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NEO212, a Perillyl Alcohol-Temozolomide Conjugate, Triggers Macrophage Differentiation of Acute Myeloid Leukemia Cells and Blocks Their Tumorigenicity. Cancers (Basel) 2022; 14:cancers14246065. [PMID: 36551551 PMCID: PMC9776529 DOI: 10.3390/cancers14246065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 12/01/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022] Open
Abstract
Many patients with acute myeloid leukemia (AML) are still dying from this disease. In the past, the alkylating agent temozolomide (TMZ) has been investigated for AML and found to be partially effective; however, the presence of O6-methylguanine DNA methyltransferase (MGMT; a DNA repair enzyme) in tumor cells confers profound treatment resistance against TMZ. We are developing a novel anticancer compound, called NEO212, where TMZ was covalently conjugated to perillyl alcohol (a naturally occurring monoterpene). NEO212 has revealed robust therapeutic activity in a variety of preclinical cancer models, including AML. In the current study, we investigated its impact on a panel of human AML cell lines and found that it exerted cytotoxic potency even against MGMT-positive cells that were highly resistant to TMZ. Furthermore, NEO212 strongly stimulated the expression of a large number of macrophage-associated marker genes, including CD11b/ITGAM. This latter effect could not be mimicked when cells were treated with TMZ or an equimolar mix of individual agents, TMZ plus perillyl alcohol. The superior cytotoxic impact of NEO212 appeared to involve down-regulation of MGMT protein levels. In a mouse model implanted with TMZ-resistant, MGMT-positive AML cells, two 5-day cycles of 25 mg/kg NEO212 achieved an apparent cure, as mice survived >300 days without any signs of disease. In parallel toxicity studies with rats, a 5-day cycle of 200 mg/kg NEO212 was well tolerated by these animals, whereas animals that were given 200 mg/kg TMZ all died due to severe leukopenia. Together, our results show that NEO212 exerts pleiotropic effects on AML cells that include differentiation, proliferation arrest, and eventual cell death. In vivo, NEO212 was well tolerated even at dosages that far exceed the therapeutic need, indicating a large therapeutic window. These results present NEO212 as an agent that should be considered for development as a therapeutic agent for AML.
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Ortiz R, Perazzoli G, Cabeza L, Jiménez-Luna C, Luque R, Prados J, Melguizo C. Temozolomide: An Updated Overview of Resistance Mechanisms, Nanotechnology Advances and Clinical Applications. Curr Neuropharmacol 2021; 19:513-537. [PMID: 32589560 PMCID: PMC8206461 DOI: 10.2174/1570159x18666200626204005] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 06/17/2020] [Accepted: 06/21/2020] [Indexed: 12/22/2022] Open
Abstract
Temozolomide (TMZ), an oral alkylating prodrug which delivers a methyl group to purine bases of DNA (O6-guanine; N7-guanine and N3-adenine), is frequently used together with radiotherapy as part of the first-line treatment of high-grade gliomas. The main advantages are its high oral bioavailability (almost 100% although the concentration found in the cerebrospinal fluid was approximately 20% of the plasma concentration of TMZ), its lipophilic properties, and small size that confer the ability to cross the blood-brain barrier. Furthermore, this agent has demonstrated activity not only in brain tumors but also in a variety of solid tumors. However, conventional therapy using surgery, radiation, and TMZ in glioblastoma results in a median patient survival of 14.6 months. Treatment failure has been associated with tumor drug resistance. This phenomenon has been linked to the expression of O6-methylguanine-DNA methyltransferase, but the mismatch repair system and the presence of cancer stem-like cells in tumors have also been related to TMZ resistance. The understanding of these mechanisms is essential for the development of new therapeutic strategies in the clinical use of TMZ, including the use of nanomaterial delivery systems and the association with other chemotherapy agents. The aim of this review is to summarize the resistance mechanisms of TMZ and the current advances to improve its clinical use.
