1
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Ayinde O, Sharpe C, Stahl E, Tokarski RJ, Lerma JR, Muthusamy N, Byrd JC, Fuchs JR. Examination of the Impact of Triazole Position within Linkers on Solubility and Lipophilicity of a CDK9 Degrader Series. ACS Med Chem Lett 2023; 14:936-942. [PMID: 37465296 PMCID: PMC10351057 DOI: 10.1021/acsmedchemlett.3c00082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 06/02/2023] [Indexed: 07/20/2023] Open
Abstract
Optimization of degrader properties is often a challenge due to their beyond-rule-of-5 nature. Given the paucity of known E3 ligases and the often-limited choice of ligands with varied chemical structures for a given protein target, degrader linkers represent the best position within the chimeric molecules to modify their overall physicochemical properties. In this work, a series of AT7519-based CDK9 degraders was assembled using click chemistry, facilitating the tuning of aqueous solubility and lipophilicity while retaining their linker type and molecular weight. Using chromatographic logD and kinetic solubility experiments, we show that degraders with similar chemical constitution but varied position of the embedded triazole demonstrate different lipophilicity and aqueous solubility properties. Overall, this work highlights the impact of triazole placement on linker composition through application of click chemistry for degrader synthesis and its ability to be used to promote the achievement of favorable physicochemical properties.
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Affiliation(s)
- Oluwatosin
R. Ayinde
- Division
of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, United States
| | - Chia Sharpe
- Department
of Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati Ohio 45267, United States
| | - Emily Stahl
- Division
of Hematology, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio 43210, United States
| | - Robert J. Tokarski
- Division
of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, United States
| | - James R. Lerma
- Department
of Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati Ohio 45267, United States
| | - Natarajan Muthusamy
- Division
of Hematology, Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio 43210, United States
- The
Ohio State University Comprehensive Cancer Center, College of Medicine, The Ohio State University, Columbus Ohio 43210, United States
| | - John C. Byrd
- Department
of Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati Ohio 45267, United States
- University
of Cincinnati Cancer Center, College of Medicine, University of Cincinnati, Cincinnati Ohio 45267, United States
| | - James R. Fuchs
- Division
of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, United States
- The
Ohio State University Comprehensive Cancer Center, College of Medicine, The Ohio State University, Columbus Ohio 43210, United States
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2
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Thieme E, Bruss N, Sun D, Dominguez EC, Coleman D, Liu T, Roleder C, Martinez M, Garcia-Mansfield K, Ball B, Pirrotte P, Wang L, Xia Z, Danilov AV. CDK9 inhibition induces epigenetic reprogramming revealing strategies to circumvent resistance in lymphoma. Mol Cancer 2023; 22:64. [PMID: 36998071 PMCID: PMC10061728 DOI: 10.1186/s12943-023-01762-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 03/14/2023] [Indexed: 03/31/2023] Open
Abstract
Diffuse large B-cell lymphoma (DLBCL) exhibits significant genetic heterogeneity which contributes to drug resistance, necessitating development of novel therapeutic approaches. Pharmacological inhibitors of cyclin-dependent kinases (CDK) demonstrated pre-clinical activity in DLBCL, however many stalled in clinical development. Here we show that AZD4573, a selective inhibitor of CDK9, restricted growth of DLBCL cells. CDK9 inhibition (CDK9i) resulted in rapid changes in the transcriptome and proteome, with downmodulation of multiple oncoproteins (eg, MYC, Mcl-1, JunB, PIM3) and deregulation of phosphoinotiside-3 kinase (PI3K) and senescence pathways. Following initial transcriptional repression due to RNAPII pausing, we observed transcriptional recovery of several oncogenes, including MYC and PIM3. ATAC-Seq and ChIP-Seq experiments revealed that CDK9i induced epigenetic remodeling with bi-directional changes in chromatin accessibility, suppressed promoter activation and led to sustained reprograming of the super-enhancer landscape. A CRISPR library screen suggested that SE-associated genes in the Mediator complex, as well as AKT1, confer resistance to CDK9i. Consistent with this, sgRNA-mediated knockout of MED12 sensitized cells to CDK9i. Informed by our mechanistic findings, we combined AZD4573 with either PIM kinase or PI3K inhibitors. Both combinations decreased proliferation and induced apoptosis in DLBCL and primary lymphoma cells in vitro as well as resulted in delayed tumor progression and extended survival of mice xenografted with DLBCL in vivo. Thus, CDK9i induces reprogramming of the epigenetic landscape, and super-enhancer driven recovery of select oncogenes may contribute to resistance to CDK9i. PIM and PI3K represent potential targets to circumvent resistance to CDK9i in the heterogeneous landscape of DLBCL.
