (e) and RT-qPCR assay (f) showed that the expression level of BCL-2 was significantly reduced after CASC9 was silenced, and the BAX expression level was significantly increased. All data represent three independent experiments. Data are presented as the mean ± SD (n ≥ 3). *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001