Abstract: Objective To investigate the expression of IFITM1 in colon cancer and the mechanism of its promotion of colon cancer cell proliferation. Methods The expression and prognosis of IFITM1 in colorectal cancer were analyzed by bioinformatics, and the correlation between IFITM1 and β-catenin was researched. Immunohistochemical SP staining was examined to observe the expression of IFITM1 and β-catenin in colon cancer tissues. The overexpressed cell model of IFITM1 was constructed, the changes of cell proliferation capacity were detected by CCK-8 assay, and the changes of TCF/LEF transcription factor activity were tested by dual luciferase reporter gene. The results of dual luciferase reporter gene showed that the promoter activity of OE-IFITM1 group was higher than that of OE-NC group (P<0.05), and there was no difference between OE-NC group and MOCK group (P>0.05). The expressions of key proteins β-catenin, C-myc and CyclinD1 in the Wnt/β-catenin signaling pathway were detected by Western blot. Results The results of online database analysis showed that IFITM1 was highly expressed in colon cancer (P<0.05), and significantly correlated with poor prognosis. There was positive correlation between IFITM1 and β-catenin. Immunohistochemical results showed that the expression level of IFITM1 was correlated with tumor diameter and tissue invasion degree (P<0.05), ranther than others factors(P>0.05). The expression of β-catenin was only correlated with tumor diameter(P<0.05), instead of other factors(P>0.05), and there was a positive correlation between IFITM1 and β-catenin. After overexpression of IFITM1 in HCT-15 colon cancer cells, the proliferation capacity of OE-IFITM1 group was significantly higher than that of OE-NC group (P<0.05), but there was no difference between OE-NC group and MOCK group (P>0.05). Western blot results showed that the expression levels of β-catenin, CyclinD1 and C-myc in OE-IFITM1 group were higher than those in OE-NC group (P<0.05), but there was no difference in protein expression between OE-NC group and MOCK group (P>0.05). Conclusion The expression of IFITM1 in colon cancer tissues is significantly higher than that in para-cancer tissues, and IFITM1 may promote cell proliferation through Wnt/β-catenin signaling pathway.

Key words: IFITM1, colon cancer, β-catenin, TCF/LEF transcription factor

摘要： 目的 探究干扰素诱导跨膜蛋白1（IFITM1）在结肠癌中的表达以及其在结肠癌中发挥的作用。方法 应用生物信息学分析IFITM1在结肠癌中的表达情况和预后情况,并分析IFITM1与β-连环蛋白的相关性。免疫组化观察IFITM1和β-catenin在结肠癌及癌旁组织中的表达情况。构建IFITM1过表达细胞模型,CCK-8实验检测细胞增殖能力的变化,双荧光素酶报告基因检测TCF/LEF转录因子的激活情况,Western blot检测Wnt/β-catenin信号通路上关键蛋白β-catenin、C-myc、CyclinD1的表达情况。结果 在线数据库分析结果显示,IFITM1在结肠癌中高表达（P<0.05）,且与患者的预后不良显著相关;IFITM1与β-catenin之间存在正相关关系。免疫组化染色结果显示,IFITM1和β-catenin在结肠癌组织中的表达显著高于癌旁组织,IFITM1的表达同肿瘤直径大小及组织浸润程度有关（P<0.05),与其他因素无关（P>0.05);β-catenin的表达与仅与肿瘤直径大小有关(P<0.05),与其余因素无关(P>0.05),且二者之间存在正向相关性。在结肠癌细胞HCT-15中过表达IFITM1后,OE-IFITM1组细胞的增殖能力显著高于OE-NC组（P<0.05）,OE-NC组和MOCK组之间无差异（P>0.05）。双荧光素酶报告基因结果显示,OE-IFITM1组的启动子活性高于OE-NC组（P<0.05）,OE-NC组与MOCK组之间无差异（P>0.05）。Western blot结果显示,OE-IFITM1组的β-catenin,CyclinD1,C-myc的表达量高于OE-NC组（P<0.05）,OE-NC组和MOCK组之间蛋白表达无差异（P>0.05）。结论 IFITM1在结肠癌组织中的表达显著高于癌旁组织,并可能通过Wnt/β-catenin信号通路促进细胞增殖。

关键词: IFITM1, 结肠癌, β-catenin, TCF/LEF转录因子