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Shams F, Bayat H, Mohammadian O, Mahboudi S, Vahidnezhad H, Soosanabadi M, Rahimpour A. Advance trends in targeting homology-directed repair for accurate gene editing: An inclusive review of small molecules and modified CRISPR-Cas9 systems. BIOIMPACTS 2022; 12:371-391. [PMID: 35975201 PMCID: PMC9376165 DOI: 10.34172/bi.2022.23871] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 11/21/2021] [Accepted: 11/21/2021] [Indexed: 11/25/2022]
Abstract
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Introduction: Clustered regularly interspaced short palindromic repeat and its associated protein (CRISPR-Cas)-based technologies generate targeted modifications in host genome by inducing site-specific double-strand breaks (DSBs) that can serve as a substrate for homology-directed repair (HDR) in both in vitro and in vivo models. HDR pathway could enhance incorporation of exogenous DNA templates into the CRISPR-Cas9-mediated DSB site. Owing to low rate of HDR pathway, the efficiency of accurate genome editing is diminished. Enhancing the efficiency of HDR can provide fast, easy, and accurate technologies based on CRISPR-Cas9 technologies.
Methods: The current study presents an overview of attempts conducted on the precise genome editing strategies based on small molecules and modified CRISPR-Cas9 systems.
Results: In order to increase HDR rate in targeted cells, several logical strategies have been introduced such as generating CRISPR effector chimeric proteins, anti-CRISPR proteins, modified Cas9 with donor template, and using validated synthetic or natural small molecules for either inhibiting non-homologous end joining (NHEJ), stimulating HDR, or synchronizing cell cycle. Recently, high-throughput screening methods have been applied for identification of small molecules which along with the CRISPR system can regulate precise genome editing through HDR.
Conclusion: The stimulation of HDR components or inhibiting NHEJ can increase the accuracy of CRISPR-Cas-mediated engineering systems. Generating chimeric programmable endonucleases provide this opportunity to direct DNA template close proximity of CRISPR-Cas-mediated DSB. Small molecules and their derivatives can also proficiently block or activate certain DNA repair pathways and bring up novel perspectives for increasing HDR efficiency, especially in human cells. Further, high throughput screening of small molecule libraries could result in more discoveries of promising chemicals that improve HDR efficiency and CRISPR-Cas9 systems.
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Affiliation(s)
- Forough Shams
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hadi Bayat
- Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Omid Mohammadian
- Medical Nano-Technology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Somayeh Mahboudi
- Department of Food Science and Technology, School of Agriculture, Shiraz University, Shiraz, Iran
| | - Hassan Vahidnezhad
- Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
- Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Mohsen Soosanabadi
- Department of Medical Genetics, Semnan University of Medical Sciences, Semnan, Iran
| | - Azam Rahimpour
- Medical Nano-Technology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Maksoud S. The DNA Double-Strand Break Repair in Glioma: Molecular Players and Therapeutic Strategies. Mol Neurobiol 2022; 59:5326-5365. [PMID: 35696013 DOI: 10.1007/s12035-022-02915-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 06/05/2022] [Indexed: 12/12/2022]
Abstract
Gliomas are the most frequent type of tumor in the central nervous system, which exhibit properties that make their treatment difficult, such as cellular infiltration, heterogeneity, and the presence of stem-like cells responsible for tumor recurrence. The response of this type of tumor to chemoradiotherapy is poor, possibly due to a higher repair activity of the genetic material, among other causes. The DNA double-strand breaks are an important type of lesion to the genetic material, which have the potential to trigger processes of cell death or cause gene aberrations that could promote tumorigenesis. This review describes how the different cellular elements regulate the formation of DNA double-strand breaks and their repair in gliomas, discussing the therapeutic potential of the induction of this type of lesion and the suppression of its repair as a control mechanism of brain tumorigenesis.
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Affiliation(s)
- Semer Maksoud
- Experimental Therapeutics and Molecular Imaging Unit, Department of Neurology, Neuro-Oncology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA.
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3
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Chen S, Chen D, Liu B, Haisma HJ. Modulating CRISPR/Cas9 genome-editing activity by small molecules. Drug Discov Today 2021; 27:951-966. [PMID: 34823004 DOI: 10.1016/j.drudis.2021.11.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 10/25/2021] [Accepted: 11/17/2021] [Indexed: 12/12/2022]
Abstract
Clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9)-mediated genome engineering has become a standard procedure for creating genetic and epigenetic changes of DNA molecules in basic biology, biotechnology, and medicine. However, its versatile applications have been hampered by its overall low precise gene modification efficiency and uncontrollable prolonged Cas9 activity. Therefore, overcoming these problems could broaden the therapeutic use of CRISPR/Cas9-based technologies. Here, we review small molecules with the clinical potential to precisely modulate CRISPR/Cas9-mediated genome-editing activity and discuss their mechanisms of action. Based on these data, we suggest that direct-acting small molecules for Cas9 are more suitable for precisely regulating Cas9 activity. These findings provide useful information for the identification of novel small-molecule enhancers and inhibitors of Cas9 and Cas9-associated endonucleases.
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Affiliation(s)
- Siwei Chen
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Groningen 9713 AV, the Netherlands
| | - Deng Chen
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Groningen 9713 AV, the Netherlands
| | - Bin Liu
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Groningen 9713 AV, the Netherlands; RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA(1)
| | - Hidde J Haisma
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, Groningen 9713 AV, the Netherlands.
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Li L, Kumar AK, Hu Z, Guo Z. Small Molecule Inhibitors Targeting Key Proteins in the DNA Damage Response for Cancer Therapy. Curr Med Chem 2021; 28:963-985. [PMID: 32091326 DOI: 10.2174/0929867327666200224102309] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 01/17/2020] [Accepted: 01/29/2020] [Indexed: 11/22/2022]
Abstract
DNA damage response (DDR) is a complicated interactional pathway. Defects that occur in subordinate pathways of the DDR pathway can lead to genomic instability and cancer susceptibility. Abnormal expression of some proteins in DDR, especially in the DNA repair pathway, are associated with the subsistence and resistance of cancer cells. Therefore, the development of small molecule inhibitors targeting the chief proteins in the DDR pathway is an effective strategy for cancer therapy. In this review, we summarize the development of small molecule inhibitors targeting chief proteins in the DDR pathway, particularly focusing on their implications for cancer therapy. We present the action mode of DDR molecule inhibitors in preclinical studies and clinical cancer therapy, including monotherapy and combination therapy with chemotherapeutic drugs or checkpoint suppression therapy.
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Affiliation(s)
- Lulu Li
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing 210023, China
| | - Alagamuthu Karthick Kumar
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing 210023, China
| | - Zhigang Hu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing 210023, China
| | - Zhigang Guo
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing 210023, China
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5
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Genomic, Transcriptomic, and Functional Alterations in DNA Damage Response Pathways as Putative Biomarkers of Chemotherapy Response in Ovarian Cancer. Cancers (Basel) 2021; 13:cancers13061420. [PMID: 33804647 PMCID: PMC8003626 DOI: 10.3390/cancers13061420] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/17/2021] [Accepted: 03/17/2021] [Indexed: 12/24/2022] Open
Abstract
Simple Summary Several chemotherapy drugs are approved for ovarian cancer treatment in the neo-adjuvant/adjuvant setting as well as following relapse. These include carboplatin, paclitaxel, doxorubicin, topotecan, PARP inhibitors (PARPi), and gemcitabine. However, except for PAPRi, there are no predictive biomarkers to guide the choice of drug. The majority of chemotherapeutic drugs function by inducing DNA damage or inhibiting its repair. However, the association of DNA damage repair (DDR) pathway alterations with therapy response remain unclear. In this study, using a panel of 14 ovarian cancer cell lines, 10 patient ascites-derived primary cultures and bioinformatic analysis of The Cancer Genome Atlas (TCGA) ovarian cancer dataset, we identified the role of genomic/transcriptomic and/or functional alterations in DDR pathways as determinants of therapy response. Abstract Defective DNA damage response (DDR) pathways are enabling characteristics of cancers that not only can be exploited to specifically target cancer cells but also can predict chemotherapy response. Defective Homologous Recombination Repair (HRR) function, e.g., due to BRCA1/2 loss, is a determinant of response to platinum agents and PARP inhibitors in ovarian cancers. Most chemotherapies function by either inducing DNA damage or impacting on its repair but are generally used in the clinic unselectively. The significance of HRR and other DDR pathways in determining response to several other chemotherapy drugs is not well understood. In this study, the genomic, transcriptomic and functional analysis of DDR pathways in a panel of 14 ovarian cancer cell lines identified that defects in DDR pathways could determine response to several chemotherapy drugs. Carboplatin, rucaparib, and topotecan sensitivity were associated with functional loss of HRR (validated in 10 patient-derived primary cultures) and mismatch repair. Two DDR gene expression clusters correlating with treatment response were identified, with PARP10 identified as a novel marker of platinum response, which was confirmed in The Cancer Genome Atlas (TCGA) ovarian cancer cohort. Reduced non-homologous end-joining function correlated with increased sensitivity to doxorubicin, while cells with high intrinsic oxidative stress showed sensitivity to gemcitabine. In this era of personalised medicine, molecular/functional characterisation of DDR pathways could guide chemotherapy choices in the clinic allowing specific targeting of ovarian cancers.
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Bürkel F, Jost T, Hecht M, Heinzerling L, Fietkau R, Distel L. Dual mTOR/DNA-PK Inhibitor CC-115 Induces Cell Death in Melanoma Cells and Has Radiosensitizing Potential. Int J Mol Sci 2020; 21:ijms21239321. [PMID: 33297429 PMCID: PMC7730287 DOI: 10.3390/ijms21239321] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/03/2020] [Accepted: 12/05/2020] [Indexed: 12/20/2022] Open
Abstract
CC-115 is a dual inhibitor of the mechanistic target of rapamycin (mTOR) kinase and the DNA-dependent protein kinase (DNA-PK) that is currently being studied in phase I/II clinical trials. DNA-PK is essential for the repair of DNA-double strand breaks (DSB). Radiotherapy is frequently used in the palliative treatment of metastatic melanoma patients and induces DSBs. Melanoma cell lines and healthy-donor skin fibroblast cell lines were treated with CC‑115 and ionizing irradiation (IR). Apoptosis, necrosis, and cell cycle distribution were analyzed. Colony forming assays were conducted to study radiosensitizing effects. Immunofluorescence microscopy was performed to determine the activity of homologous recombination (HR). In most of the malign cell lines, an increasing concentration of CC-115 resulted in increased cell death. Furthermore, strong cytotoxic effects were only observed in malignant cell lines. Regarding clonogenicity, all cell lines displayed decreased survival fractions during combined inhibitor and IR treatment and supra-additive effects of the combination were observable in 5 out of 9 melanoma cell lines. CC-115 showed radiosensitizing potential in 7 out of 9 melanoma cell lines, but not in healthy skin fibroblasts. Based on our data CC-115 treatment could be a promising approach for patients with metastatic melanoma, particularly in the combination with radiotherapy.
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Affiliation(s)
- Felix Bürkel
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstr. 27, 91054 Erlangen, Germany; (F.B.); (T.J.); (M.H.); (R.F.)
| | - Tina Jost
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstr. 27, 91054 Erlangen, Germany; (F.B.); (T.J.); (M.H.); (R.F.)
| | - Markus Hecht
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstr. 27, 91054 Erlangen, Germany; (F.B.); (T.J.); (M.H.); (R.F.)
| | - Lucie Heinzerling
- Department of Dermatology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Ulmenweg 18, 91054 Erlangen, Germany;
| | - Rainer Fietkau
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstr. 27, 91054 Erlangen, Germany; (F.B.); (T.J.); (M.H.); (R.F.)
| | - Luitpold Distel
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstr. 27, 91054 Erlangen, Germany; (F.B.); (T.J.); (M.H.); (R.F.)
