局部热化疗对鼠胶质瘤血管再生及细胞凋亡的影响

The effects of localized thermochemotherapy on angiogenesis and apoptosis of C6 glioma in rat

目的 研究局部热化疗对大鼠胶质瘤血管再生及细胞凋亡的影响 ,探讨其治疗胶质瘤的机理。方法 制作大鼠胶质瘤动物模型并分组 ,各组分别进行局部热疗、化疗或热化疗。用FⅧ RA染色标记血管内皮细胞 ,以微血管密度作为定量检测指标 ;用免疫组化S P法检测VEGF、bax及bcl 2蛋白表达 ,用透射电镜观察肿瘤细胞及血管结构的变化。结果 热疗组、化疗组、热化疗组与对照组比较 ,发现各治疗组胶质瘤体积明显缩小 ,重量减轻 ;VEGF蛋白表达降低 ,bax蛋白表达增强 ,bcl 2蛋白表达则无明显变化 ,VEGF表达与MVD呈正相关。大鼠胶质瘤经热化疗后 ,肿瘤微血管外径变小 ,血管壁变厚 ,血管密度降低 ,血管内皮细胞紧密连接增多 ,细胞连接间隙减小 ,有的血管甚至只能观察到完整的基膜而缺乏内皮细胞。结论 ①热疗、化疗、热化疗均能抑制肿瘤血管再生 ,且化疗与热疗联用具有协同作用 ,可提高疗效 ;②热化疗能显著降低肿瘤细胞VEGF的合成与分泌 ,抑制肿瘤血管再生 ;③热化疗能增强bax蛋白表达 ,使bcl 2 /bax比值降低 ,诱导肿瘤细胞凋亡。

Objective To study the effects of localized thermochemotherapy on angiogenesis and apoptosis of C6 glioma in rat,and to explore the underlying mechanisms of the localized thermochemotherapy in treating C6 glioma in rat. Methods A total of rats with C6 glioma were randomly divided intoa control group and 3 experimental groups. All the rats in the treatment groups were treated by localized hyperthermia, chemotherapy and thermochemotherapy, respectively. The expression of VEGF,bax,bcl 2 and FⅧ RA protein were detected by S P immunohistochemistry method. The vascular structure in rats glioma was observed by immunohistochemistry and electron microscopy techniques. Results As compared with the control group, the volume of tumor was decreased in the hyperthermia and chemotherapy groups, as well as in the thermochemotherapy group, the weight of the tumor was decreased;the expression of VEGF protein was decreased, the expression of bax protein was increased, whereas the expression of bcl 2 proteinwas not significantly changed. The expression of VEGF protein was positively correlated with the microvessel density in the tumor. Electron microscopic observation also showed that angiogenesis were inhibited by localized thermochemotherapy in the glioma tissue. Conclusion Hyperthermia, chemotherapy and thermochemotherapy could inhibit angiogenesis in tumor, and the thermochemotherapy showed remarkable synergic effects in treating C6 glioma of rat. Thermochemotherapy could inhibit the synthesis and secretion of VEGF,and restrained angiogensis in tumor. Thermochemotherapy could increased the expression of bax protein and decreased bcl 2/bax ratio,and induce apoptosis of C6 glioma in rat.