The Mechanism Of EGFR-TKIs Resistance In HOTAIR In Non-small Cell Lung Cancer

Background and objective: HOTAIR deserved high expression in various cancers and associated with tumorigenesis.As a superstar molecule in lnc RNA,HOTAIR has been stuied in many kinds of cancer,and there were also got some progress in lung cancer.Faced high incidence and mortality of lung cancer in China so many years,there are many therapies and targeted molecular drugs continually being updated and molecular targeted therapy made a significant contribution to therapy.history.However,acquired resistance was eventually leading to recurrence and treatment failure,this has become a difficult problem in cancer therapy.In this study,we made a series of mechanical discussion about HOTAIR through the cell cycle regulate EGFR-TKIs resistance in non-small cell lung cancer.Method:Through the analysis of the previous experiments,this study adopted cell lines(PC-9,PC-9/AB2)which used in the previous experiments,and established stable-transfection of them,include PC-9 overexpressed HOTAIR and PC-9/AB2 knocked down HOTAIR,Firstly,we used flow cytometry analysis,CCK8 test to detect cell resistance,Western Blot and other experiments showed that HOTAIR can regulate cell cycle at protein level;next,through si-RNA interference technology,Chromatin immunoprecipitation technique,EDU detection cell proliferation,all of this result showed HOTAIR could regulated cell cycle-mediated resistance through epigenetic level,Last,mi RNA sequencing and target gene prediction and fluorescein plum reporter gene assay and transfection.The method deserved that HOTAIR participated in resistance mechanism through mi RNA regulate cell cycle,and we also use some inhibitors to clarify this mechanism at key regulatory points.Result: First,we found that HOTAIR is highly expressed in drug-resistant cell lines,especially in acquired drug-resistant cell lines(PC-9/AB2),and we found that overexpression of HOTAIR can silence the expression of P16 and P21 after immunohistochemical staining.Subsequent experiments showed that HOTAIR could block the G1 phase of cell division,prolong the S phase in cell division,and HOTAIR promote cell cycle progression mediating resistance through silence P16,P21;phosphorylate Rb,up-regulate E2F1,CDK4,CDK6,Cyclin D1 expression at protein level.Then we also found that HOTAIR can up-regulate the expression of EZH2/H3K24,and the results of the experiment suggested that HOTAIR participate in the resistance mechanism in epigenetic modification of EZH2/H3K24 to regulated P16,P21 and E2F1 to promote cell cycle and.Following mi RNA sequencing showed high expression of HOTAIR also elevated the expression of mi R-1249-5P and mi R-1910-3P in cells,and the results suggested that HOTAIR and mi R-1249-5P and mi R-1910-3P complement each other to regulate the cell cycle.Lead to resistance.Conclusion: 1.HOTAIR can regulate the resistance of EGFR-TKIs in non-small cell lung cancer by promoting cell cycle.2,HOTAIR participates in the EGFR-TKIs resistance mechanism by epigenetic modifying EZH2/H3K27 to regulate cell cycle.3,HOTAIR and mi R-1249-5P and mi R-1910-3P regulate cell cycle-mediated EGFR-TKIs resistance complementary in non-small cell lung cancer.