Tetraspanins: Spanning from solid tumors to hematologic malignancies.

Tetraspanins (tetraspans or TM4SF) are a family of integral membrane proteins with four transmembrane helices, a small extracellular loop, and a large extracellular loop. Although tetraspanins are expressed in many types of cells, including immune cells, their biological roles are not fully defined. Nonetheless, recent studies have revealed the important roles of tetraspanins in solid tumors and hematologic malignancies, and expression of tetraspanins is associated with the malignancy of human tumors. Furthermore, genetic mouse models of tetraspanins highlight their contribution to tumorigenesis. In this review, we summarize the implication of tetraspanins in cancer with a special focus on tetraspanin 3 in myeloid leukemia. Our increasing knowledge of tetraspanins and the pathologies that alter their function will undoubtedly inform the rational design of novel cancer therapies.