Evaluation of miR-143 and miR-145 expression in tumors and tumor margins in patients with colorectal cancer

Abstract

Background: microRNAs are non-coding RNAs with about 22 nucleotides in length which modulate gene expression by binding to the gene target mRNA; they have eminent role as oncomiRs or microRNAs tumor suppressors. Changes in microRNAs expression have a radical role in pathobiology of different cancers. In this research, miR-143 and miR-145 expression in the tumor cells and tumor margins of patients with colorectal cancer were evaluated. Methods: Tumor cells and tumor margins were examined after being biopsied from 30 patients with colorectal cancer. Total RNA content was extracted from both tissue types with TRIzol reagent and then, complementary DNA (cDNA) of miRNAs were synthesized. microRNAs expression level was assessed through reverse transcription-polymerase chain reaction (RT-PCR) method using the SYBR Green. For statistical analysis, GraphPad Prism software was applied to compare the expression level of the microRNAs between tumor cells and tumor margins. Findings: The expression level of miR-143 and miR-145 were significantly lower in tumors compared to the margins (P < 0.0001 for both). Conclusion: Expression level of miR-143 and miR-145 were down-regulated in tumors compared to the margins. Lower expression level revealed that miR-143 and miR-145 can be utilized as diagnostic biomarkers in colorectal cancer. This may also introduce these microRNAs as colorectal cancer therapeutic targets. é 2017, Isfahan University of Medical Sciences(IUMS). All rights reserved.