New cancer pathway boosts chemotherapeutic efficacy
Dijon – French researchers have unravelled a mechanism that boosts the antitumour effects of the chemotherapeutic drug cyclophosphamide in three different cancer mouse models. The drug efficacy-boosting effect occurred when François Ghiringhelli and colleagues at the French University of Burgundy pharmacologically decreased the release of so-called exosomes. According to the researchers’ results (JCI, 20. January), high concentrations of exosomes, which are released by tumour cells, enhanced the immunosuppressive functions of so-called tumour-associated MDSCs (myeloid-derived suppressor cells) in both mice and humans. The activation of the MCDCs is mediated by the binding of the exosome surface factor Hsp72 to the protein TLR2 on MDSCs, which triggers a signal pathway that results in enhanced MDSC-suppressive function. The scientists believe that inhibition of exosome release in tumours could be beneficial to cancer patients undergoing chemotherapy.