Raltitrexed increases radiation sensitivity of esophageal squamous carcinoma cells

Raltitrexed (Ral) inhibited cell viability of esophageal squamous cancer cell lines and potentiated the inhibitory effect on cell viability and colony formation by irradiation (IR). The effects of different doses of Ral on the cell viability 24, 48 or 72 h’ treatment were determined in TE-13 (a) and Kyse150 cell lines (b); the effects of IR in different doses with or without Ral (4 nM) pretreatment (24 h) on the proliferation of TE-13 (c) and Kyse150 cell lines (d) were studied after 48 h using Cell counting kit 8 assay; the radiosensitization effect of Ral (4 nM, 8 nM) was studied in TE-13 (e) and Kyse150 cell lines (f) using clonogenic survival assay. Error bar: standard deviation; *p？<？0.05, **p？<？0.01, ***p？<？0.001, ****p？<？0.000