1
|
Walker RL, Hornicek FJ, Duan Z. Transcriptional regulation and therapeutic potential of cyclin-dependent kinase 9 (CDK9) in sarcoma. Biochem Pharmacol 2024; 226:116342. [PMID: 38848777 DOI: 10.1016/j.bcp.2024.116342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 05/17/2024] [Accepted: 06/04/2024] [Indexed: 06/09/2024]
Abstract
Sarcomas include various subtypes comprising two significant groups - soft tissue and bone sarcomas. Although the survival rate for some sarcoma subtypes has improved over time, the current methods of treatment remain efficaciously limited, as recurrent, and metastatic diseases remain a major obstacle. There is a need for better options and therapeutic strategies in treating sarcoma. Cyclin dependent kinase 9 (CDK9) is a transcriptional kinase and has emerged as a promising target for treating various cancers. The aberrant expression and activation of CDK9 have been observed in several sarcoma subtypes, including rhabdomyosarcoma, synovial sarcoma, osteosarcoma, Ewing sarcoma, and chordoma. Enhanced CDK9 expression has also been correlated with poorer prognosis in sarcoma patients. As a master regulator of transcription, CDK9 promotes transcription elongation by phosphorylation and releasing RNA polymerase II (RNAPII) from its promoter proximal pause. Release of RNAPII from this pause induces transcription of critical genes in the tumor cell. Overexpression and activation of CDK9 have been observed to lead to the expression of oncogenes, including MYC and MCL-1, that aid sarcoma development and progression. Inhibition of CDK9 in sarcoma has been proven to reduce these oncogenes' expression and decrease proliferation and growth in different sarcoma cells. Currently, there are several CDK9 inhibitors in preclinical and clinical investigations. This review aims to highlight the recent discovery and results on the transcriptional role and therapeutic potential of CDK9 in sarcoma.
Collapse
Affiliation(s)
- Robert L Walker
- Department of Orthopedic Surgery, Sarcoma Biology Laboratory, Sylvester Comprehensive Cancer Center, and the University of Miami Miller School of Medicine, Papanicolaou Cancer Research Building, 1550 N.W. 10(th) Avenue, Miami, FL 33136. USA
| | - Francis J Hornicek
- Department of Orthopedic Surgery, Sarcoma Biology Laboratory, Sylvester Comprehensive Cancer Center, and the University of Miami Miller School of Medicine, Papanicolaou Cancer Research Building, 1550 N.W. 10(th) Avenue, Miami, FL 33136. USA
| | - Zhenfeng Duan
- Department of Orthopedic Surgery, Sarcoma Biology Laboratory, Sylvester Comprehensive Cancer Center, and the University of Miami Miller School of Medicine, Papanicolaou Cancer Research Building, 1550 N.W. 10(th) Avenue, Miami, FL 33136. USA.
| |
Collapse
|
2
|
Taghizadeh MS, Taherishirazi M, Niazi A, Afsharifar A, Moghadam A. Structure-guided design and cloning of peptide inhibitors targeting CDK9/cyclin T1 protein-protein interaction. Front Pharmacol 2024; 15:1327820. [PMID: 38808256 PMCID: PMC11130503 DOI: 10.3389/fphar.2024.1327820] [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: 10/25/2023] [Accepted: 01/18/2024] [Indexed: 05/30/2024] Open
Abstract
CDK9 (cyclin-dependent kinase 9) plays a significant role in numerous pathological conditions, such as HIV-1 infection and cancer. The interaction between CDK9 and cyclin T1 is crucial for maintaining the kinase's active state. Therefore, targeting this protein-protein interaction offers a promising strategy for inhibiting CDK9. In this study, we aimed to design and characterize a library of mutant peptides based on the binding region of cyclin T1 to CDK9. Using Osprey software, a total of 7,776 mutant peptides were generated. After conducting a comprehensive analysis, three peptides, namely, mp3 (RAADVEGQRKRRE), mp20 (RAATVEGQRKRRE), and mp29 (RAADVEGQDKRRE), were identified as promising inhibitors that possess the ability to bind to CDK9 with high affinity and exhibit low free binding energy. These peptides exhibited favorable safety profiles and displayed promising dynamic behaviors. Notably, our findings revealed that the mp3 and mp29 peptides interacted with a conserved sequence in CDK9 (residues 60-66). In addition, by designing the structure of potential peptides in the plasmid vector pET28a (+), we have been able to pave the way for facilitating the process of their recombinant production in an Escherichia coli expression system in future studies. Predictions indicated good solubility upon overexpression, further supporting their potential for downstream applications. While these results demonstrate the promise of the designed peptides as blockers of CDK9 with high affinity, additional experimental studies are required to validate their biological activity and assess their selectivity. Such investigations will provide valuable insights into their therapeutic potential and pave the way for the future development of peptide-based inhibitors targeting the CDK9-cyclin T1 complex.
Collapse
Affiliation(s)
| | | | - Ali Niazi
- Institute of Biotechnology, Shiraz University, Shiraz, Iran
| | - Alireza Afsharifar
- Plant Virology Research Center, School of Agriculture, Shiraz University, Shiraz, Iran
| | - Ali Moghadam
- Institute of Biotechnology, Shiraz University, Shiraz, Iran
| |
Collapse
|
3
|
Alfano L, Iannuzzi CA, Barone D, Forte IM, Ragosta MC, Cuomo M, Mazzarotti G, Dell'Aquila M, Altieri A, Caporaso A, Roma C, Marra L, Boffo S, Indovina P, De Laurentiis M, Giordano A. CDK9-55 guides the anaphase-promoting complex/cyclosome (APC/C) in choosing the DNA repair pathway choice. Oncogene 2024; 43:1263-1273. [PMID: 38433256 DOI: 10.1038/s41388-024-02982-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 02/08/2024] [Accepted: 02/13/2024] [Indexed: 03/05/2024]
Abstract
DNA double-strand breaks (DSBs) contribute to genome instability, a key feature of cancer. DSBs are mainly repaired by homologous recombination (HR) and non-homologous end-joining (NHEJ). We investigated the role of an isoform of the multifunctional cyclin-dependent kinase 9, CDK9-55, in DNA repair, by generating CDK9-55-knockout HeLa clones (through CRISPR-Cas9), which showed potential HR dysfunction. A phosphoproteomic screening in these clones treated with camptothecin revealed that CDC23 (cell division cycle 23), a component of the E3-ubiquitin ligase APC/C (anaphase-promoting complex/cyclosome), is a new substrate of CDK9-55, with S588 being its putative phosphorylation site. Mutated non-phosphorylatable CDC23(S588A) affected the repair pathway choice by impairing HR and favouring error-prone NHEJ. This CDK9 role should be considered when designing CDK-inhibitor-based cancer therapies.
Collapse
Affiliation(s)
- Luigi Alfano
- Cell Biology and Biotherapy Unit, Istituto Nazionale Tumori-Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS)-Fondazione G. Pascale, Napoli, Italy.
| | - Carmelina Antonella Iannuzzi
- Cell Biology and Biotherapy Unit, Istituto Nazionale Tumori-Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS)-Fondazione G. Pascale, Napoli, Italy
| | - Daniela Barone
- Cell Biology and Biotherapy Unit, Istituto Nazionale Tumori-Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS)-Fondazione G. Pascale, Napoli, Italy
| | - Iris Maria Forte
- Breast Unit, Istituto Nazionale Tumori-Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS)-Fondazione G. Pascale, Napoli, Italy
| | | | - Maria Cuomo
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Giulio Mazzarotti
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Milena Dell'Aquila
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA
| | - Angela Altieri
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA
| | - Antonella Caporaso
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA
| | - Cristin Roma
- Cell Biology and Biotherapy Unit, Istituto Nazionale Tumori-Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS)-Fondazione G. Pascale, Napoli, Italy
| | - Laura Marra
- Cell Biology and Biotherapy Unit, Istituto Nazionale Tumori-Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS)-Fondazione G. Pascale, Napoli, Italy
| | - Silvia Boffo
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA
| | - Paola Indovina
- Sbarro Research Health Organization, Candiolo, Torino, Italy
| | - Michelino De Laurentiis
- Breast Unit, Istituto Nazionale Tumori-Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS)-Fondazione G. Pascale, Napoli, Italy
| | - Antonio Giordano
- Department of Medical Biotechnologies, University of Siena, Siena, Italy.
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA.
| |
Collapse
|
4
|
Mustafa EH, Laven-Law G, Kikhtyak Z, Nguyen V, Ali S, Pace AA, Iggo R, Kebede A, Noll B, Wang S, Winter JM, Dwyer AR, Tilley WD, Hickey TE. Selective inhibition of CDK9 in triple negative breast cancer. Oncogene 2024; 43:202-215. [PMID: 38001268 PMCID: PMC10786725 DOI: 10.1038/s41388-023-02892-3] [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: 03/24/2023] [Revised: 11/02/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023]
Abstract
Targeted therapy for triple-negative breast cancers (TNBC) remains a clinical challenge due to tumour heterogeneity. Since TNBC have key features of transcriptionally addicted cancers, targeting transcription via regulators such as cyclin-dependent kinase 9 (CDK9) has potential as a therapeutic strategy. Herein, we preclinically tested a new selective CDK9 inhibitor (CDDD11-8) in TNBC using cell line, patient-derived organoid, and patient-derived explant models. In vitro, CDDD11-8 dose-dependently inhibited proliferation (IC50 range: 281-734 nM), induced cell cycle arrest, and increased apoptosis of cell lines, which encompassed the three major molecular subtypes of TNBC. On target inhibition of CDK9 activity was demonstrated by reduced RNAPII phosphorylation at a CDK9 target peptide and down-regulation of the MYC and MCL1 oncogenes at the mRNA and protein levels in all cell line models. Drug induced RNAPII pausing was evident at gene promoters, with strongest pausing at MYC target genes. Growth of five distinct patient-derived organoid models was dose-dependently inhibited by CDDD11-8 (IC50 range: 272-771 nM), including three derived from MYC amplified, chemo-resistant TNBC metastatic lesions. Orally administered CDDD11-8 also inhibited growth of mammary intraductal TNBC xenograft tumours with no overt toxicity in vivo (mice) or ex vivo (human breast tissues). In conclusion, our studies indicate that CDK9 is a viable therapeutic target in TNBC and that CDDD11-8, a novel selective CDK9 inhibitor, has efficacy in TNBC without apparent toxicity to normal tissues.
Collapse
Affiliation(s)
- Ebtihal H Mustafa
- Dame Roma Mitchell Cancer Research Laboratories, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Geraldine Laven-Law
- Dame Roma Mitchell Cancer Research Laboratories, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Zoya Kikhtyak
- Dame Roma Mitchell Cancer Research Laboratories, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Van Nguyen
- Department of Surgery & Cancer, Imperial College London, London, UK
| | - Simak Ali
- Department of Surgery & Cancer, Imperial College London, London, UK
| | - Alex A Pace
- Dame Roma Mitchell Cancer Research Laboratories, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Richard Iggo
- Dame Roma Mitchell Cancer Research Laboratories, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
- Institut Bergonié, University of Bordeaux, Bordeaux, France
| | - Alemwork Kebede
- Drug Discovery and Development, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Ben Noll
- Drug Discovery and Development, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Shudong Wang
- Drug Discovery and Development, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Jean M Winter
- Dame Roma Mitchell Cancer Research Laboratories, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Amy R Dwyer
- Dame Roma Mitchell Cancer Research Laboratories, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Wayne D Tilley
- Dame Roma Mitchell Cancer Research Laboratories, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
| | - Theresa E Hickey
- Dame Roma Mitchell Cancer Research Laboratories, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia.
| |
Collapse
|
5
|
Montinaro A, Walczak H. Harnessing TRAIL-induced cell death for cancer therapy: a long walk with thrilling discoveries. Cell Death Differ 2023; 30:237-249. [PMID: 36195672 PMCID: PMC9950482 DOI: 10.1038/s41418-022-01059-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 02/10/2023] Open
Abstract
Tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL) can induce apoptosis in a wide variety of cancer cells, both in vitro and in vivo, importantly without killing any essential normal cells. These findings formed the basis for the development of TRAIL-receptor agonists (TRAs) for cancer therapy. However, clinical trials conducted with different types of TRAs have, thus far, afforded only limited therapeutic benefit, as either the respectively chosen agonist showed insufficient anticancer activity or signs of toxicity, or the right TRAIL-comprising combination therapy was not employed. Therefore, in this review we will discuss molecular determinants of TRAIL resistance, the most promising TRAIL-sensitizing agents discovered to date and, importantly, whether any of these could also prove therapeutically efficacious upon cancer relapse following conventional first-line therapies. We will also discuss the more recent progress made with regards to the clinical development of highly active non-immunogenic next generation TRAs. Based thereupon, we next propose how TRAIL resistance might be successfully overcome, leading to the possible future development of highly potent, cancer-selective combination therapies that are based on our current understanding of biology TRAIL-induced cell death. It is possible that such therapies may offer the opportunity to tackle one of the major current obstacles to effective cancer therapy, namely overcoming chemo- and/or targeted-therapy resistance. Even if this were achievable only for certain types of therapy resistance and only for particular types of cancer, this would be a significant and meaningful achievement.
