title: Gene regulation is governed by a core network in hepatocellular carcinoma.
abstract: BACKGROUND
  Hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide, and the mechanisms that lead to the disease are still relatively unclear. However, with the development of high-throughput technologies it is possible to gain a systematic view of biological systems to enhance the understanding of the roles of genes associated with HCC. Thus, analysis of the mechanism of molecule interactions in the context of gene regulatory networks can reveal specific sub-networks that lead to the development of HCC.
  
  
  RESULTS
  In this study, we aimed to identify the most important gene regulations that are dysfunctional in HCC generation. Our method for constructing gene regulatory network is based on predicted target interactions, experimentally-supported interactions, and co-expression model. Regulators in the network included both transcription factors and microRNAs to provide a complete view of gene regulation. Analysis of gene regulatory network revealed that gene regulation in HCC is highly modular, in which different sets of regulators take charge of specific biological processes. We found that microRNAs mainly control biological functions related to mitochondria and oxidative reduction, while transcription factors control immune responses, extracellular activity and the cell cycle. On the higher level of gene regulation, there exists a core network that organizes regulations between different modules and maintains the robustness of the whole network. There is direct experimental evidence for most of the regulators in the core gene regulatory network relating to HCC. We infer it is the central controller of gene regulation. Finally, we explored the influence of the core gene regulatory network on biological pathways.
  
  
  CONCLUSIONS
  Our analysis provides insights into the mechanism of transcriptional and post-transcriptional control in HCC. In particular, we highlight the importance of the core gene regulatory network; we propose that it is highly related to HCC and we believe further experimental validation is worthwhile.
authors.affiliation: The State Key Laboratory of Pharmaceutical Biotechnology and Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, School of Life Science, Nanjing University, Nanjing 210093, China.
authors.forename: Zuguang
authors.initials: Z
authors.lastname: Gu
authors.forename: Chenyu
authors.initials: C
authors.lastname: Zhang
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000821:virology; D015972:Gene Expression Regulation, Neoplastic; D053263:Gene Regulatory Networks; D006509:Hepatitis B / Q000150:complications; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism* / Q000821:virology; D035683:MicroRNAs / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D035683:MicroRNAs; D014157:Transcription Factors