CD47 Expression in Solid Tumors Correlates with Phagocytic Tumor-Associated Macrophage Gene Signature

CD47 is a “don’t eat me” signal that is frequently overexpressed in tumors to evade phagocytosis by tumor associated macrophages (TAM). Investigational agents targeting CD47, such as magrolimab, aim to induce phagocytosis of tumor cells by TAMs. Previously, two functionally defined key TAM subsets have been identified: complement C1q C chain positive (C1QC) TAMs, which display pro-phagocytic activity, and secreted phosphoprotein 1 positive (SPP1) TAMs that express pro-angiogenic markers. Here we characterize CD47 expression and its relationship with tumor macrophages in solid tumor samples. Resectable tumors from patients with head and neck squamous cell carcinoma (HNSCC), breast cancer (BC), and colorectal cancer (CRC) were profiled by RNA sequencing. FFPE samples were procured from commercial sources. Whole slide FFPE samples of tumor biopsies were used without further microdissection. RNA was extracted from all samples and subjected to mRNA sequencing