关键词: N6-甲基腺苷, 预后模型, 风险评分, 肺腺癌

Abstract: Objective The Objective of this study was to construct a prognostic risk model for lung adenocarcinoma based on N6-methyladenosine(m6A)regulators,and to provide a scientific basis for the prognostic evaluation of lung adenocarcinoma. Methods The mRNA expression and clinical data were downloaded from TCGA database.Differential expression analysis of the 24 methylation regulatory factors was performed using R software.Univariate Cox regression analysis was used to initially screen out m6A regulators associated with lung adenocarcinoma survival,on which variables included in the model were further screened by Lasso regression.The m6A regulators obtained from Lasso regression was used to construct the Cox regression model and to calculate the risk score for each sample.The expression of model genes IGF2BP1 and HNRNPC in normal lung epithelial cells(REAS-2B)and lung adenocarcinoma cell lines(A549 cells,H1299 cells and PC-9 cells)were detected by qRT-PCR(P＜0.01).Differential analysis of the paired tissues in TCGA database was used to detect the differential expression of the model genes in lung adenocarcinoma and normal lung tissues(P＜0.001).The model performance was assessed using the Kaplan-Meier survival curves and the ROC curve.The clinical characteristics of different risk groups were analyzed by a heatmap,and the independent prognosis of risk models was tested by univariate and multivariate Cox regression analysis combined other clinical parameters. Results Nineteen m6A methylation regulators were significantly differentially expressed in lung adenocarcinoma and normal tissues.Univariate regression analysis found four significant m6A-related regulatory factors for the prognosis of lung adenocarcinoma(P＜0.01),and a prognostic risk model including two genes(IGF2BP1 and HNRNPC)was constructed using Lasso and Cox regression regression algorithm.The results of qRT-PCR showed that the relative expression of IGF2BP1 and HNRNPC was higher in A549 cells,H1299 cells and PC-9 cells than that in REAS-2B cells,and the difference was statistically significant(P＜0.001).Matched difference analysis for 59 pairs of lung adenocarcinoma and adjacent normal lung tissues from TCGA found that the expression of IGF2BP1 and HNRNPC in lung adenocarcinoma was higher than that in normal lung tissues,and the difference was significant difference(P＜0.001).Survival curve analysis showed that the survival time of high-risk patients was significantly shorter than that of low-risk patients(P＜0.01).The ROC curve results showed that the model could better predict the prognosis of lung adenocarcinoma patients(AUC=0.724).Multivariate Cox regression showed that the prognostic risk model could be used as an independent prognostic factor(HR=2.357,P＜0.001). Conclusion In this study,a prognostic risk assessment model based on m6A methylation regulators was constructed,and the model has good predictive ability,which has potential reference value for formulating reasonable and effective individualized treatment plan.

Key words: N6-methyladenosine, Prognostic model, Risk score, Lung adenocarcinoma