Identification of CALM as the Potential Serum Biomarker for Predicting Recurrence of Nasopharyngeal Carcinoma Using Mass Spectrometry-Based Comparative Proteomic Approach

Abstract

To date, there are no serum biomarkers for prediction of recurrent nasopharyngeal carcinoma (rNPC). Diagnosis of rNPC depends on imaging and biopsy of diseased tissue mostly, both two ways work mostly if target tumor in an advanced stage. Therefore, predicting recurrent biomarkers are urgently required. In this study, we used tandem mass tags(TMT) labeling and high performance liquid chromatography(HPLC)fractionation followed by liquid chromatograph-tandem mass spectrometry (LC-MS/MS) analysis to identify differentially expressed proteins, and serum was collected from 40 nasopharyngeal carcinoma (NPC)patients (recurrence (n = 20) and no-recurrence (n = 20). Compared to nrNPC, we found 59 proteins significantly dysregulated in rNPC, most were previously reported to play a role in carcinogenesis. Dysregulation of Calmodulinis (CALM) was confirmed in 74 new patients (recurrence (n = 32) and no-recurrence (n = 42) by ELISA. Moreover, we performed a preliminary pathway analysis showed Oxidative phosphorylation was altered in rNPC compared to nrNPC patients. These data together identify potential diagnostic biomarker for rNPC and elucidate the potential molecular mechanisms that are dysregulated and contribute to the pathogenesis of rNPC.