Searching the Detection and Metastasis Biomarkers in the Body Fluids and Tissues from Patients with Oral Cavity Cancers Based on the Secretomic and Tissue Proteomic Databases

Oral squamous cell carcinoma (OSCC) is the most common cancer of the head and neck and a major cause of cancer death in Taiwan. It is thought to develop by multistep carcinogenetic processes including oncogenes activation and loss of the tumor suppressor genes. Unfortunately, although the presenting stages are a major factor for prognosis, most OSCC patients in Taiwan still presented with advanced stages. Cervical metastasis has also been regarded as a most important factor for predicting prognosis. In our previous study, the 5-year overall survival for patients with cervical metastasis and extracapsular spread was even only approximately 35%. Therefore, searching the detection and metastasis markers in body fluids and tissue of OSCC patients should be feasible for improving the treatment outcome for OSCC. In the past few years, we have used cDNA microarray to delineate the transcriptomic profiles of differentially-expressed genes between OSCC tumors and normal epithelium. By supervised hierarachical clustering analysis, we further analyzed and validated the differentially-expressed genes up-regulating and being associated with metastasis in OSCC tumors, including novel serum markers MIP-3alpha (Chang KP et al. Oral Oncol. 2011; 47: 108-113.) and activin A (Chang KP et al. Ann Surg Oncol 2010; 17(7):1945-56). In proteomic approach, our group has used the supernatant secreted from the cancer cell lines to establish the secretome databases derived from oral cancer cell lines (Chang KP et al. J Proteome Res. 2011; 10(8): 378-88) and derived from 23 different cancer cell lines (Wu CC et al. Mol Cell Proteomics, 2010; 9: 1100-17). Meanwhile, we also constructed the proteomics database using O16/18-isotope labeling for dysregulated protein expression in comparison between OSCC cells and normal epithelium (Chi LM et al, J Proteome Res. 2011; 10(8):3778-88.) Furthermore, in our previous study, we also performed a multidimensional iTRAQ proteomic analysis using an LC MS/MS system, and a computational data analysis pipeline to identify proteins that are differentially expressed in microdissected metastatic OSCC tumor cells, relative to primary OSCC tumor cells. We identified many unique proteins in microdissected oral squamous epithelia obtained from three pairs of OSCC specimens and revealed some metastasis-related dysregulated proteins (Chang KP et al. J Proteome Res. 2011; 10(11):4935-47). Unfortunately, although we have found few proteins up-regulated in OSCC tumors or associated with OSCC metastasis based on these previous works, many potential candidates still remained undiscovered for their roles in OSCC tumors. In this proposal, we plan to collect the blood and saliva samples from 300 OSCC patients and 300 healthy volunteers, and tissue samples from the surgical specimen after these OSCC patients receive the operation to (1) use the immunohistochemistry, Western blotting, and Q-PCR to validate if these potential candidate proteins are overexpressed or associated with metastasis in OSCC tumors; (2) use the ELISA techniques or multiplex suspension arrays system to measure if the concentrations of these candidates were differential in blood or saliva between OSCC patients and controls; (3) By using a series of in-vivo experiments including cell function assays, cDNA transfection, siRNA experiments to verify these putative pathways for associated markers. The aim of this proposal is to identify clinically applicable markers and prognosticators for personalized OSCC treatment.

Project ID:PC10301-0133
External Project ID:NSC102-2628-B182-015-MY3