Analysis of prognosis for colon cancer patients based on the characteristics of ferroptosis-related long non-coding RNA / 肿瘤研究与临床

ABSTRACT

Objective:To explore the value of prognostic model based on ferroptosis-related long non-coding RNA (lncRNA) in predicting the prognosis of patients with colon cancer.Methods:Ferroptosis-related genes were downloaded from FerrDb database, and the RNA sequencing gene data and clinical data of colon cancer patients from the establishment of the database to November 2021 were downloaded from the Cancer Genome Atlas (TCGA) database. Through R3.6.3 software, the colon cancer gene expression data obtained from TCGA database and ferroptosis-related genes obtained from FerreDb database were analyzed to obtain differentially expressed ferroptosis-related genes in colon cancer and normal tissues. The expression correlation between ferroptosis-related genes and lncRNA in colon cancer was calculated by using R3.6.3 software to determine ferroptosis-related lncRNA in colon cancer. The survival-related differentially expressed ferroptosis-related lncRNA was screened and included in the multivariate Cox proportional hazards model to construct a colon cancer prognosis model; and the risk score of colon cancer patients was calculated by the prognostic model according to the lncRNA expression. According to the median risk score, the clinical cases collected from TCGA database were divided into high-risk group and low-risk group with 223 cases in each group. Kaplan-Meier survival analysis was performed for the two groups. The receiver operating characteristic (ROC) curve was used to analyze the effect of prognostic model risk score and clinical characteristics on predicting the survival of all patients. GSEA 4.1.0 software was used for gene set enrichment analysis (GSEA) of lncRNA in high-risk and low-risk groups, and ggpubr package of R3.6.3 software was used for single sample GSEA (ssGSEA) of immune cells and immune function of differentially expressed lncRNA between high-risk and low-risk groups.Results:According to the intersection of ferroptosis-related genes and differentially expressed genes obtained from databases, 65 differentially expressed ferroptosis-related genes were obtained, and 24 lncRNA related to the prognosis of colon cancer were analyzed, and then prognostic model was constructed based on lncRNA. Kaplan-Meier survival analysis showed that the survival of low-risk group was better than that of high-risk group ( P < 0.001); ROC curve analysis showed that the area under the curve (AUC) of 1-, 2-, 3-year survival predicted by the prognostic model risk score was more than 0.75, and the AUC of 1-year survival predicted by the risk score for all patients was greater than age, gender, the National Comprehensive Cancer Network (NCCN), T staging, N staging and M staging. GSEA showed that differentially expressed lncRNA in high-risk and low-risk groups concentrated in tumor and immune-related pathways; ssGSEA showed that there were differences in T cells, macrophages, mast cells, neutrophils, immune stimulation, human leukocyte antigen, type Ⅰ and type Ⅱ interferon response between high-risk group and low-risk group (all P < 0.05), and the expression levels of CD200 and TNFRSF14 at the immune checkpoint were significantly different (both P < 0.01). Conclusions:Ferroptosis-related lncRNA may play an important role in tumor immunity of colon cancer, and it can be used for the prognosis analysis of patients with colon cancer.