miR-21和PDCD4mRNA在大肠癌组织中的表达及其临床意义

Expression and significance of miR-21 and PDCD4mRNA in human colorectal cancer

目的 探讨miR-21和PDCD4mRNA在大肠癌组织中的表达及与其临床病理特征的关系,并阐明在大肠癌活体组织中miR-21与其靶基因PDCD4表达的关系.方法 用荧光定量PCR技术检测43对大肠癌组织及其对应的正常黏膜组织中的miR-21和PDCD4 mRNA表达量；免疫组化SP法检测PDCD4蛋白的表达.结果 大肠癌组织中miR-21的表达升高（P＜0.05）,而PDCD4mRNA的表达降低（P＜0.05）.miR-21的表达与大肠癌的淋巴结转移、临床分期（Ⅰ＋Ⅱ、Ⅲ＋Ⅳ）有关（P＜0.05）,而与患者的性别、肿瘤位置、肿瘤大小、浸润深度、远处转移、临床分期（Ⅰ、Ⅱ）无关（P＞0.05）；PDCD4mRNA的表达与大肠癌的浸润深度、临床分期（Ⅰ、Ⅱ）有关（P＜0.05）,而与患者的性别、肿瘤位置、肿瘤大小、淋巴结转移、远处转移、临床分期（Ⅰ＋Ⅱ、Ⅲ＋Ⅳ）无关（P＞0.05）.miR-21的表达与PDCD4蛋白的核表达、核与浆表达之和存在负相关（P＜0.05）,而与PDCD4mRNA、PDCD4蛋白的浆表达无相关性（P＞0.05）.结论 miR-21和PDCD4mRNA在大肠癌中的异常表达与大肠癌的预后有关；在大肠癌活体组织中,miR-21通过与PDCD4mRNA的3’非编码区结合抑制PDCD4mRNA翻译成蛋白质.

Objective To investigate the expression of miR-21 and PDCD4mRNA in colorectal cancer and their correlation with clinicopathological characteristics,to elucidate relationship between PDCD4and miR-21 in vivo.Methods Expression of RNA （including miR-21and PDCD4mRNA） and PDCD4 protein were detected respectively by quantitative real-time reverse transcriptase-PCR and SP immunohistochemical staining in 43 cases of colorectal carcinoma and corresponding normal mucous membrane tissue.Results In colorectal carcinoma,expression of miR-21 was higher than that of the control （ P 〈 0.05 ）,and expression of PDCD4mRNA lower than the control （ P 〈 0.05 ）.Expression of miR21 was associated with lymph node metastasis and clinical stages （ Ⅰ ＋ Ⅱ,Ⅲ ＋ Ⅳ ） （ P 〈 0.05 ）.On the other hand,no significant differences were observed regarding sex,tumor site,size,local invasion,distant metastases,clinical stages（ Ⅰ,Ⅱ ） （P 〉 0.05 ）.Expression of PDCD4mRNA was associated with local invasion,clinical stages （ Ⅰ,Ⅱ ） （ P 〈 0.05 ）.While no significant differences were found concerning sex,site,size,lymph node metastasis,distant metastases,clinical stages（ Ⅰ ＋ Ⅱ,Ⅲ ＋ Ⅳ ） （ P 〉 0.05 ）.miR21 levels was negatively correlated with PDCD4 expression including nuclear and nuclear and cytoplasmic put together （P 〈 0.05 ）,in contrast to PDCD4mRNA and PDCD4 expression in cytoplasmic （ P 〉 0.05 ）.Conclusions （ 1 ） Abnormal expression of PDCD4 mRNA and miR-21 correlate with prognosis in colorectal cancer.（2） miR-21 suppress translation of PDCD4mRNA by binding to the 3＇-untranslated region （3＇-UTR）of target PDCD4mRNA.