1
|
Sharma A, Das A, Bal A, Srinivasan R, Malhotra P, Prakash G, Kumar R. Prognostic Value of Differential Expression of Polymerase Eta Gene in Nonresponding Patients With Diffuse Large B-cell Lymphoma. Appl Immunohistochem Mol Morphol 2024; 32:32-36. [PMID: 37867373 DOI: 10.1097/pai.0000000000001168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 09/19/2023] [Indexed: 10/24/2023]
Abstract
Diffuse large B-cell lymphoma (DLBCL) represents the most common subtype of non-Hodgkins lymphoma. After the introduction of rituximab therapy like rituximab, cyclophosphamide, doxorubicin vincristine, prednisolone, there has been considerable improvement in the 5-year overall survival in this group of patients, but the nonresponding patients are a challenge to the clinician. The translesion polymerases are unique polymerases that make cells tolerant to DNA damage. Many point mutations are introduced owing to their inherent property of bypassing the points of lesions, preventing the cell from stalling replication. However, the impaired activity of these polymerases can lead to the development of tumors with aggressive clinical course. In this study, the gene expression levels of polymerase eta ( POLE ) were compared in 2 cohorts of patients with DLBCL: the first cohort, patients who had achieved complete response, and the second cohort, patients who were refractory to the treatment or had relapse within 2 years of treatment. There was a significantly upregulated expression in the refractory/relapse cohort compared with the complete remission cohort ( P = 0.0001). The high POLE expression levels correlated significantly with advanced disease stages (III and IV) and poor disease-free survival in the Kaplan-Meier curve. The high POLE expression levels were correlated with poor disease-free survival in nonresponder patients with DLBCL. The results concluded that patients with DLBCL with a high polymerase gene expression may show nonresponsiveness to chemotherapy; hence the functional impact of upregulated expression of POLE in DLBCL requires an in-depth assessment.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Rajendar Kumar
- Department of Nuclear Medicine, PGIMER, Chandigarh, India
| |
Collapse
|
2
|
Mauney CH, Hollis T. SAMHD1: Recurring roles in cell cycle, viral restriction, cancer, and innate immunity. Autoimmunity 2018; 51:96-110. [PMID: 29583030 PMCID: PMC6117824 DOI: 10.1080/08916934.2018.1454912] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 03/16/2018] [Indexed: 12/24/2022]
Abstract
Sterile alpha motif and histidine-aspartic acid domain-containing protein 1 (SAMHD1) is a deoxynucleotide triphosphate (dNTP) hydrolase that plays an important role in the homeostatic balance of cellular dNTPs. Its emerging role as an effector of innate immunity is affirmed by mutations in the SAMHD1 gene that cause the severe autoimmune disease, Aicardi-Goutieres syndrome (AGS) and that are linked to cancer. Additionally, SAMHD1 functions as a restriction factor for retroviruses, such as HIV. Here, we review the current biochemical and biological properties of the enzyme including its structure, activity, and regulation by post-translational modifications in the context of its cellular function. We outline open questions regarding the biology of SAMHD1 whose answers will be important for understanding its function as a regulator of cell cycle progression, genomic integrity, and in autoimmunity.
Collapse
Affiliation(s)
- Christopher H Mauney
- a Department of Biochemistry , Center for Structural Biology, Wake Forest School of Medicine , Winston Salem , NC , USA
| | - Thomas Hollis
- a Department of Biochemistry , Center for Structural Biology, Wake Forest School of Medicine , Winston Salem , NC , USA
| |
Collapse
|
3
|
Niu M, Wang Y, Wang C, Lyu J, Wang Y, Dong H, Long W, Wang D, Kong W, Wang L, Guo X, Sun L, Hu T, Zhai H, Wang H, Wan J. ALR encoding dCMP deaminase is critical for DNA damage repair, cell cycle progression and plant development in rice. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:5773-5786. [PMID: 29186482 DOI: 10.1093/jxb/erx380] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
Deoxycytidine monophosphate deaminase (dCMP deaminase, DCD) is crucial to the production of dTTP needed for DNA replication and damage repair. However, the effect of DCD deficiency and its molecular mechanism are poorly understood in plants. Here, we isolated and characterized a rice albinic leaf and growth retardation (alr) mutant that is manifested by albinic leaves, dwarf stature and necrotic lesions. Map-based cloning and complementation revealed that ALR encodes a DCD protein. OsDCD was expressed ubiquitously in all tissues. Enzyme activity assays showed that OsDCD catalyses conversion of dCMP to dUMP, and the ΔDCD protein in the alr mutant is a loss-of-function protein that lacks binding ability. We report that alr plants have typical DCD-mediated imbalanced dNTP pools with decreased dTTP; exogenous dTTP recovers the wild-type phenotype. A comet assay and Trypan Blue staining showed that OsDCD deficiency causes accumulation of DNA damage in the alr mutant, sometimes leading to cell apoptosis. Moreover, OsDCD deficiency triggered cell cycle checkpoints and arrested cell progression at the G1/S-phase. The expression of nuclear and plastid genome replication genes was down-regulated under decreased dTTP, and together with decreased cell proliferation and defective chloroplast development in the alr mutant this demonstrated the molecular and physiological roles of DCD-mediated dNTP pool balance in plant development.
