[Effect and mechanism of siRNA targeting α-enolase gene combined with paclitaxel on proliferation, invasion and apoptosis of hepatocellular carcinoma cell].

Objective: To investigate the effect of siRNA targeting inhibition of α-enolase (ENO1) combined with paclitaxel on the proliferation, invasion and apoptosis of hepatocellular carcinoma SK-HEP-1 cell and its mechanism. Methods: siRNA-ENO1 (siRNA-ENO1 group) and siRNA-negative control (siRNA-NC group) were transfected into SK-HEP-1 cells in vitro, the untransfected SK-HEP-1 cells were used as the control group, and the transfection effect was detected by real-time fluorescent quantitative polymerase chain reaction and western blotting. After SK-HEP-1 cells were treated with 0, 2.5, 5, 10, 20 and 40 μg/L paclitaxel for 48 hours, the cell survival rate was measured by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) method and the semi inhibitory concentration of paclitaxel was calculated. SK-HEP-1 cells transfected with siRNA-ENO1 or siRNA-NC were treated with 10 μg/L paclitaxel as paclitaxel+ siRNA-ENO1 group and paclitaxel+ siRNA-NC group. The proliferation, clonogenesis, invasion and apoptosis of siRNA-NC group, siRNA-ENO1 group, paclitaxel+ siRNA-ENO1 group and paclitaxel+ siRNA-NC group were detected by MTT, clonogenesis, Transwell chamber and flow cytometry respectively. The expression levels of the phosphorylation of phosphatidylinositol-3-kinase (p-PI3K), p-protein kinase B (Akt) and proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 9 (MMP-9) and B lymphocytoma-2 gene (Bcl-2) were detected by western blotting. Results: Compared with the control group (1.00±0.00 and 0.69±0.04, respectively), the expression levels of ENO1 mRNA and protein (0.25±0.03 and 0.23±0.02, respectively) in siRNA-ENO1 group decreased significantly (P<0.05), but there were no significant differences in the expression levels of ENO1 mRNA and protein in siRNA-NC group (P>0.05). Compared without treatment group [(100.00±0.00)%, P<0.05], the survival rates of SK-HEP-1 cells treated with 2.5, 5, 10, 20 and 40 μg/L paclitaxel [(88.65±6.46)%, (72.36±6.08)%, (60.48±4.23)%, (38.52±3.56)% and (20.75±2.32)%, respectively] decreased significantly (P<0.05), and the semi inhibitory concentration of paclitaxel was 13.26 μg/L. The cell survival rate and clone formation rate of siRNA-ENO1 group [(68.86±5.12)% and (18.12±2.25)%, respectively] were lower than those of siRNA-NC group [(100.00±0.00)% and (29.65±3.06)%, respectively, P<0.05]. The cell survival rate and clone formation rate of the paclitaxel+ siRNA-ENO1 group [(43.28±2.64)% and (8.72±0.52)%, respectively] were significantly different from those of the paclitaxel+ siRNA-NC group [(61.75±5.06)% and (13.48±2.16)%, respectively, P<0.05] and siRNA-ENO1 groups [(68.86±5.12)% and (18.12±2.25)%, respectively, P<0.05]. Cell invasion