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Affiliation(s)
- Raúl Ortiz
- Institute of Biopathology and Regenerative Medicine (IBIMER), Biomedical Research Centre (CIBM), University of Granada, Spain
| | | | - Laura Cabeza
- Institute of Biopathology and Regenerative Medicine (IBIMER), Biomedical Research Centre (CIBM), University of Granada, Spain
| | - Cristina Jiménez-Luna
- Department of Oncology, Ludwig Institute for Cancer Research, University of Lausanne, Epalinges 1066, Switzerland
| | - Raquel Luque
- Medical Oncology Service, Virgen de las Nieves Hospital, Granada, Spain
| | - Jose Prados
- Institute of Biopathology and Regenerative Medicine (IBIMER), Biomedical Research Centre (CIBM), University of Granada, Spain
| | - Consolación Melguizo
- Institute of Biopathology and Regenerative Medicine (IBIMER), Biomedical Research Centre (CIBM), University of Granada, Spain
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Nagel ZD, Beharry AA, Mazzucato P, Kitange GJ, Sarkaria JN, Kool ET, Samson LD. Fluorescent reporter assays provide direct, accurate, quantitative measurements of MGMT status in human cells. PLoS One 2019; 14:e0208341. [PMID: 30811507 PMCID: PMC6392231 DOI: 10.1371/journal.pone.0208341] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 11/15/2018] [Indexed: 12/21/2022] Open
Abstract
The DNA repair protein O6-methylguanine DNA methyltransferase (MGMT) strongly influences the effectiveness of cancer treatment with chemotherapeutic alkylating agents, and MGMT status in cancer cells could potentially contribute to tailored therapies for individual patients. However, the promoter methylation and immunohistochemical assays presently used for measuring MGMT in clinical samples are indirect, cumbersome and sometimes do not accurately report MGMT activity. Here we directly compare the accuracy of 6 analytical methods, including two fluorescent reporter assays, against the in vitro MGMT activity assay that is considered the gold standard for measuring MGMT DNA repair capacity. We discuss the relative advantages of each method. Our data indicate that two recently developed fluorescence-based assays measure MGMT activity accurately and efficiently, and could provide a functional dimension to clinical efforts to identify patients who are likely to benefit from alkylating chemotherapy.
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Affiliation(s)
- Zachary D. Nagel
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Andrew A. Beharry
- Department of Chemistry, Stanford University, Stanford, California, United States of America
| | - Patrizia Mazzucato
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Gaspar J. Kitange
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Jann N. Sarkaria
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Eric T. Kool
- Department of Chemistry, Stanford University, Stanford, California, United States of America
| | - Leona D. Samson
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail:
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4
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Wu CX, Wang YH, Li Y, Guan ZZ, Qi XL. Changes of DNA repair gene methylation in blood of chronic fluorosis patients and rats. J Trace Elem Med Biol 2018; 50:223-228. [PMID: 30262283 DOI: 10.1016/j.jtemb.2018.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 07/05/2018] [Accepted: 07/10/2018] [Indexed: 02/06/2023]
Abstract
To investigate the relationship between DNA repair gene methylation and chronic coal-burning fluorosis. The methylation rates of O6-methylguanine-DNA- methyltransferase gene MGMT, a DNA repair gene and mismatch repair gene MutL homolog 1 (MLH1) were analysed by methylation of specific PCR (MSP), and the levels of mRNA in the blood of the chronic fluorosis rats and the patients in the region of endemic coal-burning fluorosis were determined by real-time PCR. The levels of mRNA and protein of MGMT and MLH1 in the liver tissue of the chronic fluorosis rats were determined by real-time PCR and Western blot respectively. The results showed an increased methylation of the MGMT and MLH1 genes in the blood of the patients in the fluorosis region that correlated positively with the severity of fluorosis. The mRNA levels of MGMT and MLH1 genes from the patients in fluorosis region were lower than those of a control group, and also showed a positive correlation with the severity of fluorosis. Both the protein and mRNA levels of MGMT and MLH1 genes from the blood of rats and liver tissue in a fluoride-treated group were lower than those of a control non-fluoride treated group. These results indicate that the degree of methylation of MGMT and MLH1 genes is altered in fluorosis disease, the resulting changed expression of these repair genes may play a role in the liver damage caused by fluoride.
