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Chen Y, Feng X, Wu Z, Yang Y, Rao X, Meng R, Zhang S, Dong X, Xu S, Wu G, Jie X. USP9X-mediated REV1 deubiquitination promotes lung cancer radioresistance via the action of REV1 as a Rad18 molecular scaffold for cystathionine γ-lyase. J Biomed Sci 2024; 31:55. [PMID: 38802791 PMCID: PMC11131313 DOI: 10.1186/s12929-024-01044-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 05/17/2024] [Indexed: 05/29/2024] Open
Abstract
BACKGROUND Radioresistance is a key clinical constraint on the efficacy of radiotherapy in lung cancer patients. REV1 DNA directed polymerase (REV1) plays an important role in repairing DNA damage and maintaining genomic stability. However, its role in the resistance to radiotherapy in lung cancer is not clear. This study aims to clarify the role of REV1 in lung cancer radioresistance, identify the intrinsic mechanisms involved, and provide a theoretical basis for the clinical translation of this new target for lung cancer treatment. METHODS The effect of targeting REV1 on the radiosensitivity was verified by in vivo and in vitro experiments. RNA sequencing (RNA-seq) combined with nontargeted metabolomics analysis was used to explore the downstream targets of REV1. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to quantify the content of specific amino acids. The coimmunoprecipitation (co-IP) and GST pull-down assays were used to validate the interaction between proteins. A ubiquitination library screening system was constructed to investigate the regulatory proteins upstream of REV1. RESULTS Targeting REV1 could enhance the radiosensitivity in vivo, while this effect was not obvious in vitro. RNA sequencing combined with nontargeted metabolomics revealed that the difference result was related to metabolism, and that the expression of glycine, serine, and threonine (Gly/Ser/Thr) metabolism signaling pathways was downregulated following REV1 knockdown. LC-MS/MS demonstrated that REV1 knockdown results in reduced levels of these three amino acids and that cystathionine γ-lyase (CTH) was the key to its function. REV1 enhances the interaction of CTH with the E3 ubiquitin ligase Rad18 and promotes ubiquitination degradation of CTH by Rad18. Screening of the ubiquitination compound library revealed that the ubiquitin-specific peptidase 9 X-linked (USP9X) is the upstream regulatory protein of REV1 by the ubiquitin-proteasome system, which remodels the intracellular Gly/Ser/Thr metabolism. CONCLUSION USP9X mediates the deubiquitination of REV1, and aberrantly expressed REV1 acts as a scaffolding protein to assist Rad18 in interacting with CTH, promoting the ubiquitination and degradation of CTH and inducing remodeling of the Gly/Ser/Thr metabolism, which leads to radioresistance. A novel inhibitor of REV1, JH-RE-06, was shown to enhance lung cancer cell radiosensitivity, with good prospects for clinical translation.
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Affiliation(s)
- Yunshang Chen
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Xue Feng
- Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Zilong Wu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Yongqiang Yang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Xinrui Rao
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Rui Meng
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Sheng Zhang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Xiaorong Dong
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Shuangbing Xu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China
| | - Gang Wu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China.
| | - Xiaohua Jie
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
- Institute of Radiation Oncology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, 430022, China.
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Lin C, Liu P, Shi C, Qiu L, Shang D, Lu Z, Tu Z, Liu H. Therapeutic targeting of DNA damage repair pathways guided by homologous recombination deficiency scoring in ovarian cancers. Fundam Clin Pharmacol 2023; 37:194-214. [PMID: 36130021 DOI: 10.1111/fcp.12834] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 07/23/2022] [Accepted: 09/20/2022] [Indexed: 12/01/2022]
Abstract
The susceptibility of cells to DNA damage and their DNA repair ability are crucial for cancer therapy. Homologous recombination is one of the major repairing mechanisms for DNA double-strand breaks. Approximately half of ovarian cancer (OvCa) cells harbor homologous recombination deficiency (HRD). Considering that HRD is a major hallmark of OvCas, scholars proposed HRD scoring to evaluate the HRD degree and guide the choice of therapeutic strategies for OvCas. In the last decade, synthetic lethal strategy by targeting poly (ADP-ribose) polymerase (PARP) in HR-deficient OvCas has attracted considerable attention in view of its favorable clinical effort. We therefore suggested that the uses of other DNA damage/repair-targeted drugs in HR-deficient OvCas might also offer better clinical outcome. Here, we reviewed the current small molecule compounds that targeted DNA damage/repair pathways and discussed the HRD scoring system to guide their clinical uses.
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Affiliation(s)
- Chunxiu Lin
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Peng Liu
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Chaowen Shi
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Lipeng Qiu
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Dongsheng Shang
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Ziwen Lu
- School of Pharmacy, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Zhigang Tu
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Hanqing Liu
- School of Pharmacy, Jiangsu University, Zhenjiang, Jiangsu, China
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Kuzmina NS. Radiation-Induced DNA Methylation Disorders: In Vitro and In Vivo Studies. BIOL BULL+ 2022. [DOI: 10.1134/s1062359021110066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Park MT, Kim SD, Han YK, Hyun JW, Lee HJ, Yi JM. Enhancement of Radiosensitivity by DNA Hypomethylating Drugs through Apoptosis and Autophagy in Human Sarcoma Cells. Biomol Ther (Seoul) 2022; 30:80-89. [PMID: 34887366 PMCID: PMC8724837 DOI: 10.4062/biomolther.2021.174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 12/16/2022] Open
Abstract
The targeting of DNA methylation in cancer using DNA hypomethylating drugs has been well known to sensitize cancer cells to chemotherapy and immunotherapy by affecting multiple pathways. Herein, we investigated the combinational effects of DNA hypomethylating drugs and ionizing radiation (IR) in human sarcoma cell lines both in vitro and in vivo. Clonogenic assays were performed to determine the radiosensitizing properties of two DNA hypomethylating drugs on sarcoma cell lines we tested in this study with multiple doses of IR. We analyzed the effects of 5-aza-dC or SGI-110, as DNA hypomethylating drugs, in combination with IR in vitro on the proliferation, apoptosis, caspase-3/7 activity, migration/invasion, and Western blotting using apoptosis- or autophagy-related factors. To confirm the combined effect of DNA hypomethylating drugs and IR in our in vitro experiment, we generated the sarcoma cells in nude mouse xenograft models. Here, we found that the combination of DNA hypomethylating drugs and IR improved anticancer effects by inhibiting cell proliferation and by promoting synergistic cell death that is associated with both apoptosis and autophagy in vitro and in vivo. Our data demonstrated that the combination effects of DNA hypomethylating drugs with radiation exhibited greater cellular effects than the use of a single agent treatment, thus suggesting that the combination of DNA hypomethylating drugs and radiation may become a new radiotherapy to improve therapeutic efficacy for cancer treatment.
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Affiliation(s)
- Moon-Taek Park
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan 46033, Republic of Korea
| | - Sung-Dae Kim
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan 46033, Republic of Korea
| | - Yu Kyeong Han
- Department of Microbiology and Immunology, College of Medicine, Inje University, Busan 47392, Republic of Korea
| | - Jin Won Hyun
- Jeju National University School of Medicine and Jeju Research Center for Natural Medicine, Jeju 63243, Republic of Korea
| | - Hae-June Lee
- Division of Radiation Biomedical Research, Korea Institute of Radiological & Medical Sciences, Seoul 01812, Republic of Korea
| | - Joo Mi Yi
- Department of Microbiology and Immunology, College of Medicine, Inje University, Busan 47392, Republic of Korea
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Prochazkova K, Finke A, Tomaštíková ED, Filo J, Bente H, Dvořák P, Ovečka M, Šamaj J, Pecinka A. Zebularine induces enzymatic DNA-protein crosslinks in 45S rDNA heterochromatin of Arabidopsis nuclei. Nucleic Acids Res 2021; 50:244-258. [PMID: 34904670 PMCID: PMC8754632 DOI: 10.1093/nar/gkab1218] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/01/2021] [Indexed: 11/14/2022] Open
Abstract
Loss of genome stability leads to reduced fitness, fertility and a high mutation rate. Therefore, the genome is guarded by the pathways monitoring its integrity and neutralizing DNA lesions. To analyze the mechanism of DNA damage induction by cytidine analog zebularine, we performed a forward-directed suppressor genetic screen in the background of Arabidopsis thaliana zebularine-hypersensitive structural maintenance of chromosomes 6b (smc6b) mutant. We show that smc6b hypersensitivity was suppressed by the mutations in EQUILIBRATIVE NUCLEOSIDE TRANSPORTER 3 (ENT3), DNA METHYLTRANSFERASE 1 (MET1) and DECREASE IN DNA METHYLATION 1 (DDM1). Superior resistance of ent3 plants to zebularine indicated that ENT3 is likely necessary for the import of the drug to the cells. Identification of MET1 and DDM1 suggested that zebularine induces DNA damage by interference with the maintenance of CG DNA methylation. The same holds for structurally similar compounds 5-azacytidine and 2-deoxy-5-azacytidine. Based on our genetic and biochemical data, we propose that zebularine induces enzymatic DNA–protein crosslinks (DPCs) of MET1 and zebularine-containing DNA in Arabidopsis, which was confirmed by native chromatin immunoprecipitation experiments. Moreover, zebularine-induced DPCs accumulate preferentially in 45S rDNA chromocenters in a DDM1-dependent manner. These findings open a new avenue for studying genome stability and DPC repair in plants.
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Affiliation(s)
| | | | - Eva Dvořák Tomaštíková
- Institute of Experimental Botany, The Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, 77900 Olomouc, Czech Republic
| | - Jaroslav Filo
- Institute of Experimental Botany, The Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, 77900 Olomouc, Czech Republic
| | - Heinrich Bente
- Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany
| | - Petr Dvořák
- Department of Botany, Faculty of Science, Palacký University Olomouc, Šlechtitelů 27, 78371 Olomouc, Czech Republic
| | - Miroslav Ovečka
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Šlechtitelů 27, 78371 Olomouc, Czech Republic
| | - Jozef Šamaj
- Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Šlechtitelů 27, 78371 Olomouc, Czech Republic
| | - Ales Pecinka
- To whom correspondence should be addressed. Tel: +420 585 238 709;
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Camero S, Vitali G, Pontecorvi P, Ceccarelli S, Anastasiadou E, Cicchetti F, Flex E, Pomella S, Cassandri M, Rota R, Marampon F, Marchese C, Schiavetti A, Megiorni F. DNMT3A and DNMT3B Targeting as an Effective Radiosensitizing Strategy in Embryonal Rhabdomyosarcoma. Cells 2021; 10:2956. [PMID: 34831178 PMCID: PMC8616246 DOI: 10.3390/cells10112956] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 10/21/2021] [Accepted: 10/28/2021] [Indexed: 01/10/2023] Open
Abstract
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in childhood. Recently, we demonstrated the overexpression of both DNA methyltransferase 3A (DNMT3A) and 3B (DNMT3B) in RMS tumour biopsies and cell lines compared to normal skeletal muscle. Radiotherapy may often fail due to the abnormal expression of some molecules able to drive resistance mechanisms. The aim of this study was to analyse the involvement of DNMT3A and DNMT3B in radioresistance in RMS. RNA interference experiments against DNMT3A/3B were performed in embryonal RMS cells, upon ionizing radiation (IR) exposure and the effects of the combined treatment on RMS cells were analysed. DNMT3A and DNMT3B knocking down increased the sensitivity of RMS cells to IR, as indicated by the drastic decrease of colony formation ability. Interestingly, DNMT3A/3B act in two different ways: DNMT3A silencing triggers the cellular senescence program by up-regulating p16 and p21, whilst DNMT3B depletion induces significant DNA damage and impairs the DNA repair machinery (ATM, DNA-PKcs and Rad51 reduction). Our findings demonstrate for the first time that DNMT3A and DNMT3B overexpression may contribute to radiotherapy failure, and their inhibition might be a promising radiosensitizing strategy, mainly in the treatment of patients with metastatic or recurrent RMS tumours.
