| At present,lung cancer is one of the malignant tumors with the highest morbidity and mo.rtality among tumor diseases,and its incidence is still increasing year by year,and lung cancer ranks first in cancer-related mortality.Histologically,lu.ng cancer can be divided into small cell lung ca.ncer(small cell lung carcinoma,SCLC)and non-small cell lung cancer(non-small c.ell lung cancer,NSCLC).The two most common types of NSCLC are lung adenocarcinoma and lung squamous c.ell carcinoma.The prognosis of patients with lung cancer is extremely closely related to the clinicopathological stage of the tumor.After ea.rl.y treatment of NSCLC,the five-year survival rate is satisfactor.y,more than 40%.Although great progress has been made in early detection and standard treatment,most patients are diagnosed with advanced lung cancer,and the overall prognosis is still poor,with an overall 5-year survival rate of 10% to 15%.In recent years,specific genetic abnormalities have been found in a large number of patients with lung cancer,which has led to the rapid development of individualized targeted therapy,which has opened up a new perspective and hope for the treatment of these patients.To find more effective biological markers and gene therapy targets is still the most important task for the prevention and treatment of lung cancer.Many studies have shown that keratin 17(Keratin 17,KRT17)acts as a proto-oncogene to promote tumorigenesis and progression in a variety of malignant tumors.However,the specific mechanism and role of KRT17 in tumor is not clear,and its role and mechanism in NSCLC also need to be discussed and clarified.Objective: To study the expression of KRT17 in NSCLC and its correlation with clinicopathological factors and prognosis of patients with lung cancer,and to explore the specific role and possible mechanism of KRT17 in the proliferation and invasion of non-small cell lung cancer cells.Methods: 1.A total of 158 cases of NSCLC tissues and 32 cases of paracancer lung tissues that were surgically resected in the department of pathology of our hospital were collected.Immunohistochemical staining of KRT17 was performed on paraffin specimens,and the relationship between KRT17 and clinicopathological factors of NSCLC and patient prognosis was statistically analyzed.2.Western Blot was used to detect KRT17 protein levels in 30 pairs of fresh lung cancer tissues and adjacent normal tissue,and the difference of KRT17 protein expression levels between lung cancer and normal lung tissues was analyzed.3.Combined with the TCGA online database(UALCAN database),the m RNA expression of KRT17 in lung cancer was analyzed.4.To detect the expression of KRT17 in a variety of lung cancer cell lines,and to screen the cell lines with relatively low expression of KRT17 and relatively high expression of KRT17.In SK-MES-1 cells with high expression of KRT17,si RNA interference was used to down-regulate the expression of KRT17.In H1299 and A549 cells with low expression of KRT17,Lipo3000 liposome was used to transfect KRT17 gene and up-regulate the expression of KRT17.5.CCK8 proliferation test and colony formation test were used to detect the effect of KRT17 on the proliferation of cell lung cancer.6.Matrix gel invasion assay was used to detect the effect of KRT17 on the invasion ability of lung cancer cells.7.Western Blot was used to detect the changes of key proteins and targets of Wnt signal pathway in lung cancer cells after over-expression or down-regulation of KRT17,as well as the expression changes of key proteins in epithelial-mesenchymal transformation(EMT).8.The correlation between KRT17 and ?-catenin(CTNNB1)was searched through GEPIA database,and the Wnt pathway inhibitor XVA-939 was used to observe whether KRT17 could reverse the promotion of proliferation and invasion ability in lung cancer cells and to observe the induction effect of downstream target proteins of Wnt pathway.Results:1.KRT17 m RNA expression was significantly increased in NSCLC compared with normal adjacent lung tissue(P < 0.001).Similarly,the protein expression of KRT17 in lung squamous cell carcinoma and adenocarcinoma was also significantly higher than that in adjacent normal lung tissue(P < 0.001),and the increase of KRT17 in lung squamous cell carcinoma is more significant.2.The high expression of KRT17 was correlated with histological type,lymph node metastasis,differentiation and age of NSCLC,but not with TNM stage,and the survival time of patients with high expression of KRT17 was shorter than that of patients with low expression of KRT17(P < 0.001).3.According to the statistics of lung squamous cell carcinoma and adenocarcinoma,it was found that the high expression of KRT17 was positively correlated with poor differentiation,lymph node metastasis and high TNM stage of lung adenocarcinoma,but not with the age and sex of the patients.The survival time of adenocarcinoma patients with high expression of KRT17 was significantly shorter than that of patients with low expression of KRT17.However,in lung squamous cell carcinoma,the high expression of KRT17 was only related to sex,but not to tumor differentiation,lymph node metastasis,age and TNM stage,and the high expression of KRT17 had no effect on the survival time of patients.4.After transfection of KRT17 gene,the expression level of KRT17 protein was significantly increased in A549(A549-KRT17)and H1299(H1299-KRT17)cells.Compared with the control group,the proliferation and invasion ability of lung cancer cells increased significantly(P < 0.05).After down-regulating the expression of KRT17 in SK-MES-1(SK-MES-1-si KRT17)cells by si RNA,compared with the control group,the ability of proliferation,the number of colony formation and the ability of invasion of lung cancer cells decreased significantly(P < 0.05).5.After KRT17 transfection into H1299 and A549 cells,the expression of activated?-catenin,the core protein of Wnt signal pathway,and the target proteins of Wnt signal pathway,MMP-7,c-myc and cyclin D1,were also significantly up-regulated.Nucleo-plasma separation experiments further confirmed that the expression of ?-catenin entering into the nucleus increased.The expression of vimentin,snail and MMP9 related to EMT process was significantly up-regulated,while the expression of E-cadherin protein was significantly down-regulated.In SK-MES-1-si KRT17 cells,the opposite results were obtained after interfering with the expression of KRT17.6.After transfection of KRT17 gene into A549 and H1299 cells and addition of Wnt/?-catenin signaling pathway inhibitor XAV-939,the results showed that the Wnt inhibitor XAV-939 could reverse the upregulation of KRT17 on Wnt signaling pathway and EMT.Moreover,the addition of XAV-939 also partially reversed the effects of KRT17 on proliferation,colony formation and invasion of A549 and H1299 cells.Conclusion:1.KRT17 is highly expressed in NSCLC and is associated with poor differentiation,lymph node metastasis,high TNM stage and poor prognosis of lung adenocarcinoma.2.High expression of KRT17 promotes the proliferation and invasion of lung c.ancer c.ells.3.High expression of KRT17 promotes activation of Wnt signaling pathway and EMT process in lung cancer cells. |
PDF Full Text Request