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Mitchell RJ, Gowda AS, Olivelli AG, Huckaba AJ, Parkin S, Unrine JM, Oza V, Blackburn JS, Ladipo F, Heidary DK, Glazer EC. Triarylphosphine-Coordinated Bipyridyl Ru(II) Complexes Induce Mitochondrial Dysfunction. Inorg Chem 2023; 62:10940-10954. [PMID: 37405779 DOI: 10.1021/acs.inorgchem.3c00736] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2023]
Abstract
While cancer cells rely heavily upon glycolysis to meet their energetic needs, reducing the importance of mitochondrial oxidative respiration processes, more recent studies have shown that their mitochondria still play an active role in the bioenergetics of metastases. This feature, in combination with the regulatory role of mitochondria in cell death, has made this organelle an attractive anticancer target. Here, we report the synthesis and biological characterization of triarylphosphine-containing bipyridyl ruthenium (Ru(II)) compounds and found distinct differences as a function of the substituents on the bipyridine and phosphine ligands. 4,4'-Dimethylbipyridyl-substituted compound 3 exhibited especially high depolarizing capabilities, and this depolarization was selective for the mitochondrial membrane and occurred within minutes of treatment in cancer cells. The Ru(II) complex 3 exhibited an 8-fold increase in depolarized mitochondrial membranes, as determined by flow cytometry, which compares favorably to the 2-fold increase observed by carbonyl cyanide chlorophenylhydrazone (CCCP), a proton ionophore that shuttles protons across membranes, depositing them into the mitochondrial matrix. Fluorination of the triphenylphosphine ligand provided a scaffold that maintained potency against a range of cancer cells but avoided inducing toxicity in zebrafish embryos at higher concentrations, displaying the potential of these Ru(II) compounds for anticancer applications. This study provides essential information regarding the role of ancillary ligands for the anticancer activity of Ru(II) coordination compounds that induce mitochondrial dysfunction.
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Affiliation(s)
- Richard J Mitchell
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, Kentucky 40506, United States
| | - Anitha S Gowda
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, Kentucky 40506, United States
| | - Alexander G Olivelli
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, Kentucky 40506, United States
| | - Aron J Huckaba
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, Kentucky 40506, United States
| | - Sean Parkin
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, Kentucky 40506, United States
| | - Jason M Unrine
- Department of Plant and Soil Sciences, University of Kentucky, 1100 S. Limestone Street, Lexington, Kentucky 40546, United States
| | - Viral Oza
- Department of Molecular and Cell Biology, University of Kentucky, 741 S. Limestone Street, Lexington, Kentucky 40536, United States
| | - Jessica S Blackburn
- Department of Molecular and Cell Biology, University of Kentucky, 741 S. Limestone Street, Lexington, Kentucky 40536, United States
| | - Folami Ladipo
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, Kentucky 40506, United States
| | - David K Heidary
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, Kentucky 40506, United States
| | - Edith C Glazer
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, Kentucky 40506, United States
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2
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Zhao J, Xu Y, Wang J, Liu J, Zhang R, Yan X. Dual-Specificity Tyrosine Phosphorylation-Regulated Kinase 1B Inhibition Promotes Megakaryocyte Polyploidization and Platelet Production. Thromb Haemost 2023; 123:192-206. [PMID: 36126948 DOI: 10.1055/a-1947-7615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Platelets are produced from mature megakaryocytes which undergo polyploidization and proplatelet formation. Cell-cycle regulation plays a crucial role in megakaryocyte terminal differentiation especially in polyploidization. Dual-specificity tyrosine phosphorylation-regulated kinase 1B (DYRK1B) controls cell-cycle progression in cancer cells. The objective of this study was to determine DYRK1B function in megakaryocyte maturation and platelet production. A DYRK1B knock-out mouse was generated with increased peripheral platelet count compared with the wild type mouse without affecting megakaryocyte numbers in bone marrow. Polyploidy and proplatelet formations were significantly enhanced when DYRK1B was depleted in vitro. DYRK1B inhibition promoted megakaryocyte maturation by simultaneously upregulating cyclin D1 and downregulating P27. Furthermore, there was platelet restoration in two mice disease models of transient thrombocytopenia. In summary, DYRK1B plays an important role in megakaryocyte maturation and platelet production by interacting with cyclin D1 and P27. DYRK1B inhibition has potential therapeutic value in transient thrombocytopenia treatment. Graphic Abstract.
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Affiliation(s)
- Jiaxin Zhao
- Department of Cardiovascular Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Yanyan Xu
- Department of Endocrinology and Metabolism, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Jiqiu Wang
- Department of Endocrinology and Metabolism, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Junling Liu
- Department of Biochemistry and Molecular Cell Biology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Ruiyan Zhang
- Department of Cardiovascular Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Xiaoxiang Yan
- Department of Cardiovascular Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
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3
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Cho CS, Jo DH, Kim JH, Kim JH. Establishment and Characterization of Carboplatin-Resistant Retinoblastoma Cell Lines. Mol Cells 2022; 45:729-737. [PMID: 36047446 PMCID: PMC9589373 DOI: 10.14348/molcells.2022.2014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 03/02/2022] [Accepted: 05/29/2022] [Indexed: 11/27/2022] Open
Abstract
Carboplatin-based chemotherapy is the primary treatment option for the management of retinoblastoma, an intraocular malignant tumor observed in children. The aim of the present study was to establish carboplatin-resistant retinoblastoma cell lines to facilitate future research into the treatment of chemoresistant retinoblastoma. In total, two retinoblastoma cell lines, Y79 and SNUOT-Rb1, were treated with increasing concentrations of carboplatin to develop the carboplatin-resistant retinoblastoma cell lines (termed Y79/CBP and SNUOT-Rb1/CBP, respectively). To verify resistance to carboplatin, the degree of DNA fragmentation and the expression level of cleaved caspase-3 were evaluated in the cells, following carboplatin treatment. In addition, the newly developed carboplatin-resistant retinoblastoma cells formed in vivo intraocular tumors more effectively than their parental cells, even after the intravitreal injection of carboplatin. Interestingly, the proportion of cells in the G0/G1 phase was higher in Y79/CBP and SNUOT-Rb1/CBP cells than in their respective parental cells. In line with these data, the expression levels of cyclin D1 and cyclin D3 were decreased, whereas p18 and p27 expression was increased in the carboplatin-resistant cells. In addition, the expression levels of genes associated with multidrug resistance were increased. Thus, these carboplatin-resistant cell lines may serve as a useful tool in the study of chemoresistance in retinoblastoma and for the development potential therapeutics.
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Affiliation(s)
- Chang Sik Cho
- Fight against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul 03080, Korea
| | - Dong Hyun Jo
- Department of Anatomy and Cell Biology, Seoul National University College of Medicine, Seoul 03080, Korea
| | | | - Jeong Hun Kim
- Fight against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul 03080, Korea
- Department of Ophthalmology, Seoul National University Hospital, Seoul 03080, Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea
- Institute of Reproductive Medicine and Population, Seoul National University College of Medicine, Seoul 03080, Korea
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4
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Wu YH, Chen HY, Hong WC, Wei CY, Pang JHS. Carboplatin-Induced Thrombocytopenia through JAK2 Downregulation, S-Phase Cell Cycle Arrest and Apoptosis in Megakaryocytes. Int J Mol Sci 2022; 23:ijms23116290. [PMID: 35682967 PMCID: PMC9181531 DOI: 10.3390/ijms23116290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 05/28/2022] [Accepted: 06/02/2022] [Indexed: 02/01/2023] Open
Abstract
Chemotherapy-induced thrombocytopenia (CIT) is a common complication when treating malignancies with cytotoxic agents wherein carboplatin is one of the most typical agents causing CIT. Janus kinase 2 (JAK2) is one of the critical enzymes to megakaryocyte proliferation and differentiation. However, the role of the JAK2 in CIT remains unclear. In this study, we used both carboplatin-induced CIT mice and MEG-01 cell line to examine the expression of JAK2 and signal transducer and activator of transcription 3 (STAT3) pathway. Under CIT, the expression of JAK2 was significantly reduced in vivo and in vitro. More surprisingly, the JAK2/STAT3 pathway remained inactivated even when thrombopoietin (TPO) was administered. On the other hand, carboplatin could cause prominent S phase cell cycle arrest and markedly increased apoptosis in MEG-01 cells. These results showed that the thrombopoiesis might be interfered through the downregulation of JAK2/STAT3 pathway by carboplatin in CIT, and the fact that exogenous TPO supplement cannot reactivate this pathway.
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Affiliation(s)
- Yi-Hong Wu
- Department of Chinese Medicine, Chang Gung Memorial Hospital, Guishan, Taoyuan 333, Taiwan; (Y.-H.W.); (H.-Y.C.); (W.-C.H.); (C.-Y.W.)