Collapse
Affiliation(s)
- Antonella Montinaro
- Centre for Cell Death, Cancer, and Inflammation (CCCI), UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK.
| | - Henning Walczak
- Centre for Cell Death, Cancer, and Inflammation (CCCI), UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK.
- CECAD Cluster of Excellence, University of Cologne, 50931, Cologne, Germany.
- Center for Biochemistry, Medical Faculty, Joseph-Stelzmann-Str. 52, University of Cologne, 50931, Cologne, Germany.
| |
Collapse
|
6
|
He XL, Hu YH, Chen JM, Zhang DQ, Yang HL, Zhang LZ, Mu YP, Zhang H, Chen GF, Liu W, Liu P. SNS-032 attenuates liver fibrosis by anti-active hepatic stellate cells via inhibition of cyclin dependent kinase 9. Front Pharmacol 2022; 13:1016552. [PMID: 36313366 PMCID: PMC9597511 DOI: 10.3389/fphar.2022.1016552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 09/29/2022] [Indexed: 11/13/2022] Open
Abstract
Liver fibrosis is a common pathological process of all chronic liver diseases. Hepatic stellate cells (HSCs) play a central role in the development of liver fibrosis. Cyclin-dependent kinase 9 (CDK9) is a cell cycle kinase that regulates mRNA transcription and elongation. A CDK9 inhibitor SNS-032 has been reported to have good effects in anti-tumor. However, the role of SNS-032 in the development of liver fibrosis is unclear. In this study, SNS-032 was found to alleviate hepatic fibrosis by inhibiting the activation and inducing the apoptosis of active HSCs in carbon tetrachloride-induced model mice. In vitro, SNS-032 inhibited the activation and proliferation of active HSCs and induced the apoptosis of active HSCs by downregulating the expression of CDK9 and its downstream signal transductors, such phosphorylated RNA polymerase II and Bcl-2. CDK9 short hairpin RNA was transfected into active HSCs to further elucidate the mechanism of the above effects. Similar results were observed in active HSCs after CDK9 knockdown. In active HSCs with CDK9 knockdown, the expression levels of CDK9, phosphorylated RNA polymerase II, XIAP, Bcl-2, Mcl-1, and ɑ-SMA significantly decreased, whereas those of cleaved-PARP1 and Bax decreased prominently. These results indicated that SNS-032 is a potential drug and CDK9 might be a new prospective target for the treatment of liver fibrosis.
Collapse
Affiliation(s)
- Xiao-Li He
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Department of Endocrinology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yong-Hong Hu
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jia-Mei Chen
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ding-Qi Zhang
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Hai-Lin Yang
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Lin-Zhang Zhang
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yong-Ping Mu
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Hua Zhang
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Gao-Feng Chen
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Wei Liu
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
- *Correspondence: Wei Liu, ; Ping Liu,
| | - Ping Liu
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- *Correspondence: Wei Liu, ; Ping Liu,
| |
Collapse
|
7
|
Sun J, Yang T, Wei T, Zhou L, Shan T, Chen J, Gu L, Chen B, Liu L, Jiang Q, Du C, Ma Y, Wang H, Chen F, Guo X, Ji Y, Wang L. CDK9 binds and activates SGK3 to promote cardiac repair after injury via the GSK-3β/β-catenin pathway. Front Cardiovasc Med 2022; 9:970745. [PMID: 36082129 PMCID: PMC9445272 DOI: 10.3389/fcvm.2022.970745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
The mammalian heart possesses entire regeneration capacity after birth, which is lost in adulthood. The role of the kinase network in myocardial regeneration remains largely elusive. SGK3 (threonine-protein kinase 3) is a functional kinase we identified previously with the capacity to promote cardiomyocyte proliferation and cardiac repair after myocardial infarction. However, the upstream signals regulating SGK3 are still unknown. Based on the quantitative phosphoproteomics data and pulldown assay, we identified cyclin-dependent kinase 9 (CDK9) as a novel therapeutic target in regeneration therapy. The direct combination between CDK9 and SGK3 was further confirmed by co-immunoprecipitation (Co-IP). CDK9 is highly expressed in the newborn period and rarely detected in the adult myocardium. In vitro, the proliferation ratio of primary cardiomyocytes was significantly elevated by CDK9 overexpression while inhibited by CDK9 knockdown. In vivo, inhibition of CDK9 shortened the time window of cardiac regeneration after apical resection (AR) in neonatal mice, while overexpression of CDK9 significantly promoted mature cardiomyocytes (CMs) to re-enter the cell cycle and cardiac repair after myocardial infarction (MI) in adult mice. Mechanistically, CDK9 promoted cardiac repair by directly activating SGK3 and downstream GSK-3β/β-catenin pathway. Consequently, our study indicated that CDK9 might be a novel target for MI therapy by stimulating myocardial regeneration.
Collapse
Affiliation(s)
- Jiateng Sun
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Tongtong Yang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Tianwen Wei
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Liuhua Zhou
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Tiankai Shan
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jiawen Chen
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Lingfeng Gu
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Bingrui Chen
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Liu Liu
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Qiqi Jiang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Chong Du
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yao Ma
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Hao Wang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Feng Chen
- Department of Biostatistics, School of Public Health, China International Cooperation Center for Environment and Human Health, Nanjing Medical University, Nanjing, China
| | - Xuejiang Guo
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing, China
| | - Yong Ji
- Key Laboratory of Cardiovascular and Cerebrovascular Medicine, Collaborative Innovation Center for Cardiovascular Disease Translation, Nanjing Medical University, Nanjing, China
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translation, Nanjing Medical University, Nanjing, China
| | - Liansheng Wang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
- *Correspondence: Liansheng Wang,
| |
Collapse
|
8
|
Commuting to Work: Nucleolar Long Non-Coding RNA Control Ribosome Biogenesis from Near and Far. Noncoding RNA 2021; 7:ncrna7030042. [PMID: 34287370 PMCID: PMC8293466 DOI: 10.3390/ncrna7030042] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/09/2021] [Accepted: 07/11/2021] [Indexed: 12/26/2022] Open
Abstract
Gene expression is an essential process for cellular growth, proliferation, and differentiation. The transcription of protein-coding genes and non-coding loci depends on RNA polymerases. Interestingly, numerous loci encode long non-coding (lnc)RNA transcripts that are transcribed by RNA polymerase II (RNAPII) and fine-tune the RNA metabolism. The nucleolus is a prime example of how different lncRNA species concomitantly regulate gene expression by facilitating the production and processing of ribosomal (r)RNA for ribosome biogenesis. Here, we summarise the current findings on how RNAPII influences nucleolar structure and function. We describe how RNAPII-dependent lncRNA can both promote nucleolar integrity and inhibit ribosomal (r)RNA synthesis by modulating the availability of rRNA synthesis factors in trans. Surprisingly, some lncRNA transcripts can directly originate from nucleolar loci and function in cis. The nucleolar intergenic spacer (IGS), for example, encodes nucleolar transcripts that counteract spurious rRNA synthesis in unperturbed cells. In response to DNA damage, RNAPII-dependent lncRNA originates directly at broken ribosomal (r)DNA loci and is processed into small ncRNA, possibly to modulate DNA repair. Thus, lncRNA-mediated regulation of nucleolar biology occurs by several modes of action and is more direct than anticipated, pointing to an intimate crosstalk of RNA metabolic events.
Collapse
|
9
|
CDK9 keeps RNA polymerase II on track. Cell Mol Life Sci 2021; 78:5543-5567. [PMID: 34146121 PMCID: PMC8257543 DOI: 10.1007/s00018-021-03878-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 05/26/2021] [Accepted: 06/08/2021] [Indexed: 12/30/2022]
Abstract
Cyclin-dependent kinase 9 (CDK9), the kinase component of positive transcription elongation factor b (P-TEFb), is essential for transcription of most protein-coding genes by RNA polymerase II (RNAPII). By releasing promoter-proximally paused RNAPII into gene bodies, CDK9 controls the entry of RNAPII into productive elongation and is, therefore, critical for efficient synthesis of full-length messenger (m)RNAs. In recent years, new players involved in P-TEFb-dependent processes have been identified and an important function of CDK9 in coordinating elongation with transcription initiation and termination has been unveiled. As the regulatory functions of CDK9 in gene expression continue to expand, a number of human pathologies, including cancers, have been associated with aberrant CDK9 activity, underscoring the need to properly regulate CDK9. Here, I provide an overview of CDK9 function and regulation, with an emphasis on CDK9 dysregulation in human diseases.
Collapse
|
10
|
Anshabo AT, Milne R, Wang S, Albrecht H. CDK9: A Comprehensive Review of Its Biology, and Its Role as a Potential Target for Anti-Cancer Agents. Front Oncol 2021; 11:678559. [PMID: 34041038 PMCID: PMC8143439 DOI: 10.3389/fonc.2021.678559] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/16/2021] [Indexed: 12/25/2022] Open
Abstract
Cyclin-dependent kinases (CDKs) are proteins pivotal to a wide range of cellular functions, most importantly cell division and transcription, and their dysregulations have been implicated as prominent drivers of tumorigenesis. Besides the well-established role of cell cycle CDKs in cancer, the involvement of transcriptional CDKs has been confirmed more recently. Most cancers overtly employ CDKs that serve as key regulators of transcription (e.g., CDK9) for a continuous production of short-lived gene products that maintain their survival. As such, dysregulation of the CDK9 pathway has been observed in various hematological and solid malignancies, making it a valuable anticancer target. This therapeutic potential has been utilized for the discovery of CDK9 inhibitors, some of which have entered human clinical trials. This review provides a comprehensive discussion on the structure and biology of CDK9, its role in solid and hematological cancers, and an updated review of the available inhibitors currently being investigated in preclinical and clinical settings.
