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Owoloye AJ, Olubode SO, Ogunleye A, Idowu ET, Oyebola KM. Computational identification of potential modulators of heme-regulated inhibitor (HRI) for pharmacological intervention against sickle cell disease. J Biomol Struct Dyn 2024:1-13. [PMID: 38555858 DOI: 10.1080/07391102.2024.2331097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 03/10/2024] [Indexed: 04/02/2024]
Abstract
Sickle cell disease (SCD) poses a significant health challenge and therapeutic approaches often target fetal hemoglobin (HbF) to ameliorate symptoms. Hydroxyurea, a current therapeutic option for SCD, has shown efficacy in increasing HbF levels. However, concerns about myelosuppression and thrombocytopenia necessitate the exploration of alternative compounds. Heme-regulated inhibitor (HRI) presents a promising target for pharmacological intervention in SCD due to its association with HbF modulation. This study screened compounds for their potential inhibitory functions against HRI. Small-molecule compounds from 17 folkloric plants were subjected to in silico screening against HRI. Molecular docking was performed, and free binding energy calculations were determined using molecular mechanics with generalized born and surface area (MMGBSA). Lead compounds were subjected to molecular dynamics simulation at 100 ns. Computational quantum mechanical modeling of the lead compounds was subsequently performed. We further examined the pharmacodynamics, pharmacokinetic and physiological properties of the identified compounds. Five potential HRI inhibitors, including kaempferol-3-(2G-glucosyrutinoside), epigallocatechin gallate, tiliroside, myricetin-3-O-glucoside and cannabiscitrin, with respective docking scores of -16.0, -12.17, -11.37, -11.56 and 11.07 kcal/mol, were identified. The MMGBSA analysis of the complexes yielded free-binding energies of -69.76, -71.17, -60.44, -53.55 and -55 kcal/mol, respectively. The identified leads were stable within HRI binding pocket for the duration of the 100 ns simulation. The study identified five phytoligands with potential inhibitory effects on HRI. This finding holds promise for advancing SCD treatment strategies. However, additional preclinical analyses are warranted to validate the chemotherapeutic properties of the lead compounds.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Afolabi J Owoloye
- Centre for Genomic Research in Biomedicine (CeGRIB), Mountain Top University, Ibafo, Nigeria
- Nigerian Institute of Medical Research, Lagos, Nigeria
- Parasitology and Bioinformatics Unit, Department of Zoology, Faculty of Science, University of Lagos, Lagos, Nigeria
| | - Samuel O Olubode
- Department of Biochemistry, Adekunle Ajasin University, Akungba, Ondo State, Nigeria
| | - Adewale Ogunleye
- Department of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Emmanuel T Idowu
- Parasitology and Bioinformatics Unit, Department of Zoology, Faculty of Science, University of Lagos, Lagos, Nigeria
| | - Kolapo M Oyebola
- Centre for Genomic Research in Biomedicine (CeGRIB), Mountain Top University, Ibafo, Nigeria
- Nigerian Institute of Medical Research, Lagos, Nigeria
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Zuo Z, Zhou Z, Chang Y, Liu Y, Shen Y, Li Q, Zhang L. Ribonucleotide reductase M2 (RRM2): Regulation, function and targeting strategy in human cancer. Genes Dis 2024; 11:218-233. [PMID: 37588202 PMCID: PMC10425756 DOI: 10.1016/j.gendis.2022.11.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 10/26/2022] [Accepted: 11/14/2022] [Indexed: 12/29/2022] Open
Abstract
Ribonucleotide reductase M2 (RRM2) is a small subunit in ribonucleotide reductases, which participate in nucleotide metabolism and catalyze the conversion of nucleotides to deoxynucleotides, maintaining the dNTP pools for DNA biosynthesis, repair, and replication. RRM2 performs a critical role in the malignant biological behaviors of cancers. The structure, regulation, and function of RRM2 and its inhibitors were discussed. RRM2 gene can produce two transcripts encoding the same ORF. RRM2 expression is regulated at multiple levels during the processes from transcription to translation. Moreover, this gene is associated with resistance, regulated cell death, and tumor immunity. In order to develop and design inhibitors of RRM2, appropriate strategies can be adopted based on different mechanisms. Thus, a greater appreciation of the characteristics of RRM2 is a benefit for understanding tumorigenesis, resistance in cancer, and tumor microenvironment. Moreover, RRM2-targeted therapy will be more attention in future therapeutic approaches for enhancement of treatment effects and amelioration of the dismal prognosis.
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Affiliation(s)
- Zanwen Zuo
- Innovative Drug R&D Center, College of Life Sciences, Huaibei Normal University, Huaibei, Anhui 235000, China
- National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), and School of Food and Biological Engineering, Hubei University of Technology, Wuhan, Hubei 430068, China
| | - Zerong Zhou
- Innovative Drug R&D Center, College of Life Sciences, Huaibei Normal University, Huaibei, Anhui 235000, China
- National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), and School of Food and Biological Engineering, Hubei University of Technology, Wuhan, Hubei 430068, China
| | - Yuzhou Chang
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH 43210, USA
| | - Yan Liu
- School of Agriculture and Biology, and Engineering Research Center of Cell & Therapeutic Antibody, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yuping Shen
- College of Chemistry and Bioengineering, Hunan University of Science and Engineering, Yongzhou, Hunan 425199, China
| | - Qizhang Li
- Innovative Drug R&D Center, College of Life Sciences, Huaibei Normal University, Huaibei, Anhui 235000, China
- National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), and School of Food and Biological Engineering, Hubei University of Technology, Wuhan, Hubei 430068, China
| | - Lei Zhang
- Innovative Drug R&D Center, College of Life Sciences, Huaibei Normal University, Huaibei, Anhui 235000, China
- Department of Pharmaceutical Botany, School of Pharmacy, Naval Medical University, Shanghai 200433, China
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Owoloye AJ, Olubode SO, Ogunleye A, Idowu ET, Oyebola KM. Computational identification of potential modulators of heme-regulated inhibitor (HRI) for pharmacological intervention against sickle cell disease. RESEARCH SQUARE 2023:rs.3.rs-3755458. [PMID: 38168168 PMCID: PMC10760220 DOI: 10.21203/rs.3.rs-3755458/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Background Sickle cell disease (SCD) poses a significant health challenge and therapeutic approaches often target fetal hemoglobin (HbF) to ameliorate symptoms. Hydroxyurea, a current therapeutic option for SCD, has shown efficacy in increasing HbF levels. However, concerns about myelosuppression and thrombocytopenia necessitate the exploration of alternative compounds. Heme-regulated inhibitor (HRI) presents a promising target for pharmacological intervention in SCD due to its association with HbF modulation. This study systematically screened compounds for their potential inhibitory functions against HRI. Methods Small-molecule compounds from 17 plants commonly utilized in traditional SCD management were subjected to in silico screening against HRI. Molecular docking was performed, and free binding energy calculations were determined using molecular mechanics with generalized born and surface area (MMGBSA). The lead compounds were subjected to molecular dynamics simulation at 100 ns. Computational quantum mechanical modelling of the lead compounds was subsequently performed. We further examined the pharmacodynamics, pharmacokinetic and physiological properties of the identified compounds. Results Five potential HRI inhibitors, including kaempferol-3-(2G-glucosyrutinoside), epigallocatechin gallate, tiliroside, myricetin-3-O-glucoside, and cannabiscitrin, with respective docking scores of -16.0, -12.17, -11.37, -11.56 and 11.07 kcal/mol, were identified. The MMGBSA analysis of the complexes yielded free-binding energies of -69.76, -71.17, -60.44, 53.55, and - 55 kcal/mol, respectively. The identified leads were stable within HRI binding pocket for the duration of 100 ns simulation. Conclusions The study successfully identified five phytoligands with potential inhibitory effects on HRI, opening avenues for their use as modulators of HbF in SCD patients. This finding holds promise for advancing treatment strategies in SCD. However, additional preclinical analyses are warranted to validate the chemotherapeutic properties of the lead compounds.
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Bowen NE, Tao S, Cho YJ, Schinazi RF, Kim B. Vpx requires active cellular dNTP biosynthesis to effectively counteract the anti-lentivirus activity of SAMHD1 in macrophages. J Biol Chem 2023; 299:104984. [PMID: 37390988 PMCID: PMC10374972 DOI: 10.1016/j.jbc.2023.104984] [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: 06/01/2023] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 07/02/2023] Open
Abstract
HIV-1 replication in primary monocyte-derived macrophages (MDMs) is kinetically restricted at the reverse transcription step due to the low deoxynucleoside triphosphates (dNTP) pools established by host dNTPase, SAM and HD domain containing protein 1 (SAMHD1). Lentiviruses such as HIV-2 and some Simian immunodeficiency virus counteract this restriction using viral protein X (Vpx), which proteosomally degrades SAMHD1 and elevates intracellular dNTP pools. However, how dNTP pools increase after Vpx degrades SAMHD1 in nondividing MDMs where no active dNTP biosynthesis is expected to exists remains unclear. In this study, we monitored known dNTP biosynthesis machinery during primary human monocyte differentiation to MDMs and unexpectedly found MDMs actively express dNTP biosynthesis enzymes such as ribonucleotide reductase, thymidine kinase 1, and nucleoside-diphosphate kinase. During differentiation from monocytes the expression levels of several biosynthesis enzymes are upregulated, while there is an increase in inactivating SAMHD1 phosphorylation. Correspondingly, we observed significantly lower levels of dNTPs in monocytes compared to MDMs. Without dNTP biosynthesis availability, Vpx failed to elevate dNTPs in monocytes, despite SAMHD1 degradation. These extremely low monocyte dNTP concentrations, which cannot be elevated by Vpx, impaired HIV-1 reverse transcription in a biochemical simulation. Furthermore, Vpx failed to rescue the transduction efficiency of a HIV-1 GFP vector in monocytes. Collectively, these data suggest that MDMs harbor active dNTP biosynthesis and Vpx requires this dNTP biosynthesis to elevate dNTP levels to effectively counteract SAMHD1 and relieve the kinetic block to HIV-1 reverse transcription in MDMs.
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Affiliation(s)
- Nicole E Bowen
- Department of Pediatrics, Center for ViroScience and Cure, School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Sijia Tao
- Department of Pediatrics, Center for ViroScience and Cure, School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Young-Jae Cho
- Department of Pediatrics, Center for ViroScience and Cure, School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Raymond F Schinazi
- Department of Pediatrics, Center for ViroScience and Cure, School of Medicine, Emory University, Atlanta, Georgia, USA; Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Baek Kim
- Department of Pediatrics, Center for ViroScience and Cure, School of Medicine, Emory University, Atlanta, Georgia, USA; Children's Healthcare of Atlanta, Atlanta, Georgia, USA.
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Kitab B, Tsukiyama-Kohara K. Regulatory Role of Ribonucleotide Reductase Subunit M2 in Hepatocyte Growth and Pathogenesis of Hepatitis C Virus. Int J Mol Sci 2023; 24:ijms24032619. [PMID: 36768940 PMCID: PMC9916403 DOI: 10.3390/ijms24032619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/27/2023] [Accepted: 01/27/2023] [Indexed: 01/31/2023] Open
Abstract
Hepatitis C virus (HCV) frequently causes chronic infection in the human liver, which may progress to advanced hepatic fibrosis, cirrhosis, and hepatocellular carcinoma. HCV primarily infects highly differentiated quiescent hepatocytes and can modulate cell cycle-regulatory genes and proliferation pathways, which ultimately contribute to persistent infection and pathogenesis. On the other hand, several studies have shown differential regulation of HCV RNA and viral protein expression levels, depending on the proliferation state of hepatocytes and the phase of the cell cycle. HCV typically requires factors provided by host cells for efficient and persistent viral replication. Previously, we found that HCV infection upregulates the expression of ribonucleotide reductase subunit M2 (RRM2) in quiescent hepatocytes. RRM2 is a rate-limiting protein that catalyzes de novo synthesis of deoxyribonucleotide triphosphates, and its expression is highly regulated during various phases of the cell cycle. RRM2 functions as a pro-viral factor essential for HCV RNA synthesis, but its functional role in HCV-induced liver diseases remains unknown. Here, we present a comprehensive review of the role of the hepatocyte cell cycle, in correlation with RRM2 expression, in the regulation of HCV replication. We also discuss the potential relevance of this protein in the pathogenesis of HCV, particularly in the development of hepatocellular carcinoma.