- School of Traditional Chinese Medicine, Chang Gung University, Guishan, Taoyuan 333, Taiwan
| | - Hsing-Yu Chen
- Department of Chinese Medicine, Chang Gung Memorial Hospital, Guishan, Taoyuan 333, Taiwan; (Y.-H.W.); (H.-Y.C.); (W.-C.H.); (C.-Y.W.)
- School of Traditional Chinese Medicine, Chang Gung University, Guishan, Taoyuan 333, Taiwan
- Graduate Institute of Clinical Medical Sciences, Chang Gung University, Guishan, Taoyuan 333, Taiwan
| | - Wei-Chin Hong
- Department of Chinese Medicine, Chang Gung Memorial Hospital, Guishan, Taoyuan 333, Taiwan; (Y.-H.W.); (H.-Y.C.); (W.-C.H.); (C.-Y.W.)
| | - Chen-Ying Wei
- Department of Chinese Medicine, Chang Gung Memorial Hospital, Guishan, Taoyuan 333, Taiwan; (Y.-H.W.); (H.-Y.C.); (W.-C.H.); (C.-Y.W.)
| | - Jong-Hwei Su Pang
- Graduate Institute of Clinical Medical Sciences, Chang Gung University, Guishan, Taoyuan 333, Taiwan
- Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Guishan, Taoyuan 333, Taiwan
- Correspondence: ; Tel.: +886-3-2118800 (ext. 3482); Fax: +886-3-2118800 (ext. 3484)
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Latancia MT, Moreno NC, Leandro GS, Ribeiro VC, de Souza I, Vieira WKM, Bastos AU, Hoch NC, Rocha CRR, Menck CFM. DNA polymerase eta protects human cells against DNA damage induced by the tumor chemotherapeutic temozolomide. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2022; 878:503498. [PMID: 35649682 DOI: 10.1016/j.mrgentox.2022.503498] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 03/24/2022] [Accepted: 05/02/2022] [Indexed: 11/16/2022]
Abstract
Human DNA polymerases can bypass DNA lesions performing translesion synthesis (TLS), a mechanism of DNA damage tolerance. Tumor cells use this mechanism to survive lesions caused by specific chemotherapeutic agents, resulting in treatment relapse. Moreover, TLS polymerases are error-prone and, thus, can lead to mutagenesis, increasing the resistance potential of tumor cells. DNA polymerase eta (pol eta) - a key protein from this group - is responsible for protecting against sunlight-induced tumors. Xeroderma Pigmentosum Variant (XP-V) patients are deficient in pol eta activity, which leads to symptoms related to higher sensitivity and increased incidence of skin cancer. Temozolomide (TMZ) is a chemotherapeutic agent used in glioblastoma and melanoma treatment. TMZ damages cells' genomes, but little is known about the role of TLS in TMZ-induced DNA lesions. This work investigates the effects of TMZ treatment in human XP-V cells, which lack pol eta, and in its complemented counterpart (XP-V comp). Interestingly, TMZ reduces the viability of XP-V cells compared to TLS proficient control cells. Furthermore, XP-V cells treated with TMZ presented increased phosphorylation of H2AX, forming γH2AX, compared to control cells. However, cell cycle assays indicate that XP-V cells treated with TMZ replicate damaged DNA and pass-through S-phase, arresting in the G2/M-phase. DNA fiber assay also fails to show any specific effect of TMZ-induced DNA damage blocking DNA elongation in pol eta deficient cells. These results show that pol eta plays a role in protecting human cells from TMZ-induced DNA damage, but this can be different from its canonical TLS mechanism. The new role opens novel therapeutic possibilities of using pol eta as a target to improve the efficacy of TMZ-based therapies against cancer.
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Affiliation(s)
- Marcela T Latancia
- Instituto de Ciências Biomédicas, Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | - Natália C Moreno
- Instituto de Ciências Biomédicas, Universidade de São Paulo (USP), São Paulo, SP, Brazil; Instituto de Química, Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | - Giovana S Leandro
- Instituto de Ciências Biomédicas, Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | | | - Izadora de Souza
- Departamento de Clínica e Oncologia Experimental, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | | | - André Uchimura Bastos
- Instituto de Ciências Biomédicas, Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | - Nicolas Carlos Hoch
- Instituto de Química, Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | - Clarissa R R Rocha
- Instituto de Ciências Biomédicas, Universidade de São Paulo (USP), São Paulo, SP, Brazil; Departamento de Clínica e Oncologia Experimental, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Carlos F M Menck
- Instituto de Ciências Biomédicas, Universidade de São Paulo (USP), São Paulo, SP, Brazil.
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6
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Ler AAL, Carty MP. DNA Damage Tolerance Pathways in Human Cells: A Potential Therapeutic Target. Front Oncol 2022; 11:822500. [PMID: 35198436 PMCID: PMC8859465 DOI: 10.3389/fonc.2021.822500] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 12/30/2021] [Indexed: 12/26/2022] Open
Abstract
DNA lesions arising from both exogenous and endogenous sources occur frequently in DNA. During DNA replication, the presence of unrepaired DNA damage in the template can arrest replication fork progression, leading to fork collapse, double-strand break formation, and to genome instability. To facilitate completion of replication and prevent the generation of strand breaks, DNA damage tolerance (DDT) pathways play a key role in allowing replication to proceed in the presence of lesions in the template. The two main DDT pathways are translesion synthesis (TLS), which involves the recruitment of specialized TLS polymerases to the site of replication arrest to bypass lesions, and homology-directed damage tolerance, which includes the template switching and fork reversal pathways. With some exceptions, lesion bypass by TLS polymerases is a source of mutagenesis, potentially contributing to the development of cancer. The capacity of TLS polymerases to bypass replication-blocking lesions induced by anti-cancer drugs such as cisplatin can also contribute to tumor chemoresistance. On the other hand, during homology-directed DDT the nascent sister strand is transiently utilised as a template for replication, allowing for error-free lesion bypass. Given the role of DNA damage tolerance pathways in replication, mutagenesis and chemoresistance, a more complete understanding of these pathways can provide avenues for therapeutic exploitation. A number of small molecule inhibitors of TLS polymerase activity have been identified that show synergy with conventional chemotherapeutic agents in killing cancer cells. In this review, we will summarize the major DDT pathways, explore the relationship between damage tolerance and carcinogenesis, and discuss the potential of targeting TLS polymerases as a therapeutic approach.
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Affiliation(s)
- Ashlynn Ai Li Ler
- Biochemistry, School of Biological and Chemical Sciences, The National University of Ireland (NUI) Galway, Galway, Ireland
| | - Michael P. Carty
- Biochemistry, School of Biological and Chemical Sciences, The National University of Ireland (NUI) Galway, Galway, Ireland
- DNA Damage Response Laboratory, Centre for Chromosome Biology, NUI Galway, Galway, Ireland
- *Correspondence: Michael P. Carty,
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7
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Kay JE, Corrigan JJ, Armijo AL, Nazari IS, Kohale IN, Torous DK, Avlasevich SL, Croy RG, Wadduwage DN, Carrasco SE, Dertinger SD, White FM, Essigmann JM, Samson LD, Engelward BP. Excision of mutagenic replication-blocking lesions suppresses cancer but promotes cytotoxicity and lethality in nitrosamine-exposed mice. Cell Rep 2021; 34:108864. [PMID: 33730582 PMCID: PMC8527524 DOI: 10.1016/j.celrep.2021.108864] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/05/2021] [Accepted: 02/23/2021] [Indexed: 02/07/2023] Open
Abstract
N-Nitrosodimethylamine (NDMA) is a DNA-methylating agent that has been discovered to contaminate water, food, and drugs. The alkyladenine DNA glycosylase (AAG) removes methylated bases to initiate the base excision repair (BER) pathway. To understand how gene-environment interactions impact disease susceptibility, we study Aag-knockout (Aag-/-) and Aag-overexpressing mice that harbor increased levels of either replication-blocking lesions (3-methyladenine [3MeA]) or strand breaks (BER intermediates), respectively. Remarkably, the disease outcome switches from cancer to lethality simply by changing AAG levels. To understand the underlying basis for this observation, we integrate a suite of molecular, cellular, and physiological analyses. We find that unrepaired 3MeA is somewhat toxic, but highly mutagenic (promoting cancer), whereas excess strand breaks are poorly mutagenic and highly toxic (suppressing cancer and promoting lethality). We demonstrate that the levels of a single DNA repair protein tip the balance between blocks and breaks and thus dictate the disease consequences of DNA damage.