- Correspondence: ; Tel.: +49-9131-85-32312
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7
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Inhibitors of DNA double-strand break repair at the crossroads of cancer therapy and genome editing. Biochem Pharmacol 2020; 182:114195. [DOI: 10.1016/j.bcp.2020.114195] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/03/2020] [Accepted: 08/10/2020] [Indexed: 12/17/2022]
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8
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Rahimian E, Amini A, Alikarami F, Pezeshki SMS, Saki N, Safa M. DNA repair pathways as guardians of the genome: Therapeutic potential and possible prognostic role in hematologic neoplasms. DNA Repair (Amst) 2020; 96:102951. [PMID: 32971475 DOI: 10.1016/j.dnarep.2020.102951] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/30/2020] [Accepted: 08/10/2020] [Indexed: 11/30/2022]
Abstract
DNA repair pathways, which are also identified as guardians of the genome, protect cells from frequent damage that can lead to DNA breaks. The most deleterious types of damage are double-strand breaks (DSBs), which are repaired by homologous recombination (HR) and non-homologous end joining (NHEJ). Single strand breaks (SSBs) can be corrected through base excision repair (BER), nucleotide excision repair (NER), and mismatch repair (MMR). Failure to restore DNA lesions or inappropriately repaired DNA damage culminates in genomic instability and changes in the regulation of cellular functions. Intriguingly, particular mutations and translocations are accompanied by special types of leukemia. Besides, expression patterns of certain repair genes are altered in different hematologic malignancies. Moreover, analysis of mutations in key mediators of DNA damage repair (DDR) pathways, as well as investigation of their expression and function, may provide us with emerging biomarkers of response/resistance to treatment. Therefore, defective DDR pathways can offer a rational starting point for developing DNA repair-targeted drugs. In this review, we address genetic alterations and gene/protein expression changes, as well as provide an overview of DNA repair pathways.
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Affiliation(s)
- Elahe Rahimian
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Ali Amini
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Alikarami
- Center for Childhood Cancer Research, Children's Hospital of Philadelphia (CHOP), Philadelphia, PA 19104, USA
| | - Seyed Mohammad Sadegh Pezeshki
- Thalassemia & Hemoglobinopathy Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Najmaldin Saki
- Thalassemia & Hemoglobinopathy Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Majid Safa
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran; Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.
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9
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Kopa P, Macieja A, Gulbas I, Pastwa E, Poplawski T. Inhibition of DNA-PK potentiates the synergistic effect of NK314 and etoposide combination on human glioblastoma cells. Mol Biol Rep 2019; 47:67-76. [PMID: 31583565 DOI: 10.1007/s11033-019-05105-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 09/25/2019] [Indexed: 12/20/2022]
Abstract
Etoposide (VP-16) is the topoisomerase 2 (Top2) inhibitor used for treating of glioma patients however at high dose with serious side effects. It induces DNA double-strand breaks (DSBs). These DNA lesions are repaired by non-homologous DNA end joining (NHEJ) mediated by DNA-dependent protein kinase (DNA-PK). One possible approach to decrease the toxicity of etoposide is to reduce the dose while maintaining the anticancer potential. It could be achieved through combined therapy with other anticancer drugs. We have assumed that this objective can be obtained by (1) a parallel topo2 α inhibition and (2) sensitization of cancer cells to DSBs. In this work we investigated the effect of two Top2 inhibitors NK314 and VP-16 in glioma cell lines (MO59 K and MO59 J) sensitized by DNA-PK inhibitor, NU7441. Cytotoxic effect of VP-16, NK314 alone and in combination on human glioblastoma cell lines, was assessed by a colorimetric assay. Genotoxic effect of anticancer drugs in combination with NU7441 was assessed by comet assay. Cell cycle distribution and apoptosis were analysed by flow cytometry. Compared with VP-16 or NK314 alone, the combined treatment significantly inhibited cell proliferation. Combination treatment was associated with a strong accumulation of DSBs, modulated cell cycle phases distribution and apoptotic cell death. NU7441 potentiated these effects and additionally postponed DNA repair. Our findings suggest that NK314 could overcome resistance of MO59 cells to VP-16 and NU7441 could serve as sensitizer to VP-16/NK314 combined treatment. The combined tripartite approach of chemotherapy could reduce the overall toxicity associated with each individual therapy, while concomitantly enhancing the anticancer effect to treat human glioma cells. Thus, the use of a tripartite combinatorial approach could be promising and more efficacious than mono therapy or dual therapy to treat and increase the survival of the glioblastoma patients.
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Affiliation(s)
- Paulina Kopa
- Department of Immunopathology, Division of Allergology, Immunology and Immunopathology, Faculty of Biomedical Sciences and Postgraduate Training, Medical University of Lodz, Lodz, Poland
| | - Anna Macieja
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Izabela Gulbas
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Elzbieta Pastwa
- Functional Genomics & Proteomics Unit, ITSI-Biosciences, Johnstown, PA, USA
| | - Tomasz Poplawski
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.
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10
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Kinase-independent inhibition of cyclophosphamide-induced pathways protects the ovarian reserve and prolongs fertility. Cell Death Dis 2019; 10:726. [PMID: 31562295 PMCID: PMC6765024 DOI: 10.1038/s41419-019-1961-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 08/07/2019] [Accepted: 08/27/2019] [Indexed: 01/27/2023]
Abstract
Premature ovarian failure and infertility are adverse effects of cancer therapies. The mechanism underlying chemotherapy-mediated depletion of the ovarian reserve remains unclear. Here, we aim to identify the signaling pathways involved in the loss of the ovarian reserve to prevent the damaging effects of chemotherapy. We evaluated the effects of cyclophosphamide, one of the most damaging chemotherapeutic drugs, against follicle reserve. In vivo studies showed that the cyclophosphamide-induced loss of ovarian reserve occurred through a sequential mechanism. Cyclophosphamide exposure induced the activation of both DNAPK-γH2AX-checkpoint kinase 2 (CHK2)-p53/TAp63α isoform and protein kinase B (AKT)-forkhead box O3 (FOXO3a) signaling axes in the nucleus of oocytes. Concomitant administration of an allosteric ABL inhibitor and cyclophosphamide modulated both pathways while protecting the ovarian reserve from chemotherapy assaults. As a consequence, the fertility of the treated mice was prolonged. On the contrary, the administration of an allosteric ABL activator enhanced the lethal effects of cyclophosphamide while shortening mouse fertility. Therefore, kinase-independent inhibition may serve as an effective ovarian-protective strategy in women under chemotherapy.
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11
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Wong WW, Jackson RK, Liew LP, Dickson BD, Cheng GJ, Lipert B, Gu Y, Hunter FW, Wilson WR, Hay MP. Hypoxia-selective radiosensitisation by SN38023, a bioreductive prodrug of DNA-dependent protein kinase inhibitor IC87361. Biochem Pharmacol 2019; 169:113641. [PMID: 31541630 DOI: 10.1016/j.bcp.2019.113641] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 09/16/2019] [Indexed: 02/06/2023]
Abstract
DNA-dependent protein kinase (DNA-PK) plays a key role in repair of radiation-induced DNA double strand breaks (DSB) by non-homologous end-joining. DNA-PK inhibitors (DNA-PKi) are therefore efficient radiosensitisers, but normal tissue radiosensitisation represents a risk for their use in radiation oncology. Here we describe a novel prodrug, SN38023, that is metabolised to a potent DNA-PKi (IC87361) selectively in radioresistant hypoxic cells. DNA-PK inhibitory potency of SN38023 was 24-fold lower than IC87361 in cell-free assays, consistent with molecular modelling studies suggesting that SN38023 is unable to occupy one of the predicted DNA-PK binding modes of IC87361. One-electron reduction of the prodrug by radiolysis of anoxic formate solutions, and by metabolic reduction in anoxic HCT116/POR cells that overexpress cytochrome P450 oxidoreductase (POR), generated IC87361 efficiently as assessed by LC-MS. SN38023 inhibited radiation-induced Ser2056 autophosphorylation of DNA-PK catalytic subunit and radiosensitised HCT116/POR and UT-SCC-54C cells selectively under anoxia. SN38023 was an effective radiosensitiser in anoxic HCT116 spheroids, demonstrating potential for penetration into hypoxic tumour tissue, but in spheroid co-cultures of high-POR and POR-null cells it showed no evidence of bystander effects resulting from local diffusion of IC87361. Pharmacokinetics of IC87361 and SN38023 at maximum achievable doses in NIH-III mice demonstrated sub-optimal exposure of UT-SCC-54C tumour xenografts and did not provide significant tumour radiosensitisation. In conclusion, SN38023 has potential for exploiting hypoxia for selective delivery of a potent DNA-PKi to the most radioresistant subpopulation of cells in tumours. However, prodrugs providing improved systemic pharmacokinetics and that release DNA-PKi that elicit bystander effects are needed to maximise therapeutic utility.
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Affiliation(s)
- Way Wua Wong
- Auckland Cancer Society Research Centre, University of Auckland, New Zealand
| | - Rosanna K Jackson
- Auckland Cancer Society Research Centre, University of Auckland, New Zealand
| | - Lydia P Liew
- Auckland Cancer Society Research Centre, University of Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Benjamin D Dickson
- Auckland Cancer Society Research Centre, University of Auckland, New Zealand
| | - Gary J Cheng
- Auckland Cancer Society Research Centre, University of Auckland, New Zealand
| | - Barbara Lipert
- Auckland Cancer Society Research Centre, University of Auckland, New Zealand
| | - Yongchuan Gu
- Auckland Cancer Society Research Centre, University of Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - Francis W Hunter
- Auckland Cancer Society Research Centre, University of Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - William R Wilson
- Auckland Cancer Society Research Centre, University of Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand.
| | - Michael P Hay
- Auckland Cancer Society Research Centre, University of Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
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12
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Kopa P, Macieja A, Galita G, Witczak ZJ, Poplawski T. DNA Double Strand Breaks Repair Inhibitors: Relevance as Potential New Anticancer Therapeutics. Curr Med Chem 2019; 26:1483-1493. [PMID: 29446719 DOI: 10.2174/0929867325666180214113154] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 01/22/2018] [Accepted: 01/23/2018] [Indexed: 12/19/2022]
Abstract
DNA double-strand breaks are considered one of the most lethal forms of DNA damage. Many effective anticancer therapeutic approaches used chemical and physical methods to generate DNA double-strand breaks in the cancer cells. They include: IR and drugs which mimetic its action, topoisomerase poisons, some alkylating agents or drugs which affected DNA replication process. On the other hand, cancer cells are mostly characterized by highly effective systems of DNA damage repair. There are two main DNA repair pathways used to fix double-strand breaks: NHEJ and HRR. Their activity leads to a decreased effect of chemotherapy. Targeting directly or indirectly the DNA double-strand breaks response by inhibitors seems to be an exciting option for anticancer therapy and is a part of novel trends that arise after the clinical success of PARP inhibitors. These trends will provide great opportunities for the development of DNA repair inhibitors as new potential anticancer drugs. The main objective of this article is to address these new promising advances.