Collapse
Affiliation(s)
- Abel Tesfaye Anshabo
- Drug Discovery and Development, Centre for Cancer Diagnostics and Therapeutics, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Robert Milne
- Drug Discovery and Development, Centre for Cancer Diagnostics and Therapeutics, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Shudong Wang
- Drug Discovery and Development, Centre for Cancer Diagnostics and Therapeutics, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Hugo Albrecht
- Drug Discovery and Development, Centre for Cancer Diagnostics and Therapeutics, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| |
Collapse
|
11
|
Mandal R, Becker S, Strebhardt K. Targeting CDK9 for Anti-Cancer Therapeutics. Cancers (Basel) 2021; 13:2181. [PMID: 34062779 PMCID: PMC8124690 DOI: 10.3390/cancers13092181] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/28/2021] [Accepted: 04/29/2021] [Indexed: 12/23/2022] Open
Abstract
Cyclin Dependent Kinase 9 (CDK9) is one of the most important transcription regulatory members of the CDK family. In conjunction with its main cyclin partner-Cyclin T1, it forms the Positive Transcription Elongation Factor b (P-TEFb) whose primary function in eukaryotic cells is to mediate the positive transcription elongation of nascent mRNA strands, by phosphorylating the S2 residues of the YSPTSPS tandem repeats at the C-terminus domain (CTD) of RNA Polymerase II (RNAP II). To aid in this process, P-TEFb also simultaneously phosphorylates and inactivates a number of negative transcription regulators like 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DRB) Sensitivity-Inducing Factor (DSIF) and Negative Elongation Factor (NELF). Significantly enhanced activity of CDK9 is observed in multiple cancer types, which is universally associated with significantly shortened Overall Survival (OS) of the patients. In these cancer types, CDK9 regulates a plethora of cellular functions including proliferation, survival, cell cycle regulation, DNA damage repair and metastasis. Due to the extremely critical role of CDK9 in cancer cells, inhibiting its functions has been the subject of intense research, resulting the development of multiple, increasingly specific small-molecule inhibitors, some of which are presently in clinical trials. The search for newer generation CDK9 inhibitors with higher specificity and lower potential toxicities and suitable combination therapies continues. In fact, the Phase I clinical trials of the latest, highly specific CDK9 inhibitor BAY1251152, against different solid tumors have shown good anti-tumor and on-target activities and pharmacokinetics, combined with manageable safety profile while the phase I and II clinical trials of another inhibitor AT-7519 have been undertaken or are undergoing. To enhance the effectiveness and target diversity and reduce potential drug-resistance, the future of CDK9 inhibition would likely involve combining CDK9 inhibitors with inhibitors like those against BRD4, SEC, MYC, MCL-1 and HSP90.
Collapse
Affiliation(s)
- Ranadip Mandal
- Department of Gynecology and Obstetrics, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (R.M.); (S.B.)
| | - Sven Becker
- Department of Gynecology and Obstetrics, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (R.M.); (S.B.)
| | - Klaus Strebhardt
- Department of Gynecology and Obstetrics, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (R.M.); (S.B.)
- German Cancer Consortium (DKTK), 69120 Heidelberg, Germany
| |
Collapse
|
12
|
Barclay RA, Khatkar P, Mensah G, DeMarino C, Chu JSC, Lepene B, Zhou W, Gillevet P, Torkzaban B, Khalili K, Liotta L, Kashanchi F. An Omics Approach to Extracellular Vesicles from HIV-1 Infected Cells. Cells 2019; 8:cells8080787. [PMID: 31362387 PMCID: PMC6724219 DOI: 10.3390/cells8080787] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 01/08/2023] Open
Abstract
Human Immunodeficiency Virus-1 (HIV-1) is the causative agent of Acquired Immunodeficiency Syndrome (AIDS), infecting nearly 37 million people worldwide. Currently, there is no definitive cure, mainly due to HIV-1's ability to enact latency. Our previous work has shown that exosomes, a small extracellular vesicle, from uninfected cells can activate HIV-1 in latent cells, leading to increased mostly short and some long HIV-1 RNA transcripts. This is consistent with the notion that none of the FDA-approved antiretroviral drugs used today in the clinic are transcription inhibitors. Furthermore, these HIV-1 transcripts can be packaged into exosomes and released from the infected cell. Here, we examined the differences in protein and nucleic acid content between exosomes from uninfected and HIV-1-infected cells. We found increased cyclin-dependent kinases, among other kinases, in exosomes from infected T-cells while other kinases were present in exosomes from infected monocytes. Additionally, we found a series of short antisense HIV-1 RNA from the 3' LTR that appears heavily mutated in exosomes from HIV-1-infected cells along with the presence of cellular noncoding RNAs and cellular miRNAs. Both physical and functional validations were performed on some of the key findings. Collectively, our data indicate distinct differences in protein and RNA content between exosomes from uninfected and HIV-1-infected cells, which can lead to different functional outcomes in recipient cells.
Collapse
Affiliation(s)
- Robert A Barclay
- Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Pooja Khatkar
- Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Gifty Mensah
- Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Catherine DeMarino
- Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Jeffery S C Chu
- Applied Biological Materials Inc., 1-3671 Viking Way, Richmond, BC V6V 2J5, Canada
| | | | - Weidong Zhou
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, VA 20110, USA
| | - Patrick Gillevet
- Microbiome Analysis Center, George Mason University, Manassas, VA 20110, USA
| | - Bahareh Torkzaban
- Center for Neurovirology, Temple University, Philadelphia, PA 19122, USA
| | - Kamel Khalili
- Center for Neurovirology, Temple University, Philadelphia, PA 19122, USA
| | - Lance Liotta
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, VA 20110, USA
| | - Fatah Kashanchi
- Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA.
| |
Collapse
|
13
|
Li X, Seebacher NA, Xiao T, Hornicek FJ, Duan Z. Targeting regulation of cyclin dependent kinase 9 as a novel therapeutic strategy in synovial sarcoma. J Orthop Res 2019; 37:510-521. [PMID: 30488489 DOI: 10.1002/jor.24189] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 11/15/2018] [Indexed: 02/04/2023]
Abstract
Synovial sarcomas hold a low genomic complexity, making it distinct from other types of soft-tissue sarcomas. Many studies focused on targeting the SS18-SSX fusion protein, which presents in over 90% of human synovial sarcomas. This protein acts as an oncogenic promoter in the tumorigenesis of synovial sarcomas, making it an ideal therapeutic target. However, to date there have been no effective strategies targeting SS18-SSX for the treatment of synovial sarcomas. Therefore, it is an urgent need to identify alternative therapeutic targets. More recently, CDK9, a protein involved in RNA transcription regulation, has been investigated for its role in the pathogenesis of cancer. However, the expression and function of CDK9 in synovial sarcomas remains to be elucidated. In the present study, we found that CDK9 was to be largely localized to the cell nucleus, and highly expressed in all tested human synovial sarcoma cell lines and over 90% of human sarcoma tissue microarray samples. High-CDK9 expression was associated with a poorer patient prognosis of human sarcomas. Inhibition of CDK9, with either siRNA or a CDK9 inhibitor, prevented synovial sarcoma cell growth and proliferation in a dose-dependent manner. This was also accompanied with a reduction in the phosphorylation of RNA polymerase II and an increase in the expression of anti-apoptotic proteins. Moreover, CDK9 inhibition decreased sarcoma cell spheroid formation and cell motility. Collectively, these findings highlight the importance of CDK9 in human synovial sarcoma cell growth and proliferation. Therefore, CDK9 may represent a promising target for the treatment of synovial sarcomas. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:510-521, 2019.
Collapse
Affiliation(s)
- Xiaoyang Li
- Sarcoma Biology Laboratory, Department of Orthopaedic Surgery, David Geffen School of Medicine at University of California Los Angeles, 615 Charles E. Young Dr. S., Los Angeles, California, 90095.,Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, People's Republic of China
| | - Nicole A Seebacher
- Sarcoma Biology Laboratory, Department of Orthopaedic Surgery, David Geffen School of Medicine at University of California Los Angeles, 615 Charles E. Young Dr. S., Los Angeles, California, 90095
| | - Tao Xiao
- Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, People's Republic of China
| | - Francis J Hornicek
- Sarcoma Biology Laboratory, Department of Orthopaedic Surgery, David Geffen School of Medicine at University of California Los Angeles, 615 Charles E. Young Dr. S., Los Angeles, California, 90095
| | - Zhenfeng Duan
- Sarcoma Biology Laboratory, Department of Orthopaedic Surgery, David Geffen School of Medicine at University of California Los Angeles, 615 Charles E. Young Dr. S., Los Angeles, California, 90095
| |
Collapse
|
14
|
Combined protein and ligand based physicochemical aspects of molecular recognition for the discovery of CDK9 inhibitor. GENE REPORTS 2018. [DOI: 10.1016/j.genrep.2018.10.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
15
|
Abstract
The fact that many cancer types display transcriptional addiction driven by dysregulation of oncogenic enhancers and transcription factors has led to increased interest in a group of protein kinases, known as transcriptional cyclin dependent kinases (tCDKs), as potential therapeutic targets. Despite early reservations about targeting a process that is essential to healthy cell types, there is now evidence that targeting tCDKs could provide enough therapeutic window to be effective in the clinic. Here, we discuss recent developments in this field, with an emphasis on highly-selective inhibitors and the challenges to be addressed before these inhibitors could be used for therapeutic purposes. Abbreviations: CAK: CDK-activating kinase;CDK: cyclin-dependent kinase;CMGC group: CDK-, MAPK-, GSK3-, and CLK-like;CTD: C-terminal repeat domain of the RPB1 subunit of RNA polymerase II;DRB: 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole;mCRPC: metastatic castration-resistant prostate cancer;NSCLC: non-small cell lung cancer;P-TEFb: positive elongation factor b;RNAPII: RNA polymerase II;S2: serine-2 of CTD repeats;S5: serine-5 of CTD repeats;S7: serine-7 of CTD repeats;SEC: super elongation complex;tCDK: transcriptional cyclin-dependent kinase;TNBC: triple-negative breast cancer
Collapse
Affiliation(s)
- Matthew D Galbraith
- a Linda Crnic Institute for Down Syndrome, School of Medicine , University of Colorado Anschutz Medical Campus , Aurora , CO , USA.,b Department of Pharmacology, School of Medicine , University of Colorado Anschutz Medical Campus , Aurora , CO , USA
| | - Heather Bender
- a Linda Crnic Institute for Down Syndrome, School of Medicine , University of Colorado Anschutz Medical Campus , Aurora , CO , USA.,b Department of Pharmacology, School of Medicine , University of Colorado Anschutz Medical Campus , Aurora , CO , USA
| | - Joaquín M Espinosa
- a Linda Crnic Institute for Down Syndrome, School of Medicine , University of Colorado Anschutz Medical Campus , Aurora , CO , USA.,b Department of Pharmacology, School of Medicine , University of Colorado Anschutz Medical Campus , Aurora , CO , USA.,c Department of Molecular, Cellular and Developmental Biology , University of Colorado Boulder , Boulder , CO , USA
| |
Collapse
|
16
|
García-Reyes B, Kretz AL, Ruff JP, von Karstedt S, Hillenbrand A, Knippschild U, Henne-Bruns D, Lemke J. The Emerging Role of Cyclin-Dependent Kinases (CDKs) in Pancreatic Ductal Adenocarcinoma. Int J Mol Sci 2018; 19:E3219. [PMID: 30340359 PMCID: PMC6214075 DOI: 10.3390/ijms19103219] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 09/27/2018] [Accepted: 10/11/2018] [Indexed: 02/07/2023] Open
Abstract
The family of cyclin-dependent kinases (CDKs) has critical functions in cell cycle regulation and controlling of transcriptional elongation. Moreover, dysregulated CDKs have been linked to cancer initiation and progression. Pharmacological CDK inhibition has recently emerged as a novel and promising approach in cancer therapy. This idea is of particular interest to combat pancreatic ductal adenocarcinoma (PDAC), a cancer entity with a dismal prognosis which is owed mainly to PDAC's resistance to conventional therapies. Here, we review the current knowledge of CDK biology, its role in cancer and the therapeutic potential to target CDKs as a novel treatment strategy for PDAC.
Collapse
Affiliation(s)
- Balbina García-Reyes
- Department of General and Visceral Surgery, Ulm University Hospital, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
| | - Anna-Laura Kretz
- Department of General and Visceral Surgery, Ulm University Hospital, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
| | - Jan-Philipp Ruff
- Department of General and Visceral Surgery, Ulm University Hospital, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
| | - Silvia von Karstedt
- Department of Translational Genomics, University Hospital Cologne, Weyertal 115b, 50931 Cologne, Germany.
