ABSTRACT. This study aims to identify the crucial miRNAs in Epstein-Barr virus-positive nasopharyngeal carcinoma (NPC) and their target genes. Gene expression profile data (GSE12452) that included 31 NPC and 10 normal nasopharyngeal tissue specimens were downloaded. Differentially expressed genes (DEGs) were identified using significance analysis of microarrays. The underlying function of DEGs was predicted via Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses. The miRNA sequencing dataset GSE14738 was also downloaded, and expression levels of miRNA were calculated by the number of reads mapped to each miRNA. The selected miRNAs were integrated into the miRecords 6029 Integrated miRNA-mRNA analysis of NPC ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (2): 6028-6036 (2015) database to obtain their target genes. Target genes associated with DEGs were used to construct the interaction network via Cytoscape. A total of 1437 DEGs between NPC and control were identified, most of which were enriched in cell cycle and extracellular matrix-receptor interaction signaling pathways. Furthermore, 112 miRNAs were considered upregulated in NPC samples. A total of 2228 relationships between 39 miRNAs and 1247 target genes were obtained, of which 182 relationships between 32 miRNAs and 97 target genes were chosen to construct an interaction network. The interactions between DEGs and the let-7 or miR-29 families appeared strongest in this network, where CDC25A, COL3A1, and COL1A1 were regulated by several let-7 family members, while COL4A1 and COL5A2 were regulated by several miR-29 family members. The let-7 and miR-29 families may be related to the development of NPC by regulating the genes involved in cell cycle and ECM-receptor interaction.

BackgroundHashimoto’s thyroiditis (HT) is a chronic autoimmune disease that poses a risk factor for papillary thyroid carcinoma (PTC). The present study aimed to identify the key genes shared by HT and PTC for advancing the current understanding of their shared pathogenesis and molecular mechanisms.MethodsHT- and PTC-related datasets (GSE138198 and GSE33630, respectively) were retrieved from the Gene Expression Omnibus (GEO) database. Genes significantly related to the PTC phenotype were identified using weighted gene co-expression network analysis (WGCNA). Differentially expressed genes (DEGs) were identified between PTC and healthy samples from GSE33630, and between HT and normal samples from GSE138198. Subsequently, functional enrichment analysis was performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Transcription factors and miRNAs regulating the common genes in PTC and HT were forecasted using the Harmonizome and miRWalk databases, respectively, and drugs targeting these genes were investigated using the Drug-Gene Interaction Database (DGIdb). The key genes in both GSE138198 and GSE33630 were further identified via Receiver Operating Characteristic (ROC) analysis. The expression of key genes was verified in external validation set and clinical samples using quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC).ResultsIn total, 690 and 1945 DEGs were associated with PTC and HT, respectively; of these, 56 were shared and exhibited excellent predictive accuracy in the GSE138198 and GSE33630 cohorts. Notably, four genes, Alcohol Dehydrogenase 1B (ADH1B), Active BCR-related (ABR), alpha-1 antitrypsin (SERPINA1), and lysophosphatidic acid receptor 5 (LPAR5) were recognized as key genes shared by HT and PTC. Subsequently, EGR1 was identified as a common transcription factor regulating ABR, SERPINA1, and LPAR5 expression. These findings were confirmed using qRT-PCR and immunohistochemical analysis.ConclusionFour (ADH1B, ABR, SERPINA1, and LPAR5) out of 56 common genes exhibited diagnostic potential in HT and PTC. Notably, this study, for the first time, defined the close relationship between ABR and HT/PTC progression. Overall, this study provides a basis for understanding the shared pathogenesis and underlying molecular mechanisms of HT and PTC, which might help improve patient diagnosis and prognosis.