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Affiliation(s)
- Paulina Kopa
- Department of Immunopathology, Faculty of Biomedical Sciences and Postgraduate Training, Medical University of Lodz, Lodz 90-752, Poland
| | - Anna Macieja
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz 90-236, Poland
| | - Grzegorz Galita
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz 90-236, Poland
| | - Zbigniew J Witczak
- Department of Pharmaceutical Sciences, Nesbitt School of Pharmacy, Wilkes University, Wilkes-Barre, PA 18766, United States
| | - Tomasz Poplawski
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz 90-236, Poland
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13
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Ihara M, Ashizawa K, Shichijo K, Kudo T. Expression of the DNA-dependent protein kinase catalytic subunit is associated with the radiosensitivity of human thyroid cancer cell lines. JOURNAL OF RADIATION RESEARCH 2019; 60:171-177. [PMID: 30476230 PMCID: PMC6430255 DOI: 10.1093/jrr/rry097] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/13/2018] [Indexed: 05/02/2023]
Abstract
The prognosis and treatment of thyroid cancer depends on the type and stage of the disease. Radiosensitivity differs among cancer cells owing to their varying capacity for repair after irradiation. Radioactive iodine can be used to destroy thyroid cancer cells. However, patient prognosis and improvement after irradiation varies. Therefore, predictive measures are important for avoiding unnecessary exposure to radiation. We describe a new method for predicting the effects of radiation in individual cases of thyroid cancer based on the DNA-dependent protein kinase (DNA-PK) activity level in cancer cells. The radiation sensitivity, DNA-PK activity, and cellular levels of DNA-PK complex subunits in five human thyroid cancer cell lines were analyzed in vitro. A positive correlation was observed between the D10 value (radiation dose that led to 10% survival) of cells and DNA-PK activity. This correlation was not observed after treatment with NU7441, a DNA-PK-specific inhibitor. A significant correlation was also observed between DNA-PK activity and expression levels of the DNA-PK catalytic subunit (DNA-PKcs). Cells expressing low DNA-PKcs levels were radiation-sensitive, and cells expressing high DNA-PKcs levels were radiation-resistant. Our results indicate that radiosensitivity depends on the expression level of DNA-PKcs in thyroid cancer cell lines. Thus, the DNA-PKcs expression level is a potential predictive marker of the success of radiation therapy for thyroid tumors.
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Affiliation(s)
- Makoto Ihara
- Department of Radioisotope Medicine, Atomic Bomb Disease and Hibakusha Medicine Unit, Atomic Bomb Disease Institute Nagasaki University, 1-12-4 Sakamoto, Nagasaki, Nagasaki, Japan
- Corresponding author. Department of Radioisotope Medicine, Atomic Bomb Disease and Hibakusha Medicine Unit, Atomic Bomb Disease Institute, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, Nagasaki 852-8523, Japan. Tel: +81-95-819-71013; Fax: +81-95-849-7104;
| | - Kiyoto Ashizawa
- Department of Radioisotope Medicine, Atomic Bomb Disease and Hibakusha Medicine Unit, Atomic Bomb Disease Institute Nagasaki University, 1-12-4 Sakamoto, Nagasaki, Nagasaki, Japan
| | - Kazuko Shichijo
- Department of Tumor and Diagnostic Pathology, Atomic Bomb Disease and Hibakusha Medicine Unit, Atomic Bomb Disease Institute, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, Nagasaki, Japan
| | - Takashi Kudo
- Department of Radioisotope Medicine, Atomic Bomb Disease and Hibakusha Medicine Unit, Atomic Bomb Disease Institute Nagasaki University, 1-12-4 Sakamoto, Nagasaki, Nagasaki, Japan
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14
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Kohutova A, Raška J, Kruta M, Seneklova M, Barta T, Fojtik P, Jurakova T, Walter CA, Hampl A, Dvorak P, Rotrekl V. Ligase 3–mediated end‐joining maintains genome stability of human embryonic stem cells. FASEB J 2019; 33:6778-6788. [DOI: 10.1096/fj.201801877rr] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Aneta Kohutova
- Department of BiologyMasaryk UniversityBrnoCzech Republic
- International Clinical Research Center (ICRC)St. Anne's University HospitalBrnoCzech Republic
| | - Jan Raška
- Department of BiologyMasaryk UniversityBrnoCzech Republic
| | - Miriama Kruta
- Department of BiologyMasaryk UniversityBrnoCzech Republic
| | | | - Tomas Barta
- Department of BiologyMasaryk UniversityBrnoCzech Republic
| | - Petr Fojtik
- Department of BiologyMasaryk UniversityBrnoCzech Republic
| | | | - Christi A. Walter
- Department of Cell Systems and AnatomyThe University of Texas Health Science Center at San AntonioSan AntonioTexasUSA
| | - Ales Hampl
- Department of Histology and EmbryologyFaculty of MedicineMasaryk UniversityBrnoCzech Republic
- International Clinical Research Center (ICRC)St. Anne's University HospitalBrnoCzech Republic
| | - Petr Dvorak
- Department of BiologyMasaryk UniversityBrnoCzech Republic
- International Clinical Research Center (ICRC)St. Anne's University HospitalBrnoCzech Republic
| | - Vladimir Rotrekl
- Department of BiologyMasaryk UniversityBrnoCzech Republic
- International Clinical Research Center (ICRC)St. Anne's University HospitalBrnoCzech Republic
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15
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16
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Purin-6-one and pyrrolo[2,3-d]pyrimidin-4-one derivatives as potentiating agents of doxorubicin cytotoxicity. Future Med Chem 2018; 10:2029-2038. [PMID: 30067076 DOI: 10.4155/fmc-2018-0086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
AIM DNA damage response plays an eminent role in patients' response to conventional chemotherapy and radiotherapy. Its inhibition is of great interest as it can overcome cancer cell resistance and reduce the effective doses of DNA damaging agents. Results & methodology: We have focused our research on phosphatidylinositol 3-kinase-related kinases and prepared 35 novel compounds through a scaffold hopping approach. The newly synthesized inhibitors were tested on a panel of nine cancer and one healthy cell lines alone and in combination with appropriate doses of doxorubicin. CONCLUSION Five novel compounds 4f, 10b, 15g, 7e and 15f in combination with doxorubicin showed significant antiproliferative effect on seven cancer cell lines while not affecting the cell growth alone.
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17
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Prakash A, Garcia-Moreno JF, Brown JAL, Bourke E. Clinically Applicable Inhibitors Impacting Genome Stability. Molecules 2018; 23:E1166. [PMID: 29757235 PMCID: PMC6100577 DOI: 10.3390/molecules23051166] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 04/27/2018] [Accepted: 05/01/2018] [Indexed: 12/14/2022] Open
Abstract
Advances in technology have facilitated the molecular profiling (genomic and transcriptomic) of tumours, and has led to improved stratification of patients and the individualisation of treatment regimes. To fully realize the potential of truly personalised treatment options, we need targeted therapies that precisely disrupt the compensatory pathways identified by profiling which allow tumours to survive or gain resistance to treatments. Here, we discuss recent advances in novel therapies that impact the genome (chromosomes and chromatin), pathways targeted and the stage of the pathways targeted. The current state of research will be discussed, with a focus on compounds that have advanced into trials (clinical and pre-clinical). We will discuss inhibitors of specific DNA damage responses and other genome stability pathways, including those in development, which are likely to synergistically combine with current therapeutic options. Tumour profiling data, combined with the knowledge of new treatments that affect the regulation of essential tumour signalling pathways, is revealing fundamental insights into cancer progression and resistance mechanisms. This is the forefront of the next evolution of advanced oncology medicine that will ultimately lead to improved survival and may, one day, result in many cancers becoming chronic conditions, rather than fatal diseases.
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Affiliation(s)
- Anu Prakash
- Discipline of Pathology, Lambe Institute for Translational Research, School of Medicine, National University of Ireland Galway, H91 YR71 Galway, Ireland.
| | - Juan F Garcia-Moreno
- Discipline of Surgery, Lambe Institute for Translational Research, School of Medicine, National University of Ireland Galway, H91 YR71 Galway, Ireland.
| | - James A L Brown
- Discipline of Surgery, Lambe Institute for Translational Research, School of Medicine, National University of Ireland Galway, H91 YR71 Galway, Ireland.
| | - Emer Bourke
- Discipline of Pathology, Lambe Institute for Translational Research, School of Medicine, National University of Ireland Galway, H91 YR71 Galway, Ireland.
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18
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Timme CR, Rath BH, O'Neill JW, Camphausen K, Tofilon PJ. The DNA-PK Inhibitor VX-984 Enhances the Radiosensitivity of Glioblastoma Cells Grown In Vitro and as Orthotopic Xenografts. Mol Cancer Ther 2018; 17:1207-1216. [PMID: 29549168 DOI: 10.1158/1535-7163.mct-17-1267] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 02/05/2018] [Accepted: 03/12/2018] [Indexed: 11/16/2022]
Abstract
Radiotherapy is a primary treatment modality for glioblastomas (GBM). Because DNA-PKcs is a critical factor in the repair of radiation-induced double strand breaks (DSB), this study evaluated the potential of VX-984, a new DNA-PKcs inhibitor, to enhance the radiosensitivity of GBM cells. Treatment of the established GBM cell line U251 and the GBM stem-like cell (GSC) line NSC11 with VX-984 under in vitro conditions resulted in a concentration-dependent inhibition of radiation-induced DNA-PKcs phosphorylation. In a similar concentration-dependent manner, VX-984 treatment enhanced the radiosensitivity of each GBM cell line as defined by clonogenic analysis. As determined by γH2AX expression and neutral comet analyses, VX-984 inhibited the repair of radiation-induced DNA double-strand break in U251 and NSC11 GBM cells, suggesting that the VX-984-induced radiosensitization is mediated by an inhibition of DNA repair. Extending these results to an in vivo model, treatment of mice with VX-984 inhibited radiation-induced DNA-PKcs phosphorylation in orthotopic brain tumor xenografts, indicating that this compound crosses the blood-brain tumor barrier at sufficient concentrations. For mice bearing U251 or NSC11 brain tumors, VX-984 treatment alone had no significant effect on overall survival; radiation alone increased survival. The survival of mice receiving the combination protocol was significantly increased as compared with control and as compared with radiation alone. These results indicate that VX-984 enhances the radiosensitivity of brain tumor xenografts and suggest that it may be of benefit in the therapeutic management of GBM. Mol Cancer Ther; 17(6); 1207-16. ©2018 AACR.
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Affiliation(s)
- Cindy R Timme
- Radiation Oncology Branch, National Cancer Institute, Bethesda, Maryland
| | - Barbara H Rath
- Radiation Oncology Branch, National Cancer Institute, Bethesda, Maryland
| | - John W O'Neill
- Radiation Oncology Branch, National Cancer Institute, Bethesda, Maryland
| | - Kevin Camphausen
- Radiation Oncology Branch, National Cancer Institute, Bethesda, Maryland
| | - Philip J Tofilon
- Radiation Oncology Branch, National Cancer Institute, Bethesda, Maryland.
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19
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Adamowicz M, d'Adda di Fagagna F, Vermezovic J. NOTCH1 modulates activity of DNA-PKcs. Mutat Res 2018; 808:20-27. [PMID: 29482073 DOI: 10.1016/j.mrfmmm.2018.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 01/13/2018] [Indexed: 11/18/2022]
Abstract
DNA-dependent protein kinase catalytic subunit (DNA-PKcs) controls one of the most frequently used DNA repair pathways in a cell, the non-homologous end joining (NHEJ) pathway. However, the exact role of DNA-PKcs in NHEJ remains poorly defined. Here we show that NOTCH1 attenuates DNA-PKcs-mediated autophosphorylation, as well as the phosphorylation of its specific substrate XRCC4. Surprisingly, NOTCH1-expressing cells do not display any significant impairment in the DNA damage repair, nor cellular survival, and remain sensitive to small molecule DNA-PKcs inhibitor. Additionally, in vitro DNA-PKcs kinase assay shows that NOTCH1 does not inhibit DNA-PKcs kinase activity, implying that NOTCH1 acts on DNA-PKcs through a different mechanism. Together, our set of results suggests that NOTCH1 is a physiological modulator of DNA-PKcs, and that it can be a useful tool to clarify the mechanisms by which DNA-PKcs governs NHEJ DNA repair.
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Affiliation(s)
- Marek Adamowicz
- IFOM Foundation - FIRC Institute of Molecular Oncology Foundation, 20139 Milan, Italy; Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RH, UK.
| | - Fabrizio d'Adda di Fagagna
- IFOM Foundation - FIRC Institute of Molecular Oncology Foundation, 20139 Milan, Italy; Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche, 27100 Pavia, Italy
| | - Jelena Vermezovic
- IFOM Foundation - FIRC Institute of Molecular Oncology Foundation, 20139 Milan, Italy.
