Transcriptome profiles of moderate dysplasia in oral mucosa associated with malignant conversion

Background: Oral malignancies are among the top most deadly cancers in the world. Early diagnosis of oral premalignant and malignant lesions is essential for treatment decision-making and prognosis improvement. Methods: RNA sequencing was applied to diseased tissues and paired normal tissue from three patients with moderate epithelial dysplasia (MED). Hierarchical clustering analysis was performed to evaluate the correlation of gene expression patterns of different specimens. EdgeR software was used to identify differentially expressed genes between MED and paired normal tissues, gene ontology analysis was carried out on DAVID online platform. qRT-PCR was conducted to confirm the accuracy of our RNA-seq data. Results: A total of 21556 genes were detected in microdissected MED and paired normal tissues. Hierarchical clustering analysis revealed distinct gene expression patterns between the moderate dysplasia samples. 346 differentially expressed genes that may contribute to the pathogenesis of moderate dysplasia were identified. Among these genes, ISG15 showed different transcription profiles that close related with the alterations of gene expression patterns in moderate dysplasia samples and paired normal tissues. Conclusions: We speculated that, as the potential marker to signal the risk of malignant transformation, ISG15 together with its close related genes may involve in the malignant conversion from oral dysplasia to oral squamous cell carcinoma.