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Affiliation(s)
- Jennifer E Kay
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 01239, USA
| | - Joshua J Corrigan
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 01239, USA
| | - Amanda L Armijo
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA 01239, USA
| | - Ilana S Nazari
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 01239, USA
| | - Ishwar N Kohale
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Center for Precision Cancer Medicine, Massachusetts Institute of Technology, Cambridge, MA 01239, USA
| | | | | | - Robert G Croy
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 01239, USA
| | - Dushan N Wadduwage
- The John Harvard Distinguished Science Fellows Program, Harvard University, Cambridge, MA 02138, USA; Center for Advanced Imaging, Harvard University, Cambridge, MA 02138, USA
| | - Sebastian E Carrasco
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA 01239, USA
| | | | - Forest M White
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Center for Precision Cancer Medicine, Massachusetts Institute of Technology, Cambridge, MA 01239, USA
| | - John M Essigmann
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 01239, USA
| | - Leona D Samson
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 01239, USA
| | - Bevin P Engelward
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 01239, USA; Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, MA 01239, USA.
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8
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Stewart JA, Schauer G, Bhagwat AS. Visualization of uracils created by APOBEC3A using UdgX shows colocalization with RPA at stalled replication forks. Nucleic Acids Res 2020; 48:e118. [PMID: 33074285 PMCID: PMC7672425 DOI: 10.1093/nar/gkaa845] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 09/11/2020] [Accepted: 09/18/2020] [Indexed: 12/19/2022] Open
Abstract
The AID/APOBEC enzymes deaminate cytosines in single-stranded DNA (ssDNA) and play key roles in innate and adaptive immunity. The resulting uracils cause mutations and strand breaks that inactivate viruses and diversify antibody repertoire. Mutational evidence suggests that two members of this family, APOBEC3A (A3A) and APOBEC3B, deaminate cytosines in the lagging-strand template during replication. To obtain direct evidence for the presence of these uracils, we engineered a protein that covalently links to DNA at uracils, UdgX, for mammalian expression and immunohistochemistry. We show that UdgX strongly prefers uracils in ssDNA over those in U•G or U:A pairs, and localizes to nuclei in a dispersed form. When A3A is expressed in these cells, UdgX tends to form foci. The treatment of cells with cisplatin, which blocks replication, causes a significant increase in UdgX foci. Furthermore, this protein- and hence the uracils created by A3A- colocalize with replication protein A (RPA), but not with A3A. Using purified proteins, we confirm that RPA inhibits A3A by binding ssDNA, but despite its overexpression following cisplatin treatment, RPA is unable to fully protect ssDNA created by cisplatin adducts. This suggests that cisplatin treatment of cells expressing APOBEC3A should cause accumulation of APOBEC signature mutations.
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Affiliation(s)
- Jessica A Stewart
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA
| | - Grant Schauer
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Ashok S Bhagwat
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA.,Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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9
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The Cytotoxic Effect of Newly Synthesized Ferrocenes against Cervical Carcinoma Cells Alone and in Combination with Radiotherapy. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10113728] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cervical cancer is one of the most common types of cancer in women, with approximately 500,000 new cases and 250,000 deaths every year. Radiotherapy combined with chemotherapy represents the treatment of choice for advanced cervical carcinomas. The role of the chemotherapy is to increase the sensitivity of the cancer cells to irradiation. Cisplatin, the most commonly used drug for this purpose, has its limitations. Thus, we used a family of ferrocene derivatives (in addition, one new species was prepared using standard Schlenk techniques) and studied their effects on cervical cancer cells alone and in combination with irradiation. We applied colorimetric assay to determine the cytotoxicity of the compounds; flow cytometry to analyze the production of reactive oxygen species (ROS), cell cycle, and mitochondrial membrane potential (MMP); immunochemistry to study protein expression; and colony forming assay to evaluate changes in radiosensitivity. Treatment with ferrocenes exhibited significant cytotoxicity against cervical cancer cells, associated with increasing ROS production and MMP changes, suggesting the induction of apoptosis. The combined activity of ferrocenes and ionizing radiation highlighted ferrocenes as potential radiosensitizing drugs, while their higher single-agent toxicity in comparison with routinely used cisplatin could also be promising. Our results demonstrate antitumor activity of several tested ferrocenes both alone and in combination with radiotherapy.
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10
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Genotoxicity of cisplatin and carboplatin in cultured human lymphocytes: a comparative study. Interdiscip Toxicol 2020; 12:93-97. [PMID: 32206030 PMCID: PMC7071837 DOI: 10.2478/intox-2019-0011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Accepted: 08/10/2019] [Indexed: 01/03/2023] Open
Abstract
Cisplatin and carboplatin are integral parts of many antineoplastic management regimens. Both platinum analogues are potent DNA alkylating agents that robustly induce genomic instability and promote apoptosis in tumor cells. Although the mechanism of action of both drugs is similar, cisplatin appears to be more cytotoxic. In this study, the genotoxic potential of cisplatin and carboplatin was compared using chromosomal aberrations (CAs) and sister-chromatid exchange (SCE) assays in cultured human lymphocytes. Results showed that cisplatin and carboplatin induced a significant increase in CAs and SCEs compared to the control group (p<0.01). Levels of induced CAs were similar in both drugs; however, the magnitude of SCEs induced by cisplatin was significantly higher than that induced by carboplatin (p<0.01). With respect to the mitotic and proliferative indices, both cisplatin and carboplatin significantly decreased mitotic index (p<0.01) without affecting the proliferative index (p>0.05). In conclusion, cisplatin was found to be more genotoxic than carboplatin in the SCE assay in cultured human lymphocytes, and that might explain the higher cytotoxicity of cisplatin.
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11
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Bohn-Wippert K, Tevonian EN, Lu Y, Huang MY, Megaridis MR, Dar RD. Cell Size-Based Decision-Making of a Viral Gene Circuit. Cell Rep 2019; 25:3844-3857.e5. [PMID: 30590053 PMCID: PMC7050911 DOI: 10.1016/j.celrep.2018.12.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 07/23/2018] [Accepted: 11/30/2018] [Indexed: 12/22/2022] Open
Abstract
Latently infected T cells able to reinitiate viral propagation throughout the body remain a major barrier to curing HIV. Distinguishing between latently infected cells and uninfected cells will advance efforts for viral eradication. HIV decision-making between latency and active replication is stochastic, and drug cocktails that increase bursts of viral gene expression enhance reactivation from latency. Here, we show that a larger host-cell size provides a natural cellular mechanism for enhancing burst size of viral expression and is necessary to destabilize the latent state and bias viral decision-making. Latently infected Jurkat and primary CD4+ T cells reactivate exclusively in larger activated cells, while smaller cells remain silent. In addition, reactivation is cell-cycle dependent and can be modulated with cell-cycle-arresting compounds. Cell size and cell-cycle dependent decision-making of viral circuits may guide stochastic design strategies and applications in synthetic biology and may provide important determinants to advance diagnostics and therapies. Bohn-Wippert et al. investigate reactivation of T cells latently infected with HIV. They discover that only larger cells exit latency, while smaller cells remain silent. Viral expression bursts are cell size and cell-cycle dependent, presenting dynamic cell states, capable of active control, as sources of viral fate determination.
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Affiliation(s)
- Kathrin Bohn-Wippert
- Department of Bioengineering, University of Illinois at Urbana-Champaign, 321 Everitt Laboratory, 1406 West Green Street, Urbana, IL 61801, USA
| | - Erin N Tevonian
- Department of Bioengineering, University of Illinois at Urbana-Champaign, 321 Everitt Laboratory, 1406 West Green Street, Urbana, IL 61801, USA
| | - Yiyang Lu
- Department of Bioengineering, University of Illinois at Urbana-Champaign, 321 Everitt Laboratory, 1406 West Green Street, Urbana, IL 61801, USA
| | - Meng-Yao Huang
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, IL 61801, USA
| | - Melina R Megaridis
- Department of Bioengineering, University of Illinois at Urbana-Champaign, 321 Everitt Laboratory, 1406 West Green Street, Urbana, IL 61801, USA
| | - Roy D Dar
- Department of Bioengineering, University of Illinois at Urbana-Champaign, 321 Everitt Laboratory, 1406 West Green Street, Urbana, IL 61801, USA; Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 306 North Wright St, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, IL 61801, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, IL 61801, USA.