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Affiliation(s)
- Elana Thieme
- grid.410425.60000 0004 0421 8357City of Hope National Medical Center, 1500 E Duarte Road, Duarte, CA 91010 USA
| | - Nur Bruss
- grid.410425.60000 0004 0421 8357City of Hope National Medical Center, 1500 E Duarte Road, Duarte, CA 91010 USA
| | - Duanchen Sun
- grid.516136.6Knight Cancer Institute, Oregon Health & Science University, Portland, OR USA
- grid.5288.70000 0000 9758 5690Division of Bioinformatics and Computational Biology, Department of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Portland, OR USA
- grid.27255.370000 0004 1761 1174Present address: School of Mathematics, Shandong University, Jinan, 250100 Shandong China
| | - Edward C. Dominguez
- grid.410425.60000 0004 0421 8357City of Hope National Medical Center, 1500 E Duarte Road, Duarte, CA 91010 USA
| | - Daniel Coleman
- grid.516136.6Knight Cancer Institute, Oregon Health & Science University, Portland, OR USA
| | - Tingting Liu
- grid.410425.60000 0004 0421 8357City of Hope National Medical Center, 1500 E Duarte Road, Duarte, CA 91010 USA
| | - Carly Roleder
- grid.410425.60000 0004 0421 8357City of Hope National Medical Center, 1500 E Duarte Road, Duarte, CA 91010 USA
| | - Melissa Martinez
- grid.250942.80000 0004 0507 3225Translational Genomics Research Institute, Phoenix, AZ 85004 USA
- grid.410425.60000 0004 0421 8357Integrated Mass Spectrometry Shared Resource, City of Hope National Medical Center, Duarte, CA USA
| | - Krystine Garcia-Mansfield
- grid.250942.80000 0004 0507 3225Translational Genomics Research Institute, Phoenix, AZ 85004 USA
- grid.410425.60000 0004 0421 8357Integrated Mass Spectrometry Shared Resource, City of Hope National Medical Center, Duarte, CA USA
| | - Brian Ball
- grid.410425.60000 0004 0421 8357City of Hope National Medical Center, 1500 E Duarte Road, Duarte, CA 91010 USA
| | - Patrick Pirrotte
- grid.250942.80000 0004 0507 3225Translational Genomics Research Institute, Phoenix, AZ 85004 USA
- grid.410425.60000 0004 0421 8357Integrated Mass Spectrometry Shared Resource, City of Hope National Medical Center, Duarte, CA USA
| | - Lili Wang
- grid.410425.60000 0004 0421 8357City of Hope National Medical Center, 1500 E Duarte Road, Duarte, CA 91010 USA
| | - Zheng Xia
- grid.516136.6Knight Cancer Institute, Oregon Health & Science University, Portland, OR USA
- grid.5288.70000 0000 9758 5690Biomedical Engineering Department, Oregon Health & Science University, Portland, OR USA
| | - Alexey V. Danilov
- grid.410425.60000 0004 0421 8357City of Hope National Medical Center, 1500 E Duarte Road, Duarte, CA 91010 USA
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3
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Guo T, Liu DF, Peng SH. CDK9 is up-regulated and associated with prognosis in patients with papillary thyroid carcinoma. Medicine (Baltimore) 2022; 101:e28309. [PMID: 35119000 PMCID: PMC8812708 DOI: 10.1097/md.0000000000028309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 11/29/2021] [Indexed: 01/04/2023] Open
Abstract
Papillary thyroid carcinoma (PTC) is the most common type of thyroid malignancy but shows excellent prognosis. We investigated the clinical significance of cyclin-dependent kinase 9 (CDK9) in patients with PTC.This prospective observational study included 192 patients with PTC, who visited our hospital between August 2018 and February 2020. We obtained 93 tissue samples from patients with benign thyroid disease during the same period as controls. Immunohistochemical evaluation and reverse transcription-quantitative polymerase chain reaction assay were performed to evaluate CDK9 expression. Patients' demographic and clinical characteristics were analyzed.Delphian lymph node (DLN) metastasis in patients with PTC was associated with clinicopathological characteristics. CDK9 expression was up-regulated in patients with PTC, and those with DLN metastasis showed higher CDK9 expression. We also observed that tumor size, capsule invasion, tumor-node-metastasis classification (TNM) stage, and multifocality were the risk factors for DLN metastasis in patients with PTC. Additionally, CDK9 expression was strongly associated with tumor size, capsule invasion, TNM stage, and multifocality and weakly associated with the number of metastatic DLN.CDK9 is up-regulated in patients with PTC and associated with prognosis in these patients.