- Cologne Excellence Cluster on Cellular Stress Response in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Straße 26, 50931 Cologne, Germany.
| | - Andreas Hillenbrand
- Department of General and Visceral Surgery, Ulm University Hospital, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
| | - Uwe Knippschild
- Department of General and Visceral Surgery, Ulm University Hospital, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
| | - Doris Henne-Bruns
- Department of General and Visceral Surgery, Ulm University Hospital, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
| | - Johannes Lemke
- Department of General and Visceral Surgery, Ulm University Hospital, Albert-Einstein-Allee 23, 89081 Ulm, Germany.
| |
Collapse
|
17
|
Boffo S, Damato A, Alfano L, Giordano A. CDK9 inhibitors in acute myeloid leukemia. J Exp Clin Cancer Res 2018; 37:36. [PMID: 29471852 PMCID: PMC5824552 DOI: 10.1186/s13046-018-0704-8] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 02/12/2018] [Indexed: 02/07/2023] Open
Abstract
Current treatment for acute myeloid leukemia (AML) is less than optimal, but increased understanding of disease pathobiology and genomics has led to clinical investigation of novel targeted therapies and rational combinations. Targeting the cyclin-dependent kinase 9 (CDK9) pathway, which is dysregulated in AML, is an attractive approach. Inhibition of CDK9 leads to downregulation of cell survival genes regulated by super enhancers such as MCL-1, MYC, and cyclin D1. As CDK9 inhibitors are nonselective, predictive biomarkers that may help identify patients most likely to respond to CDK9 inhibitors are now being utilized, with the goal of improving efficacy and safety.
Collapse
Affiliation(s)
- Silvia Boffo
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Temple University, 1900 N. 12th St., Room 431, Philadelphia, PA 19122-6017 USA
| | - Angela Damato
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Temple University, 1900 N. 12th St., Room 431, Philadelphia, PA 19122-6017 USA
- Medical Oncology Unit, Clinical Cancer Centre, IRCCS–Arcispedale S. Maria Nuova, Reggio Emilia, Italy
| | - Luigi Alfano
- Oncology Research Center of Mercogliano (CROM), Istituto Nazionale Per Lo Studio E La Cura Dei Tumori “Fondazione Giovanni Pascale”, IRCCS, Naples, Italy
| | - Antonio Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Temple University, 1900 N. 12th St., Room 431, Philadelphia, PA 19122-6017 USA
- Department of Medicine, Surgery, and Neuroscience, University of Siena, Siena, Italy
| |
Collapse
|
18
|
Zhan Y, Han Y, Sun H, Liang T, Zhang C, Song J, Hou G. Down-regulating cyclin-dependent kinase 9 of alloreactive CD4+ T cells prolongs allograft survival. Oncotarget 2018; 7:24983-94. [PMID: 27102157 PMCID: PMC5041884 DOI: 10.18632/oncotarget.8804] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 04/06/2016] [Indexed: 01/27/2023] Open
Abstract
CDK9 (Cyclin-dependent kinase 9)/Cyclin T1/RNA polymerase II pathway has been demonstrated to promote the development of several inflammatory diseases, such as arthritis or atherosclerosis, however, its roles in allotransplantation rejection have not been addressed. Here, we found that CDK9/Cyclin T1 were apparently up-regulated in the allogeneic group, which was positively correlated with allograft damage. CDK9 was inhibited obviously in naive splenic CD4+ T cells treated 6 h with 3 μM PHA767491 (a CDK9 inhibitor), and adoptive transfer of these CD4+ T cells into allografted SCID mice resulted in prolonged survival compared with the group without PHA767491 pretreated. Decelerated rejection was correlated with enhanced IL-4 and IL-10 production and with decreased IFN-γ production by alloreactive T cells. More interestingly, we found that CDK942, not CDK955, was high expressed in allorejection group, which could be prominently dampened with PHA767491 treatment. The expression of CDK942 was consistent with its downstream molecule RNA polymerase II. Altogether, our findings revealed the crucial role of CDK9/Cyclin T1/Pol II pathway in promoting allorejection at multiple levels and may provide a new approach for transplantation tolerance induction through targeting CDK9.
Collapse
Affiliation(s)
- Yang Zhan
- Laboratory of Experimental Teratology, Ministry of Education and Institute of Experimental Nuclear Medicine, School of Medicine, Shandong University, Jinan, Shandong, China
| | - Yeming Han
- Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Department of Cardiology, Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Hukui Sun
- Laboratory of Experimental Teratology, Ministry of Education and Institute of Experimental Nuclear Medicine, School of Medicine, Shandong University, Jinan, Shandong, China
| | - Ting Liang
- Laboratory of Experimental Teratology, Ministry of Education and Institute of Experimental Nuclear Medicine, School of Medicine, Shandong University, Jinan, Shandong, China
| | - Chao Zhang
- Laboratory of Experimental Teratology, Ministry of Education and Institute of Experimental Nuclear Medicine, School of Medicine, Shandong University, Jinan, Shandong, China
| | - Jing Song
- Laboratory of Experimental Teratology, Ministry of Education and Institute of Experimental Nuclear Medicine, School of Medicine, Shandong University, Jinan, Shandong, China
| | - Guihua Hou
- Laboratory of Experimental Teratology, Ministry of Education and Institute of Experimental Nuclear Medicine, School of Medicine, Shandong University, Jinan, Shandong, China
| |
Collapse
|
19
|
Lu P, Shen Y, Yang H, Wang Y, Jiang Z, Yang X, Zhong Y, Pan H, Xu J, Lu H, Zhu H. BET inhibitors RVX-208 and PFI-1 reactivate HIV-1 from latency. Sci Rep 2017; 7:16646. [PMID: 29192216 PMCID: PMC5709369 DOI: 10.1038/s41598-017-16816-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 11/16/2017] [Indexed: 02/02/2023] Open
Abstract
Persistent latent reservoir in resting CD4+ T cells is a major obstacle in curing HIV-1 infection. Effective strategies for eradication of the HIV-1 reservoir are urgently needed. We report here for the first time that two BET inhibitors, RVX-208, which has entered phase II clinical trials for diverse cardiovascular disorders, and PFI-1, which has been widely studied in oncology, can reactivate HIV-1 from latency. RVX-208 and PFI-1 treatment alone or in combination with other latency reversing agents efficiently reactivated HIV-1 transcription through an up-regulation of P-TEFb by increasing CDK9 Thr-186 phosphorylation in latently infected Jurkat T cells in vitro. The two BET inhibitors also reactivated HIV-1 transcription in cART treated patient-derived resting CD4+ T cells ex vivo, without influence on global immune cell activation. Our findings, in combination with previous reports, further confirm that BET inhibitors are a group of leading compounds for combating HIV-1 latency for viral eradication.
Collapse
Affiliation(s)
- Panpan Lu
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Yinzhong Shen
- Department of Infectious Diseases, and Key Laboratory of Medical Molecular Virology of Ministry of Education/Health, Shanghai Public Health Clinical Center, Fudan University, Shanghai, 200433, China
| | - He Yang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Yanan Wang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Zhengtao Jiang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Xinyi Yang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Yangcheng Zhong
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Hanyu Pan
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Jianqing Xu
- Department of Infectious Diseases, and Key Laboratory of Medical Molecular Virology of Ministry of Education/Health, Shanghai Public Health Clinical Center, Fudan University, Shanghai, 200433, China
| | - Hongzhou Lu
- Department of Infectious Diseases, and Key Laboratory of Medical Molecular Virology of Ministry of Education/Health, Shanghai Public Health Clinical Center, Fudan University, Shanghai, 200433, China
| | - Huanzhang Zhu
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, 200438, China.
| |
Collapse
|
20
|
Hussain A, Verma CK, Chouhan U. Identification of novel inhibitors against Cyclin Dependent Kinase 9/Cyclin T1 complex as: Anti cancer agent. Saudi J Biol Sci 2017; 24:1229-1242. [PMID: 28855816 PMCID: PMC5562455 DOI: 10.1016/j.sjbs.2015.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 10/05/2015] [Accepted: 10/07/2015] [Indexed: 12/20/2022] Open
Abstract
Cell cycle consists of different types of phases, transition from G1, S, G2, M. Inhibition of associated CDKs like CDK9/Cyclin T1 complex, which are indirectly involved in the Cell cycle progression in the form of transcription elongation, reduces diverse diseases such as Cardiac Hypertrophy, Alzheimer’s, Cancer, AIDS and Inflammation. Glide tool of the Schrodinger software has been used for performing Structure Based Virtual Screening and Docking against Drug Bank and MDPI database. The best hits were identified which go and bind in the active site of the target where ATP binds for the activity. The ADMET, MM-GBSA and DFT analysis is also done for the same. Compound 4-{4-[4-(3-aminopropoxy)phenyl]-1H-pyrazol-5-yl}-6-chlorobenzene-1,3-diol (DB08045) was found to be more potent, novel and selective as an inhibitor. Hopefully compound (DB08045) could be used as an anti-cancer agent for the treatment of life-threatening diseases.
Collapse
Key Words
- ATP, adenosine triphosphate
- CDK
- CDK9, Cyclin Dependent Kinase 9
- CTD, carboxy terminal domain
- Cancer
- Cell cycle
- DFT, density functional theory
- Drug Bank
- HOMO, high occupied molecular orbital
- LUMO, lowest unoccupied molecular orbital
- MDPI
- MDPI, molecular diversity preservation international
- MW, molecular weight
- P-TEFB, positive transcription elongation factor B
- Potent
- SBVS, structure based virtual screening
Collapse
Affiliation(s)
- Afzal Hussain
- Department of Bioinformatics, MANIT, Bhopal, M.P. 462003, India
| | | | - Usha Chouhan
- Department of Bioinformatics, MANIT, Bhopal, M.P. 462003, India
| |
Collapse
|
21
|
Paparidis NFDS, Durvale MC, Canduri F. The emerging picture of CDK9/P-TEFb: more than 20 years of advances since PITALRE. MOLECULAR BIOSYSTEMS 2017; 13:246-276. [PMID: 27833949 DOI: 10.1039/c6mb00387g] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
CDK9 is a prominent member of the transcriptional CDKs subfamily, a group of kinases whose function is to control the primary steps of mRNA synthesis and processing by eukaryotic RNA polymerase II. As a cyclin-dependent kinase, CDK9 activation in vivo depends upon its association with T-type cyclins to assemble the positive transcription elongation factor (P-TEFb). Although CDK9/P-TEFb phosphorylates the C-terminal domain of RNAP II in the same positions targeted by CDK7 (TFIIH) and CDK8 (Mediator), the former does not participate in the transcription initiation, but rather plays a unique role by driving the polymerase to productive elongation. In addition to RNAP II CTD, the negative transcription elongation factors DSIF and NELF also represent major CDK9 substrates, whose phosphorylation is required to overcome the proximal pause of the polymerase. CDK9 is recruited to specific genes through proteins that interact with both P-TEFb and distinct elements in DNA, RNA or chromatin, where it modulates the activity of individual RNAP II transcription complexes. The regulation of CDK9 function is an intricate network that includes post-translational modifications (phosphorylation/dephosphorylation and acetylation/deacetylation of key residues) as well as the association of P-TEFb with various proteins that can stimulate or inhibit its kinase activity. Several cases of CDK9 deregulation have been linked to important human diseases, including various types of cancer and also AIDS (due to its essential role in HIV replication). Not only HIV, but also many other human viruses have been shown to depend strongly on CDK9 activity to be transcribed within host cells. This review summarizes the main advances made on CDK9/P-TEFb field in more than 20 years, introducing the structural, functional and genetic aspects that have been elucidated ever since.