Collapse
Affiliation(s)
- Mei Niu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
| | - Yihua Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
| | - Chunming Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
| | - Jia Lyu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
| | - Yunlong Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
| | - Hui Dong
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
| | - Wuhua Long
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
| | - Di Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
| | - Weiyi Kong
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
| | - Liwei Wang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
| | - Xiuping Guo
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, China
| | - Liting Sun
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
| | - Tingting Hu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
| | - Huqu Zhai
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, China
| | - Haiyang Wang
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, China
| | - Jianmin Wan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, China
- National Key Facility for Crop Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, China
| |
Collapse
|
4
|
Alekseenko IV, Kuzmich AI, Pleshkan VV, Tyulkina DV, Zinovyeva MV, Kostina MB, Sverdlov ED. The cause of cancer mutations: Improvable bad life or inevitable stochastic replication errors? Mol Biol 2016. [DOI: 10.1134/s0026893316060030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
5
|
Fouquerel E, Lormand J, Bose A, Lee HT, Kim GS, Li J, Sobol RW, Freudenthal BD, Myong S, Opresko PL. Oxidative guanine base damage regulates human telomerase activity. Nat Struct Mol Biol 2016; 23:1092-1100. [PMID: 27820808 PMCID: PMC5140714 DOI: 10.1038/nsmb.3319] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 10/11/2016] [Indexed: 12/19/2022]
Abstract
Changes in telomere length are associated with degenerative diseases and cancer. Oxidative stress and DNA damage have been linked to both positive and negative alterations in telomere length and integrity. Here we examined how the common oxidative lesion 8-oxo-7,8-dihydro-2′-deoxyguanine (8-oxoG) regulates telomere elongation by telomerase. When present in the deoxynucleoside triphosphate pool as 8-oxodGTP, telomerase utilization of the oxidized nucleotide during telomere extension is mutagenic and terminates further elongation. Depletion of the enzyme that removes oxidized dNTPs, MTH1, increases telomere dysfunction and cell death in telomerase positive cancer cells harboring shortened telomeres. In contrast, a pre-existing 8-oxoG within the telomeric DNA sequence promotes telomerase activity by destabilizing G-quadruplex structure in the DNA. We show that the mechanism by which 8-oxoG arises in the telomere, either by insertion of oxidized nucleotides or by direct reaction with free radicals, dictates whether telomerase is inhibited or stimulated and thereby, mediates the biological outcome.
