MiR-195和DLL4蛋白表达与结直肠癌临床病理特征及预后的关系

Relationship between MiR-195 and DLL4 expression and clinical features of colorectal cancer

目的分析MiR-195与DLL4蛋白在结直肠癌组织中的表达模式,探讨二者与结直肠癌患者临床病理指标及预后的关系。方法采用实时荧光定量PCR检测miR-195在56例结直肠癌组织中microRNA相对表达量,用Westerm blot和免疫组化检测DLI4蛋白的表达和肿瘤微血管密度,分析二者表达模式与结直肠癌患者临床病理学指标及预后的关系。采用基因过表达miR-195处理结肠癌细胞系SW480,Westem blot检测通路相关蛋白DLL4、Jagged1、Noth受体胞内段、CyclinD1、Hesl、Bcl-2及NF-kB的表达。结果结直肠癌组织中DLL4蛋白表达水平高于正常结直肠组织,平均为正常结直肠组织中的(2.342±0.004)倍(t=5.323,P=0.018);而miR-195表达水平低于正常结直肠组织,平均为正常结直肠组织的(0.277±0.005)倍(t=2.371,P=0.008)。DLL4蛋白表达水平与miR-195表达呈负相关(r=-0.881,P=0.015)。二者表达与结直肠癌的分化程度、淋巴结转移、TNM分期密切相关。DLL4蛋白高表达患者的预后差于DLL4蛋白低表达的患者(P=0.013),miR-195低表达患者的预后差于miR-195高表达患者(P=0.009),差异均有统计学意义。miR-195可阻断Notch通路,其相关蛋白ICN、Hes-1随作用时间延长而表达下降。结论miR-195与Notch拮抗性表.达可能与结直肠癌发生发展密切相关,可作为结直肠癌判定预后的新的指标。

Objective To observe the expression patterns of miR-195 and DLL4 in colorectal cancer,and to explore the relationship between miR-195 and DLL4 and clinicopathological parameters and prognosis of patients with colorectal cancer.Methods The relative expression of miR-195 in 56 colorectal cancer tissues was detected by real-time fluorescent quantitative PCR the expression of DLL4 protein and tumor microvessel density(MVD)were detected by bloting and immunohistochemistry.Colon cancer cell line SW480 was treated with miR-195.The expression of DLL4,Jagged1,(the intracellular domain of notch,NICD),CyclinD1,Hes1,Bcl-2 and NF-kB were detected by bloting.Results The expression level of DLL4 protein in colorectal cancer tissues was significantly higher than that in normal intestinal mucosa(30/56 us.16/56,t=5.323,P=0.018).The expression level of miR-195 was signifcantly lower than that in normal intestinal mucosa(36/56 vs.20/56,t=2.371,P=0.008).The expression of DLL4 was negatively correlated with the expression of miR-195(r=-0.881,P=0.015),which was closely related to the differentiation degree,lymph node metastasis and TNM stage.The prognosis of patients with high expression of DLL4 was significantly worse than that with low expression of DLL4(P=0.013).The prognosis of patients with low expression of miR-195 was worse than that with high expression of miR-195(P=0.009).Conclusion The antagonistic expression of miR-195 and Notch might be closely related to the occurrence and development of colorectal cancer,which can be used as a new reference index for prognosis of colorectal cancer.