Protein-Protein Interaction Network Analysis of Salivary Proteomic Data in Oral Cancer Cases

Background: Oral cancer is a frequently encountered neoplasm of the head and neck region, being the eight mostcommon type of human malignancy worldwide. Despite improvement in its control, morbidity and mortality rates haveimproved little in the past decades. Therefore, prevention and/or early detection are a high priority. Proteomics withnetwork analysis have emerged as a powerful tool to identify important proteins associated with cancer developmentand progression that can be potential targets for early diagnosis. In the present study, network- based protein- proteininteractions (PPI) for oral cancer were identified and then analyzed for use as key proteins/potential biomarkers.Material and Methods: Gene expression data in articles which focused on saliva proteomics of oral cancer werecollected and 74 candidate genes or proteins were extracted. Related protein networks of differentially expressed proteinswere explored and visualized using cytoscape software. Further PPI analysis was performed by Molecular ComplexDetection (MCODE) and BiNGO methods. Results: Network analysis of genes/proteins related to oral cancer identifiedkininogen-1, angiotensinogen, annexin A1, IL-8, IgG heavy variable and constant chains, CRP, collagen alpha-1 andfibronectin as 9 hub-bottleneck proteins. In addition, based on clustering with the MCODE tool, vitronectin, collagenalpha-2, IL-8 and integrin alpha-v were established as 5 distinct seed proteins. Conclusion: A hub-bottleneck proteinpanel may offer a potential /candidate biomarker pattern for diagnosis and treatment of oral cancer disease. Furtherinvestigation and validation of these proteins are warranted.