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4
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Qiu Z, Zhao L, Shen JZ, Liang Z, Wu Q, Yang K, Min L, Gimple RC, Yang Q, Bhargava S, Jin C, Kim C, Hinz D, Dixit D, Bernatchez JA, Prager BC, Zhang G, Dong Z, Lv D, Wang X, Kim LJ, Zhu Z, Jones KA, Zheng Y, Wang X, Siqueira-Neto JL, Chavez L, Fu XD, Spruck C, Rich JN. Transcription Elongation Machinery Is a Druggable Dependency and Potentiates Immunotherapy in Glioblastoma Stem Cells. Cancer Discov 2022; 12:502-521. [PMID: 34615656 PMCID: PMC8831451 DOI: 10.1158/2159-8290.cd-20-1848] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 07/03/2021] [Accepted: 10/01/2021] [Indexed: 11/16/2022]
Abstract
Glioblastoma (GBM) is the most lethal primary brain cancer characterized by therapeutic resistance, which is promoted by GBM stem cells (GSC). Here, we interrogated gene expression and whole-genome CRISPR/Cas9 screening in a large panel of patient-derived GSCs, differentiated GBM cells (DGC), and neural stem cells (NSC) to identify master regulators of GSC stemness, revealing an essential transcription state with increased RNA polymerase II-mediated transcription. The YY1 and transcriptional CDK9 complex was essential for GSC survival and maintenance in vitro and in vivo. YY1 interacted with CDK9 to regulate transcription elongation in GSCs. Genetic or pharmacologic targeting of the YY1-CDK9 complex elicited RNA m6A modification-dependent interferon responses, reduced regulatory T-cell infiltration, and augmented efficacy of immune checkpoint therapy in GBM. Collectively, these results suggest that YY1-CDK9 transcription elongation complex defines a targetable cell state with active transcription, suppressed interferon responses, and immunotherapy resistance in GBM. SIGNIFICANCE: Effective strategies to rewire immunosuppressive microenvironment and enhance immunotherapy response are still lacking in GBM. YY1-driven transcriptional elongation machinery represents a druggable target to activate interferon response and enhance anti-PD-1 response through regulating the m6A modification program, linking epigenetic regulation to immunomodulatory function in GBM.This article is highlighted in the In This Issue feature, p. 275.