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Affiliation(s)
- Chang-Xue Wu
- Key Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University), Ministry of Education, PR China; Key Laboratory of Medical Molecular Biology (Guizhou Medical University), Guiyang 550004, PR China
| | - Yi-Heng Wang
- Key Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University), Ministry of Education, PR China; Key Laboratory of Medical Molecular Biology (Guizhou Medical University), Guiyang 550004, PR China
| | - Yi Li
- Key Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University), Ministry of Education, PR China
| | - Zhi-Zhong Guan
- Key Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University), Ministry of Education, PR China; Key Laboratory of Medical Molecular Biology (Guizhou Medical University), Guiyang 550004, PR China; Department of Pathology, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, PR China.
| | - Xiao-Lan Qi
- Key Laboratory of Endemic and Ethnic Diseases (Guizhou Medical University), Ministry of Education, PR China; Key Laboratory of Medical Molecular Biology (Guizhou Medical University), Guiyang 550004, PR China.
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5
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Wilson DL, Beharry AA, Srivastava A, O'Connor TR, Kool ET. Fluorescence Probes for ALKBH2 Allow the Measurement of DNA Alkylation Repair and Drug Resistance Responses. Angew Chem Int Ed Engl 2018; 57:12896-12900. [PMID: 30098084 DOI: 10.1002/anie.201807593] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Indexed: 01/18/2023]
Abstract
The DNA repair enzyme ALKBH2 is implicated in both tumorigenesis as well as resistance to chemotherapy in certain cancers. It is currently under study as a potential diagnostic marker and has been proposed as a therapeutic target. To date, however, there exist no direct methods for measuring the repair activity of ALKBH2 in vitro or in biological samples. Herein, we report a highly specific, fluorogenic probe design based on an oligonucleotide scaffold that reports directly on ALKBH2 activity both in vitro and in cell lysates. Importantly, the probe enables the monitoring of cellular regulation of ALKBH2 activity in response to treatment with the chemotherapy drug temozolomide through a simple fluorescence assay, which has only previously been observed through indirect means such as qPCR and western blots. Furthermore, the probe provides a viable high-throughput assay for drug discovery.
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Affiliation(s)
- David L Wilson
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Andrew A Beharry
- Department of Chemical and Physical Sciences, University of Toronto, Mississauga, ON, L5L 1C6, Canada
| | - Avinash Srivastava
- Department of Cancer Biology, Beckman Research Institute, Duarte, CA, 91010, USA
| | - Timothy R O'Connor
- Department of Cancer Biology, Beckman Research Institute, Duarte, CA, 91010, USA
| | - Eric T Kool
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
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6
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Wilson DL, Beharry AA, Srivastava A, O'Connor TR, Kool ET. Fluorescence Probes for ALKBH2 Allow the Measurement of DNA Alkylation Repair and Drug Resistance Responses. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201807593] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- David L. Wilson
- Department of Chemistry; Stanford University; Stanford CA 94305 USA
| | - Andrew A. Beharry
- Department of Chemical and Physical Sciences; University of Toronto; Mississauga ON L5L 1C6 Canada
| | - Avinash Srivastava
- Department of Cancer Biology; Beckman Research Institute; Duarte CA 91010 USA
| | - Timothy R. O'Connor
- Department of Cancer Biology; Beckman Research Institute; Duarte CA 91010 USA
| | - Eric T. Kool
- Department of Chemistry; Stanford University; Stanford CA 94305 USA
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7
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Shi J, Dong B, Zhou P, Guan W, Peng Y. Functional network analysis of gene-phenotype connectivity associated with temozolomide. Oncotarget 2017; 8:87554-87567. [PMID: 29152101 PMCID: PMC5675653 DOI: 10.18632/oncotarget.20848] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/17/2017] [Indexed: 02/07/2023] Open
Abstract
Rationale Glioma has a poor survival rate in patients even with aggressive treatment. Temozolomide (TMZ) is the standard chemotherapeutic choice for treating glioma, but TMZ treatment consistently leads to high resistance. Aim To investigate the underlying mechanisms of TMZ action with new therapeutic regimens in glioma. Methods and results The biological effects of TMZ mainly depend on the three following DNA repair systems: methylguanine methyltransferase (MGMT), mismatch repair (MMR) and base excision repair (BER). Based on related genes in these three systems, web-based tools containing data compiled from open-source databases, including DrugBank, STRING, WebGestalt and ClueGO, were queried, and five common genes along with the top fifteen pathways, including the glioma pathway, were identified. A genomic analysis of the six genes identified in the glioma pathway by cBioPortal indicated that TMZ might exert biological effects via interaction with the tumor protein P53(TP53) signaling axis. Finally, a survival analysis with the six genes in glioma cases (low-grade glioma and glioblastoma multiforme) was conducted using OncoLnc, which might provide directions for the future exploration of prognosis in glioma. Conclusions This study indicates that a functional network analysis resembles a "BioGPS", with the ability to draw a web-based scientific map that can productively and cost-effectively associate TMZ with its primary and secondary biological targets.
