Investigation Of Molecular Mechanisms Whereby ZIC5 Promotes The Malignant Process Of Non-small-cell Lung Cancer

Part Ⅰ:Expression of ZIC5 in non-small cell lung cancer and its correlation with Clinic pathological stage.ObjectiveLung cancer is the highest incidence of malignant tumors in the world,but also the leading cause of death in patients with cancer.The Zinc family member protein is closely related to the development of many kinds of tumors.The aim of this study was to investigate the specific expression of zinc finger protein family member 5(ZIC5)in non-small cell lung cancer,and to analyze the relationship between ZIC5 expression and clinicopathological stage.MethodsZIC5,which is highly expressed in non-small cell lung cancer,was screened from the public database of the cancer genome atlas(TCGA),and 50 cases of lung cancer and carcinoma with complete clinical data were selected from Cardiothoracic Surgery General Hospital of Nanjing Military Region.(QRT-PCR)was used to detect the mRNA expression of ZIC5 mRNA and analyze the relationship between ZIC5 mRNA expression and clinicopathological typing.Materials and Methods:The expression of ZIC5 mRNA was detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction(qRT-PCR)ResultsThe expression of ZIC5 in lung adenocarcinoma tissues and lung squamous cell carcinoma tissues was higher than that in adjacent normal tissues.In 50 cases of non-small cell lung cancer,the expression of ZIC5 mRNA was higher in 45 cases(90%)than that in adjacent normal tissues(p<0.01),and the higher expression of ZIC5 was associated with larger tumor volume(p = 0.032),sex(p = 0.048),and tumor type(p =0.0017).ConclusionZIC5 mRNA is highly expressed in non-small cell lung cancer,and ZIC5 may be involved in the malignant progression of non-small cell lung cancer,which is a potential therapeutic target for lung cancer.Part Ⅱ:Mechanism of zinc finger protein family member 5 promoting malignant phenotype of non-small cell lung cancerObjective Zinc family member 5(ZIC5)may be a potential oncogene for promoting the malignant phenotype of non-small cell lung cancer.The aim of this study was to investigate the expression of ZIC5 protein in non-small cell lung cancer(NSCLC)and to analyze its relationship with the malignant phenotype of NSCLC and its potential regulatory mechanism,and to provide a new target for the clinical treatment of lung cancer.Methods1.The mRNA and protein expression of ZIC5 in NSCLC cell line was detected by qRT-PCR and western blot.2.We designed siRNAs to silence the expression of ZIC5 and observe the effect of ZIC5 on tumor proliferation,migration ability,cell cycle and apoptosis.3.We conducted nude mice xenograft experiment to investigate the effect of ZIC5 on the growtih of NSCLC tumor.4.The mRNA and protein expression of the cell cycle proteins of ZIC5 was detected by qRT-PCR and western blot.Results1.The expression of ZIC5 in lung adenocarcinoma cell lines was significantly higher than that in normal lung epithelial cells.The proliferation,migration and invasion of H1703 and H1299 cells were significantly decreased after ZIC5 was knocked down,and the cell cycle was arrested in G2/M phase.2.The result of in vivo tumorigenesis experiments showed that the growth rate and volume of the tumor after silencing ZIC5 were smaller than those of the control group.Immunohistochemical staining of transplanted tumors showed that the expression of KI67 and CCNB1 in the experimental group was lower than that in the control group(p<0.05).3.qRT-PCR and western blot results showed that the expression of CCNB1 and phospho-CDK1 was significantly inhibited after ZIC5 was knocked down,when other cell cycle related protein showed no significant change.ConclusionOur results show that ZIC5 is highly expressed in non-small cell lung cancer and can promote the proliferation and migration of NSCLC cells.ZIC5 may exert its oncogene function by influencing the expression of CCNB and CDK1 complex.So ZIC5 may serve as a potential therapeutic target to provide new ideas for the diagnosis and treatment of future NSCLC.