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12
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Evaluation for Synergistic Effects by Combinations of Photodynamic Therapy (PDT) with Temoporfin (mTHPC) and Pt(II) Complexes Carboplatin, Cisplatin or Oxaliplatin in a Set of Five Human Cancer Cell Lines. Int J Mol Sci 2018; 19:ijms19103183. [PMID: 30332729 PMCID: PMC6214074 DOI: 10.3390/ijms19103183] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 09/27/2018] [Accepted: 10/10/2018] [Indexed: 12/17/2022] Open
Abstract
The platinum(II) complexes carboplatin (CBDCA), cisplatin (CDDP) and oxaliplatin (1-OHP) are used as anticancer drugs in a large number of tumour chemotherapy regimens. Many attempts have been made to combine Pt(II)-based chemotherapy with alternative treatment strategies. One such alternative anticancer approach is known as photodynamic therapy (PDT), where a non-toxic photosensitizer (PS) produces oxidative stress via the formation of reactive oxygen species (ROS) after local illumination of the affected tissue. A very promising PS is 5,10,15,20-tetra(m-hydroxyphenyl)chlorin (mTHPC, Temoporfin), which is approved for the treatment of head and neck cancer in Europe. In the present study, a combination of mTHPC-mediated PDT and either CBDCA, CDDP, or 1-OHP was applied to five human cancer cell lines from different tumour origins. Cytotoxicity was determined by the MTT assay and synergistic effects on cytotoxicity were evaluated by calculation of Combination Indices (CI). Synergy was identified in some of the combinations, for example, with 1-OHP in three of the tested cell lines but antagonism was also observed for a number of combinations in certain cell lines. In cases of synergy, elevated ROS levels were observed after combination but apoptosis induction was not necessarily increased compared to a treatment with a single compound. Cell cycle analysis revealed a formation of apoptotic subG1 populations and S phase as well as G2/M phase arrests after combination. In conclusion, pre-treatment with mTHPC-PDT has the potential to sensitize some types of tumour cells towards Pt(II) complexes, in particular 1-OHP but synergy is highly dependent on the type of cancer.
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13
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Stevens DR, Hammes-Schiffer S. Exploring the Role of the Third Active Site Metal Ion in DNA Polymerase η with QM/MM Free Energy Simulations. J Am Chem Soc 2018; 140:8965-8969. [PMID: 29932331 DOI: 10.1021/jacs.8b05177] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The enzyme human DNA polymerase η (Pol η) is critical for bypassing lesions during DNA replication. In addition to the two Mg2+ ions aligning the active site, experiments suggest that a third Mg2+ ion could play an essential catalytic role. Herein the role of this third metal ion is investigated with quantum mechanical/molecular mechanical (QM/MM) free energy simulations of the phosphoryl transfer reaction and a proposed self-activating proton transfer from the incoming nucleotide to the pyrophosphate leaving group. The simulations with only two metal ions in the active site support a sequential mechanism, with phosphoryl transfer followed by relatively fast proton transfer. The simulations with three metal ions in the active site suggest that the third metal ion may play a catalytic role through electrostatic interactions with the leaving group. These electrostatic interactions stabilize the product, making the phosphoryl transfer reaction more thermodynamically favorable with a lower free energy barrier relative to the activated state corresponding to the deprotonated 3'OH nucleophile, and also inhibit the subsequent proton transfer. The possibility that Mg2+-bound hydroxide acts as the base deprotonating the 3'OH nucleophile is also explored.
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Affiliation(s)
- David R Stevens
- Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520 , United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520 , United States
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14
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Olaparib modulates DNA repair efficiency, sensitizes cervical cancer cells to cisplatin and exhibits anti-metastatic property. Sci Rep 2017; 7:12876. [PMID: 28993682 PMCID: PMC5634505 DOI: 10.1038/s41598-017-13232-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 09/20/2017] [Indexed: 11/08/2022] Open
Abstract
PARP1 trapping at DNA lesion by pharmacological inhibitors has been exploited in several cancers exhibiting defects in DNA repair mechanisms. PARP1 hyperactivation is involved in therapeutic resistance in multiple cancers. The role of PARP1 in cervical cancer (CC) resistance and implication of PARP inhibitor is yet to be elucidated. Our data demonstrates significantly higher expression of PARP1 in primary cervical tumors and CC cell lines SiHa and ME180. Upon cisplatin treatment CC cells display significant overexpression of PARP1 and its hyperactivation. PARP inhibitor olaparib shows significant anti-proliferative effect on CC cells and drive loss of clonogenic survival and enhanced cell death in combination with cisplatin. PARP inhibited cells show delay in resolution of γH2A.X foci and prolonged late S and G2-M phase arrest resulting in apoptosis. Further, PARP inhibition disrupts the localization of base excision repair (BER) effector XRCC1 and non-homologous end joining (NHEJ) proteins Ku80 and XRCC4. Due to disrupted relocation of repair factors, cisplatin induced stalled replication forks collapse and convert into double strand breaks (DSBs). Interestingly, PARP inhibition also shows anti-migratory and anti-invasive properties in CC cells, increases anchorage independent cell death and induces anoikis. Collectively, our data demonstrates therapeutic potential of PARP inhibitor in cervical cancer.
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15
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Fischer MM, Cancilla B, Yeung VP, Cattaruzza F, Chartier C, Murriel CL, Cain J, Tam R, Cheng CY, Evans JW, O’Young G, Song X, Lewicki J, Kapoun AM, Gurney A, Yen WC, Hoey T. WNT antagonists exhibit unique combinatorial antitumor activity with taxanes by potentiating mitotic cell death. SCIENCE ADVANCES 2017; 3:e1700090. [PMID: 28691093 PMCID: PMC5479655 DOI: 10.1126/sciadv.1700090] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 05/09/2017] [Indexed: 05/26/2023]
Abstract
The WNT pathway mediates intercellular signaling that regulates cell fate in both normal development and cancer. It is widely appreciated that the WNT pathway is frequently dysregulated in human cancers through a variety of genetic and epigenetic mechanisms. Targets in the WNT pathway are being extensively pursued for the development of new anticancer therapies, and we have advanced two WNT antagonists for clinical development: vantictumab (anti-FZD) and ipafricept (FZD8-Fc). We examined the antitumor efficacy of these WNT antagonists in combination with various chemotherapies in a large set of patient-derived xenograft models. In responsive models, WNT blockade led to profound synergy with taxanes such as paclitaxel, and the combination activity with taxanes was consistently more effective than with other classes of chemotherapy. Taxane monotherapy increased the frequency of cells with active WNT signaling. This selection of WNT-active chemotherapy-resistant tumorigenic cells was prevented by WNT-antagonizing biologics and required sequential dosing of the WNT antagonist followed by the taxane. The WNT antagonists potentiated paclitaxel-mediated mitotic blockade and promoted widespread mitotic cell death. By blocking WNT/β-catenin signaling before mitotic blockade by paclitaxel, we found that this treatment effectively sensitizes cancer stem cells to taxanes. This combination strategy and treatment regimen has been incorporated into ongoing clinical testing for vantictumab and ipafricept.
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16
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HuCOP1 contributes to the regulation of DNA repair in keratinocytes. Mol Cell Biochem 2016; 427:103-109. [PMID: 27995412 DOI: 10.1007/s11010-016-2901-0] [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: 10/06/2016] [Accepted: 12/02/2016] [Indexed: 10/20/2022]
Abstract
We have previously demonstrated that the E3 ligase Human Constitutive Photomorphogenic Protein (huCOP1) is expressed in human keratinocytes and negatively regulates p53. The MutS homolog 2 (MSH2) protein plays a central role in DNA MMR mechanism and is implicated in the cellular response to anticancer agents, such as cisplatin. Our aim was to clarify whether huCOP1 plays a role in DNA MMR by affecting MSH2 protein level in human keratinocytes. To define the role of huCOP1 in DNA mismatch repair, we determined whether huCOP1 affects MSH2 abundance. MSH2 protein level was detected by immunocytochemical staining using a keratinocyte cell line in which the expression level of huCOP1 was stably decreased (siCOP1). To investigate whether huCOP1 silencing influences cisplatin-induced cell death, control and siCOP1 keratinocyte cells were treated with increasing concentrations of cisplatin and cell viability was recorded after 48 and 96 h. Stable silencing of huCOP1 in human keratinocytes resulted in a reduced level of MSH2 protein. huCOP1 silencing also sensitized keratinocytes to the interstrand crosslinking inducer cisplatin. Our results indicate that decreased huCOP1 correlates with lower MSH2 levels. These protein level changes lead to increased sensitivity toward cisplatin treatment, implicating that huCOP1 plays a positive role in maintaining genome integrity in human keratinocytes.
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17
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Malvezzi S, Angelov T, Sturla SJ. Minor Groove 3-Deaza-Adenosine Analogues: Synthesis and Bypass in Translesion DNA Synthesis. Chemistry 2016; 23:1101-1109. [PMID: 27862447 DOI: 10.1002/chem.201604289] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Indexed: 11/07/2022]
Abstract
Anticancer drugs that alkylate DNA in the minor groove may give rise to 3-alkyl-adenosine adducts that interfere with replication, inducing apoptosis in rapidly dividing cancer cells. However, translesion DNA synthesis (TLS) by polymerase enzymes (Pols) with the capacity to bypass DNA adducts may contribute to damage tolerance and drug resistance. 3-Alkyl-adenosine adducts are unstable and depurinate, which is a barrier to addressing chemical and enzymatic aspects of how they impact the progress of DNA Pols. To characterize structure-based relationships of 3-adenine alkylation relevant to cancer drugs on duplex stability and DNA Pol-catalyzed DNA synthesis, we synthesized stable 3-deaza-3-alkyl-adenosine analogues, including 3-deaza-3-phenethyl-adenosine and 3-deaza-3-methoxynaphthylethyl-adenosine, and incorporated them into oligonucleotides. A moderate reduction of duplex stability was observed on the basis of thermal denaturation data. Replication studies using purified Y-family human DNA Pols hPol η, κ, and ι indicated that these enzymes can perform TLS over the modified bases. hPol η had higher misincorporation rates when synthesizing opposite the modified bases compared with adenine, whereas hPol κ and ι maintained high fidelity. These results provide insight into how alterations in chemical structure reduce bypass of minor-groove adducts, and provide novel chemical probes for evaluating minor-groove DNA alkylation.