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Affiliation(s)
- Simona Camero
- Department of Maternal, Infantile and Urological Sciences, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy; (S.C.); (A.S.)
| | - Giulia Vitali
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy; (G.V.); (P.P.); (S.C.); (E.A.); (C.M.)
| | - Paola Pontecorvi
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy; (G.V.); (P.P.); (S.C.); (E.A.); (C.M.)
| | - Simona Ceccarelli
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy; (G.V.); (P.P.); (S.C.); (E.A.); (C.M.)
| | - Eleni Anastasiadou
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy; (G.V.); (P.P.); (S.C.); (E.A.); (C.M.)
| | - Francesca Cicchetti
- Policlinico Umberto I Hospital, Viale del Policlinico 155, 00161 Rome, Italy;
| | - Elisabetta Flex
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy;
| | - Silvia Pomella
- Group of Epigenetics of Pediatric Sarcomas, Department of Oncohematology, Bambino Gesù Children’s Hospital, IRCCS, Via San Paolo 15, 00146 Rome, Italy; (S.P.); (M.C.); (R.R.)
| | - Matteo Cassandri
- Group of Epigenetics of Pediatric Sarcomas, Department of Oncohematology, Bambino Gesù Children’s Hospital, IRCCS, Via San Paolo 15, 00146 Rome, Italy; (S.P.); (M.C.); (R.R.)
| | - Rossella Rota
- Group of Epigenetics of Pediatric Sarcomas, Department of Oncohematology, Bambino Gesù Children’s Hospital, IRCCS, Via San Paolo 15, 00146 Rome, Italy; (S.P.); (M.C.); (R.R.)
| | - Francesco Marampon
- Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy
| | - Cinzia Marchese
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy; (G.V.); (P.P.); (S.C.); (E.A.); (C.M.)
| | - Amalia Schiavetti
- Department of Maternal, Infantile and Urological Sciences, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy; (S.C.); (A.S.)
| | - Francesca Megiorni
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy; (G.V.); (P.P.); (S.C.); (E.A.); (C.M.)
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Khotimchenko R, Bryukhovetskiy I, Khotimchenko M, Khotimchenko Y. Bioactive Compounds with Antiglioma Activity from Marine Species. Biomedicines 2021; 9:biomedicines9080886. [PMID: 34440090 PMCID: PMC8389718 DOI: 10.3390/biomedicines9080886] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 11/21/2022] Open
Abstract
The search for new chemical compounds with antitumor pharmacological activity is a necessary process for creating more effective drugs for each specific malignancy type. This review presents the outcomes of screening studies of natural compounds with high anti-glioma activity. Despite significant advances in cancer therapy, there are still some tumors currently considered completely incurable including brain gliomas. This review covers the main problems of the glioma chemotherapy including drug resistance, side effects of common anti-glioma drugs, and genetic diversity of brain tumors. The main emphasis is made on the characterization of natural compounds isolated from marine organisms because taxonomic diversity of organisms in seawaters significantly exceeds that of terrestrial species. Thus, we should expect greater chemical diversity of marine compounds and greater likelihood of finding effective molecules with antiglioma activity. The review covers at least 15 classes of organic compounds with their chemical formulas provided as well as semi-inhibitory concentrations, mechanisms of action, and pharmacokinetic profiles. In conclusion, the analysis of the taxonomic diversity of marine species containing bioactives with antiglioma activity is performed noting cytotoxicity indicators and to the tumor cells in comparison with similar indicators of antitumor agents approved for clinical use as antiglioblastoma chemotherapeutics.
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Affiliation(s)
- Rodion Khotimchenko
- School of Biomedicine, Far Eastern Federal University, 690090 Vladivostok, Russia; (R.K.); (I.B.); (M.K.)
| | - Igor Bryukhovetskiy
- School of Biomedicine, Far Eastern Federal University, 690090 Vladivostok, Russia; (R.K.); (I.B.); (M.K.)
| | - Maksim Khotimchenko
- School of Biomedicine, Far Eastern Federal University, 690090 Vladivostok, Russia; (R.K.); (I.B.); (M.K.)
| | - Yuri Khotimchenko
- School of Biomedicine, Far Eastern Federal University, 690090 Vladivostok, Russia; (R.K.); (I.B.); (M.K.)
- Laboratory of Pharmacology, A. V. Zhirmunsky National Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, 690950 Vladivostok, Russia
- Correspondence:
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Adiga D, Eswaran S, Pandey D, Sharan K, Kabekkodu SP. Molecular landscape of recurrent cervical cancer. Crit Rev Oncol Hematol 2020; 157:103178. [PMID: 33279812 DOI: 10.1016/j.critrevonc.2020.103178] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 11/06/2020] [Accepted: 11/11/2020] [Indexed: 02/07/2023] Open
Abstract
Cervical cancer (CC) is a major gynecological problem in developing and underdeveloped countries. Despite the significant advancement in early detection and treatment modalities, several patients recur. Moreover, the molecular mechanisms responsible for CC recurrence remains obscure. The patients with CC recurrence often show poor prognosis and significantly high mortality rates. The clinical management of recurrent CC depends on treatment history, site, and extent of the recurrence. Owing to poor prognosis and limited treatment options, recurrent CC often presents a challenge to the clinicians. Several in vitro, in vivo, and patient studies have led to the identification of the critical molecular changes responsible for CC recurrence. Both aberrant genetic and epigenetic modifications leading to altered cell signaling pathways have been reported to impact CC recurrence. Researchers are currently trying to dissect the molecular pathways in CC and translate these findings for better management of disease. This article attempts to review the existing knowledge of disease relapse, accompanying challenges, and associated molecular players in CC.
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Affiliation(s)
- Divya Adiga
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Sangavi Eswaran
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Deeksha Pandey
- Department of OBGYN, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Krishna Sharan
- Department of Radiotherapy and Oncology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Shama Prasada Kabekkodu
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
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Lou M, Li R, Lang TY, Zhang LY, Zhou Q, Li L. Aberrant methylation of GADD45A is associated with decreased radiosensitivity in cervical cancer through the PI3K/AKT signaling pathway. Oncol Lett 2020; 21:8. [PMID: 33240414 PMCID: PMC7681222 DOI: 10.3892/ol.2020.12269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 10/08/2020] [Indexed: 12/12/2022] Open
Abstract
Epigenetic inactivation of GADD45A is a common occurrence in different types of cancer. However, little is known regarding its association with radiosensitivity in cervical cancer (CC). Thus, the present study aimed to investigate the association between aberrant GADD45A methylation and radiosensitivity in CC. SiHa, HeLa and CaSki CC cells were treated with 5-azacytidine (5-azaC), with or without irradiation. The expression levels of GADD45A and AKT related molecules were detected via reverse transcription-quantitative PCR and western blot analyses. The methylation status of GADD45A was assessed via methylation-specific PCR and cell proliferation assays, while clonogenic assays and flow cytometric analysis were performed to assess the function of the genes (GADD45A and AKT) in the CC cell lines. The results demonstrated that methylation of GADD45A was significantly higher in the radioresistant tissues (63.16%) compared with the radiosensitive samples (33.33%). In addition, the surviving fraction of SiHa cells following irradiation with 2 Gy was demonstrated to be highest amongst the three CC cells (CaSki, 57±9.5%; HeLa, 70±4% and SiHa, 75±10%). The survival rate of SiHa cells following treatment with 5-azaC and ionizing radiation (IR) significantly decreased as the radiation dose increased, compared with treatment with IR alone. Following overexpression of GADD45A or treatment with 5-azaC, the radiosensitivity of SiHa cells significantly increased compared with both the control vector and PBS treated groups. In addition, the AKT inhibitor, MK-2206, increased the radiosensitivity of SiHa cells. Notably, aberrant methylation of GADD45A was associated with decreased radiosensitivity in CC, and the PI3K/AKT signaling pathway was essential for radioresistance, which was mediated through downregulation of GADD45A.
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Affiliation(s)
- Meng Lou
- Department of Gynecologic Oncology, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Rong Li
- Department of Gynecologic Oncology, Chongqing University Cancer Hospital and Chongqing Cancer Institute and Chongqing Cancer Hospital, Chongqing 400030, P.R. China
| | - Ting-Yuan Lang
- Department of Gynecologic Oncology, Chongqing University Cancer Hospital and Chongqing Cancer Institute and Chongqing Cancer Hospital, Chongqing 400030, P.R. China
| | - Li-Ying Zhang
- Department of Gynecology, The Second Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi 530000, P.R. China
| | - Qi Zhou
- Department of Gynecologic Oncology, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.,Department of Gynecologic Oncology, Chongqing University Cancer Hospital and Chongqing Cancer Institute and Chongqing Cancer Hospital, Chongqing 400030, P.R. China.,Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital and Chongqing Cancer Institute and Chongqing Cancer Hospital, Chongqing 400030, P.R. China.,Key Laboratory for Biorheological Science and Technology of Ministry of Education, Chongqing University Cancer Hospital and Chongqing Cancer Institute and Chongqing Cancer Hospital, Chongqing 400030, P.R. China
| | - Li Li
- Department of Gynecologic Oncology, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
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10
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Raviraj R, Nagaraja SS, Selvakumar I, Mohan S, Nagarajan D. The epigenetics of brain tumors and its modulation during radiation: A review. Life Sci 2020; 256:117974. [PMID: 32553924 DOI: 10.1016/j.lfs.2020.117974] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/23/2020] [Accepted: 06/10/2020] [Indexed: 10/24/2022]
Abstract
The brain tumor is the abnormal growth of heterogeneous cells around the central nervous system and spinal cord. Most clinically prominent brain tumors affecting both adult and pediatric are glioblastoma, medulloblastoma, and ependymoma and they are classified according to their origin of tissue. Chemotherapy, radiotherapy, and surgery are important treatments available to date. However, these treatments fail due to multiple reasons, including chemoresistance and radiation resistance of cancer cells. Thus, there is a need of new therapeutic designs to target cell signaling and molecular events which are responsible for this resistance. Recently epigenetic changes received increased attention because it helps in understanding chromatin-mediated disease mechanism. The epigenetic modification alters chromatin structure that affects the docking site of many drugs which cause chemo-resistance of cancer therapy. This review centers the mechanism of how epigenetic changes affect the transcription repression and activation of various genes including Polycomb gene, V-Myc avian myelocytomatosis viral oncogene (MYCN). This review also put forth the pathway of radiation-induced reactive oxygen species generation and its role in epigenetic changes in the cellular level and its impact on tissue physiology. Additionally, there is a strong relationship between the behavior of an individual and environment-induced epigenetic regulation of gene expression. The review also discusses Transcriptome heterogeneity and role of tumor microenvironment in glioblastoma. Overall, this review emphasis important and novel epigenetic targets that could be of therapeutic benefit, which helps in overcoming the unsolved chromatin alteration in brain cancer.
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Affiliation(s)
- Raghavi Raviraj
- Radiation Biology Lab, 206, ASK-II, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, Tamil Nadu 613401, India
| | - SunilGowda Sunnaghatta Nagaraja
- Radiation Biology Lab, 206, ASK-II, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, Tamil Nadu 613401, India
| | - Ilakya Selvakumar
- Radiation Biology Lab, 206, ASK-II, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, Tamil Nadu 613401, India
| | - Suma Mohan
- Department of Bioinformatics, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, Tamil Nadu 613401, India
| | - Devipriya Nagarajan
- Radiation Biology Lab, 206, ASK-II, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, Tamil Nadu 613401, India.
