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Park SY, Shin D, Yoon YS, Park S, Im SS, Kim Y, Kim YS, Choi C, Hur MW. TAT38 and TAT38 mimics potently inhibit adipogenesis by repressing C/EBPα, PPARγ, Pi-PPARγ, and SREBP1 expression. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2024; 1867:195030. [PMID: 38670485 DOI: 10.1016/j.bbagrm.2024.195030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/17/2024] [Accepted: 04/18/2024] [Indexed: 04/28/2024]
Abstract
Antiretroviral therapy-naive people living with HIV possess less fat than people without HIV. Previously, we found that HIV-1 transactivator of transcription (TAT) decreases fat in ob/ob mice. The TAT38 (a.a. 20-57) is important in the inhibition of adipogenesis and contains three functional domains: Cys-ZF domain (a.a. 20-35 TACTNCYCAKCCFQVC), core-domain (a.a. 36-46, FITKALGISYG), and protein transduction domain (PTD)(a.a. 47-57, RAKRRQRRR). Interestingly, the TAT38 region interacts with the Cyclin T1 of the P-TEFb complex, of which expression increases during adipogenesis. The X-ray crystallographic structure of the complex showed that the Cys-ZF and the core domain bind to the Cyclin T1 via hydrophobic interactions. To prepare TAT38 mimics with structural and functional similarities to TAT38, we replaced the core domain with a hydrophobic aliphatic amino acid (from carbon numbers 5 to 8). The TAT38 mimics with 6-hexanoic amino acid (TAT38 Ahx (C6)) and 7-heptanoic amino acid (TAT38 Ahp (C7)) inhibited adipogenesis of 3T3-L1 potently, reduced cellular triglyceride content, and decreased body weight of diet-induced obese (DIO) mice by 10.4-11 % in two weeks. The TAT38 and the TAT38 mimics potently repressed the adipogenic transcription factors genes, C/EBPα, PPARγ, and SREBP1. Also, they inhibit the phosphorylation of PPARγ. The TAT peptides may be promising candidates for development into a drug against obesity or diabetes.
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Affiliation(s)
- Sun-Young Park
- Department of Biochemistry and Molecular Biology, Yonsei University College of Medicine, 134, ShinChon-Dong, SeoDaeMoon-Ku, Seoul 120-752, Republic of Korea
| | - Dongyoon Shin
- Proteomics Research Team, CHA Institute of Future Medicine, Seongnam, Republic of Korea; Department of Medical Science, School of Medicine, CHA University, Seongnam, Republic of Korea
| | - Young So Yoon
- Department of Biochemistry and Molecular Biology, Yonsei University College of Medicine, 134, ShinChon-Dong, SeoDaeMoon-Ku, Seoul 120-752, Republic of Korea
| | - Sujin Park
- Department of Biochemistry and Molecular Biology, Yonsei University College of Medicine, 134, ShinChon-Dong, SeoDaeMoon-Ku, Seoul 120-752, Republic of Korea
| | - Seung-Soon Im
- Department of Physiology, Keimyung University School of Medicine, 1095 Dalgubeol-daero, Dalseo-gu, Daegu 42601, Republic of Korea
| | - Yeongshin Kim
- Proteomics Research Team, CHA Institute of Future Medicine, Seongnam, Republic of Korea; Department of Medical Science, School of Medicine, CHA University, Seongnam, Republic of Korea
| | - Young-Soo Kim
- Proteomics Research Team, CHA Institute of Future Medicine, Seongnam, Republic of Korea; Department of Medical Science, School of Medicine, CHA University, Seongnam, Republic of Korea
| | - CheolSoo Choi
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Republic of Korea; Division of Endocrinology & Metabolism, Department of Internal Medicine, Gil Medical Center, Gachon University College of Medicine, Incheon 21565, Republic of Korea
| | - Man-Wook Hur
- Department of Biochemistry and Molecular Biology, Yonsei University College of Medicine, 134, ShinChon-Dong, SeoDaeMoon-Ku, Seoul 120-752, Republic of Korea.
