缺氧诱导因子1α对CO2气腹环境下人胃癌细胞凋亡的影响

目的 通过体外模拟CO2气腹环境,构建沉默缺氧诱导因子1α(HIF-1α)的RNAi表达载体,探讨HIF-1α对CO2气腹环境下人胃癌细胞MKN-45凋亡的影响及机制.方法 利用密闭培养箱模拟CO2气腹,气腹机维持培养箱内压力分别为0、5、10、15mm Hg.采用荧光定量RT-PCR方法和Western blot方法观察沉默HIF-1α前后MKN-45细胞HIF-1α mRNA和蛋白表达的变化;免疫细胞化学技术观察沉默HIF-1α前后细胞bcl-2/bax表达的变化;Annexin V-FITC/PI双标染色、流式细胞仪检测沉默HIF-1α前后细胞凋亡比例的变化.结果 沉默HIF-1α前15 mm Hg组细胞HIF-1αmRNA和蛋白表达(分别为1.51±0.04、4.44±0.30)均显著高于对照组(0.584±0.06、2.01±0.06)(P<0.01).沉默HIF-1α前15mmHg组细胞bcl-2/bax比值(0.77±0.05)较对照组(1.43±0.02)明显降低(P<0.05),细胞凋亡比例(11.60±2.11)较对照组(0.30±0.02)增加.而在沉默HI-1α后15 mm Hg组细胞HIF-1α mRNA(0.464±0.04)和蛋白表达(0.92±0.02)、bcl-2/bax比值(1.61±0.04)、细胞凋亡比例(0.4±0.03)与对照组相比差异均无统计学意义(P>0.05).结论 在CO2气腹环境压力为0、5、10mm Hg CO2时MKN-45细胞凋亡比例与对照组比较无差异,压力为15mm Hg时CO2气腹可促进胃癌细胞凋亡.HIF-1α可能为促进细胞凋亡的原因之一.

Effects of HIF-1α on human gastric cancer cell's apoptosis in CO2 pneumoperitoneum environment

Objective To study the effect and mechanism of human gastric cancer cell's apoptosis in simulated CO2 pneumoperitoneum environment by HIF-1α. Methods We used a closed box to simulate CO2 pneumoperitoneum environment, a standard surgical insufflator maintained pressure of the box at 0,5,10 and 15 mm Hg respectively. MKN-45 cell's HIF-1α mRNA and protein expression were observed before and after silencing cell's HIF-1α by real time RT-PCR and Western blot. Cell's bcl-2/bax was studied by immunohistochemistry before and after silencing HIF-1α. Cell's apoptosis ratio was measured using Annexin V-FITC/PI double labelled staining. Results In 15 mm Hg group, MKN-45 cell's HIF-1α mRNA and protein expression were significantly higher than control group (P<0.01 ), while the difference was not significant among 0,5,10 mm Hg group and control group (P>0.05). In 15 mm Hg CO2 pressure, cell's bcl-2/bax was obviously lower than in control group (P<0.05) and apoptosis ratio was more than control group(P<0.01). When HIF-1α was silenced, cell's bel-2/bax and apoptosis ratio weren't significantly different between 15 mm Hg group and control group (P>0.05 ). Conclusions MKN-45 cell's apoptosis did not experience any alterations under 0,5,10 mm Hg.15 mm Hg CO2 pneumoperitoneum environment enhanced cell's apoptosis probably by way of HIF-1α.