【作者】 甘伟；

【导师】 赵华；

【作者基本信息】 中南大学 ， 外科学， 2010， 硕士

【摘要】 目的：本实验拟从直肠腺癌、直肠腺瘤和直肠良性病变组织的miRNA-143表达差异及c-Myc蛋白表达,从而研究miRNA-143, c-Myc与直肠腺癌之间的内在联系及表达与直肠腺癌临床病理特征的关系。方法：MicroRNA-143的表达收集中南大学湘雅二医院2006年12月~2010年1月术后病检结果已经证实的直肠标本60例,其中直肠腺癌20例,直肠腺瘤20例,直肠良性病变20例。提取石蜡包埋的肿瘤组织和直肠良性病变组织的总RNA,采用美国Applied Biosystems公司设计的特异茎环状引物进行逆转录反应,以U6为内参照基因,实时定量PCR技术检测MicroRNA-143的表达。根据实时获得的反应初始浓度的Ct值,分别计算各样本的△Ct值,再用SPSS16·0软件进行双尾异方差t检验。免疫组化分析c-Myc蛋白含量收集中南大学湘雅二医院2006年12月-2010年1月术后病检结果已经证实的直肠标本75例,其中直肠腺癌35例,直肠腺瘤20例,直肠良性病变20例,并用免疫组化链霉菌抗生物素蛋白-过氧化物酶连接法(S-P法)检测C-Myc在直肠腺癌、腺瘤和直肠良性病变中的表达。采用χ2检验。P<0.05差异有显著性。统计学分析均采用SPSS16·0软件包完成。结果：直肠腺癌组织的miRNA-143表达显著低于直肠良性病变组织的MicroRNA-143表达。(P<0.05)。直肠腺癌组织的miRNA-143表达显著低于直肠腺瘤组织的MicroRNA-143表达。(P<0.05)。直肠腺瘤组织的miRNA-143表达总体低于直肠良性病变组织的MicroRNA-143表达。(P=0.084>0.05)不具有统计学意义。miRNA-143的表达与直肠腺瘤的不典型增生程度有相关性。(P<0.05)。直肠腺癌组织的C-Myc阳性表达率(74.3%)显著高于直肠良性病变组织阳性表达率(15.o%)。(χ2=15.647 P<0.05)。直肠腺癌组织的C-Myc阳性表达率(74.3%)显著高于直肠腺瘤组织的阳性表达率(45.o%)。(χ2=4.717 P<0.05)。直肠腺瘤组织的C-Myc阳性表达率(45.0%)高于直肠良性病变组织的阳性表达率(15.o%)。(χ2=4.286 P<0.05)。结论1 MicroRNA-143的低表达与直肠腺癌的发生相关。2 C-myc过度表达与直肠腺癌的发生相关。3 MiRNA143和C-Myc在直肠腺癌中的表达,不能作为直肠腺癌恶性程度及预后的有效评估指标。4 MiRNA143的低表达有望成为诊断早期直肠腺癌的依据之一。5 MiRNA-143表达降低可能是原癌基因C-myc高表达的原因之一,可能是诱发直肠腺癌的重要途径,并在直肠腺癌发生中起重要作用。更多还原

【Abstract】 Objective:To investigate the expression of c-myc and microRNA-143 in the benign rectal lesion, rectal adenoma and rectal adenocarcinoma tissue.Compare their expression difference in a bove tissues,also with clinical pathological features in rectal adenocarcinoma.Methods:Collection of 20 rectal adenocarcinomas,20 adenomas and 20 benign rectal lesions in operations in the 2nd Xiangya hospital of Central South University from December 2006 to January 2010.Total RNA was extracted from paraffin-embedded rectal cancer tissues and corresponding benign lesion tissues. Reverse transcription reactions were done with special looped primer from Applied Biosystems. The expression of miR-143 were then detected by real time PCR with a reference gene U6. We calculated△Ct values of each sample and analized on 2-△Ct by t-test statistical method.Collection of 35 rectal adenocarcinomas,20 adenomas and 20 benign rectal lesions in operations in the 2nd Xiangya hospital of Central South University from December 2006 to January 2010.The expressions of c-Myc protein in benign lesion rectal tissues(n=20), adenoma tissues(n=20) and primary rectal adenocarcinoma tissues(n=35) were observed by S-P immunohi to chemical assay. Results The results showed that the expression of miRNA-143 in rectal adenocarcinoma tissues was lower significantly than that in benign lesion tissues.(P<0.05)The expression of miRNA-143 in rectal adenocarcinoma tissues was lower significantly than that in adenoma tissues.(P<0.05)The expression of miRNA-143 in adenoma tissues was lower than that in benign lesion tissues.(P>0.05)The expression lever of miRNA-143 was correlated with the degree of atypical hyperplasia in rectal adenocarcinoma. (P<0.05)The expression rate of c-Myc in the rectal adenocarcinoma tissues(74.3%) was significantly higher than that in the benign lesion tissues(15.0%). (χ2=15.647 P<0.05)The expression rate of c-Myc in the rectal adenocarcinoma tissues(74.3%) was significantly higher than that in the adenoma tissues(45.0%). (χ2=4.717P<0.05)The expression rate of c-Myc in the adenoma tissues(45.0%) was significantly higher than that in the benign lesion tissues(15.0%). (χ2=4.286 P<0.05)Conclusion:1 The expression of miRNA-143 decreased from benign lesion tissues, adenoma to rectal adenocarcinoma. Our study showed that the down-regulation of miRNA-143 were associated with rectal carcinogenesis. Formalin-fixed paraffin-embedded specimens could act as satisfactory resources for miRNA study.2 The overexpression of c-Myc from benign lesion tissues,adenoma to rectal adenocarcinoma.There were statistical significance between every two groups. Our study showed that the overexpression of c-Myc may play a pivotal role in the carcinogenesis of rectal adenocarcinoma.3 Both miRNA-143 and c-Myc protein expression in primary rectal adenocarcinoma had no significant correlation with patient’s sex,age,cell differentiation level, Dukes stages and lymph nodes metastasis or not.4 The lower-expression of miRNA-143 could be regarded as one of the parameters for early diagnosis of rectal adenocarcinoma.5 The lower-expression of miRNA-143 may be lead to the overexpression of c-Myc in rectal adenocarcinoma,which contributes to the rectal carcinogenesis may be conferred through transactivation of c-Myc by miRNA-143.更多还原