number in paclitaxel+ siRNA-ENO1 group (23.64±2.12) was lower than that in siRNA-ENO1 group and paclitaxel+ siRNA-NC group (42.16±2.75 and 37.35±2.42, respectively, P<0.05). The apoptosis rates of paclitaxel+ siRNA-NC group and siRNA-ENO1 group [(17.49±1.35)% and (15.29±1.50)%, respectively] were higher than that of siRNA-NC group [(7.21±0.70)%, P<0.05]. The apoptosis rate in the paclitaxel+ siRNA-ENO1 group [(24.59±2.40)%] was higher than those in the paclitaxel+ siRNA-NC group and siRNA-ENO1 group [(17.49±1.35)% and (15.29±1.50)%, respectively, P<0.05]. The expression levels of ENO1, PI3K/Akt signaling pathway related proteins including p-PI3K and p-Akt and the expression levels of PCNA, MMP-9 and Bcl-2 in siRNA-ENO1 group and paclitaxel+ siRNA-NC group were lower than those in siRNA-NC group (P<0.05). The expression levels of ENO1, p-PI3K, p-Akt, PCNA, MMP-9 and Bcl-2 in paclitaxel+ siRNA-ENO1 group were lower than those in siRNA-ENO1 group or paclitaxel+ siRNA-NC group (P<0.05). Conclusion: siRNA targeting inhibition of ENO1 expression can enhance the inhibitory effect of paclitaxel on proliferation, invasion and apoptosis of SK-HEP-1 cells, and its mechanism may be related to the inhibition of PI3K/AKT signaling pathway.目的： 探讨抑制α-烯醇化酶(ENO1)联合紫杉醇对肝癌细胞系SK-HEP-1增殖、侵袭和凋亡的影响及其分子机制。 方法： 采用脂质体法将siRNA-ENO1(siRNA-ENO1组)及siRNA-NC(siRNA-NC组)转染至肝癌SK-HEP-1细胞，将未转染的SK-HEP-1细胞作为对照组，采用实时荧光定量PCR和Western blot法检测转染效果。使用0、2.5、5、10、20和40 μg/L紫杉醇处理SK-HEP-1细胞48 h，采用四甲基偶氮唑蓝(MTT)法检测细胞存活率并计算紫杉醇的半抑制浓度。使用10 μg/L紫杉醇处理转染siRNA-ENO1(紫杉醇+siRNA-ENO1组)和siRNA-NC(紫杉醇+siRNA-NC组)的SK-HEP-1细胞，采用MTT法、克隆形成实验、Transwell实验和流式细胞术检测各组细胞的增殖、克隆形成、侵袭和凋亡能力，Western blot法检测磷脂酰肌醇-3-激酶(PI3K)、蛋白激酶B(Akt)、增殖细胞核抗原(PCNA)、基质金属蛋白酶9(MMP-9)、B淋巴细胞瘤-2基因(Bcl-2)蛋白表达水平。 结果： siRNA-ENO1组细胞中ENO1 mRNA和蛋白表达表达水平(分别为0.25±0.03和0.23±0.02)均低于对照组(分别为1.00±0.00和0.69±0.04，均P<0.05)。2.5、5、10、20和40 μg/L紫杉醇作用48 h，肝癌SK-HEP-1细胞存活率[分别为(88.65±6.46)%、(72.36±6.08)%、(60.48±4.23)%、(38.52±3.56)%和(20.75±2.32)%]均低于对照(0 μg/L)组[(100.00±0.00)%，均P<0.05]。紫杉醇半抑制浓度为13.26 μg/L。siRNA-ENO1组细胞存活率和克隆形成率[分别为(68.86±5.12)%和(18.12±2.25)%]均低于siRNA-NC组[分别为(100.00±0.00)%和(29.65±3.06)%)，均P<0.05]；紫杉醇+siRNA-ENO1组细胞存活率和克隆形成率[分别为(43.28±2.64)%和(8.72±0.52)%]与紫杉醇+siRNA-NC组[分别为(61.75±5.06)%和(13.48±2.16)%)]和siRNA-ENO1组[分别为(68.86±5.12)%和(18.12±2.25)%)]比较，差异均有统计学意义(均P<0.05)。紫杉醇+siRNA-ENO1组细胞侵袭数[(23.64±2.12)个]低于siRNA-ENO1组和紫杉醇+siRNA-NC组[分别为(42.16±2.75)个和(37.35±2.42)个，均P<0.05]。紫杉醇+siRNA-NC组和siRNA-ENO1组细胞凋亡率[分别为(17.49±1.35)%和(15.29±1.50)%]高于siRNA-NC组[(7.21±0.70)%，均P<0.05]；紫杉醇+siRNA-ENO1组细胞凋亡率[(24.59±2.40)%]高于紫杉醇+siRNA-NC组和siRNA-ENO1组[分别为(17.49±1.35)%和(15.29±1.50)%，均P<0.05]。siRNA-ENO1组和紫杉醇+siRNA-NC组细胞中ENO1、PI3K/Akt信号通路相关蛋白p-PI3K、p-Akt表达水平及PCNA、MMP-9、Bcl-2表达水平均低于siRNA-NC组(均P<0.05)；紫杉醇+siRNA-ENO1组细胞中ENO1、p-PI3K、p-Akt及PCNA、MMP-9、Bcl-2表达水平均低于siRNA-ENO1组和紫杉醇+siRNA-NC组(均P<0.05)。 结论： 抑制ENO1表达可增强紫杉醇对肝癌SK-HEP-1细胞的抑增殖、侵袭和促凋亡作用，其作用机制可能与抑制PI3K/AKT信号通路有关。.