Fig. 4: Effect of GPR37 overexpression and silencing on radioresistance of ESCC cells.

A Western blotting was used to detect the protein expression of GPR37. B qRT‒PCR was used to detect the mRNA expression level of the genes (n = 3). KYSE150 (C) and KYSE450 (D) cells were exposed to different radiation doses (0, 2, 4, 6, and 8 Gy, 2 Gy/min) and cultured for 14 days, after which colony formation was assessed to determine their radiosensitivity. The 0 Gy is used as the control group and a single-target multitarget model was used to fit the cell survival curve (n = 3). After 8 Gy X-ray treatment, immunofluorescence was used to detect the lesion density of γ-H2AX in KYSE150 (E) and KYSE450 (F) cells at 0.5 h and 4 h, and the 0 Gy group is used as the control group (n = 3). Scale bar: 10 µm. Apoptosis in KYSE150 (G) and KYSE450 (H) cells after 8 Gy irradiation was assessed by flow cytometry (n = 3). I, J KYSE150 cells overexpressing GPR37 were injected subcutaneously into the hind limbs of BALB/c mice (n = 5 per group). I Transplanted tumors (tumor volume measured every 4 days) and (J) tumor weight. ns not significant, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.