The Expression And Meaning Of MicroRNA-143 And C-myc In The Rectal Adenocarcinoma

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.