Exosomes and their roles in the chemoresistance of pancreatic cancer.

Pancreatic cancer (PC) remains one of the most lethal human malignancies worldwide. Due to the insidious onset and the rapid progression, most patients with PC are diagnosed at an advanced stage rendering them inoperable. Despite the development of multiple promising chemotherapeutic agents as recommended first-line treatment for PC, the therapeutic efficacy is largely limited by unwanted drug resistance. Recent studies have identified exosomes as essential mediators of intercellular communications during the occurrence of drug resistance. Understanding the underlying molecular mechanisms and complex signaling pathways of exosome-mediated drug resistance will contribute to the improvement of the design of new oncologic therapy regimens. This review focuses on the intrinsic connections between the chemoresistance of PC cells and exosomes in the tumor microenvironment (TME).