Differential expression of a set of microRNA genes reveals the potential mechanism of papillary thyroid carcinoma.

Background: Our aim was to explore the potential mechanism underlying papillary thyroid carcinoma (PTC) development.

Methods: Gene expression profile data GSE3467 and microRNA (miRNA) expression profile data E-TABM-68 were downloaded from Gene Expression Omnibus and Array Express database respectively. The differentially expressed genes (DEGs) and miRNAs between PTC patients and normal individuals were screened. Then, the significant target DEGs regulated by differentially expressed miRNAs were mapped to protein-protein interaction (PPI) network and functional modules were screened. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis for miRNA genes were performed using DAVID (the Database for Annotation, Visualization and Integration Discovery) tool.

Results: Total 4307 DEGs and 23 differentially expressed miRNAs were identified. A PPI subnetwork containing 612 nodes and 713 edges was constructed. Total 5 DEGs such as SPARC (secreted protein acidic and rich in cysteine), FN1 (fibronectin 1), THBS1 (thrombospondin 1), COL1A1 (collagen, type I, alpha 1) and COL7A1 (collagen, type VII, alpha 1) were found in module M1. The up-regulated DEGs were significantly related with cell adhesion molecules (CAMs), response to wounding and immune response. The down-regulated DEGs were significantly enriched in metabolism related pathways and transcription related with GO terms.

Conclusions: ECM-receptor interaction and amino acid degradation may play key roles in the mechanism of PTC progression.