Differential expression of miR-20a and miR-145 in colorectal tumors as potential location-specific miRNAs.

BACKGROUND MicroRNAs (miRNAs), as tissue specific regulators of gene transcription, may be served as biomarkers for colorectal cancer (CRC). OBJECTIVE This study aimed to investigate the potential role of the cancer-related hsa-miRNAs as biomarkers in colon cancer (CC) and rectal cancer (RC). METHODS 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). RESULTS The significantly elevated levels of miR-21, miR-133b, miR-18a, miR-20a, 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). HsamiR-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 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. CONCLUSION 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.