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Kilroy JM, Leal AA, Henderson AJ. Chronic HIV Transcription, Translation, and Persistent Inflammation. Viruses 2024; 16:751. [PMID: 38793632 PMCID: PMC11125830 DOI: 10.3390/v16050751] [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: 04/16/2024] [Revised: 05/02/2024] [Accepted: 05/07/2024] [Indexed: 05/26/2024] Open
Abstract
People with HIV exhibit persistent inflammation that correlates with HIV-associated comorbidities including accelerated aging, increased risk of cardiovascular disease, and neuroinflammation. Mechanisms that perpetuate chronic inflammation in people with HIV undergoing antiretroviral treatments are poorly understood. One hypothesis is that the persistent low-level expression of HIV proviruses, including RNAs generated from defective proviral genomes, drives the immune dysfunction that is responsible for chronic HIV pathogenesis. We explore factors during HIV infection that contribute to the generation of a pool of defective proviruses as well as how HIV-1 mRNA and proteins alter immune function in people living with HIV.
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Affiliation(s)
- Jonathan M. Kilroy
- Department of Virology, Immunology, Microbiology, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA; (J.M.K.); (A.A.L.)
| | - Andrew A. Leal
- Department of Virology, Immunology, Microbiology, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA; (J.M.K.); (A.A.L.)
| | - Andrew J. Henderson
- Department of Virology, Immunology, Microbiology, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA; (J.M.K.); (A.A.L.)
- Department of Medicine and Virology, Immunology, Microbiology, Boston University Chobanian and Avedisian School of Medicine, Boston, MA 02118, USA
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Zhou Z, Jiang Y, Zhong X, Yang J, Yang G. Characteristics and mechanisms of latency-reversing agents in the activation of the human immunodeficiency virus 1 reservoir. Arch Virol 2023; 168:301. [PMID: 38019293 DOI: 10.1007/s00705-023-05931-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 10/23/2023] [Indexed: 11/30/2023]
Abstract
The "Shock and Kill" method is being considered as a potential treatment for eradicating HIV-1 and achieving a functional cure for acquired immunodeficiency syndrome (AIDS). This approach involves using latency-reversing agents (LRAs) to activate human immunodeficiency virus (HIV-1) transcription in latent cells, followed by treatment with antiviral drugs to kill these cells. Although LRAs have shown promise in HIV-1 patient research, their widespread clinical use is hindered by side effects and limitations. In this review, we categorize and explain the mechanisms of these agonists in activating HIV-1 in vivo and discuss their advantages and disadvantages. In the future, combining different HIV-1 LRAs may overcome their respective shortcomings and facilitate a functional cure for HIV-1.
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Affiliation(s)
- Zhujiao Zhou
- Department of Clinical Medicine, School of Medicine, Hangzhou City University, Hangzhou, China
- College of Pharmacy, Zhejiang University of Technology, Hangzhou, 310013, China
| | - Yashuang Jiang
- Department of Clinical Medicine, School of Medicine, Hangzhou City University, Hangzhou, China
| | - Xinyu Zhong
- Department of Clinical Medicine, School of Medicine, Hangzhou City University, Hangzhou, China
- College of Pharmacy, Zhejiang University of Technology, Hangzhou, 310013, China
| | - Jingyi Yang
- Department of Clinical Medicine, School of Medicine, Hangzhou City University, Hangzhou, China
| | - Geng Yang
- Department of Clinical Medicine, School of Medicine, Hangzhou City University, Hangzhou, China.
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou, 310013, China.
