肿瘤坏死因子相关凋亡诱导配体对胰腺癌细胞凋亡的影响

Effects of TNF-related apoptosis-inducing ligand on cell apoptosis of pancreatic cancer

目的探讨肿瘤坏死因子相关凋亡诱导配体(TRAIL)促进胰腺癌细胞SW1990、PaTu8988和BxPC3凋亡的机制。方法将携带TRAIL基因的pCA13质粒分别转染胰腺癌SW1990、PaTu8988和BxPC3细胞(pCA13-TRAIL组),以空质粒转染作为对照组(pCA13组)。采用RT-PCR及蛋白质免疫印迹法检测转染细胞TRAIL mRNA和蛋白的表达。流式细胞仪检测转染细胞的凋亡率和TRAIL受体R1、R2的表达,TUNEL和Hoechst双染色法及透射电镜观察细胞凋亡,免疫组织化学法检测转染细胞caspase-3蛋白的表达。结果SW1990、PaTu8988和BxPC3细胞转染pCA13-TRAIL 24 h即有TRAIL mRNA和蛋白的表达;转染后24 h细胞的凋亡率分别为(27.30±5.14)%、(13.52±0.95)%和(31.40±8.70)%,均显著高于相应pCA13组的(10.58±1.88)%、(8.42±0.46)%和(16.11±1.66)%;转染后48 h TRAIL-R1阳性表达率分别为(61.37±3.05)%、(42.10±5.11)%和(36.64±4.84)%,TRAIL-R2阳性表达率分别为(36.20±4.83)%、(37.26±8.46)%和(24.32±3.71)%,除PaTu8988细胞,均显著高于相应的pCA13组;caspase-3阳性率分别为(14.64±5.35)%、(9.92±5.50)%和(16.12±6.74)%,显著高于pCA13组的(3.01±1.50)%、(1.75±0.50)%和(3.79±1.58)%,差异均有统计学意义(P值均<0.05)。结论TRAIL在体外可通过上调多株胰腺癌细胞TRAIL-R1、R2的表达从而促进其凋亡。

Objective To investigate the mechanism of TNF-related apoptosis-inducing ligand (TRAIL) promoting apoptosis of pancreatic cancer cells SW1990, Patu8988 and BxPC3. Methods Three kinds of pancreatic cancer cells SW1990, Patu8988 and BxPC3 were transfected with the pCA13 plasmid carrying TRAIL gene (pCA13 TRAIL group) and the blank plasmid control (pCA13 group), respectively. The expression of TRAIL mRNA in transfected cells was detected by RT-PCR, and the expression of TRAIL protein was detected by Western blot. The apoptosis rate and expression of TRAIL receptor R1 and R2 were detected by flow cytometry. Apoptosis was detected by TUNEL and Hoechst double staining, and observed by electron microscopy. The expression of caspase-3 in transfected cells was detected by immunohistochemistry. Results SW1990, Patu8988 and BxPC3 cells can expresse TRAIL mRNA and protein within 24 h after transfection. The apoptotic rate at 24 h after transfection was (27.30±5.14)%,(13.52±0.95)% and (31.40±8.70)%, respectively, which was higher than that of pCA13 group [(10.58±1.88)%,(8.42±0.46)% and (16.11±1.66)%], respectively. The expression rates of TRAIL-R1 were (61.37±3.05)%,(42.10±5.11)% and (36.64±4.84)%, respectively, and the expression rates of TRAIL-R2 were (36.20±4.83)%,(37.26±8.46)% and (24.32±3.71)%, respectively, which were higher than those of pCA13 group except PATU8988 cells. Positivity rates of caspase-3 were(14.64±5.35)%,(9.92±5.50)% and (16.12±6.74)%, which were obviously higher than(3.01±1.50)%,(1.75±0.50)% and (3.79±1.58)% in pCA13 group, and the differences were statistically significant(P<0.05). Conclusions TRAIL could up-regulate the expression of TRAIL R1 and R2 in multiple pancreatic cancer cell lines in vitro, and thus promote cell apoptosis.