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20
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Dong J, Ren Y, Zhang T, Wang Z, Ling CC, Li GC, He F, Wang C, Wen B. Inactivation of DNA-PK by knockdown DNA-PKcs or NU7441 impairs non-homologous end-joining of radiation-induced double strand break repair. Oncol Rep 2018; 39:912-920. [PMID: 29344644 PMCID: PMC5802037 DOI: 10.3892/or.2018.6217] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 12/20/2017] [Indexed: 12/15/2022] Open
Abstract
The DNA-dependent protein kinase (DNA-PK) complex plays a pivotal role in non-homologous end-joining (NHEJ) repair. We investigated the mechanism of NU7441, a highly selective DNA-PK inhibitor, in NHEJ-competent mouse embryonic fibroblast (MEF) cells and NHEJ-deficient cells and explored the feasibility of its application in radiosensitizing nasopharyngeal carcinoma (NPC) cells. We generated wild-type and DNA-PKcs−/− MEF cells. Clonogenic survival assays, flow cytometry, and immunoblotting were performed to study the effect of NU7441 on survival, cell cycle, and DNA repair. NU7441 profoundly radiosensitized wild-type MEF cells and SUNE-1 cells, but not DNA-PKcs−/− MEF cells. NU7441 significantly suppressed radiation-induced DSB repair post-irradiation through unrepaired and lethal DNA damage, the cell cycle arrest. The effect was associated with the activation of cell cycle checkpoints. The present study revealed a mechanism by which inhibition of DNA-PK sensitizes cells to irradiation suggesting that radiotherapy in combination with DNA-PK inhibitor is a promising paradigm for the management of NPC which merits further investigation.
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Affiliation(s)
- Jun Dong
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Yufeng Ren
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Tian Zhang
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Zhenyu Wang
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Clifton C Ling
- Department of Medical Physics and Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
| | - Gloria C Li
- Department of Medical Physics and Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
| | - Fuqiu He
- Department of Medical Physics and Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA
| | - Chengtao Wang
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Bixiu Wen
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
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21
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CC-115, a dual inhibitor of mTOR kinase and DNA-PK, blocks DNA damage repair pathways and selectively inhibits ATM-deficient cell growth in vitro. Oncotarget 2017; 8:74688-74702. [PMID: 29088817 PMCID: PMC5650372 DOI: 10.18632/oncotarget.20342] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 07/25/2017] [Indexed: 12/15/2022] Open
Abstract
CC-115, a selective dual inhibitor of the mammalian target of rapamycin (mTOR) kinase and DNA-dependent protein kinase (DNA-PK), is undergoing Phase 1 clinical studies. Here we report the characterization of DNA-PK inhibitory activity of CC-115 in cancer cell lines. CC-115 inhibits auto-phosphorylation of the catalytic subunit of DNA-PK (DNA-PKcs) at the S2056 site (pDNA-PK S2056), leading to blockade of DNA-PK-mediated non-homologous end joining (NHEJ). CC-115 also indirectly reduces the phosphorylation of ataxia-telangiectasia mutated kinase (ATM) at S1981 and its substrates as well as homologous recombination (HR). The mTOR kinase and DNA-PK inhibitory activity of CC-115 leads to not only potent anti-tumor activity against a large panel of hematopoietic and solid cancer cell lines but also strong induction of apoptosis in a subset of cancer lines. Mechanistically, CC-115 prevents NHEJ by inhibiting the dissociation of DNA-PKcs, X-ray repair cross-complementing protein 4 (XRCC4), and DNA ligase IV from DNA ends. CC-115 inhibits colony formation of ATM-deficient cells more potently than ATM-proficient cells, indicating that inhibition of DNA-PK is synthetically lethal with the loss of functional ATM. In conclusion, CC-115 inhibits both mTOR signaling and NHEJ and HR by direct inhibition of DNA-PK. The mechanistic data not only provide selection of potential pharmacodynamic (PD) markers but also support CC-115 clinical development in patients with ATM-deficient tumors.
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22
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Ihmaid S, Ahmed HE, Al-Sheikh Ali A, Sherif YE, Tarazi HM, Riyadh SM, Zayed MF, Abulkhair HS, Rateb HS. Rational design, synthesis, pharmacophore modeling, and docking studies for identification of novel potent DNA-PK inhibitors. Bioorg Chem 2017; 72:234-247. [DOI: 10.1016/j.bioorg.2017.04.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Revised: 04/12/2017] [Accepted: 04/13/2017] [Indexed: 10/19/2022]
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23
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Sunada S, Kanai H, Lee Y, Yasuda T, Hirakawa H, Liu C, Fujimori A, Uesaka M, Okayasu R. Nontoxic concentration of DNA-PK inhibitor NU7441 radio-sensitizes lung tumor cells with little effect on double strand break repair. Cancer Sci 2016; 107:1250-5. [PMID: 27341700 PMCID: PMC5021029 DOI: 10.1111/cas.12998] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/21/2016] [Accepted: 06/23/2016] [Indexed: 12/19/2022] Open
Abstract
High‐linear energy transfer (LET) heavy ions have been increasingly employed as a useful alternative to conventional photon radiotherapy. As recent studies suggested that high LET radiation mainly affects the nonhomologous end‐joining (NHEJ) pathway of DNA double strand break (DSB) repair, we further investigated this concept by evaluating the combined effect of an NHEJ inhibitor (NU7441) at a non‐toxic concentration and carbon ions. NU7441‐treated non‐small cell lung cancer (NSCLC) A549 and H1299 cells were irradiated with X‐rays and carbon ions (290 MeV/n, 50 keV/μm). Cell survival was measured by clonogenic assay. DNA DSB repair, cell cycle distribution, DNA fragmentation and cellular senescence induction were studied using a flow cytometer. Senescence‐associated protein p21 was detected by western blotting. In the present study, 0.3 μM of NU7441, nontoxic to both normal and tumor cells, caused a significant radio‐sensitization in tumor cells exposed to X‐rays and carbon ions. This concentration did not seem to cause inhibition of DNA DSB repair but induced a significant G2/M arrest, which was particularly emphasized in p53‐null H1299 cells treated with NU7441 and carbon ions. In addition, the combined treatment induced more DNA fragmentation and a higher degree of senescence in H1299 cells than in A549 cells, indicating that DNA‐PK inhibitor contributes to various modes of cell death in a p53‐dependent manner. In summary, NSCLC cells irradiated with carbon ions were radio‐sensitized by a low concentration of DNA‐PK inhibitor NU7441 through a strong G2/M cell cycle arrest. Our findings may contribute to further effective radiotherapy using heavy ions.
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Affiliation(s)
- Shigeaki Sunada
- Department of Nuclear Engineering and Management, School of Engineering, University of Tokyo, Tokyo, Japan.,Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba, Japan
| | - Hideki Kanai
- Department of Nuclear Engineering and Management, School of Engineering, University of Tokyo, Tokyo, Japan.,Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba, Japan
| | - Younghyun Lee
- Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba, Japan
| | - Takeshi Yasuda
- Research Center for Radiation Emergency Medicine, National Institute of Radiological Sciences, Chiba, Japan
| | - Hirokazu Hirakawa
- Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba, Japan
| | - Cuihua Liu
- Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba, Japan
| | - Akira Fujimori
- Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba, Japan
| | - Mitsuru Uesaka
- Department of Nuclear Engineering and Management, School of Engineering, University of Tokyo, Tokyo, Japan
| | - Ryuichi Okayasu
- Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba, Japan.
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24
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Colis LC, Herzon SB. Synergistic potentiation of (-)-lomaiviticin A cytotoxicity by the ATR inhibitor VE-821. Bioorg Med Chem Lett 2016; 26:3122-3126. [PMID: 27177826 PMCID: PMC4899226 DOI: 10.1016/j.bmcl.2016.04.090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Revised: 04/28/2016] [Accepted: 04/29/2016] [Indexed: 11/23/2022]
Abstract
(-)-Lomaiviticin A (1) is a cytotoxic bacterial metabolite that induces double-strand breaks in DNA. Here we show that the cytotoxicity of (-)-lomaiviticin A (1) is synergistically potentiated in the presence of VE-821 (7), an inhibitor of ataxia telangiectasia and Rad3-related protein (ATR). While 0.5nM 1 or 10μM 7 alone are non-lethal to K562 cells, co-incubation of the two leads to high levels of cell kill (81% and 94% after 24 and 48h, respectively). Mechanistic data indicate that cells treated with 1 and 7 suffer extensive DNA double-strand breaks and apoptosis. These data suggest combinations of 1 and 7 may be a valuable chemotherapeutic strategy.
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Affiliation(s)
- Laureen C Colis
- Department of Chemistry, Yale University, New Haven, CT 06520, United States
| | - Seth B Herzon
- Department of Chemistry, Yale University, New Haven, CT 06520, United States; Department of Pharmacology, Yale School of Medicine, New Haven, CT 06520, United States.
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25
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Durisova K, Salovska B, Pejchal J, Tichy A. Chemical inhibition of DNA repair kinases as a promising tool in oncology. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2016; 160:11-9. [DOI: 10.5507/bp.2015.046] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 09/10/2015] [Indexed: 11/23/2022] Open
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26
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Surovtseva YV, Jairam V, Salem AF, Sundaram RK, Bindra RS, Herzon SB. Characterization of Cardiac Glycoside Natural Products as Potent Inhibitors of DNA Double-Strand Break Repair by a Whole-Cell Double Immunofluorescence Assay. J Am Chem Soc 2016; 138:3844-55. [PMID: 26927829 DOI: 10.1021/jacs.6b00162] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Small-molecule inhibitors of DNA repair pathways are being intensively investigated as primary and adjuvant chemotherapies. We report the discovery that cardiac glycosides, natural products in clinical use for the treatment of heart failure and atrial arrhythmia, are potent inhibitors of DNA double-strand break (DSB) repair. Our data suggest that cardiac glycosides interact with phosphorylated mediator of DNA damage checkpoint protein 1 (phospho-MDC1) or E3 ubiquitin-protein ligase ring finger protein 8 (RNF8), two factors involved in DSB repair, and inhibit the retention of p53 binding protein 1 (53BP1) at the site of DSBs. These observations provide an explanation for the anticancer activity of this class of compounds, which has remained poorly understood for decades, and provide guidance for their clinical applications. This discovery was enabled by the development of the first high-throughput unbiased cellular assay to identify new small-molecule inhibitors of DSB repair. Our assay is based on the fully automated, time-resolved quantification of phospho-SER139-H2AX (γH2AX) and 53BP1 foci, two factors involved in the DNA damage response network, in cells treated with small molecules and ionizing radiation (IR). This primary assay is supplemented by robust secondary assays that establish lead compound potencies and provide further insights into their mechanisms of action. Although the cardiac glycosides were identified in an evaluation of 2366 small molecules, the assay is envisioned to be adaptable to larger compound libraries. The assay is shown to be compatible with small-molecule DNA cleaving agents, such as bleomycin, neocarzinostatin chromophore, and lomaiviticin A, in place of IR.