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6
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Bowen NE, Oo A, Kim B. Mechanistic Interplay between HIV-1 Reverse Transcriptase Enzyme Kinetics and Host SAMHD1 Protein: Viral Myeloid-Cell Tropism and Genomic Mutagenesis. Viruses 2022; 14:v14081622. [PMID: 35893688 PMCID: PMC9331428 DOI: 10.3390/v14081622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 11/23/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) has been the primary interest among studies on antiviral discovery, viral replication kinetics, drug resistance, and viral evolution. Following infection and entry into target cells, the HIV-1 core disassembles, and the viral RT concomitantly converts the viral RNA into double-stranded proviral DNA, which is integrated into the host genome. The successful completion of the viral life cycle highly depends on the enzymatic DNA polymerase activity of RT. Furthermore, HIV-1 RT has long been known as an error-prone DNA polymerase due to its lack of proofreading exonuclease properties. Indeed, the low fidelity of HIV-1 RT has been considered as one of the key factors in the uniquely high rate of mutagenesis of HIV-1, which leads to efficient viral escape from immune and therapeutic antiviral selective pressures. Interestingly, a series of studies on the replication kinetics of HIV-1 in non-dividing myeloid cells and myeloid specific host restriction factor, SAM domain, and HD domain-containing protein, SAMHD1, suggest that the myeloid cell tropism and high rate of mutagenesis of HIV-1 are mechanistically connected. Here, we review not only HIV-1 RT as a key antiviral target, but also potential evolutionary and mechanistic crosstalk among the unique enzymatic features of HIV-1 RT, the replication kinetics of HIV-1, cell tropism, viral genetic mutation, and host SAMHD1 protein.
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Affiliation(s)
- Nicole E. Bowen
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30329, USA; (N.E.B.); (A.O.)
| | - Adrian Oo
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30329, USA; (N.E.B.); (A.O.)
| | - Baek Kim
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30329, USA; (N.E.B.); (A.O.)
- Center for Drug Discovery, Children’s Healthcare of Atlanta, Atlanta, GA 30329, USA
- Correspondence:
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Evidence for a Hepatitis B Virus Short RNA Fragment Directly Targeting the Cellular RRM2 Gene. Cells 2022; 11:cells11142248. [PMID: 35883690 PMCID: PMC9318981 DOI: 10.3390/cells11142248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/14/2022] [Accepted: 07/18/2022] [Indexed: 11/29/2022] Open
Abstract
The hepatitis B virus (HBV) is one of the smallest but most highly infectious human pathogens. With a DNA genome of only 3.2 kb and only four genes, HBV successfully completes its life cycle by using intricate processes to hijack the host machinery. HBV infects non-dividing liver cells in which dNTPs are limited. As a DNA virus, HBV requires dNTPs for its replication. HBV induces the ATR-mediated cellular DNA damage response pathway to overcome this constraint. This pathway upregulates R2 (RRM2) expression in generating an active RNR holoenzyme catalyzing de novo dNTP synthesis. Previously we reported that ERE, a small RNA fragment within the HBx ORF, is sufficient to induce R2 upregulation. Interestingly, there is high sequence similarity between ERE and a region within the R2 5′UTR that we named R2-box. Here, we established a mutant cell line in the R2-box region of the R2 gene using CRISPR-Cas9 technology to investigate the R2 regulation by ERE. This cell line expresses a much lower R2 level than the parental cell line. Interestingly, the HBV infection and life cycle were severely impaired. These cells became permissive to HBV infection upon ectopically R2 expression. These results validate the requirement of the R2 gene expression for HBV replication. Remarkably, the R2-box mutated cells became ERE refractory, suggesting that the homology region between ERE and R2 gene is critical for ERE-mediated R2 upregulation. Thus, along with the induction of the ATR pathway of the DNA damage response, ERE might also directly target the R2 gene via the R2-box.
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Chakraborty S, Mukherjee P, Sengupta R. Ribonucleotide reductase: Implications of thiol S-nitrosylation and tyrosine nitration for different subunits. Nitric Oxide 2022; 127:26-43. [PMID: 35850377 DOI: 10.1016/j.niox.2022.07.002] [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: 02/15/2022] [Revised: 05/20/2022] [Accepted: 07/08/2022] [Indexed: 11/20/2022]
Abstract
Ribonucleotide reductase (RNR) is a multi-subunit enzyme responsible for catalyzing the rate-limiting step in the production of deoxyribonucleotides essential for DNA synthesis and repair. The active RNR complex is composed of multimeric R1 and R2 subunits. The RNR catalysis involves the formation of tyrosyl radicals in R2 subunits and thiyl radicals in R1 subunits. Despite the quaternary structure and cofactor diversity, all the three classes of RNR have a conserved cysteine residue at the active site which is converted into a thiyl radical that initiates the substrate turnover, suggesting that the catalytic mechanism is somewhat similar for all three classes of the RNR enzyme. Increased RNR activity has been associated with malignant transformation, cancer cell growth, and tumorigenesis. Efforts concerning the understanding of RNR inhibition in designing potent RNR inhibitors/drugs as well as developing novel approaches for antibacterial, antiviral treatments, and cancer therapeutics with improved radiosensitization have been made in clinical research. This review highlights the precise and potent roles of NO in RNR inhibition by targeting both the subunits. Under nitrosative stress, the thiols of the R1 subunits have been found to be modified by S-nitrosylation and the tyrosyl radicals of the R2 subunits have been modified by nitration. In view of the recent advances and progresses in the field of nitrosative modifications and its fundamental role in signaling with implications in health and diseases, the present article focuses on the regulations of RNR activity by S-nitrosylation of thiols (R1 subunits) and nitration of tyrosyl residues (R2 subunits) which will further help in designing new drugs and therapies.
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Affiliation(s)
- Surupa Chakraborty
- Amity Institute of Biotechnology, Amity University, Kolkata, 700135, West Bengal, India
| | - Prerona Mukherjee
- Amity Institute of Biotechnology, Amity University, Kolkata, 700135, West Bengal, India
| | - Rajib Sengupta
- Amity Institute of Biotechnology, Amity University, Kolkata, 700135, West Bengal, India.
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Tarangelo A, Rodencal J, Kim JT, Magtanong L, Long JZ, Dixon SJ. Nucleotide biosynthesis links glutathione metabolism to ferroptosis sensitivity. Life Sci Alliance 2022; 5:5/4/e202101157. [PMID: 35074928 PMCID: PMC8807879 DOI: 10.26508/lsa.202101157] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 01/06/2022] [Accepted: 01/11/2022] [Indexed: 01/01/2023] Open
Abstract
The tumor suppressor protein p53 inhibits ferroptosis by reducing the consumption of glutathione in nucleotide biosynthesis. Nucleotide synthesis is a metabolically demanding process essential for DNA replication and other processes in the cell. Several anticancer drugs that inhibit nucleotide metabolism induce apoptosis. How inhibition of nucleotide metabolism impacts non-apoptotic cell death is less clear. Here, we report that inhibition of nucleotide metabolism by the p53 pathway is sufficient to suppress the non-apoptotic cell death process of ferroptosis. Mechanistically, stabilization of wild-type p53 and induction of the p53 target gene CDKN1A (p21) leads to decreased expression of the ribonucleotide reductase (RNR) subunits RRM1 and RRM2. RNR is the rate-limiting enzyme of de novo nucleotide synthesis that reduces ribonucleotides to deoxyribonucleotides in a glutathione-dependent manner. Direct inhibition of RNR results in conservation of intracellular glutathione, limiting the accumulation of toxic lipid peroxides and preventing the onset of ferroptosis in response to cystine deprivation. These results support a mechanism linking p53-dependent regulation of nucleotide metabolism to non-apoptotic cell death.
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Affiliation(s)
- Amy Tarangelo
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Jason Rodencal
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Joon Tae Kim
- Department of Pathology and Stanford, Chemistry, Engineering and Medicine for Human Health (ChEM-H), Stanford University School of Medicine, Stanford, CA, USA
| | | | - Jonathan Z Long
- Department of Pathology and Stanford, Chemistry, Engineering and Medicine for Human Health (ChEM-H), Stanford University School of Medicine, Stanford, CA, USA
| | - Scott J Dixon
- Department of Biology, Stanford University, Stanford, CA, USA
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10
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Mechanisms of Hydroxyurea-Induced Cellular Senescence: An Oxidative Stress Connection? OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:7753857. [PMID: 34707779 PMCID: PMC8545575 DOI: 10.1155/2021/7753857] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 08/09/2021] [Accepted: 09/25/2021] [Indexed: 01/10/2023]
Abstract
Hydroxyurea (HU) is a water-soluble antiproliferative agent used for decades in neoplastic and nonneoplastic conditions. HU is considered an essential medicine because of its cytoreduction functions. HU is an antimetabolite that inhibits ribonucleotide reductase, which causes a depletion of the deoxyribonucleotide pool and dramatically reduces cell proliferation. The proliferation arrest, depending on drug concentration and exposure, may promote a cellular senescence phenotype associated with cancer cell therapy resistance and inflammation, influencing neighboring cell functions, immunosuppression, and potential cancer relapse. HU can induce cellular senescence in both healthy and transformed cells in vitro, in part, because of increased reactive oxygen species (ROS). Here, we analyze the main molecular mechanisms involved in cytotoxic/genotoxic HU function, the potential to increase intracellular ROS levels, and the principal features of cellular senescence induction. Understanding the mechanisms involved in HU's ability to induce cellular senescence may help to improve current chemotherapy strategies and control undesirable treatment effects in cancer patients and other diseases.
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11
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SAMHD1 … and Viral Ways around It. Viruses 2021; 13:v13030395. [PMID: 33801276 PMCID: PMC7999308 DOI: 10.3390/v13030395] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 12/19/2022] Open
Abstract
The SAM and HD domain-containing protein 1 (SAMHD1) is a dNTP triphosphohydrolase that plays a crucial role for a variety of different cellular functions. Besides balancing intracellular dNTP concentrations, facilitating DNA damage repair, and dampening excessive immune responses, SAMHD1 has been shown to act as a major restriction factor against various virus species. In addition to its well-described activity against retroviruses such as HIV-1, SAMHD1 has been identified to reduce the infectivity of different DNA viruses such as the herpesviruses CMV and EBV, the poxvirus VACV, or the hepadnavirus HBV. While some viruses are efficiently restricted by SAMHD1, others have developed evasion mechanisms that antagonize the antiviral activity of SAMHD1. Within this review, we summarize the different cellular functions of SAMHD1 and highlight the countermeasures viruses have evolved to neutralize the restriction factor SAMHD1.
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12
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Komoto K, Nomoto T, El Muttaqien S, Takemoto H, Matsui M, Miura Y, Nishiyama N. Iron chelation cancer therapy using hydrophilic block copolymers conjugated with deferoxamine. Cancer Sci 2020; 112:410-421. [PMID: 32770631 PMCID: PMC7780030 DOI: 10.1111/cas.14607] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/14/2020] [Accepted: 08/02/2020] [Indexed: 01/20/2023] Open
Abstract
Cancer cells have high iron requirements due to their rapid growth and proliferation. Iron depletion using iron chelators has a potential in cancer treatment. Previous studies have demonstrated that deferoxamine (DFO) specifically chelates Fe(III) and exhibited antitumor activity in clinical studies. However, its poor pharmacokinetics has limited the therapeutic potential and practical application. Although polymeric iron chelators have been developed to increase the blood retention, none of previous studies has demonstrated their potential in iron chelation cancer therapy. Here, we developed polymeric DFO by the covalent conjugation of DFO to poly(ethylene glycol)‐poly(aspartic acid) (PEG‐PAsp) block copolymers. The polymeric DFO exhibited iron‐chelating ability comparable with free DFO, thereby arresting cell cycle and inducing apoptosis and antiproliferative activity. After intravenous administration, the polymeric DFO showed marked increase in blood retention and tumor accumulation in subcutaneous tumor models. Consequently, polymeric DFO showed significant suppression of the tumor growth compared with free DFO. This study reveals the first success of the design of polymeric DFO for enhancing iron chelation cancer therapy.
