Proteomic surfaceome analysis of mesothelioma

Abstract

Identification of new markers for malignant pleural mesothelioma (MPM) is a challenging clinical need. Here, we propose a quantitative proteomics primary screen of the cell surface exposed MPM Nglycoproteins, which provides the basis for the development of new protein-based diagnostic assays. Using the antibody-independent mass-spectrometry based cell surface capturing (CSC) technology, we specifically investigated the N-glycosylated surfaceome of MPM towards the identification of proteinmarker candidates discriminatory between MPM and lung adenocarcinoma (ADCA). Relative quantitative CSC analysis of MPM cell line ZL55 in comparison with ADCA cell line Calu-3 revealed a bird’s eye view of their respective surfaceomes.Ina secondary screenoffifteenMPMandsixADCA, weusedhighthroughput low density microarrays (LDAs) to verify specificity and sensitivity of nineteen N-glycoproteins overregulated in the surfaceome of MPM. This proteo-transcriptomic approach revealed thy-1/CD90 (THY1) and teneurin-2 (ODZ2) as protein-marker candidates for the discrimination of MPM from ADCA. Thy1/CD90 was further validated by immunohistochemistry on frozen tissue sections of MPM and ADCA samples. Together, we present a combined proteomic and transcriptomic approach enabling the relative quantitative identification and pre-clinical selection of new MPM marker candidates.