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Affiliation(s)
- Yulia V Surovtseva
- Yale Center for Molecular Discovery , West Haven, Connecticut 06516, United States
| | - Vikram Jairam
- Department of Therapeutic Radiology, Yale University School of Medicine , New Haven, Connecticut 06511, United States
| | - Ahmed F Salem
- Department of Therapeutic Radiology, Yale University School of Medicine , New Haven, Connecticut 06511, United States
| | - Ranjini K Sundaram
- Department of Therapeutic Radiology, Yale University School of Medicine , New Haven, Connecticut 06511, United States
| | - Ranjit S Bindra
- Department of Therapeutic Radiology, Yale University School of Medicine , New Haven, Connecticut 06511, United States
| | - Seth B Herzon
- Department of Chemistry, Yale University , New Haven, Connecticut 06520, United States.,Department of Pharmacology, Yale School of Medicine , New Haven, Connecticut 06511, United States
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27
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Dolman MEM, van der Ploeg I, Koster J, Bate-Eya LT, Versteeg R, Caron HN, Molenaar JJ. DNA-Dependent Protein Kinase As Molecular Target for Radiosensitization of Neuroblastoma Cells. PLoS One 2015; 10:e0145744. [PMID: 26716839 PMCID: PMC4696738 DOI: 10.1371/journal.pone.0145744] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 12/08/2015] [Indexed: 11/18/2022] Open
Abstract
Tumor cells might resist therapy with ionizing radiation (IR) by non-homologous end-joining (NHEJ) of IR-induced double-strand breaks. One of the key players in NHEJ is DNA-dependent protein kinase (DNA-PK). The catalytic subunit of DNA-PK, i.e. DNA-PKcs, can be inhibited with the small-molecule inhibitor NU7026. In the current study, the in vitro potential of NU7026 to radiosensitize neuroblastoma cells was investigated. DNA-PKcs is encoded by the PRKDC (protein kinase, DNA-activated, catalytic polypeptide) gene. We showed that PRKDC levels were enhanced in neuroblastoma patients and correlated with a more advanced tumor stage and poor prognosis, making DNA-PKcs an interesting target for radiosensitization of neuroblastoma tumors. Optimal dose finding for combination treatment with NU7026 and IR was performed using NGP cells. One hour pre-treatment with 10 μM NU7026 synergistically sensitized NGP cells to 0.63 Gy IR. Radiosensitizing effects of NU7026 increased in time, with maximum effects observed from 96 h after IR-exposure on. Combined treatment of NGP cells with 10 μM NU7026 and 0.63 Gy IR resulted in apoptosis, while no apoptotic response was observed for either of the therapies alone. Inhibition of IR-induced DNA-PK activation by NU7026 confirmed the capability of NGP cells to, at least partially, resist IR by NHEJ. NU7026 also synergistically radiosensitized other neuroblastoma cell lines, while no synergistic effect was observed for low DNA-PKcs-expressing non-cancerous fibroblasts. Results obtained for NU7026 were confirmed by PRKDC knockdown in NGP cells. Taken together, the current study shows that DNA-PKcs is a promising target for neuroblastoma radiosensitization.
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Affiliation(s)
- M. Emmy M. Dolman
- Department of Oncogenomics, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
- * E-mail:
| | - Ida van der Ploeg
- Department of Oncogenomics, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Jan Koster
- Department of Oncogenomics, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Laurel Tabe Bate-Eya
- Department of Oncogenomics, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Rogier Versteeg
- Department of Oncogenomics, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Huib N. Caron
- Department of Pediatric Oncology, Emma Kinderziekenhuis, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Jan J. Molenaar
- Department of Oncogenomics, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
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DNA Damage Signalling and Repair Inhibitors: The Long-Sought-After Achilles' Heel of Cancer. Biomolecules 2015; 5:3204-59. [PMID: 26610585 PMCID: PMC4693276 DOI: 10.3390/biom5043204] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/09/2015] [Indexed: 12/16/2022] Open
Abstract
For decades, radiotherapy and chemotherapy were the two only approaches exploiting DNA repair processes to fight against cancer. Nowadays, cancer therapeutics can be a major challenge when it comes to seeking personalized targeted medicine that is both effective and selective to the malignancy. Over the last decade, the discovery of new targeted therapies against DNA damage signalling and repair has offered the possibility of therapeutic improvements in oncology. In this review, we summarize the current knowledge of DNA damage signalling and repair inhibitors, their molecular and cellular effects, and future therapeutic use.
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Dungl DA, Maginn EN, Stronach EA. Preventing Damage Limitation: Targeting DNA-PKcs and DNA Double-Strand Break Repair Pathways for Ovarian Cancer Therapy. Front Oncol 2015. [PMID: 26579492 DOI: 10.3389/fonc.2015.00240] [] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Platinum-based chemotherapy is the cornerstone of ovarian cancer treatment, and its efficacy is dependent on the generation of DNA damage, with subsequent induction of apoptosis. Inappropriate or aberrant activation of the DNA damage response network is associated with resistance to platinum, and defects in DNA repair pathways play critical roles in determining patient response to chemotherapy. In ovarian cancer, tumor cell defects in homologous recombination - a repair pathway activated in response to double-strand DNA breaks (DSB) - are most commonly associated with platinum-sensitive disease. However, despite initial sensitivity, the emergence of resistance is frequent. Here, we review strategies for directly interfering with DNA repair pathways, with particular focus on direct inhibition of non-homologous end joining (NHEJ), another DSB repair pathway. DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a core component of NHEJ and it has shown considerable promise as a chemosensitization target in numerous cancer types, including ovarian cancer where it functions to promote platinum-induced survival signaling, via AKT activation. The development of pharmacological inhibitors of DNA-PKcs is on-going, and clinic-ready agents offer real hope to patients with chemoresistant disease.
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Affiliation(s)
- Daniela A Dungl
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| | - Elaina N Maginn
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| | - Euan A Stronach
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
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30
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Dungl DA, Maginn EN, Stronach EA. Preventing Damage Limitation: Targeting DNA-PKcs and DNA Double-Strand Break Repair Pathways for Ovarian Cancer Therapy. Front Oncol 2015. [PMID: 26579492 DOI: 10.3389/fonc.2015.00240]+[] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Platinum-based chemotherapy is the cornerstone of ovarian cancer treatment, and its efficacy is dependent on the generation of DNA damage, with subsequent induction of apoptosis. Inappropriate or aberrant activation of the DNA damage response network is associated with resistance to platinum, and defects in DNA repair pathways play critical roles in determining patient response to chemotherapy. In ovarian cancer, tumor cell defects in homologous recombination - a repair pathway activated in response to double-strand DNA breaks (DSB) - are most commonly associated with platinum-sensitive disease. However, despite initial sensitivity, the emergence of resistance is frequent. Here, we review strategies for directly interfering with DNA repair pathways, with particular focus on direct inhibition of non-homologous end joining (NHEJ), another DSB repair pathway. DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a core component of NHEJ and it has shown considerable promise as a chemosensitization target in numerous cancer types, including ovarian cancer where it functions to promote platinum-induced survival signaling, via AKT activation. The development of pharmacological inhibitors of DNA-PKcs is on-going, and clinic-ready agents offer real hope to patients with chemoresistant disease.
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Affiliation(s)
- Daniela A Dungl
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| | - Elaina N Maginn
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| | - Euan A Stronach
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
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31
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Dungl DA, Maginn EN, Stronach EA. Preventing Damage Limitation: Targeting DNA-PKcs and DNA Double-Strand Break Repair Pathways for Ovarian Cancer Therapy. Front Oncol 2015; 5:240. [PMID: 26579492 PMCID: PMC4620694 DOI: 10.3389/fonc.2015.00240] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 10/10/2015] [Indexed: 12/22/2022] Open
Abstract
Platinum-based chemotherapy is the cornerstone of ovarian cancer treatment, and its efficacy is dependent on the generation of DNA damage, with subsequent induction of apoptosis. Inappropriate or aberrant activation of the DNA damage response network is associated with resistance to platinum, and defects in DNA repair pathways play critical roles in determining patient response to chemotherapy. In ovarian cancer, tumor cell defects in homologous recombination – a repair pathway activated in response to double-strand DNA breaks (DSB) – are most commonly associated with platinum-sensitive disease. However, despite initial sensitivity, the emergence of resistance is frequent. Here, we review strategies for directly interfering with DNA repair pathways, with particular focus on direct inhibition of non-homologous end joining (NHEJ), another DSB repair pathway. DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a core component of NHEJ and it has shown considerable promise as a chemosensitization target in numerous cancer types, including ovarian cancer where it functions to promote platinum-induced survival signaling, via AKT activation. The development of pharmacological inhibitors of DNA-PKcs is on-going, and clinic-ready agents offer real hope to patients with chemoresistant disease.
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Affiliation(s)
- Daniela A Dungl
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| | - Elaina N Maginn
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
| | - Euan A Stronach
- Molecular Therapy Laboratory, Department of Surgery and Cancer, Ovarian Cancer Action Research Centre, Imperial College London , London , UK
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32
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Robert F, Barbeau M, Éthier S, Dostie J, Pelletier J. Pharmacological inhibition of DNA-PK stimulates Cas9-mediated genome editing. Genome Med 2015; 7:93. [PMID: 26307031 PMCID: PMC4550049 DOI: 10.1186/s13073-015-0215-6] [Citation(s) in RCA: 167] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/06/2015] [Indexed: 11/22/2022] Open
Abstract
Background The ability to modify the genome of any cell at a precise location has drastically improved with the recent discovery and implementation of CRISPR/Cas9 editing technology. However, the capacity to introduce specific directed changes at given loci is hampered by the fact that the major cellular repair pathway that occurs following Cas9-mediated DNA cleavage is the erroneous non-homologous end joining (NHEJ) pathway. Homology-directed recombination (HDR) is far less efficient than NHEJ and makes screening of clones containing directed changes time-consuming and labor-intensive. Methods We investigated the possibility of pharmacologically inhibiting DNA-PKcs, a key player in NHEJ, using small molecule inhibitors (NU7441 and KU-0060648), to ameliorate the rates of HDR repair events. These compounds were tested in a sensitive reporter assay capable of simultaneously informing on NHEJ and HDR, as well as on an endogenous gene targeted by Cas9. Results We find that NU7441 and KU-0060648 reduce the frequency of NHEJ while increasing the rate of HDR following Cas9-mediated DNA cleavage. Conclusions Our results identify two small molecules compatible for use with Cas9-editing technology to improve the frequency of HDR. Electronic supplementary material The online version of this article (doi:10.1186/s13073-015-0215-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Francis Robert
- Department of Biochemistry, McGill University, Montréal, Québec, H3G 1Y6, Canada.
| | - Mathilde Barbeau
- Department of Biochemistry, McGill University, Montréal, Québec, H3G 1Y6, Canada.
| | - Sylvain Éthier
- Department of Biochemistry, McGill University, Montréal, Québec, H3G 1Y6, Canada.
| | - Josée Dostie
- Department of Biochemistry, McGill University, Montréal, Québec, H3G 1Y6, Canada.
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montréal, Québec, H3G 1Y6, Canada. .,Department of Oncology, McGill University, Montréal, Québec, H3G 1Y6, Canada. .,The Rosalind and Morris Goodman Cancer Research Center, McGill University, Montréal, Québec, H3G 1Y6, Canada.
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Kelley MR, Logsdon D, Fishel ML. Targeting DNA repair pathways for cancer treatment: what's new? Future Oncol 2015; 10:1215-37. [PMID: 24947262 DOI: 10.2217/fon.14.60] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Disruptions in DNA repair pathways predispose cells to accumulating DNA damage. A growing body of evidence indicates that tumors accumulate progressively more mutations in DNA repair proteins as cancers progress. DNA repair mechanisms greatly affect the response to cytotoxic treatments, so understanding those mechanisms and finding ways to turn dysregulated repair processes against themselves to induce tumor death is the goal of all DNA repair inhibition efforts. Inhibition may be direct or indirect. This burgeoning field of research is replete with promise and challenge, as more intricacies of each repair pathway are discovered. In an era of increasing concern about healthcare costs, use of DNA repair inhibitors can prove to be highly effective stewardship of R&D resources and patient expenses.