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Affiliation(s)
- Kana Komoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Takahiro Nomoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Sjaikhurrizal El Muttaqien
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan.,Center for Pharmaceutical and Medical Technology, Agency for the Assessment and Application of Technology (BPPT), LAPTIAB I, PUSPIPTEK, Serpong, Indonesia
| | - Hiroyasu Takemoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Makoto Matsui
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Yutaka Miura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Nobuhiro Nishiyama
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan.,Innovation Center of Nanomedicine (iCONM), Kawasaki Institute of Industrial Promotion, Kawasaki, Japan
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13
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Wang L, Sun R, Eriksson S. Basic biochemical characterization of cytosolic enzymes in thymidine nucleotide synthesis in adult rat tissues: implications for tissue specific mitochondrial DNA depletion and deoxynucleoside-based therapy for TK2-deficiency. BMC Mol Cell Biol 2020; 21:33. [PMID: 32345222 PMCID: PMC7189545 DOI: 10.1186/s12860-020-00272-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Deficiency in thymidine kinase 2 (TK2) or p53 inducible ribonucleotide reductase small subunit (p53R2) is associated with tissue specific mitochondrial DNA (mtDNA) depletion. To understand the mechanisms of the tissue specific mtDNA depletion we systematically studied key enzymes in dTMP synthesis in mitochondrial and cytosolic extracts prepared from adult rat tissues. RESULTS In addition to mitochondrial TK2 a cytosolic isoform of TK2 was characterized, which showed similar substrate specificity to the mitochondrial TK2. Total TK activity was highest in spleen and lowest in skeletal muscle. Thymidylate synthase (TS) was detected in cytosols and its activity was high in spleen but low in other tissues. TS protein levels were high in heart, brain and skeletal muscle, which deviated from TS activity levels. The p53R2 proteins were at similar levels in all tissues except liver where it was ~ 6-fold lower. Our results strongly indicate that mitochondria in most tissues are capable of producing enough dTTP for mtDNA replication via mitochondrial TK2, but skeletal muscle mitochondria do not and are most likely dependent on both the salvage and de novo synthesis pathways. CONCLUSION These results provide important information concerning mechanisms for the tissue dependent variation of dTTP synthesis and explained why deficiency in TK2 or p53R2 leads to skeletal muscle dysfunctions. Furthermore, the presence of a putative cytosolic TK2-like enzyme may provide basic knowledge for the understanding of deoxynucleoside-based therapy for mitochondrial disorders.
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Affiliation(s)
- Liya Wang
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, SE-750 07, Uppsala, Sweden.
| | - Ren Sun
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, SE-750 07, Uppsala, Sweden
| | - Staffan Eriksson
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, SE-750 07, Uppsala, Sweden
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14
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Ding Y, Zhong T, Wang M, Xiang X, Ren G, Jia Z, Lin Q, Liu Q, Dong J, Li L, Li X, Jiang H, Zhu L, Li H, Shen D, Teng L, Li C, Shao J. Integrative Analysis Reveals Across-Cancer Expression Patterns and Clinical Relevance of Ribonucleotide Reductase in Human Cancers. Front Oncol 2019; 9:956. [PMID: 31637211 PMCID: PMC6788385 DOI: 10.3389/fonc.2019.00956] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 09/10/2019] [Indexed: 12/15/2022] Open
Abstract
Mining cancer-omics databases deepens our understanding of cancer biology and can lead to potential breakthroughs in cancer treatment. Here, we propose an integrative analytical approach to reveal across-cancer expression patterns and identify potential clinical impacts for genes of interest from five representative public databases. Using ribonucleotide reductase (RR), a key enzyme in DNA synthesis and cancer-therapeutic targeting, as an example, we characterized the mRNA expression profiles and inter-component associations of three RR subunit genes and assess their differing pathological and prognostic significance across over 30-types of cancers and their related subtypes. Findings were validated by immunohistochemistry with clinical tissue samples (n = 211) collected from multiple cancer centers in China and with clinical follow-up. Underlying mechanisms were further explored and discussed using co-expression gene network analyses. This framework represents a simple, efficient, accurate, and comprehensive approach for cancer-omics resource analysis and underlines the necessity to separate the tumors by their histological or pathological subtypes during the clinical evaluation of molecular biomarkers.
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Affiliation(s)
- Yongfeng Ding
- Department of Pathology & Pathophysiology, and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Disease Proteomics of Zhejiang Province, Key Laboratory of Cancer Prevention and Intervention of China National Ministry of Education, Research Center for Air Pollution and Health, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province, Department of Medical Oncology, Department of Pathology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Tingting Zhong
- Department of Pathology & Pathophysiology, and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Disease Proteomics of Zhejiang Province, Key Laboratory of Cancer Prevention and Intervention of China National Ministry of Education, Research Center for Air Pollution and Health, Zhejiang University School of Medicine, Hangzhou, China.,Department of Pathology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Min Wang
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
| | - Xueping Xiang
- Department of Pathology & Pathophysiology, and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Disease Proteomics of Zhejiang Province, Key Laboratory of Cancer Prevention and Intervention of China National Ministry of Education, Research Center for Air Pollution and Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Guoping Ren
- Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province, Department of Medical Oncology, Department of Pathology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhongjuan Jia
- Department of Pathology & Pathophysiology, and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qinghui Lin
- Department of Pathology & Pathophysiology, and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qian Liu
- Department of Pathology & Pathophysiology, and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jingwen Dong
- Department of Pathology & Pathophysiology, and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Linrong Li
- Department of Pathology & Pathophysiology, and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiawei Li
- Department of Pathology & Pathophysiology, and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Haiping Jiang
- Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province, Department of Medical Oncology, Department of Pathology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Lijun Zhu
- Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province, Department of Medical Oncology, Department of Pathology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Haoran Li
- Discovery Biochemistry, Kymera Therapeutics, Cambridge, MA, United States
| | - Dejun Shen
- Southern California Permanente Medical Group, Department of Pathology, Downey Medical Center, Downey, CA, United States
| | - Lisong Teng
- Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province, Department of Medical Oncology, Department of Pathology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Chen Li
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
| | - Jimin Shao
- Department of Pathology & Pathophysiology, and Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Disease Proteomics of Zhejiang Province, Key Laboratory of Cancer Prevention and Intervention of China National Ministry of Education, Research Center for Air Pollution and Health, Zhejiang University School of Medicine, Hangzhou, China
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15
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Long MJC, Liu X, Aye Y. Chemical Biology Gateways to Mapping Location, Association, and Pathway Responsivity. Front Chem 2019; 7:125. [PMID: 30949469 PMCID: PMC6437114 DOI: 10.3389/fchem.2019.00125] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 02/18/2019] [Indexed: 12/14/2022] Open
Abstract
Here we discuss, how by applying chemical concepts to biological problems, methods have been developed to map spatiotemporal regulation of proteins and small-molecule modulation of proteome signaling responses. We outline why chemical-biology platforms are ideal for such purposes. We further discuss strengths and weaknesses of chemical-biology protocols, contrasting them against classical genetic and biochemical approaches. We make these evaluations based on three parameters: occupancy; functional information; and spatial restriction. We demonstrate how the specific choice of chemical reagent and experimental set-up unite to resolve biological problems. Potential improvements/extensions as well as specific controls that in our opinion are often overlooked or employed incorrectly are also considered. Finally, we discuss some of the latest emerging methods to illuminate how chemical-biology innovations provide a gateway toward information hitherto inaccessible by conventional genetic/biochemical means. Finally, we also caution against solely relying on chemical-biology strategies and urge the field to undertake orthogonal validations to ensure robustness of results.
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Affiliation(s)
| | - Xuyu Liu
- École Polytechnique Fédérale de Lausanne, Institute of Chemical Sciences and Engineering, Lausanne, Switzerland
| | - Yimon Aye
- École Polytechnique Fédérale de Lausanne, Institute of Chemical Sciences and Engineering, Lausanne, Switzerland
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16
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Lan X, Field MS, Stover PJ. Cell cycle regulation of folate-mediated one-carbon metabolism. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2018; 10:e1426. [DOI: 10.1002/wsbm.1426] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 04/26/2018] [Accepted: 04/27/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Xu Lan
- Division of Nutritional Sciences; Cornell University; Ithaca New York
| | - Martha S. Field
- Division of Nutritional Sciences; Cornell University; Ithaca New York
| | - Patrick J. Stover
- Division of Nutritional Sciences; Cornell University; Ithaca New York
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17
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Lambrecht MJ, Kelly JW, Shenvi RA. Mechanism of Action of the Cytotoxic Asmarine Alkaloids. ACS Chem Biol 2018; 13:1299-1306. [PMID: 29653046 DOI: 10.1021/acschembio.8b00096] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The asmarines are a family of cytotoxic natural products whose mechanism of action is unknown. Here, we used chemical synthesis to reverse engineer the asmarines and understand the functions of their individual components. We found that the potent asmarine analog "delmarine" arrested the mammalian cell cycle in the G1 phase and that both cell cycle arrest and cytotoxicity were rescued by cotreatment with ferric and ferrous salts. Cellular iron deprivation was clearly indicated by changes in iron-responsive protein markers, and cytotoxicity occurred independently of radical oxygen species (ROS) production. Chemical synthesis allowed for annotation of the distinct structural motifs required for these effects, especially the unusual diazepine, which we found enforced an iron-binding tautomer without distortion of the NCNO dihedral angle out of plane. With this information and a correlation of cytotoxicity with logP, we could replace the diazepine by lipophilic group appendage to N9, which avoided steric clash with the N6-alkyl required to access the aminopyridine. This study transformed the asmarines, scarce marine metabolites, into easily synthesized, modular chemotypes that may complement or succeed iron-selective binders in clinical trials and use.
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Affiliation(s)
- Michael J. Lambrecht
- Department of Chemistry and Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Jeffery W. Kelly
- Department of Chemistry and Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Ryan A. Shenvi
- Department of Chemistry and Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, United States
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18
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Kunos CA, Ivy SP. Triapine Radiochemotherapy in Advanced Stage Cervical Cancer. Front Oncol 2018; 8:149. [PMID: 29868473 PMCID: PMC5949312 DOI: 10.3389/fonc.2018.00149] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/23/2018] [Indexed: 12/23/2022] Open
Abstract
Clinical ribonucleotide reductase (RNR) inhibitors have reinvigorated enthusiasm for radiochemotherapy treatment of patients with regionally advanced stage cervical cancers. About two-thirds of patients outlive their cervical cancer (1), even though up to half of their tumors retain residual microscopic disease (2). The National Cancer Institute Cancer Therapy Evaluation Program conducted two prospective trials of triapine–cisplatin–radiation to improve upon this finding by precisely targeting cervical cancer’s overactive RNR. Triapine’s potent inactivation of RNR arrests cells at the G1/S cell cycle restriction checkpoint and enhances cisplatin–radiation cytotoxicity. In this article, we provide perspective on challenges encountered in and future potential of clinical development of a triapine–cisplatin–radiation combination for patients with regionally advanced cervical cancer. New trial results and review presented here suggest that a triapine–cisplatin–radiation combination may offer molecular cell cycle target control to maximize damage in cancers and to minimize injury to normal cells. A randomized trial now accrues patients with regionally advanced stage cervical cancer to evaluate triapine’s contribution to clinical benefit after cisplatin–radiation (clinicaltrials.gov, NCT02466971).
