Comprehensive proteomic analysis of cerebrospinal fluid exosomes derived from non-small cell lung cancer related leptomeningeal carcinomatosis

Abstract

Abstract Background Leptomeningeal carcinomatosis might happen in late non-small cell lung cancer patients and causes a poor median survival period. CSF of leptomeningeal carcinomatosis patients is a special kind of tumor microenvironment. Exosomes are key components of tumor microenvironment and participate in a variety of physiological and pathological processes. There is a great need of comprehensive proteomic analysis of exosomes in these patients. Methods In this study, exosomes in CSF derived from different groups (leptomeningeal carcinomatosis group, non-small cell lung cancer group without leptomeningeal carcinomatosis and normal group) were isolated by ultracentrifugation and proteomics analysis was performed by label-free method. Results A total of 814 proteins were detected. Bioinformatics analysis revealed their shared function in the complement activation, extracellular region, and complement and coagulation cascades. 20 proteins were differentially expressed between groups. In protein-protein interaction network analysis, ACTB, ENO1, TIMP1 and RTN4R had higher betweenness than others. Conclusions This study is the first comprehensively CSF exosomes proteomic profile of leptomeningeal carcinomatosis patients. Further research is needed to clarify the importance of ACTB, ENO1, TIMP1 and RTN4R in leptomeningeal carcinomatosis patients.