The multifaceted roles of mesenchymal stem cell-derived exosomes in digestive system malignancies: mechanisms and therapeutic implications

Mesenchymal stem cell-derived exosomes (MSC-Exos) have emerged as key mediators of intercellular communication within the tumor microenvironment. However, a comprehensive synthesis of their paradoxical roles in digestive system tumors remains absent. This review provides an in-depth analysis of the molecular mechanisms by which MSC-Exos regulate tumor progression, with a focus on how they transfer specific non-coding RNAs and proteins to target cells, thereby modulating angiogenesis, epithelial-mesenchymal transition, immune evasion, and drug resistance. We highlight the functional heterogeneity of MSC-Exos in colorectal, liver, gastric, and pancreatic cancers, and examine how signals from the tumor microenvironment remodel their molecular cargo, establishing complex feedback loops. Furthermore, we discuss emerging translational frontiers, including the engineering of MSC-Exos as targeted drug delivery vehicles. By integrating mechanistic insights with clinical challenges, this review aims to elucidate the complex biology of MSC-Exos and pave new avenues for their application in precision oncology for digestive system tumors.