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Yao Y, Vasoya D, Kgosana L, Smith LP, Gao Y, Wang X, Watson M, Nair V. Activation of gga-miR-155 by reticuloendotheliosis virus T strain and its contribution to transformation. J Gen Virol 2017; 98:810-820. [PMID: 28113043 PMCID: PMC5657028 DOI: 10.1099/jgv.0.000718] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The v-rel oncoprotein encoded by reticuloendotheliosis virus T strain (Rev-T) is a member of the rel/NF-κB family of transcription factors capable of transformation of primary chicken spleen and bone marrow cells. Rapid transformation of avian haematopoietic cells by v-rel occurs through a process of deregulation of multiple protein-encoding genes through its direct effect on their promoters. More recently, upregulation of oncogenic miR-155 and its precursor pre-miR-155 was demonstrated in both Rev-T-infected chicken embryo fibroblast cultures and Rev-T-induced B-cell lymphomas. Through electrophoresis mobility shift assay and reporter analysis on the gga-miR-155 promoter, we showed that the v-rel-induced miR-155 overexpression occurred by the direct binding to one of the putative NF-κB binding sites. Using the v-rel-induced transformation model on chicken embryonic splenocyte cultures, we could demonstrate a dynamic increase in miR-155 levels during the transformation. Transcriptome profiles of lymphoid cells transformed by v-rel showed upregulation of miR-155 accompanied by downregulation of a number of putative miR-155 targets such as Pu.1 and CEBPβ. We also showed that v-rel could rescue the suppression of miR-155 expression observed in Marek's disease virus (MDV)-transformed cell lines, where its functional viral homologue MDV-miR-M4 is overexpressed. Demonstration of gene expression changes affecting major molecular pathways, including organismal injury and cancer in avian macrophages transfected with synthetic mature miR-155, underlines its potential direct role in transformation. Our study suggests that v-rel-induced transformation involves a complex set of events mediated by the direct activation of NF-κB targets, together with inhibitory effects on microRNA targets.
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Affiliation(s)
- Yongxiu Yao
- Avian Viral Disease Programme & UK-China Centre of Excellence on Avian Disease Research, The Pirbright Institute, Pirbright, Ash Road, Guildford, Surrey GU24 0NF, UK
| | - Deepali Vasoya
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush EH25 9RG, UK
| | - Lydia Kgosana
- Avian Viral Disease Programme & UK-China Centre of Excellence on Avian Disease Research, The Pirbright Institute, Pirbright, Ash Road, Guildford, Surrey GU24 0NF, UK
| | - Lorraine P Smith
- Avian Viral Disease Programme & UK-China Centre of Excellence on Avian Disease Research, The Pirbright Institute, Pirbright, Ash Road, Guildford, Surrey GU24 0NF, UK
| | - Yulong Gao
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, PR China
| | - Xiaomei Wang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, PR China
| | - Mick Watson
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush EH25 9RG, UK
| | - Venugopal Nair
- Avian Viral Disease Programme & UK-China Centre of Excellence on Avian Disease Research, The Pirbright Institute, Pirbright, Ash Road, Guildford, Surrey GU24 0NF, UK
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Haery L, Mussakhan S, Waxman DJ, Gilmore TD. Evidence for an oncogenic modifier role for mutant histone acetyltransferases in diffuse large B-cell lymphoma. Leuk Lymphoma 2016; 57:2661-71. [PMID: 27003102 DOI: 10.3109/10428194.2016.1160083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Mutations in histone acetyltransferases (HATs) are among the most common mutations in diffuse large B-cell lymphoma (DLBCL). We previously showed that two human DLBCL cell lines, RC-K8 and SUDHL2, express C-terminally truncated, HAT domain-deficient p300 proteins (p300ΔC) that are required for optimal cell proliferation. Microarray analysis of mRNA expression in RC-K8 cells following p300ΔC knockdown shows upregulation of NF-κB and p53 gene expression programs and downregulation of a MYC gene expression program. Experiments indicate that these gene expression changes are due to inhibitory effects of p300ΔC on NF-κB activity and on p53 protein levels and stimulatory effects on MYC protein levels, suggesting that p300ΔC mutants enhance the proliferation of DLBCL cells by adjusting the transcriptional output of cell-specific oncoproteins. We propose that p300/CBP gene truncation represents a new class of oncogenic mutation that optimizes the activity of context-specific oncogenic transcription factors. We propose 'oncogenic modifier' to describe such mutations.
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Affiliation(s)
- Leila Haery
- a Department of Biology , Boston University , Boston , MA , USA
| | | | - David J Waxman
- a Department of Biology , Boston University , Boston , MA , USA
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