Evaluation of level of expression of microRNA-21 and let-7g in serum and stool of patients with colorectal cancer
Abstract Background MicroRNAs (miRs) are involved in the pathogenesis of various malignancies such as colorectal cancer through regulating multiple cellular processes, including cell proliferation, cell cycle, apoptosis and migrationMiR-21 and let-7 are two important genes that have confirmed in this pathway. The role of the let-7 gene as a gene tumor process in various cancers and the role of miR-21 in the development and progression of cancer has been conclusively identified also this gene has an oncogenic role in various cancers. In this study, the expression patterns of miR-21 and let-7 in serum and stool samples of colorectal cancer patients were evaluated. Materials and Methods During the present study, 120 samples including 40 serum samples of CRC and 40 stool samples from the same patients and 40 healthy samples were collected. After total RNA extraction, real-time PCR was used to measure changes in genes expression. Statistical analysis of data was performed with GraphPad Prism statistical software (Version 6.0) with a significance level of 5%. Results The relative expression level of miR-21 in the serum samples of CRC increased compared to the healthy group, which was statistically significant. On the other hand, the relative expression level of let-7g in the serum samples of CRC showed a significant decrease compared to the healthy sample. In stool samples, the expression changes of either of the two genes were not significant. Conclusion Our findings indicate that the relative expression of miR-21 and let-7g genes can be used as a diagnostic or predictive biomarker in colorectal cancer serum samples. While, this is not the case in stool samples. Moreover, further investigations at the protein level should be performed.