Mechanism Of MiR-4293 Affecting STAT3 Signaling Pathway By Up-regulating Lnc-DC In Tumorigenesis Of Lung Adenocarcinomia

Non-coding RNAs include long non-coding RNAs(lncRNAs)and microRNAs(miRNAs),which are closely related to a variety of cellular activities and therefore plays a key role in tumor progression.It is known that non-coding RNA is compactly connected with the development of lung cancer.At present,it is urgent to understand the molecular mechanism of lung cancer and provide a new target for early diagnosis and targeted therapy of lung cancer.Objective:The aim of this study was to investigate the biological functions and mechanisms of miR-4293 and lnc-DC in lung adenocarcinoma,and to find new targets for the prevention and treatment of lung adenocarcinomaMethods:1.20 cases of lung adenocarcinoma and para-carcinoma tissues were collected from Yantai Shan Hospital,and the expression of lnc-DC was detected by qRT-PCR2.The overexpression plasmid of lnc-DC was constructed and small interfering RNA was designed to knockdown lnc-DC expression.Lung adenocarcinoma cells were transfected the abovementioned plasmid and siRNA,respectively.After 48 hours of transfection,cell proliferation,migration and apoptosis were analyzed.The expression of lnc-DC was detected by real-time PCR,and the levels of STAT3 and its downstream factors were detected by western blot3.The mechanism of interaction between miR-4293 and lnc-DC were analyzed by RIP etc4.Detection of miR-4293 expression in lung adenocarcinoma and para-carcinoma tissues in the same cases.5.Predictive software analysisinvestigated whether miR-4293 could bind with DCP2.6.The miR-4293 mimic and inhibitor were designed and transfected into lung adenocarcinoma cells.After 48 hours,cell proliferation,migration and apoptosis were analyzed.The expression of lnc-DC was detected by real-time PCR,and the levels of downstream factors were detected by western blot.7.Models were constructed in nude mice.Changes of tumor growth and gene expression were analyzed to examine the effects of miR-4293 and lnc-DC.Results:1.We discovered that the expression of lnc-DC in lung adenocarcinoma tissues was notably greater than that in para-carcinoma controls.2.We successfully constructed the pcDNA3.1-GFP-lnc-DC.MTT assay indicated that the number of alive lung adenocarcinoma cells in lnc-DC-treated groups significantly increased compared with the scrambled oligo-treated cells,while the proliferation of lung adenocarcinoma cells obviously decreased after siRNA inhibiting lnc-DC,which demonstrated that lnc-DC promotes the proliferation of lung adenocarcinoma cells.Cell migration results proved that lnc-DC promoted cell migration of lung adenocarcinoma.Flow cytometry certified that inhibition of lnc-DC increased apoptotic number of lung adenocarcinoma cells.Western blot demonstrated that p-STAT3 and STAT3 expression were notably up-regulated after overexpression of lnc-DC,and anti-apoptotic protein Bcl-2 was obviously up-regulated,but pro-apoptotic protein Bax was markedly down-regulated,and the expression of total-caspase-3,-8 and-9 was also down-regulated.Suppressing lnc-DC resulted in the opposite results.3.After transfection of miR-4293 in lung adenocarcinoma cells,the expression levels of lnc-DC significantly increased by qRT-PCR detection.4.We proved that miR-4293 could affect the expression of lnc-DC by directly decreasing DCP2,and the RIP experiment revealed that DCP2 could directly interact with lnc-DC.5.The expression level of miR-4293was higher in lung adenocarcinomia tissues than that in para-carcinoma tissues.6.Campared with the scrambled control treatment,an increased number of alive lung adenocarcinom cells was observed in the miR-4293-treated cells,while the proliferation of lung adenocarcinoma cells was markedly reduced after inhibiting miR-4293,which suggested that miR-4293 promoted the proliferation of lung adenocarcinoma cells.Cell migration results proved that miR-4293 could promote the migration of lung adenocarcinoma cells.Flow cytometry results showed that the apoptotic number of of lung adenocarcinoma cells increased after downregulation of miR-4293 by inhibitor.Western blot results showed that p-STAT3,STAT3,Bcl-2,and the expression of total-caspase-3,-8 and-9 were up-regulated but Bax was significantly down-regulated after overexpression of miR-4293.Suppressing miR-4293 resulted in the opposite results.7.When lnc-DC or miR-4293 is overexpressed in lung adenocarcinoma cells,the tumor xenograft grew quickly,the size of the xenograft becomed larger,and the weight is increased.Suppressing lnc-DC or miR-4293 resulted in opposite results.Conclusion:In summary,lnc-DC was able to effectively promote the proliferation and migration,but inhibit apoptosis of lung adenocarcinoma cells,which was related to regulate the expression of some molecules in STAT3 signaling pathway.Next,we found that miR-4293 played a part in axtivating the STAT3 signaling pathway and promoting cell proliferation by directly decreasing DCP2 expression.Therefore,miR-4293 and lnc-DC might be used as biomarkers of tumorigenesis and diagnosis of lung adenocarcinomia,which was crucial to the clinical diagnosis and therapy to lung cancer.