Identification of immune infiltration-related LncRNA FAM83C-AS1 for predicting prognosis and immunotherapy response in colon cancer.

BACKGROUND Increasing evidence has demonstrated the functional relevance of long non-coding RNAs (lncRNAs) to the occurrence and progression of tumors. However, the role of lncRNA FAM83C-AS1 in tumors remains unclear. We aim to prove the relationship between FAM83C-AS1 and colon cancer (CCa). METHODS The expression level of FAM83C-AS1 in CCa were explored through bioinformatics analysis. Receiver operating characteristic (ROC) curves, Kaplan-Meier method and Cox regression analysis were used to evaluated to its roles in the prognosis of CCa. The biological function was explored through gene set enrichment analysis (GSEA). The correlation between FAM83C-AS1 expression and immune infiltration and immunotherapy response was analyzed through single-sample GSEA (ssGSEA) and Spearman correlation. RESULTS FAM83C-AS1 was up-regulated in multiple cancers including CCa. Increased FAM83C-AS1 expression in CCa was correlated with advanced clinical pathologic characteristics (histological type, M stage; p < 0.05). ROC curve suggested the significant diagnostic and prognostic ability of FAM83C-AS1 (AUC = 0.759). High FAM83C-AS1 expression predicted a poorer overall survival (OS, p = 0.033) and disease-free survival (DFS, p = 0.043), and FAM83C-AS1 expression was independently correlated with OS in CCa patients (HR:1.69; 95% CI:1.07-2.67; p = 0.024). In addition, GSEA suggested the involvement of FAM83C-AS1 in immune-related pathways. We also found the correlation of FAM83C-AS1 with DC cells and T helper cells and a potential of the measurement in response to immunotherapy. CONCLUSION High expression of FAM83C-AS1 indicated poor prognosis and correlation with immune infiltrations and immune response in CCa, and it may be a promising biomarker of prognosis and response to immunotherapy for CCa.