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11
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Chovanec M, Taza F, Kalra M, Hahn N, Nephew KP, Spinella MJ, Albany C. Incorporating DNA Methyltransferase Inhibitors (DNMTis) in the Treatment of Genitourinary Malignancies: A Systematic Review. Target Oncol 2019; 13:49-60. [PMID: 29230671 DOI: 10.1007/s11523-017-0546-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Inhibition of DNA methyltransferases (DNMTs) has emerged as a novel treatment strategy in solid tumors. Aberrant hypermethylation in promoters of critical tumor suppressor genes is the basis for the idea that treatment with hypomethylating agents may lead to the restoration of a "normal" epigenome and produce clinically meaningful therapeutic outcomes. The aim of this review article is to summarize the current state of knowledge of DNMT inhibitors in the treatment of genitourinary malignancies. The efficacy of these agents in genitourinary malignancies was reported in a number of studies and suggests a role of induced DNA hypomethylation in overcoming resistance to conventional cytotoxic treatments. The clinical significance of these findings should be further investigated.
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Affiliation(s)
- Michal Chovanec
- Division of Hematology/Oncology, Indiana University Simon Cancer Center, Indianapolis, IN, USA.
- 2nd Department of Oncology, Faculty of Medicine, Comenius University and National Cancer Institute, Bratislava, Slovakia.
| | - Fadi Taza
- Division of Hematology/Oncology, Indiana University Simon Cancer Center, Indianapolis, IN, USA
| | - Maitri Kalra
- Division of Hematology/Oncology, Indiana University Simon Cancer Center, Indianapolis, IN, USA
| | - Noah Hahn
- The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kenneth P Nephew
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, IN, USA
| | - Michael J Spinella
- Department of Comparative Biosciences, the University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Costantine Albany
- Division of Hematology/Oncology, Indiana University Simon Cancer Center, Indianapolis, IN, USA
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12
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Sutton LP, Jeffreys SA, Phillips JL, Taberlay PC, Holloway AF, Ambrose M, Joo JHE, Young A, Berry R, Skala M, Brettingham-Moore KH. DNA methylation changes following DNA damage in prostate cancer cells. Epigenetics 2019; 14:989-1002. [PMID: 31208284 PMCID: PMC6691980 DOI: 10.1080/15592294.2019.1629231] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Many cancer therapies operate by inducing double-strand breaks (DSBs) in cancer cells, however treatment-resistant cells rapidly initiate mechanisms to repair damage enabling survival. While the DNA repair mechanisms responsible for cancer cell survival following DNA damaging treatments are becoming better understood, less is known about the role of the epigenome in this process. Using prostate cancer cell lines with differing sensitivities to radiation treatment, we analysed the DNA methylation profiles prior to and following a single dose of radiotherapy (RT) using the Illumina Infinium HumanMethylation450 BeadChip platform. DSB formation and repair, in the absence and presence of the DNA hypomethylating agent, 5-azacytidine (5-AzaC), were also investigated using γH2A.X immunofluorescence staining. Here we demonstrate that DNA methylation is generally stable following a single dose of RT; however, a small number of CpG sites are stably altered up to 14 d following exposure. While the radioresistant and radiosensitive cells displayed distinct basal DNA methylation profiles, their susceptibility to DNA damage appeared similar demonstrating that basal DNA methylation has a limited influence on DSB induction at the regions examined. Recovery from DSB induction was also similar between these cells. Treatment with 5-AzaC did not sensitize resistant cells to DNA damage, but rather delayed recruitment of phosphorylated BRCA1 (S1423) and repair of DSBs. These results highlight that stable epigenetic changes are possible following a single dose of RT and may have significant clinical implications for cancer treatment involving recurrent or fractionated dosing regimens.
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Affiliation(s)
- Laura P Sutton
- a School of Medicine, College of Health and Medicine, University of Tasmania , Hobart , Australia
| | - Sarah A Jeffreys
- a School of Medicine, College of Health and Medicine, University of Tasmania , Hobart , Australia
| | - Jessica L Phillips
- a School of Medicine, College of Health and Medicine, University of Tasmania , Hobart , Australia
| | - Phillippa C Taberlay
- a School of Medicine, College of Health and Medicine, University of Tasmania , Hobart , Australia
| | - Adele F Holloway
- a School of Medicine, College of Health and Medicine, University of Tasmania , Hobart , Australia
| | - Mark Ambrose
- a School of Medicine, College of Health and Medicine, University of Tasmania , Hobart , Australia
| | - Ji-Hoon E Joo
- b Colorectal Oncogenomics Group, Department of Clinical Pathology & University of Melbourne Centre for Cancer Research, The University of Melbourne , Parkville , Australia
| | - Arabella Young
- a School of Medicine, College of Health and Medicine, University of Tasmania , Hobart , Australia
| | - Rachael Berry
- a School of Medicine, College of Health and Medicine, University of Tasmania , Hobart , Australia
| | - Marketa Skala
- c Department of Radiation Oncology, Royal Hobart Hospital , Hobart , Australia
| | - Kate H Brettingham-Moore
- a School of Medicine, College of Health and Medicine, University of Tasmania , Hobart , Australia
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13
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Koturbash I, Griffin RJ. Harnessing epigenetics and metabolism to modulate tissue response to radiotherapy. Int J Radiat Biol 2019; 95:379-381. [PMID: 30856046 DOI: 10.1080/09553002.2019.1587268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Igor Koturbash
- a Department of Environmental and Occupational Health , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Robert J Griffin
- b Department of Radiation Oncology , University of Arkansas for Medical Sciences , Little Rock , AR , USA
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14
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Kang HC, Chie EK, Kim HJ, Kim JH, Kim IH, Kim K, Shin BS, Ma E. A phthalimidoalkanamide derived novel DNMT inhibitor enhanced radiosensitivity of A549 cells by inhibition of homologous recombination of DNA damage. Invest New Drugs 2019; 37:1158-1165. [PMID: 30793218 DOI: 10.1007/s10637-019-00730-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 01/16/2019] [Indexed: 12/18/2022]
Abstract
Purpose To elucidate the radiosensitizing effect and underlying mechanism of a new kind of DNA methyltransferase (DNMT) inhibitor with biological availability. Methods A novel non-nucleoside compound, designated as MA-17, was recently derived from a phthalimido alkanamide structure. DNMT expressions were confirmed in cultured human lung cancer (A549) and normal astrocyte (NHA) cells, radiosensitivity was measured using clonogenic assay, and assays of cell cycle alteration, apoptosis, DNA damage repair, and differential gene expression were undertaken. Results MA-17 significantly radiosensitized A549 cells with a mean dose enhancement ratio (DER) of 1.43 at the surviving fraction of 0.2 (p < 0.05 by one-tailed ratio paired t-test). MA-17 did not affect normal astrocytes (mean DER0.2, 1.016; p = 0.420). MA-17 demonstrated a mean half-life of 1.0 h in vivo and a relatively even distribution in various tissues. Pretreatment with MA-17 increased sub-G1 fractions and inhibited the repair of DNA double-strand breaks, which are induced by irradiation. We found that MA-17 also down-regulated DNA homologous recombination and the Fanconi anemia pathway (FANCA, BRCA1, and RAD51C) in A549 cells. This bioinformatics finding was confirmed in validation Western blot to evaluate the expression of vital proteins. Conclusions A novel phthalimido alkanamide derivative, a DNMT inhibitor, possessed both biostability and favorable and substantial radiosensitizing effects by augmenting apoptosis or inhibiting DNA damage repair.
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Affiliation(s)
- Hyun-Cheol Kang
- Department of Radiation Oncology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.,Cancer Research Institute, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea
| | - Eui Kyu Chie
- Department of Radiation Oncology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.,Cancer Research Institute, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea
| | - Hak Jae Kim
- Department of Radiation Oncology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.,Cancer Research Institute, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea
| | - Jin Ho Kim
- Department of Radiation Oncology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.,Cancer Research Institute, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea
| | - Il Han Kim
- Department of Radiation Oncology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea. .,Cancer Research Institute, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.
| | - Kwangsoo Kim
- Division of Clinical Bioinformatics, Biomedical Research Institute, Seoul National University Hospital, Seoul, South Korea
| | - Beom Su Shin
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - EunSook Ma
- College of Pharmacy, Daegu Catholic University, Gyeongsan-si, Gyeongbuk, South Korea
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15
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Fabbrizi MR, Warshowsky KE, Zobel CL, Hallahan DE, Sharma GG. Molecular and epigenetic regulatory mechanisms of normal stem cell radiosensitivity. Cell Death Discov 2018; 4:117. [PMID: 30588339 PMCID: PMC6299079 DOI: 10.1038/s41420-018-0132-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/01/2018] [Accepted: 11/20/2018] [Indexed: 12/14/2022] Open
Abstract
Ionizing radiation (IR) therapy is a major cancer treatment modality and an indispensable auxiliary treatment for primary and metastatic cancers, but invariably results in debilitating organ dysfunctions. IR-induced depletion of neural stem/progenitor cells in the subgranular zone of the dentate gyrus in the hippocampus where neurogenesis occurs is considered largely responsible for deficiencies such as learning, memory, and spatial information processing in patients subjected to cranial irradiation. Similarly, IR therapy-induced intestinal injuries such as diarrhea and malabsorption are common side effects in patients with gastrointestinal tumors and are believed to be caused by intestinal stem cell drop out. Hematopoietic stem cell transplantation is currently used to reinstate blood production in leukemia patients and pre-clinical treatments show promising results in other organs such as the skin and kidney, but ethical issues and logistic problems make this route difficult to follow. An alternative way to restore the injured tissue is to preserve the stem cell pool located in that specific tissue/organ niche, but stem cell response to ionizing radiation is inadequately understood at the molecular mechanistic level. Although embryonic and fetal hypersensity to IR has been very well known for many decades, research on embryonic stem cell models in culture concerning molecular mechanisms have been largely inconclusive and often in contradiction of the in vivo observations. This review will summarize the latest discoveries on stem cell radiosensitivity, highlighting the possible molecular and epigenetic mechanism(s) involved in DNA damage response and programmed cell death after ionizing radiation therapy specific to normal stem cells. Finally, we will analyze the possible contribution of stem cell-specific chromatin's epigenetic constitution in promoting normal stem cell radiosensitivity.
