Analysis of the gene expression profile for Oral tongue squamous cell carcinoma

Oral tongue squamous cell carcinoma (OTSCC) is the most common cancer diagnosed in the oral cavity and represents one of the main causes of cancer-related death worldwide. The aim of this study was to explore novel biomarkers with diagnostic and therapeutic potentials in OTSCC. The micro-array data GSE9844 were downloaded from Gene Expression Omnibus (GEO), including 26 OTSCC samples and 12 control samples. The differentially expressed genes (DEGs) between OTSCC and normal samples were screened. We performed GO enrichment and KEGG pathway analysis on the DEGs. Then the top 20 DEGs were subjected to do principal component analysis. Finally a PPI (protein-protein interaction) network of top 20 DEGs was constructed by String software. A total of 634 DEGs were identified, including 289 up-regulated and 345 down-regulated ones. The top 20 DEGs could well distinguish OTSCC samples from normal samples in principal component analysis. DEGs were mainly associated with immunoreaction analyzed through gene expression profile. The pivotal genes including collagen proteins (such as COL4A1, COL4A2, COL4A6, COL5A1, COL5A2 and COL11A1), interleukin (like IL8) and metallopeptidase (such as MMP1 and MMP9) in three KEGG pathways were also significantly over-expressed in OTSCC. In the PPI network of the top 20 DEGs, interactions between only 6 proteins were found. Hereinto, furthermore interleukin (IL) and metallopeptidase played important roles. The important genes like IL-8 and MMP9 obtained in this study may help identifying new biomarkers with diagnostic and therapeutic potentials in OTSCC. However, additional studies were still needed.