Expression Of LncRNA-KAT7 In Non-small Cell Lung Cancer And Its Effect On Invasion And Metastasis Of Lung Cancer Cells

Background And Objective: Lung cancer is one of the malignant tumors with the highest morbidity and mortality in the world,which poses a serious threat to human health and life.Non-small cell lung cancer(NSCLC)accounts for 80-85% of all types of lung cancer.Although the therapeutic level and therapeutic effect of lung cancer are increasing,most of the patients with lung cancer have already had strong invasion and metastasis of blood and lymphatic vessels even at the final diagnosis,and lack of effective treatment measures.The median survival time of the patients was less than 1 year,and the five-year survival rate was less than 5%.The metastasis of non-small cell lung cancer is a complicated and multivariate dynamic process,and the molecular mechanism of it is not clear.Therefore,the study of tumor metastasis mechanism is of great significance for the development of new therapies to prevent the development and metastasis of NSCLC.lncRNA is a kind of non-coding RNA,regulates gene expression and transcripts more than 200 nt.lncRNA can participate in regμlating gene expression in mμltiple level,affect cell growth and development,and disease,especially the occurrence,development and prognosis of tumor.In the previous experiment,lncRNA was selected by using lncRNA gene chip technology to select multiple differentially expressed lncRNA.lncRNA-KAT7 is one of the lncRNA with significant differences in expression.In this study,we observed the expression of lncRNA-KAT7 gene in NSCLC patients in lung cancer tissues and adjacent tissues,and Analyzed its relevance to clinical pathology and explored the effect and mechanism of lncRNA-KAT7 in non-small cell lung cancer.Methods:Materials: The tumor tissues of NSCLC primary lesions and normal tissue adjacent to carcinoma specimens and matching(normal tissues from tumor tissue adjacent to carcinoma edge more than 5cm)were collected by means of sampling with purpose in the First People’s Hospital of Changde City and Chenzhou NO.1 People’s Hospital,both were surgical resection of the thoracic surgery in February to June 2017.A total of 22 cases of squamous cell carcinoma and 16 cases of adenocarcinoma were successfully collected.Experimental methods:1.The expression of lncRNA-KAT7 in 38 patients with NSCLC primary lesion and the adjacent normal lung tissue was detected by real-time fluorescent quantitative PCR(qRT-PCR),and connecting with the correlation analysis of clinicopathologic features on NSCLC patients.2.Lung cancer cell A549 normal cells were cultured and digested by 0.25% pancreatic enzyme.and then,passed on when the cells in the culture bottle growth and fusion about 80-90%,the logarithmic growth cells were collected for the experiment.3.lncRNA-KAT7 sequence was imported into the empty vector pcDNA-3.1+ by molecμlar cloning,and the expression vector pcDNA-lncRNA-kat7 of lncRNA-KAT7 was constructed.By using Lip2000 liposome transient transfection,the null vector pcDNA-3.1 and pcDNAlnc RNA-KAT7 were transfected into lung cancer cell line A549.And then,the expression level of lncRNA-KAT7 was detected by real-time fluorescence quantitative PCR.Subsequent cell experiments were conducted through increasing the expression of lncRNA-KAT7.4.The effect of lncRNA-KAT7 on migration and invasion ability of A549 cells was evaluated by transwell experiment.Results:1.The expression level of lncRNA-KAT7 in NSCLC tissues was significantly lower than that of the adjacent normal lung tissue(P<0.05).The average expression multiple of lncRNA-KAT7 in NSCLC tissues was 0.55±0.88 times of normal lung tissue.The ratio of the expression of lncRNA-KAT7 in NSCLC tissues to the expression level in the adjacent normal lung tissue was >1 as the boundary standard,Among the 38 patients with NSCLC,the expression level of lncRNA-KAT7 in 32 cases(84%)was significantly lower than that in the adjacent normal lung tissue.2.The expression level of lncRNA-KAT7 in NSCLC was negatively correlated with age and lymph node metastasis,and significant correlation with NSCLC histological type(P<0.05).However,it was no related to patient gender,tumor size,tumor differentiation degree(P > 0.05).3.The lncRNA-KAT7 expression level in A549 cell lines overexpressing lncRNA-KAT7 was significantly higher than that in the cell lines transfected with empty vectors,and the difference was statistically significant(p<0.05).The results of Transwell migration and invasion showed that the migration and invasion ability of A549 cells transfected with lncRNA-KAT7 were significantly decreased,and the difference was statistically significant(p<0.05).Conclusion:1.lncRNA-KAT7 was significantly underexpressed in NSCLC tissues,The expression level of lncRNA-KAT7 in NSCLC was negatively correlated with age and lymph node metastasis,and significant correlation with NSCLC histological type(P<0.05),but with the patient gender,tumor size,tumor differentiation degree no significant correlation(P > 0.05).2.lncRNA-KAT7 can inhibits the migration and invasiveness of NSCLC cells.