内皮抑素基因联合放射治疗对大鼠Walker-256细胞种植性肿瘤的抑制作用

目的探讨鼠源性内皮抑素（endostatin）基因联合放射治疗对大鼠种植性肿瘤的抑制效应。方法制作大鼠乳腺癌Walker-256细胞种植性肿瘤的动物模型，通过检测肿瘤重量和肿瘤生长速率观察内皮抑素基因治疗联合放疗的抑瘤效应。体外采用Western blot检测构建pCMV-endostatin质粒转染的Walke-256细胞endostatin蛋白表达，体内采用BT-PCR观察各组endostatin mRNA表达。结果基因治疗组和基因治疗联合放射治疗组均可见到endostatin mRNA及其蛋白明显表达，但两组间表达无统计学意义；基因与放射联合组肿瘤的生长速率和重量均明显小于单纯基因治疗和放疗组（P〈0．01），后两组其肿瘤的生长速率和重量明显低于对照组（P〈0．01），但二者之间差异无统计学意义。结论pCMV-endostatin在Walker-256细胞内有明显表达endostatin mRNA及其蛋白；endostatin基因治疗有明显的抑瘤作用，但endostatin基因联合放疗的抑瘤效应更明显，促进放疗的抑瘤效果。

The effect of endostatin gene in combination with radiotherapy on rats with implanted tumor

Objective To study the effect of combinating of the radiotherapy with endostatin gene therapy on the rats with implanted tumor. Methods Immediate Walker-256 cancerous ascetic injection method was used to make a rat tumor-bearing model, then the tumor was treated with saline,endostatin gene,irradiation or endostatin gene plus irradiation. The tumor growth rate and weight were observed, Western blot and RT-PCR were adopted to check the expressions of endostatin mRNA and protein. Results The expressions of endostatin mRNA and protein were significant in the gene therapy group and the gene plus radiotherapy group, but there was a significant difference between these two groups. As compared with the control group, the tumor growth rate and weight decreased significantly in all the therapy groups (P<0.001). The effect of gene plus radiotherapy on the implanted tumor was the best among all groups. There was no significant difference in therapeutic effect between the gene therapy group and the radiation therapy group (P>0.05). Conclusion After the pCMV-Endostatin was induced, the expressions of endostatin mRNA and protein was significant in Walker-256 tumor and the tumor growth was inhibited. However,the effect of the endostatin gene plus radiotherapy was obviously better than that of the endostatin gene therapy group or the radiotherapy group for inhibiting tumor growth. ;