Circulating Microvesicles and Exosomes in Small Cell Lung Cancer by Quantitative Proteomics

Early detection of small cell lung cancer crucially demands highly reliable markers. Growing evidence suggests that extracellular vesicles carry tumor cell-specific cargo suitable as protein markers in cancer. Therefore, we isolated plasma-derived exosomes from newly diagnosed small cell lung cancer patients and investigated proteome dynamics of these exosomes aiming at improving the detection of small cell lung cancer. A total of 1,016 proteins were initially identified. After data processing and statistical analysis, several proteins were found to be differentially expressed in comparing small cell lung cancer patients and healthy individuals, indicating that circulating exosomes may encompass specific proteins with potential diagnostic attributes for small cell lung cancer. Furthermore, our data may indicate a novel tumor-suppressing role of blood coagulation and involvement of complement activation in small cell lung cancer pathogenesis.