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4
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Shin YH, Kim DE, Yu KL, Park CM, Kim HG, Kim KC, Bae S, Yoon CH. A Novel Time-Resolved Fluorescence Resonance Energy Transfer Assay for the Discovery of Small-Molecule Inhibitors of HIV-1 Tat-Regulated Transcription. Int J Mol Sci 2023; 24:ijms24119139. [PMID: 37298089 DOI: 10.3390/ijms24119139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 05/17/2023] [Accepted: 05/18/2023] [Indexed: 06/12/2023] Open
Abstract
Human immunodeficiency virus-1 (HIV-1) transactivator (Tat)-mediated transcription is essential for HIV-1 replication. It is determined by the interaction between Tat and transactivation response (TAR) RNA, a highly conserved process representing a prominent therapeutic target against HIV-1 replication. However, owing to the limitations of current high-throughput screening (HTS) assays, no drug that disrupts the Tat-TAR RNA interaction has been uncovered yet. We designed a homogenous (mix-and-read) time-resolved fluorescence resonance energy transfer (TR-FRET) assay using europium cryptate as a fluorescence donor. It was optimized by evaluating different probing systems for Tat-derived peptides or TAR RNA. The specificity of the optimal assay was validated by mutants of the Tat-derived peptides and TAR RNA fragment, individually and by competitive inhibition with known TAR RNA-binding peptides. The assay generated a constant Tat-TAR RNA interaction signal, discriminating the compounds that disrupted the interaction. Combined with a functional assay, the TR-FRET assay identified two small molecules (460-G06 and 463-H08) capable of inhibiting Tat activity and HIV-1 infection from a large-scale compound library. The simplicity, ease of operation, and rapidity of our assay render it suitable for HTS to identify Tat-TAR RNA interaction inhibitors. The identified compounds may also act as potent molecular scaffolds for developing a new HIV-1 drug class.
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Affiliation(s)
- Young Hyun Shin
- Division of Chronic Viral Diseases, Center for Emerging Virus Research, Korea National Institute of Health, 187 Osongsaengmyeong 2-ro, Cheongju 363951, Republic of Korea
| | - Dong-Eun Kim
- Division of Chronic Viral Diseases, Center for Emerging Virus Research, Korea National Institute of Health, 187 Osongsaengmyeong 2-ro, Cheongju 363951, Republic of Korea
| | - Kyung Lee Yu
- Division of Chronic Viral Diseases, Center for Emerging Virus Research, Korea National Institute of Health, 187 Osongsaengmyeong 2-ro, Cheongju 363951, Republic of Korea
| | - Chul Min Park
- Department for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Daejeon 34114, Republic of Korea
| | - Hong Gi Kim
- Department for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Daejeon 34114, Republic of Korea
| | - Kyung-Chang Kim
- Division of Chronic Viral Diseases, Center for Emerging Virus Research, Korea National Institute of Health, 187 Osongsaengmyeong 2-ro, Cheongju 363951, Republic of Korea
| | - Songmee Bae
- Division of Chronic Viral Diseases, Center for Emerging Virus Research, Korea National Institute of Health, 187 Osongsaengmyeong 2-ro, Cheongju 363951, Republic of Korea
| | - Cheol-Hee Yoon
- Division of Chronic Viral Diseases, Center for Emerging Virus Research, Korea National Institute of Health, 187 Osongsaengmyeong 2-ro, Cheongju 363951, Republic of Korea
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Fujinaga K, Huang F, Peterlin BM. P-TEFb: The master regulator of transcription elongation. Mol Cell 2023; 83:393-403. [PMID: 36599353 PMCID: PMC9898187 DOI: 10.1016/j.molcel.2022.12.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/10/2022] [Accepted: 12/08/2022] [Indexed: 01/05/2023]
Abstract
The positive transcription elongation factor b (P-TEFb) is composed of cyclins T1 or T2 and cyclin-dependent kinase 9 that regulate the elongation phase of transcription by RNA polymerase II. By antagonizing negative elongation factors and phosphorylating the C-terminal domain of RNA polymerase II, P-TEFb facilitates the elongation and co-transcriptional processing of nascent transcripts. This step is critical for the expression of most eukaryotic genes. In growing cells, P-TEFb is regulated negatively by its reversible associations with HEXIM1/2 in the 7SK snRNP and positively by a number of transcription factors, as well as the super elongation complex. In resting cells, P-TEFb falls apart, and cyclin T1 is degraded by the proteasome. This complex regulation of P-TEFb has evolved for the precise temporal and spatial regulation of gene expression in the organism. Its dysregulation contributes to inflammatory and neoplastic conditions.
