| Colorectal cancer(CRC)is a common malignant tumor of digestive tract,the causes of which are affected by many factors,such as age,eating habits and genetics.There have already been data indicating that the incidence of CRC has been increasing in recent years,with a trend of younger age,which seriously threatens the safety and security of human life and health.At present,the most effective treatment is still surgical treatment,but with the emergence of postoperative recurrence,drug resistance and other problems,the prognosis of most CRC remains poor.Therefore,it is particularly important to explore the prognostic factors of CRC and find new tumor markers.In this study,we first downloaded colorectal cancer samples from TCGA database,and obtained nine different gene modules using weighted gene co-expression network analysis(WGCNA).Associating these gene modules with clinical traits,we got the purple gene module with the strongest correlation with immunity.Then,constructing the protein-protein interaction network model for the genes in purple module,and we screened out two genes that can independently affect the prognosis of CRC patients based on the TCGA and GEO samples using Cox univariate and multivariate analysis,namely AIF1 L and DMPK.Based on the two genes,we established a immune-related model to calculate the risk Score,and divided the samples respectively in TCGA and GEO database into high-and low-risk groups.Then,the survival analysis,ROC prediction accuracy test and risk assessment were performed and found that there were significant differences between high-and low-risk groups.At the same time,interaction between genes and their expression in different risk groups were also investigated.By analyzing the influence of different clinical characteristics on prognosis,we found that age and TNM stage can be used as independent prognostic factors.Through analyzing the infiltration of immune cells of high-and low-risk groups in two databases,we found that the infiltration of CD4 memory activated T cells in high-and low-risk groups were significantly different.Among the genes that regulating CD4 memory activated T cells,CCL21,CX3CL1,CXCR5,and CCL19 were found been associated with the risk Score,and the expression in high-and low-risk group has significant differences.Therefore,our study determined two genes AIF1 L and DMPK that can independently influence the prognosis of CRC,which may become new molecular markers.At the same time,we discussed in detail the influence of clinical characteristics on prognosis,the enrichment of immune-related gene pathways,and the infiltration of immune cells in tumor microenvironment,which will provide a new scientific basis for the follow-up study of CRC,and can contribute to the development of new immunotherapy. |