Collapse
Affiliation(s)
- Nikolas Ferreira Dos Santos Paparidis
- Department of Chemistry and Molecular Physics, Institute of Chemistry of Sao Carlos, Sao Paulo University, Av. Trabalhador Sãocarlense, 400, Zip Code 780, 13560-970, São Carlos-SP, Brazil.
| | - Maxwell Castro Durvale
- Department of Biochemistry, Institute of Chemistry, Sao Paulo University, Av. Prof. Lineu Prestes, 748, 05508-000, Butantã - São Paulo - SP, Brazil
| | - Fernanda Canduri
- Department of Chemistry and Molecular Physics, Institute of Chemistry of Sao Carlos, Sao Paulo University, Av. Trabalhador Sãocarlense, 400, Zip Code 780, 13560-970, São Carlos-SP, Brazil.
| |
Collapse
|
22
|
Abstract
CDK9 is a protein in constant development in cancer therapy. Herein we present an overview of the enzyme as a target for cancer therapy. We provide data on its characteristics and mechanism of action. In recent years, CDK9 inhibitors that have been designed with molecular modeling have demonstrated good antitumoral activity in vitro. Clinical studies of the drugs flavopiridol, dinaciclib, seliciclib, SNS-032 and RGB-286638 used as CDK9 inhibitors are also reviewed, with their additional targets and their relative IC50 values. Unfortunately, treatment with these drugs remains unsuccessful and involves many adverse effects. We could conclude that there are many small molecules that bind to CDK9, but their lack of selectivity against other CDKs do not allow them to get to the clinical use. However, drug designers currently have the tools needed to improve the selectivity of CDK9 inhibitors and to make successful treatment available to patients.
Collapse
Affiliation(s)
- Fatima Morales
- a Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University , Philadelphia , PA , USA
| | - Antonio Giordano
- a Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University , Philadelphia , PA , USA.,b Department of Medicine , Surgery and Neuroscience, University of Siena , Siena , Italy
| |
Collapse
|
23
|
Rahaman MH, Kumarasiri M, Mekonnen LB, Yu M, Diab S, Albrecht H, Milne RW, Wang S. Targeting CDK9: a promising therapeutic opportunity in prostate cancer. Endocr Relat Cancer 2016; 23:T211-T226. [PMID: 27582311 DOI: 10.1530/erc-16-0299] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 08/31/2016] [Indexed: 12/18/2022]
Abstract
Cyclin-dependent kinase 9 (CDK9) is a key transcriptional regulator and a lucrative target for cancer treatment. Targeting CDK9 can effectively confine the hyperactivity of androgen receptor and the constitutive expression of anti-apoptotic proteins; both being main causes of prostate cancer (PCa) development and progression. In castrate-resistant PCa, traditional therapies that only target androgen receptor (AR) have become obsolete due to reprograming in AR activity to make the cells independent of androgen. CDK9 inhibitors may provide a new and better therapeutic opportunity over traditional treatment options by targeting both androgen receptor activity and anti-apoptotic proteins, improving the chances of positive outcomes, especially in patients with the advanced disease. This review focuses on biological functions of CDK9, its involvement with AR and the potential for therapeutic opportunities in PCa treatment.
Collapse
Affiliation(s)
| | | | - Laychiluh B Mekonnen
- Centre for Drug Discovery and DevelopmentSansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Mingfeng Yu
- Centre for Drug Discovery and DevelopmentSansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sarah Diab
- Centre for Drug Discovery and DevelopmentSansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Hugo Albrecht
- Centre for Drug Discovery and DevelopmentSansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Robert W Milne
- Centre for Drug Discovery and DevelopmentSansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Shudong Wang
- Centre for Drug Discovery and DevelopmentSansom Institute for Health Research and School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| |
Collapse
|
24
|
An evolutionary conserved Hexim1 peptide binds to the Cdk9 catalytic site to inhibit P-TEFb. Proc Natl Acad Sci U S A 2016; 113:12721-12726. [PMID: 27791144 DOI: 10.1073/pnas.1612331113] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The positive transcription elongation factor (P-TEFb) is required for the transcription of most genes by RNA polymerase II. Hexim proteins associated with 7SK RNA bind to P-TEFb and reversibly inhibit its activity. P-TEFb comprises the Cdk9 cyclin-dependent kinase and a cyclin T. Hexim proteins have been shown to bind the cyclin T subunit of P-TEFb. How this binding leads to inhibition of the kinase activity of Cdk9 has remained elusive, however. Using a photoreactive amino acid incorporated into proteins, we show that in live cells, cell extracts, and in vitro reconstituted complexes, Hexim1 cross-links and thus contacts Cdk9. Notably, replacement of a phenylalanine, F208, belonging to an evolutionary conserved Hexim1 peptide (202PYNTTQFLM210) known as the "PYNT" sequence, cross-links a peptide within the activation segment that controls access to the Cdk9 catalytic cleft. Reciprocally, Hexim1 is cross-linked by a photoreactive amino acid replacing Cdk9 W193, a tryptophan within this activation segment. These findings provide evidence of a direct interaction between Cdk9 and its inhibitor, Hexim1. Based on similarities with Cdk2 3D structure, the Cdk9 peptide cross-linked by Hexim1 corresponds to the substrate binding-site. Accordingly, the Hexim1 PYNT sequence is proposed to interfere with substrate binding to Cdk9 and thereby to inhibit its kinase activity.
Collapse
|
25
|
Oqani RK, Lin T, Lee JE, Kim SY, Sa SJ, Woo JS, Jin DI. Inhibition of P-TEFb disrupts global transcription, oocyte maturation, and embryo development in the mouse. Genesis 2016; 54:470-82. [PMID: 27488304 DOI: 10.1002/dvg.22961] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/30/2016] [Accepted: 08/01/2016] [Indexed: 11/11/2022]
Abstract
Positive transcription elongation factor b (P-TEFb) is an RNA polymerase II kinase that phosphorylates Ser2 of the carboxyl-terminal domain and promotes the elongation phase of transcription. Despite the fact that P-TEFb has role in many cellular processes, the role of this kinase complex remains to be understood in early developmental events. In this study, using immunocytochemical analyses, we find that the P-TEFb components, Cyclin T1, CDK9, and its T-loop phosphorylated form, are localized to nuclear speckles, as well as in nucleoli in mouse germinal vesicle oocytes. Moreover, using fluorescence in situ hybridization, we show that in absence of CDK9 activity, nucleolar integration, as well as production of 28S rRNA is impaired in oocytes and embryos. We also present evidence indicating that P-TEFb kinase activity is essential for completion of mouse oocyte maturation and embryo development. Treatment with CDK9 inhibitor, flavopiridol resulted in metaphase I arrest in maturing oocytes. Inhibition of CDK9 kinase activity did not interfere with in vitro fertilization and pronuclear formation. However, when zygotes or 2-cell embryos were treated with flavopiridol only in their G2 phase of the cell cycle, development to the blastocyst stage was impaired. Inhibition of the CDK9 activity after embryonic genome activation resulted in failure to form normal blastocysts and aberrant phosphorylation of RNA polymerase II CTD. In all stages analyzed, treatment with flavopiridol abrogated global transcriptional activity. Collectively, our data suggest that P-TEFb kinase activity is crucial for oocyte maturation, embryo development, and regulation of global RNA transcription in mouse early development.
Collapse
Affiliation(s)
- Reza K Oqani
- Department of Animal Science and Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Tao Lin
- Department of Animal Science and Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Jae Eun Lee
- Department of Animal Science and Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - So Yeon Kim
- Department of Animal Science and Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Soo Jin Sa
- Department of Animal Resource Development, National Institute of Animal Science, Cheonan, 31001, Korea
| | - Je Seok Woo
- Department of Animal Resource Development, National Institute of Animal Science, Cheonan, 31001, Korea
| | - Dong Il Jin
- Department of Animal Science and Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University, Daejeon, 34134, Republic of Korea.
| |
Collapse
|
26
|
Zaborowska J, Isa NF, Murphy S. P-TEFb goes viral. Bioessays 2016; 38 Suppl 1:S75-85. [DOI: 10.1002/bies.201670912] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 09/23/2015] [Accepted: 09/26/2015] [Indexed: 01/31/2023]
Affiliation(s)
| | - Nur F. Isa
- Sir William Dunn School of Pathology; University of Oxford; Oxford UK
- Department of Biotechnology; Kulliyyah of Science, IIUM; Kuantan Pahang Malaysia
| | - Shona Murphy
- Sir William Dunn School of Pathology; University of Oxford; Oxford UK
| |
Collapse
|
27
|
Jamaluddin MS, Hu PW, Jan Y, Siwak EB, Rice AP. Short Communication: The Broad-Spectrum Histone Deacetylase Inhibitors Vorinostat and Panobinostat Activate Latent HIV in CD4(+) T Cells In Part Through Phosphorylation of the T-Loop of the CDK9 Subunit of P-TEFb. AIDS Res Hum Retroviruses 2016; 32:169-73. [PMID: 26727990 DOI: 10.1089/aid.2015.0347] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Cessation of highly active antiretroviral therapy (HAART) in HIV-infected individual leads to a rebound of viral replication due to reactivation of a viral reservoir composed largely of latently infected memory CD4(+) T cells. Efforts to deplete this reservoir have focused on reactivation of transcriptionally silent latent proviruses. HIV provirus transcription depends critically on the positive transcription elongation factor b (P-TEFb), whose core components are cyclin-dependent kinase 9 (CDK9) and cyclin T1. In resting CD4(+) cells, the functional levels of P-TEFb are extremely low. Cellular activation upregulates cyclin T1 protein levels and CDK9 T-loop (T186) phosphorylation. The broad-spectrum histone deacetylase inhibitors (HDACis) vorinostat and panobinostat have been shown to reactivate latent virus in vivo in HAART-treated individuals. In this study, we have found that vorinostat and panobinostat activate P-TEFb in resting primary CD4(+) T cells through induction of CDK9 T-loop phosphorylation. In contrast, tacedinaline and romidepsin, HDAC 1 and 2 inhibitors, were unable to activate CDK9 T-loop phosphorylation. We used a CCL19 primary CD4(+) T-cell model HIV latency to assess the correlation between induction of CDK9 T-loop phosphorylation and reactivation of latent HIV virus by HDACis. Vorinostat and panobinostat treatment of cells harboring latent HIV increased CDK9 T-loop phosphorylation and reactivation of latent virus, whereas tacedinaline and romidepsin failed to induce T-loop phosphorylation or reactivate latent virus. We conclude that the ability of vorinostat and panobinostat to induce latent HIV is, in part, likely due to the ability of the broad-spectrum HDACis to upregulate P-TEFb through increased CDK9 T-loop phosphorylation.
Collapse
Affiliation(s)
- Md Saha Jamaluddin
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| | - Pei-Wen Hu
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| | - Yih Jan
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| | - Edward B. Siwak
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| | - Andrew P. Rice
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| |
Collapse
|
28
|
Yeh YY, Chen R, Hessler J, Mahoney E, Lehman AM, Heerema NA, Grever MR, Plunkett W, Byrd JC, Johnson AJ. Up-regulation of CDK9 kinase activity and Mcl-1 stability contributes to the acquired resistance to cyclin-dependent kinase inhibitors in leukemia. Oncotarget 2015; 6:2667-79. [PMID: 25596730 PMCID: PMC4413609 DOI: 10.18632/oncotarget.2096] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 06/11/2014] [Indexed: 11/25/2022] Open
Abstract
Flavopiridol is a small molecule inhibitor of cyclin-dependent kinases (CDK) known to impair global transcription via inactivation of positive transcription elongation factor b. It has been demonstrated to have significant activity predominantly in chronic lymphocytic leukemia and acute myeloid leukemia in phase I/II clinical trials while other similar CDK inhibitors are vigorously being pursued in pre-clinical and clinical studies. Although flavopiridol is a potent therapeutic agent against blood diseases, some patients still have primary or acquired resistance throughout their clinical course. Considering the limited knowledge of resistance mechanisms of flavopiridol, we investigated the potential mechanisms of resistance to flavopiridol in a cell line system, which gradually acquired resistance to flavopiridol in vitro, and then confirmed the mechanism in patient samples. Herein, we present that this resistant cell line developed resistance through up-regulation of phosphorylation of RNA polymerase II C-terminal domain, activation of CDK9 kinase activity, and prolonged Mcl-1 stability to counter flavopiridol's drug actions. Further analyses suggest MAPK/ERK activation-mediated Mcl-1 stabilization contributes to the resistance and knockdown of Mcl-1 in part restores sensitivity to flavopiridol-induced cytotoxicity. Altogether, these findings demonstrate that CDK9 is the most relevant target of flavopiridol and provide avenues to improve the therapeutic strategies in blood malignancies.