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Affiliation(s)
- Zhixin Qiu
- Hillman Cancer Center and Department of Neurology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.,Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
| | - Linjie Zhao
- Hillman Cancer Center and Department of Neurology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.,Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
| | - Jia Z. Shen
- Tumor Initiation and Maintenance Program, NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Zhengyu Liang
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Qiulian Wu
- Hillman Cancer Center and Department of Neurology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.,Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
| | - Kailin Yang
- Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Lihua Min
- Hillman Cancer Center and Department of Neurology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | - Ryan C. Gimple
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA.,Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Qiyuan Yang
- NOMIS Center for Immunobiology and Microbial Pathogenesis, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Shruti Bhargava
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
| | - Chunyu Jin
- Howard Hughes Medical Institute, Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Cheryl Kim
- Flow Cytometry Core Facility, La Jolla Institute for Immunology (LJI), La Jolla, CA 92037, USA
| | - Denise Hinz
- Flow Cytometry Core Facility, La Jolla Institute for Immunology (LJI), La Jolla, CA 92037, USA
| | - Deobrat Dixit
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
| | - Jean A. Bernatchez
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92037, USA
| | - Briana C. Prager
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA.,Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Guoxin Zhang
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
| | - Zhen Dong
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
| | - Deguan Lv
- Hillman Cancer Center and Department of Neurology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.,Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
| | - Xujun Wang
- SJTU-Yale Joint Center for Biostatistics, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Leo J.Y. Kim
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA.,Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Zhe Zhu
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA
| | - Katherine A. Jones
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Ye Zheng
- NOMIS Center for Immunobiology and Microbial Pathogenesis, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Xiuxing Wang
- Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA.,School of Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Jair L. Siqueira-Neto
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92037, USA
| | - Lukas Chavez
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Xiang-Dong Fu
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Charles Spruck
- Tumor Initiation and Maintenance Program, NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California.
| | - Jeremy N. Rich
- Hillman Cancer Center and Department of Neurology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA.,Division of Regenerative Medicine, Department of Medicine, University of California, San Diego, La Jolla, CA 92037, USA.,Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA.,Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA.,Corresponding Authors: Jeremy N. Rich: ; +1(412) 623-3364; Address: UPMC Hillman Cancer Center, 5115 Centre Ave, Pittsburgh, PA 15232; Charles Spruck: ; +1(858) 401-3459; Address: 10901 N Torrey Pines Rd, La Jolla, CA 92037
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5
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Hu Z, Yik J, Cissell D, Michelier P, Athanasiou K, Haudenschild D, Haudenschild DR. Inhibition of CDK9 prevents mechanical injury-induced inflammation, apoptosis and matrix degradation in cartilage explants. Eur Cell Mater 2016; 30:200-9. [PMID: 26859911 PMCID: PMC4750484 DOI: 10.22203/ecm.v030a14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Joint injury often leads to post-traumatic osteoarthritis (PTOA). Acute injury responses to trauma induce production of pro-inflammatory cytokines and catabolic enzymes, which promote chondrocyte apoptosis and degrade cartilage to potentiate PTOA development. Recent studies show that the rate-limiting step for transcriptional activation of injury response genes is controlled by cyclin-dependent kinase 9 (CDK9), and thus it is an attractive target for limiting the injury response. Here, we determined the effects of CDK9 inhibition in suppressing the injury response in mechanically-injured cartilage explants. Bovine cartilage explants were injured by a single compressive load of 30 % strain at 100 %/s, and then treated with the CDK9 inhibitor Flavopiridol. To assess acute injury responses, we measured the mRNA expression of pro-inflammatory cytokines, catabolic enzymes, and apoptotic genes by RT-PCR, and chondrocyte viability and apoptosis by TUNEL staining. For long-term outcome, cartilage matrix degradation was assessed by soluble glycosaminoglycan release, and by determining the mechanical properties with instantaneous and relaxation moduli. Our data showed CDK9 inhibitor markedly reduced injury-induced inflammatory cytokine and catabolic gene expression. CDK9 inhibitor also attenuated chondrocyte apoptosis and reduced cartilage matrix degradation. Lastly, the mechanical properties of the injured explants were preserved by CDK9 inhibitor. Our results provide a temporal profile connecting the chain of events from mechanical impact, acute injury responses, to the subsequent induction of chondrocyte apoptosis and cartilage matrix deterioration. Thus, CDK9 is a potential disease-modifying agent for injury response after knee trauma to prevent or delay PTOA development.
