人结直肠癌微小核糖核酸的差异表达及其临床意义

Clinical significance of aberrant microRNAs expression in human colorectal cancer

目的:研究人结直肠癌、腺瘤和癌旁正常组织中微小核糖核酸(microRNAs,miRNAs)的差异表达谱,并初步探讨其临床意义.方法:选取2008-01/07苏州大学附属第一医院和泰州市人民医院结直肠癌、对应癌旁正常组织以及结直肠腺瘤标本,提取组织总RNA,采用illumina microRNA芯片技术检测3种不同类型组织中miRNAs的表达,采用实时定量PCR技术对芯片检测结果进行验证.将结直肠癌组织中异常表达的miRNAs与结直肠癌患者的临床病理资料进行分析.结果:3种不同类型结直肠组织中miRNAs表达有明显差异,结直肠癌与癌旁正常组织相比,有65个miRNAs表达异常(P<0.001),其中35个上调,30个下调,而腺瘤与正常结直肠组织相比,有55个miRNAs表达差异(P<0.001),其中上调29个,下调26个.有25个miRNAs相对于正常组织同时在结直肠癌和腺瘤中异常表达,其中高表达12个,低表达有13个.与腺瘤相比,结直肠癌中有25个miRNAs表达异常(P<0.01),其中13个上调,12个下调.进一步定量PCR验证结果显示与正常结直肠黏膜组织相比,在癌组织中miR-552,miR-142-3p上调(2.97±2.72vs0.98±0.48;3.64±3.41vs1.31±0.61,均P<0.05),miR-139-3p和miR-133b下调(0.10±0.26vs0.82±0.70,0.81±0.67vs1.71±1.29,均P<0.05),与芯片结果相吻合.miR-552和miR-139-3p与结直肠癌患者年龄、性别、组织学、肿瘤大小和浸润深度无关(P>0.05),而miR-552与TNM分期、淋巴结和肝转移相关(P<0.05),miR-139-3p与TNM分期和肝转移相关(P<0.05),miR-142-3p除与组织学有关外,与其他临床病理参数无关,miR-133b与年龄相关,而与其他临床病理参数无关.结论:miRNAs参与了结直肠的癌变过程,特异的miRNAs的表达可能成为结直肠癌潜在的早期诊断和治疗新靶点.

AIM：To investigate the expression profile of microRNAs（miRNAs） in human colorectal cancer and to analyze the clinical significance of aber-rant miRNA expression. METHODS：The expression of miRNAs in colorectal cancer specimens,matched normal mucosal specimens,and adenoma specimens was detected by miRNA microarray.The differential expression of some miRNAs was verified by real-time RT-PCR.The correlation of aberrant miRNA expression with clinical and biopathologic features in colorectal cancer,such as age,gender,tumor size,lymph node and distance metastasis,clinical stage as well as histological grade,was analyzed. RESULTS：Microarray analysis revealed many miRNAs that could clearly differentiate colorectal cancer from adenoma and normal tissue. Thirty-five significantly up-regulated miRNAs and 30 down-regulated miRNAs were identified in carcinoma in comparison to normal tissue（P 〈0.001） ,whereas 25 aberrantly expressed miRNAs were identified in cancer in comparison to adenoma（P〈0.01） .In addition,55 miRNAs could distinguish adenoma from normal colorectal mucosa（P〈0.001） .Twelve up-regulated miRNAs and 13 down-regulated ones were simultaneously aberrantly expressed in cancer and adenoma.Quantitative RT-PCR analysis showed that miR-552 and miR-142-3p were significantly up-regulated（2.97±2.72 vs 0.98±0.48,P〈0.05;3.64±3.41 vs 1.31±0.61,P〈0.05） and miR-139-3p and miR-133b were down-regulated in cancer tissue compared with normal mucosa（0.10±0.26 vs 0.82±0.70,P〈0.05;0.81±0.67 vs 1.71±1.29,P〈0.05） ,which is consistent with the microarray results.Aberrant miR-552 expression was correlated with TNM stage and lymph node and distance metastasis（all P〈0.05） ,but not with age,gender,tumor size or histological grade.Aberrant miR-139-3P expression was correlated with TNM stage and distance metastasis,while differential expression of miR-142-3p was correlated with histological grade. CONCLUSION：Differential miRNA expression could help distinguish malignant tissue from adenoma and normal mucosa,suggesting that aberrant miRNA expression might be involvedin colorectal tumorigenesis.Differentially expressed miRNAs might be used as early diagnosis markers or therapeutic targets for human colorectal cancer.