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Affiliation(s)
- Charles A Kunos
- Cancer Therapy Evaluation Program, National Cancer Institute, Bethesda, MD, United States
| | - S Percy Ivy
- Cancer Therapy Evaluation Program, National Cancer Institute, Bethesda, MD, United States
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19
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Buj R, Aird KM. Deoxyribonucleotide Triphosphate Metabolism in Cancer and Metabolic Disease. Front Endocrinol (Lausanne) 2018; 9:177. [PMID: 29720963 PMCID: PMC5915462 DOI: 10.3389/fendo.2018.00177] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 04/03/2018] [Indexed: 12/22/2022] Open
Abstract
The maintenance of a healthy deoxyribonucleotide triphosphate (dNTP) pool is critical for the proper replication and repair of both nuclear and mitochondrial DNA. Temporal, spatial, and ratio imbalances of the four dNTPs have been shown to have a mutagenic and cytotoxic effect. It is, therefore, essential for cell homeostasis to maintain the balance between the processes of dNTP biosynthesis and degradation. Multiple oncogenic signaling pathways, such as c-Myc, p53, and mTORC1 feed into dNTP metabolism, and there is a clear role for dNTP imbalances in cancer initiation and progression. Additionally, multiple chemotherapeutics target these pathways to inhibit nucleotide synthesis. Less is understood about the role for dNTP levels in metabolic disorders and syndromes and whether alterations in dNTP levels change cancer incidence in these patients. For instance, while deficiencies in some metabolic pathways known to play a role in nucleotide synthesis are pro-tumorigenic (e.g., p53 mutations), others confer an advantage against the onset of cancer (G6PD). More recent evidence indicates that there are changes in nucleotide metabolism in diabetes, obesity, and insulin resistance; however, whether these changes play a mechanistic role is unclear. In this review, we will address the complex network of metabolic pathways, whereby cells can fuel dNTP biosynthesis and catabolism in cancer, and we will discuss the potential role for this pathway in metabolic disease.
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Affiliation(s)
| | - Katherine M. Aird
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, United States
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20
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Chitambar CR, Al-Gizawiy MM, Alhajala HS, Pechman KR, Wereley JP, Wujek R, Clark PA, Kuo JS, Antholine WE, Schmainda KM. Gallium Maltolate Disrupts Tumor Iron Metabolism and Retards the Growth of Glioblastoma by Inhibiting Mitochondrial Function and Ribonucleotide Reductase. Mol Cancer Ther 2018; 17:1240-1250. [PMID: 29592883 DOI: 10.1158/1535-7163.mct-17-1009] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 02/15/2018] [Accepted: 03/23/2018] [Indexed: 11/16/2022]
Abstract
Gallium, a metal with antineoplastic activity, binds transferrin (Tf) and enters tumor cells via Tf receptor1 (TfR1); it disrupts iron homeostasis leading to cell death. We hypothesized that TfR1 on brain microvascular endothelial cells (BMEC) would facilitate Tf-Ga transport into the brain enabling it to target TfR-bearing glioblastoma. We show that U-87 MG and D54 glioblastoma cell lines and multiple glioblastoma stem cell (GSC) lines express TfRs, and that their growth is inhibited by gallium maltolate (GaM) in vitro After 24 hours of incubation with GaM, cells displayed a loss of mitochondrial reserve capacity followed by a dose-dependent decrease in oxygen consumption and a decrease in the activity of the iron-dependent M2 subunit of ribonucleotide reductase (RRM2). IHC staining of rat and human tumor-bearing brains showed that glioblastoma, but not normal glial cells, expressed TfR1 and RRM2, and that glioblastoma expressed greater levels of H- and L-ferritin than normal brain. In an orthotopic U-87 MG glioblastoma xenograft rat model, GaM retarded the growth of brain tumors relative to untreated control (P = 0.0159) and reduced tumor mitotic figures (P = 0.045). Tumors in GaM-treated animals displayed an upregulation of TfR1 expression relative to control animals, thus indicating that gallium produced tumor iron deprivation. GaM also inhibited iron uptake and upregulated TfR1 expression in U-87 MG and D54 cells in vitro We conclude that GaM enters the brain via TfR1 on BMECs and targets iron metabolism in glioblastoma in vivo, thus inhibiting tumor growth. Further development of novel gallium compounds for brain tumor treatment is warranted. Mol Cancer Ther; 17(6); 1240-50. ©2018 AACR.
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Affiliation(s)
| | - Mona M Al-Gizawiy
- Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Hisham S Alhajala
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Kimberly R Pechman
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Janine P Wereley
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Robert Wujek
- Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Paul A Clark
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - John S Kuo
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - William E Antholine
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Kathleen M Schmainda
- Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin
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21
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Potts KG, Irwin CR, Favis NA, Pink DB, Vincent KM, Lewis JD, Moore RB, Hitt MM, Evans DH. Deletion of F4L (ribonucleotide reductase) in vaccinia virus produces a selective oncolytic virus and promotes anti-tumor immunity with superior safety in bladder cancer models. EMBO Mol Med 2017; 9:638-654. [PMID: 28289079 PMCID: PMC5412795 DOI: 10.15252/emmm.201607296] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Bladder cancer has a recurrence rate of up to 80% and many patients require multiple treatments that often fail, eventually leading to disease progression. In particular, standard of care for high-grade disease, Bacillus Calmette-Guérin (BCG), fails in 30% of patients. We have generated a novel oncolytic vaccinia virus (VACV) by mutating the F4L gene that encodes the virus homolog of the cell-cycle-regulated small subunit of ribonucleotide reductase (RRM2). The F4L-deleted VACVs are highly attenuated in normal tissues, and since cancer cells commonly express elevated RRM2 levels, have tumor-selective replication and cell killing. These F4L-deleted VACVs replicated selectively in immune-competent rat AY-27 and xenografted human RT112-luc orthotopic bladder cancer models, causing significant tumor regression or complete ablation with no toxicity. It was also observed that rats cured of AY-27 tumors by VACV treatment developed anti-tumor immunity as evidenced by tumor rejection upon challenge and by ex vivo cytotoxic T-lymphocyte assays. Finally, F4L-deleted VACVs replicated in primary human bladder cancer explants. Our findings demonstrate the enhanced safety and selectivity of F4L-deleted VACVs, with application as a promising therapy for patients with BCG-refractory cancers and immune dysregulation.
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Affiliation(s)
- Kyle G Potts
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Li Ka Shing Institute of Virology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Cancer Research Institute of Northern Alberta (CRINA), Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Chad R Irwin
- Li Ka Shing Institute of Virology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Cancer Research Institute of Northern Alberta (CRINA), Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Department of Medical Microbiology & Immunology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Nicole A Favis
- Li Ka Shing Institute of Virology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Cancer Research Institute of Northern Alberta (CRINA), Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Department of Medical Microbiology & Immunology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Desmond B Pink
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Cancer Research Institute of Northern Alberta (CRINA), Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Krista M Vincent
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Cancer Research Institute of Northern Alberta (CRINA), Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Department of Anatomy & Cell Biology, Faculty of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
| | - John D Lewis
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Cancer Research Institute of Northern Alberta (CRINA), Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Ronald B Moore
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Cancer Research Institute of Northern Alberta (CRINA), Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Mary M Hitt
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Li Ka Shing Institute of Virology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Cancer Research Institute of Northern Alberta (CRINA), Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - David H Evans
- Li Ka Shing Institute of Virology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada .,Cancer Research Institute of Northern Alberta (CRINA), Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Department of Medical Microbiology & Immunology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
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22
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Łupicka-Słowik A, Psurski M, Grzywa R, Bobrek K, Smok P, Walczak M, Gaweł A, Stefaniak T, Oleksyszyn J, Sieńczyk M. Development of Adenosine Deaminase-Specific IgY Antibodies: Diagnostic and Inhibitory Application. Appl Biochem Biotechnol 2017; 184:1358-1374. [PMID: 29043661 PMCID: PMC5889419 DOI: 10.1007/s12010-017-2626-x] [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] [Received: 06/19/2017] [Accepted: 10/02/2017] [Indexed: 12/19/2022]
Abstract
Adenosine deaminase (ADA) is currently used as a diagnostic marker for tuberculous pleuritis. Although ADA has been suggested as a potential marker for several types of cancer, the importance of each of ADA isoforms as well as their levels and enzymatic activities in tumors need to be further investigated. Herein we developed avian immunoglobulin Y highly specific to human ADA via hens immunization with calf adenosine deaminase. The obtained antibodies were used for the development of a sensitive double-egg yolk immunoglobulin (IgY) sandwich ELISA assay with an ADA detection limit of 0.5 ng/ml and a linearity range of up to 10 ng/ml. Specific, affinity-purified IgYs were able to recognize human recombinant ADA and ADA present in human cancer cell lines. In addition, antigen-specific IgY antibodies were able to inhibit catalytic activity of calf ADA with an IC50 value of 47.48 nM. We showed that generated IgY antibodies may be useful for ADA detection, thus acting as a diagnostic agent in immunoenzymatic assays.
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Affiliation(s)
- Agnieszka Łupicka-Słowik
- Faculty of Chemistry, Division of Medicinal Chemistry and Microbiology, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland
| | - Mateusz Psurski
- Laboratory of Experimental Anticancer Therapy, Department of Experimental Oncology, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, 53-114, Wrocław, Poland
| | - Renata Grzywa
- Faculty of Chemistry, Division of Medicinal Chemistry and Microbiology, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland
| | - Kamila Bobrek
- Faculty of Veterinary Medicine, Department of Epizootiology and Clinic of Bird and Exotic Animals, Wroclaw University of Environmental and Life Sciences, Pl. Grunwaldzki 45, 50-366, Wrocław, Poland
| | - Patrycja Smok
- Faculty of Chemistry, Division of Medicinal Chemistry and Microbiology, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland
| | - Maciej Walczak
- Faculty of Chemistry, Division of Medicinal Chemistry and Microbiology, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland
| | - Andrzej Gaweł
- Faculty of Veterinary Medicine, Department of Epizootiology and Clinic of Bird and Exotic Animals, Wroclaw University of Environmental and Life Sciences, Pl. Grunwaldzki 45, 50-366, Wrocław, Poland
| | - Tadeusz Stefaniak
- Faculty of Veterinary Medicine, Department of Immunology, Pathophysiology and Veterinary Preventive Medicine, Wroclaw University of Environmental and Life Sciences, Norwida 31, 50-375, Wrocław, Poland
| | - Józef Oleksyszyn
- Faculty of Chemistry, Division of Medicinal Chemistry and Microbiology, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland
| | - Marcin Sieńczyk
- Faculty of Chemistry, Division of Medicinal Chemistry and Microbiology, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
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23
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Łomzik M, Mazuryk O, Rutkowska-Zbik D, Stochel G, Gros PC, Brindell M. New ruthenium compounds bearing semicarbazone 2-formylopyridine moiety: Playing with auxiliary ligands for tuning the mechanism of biological activity. J Inorg Biochem 2017; 175:80-91. [PMID: 28738277 DOI: 10.1016/j.jinorgbio.2017.07.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/04/2017] [Accepted: 07/09/2017] [Indexed: 01/18/2023]
Abstract
Two ruthenium(II) complexes Ru1 and Ru2 bearing as a one ligand 2,2'-bipyridine substituted by a semicarbazone 2-formylopyridine moiety (bpySC: 5-(4-{4'-methyl-[2,2'-bipyridine]-4-yl}but-1-yn-1-yl)pyridine-2-carbaldehyde semicarbazone) and as the others 2,2'-bipyridine (bpy) and 4,7-diphenyl-1,10-phenanthroline (dip), respectively, as auxiliary ligands have been prepared. Their biological activity has been studied on murine colon carcinoma (CT26) and human lung adenocarcinoma (A549) cell lines. The anti-proliferative activity was dependent on the presence of bpy or dip in the complex, with one order of magnitude higher cytotoxicity for Ru2 (dip ligands). Ru1 (bpy ligands) exhibited a distinct increase in cytotoxicity going from 24 to 72h of incubation with cells as was not observed for Ru2. Even though both studied compounds were powerful apoptosis inducing agents, the mechanism of their action was entirely different. Ru1-incubated A549 cells showed a notable increase in cells number in the S-phase of the cell cycle, with concomitant decrease in the G2/M phase, while Ru2 promoted a cell accumulation in the G0/G1 phase. In contrast, Ru1 induced marginal oxidative stress in A549 cell lines even upon increasing the incubation time. Even though Ru1 preferably accumulated in lysosomes it triggered the apoptotic cellular death via an intrinsic mitochondrial pathway. Ru1-incubated A549 cells showed swelling and enlarging of the mitochondria. It was not observed in case of Ru2 for which mitochondria and endoplasmic reticulum were found as primarily localization site. Despite this the apoptosis induced by Ru2 was caspase-independent. All these findings point to a pronounced role of auxiliary ligands in tuning the mode of biological activity.