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Affiliation(s)
- Stefano Malvezzi
- Department of Health Sciences and Technology, ETH Zurich, Schmelzbergstrasse 9, 8092, Zurich, Switzerland
| | - Todor Angelov
- Department of Health Sciences and Technology, ETH Zurich, Schmelzbergstrasse 9, 8092, Zurich, Switzerland
| | - Shana J Sturla
- Department of Health Sciences and Technology, ETH Zurich, Schmelzbergstrasse 9, 8092, Zurich, Switzerland
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18
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Ucisik MN, Hammes-Schiffer S. Effects of Active Site Mutations on Specificity of Nucleobase Binding in Human DNA Polymerase η. J Phys Chem B 2016; 121:3667-3675. [PMID: 28423907 PMCID: PMC5402696 DOI: 10.1021/acs.jpcb.6b09973] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
![]()
Human DNA polymerase η (Pol
η) plays a vital role in
protection against skin cancer caused by damage from ultraviolet light.
This enzyme rescues stalled replication forks at cyclobutane thymine–thymine
dimers (TTDs) by inserting nucleotides opposite these DNA lesions.
Residue R61 is conserved in the Pol η enzymes across species,
but the corresponding residue, as well as its neighbor S62, is different
in other Y-family polymerases, Pol ι and Pol κ. Herein,
R61 and S62 are mutated to their Pol ι and Pol κ counterparts.
Relative binding free energies of dATP to mutant Pol η•DNA
complexes with and without a TTD were calculated using thermodynamic
integration. The binding free energies of dATP to the Pol η•DNA
complex with and without a TTD are more similar for all of these mutants
than for wild-type Pol η, suggesting that these mutations decrease
the ability of this enzyme to distinguish between a TTD lesion and
undamaged DNA. Molecular dynamics simulations of the mutant systems
provide insights into the molecular level basis for the changes in
relative binding free energies. The simulations identified differences
in hydrogen-bonding, cation−π, and π–π
interactions of the side chains with the dATP and the TTD or thymine–thymine
(TT) motif. The simulations also revealed that R61 and Q38 act as
a clamp to position the dATP and the TTD or TT and that the mutations
impact the balance among the interactions related to this clamp. Overall,
these calculations suggest that R61 and S62 play key roles in the
specificity and effectiveness of Pol η for bypassing TTD lesions
during DNA replication. Understanding the basis for this specificity
is important for designing drugs aimed at cancer treatment.
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Affiliation(s)
- Melek N Ucisik
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801-3364, United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801-3364, United States
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19
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Genna V, Gaspari R, Dal Peraro M, De Vivo M. Cooperative motion of a key positively charged residue and metal ions for DNA replication catalyzed by human DNA Polymerase-η. Nucleic Acids Res 2016; 44:2827-36. [PMID: 26935581 PMCID: PMC4824119 DOI: 10.1093/nar/gkw128] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 02/19/2016] [Indexed: 12/18/2022] Open
Abstract
Trans-lesion synthesis polymerases, like DNA Polymerase-η (Pol-η), are essential for cell survival. Pol-η bypasses ultraviolet-induced DNA damages via a two-metal-ion mechanism that assures DNA strand elongation, with formation of the leaving group pyrophosphate (PPi). Recent structural and kinetics studies have shown that Pol-η function depends on the highly flexible and conserved Arg61 and, intriguingly, on a transient third ion resolved at the catalytic site, as lately observed in other nucleic acid-processing metalloenzymes. How these conserved structural features facilitate DNA replication, however, is still poorly understood. Through extended molecular dynamics and free energy simulations, we unravel a highly cooperative and dynamic mechanism for DNA elongation and repair, which is here described by an equilibrium ensemble of structures that connect the reactants to the products in Pol-η catalysis. We reveal that specific conformations of Arg61 help facilitate the recruitment of the incoming base and favor the proper formation of a pre-reactive complex in Pol-η for efficient DNA editing. Also, we show that a third transient metal ion, which acts concertedly with Arg61, serves as an exit shuttle for the leaving PPi. Finally, we discuss how this effective and cooperative mechanism for DNA repair may be shared by other DNA-repairing polymerases.
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Affiliation(s)
- Vito Genna
- Laboratory of Molecular Modeling & Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy
| | - Roberto Gaspari
- CONCEPT Lab., Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa, Italy
| | - Matteo Dal Peraro
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland Swiss Institute of Bioinformatics (SIB), CH-1015, Lausanne, Switzerland
| | - Marco De Vivo
- Laboratory of Molecular Modeling & Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genoa, Italy IAS-5 / INM-9 Computational Biomedicine Forschungszentrum Jülich, Wilhelm-Johnen-Straße 52428 Jülich, Germany
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20
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Ucisik MN, Hammes-Schiffer S. Comparative Molecular Dynamics Studies of Human DNA Polymerase η. J Chem Inf Model 2015; 55:2672-81. [PMID: 26562587 PMCID: PMC4696480 DOI: 10.1021/acs.jcim.5b00606] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
High-energy
ultraviolet radiation damages DNA through the formation
of cyclobutane pyrimidine dimers, which stall replication. When the
lesion is a thymine–thymine dimer (TTD), human DNA polymerase
η (Pol η) assists in resuming the replication process
by inserting nucleotides opposite the damaged site. We performed extensive
molecular dynamics (MD) simulations to investigate the structural
and dynamical effects of four different Pol η complexes with
or without a TTD and with either dATP or dGTP as the incoming base.
No major differences in the overall structures and equilibrium dynamics
were detected among the four systems, suggesting that the specificity
of this enzyme is due predominantly to differences in local interactions
in the binding regions. Analysis of the hydrogen-bonding interactions
between the enzyme and the DNA and dNTP provided molecular-level insights.
Specifically, the TTD was observed to engage in more hydrogen-bonding
interactions with the enzyme than its undamaged counterpart of two
normal thymines. The resulting greater rigidity and specific orientation
of the TTD are consistent with the experimental observation of higher
processivity and overall efficiency at TTD sites than at analogous
sites with two normal thymines. The similarities between the systems
containing dATP and dGTP are consistent with the experimental observation
of relatively low fidelity with respect to the incoming base. Moreover,
Q38 and R61, two strictly conserved amino acids across the Pol η
family, were found to exhibit persistent hydrogen-bonding interactions
with the TTD and cation-π interactions with the free base, respectively.
Thus, these simulations provide molecular level insights into the
basis for the selectivity and efficiency of this enzyme, as well as
the roles of the two most strictly conserved residues.
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Affiliation(s)
- Melek N Ucisik
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801-3364, United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801-3364, United States
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21
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Ucisik MN, Hammes-Schiffer S. Relative Binding Free Energies of Adenine and Guanine to Damaged and Undamaged DNA in Human DNA Polymerase η: Clues for Fidelity and Overall Efficiency. J Am Chem Soc 2015; 137:13240-3. [PMID: 26434497 PMCID: PMC4617179 DOI: 10.1021/jacs.5b08451] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Human DNA polymerase η (Pol η) plays an essential protective role against skin cancer caused by cyclobutane thymine-thymine dimers (TTDs), a frequent form of DNA damage arising from exposure to the sun. This enzyme rescues stalled replication forks at the TTDs by inserting bases opposite these DNA defects. Herein we calculate binding free energies for a free deoxyribose nucleotide triphosphate, dATP or dGTP, to Pol η complexed with undamaged or damaged DNA. The calculations indicate that the binding of dATP to the enzyme-DNA complex is thermodynamically favored for TTD-containing DNA over undamaged DNA, most likely because of more extensive hydrogen-bonding interactions between the TTD and the enzyme that hold the TTD more rigidly in place. The calculations also illustrate that dATP binding is thermodynamically favored over dGTP binding at both thymine positions of the TTD, most likely due to more persistent and stable hydrogen-bonding interactions between the TTD and dATP than between the TTD and dGTP. This free energy difference is slightly greater for binding at the 5' thymine position than at the 3' thymine position, presumably because of stabilization arising from the A:T base pair formed at the 3' position of the TTD in the previous step of Pol η function. All of these trends in binding free energies are consistent with experimental measurements of binding strength, fidelity, processivity, and overall efficiency. The insights gained from this analysis have implications for drug design efforts aimed at modifying the binding properties of this enzyme for improving cancer chemotherapy treatments.
