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.