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Affiliation(s)
- Z. Hu
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, 310016 PR China,University of California Davis, Department of Orthopaedic Surgery, Lawrence J. Ellison Musculoskeletal Research Center, Research Building 1 Suite 2000, 4635 Second Avenue, Sacramento, CA 95817, USA
| | - J.H.N. Yik
- University of California Davis, Department of Orthopaedic Surgery, Lawrence J. Ellison Musculoskeletal Research Center, Research Building 1 Suite 2000, 4635 Second Avenue, Sacramento, CA 95817, USA
| | - D.D. Cissell
- Department of Biomedical Engineering, College of Engineering, University of California, Davis, California 95618, USA
| | - P.V. Michelier
- University of California Davis, Department of Orthopaedic Surgery, Lawrence J. Ellison Musculoskeletal Research Center, Research Building 1 Suite 2000, 4635 Second Avenue, Sacramento, CA 95817, USA
| | - K.A. Athanasiou
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, 310016 PR China,Department of Biomedical Engineering, College of Engineering, University of California, Davis, California 95618, USA
| | - D.R. Haudenschild
- University of California Davis, Department of Orthopaedic Surgery, Lawrence J. Ellison Musculoskeletal Research Center, Research Building 1 Suite 2000, 4635 Second Avenue, Sacramento, CA 95817, USA,Address for correspondence: Dominik R. Haudenschild, University of California Davis, Department of Orthopaedic Surgery, Lawrence J. Ellison Musculoskeletal Research Center, Research Building 1 Suite 2000, 4635 Second Avenue, Sacramento, CA 95817, USA, Tel: +1 916-734-5015, Fax: +1 916-734-5750,
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6
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Lam F, Abbas AY, Shao H, Teo T, Adams J, Li P, Bradshaw TD, Fischer PM, Walsby E, Pepper C, Chen Y, Ding J, Wang S. Targeting RNA transcription and translation in ovarian cancer cells with pharmacological inhibitor CDKI-73. Oncotarget 2014; 5:7691-704. [PMID: 25277198 PMCID: PMC4202154 DOI: 10.18632/oncotarget.2296] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 07/31/2014] [Indexed: 01/09/2023] Open
Abstract
Dysregulation of cellular transcription and translation is a fundamental hallmark of cancer. As CDK9 and Mnks play pivotal roles in the regulation of RNA transcription and protein synthesis, respectively, they are important targets for drug development. We herein report the cellular mechanism of a novel CDK9 inhibitor CDKI-73 in an ovarian cancer cell line (A2780). We also used shRNA-mediated CDK9 knockdown to investigate the importance of CDK9 in the maintenance of A2780 cells. This study revealed that CDKI-73 rapidly inhibited cellular CDK9 kinase activity and down-regulated the RNAPII phosphorylation. This subsequently caused a decrease in the eIF4E phosphorylation by blocking Mnk1 kinase activity. Consistently, CDK9 shRNA was also found to down-regulate the Mnk1 expression. Both CDKI-73 and CDK9 shRNA decreased anti-apoptotic proteins Mcl-1 and Bcl-2 and induced apoptosis. The study confirmed that CDK9 is required for cell survival and that ovarian cancer may be susceptible to CDK9 inhibition strategy. The data also implied a role of CDK9 in eIF4E-mediated translational control, suggesting that CDK9 may have important implication in the Mnk-eIF4E axis, the key determinants of PI3K/Akt/mTOR- and Ras/Raf/MAPK-mediated tumorigenic activity. As such, CDK9 inhibitor drug candidate CDKI-73 should have a major impact on these pathways in human cancers.
