Study On The Correlation Between LncRNA Differential Genes And Immune Cell Infiltration In Colorectal Cancer

Objective:We investigate the lncRNA(long non-coding RNA)and molecular mechanisms associated with colorectal cancer metastasis,and study the differential expression of key genes in colorectal cancer tissues and their impact on prognosis of patients,in order to explore the relationship between its expression level and immune cell infiltration in the tumor microenvironment,so that it could provide potential targets and biomarkers for the treatment of colorectal cancer metastasis.Methods:We extract the lncRNA by the means of GSE32323 in the GEO(Gene Expression Omnibus)database,while downloading gene expression information and clinical information of CRC-related data from the TCGA database,and screen the data set,and then screen for genes with significant expression differences ln DEGs(Long non-coding RNA Differential Expression Genes)through the limma package in the R software,draw the Venn diagram of the difference analysis results and take the intersection,conduct the survival analysis of differential genes via the platform GEPIA(Gene Expression Profiling Interactive Analysis),and analyze the relationship between expression of key genes and immune cell infiltration in tissue samples throuth the TIMER(Tumor Immune Estimation Resource)database.Result:43 ln DEGs were screened out from GSE32323 by differential analysis,including20 up-regulated genes and 23 down-regulated genes.425 ln DEGs were screened out from TCGA by differential analysis,including 163 up-regulated genes and 262down-regulated genes.After taking the intersection,the survival analysis of the four genes screened out showed that HOXC6 and CLCA1 are meaningful for the prognosis of CRC(P<0.05).Survival analysis found that high expression of HOXC6(homeobox C6)indicates poor prognosis in colorectal cancer(P<0.05),and low expression of CLCA1(Human Chloride Channel Accessory 1)indicates poor prognosis in colorectal cancer(P<0.05).The expression of HOXC6 was positively correlated with the infiltration of common humoral immune B cells,CD8~+T cells,CD4~+T cells,macrophages,neutrophils and dendritic cells(r=0.128,P=1.01E-02;r=0.293,P=1.79E-09;r=0.102,P=4.08E-02;r=0.214,P=1.49E-05;r=0.34,P=2.83E-12;r=0.293,P=2.10 E-09);CLCA1 expression was positively correlated with common humoral immune B cell and CD4~+T cell infiltration(r=0.207,P=2.71E-05;r=0.099,P=4.84E-02).Conclusion:The biological functions and signaling pathway of lncRNA differential genes are related to the occurrence and development of colorectal cancer metastasis.Two key colorectal cancer genes:HOXC6 and CLCA1 may become the potential targets and new prognostic markers for colorectal cancer metastasis therapy.The expression level of HOXC6 is positively correlated with B cells,CD8~+T cells,CD4~+T cells,macrophages,neutrophils,and dendritic cells in the tumor microenvironment of colorectal cancer.The expression level of CLCA1 is positively related to B cells and CD4~+T cells in the tumor microenvironment of colorectal cancer are related.