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Affiliation(s)
- Maria Rita Fabbrizi
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 4511 Forest Park, Saint Louis, MO 63108 USA
| | - Kacie E. Warshowsky
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 4511 Forest Park, Saint Louis, MO 63108 USA
| | - Cheri L. Zobel
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 4511 Forest Park, Saint Louis, MO 63108 USA
| | - Dennis E. Hallahan
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 4511 Forest Park, Saint Louis, MO 63108 USA
- Siteman Cancer Center, Washington University School of Medicine, Saint Louis, MO 63108 USA
| | - Girdhar G. Sharma
- Cancer Biology Division, Department of Radiation Oncology, Washington University School of Medicine, 4511 Forest Park, Saint Louis, MO 63108 USA
- Siteman Cancer Center, Washington University School of Medicine, Saint Louis, MO 63108 USA
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16
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Barlas F, Aydindogan E, Arslan M, Timur S, Yagci Y. Gold nanoparticle conjugated poly(p
-phenylene-β-cyclodextrin)-graft
-poly(ethylene glycol) for theranostic applications. J Appl Polym Sci 2018. [DOI: 10.1002/app.47250] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- F.B. Barlas
- Department of Biochemistry; Faculty of Science, Ege University; 35100 Bornova, Izmir Turkey
| | - E. Aydindogan
- Department of Biochemistry; Faculty of Science, Ege University; 35100 Bornova, Izmir Turkey
| | - M. Arslan
- Department of Chemistry; Faculty of Science and Letters, Istanbul Technical University; 34469 Maslak, Istanbul Turkey
| | - S. Timur
- Department of Biochemistry; Faculty of Science, Ege University; 35100 Bornova, Izmir Turkey
- Central Research Testing and Analysis Laboratory Research and Application Center; Ege University; 35100 Bornova, Izmir Turkey
| | - Y. Yagci
- Department of Chemistry; Faculty of Science and Letters, Istanbul Technical University; 34469 Maslak, Istanbul Turkey
- Chemistry Department; King Abdulaziz University, Faculty of Science; Jeddah Saudi Arabia
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17
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Pefani DE, Tognoli ML, Pirincci Ercan D, Gorgoulis V, O'Neill E. MST2 kinase suppresses rDNA transcription in response to DNA damage by phosphorylating nucleolar histone H2B. EMBO J 2018; 37:e98760. [PMID: 29789391 PMCID: PMC6068430 DOI: 10.15252/embj.201798760] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 04/18/2018] [Accepted: 04/27/2018] [Indexed: 12/15/2022] Open
Abstract
The heavily transcribed rDNA repeats that give rise to the ribosomal RNA are clustered in a unique chromatin structure, the nucleolus. Due to its highly repetitive nature and transcriptional activity, the nucleolus is considered a hotspot of genomic instability. Breaks in rDNA induce a transient transcriptional shut down to conserve energy and promote rDNA repair; however, how nucleolar chromatin is modified and impacts on rDNA repair is unknown. Here, we uncover that phosphorylation of serine 14 on histone H2B marks transcriptionally inactive nucleolar chromatin in response to DNA damage. We identified that the MST2 kinase localises at the nucleoli and targets phosphorylation of H2BS14p in an ATM-dependent manner. We show that establishment of H2BS14p is necessary for damage-induced rDNA transcriptional shut down and maintenance of genomic integrity. Ablation of MST2 kinase, or upstream activators, results in defective establishment of nucleolar H2BS14p, perturbed DNA damage repair, sensitisation to rDNA damage and increased cell lethality. We highlight the impact of chromatin regulation in the rDNA damage response and targeting of the nucleolus as an emerging cancer therapeutic approach.
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Affiliation(s)
- Dafni Eleftheria Pefani
- CRUK/MRC Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
| | - Maria Laura Tognoli
- CRUK/MRC Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
| | - Deniz Pirincci Ercan
- CRUK/MRC Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
- Radboud University, Nijmegen, The Netherlands
| | - Vassilis Gorgoulis
- Laboratory of Histology and Embryology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- Biomedical Research Foundation of the Academy of Athens, Athens, Greece
- Faculty of Biology, Medicine and Health, Manchester Academic Health Centre, University of Manchester, Manchester, UK
| | - Eric O'Neill
- CRUK/MRC Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
- Systems Biology Ireland, University College Dublin, Dublin 4, Ireland
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18
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Zhu X, Wang Y, Tan L, Fu X. The pivotal role of DNA methylation in the radio-sensitivity of tumor radiotherapy. Cancer Med 2018; 7:3812-3819. [PMID: 29952116 PMCID: PMC6089158 DOI: 10.1002/cam4.1614] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/15/2018] [Accepted: 05/21/2018] [Indexed: 12/23/2022] Open
Abstract
Radiotherapy is an important modality for treatment of carcinomas; however, radio‐resistance is still a difficult problem. Aberrant epigenetic alterations play an important role in cancer development. Among epigenetic parameters, DNA methylation has arguably attracted the most attention in the radio‐resistance process. To determine the role of DNA methylation in radiation resistance, several studies were conducted. We summarized previous studies on the role of DNA methylation in radiotherapy. We observed this significant role of DNA methylation in genes related to DNA repair, cell proliferation, cell cycle process, and re‐oxygenation. Furtherly, we also conclude the predictive effect of DNA methylation on tumor radio‐sensitivity and the using of DNA methyltransferase inhibitors in clinical practice. DNA methylation plays a pivotal role in the radio‐sensitivity of tumor radio‐therapy. While hyper‐methylation or hypo‐methylation of genes is related to gene functions.
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Affiliation(s)
- Xueru Zhu
- Department of Radiation Oncology, Shanghai Jiao Tong University Affiliated Chest Hospital, Shanghai, China
| | - Yiting Wang
- Department of Radiation Oncology, Shanghai Jiao Tong University Affiliated Chest Hospital, Shanghai, China
| | - Li Tan
- Department of Cellular and Genetic Medicine, Fudan University School of Basic Medical Sciences, Shanghai, China
| | - Xiaolong Fu
- Department of Radiation Oncology, Shanghai Jiao Tong University Affiliated Chest Hospital, Shanghai, China
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19
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Chi HC, Tsai CY, Tsai MM, Lin KH. Impact of DNA and RNA Methylation on Radiobiology and Cancer Progression. Int J Mol Sci 2018; 19:ijms19020555. [PMID: 29439529 PMCID: PMC5855777 DOI: 10.3390/ijms19020555] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/09/2018] [Accepted: 02/10/2018] [Indexed: 12/24/2022] Open
Abstract
Radiotherapy is a well-established regimen for nearly half the cancer patients worldwide. However, not all cancer patients respond to irradiation treatment, and radioresistance is highly associated with poor prognosis and risk of recurrence. Elucidation of the biological characteristics of radioresistance and development of effective prognostic markers to guide clinical decision making clearly remain an urgent medical requirement. In tumorigenic and radioresistant cancer cell populations, phenotypic switch is observed during the course of irradiation treatment, which is associated with both stable genetic and epigenetic changes. While the importance of epigenetic changes is widely accepted, the irradiation-triggered specific epigenetic alterations at the molecular level are incompletely defined. The present review provides a summary of current studies on the molecular functions of DNA and RNA m6A methylation, the key epigenetic mechanisms involved in regulating the expression of genetic information, in resistance to irradiation and cancer progression. We additionally discuss the effects of DNA methylation and RNA N6-methyladenosine (m6A) of specific genes in cancer progression, recurrence, and radioresistance. As epigenetic alterations could be reversed by drug treatment or inhibition of specific genes, they are also considered potential targets for anticancer therapy and/or radiotherapy sensitizers. The mechanisms of irradiation-induced alterations in DNA and RNA m6A methylation, and ways in which this understanding can be applied clinically, including utilization of methylation patterns as prognostic markers for cancer radiotherapy and their manipulation for anticancer therapy or use as radiotherapy sensitizers, have been further discussed.
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Affiliation(s)
- Hsiang-Cheng Chi
- Radiation Biology Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Linkou, Taoyuan 333, Taiwan.
| | - Chung-Ying Tsai
- Kidney Research Center and Department of Nephrology, Chang Gung Immunology Consortium, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan 333, Taiwan.
| | - Ming-Ming Tsai
- Department of Nursing, Chang-Gung University of Science and Technology, Taoyuan 333, Taiwan.
- Department of General Surgery, Chang Gung Memorial Hospital, Chiayi 613, Taiwan.
| | - Kwang-Huei Lin
- Liver Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan 333, Taiwan.
- Department of Biochemistry, College of Medicine, Chang-Gung University, Taoyuan 333, Taiwan.
- Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 333, Taiwan.
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20
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Miousse IR, Ewing LE, Kutanzi KR, Griffin RJ, Koturbash I. DNA Methylation in Radiation-Induced Carcinogenesis: Experimental Evidence and Clinical Perspectives. Crit Rev Oncog 2018; 23:1-11. [PMID: 29953365 PMCID: PMC6369919 DOI: 10.1615/critrevoncog.2018025687] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Ionizing radiation is a valuable tool in many spheres of human life. At the same time, it is a genotoxic agent with a well-established carcinogenic potential. Progress achieved in the last two decades has demonstrated convincingly that ionizing radiation can also target the cellular epigenome. Epigenetics is defined as heritable changes in the expression of genes that are not due to alterations of DNA sequence but consist of specific covalent modifications of chromatin components, such as methylation of DNA, histone modifications, and control performed by non-coding RNAs. Accumulating evidence suggests that DNA methylation, a key epigenetic mechanism involved in the control of expression of genetic information, may serve as one of the driving mechanisms of radiation-induced carcinogenesis. Here, we review the literature on the effects of ionizing radiation on DNA methylation in various biological systems, discuss the role of DNA methylation in radiation carcinogenesis, and provide our opinion on the potential utilization of this knowledge in radiation oncology.
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Affiliation(s)
- Isabelle R. Miousse
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Laura E. Ewing
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Kristy R. Kutanzi
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Robert J. Griffin
- Department of Radiation Oncology, Radiation Biology Division, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Igor Koturbash
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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21
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Wang X, Wang Y, Xiao G, Wang J, Zu L, Hao M, Sun X, Fu Y, Hu G, Wang J. Hypermethylated in cancer 1(HIC1) suppresses non-small cell lung cancer progression by targeting interleukin-6/Stat3 pathway. Oncotarget 2017; 7:30350-64. [PMID: 27107418 PMCID: PMC5058685 DOI: 10.18632/oncotarget.8734] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 04/06/2016] [Indexed: 11/25/2022] Open
Abstract
Non-small cell lung cancer (NSCLC), which accounts for more than 80% of lung cancers, is a leading cause of cancer mortality worldwide. However, the mechanism underlying its progression remains unclear. Here we found that HIC1 promoter was heavily methylated in NSCLC cell lines and tissues contributing to its low expression compared to normal controls. Restoring HIC1 expression inhibited migration, invasion and promoted inducible apoptosis of NSCLC cells. Notably, HIC1 is a tumor suppressor through inhibiting the transcription of IL-6 by sequence-specific binding on its promoter. Restoring IL-6 expression could partially rescue these phenotypes induced by HIC1 in vitro and in vivo. Mechanistic analyses show that autocrine secretion of IL-6 induced by loss of HIC1 activated STAT3 through IL-6/JAK pathway and was associated with NSCLC progression. The HIC1/IL-6 axis may serve as a prognostic biomarker and provide an attractive therapeutic target for NSCLC.
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Affiliation(s)
- Xiumin Wang
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yingying Wang
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Gang Xiao
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jinglong Wang
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lidong Zu
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mingang Hao
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xueqing Sun
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yujie Fu
- Department of Chest Surgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Guohong Hu
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jianhua Wang
- Cancer institute, Fudan University Shanghai Cancer Center, Shanghai, China
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22
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Kwon HM, Kang EJ, Kang K, Kim SD, Yang K, Yi JM. Combinatorial effects of an epigenetic inhibitor and ionizing radiation contribute to targeted elimination of pancreatic cancer stem cell. Oncotarget 2017; 8:89005-89020. [PMID: 29179494 PMCID: PMC5687664 DOI: 10.18632/oncotarget.21642] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/27/2017] [Indexed: 01/03/2023] Open
Abstract
Pancreatic cancer is associated with a high mortality rate, owing to de novo and acquired drug resistance, thereby leading to highly invasive and metastatic pancreatic cancer cells. Therefore, targeting pancreatic cancer stem cells (CSCs) may be a novel therapeutic strategy for the treatment of pancreatic cancer. Here, we combined a DNA methylation inhibitor (5-aza-2'-deoxycytidine; 5-aza-dC) and ionizing radiation (IR) to improve anti-cancer effects by inhibiting growth and proliferation and promoting apoptosis of pancreatic cancer cells in vitro and in vivo. Importantly, the combinatorial effect of 5-aza-dC with IR on sphere-forming pancreatic cancer cells was preferentially targeted toward CSCs through the downregulation of regulatory factors of self-renewal and CSC surface markers. We next performed the RNA sequencing to understand the underlying cellular mechanisms of the combined treatment with IR and 5-aza-dC in pancreatic cancer cells. Global transcriptome profiling indicated that the expression of the Oct4-centered transcriptional network of genes was significantly downregulated in cells with combination treatment. Our data suggested that combination treatment with DNA methylation inhibitor and IR may be a novel therapeutic strategy for pancreatic cancer. Overall, these findings support the use of epigenetic therapy in combination with radiotherapy to improve therapeutic efficacy by targeting and eradicating pancreatic CSCs.
