Identification of hub genes and transcription factors involved in periodontitis on the basis of multiple microarray analysis.

OBJECTIVES: To identify the differentially expressed genes (DEGs) during the pathogenesis of periodontitis by bioinformatics analysis. METHODS: GEO2R was used to screen DEGs in GSE10334 and GSE16134. Then, the overlapped DEGs were used for further analysis. g:Profiler was used to perform Gene Ontology analysis and pathway analysis for upregulated and downregulated DEGs. The STRING database was used to construct the protein-protein interaction (PPI) network, which was further visua-lized and analyzed by Cytoscape software. Hub genes and key modules were identified by cytoHubba and MCODE plug-ins, respectively. Finally, transcription factors were predicted via iRegulon plug-in. RESULTS: A total of 196 DEGs were identified, including 139 upregulated and 57 downregulated DEGs. Functional enrichment analysis showed that the upregulated DEGs were mainly enriched in immune-related pathways including immune system, viral protein interaction with cytokine and cytokine receptor, cytokine-cytokine receptor interaction, leukocyte transendothelial migration, and chemokine receptors bind chemokines. On the contrary, the downregulated DEGs were mainly related to the formation of the cornified envelope and keratinization. The identified hub genes in the PPI network were CXCL8, CXCL1, CXCR4, SEL, CD19, and IKZF1. The top three modules were involved in chemokine response, B cell receptor signaling pathway, and interleukin response, respectively. iRegulon analysis revealed that IRF4 scored the highest. CONCLUSIONS: The pathogenesis of periodontitis was closely associated with the expression levels of the identified hub genes including CXCL8, CXCL1, CXCR4, SELL, CD19, and IKZF1. IRF4, the predicted transcription factor, might serve as a dominant upstream regulator.

miR128-1 inhibits the growth of glioblastoma multiforme and glioma stem-like cells via targeting BMI1 and E2F3.

MicroRNA128-1 (miR128-1), as a brain-specific miRNA, is downregulated in glioblastoma multiforme (GBM) and closely associated with the progression of GBM. However, the underlying molecular mechanism of the downregulation and its role in the regulation of tumorigenesis and anticancer drug resistance in GBM remains largely unknown. In the current study,we found that miR128-1 was downregulated in GBM and glioma stem-like cells (GSCs). Intriguingly, treatment with the DNA methylation inhibitors 5-Aza-CdR (Aza) and 4-phenylbutyric acid (PBA) resulted in miR128-1 upregulation in both GBM cells and GSCs. Either forced expression of miR128-1 or Aza/PBA treatment inhibited tumor cell proliferation, migration and invasion in vitro. Moreover, overexpression of miR128-1 inhibited the growth of transplant tumor in vivo. BMI1 and E2F3 were found to be direct targets of miR128-1 and downregulated by miR128-1 in vitro and in vivo. Our results revealed a mechanism of methylation that controls miR128-1 expression in GBM cells and GSCs and indicate miR128-1 could function as a tumor suppressor in GBM by negatively regulating tumor cell proliferation, invasion and self-renewal through direct targeting BMI1 and E2F3. Our findings suggest that DNA methylation inhibitors are potential agents for GBM treatment by upregulating miR-128-1.