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Affiliation(s)
- Melek N Ucisik
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801-3364, United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801-3364, United States
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22
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Jagodinsky JC, Sulima A, Cao Y, Poprawski JE, Blackman BN, Lloyd JR, Swenson RE, Gottesman MM, Hall MD. Evaluation of fluorophore-tethered platinum complexes to monitor the fate of cisplatin analogs. J Biol Inorg Chem 2015; 20:1081-95. [PMID: 26323351 DOI: 10.1007/s00775-015-1290-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 08/01/2015] [Indexed: 12/28/2022]
Abstract
The platinum drugs cisplatin, carboplatin, and oxaliplatin are highly utilized in the clinic and as a consequence have been extensively studied in the laboratory setting, sometimes by generating fluorophore-tagged analogs. Here, we synthesized two Pt(II) complexes containing ethane-1,2-diamine ligands linked to a BODIPY fluorophore, and compared their biological activity with previously reported Pt(II) complexes conjugated to carboxyfluorescein and carboxyfluorescein diacetate. The cytotoxicity and DNA damage capacity of Pt-fluorophore complexes was compared to cisplatin, and the Pt-BODIPY complexes were found to be more cytotoxic with reduced cytotoxicity in cisplatin-resistant cells. Microscopy revealed a predominately cytosolic localization, with nuclear distribution at higher concentrations. Spheroids grown from parent and resistant cells revealed penetration of Pt-BODIPY into spheroids, and retention of the cisplatin-resistant spheroid phenotype. While most activity profiles were retained for the Pt-BODIPY complexes, accumulation in resistant cells was only slightly affected, suggesting that some aspects of Pt-fluorophore cellular pharmacology deviate from cisplatin.
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Affiliation(s)
- Justin C Jagodinsky
- Laboratory of Cell Biology, National Cancer Institute, Center for Cancer Research, National Institutes of Health, 37 Convent Drive, Rm. 2108, Bethesda, MD, 20892, USA
| | - Agnieszka Sulima
- Imaging Probe Development Center, National Institutes of Health, Rockville, MD, USA
| | - Yiqi Cao
- Laboratory of Cell Biology, National Cancer Institute, Center for Cancer Research, National Institutes of Health, 37 Convent Drive, Rm. 2108, Bethesda, MD, 20892, USA
| | - Joanna E Poprawski
- Laboratory of Cell Biology, National Cancer Institute, Center for Cancer Research, National Institutes of Health, 37 Convent Drive, Rm. 2108, Bethesda, MD, 20892, USA
| | - Burchelle N Blackman
- Imaging Probe Development Center, National Institutes of Health, Rockville, MD, USA
| | - John R Lloyd
- Advanced Mass Spectrometry Facility, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Rolf E Swenson
- Imaging Probe Development Center, National Institutes of Health, Rockville, MD, USA
| | - Michael M Gottesman
- Laboratory of Cell Biology, National Cancer Institute, Center for Cancer Research, National Institutes of Health, 37 Convent Drive, Rm. 2108, Bethesda, MD, 20892, USA.
| | - Matthew D Hall
- Laboratory of Cell Biology, National Cancer Institute, Center for Cancer Research, National Institutes of Health, 37 Convent Drive, Rm. 2108, Bethesda, MD, 20892, USA
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23
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Nilforoushan A, Furrer A, Wyss LA, van Loon B, Sturla SJ. Nucleotides with altered hydrogen bonding capacities impede human DNA polymerase η by reducing synthesis in the presence of the major cisplatin DNA adduct. J Am Chem Soc 2015; 137:4728-34. [PMID: 25786104 DOI: 10.1021/ja512547g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human DNA polymerase η (hPol η) contributes to anticancer drug resistance by catalyzing the replicative bypass of DNA adducts formed by the widely used chemotherapeutic agent cis-diamminedichloroplatinum (cisplatin). A chemical basis for overcoming bypass-associated resistance requires greater knowledge of how small molecules influence the hPol η-catalyzed bypass of DNA adducts. In this study, we demonstrated how synthetic nucleoside triphosphates act as hPol η substrates and characterized their influence on hPol η-mediated DNA synthesis over unmodified and platinated DNA. The single nucleotide incorporation efficiency of the altered nucleotides varied by more than 10-fold and the higher incorporation rates appeared to be attributable to the presence of an additional hydrogen bond between incoming dNTP and templating base. Finally, full-length DNA synthesis in the presence of increasing concentrations of synthetic nucleotides reduced the amount of DNA product independent of the template, representing the first example of hPol η inhibition in the presence of a platinated DNA template.
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Affiliation(s)
- Arman Nilforoushan
- §Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland
| | - Antonia Furrer
- ‡Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Wintherthurerstrasse 190, 8057 Zürich, Switzerland
| | - Laura A Wyss
- §Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland
| | - Barbara van Loon
- ‡Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Wintherthurerstrasse 190, 8057 Zürich, Switzerland
| | - Shana J Sturla
- §Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland
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24
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Van Allen EM, Garraway LA, Rosenberg JE. Re: Floris H. Groenendijk, Jeroen de Jong, Elisabeth E. Fransen van de Putte, et al. ERBB2 Mutations Characterize a Subgroup of Muscle-invasive Bladder Cancers with Excellent Response to Neoadjuvant Chemotherapy. Eur Urol. In press. http://dx.doi.org/10.1016/j.eururo.2015.01.014. Eur Urol 2015; 68:e31-2. [PMID: 25770487 DOI: 10.1016/j.eururo.2015.02.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 02/27/2015] [Indexed: 11/24/2022]
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25
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Tzeng TJ, Cao L, Fu Y, Zeng H, Cheng WH. Methylseleninic acid sensitizes Notch3-activated OVCA429 ovarian cancer cells to carboplatin. PLoS One 2014; 9:e101664. [PMID: 25010594 PMCID: PMC4092030 DOI: 10.1371/journal.pone.0101664] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 06/10/2014] [Indexed: 11/18/2022] Open
Abstract
Ovarian cancer, the deadliest of gynecologic cancers, is usually not diagnosed until advanced stages. Although carboplatin has been popular for treating ovarian cancer for decades, patients eventually develop resistance to this platinum-containing drug. Expression of neurogenic locus notch homolog 3 (Notch3) is associated with chemoresistance and poor overall survival in ovarian cancer patients. Overexpression of NICD3 (the constitutively active form of Notch3) in OVCA429 ovarian cancer cells (OVCA429/NICD3) renders them resistance to carboplatin treatment compared to OVCA429/pCEG cells expressing an empty vector. We have previously shown that methylseleninic acid (MSeA) induces oxidative stress and activates ataxia-telangiectasia mutated and DNA-dependent protein kinase in cancer cells. Here we tested the hypothesis that MSeA and carboplatin exerted a synthetic lethal effect on OVCA429/NICD3 cells. Co-treatment with MSeA synergistically sensitized OVCA429/NICD3 but not OVCA429/pCEG cells to the killing by carboplatin. This synergism was associated with a cell cycle exit at the G2/M phase and the induction of NICD3 target gene HES1. Treatment of N-acetyl cysteine or inhibitors of the above two kinases did not directly impact on the synergism in OVCA429/NICD3 cells. Taken together, these results suggest that the efficacy of carboplatin in the treatment of high grade ovarian carcinoma can be enhanced by a combinational therapy with MSeA.
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Affiliation(s)
- Tiffany J. Tzeng
- Department of Nutrition and Food Science, University of Maryland, College Park, Maryland, United States of America
| | - Lei Cao
- Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Mississippi State, Mississippi, United States of America
| | - YangXin Fu
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Huawei Zeng
- USDA, Agriculture Research Service, Grand Forks Human Research Center, Grand Forks, North Dakota, United States of America
| | - Wen-Hsing Cheng
- Department of Nutrition and Food Science, University of Maryland, College Park, Maryland, United States of America
- Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Mississippi State, Mississippi, United States of America
- * E-mail:
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Hall MD, Telma KA, Chang KE, Lee TD, Madigan JP, Lloyd JR, Goldlust IS, Hoeschele JD, Gottesman MM. Say no to DMSO: dimethylsulfoxide inactivates cisplatin, carboplatin, and other platinum complexes. Cancer Res 2014; 74:3913-22. [PMID: 24812268 DOI: 10.1158/0008-5472.can-14-0247] [Citation(s) in RCA: 238] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The platinum drugs cisplatin, carboplatin, and oxaliplatin are highly utilized in the clinic and as a consequence are extensively studied in the laboratory setting. In this study, we examined the literature and found a significant number of studies (11%-34%) in prominent cancer journals utilizing cisplatin dissolved in DMSO. However, dissolving cisplatin in DMSO for laboratory-based studies results in ligand displacement and changes to the structure of the complex. We examined the effect of DMSO on platinum complexes, including cisplatin, carboplatin, and oxaliplatin, finding that DMSO reacted with the complexes, inhibited their cytotoxicity and their ability to initiate cell death. These results render a substantial portion of the literature on cisplatin uninterpretable. Raising awareness of this significant issue in the cancer biology community is critical, and we make recommendations on appropriate solvation of platinum drugs for research.
