Effects Of LncRNA-HCG11 On Proliferation And Apoptosis Of Non-small Cell Lung Cancer Cells By Sponging MiR-224-3p And Its Mechanisms

IntroductionLung cancer is the most common malignant tumor with the highest mortality and the second highest incidence,and the most common pathological type is non-small cell lung cancer(NSCLC).Most of the patients with lung cancer lose the chance of surgery when diagnosed due to advanced stage.The main treatment methods for these people are chemotherapy,radiotherapy,targeted therapy and immunotherapy.However,even though the treatment has been so diversified,the overall survival rate of lung cancer patients has not changed significantly with the disadvantages of easy recurrence and poor tolerance.Therefore,it is of great significance to continue to find new therapeutic targets for the treatment of lung cancer.Long non-coding RNA(lncRNA)and miRNA play an important role in the biological process of a variety of cancer cells,including cell proliferation,invasion,metastasis and apoptosis.The relationship between lncRNA and miRNA is a hot topic.LncRNA could reduce the activity and quantity of miRNA by competitive binding miRNA or promoting the degradation of miRNA,thus affecting the expression of downstream genes,and ultimately affect the biological function of cells.In order to elucidate the interaction and regulation mechanism between lncRNA and miRNA in NSCLC,and to find potential therapeutic targets for lung cancer,we found that lncRNA-HCG11 and miR-224-3p have potential interaction through TCGA database analysis and prediction tools.However,the role and mechanism of lncRNA-HCG11 and miR-224-3p in the occurrence and development of NSCLC are still unclear.This study may provide a new target for the treatment of NSCLC.Objective1.To explore the relationship between lncRNA-HCG11 and miR-224-3p and their effects on proliferation,invasion,migration and apoptosis of NSCLC cells.2.To study the downstream target genes of lncRNA-HCG11 and miR-224-3p and to elucidate the mechanism of interaction.3.To further elucidate the effects of lncRNA-HCG11 and miR-224-3p on the occurrence and development of NSCLC in vivo.Methods1.The expression level of lncRNA-HCG11 in several NSCLC cell lines and normal cell line were analyzed by qRT-PCR,and verified by clinical specimens.2.The effects of lncRNA-HCG1 1 on proliferation,invasion,migration and apoptosis of NSCLC cells were determined by Edu assay,CCK-8 assay,Transwell invasion and migration assay,Annexin V-FITC/PI assay and Western Blot;3.The expression level of miR-224-3p in NSCLC cell lines was detected by qRT-PCR and the interaction between lncRNA-HCG11 and miR-224-3p was explored by dual luciferase reporter system;4.LncRNA-HCG11 and miR-224-3p were co-transfected into NSCLC cells.The interaction mechanism of lncRNA-HCG11 and miR-224-3p and their effects on proliferation,invasion,migration and apoptosis of NSCLC cells were elucidated by cell proliferation test,transwell invasion and migration assay and apoptosis test.5.The target gene SOCS6 of miR-224-3p was initially found by starbase,and the dual luciferase reporter test was used to determine the target gene of miR-224-3p.The interactions among lncRNA-HCG11,miR-224-3p and SOCS6 were determined by the expression level of target gene in lncRNA-HCG11 group and control group;6.The effect of lncRNA-HCG11 and miR-224-3p interaction on non-small cell lung cancer cells in vitro was verified by xenograft model of nude mice.Results1.The expression of lncRNA-HCG11 was decreased in NSCLC,while the expression of miR-224-3p was increased in NSCLC.2.Compared with the control group,lncRNA-HCG11 overexpression significantly inhibited cell proliferation,invasion and migration,but induced apoptosis.3.miR-224-3p significantly decreased the activity of wild-type-lncRNA-HCG11-luciferase,but had no significant effect on the activity of mutant-type-lncRNA-HCG11-luciferase.4.LncRNA-HCG11 could significantly inhibit the proliferation,invasion and migration of NSCLC cells,and promote apoptosis,while miR-224-3p could partially eliminate the effects of lncRNA-HCG11 on cell proliferation,invasion,migration and apoptosis.5.miR-224-3p significantly decreased the luciferase activity of wild-type-SOCS6-luciferase,but had no significant effect on the luciferase activity of mutant-type-HCG11-luciferase;the expression of SOCS6 was significantly increased in lncRNA-HCG11 over-expression group.6.LncRNA-HCG11 could still interact with miR-224-3p to inhibit cell proliferation and promote apoptosis in xenograft model of nude mice.Conclusions1.LncRNA-HCG11 is a tumor suppressor lncRNA,with low expression in NSCLC tissues and cells.2.LncRNA-HCG11 inhibits the function of miR-224-3p through sponging effect,and then inhibits the proliferation,invasion and migration of NSCLC cells,and promotes apoptosis.3.MiR-224-3p inhibits the expression of SOCS6 through 3'UTR.4.In vivo,lncRNA-HCG11 can still affect the biological function of NSCLC cells by interacting with miR-224-3p.