姜黄素下调Notch1抑制人结肠腺癌细胞系SW480的增殖活性

摘要

目的 检测Notch1在人大肠腺癌中的表达,分析其临床病理意义；探讨姜黄素抑制人结肠腺癌细胞系SW480增殖活性的可能机制.方法 免疫组化EnVision二步法检测100例人大肠腺癌及30例癌旁正常大肠组织石蜡切片中Notchl的表达情况,判断其与人大肠癌的关系；不同浓度姜黄素作用于人高分化大肠腺癌细胞系SW480细胞24 h和48 h,MTT法检测姜黄素对SW480的增殖抑制作用,20 μmol/L、40 μmol/L姜黄素作用SW480细胞24 h,Western blot法检测Notch1及CyclinE的蛋白表达情况,分别设空白对照及溶剂对照组.结果 Notch1在人大肠腺癌及癌旁正常大肠组织中均有表达,阳性率分别为78％和40％,2者差异有统计学意义(P＜0.01),进一步统计结果表明其与大肠癌的肿瘤部位、分化程度及Dukes分期有关(P＜0.05),而与性别、年龄、肿瘤大小及淋巴结转移无关(P＞0.05)；姜黄素能够抑制SW480的增殖活性,呈时间-剂量依赖性；姜黄素下调Notch1及CyclinE蛋白的表达.结论 Notch信号通路在人大肠癌的发生发展中可能作为致癌基因存在；姜黄素能够抑制结肠腺癌细胞系SW480的增殖活性且其机制可能与下调Notch1信号通路有关.%Objective To detect the expression of Notch 1 in human colorectal adenocarcinoma,and analysis its clinical pathological significance;and to investigate the potential mechanism of curcumin in inhibiting the proliferation activity of the human colon adenoearcinoma cell line SW480.Methods The immunohistochemical EnVision method was used to detect the expression of Notch 1 in paraffin sections for 100 cases of hunman colorectal carcinoma and 30 cases of adjacent normal colorectal tissues,and determine its relationship with human colorectal cancer; different concentrations of curcumin acted on highly differentiated colon adenocarcinoma cell line SW480 for 24 and 48 h,then MTT was used to intestigate the inhibiton effect of curcumin on the proliferation of SW480.The Western bolt assay was used to detect the protein expression of Notch 1 and Cyclin E after 20 μmol/L aand 40 μmol/L curcumin acted on SW480 cells for 24 h.Meanwhile blank control and solvent control groups were established.Results Notch 1 was expressed in both human colorectal cancer and adjacent normal tissues,the positive rates were 78％ and 40％,respectively,and the difference was statistically significant (P ＜ 0.01).Futher statistical results showed that the expression was related to tumor location,differentiation degree and Dukes stage (P ＜ 0.01),but not to gender,age,tumor size or lymph node metastasis (P ＞ 0.05).Curcumin could inhibit the proliferation activity of SW480,with a time-dose dependence ; and curcumin downregulated the expression of Notch 1 and Cyclin E.Conclusion Notch signaling pathway may exist as an oncogene in the development of human colorectal carcinoma;curcumin can inhibit the proliferation activity of SW480,and its mechanism may be related to the downregulation of Notch 1 signaling pathway.