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Affiliation(s)
- Mark R Kelley
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
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Albarakati N, Abdel-Fatah TMA, Doherty R, Russell R, Agarwal D, Moseley P, Perry C, Arora A, Alsubhi N, Seedhouse C, Rakha EA, Green A, Ball G, Chan S, Caldas C, Ellis IO, Madhusudan S. Targeting BRCA1-BER deficient breast cancer by ATM or DNA-PKcs blockade either alone or in combination with cisplatin for personalized therapy. Mol Oncol 2015; 9:204-17. [PMID: 25205036 PMCID: PMC5528668 DOI: 10.1016/j.molonc.2014.08.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 07/23/2014] [Accepted: 08/11/2014] [Indexed: 11/17/2022] Open
Abstract
BRCA1, a key factor in homologous recombination (HR) repair may also regulate base excision repair (BER). Targeting BRCA1-BER deficient cells by blockade of ATM and DNA-PKcs could be a promising strategy in breast cancer. We investigated BRCA1, XRCC1 and pol β protein expression in two cohorts (n = 1602 sporadic and n = 50 germ-line BRCA1 mutated) and mRNA expression in two cohorts (n = 1952 and n = 249). Artificial neural network analysis for BRCA1-DNA repair interacting genes was conducted in 249 tumours. Pre-clinically, BRCA1 proficient and deficient cells were DNA repair expression profiled and evaluated for synthetic lethality using ATM and DNA-PKcs inhibitors either alone or in combination with cisplatin. In human tumours, BRCA1 negativity was strongly associated with low XRCC1, and low pol β at mRNA and protein levels (p < 0.0001). In patients with BRCA1 negative tumours, low XRCC1 or low pol β expression was significantly associated with poor survival in univariate and multivariate analysis compared to high XRCC1 or high pol β expressing BRCA1 negative tumours (ps < 0.05). Pre-clinically, BRCA1 negative cancer cells exhibit low mRNA and low protein expression of XRCC1 and pol β. BRCA1-BER deficient cells were sensitive to ATM and DNA-PKcs inhibitor treatment either alone or in combination with cisplatin and synthetic lethality was evidenced by DNA double strand breaks accumulation, cell cycle arrest and apoptosis. We conclude that XRCC1 and pol β expression status in BRCA1 negative tumours may have prognostic significance. BRCA1-BER deficient cells could be targeted by ATM or DNA-PKcs inhibitors for personalized therapy.
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Affiliation(s)
- Nada Albarakati
- Academic Unit of Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham University Hospitals, Nottingham NG51PB, UK
| | | | - Rachel Doherty
- Academic Unit of Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham University Hospitals, Nottingham NG51PB, UK
| | - Roslin Russell
- Cancer Research UK, Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK
| | - Devika Agarwal
- School of Science and Technology, Nottingham Trent University, Clifton Campus, Nottingham NG11 8NS, UK
| | - Paul Moseley
- Department of Oncology, Nottingham University Hospitals, Nottingham NG51PB, UK
| | - Christina Perry
- Academic Unit of Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham University Hospitals, Nottingham NG51PB, UK
| | - Arvind Arora
- Academic Unit of Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham University Hospitals, Nottingham NG51PB, UK
| | - Nouf Alsubhi
- Academic Unit of Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham University Hospitals, Nottingham NG51PB, UK
| | - Claire Seedhouse
- Academic Haematology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham University Hospitals, Nottingham NG51PB, UK
| | - Emad A Rakha
- Department of Pathology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham University Hospitals, Nottingham NG51PB, UK
| | - Andrew Green
- Department of Pathology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham University Hospitals, Nottingham NG51PB, UK
| | - Graham Ball
- School of Science and Technology, Nottingham Trent University, Clifton Campus, Nottingham NG11 8NS, UK
| | - Stephen Chan
- Department of Oncology, Nottingham University Hospitals, Nottingham NG51PB, UK
| | - Carlos Caldas
- Cancer Research UK, Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK
| | - Ian O Ellis
- Department of Pathology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham University Hospitals, Nottingham NG51PB, UK
| | - Srinivasan Madhusudan
- Academic Unit of Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham University Hospitals, Nottingham NG51PB, UK; Department of Oncology, Nottingham University Hospitals, Nottingham NG51PB, UK.
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Goglia AG, Delsite R, Luz AN, Shahbazian D, Salem AF, Sundaram RK, Chiaravalli J, Hendrikx PJ, Wilshire JA, Jasin M, Kluger HM, Glickman JF, Powell SN, Bindra RS. Identification of novel radiosensitizers in a high-throughput, cell-based screen for DSB repair inhibitors. Mol Cancer Ther 2014; 14:326-42. [PMID: 25512618 DOI: 10.1158/1535-7163.mct-14-0765] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Most cancer therapies involve a component of treatment that inflicts DNA damage in tumor cells, such as double-strand breaks (DSBs), which are considered the most serious threat to genomic integrity. Complex systems have evolved to repair these lesions, and successful DSB repair is essential for tumor cell survival after exposure to ionizing radiation (IR) and other DNA-damaging agents. As such, inhibition of DNA repair is a potentially efficacious strategy for chemo- and radiosensitization. Homologous recombination (HR) and nonhomologous end-joining (NHEJ) represent the two major pathways by which DSBs are repaired in mammalian cells. Here, we report the design and execution of a high-throughput, cell-based small molecule screen for novel DSB repair inhibitors. We miniaturized our recently developed dual NHEJ and HR reporter system into a 384-well plate-based format and interrogated a diverse library of 20,000 compounds for molecules that selectively modulate NHEJ and HR repair in tumor cells. We identified a collection of novel hits that potently inhibit DSB repair, and we have validated their functional activity in a comprehensive panel of orthogonal secondary assays. A selection of these inhibitors was found to radiosensitize cancer cell lines in vitro, which suggests that they may be useful as novel chemo- and radio sensitizers. Surprisingly, we identified several FDA-approved drugs, including the calcium channel blocker mibefradil dihydrochloride, that demonstrated activity as DSB repair inhibitors and radiosensitizers. These findings suggest the possibility for repurposing them as tumor cell radiosensitizers in the future. Accordingly, we recently initiated a phase I clinical trial testing mibefradil as a glioma radiosensitizer.
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Affiliation(s)
- Alexander G Goglia
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Robert Delsite
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Antonio N Luz
- High Throughput and Spectroscopy Resource Center, Rockefeller University, New York, New York
| | - David Shahbazian
- Section of Medical Oncology, Yale Cancer Center, Yale University School of Medicine, New Haven, Connecticut
| | - Ahmed F Salem
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Ranjini K Sundaram
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Jeanne Chiaravalli
- High Throughput and Spectroscopy Resource Center, Rockefeller University, New York, New York
| | - Petrus J Hendrikx
- Flow Cytometry Core Facility, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Jennifer A Wilshire
- Flow Cytometry Core Facility, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Harriet M Kluger
- Section of Medical Oncology, Yale Cancer Center, Yale University School of Medicine, New Haven, Connecticut
| | - J Fraser Glickman
- High Throughput and Spectroscopy Resource Center, Rockefeller University, New York, New York
| | - Simon N Powell
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.
| | - Ranjit S Bindra
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut.
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Andrs M, Korabecny J, Jun D, Hodny Z, Bartek J, Kuca K. Phosphatidylinositol 3-Kinase (PI3K) and phosphatidylinositol 3-kinase-related kinase (PIKK) inhibitors: importance of the morpholine ring. J Med Chem 2014; 58:41-71. [PMID: 25387153 DOI: 10.1021/jm501026z] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Phosphatidylinositol 3-kinases (PI3Ks) and phosphatidylinositol 3-kinase-related protein kinases (PIKKs) are two related families of kinases that play key roles in regulation of cell proliferation, metabolism, migration, survival, and responses to diverse stresses including DNA damage. To design novel efficient strategies for treatment of cancer and other diseases, these kinases have been extensively studied. Despite their different nature, these two kinase families have related origin and share very similar kinase domains. Therefore, chemical inhibitors of these kinases usually carry analogous structural motifs. The most common feature of these inhibitors is a critical hydrogen bond to morpholine oxygen, initially present in the early nonspecific PI3K and PIKK inhibitor 3 (LY294002), which served as a valuable chemical tool for development of many additional PI3K and PIKK inhibitors. While several PI3K pathway inhibitors have recently shown promising clinical responses, inhibitors of the DNA damage-related PIKKs remain thus far largely in preclinical development.
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Affiliation(s)
- Martin Andrs
- Biomedical Research Center, University Hospital Hradec Kralove , Sokolska 81, 500 05 Hradec Kralove, Czech Republic
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Cornell L, Munck JM, Alsinet C, Villanueva A, Ogle L, Willoughby CE, Televantou D, Thomas HD, Jackson J, Burt AD, Newell D, Rose J, Manas DM, Shapiro GI, Curtin NJ, Reeves HL. DNA-PK-A candidate driver of hepatocarcinogenesis and tissue biomarker that predicts response to treatment and survival. Clin Cancer Res 2014; 21:925-33. [PMID: 25480831 DOI: 10.1158/1078-0432.ccr-14-0842] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
PURPOSE Therapy resistance and associated liver disease make hepatocellular carcinomas (HCC) difficult to treat with traditional cytotoxic therapies, whereas newer targeted approaches offer only modest survival benefit. We focused on DNA-dependent protein kinase, DNA-PKcs, encoded by PRKDC and central to DNA damage repair by nonhomologous end joining. Our aim was to explore its roles in hepatocarcinogenesis and as a novel therapeutic candidate. EXPERIMENTAL DESIGN PRKDC was characterized in liver tissues from of 132 patients [normal liver (n = 10), cirrhotic liver (n = 13), dysplastic nodules (n = 18), HCC (n = 91)] using Affymetrix U133 Plus 2.0 and 500 K Human Mapping SNP arrays (cohort 1). In addition, we studied a case series of 45 patients with HCC undergoing diagnostic biopsy (cohort 2). Histological grading, response to treatment, and survival were correlated with DNA-PKcs quantified immunohistochemically. Parallel in vitro studies determined the impact of DNA-PK on DNA repair and response to cytotoxic therapy. RESULTS Increased PRKDC expression in HCC was associated with amplification of its genetic locus in cohort 1. In cohort 2, elevated DNA-PKcs identified patients with treatment-resistant HCC, progressing at a median of 4.5 months compared with 16.9 months, whereas elevation of activated pDNA-PK independently predicted poorer survival. DNA-PKcs was high in HCC cell lines, where its inhibition with NU7441 potentiated irradiation and doxorubicin-induced cytotoxicity, whereas the combination suppressed HCC growth in vitro and in vivo. CONCLUSIONS These data identify PRKDC/DNA-PKcs as a candidate driver of hepatocarcinogenesis, whose biopsy characterization at diagnosis may impact stratification of current therapies, and whose specific future targeting may overcome resistance.
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Affiliation(s)
- Liam Cornell
- Northern Institute for Cancer Research, Framlington Place, The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom. Early Drug Development Center and Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Joanne M Munck
- Northern Institute for Cancer Research, Framlington Place, The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Clara Alsinet
- Barcelona Clinic Liver Cancer Group (BCLC, Translational Research laboratory and Liver Unit), Hospital Clinic, IDIBAPS, Centro de Investigacion Biomedica en Red de Enfermedades Hepaticas y Digestivas (CIBERehd), University of Barcelona, Catalonia, Spain
| | - Augusto Villanueva
- Barcelona Clinic Liver Cancer Group (BCLC, Translational Research laboratory and Liver Unit), Hospital Clinic, IDIBAPS, Centro de Investigacion Biomedica en Red de Enfermedades Hepaticas y Digestivas (CIBERehd), University of Barcelona, Catalonia, Spain. Institute of Liver Studies, Division of Transplantation and Mucosal Biology, King's College, Denmark Hill, London, United Kingdom
| | - Laura Ogle
- Northern Institute for Cancer Research, Framlington Place, The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Catherine E Willoughby
- Northern Institute for Cancer Research, Framlington Place, The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Despina Televantou
- Northern Institute for Cancer Research, Framlington Place, The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Huw D Thomas
- Northern Institute for Cancer Research, Framlington Place, The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Jennifer Jackson
- Northern Institute for Cancer Research, Framlington Place, The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Alastair D Burt
- Institute of Cell and Molecular Biosciences, Framlington Place, The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom. School of Medicine, The University of Adelaide, Adelaide, Australia
| | - David Newell
- Northern Institute for Cancer Research, Framlington Place, The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - John Rose
- Radiology Department, The Freeman Hospital, Newcastle upon Tyne, United Kingdom
| | - Derek M Manas
- Hepatopancreatobiliary Team, The Freeman Hospital, Newcastle upon Tyne, United Kingdom
| | - Geoffrey I Shapiro
- Early Drug Development Center and Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Nicola J Curtin
- Northern Institute for Cancer Research, Framlington Place, The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom.
