Endosialin in Cancer: Expression Patterns, Mechanistic Insights, and Therapeutic Approaches

Endosialin, also known as tumor endothelial marker 1 (TEM1) or CD248, is a single transmembrane glycoprotein with a C-type lectin-like domain. Endosialin is mainly expressed in the stroma, especially in cancer-associated fibroblasts and pericytes, in most solid tumors. Endosialin is also expressed in tumor cells of most sarcomas. Endosialin can promote tumor progression through different mechanisms, such as promoting tumor cell proliferation, adhesion and migration, stimulating tumor angiogenesis, and inducing an immunosuppressive tumor microenvironment. Thus, it is considered an ideal target for cancer treatment. Several endosialin-targeted antibodies and therapeutic strategies have been developed and have shown preliminary antitumor effects. Here, we reviewed the endosialin expression pattern in different cancer types, discussed the mechanisms by which endosialin promotes tumor progression, and summarized current therapeutic strategies targeting endosialin.