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Affiliation(s)
- Hyun-Mi Kwon
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan 46033, South Korea
| | - Eun-Jin Kang
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan 46033, South Korea
| | - Keunsoo Kang
- Department of Microbiology, Dankook Universty, Cheonan 31116, South Korea
| | - Sung-Dae Kim
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan 46033, South Korea
| | - Kwangmo Yang
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan 46033, South Korea
| | - Joo Mi Yi
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan 46033, South Korea
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23
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Miousse IR, Kutanzi KR, Koturbash I. Effects of ionizing radiation on DNA methylation: from experimental biology to clinical applications. Int J Radiat Biol 2017; 93:457-469. [PMID: 28134023 PMCID: PMC5411327 DOI: 10.1080/09553002.2017.1287454] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE Ionizing radiation (IR) is a ubiquitous environmental stressor with genotoxic and epigenotoxic capabilities. Terrestrial IR, predominantly a low-linear energy transfer (LET) radiation, is being widely utilized in medicine, as well as in multiple industrial applications. Additionally, an interest in understanding the effects of high-LET irradiation is emerging due to the potential of exposure during space missions and the growing utilization of high-LET radiation in medicine. CONCLUSIONS In this review, we summarize the current knowledge of the effects of IR on DNA methylation, a key epigenetic mechanism regulating the expression of genetic information. We discuss global, repetitive elements and gene-specific DNA methylation in light of exposure to high and low doses of high- or low-LET IR, fractionated IR exposure, and bystander effects. Finally, we describe the mechanisms of IR-induced alterations to DNA methylation and discuss ways in which that understanding can be applied clinically, including utilization of DNA methylation as a predictor of response to radiotherapy and in the manipulation of DNA methylation patterns for tumor radiosensitization.
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Affiliation(s)
- Isabelle R Miousse
- a Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Kristy R Kutanzi
- a Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health , University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Igor Koturbash
- a Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health , University of Arkansas for Medical Sciences , Little Rock , AR , USA
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24
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Liang G, Weisenberger DJ. DNA methylation aberrancies as a guide for surveillance and treatment of human cancers. Epigenetics 2017; 12:416-432. [PMID: 28358281 DOI: 10.1080/15592294.2017.1311434] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
DNA methylation aberrancies are hallmarks of human cancers and are characterized by global DNA hypomethylation of repetitive elements and non-CpG rich regions concomitant with locus-specific DNA hypermethylation. DNA methylation changes may result in altered gene expression profiles, most notably the silencing of tumor suppressors, microRNAs, endogenous retorviruses and tumor antigens due to promoter DNA hypermethylation, as well as oncogene upregulation due to gene-body DNA hypermethylation. Here, we review DNA methylation aberrancies in human cancers, their use in cancer surveillance and the interplay between DNA methylation and histone modifications in gene regulation. We also summarize DNA methylation inhibitors and their therapeutic effects in cancer treatment. In this context, we describe the integration of DNA methylation inhibitors with conventional chemotherapies, DNA repair inhibitors and immune-based therapies, to bring the epigenome closer to its normal state and increase sensitivity to other therapeutic agents to improve patient outcome and survival.
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Affiliation(s)
- Gangning Liang
- a Department of Urology , University of Southern California, USC Norris Comprehensive Cancer Center , Los Angeles , CA , USA
| | - Daniel J Weisenberger
- b Department of Biochemistry and Molecular Medicine , University of Southern California, USC Norris Comprehensive Cancer Center , Los Angeles , CA , USA
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25
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Aranda J, Attana F, Tuñón I. Molecular Mechanism of Inhibition of DNA Methylation by Zebularine. ACS Catal 2017. [DOI: 10.1021/acscatal.6b03381] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Juan Aranda
- Departamento Química
Física, Universitat de València, 46100 Burjassot, Spain
| | - Fedaa Attana
- Departamento Química
Física, Universitat de València, 46100 Burjassot, Spain
| | - Iñaki Tuñón
- Departamento Química
Física, Universitat de València, 46100 Burjassot, Spain
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26
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Zielske SP. Epigenetic DNA methylation in radiation biology: on the field or on the sidelines? J Cell Biochem 2015; 116:212-7. [PMID: 25186310 DOI: 10.1002/jcb.24959] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 08/29/2014] [Indexed: 01/05/2023]
Abstract
DNA methylation has been studied with regard to chemotherapeutics for a number of years. The radiation field has just begun to look at this in the context of radiotherapy or radiation exposure. So far, the data suggest that radiation induces epigenetic reprogramming which indicates a purposeful response that influences the cell fate or alters the response to future exposure. Further studies may result in discovery of biomarkers for radiotherapy outcome or prediction of the degree of radiation resistance. Past and ongoing development of DNMT1 inhibitors that lead to DNA hypomethylation appear to sensitize many tumor types to radiation and may be an area with long term clinical implications.
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Affiliation(s)
- Steven P Zielske
- Department of Radiation Oncology, Wayne State University, Detroit, Michigan 48201
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27
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Fulkerson CM, Dhawan D, Jones DR, Marquez VE, Jones PA, Wang Z, Wu Q, Klaunig JE, Fourez LM, Bonney PL, Knapp DW. Pharmacokinetics and toxicity of the novel oral demethylating agent zebularine in laboratory and tumor bearing dogs. Vet Comp Oncol 2015; 15:226-236. [PMID: 26178438 DOI: 10.1111/vco.12159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 05/07/2015] [Accepted: 05/07/2015] [Indexed: 12/31/2022]
Abstract
The purpose of this study was to determine the plasma pharmacokinetics (PK) and toxicity of zebularine, an oral cytidine analog with demethylating activity, in dogs. Plasma zebularine concentrations were determined by HPLC-MS/MS following an oral zebularine dose of 8 or 4 mg kg-1 . Plasma zebularine clearance was constant. Mean maximum concentration (Cmax ) was 23 ± 4.8 and 8.6 ± 1.4 µM following 8 and 4 mg kg-1 , respectively. Mean half-life was 5.7 ± 0.84 and 7.1 ± 2.1 following 8 and 4 mg kg-1 , respectively. A single 8 mg kg-1 dose was well tolerated. Daily 4 mg kg-1 treatment in three laboratory dogs resulted in grade 4 neutropenia (n = 3), grade 1 anorexia (n = 2) and grade 1 or 2 dermatologic changes (n = 2). All adverse events resolved with supportive care. A 4 mg kg-1 dose every 21 days was well tolerated. A follow-up dose escalation study is in progress with a lower starting dose.
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Affiliation(s)
- C M Fulkerson
- Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN, USA
| | - D Dhawan
- Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN, USA
| | - D R Jones
- Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - V E Marquez
- Center for Cancer Research, Chemical Biology Laboratory, National Cancer Institute, Frederick, MD, USA
| | - P A Jones
- Van Adel Research Institute, Grand Rapids, MI, USA
| | - Z Wang
- Department of Environmental Health, School of Public Health, Indiana University, Bloomington, IN, USA
| | - Q Wu
- Department of Environmental Health, School of Public Health, Indiana University, Bloomington, IN, USA
| | - J E Klaunig
- Department of Environmental Health, School of Public Health, Indiana University, Bloomington, IN, USA
| | - L M Fourez
- Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN, USA
| | - P L Bonney
- Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN, USA
| | - D W Knapp
- Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN, USA.,Purdue University Center for Cancer Research, West Lafayette, IN, USA
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28
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DNA Methyltransferase Inhibitor Zebularine Induces Human Cholangiocarcinoma Cell Death through Alteration of DNA Methylation Status. PLoS One 2015. [DOI: 10.1371/journal.pone.0120545
expr 911344426 + 964939221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
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29
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Nakamura K, Nakabayashi K, Htet Aung K, Aizawa K, Hori N, Yamauchi J, Hata K, Tanoue A. DNA methyltransferase inhibitor zebularine induces human cholangiocarcinoma cell death through alteration of DNA methylation status. PLoS One 2015; 10:e0120545. [PMID: 25799509 PMCID: PMC4370694 DOI: 10.1371/journal.pone.0120545] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 01/23/2015] [Indexed: 12/12/2022] Open
Abstract
Cholangiocarcinoma (CCA) is a cancer arising from the neoplastic transformation of cholangiocytes. During tumorigenesis, tumor suppressor and cancer-related genes are commonly silenced by aberrant DNA methylation in their promoter regions. Zebularine (1-(β-D-ribofuranosyl)-1,2-dihydropyrimidin-2-one) acts as an inhibitor of DNA methylation and exhibits chemical stability and minimal cytotoxicity both in vitro and in vivo. In this study, we explore the effect and possible mechanism of action of zebularine on CCA cells. We demonstrate that zebularine exerts an antitumor effect on CCA cells. Zebularine treatment decreased the concentrations of DNA methyltransferase (DNMT) proteins, and DNMT1 knockdown led to apoptotic cell death in the CCA cell lines TFK-1 and HuCCT1. DNA methylation analysis demonstrated that zebularine induced DNA demethylation, and the GO Biological Process terms “hemophilic cell adhesion”, “regulation of transcription, DNA-dependent” and “Wnt signaling pathway” were found to be significantly enriched in association with demethylated genes. Furthermore, we observed that zebularine treatment decreased β-catenin protein levels in TFK-1 and HuCCT1 cells. These results suggest that zebularine alters DNA methylation status, and that some aspect of DNA demethylation by zebularine induces suppression of the Wnt signaling pathway, which leads to apoptotic cell death in CCA. We previously reported a novel mechanism of zebularine-induced cell growth arrest and apoptosis in hepatocellular carcinoma via a DNA methylation-independent pathway. Together, our present and previous studies indicate that zebularine could function as both a DNMT inhibitor and a non-DNMT inhibitor reagent, and that, while the optimal usage of zebularine may depend on cancer type, zebularine may be useful for chemotherapy against cancer.
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Affiliation(s)
- Kazuaki Nakamura
- Department of Pharmacology, National Research Institute for Child Health and Development, Tokyo, Japan
- * E-mail:
| | - Kazuhiko Nakabayashi
- Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Kyaw Htet Aung
- Department of Pharmacology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Kazuko Aizawa
- Department of Pharmacology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Naoko Hori
- Department of Pharmacology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Junji Yamauchi
- Department of Pharmacology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Kenichiro Hata
- Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Akito Tanoue
- Department of Pharmacology, National Research Institute for Child Health and Development, Tokyo, Japan
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30
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Bae JH, Kim JG, Heo K, Yang K, Kim TO, Yi JM. Identification of radiation-induced aberrant hypomethylation in colon cancer. BMC Genomics 2015; 16:56. [PMID: 25887185 PMCID: PMC4342812 DOI: 10.1186/s12864-015-1229-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Accepted: 01/09/2015] [Indexed: 12/22/2022] Open
Abstract
Background Exposure to ionizing radiation (IR) results in the simultaneous activation or downregulation of multiple signaling pathways that play critical roles in cell type-specific control of survival or death. IR is a well-known genotoxic agent and human carcinogen that induces cellular damage through direct and indirect mechanisms. However, its impact on epigenetic mechanisms has not been elucidated, and more specifically, little information is available regarding genome-wide DNA methylation changes in cancer cells after IR exposure. Recently, genome-wide DNA methylation profiling technology using the Illumina HumanMethylation450K platform has emerged that allows us to query >450,000 loci within the genome. This improved technology is capable of identifying genome-wide DNA methylation changes in CpG islands and other CpG island-associated regions. Results In this study, we employed this technology to test the hypothesis that exposure to IR not only induces differential DNA methylation patterns at a genome-wide level, but also results in locus- and gene-specific DNA methylation changes. We screened for differential DNA methylation changes in colorectal cancer cells after IR exposure with 2 and 5 Gy. Twenty-nine genes showed radiation-induced hypomethylation in colon cancer cells, and of those, seven genes showed a corresponding increase in gene expression by reverse transcriptase polymerase chain reaction (RT-PCR). In addition, we performed chromatin immunoprecipitation (ChIP) to confirm that the DNA-methyltransferase 1 (DNMT1) level associated with the promoter regions of these genes correlated with their methylation level and gene expression changes. Finally, we used a gene ontology (GO) database to show that a handful of hypomethylated genes induced by IR are associated with a variety of biological pathways related to cancer. Conclusion We identified alterations in global DNA methylation patterns and hypomethylation at specific cancer-related genes following IR exposure, which suggests that radiation exposure plays a critical role in conferring epigenetic alterations in cancer. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1229-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jin-Han Bae
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, 619-953, South Korea.
| | - Joong-Gook Kim
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, 619-953, South Korea.
| | - Kyu Heo
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, 619-953, South Korea.
| | - Kwangmo Yang
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, 619-953, South Korea. .,Department of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seoul, 139-709, Korea.
| | - Tae-Oh Kim
- Department of Internal Medicine, Inje University Haeundae Paik hospital, Busan, 612-896, South Korea.
| | - Joo Mi Yi
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, 619-953, South Korea.
