Novel Transcripts of EMT Driving the Malignant Transformation of Oral Submucous Fibrosis [mRNA-seq]

OSF is a chronic, progressive, fibrotic condition of the oral mucosa that carries an elevated risk of undergoing malignant transformation. We aimed to identify and validate novel genes associated with the regulation of epithelial to mesenchymal transition (EMT) in Oral submucous fibrosis (OSF). Genes regulating EMT were identified through differential gene expression analysis, with a LogFC threshold of -1 and +1, and padj value < 0.05, utilizing data retrieved from GEO datasets, TCGA-HNSC dataset and whole transcriptome data generated from tissue samples of OSF, OSFSCC (OSF associated with OSCC) and OSCC (Oral squamous cell carcinoma). The curated EMT genes were correlated with functional states of cancer, subjected to clustering to identify the candidate genes. The EMT genes, namely MMP9, SPARC and ITGA5 were identified to be the novel candidate genes. Comprehensive pathway analysis and immunohistochemical analysis confirmed their role in regulating EMT in OSF, OSCC, and OSFSCC. Integration of bioinformatics and proteomics led to the discovery of novel candidate genes regulating EMT. The significant role of candidate genes MMP9, SPARC, and ITGA5 observed in fibrosis and malignancy indicates a novel mechanism of transition from fibrosis associated type 2 EMT to type 3 EMT, driving OSF to malignancy. Overall design: The mRNA sequencing of matched case-adjacent normal samples (MN)(n=2 each) of oral submucous fibrosis associated with oral squamous cell carcinoma (OSFSCC) was performed using HiSeq X Ten/Novaseq with the parameters of 2x100bp, 30M reads per sample.