Discovery of Novel Biomarkers in Oral Submucous Fibrosis by Microarray Analysis

Abstract

Oral submucous fibrosis (OSF) is a high-risk precancerous condition of the oral cavity. Areca nut chewing is its key etiologic factor, but the full pathogenesis is still obscure. In this study, microarray analysis was used to characterize the mRNA changes of 14,500 genes in four OSF and four normal buccal mucosa samples to identify novel biomarkers of OSF. Five candidate genes with the most differential changes were chosen for validation. The correlation between clinicopathologic variables of 66 OSF patients and the expression of each gene was assessed by immunohistochemistry. The microarray analysis showed that 661 genes were up-regulated (fold value >2) and 129 genes were downregulated (fold value <0.5) in OSF (q < 0.01). The top three up-regulated genes [Loricrin, Cartilage oligomeric matrix protein (COMP), Cys-X-Cys ligand 9 (CXCL9)] with the largest fold changes and the top two downregulated genes [keratin 19 (KRT19), cytochrome P450 3A5 (CYP 3A5)] with the most significantly differential changes in OSF were chosen as candidate biomarkers. In immunohistochemical results, the expression of Loricrin and COMP showed statistically significant association with histologic grade of OSF (P = 0.03 and 0.006, respectively). COMP was found to be overexpressed frequently in patients with the habit of areca nut chewing for more than 4 years (P = 0.002). CYP 3A5 was revealed an inverse correlation with histologic grade (P = 0.04). This pilot study showed that five novel genes might play important roles in the pathogenesis of OSF and may be clinically useful for early detection of OSF. (Cancer Epidemiol Biomarkers Prev 2008;17(9):2249 -59)

Loss of ELF3 immunoexpression is useful for detecting oral squamous cell carcinoma but not for distinguishing between grades of epithelial dysplasia

“…Microarray analysis permits simultaneous analysis of tens of thousands of genes, making it a potent tool for discovering novel markers [4]. From a review of published microarray differential gene expression data for PMOLs [5][6][7][8][9][10][11], we identified a set of 31 commonly dysregulated genes that have not been validated by alternative experimental methods. For the current study, we selected the following subset of 5 genes that are linked with human cancer but have not been examined in OED or oral cancer: calmodulin-like skin protein (CLSP), E74-like factor 3 (ELF3), interferon-induced protein 44 (IFI44), ubiquitin specific peptidase 18 (USP18), and chemokine-CXC-motif ligand 13 (CXCL13).…”

“…Expression of CLSP is up-regulated in oral leukoplakia [8] and PMOLs [6], but down-regulated in advanced OSCC [12]. ELF3 is a member of ETS (E26 transformation-specific) family of transcription factors which is induced during keratinocyte differentiation in normal epithelia [13] and has been shown to be down-regulated in PMOLs [8,9]. USP18, otherwise known as ubiquitin-processing protease-43 (UBP43), is a member of the ubiquitin-specific protease family that is an interferon-stimulated gene 15 (ISG15)-specific isopeptidase [14].…”

“…CXCL13 is a member of CXC chemokine family and agonist for the CXCR5 receptor which mediates diverse biological functions. CXCL13 is up-regulated in PMOLs [6,9] and is part of a gene signature that distinguishes OSCC from normal tissue [19].…”

Clinico-Pathological Evaluation and Correlation of Stages of Oral Submucous Fibrosis with Different Habits

“…Oral submucous fibrosis (OSF) is a chronic and potentially malignant condition of the oral cavity [8]. It is characterized by a juxtaepithelial inflammatory reaction followed by progressive fibrosis of the lamina propria and the underlying submucosal layer, with associated epithelial atrophy and is particularly associated with arecanut and tobacco chewing products [2,9].…”

Etiopathogenesis of oral submucous fibrosis

“…[39] Other gene changes demonstrated in OSF were cartilage oligomeric matrix protein, CYP 3A5, [40] antinuclear, antismooth muscle, antigastric parietal cell, antithyroid microsomal, antireticulin antibodies, endothelin-1, and vimentin. [41] Immunohistochemistry showed predominance of T-lymphocytes and macrophages in epithelium and subepithelial connective tissue with CD4+ to CD8+ lymphocyte ratio of 2.1:1.…”