Fig. 3

Overexpression of SOX17 sensitized ESCC radiation resistant cell line to CCRT treatment. a Cells were treated with radiation (0~2 Gy). The foci were stained and scored on day 6 after radiation. b KYSE510 radio-resistant (KYSE510-R) cells showed higher clonogenic survival under radiation condition compared with KYSE510 parental (KYSE510) cells. P values were calculated by two-tailed Student’s t test from three independent experiments. c The RT-qPCR results showed that KYSE510-R cells had lower SOX17 mRNA expression than KYSE510 parental cells (left). The DNA pyrosequencing methylation results indicated that KYSE510-R cells had 1.38-fold higher SOX17 DNA methylation level compared to KYSE510 cells (right). P values were calculated by two-tailed t test. d Western blot analysis confirmed that SOX17 protein was expressed in KYSE510-R-SOX17 cell. e Clonogenic survival was measured at day 6 after replating the KYSE510-R-SOX17 and KYSE510-R-EV cells treated with different doses of cisplatin (0~2.5 μM), radiation (0~2 Gy), or CCRT for 72 h. f The colony formation ability of KYSE510-R-SOX17 cells were inhibited compared to KYSE510-R-EV cells after CCRT treatment with 1 μM of cisplatin and 1 Gy of radition. P values were calculated by two-way ANOVA. P-values were determined by two-tailed Student’s t-test. *P < 0.05; **P < 0.01; ***P < 0.001