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31
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Flesner BK, Kumar SR, Bryan JN. 6-Thioguanine and zebularine down-regulate DNMT1 and globally demethylate canine malignant lymphoid cells. BMC Vet Res 2014; 10:290. [PMID: 25480665 PMCID: PMC4272768 DOI: 10.1186/s12917-014-0290-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 11/25/2014] [Indexed: 11/21/2022] Open
Abstract
Background The antimetabolite 6-thioguanine (6-TG) has been used to treat both human and canine lymphoid malignancies. 6-TG has been shown to be epigenetically active as a demethylating agent in a human lymphoma cell line, causing downregulation of DNA methyltransferase 1 (DNMT1) through ubiquitin-targeted degradation. Zebularine (Zeb), a similar cytidine analog, also has demethylating activity as well as oral bioavailability. The hypothesis of the present study was that 6-TG and Zeb would cause downregulation of DNMT1 and globally demethylate the genomic DNA of canine lymphoma cells. The secondary hypothesis was that these agents would cause a dose-dependent decrease in cell proliferation in canine lymphoma cells. Canine CLGL-90 malignant T cells and CLL 17–7 cells were incubated in modified RPMI media. They were treated with 6-TG, Zeb, or control media at biologically relevant concentrations. Results Following treatment with each agent, DNMT1 protein and global DNA methylation were significantly decreased. A dose-dependent decrease in cell survival was also observed, with apoptosis being the primary mode of cell death in the CLGL-90 cell line. Conclusions These results confirm the demethylating action of 6-TG and Zeb in canine cells which is similar to that shown in human cell lines. Confirmation of this mechanism supports the clinical application of these compounds as demethylating drugs in veterinary patients.
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Affiliation(s)
- Brian K Flesner
- Department of Veterinary Medicine and Surgery, Comparative Oncology and Epigenetics Laboratory, College of Veterinary Medicine, University of Missouri-Columbia, 900 E. Campus Drive, Columbia, MO, 65211, USA. .,Current address: School of Veterinary Medicine, Louisiana State University, Skip Bertman Drive, Baton Rouge, LA, 70803, USA.
| | - Senthil R Kumar
- Department of Veterinary Medicine and Surgery, Comparative Oncology and Epigenetics Laboratory, College of Veterinary Medicine, University of Missouri-Columbia, 900 E. Campus Drive, Columbia, MO, 65211, USA.
| | - Jeffrey N Bryan
- Department of Veterinary Medicine and Surgery, Comparative Oncology and Epigenetics Laboratory, College of Veterinary Medicine, University of Missouri-Columbia, 900 E. Campus Drive, Columbia, MO, 65211, USA.
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32
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Kim JG, Bae JH, Kim JA, Heo K, Yang K, Yi JM. Combination effect of epigenetic regulation and ionizing radiation in colorectal cancer cells. PLoS One 2014; 9:e105405. [PMID: 25136811 PMCID: PMC4138159 DOI: 10.1371/journal.pone.0105405] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Accepted: 07/21/2014] [Indexed: 12/30/2022] Open
Abstract
Exposure of cells to ionizing radiation (IR) induces, not only, activation of multiple signaling pathways that play critical roles in cell fate determination, but also alteration of molecular pathways involved in cell death or survival. Recently, DNA methylation has been established as a critical epigenetic process involved in the regulation of gene expression in cancer cells, suggesting that DNA methylation inhibition may be an effective cancer treatment strategy. Because alterations of gene expression by DNA methylation have been considered to influence radioresponsiveness, we investigated the effect of a DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine (5-aza-dC), on radiosensitivity. In addition, we investigated the underlying cellular mechanisms of combination treatments of ionizing irradiation (IR) and 5-aza-dC in human colon cancer cells. Colon cancer cell lines were initially tested for radiation sensitivity by IR in vitro and were treated with two different doses of 5-aza-dC. Survival of these cell lines was measured using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and clonogenic assays. The effects of 5-aza-dC along with irradiation on cell growth, cell cycle distribution, apoptosis, and apoptosis-related gene expression were examined. Combination irradiation treatment with 5-aza-dC significantly decreased growth activity compared with irradiation treatment alone or with 5-aza-dC treatment alone. The percentage of HCT116 cells in the sub-G1 phase and their apoptotic rate was increased when cells were treated with irradiation in combination with 5-aza-dC compared with either treatment alone. These observations were strongly supported by increased caspase activity, increased comet tails using comet assays, and increased protein levels of apoptosis-associated molecules (caspase 3/9, cleaved PARP). Our data demonstrated that 5-aza-dC enhanced radiosensitivity in colon cancer cells, and the combination effects of 5-aza-dC with radiation showed greater cellular effects than that of single treatment, suggesting that the combination of 5-aza-dC and radiation has the potential to become a clinical strategy for the treatment of cancer.
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Affiliation(s)
- Joong-Gook Kim
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, South Korea
| | - Jin-Han Bae
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, South Korea
| | - Jin-Ah Kim
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, South Korea
| | - Kyu Heo
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, South Korea
| | - Kwangmo Yang
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, South Korea
- Department of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Joo Mi Yi
- Research Center, Dongnam Institute of Radiological & Medical Sciences (DIRAMS), Busan, South Korea
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33
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Smits KM, Melotte V, Niessen HE, Dubois L, Oberije C, Troost EG, Starmans MH, Boutros PC, Vooijs M, van Engeland M, Lambin P. Epigenetics in radiotherapy: Where are we heading? Radiother Oncol 2014; 111:168-77. [DOI: 10.1016/j.radonc.2014.05.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 03/17/2014] [Accepted: 05/01/2014] [Indexed: 12/20/2022]
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34
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Pouliliou S, Koukourakis MI. Gamma histone 2AX (γ-H2AX)as a predictive tool in radiation oncology. Biomarkers 2014; 19:167-80. [DOI: 10.3109/1354750x.2014.898099] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Stamatia Pouliliou
- Department of Radiotherapy/Oncology, Radiobiology and Radiopathology Unit, Democritus University of Thrace
AlexandroupolisGreece
| | - Michael I. Koukourakis
- Department of Radiotherapy/Oncology, Radiobiology and Radiopathology Unit, Democritus University of Thrace
AlexandroupolisGreece
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Bryan JN, Kumar SR, Jia F, Balkin ER, Lewis MR. Zebularine significantly sensitises MEC1 cells to external irradiation and radiopharmaceutical therapy when administered sequentially in vitro. Cell Biol Int 2014; 38:187-97. [PMID: 24323360 PMCID: PMC3947096 DOI: 10.1002/cbin.10215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 09/10/2013] [Indexed: 01/13/2023]
Abstract
Zebularine is a cytidine analogue incorporated into DNA during replication, inhibiting DNA methyltransferase 1 (DNMT1), resulting in demethylation and changes in gene expression. Such modification may improve radiosensitivity in resistant lymphoma cells. The hypothesis of this study was that zebularine and radiation would synergistically inhibit cell growth and viability. Human MEC1 malignant B cells were incubated with 0-200 µM zebularine for 48 h. Media containing zebularine was removed, and the cells were irradiated with 0-2 Gy of either external beam irradiation or (177) Lu-DOTA-TATE, a radiolabelled somatostatin analogue. Concentration and viability were measured over 48-72 h. The proportion of apoptotic cells was identified using an active Caspase 3/7 assay. Zebularine inhibited growth of cells in a dose-dependent manner during exposure. No residual growth inhibition occurred following removal of the drug. Zebularine and external irradiation inhibited cell proliferation in a dose-dependent, synergistic interaction, but the effect on viability was additive. Treatment with zebularine and (177) Lu-DOTA-TATE resulted in less inhibition of proliferation (P = 0.0135), but a synergistic decrease in viability. Apoptotic fraction was much higher in cells irradiated with (177) Lu-DOTA-TATE than external irradiation. External irradiation induces growth arrest rather than apoptosis. Apoptosis is the primary effect of radiopharmaceutical therapy on tumour cells. Treatment with the methylation inhibitor, zebularine, appears to synergistically augment these natural effects in vitro, which could be exploited clinically.
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Affiliation(s)
- Jeffrey N. Bryan
- Dept of Veterinary Medicine and Surgery, University of Missouri-Columbia, Columbia, MO 65211
- Research Service, Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO 65211
- Area of Pathobiology, University of Missouri-Columbia, Columbia MO 65211
| | - Senthil R. Kumar
- Dept of Veterinary Medicine and Surgery, University of Missouri-Columbia, Columbia, MO 65211
- Research Service, Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO 65211
| | - Fang Jia
- Dept of Veterinary Medicine and Surgery, University of Missouri-Columbia, Columbia, MO 65211
- Research Service, Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO 65211
| | - Ethan R. Balkin
- Area of Pathobiology, University of Missouri-Columbia, Columbia MO 65211
| | - Michael R. Lewis
- Dept of Veterinary Medicine and Surgery, University of Missouri-Columbia, Columbia, MO 65211
- Research Service, Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO 65211
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36
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Li Y, Geng P, Jiang W, Wang Y, Yao J, Lin X, Liu J, Huang L, Su B, Chen H. Enhancement of radiosensitivity by 5-Aza-CdR through activation of G2/M checkpoint response and apoptosis in osteosarcoma cells. Tumour Biol 2014; 35:4831-9. [PMID: 24474250 DOI: 10.1007/s13277-014-1634-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 01/07/2014] [Indexed: 02/07/2023] Open
Abstract
Radiation resistance is a major problem preventing successful treatment. Therefore, identifying sensitizers is vitally important for radiotherapy success. Epigenetic events such as DNA methylation have been proposed to mediate the sensitivity of tumor therapy. In this study, we investigated the influence of demethylating agent 5-Aza-2'-deoxycytidine (5-Aza-CdR) on the radiosensitivity of human osteosarcoma cell lines. 5-Aza-CdR was capable of sensitizing three osteosarcoma cells to irradiation in a time-dependent manner, with the maximum effect attained by 48 h. Pretreatment with 5-Aza-CdR synchronized cells in G2/M phase of the cell cycle and enhanced irradiation-induced apoptosis compared with irradiation alone in SaOS2, HOS, and U2OS cells. Moreover, 5-Aza-CdR restored mRNA expressions of 14-3-3σ, CHK2, and DAPK-1 in the three cells, accompanied with demethylation of their promoters. These findings demonstrate that demethylation with 5-Aza-CdR increases radiosensitivity in some osteosarcoma cells through arresting cells at G2/M phase and increasing apoptosis, which is partly mediated by upregulation of 14-3-3σ, CHK2, and DAPK-1 genes, suggesting that 5-Aza-CdR may be a potential radiosensitizer to improve the therapy effect in osteosarcoma.
