Bioinformatics analyses of differentially expressed genes associated with bisphosphonate-related osteonecrosis of the jaw in patients with multiple myeloma
ONCOTARGETS AND THERAPY
Authors: Sun, Jingnan; Wen, Xue; Jin, Fengyan; Li, Yuying; Hu, Jifan; Sun, Yunpeng
Abstract
Purpose: This study aimed to explore the molecular mechanisms associated with bisphosphonate (BP)-related osteonecrosis of the jaw (ONJ) in patients with multiple myeloma (MM). Methods: The gene expression profile GSE7116 was downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) from eleven patients with ONJ resulting from MM treated with BPs (ONJBPs) and ten MM patients without ONJ treated with BPs (MMBPs) were analyzed. Gene ontology (GO) and pathway enrichment analyses of DEGs were performed, followed by functional annotation and protein-protein interaction network construction. Finally, sub-network modules were constructed and analyzed. Results: A total of 166 up-and 473 down-regulated DEGs were identified. The up-regulated DEGs were enriched in pathways related to cancer, and the down-regulated DEGs were enriched in pathways related to the immune system. Moreover, the GO terms enriched by the up-regulated DEGs were associated with misfolded proteins, and the down-regulated DEGs were associated with immune responses. After functional annotation, 16 transcription factors were identified, including X-box binding protein 1 (XBP1). In protein-protein interaction network analysis, tumor necrosis factor (TNF) and interleukin 1, beta (IL1B) had higher connectivity degrees. Among the constructed sub-network modules, module 1 was the best one, and DEAD (Asp-Glu-Ala-Asp) box helicase 5 (DDX5) was a hub gene. The DEGs in module 1 were mainly enriched in GO terms related to RNA splicing. Conclusion: DEGs of ONJ were mainly enriched in pathways related to the immune system and RNA splicing. DEGs such as TNF, ILB1, DDX5, and XBP1 may be the potential targets of ONJ treatment.
Direct Identification of Insulator Components by Insertional Chromatin Immunoprecipitation
PLOS ONE
Authors: Fujita, Toshitsugu; Fujii, Hodaka
Abstract
Comprehensive understanding of mechanisms of epigenetic regulation requires identification of molecules bound to genomic regions of interest in vivo. However, non-biased methods to identify molecules bound to specific genomic loci in vivo are limited. Here, we applied insertional chromatin immunoprecipitation (iChIP) to direct identification of components of insulator complexes, which function as boundaries of chromatin domain. We found that the chicken beta-globin HS4 (cHS4) insulator complex contains an RNA helicase protein, p68/DDX5; an RNA species, steroid receptor RNA activator 1; and a nuclear matrix protein, Matrin-3, in vivo. Binding of p68 and Matrin-3 to the cHS4 insulator core sequence was mediated by CCCTC-binding factor (CTCF). Thus, our results showed that it is feasible to directly identify proteins and RNA bound to a specific genomic region in vivo by using iChIP.