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Affiliation(s)
- Michał Łomzik
- Department of Inorganic Chemistry, Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow, Poland; Université de Lorraine, CNRS, UMR SRSMC, HecRIn, Boulevard des Aiguillettes, Vandoeuvre-Lès-Nancy, France
| | - Olga Mazuryk
- Department of Inorganic Chemistry, Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow, Poland
| | - Dorota Rutkowska-Zbik
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Krakow, Poland
| | - Grażyna Stochel
- Department of Inorganic Chemistry, Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow, Poland
| | - Philippe C Gros
- Université de Lorraine, CNRS, UMR SRSMC, HecRIn, Boulevard des Aiguillettes, Vandoeuvre-Lès-Nancy, France.
| | - Małgorzata Brindell
- Department of Inorganic Chemistry, Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow, Poland.
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Abstract
In infected cells rotavirus (RV) replicates in viroplasms, cytosolic structures that require a stabilized microtubule (MT) network for their assembly, maintenance of the structure and perinuclear localization. Therefore, we hypothesized that RV could interfere with the MT-breakdown that takes place in mitosis during cell division. Using synchronized RV-permissive cells, we show that RV infection arrests the cell cycle in S/G2 phase, thus favoring replication by improving viroplasms formation, viral protein translation, and viral assembly. The arrest in S/G2 phase is independent of the host or viral strain and relies on active RV replication. RV infection causes cyclin B1 down-regulation, consistent with blocking entry into mitosis. With the aid of chemical inhibitors, the cytoskeleton network was linked to specific signaling pathways of the RV-induced cell cycle arrest. We found that upon RV infection Eg5 kinesin was delocalized from the pericentriolar region to the viroplasms. We used a MA104-Fucci system to identify three RV proteins (NSP3, NSP5, and VP2) involved in cell cycle arrest in the S-phase. Our data indicate that there is a strong correlation between the cell cycle arrest and RV replication.
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The Cell Killing Mechanisms of Hydroxyurea. Genes (Basel) 2016; 7:genes7110099. [PMID: 27869662 PMCID: PMC5126785 DOI: 10.3390/genes7110099] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/03/2016] [Accepted: 11/09/2016] [Indexed: 11/23/2022] Open
Abstract
Hydroxyurea is a well-established inhibitor of ribonucleotide reductase that has a long history of scientific interest and clinical use for the treatment of neoplastic and non-neoplastic diseases. It is currently the staple drug for the management of sickle cell anemia and chronic myeloproliferative disorders. Due to its reversible inhibitory effect on DNA replication in various organisms, hydroxyurea is also commonly used in laboratories for cell cycle synchronization or generating replication stress. However, incubation with high concentrations or prolonged treatment with low doses of hydroxyurea can result in cell death and the DNA damage generated at arrested replication forks is generally believed to be the direct cause. Recent studies in multiple model organisms have shown that oxidative stress and several other mechanisms may contribute to the majority of the cytotoxic effect of hydroxyurea. This review aims to summarize the progress in our understanding of the cell-killing mechanisms of hydroxyurea, which may provide new insights towards the improvement of chemotherapies that employ this agent.
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Anacker DC, Aloor HL, Shepard CN, Lenzi GM, Johnson BA, Kim B, Moody CA. HPV31 utilizes the ATR-Chk1 pathway to maintain elevated RRM2 levels and a replication-competent environment in differentiating Keratinocytes. Virology 2016; 499:383-396. [PMID: 27764728 DOI: 10.1016/j.virol.2016.09.028] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 09/26/2016] [Accepted: 09/27/2016] [Indexed: 01/19/2023]
Abstract
Productive replication of human papillomaviruses (HPV) is restricted to the uppermost layers of the differentiating epithelia. How HPV ensures an adequate supply of cellular substrates for viral DNA synthesis in a differentiating environment is unclear. Here, we demonstrate that HPV31 positive cells exhibit increased dNTP pools and levels of RRM2, a component of the ribonucleotide reductase (RNR) complex, which is required for de novo synthesis of dNTPs. RRM2 depletion blocks productive replication, suggesting RRM2 provides dNTPs for viral DNA synthesis in differentiating cells. We demonstrate that HPV31 regulates RRM2 levels through expression of E7 and activation of the ATR-Chk1-E2F1 DNA damage response, which is essential to combat replication stress upon entry into S-phase, as well as for productive replication. Our findings suggest a novel way in which viral DNA synthesis is regulated through activation of ATR and Chk1 and highlight an intriguing new virus/host interaction utilized for viral replication.
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Affiliation(s)
- Daniel C Anacker
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Heather L Aloor
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Caitlin N Shepard
- The Center for Drug Discovery, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Gina M Lenzi
- The Center for Drug Discovery, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Bryan A Johnson
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Baek Kim
- The Center for Drug Discovery, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA; Children's Healthcare of Atlanta, USA
| | - Cary A Moody
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, North Carolina, USA; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, North Carolina, USA.
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Gallium and its competing roles with iron in biological systems. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2044-53. [DOI: 10.1016/j.bbamcr.2016.04.027] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 04/27/2016] [Accepted: 04/30/2016] [Indexed: 12/12/2022]
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Crona M, Codó P, Jonna VR, Hofer A, Fernandes AP, Tholander F. A ribonucleotide reductase inhibitor with deoxyribonucleoside-reversible cytotoxicity. Mol Oncol 2016; 10:1375-1386. [PMID: 27511871 DOI: 10.1016/j.molonc.2016.07.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 07/18/2016] [Accepted: 07/19/2016] [Indexed: 11/25/2022] Open
Abstract
Ribonucleotide Reductase (RNR) is the sole enzyme that catalyzes the reduction of ribonucleotides into deoxyribonucleotides. Even though RNR is a recognized target for antiproliferative molecules, and the main target of the approved drug hydroxyurea, few new leads targeted to this enzyme have been developed. We have evaluated a recently identified set of RNR inhibitors with respect to inhibition of the human enzyme and cellular toxicity. One compound, NSC73735, is particularly interesting; it is specific for leukemia cells and is the first identified compound that hinders oligomerization of the mammalian large RNR subunit. Similar to hydroxyurea, it caused a disruption of the cell cycle distribution of cultured HL-60 cells. In contrast to hydroxyurea, the disruption was reversible, indicating higher specificity. NSC73735 thus defines a potential lead candidate for RNR-targeted anticancer drugs, as well as a chemical probe with better selectivity for RNR inhibition than hydroxyurea.
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Affiliation(s)
- Mikael Crona
- Department of Medicinal Biochemistry and Biophysics, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Paula Codó
- Department of Medicinal Biochemistry and Biophysics, Karolinska Institutet, 171 77, Stockholm, Sweden
| | | | - Anders Hofer
- Department of Medical Biochemistry and Biophysics, Umeå University, 90187, Umeå, Sweden
| | - Aristi P Fernandes
- Department of Medicinal Biochemistry and Biophysics, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Fredrik Tholander
- Department of Medicinal Biochemistry and Biophysics, Karolinska Institutet, 171 77, Stockholm, Sweden.
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Kuo ML, Lee MBE, Tang M, den Besten W, Hu S, Sweredoski MJ, Hess S, Chou CM, Changou CA, Su M, Jia W, Su L, Yen Y. PYCR1 and PYCR2 Interact and Collaborate with RRM2B to Protect Cells from Overt Oxidative Stress. Sci Rep 2016; 6:18846. [PMID: 26733354 PMCID: PMC4702135 DOI: 10.1038/srep18846] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 11/26/2015] [Indexed: 12/20/2022] Open
Abstract
Ribonucleotide reductase small subunit B (RRM2B) is a stress response protein that protects normal human fibroblasts from oxidative stress. However, the underlying mechanism that governs this function is not entirely understood. To identify factors that interact with RRM2B and mediate anti-oxidation function, large-scale purification of human Flag-tagged RRM2B complexes was performed. Pyrroline-5-carboxylate reductase 1 and 2 (PYCR1, PYCR2) were identified by mass spectrometry analysis as components of RRM2B complexes. Silencing of both PYCR1 and PYCR2 by expressing short hairpin RNAs induced defects in cell proliferation, partial fragmentation of the mitochondrial network, and hypersensitivity to oxidative stress in hTERT-immortalized human foreskin fibroblasts (HFF-hTERT). Moderate overexpression of RRM2B, comparable to stress-induced level, protected cells from oxidative stress. Silencing of both PYCR1 and PYCR2 completely abolished anti-oxidation activity of RRM2B, demonstrating a functional collaboration of these metabolic enzymes in response to oxidative stress.
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Affiliation(s)
- Mei-Ling Kuo
- Department of Molecular Pharmacology, Beckman Research Institute at City of Hope, Duarte, CA 91010, USA
| | - Mabel Bin-Er Lee
- Department of Molecular Pharmacology, Beckman Research Institute at City of Hope, Duarte, CA 91010, USA
| | - Michelle Tang
- Department of Molecular Pharmacology, Beckman Research Institute at City of Hope, Duarte, CA 91010, USA
| | - Willem den Besten
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Shuya Hu
- Department of Molecular Pharmacology, Beckman Research Institute at City of Hope, Duarte, CA 91010, USA
| | - Michael J. Sweredoski
- Proteome Exploration Laboratory, Division of Biology and Biological Engineering, Beckman Institute, California Institute of Technology, Pasadena, CA, 91125
| | - Sonja Hess
- Proteome Exploration Laboratory, Division of Biology and Biological Engineering, Beckman Institute, California Institute of Technology, Pasadena, CA, 91125
| | - Chih-Ming Chou
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan 110
| | - Chun A. Changou
- Integrated Laboratory, Center of Translational Medicine, Taipei Medical University, Taipei, Taiwan 110
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan 110
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan 110
| | - Mingming Su
- University of Hawaii Cancer Center, HI 96813, USA
| | - Wei Jia
- University of Hawaii Cancer Center, HI 96813, USA
| | - Leila Su
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan 110
| | - Yun Yen
- Department of Molecular Pharmacology, Beckman Research Institute at City of Hope, Duarte, CA 91010, USA
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan 110
- Integrated Laboratory, Center of Translational Medicine, Taipei Medical University, Taipei, Taiwan 110
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan 110
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan 110
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Barnard D, Diaz HB, Burke T, Donoho G, Beckmann R, Jones B, Barda D, King C, Marshall M. LY2603618, a selective CHK1 inhibitor, enhances the anti-tumor effect of gemcitabine in xenograft tumor models. Invest New Drugs 2015; 34:49-60. [PMID: 26612134 DOI: 10.1007/s10637-015-0310-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 11/16/2015] [Indexed: 12/17/2022]
Abstract
Pharmacological inhibition of CHK1 in the absence of p53 functionality leads to abrogation of the S and G2/M DNA damage checkpoints. We report the preclinical therapeutic activity of LY2603618 (CHK1 inhibitor) at inhibiting CHK1 activation by gemcitabine and enhancing in vivo efficacy. The in vivo biochemical effects of CHK1 inhibition in the absence or presence of DNA damage were measured in human tumor xenograft models. Colon, lung and pancreatic xenografts models were treated with gemcitabine, LY2603618, or gemcitabine plus LY2603618. Gemcitabine treatment alone induced a significant increase in CHK1 autophosphorylation over untreated tumors. Co-administration of LY2603618 with gemcitabine showed a clear inhibition of CHK1 autophosphorylation for at least 24 h. Combining LY2603618 with gemcitabine resulted in an increase in H2AX serine 139 phosphorylation, indicating a corresponding increase in damaged DNA in the tumors. LY2603618 abrogated the S-phase DNA damage checkpoint in Calu-6 xenograft tumors treated with gemcitabine but did not significantly alter the G2/M checkpoint. Combining gemcitabine with LY2603618 resulted in a significant increase in tumor growth inhibition in Calu-6, HT-29 and PAXF 1869 xenografts over gemcitabine treatment alone. The best combination efficacy occurred when LY2603618 was given 24 h following dosing with gemcitabine. LY2603618 worked effectively to remove the S-phase DNA damage checkpoint and increase the DNA damage and the antitumor activity of gemcitabine treatment.
