Colorectal cancer (CRC) is the leading cause of 10% of cancer related death throughout the world. Early detection and removal of early-stage cancer would allow to prevent cancer progression significantly. microRNAs are 18-22 nucleotide non-coding RNA molecules, that have a crucial role in regulation of mRNA expression and stability that are related to tumor initiation and progression. The aim of this study was to measure the miR-21 and miR-92a expression in CRC and adenoma cases.

We assessed the level of miR-21 and miR-92a expression in 5ml whole blood sample from 35 CRC patients ,44 adenoma patients and 40 healthy control by quantitative Real time PCR with specific primers. RNA was extracted by RNX-plus solution. Reverse transcriptase PCR was performed for cDNA synthesis by microRNA cDNA synthesis kit. Data analysis has been done by SPSS 17 using the Mann-Whitney U test, student T test and one-way ANOVA.

In our study, the level of miR-21 in patients with CRC (p=0.056) and adenoma (p=0.006) was significantly lower than control group. In addition, no significant differences were observed in the level of miR-92a between CRC and adenoma groups compared to the control group. miR-21 yielded an area under the ROC curve (AUC) of 0.0599 in discriminating cancer from control and AUC of 0.673 discriminating adenoma from control.

Our result showed that miR21 have potential value for detection of CRC and Adenoma and might be a good noninvasive factor for early diagnosis of premalignant lesion of colorectal cancer.