Abstract: Objective　To investigate the plasma microRNA（miRNA） expression changes in preoperative and postoperative patients with colorectal cancer（CRC），and the correlation between preoperative plasma and cancerous tissues.Methods　This study selected 32 patients with CRC who attended Department of Gastrointestinal Surgery at Shanghai Tenth People's Hospital of Tongji University from June 2014 to August 2016，and 33 healthy people were enrolled during the same period.Peripheral venous plasma of CRC patients was collected before and after surgery，as well as healthy people，and cancerous tissues and paracancerous tissues collected in CRC patients.Quantitative real-time polymerase chain reaction （qRT-PCR） was used to detect the expression of miR-21，miR-17，miR-145，miR-15b，miR-150 in plasma，cancerous tissues and paracancerous tissues.Results　Compared to healthy people，the expression of miR-21，miR-17，miR-145 and miR-15b in CRC patients were significantly higher（P<0.05）．Also，we found that the expression of miR-21，miR-17，and miR-15b decreased in postoperative plasma compared with preoperative plasma（P<0.05）；the expression of miR-21，miR-17，miR-145 and miR-15b were significantly higher in cancerous tissues than in paracancerous tissues （P<0.05），while the expression of miR-150 was lower（P<0.05）．Correlation analysis showed that there was a positive correlation between cancerous tissues and plasma of miR-21 （r=0.516，P=0.002） and miR-15b （r=0.526，P=0.001）．Conclusion　The expression levels of miR-21，miR-17，miR-145 and miR-15b are obviously imbalanced in plasma and cancerous tissues of patients with CRC.Moreover，plasma miR-21 and miR-15b are expected to be the new non-invasive markers for CRC diagnosis.

Key words: Colorectal neoplasms；MicroRNAs；Tumor markers, biological；Diagnosis

摘要： 目的　探讨结直肠癌（CRC）患者术前、术后血浆微小RNA（miRNA）表达水平变化，以及术前血浆与癌组织miRNA表达水平的相关性。方法　选取2014年6月—2016年8月同济大学附属上海第十人民医院胃肠外科就诊的CRC患者32例，另选取同期体检健康者33例。采集健康者及CRC患者术前、术后1个月外周静脉血，留取CRC患者癌及癌旁组织。通过实时荧光定量聚合酶链反应检测血浆、癌组织与癌旁组织中miR-21、miR-17、miR-145、miR-15b、miR-150表达水平。结果　与健康者比较，CRC患者术前血浆miR-21、miR-17、miR-145、miR-15b表达水平上调（P<0.05）；与术前比较，CRC患者术后1个月血浆miR-21、miR-17、miR-15b表达水平下调（P<0.05）；与癌旁组织比较，CRC患者癌组织中miR-21、miR-17、miR-145、miR-15b表达水平上调，miR-150表达水平下调（P<0.05）。相关性分析显示，CRC患者术前血浆与癌组织miR-21（r=0.516，P=0.002）、miR-15b（r=0.526，P=0.001）表达水平呈正相关。结论　CRC患者血浆和癌组织miR-21、miR-17、miR-145、miR-15b表达水平失调，其中血浆miR-21、miR-15b有望成为CRC新型非侵袭性诊断标志物。

关键词: 结直肠肿瘤, 微RNAs, 肿瘤标记, 生物学, 诊断