pEgr-Endostatin重组质粒联合电离辐射抗肿瘤效应的实验研究

目的研究pEgr-Endostatin辐射诱导肿瘤的表达特性及其抗肿瘤作用,为提高临床肿瘤放疗疗效提供实验证据.方法 Western blotting法检测pEgr-Endostatin重组质粒联合电离辐射诱导黑色素瘤B16细胞蛋白表达;建立动物模型,用ELISA法检测不同处理组Endostatin的剂量水平,比较不同处理方式的差异.结果 Western blotting法检测结果显示:重组质粒转染的黑色素瘤B16细胞上清中均有Endostatin蛋白表达,而未转染重组质粒的B16细胞和转染空质粒的B16细胞上清中未见Endostatin蛋白表达.ELISA法检测结果表明:体外接受2~10 Gy X射线照射,Endostatin表达水平明显增加,且照射剂量为4 Gy时Endostatin的表达水平最高.2 Gy照射8~72 h后,Endostatin表达水平与假照射组比较明显增加,在48 h时Endostatin表达水平最高.动物实验表明:荷瘤+25 Gy照射组、荷瘤+pEgr-Endostatin照射组、荷瘤+pc DNA3.1+25 Gy照射组和荷瘤+pEgr-Endostatin+25Gy照射组肿瘤生长率显著低于单纯荷瘤组(P0.05#0.01),荷瘤+pEgr-Endostatin+25 Gy照射组亦明显低于荷瘤+25 Gy照射组和荷瘤+pEgr-Endostatin组(P0.05#0.01).结论 pEgr-Endostatin重组质粒联合电离辐射能使Endostatin蛋白表达增加,从而抑制血管内皮细胞生长、发挥抗肿瘤作用.

Experimental Research on Anti-tumor Effects of pEgr-Endostatin Recombinant Plasmid in Combination with Ionizing Radiation

Objective To investigate the induced expression characteristics and anti-tumor effects of pEgr-Endostatin recombinant plasmid in combination with ionizing radiation,and to provide experimental evidence for improving the clinical curative effect of tumor radiotherapy. Method Protein expression of melanoma B16 cells induced by pEgr-Endostatin recombinant plasmid combined with ionizing radiation was tested by Western blotting. Animal model was established. The dose levels of Endostatin in different treatment groups were measured by using ELISA method, and the difference were compared. Results Results of Western blotting showed that Endostatin protein expressed in the supernatant of melanoma B16 cells transfected by recombinant plasmid,and no Endostatin protein expression was seen in the supernatant of B16 cells without transfection or the transfected empty plasmid. ELISA detection results showed that when B16 cells accepted 2~10 Gy X-ray irradiation in vitro, Endostatin expression level increased significantly,and the highest level reached at the dose of 4 Gy. After 2 Gy X-ray irradiation for 8~72 h,Endostatin expression level increased significantly compared with the fake exposure group,and the expression of Endostatin reached the highest levels at 48 h. Animal experiments showed that the growth rates of tumor-burdened +25 Gy irradiation group, tumor-burdened+pEgr-Endostatin exposure group, tumor-burdened+pcDNA3. 1 +25 Gy exposure group and tumor-burdened+pEgr Endostatin +25 Gy irradiation tumor were significantly lower than that of the pure tumor-burdened groups ( P<0 . 05 to 0 . 01 ) . And the rate of tumor-burdened+pEgr Endostatin +25 Gy exposure group was significantly lower than that of the tumor-burdened +25 Gy exposure group and tumor-burdened+pEgr-Endostatin group (P<0. 05 to 0. 01). Conclusion pEgr-Endostatin recombinant plasmid in combination with ionizing radiation can increase Endostatin protein expression,thus inhibit vascular endothelial cell growth,and play an important role in anti-tumor process.