Exosomal protein FAM3C as a potential novel biomarker for non-small cell lung cancer.

e22162 Background: Low-dose computed tomography screening has been shown to reduce lung cancer-specific mortality, but has a high false-positive detection rate. The discovery of biomarkers for lung cancer is therefore urgently needed. Exosomes are small membrane bound vesicles extruded from cells that mediate local and systemic cell communications via the transfer of proteins, miRNAs and RNAs. Circulating exosomal proteins may thus have diagnostic and prognostic potential. We conducted a study to determine the utility of exosomes as non-invasive diagnostic and prognostic markers in non-small cell lung cancer (NSCLC). Methods: Quantitative proteomic profiling of exosomes using LTQ-FT mass spectrometer was performed in NSCLC cell lines and normal lung fibroblast as study models. Potential biomarkers were verified in lung cancer patients by western blot (WB), ELISA and immunohistochemistry (IHC). Results: More than 1,000 exosomal proteins were identified for each cell line. 158 proteins were detectable only ...