The enhanced radiosensitivity of HCT116 cells induced by celecoxib is dependent on BCCIP. A, B. After transfection with the plasmids (pPUR/U6-NC, pSilencer2.1Hyg-NC, pPUR/U6-sh1, pSilencer2.1Hyg-sh2, pSilencer2.1Hyg-sh3, pPUR/U6-sh1+pSilencer2.1Hyg-sh2 or pPUR/U6-sh1+pSilencer2.1Hyg-sh3), qRT-PCR was used to evaluate the transcriptional level of BCCIP in HCT116 cells. Blank: no plasmid transfection; NC: transfection with pPUR/U6-NC; RNAi1: transfection with pPUR/U6-sh1; RNAi2: transfection with pSilencer2.1Hyg-sh2; RNAi3: transfection with pSilencer2.1Hyg-sh3; RNAi1+2: transfection with pPUR/U6-sh1 and pSilencer2.1Hyg-sh2; RNAi1+3: transfection with pPUR/U6-sh1 and pSilencer2.1Hyg-sh3. C. BCCIP stably silenced HCT116 cell line (S-BCCIP) was established by transfection with the plasmid combination (pPUR/U6-sh1+pSilencer2.1Hyg-sh3) and the subsequent antibiotic screening. Meanwhile the corresponding NC cell line was established. The efficiency of BCCIP silencing was verified by western blotting. D. Clonogenic survival assay was performed to evaluate the radiosensitivity of NC and S-BCCIP cells after pre-treatment with celecoxib (30 μM) and/or irradiation (0, 1, 2, 4, 6, or 8 Gy). The data are presented as mean ± SD. **P<0.01 and ***P<0.001 (one-way ANOVA).