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Affiliation(s)
- Yi Li
- Key Laboratory of Oncology, Cancer Center, Division of Internal Medicine, Chinese PLA General Hospital and Chinese PLA Medical School, Beijing, 100853, China
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Lara PC, López-Peñalver JJ, Farias VDA, Ruiz-Ruiz MC, Oliver FJ, Ruiz de Almodóvar JM. Direct and bystander radiation effects: a biophysical model and clinical perspectives. Cancer Lett 2013; 356:5-16. [PMID: 24045041 DOI: 10.1016/j.canlet.2013.09.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 09/03/2013] [Accepted: 09/08/2013] [Indexed: 12/12/2022]
Abstract
In planning treatment for each new patient, radiation oncologists pay attention to the aspects that they control. Thus their attention is usually focused on volume and dose. The dilemma for the physician is how to protract the treatment in a way that maximizes control of the tumor and minimizes normal tissue injury. The initial radiation-induced damage to DNA may be a biological indicator of the quantity of energy transferred to the DNA. However, until now the biophysical models proposed cannot explain either the early or the late adverse effects of radiation, and a more general theory appears to be required. The bystander component of tumor cell death after radiotherapy measured in many experimental works highlights the importance of confirming these observations in a clinical situation.
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Affiliation(s)
- Pedro Carlos Lara
- Radiation Oncology Department, Hospital Universitario de Gran Canaria Dr Negrín, Barranco de La Ballena s/n, Las Palmas de Gran Canaria, CP 35010, Spain
| | - Jesús Joaquín López-Peñalver
- Instituto de Biopatología y Medicina Regenerativa, Centro de Investigación Biomédica, Universidad de Granada, Avda. Conocimiento 2, 18016 Granada, Spain
| | - Virgínea de Araújo Farias
- Instituto de Biopatología y Medicina Regenerativa, Centro de Investigación Biomédica, Universidad de Granada, Avda. Conocimiento 2, 18016 Granada, Spain
| | - M Carmen Ruiz-Ruiz
- Instituto de Biopatología y Medicina Regenerativa, Centro de Investigación Biomédica, Universidad de Granada, Avda. Conocimiento 2, 18016 Granada, Spain
| | - Francisco Javier Oliver
- Instituto de Parasitología y Biomedicina López Neyra, CSIC, Avda. Conocimiento 4, 18016 Granada, Spain
| | - José Mariano Ruiz de Almodóvar
- Instituto de Biopatología y Medicina Regenerativa, Centro de Investigación Biomédica, Universidad de Granada, Avda. Conocimiento 2, 18016 Granada, Spain; Hospital Universitario San Cecilio, Avda. Dr. Olóriz s/n, 18012 Granada, Spain.
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DNA methylation in tumour and normal mucosal tissue of head and neck squamous cell carcinoma (HNSCC) patients: new diagnostic approaches and treatment. Med Oncol 2013; 30:654. [PMID: 23824644 DOI: 10.1007/s12032-013-0654-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 06/24/2013] [Indexed: 12/31/2022]
Abstract
Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide. Long-term survival of this patient group has been marginally improved during the last 30 years. This is due to the high recurrence rate of local primary or development of second primary tumours in the patients. We found that normal-appearing surgical margins and distant mucosal tissue of HNSCC patients contained tumour suppressor genes DNA methylation. These cells might be the progenitors of the tumour recurrences. Such molecular abnormalities in the normal-appearing mucosa tissue were not possible to detect in the clinic or by standard histopathologically analysis. To improve clinical outcome, the convenient and cost-effective molecular analysis such as methylation-specific PCR should be added to the pathological diagnosis armamentarium for HNSCC patients. The beneficial effect of antimethylating agents as additional treatment or for cancer chemoprevention, in this high-risk patient group, warrants further investigation.
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Sabatino MA, Geroni C, Ganzinelli M, Ceruti R, Broggini M. Zebularine partially reverses GST methylation in prostate cancer cells and restores sensitivity to the DNA minor groove binder brostallicin. Epigenetics 2013; 8:656-65. [PMID: 23771052 DOI: 10.4161/epi.24916] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Brostallicin is a DNA minor groove binder that shows enhanced antitumor activity in cells with high glutathione S-transferase (GST)/glutathione content. Prostate cancer cells present, almost invariably, methylation of the GSTP1 gene promoter and, as a consequence, low levels of GST-pi expression and activity. In these cells, brostallicin shows very little activity. We tested whether pretreatment of heavily GST-methylated prostate cancer cells with demethylating agents could enhance the activity of brostallicin. Human prostate cancer cells LNCaP and DU145 were used for these studies both in vitro and in vivo. The demethylating agent zebularine was used in combination with brostallicin. Methylation specific PCR and pyrosequencing were used to determine the level of GST methylation. Pretreatment with demethylating agents enhanced the in vitro activity of brostallicin in LNCaP cells. Zebularine, in particular, induced an enhancement of activity in vivo comparable to that obtained by transfecting the human GSTP1 gene in LNCaP cells in vitro. Molecular analysis performed on tumor xenografts in mice pretreated with zebularine failed to detect re-expression of GST-pi and demethylation of GSTP1. However, we found demethylation in the GSTM1 gene, with consequent re-expression of GST-mu at the mRNA level. These results indicate that zebularine, both in vitro and in vivo, enhances the activity of brostallicin and that this enhancement correlates with re-expression of GST-pi and GST-mu. These findings highlight the potential therapeutic value of combining demethylating agents and brostallicin in tumors with GST methylation that poorly respond to brostallicin.
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Affiliation(s)
- Maria Antonietta Sabatino
- Laboratory of Molecular Pharmacology; Department of Oncology; IRCCS-Istituto di Ricerche Farmacologiche Mario Negri; Milan, Italy
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Gertych A, Oh JH, Wawrowsky KA, Weisenberger DJ, Tajbakhsh J. 3-D DNA methylation phenotypes correlate with cytotoxicity levels in prostate and liver cancer cell models. BMC Pharmacol Toxicol 2013; 14:11. [PMID: 23394161 PMCID: PMC3598242 DOI: 10.1186/2050-6511-14-11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 01/14/2013] [Indexed: 11/10/2022] Open
Abstract
Background The spatial organization of the genome is being evaluated as a novel indicator of toxicity in conjunction with drug-induced global DNA hypomethylation and concurrent chromatin reorganization. 3D quantitative DNA methylation imaging (3D-qDMI) was applied as a cell-by-cell high-throughput approach to investigate this matter by assessing genome topology through represented immunofluorescent nuclear distribution patterns of 5-methylcytosine (MeC) and global DNA (4,6-diamidino-2-phenylindole = DAPI) in labeled nuclei. Methods Differential progression of global DNA hypomethylation was studied by comparatively dosing zebularine (ZEB) and 5-azacytidine (AZA). Treated and untreated (control) human prostate and liver cancer cells were subjected to confocal scanning microscopy and dedicated 3D image analysis for the following features: differential nuclear MeC/DAPI load and codistribution patterns, cell similarity based on these patterns, and corresponding differences in the topology of low-intensity MeC (LIM) and low in intensity DAPI (LID) sites. Results Both agents generated a high fraction of similar MeC phenotypes across applied concentrations. ZEB exerted similar effects at 10–100-fold higher drug concentrations than its AZA analogue: concentration-dependent progression of global cytosine demethylation, validated by measuring differential MeC levels in repeat sequences using MethyLight, and the concurrent increase in nuclear LIM densities correlated with cellular growth reduction and cytotoxicity. Conclusions 3D-qDMI demonstrated the capability of quantitating dose-dependent drug-induced spatial progression of DNA demethylation in cell nuclei, independent from interphase cell-cycle stages and in conjunction with cytotoxicity. The results support the notion of DNA methylation topology being considered as a potential indicator of causal impacts on chromatin distribution with a conceivable application in epigenetic drug toxicology.
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Affiliation(s)
- Arkadiusz Gertych
- Translational Cytomics Group, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
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Nakamura K, Aizawa K, Nakabayashi K, Kato N, Yamauchi J, Hata K, Tanoue A. DNA methyltransferase inhibitor zebularine inhibits human hepatic carcinoma cells proliferation and induces apoptosis. PLoS One 2013; 8:e54036. [PMID: 23320119 PMCID: PMC3540068 DOI: 10.1371/journal.pone.0054036] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 12/07/2012] [Indexed: 12/21/2022] Open
Abstract
Hepatocellular carcinoma is one of the most common cancers worldwide. During tumorigenesis, tumor suppressor and cancer-related genes are commonly silenced by aberrant DNA methylation in their promoter regions. Zebularine (1-(β-(D)-ribofuranosyl)-1,2-dihydropyrimidin-2-one) acts as an inhibitor of DNA methylation and exhibits chemical stability and minimal cytotoxicity both in vitro and in vivo. In this study, we explore the effect and possible mechanism of action of zebularine on hepatocellular carcinoma cell line HepG2. We demonstrate that zebularine exhibits antitumor activity on HepG2 cells by inhibiting cell proliferation and inducing apoptosis, however, it has little effect on DNA methylation in HepG2 cells. On the other hand, zebularine treatment downregulated CDK2 and the phosphorylation of retinoblastoma protein (Rb), and upregulated p21(WAF/CIP1) and p53. We also found that zebularine treatment upregulated the phosphorylation of p44/42 mitogen-activated protein kinase (MAPK). These results suggest that the p44/42 MAPK pathway plays a role in zebularine-induced cell-cycle arrest by regulating the activity of p21(WAF/CIP1) and Rb. Furthermore, although the proapoptotic protein Bax levels were not affected, the antiapoptotic protein Bcl-2 level was downregulated with zebularine treatment. In addition, the data in the present study indicate that inhibition of the double-stranded RNA-dependent protein kinase (PKR) is involved in inducing apoptosis with zebularine. These results suggest a novel mechanism of zebularine-induced cell growth arrest and apoptosis via a DNA methylation-independent pathway in hepatocellular carcinoma.
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Affiliation(s)
- Kazuaki Nakamura
- Department of Pharmacology, National Research Institute for Child Health and Development, Tokyo, Japan.
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Folic Acid Acts Through DNA Methyltransferases to Induce the Differentiation of Neural Stem Cells into Neurons. Cell Biochem Biophys 2013; 66:559-66. [DOI: 10.1007/s12013-012-9503-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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The DNA methyltransferase inhibitor zebularine induces mitochondria-mediated apoptosis in gastric cancer cells in vitro and in vivo. Biochem Biophys Res Commun 2013; 430:250-5. [PMID: 23167995 DOI: 10.1016/j.bbrc.2012.10.143] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 10/31/2012] [Indexed: 12/31/2022]
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Friedl AA, Mazurek B, Seiler DM. Radiation-induced alterations in histone modification patterns and their potential impact on short-term radiation effects. Front Oncol 2012; 2:117. [PMID: 23050241 PMCID: PMC3445916 DOI: 10.3389/fonc.2012.00117] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 08/28/2012] [Indexed: 12/12/2022] Open
Abstract
Detection and repair of radiation-induced DNA damage occur in the context of chromatin. An intricate network of mechanisms defines chromatin structure, including DNA methylation, incorporation of histone variants, histone modifications, and chromatin remodeling. In the last years it became clear that the cellular response to radiation-induced DNA damage involves all of these mechanisms. Here we focus on the current knowledge on radiation-induced alterations in post-translational histone modification patterns and their effect on the chromatin accessibility, transcriptional regulation and chromosomal stability.