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Affiliation(s)
- Matthew D Hall
- Authors' Affiliations: Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute
| | - Katherine A Telma
- Authors' Affiliations: Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute
| | - Ki-Eun Chang
- Authors' Affiliations: Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute
| | - Tobie D Lee
- Authors' Affiliations: Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute
| | - James P Madigan
- Authors' Affiliations: Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute
| | - John R Lloyd
- Advanced Mass Spectrometry Facility, National Institute of Diabetes & Digestive & Kidney Diseases, NIH, Bethesda
| | - Ian S Goldlust
- Division of Preclinical Innovation, National Institutes of Health Chemical Genomics Center, National Center for Advancing Translational Sciences, NIH, Rockville, Maryland; and
| | - James D Hoeschele
- Department of Chemistry, Eastern Michigan University, Ypsilanti, Michigan
| | - Michael M Gottesman
- Authors' Affiliations: Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute;
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Sokol AM, Cruet-Hennequart S, Pasero P, Carty MP. DNA polymerase η modulates replication fork progression and DNA damage responses in platinum-treated human cells. Sci Rep 2013; 3:3277. [PMID: 24253929 PMCID: PMC6505966 DOI: 10.1038/srep03277] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 11/05/2013] [Indexed: 01/03/2023] Open
Abstract
Human cells lacking DNA polymerase η (polη) are sensitive to platinum-based cancer chemotherapeutic agents. Using DNA combing to directly investigate the role of polη in bypass of platinum-induced DNA lesions in vivo, we demonstrate that nascent DNA strands are up to 39% shorter in human cells lacking polη than in cells expressing polη. This provides the first direct evidence that polη modulates replication fork progression in vivo following cisplatin and carboplatin treatment. Severe replication inhibition in individual platinum-treated polη-deficient cells correlates with enhanced phosphorylation of the RPA2 subunit of replication protein A on serines 4 and 8, as determined using EdU labelling and immunofluorescence, consistent with formation of DNA strand breaks at arrested forks in the absence of polη. Polη-mediated bypass of platinum-induced DNA lesions may therefore represent one mechanism by which cancer cells can tolerate platinum-based chemotherapy.
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Affiliation(s)
- Anna M Sokol
- 1] DNA Damage Response Laboratory, Centre for Chromosome Biology, Biochemistry, School of Natural Sciences, National University of Ireland, Galway, Ireland [2]
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Carminati PO, Donaires FS, Marques MM, Donadi EA, Passos GAS, Sakamoto-Hojo ET. Cisplatin associated with LY294002 increases cytotoxicity and induces changes in transcript profiles of glioblastoma cells. Mol Biol Rep 2013; 41:165-77. [DOI: 10.1007/s11033-013-2849-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Accepted: 10/29/2013] [Indexed: 02/03/2023]
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29
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Navitoclax augments the activity of carboplatin and paclitaxel combinations in ovarian cancer cells. Gynecol Oncol 2013; 128:377-82. [DOI: 10.1016/j.ygyno.2012.11.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 11/12/2012] [Accepted: 11/14/2012] [Indexed: 11/23/2022]
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30
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LEE EUNJUNG, LEE SEUNGJIN. Etoposide increases equilibrative nucleoside transporter 1 activity and fluorothymidine uptake: Screening of 60 cytotoxic agents. Oncol Rep 2012; 29:763-70. [DOI: 10.3892/or.2012.2172] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 09/17/2012] [Indexed: 11/06/2022] Open
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31
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Krishnan A, Gopinath VR, Johnson A, Nair SA, Pillai MR. Cell-cycle analysis and micronuclei frequency reveals G0/G1 blockers as weak micronuclei inducers. Drug Chem Toxicol 2012; 36:249-54. [PMID: 23126466 DOI: 10.3109/01480545.2012.737803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Micronuclei (MN) formation is generally attributed to error in DNA synthesis or mitosis, which are represented by the S or G(2)/M phase respectively, in the cell-cycle histogram. Interestingly, many of the known anticancer drugs target these cell-cycle phases to elicit cytotoxicity. Here, we attempted to identify whether any correlation exists between the cell-cycle effect and MN induction potential using various treatments. In addition, we tracked down MN in cycling cells to assess its final fate. We treated SiHa cells with various known drugs and correlated their effects on cell-cycle and MN frequency. MN-tracking studies were performed in peripheral mononuclear and siHa cells upon staining with Giemsa and ethidium bromide respectively. We observed MN induction by all the tested drugs irrespective of their basic effect on cell cycle. However, MN induction was more with drugs which interfere with the S or G(2)/M than the G(0)/G(1) phase. Our results indicate G(0)/G(1) blockers to be comparatively safer drugs. Additionally, our results show that expulsion out of cells may be one of the main fates of drug-induced MN.
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Affiliation(s)
- Anand Krishnan
- Cancer Research, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, India
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32
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Cruet-Hennequart S, Prendergast ÁM, Shaw G, Barry FP, Carty MP. Doxorubicin induces the DNA damage response in cultured human mesenchymal stem cells. Int J Hematol 2012; 96:649-56. [PMID: 23076878 DOI: 10.1007/s12185-012-1196-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 09/22/2012] [Accepted: 09/24/2012] [Indexed: 12/19/2022]
Abstract
Anthracyclines, including doxorubicin, are widely used in the treatment of leukemia. While the effects of doxorubicin on hematopoietic cells have been characterized, less is known about the response of human mesenchymal stem cells (hMSCs) in the bone marrow stroma to anthracyclines. We characterized the effect of doxorubicin on key DNA damage responses in hMSCs, and compared doxorubicin sensitivity and DNA damage response activation between isolated hMSCs and the chronic myelogenous leukemia cell line, K562. Phosphorylation of H2AX, Chk1, and RPA2 was more strongly activated in K562 cells than in hMSCs, at equivalent doses of doxorubicin. hMSCs were relatively resistant to doxorubicin such that, following exposure to 15 μM doxorubicin, the level of cleaved caspase-3 detected by western blotting was lower in hMSCs compared to K562 cells. Flow cytometric analysis of cell cycle progression demonstrated that exposure to doxorubicin induced G2/M phase arrest in hMSCs, while 48 h after exposure, 15.6 % of cells were apoptotic, as determined from the percentage of cells having sub-G1 DNA content. We also show that the doxorubicin sensitivity of hMSCs isolated from a healthy donor was comparable to that of hMSCs isolated from a chronic lymphocytic leukemia patient. Overall, our results demonstrate that high doses of doxorubicin induce the DNA damage response in hMSCs, and that cultured hMSCs are relatively resistant to doxorubicin.
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Affiliation(s)
- Séverine Cruet-Hennequart
- DNA Damage Response Laboratory, Centre for Chromosome Biology and School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
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Hu G, Huang H, Yang L, Zhong C, Xia B, Yang Y, Liu J, Wu D, Liu Q, Zhuang Z. Down-regulation of Polη expression leads to increased DNA damage, apoptosis and enhanced S phase arrest in L-02 cells exposed to hydroquinone. Toxicol Lett 2012; 214:209-17. [DOI: 10.1016/j.toxlet.2012.08.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 08/27/2012] [Accepted: 08/28/2012] [Indexed: 01/25/2023]
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Targeting Notch, a key pathway for ovarian cancer stem cells, sensitizes tumors to platinum therapy. Proc Natl Acad Sci U S A 2012; 109:E2939-48. [PMID: 23019585 DOI: 10.1073/pnas.1206400109] [Citation(s) in RCA: 252] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Chemoresistance to platinum therapy is a major obstacle that needs to be overcome in the treatment of ovarian cancer patients. The high rates and patterns of therapeutic failure seen in patients are consistent with a steady accumulation of drug-resistant cancer stem cells (CSCs). This study demonstrates that the Notch signaling pathway and Notch3 in particular are critical for the regulation of CSCs and tumor resistance to platinum. We show that Notch3 overexpression in tumor cells results in expansion of CSCs and increased platinum chemoresistance. In contrast, γ-secretase inhibitor (GSI), a Notch pathway inhibitor, depletes CSCs and increases tumor sensitivity to platinum. Similarly, a Notch3 siRNA knockdown increases the response to platinum therapy, further demonstrating that modulation of tumor chemosensitivity by GSI is Notch specific. Most importantly, the cisplatin/GSI combination is the only treatment that effectively eliminates both CSCs and the bulk of tumor cells, indicating that a dual combination targeting both populations is needed for tumor eradication. In addition, we found that the cisplatin/GSI combination therapy has a synergistic cytotoxic effect in Notch-dependent tumor cells by enhancing the DNA-damage response, G(2)/M cell-cycle arrest, and apoptosis. Based on these results, we conclude that targeting the Notch pathway could significantly increase tumor sensitivity to platinum therapy. Our study suggests important clinical applications for targeting Notch as part of novel treatment strategies upon diagnosis of ovarian cancer and at recurrence. Both platinum-resistant and platinum-sensitive relapses may benefit from such an approach as clinical data suggest that all relapses after platinum therapy are increasingly platinum resistant.