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Affiliation(s)
- Darlene Barnard
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - H Bruce Diaz
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Teresa Burke
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Gregory Donoho
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Richard Beckmann
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Bonita Jones
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - David Barda
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Constance King
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA
| | - Mark Marshall
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, 46285, USA.
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Xie M, Doetsch PW, Deng X. Bcl2 inhibition of mitochondrial DNA repair. BMC Cancer 2015; 15:586. [PMID: 26268226 PMCID: PMC4535531 DOI: 10.1186/s12885-015-1594-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 08/06/2015] [Indexed: 01/11/2023] Open
Abstract
Background Accumulation of mitochondrial DNA (mtDNA) damage could enhance the frequency of mitochondrial mutations and promote a variety of mitochondria-related diseases, including cancer. However, the mechanism(s) involved are not fully understood. Methods Quantitative extended length PCR was used to compare mtDNA and nDNA damage in human lung H1299 cells expressing WT Bcl2 or vector-only control. mtAPE1 endonuclease activity was analyzed by AP oligonucleotide assay. mtDNA mutation was measured by single molecule PCR. Subcellular localization of Bcl2 and APE1 was analyzed by subcellular fractionation. Results Bcl2, an anti-apoptotic molecule and oncoprotein, effectively inhibits the endonuclease activity of mitochondrial APE1 (mtAPE1), leading to significant retardation of mtDNA repair and enhanced frequency of mtDNA mutations following exposure of cells to hydrogen peroxide (H2O2) or nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK, a carcinogen in cigarette smoke). Inversely, depletion of endogenous Bcl2 by RNA interference increases mtAPE1 endonuclease activity leading to accelerated mtDNA repair and decreased mtDNA mutation. Higher levels of mtAPE1 were observed in human lung cancer cells than in normal human bronchial epithelial cells (i.e. BEAS-2B). Bcl2 partially co-localizes with APE1 in the mitochondria of human lung cancer cells. Bcl2 directly interacts with mtAPE1 via its BH domains. Removal of any of the BH domains from Bcl2 abolishes Bcl2’s capacity to interact with mtAPE1 as well as its inhibitory effects on mtAPE1 activity and mtDNA repair. Conclusions Based our findings, we propose that Bcl2 suppression of mtDNA repair occurs through direct interaction with mtAPE1 and inhibition of its endonuclease activity in mitochondria, which may contribute to enhanced mtDNA mutations and carcinogenesis. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1594-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Maohua Xie
- Division of Cancer Biology, Departments of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, GA, 30322, USA.
| | - Paul W Doetsch
- Division of Cancer Biology, Departments of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, GA, 30322, USA. .,Biochemistry, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, GA, 30322, USA.
| | - Xingming Deng
- Division of Cancer Biology, Departments of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute of Emory University, Atlanta, GA, 30322, USA.
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Lopez-Contreras AJ, Specks J, Barlow JH, Ambrogio C, Desler C, Vikingsson S, Rodrigo-Perez S, Green H, Rasmussen LJ, Murga M, Nussenzweig A, Fernandez-Capetillo O. Increased Rrm2 gene dosage reduces fragile site breakage and prolongs survival of ATR mutant mice. Genes Dev 2015; 29:690-5. [PMID: 25838540 PMCID: PMC4387711 DOI: 10.1101/gad.256958.114] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In S. cerevisiae, deletion of the checkpoint kinase Mec1 (ATR) is viable upon mutations that increase the activity of the ribonucleotide reductase (RNR) complex. Lopez-Contreras et al. show that cells from mice carrying extra alleles of the RNR regulatory subunit RRM2 present supraphysiological RNR activity and reduced chromosomal breakage at fragile sites. Increased Rrm2 gene dosage also extends the life span of ATR mutant mice. In Saccharomyces cerevisiae, absence of the checkpoint kinase Mec1 (ATR) is viable upon mutations that increase the activity of the ribonucleotide reductase (RNR) complex. Whether this pathway is conserved in mammals remains unknown. Here we show that cells from mice carrying extra alleles of the RNR regulatory subunit RRM2 (Rrm2TG) present supraphysiological RNR activity and reduced chromosomal breakage at fragile sites. Moreover, increased Rrm2 gene dosage significantly extends the life span of ATR mutant mice. Our study reveals the first genetic condition in mammals that reduces fragile site expression and alleviates the severity of a progeroid disease by increasing RNR activity.
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Affiliation(s)
| | - Julia Specks
- Genomic Instability Group, Spanish National Cancer Research Centre (CNIO), Madrid 28029, Spain
| | - Jacqueline H Barlow
- Laboratory of Genome Integrity, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Chiara Ambrogio
- Experimental Oncology Group, Spanish National Cancer Research Centre (CNIO), Madrid 28029, Spain
| | - Claus Desler
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Svante Vikingsson
- Division of Drug Research/Clinical Pharmacology, Department of Medical and Health Sciences, Linköping University, SE-581 85 Linköping, Sweden
| | - Sara Rodrigo-Perez
- Genomic Instability Group, Spanish National Cancer Research Centre (CNIO), Madrid 28029, Spain
| | - Henrik Green
- Division of Drug Research/Clinical Pharmacology, Department of Medical and Health Sciences, Linköping University, SE-581 85 Linköping, Sweden; Department of Forensic Genetics and Forensic Toxicology, National Board of Forensic Medicine, SE-581 85 Linköping, Sweden
| | - Lene Juel Rasmussen
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Matilde Murga
- Genomic Instability Group, Spanish National Cancer Research Centre (CNIO), Madrid 28029, Spain
| | - André Nussenzweig
- Laboratory of Genome Integrity, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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Mah V, Alavi M, Márquez-Garbán DC, Maresh EL, Kim SR, Horvath S, Bagryanova L, Huerta-Yepez S, Chia D, Pietras R, Goodglick L. Ribonucleotide reductase subunit M2 predicts survival in subgroups of patients with non-small cell lung carcinoma: effects of gender and smoking status. PLoS One 2015; 10:e0127600. [PMID: 26001082 PMCID: PMC4441434 DOI: 10.1371/journal.pone.0127600] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 04/16/2015] [Indexed: 12/25/2022] Open
Abstract
Background Ribonucleotide reductase catalyzes the conversion of ribonucleotide diphosphates to deoxyribonucleotide diphosphates. The functional enzyme consists of two subunits - one large (RRM1) and one small (RRM2 or RRM2b) subunit. Expression levels of each subunit have been implicated in prognostic outcomes in several different types of cancers. Experimental Design Immunohistochemistry for RRM1 and RRM2 was performed on a lung cancer tissue microarray (TMA) and analyzed. 326 patients from the microarray were included in this study. Results In non-small cell lung cancer (NSCLC), RRM2 expression was strongly predictive of disease-specific survival in women, non-smokers and former smokers who had quit at least 10 years prior to being diagnosed with lung cancer. Higher expression was associated with worse survival. This was not the case for men, current smokers and those who had stopped smoking for shorter periods of time. RRM1 was not predictive of survival outcomes in any subset of the patient group. Conclusion RRM2, but not RRM1, is a useful predictor of survival outcome in certain subsets of NSCLC patients.
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Affiliation(s)
- Vei Mah
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, 90095, United States of America
- * E-mail:
| | - Mohammad Alavi
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, 90095, United States of America
| | - Diana C. Márquez-Garbán
- Department of Medicine, Division of Hematology-Oncology, UCLA, Los Angeles, California, 90095, United States of America
- Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, United States of America
| | - Erin L. Maresh
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, 90095, United States of America
| | - Sara R. Kim
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, 90095, United States of America
| | - Steve Horvath
- Department of Biostatistics, UCLA, Los Angeles, California, 90095, United States of America
- Department of Human Genetics, UCLA, Los Angeles, California, 90095, United States of America
- Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, United States of America
| | - Lora Bagryanova
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, 90095, United States of America
| | - Sara Huerta-Yepez
- Unidad de Investigación en Enfermedades Oncológicas, Hospital Infantil de México, Federico Gómez, SSa, México
| | - David Chia
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, 90095, United States of America
- Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, United States of America
| | - Richard Pietras
- Department of Medicine, Division of Hematology-Oncology, UCLA, Los Angeles, California, 90095, United States of America
- Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, United States of America
| | - Lee Goodglick
- Department of Pathology and Laboratory Medicine, UCLA, Los Angeles, California, 90095, United States of America
- Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, Los Angeles, California, 90095, United States of America
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Siriwardana G, Seligman PA. Iron depletion results in Src kinase inhibition with associated cell cycle arrest in neuroblastoma cells. Physiol Rep 2015; 3:3/3/e12341. [PMID: 25825542 PMCID: PMC4393172 DOI: 10.14814/phy2.12341] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Iron is required for cellular proliferation. Recently, using systematic time studies of neuroblastoma cell growth, we better defined the G1 arrest caused by iron chelation to a point in mid-G1, where cyclin E protein is present, but the cyclin E/CDK2 complex kinase activity is inhibited. In this study, we again used the neuroblastoma SKNSH cells lines to pinpoint the mechanism responsible for this G1 block. Initial studies showed in the presence of DFO, these cells have high levels of p27 and after reversal of iron chelation p27 is degraded allowing for CDK2 kinase activity. The initial activation of CDK2 kinase allows cells to exit G1 and enter S phase. Furthermore, we found that inhibition of p27 degradation by DFO is directly associated with inhibition of Src kinase activity measured by lack of phosphorylation of Src at the 416 residue. Activation of Src kinase occurs very early after reversal from the DFO G1 block and is temporally associated with initiation of cellular proliferation associated with entry into S phase. For the first time therefore we show that iron chelation inhibits Src kinase activity and this activity is a requirement for cellular proliferation.
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Affiliation(s)
- Gamini Siriwardana
- Division of Hematology, University of Colorado School of Medicine, Aurora, Colorado
| | - Paul A Seligman
- Division of Hematology, University of Colorado School of Medicine, Aurora, Colorado
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Aye Y, Li M, Long MJC, Weiss RS. Ribonucleotide reductase and cancer: biological mechanisms and targeted therapies. Oncogene 2014; 34:2011-21. [PMID: 24909171 DOI: 10.1038/onc.2014.155] [Citation(s) in RCA: 276] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 04/25/2014] [Accepted: 04/26/2014] [Indexed: 12/16/2022]
Abstract
Accurate DNA replication and repair is essential for proper development, growth and tumor-free survival in all multicellular organisms. A key requirement for the maintenance of genomic integrity is the availability of adequate and balanced pools of deoxyribonucleoside triphosphates (dNTPs), the building blocks of DNA. Notably, dNTP pool alterations lead to genomic instability and have been linked to multiple human diseases, including mitochondrial disorders, susceptibility to viral infection and cancer. In this review, we discuss how a key regulator of dNTP biosynthesis in mammals, the enzyme ribonucleotide reductase (RNR), impacts cancer susceptibility and serves as a target for anti-cancer therapies. Because RNR-regulated dNTP production can influence DNA replication fidelity while also supporting genome-protecting DNA repair, RNR has complex and stage-specific roles in carcinogenesis. Nevertheless, cancer cells are dependent on RNR for de novo dNTP biosynthesis. Therefore, elevated RNR expression is a characteristic of many cancers, and an array of mechanistically distinct RNR inhibitors serve as effective agents for cancer treatment. The dNTP metabolism machinery, including RNR, has been exploited for therapeutic benefit for decades and remains an important target for cancer drug development.
