Establishment of a specific serum proteomic profile model for liver organ-specific metastasis of nasopharyngeal carcinoma by matrix-assisted laser desorption/ionization time of flight mass spectrometry

Abstract

Objective: To investigate the specific serum peptide profile of LM (liver metastasis) associated with NPC (nasopharyngeal carcinoma) by comparing the patients who have NPC with LM and without LM and the patients with LM not from NPC, and to provide the model for diagnosis of LM from NPC. Methods: Pre-treatment serum samples from 50 patients who had pathologically confirmed NPC and 14 patients who had pathologically confirmed non-NPC with LM were collected and assayed by MALDl-TOF-MS (matrix-assisted laser desorption/ionization time of flight mass spectrometry) analysis. During follow-up of more than 3 years after radiotherapy, 16 NPC patients with LM (LM NPC group), 16 NPC patients with non-LM (non-LM NPC group) and 18 NPC pateints without metastasis (non-M NPC group) were confirmed. Mass spectrographic data were analyzed with ClinProt software Tools. The specific serum peptide model of NPC-associated LM was established by using both data mining analysis and decision tree classification analysis. Results: Differential expressions of 28 peptide peaks were detected between LM NPC group and non-M NPC group, 9 peptide peaks between LM NPC group and non-LM NPC group, 45 peptide peaks between LM NPC group and LM non-NPC group, and 10 peptide peaks between non-LM NPC group and non-M NPC group. Using comparative proteomics analysis, 4 protein mass peaks (their mass to charge ratios were 4 155.34 m/z, 4 194.87 m/z, 4 210.78 m/z and 4 249.56 m/z, respectively) were identified as the liver-specific metastasis-associated protein peaks in NPC. The models based on the 4 sieved markers of NPC could discriminate LM NPC group from non-LM NPC group, non-M NPC group and non-NPC LM group. The recognition capability was 100.0% and the cross-validation of these models for differentiating the above 4 groups were 73.3%-100.0%. Conclusion: NPC with LM has a specific serum peptide profile. The established specific serum peptide model may have certain application in the diagnosis of LM associated with NPC, and provide a clinical diagnostic platform for detecting potential liver-specific metastasis-associated biomakers in NPC. DOI:10.3781/j.issn.1000-7431.2013.09.011