| | - Helen L Reeves
- Northern Institute for Cancer Research, Framlington Place, The Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom. Hepatopancreatobiliary Team, The Freeman Hospital, Newcastle upon Tyne, United Kingdom
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38
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Gustafsson AS, Abramenkovs A, Stenerlöw B. Suppression of DNA-dependent protein kinase sensitize cells to radiation without affecting DSB repair. Mutat Res 2014; 769:1-10. [PMID: 25771720 DOI: 10.1016/j.mrfmmm.2014.06.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 06/04/2014] [Accepted: 06/16/2014] [Indexed: 06/04/2023]
Abstract
Efficient and correct repair of DNA double-strand break (DSB) is critical for cell survival. Defects in the DNA repair may lead to cell death, genomic instability and development of cancer. The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is an essential component of the non-homologous end joining (NHEJ) which is the major DSB repair pathway in mammalian cells. In the present study, by using siRNA against DNA-PKcs in four human cell lines, we examined how low levels of DNA-PKcs affected cellular response to ionizing radiation. Decrease of DNA-PKcs levels by 80-95%, induced by siRNA treatment, lead to extreme radiosensitivity, similar to that seen in cells completely lacking DNA-PKcs and low levels of DNA-PKcs promoted cell accumulation in G2/M phase after irradiation and blocked progression of mitosis. Surprisingly, low levels of DNA-PKcs did not affect the repair capacity and the removal of 53BP1 or γ-H2AX foci and rejoining of DSB appeared normal. This was in strong contrast to cells completely lacking DNA-PKcs and cells treated with the DNA-PKcs inhibitor NU7441, in which DSB repair were severely compromised. This suggests that there are different mechanisms by which loss of DNA-PKcs functions can sensitize cells to ionizing radiation. Further, foci of phosphorylated DNA-PKcs (T2609 and S2056) co-localized with DSB and this was independent of the amount of DNA-PKcs but foci of DNA-PKcs was only seen in siRNA-treated cells. Our study emphasizes on the critical role of DNA-PKcs for maintaining survival after radiation exposure which is uncoupled from its essential function in DSB repair. This could have implications for the development of therapeutic strategies aiming to radiosensitize tumors by affecting the DNA-PKcs function.
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Affiliation(s)
- Ann-Sofie Gustafsson
- Section of Biomedical Radiation Sciences, Department of Radiology, Oncology and Radiation Science, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds Väg 20, SE-751 85 Uppsala, Sweden.
| | - Andris Abramenkovs
- Section of Biomedical Radiation Sciences, Department of Radiology, Oncology and Radiation Science, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds Väg 20, SE-751 85 Uppsala, Sweden
| | - Bo Stenerlöw
- Section of Biomedical Radiation Sciences, Department of Radiology, Oncology and Radiation Science, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds Väg 20, SE-751 85 Uppsala, Sweden
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Ramzan Z, Nassri AB, Huerta S. Genotypic characteristics of resistant tumors to pre-operative ionizing radiation in rectal cancer. World J Gastrointest Oncol 2014; 6:194-210. [PMID: 25024812 PMCID: PMC4092337 DOI: 10.4251/wjgo.v6.i7.194] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 03/19/2014] [Accepted: 05/08/2014] [Indexed: 02/05/2023] Open
Abstract
Due to a wide range of clinical response in patients undergoing neo-adjuvant chemoradiation for rectal cancer it is essential to understand molecular factors that lead to the broad response observed in patients receiving the same form of treatment. Despite extensive research in this field, the exact mechanisms still remain elusive. Data raging from DNA-repair to specific molecules leading to cell survival as well as resistance to apoptosis have been investigated. Individually, or in combination, there is no single pathway that has become clinically applicable to date. In the following review, we describe the current status of various pathways that might lead to resistance to the therapeutic applications of ionizing radiation in rectal cancer.
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Farber-Katz SE, Dippold HC, Buschman MD, Peterman MC, Xing M, Noakes CJ, Tat J, Ng MM, Rahajeng J, Cowan DM, Fuchs GJ, Zhou H, Field SJ. DNA damage triggers Golgi dispersal via DNA-PK and GOLPH3. Cell 2014; 156:413-27. [PMID: 24485452 DOI: 10.1016/j.cell.2013.12.023] [Citation(s) in RCA: 168] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 09/04/2013] [Accepted: 11/14/2013] [Indexed: 01/29/2023]
Abstract
The response to DNA damage, which regulates nuclear processes such as DNA repair, transcription, and cell cycle, has been studied thoroughly. However, the cytoplasmic response to DNA damage is poorly understood. Here, we demonstrate that DNA damage triggers dramatic reorganization of the Golgi, resulting in its dispersal throughout the cytoplasm. We further show that DNA-damage-induced Golgi dispersal requires GOLPH3/MYO18A/F-actin and the DNA damage protein kinase, DNA-PK. In response to DNA damage, DNA-PK phosphorylates GOLPH3, resulting in increased interaction with MYO18A, which applies a tensile force to the Golgi. Interference with the Golgi DNA damage response by depletion of DNA-PK, GOLPH3, or MYO18A reduces survival after DNA damage, whereas overexpression of GOLPH3, as is observed frequently in human cancers, confers resistance to killing by DNA-damaging agents. Identification of the DNA-damage-induced Golgi response reveals an unexpected pathway through DNA-PK, GOLPH3, and MYO18A that regulates cell survival following DNA damage.
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Affiliation(s)
- Suzette E Farber-Katz
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0707, USA
| | - Holly C Dippold
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0707, USA
| | - Matthew D Buschman
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0707, USA
| | - Marshall C Peterman
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0707, USA
| | - Mengke Xing
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0707, USA
| | - Christopher J Noakes
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0707, USA
| | - John Tat
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0707, USA
| | - Michelle M Ng
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0707, USA
| | - Juliati Rahajeng
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0707, USA
| | - David M Cowan
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0707, USA
| | - Greg J Fuchs
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093-0653, USA
| | - Huilin Zhou
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093-0653, USA
| | - Seth J Field
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0707, USA.
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Jekimovs C, Bolderson E, Suraweera A, Adams M, O’Byrne KJ, Richard DJ. Chemotherapeutic compounds targeting the DNA double-strand break repair pathways: the good, the bad, and the promising. Front Oncol 2014; 4:86. [PMID: 24795863 PMCID: PMC4001069 DOI: 10.3389/fonc.2014.00086] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 04/08/2014] [Indexed: 01/09/2023] Open
Abstract
The repair of DNA double-strand breaks (DSBs) is a critical cellular mechanism that exists to ensure genomic stability. DNA DSBs are the most deleterious type of insult to a cell's genetic material and can lead to genomic instability, apoptosis, or senescence. Incorrectly repaired DNA DSBs have the potential to produce chromosomal translocations and genomic instability, potentially leading to cancer. The prevalence of DNA DSBs in cancer due to unregulated growth and errors in repair opens up a potential therapeutic window in the treatment of cancers. The cellular response to DNA DSBs is comprised of two pathways to ensure DNA breaks are repaired: homologous recombination and non-homologous end joining. Identifying chemotherapeutic compounds targeting proteins involved in these DNA repair pathways has shown promise as a cancer therapy for patients, either as a monotherapy or in combination with genotoxic drugs. From the beginning, there have been a number of chemotherapeutic compounds that have yielded successful responses in the clinic, a number that have failed (CGK-733 and iniparib), and a number of promising targets for future studies identified. This review looks in detail at how the cell responds to these DNA DSBs and investigates the chemotherapeutic avenues that have been and are currently being explored to target this repair process.
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Affiliation(s)
- Christian Jekimovs
- Cancer and Ageing Research Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Emma Bolderson
- Cancer and Ageing Research Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Amila Suraweera
- Cancer and Ageing Research Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Mark Adams
- Cancer and Ageing Research Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Kenneth J. O’Byrne
- Cancer and Ageing Research Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Derek J. Richard
- Cancer and Ageing Research Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
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Tichy A, Durisova K, Salovska B, Pejchal J, Zarybnicka L, Vavrova J, Dye NA, Sinkorova Z. Radio-sensitization of human leukaemic MOLT-4 cells by DNA-dependent protein kinase inhibitor, NU7441. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2014; 53:83-92. [PMID: 24100951 DOI: 10.1007/s00411-013-0494-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 09/17/2013] [Indexed: 06/02/2023]
Abstract
We studied the effect of pre-incubation with NU7441, a specific inhibitor of DNA-dependent protein kinase (DNA-PK), on molecular mechanisms triggered by ionizing radiation (IR). The experimental design involved four groups of human T-lymphocyte leukaemic MOLT-4 cells: control, NU7441-treated (1 μM), IR-treated (1 Gy), and combination of NU7441 and IR. We used flow cytometry for apoptosis assessment, Western blotting and ELISA for detection of proteins involved in DNA repair signalling and epifluorescence microscopy for detection of IR-induced phosphorylation of histone H2A.X. We did not observe any major changes in the amount of DNA-PK subunits Ku70/80 caused by the combination of NU7441 and radiation. Their combination led to an increased phosphorylation of H2A.X, a hallmark of DNA damage. However, it did not prevent up-regulation of neither p53 (and its phosphorylation at Ser 15 and 392) nor p21. We observed a decrease in the levels of anti-apoptotic Mcl-1, cdc25A phosphatase, cleavage of PARP and a significant increase in apoptosis in the group treated with combination. In conclusion, the combination of NU7441 with IR caused increased phosphorylation of H2A.X early after irradiation and subsequent induction of apoptosis. It was efficient in MOLT-4 cells in 10× lower concentration than the inhibitor NU7026. NU7441 proved as a potent radio-sensitizing agent, and it might provide a platform for development of new radio-sensitizers in radiotherapy.
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Affiliation(s)
- Ales Tichy
- Department of Radiobiology, Faculty of Health Sciences in Hradec Kralove, University of Defence in Brno, Brno, Czech Republic,
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Mould E, Berry P, Jamieson D, Hill C, Cano C, Tan N, Elliott S, Durkacz B, Newell D, Willmore E. Identification of dual DNA-PK MDR1 inhibitors for the potentiation of cytotoxic drug activity. Biochem Pharmacol 2014; 88:58-65. [PMID: 24418411 DOI: 10.1016/j.bcp.2014.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 12/20/2013] [Accepted: 01/03/2014] [Indexed: 01/22/2023]
Abstract
Inhibition of DNA repair is an attractive therapeutic approach to enhance the activity of DNA-damaging anticancer chemotherapeutic agents. Similarly, blockade of the multidrug-resistance protein 1 (MDR1) can overcome efflux-mediated resistance. DNA-dependent protein kinase (DNA-PK) is essential for the non-homologous end-joining DNA repair pathway. NU7441 is a potent DNA-PK inhibitor (IC50=14nM) that is used widely to study the effects of DNA-PK inhibition in vitro. In growth inhibition studies, 1μM NU7441 sensitised vincristine-resistant CCRF-CEM VCR/R leukaemia cells (1200-fold resistant) to a range of MDR1 substrates, including doxorubicin (8-fold, p=0.03), vincristine (14-fold, p=0.01) and etoposide (63-fold, p=0.02), compared with 1.4-fold (p=0.02), 2.2-fold (p=0.04) and 3.6-fold (p=0.01) sensitisation, respectively, in parental CCRF-CEM cells. This difference in NU7441 sensitivity was confirmed in another two parental and MDR1-overexpressing cell line pairs. A doxorubicin fluorescence assay showed that in MDR1-overexpressing canine kidney MDCKII-MDR1 cells, 1μM NU7441 increased doxorubicin nuclear fluorescence 16-fold. NU7441 and 3 structurally related compounds (NU7742 (an NU7441 analogue that does not inhibit DNA-PK - IC50>10μM), DRN1 (DNA-PK-inhibitory atropisomeric NU7441 derivative - IC50=2nM) and DRN2 (DNA-PK non-inhibitory atropisomeric NU7441 derivative - IC50=7μM)) all increased intracellular vincristine accumulation in the CCRF-CEM VCR/R cells to a level similar to verapamil, as measured by LC-MS. This paper demonstrates that NU7441 is a dual DNA-PK and MDR1 inhibitor, and this extends the therapeutic potential of the compound when used in combination with MDR substrates.
