Targeting EphA2 with miR-124 mediates Erlotinib resistance in K-RAS mutated pancreatic cancer

Abstract

Objectives: Chemotheraputic drug resistance is a critical factor associated with the poor survival in advanced/metastatic pancreatic cancer (PC) patients. Methods: Human pancreatic cell lines Capan-1 and BXPC-3 were cultured with different concentrations of erlotinib (0, 10, 50, and 100 μm) for 48 h. The relative cell viability and apoptosis was detected using MTT assays and flow cytometry apoptosis analysis, respectively. Transfection of pcDNA-EphA2, si-EphA2 and miR-124 mimic/inhibitor was used to modulate the intracellular level of EphA2 and miR-124. The interaction between miR-124 and the 3′UTR of EphA2 was explored using dual luciferase reporter assay. Key findings: Compared with BXPC-3 cells, Capan-1 cells showed resistance to differential concentration treatment of erlotinib. The expression of EphA-2 was significantly increased and the expression of miR-124 was significantly decreased in Capan-1 cells. Overexpressing EphA2 induced resistance of BXPC-3 cells to erlotinib treatment. And EphA2 was identified as a novel target gene for miR-124. MiR-124 overexpression was able to sensitize the response of Capan-1 cells to erlotinib through inhibiting EphA2. Furthermore, both miR-124 overexpression and EphA2 inhibition sensitized Capan-1 cells to erlotinib in xenograft model. Conclusions: Our study demonstrated that EphA2 rescued by miR-124 downregulation conferred the erlotinib resistance of PC cell Capan-1 with K-RAS mutation.