Based On TCGA Data And In Vitro Studies On The Mechanism Of Radiosensitivity In NSCLC

Objective: The status of radiotherapy in the treatment of NSCLC is increasingly important.However,it is still not possible to conduct individualized radiotherapy based on the genetic information of patients with NSCLC.The aim of this study is to analyze the multi-omics information of patients with NSCLC in TCGA database and detect the clonogenic capacity of ATCC Cell Bank NSCLC cell lines to explore the specific mechanism of NSCLC radiosensitivity.Methods:(1)The clinical data of lung squamous cell carcinomas and lung adenocarcinomas in TCGA database were downloaded.There were 20 lung adenocarcinoma patients and 17 squamous cell carcinoma patients with the TNM staging phase III who received radiotherapy were enrolled.Download and analyze SNV,CNV,m RNA expression,mi RNA expression and DNA methylation data of 37 patients.The patients were divided into radiosensitive group(group S,n=18)and radioresistant group(group R,n=19)according to the median DFS of 391 days.The differences of SNP loci,signatures,CNV,mi RNA expression and methylation genes in S group and R group were compared by Student’s t-test.(2)The untreated human NSCLC adherent cell lines were screened from the ATCC cell bank,and NSCLC cell lines in the logarithmic growth phase were placed in 6MV Varian electron linear accelerator for 1Gy,2 Gy,4 Gy,6 Gy and 8 Gy irradiation,and then were conducted the clonogenic formation experiment of the control group and five irradiation group cells.Until the formation of cloned cells were visible without microscopy,stop culturing and count the number of clones in different experimental groups.Calculate the clone formation rates and survival fractions of 6 groups in each cell line,and the obtained values were analyzed by SPSS 25.0 software to fit the single-hit multi-target model and the Linear-quadratic(LQ)model.The respective parameters and goodness of fit of the two models were obtained,then the fitting performance of the two models was compared.According to the radiosensitivity evaluation index SF2,we divided the 25 NSCLC cell lines into relatively sensitive group,moderately sensitive group and relatively resistant group.Results:(1)Multi-dimensional data mining based on TCGA database suggested that among NSCLC patients with stage III who received radiotherapy,between the two groups of patients who had different radiosensitivity,there were different XIRP2 mutations in the SNV level,256 different deleted genes on chromosome 6,89 different deleted genes on chromosome 4,81 different amplified genes on chromosome 1 in the CNV level.There are five gene expression differences of CNOT6,FLT4,KCNV2,PXT1 and SCD5 at the m RNA level,11 mi RNAs in mi RNA,and 22 differentially methylated genes in the DNA methylation level.The signaling pathways involved in different levels mainly include the taste transduction pathway,the TLR pathway,the glutamate receptor pathway and the MAPK pathway involved in amyotrophic lateral sclerosis.(2)For the curve of 25 NSCLC cell lines by single-hit multi-target model and LQ model,except H520 and H2347 cell lines can only fit LQ model,the other 23 cell lines can be successfully fitted to the two models.According to the curve fitting goodness obtained by SPSS,15 cell lines were better than LQ model by single-hit multi-target model fitting,and LQ model of 7 cell lines was better than single-hit.The three cell lines have the same goodness of fit between the two models,so both models should be considered as fitting models of survival curves after irradiation.The 25 NSCLC cell lines were divided into three groups based on SF2 values,including 8 cell lines in the relatively sensitive group,9 cell lines in the moderately sensitive group and 8 cell lines in the relatively resistant group.However,no clear correlation was found between the SF2 value and the pathological type,tissue source as well as TNM staging.Conclusions:(1)Based on analysis on the multi-omics information of patients with stage III NSCLC receiving radiotherapy in the TCGA database,it is suggested that there may be mutation genes,CNV status,methylation genes and related signaling pathways that may be involved in radiotherapy response.(2)Based on the differences in the clonogenic capacity of NSCLC cell lines after 2 Gy radiation,we divided them into relatively sensitive group,moderately sensitive group and relatively resistance group.No correlation was found with pathological type,tissue source and TNM staging.(3)The above conclusions need to be validated in larger clinical samples and in larger cell lines.(4)In the future,it is necessary to explore the basis of differences in radiosensitivity of NSCLC from the differences of omics data.