Non-coding RNAs miR-20a and miR-145 could differentiate between colon and rectum tumors

MicroRNAs (miRNAs), as small non-coding RNAs and tissue specific regulators of gene transcription, have been shown to involve in initiation and progression of cancers. Colorectal cancer (CRC), affects both colon and rectum tumors as a common entity and whereas the clinical behavior and treatment of these two types are distinctly different. There is only limited evidence about different molecular characteristics between the colon and rectum tumors. The main purpose of this study was to evaluate the expression level of oncogenic and suppressor miRNAs whether could differentiate between colon and rectum cancers.A total of 74 CRC samples (37 rectal tumor tissues and 37 colon tumor tissues) and 74 matched adjacent normal tissues were collected. The differential expression of 10 selected miRNAs (miR-20a, 22, 34a, 133b,135b, 21,145,18a, 200c and let-7g) was evaluated using quantitative Real-time PCR (qPCR). MiRNA expression levels were adjusted for multiple comparisons and tumor tissues was compared with noncancerous tissues from the same site.The significant elevated levels of miR-21, miR-22, miR-18a, miR-20a, miR-135b, and decreased levels of miR-34a, miR-200c, miR-145, and let-7g were detected in both colon and rectal tumor samples compared to the normal groups (P<0.05). A difference in expression level for miR-20a and miR-145 was found (P<0.001). Further analysis revealed that these miRNAs were associated with tumor type and cancer localization (P<0.05). We identified that miR-20a and miR-145 differentially expressed between rectal and colon cancer and may be as tissue-specific biomarkers for distinguishing between these two cancers. This finding improves understanding the molecular differences between colon and rectal cancer, suggesting microRNAs as tools for better understanding personalized cancer biogenesis, evolution, diagnosis and treatment

کلیدواژه ها:

Cancer ، Colon ، MiRNA ، Rectum