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Affiliation(s)
- Koh Fujinaga
- Departments of Medicine, Microbiology and Immunology, University of California at San Francisco, San Francisco, CA 94143, USA.
| | - Fang Huang
- Departments of Medicine, Microbiology and Immunology, University of California at San Francisco, San Francisco, CA 94143, USA
| | - B Matija Peterlin
- Departments of Medicine, Microbiology and Immunology, University of California at San Francisco, San Francisco, CA 94143, USA.
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Spitale RC, Incarnato D. Probing the dynamic RNA structurome and its functions. Nat Rev Genet 2023; 24:178-196. [PMID: 36348050 PMCID: PMC9644009 DOI: 10.1038/s41576-022-00546-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2022] [Indexed: 11/09/2022]
Abstract
RNA is a key regulator of almost every cellular process, and the structures adopted by RNA molecules are thought to be central to their functions. The recent fast-paced evolution of high-throughput sequencing-based RNA structure mapping methods has enabled the rapid in vivo structural interrogation of entire cellular transcriptomes. Collectively, these studies are shedding new light on the long underestimated complexity of the structural organization of the transcriptome - the RNA structurome. Moreover, recent analyses are challenging the view that the RNA structurome is a static entity by revealing how RNA molecules establish intricate networks of alternative intramolecular and intermolecular interactions and that these ensembles of RNA structures are dynamically regulated to finely tune RNA functions in living cells. This new understanding of how RNA can shape cell phenotypes has important implications for the development of RNA-targeted therapeutic strategies.
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Affiliation(s)
- Robert C. Spitale
- grid.266093.80000 0001 0668 7243Department of Pharmaceutical Sciences, University of California, Irvine, CA USA
| | - Danny Incarnato
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Groningen, The Netherlands.
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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.
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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,
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8
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Mediouni S, Lyu S, Schader SM, Valente ST. Forging a Functional Cure for HIV: Transcription Regulators and Inhibitors. Viruses 2022; 14:1980. [PMID: 36146786 PMCID: PMC9502519 DOI: 10.3390/v14091980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 08/28/2022] [Accepted: 09/01/2022] [Indexed: 11/16/2022] Open
Abstract
Current antiretroviral therapy (ART) increases the survival of HIV-infected individuals, yet it is not curative. The major barrier to finding a definitive cure for HIV is our inability to identify and eliminate long-lived cells containing the dormant provirus, termed viral reservoir. When ART is interrupted, the viral reservoir ensures heterogenous and stochastic HIV viral gene expression, which can reseed infection back to pre-ART levels. While strategies to permanently eradicate the virus have not yet provided significant success, recent work has focused on the management of this residual viral reservoir to effectively limit comorbidities associated with the ongoing viral transcription still observed during suppressive ART, as well as limit the need for daily ART. Our group has been at the forefront of exploring the viability of the block-and-lock remission approach, focused on the long-lasting epigenetic block of viral transcription such that without daily ART, there is no risk of viral rebound, transmission, or progression to AIDS. Numerous studies have reported inhibitors of both viral and host factors required for HIV transcriptional activation. Here, we highlight and review some of the latest HIV transcriptional inhibitor discoveries that may be leveraged for the clinical exploration of block-and-lock and revolutionize the way we treat HIV infections.