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Affiliation(s)
- Frankie Lam
- Centre for Drug Discovery and Development, Sansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Abdullahi Y. Abbas
- School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Hao Shao
- School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Theodosia Teo
- Centre for Drug Discovery and Development, Sansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Julian Adams
- Centre for Drug Discovery and Development, Sansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Peng Li
- Centre for Drug Discovery and Development, Sansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Tracey D. Bradshaw
- School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Peter M. Fischer
- School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Elisabeth Walsby
- Cardiff CLL Research Group, Institute of Cancer and Genetics, School of Medicine, Cardiff University, Health Park, Cardiff, United Kingdom
| | - Chris Pepper
- Cardiff CLL Research Group, Institute of Cancer and Genetics, School of Medicine, Cardiff University, Health Park, Cardiff, United Kingdom
| | - Yi Chen
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, People's Republic of China
| | - Jian Ding
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, People's Republic of China
| | - Shudong Wang
- Centre for Drug Discovery and Development, Sansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
- School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham, United Kingdom
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7
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Walsby E, Pratt G, Shao H, Abbas AY, Fischer PM, Bradshaw TD, Brennan P, Fegan C, Wang S, Pepper C. A novel Cdk9 inhibitor preferentially targets tumor cells and synergizes with fludarabine. Oncotarget 2014; 5:375-85. [PMID: 24495868 PMCID: PMC3964214 DOI: 10.18632/oncotarget.1568] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 12/18/2013] [Indexed: 01/22/2023] Open
Abstract
Cdk9 is a key elongation factor for RNA transcription and functions by phosphorylating the C-terminal domain of RNA polymerase II. Here we present direct evidence that cdk9 is important for cancer cell survival and describe the characterization of the potent cdk9 inhibitor CDKI-73 in primary human leukemia cells. CDKI-73 induced caspase-dependent apoptosis that was preceded by dephosphorylation of cdk9 and serine 2 of RNA polymerase II. CDKI-73 was more potent than the pan-cdk inhibitor flavopiridol and showed >200-fold selectivity against primary leukemia cells when compared with normal CD34+ cells. Furthermore, CDKI-73 was equipotent in poor prognostic sub-groups of leukemia patients and showed cytotoxic synergy with the nucleoside analog fludarabine. The Mechanism of synergy was associated with CDKI-73-mediated transcriptional inhibition of MCL1 and XIAP that was maintained when used in combination with fludarabine. Our data present a strong rationale for the development of cdk9 inhibitors such as CDKI-73 as anticancer therapeutics.
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MESH Headings
- Animals
- Antineoplastic Combined Chemotherapy Protocols/pharmacology
- Apoptosis
- Case-Control Studies
- Cyclin-Dependent Kinase 9/antagonists & inhibitors
- Cyclin-Dependent Kinase 9/genetics
- Drug Synergism
- HEK293 Cells
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/enzymology
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Mice
- Phosphorylation
- Prognosis
- Protein Kinase Inhibitors/administration & dosage
- Protein Kinase Inhibitors/pharmacology
- Pyrimidines/administration & dosage
- Pyrimidines/pharmacology
- Sulfonamides/administration & dosage
- Sulfonamides/pharmacology
- Transcription, Genetic/drug effects
- Vidarabine/administration & dosage
- Vidarabine/analogs & derivatives
- Vidarabine/pharmacology
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Affiliation(s)
- Elisabeth Walsby
- Cardiff CLL Research Group, Institute of Cancer & Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff, UK
| | - Guy Pratt
- CRUK Institute for Cancer Studies, University of Birmingham, Birmingham, UK
| | - Hao Shao
- School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Abdullah Y. Abbas
- School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Peter M. Fischer
- School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Tracey D. Bradshaw
- School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Paul Brennan
- Cardiff CLL Research Group, Institute of Cancer & Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff, UK
| | - Chris Fegan
- Cardiff CLL Research Group, Institute of Cancer & Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff, UK
| | - Shudong Wang
- School of Pharmacy and Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia
| | - Chris Pepper
- Cardiff CLL Research Group, Institute of Cancer & Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff, UK
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8
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Blazek D, Kohoutek J, Bartholomeeusen K, Johansen E, Hulinkova P, Luo Z, Cimermancic P, Ule J, Peterlin BM. The Cyclin K/Cdk12 complex maintains genomic stability via regulation of expression of DNA damage response genes. Genes Dev 2011; 25:2158-72. [PMID: 22012619 PMCID: PMC3205586 DOI: 10.1101/gad.16962311] [Citation(s) in RCA: 341] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Accepted: 09/12/2011] [Indexed: 12/16/2022]
Abstract
Various cyclin-dependent kinase (Cdk) complexes have been implicated in the regulation of transcription. In this study, we identified a 70-kDa Cyclin K (CycK) that binds Cdk12 and Cdk13 to form two different complexes (CycK/Cdk12 or CycK/Cdk13) in human cells. The CycK/Cdk12 complex regulates phosphorylation of Ser2 in the C-terminal domain of RNA polymerase II and expression of a small subset of human genes, as revealed in expression microarrays. Depletion of CycK/Cdk12 results in decreased expression of predominantly long genes with high numbers of exons. The most prominent group of down-regulated genes are the DNA damage response genes, including the critical regulators of genomic stability: BRCA1 (breast and ovarian cancer type 1 susceptibility protein 1), ATR (ataxia telangiectasia and Rad3-related), FANCI, and FANCD2. We show that CycK/Cdk12, rather than CycK/Cdk13, is necessary for their expression. Nuclear run-on assays and chromatin immunoprecipitations with RNA polymerase II on the BRCA1 and FANCI genes suggest a transcriptional defect in the absence of CycK/Cdk12. Consistent with these findings, cells without CycK/Cdk12 induce spontaneous DNA damage and are sensitive to a variety of DNA damage agents. We conclude that through regulation of expression of DNA damage response genes, CycK/Cdk12 protects cells from genomic instability. The essential role of CycK for organisms in vivo is further supported by the result that genetic inactivation of CycK in mice causes early embryonic lethality.
