RESUMO
ObjectiveTo investigate whether there was inhibitory effect of angiotensin-Ⅰ converting enzyme inhibitors (ACEI) on esophageal carcinoma cell line.Methods The highest expression of vascular endothelial growth factor (VEGF) at mRNA level was screened in esophageal squamous cell carcinoma cell lines KYSE30,TE-1,EC109 and EC9706 by reverse transcriptionpolymerase chain reaction (RT-PCR) and which was transplanted and established nude mice xenografts model.After tumor formed,the nude mice were evenly divided into control group,perindopril group and benazepril group (n=6) of which 0.9％ saline,4 mg/kg perindopril and 6 mg/kg benazepril was given respectively to nude mice in each group.The tumor size and the tumor inhibitory rate were measured.The expression of CD31 in xenograft tumor was tested by immunohistochemistry and the microvessel density (MVD) was assessed.ResultsThe highest expression of VEGF at mRNA level was in EC9706 cell line.At second and third week,there was no significant difference in xenograft tumor size between each group. At fourth and fifth week,there was no significant difference in xenograft tumor size between perindopril group and control group,and the tumor inhibitory rate was 24.6 ％ and 21.1 ％.There was significant difference between benazepril group and control group (t=-2.450 and -3.120,P=0.035 and 0.008),and the tumor inhibitory rate was 33.1％ and 45.4％.After treated with perindopril and benazepril,the expression of CD31 in xenograft tumor of nude mice decreased.The MVD of benazepril group was significantly lower than that of control group (10.98±1.18 vs 13.98 ± 1.76； t =-3.732,P =0.002),and there was no significant difference between perindopril group (12.41±1.15) and control group (t=-2.053,P=0.07).ConclusionsBenazepril (6 mg/kg) could significantly inhibit the growth of EC9706 cell line formed xenograft tumor of nude mice.One of the possible tumor inhibitory mechanisms was inhibiting new vessel forming in tumor.Perindopril (4 mg/kg) may have the similar effect.