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Affiliation(s)
- Sonia Mediouni
- Department of Immunology and Microbiology, UF Scripps Biomedical Research, 130 Scripps Way, 3C1, Jupiter, FL 33458, USA
| | - Shuang Lyu
- Department of Immunology and Microbiology, UF Scripps Biomedical Research, 130 Scripps Way, 3C1, Jupiter, FL 33458, USA
| | - Susan M. Schader
- Department of Infectious Disease Research, Drug Development Division, Southern Research, 431 Aviation Way, Frederick, MD 21701, USA
| | - Susana T. Valente
- Department of Immunology and Microbiology, UF Scripps Biomedical Research, 130 Scripps Way, 3C1, Jupiter, FL 33458, USA
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9
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Huang F, Feng Y, Peterlin BM, Fujinaga K. P-TEFb is degraded by Siah1/2 in quiescent cells. Nucleic Acids Res 2022; 50:5000-5013. [PMID: 35524561 PMCID: PMC9122529 DOI: 10.1093/nar/gkac291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 04/05/2022] [Accepted: 04/12/2022] [Indexed: 11/12/2022] Open
Abstract
P-TEFb, composed of CycT1 and CDK9, regulates the elongation of transcription by RNA polymerase II. In proliferating cells, it is regulated by 7SK snRNA in the 7SK snRNP complex. In resting cells, P-TEFb is absent, because CycT1 is dephosphorylated, released from CDK9 and rapidly degraded. In this study, we identified the mechanism of this degradation. We mapped the ubiquitination and degradation of free CycT1 to its N-terminal region from positions 1 to 280. This region is ubiquitinated at six lysines, where E3 ligases Siah1 and Siah2 bind and degrade these sequences. Importantly, the inhibition of Siah1/2 rescued the expression of free CycT1 in proliferating as well as resting primary cells. We conclude that Siah1/2 are the E3 ligases that bind and degrade the dissociated CycT1 in resting, terminally differentiated, anergic and/or exhausted cells.
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Affiliation(s)
- Fang Huang
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Yongmei Feng
- Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - B Matija Peterlin
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Koh Fujinaga
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
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10
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Ali HA, Li Y, Bilal AHM, Qin T, Yuan Z, Zhao W. A Comprehensive Review of BET Protein Biochemistry, Physiology, and Pathological Roles. Front Pharmacol 2022; 13:818891. [PMID: 35401196 PMCID: PMC8990909 DOI: 10.3389/fphar.2022.818891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/26/2022] [Indexed: 11/13/2022] Open
Abstract
Epigenetic modifications, specifically acetylation of histone plays a decisive role in gene regulation and transcription of normal cellular mechanisms and pathological conditions. The bromodomain and extraterminal (BET) proteins (BRD2, BRD3, BRD4, and BRDT), being epigenetic readers, ligate to acetylated regions of histone and synchronize gene transcription. BET proteins are crucial for normal cellular processing as they control cell cycle progression, neurogenesis, differentiation, and maturation of erythroids and spermatogenesis, etc. Research-based evidence indicated that BET proteins (mainly BRD4) are associated with numeral pathological ailments, including cancer, inflammation, infections, renal diseases, and cardiac diseases. To counter the BET protein-related pathological conditions, there are some BET inhibitors developed and also under development. BET proteins are a topic of most research nowadays. This review, provides an ephemeral but comprehensive knowledge about BET proteins’ basic structure, biochemistry, physiological roles, and pathological conditions in which the role of BETs have been proven. This review also highlights the current and future approaches to pledge BET protein-related pathologies.
