RESUMO
Objective To investigate the effect of blocking VEGF expression on the radiation sensitivity of esophageal cancer cell line TE-1 in vivo. Methods 32 male Balb/c/nu nude mice were randomly divided into four groups, including control group, radiation group, anti-VEGF group, and anti-VEGF + radiation group. The anti-VEGFcDNA cells were subcutaneously injected into the paw pats of mice (2 × 106/100 μl). The subcutaneous tumors were irradiated with 18 Gy of 60Co y-rays when the diameter of tumors varied from 0. 8 to 1.0 cm. The volume of the tumors was measured before and after irradiation, respectively. The expression level of VEGF mRNA and protein were examined by RT-PCR and Western blotting, respectively. Apoptotic cells were detected by electron micrographs. Results Latent period of the tumor formation of anti-VEGF group was lengthened compared with other groups(t = 13. 898,P ＜0.01 ). The volumes of tumor in anti-VEGF group [ ( 1207. 50 ± 97.07 ) mm3 ] and anti-VEGF +radiation group [ ( 1057. 5 ± 91.50 ) mm3 ] were not statistically different post-irradiation ( t = 1. 124, P ＞0.05 ) , but smaller than those in control group [ ( 5442. 50 ± 185.08 ) mm3 ] and radiation group [ (2922. 50 ± 152. 773)mm3 ] with statistical differences( t = 9. 475-21. 238, P ＜ 0. 01 ). The expression level of endogenous VEGFmRNA and protein in anti-VEGF group and anti-VEGF + radiation group were statistically different from control group and radiation group (F = 387.394, 13.519, P ＜ 0.01 ).Conclusions Antisense VEGF could inhibit the proliferation of esophageal cancer cell in the nude mice.Effect of blocking VEGF expression before irradiation on esophageal cancer xenografts might be limited.