辐射诱导pEgr-p16表达增强及其体外抑制B16黑色素瘤作用

目的研究pEgr-p16重组质粒在转染的黑色素瘤B16细胞中的辐射诱导表达特性,验证其联合放射治疗体外抑制B16细胞增殖的作用。方法将脂质体包裹的pEgr-p16重组质粒,转染B16细胞株;采用定量PCR方法检测不同剂量X射线诱导后p16的表达和同一剂量X射线诱导下p16的表达时程,流式细胞数术检测细胞凋亡率的变化;MTT法检测pEgr-p16基因协同放射治疗后B16细胞的存活情况。结果pEgr-p16重组质粒转染B16细胞,不同剂量X射线均可诱导p16表达增强,为假照组的3.78-6.67倍（P〈0.01）;2GyX射线照射后,p16表达随时间延长而逐渐增强,在照射后72h达到最高值。p16基因联合放射可诱导B16细胞凋亡,凋亡率高于单纯照射组和单纯基因诱导组（P〈0.05-0.01）;转染pEgr-p16质粒的细胞经2GyX射线照射,8d后细胞数明显低于同时间其他实验组（P〈0.05-0.001）。结论pEgr-p16基因-放射联合治疗有明显的抑制黑色素瘤B16细胞生长的作用,其作用优于单纯给予射线或基因转染。

Enhancement of pEgr-p16 expression induced by irradiation and its anti-tumor effect on B16 melanoma cells in vitro

Objective To study the antitumour effect of irradiation combination with recombined pEgr-p16 plasmid on melanoma B16 cells. Methods pEgr-p16 plasmids were transfected into B16 cell line. Quantitative RT-PCR, flow cytometry and MTT methods were used to detect the expression of p16, cell apoptosis and inhibition effect,respectively. Results The p16 expressions in different doses X-ray irradiation group were about 3.78-6.67 times higher than that in sham-irradiation group (P<0.01). The expressions of p16 gradually increased with time after exposure to 2 Gy X-ray irradiation and reached to maximum at 72 h. Apoptosis rate in transfected p16 combined with irradiation group was higher than that in either plasmid or irradiation group alone (P<0.05-0.01). The number of pEgr-p16-transfected B16 cells exposed to 2 Gy X-ray irradiation was significantly less than those in other experimental groups (P<0.05-0.001). Conclusions pEgr-p16 gene transfection combined with irradiation could suppress melanoma B16 cell growth.And the inhibition was more effective than those in gene-or irradiation-therapy alone.