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Affiliation(s)
- Hafiz Akbar Ali
- Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China.,Key Laboratory of Advanced Drug Preparation Technologies, Ministry of Education, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Yalan Li
- Key Laboratory of Advanced Drug Preparation Technologies, Ministry of Education, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Akram Hafiz Muhammad Bilal
- Key Laboratory of Advanced Drug Preparation Technologies, Ministry of Education, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Tingting Qin
- Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Ziqiao Yuan
- Key Laboratory of Advanced Drug Preparation Technologies, Ministry of Education, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Wen Zhao
- Key Laboratory of Advanced Drug Preparation Technologies, Ministry of Education, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China.,State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, China
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11
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Ji L, Wang Z, Ji Y, Wang H, Guo M, Zhang L, Wang P, Xiao H. Proteomics and phosphoproteomics analysis of tissues for the reoccurrence prediction of colorectal cancer. Expert Rev Proteomics 2022; 19:263-277. [PMID: 36308708 DOI: 10.1080/14789450.2022.2142566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Many stage II/III colorectal cancer (CRC) patients may relapse after routine treatments. Aberrant phosphorylation can regulate pathophysiological processes of tumors, and finding characteristic protein phosphorylation is an efficient approach for the prediction of CRC relapse. RESEARCH DESIGN AND METHODS We compared the tissue proteome and phosphoproteome of stage II/III CRC patients between the relapsed group (n = 5) and the non-relapsed group (n = 5). Phosphopeptides were enriched with Ti4+-IMAC material. We utilized label-free quantification-based proteomics to screen differentially expressed proteins and phosphopeptides between the two groups. Gene Ontology (GO) analysis and Ingenuity Pathway Analysis (IPA) were used for bioinformatics analysis. RESULTS The immune response of the relapsed group (Z-score -2.229) was relatively poorer than that of the non-relapsed group (Z-score 1.982), while viability of tumor was more activated (Z-score 2.895) in the relapsed group, which might cause increased relapse risk. The phosphorylation degrees of three phosphosites (phosphosite 1362 of TP53BP1, phosphosite 809 of VCL and phosphosite 438 of STK10) might be reliable prognostic biomarkers. CONCLUSIONS Some promising proteins and phosphopeptides were discovered to predict the relapse risk in postoperative follow-ups.
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Affiliation(s)
- Liyun Ji
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University 200240, Shanghai, China
| | - Zeyuan Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University 200240, Shanghai, China
| | - Yin Ji
- State Key Laboratory of Translational Medicine and Innovative Drug Development, Jiangsu Simcere Pharmaceutical Co Ltd 210042, Nanjing, China
| | - Huiyu Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University 200240, Shanghai, China
| | - Miao Guo
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University 200240, Shanghai, China
| | - Lu Zhang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University 200240, Shanghai, China
| | - Peng Wang
- State Key Laboratory of Translational Medicine and Innovative Drug Development, Jiangsu Simcere Pharmaceutical Co Ltd 210042, Nanjing, China
| | - Hua Xiao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University 200240, Shanghai, China
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12
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Fraschilla I, Amatullah H, Jeffrey KL. One genome, many cell states: epigenetic control of innate immunity. Curr Opin Immunol 2022; 75:102173. [PMID: 35405493 PMCID: PMC9081230 DOI: 10.1016/j.coi.2022.102173] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 02/23/2022] [Accepted: 02/23/2022] [Indexed: 12/15/2022]
Abstract
A hallmark of the innate immune system is its ability to rapidly initiate short-lived or sustained transcriptional programs in a cell-specific and pathogen-specific manner that is dependent on dynamic chromatin states. Much of the epigenetic landscape is set during cellular differentiation; however, pathogens and other environmental cues also induce changes in chromatin that can either promote tolerance or 'train' innate immune cells for amplified secondary responses. We review chromatin processes that enable innate immune cell differentiation and functional transcriptional responses in naive or experienced cells, in concert with signal transduction and cellular metabolic shifts. We discuss how immune chromatin mechanisms are maladapted in disease and novel therapeutic approaches for cellular reprogramming.
