Panitumumab and cetuximab affect differently miRNA expression in colorectal cancer cells.

Background & aim: Resistance to anti-EGFR monoclonal antibodies in metastatic colorectal cancer (CRC) is frequent and prognostic biomarkers are lacking. MicroRNAs (miR) are good candidates in this context. We aimed to characterize cetuximab and panitumumab exposure influence on miR expression in colorectal cancer cells to identify those regulating the EGFR pathway and implicated in resistance to treatment. Finally, we aimed to identify miR expression in serum of patients with advanced CRC treated with cetuximab or panitumumab. Results: Cetuximab and panitumumab exposure induced significant expression variations of 17 miR out of a miRnome panel of 752. Six of those miR interacted with at least one downstream element of the EGFR pathway. Conclusion: After the bioinformatics two-phase process, five miR rarely described before could be potential actors of anti-EGFR monoclonal antibody resistance: miR-95-3p, miR-139-5p, miR-145-5p, miR-429 and miR-1247-5p. In vivo, we detected the expression of miR-139-5p and miR-145-5p in serum of patients with metastatic CRC.