转录因子和miRNA在复杂疾病中的共调控网络研究
Transcription factors (TFs) are key regulators controlling the transcription of target genes by binding to specific DNA sequences on the promoter of target genes. Both the TFs and miRNAs are regulators of gene expression and they may mutual regulate each other to form feedback loops (FBL), or they regulate the same target gene to form a feed-forward loop (FFL). It has been reported that hundreds of potential miRNA-mediated feedback and feed-forward loops are available at the genome level. To predict the TF-miRNA co-regulatory FFL and FBL loops, we integrated multiple data of TF targets and miRNA targets including both experimentally validated and predicted. Thus, we developed a strategy to predict the TF-miRNA co-regulatory FFL and FBL loops. We used these methods to study the TF-miRNA co-regulation in specific diseases including schizophrenia and T-cell acute lymphoblastic leukemia (T-ALL). We identified and verified some key miRNA and genes in these diseases. In the T-ALL, we obtained 120 FFLs among T-ALL related genes, miRNAs and TFs. Afterwards, a T-ALL miRNA and TF co-regulatory network was constructed and its significance was tested by statistical methods. Four miRNAs in the miR-17~92 cluster and 4 important genes (CYLD, HOXA9, BCL2L11, and RUNX1) were found as hubs in the network. Particularly, we found that miR-19 was highly expressed in T-ALL patients and cell lines. Ectopic expression of miR-19 repress CYLD expression, while miR-19 inhibitor treatment induce CYLD protein expression and decreases NF-κB expression in the downstream signaling pathway. Thus, miR-19, CYLD and NF-κB form a regulatory feed-forward loop, which provides new clues for sustained activation of NF-κB in T-ALL. Some single nucleotide polymorphisms (SNPs) in miRNA genes or target sites (miRNA-related SNPs) have been proved to be associated with human diseases by affecting the miRNA mediated regulatory function. To systematically analyze miRNA-related SNPs and their effects, we performed a genome-wide scan for SNPs in human pre-miRNAs, miRNA flanking regions, target sites and designed a pipeline to predict the effects of them on miRNA-target interaction. As a result, we identified 48 SNPs in human miRNA seed regions and thousands of SNPs in 3'- untranslated regions with the potential to either disturb or create miRNA-target interactions. Furthermore, we experimentally confirmed 7 loss-of-function SNPs and 1 gain-of-function SNP by luciferase assay. All useful data were complied into miRNASNP, a user-friendly free online database (http://www.bioguo.org/miRNASNP/). These data will be a useful resource for studying miRNA function, identifying disease-associated miRNAs, and further personalized medicine.
转录因子和miRNA在复杂疾病中的共调控网络研究
Transcription factors (TFs) are key regulators controlling the transcription of target genes by binding to specific DNA sequences on the promoter of target genes. Both the TFs and miRNAs are regulators of gene expression and they may mutual regulate each other to form feedback loops (FBL), or they regulate the same target gene to form a feed-forward loop (FFL). It has been reported that hundreds of potential miRNA-mediated feedback and feed-forward loops are available at the genome level.
毛新良：转录因子c-Maf泛素化酶的发现和功能性分析
介绍了染色体易位与多发性骨髓瘤，Maf、c-Maf在多发性肿瘤中的基因表达。提到了蛋白质泛素化酶系统，提到了HERC4基因表达相关问题。