Stem Cells, Cancer, and MUSASHI in Blood and Guts

The mammalian MSI family of RNA-binding proteins (RBPs) have important roles as oncoproteins in an array of tumor types, including leukemias, glioblastomas, and pancreatic, breast, lung, and colorectal cancers. The mammalian Msi genes, Msi1 and Msi2, have been most thoroughly investigated in two highly proliferative tissues prone to oncogenic transformation: the hematopoietic lineage and the intestinal epithelium. Despite their vast phenotypic differences, MSI proteins appear to have an analogous role in governing the stem cell compartment in both of these tissues, potentially providing a paradigm for a broader understanding of MSI function and oncogenic activities. In this review, we focus on the function of MSI in the blood and the intestine, and discuss therapeutic strategies for targeting this pathway.