SPOCK1 and POSTN are Valuable Prognostic Biomarkers and Correlate With Tumor Immune Infiltrates in Colorectal Cancer
Abstract BackgroundImmune cells and stromal cells in the tumor microenvironment (TME) play a vital role in the initiation and progression of colorectal cancer (CRC). The study aimed to screen valuable prognostic biomarkers in CRC on the basis of stromal and immune scores.MethodsWe used the ESTIMATE algorithm to calculate the immune and stromal scores of CRC samples in TCGA. Then the CRC samples were divided into high and low score groups based on the median value of the immune and stromal scores. Differentially expressed genes (DEGs) associated with immune score and stromal score were screened. WGCNA and univariate COX regression analysis were performed to further identify key prognostic genes. The prognostic value of key genes was validated based on The Gene Expression Profiling Interactive Analysis (GEPIA) and GSE17536 dataset. TIMER and CIBERSORT algorithms were applied to analyze the correlations among key genes and tumor-infiltrating immune cells. Results1314 upregulated and 4 downregulated genes associated with immune score and stromal score were identified, which were significantly enriched in immune-related biological processes and pathways. Among these DEGs, SPOCK1 and POSTN were identified as key prognostic genes. High expression of SPCOK1 and POSTN was associated with advanced clinical stage, T stage, N stage, and poor prognosis of CRC. The results from CIBERSORT and TIMER revealed that SPOCK1 and POSTN were associated with tumor-infiltrating immune cells, especially macrophages and neutrophils. Besides, SPOCK1 and POSTN expression were positively correlated with the expression of immune checkpoints.ConclusionCollectively, our results indicate that SPOCK1 and POSTN may be novel prognostic biomarkers in CRC and correlate with immune infiltrates.