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Affiliation(s)
- Jia Shi
- Department of Neurosurgery, The Third Affiliated Hospital of Soochow University, Changzhou City, 213003, China
| | - Bo Dong
- Department of Neurosurgery, The Third Affiliated Hospital of Soochow University, Changzhou City, 213003, China
| | - Peng Zhou
- Department of Neurosurgery, The Third Affiliated Hospital of Soochow University, Changzhou City, 213003, China
| | - Wei Guan
- Department of Neurosurgery, The Third Affiliated Hospital of Soochow University, Changzhou City, 213003, China
| | - Ya Peng
- Department of Neurosurgery, The Third Affiliated Hospital of Soochow University, Changzhou City, 213003, China
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8
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Gojo I, Beumer JH, Pratz KW, McDevitt MA, Baer MR, Blackford AL, Smith BD, Gore SD, Carraway HE, Showel MM, Levis MJ, Dezern AE, Gladstone DE, Ji JJ, Wang L, Kinders RJ, Pouquet M, Ali-Walbi I, Rudek MA, Poh W, Herman JG, Karnitz LM, Kaufmann SH, Chen A, Karp JE. A Phase 1 Study of the PARP Inhibitor Veliparib in Combination with Temozolomide in Acute Myeloid Leukemia. Clin Cancer Res 2017; 23:697-706. [PMID: 27503200 PMCID: PMC5290001 DOI: 10.1158/1078-0432.ccr-16-0984] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 06/23/2016] [Accepted: 07/17/2016] [Indexed: 11/16/2022]
Abstract
PURPOSE In preclinical studies, the PARP inhibitor veliparib enhanced the antileukemic action of temozolomide through potentiation of DNA damage. Accordingly, we conducted a phase 1 study of temozolomide with escalating doses of veliparib in patients with relapsed, refractory acute myeloid leukemia (AML) or AML arising from aggressive myeloid malignancies. EXPERIMENTAL DESIGN Patients received veliparib [20-200 mg once a day on day 1 and twice daily on days 4-12 in cycle 1 (days 1-8 in cycle ≥2)] and temozolomide [150-200 mg/m2 daily on days 3-9 in cycle 1 (days 1-5 in cycle ≥2)] every 28 to 56 days. Veliparib pharmacokinetics and pharmacodynamics [ability to inhibit poly(ADP-ribose) polymer (PAR) formation and induce H2AX phosphorylation] were assessed. Pretreatment levels of MGMT and PARP1 protein, methylation of the MGMT promoter, and integrity of the Fanconi anemia pathway were also examined. RESULTS Forty-eight patients were treated at seven dose levels. Dose-limiting toxicities were oral mucositis and esophagitis lasting >7 days. The MTD was veliparib 150 mg twice daily with temozolomide 200 mg/m2 daily. The complete response (CR) rate was 17% (8/48 patients). Veliparib exposure as well as inhibition of PAR polymer formation increased dose proportionately. A veliparib-induced increase in H2AX phosphorylation in CD34+ cells was observed in responders. Three of 4 patients with MGMT promoter methylation achieved CR. CONCLUSIONS Veliparib plus temozolomide is well tolerated, with activity in advanced AML. Further evaluation of this regimen and of treatment-induced phosphorylation of H2AX and MGMT methylation as potential response predictors appears warranted. Clin Cancer Res; 23(3); 697-706. ©2016 AACR.
