The emerging role of exosomes in Wnt secretion and transport

Exosomes are small extracellular microvesicles that have an endosomal origin and are gaining increasing recognition for their important roles in mediating cell-cell communication. The content of exosomes includes a broad range of bioactive molecules, such as miRNA and signaling molecules that can mediate intercellular communication in various functional contexts. Recent studies have pointed to a critical role of exosomes in transmitting morphogen signaling during embryonic development and cancer progression. In this review we focus on recent progress that has revealed a role for exosomes in the secretion and processing of Wnt proteins, a family of morphogens with fundamental roles in homeostasis and cancer.