Collapse
Affiliation(s)
- Yuh-Ying Yeh
- Division of Hematology, Department of Internal Medicine, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA
| | - Rong Chen
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Joshua Hessler
- Division of Hematology, Department of Internal Medicine, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA
| | - Emilia Mahoney
- Division of Hematology, Department of Internal Medicine, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA
| | - Amy M Lehman
- Center for Biostatistics, The Ohio State University, Columbus, Ohio, USA
| | - Nyla A Heerema
- Department of Pathology, The Ohio State University, Columbus, Ohio, USA
| | - Michael R Grever
- Division of Hematology, Department of Internal Medicine, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA
| | - William Plunkett
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - John C Byrd
- Division of Hematology, Department of Internal Medicine, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA.,Division of Medicinal Chemistry, College of Pharmacy, The Ohio State University, Columbus, Ohio, USA
| | - Amy J Johnson
- Division of Hematology, Department of Internal Medicine, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA.,Division of Medicinal Chemistry, College of Pharmacy, The Ohio State University, Columbus, Ohio, USA
| |
Collapse
|
29
|
Zaborowska J, Isa NF, Murphy S. P-TEFb goes viral. ACTA ACUST UNITED AC 2015; 1:106-116. [PMID: 27398404 PMCID: PMC4863834 DOI: 10.1002/icl3.1037] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 09/23/2015] [Accepted: 09/26/2015] [Indexed: 01/30/2023]
Abstract
Positive transcription elongation factor b (P‐TEFb), which comprises cyclin‐dependent kinase 9 (CDK9) kinase and cyclin T subunits, is an essential kinase complex in human cells. Phosphorylation of the negative elongation factors by P‐TEFb is required for productive elongation of transcription of protein‐coding genes by RNA polymerase II (pol II). In addition, P‐TEFb‐mediated phosphorylation of the carboxyl‐terminal domain (CTD) of the largest subunit of pol II mediates the recruitment of transcription and RNA processing factors during the transcription cycle. CDK9 also phosphorylates p53, a tumor suppressor that plays a central role in cellular responses to a range of stress factors. Many viral factors affect transcription by recruiting or modulating the activity of CDK9. In this review, we will focus on how the function of CDK9 is regulated by viral gene products. The central role of CDK9 in viral life cycles suggests that drugs targeting the interaction between viral products and P‐TEFb could be effective anti‐viral agents.
Collapse
Affiliation(s)
| | - Nur F Isa
- Sir William Dunn School of Pathology University of Oxford Oxford UK; Department of Biotechnology Kulliyyah of Science, IIUM Kuantan Pahang Malaysia
| | - Shona Murphy
- Sir William Dunn School of Pathology University of Oxford Oxford UK
| |
Collapse
|
30
|
Zhang Y, Huang Z, Zhu Z, Liu J, Zheng X, Zhang Y. Network analysis of ChIP-Seq data reveals key genes in prostate cancer. Eur J Med Res 2014; 19:47. [PMID: 25183411 PMCID: PMC4171560 DOI: 10.1186/s40001-014-0047-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 08/08/2014] [Indexed: 11/10/2022] Open
Abstract
Background Prostate cancer (PC) is the second most common cancer among men in the United States, and it imposes a considerable threat to human health. A deep understanding of its underlying molecular mechanisms is the premise for developing effective targeted therapies. Recently, deep transcriptional sequencing has been used as an effective genomic assay to obtain insights into diseases and may be helpful in the study of PC. Methods In present study, ChIP-Seq data for PC and normal samples were compared, and differential peaks identified, based upon fold changes (with P-values calculated with t-tests). Annotations of these peaks were performed. Protein–protein interaction (PPI) network analysis was performed with BioGRID and constructed with Cytoscape, following which the highly connected genes were screened. Results We obtained a total of 5,570 differential peaks, including 3,726 differentially enriched peaks in tumor samples and 1,844 differentially enriched peaks in normal samples. There were eight significant regions of the peaks. The intergenic region possessed the highest score (51%), followed by intronic (31%) and exonic (11%) regions. The analysis revealed the top 35 highly connected genes, which comprised 33 differential genes (such as YWHAQ, tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein and θ polypeptide) from ChIP-Seq data and 2 differential genes retrieved from the PPI network: UBA52 (ubiquitin A-52 residue ribosomal protein fusion product 1) and SUMO2 (SMT3 suppressor of mif two 3 homolog 2) . Conclusions Our findings regarding potential PC-related genes increase the understanding of PC and provides direction for future research. Electronic supplementary material The online version of this article (doi:10.1186/s40001-014-0047-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Yu Zhang
- Department of Urology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
| | | | | | | | | | | |
Collapse
|
31
|
Burlein C, Bahnck C, Bhatt T, Murphy D, Lemaire P, Carroll S, Miller MD, Lai MT. Development of a sensitive amplified luminescent proximity homogeneous assay to monitor the interactions between pTEFb and Tat. Anal Biochem 2014; 465:164-71. [PMID: 25132562 DOI: 10.1016/j.ab.2014.08.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 08/03/2014] [Accepted: 08/06/2014] [Indexed: 12/31/2022]
Abstract
The viral transactivator protein (Tat) plays an essential role in the replication of human immunodeficiency type 1 virus (HIV-1) by recruiting the host positive transcription elongation factor (pTEFb) to the RNA polymerase II transcription machinery to enable an efficient HIV-1 RNA elongation process. Blockade of the interaction between Tat and pTEFb represents a novel strategy for developing a new class of antiviral agents. In this study, we developed a homogeneous assay in AlphaLISA (amplified luminescent proximity homogeneous assay) format using His-tagged pTEFb and biotinylated Tat to monitor the interaction between Tat and pTEFb. On optimizing the assay conditions, the signal-to-background ratio was found to be greater than 10-fold. The assay was validated with untagged Tat and peptides known to compete with Tat for pTEFb binding. The Z' of the assay is greater than 0.5, indicating that the assay is robust and can be easily adapted to a high-throughput screening format. Furthermore, the affinity between Tat and pTEFb was determined to be approximately 20 pM, and only 7% of purified Tat was found to be active in forming tertiary complex with pTEFb. Development of this assay should facilitate the discovery of a new class of antiviral agents providing HIV-1 patients with broader treatment choices.
Collapse
Affiliation(s)
- Christine Burlein
- Department of In Vitro Pharmacology, Merck Research Laboratories, West Point, PA 19486, USA
| | - Carolyn Bahnck
- Department of In Vitro Pharmacology, Merck Research Laboratories, West Point, PA 19486, USA
| | - Triveni Bhatt
- Department of In Vitro Pharmacology, Merck Research Laboratories, West Point, PA 19486, USA
| | - Dennis Murphy
- Department of In Vitro Pharmacology, Merck Research Laboratories, West Point, PA 19486, USA
| | - Peter Lemaire
- Department of In Vitro Pharmacology, Merck Research Laboratories, West Point, PA 19486, USA
| | - Steve Carroll
- Department of In Vitro Pharmacology, Merck Research Laboratories, West Point, PA 19486, USA
| | - Michael D Miller
- Antiviral Research, Merck Research Laboratories, West Point, PA 19486, USA
| | - Ming-Tain Lai
- Antiviral Research, Merck Research Laboratories, West Point, PA 19486, USA.
| |
Collapse
|
32
|
In silico design of small molecule inhibitors of CDK9/cyclin T1 interaction. J Mol Graph Model 2014; 50:100-12. [PMID: 24769691 DOI: 10.1016/j.jmgm.2014.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 04/02/2014] [Accepted: 04/03/2014] [Indexed: 11/23/2022]
Abstract
In order to design a small molecule which potentially may interfere with CDK9/cyclin T1 complex formation and therefore influence its physiological role, a computational study of dynamics and druggability of CDK9 binding surface was conducted. Druggability estimates and pocket opening analyses indicated binding regions of cyclin T1 residues, Phe 146 and Lys 6, as starting points for the design of small molecules with the potential to inhibit the CDK9/cyclin T1 association. A pharmacophore model was created, based on these two residues and used to select potential inhibitor structures. Binding energies of the inhibitors were estimated with MM-GBSA. A good correlation of MM-GBSA energies and FTMap druggability predictions was observed. Amongst studied compounds a derivative of 2-amino-8-hydroxyquinoline was identified as the best potential candidate to inhibit CDK9/cyclin T1 interactions.
Collapse
|
33
|
Brd4 and HEXIM1: multiple roles in P-TEFb regulation and cancer. BIOMED RESEARCH INTERNATIONAL 2014; 2014:232870. [PMID: 24592384 PMCID: PMC3925632 DOI: 10.1155/2014/232870] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 12/19/2013] [Indexed: 12/31/2022]
Abstract
Bromodomain-containing protein 4 (Brd4) and hexamethylene bisacetamide (HMBA) inducible protein 1 (HEXIM1) are two opposing regulators of the positive transcription elongation factor b (P-TEFb), which is the master modulator of RNA polymerase II during transcriptional elongation. While Brd4 recruits P-TEFb to promoter-proximal chromatins to activate transcription, HEXIM1 sequesters P-TEFb into an inactive complex containing the 7SK small nuclear RNA. Besides regulating P-TEFb's transcriptional activity, recent evidence demonstrates that both Brd4 and HEXIM1 also play novel roles in cell cycle progression and tumorigenesis. Here we will discuss the current knowledge on Brd4 and HEXIM1 and their implication as novel therapeutic options against cancer.
