ZMIZ2 Promotes Lung Adenocarcinoma Cell Proliferation And Metastasis By Upregulation Of IL-6 Expression And Inducement Of JAK/STAT3 Signaling Pathway

Background and Objectives:Lung cancer is the second highest incidence malignant tumor and the leading cause of cancer death in USA.In China,the rates of incidence and mortality of lung cancer have taken the first place for a long time.The high death rate and low 5-year survival rate of lung cancer mainly result from the poor prognosis and the uncontrollability for tumor metastasis.(IL)-6 is one of the best-studied cancer-associated cytokines.High circulating levels of IL-6 were reported to be associated with lung cancer progression and poor prognosis in lung cancer patients.The Jauns kinase(JAK)– signal transducer and activator of transcription 3(STAT3)pathway has been demonstrated to be the major pathway that can be activated by IL-6,and is recognized as a promoter in cancer progression.The zinc finger MIZ-type containing 2(ZMIZ2)gene was firstly identified by Huang et,al.,who named this gene human zinc finger-containing,Miz1,PIAS like protein on chromosome 7(h ZIMP7)because it share a zinc finger domain,termed MIZ,with the PIAS(protein inhibitor of STAT)protein.However,the mechanisms by which ZMIZ2 impacts on lung cancer remains unclear.Especially,whether there is any influence for ZMIZ2 on JAK-STAT signaling in lung cancer development requires further exploration.In order to solve the issues above,in the present study,we determined the effects of ZMIZ2 on cell biological functions in lung adenocarcinoma cells.We found that ZMIZ2 promotes the proliferation and invasion in lung adenocarcinoma cells and elevates the IL-6 expression,in turn enhancing the JAK-STAT3 signaling,which suggests an oncogenic role for ZMIZ2 in lung cancer progression.Methods:(1)Expression of ZMIZ2 m RNA were detected in 66 paired NSCLC tissue samples and paired non-cancerours tissues using quantitative real-time PCR(q RT-PCR),and analyzed by Prism software.(2)Cell proliferation was detected using CCK-8 assay and colony foration in A549 and SPC-A1 cells,respectively,in which the ZMIZ2 was silenced by transfection of small interference RNAs.(3)CCK-8 assay and clonogenic analysis was prepared to determine cell viability in A549 and SPC-A1 cells overexpressing ZMIZ2.(4)Cell cycle was detected using propidium iodide(PI)staining flow cytometry in A549 and SPC-A1 cells in which the ZMIZ2 was silenced,respectively.(5)Flow cytometry cell cycle analysis of A549 and SPC-A1 cells with overexpression of ZMIZ2.(6)Real-time quantitative reverse transcriptase-polymerase chain reaction(q RT-PCR)and Western blot were used to detect the expression levels of ZMIZ2,p-C/EBPβ,C/EBPβ,p-STAT3 and STAT3.(7)Transwell assay were performed to evaluate the migration and invasion ability of cells in vitro.Results:(1)Real-time PCR results showed that the ZMIZ2 m RNA expression levels were lower in 67 non-small cell lung cancer tissues than in paired non-cancerours tissues(p<0.01).(2)Knockdown of ZMIZ2 represses cell viability in NSCLC cells.Overexpression of ZMIZ2 gene in cells,the proliferation of A549 and SPC-A1 cell lines was significantly enhanced.(3)Knockdown ZMIZ2 expression in lung adenocarcinoma cells showed that the proportion of S phase was decreased and the G1 phase was up-regulated.Overexpression of ZMIZ2 in lung adenocarcinoma cells showed that the proportion of S phase was up-regulated and the G1 phase was decreased.(4)Knockdown of ZMIZ2 inhibits cell migratory and invasive abilities of A549 and SPC-A1 cells.Overexpression of ZMIZ2 enhances EMT and invasion of A549 and SPC-A1 cells.(5)Knockdown of ZMIZ2 in NSCLC cell lines can significantly inhibit the expression of IL-6,C/EBPβ,p-C/EBPβ and p-STAT3 in NSCLC cells.In contrast,overexpression of ZMIZ2 can significantly enhance the expression of these genes.Conclusion:ZMIZ2 has a strong cancer-promoting effect,which is achieved by affecting autocrine of IL-6 in NSCLC cells and activating the JAK/STA3 signaling pathway.