Immune-Cell-Derived Exosomes as a Potential Novel Tool to Investigate Immune Responsiveness in SCLC Patients: A Proof-of-Concept Study

In the era of precision medicine and immunotherapy, the isolation and characterization of exosomes from the peripheral blood mononuclear cells (PBMC-EXs) of SCLC patients may represent a new tool to define responder (BR) from non-responder (NR) patients undergoing chemoimmunotherapy treatment. In this proof-of-concept study, we isolated PBMC-EXs from the peripheral blood of SCLC patients and investigated the potential role of such extracellular vesicles (EVs) in monitoring tumor response to drug stimuli. Interestingly, we found increased exosome levels of c-Myc and Snail along with reduced levels of the immune markers MAVS and STING in NR patients. Also, we showed that PBMC-EXs from BR patients induced an increase in apoptosis and a reduction in the cell viability of SCLC cells compared to PBMC-EXs from NR SCLC patients. Thus, we suggest that PBMC-EXs may represent an innovative strategy to be further explored for the therapy and selection of immune-responsive SCLC patients.