The study on the mechanism by which circ_MTHFD2 promotes lung cancer resistance to pemetrexed through microRNA-124
XU Fei
MA Leina
FENG Lingxin
WU Yinjie
XU Xiaoyan
YU Zhuang
Abstract：Objective To investigate the effect of microRNA-124(miR-124)mediated by circ_MTHFD2 on the resistance of lung cancer against pemetrexed.Methods The pemetrexed-resistant human lung cancer cell line was established by exposing pemetrexed repeatedly to high-level concentration.The xenograft model of pemetrexed resistant nude mice by intratumoral injection was established.MiR-124 mimics,miR-124 inhibitors and negative controls were transfected into A549 and A549/PEM cells by Lipofectamine liposome method,and divided into miR-124 up-regulation group,miR-124 inhibitory group and negative control group;then the sensitivity to pemetrexed was estimated by CCK-8 assay and flow cytometry.Real time fluorescent quantitative PCR(QPCR) and gene chip were used to detect the expression of miR-124 and circular RNA.Sequencing and bioinformatic analysis were used to detect the expression of circular RNA in different cells and tissue and to predict the binding sites between miR-124 and circular RNA.Results The IC50 of parental strains A549 was (30.78± 1.97)μmol/L,and the resistant strains A549/PEM was (913.53± 14.1)μmol/L.The resistance index (RI) of pemetrexed-resistant human lung cancer cell line A549 named A549/PEM was 29.69± 1.49.The expression of miR-124 in drug-resistant cell line A549/PEM was significantly decreased,which was about 145.952 times lower than that in A549 cells.Compared with the negative control group,the sensitivity to pemetrexed was significantly reduced in miR-124 inhibitor group,and the IC50was(9.94±1.90) μmol/L and (80.45±3.50) μmol/L respectively,with significant difference between two groups (P＜0.05).Flow cytometry showed that up-regulation of miR-124 expression could induce the apoptosis of A549 and A549/PEM cells compared with the control group.The sequencing indicated that the expression of many circular RNAs were up-regulated in resistant cells and tissues,and up-regulated circ_MTHFD2 was proposed to bind miR-124.Conclusion Circ_MTHFD2 may be involved in the development of pemetrexed resistance in lung cancer by regulating the expression of miR-124.
Keywords：Lung cancerPemetrexedResistanceCircular RNAMicroRNA-124
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 961-967 )