Expectation of benefit from the antiepidermal growth factor receptor (anti-EGFR) therapeutics is a not yet solved question in metastatic colorectal cancer (mCC). MicroRNAs (miRNAs), which are short non-coding RNA molecules and important regulators of cell signaling pathways crucial for the growth of human cancer cells. Several studies have examined the expression profiles of miRNAs in response to different chemotherapy treatments and found that the expression patterns may be associated with the treatment response. Therefore, our aim was to evaluate the differential expression profiles of miRNAs in mCC treated with anti-EGFR therapeutics (cetuximab, panitumumab).
Overall 21 patients with wild type KRAS, BRAF, NRAS, PTEN and PI3 CC were included into our analysis. Using real-time PCR, we analyzed the expression levels of 18 different human miRNAs in the twenty-one CC tumor samples. Relationship between data and disease-free survival (DFS) were analysed by using SPSS.
Among evaluated miRNAs, miR-31-5p exhibited the most dramatic difference in expression, with 5.01-fold in cancer tissues compared with the controls (P = 0,01). The expression levels of miR-21 and miR-31-5p were significantly higher, miR-451 was lower in non-responders tissues (P = 0.02, P = 0.03, P = 0.01; respectively). In Kaplan–Meier analysis, a high miR-31-5p expression level was significantly associated with shorter DFS (P = 0.003).
This study indicated that up regulation of miR-31-5p and miR-21; down regulation of miR-451 might serve as a potential indicator for anti-EGFR resistance in mCC patients who are expected to benefit from anti-EGFR therapeutics.
Ozkan Kanat
Has not received any funding
All authors have declared no conflicts of interest.