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Huang G, Cai X, Li D. Significance of targeting DNMT3A mutations in AML. Ann Hematol 2024:10.1007/s00277-024-05885-8. [PMID: 39078434 DOI: 10.1007/s00277-024-05885-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Accepted: 07/05/2024] [Indexed: 07/31/2024]
Abstract
Acute myeloid leukemia (AML) is the most prevalent form of leukemia among adults, characterized by aggressive behavior and significant genetic diversity. Despite decades of reliance on conventional chemotherapy as the mainstay treatment, patients often struggle with achieving remission, experience rapid relapses, and have limited survival prospects. While intensified induction chemotherapy and allogeneic stem cell transplantation have enhanced patient outcomes, these benefits are largely confined to younger AML patients capable of tolerating intensive treatments. DNMT3A, a crucial enzyme responsible for establishing de novo DNA methylation, plays a pivotal role in maintaining the delicate balance between hematopoietic stem cell differentiation and self-renewal, thereby influencing gene expression programs through epigenetic regulation. DNMT3A mutations are the most frequently observed genetic abnormalities in AML, predominantly in older patients, occurring in approximately 20-30% of adult AML cases and over 30% of AML with a normal karyotype. Consequently, the molecular underpinnings and potential therapeutic targets of DNMT3A mutations in AML are currently being thoroughly investigated. This article provides a comprehensive summary and the latest insights into the structure and function of DNMT3A, examines the impact of DNMT3A mutations on the progression and prognosis of AML, and explores potential therapeutic approaches for AML patients harboring DNMT3A mutations.
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Affiliation(s)
- Guiqin Huang
- Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoya Cai
- Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dengju Li
- Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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Wulfridge P, Sarma K. Intertwining roles of R-loops and G-quadruplexes in DNA repair, transcription and genome organization. Nat Cell Biol 2024; 26:1025-1036. [PMID: 38914786 DOI: 10.1038/s41556-024-01437-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 05/10/2024] [Indexed: 06/26/2024]
Abstract
R-loops are three-stranded nucleic acid structures that are abundant and widespread across the genome and that have important physiological roles in many nuclear processes. Their accumulation is observed in cancers and neurodegenerative disorders. Recent studies have implicated a function for R-loops and G-quadruplex (G4) structures, which can form on the displaced single strand of R-loops, in three-dimensional genome organization in both physiological and pathological contexts. Here we discuss the interconnected functions of DNA:RNA hybrids and G4s within R-loops, their impact on DNA repair and gene regulatory networks, and their emerging roles in genome organization during development and disease.
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Affiliation(s)
- Phillip Wulfridge
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA, USA
- Penn Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Kavitha Sarma
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA, USA.
- Penn Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA.
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Zhuk AS, Stepchenkova EI, Zotova IV, Belopolskaya OB, Pavlov YI, Kostroma II, Gritsaev SV, Aksenova AY. G-Quadruplex Forming DNA Sequence Context Is Enriched around Points of Somatic Mutations in a Subset of Multiple Myeloma Patients. Int J Mol Sci 2024; 25:5269. [PMID: 38791307 PMCID: PMC11121618 DOI: 10.3390/ijms25105269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 05/03/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Multiple myeloma (MM) is the second most common hematological malignancy, which remains incurable despite recent advances in treatment strategies. Like other forms of cancer, MM is characterized by genomic instability, caused by defects in DNA repair. Along with mutations in DNA repair genes and genotoxic drugs used to treat MM, non-canonical secondary DNA structures (four-stranded G-quadruplex structures) can affect accumulation of somatic mutations and chromosomal abnormalities in the tumor cells of MM patients. Here, we tested the hypothesis that G-quadruplex structures may influence the distribution of somatic mutations in the tumor cells of MM patients. We sequenced exomes of normal and tumor cells of 11 MM patients and analyzed the data for the presence of G4 context around points of somatic mutations. To identify molecular mechanisms that could affect mutational profile of tumors, we also analyzed mutational signatures in tumor cells as well as germline mutations for the presence of specific SNPs in DNA repair genes or in genes regulating G-quadruplex unwinding. In several patients, we found that sites of somatic mutations are frequently located in regions with G4 context. This pattern correlated with specific germline variants found in these patients. We discuss the possible implications of these variants for mutation accumulation and specificity in MM and propose that the extent of G4 context enrichment around somatic mutation sites may be a novel metric characterizing mutational processes in tumors.
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Affiliation(s)
- Anna S. Zhuk
- Laboratory of Amyloid Biology, St. Petersburg State University, 199034 St. Petersburg, Russia; (A.S.Z.); (I.V.Z.)
