1
|
Ghazzaui N, Issaoui H, Ferrad M, Carrion C, Cook-Moreau J, Denizot Y, Boyer F. Eμ and 3'RR transcriptional enhancers of the IgH locus cooperate to promote c-myc-induced mature B-cell lymphomas. Blood Adv 2020; 4:28-39. [PMID: 31899800 PMCID: PMC6960469 DOI: 10.1182/bloodadvances.2019000845] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 11/12/2019] [Indexed: 01/18/2023] Open
Abstract
Numerous B-cell lymphomas feature translocations linking oncogenes to different locations in the immunoglobulin heavy chain (IgH) locus. During Burkitt lymphoma (BL), IgH breakpoints for c-myc translocation stand either close to JH segments or within switch regions. Transcription, accessibility, and remodeling of the IgH locus are under the control of the 2 potent cis-acting enhancer elements: Eμ and the 3' regulatory region (3'RR). To ensure their respective contributions to oncogene deregulation in the context of the endogenous IgH locus, we studied transgenic mice harboring a knock-in of c-myc in various positions of the IgH locus (3' to JH segments, 5' to Cμ with Eμ deletion and Cα). The observed spectrum of tumors, kinetics of emergence, and transcriptome analysis provide strong evidence that both Eμ and 3'RR deregulate c-myc and cooperate together to promote B-cell lymphomagenesis. Transgenics mimicking endemic BL (with c-myc placed 3' to JH segments) exhibited the highest rate of B-cell lymphoma emergence, the highest Ki67 index of proliferation, and the highest transcriptomic similarities to human BL. The 3'RR enhancer alone deregulated c-myc and initiated the development of BL-like lymphomas, suggesting that its targeting would be of therapeutic interest to reduce c-myc oncogenicity in vivo.
Collapse
Affiliation(s)
- Nour Ghazzaui
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
| | - Hussein Issaoui
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
| | - Mélissa Ferrad
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
| | - Claire Carrion
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
| | - Jeanne Cook-Moreau
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
| | - Yves Denizot
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
| | - François Boyer
- Unité Mixte de Recherche Centre National de la Recherche Scientifique 7276, Institut National de la Santé et de la Recherche Médicale U1262, Equipe Labellisée Ligue 2018, Université de Limoges, Limoges, France
| |
Collapse
|
2
|
The IgH 3' regulatory region and c-myc-induced B-cell lymphomagenesis. Oncotarget 2018; 8:7059-7067. [PMID: 27729620 PMCID: PMC5351691 DOI: 10.18632/oncotarget.12535] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/05/2016] [Indexed: 01/18/2023] Open
Abstract
Deregulation and mutations of c-myc have been reported in multiple mature B-cell malignancies such as Burkitt lymphoma, myeloma and plasma cell lymphoma. After translocation into the immunoglobulin heavy chain (IgH) locus, c-myc is constitutively expressed under the control of active IgH cis-regulatory enhancers. Those located in the IgH 3 regulatory region (3RR) are master control elements of transcription. Over the past decade numerous convincing demonstrations of 3RRs contribution to mature c-myc-induced lymphomagenesis have been made using transgenic models with various types of IgH-c-myc translocations and transgenes. This review highlights how IgH 3RR physiological functions play a critical role in c-myc deregulation during lymphomagenesis.
Collapse
|
3
|
Efficient role of IgH 3' regulatory region deficient B-cells in the development of oil granulomas. Oncotarget 2018; 7:38741-38749. [PMID: 27231852 PMCID: PMC5122425 DOI: 10.18632/oncotarget.9588] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 04/29/2016] [Indexed: 01/18/2023] Open
Abstract
Functional B-cells are essential for the formation of oil granulomas. The IgH 3′ regulatory region (3′RR) activates important check-points during B-cell maturation. We investigated if 3′RR-deficient B-cells remain efficient to develop oil granulomas in response to pristine. B-cells expressing an IgH 3′RR-deficient allele were similarly recruited to wild type allele expressing B-cells in the granuloma. No differences were observed between 3′RR-deficient mice and control mice for granuloma numbers, cellular composition and ability to express mRNA transcripts for several pro- and anti-inflammatory cytokines. Altogether these results suggest a normal role for 3′RR-deficient B-cells in the development of an acute B-cell-mediated inflammatory response.
Collapse
|
4
|
Saintamand A, Garot A, Saad F, Moulinas R, Denizot Y. Pre-germinal center origin for mature mouse B cell lymphomas: a major discrepancy with human mature lymphomas. Cell Cycle 2016; 14:3656-8. [PMID: 26654599 DOI: 10.1080/15384101.2015.1093708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Affiliation(s)
| | - Armand Garot
- a Université de Limoges; CRIBL; UMR CNRS 7276 ; Limoges , France
| | - Faten Saad
- a Université de Limoges; CRIBL; UMR CNRS 7276 ; Limoges , France
| | - Rémi Moulinas
- b GENOLIM plateform; Université de Limoges ; Limoges, France
| | - Yves Denizot
- a Université de Limoges; CRIBL; UMR CNRS 7276 ; Limoges , France
| |
Collapse
|