ABSTRACT
In this study, two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF-MS) technology was used to examine differentially expressed proteins in oral squamous cell carcinoma (OSCC) tissues from Norway (n=15) and the UK (n=45). Twenty-nine proteins were found to be significantly overexpressed in the OSCCs examined compared to the normal controls. Identified proteins included, family of annexin proteins that play important roles in signal transduction pathways and regulation of cellular growth, keratin-1, heat-shock proteins (HSP), squamous cell carcinoma antigen (SCC-Ag), cytoskeleton proteins, and proteins involved in mitochondrial and intracellular signalling pathways. The expression of four selected proteins (annexin II and V, HSP-27, and SCC-Ag) was verified using western blot analysis of 76 fresh tissue biopsy specimens in total, from Norway (n=53) and the UK (n=23). Proteomic analysis of OSCCs examined here demonstrated involvement of several proteins that might function as potential biomarkers and molecular targets for early cancer diagnostics, and may contribute to a novel approach to therapeutics and for predicting prognosis of OSCC.
Subject(s)
Carcinoma, Squamous Cell/chemistry , Mouth Neoplasms/chemistry , Neoplasm Proteins/analysis , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Adult , Aged , Aged, 80 and over , Annexin A2/analysis , Antigens, Neoplasm/analysis , Blotting, Western , Electrophoresis, Gel, Two-Dimensional , HSP27 Heat-Shock Proteins/analysis , Humans , Middle Aged , Serpins/analysisABSTRACT
Antibody microarrays, two-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (2-DE/MALDI-TOF-MS) were used to examine protein changes in 56 oral cancers (OCs)/normal controls (NCs) from Sudanese (41 OCs vs. 31 NCs) and Sri Lankan (15 OCs vs. 15 NCs) patients. Pools of extracted proteins were prepared and used for microarrays/2-DE/MALDI-TOF-MS. From 2-DE, protein spots (differentially-expressed) were cut and identified with peptide mass fingerprinting based on MALDI-TOF-MS, and the proteins were identified by submitting peptide mass profiles to the NCBInr database. By microarrays, 6 and 8 proteins demonstrated significant differences in their abundance values as differentially-expressed in OCs examined from Sudan and Sri Lanka, respectively. For some of the proteins found, like p56dok2 and NEK2, this is the first report in OCs. By MALDI-TOF-MS/2-DE, patterns of OCs/NCs were acquired and tumour-associated proteins, like psoriasin, calgranulin-B and glutathione transferase, were found to be altered in OCs compared to NCs. The proteins found in this work (by two different methods) represent a global protein change specific to OCs from two populations. This might indicates involvement of multiple pathways in the process of tumorgenesis; thus, multiple proteins should be simultaneously targeted in OCs. The finding of few common proteins might suggest involvement of different pathways, which may parallel differences in ethnicity and/or lifestyle.
