林志玲?黎洁瑶?闵筱辉?许稷豪?于涛?陈其奎

【摘要】目的 分析高糖狀态对结肠肿瘤细胞增殖的影响，并探讨Wnt抑制因子1（WIF1）通过Wnt/β-连环蛋白（β-catenin）通路影响高糖状态下结肠肿瘤细胞增殖的机制。方法 用不同浓度的D-葡萄糖处理结肠肿瘤细胞株SW620细胞，通过实时荧光定量PCR（qPCR）和蛋白免疫印迹法测定增殖相关基因的表达，行细胞增殖活性检测、细胞计数实验，用细胞平板克隆形成实验检测细胞增殖情况，采用qPCR和蛋白免疫印迹法测定WIF1和β-catenin的表达。转染siRNA和过表达质粒调控WIF1的表达后，检测WIF1对SW620细胞增殖能力和β-catenin表达水平的影响。结果 随着糖浓度的增加，SW620细胞的增殖能力增强（P均< 0.05），WIF1的表达下降而β-catenin的表达增高（P均< 0.05）。下调WIF1的表达，SW620细胞的增殖能力增强且β-catenin的表达增高（P均< 0.05），而过表达WIF1后，SW620细胞的增殖能力受到抑制且β-catenin的表达下降（P均< 0.05）。结论 高糖状态下WIF1表达的下降，可能通过活化Wnt/β-catenin通路促进高糖状态下结肠肿瘤细胞的增殖。

【关键词】高糖;结肠肿瘤;Wnt抑制因子1;β-连环蛋白;增殖

High glucose regulates the proliferation of colon cancer cells through the WIF1-Wnt/β-catenin signaling pathway Lin Zhiling， Li Jieyao， Min Xiaohui， Xu Jihao， Yu Tao， Chen Qikui. Department of Gastroenterology， Sun Yat-sen Memorial Hospital of Sun Yat-sen University， Guangzhou 510120， China

Corresponding author， Chen Qikui， E-mail： qkchen2015@ 163. com

【Abstract】Objective To evaluate the effect of high glucose on the proliferation of colon cancer cells， and investigate the mechanism of the effect of Wnt inhibitory factor 1 （WIF1） on the proliferation of colon cancer cells under high glucose state through the Wnt/β-catenin signaling pathway. Methods Colon cancer cell line SW620 cells were treated with different doses of D-glucose. The expressions of proliferation-associated mRNA and protein were measured by real-time fluorescent quantitative PCR （qPCR） and Western blot. The proliferation ability of SW620 cells was measured by cell proliferation assay， cell counting assay and colony formation assay. The expression levels of WIF1 and β-catenin were detected by qPCR and Western blot. After regulating the expression of WIF1 by the transfection with siRNA and over-expressed plasmid， the effect of WIF1 upon the proliferation ability and the expression of β-catenin in SW620 cells was evaluated. Results Along with the increase in glucose concentration， the proliferation ability of SW620 cells was significantly increased， the expression of WIF1 was remarkably down-regulated and the expression of β-catenin was significantly up-regulated （all P < 0.05）. The proliferation ability of SW620 cells was considerably increased and the expression of β-catenin was significantly up-regulated after down-regulating the WIF1 expression （all P < 0.05）. However， after the over-expression of WIF1， cell proliferation ability was significantly inhibited and the expression of β-catenin was remarkably down-regulated （all P < 0.05）. Conclusion Down-regulation of WIF1 expression under high glucose state may promote the proliferation of colon cancer cells under high glucose state via the activation of Wnt/β-catenin signaling pathway.

【Key words】High glucose;Colon cancer;Wnt inhibitory factor 1;β-catenin;Proliferation

近年来糖尿病和结肠癌的发病率逐渐上升，越来越多的研究者发现糖尿病可增加结肠肿瘤的发生风险，但糖尿病增加结肠肿瘤发生风险的机制尚不明确[1-2]。Wnt抑制因子1（WIF1）是由WIF1基因编码的一种分泌性蛋白，是Wnt/β-连环蛋白（β-catenin）信号通路的抑制因子，其与Wnt蛋白直接结合，通过细胞膜上的卷曲蛋白受体家族将信号传至胞内，引起通路关键分子β-catenin的磷酸化，促进β-catenin的降解，从而抑制Wnt/β-catenin信号通路[3]。有研究显示WIF1具有抑制肿瘤发生的作用[4]。Wnt/β-catenin信号通路在细胞增殖、胚胎发育和成体组织再生中发挥重要作用。既往研究显示，合并糖尿病的结肠癌患者的肿瘤细胞存在Wnt信号通路的异常激活，糖尿病患者的正常结肠上皮出现β-catenin的升高，Wnt/β-catenin信号通路与其抑制因子WIF1可能参与增加糖尿病患者发生结肠癌风险[5-6]。……