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Affiliation(s)
- Anna A Friedl
- Department of Radiation Oncology, Ludwig-Maximilians-University Munich, Germany
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Wang L, Zhang Y, Li R, Chen Y, Pan X, Li G, Dai F, Yang J. 5-aza-2'-Deoxycytidine enhances the radiosensitivity of breast cancer cells. Cancer Biother Radiopharm 2012; 28:34-44. [PMID: 22917213 DOI: 10.1089/cbr.2012.1170] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To investigate the effect of the DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine (DAC), on radiosensitivity in breast cancer cells. MATERIALS AND METHODS Two breast cancer cell lines, MDA-MB-231 and MDA-MB-435, were evaluated. The methylation status and the mRNA expression of three genes (ER, PR, and HIC-1) that were frequently hypermethylated in these cell lines were determined as a function of DAC exposure. 3-(4,5)-dimethylthiahiazo-(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) absorbance and a colony-forming assay were used to estimate cell viability and radiosensitivity. Using cell-cycle analysis, γ-histone H2A (γ-H2AX) formation assays and methylation-specific polymerase chain reaction (MSP) analysis of three genes correlated with radiosensitivity (BRCA1, 14-3-3σ, and E-cadherin), the mechanism of DAC enhancement of radiosensitivity was explored. RESULTS DAC induced the demethylation and reactivation of silent genes in both cell lines. The combination of DAC and irradiation induced growth suppression in vitro. DAC, 5 μM, enhanced sensitivity to ionizing radiation. DAC followed by irradiation correlated with G2/M arrest and the retardation of repair of radiation-induced double strand breaks. DAC reversed the methylation status of genes connected with radiosensitization. The different radiosensitization effects observed with different breast cancers cells may correlate with the primary methylation status of radiosensitizing genes. CONCLUSIONS Treatment strategies that include DAC present promising options for sensitizing breast cancer cells to irradiation.
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Affiliation(s)
- Li Wang
- Department of Pathology, Kunming General Hospital, Kunming, Yunnan, China
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Armstrong CA, Jones GD, Anderson R, Iyer P, Narayanan D, Sandhu J, Singh R, Talbot CJ, Tufarelli C. DNMTs are required for delayed genome instability caused by radiation. Epigenetics 2012; 7:892-902. [PMID: 22722331 PMCID: PMC3427285 DOI: 10.4161/epi.21094] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The ability of ionizing radiation to initiate genomic instability has been harnessed in the clinic where the localized delivery of controlled doses of radiation is used to induce cell death in tumor cells. Though very effective as a therapy, tumor relapse can occur in vivo and its appearance has been attributed to the radio-resistance of cells with stem cell-like features. The molecular mechanisms underlying these phenomena are unclear but there is evidence suggesting an inverse correlation between radiation-induced genomic instability and global hypomethylation. To further investigate the relationship between DNA hypomethylation, radiosensitivity and genomic stability in stem-like cells we have studied mouse embryonic stem cells containing differing levels of DNA methylation due to the presence or absence of DNA methyltransferases. Unexpectedly, we found that global levels of methylation do not determine radiosensitivity. In particular, radiation-induced delayed genomic instability was observed at the Hprt gene locus only in wild-type cells. Furthermore, absence of Dnmt1 resulted in a 10-fold increase in de novo Hprt mutation rate, which was unaltered by radiation. Our data indicate that functional DNMTs are required for radiation-induced genomic instability, and that individual DNMTs play distinct roles in genome stability. We propose that DNMTS may contribute to the acquirement of radio-resistance in stem-like cells.
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RASSF Signalling and DNA Damage: Monitoring the Integrity of the Genome? Mol Biol Int 2012; 2012:141732. [PMID: 22577550 PMCID: PMC3337673 DOI: 10.1155/2012/141732] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 01/27/2012] [Indexed: 12/14/2022] Open
Abstract
The RASSF family of proteins has been extensively studied in terms of their genetics, structure and function. One of the functions that has been increasingly studied is the role of the RASSF proteins in the DNA damage response. Surprisingly, this research, which encompasses both the classical and N-terminal RASSF proteins, has revealed an involvement of the RASSFs in oncogenic pathways as well as the more familiar tumour suppressor pathways usually associated with the RASSF family members. The most studied protein with respect to DNA damage is RASSF1A, which has been shown, not only to be activated by ATM, a major regulator of the DNA damage response, but also to bind to and activate a number of different pathways which all lead to and feedback from the guardian of the genome, p53. In this review we discuss the latest research linking the RASSF proteins to DNA damage signalling and maintenance of genomic integrity and look at how this knowledge is being utilised in the clinic to enhance the effectiveness of traditional cancer therapies such as radiotherapy.
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Kim HJ, Kim JH, Chie EK, Da Young P, Kim IA, Kim IH. DNMT (DNA methyltransferase) inhibitors radiosensitize human cancer cells by suppressing DNA repair activity. Radiat Oncol 2012; 7:39. [PMID: 22429326 PMCID: PMC3375186 DOI: 10.1186/1748-717x-7-39] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 03/20/2012] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Histone modifications and DNA methylation are two major factors in epigenetic phenomenon. Unlike the histone deacetylase inhibitors, which are known to exert radiosensitizing effects, there have only been a few studies thus far concerning the role of DNA methyltransferase (DNMT) inhibitors as radiosensitizers. The principal objective of this study was to evaluate the effects of DNMT inhibitors on the radiosensitivity of human cancer cell lines, and to elucidate the mechanisms relevant to that process. METHODS A549 (lung cancer) and U373MG (glioblastoma) cells were exposed to radiation with or without six DNMT inhibitors (5-azacytidine, 5-aza-2'-deoxycytidine, zebularine, hydralazine, epigallocatechin gallate, and psammaplin A) for 18 hours prior to radiation, after which cell survival was evaluated via clonogenic assays. Cell cycle and apoptosis were analyzed via flow cytometry. Expressions of DNMT1, 3A/3B, and cleaved caspase-3 were detected via Western blotting. Expression of γH2AX, a marker of radiation-induced DNA double-strand break, was examined by immunocytochemistry. RESULTS Pretreatment with psammaplin A, 5-aza-2'-deoxycytidine, and zebularine radiosensitized both A549 and U373MG cells. Pretreatment with psammaplin A increased the sub-G1 fraction of A549 cells, as compared to cells exposed to radiation alone. Prolongation of γH2AX expression was observed in the cells treated with DNMT inhibitors prior to radiation as compared with those treated by radiation alone. CONCLUSIONS Psammaplin A, 5-aza-2'-deoxycytidine, and zebularine induce radiosensitivity in both A549 and U373MG cell lines, and suggest that this effect might be associated with the inhibition of DNA repair.
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Affiliation(s)
- Hak Jae Kim
- Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jin Ho Kim
- Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Eui Kyu Chie
- Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Park Da Young
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - In Ah Kim
- Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Il Han Kim
- Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Republic of Korea
- Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
- Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Republic of Korea
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Chen M, Shabashvili D, Nawab A, Yang SX, Dyer LM, Brown KD, Hollingshead M, Hunter KW, Kaye FJ, Hochwald SN, Marquez VE, Steeg P, Zajac-Kaye M. DNA methyltransferase inhibitor, zebularine, delays tumor growth and induces apoptosis in a genetically engineered mouse model of breast cancer. Mol Cancer Ther 2012; 11:370-82. [PMID: 22203734 PMCID: PMC7457145 DOI: 10.1158/1535-7163.mct-11-0458] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Zebularine is a novel potent inhibitor of both cytidine deaminase and DNA methylation. We examined the effect of zebularine on mammary tumor growth in genetically engineered MMTV-PyMT transgenic mice that develop mammary tumors at 60 days of age with 100% penetrance. The MMTV-PyMT transgenic mice were randomized at 46 days of age into control (n = 25) and zebularine (n = 25) treatment groups and monitored for parameters of tumor growth. Zebularine was administered at 5 mg/mL in drinking water. We observed a significant delay in the growth of mammary tumors in zebularine-treated mice with a statistically significant reduction (P = 0.0135) in total tumor burden at 94 days of age when the mice were sacrificed. After 48 days of zebularine treatment, the tumors were predominantly necrotic compared with untreated animals. In addition, a high apoptotic index by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay was observed as early as 13 days following treatment. Immunoblot analysis showed depletion of DNMT1 and partial depletion of DNMT3b after zebularine treatment. Microarray analyses of global gene expression identified upregulation of twelve methylation-regulated genes as well as a set of candidate cancer genes that participate in cell growth and apoptosis. In summary, zebularine inhibits the growth of spontaneous mammary tumors and causes early onset of tumor cell necrosis and apoptosis in a genetically engineered mouse model of breast cancer. Defining the parameters of zebularine-mediated tumor inhibition may advance the future development of DNA methyltransferase inhibitors as an effective cancer treatment.
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Affiliation(s)
- Min Chen
- Departments of Anatomy and Cell Biology, University of Florida, Gainesville, Florida
- Departments of Medicine, University of Florida, Gainesville, Florida
| | - Daniel Shabashvili
- Departments of Anatomy and Cell Biology, University of Florida, Gainesville, Florida
| | - Akbar Nawab
- Departments of Anatomy and Cell Biology, University of Florida, Gainesville, Florida
| | - Sherry X. Yang
- Departments of National Clinical Target Validation Laboratory, Bethesda, Maryland
| | - Lisa M. Dyer
- Departments of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida
| | - Kevin D. Brown
- Departments of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida
| | - Melinda Hollingshead
- Departments of Developmental Therapeutics Program, NCI-Frederick, Bethesda, Maryland
| | - Kent W. Hunter
- Departments of Laboratory of Cancer Biology and Genetics, Bethesda, Maryland
| | - Frederic J. Kaye
- Departments of Medicine, University of Florida, Gainesville, Florida
| | | | - Victor E. Marquez
- Departments of Laboratory of Medicinal Chemistry, Bethesda, Maryland
| | - Patricia Steeg
- Departments of Laboratory of Molecular Pharmacology, National Cancer Institute, Bethesda, Maryland
| | - Maria Zajac-Kaye
- Departments of Anatomy and Cell Biology, University of Florida, Gainesville, Florida
- Departments of Medicine, University of Florida, Gainesville, Florida
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Ruiz-Magaña MJ, Rodríguez-Vargas JM, Morales JC, Saldivia MA, Schulze-Osthoff K, Ruiz-Ruiz C. The DNA methyltransferase inhibitors zebularine and decitabine induce mitochondria-mediated apoptosis and DNA damage in p53 mutant leukemic T cells. Int J Cancer 2011; 130:1195-207. [PMID: 21455989 DOI: 10.1002/ijc.26107] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Accepted: 03/15/2011] [Indexed: 12/23/2022]
Abstract
DNA methyltransferase (DNMT)-inhibiting nucleoside analogs reactivate the expression of tumor suppressor genes and apoptosis-related genes silenced by methylation, thus favoring the induction of apoptosis in tumor cells. Moreover, induction of DNA damage seems to contribute to their antitumor effect. However, the apoptotic signaling pathway induced by these demethylating drugs is not well understood. Here, we have investigated the induction of apoptosis by two nucleoside DNMT inhibitors, decitabine and zebularine, in leukemic T cells. Both inhibitors induced caspase-dependent apoptosis in Jurkat, CEM-6 and MOLT-4 leukemia T cell lines, all with mutant p53, whereas resting and activated normal T lymphocytes were highly resistant to these demethylating agents. Although decitabine and zebularine showed different ability to induce apoptosis and cell cycle arrest among the three cell lines, they similarly activated the intrinsic apoptotic pathway by inducing mitochondrial alterations such as Bak activation, loss of transmembrane potential and generation of reactive oxygen species (ROS). Accordingly, Bcl-2- and Bcl-x(L) -overexpressing Jurkat cells, as well as caspase-9-deficient Jurkat cells, were resistant to apoptosis induced by decitabine and zebularine. Interestingly, ROS production seemed to be necessary for the induction of apoptosis. Apoptotic events, such as Bak and caspase activation, started as soon as 20 hr after treatment with either decitabine or zebularine. In addition, progression of apoptosis triggered by both DNMT inhibitors was paralleled by the induction of DNA damage. Our results suggest that the mitochondrial apoptotic pathway activated by decitabine and zebularine in p53 mutant leukemic T cells depends mainly on the induction of DNA damage.
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