- Institute of Applied Computer Science, ITMO University, 197101 St. Petersburg, Russia
| | - Elena I. Stepchenkova
- Vavilov Institute of General Genetics, St. Petersburg Branch, Russian Academy of Sciences, 199034 St. Petersburg, Russia;
- Department of Genetics and Biotechnology, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Irina V. Zotova
- Laboratory of Amyloid Biology, St. Petersburg State University, 199034 St. Petersburg, Russia; (A.S.Z.); (I.V.Z.)
- Vavilov Institute of General Genetics, St. Petersburg Branch, Russian Academy of Sciences, 199034 St. Petersburg, Russia;
| | - Olesya B. Belopolskaya
- Resource Center “Bio-Bank Center”, Research Park of St. Petersburg State University, 198504 St. Petersburg, Russia;
- The Laboratory of Genogeography, Vavilov Institute of General Genetics, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Youri I. Pavlov
- Eppley Institute for Research in Cancer, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA;
- Departments of Biochemistry and Molecular Biology, Microbiology and Pathology, Genetics Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Ivan I. Kostroma
- City Hospital No. 15, 198205 St. Petersburg, Russia; (I.I.K.); (S.V.G.)
| | | | - Anna Y. Aksenova
- Laboratory of Amyloid Biology, St. Petersburg State University, 199034 St. Petersburg, Russia; (A.S.Z.); (I.V.Z.)
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Sergeev AV, Loiko AG, Genatullina AI, Petrov AS, Kubareva EA, Dolinnaya NG, Gromova ES. Crosstalk between G-Quadruplexes and Dnmt3a-Mediated Methylation of the c-MYC Oncogene Promoter. Int J Mol Sci 2023; 25:45. [PMID: 38203216 PMCID: PMC10779317 DOI: 10.3390/ijms25010045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 12/15/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
The methylation of cytosines at CpG sites in DNA, carried out de novo by DNA methyltransferase Dnmt3a, is a basic epigenetic modification involved in gene regulation and genome stability. Aberrant CpG methylation in gene promoters leads to oncogenesis. In oncogene promoters, CpG sites often colocalize with guanine-rich sequences capable of folding into G-quadruplexes (G4s). Our in vitro study aimed to investigate how parallel G4s formed by a sequence derived from the c-MYC oncogene promoter region affect the activity of the Dnmt3a catalytic domain (Dnmt3a-CD). For this purpose, we designed synthetic oligonucleotide constructs: a c-MYC G4-forming oligonucleotide and linear double-stranded DNA containing an embedded stable extrahelical c-MYC G4. The topology and thermal stability of G4 structures in these DNA models were analyzed using physicochemical techniques. We showed that Dnmt3a-CD specifically binds to an oligonucleotide containing c-MYC G4, resulting in inhibition of its methylation activity. c-MYC G4 formation in a double-stranded context significantly reduces Dnmt3a-CD-induced methylation of a CpG site located in close proximity to the quadruplex structure; this effect depends on the distance between the non-canonical structure and the specific CpG site. One would expect DNA hypomethylation near the G4 structure, while regions distant from this non-canonical form would maintain a regular pattern of high methylation levels. We hypothesize that the G4 structure sequesters the Dnmt3a-CD and impedes its proper binding to B-DNA, resulting in hypomethylation and activation of c-MYC transcription.
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Affiliation(s)
- Alexander V. Sergeev
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia; (A.V.S.); (A.G.L.); (A.I.G.); (A.S.P.); (N.G.D.); (E.S.G.)
| | - Andrei G. Loiko
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia; (A.V.S.); (A.G.L.); (A.I.G.); (A.S.P.); (N.G.D.); (E.S.G.)
| | - Adelya I. Genatullina
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia; (A.V.S.); (A.G.L.); (A.I.G.); (A.S.P.); (N.G.D.); (E.S.G.)
| | - Alexander S. Petrov
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia; (A.V.S.); (A.G.L.); (A.I.G.); (A.S.P.); (N.G.D.); (E.S.G.)
| | - Elena A. Kubareva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia
| | - Nina G. Dolinnaya
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia; (A.V.S.); (A.G.L.); (A.I.G.); (A.S.P.); (N.G.D.); (E.S.G.)
| | - Elizaveta S. Gromova
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1, 119991 Moscow, Russia; (A.V.S.); (A.G.L.); (A.I.G.); (A.S.P.); (N.G.D.); (E.S.G.)
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