Collapse
|
34
|
Corden JL. RNA polymerase II C-terminal domain: Tethering transcription to transcript and template. Chem Rev 2013; 113:8423-55. [PMID: 24040939 PMCID: PMC3988834 DOI: 10.1021/cr400158h] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jeffry L Corden
- Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine , 725 North Wolfe Street, Baltimore Maryland 21205, United States
| |
Collapse
|
35
|
Novis CL, Archin NM, Buzon MJ, Verdin E, Round JL, Lichterfeld M, Margolis DM, Planelles V, Bosque A. Reactivation of latent HIV-1 in central memory CD4⁺ T cells through TLR-1/2 stimulation. Retrovirology 2013; 10:119. [PMID: 24156240 PMCID: PMC3826617 DOI: 10.1186/1742-4690-10-119] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 10/10/2013] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Toll-like receptors (TLRs) are crucial for recognition of pathogen-associated molecular patterns by cells of the innate immune system. TLRs are present and functional in CD4⁺ T cells. Memory CD4⁺ T cells, predominantly central memory cells (TCM), constitute the main reservoir of latent HIV-1. However, how TLR ligands affect the quiescence of latent HIV within central memory CD4⁺ T cells has not been studied. RESULTS We evaluated the ability of a broad panel of TLR agonists to reactivate latent HIV-1. The TLR-1/2 agonist Pam3CSK4 leads to viral reactivation of quiescent HIV in a model of latency based on cultured TCM and in resting CD4⁺ T cells isolated from aviremic patients. In addition, we investigated the signaling pathway associated with Pam3CSK4 involved in HIV-1 reactivation. We show that the transcription factors NFκB, NFAT and AP-1 cooperate to induce viral reactivation downstream of TLR-1/2 stimulation. Furthermore, increasing levels of cyclin T1 is not required for TLR-mediated viral reactivation, but induction of viral expression requires activated pTEFb. Finally, Pam3CSK4 reactivates latent HIV-1 in the absence of T cell activation or proliferation, in contrast to antigen stimulation. CONCLUSIONS Our findings suggest that the signaling through TLR-1/2 pathway via Pam3CSK4 or other reagents should be explored as an anti-latency strategy either alone or in combination with other anti-latency drugs.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Alberto Bosque
- Division of Microbiology and Immunology, Department of Pathology, University Of Utah School of Medicine, Emma Eccles Jones Medical Research Building, Salt Lake City, UT 84112, USA.
| |
Collapse
|
36
|
Lu H, Li Z, Xue Y, Zhou Q. Viral-host interactions that control HIV-1 transcriptional elongation. Chem Rev 2013; 113:8567-82. [PMID: 23795863 DOI: 10.1021/cr400120z] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Huasong Lu
- School of Pharmaceutical Sciences, Xiamen University , Xiamen, Fujian 361005, China
| | | | | | | |
Collapse
|
37
|
Deregulations in the cyclin-dependent kinase-9-related pathway in cancer: implications for drug discovery and development. ISRN ONCOLOGY 2013; 2013:305371. [PMID: 23840966 PMCID: PMC3690251 DOI: 10.1155/2013/305371] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 05/19/2013] [Indexed: 12/21/2022]
Abstract
The CDK9-related pathway is an important regulator of mammalian cell biology and is also involved in the replication cycle of several viruses, including the human immunodeficiency virus type 1. CDK9 is present in two isoforms termed CDK9-42 and CDK9-55 that bind noncovalently type T cyclins and cyclin K. This association forms a heterodimer, where CDK9 carries the enzymatic site and the cyclin partner functions as a regulatory subunit. This heterodimer is the main component of the positive transcription elongation factor b, which stabilizes RNA elongation via phosphorylation of the RNA pol II carboxyl terminal domain. Abnormal activities in the CDK9-related pathway were observed in human malignancies and cardiac hypertrophies. Thus, the elucidation of the CDK9 pathway deregulations may provide useful insights into the pathogenesis and progression of human malignancies, cardiac hypertrophy, AIDS and other viral-related maladies. These studies may lead to the improvement of kinase inhibitors for the treatment of the previously mentioned pathological conditions. This review describes the CDK9-related pathway deregulations in malignancies and the development of kinase inhibitors in cancer therapy, which can be classified into three categories: antagonists that block the ATP binding site of the catalytic domain, allosteric inhibitors, and small molecules that disrupt protein-protein interactions.
Collapse
|
38
|
Burger K, Mühl B, Rohrmoser M, Coordes B, Heidemann M, Kellner M, Gruber-Eber A, Heissmeyer V, Strässer K, Eick D. Cyclin-dependent kinase 9 links RNA polymerase II transcription to processing of ribosomal RNA. J Biol Chem 2013; 288:21173-21183. [PMID: 23744076 DOI: 10.1074/jbc.m113.483719] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ribosome biogenesis is a process required for cellular growth and proliferation. Processing of ribosomal RNA (rRNA) is highly sensitive to flavopiridol, a specific inhibitor of cyclin-dependent kinase 9 (Cdk9). Cdk9 has been characterized as the catalytic subunit of the positive transcription elongation factor b (P-TEFb) of RNA polymerase II (RNAPII). Here we studied the connection between RNAPII transcription and rRNA processing. We show that inhibition of RNAPII activity by α-amanitin specifically blocks processing of rRNA. The block is characterized by accumulation of 3' extended unprocessed 47 S rRNAs and the entire inhibition of other 47 S rRNA-specific processing steps. The transcription rate of rRNA is moderately reduced after inhibition of Cdk9, suggesting that defective 3' processing of rRNA negatively feeds back on RNAPI transcription. Knockdown of Cdk9 caused a strong reduction of the levels of RNAPII-transcribed U8 small nucleolar RNA, which is essential for 3' rRNA processing in mammalian cells. Our data demonstrate a pivotal role of Cdk9 activity for coupling of RNAPII transcription with small nucleolar RNA production and rRNA processing.
Collapse
Affiliation(s)
- Kaspar Burger
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Bastian Mühl
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Michaela Rohrmoser
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Britta Coordes
- Gene Center and Department of Biochemistry, Center for Integrated Protein Science Munich, Ludwig Maximilians University of Munich, Feodor-Lynen-Strasse 25, 81377 Munich, Germany, and
| | - Martin Heidemann
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Markus Kellner
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Anita Gruber-Eber
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Vigo Heissmeyer
- Institute of Molecular Immunology, Helmholtz Center Munich, Marchioninistrasse 25, 81377 Munich, Germany
| | - Katja Strässer
- Gene Center and Department of Biochemistry, Center for Integrated Protein Science Munich, Ludwig Maximilians University of Munich, Feodor-Lynen-Strasse 25, 81377 Munich, Germany, and
| | - Dirk Eick
- From the Department of Molecular Epigenetics, Helmholtz Center Munich, Center for Integrated Protein Science Munich, Marchioninistrasse 25, 81377 Munich, Germany,.
| |
Collapse
|
39
|
Gao G, Wu X, Zhou J, He M, He JJ, Guo D. Inhibition of HIV-1 transcription and replication by a newly identified cyclin T1 splice variant. J Biol Chem 2013; 288:14297-14309. [PMID: 23569210 DOI: 10.1074/jbc.m112.438465] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A variety of cellular factors participates in the HIV-1 life cycle. Among them is the well characterized cyclin T1 (CYCT1). CycT1 binds to cyclin-dependent kinase 9 (CDK9) and forms the positive transcription elongation factor-b (P-TEFb). P-TEFb is then recruited by HIV-1 TAT to the HIV-1 long terminal repeat (LTR) promoter and subsequently leads to phosphorylation of the C-terminal domain of RNA polymerase II (pol II), enhanced processivity of pol II, and transcription of a full-length HIV-1 RNA. In this study, we report the identification of a new CYCT1 splice variant, designated as CYCT1b, and accordingly we renamed CYCT1 as CYCT1a. CYCT1b was detected in several cell lines, including primary human CD4 T cells, and its expression was subject to cell cycle regulation. Similar to CYCT1a, CYCT1b was primarily localized in the nucleus. CYCT1b expression was found to be inversely correlated with HIV-1 gene expression and replication. This inverse correlation appeared to involve TAT transactivation, CDK9 binding, and subsequent recruitment of P-TEFb to the HIV-1 LTR promoter and pol II C-terminal domain phosphorylation. In agreement with these findings, CYCT1b expression led to direct inhibition of TAT-transactivated transcription of the HIV-1 LTR promoter. Taken together, these results show that the newly identified CYCT1b splice variant inhibits HIV-1 transcription and may provide new clues for the development of anti-HIV strategies.
Collapse
Affiliation(s)
- Guozhen Gao
- State Key Laboratory of Virology and Modern Virology Research Center, Wuhan University College of Life Sciences, 430072 Wuhan, China; Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Xiaoyun Wu
- State Key Laboratory of Virology and Modern Virology Research Center, Wuhan University College of Life Sciences, 430072 Wuhan, China
| | - Jieqiong Zhou
- State Key Laboratory of Virology and Modern Virology Research Center, Wuhan University College of Life Sciences, 430072 Wuhan, China
| | - Mingfeng He
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Johnny J He
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana 46202; Center for AIDS Research, Indiana University School of Medicine, Indianapolis, Indiana 46202; University of North Texas Health Science Center, Fort Worth, Texas 76107.
| | - Deyin Guo
- State Key Laboratory of Virology and Modern Virology Research Center, Wuhan University College of Life Sciences, 430072 Wuhan, China; Institute of Medical Virology, Wuhan University School of Medicine, 430071 Wuhan, China.
| |
Collapse
|
40
|
Abstract
The cell cycle of eukaryotic cells varies greatly from species to species and tissue to tissue. Since an erroneous control of the cell cycle can have disastrous consequences for cellular life, there are genetically programmed signals, so-called cell cycle checkpoints, which ensure that all events of each stage are completed before beginning the next phase. Among the numerous molecules involved in this process, the most important are the cyclin-dependent kinases (CDKs), proteins that are activated only when bound to cyclins (regulatory proteins with fluctuating concentrations). In general, more CDKs are overexpressed in cancer cells than in normal cells, which explains why cancer cells divide uncontrollably. Succeeding in modulating CDK activity with pharmacological agents could result in decreasing the abnormal proliferation rate of cancer cells. This review offers an overview of CDK-cyclin complexes in relation to different cell cycle phases, an analysis of CDK activation and inhibition of molecular mechanisms, and an extensive report, including clinical trials, regarding four new drugs acting as CDK modulators: alvocidib, P276-00, SNS-032 and seliciclib.
Collapse
|
41
|
Abstract
The cell cycle of eukaryotic cells varies greatly from species to species and tissue to tissue. Since an erroneous control of the cell cycle can have disastrous consequences for cellular life, there are genetically programmed signals, so-called cell cycle checkpoints, which ensure that all events of each stage are completed before beginning the next phase. Among the numerous molecules involved in this process, the most important are the cyclin-dependent kinases (CDKs), proteins that are activated only when bound to cyclins (regulatory proteins with fluctuating concentrations). In general, more CDKs are overexpressed in cancer cells than in normal cells, which explains why cancer cells divide uncontrollably. Succeeding in modulating CDK activity with pharmacological agents could result in decreasing the abnormal proliferation rate of cancer cells. This review offers an overview of CDK-cyclin complexes in relation to different cell cycle phases, an analysis of CDK activation and inhibition of molecular mechanisms, and an extensive report, including clinical trials, regarding four new drugs acting as CDK modulators: alvocidib, P276-00, SNS-032 and seliciclib.
Collapse
|
42
|
Marchesi I, Nieddu V, Caracciolo V, Maioli M, Gaspa L, Giordano A, Bagella L. Activation and function of murine Cyclin T2A and Cyclin T2B during skeletal muscle differentiation. J Cell Biochem 2013; 114:728-34. [DOI: 10.1002/jcb.24414] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 09/28/2012] [Indexed: 12/14/2022]
|
43
|
Ramakrishnan R, Liu H, Donahue H, Malovannaya A, Qin J, Rice AP. Identification of novel CDK9 and Cyclin T1-associated protein complexes (CCAPs) whose siRNA depletion enhances HIV-1 Tat function. Retrovirology 2012; 9:90. [PMID: 23110726 PMCID: PMC3494656 DOI: 10.1186/1742-4690-9-90] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 10/05/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND HIV-1 Tat activates RNA Polymerase II (RNAP II) elongation of the integrated provirus by recruiting a protein kinase known as P-TEFb to TAR RNA at the 5' end of nascent viral transcripts. The catalytic core of P-TEFb contains CDK9 and Cyclin T1 (CCNT1). A human endogenous complexome has recently been described - the set of multi-protein complexes in HeLa cell nuclei. We mined this complexome data set and identified 12 distinct multi-protein complexes that contain both CDK9 and CCNT1. We have termed these complexes CCAPs for CDK9/CCNT1-associated protein complexes. Nine CCAPs are novel, while three were previously identified as Core P-TEFb, the 7SK snRNP, and the Super-Elongation Complex. We have investigated the role of five newly identified CCAPs in Tat function and viral gene expression. RESULTS We examined five CCAPs that contain: 1) PPP1R10/TOX3/WDR82; 2) TTF2; 3) TPR; 4) WRNIP1; 5) FBXO11/CUL1/SKP1. SiRNA depletions of protein subunits of the five CCAPs enhanced Tat activation of an integrated HIV-1 LTR-Luciferase reporter in TZM-bl cells. Using plasmid transfection assays in HeLa cells, we also found that siRNA depletions of TTF2, FBXO11, PPP1R10, WDR82, and TOX3 enhanced Tat activation of an HIV-1 LTR-luciferase reporter, but the depletions did not enhance expression of an NF-κB reporter plasmid with the exception of PPP1R10. We found no evidence that depletion of CCAPs perturbed the level of CDK9/CCNT1 in the 7SK snRNP. We also found that the combination of siRNA depletions of both TTF2 and FBXO11 sensitized a latent provirus in Jurkat cells to reactivation by sub-optimal amounts of αCD3/CD28 antibodies. CONCLUSIONS Our results identified five novel CDK9/CCNT1 complexes that are capable of negative regulation of HIV-1 Tat function and viral gene expression. Because siRNA depletions of CCAPs enhance Tat function, it is possible that these complexes reduce the level of CDK9 and CCNT1 available for Tat, similar to the negative regulation of Tat by the 7SK snRNP. Our results highlight the complexity in the biological functions of CDK9 and CCNT1.