Collapse
Affiliation(s)
- Elise Fouquerel
- Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, and University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
| | - Justin Lormand
- Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, and University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
| | - Arindam Bose
- Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, and University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
| | - Hui-Ting Lee
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA
| | - Grace S Kim
- Department of Bioengineering, University of Illinois, Urbana, IL, USA
| | - Jianfeng Li
- University of South Alabama Mitchell Cancer Institute, Mobile, AL, USA
| | - Robert W Sobol
- University of South Alabama Mitchell Cancer Institute, Mobile, AL, USA
| | - Bret D Freudenthal
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Sua Myong
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA.,Department of Bioengineering, University of Illinois, Urbana, IL, USA
| | - Patricia L Opresko
- Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, and University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA.,Center for Nucleic Acids Science and Technology, Carnegie Mellon University, Pittsburgh, PA, USA
| |
Collapse
|
6
|
Alekseenko IV, Pleshkan VV, Monastyrskaya GS, Kuzmich AI, Snezhkov EV, Didych DA, Sverdlov ED. Fundamentally low reproducibility in molecular genetic cancer research. RUSS J GENET+ 2016. [DOI: 10.1134/s1022795416070036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
7
|
Nicolas E, Golemis EA, Arora S. POLD1: Central mediator of DNA replication and repair, and implication in cancer and other pathologies. Gene 2016; 590:128-41. [PMID: 27320729 PMCID: PMC4969162 DOI: 10.1016/j.gene.2016.06.031] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 06/10/2016] [Accepted: 06/14/2016] [Indexed: 02/06/2023]
Abstract
The evolutionarily conserved human polymerase delta (POLD1) gene encodes the large p125 subunit which provides the essential catalytic activities of polymerase δ (Polδ), mediated by 5′–3′ DNA polymerase and 3′–5′ exonuclease moieties. POLD1 associates with three smaller subunits (POLD2, POLD3, POLD4), which together with Replication Factor C and Proliferating Nuclear Cell Antigen constitute the polymerase holoenzyme. Polδ function is essential for replication, with a primary role as the replicase for the lagging strand. Polδ also has an important proofreading ability conferred by the exonuclease activity, which is critical for ensuring replicative fidelity, but also serves to repair DNA lesions arising as a result of exposure to mutagens. Polδ has been shown to be important for multiple forms of DNA repair, including nucleotide excision repair, double strand break repair, base excision repair, and mismatch repair. A growing number of studies in the past decade have linked germline and sporadic mutations in POLD1 and the other subunits of Polδ with human pathologies. Mutations in Polδ in mice and humans lead to genomic instability, mutator phenotype and tumorigenesis. The advent of genome sequencing techniques has identified damaging mutations in the proofreading domain of POLD1 as the underlying cause of some inherited cancers, and suggested that mutations in POLD1 may influence therapeutic management. In addition, mutations in POLD1 have been identified in the developmental disorders of mandibular hypoplasia, deafness, progeroid features and lipodystrophy and atypical Werner syndrome, while changes in expression or activity of POLD1 have been linked to senescence and aging. Intriguingly, some recent evidence suggests that POLD1 function may also be altered in diabetes. We provide an overview of critical Polδ activities in the context of these pathologic conditions.
Collapse
Affiliation(s)
- Emmanuelle Nicolas
- Program in Molecular Therapeutics, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Erica A Golemis
- Program in Molecular Therapeutics, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Sanjeevani Arora
- Program in Molecular Therapeutics, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
| |
Collapse
|
8
|
Heterozygous colon cancer-associated mutations of SAMHD1 have functional significance. Proc Natl Acad Sci U S A 2016; 113:4723-8. [PMID: 27071091 DOI: 10.1073/pnas.1519128113] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Even small variations in dNTP concentrations decrease DNA replication fidelity, and this observation prompted us to analyze genomic cancer data for mutations in enzymes involved in dNTP metabolism. We found that sterile alpha motif and histidine-aspartate domain-containing protein 1 (SAMHD1), a deoxyribonucleoside triphosphate triphosphohydrolase that decreases dNTP pools, is frequently mutated in colon cancers, that these mutations negatively affect SAMHD1 activity, and that several SAMHD1 mutations are found in tumors with defective mismatch repair. We show that minor changes in dNTP pools in combination with inactivated mismatch repair dramatically increase mutation rates. Determination of dNTP pools in mouse embryos revealed that inactivation of one SAMHD1 allele is sufficient to elevate dNTP pools. These observations suggest that heterozygous cancer-associated SAMHD1 mutations increase mutation rates in cancer cells.
Collapse
|
9
|
Hussain S. A new conceptual framework for investigating complex genetic disease. Front Genet 2015; 6:327. [PMID: 26583033 PMCID: PMC4631989 DOI: 10.3389/fgene.2015.00327] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 10/21/2015] [Indexed: 01/17/2023] Open
Abstract
Some common diseases are known to have an inherited component, however, their population- and familial-incidence patterns do not conform to any known monogenic Mendelian pattern of inheritance and instead they are currently much better explained if an underlying polygenic architecture is posited. Studies that have attempted to identify the causative genetic factors have been designed on this polygenic framework, but so far the yield has been largely unsatisfactory. Based on accumulating recent observations concerning the roles of somatic mosaicism in disease, in this article a second framework which posits a single gene-two hit model which can be modulated by a mutator/anti-mutator genetic background is suggested. I discuss whether such a model can be considered a viable alternative based on current knowledge, its advantages over the current polygenic framework, and describe practical routes via which the new framework can be investigated.
Collapse
Affiliation(s)
- Shobbir Hussain
- Department of Biology and Biochemistry, University of BathBath, UK
| |
Collapse
|