内质网相关降解蛋白Derlin-1通过抑制ERK信号通路抗人结肠癌细胞增殖

目的: 探讨内质网相关降解蛋白Derlin-1对人结肠癌SW480细胞凋亡的影响及其可能的作用机制。方法: 采用sh-Derlin-1-pGPU6/Neo质粒转染构建瞬时敲除Derlin-1基因的SW480细胞株，应用实时定量PCR和免疫印迹验证Derlin-1基因和蛋白的低表达，采用CCK8法检测SW480细胞增殖情况，流式细胞仪检测SW480细胞凋亡情况，Western blot检测SW480细胞中凋亡蛋白Bcl-2、Bax表达量和ERK磷酸化水平。结果: 使用pGPU6/Neo载体能够稳定地抑制SW480细胞中Derlin-1的表达，sh-Derlin-1组细胞增殖率相对于对照组显著降低、凋亡率显著升高（P<0.05），Western blot实验结果发现sh-Derlin-1组细胞中Bcl-2表达量显著降低、Bax表达量显著升高及ERK磷酸化水平显著降低，与对照组相比差异有统计学意义（P<0.05）。结论: Derlin-1表达的降低能抑制ERK信号通路活化，进而诱导人结肠癌SW480细胞凋亡、抑制增殖。

Effects of endoplasmic reticulum associated degradation protein Derlin-1 on the proliferation of human colon cancer cells via suppressing ERK pathway

AIM: To observe the effects of endoplasmic reticulum associated degradation protein Derlin-1 on the apoptosis of human colon cancer cells (SW480) and its possible mechanism. METHODS: The qualified recombinant plasmid sh-Derlin-1-pGPU6/Neo was transfected into SW480 cells with Derlin-1 knocking down. The expression level of Derlin-1 was detected at both mRNA and protein levels by real-time PCR and Western blot. CCK8 assay and flow cytometry were performed to detect the proliferation and apoptosis of SW480 cells. We examined the expression of apoptosis associated proteins (Bcl-2 and Bax) and ERK phosphorylation followed by Derlin-1 low-expression by Western blot. RESULTS: The Derlin-1 knocking down plasmid was constructed successfully. SW480 cells with Derlin-1 knocking down had been established successfully. Compared with control group, the proliferation rates of sh-Derlin-1 SW480 cells were significantly decreased, while the apoptotic rates of sh-Derlin-1 SW480 cells were significantly increased (P<0.05); the expression levels of Bcl-2 and p-ERK in sh-Derlin-1 group were significantly decreased, while the expression level of Bax was greatly increased (P<0.05). CONCLUSION: The decreased level of Derlin-1 can suppress the proliferation and induce the apoptosis of SW480 cells through suppressing the activity of ERK signaling pathway.