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Affiliation(s)
- Ivana Gojo
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland.
| | - Jan H Beumer
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Keith W Pratz
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
| | - Michael A McDevitt
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
| | - Maria R Baer
- Department of Medicine, University of Maryland Greenebaum Cancer Center, Baltimore, Maryland
| | - Amanda L Blackford
- Department of Statistics, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
| | - B Douglas Smith
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
| | - Steven D Gore
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
| | - Hetty E Carraway
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
| | - Margaret M Showel
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
| | - Mark J Levis
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
| | - Amy E Dezern
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
| | - Douglas E Gladstone
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
| | - Jiuping Jay Ji
- Laboratory of Human Toxicology and Pharmacology, Applied/Developmental Research Support Directorate, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland
| | - Lihua Wang
- Laboratory of Human Toxicology and Pharmacology, Applied/Developmental Research Support Directorate, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland
| | - Robert J Kinders
- Laboratory of Human Toxicology and Pharmacology, Applied/Developmental Research Support Directorate, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland
| | - Marie Pouquet
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Ismail Ali-Walbi
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Michelle A Rudek
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
| | - Weijie Poh
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
| | - James G Herman
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
| | - Larry M Karnitz
- Division of Oncology Research and Department of Molecular Pharmacology, Mayo Clinic, Rochester, Minnesota
| | - Scott H Kaufmann
- Division of Oncology Research and Department of Molecular Pharmacology, Mayo Clinic, Rochester, Minnesota
| | - Alice Chen
- Cancer Therapy Evaluation Program, NCI, Rockville, Maryland
| | - Judith E Karp
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital, Baltimore, Maryland
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9
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Versatile in vivo regulation of tumor phenotypes by dCas9-mediated transcriptional perturbation. Proc Natl Acad Sci U S A 2016; 113:E3892-900. [PMID: 27325776 DOI: 10.1073/pnas.1600582113] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Targeted transcriptional regulation is a powerful tool to study genetic mediators of cellular behavior. Here, we show that catalytically dead Cas9 (dCas9) targeted to genomic regions upstream or downstream of the transcription start site allows for specific and sustainable gene-expression level alterations in tumor cells in vitro and in syngeneic immune-competent mouse models. We used this approach for a high-coverage pooled gene-activation screen in vivo and discovered previously unidentified modulators of tumor growth and therapeutic response. Moreover, by using dCas9 linked to an activation domain, we can either enhance or suppress target gene expression simply by changing the genetic location of dCas9 binding relative to the transcription start site. We demonstrate that these directed changes in gene-transcription levels occur with minimal off-target effects. Our findings highlight the use of dCas9-mediated transcriptional regulation as a versatile tool to reproducibly interrogate tumor phenotypes in vivo.
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10
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Fluorogenic Real-Time Reporters of DNA Repair by MGMT, a Clinical Predictor of Antitumor Drug Response. PLoS One 2016; 11:e0152684. [PMID: 27035132 PMCID: PMC4818092 DOI: 10.1371/journal.pone.0152684] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 03/17/2016] [Indexed: 01/26/2023] Open
Abstract
Common alkylating antitumor drugs, such as temozolomide, trigger their cytotoxicity by methylating the O6-position of guanosine in DNA. However, the therapeutic effect of these drugs is dampened by elevated levels of the DNA repair enzyme, O6-methylguanine DNA methyltransferase (MGMT), which directly reverses this alkylation. As a result, assessing MGMT levels in patient samples provides an important predictor of therapeutic response; however, current methods available to measure this protein are indirect, complex and slow. Here we describe the design and synthesis of fluorescent chemosensors that report directly on MGMT activity in a single step within minutes. The chemosensors incorporate a fluorophore and quencher pair, which become separated by the MGMT dealkylation reaction, yielding light-up responses of up to 55-fold, directly reflecting repair activity. Experiments show that the best-performing probe retains near-native activity at mid-nanomolar concentrations. A nuclease-protected probe, NR-1, was prepared and tested in tumor cell lysates, demonstrating an ability to evaluate relative levels of MGMT repair activity in twenty minutes. In addition, a probe was employed to evaluate inhibitors of MGMT, suggesting utility for discovering new inhibitors in a high-throughput manner. Probe designs such as that of NR-1 may prove valuable to clinicians in selection of patients for alkylating drug therapies and in assessing resistance that arises during treatment.