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Affiliation(s)
- Y Aye
- 1] Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA [2] Department of Biochemistry, Weill Cornell Medical College, New York, NY, USA
| | - M Li
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, USA
| | - M J C Long
- Graduate Program in Biochemistry, Brandeis University, Waltham, MA, USA
| | - R S Weiss
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, USA
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Siriwardana G, Seligman PA. Two cell cycle blocks caused by iron chelation of neuroblastoma cells: separating cell cycle events associated with each block. Physiol Rep 2013; 1:e00176. [PMID: 24744856 PMCID: PMC3970748 DOI: 10.1002/phy2.176] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 11/04/2013] [Accepted: 11/06/2013] [Indexed: 12/14/2022] Open
Abstract
Studies have presented evidence that besides the well described S phase block, treatment of cancer cell lines with the iron chelator deferrioxamine (DFO) also results in an earlier block in G1 phase. In this article, measurements of cell cycle regulatory proteins define this block at a very specific point in G1. DFO treatment results in markedly decreased cyclin A protein levels. Cyclin E levels that accumulate in early to mid‐G1 are increased in cells treated with DFO as compared to the resting cells. The DFO S phase block is shown after cells are arrested at G1/S by (aphidicolin) then released into DFO. The same S phase block occurs with DFO treatment of a neuroblastoma cell line relatively resistant to the G1 DFO block. These experiments clearly differentiate the S phase DFO block from the earlier block pinpointed to a point in mid‐G1, before G1/S when cyclin E protein increases but before increased cyclin A synthesis. Apoptosis was observed in cells inhibited by DFO at both cell cycle arrest points. Iron chelation inhibits cell proliferation at two phases in the cell cycle. The block in G1 phase is now separated from the block in S phase by specific differences in expression of cell cycle regulatory events.
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Affiliation(s)
- Gamini Siriwardana
- Division of Hematology, Hematologic Malignancies and Stem Cell Transplantation, University of Colorado School of Medicine, 12700 E. 19th Avenue, Room 9122RC 2, MS B170, Aurora, 80045, Colorado
| | - Paul A Seligman
- Division of Hematology, Hematologic Malignancies and Stem Cell Transplantation, University of Colorado School of Medicine, 12700 E. 19th Avenue, Room 9122RC 2, MS B170, Aurora, 80045, Colorado
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Sandoval MR, Balakrishnan K, Luthra R, Keating M, Gandhi V. DNA repair initiation induces expression of ribonucleotide reductase in human chronic lymphocytic leukemia cells. Leuk Lymphoma 2013; 55:876-83. [PMID: 23772636 DOI: 10.3109/10428194.2013.813497] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Mammalian ribonucleotide reductase (RR) is a heterodimer enzyme responsible for maintaining levels of deoxynucleotides needed for DNA replication. The M2 subunit of RR is known to increase in tandem with progression of cells into S phase, whereas the M1 subunit is expressed at steady-state. Since the expression level of the M2 subunit increases because the cells need deoxyribonucleoside triphosphates (dNTPs) for replication, it is logical to hypothesize that the same increase will be seen during DNA repair. To test this, we used chronic lymphocytic leukemia (CLL) cells, which are replicationally quiescent and have low endogenous levels of RR and dNTPs. Cyclophosphamide was selected as the DNA damaging agent because of its clinical use in the treatment of CLL. DNA repair, measured by [(3)H]thymidine incorporation after 4 h treatment with 4-hydroperoxycyclophosphamide, increased in a dose-dependent manner at 3, 10 and 50 μM. The induction of DNA repair concomitantly increased the mRNA and protein levels of M2 subunit (median 1.6-fold; range 0.9-5.3). Maximum induction occurred at 10 μM after 4 h and correlated with [(3)H]thymidine incorporation (p = 0.02). In contrast, no change was observed in mRNA or protein levels of M1 subunit. We conclude that RR is regulated not only during replication but also during DNA repair, and in both cases M2 subunit expression is increased.
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Técher H, Koundrioukoff S, Azar D, Wilhelm T, Carignon S, Brison O, Debatisse M, Le Tallec B. Replication dynamics: biases and robustness of DNA fiber analysis. J Mol Biol 2013; 425:4845-55. [PMID: 23557832 DOI: 10.1016/j.jmb.2013.03.040] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 03/22/2013] [Accepted: 03/25/2013] [Indexed: 12/11/2022]
Abstract
The factors that govern replication programs are still poorly identified in metazoans, especially in mammalian cells. Thanks to molecular combing, the dynamics of DNA replication can be assessed at the genome-scale level from the cumulative analysis of single DNA fibers. This technique notably enables measurement of replication fork speed and fork asymmetry and that of distances separating either initiation or termination events. The results presented here aim to evaluate requirements critical to accurate measurement of replication parameters by molecular combing. We show that sample size, fiber length and DNA counterstaining are crucial to gain robust information concerning replication dynamics. Our results thus provide a methodological frame to investigate the DNA replication program through molecular combing analyses.
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Affiliation(s)
- Hervé Técher
- Institut Curie, Centre de Recherche, 26 rue d'Ulm, 75248 Paris Cedex 05, France; Université Pierre et Marie Curie Paris 06, 4 Place Jussieu, 75005 Paris, France; Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3244, 75248 Paris Cedex 05, France
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Chitambar CR, Antholine WE. Iron-targeting antitumor activity of gallium compounds and novel insights into triapine(®)-metal complexes. Antioxid Redox Signal 2013; 18:956-72. [PMID: 22900955 PMCID: PMC3557436 DOI: 10.1089/ars.2012.4880] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
SIGNIFICANCE Despite advances made in the treatment of cancer, a significant number of patients succumb to this disease every year. Hence, there is a great need to develop new anticancer agents. RECENT ADVANCES Emerging data show that malignant cells have a greater requirement for iron than normal cells do and that proteins involved in iron import, export, and storage may be altered in cancer cells. Therefore, strategies to perturb these iron-dependent steps in malignant cells hold promise for the treatment of cancer. Recent studies show that gallium compounds and metal-thiosemicarbazone complexes inhibit tumor cell growth by targeting iron homeostasis, including iron-dependent ribonucleotide reductase. Chemical similarities of gallium(III) with iron(III) enable the former to mimic the latter and interpose itself in critical iron-dependent steps in cellular proliferation. Newer gallium compounds have emerged with additional mechanisms of action. In clinical trials, the first-generation-compound gallium nitrate has exhibited activity against bladder cancer and non-Hodgkin's lymphoma, while the thiosemicarbazone Triapine(®) has demonstrated activity against other tumors. CRITICAL ISSUES Novel gallium compounds with greater cytotoxicity and a broader spectrum of antineoplastic activity than gallium nitrate should continue to be developed. FUTURE DIRECTIONS The antineoplastic activity and toxicity of the existing novel gallium compounds and thiosemicarbazone-metal complexes should be tested in animal tumor models and advanced to Phase I and II clinical trials. Future research should identify biologic markers that predict tumor sensitivity to gallium compounds. This will help direct gallium-based therapy to cancer patients who are most likely to benefit from it.
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Affiliation(s)
- Christopher R Chitambar
- Division of Hematology & Oncology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
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Abstract
The nature of the cytosolic iron pool remains largely uncharacterized, although a range of candidate ligands and chaperones have been proposed. Herein an overview is presented of cytosolic non heme and non iron-sulphur cluster protein iron binding sites and the influence of ligands on the redox activity of iron. This analysis leads to the concept of iron(II) glutathione functioning as the labile cytosolic iron pool and offers a means for the selection of iron over manganese in subsequent incorporation into a wide range of iron-dependent enzymes and electron transfer proteins. Glutathione and glutathione-binding glutaredoxins play a critical role in iron sulfur cluster synthesis and Fe(II)GS (iron(II) coordinated by the thiol function of glutathione) is a suitable iron donor for this biosynthetic route. Significantly, both glutathione and glutaredoxins are universally distributed and thus a controlling influence of glutathione on intracellular iron trafficking is likely to be a common feature of the majority of living organisms.
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Affiliation(s)
- Robert C Hider
- Institute of Pharmaceutical Science, King's College London, Franklin-Wilkins Building, Stamford Street, London SE1 9NH, UK.
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RRM2B suppresses activation of the oxidative stress pathway and is up-regulated by p53 during senescence. Sci Rep 2012; 2:822. [PMID: 23139867 PMCID: PMC3492868 DOI: 10.1038/srep00822] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 10/17/2012] [Indexed: 11/09/2022] Open
Abstract
RRM2B is the DNA damage-inducible small subunit of ribonucleotide reductase, the rate-limiting enzyme in de novo deoxyribonucleoside triphosphate synthesis. Although RRM2B is implicated in DNA repair and the maintenance of mitochondrial DNA content, the regulation and function of RRM2B in senescence have not been previously established. Here, we show that RRM2B is highly induced in a p53-dependent manner during senescence in primary human fibroblast IMR90 cells and is expressed at higher levels in senescent precancerous human prostatic intraepithelial neoplasm lesions compared to adjacent normal prostate glands. Paradoxically, silencing RRM2B expression leads to an increase in the level of reactive oxygen species, mitochondrial membrane depolarization, and premature senescence in a p38MAPK- and p53-dependent manner in young fibroblasts. Consistently, induction of senescence is accelerated in Rrm2b deficient mouse embryo fibroblasts. Our data demonstrate that RRM2B is induced by stress signals prior to the onset of senescence and prevents premature oxidative stress-induced senescence.
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Aye Y, Long MJC, Stubbe J. Mechanistic studies of semicarbazone triapine targeting human ribonucleotide reductase in vitro and in mammalian cells: tyrosyl radical quenching not involving reactive oxygen species. J Biol Chem 2012; 287:35768-35778. [PMID: 22915594 DOI: 10.1074/jbc.m112.396911] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Triapine® (3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP)) is a drug in Phase II trials. One of its established cellular targets is the β(2) subunit of ribonucleotide reductase that requires a diferric-tyrosyl-radical [(Fe(III)(2)-Y·)(Fe(III)(2))] cofactor for de novo DNA biosynthesis. Several mechanisms for 3-AP inhibition of β(2) have been proposed; one involves direct iron chelation from β(2), whereas a second involves Y· destruction by reactive oxygen species formed in situ in the presence of O(2) and reductant by Fe(II)-(3-AP). Inactivation of β(2) can thus arise from cofactor destruction by loss of iron or Y·. In vitro kinetic data on the rates of (55)Fe and Y· loss from [((55)Fe(III)(2)-Y·)((55)Fe(III)(2))]-β(2) under aerobic and anaerobic conditions reveal that Y· loss alone is sufficient for rapid β(2) inactivation. Oxyblot(TM) and mass spectrometric analyses of trypsin-digested inhibited β(2), and lack of Y· loss from H(2)O(2) and O(2)(•) treatment together preclude reactive oxygen species involvement in Y· loss. Three mammalian cell lines treated with 5 μm 3-AP reveal Y· loss and β(2) inactivation within 30-min of 3-AP-exposure, analyzed by whole-cell EPR and lysate assays, respectively. Selective degradation of apo- over [(Fe(III)(2)-Y·)(Fe(III)(2))]-β(2) in lysates, similar iron-content in β(2) immunoprecipitated from 3-AP-treated and untreated [(55)Fe]-prelabeled cells, and prolonged (12 h) stability of the inhibited β(2) are most consistent with Y· loss being the predominant mode of inhibition, with β(2) remaining iron-loaded and stable. A model consistent with in vitro and cell-based biochemical studies is presented in which Fe(II)-(3-AP), which can be cycled with reductant, directly reduces Y· of the [(Fe(III)(2)-Y·)(Fe(III)(2))] cofactor of β(2).
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Affiliation(s)
- Yimon Aye
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Marcus J C Long
- Graduate Program in Biochemistry and Biophysics, Brandeis University, Waltham, Massachusetts 02454
| | - JoAnne Stubbe
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139.
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Lei W, Feng XH, Deng WB, Ni H, Zhang ZR, Jia B, Yang XL, Wang TS, Liu JL, Su RW, Liang XH, Qi QR, Yang ZM. Progesterone and DNA damage encourage uterine cell proliferation and decidualization through up-regulating ribonucleotide reductase 2 expression during early pregnancy in mice. J Biol Chem 2012; 287:15174-92. [PMID: 22403396 DOI: 10.1074/jbc.m111.308023] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Embryo implantation into the maternal uterus is a crucial step for the successful establishment of mammalian pregnancy. Following the attachment of embryo to the uterine luminal epithelium, uterine stromal cells undergo steroid hormone-dependent decidualization, which is characterized by stromal cell proliferation and differentiation. The mechanisms underlying steroid hormone-induced stromal cell proliferation and differentiation during decidualization are still poorly understood. Ribonucleotide reductase, consisting of two subunits (RRM1 and RRM2), is a rate-limiting enzyme in deoxynucleotide production for DNA synthesis and plays an important role in cell proliferation and tumorgenicity. Based on our microarray analysis, Rrm2 expression was significantly higher at implantation sites compared with interimplantation sites in mouse uterus. However, the expression, regulation, and function of RRM2 in mouse uterus during embryo implantation and decidualization are still unknown. Here we show that although both RRM1 and RRM2 expression are markedly induced in mouse uterine stromal cells undergoing decidualization, only RRM2 is regulated by progesterone, a key regulator of decidualization. Further studies showed that the induction of progesterone on RRM2 expression in stromal cells is mediated by the AKT/c-MYC pathway. RRM2 can also be induced by replication stress and DNA damage during decidualization through the ATR/ATM-CHK1-E2F1 pathway. The weight of implantation sites and deciduoma was effectively reduced by specific inhibitors for RRM2. The expression of decidual/trophoblast prolactin-related protein (Dtprp), a reliable marker for decidualization in mice, was significantly reduced in deciduoma and steroid-induced decidual cells after HU treatment. Therefore, RRM2 may be an important effector of progesterone signaling to induce cell proliferation and decidualization in mouse uterus.
