CD47 is correlated with immune infiltration and is a prognostic biomarker in colorectal cancer

Abstract Background: Colorectal cancer (CRC) is a common malignant neoplasm, and the cluster of differentiation 47 (CD47) is an innate immune checkpoint and promising diagnostic and therapeutic target. We comprehensively examined the potential prognostic value, clinicopathological characteristics, and immune infiltration associated with CD47 in CRC patients. Results: In total, 305 differentially expressed genes (DEGs) were identified. The receiver operating characteristic (ROC) curve analysis of CD47 suggested an area under the ROC curve of 0.819. Kaplan–Meier survival analysis indicated that CRC with high CD47 expression had a better prognosis in the progression-free interval (PFI; P = 0.011). Five drug targets (ABT-510, ALX148, TTI-621, CC-90002, and Hu5F9-G4) were identified for CD47. A positive correlation existed between CD47 expression and infiltrating levels of aDC, macrophages, T helper cells, Tcm, Th1 cells, Th2 cells, CD8 T cells, cytotoxic cells, neutrophils, T cells, and Tgd. In the neoplasm type, CD47 expression was higher in colon adenocarcinoma patients than in rectal adenocarcinoma patients (P = 0.029). In PFI events, CD47 expression was higher in live patients than in dead patients (P = 0.018). Male patients with high CD47 expression showed improved overall survival compared with female patients (P = 0.014). CD47 protein was highly expressed in colorectal tumor tissue and lowly expressed in normal tissues in the Human Protein Atlas(HPA). Methylation analysis of CD47 in CRC revealed that the first and second CpG islands were hypermethylated, whereas the third CpG island was hypomethylated. Genetic alterations in CRC included amplification and deletion of CD47 in colorectal cancer. I153M was found to be a mutational hotspot for CD47. Conclusions: CD47 is correlated with immune infiltration and is a prognostic biomarker in colorectal cancer.