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11
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Inoue S, Lemonnier F, Mak TW. Roles of IDH1/2 and TET2 mutations in myeloid disorders. Int J Hematol 2016; 103:627-33. [PMID: 26980223 DOI: 10.1007/s12185-016-1973-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 02/22/2016] [Accepted: 03/02/2016] [Indexed: 12/19/2022]
Abstract
Mutations of the epigenetic enzymes isocitrate dehydrogenase (IDH) 1 and 2, and the methylcytosine dioxygenase 'ten-eleven translocation 2' (TET2), are common in human myeloid malignancies and drivers of these disorders but the underlying mechanisms remain obscure. This review examines mutant IDH1/2 and TET2 enzymes in the context of responses to DNA damage and their potential involvement in age-related genomic instability. The clinical relevance of these findings and their potential application in novel therapeutic strategies is also discussed.
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Affiliation(s)
- Satoshi Inoue
- The Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, Ontario Cancer Institute, University Health Network, 610 University Avenue, Toronto, ON, M5G 2M9, Canada
| | - François Lemonnier
- The Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, Ontario Cancer Institute, University Health Network, 610 University Avenue, Toronto, ON, M5G 2M9, Canada
| | - Tak W Mak
- The Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, Ontario Cancer Institute, University Health Network, 610 University Avenue, Toronto, ON, M5G 2M9, Canada.
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12
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Beharry AA, Lacoste S, O'Connor TR, Kool ET. Fluorescence Monitoring of the Oxidative Repair of DNA Alkylation Damage by ALKBH3, a Prostate Cancer Marker. J Am Chem Soc 2016; 138:3647-50. [PMID: 26967262 DOI: 10.1021/jacs.6b00986] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The 2-oxoglutarate-dependent iron enzyme ALKBH3 is an antitumor target and a potential diagnostic marker for several tumor types, including prostate cancer. However, there is at present no simple way to measure this enzyme's activity. Here we describe a fluorogenic probe design (MAQ) that is directly responsive to ALKBH3 repair activity. It makes use of the fluorescence-quenching properties of 1-methyladenine; removal of the alkyl group results in a >10-fold light-up signal. The probe is specific for ALKBH3 over its related homologue ALKBH2 and can be used to identify and measure the effectiveness of enzyme inhibitors. Measurements of the enzyme substrate parameters show that MAQ displays Km and kcat values essentially the same as those of the native substrate. Finally, we show that the probe functions efficiently in cells, allowing imaging and quantitation of ALKBH3 activity by microscopy and flow cytometry. We expect that MAQ probes will be broadly useful in the study of the basic biology of ALKBH3 and in clinical cancer applications as well.
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Affiliation(s)
- Andrew A Beharry
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
| | - Sandrine Lacoste
- Department of Cancer Biology, Beckman Research Institute , Duarte, California 91010, United States
| | - Timothy R O'Connor
- Department of Cancer Biology, Beckman Research Institute , Duarte, California 91010, United States
| | - Eric T Kool
- Department of Chemistry, Stanford University , Stanford, California 94305, United States
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13
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Hong Q, Chen X, Ye H, Zhou A, Gao Y, Jiang D, Wu X, Tian B, Chen Y, Wang M, Xie J, Xia Y, Duan S. Association between the methylation status of the MGMT promoter in bone marrow specimens and chemotherapy outcomes of patients with acute myeloid leukemia. Oncol Lett 2016; 11:2851-2856. [PMID: 27073563 DOI: 10.3892/ol.2016.4317] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 02/04/2016] [Indexed: 12/13/2022] Open
Abstract
The O(6)-methylguanine-DNA methyltransferase (MGMT) gene is a tumor suppressor gene that is associated with the risk of developing acute myeloid leukemia (AML). However, the association between the methylation status of the MGMT promoter and the chemotherapeutic outcomes of patients with AML remains unknown. In the present study, 30 bone marrow samples derived from patients with AML were collected prior and subsequent to chemotherapy. The methylation status of the MGMT promoter in the bone marrow specimens was determined by methylation-specific polymerase chain reaction. The results indicated that the methylation status of the MGMT promoter was influenced by different chemotherapeutic regimens. The MGMT methylation status of M4 patients (3 out of 6) were more chemosensitive, compared with that of patients with other AML subtypes (M1, 1 out of 3; M2, 0 out of 8; M3, 3 out of 7; M5, 0 out of 3; and M6, 1 out of 3). Age-based analysis revealed that the group aged ≤60 years (7 out of 24 patients) exhibited more methylation changes than patients aged >60 years (1 out of 6). Male patients (4 out of 13) were more susceptible to chemotherapy-induced methylation changes than female patients (4 out of 17). Thus, the methylation status of the MGMT promoter may serve as a potential biomarker to predict the therapeutic outcomes in male AML patients. However, further studies in larger sample sets are required to confirm the present findings.