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Affiliation(s)
- Wei Lei
- Department of Biology, Shantou University, Shantou 515063, China
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HDM-2 inhibition suppresses expression of ribonucleotide reductase subunit M2, and synergistically enhances gemcitabine-induced cytotoxicity in mantle cell lymphoma. Blood 2011; 118:4140-9. [PMID: 21844567 DOI: 10.1182/blood-2011-03-340323] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Mantle cell lymphoma (MCL) usually responds well to initial therapy but is prone to relapses with chemoresistant disease, indicating the need for novel therapeutic approaches. Inhibition of the p53 E3 ligase human homolog of the murine double minute protein-2 (HDM-2) with MI-63 has been validated as one such strategy in wild-type (wt) p53 models, and our genomic and proteomic analyses demonstrated that MI-63 suppressed the expression of the ribonucleotide reductase (RNR) subunit M2 (RRM2). This effect occurred in association with induction of p21 and cell-cycle arrest at G(1)/S and prompted us to examine combinations with the RNR inhibitor 2',2'-difluoro-2'-deoxycytidine (gemcitabine). The regimen of MI-63-gemcitabine induced enhanced, synergistic antiproliferative, and proapoptotic effects in wtp53 MCL cell lines. Addition of exogenous dNTPs reversed this effect, whereas shRNA-mediated inhibition of RRM2 was sufficient to induce synergy with gemcitabine. Combination therapy of MCL murine xenografts with gemcitabine and MI-219, the in vivo analog of MI-63, resulted in enhanced antitumor activity. Finally, synergy was seen with MI-63-gemcitabine in primary patient samples that were found to express high levels of RRM2 compared with MCL cell lines. These findings provide a framework for translation of the rational combination of an HDM-2 and RNR inhibitor to the clinic for patients with relapsed wtp53 MCL.
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Wagner DE, Wang IE, Reddien PW. Clonogenic neoblasts are pluripotent adult stem cells that underlie planarian regeneration. Science 2011; 332:811-6. [PMID: 21566185 DOI: 10.1126/science.1203983] [Citation(s) in RCA: 439] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Pluripotent cells in the embryo can generate all cell types, but lineage-restricted cells are generally thought to replenish adult tissues. Planarians are flatworms and regenerate from tiny body fragments, a process requiring a population of proliferating cells (neoblasts). Whether regeneration is accomplished by pluripotent cells or by the collective activity of multiple lineage-restricted cell types is unknown. We used ionizing radiation and single-cell transplantation to identify neoblasts that can form large descendant-cell colonies in vivo. These clonogenic neoblasts (cNeoblasts) produce cells that differentiate into neuronal, intestinal, and other known postmitotic cell types and are distributed throughout the body. Single transplanted cNeoblasts restored regeneration in lethally irradiated hosts. We conclude that broadly distributed, adult pluripotent stem cells underlie the remarkable regenerative abilities of planarians.
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Affiliation(s)
- Daniel E Wagner
- Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology (MIT), Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA
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Kunos CA, Colussi VC, Pink J, Radivoyevitch T, Oleinick NL. Radiosensitization of human cervical cancer cells by inhibiting ribonucleotide reductase: enhanced radiation response at low-dose rates. Int J Radiat Oncol Biol Phys 2011; 80:1198-204. [PMID: 21470790 DOI: 10.1016/j.ijrobp.2011.01.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 12/13/2010] [Accepted: 01/27/2011] [Indexed: 01/28/2023]
Abstract
PURPOSE To test whether pharmacologic inhibition of ribonucleotide reductase (RNR) by 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, NSC #663249) enhances radiation sensitivity during low-dose-rate ionizing radiation provided by a novel purpose-built iridium-192 cell irradiator. METHODS AND MATERIALS The cells were exposed to low-dose-rate radiation (11, 23, 37, 67 cGy/h) using a custom-fabricated cell irradiator or to high-dose-rate radiation (330 cGy/min) using a conventional cell irradiator. The radiation sensitivity of human cervical (CaSki, C33-a) cancer cells with or without RNR inhibition by 3-AP was evaluated using a clonogenic survival and an RNR activity assay. Alteration in the cell cycle distribution was monitored using flow cytometry. RESULTS Increasing radiation sensitivity of both CaSki and C33-a cells was observed with the incremental increase in radiation dose rates. 3-AP treatment led to enhanced radiation sensitivity in both cell lines, eliminating differences in cell cytotoxicity from the radiation dose rate. RNR blockade by 3-AP during low-dose-rate irradiation was associated with low RNR activity and extended G(1)-phase cell cycle arrest. CONCLUSIONS We conclude that RNR inhibition by 3-AP impedes DNA damage repair mechanisms that rely on deoxyribonucleotide production and thereby increases radiation sensitivity of human cervical cancers to low-dose-rate radiation.
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Affiliation(s)
- Charles A Kunos
- Department of Radiation Oncology, University Hospitals Case Medical Center and Case Western Reserve School of Medicine, Cleveland, OH 44106, USA.
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Kunos CA, Radivoyevitch T, Pink J, Chiu SM, Stefan T, Jacobberger J, Kinsella TJ. Ribonucleotide reductase inhibition enhances chemoradiosensitivity of human cervical cancers. Radiat Res 2010; 174:574-81. [PMID: 20954859 DOI: 10.1667/rr2273.1] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
For repair of damaged DNA, cells increase de novo synthesis of deoxyribonucleotide triphosphates through the rate-limiting, p53-regulated ribonucleotide reductase (RNR) enzyme. In this study we investigated whether pharmacological inhibition of RNR by 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, NSC #663249) enhanced chemoradiation sensitivity through a mechanism involving sustained DNA damage. RNR inactivation by 3-AP and resulting chemoradiosensitization were evaluated in human cervical (CaSki, C33-a) cancer cells through study of DNA damage (γ-H2AX signal) by flow cytometry, RNR subunit p53R2 and p21 protein steady-state levels by Western blot analysis and laser scanning imaging cytometry, and cell survival by colony formation assays. 3-AP treatment led to sustained radiation- and cisplatin-induced DNA damage (i.e. increased γ-H2AX signal) in both cell lines through a mechanism of inhibited RNR activity. Radiation, cisplatin and 3-AP exposure resulted in significantly elevated numbers and persistence of γ-H2AX foci that were associated with reduced clonogenic survival. DNA damage was associated with a rise in p53R2 but not p21 protein levels 6 h after treatment with radiation and/or cisplatin plus 3-AP. We conclude that blockage of RNR activity by 3-AP impairs DNA damage responses that rely on deoxyribonucleotide production and thereby may substantially increase chemoradiosensitivity of human cervical cancers.
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Affiliation(s)
- Charles A Kunos
- Department of Radiation Oncology, University Hospitals Case Medical Center and Case Western Reserve School of Medicine, Cleveland, Ohio 44106, USA.
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Saletta F, Suryo Rahmanto Y, Richardson DR. The translational regulator eIF3a: the tricky eIF3 subunit! Biochim Biophys Acta Rev Cancer 2010; 1806:275-86. [PMID: 20647036 DOI: 10.1016/j.bbcan.2010.07.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 07/07/2010] [Accepted: 07/11/2010] [Indexed: 01/10/2023]
Abstract
Regulation of gene expression is a fundamental step in cellular physiology as abnormalities in this process may lead to de-regulated growth and cancer. Translation of mRNA is mainly regulated at the rate-limiting initiation step, where many eukaryotic initiation factors (eIFs) are involved. The largest and most complex initiation factor is eIF3 which plays a role in translational regulation, cell growth and cancer. The largest subunit of eIF3 is eIF3a, although it is not required for the general function of eIF3 in translation initiation. However, eIF3a may play a role as a regulator of a subset of mRNAs and has been demonstrated to regulate the expression of p27(kip1), tyrosinated α-tubulin and ribonucleotide reductase M2 subunit. These molecules have a pivotal role in the regulation of the cell cycle. Moreover, the eIF3a mRNA is ubiquitously expressed in all tissues at different levels and is found elevated in a number of cancer types. eIF3a can modulate the cell cycle and may be a translational regulator for proteins important for entrance into S phase. The expression of eIF3a is decreased in differentiated cells in culture and the suppression of eIF3a expression can reverse the malignant phenotype and change the sensitivity of cells to cell cycle modulators. However, the role of eIF3a in cancer is still unclear. In fact, some studies have identified eIF3a to be involved in cancer development, while other results indicate that it could provide protection against evolution into higher malignancy. Together, these findings highlight the "tricky" and interesting nature of eIF3a.
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Affiliation(s)
- Federica Saletta
- Iron Metabolism and Chelation Program, Department of Pathology and Bosch Institute, Blackburn Building (D06), University of Sydney, Sydney, New South Wales, 2006 Australia
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Wenemoser D, Reddien PW. Planarian regeneration involves distinct stem cell responses to wounds and tissue absence. Dev Biol 2010; 344:979-91. [PMID: 20599901 DOI: 10.1016/j.ydbio.2010.06.017] [Citation(s) in RCA: 225] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Accepted: 06/11/2010] [Indexed: 10/19/2022]
Abstract
Regeneration requires signaling from a wound site for detection of the wound and a mechanism that determines the nature of the injury to specify the appropriate regenerative response. Wound signals and tissue responses to wounds that elicit regeneration remain poorly understood. Planarians are able to regenerate from essentially any type of injury and present a novel system for the study of wound responses in regeneration initiation. Newly developed molecular and cellular tools now enable study of regeneration initiation using the planarian Schmidtea mediterranea. Planarian regeneration requires adult stem cells called neoblasts and amputation triggers two peaks in neoblast mitoses early in regeneration. We demonstrate that the first mitotic peak is a body-wide response to any injury and that a second, local, neoblast response is induced only when injury results in missing tissue. This second response was characterized by recruitment of neoblasts to wounds, even in areas that lack neoblasts in the intact animal. Subsequently, these neoblasts were induced to divide and differentiate near the wound, leading to formation of new tissue. We conclude that there exist two functionally distinct signaling phases of the stem cell wound response that distinguish between simple injury and situations that require the regeneration of missing tissue.
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Affiliation(s)
- Danielle Wenemoser
- Howard Hughes Medical Institute, Whitehead Institute, Cambridge, MA, USA
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50
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Wanrooij S, Falkenberg M. The human mitochondrial replication fork in health and disease. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1378-88. [PMID: 20417176 DOI: 10.1016/j.bbabio.2010.04.015] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 04/13/2010] [Accepted: 04/15/2010] [Indexed: 11/16/2022]
Abstract
Mitochondria are organelles whose main function is to generate power by oxidative phosphorylation. Some of the essential genes required for this energy production are encoded by the mitochondrial genome, a small circular double stranded DNA molecule. Human mtDNA is replicated by a specialized machinery distinct from the nuclear replisome. Defects in the mitochondrial replication machinery can lead to loss of genetic information by deletion and/or depletion of the mtDNA, which subsequently may cause disturbed oxidative phosphorylation and neuromuscular symptoms in patients. We discuss here the different components of the mitochondrial replication machinery and their role in disease. We also review the mode of mammalian mtDNA replication.
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Affiliation(s)
- Sjoerd Wanrooij
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, P.O. Box 440, SE-40530 Gothenburg, Sweden.
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