Differential Expression of miR-20a and miR-145 in Colorectal Tumors as Potential Location-specific miRNAs

MicroRNAs (miRNAs), as tissue specific regulators of gene transcription, may be served as biomarkers for Colorectal Cancer (CRC).

This study aimed to investigate the potential role of the cancer-related hsa-miRNAs as biomarkers in Colon Cancer (CC) and Rectal Cancer (RC).

A total of 148 CRC samples (74 rectum and 74 colon) and 74 adjacent normal tissues were collected to examine the differential expression of selected ten hsa-miRNAs using quantitative Reverse Transcriptase PCR (qRT-PCR).

The significantly elevated levels of miR-21, miR-133b, miR-18a, miR-20a, and miR-135b, and decreased levels of miR-34a, miR-200c, miR-145, and let-7g were detected in colorectal tumors compared to the healthy tissues (P<0.05). Hsa-miR-20a was significantly overexpressed in rectum compared to colon (p =0.028) from a cut-off value of 3.15 with a sensitivity of 66% and a specificity of 60% and an AUC value of 0.962. Also, hsa-miR-145 was significantly overexpressed in colon compared to the rectum (p =0.02) from a cut-off value of 3.9 with a sensitivity of 55% and a specificity of 61% and an AUC value of 0.91.

In conclusion, hsa-miR-20a and hsa-miR-145, as potential tissue-specific biomarkers for distinguishing RC and CC, improve realizing the molecular differences between these local tumors.