Collapse
Affiliation(s)
- Rajesh Ramakrishnan
- Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | | | | | | | | | | |
Collapse
|
44
|
Interaction of cyclin-dependent kinase 12/CrkRS with cyclin K1 is required for the phosphorylation of the C-terminal domain of RNA polymerase II. Mol Cell Biol 2012; 32:4691-704. [PMID: 22988298 DOI: 10.1128/mcb.06267-11] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CrkRS (Cdc2-related kinase, Arg/Ser), or cyclin-dependent kinase 12 (CKD12), is a serine/threonine kinase believed to coordinate transcription and RNA splicing. While CDK12/CrkRS complexes were known to phosphorylate the C-terminal domain (CTD) of RNA polymerase II (RNA Pol II), the cyclin regulating this activity was not known. Using immunoprecipitation and mass spectrometry, we identified a 65-kDa isoform of cyclin K (cyclin K1) in endogenous CDK12/CrkRS protein complexes. We show that cyclin K1 complexes isolated from mammalian cells contain CDK12/CrkRS but do not contain CDK9, a presumed partner of cyclin K. Analysis of extensive RNA-Seq data shows that the 65-kDa cyclin K1 isoform is the predominantly expressed form across numerous tissue types. We also demonstrate that CDK12/CrkRS is dependent on cyclin K1 for its kinase activity and that small interfering RNA (siRNA) knockdown of CDK12/CrkRS or cyclin K1 has similar effects on the expression of a luciferase reporter gene. Our data suggest that cyclin K1 is the primary cyclin partner for CDK12/CrkRS and that cyclin K1 is required to activate CDK12/CrkRS to phosphorylate the CTD of RNA Pol II. These properties are consistent with a role of CDK12/CrkRS in regulating gene expression through phosphorylation of RNA Pol II.
Collapse
|
45
|
Phosphatase PPM1A negatively regulates P-TEFb function in resting CD4(+) T cells and inhibits HIV-1 gene expression. Retrovirology 2012; 9:52. [PMID: 22727189 PMCID: PMC3406988 DOI: 10.1186/1742-4690-9-52] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Accepted: 06/22/2012] [Indexed: 11/16/2022] Open
Abstract
Background Processive elongation of the integrated HIV-1 provirus is dependent on recruitment of P-TEFb by the viral Tat protein to the viral TAR RNA element. P-TEFb kinase activity requires phosphorylation of Thr186 in the T-loop of the CDK9 subunit. In resting CD4+T cells, low levels of T-loop phosphorylated CDK9 are found, which increase significantly upon activation. This suggests that the phosphorylation status of the T-loop is actively regulated through the concerted actions of cellular proteins such as Ser/Thr phosphatases. We investigated the role of phosphatase PPM1A in regulating CDK9 T-loop phosphorylation and its effect on HIV-1 proviral transcription. Results We found that overexpression of PPM1A inhibits HIV-1 gene expression during viral infection and this required PPM1A catalytic function. Using an artificial CDK tethering system, we further found that PPM1A inhibits CDK9, but not CDK8 mediated activation of the HIV-1 LTR. SiRNA depletion of PPM1A in resting CD4+T cells increased the level of CDK9 T-loop phosphorylation and enhanced HIV-1 gene expression. We also observed that PPM1A protein levels are relatively high in resting CD4+T cells and are not up-regulated upon T cell activation. Conclusions Our results establish a functional link between HIV-1 replication and modulation of CDK9 T-loop phosphorylation by PPM1A. PPM1A represses HIV-1 gene expression by inhibiting CDK9 T-loop phosphorylation, thus reducing the amount of active P-TEFb available for recruitment to the viral LTR. We also infer that PPM1A enzymatic activity in resting and activated CD4+ T cells are likely regulated by as yet undefined factors.
Collapse
|
46
|
Ramakrishnan R, Chiang K, Liu H, Budhiraja S, Donahue H, Rice AP. Making a Short Story Long: Regulation of P-TEFb and HIV-1 Transcriptional Elongation in CD4+ T Lymphocytes and Macrophages. BIOLOGY 2012; 1:94-115. [PMID: 24832049 PMCID: PMC4011037 DOI: 10.3390/biology1010094] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 06/07/2012] [Accepted: 06/11/2012] [Indexed: 12/22/2022]
Abstract
Productive transcription of the integrated HIV-1 provirus is restricted by cellular factors that inhibit RNA polymerase II elongation. The viral Tat protein overcomes this by recruiting a general elongation factor, P-TEFb, to the TAR RNA element that forms at the 5' end of nascent viral transcripts. P-TEFb exists in multiple complexes in cells, and its core consists of a kinase, Cdk9, and a regulatory subunit, either Cyclin T1 or Cyclin T2. Tat binds directly to Cyclin T1 and thereby targets the Cyclin T1/P-TEFb complex that phosphorylates the CTD of RNA polymerase II and the negative factors that inhibit elongation, resulting in efficient transcriptional elongation. P-TEFb is tightly regulated in cells infected by HIV-1-CD4+ T lymphocytes and monocytes/macrophages. A number of mechanisms have been identified that inhibit P-TEFb in resting CD4+ T lymphocytes and monocytes, including miRNAs that repress Cyclin T1 protein expression and dephosphorylation of residue Thr186 in the Cdk9 T-loop. These repressive mechanisms are overcome upon T cell activation and macrophage differentiation when the permissivity for HIV-1 replication is greatly increased. This review will summarize what is currently known about mechanisms that regulate P-TEFb and how this regulation impacts HIV-1 replication and latency.
Collapse
Affiliation(s)
- Rajesh Ramakrishnan
- Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Karen Chiang
- Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Hongbing Liu
- Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Sona Budhiraja
- Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Hart Donahue
- Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Andrew P Rice
- Department of Molecular Virology & Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
| |
Collapse
|
47
|
Abstract
The cyclin-dependent kinases (Cdks) regulate many cellular processes, including the cell cycle, neuronal development, transcription, and posttranscriptional processing. To perform their functions, Cdks bind to specific cyclin subunits to form a functional and active cyclin/Cdk complex. This review is focused on Cyclin K, which was originally considered an alternative subunit of Cdk9, and on its newly identified partners, Cdk12 and Cdk13. We briefly summarize research devoted to each of these proteins. We also discuss the proteins' functions in the regulation of gene expression via the phosphorylation of serine 2 in the C-terminal domain of RNA polymerase II, contributions to the maintenance of genome stability, and roles in the onset of human disease and embryo development.
Collapse
Affiliation(s)
- Jiri Kohoutek
- Central European Institute of Technology (CEITEC), Masaryk University, 62500 Brno, Czech Republic.
| | | |
Collapse
|
48
|
Mbonye U, Karn J. Control of HIV latency by epigenetic and non-epigenetic mechanisms. Curr HIV Res 2011; 9:554-67. [PMID: 22211660 PMCID: PMC3319922 DOI: 10.2174/157016211798998736] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 10/10/2011] [Accepted: 10/21/2011] [Indexed: 12/17/2022]
Abstract
Intensive antiretroviral therapy successfully suppresses viral replication but is unable to eradicate the virus. HIV persists in a small number of resting memory T cells where HIV has been transcriptionally silenced. This review will focus on recent insights into the HIV transcriptional control mechanisms that provide the biochemical basis for understanding latency. There are no specific repressors of HIV transcription encoded by the virus, instead latency arises when the regulatory feedback mechanism driven by HIV Tat expression is disrupted. Small changes in transcriptional initiation, induced by epigenetic silencing, lead to profound restrictions in Tat levels and force the entry of proviruses into latency. In resting memory T cells, which carry the bulk of the latent viral pool, additional restrictions, especially the limiting cellular levels of the essential Tat cofactor P-TEFb and the transcription initiation factors NF-κB and NFAT ensure that the provirus remains silenced unless the host cell is activated. The detailed understanding of HIV transcription is providing a framework for devising new therapeutic strategies designed to purge the latent viral pool. Importantly, the recognition that there are multiple restrictions imposed on latent proviruses suggest that proviral reactivation will not be achieved when only a single reactivation step is targeted and that any optimal activation strategy will require both removal of epigenetic blocks and the activation of P-TEFb.
Collapse
Affiliation(s)
| | - Jonathan Karn
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH 44106, USA
| |
Collapse
|
49
|
Cho S, Schroeder S, Ott M. CYCLINg through transcription: posttranslational modifications of P-TEFb regulate transcription elongation. Cell Cycle 2010; 9:1697-705. [PMID: 20436276 DOI: 10.4161/cc.9.9.11346] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The cyclin T/CDK9 complex, also called positive transcription elongation factor b (P-TEFb) phosphorylates the C-terminal domain of the large fragment of the RNA polymerase II. This action is a hallmark of the transition from transcription initiation to elongation. P-TEFb is itself modified by phosphorylation and ubiquitination. Recently, the core components of P-TEFb, cyclin T1 and CDK9, were identified as novel substrates of histone acetyltransferases. Here, we review how posttranslational modifications regulate the activity of the P-TEFb complex and discuss how acetylation of the complex optimizes transcription elongation in the context of other posttranslational modifications.
Collapse
Affiliation(s)
- Sungyoo Cho
- Gladstone Institute of Virology and Immunology, University of California, San Francisco, San Francisco, CA, USA
| | | | | |
Collapse
|
50
|
Liu H, Herrmann CH, Chiang K, Sung TL, Moon SH, Donehower LA, Rice AP. 55K isoform of CDK9 associates with Ku70 and is involved in DNA repair. Biochem Biophys Res Commun 2010; 397:245-50. [PMID: 20493174 DOI: 10.1016/j.bbrc.2010.05.092] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Accepted: 05/16/2010] [Indexed: 10/19/2022]
Abstract
Positive elongation factor b (P-TEFb) is a cellular protein kinase that is required for RNA polymerase II (RNAP II) transcriptional elongation of protein coding genes. P-TEFb is a set of different molecular complexes, each containing CDK9 as the catalytic subunit. There are two isoforms of the CDK9 protein - the major 42KDa CDK9 isoform and the minor 55KDa isoform that is translated from an in-frame mRNA that arises from an upstream transcriptional start site. We found that shRNA depletion of the 55K CDK9 protein in HeLa cells induces apoptosis and double-strand DNA breaks (DSBs). The levels of apoptosis and DSBs induced by the depletion were reduced by expression of a 55K CDK9 protein variant resistant to the shRNA, indicating that these phenotypes are the consequence of depletion of the 55K protein and not off-target effects. We also found that the 55K CDK9 protein, but not the 42K CDK9 protein, specifically associates with Ku70, a protein involved in DSB repair. Our findings suggest that the 55K CDK9 protein may function in repair of DNA through an association with Ku70.
Collapse
Affiliation(s)
- Hongbing Liu
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
| | | | | | | | | | | | | |
Collapse
|