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Affiliation(s)
- Emily Mould
- Newcastle Cancer Centre at the Northern Institute for Cancer Research, Medical School, Newcastle University, Paul O'Gorman Building, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
| | - Philip Berry
- Newcastle Cancer Centre at the Northern Institute for Cancer Research, Medical School, Newcastle University, Paul O'Gorman Building, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
| | - David Jamieson
- Newcastle Cancer Centre at the Northern Institute for Cancer Research, Medical School, Newcastle University, Paul O'Gorman Building, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
| | - Christopher Hill
- Newcastle Cancer Centre at the Northern Institute for Cancer Research, Medical School, Newcastle University, Paul O'Gorman Building, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
| | - Celine Cano
- Newcastle Cancer Centre at the Northern Institute for Cancer Research, School of Chemistry, Newcastle University, Bedson Building, Newcastle upon Tyne NE1 7RU, UK.
| | - Niu Tan
- Newcastle Cancer Centre at the Northern Institute for Cancer Research, Medical School, Newcastle University, Paul O'Gorman Building, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
| | - Sarah Elliott
- Newcastle Cancer Centre at the Northern Institute for Cancer Research, Medical School, Newcastle University, Paul O'Gorman Building, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
| | - Barbara Durkacz
- Newcastle Cancer Centre at the Northern Institute for Cancer Research, Medical School, Newcastle University, Paul O'Gorman Building, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
| | - David Newell
- Newcastle Cancer Centre at the Northern Institute for Cancer Research, Medical School, Newcastle University, Paul O'Gorman Building, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
| | - Elaine Willmore
- Newcastle Cancer Centre at the Northern Institute for Cancer Research, Medical School, Newcastle University, Paul O'Gorman Building, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
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Akopiants K, Mohapatra S, Menon V, Zhou T, Valerie K, Povirk LF. Tracking the processing of damaged DNA double-strand break ends by ligation-mediated PCR: increased persistence of 3'-phosphoglycolate termini in SCAN1 cells. Nucleic Acids Res 2013; 42:3125-37. [PMID: 24371269 PMCID: PMC3950721 DOI: 10.1093/nar/gkt1347] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
To track the processing of damaged DNA double-strand break (DSB) ends in vivo, a method was devised for quantitative measurement of 3′-phosphoglycolate (PG) termini on DSBs induced by the non-protein chromophore of neocarzinostatin (NCS-C) in the human Alu repeat. Following exposure of cells to NCS-C, DNA was isolated, and labile lesions were chemically stabilized. All 3′-phosphate and 3′-hydroxyl ends were enzymatically capped with dideoxy termini, whereas 3′-PG ends were rendered ligatable, linked to an anchor, and quantified by real-time Taqman polymerase chain reaction. Using this assay and variations thereof, 3′-PG and 3′-phosphate termini on 1-base 3′ overhangs of NCS-C-induced DSBs were readily detected in DNA from the treated lymphoblastoid cells, and both were largely eliminated from cellular DNA within 1 h. However, the 3′-PG termini were processed more slowly than 3′-phosphate termini, and were more persistent in tyrosyl-DNA phosphodiesterase 1-mutant SCAN1 than in normal cells, suggesting a significant role for tyrosyl-DNA phosphodiesterase 1 in removing 3′-PG blocking groups for DSB repair. DSBs with 3′-hydroxyl termini, which are not directly induced by NCS-C, were formed rapidly in cells, and largely eliminated by further processing within 1 h, both in Alu repeats and in heterochromatic α-satellite DNA. Moreover, absence of DNA-PK in M059J cells appeared to accelerate resolution of 3′-PG ends.
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Affiliation(s)
- Konstantin Akopiants
- Department of Pharmacology and Toxicology, Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA and Department of Radiation Oncology, Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
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45
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DNA-PK inhibition by NU7441 sensitizes breast cancer cells to ionizing radiation and doxorubicin. Breast Cancer Res Treat 2013; 143:47-55. [DOI: 10.1007/s10549-013-2785-6] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 11/21/2013] [Indexed: 10/26/2022]
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46
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McLuckie KE, Di Antonio M, Zecchini H, Xian J, Caldas C, Krippendorff BF, Tannahill D, Lowe C, Balasubramanian S. G-quadruplex DNA as a molecular target for induced synthetic lethality in cancer cells. J Am Chem Soc 2013; 135:9640-3. [PMID: 23782415 PMCID: PMC3964824 DOI: 10.1021/ja404868t] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Indexed: 12/16/2022]
Abstract
Synthetic lethality is a genetic concept in which cell death is induced by the combination of mutations in two sensitive genes, while mutation of either gene alone is not sufficient to affect cell survival. Synthetic lethality can also be achieved "chemically" by combination of drug-like molecules targeting distinct but cooperative pathways. Previously, we reported that the small molecule pyridostatin (PDS) stabilizes G-quadruplexes (G4s) in cells and elicits a DNA damage response by causing the formation of DNA double strand breaks (DSB). Cell death mediated by ligand-induced G4 stabilization can be potentiated in cells deficient in DNA damage repair genes. Here, we demonstrate that PDS acts synergistically both with NU7441, an inhibitor of the DNA-PK kinase crucial for nonhomologous end joining repair of DNA DSBs, and BRCA2-deficient cells that are genetically impaired in homologous recombination-mediated DSB repair. G4 targeting ligands have potential as cancer therapeutic agents, acting synergistically with inhibition or mutation of the DNA damage repair machinery.
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Affiliation(s)
- Keith
I. E. McLuckie
- Cancer Research UK
Cambridge
Institute, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE, United
Kingdom
| | - Marco Di Antonio
- Cancer Research UK
Cambridge
Institute, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE, United
Kingdom
- Department of Chemistry,
University
of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom
| | - Heather Zecchini
- Cancer Research UK
Cambridge
Institute, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE, United
Kingdom
| | - Jian Xian
- Cancer Research UK
Cambridge
Institute, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE, United
Kingdom
- Department of Oncology, University
of Cambridge, Hills Road, Cambridge, CB2 0XZ, United Kingdom
| | - Carlos Caldas
- Cancer Research UK
Cambridge
Institute, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE, United
Kingdom
- Department of Oncology, University
of Cambridge, Hills Road, Cambridge, CB2 0XZ, United Kingdom
| | - Ben-Fillippo Krippendorff
- Cancer Research UK
Cambridge
Institute, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE, United
Kingdom
| | - David Tannahill
- Cancer Research UK
Cambridge
Institute, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE, United
Kingdom
| | - Christopher Lowe
- Department of Chemistry,
University
of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom
| | - Shankar Balasubramanian
- Cancer Research UK
Cambridge
Institute, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE, United
Kingdom
- Department of Chemistry,
University
of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom
- School of Clinical Medicine, University
of Cambridge, Cambridge, CB2 0SP, United Kingdom
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Riabinska A, Daheim M, Herter-Sprie GS, Winkler J, Fritz C, Hallek M, Thomas RK, Kreuzer KA, Frenzel LP, Monfared P, Martins-Boucas J, Chen S, Reinhardt HC. Therapeutic Targeting of a Robust Non-Oncogene Addiction to PRKDC in ATM-Defective Tumors. Sci Transl Med 2013; 5:189ra78. [DOI: 10.1126/scitranslmed.3005814] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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48
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Davidson D, Amrein L, Panasci L, Aloyz R. Small Molecules, Inhibitors of DNA-PK, Targeting DNA Repair, and Beyond. Front Pharmacol 2013; 4:5. [PMID: 23386830 PMCID: PMC3560216 DOI: 10.3389/fphar.2013.00005] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 01/08/2013] [Indexed: 12/13/2022] Open
Abstract
Many current chemotherapies function by damaging genomic DNA in rapidly dividing cells ultimately leading to cell death. This therapeutic approach differentially targets cancer cells that generally display rapid cell division compared to normal tissue cells. However, although these treatments are initially effective in arresting tumor growth and reducing tumor burden, resistance and disease progression eventually occur. A major mechanism underlying this resistance is increased levels of cellular DNA repair. Most cells have complex mechanisms in place to repair DNA damage that occurs due to environmental exposures or normal metabolic processes. These systems, initially overwhelmed when faced with chemotherapy induced DNA damage, become more efficient under constant selective pressure and as a result chemotherapies become less effective. Thus, inhibiting DNA repair pathways using target specific small molecule inhibitors may overcome cellular resistance to DNA damaging chemotherapies. Non-homologous end joining a major mechanism for the repair of double-strand breaks (DSB) in DNA is regulated in part by the serine/threonine kinase, DNA dependent protein kinase (DNA-PK). The DNA-PK holoenzyme acts as a scaffold protein tethering broken DNA ends and recruiting other repair molecules. It also has enzymatic activity that may be involved in DNA damage signaling. Because of its’ central role in repair of DSBs, DNA-PK has been the focus of a number of small molecule studies. In these studies specific DNA-PK inhibitors have shown efficacy in synergizing chemotherapies in vitro. However, compounds currently known to specifically inhibit DNA-PK are limited by poor pharmacokinetics: these compounds have poor solubility and have high metabolic lability in vivo leading to short serum half-lives. Future improvement in DNA-PK inhibition will likely be achieved by designing new molecules based on the recently reported crystallographic structure of DNA-PK. Computer based drug design will not only assist in identifying novel functional moieties to replace the metabolically labile morpholino group but will also facilitate the design of molecules to target the DNA-PKcs/Ku80 interface or one of the autophosphorylation sites.
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Affiliation(s)
- David Davidson
- Department of Oncology, Segal Cancer Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, McGill University Montreal, QC, Canada
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49
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Human papillomavirus episome stability is reduced by aphidicolin and controlled by DNA damage response pathways. J Virol 2013; 87:3979-89. [PMID: 23365423 DOI: 10.1128/jvi.03473-12] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A highly reproducible quantitative PCR (Q-PCR) assay was used to study the stability of human papillomavirus (HPV) in undifferentiated keratinocytes that maintain viral episomes. The term "stability" refers to the ability of episomes to persist with little copy number variation in cells. In investigating the mechanism of action of PA25, a previously published compound that destabilizes HPV episomes, aphidicolin was also found to markedly decrease episome levels, but via a different pathway from that of PA25. Since aphidicolin is known to activate DNA damage response (DDR) pathways, effects of inhibitors and small interfering RNAs (siRNAs) acting within DDR pathways were investigated. Inhibitors of Chk1 and siRNA directed against ataxia-telangiectasia mutated (ATM) and ataxia-telangiectasia Rad3-related (ATR) pathways significantly reduced viral episomes, suggesting that these pathways play a role in maintaining HPV episome stability. Inhibitors of Chk2 and DNA-PK had no effect on episome levels. Pharmacological inhibition of ATM proteins had no effect on episome levels, but ATM knockdown by siRNA significantly reduced episome levels, suggesting that ATM proteins are playing an important role in HPV episome stability that does not require kinase activity. These results outline two pathways that trigger episome loss from cells and suggest the existence of a little-understood mechanism that mediates viral DNA elimination. Together, our results also indicate that HPV episomes have a stability profile that is remarkably similar to that of fragile sites; these similarities are outlined and discussed. This close correspondence may influence the preference of HPV for integration into fragile sites.
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50
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Sun X, Yang C, Liu H, Wang Q, Wu SX, Li X, Xie T, Brinkman KL, Teh BS, Butler EB, Xu B, Zheng S. Identification and Characterization of a Small Inhibitory Peptide That Can Target DNA-PKcs Autophosphorylation and Increase Tumor Radiosensitivity. Int J Radiat Oncol Biol Phys 2012; 84:1212-9. [DOI: 10.1016/j.ijrobp.2012.01.092] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 01/18/2012] [Accepted: 01/31/2012] [Indexed: 11/29/2022]
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