Comparative Analysis of Differentially Expressed Genes in Oral Leukoplakia and Oral Submucous Fibrosis Using Bioinformatics Approach

Aims and Objectives: There is lack of understanding of distinct molecular pathways and associated gene mediators of the Potentially malignant disorders of the oral cavity (OPMD), such as Leukoplakia and Oral sub mucous fibrosis. This microarray data analysis aims to highlight common and distinct gene signatures by identifying the differentially expressed genes and the pathways in which they participate to help researchers & clinicians to distinctly characterize the Oral Leukoplakia and Oral Submucous Fibrosis disease conditions for developing appropriate treatment strategies

Methods: Gene Expression Omnibus datasets of Oral leukoplakia GSE85195 (OL) and Oral submucous fibrosis (OSMF) GSE64216 were analyzed using GEO2R package (using Log 2 fold change; false discovery rate < 0.05). The lists of differentially expressed genes of both datasets were analyzed for common and distinct members. These were then submitted to Database for Annotation, Visualization and Integrated Discovery (DAVID) for gene set enrichment analysis and functional annotation, to identify enriched Gene Ontology terms and KEGG pathways (Fisher's Exact Test for P-value < 0.05).

Results: In total 1107 in OL, 607 in OSMF and 143 common differentially expressed genes in both OL and OSMF were identified. The gene set enrichment analysis by DAVID revealed 26% integral component of membrane, 20% extracellular region and 14% nucleus as cellular components and molecular functions. The distinct gene signatures and altered biological pathways reported here clearly distinguish molecular profiles of both OL and OSMF, which may help to identify potential drug targets for developing and designing new treatment strategies in future.