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Updated: Apr 30, 2026
Detection of a Circulating MicroRNA Custom Panel in Patients with Metastatic Colorectal Cancer
Published on: March 14, 2019
MicroRNAs 146a and 147b biomarkers for colorectal tumor's localization
Inés Omrane1, Nadia Kourda2, Nejla Stambouli1
1Laboratory of Human Genetics Immunology and Pathology, Faculty of Sciences,Tunis El Manar University, 2092 Tunis, Tunisia.
Abstract:
The recently identified class of microRNAs (miRs) provided a new insight into cancer research, since abnormalities of members of microRNAs family have been found in various types of cancer. However, the relationship between five miRNAs (miR146a, miR155, miR21, miR135a, and miR147b) and colorectal cancer remains unclear. In the present study, we examined expression of these miRNAs in 25 pair-matched colon cancer tissues and normal colon mucosa. The expression levels of miR146a, miR155, miR21, miR135a, and miR147b were quantified by real-time PCR. We found that miR21, miR146a, and miR135a were all expressed at higher levels in colon tumors. On the other hand, miR146a and miR147b expressions are significantly higher in left colon compared to right colon. These two miRs, especially miR146a, seemed to be markers for the left colon tumors. Moreover, significant proportional and inverse correlations were found between miR expressions in tumor and healthy tissue, and the correlations profiles were different depending on cancer localization. Taken together, these results lead us to suggest the presence of different mechanisms regulating miRs expression and consequently their target genes in left and right colon. So the pathway of colorectal carcinogenesis would be different according to the site of the tumor.
Insights
MicroRNAs (miRs) show altered expression in colorectal cancer. Specific miRs like miR21, miR146a, and miR135a are upregulated in tumors, with miR146a potentially marking left-sided colon cancers.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- MicroRNAs (miRs) are a newly identified class of molecules implicated in various cancers.
- The specific roles of five miRs (miR146a, miR155, miR21, miR135a, and miR147b) in colorectal cancer pathogenesis are not fully understood.
Purpose of the Study:
- To investigate the expression levels of five specific miRs in colorectal cancer tissues and normal adjacent tissues.
- To explore potential differences in miR expression between left and right colon tumors.
- To identify correlations between miR expression in tumor and healthy tissues based on cancer localization.
Main Methods:
- Quantitative real-time PCR was used to measure the expression of miR146a, miR155, miR21, miR135a, and miR147b.
- Expression levels were analyzed in 25 pairs of matched colon cancer and normal colon mucosa samples.
- Statistical analysis was performed to assess correlations and differences in expression based on tumor location.
Main Results:
- miR21, miR146a, and miR135a showed significantly higher expression in colon tumors compared to normal tissues.
- miR146a and miR147b expression was notably higher in left-sided colon tumors than in right-sided tumors.
- Inverse correlations were observed between miR expression in tumor and healthy tissues, varying by cancer location.
Conclusions:
- The findings suggest distinct mechanisms regulate miR expression in left and right colon cancers.
- miR146a may serve as a potential biomarker for left-sided colon tumors.
- The study indicates that colorectal carcinogenesis pathways may differ based on tumor location.
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