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Nicolay NH, Carter R, Hatch SB, Schultz N, Prevo R, McKenna WG, Helleday T, Sharma RA. Homologous recombination mediates S-phase-dependent radioresistance in cells deficient in DNA polymerase eta. Carcinogenesis 2012; 33:2026-34. [PMID: 22822095 DOI: 10.1093/carcin/bgs239] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
DNA polymerase eta (pol η) is the only DNA polymerase causally linked to carcinogenesis in humans. Inherited deficiency of pol η in the variant form of xeroderma pigmentosum (XPV) predisposes to UV-light-induced skin cancer. Pol η-deficient cells demonstrate increased sensitivity to cisplatin and oxaliplatin chemotherapy. We have found that XP30R0 fibroblasts derived from a patient with XPV are more resistant to cell kill by ionising radiation (IR) than the same cells complemented with wild-type pol η. This phenomenon has been confirmed in Burkitt's lymphoma cells, which either expressed wild-type pol η or harboured a pol η deletion. Pol η deficiency was associated with accumulation of cells in S-phase, which persisted after IR. Cells deficient in pol η demonstrated increased homologous recombination (HR)-directed repair of double strand breaks created by IR. Depletion of the HR protein, X-ray repair cross-complementing protein 3 (XRCC3), abrogated the radioresistance observed in pol η-deficient cells as compared with pol η-complemented cells. These findings suggest that HR mediates S-phase-dependent radioresistance associated with pol η deficiency. We propose that pol η protein levels in tumours may potentially be used to identify patients who require treatment with chemo-radiotherapy rather than radiotherapy alone for adequate tumour control.
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Affiliation(s)
- Nils H Nicolay
- Cancer Research UK-Medical Research Council Gray Institute for Radiation Oncology and Biology, Oncology Department, Old Road Campus Research Building, University of Oxford, Oxford OX3 7DQ, UK
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Pan Y, Zhang Q, Atsaves V, Yang H, Claret FX. Suppression of Jab1/CSN5 induces radio- and chemo-sensitivity in nasopharyngeal carcinoma through changes to the DNA damage and repair pathways. Oncogene 2012; 32:2756-66. [PMID: 22797071 PMCID: PMC3566273 DOI: 10.1038/onc.2012.294] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus-associated malignancy most common in East Asia and Africa. Radiotherapy and cisplatin-based chemotherapy are the main treatment options. Unfortunately, disease response to concurrent chemoradiotherapy varies among patients with NPC, and many cases are resistant to cisplatin. Increased DNA damage repair is one of the mechanisms contributing to this resistance. Jab1/CSN5 is a multifunctional protein that participates in controlling cell proliferation and the stability of multiple proteins. Jab1 overexpression has been found to correlate with poor prognosis in several tumor types. However, the biological significance of Jab1 activity in response to cancer treatment is unclear. In this study, we used three NPC cell lines (CNE1, CNE2, and HONE1) to investigate the hypothesis that Jab1 positively regulates the DNA repair protein Rad51 and, in turn, cellular response to treatment with DNA-damaging agents such as cisplatin, ionizing radiation (IR) and ultraviolet (UV). We found that Jab1 was overexpressed in two relatively cisplatin-, IR- and UV-resistant NPC cell lines, and knocking down its expression conferred sensitivity to cisplatin, IR and UV. By contrast, exogenous Jab1 expression enhanced the resistance of NPC cells to cisplatin, IR and UV Moreover, we provide a mechanism by which Jab1 positively regulated Rad51 through p53-dependent pathway, and increased ectopic expression of Rad51 conferred cellular resistance to cisplatin, IR and UV in Jab1-deficient cells. Taken together, our findings suggest that Jab1 plays an important role in the cellular response to cisplatin and irradiation by regulating DNA damage and repair pathways. Therefore, Jab1 is a novel biomarker for predicting the outcome of patients with NPC who are treated with DNA-damaging agents.
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Affiliation(s)
- Y Pan
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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37
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Hill EJ, Nicolay NH, Middleton MR, Sharma RA. Oxaliplatin as a radiosensitiser for upper and lower gastrointestinal tract malignancies: what have we learned from a decade of translational research? Crit Rev Oncol Hematol 2012; 83:353-87. [PMID: 22309673 DOI: 10.1016/j.critrevonc.2011.12.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 12/14/2011] [Accepted: 12/28/2011] [Indexed: 01/08/2023] Open
Abstract
Some of the greatest advances in the treatment of solid malignancies have resulted from the combination of chemotherapy and radiotherapy treatments. This article comprehensively reviews the current clinical evidence for oxaliplatin-based chemo-radiotherapy that may improve local control and survival. In order to understand how clinical studies should be designed, the pre-clinical evidence for the use of oxaliplatin chemotherapy as a radiosensitising agent is appraised. Particular focus is placed on oxaliplatin's biological mechanisms of action, including cell cycle effects, the formation of DNA adducts and interstrand cross-links and the role of DNA repair proteins. At a clinical level, there is currently no evidence to suggest that oxaliplatin provides an additional benefit to concurrent chemo-radiation regimes that utilise fluoropyrimidines; we evaluate the reasons for this observation, the limitations of clinical trial design and the opportunities that currently exist to design clinical trials which are underpinned by an understanding of the basic biology.
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Affiliation(s)
- Esme J Hill
- Gray Institute of Radiation Oncology and Biology, Oncology Department, Old Road Campus Research Building, Oxford OX3 7DQ, UK
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38
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He G, Kuang J, Khokhar AR, Siddik ZH. The impact of S- and G2-checkpoint response on the fidelity of G1-arrest by cisplatin and its comparison to a non-cross-resistant platinum(IV) analog. Gynecol Oncol 2011; 122:402-9. [PMID: 21592546 DOI: 10.1016/j.ygyno.2011.04.034] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Revised: 04/18/2011] [Accepted: 04/23/2011] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Cisplatin is a DNA-damaging antitumor agent that is highly effective in treating ovarian cancer. It activates the p53/p21 pathway for its cytotoxic mode of action, but it does not induce p21-dependent cell cycle arrest in G1. Therefore, we investigated this paradox, and used the model analog DAP as a positive control for p21-dependent G1-arrest. METHODS Studies were conducted in p53-proficient ovarian A2780 tumor cells to examine Cdk activity, cell cycle distribution and DNA damage signaling after cisplatin or DAP in combination with the mitotic inhibitor nocodazole. RESULTS Cisplatin consistently induced transient S-phase arrest by inhibiting Cdk2/cyclin A complex in S-phase at 12 h and then a durable G2/M-arrest by inhibiting Cdc2/cyclin B complex at 12-18 h. These inhibitions were associated with Chk1 and Chk2 activation and resultant increase in inhibitory tyrosine phosphorylation of Cdk2 and Cdc2. Cisplatin also potently inhibited G1-phase Cdk4/cyclin D1 and Cdk2/cyclin E activities at ~18 h. In agreement, exposure of cisplatin-treated A2780, HCT-116(p53-/-) and HCT-116(p21-/-) tumor cells to nocodazole revealed limited G1-arrest that was dependent on p53 and p21. In contrast, the durable G1-arrest by DAP, which failed to activate Chk1 and Chk2, was unaffected by nocodazole. CONCLUSIONS Cisplatin induced G1-arrest, but at an attenuated level. This was primarily due to orchestration of Cdk inhibition in S-phase first, then in G2, and finally in G1 that effectively blocked cells in G2 and prevented cells from progressing and arresting in G1. These studies demonstrate that cisplatin unequivocally activates G1-checkpoint response, but the fidelity of G1-arrest is compromised by Chk1/2 activation and checkpoint response in S- and G2/M-phase.
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Affiliation(s)
- Guangan He
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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39
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Köberle B, Tomicic MT, Usanova S, Kaina B. Cisplatin resistance: Preclinical findings and clinical implications. Biochim Biophys Acta Rev Cancer 2010; 1806:172-82. [PMID: 20647037 DOI: 10.1016/j.bbcan.2010.07.004] [Citation(s) in RCA: 183] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Revised: 07/07/2010] [Accepted: 07/12/2010] [Indexed: 02/03/2023]
Affiliation(s)
- Beate Köberle
- Institute of Toxicology, University Medical Center Mainz, Germany.
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