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Affiliation(s)
- Dalibor Blazek
- Department of Medicine, Microbiology, and Immunology, Rosalind Russell Medical Research Center, University of California at San Francisco (UCSF), USA.
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9
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Abstract
The metazoan transcription elongation factor P-TEFb (CDK-9/cyclin T) is essential for HIV transcription, and is recruited by some cellular activators. P-TEFb promotes elongation in vitro by overcoming pausing that requires the SPT-4/SPT-5 complex, but considerable evidence indicates that SPT-4/SPT-5 facilitates elongation in vivo. Here we used RNA interference to investigate P-TEFb functions in vivo, in the Caenorhabditis elegans embryo. We found that P-TEFb is broadly essential for expression of early embryonic genes. P-TEFb is required for phosphorylation of Ser 2 of the RNA Polymerase II C-terminal domain (CTD) repeat, but not for most CTD Ser 5 phosphorylation, supporting the model that P-TEFb phosphorylates CTD Ser 2 during elongation. Remarkably, although heat shock genes are cdk-9-dependent, they can be activated when spt-4 and spt-5 expression is inhibited along with cdk-9. This observation suggests that SPT-4/SPT-5 has an inhibitory function in vivo, and that mutually opposing influences of P-TEFb and SPT-4/SPT-5 may combine to facilitate elongation, or insure fidelity of mRNA production. Other genes are not expressed when cdk-9, spt-4, and spt-5 are inhibited simultaneously, suggesting that these genes require P-TEFb in an additional mechanism, and that they and heat shock genes are regulated through different P-TEFb-dependent elongation pathways.
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Affiliation(s)
- Eun Yong Shim
- Center for Blood Research, Harvard Medical School, Boston, Massachusetts 02115, USA
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10
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Lis JT, Mason P, Peng J, Price DH, Werner J. P-TEFb kinase recruitment and function at heat shock loci. Genes Dev 2000; 14:792-803. [PMID: 10766736 PMCID: PMC316500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/1999] [Accepted: 02/15/2000] [Indexed: 02/16/2023]
Abstract
P-TEFb, a heterodimer of the kinase Cdk9 and cyclin T, was isolated as a factor that stimulates formation of productive transcription elongation complexes in vitro. Here, we show that P-TEFb is located at >200 distinct sites on Drosophila polytene chromosomes. Upon heat shock, P-TEFb, like the regulatory factor HSF, is rapidly recruited to heat shock loci, and this recruitment is blocked in an HSF mutant. Yet, HSF binding to DNA is not sufficient to recruit P-TEFb in vivo, and HSF and P-TEFb immunostainings within a heat shock locus are not coincident. Insight to the function of P-TEFb is offered by experiments showing that the direct recruitment of a Gal4-binding domain P-TEFb hybrid to an hsp70 promoter in Drosophila cells is sufficient to activate transcription in the absence of heat shock. Analyses of point mutants show this P-TEFb stimulation is dependent on Cdk9 kinase activity and on Cdk9's interaction with cyclin T. These results, coupled with the frequent colocalization of P-TEFb and the hypophosphorylated form of RNA polymerase II (Pol II) found at promoter-pause sites, support a model in which P-TEFb acts to stimulate promoter-paused Pol II to enter into productive elongation.
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Affiliation(s)
- J T Lis
- Department of Molecular Biology and Genetics, Biotechnology Building, Cornell University, Ithaca, New York 14853, USA.
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