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Affiliation(s)
- Qingxiao Hong
- Department of Biochemistry and Molecular Biology, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Xiaoying Chen
- Department of Biochemistry and Molecular Biology, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Huadan Ye
- Department of Biochemistry and Molecular Biology, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Annan Zhou
- Department of Biochemistry and Molecular Biology, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Yuting Gao
- Department of Biochemistry and Molecular Biology, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Danjie Jiang
- Department of Biochemistry and Molecular Biology, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang 315211, P.R. China
| | - Xiaodong Wu
- Department of Hematology, Yuyao People's Hospital, Yuyao, Zhejiang 315400, P.R. China
| | - Bingru Tian
- Department of Hematology, Yuyao People's Hospital, Yuyao, Zhejiang 315400, P.R. China
| | - Youfen Chen
- Department of Hematology, Yuyao People's Hospital, Yuyao, Zhejiang 315400, P.R. China
| | - Ming Wang
- Department of Hematology, Yuyao People's Hospital, Yuyao, Zhejiang 315400, P.R. China
| | - Jiping Xie
- Department of Hematology, Yuyao People's Hospital, Yuyao, Zhejiang 315400, P.R. China
| | - Yongming Xia
- Department of Hematology, Yuyao People's Hospital, Yuyao, Zhejiang 315400, P.R. China
| | - Shiwei Duan
- Department of Biochemistry and Molecular Biology, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo, Zhejiang 315211, P.R. China
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Tintoré M, Grijalvo S, Eritja R, Fàbrega C. Synthesis of oligonucleotides carrying fluorescently labelled O(6)-alkylguanine for measuring hAGT activity. Bioorg Med Chem Lett 2015; 25:5208-11. [PMID: 26459209 DOI: 10.1016/j.bmcl.2015.09.065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 09/23/2015] [Accepted: 09/26/2015] [Indexed: 01/17/2023]
Abstract
O(6)-alkylguanine-DNA-alkyltransferase (hAGT) activity provides resistance to cancer chemotherapeutic agents and its inhibition enhances chemotherapy. We herein present the development of a novel fluorescence assay for the detection of hAGT activity. We designed a dsDNA sequence containing a fluorophore-quencher pair, where the fluorophore was attached to an O(6)-benzylguanine. This precursor was synthesized using the Mitsunobu reaction to introduce the benzyl group. The alkyl-fluorophore group is transferred to the active site during the dealkylation, producing an increase in fluorescence which is correlated to hAGT activity. This assay can be used for the evaluation of potential inhibitors of hAGT in a straightforward manner.
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Affiliation(s)
- Maria Tintoré
- Institute for Advanced Chemistry of Catalonia (IQAC), Spanish National Research Council (CSIC), Spain; Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), C/ Jordi Girona 18-26, 08034 Barcelona, Spain
| | - Santiago Grijalvo
- Institute for Advanced Chemistry of Catalonia (IQAC), Spanish National Research Council (CSIC), Spain; Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), C/ Jordi Girona 18-26, 08034 Barcelona, Spain
| | - Ramon Eritja
- Institute for Advanced Chemistry of Catalonia (IQAC), Spanish National Research Council (CSIC), Spain; Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), C/ Jordi Girona 18-26, 08034 Barcelona, Spain
| | - Carme Fàbrega
- Institute for Advanced Chemistry of Catalonia (IQAC), Spanish National Research Council (CSIC), Spain; Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), C/ Jordi Girona 18-26, 08034 Barcelona, Spain.
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