MiR-625-3p Modulates Gefitinib Resistance Through AXL In Non-small Cell Lung Cancer

Background:Recently,more and more studies have shown that microRNA plays an important role in the occurrence and development of tumors as well as resistance to targeted therapies.Anexelekto kinase,one member of the TAM family(Tyro3,Axl,Mer),can cause the resistance of EGFR-TKI in lung cancer when activated,while the cause of high expression of AXL is still need more researches.We have found that miR-625-3p can regulate the expression of AXL.Therefore,the purpose of this study was to investigate whether miR-625-3p affects cell proliferation,migration,and invasion through regulating AXL,and then Gefitinib-resistance non-small cell lung cancer cells become sensitive.Method: Established a Gefitinib-resistance cell line of HCC827,namely HCC827 GR,and then detected gene of the two strains by gene high-throughput sequencing.Cell Counting Kit-8(CCK8)assay was used to detect the IC50 of cells against Gefitinib.We used the transwell invasion、migration assay and wound healing assay to evaluate the motility of cells.RT-PCR was used to detect the m RNA expression in cell lines.Western blot were used to detect the expression of proteins in cell lines.Results:(1)HCC827 is a Gefitinib-sensitive cell line with an EGFR 19 exon mutation.HCC827 GR is resistant to gefitinib but no T790 M mutation was detected.(2)HCC827 GR has stronger ability in proliferation,invasion and migration than HCC827.(3)The expression of miR-625-3p in HCC827 GR was lower than that in HCC827(P<0.05).The m RNA(P<0.05)and protein expression of AXL in HCC827 GR was higher than that in HCC827.(4)After overexpression of miR-625-3p,the IC50 of HCC827 GR against Gefitinib was decreased,and the ability of invasion and migration were decreased,too.At the same time,the expression of AXL was lower than control group whether m RNA(P<0.05)or protein level.(5)The IC50 of cells against Gefitinib was decreased,as well as the ability of invasion and migration when interference the expression of AXL in HCC827 GR.(6)Compared with HCC827,p-AKT(308)was up-regulated in HCC827 GR,and protein E-cadherin was down-regulated,p-Smad3,ZEB1,Snail,MMP9,MMP2,N-cadherin,vimentin was up-regulated.After overexpression of miR-625-3p or interference with AXL in HCC827 GR,compared to the control group,p-AKT(308)was down-regulated,while E-cadherin was up-regulated,p-Smad3,ZEB1,Snail,MMP9,MMP2 N-cadherin and vimentin were down-regulated.Conclusion: MiR-625-3p can reduce the proliferation,invasion,and migration of cells and reduce the resistance of Gefitinib via negatively regulate the expression of AXL.It suggested that overexpression of miR-625-3p or inhibition the expression of AXL may be a new direction for targeted treatment in non-small cell lung cancer.But the study is not mature yet,more research are needed.