Potential role of differentially expressed lncRNAs in the pathogenesis of oral squamous cell carcinoma.

Long non-coding RNAs (lncRNAs) have recently attracted more attention about the role in a broad range of biological processes and complex cancers. We aimed to identify differentially expressed lncRNAs that play an important role in the pathogenesis of oral squamous cell carcinoma (OSCC). Microarray data GSE25099 consisting of 57 samples from patients with OSCC and 22 normal samples were downloaded from Gene Expression Omnibus database. Differentially expressed genes (DEGs) and lncRNAs were identified between OSCC samples and control using samr package in R and noncoder software. Co-expression network was constructed for lncRNAs and candidate target DEGs, followed by functional and pathway enrichment analysis using the Database for Annotation, Visualization and Integrated Discovery online tool. OSCC-related genes were screened by Genetic-Association-DB-Database analysis, and then protein-protein interaction (PPI) network construction of OSCC-related and co-expressed genes. Bioinformatic analysis revealed that there were 998 DEGs and 160 differentially expressed lncRNAs between OSCC and normal control. We found LOC100130547, FTH1P3, PDIA3F and GTF2IRD2P1 targeted most of DEGs. Predicted targets-related functional annotation showed significant changes in inflammation-related functions and Toll-like receptor signaling pathway. By further conducting PPI network with lncRNA co-expressed DEGs, we found that OSCC-associated genes including MMP1 (matrix metallopeptidase), MMP3, MMP9, PLAU (plasminogen activator, urokinase) and IL8 (interleukin 8) were targeted by FTH1P3, PDIA3F and GTF2IRD2P1. Our results indicate that lncRNAs FTH1P3, PDIA3F and GTF2IRD2P1 may responsible for progression and metastasis of OSCC via targeting MMP1, MMP3, MMP9, PLAU and IL8 which are key regulators of tumorigenesis.