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Affiliation(s)
- Isabella Fraschilla
- Division of Gastroenterology and Center for the Study of Inflammatory Bowel Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA; Program in Immunology, Harvard Medical School, Boston, MA 02115, USA
| | - Hajera Amatullah
- Division of Gastroenterology and Center for the Study of Inflammatory Bowel Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Kate L Jeffrey
- Division of Gastroenterology and Center for the Study of Inflammatory Bowel Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA; Program in Immunology, Harvard Medical School, Boston, MA 02115, USA; Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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13
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Cordsmeier A, Rinkel S, Jeninga M, Schulze-Luehrmann J, Ölke M, Schmid B, Hasler D, Meister G, Häcker G, Petter M, Beare PA, Lührmann A. The Coxiella burnetii T4SS effector protein AnkG hijacks the 7SK small nuclear ribonucleoprotein complex for reprogramming host cell transcription. PLoS Pathog 2022; 18:e1010266. [PMID: 35134097 PMCID: PMC8824381 DOI: 10.1371/journal.ppat.1010266] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 01/10/2022] [Indexed: 11/24/2022] Open
Abstract
Inhibition of host cell apoptosis is crucial for survival and replication of several intracellular bacterial pathogens. To interfere with apoptotic pathways, some pathogens use specialized secretion systems to inject bacterial effector proteins into the host cell cytosol. One of these pathogens is the obligate intracellular bacterium Coxiella burnetii, the etiological agent of the zoonotic disease Q fever. In this study, we analyzed the molecular activity of the anti-apoptotic T4SS effector protein AnkG (CBU0781) to understand how C. burnetii manipulates host cell viability. We demonstrate by co- and RNA-immunoprecipitation that AnkG binds to the host cell DExD box RNA helicase 21 (DDX21) as well as to the host cell 7SK small nuclear ribonucleoprotein (7SK snRNP) complex, an important regulator of the positive transcription elongation factor b (P-TEFb). The co-immunoprecipitation of AnkG with DDX21 is probably mediated by salt bridges and is independent of AnkG-7SK snRNP binding, and vice versa. It is known that DDX21 facilitates the release of P-TEFb from the 7SK snRNP complex. Consistent with the documented function of released P-TEFb in RNA Pol II pause release, RNA sequencing experiments confirmed AnkG-mediated transcriptional reprogramming and showed that expression of genes involved in apoptosis, trafficking, and transcription are influenced by AnkG. Importantly, DDX21 and P-TEFb are both essential for AnkG-mediated inhibition of host cell apoptosis, emphasizing the significance of the interaction of AnkG with both, the DDX21 protein and the 7SK RNA. In line with a critical function of AnkG in pathogenesis, the AnkG deletion C. burnetii strain was severely affected in its ability to inhibit host cell apoptosis and to generate a replicative C. burnetii-containing vacuole. In conclusion, the interference with the activity of regulatory host cell RNAs mediated by a bacterial effector protein represent a novel mechanism through which C. burnetii modulates host cell transcription, thereby enhancing permissiveness to bacterial infection. For intracellular replication, Coxiella burnetii depends on a functional type IV secretion system, which is utilized to inject ~150 virulence factors, so called effector proteins, into the host cell cytosol. Activities have only been established for few of them. These effector proteins interfere with vesicular trafficking, autophagy, lipid metabolism, apoptosis, and transcription by binding and manipulating the activity of host cell proteins. Here, we report that the C. burnetii T4SS effector protein AnkG (CBU0781, Q83DF6) binds to the host cell DExD box helicase 21 (DDX21) as well as to several host cell RNAs, including the small regulatory 7SK RNA, which is an important regulator of the positive elongation factor b (pTEFb). AnkG interferes with the function of the 7SK small nuclear ribonucleoprotein (7SK snRNP) complex, leading to significant changes in host cell transcription and ensuring host cell survival. AnkG activity is essential for efficient intracellular replication of C. burnetii and its ability to inhibit apoptosis. In summary, we identified a novel process by which a bacterial effector protein manipulates the host cell for its own benefit.
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Affiliation(s)
- Arne Cordsmeier
- Mikrobiologisches Institut, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Sven Rinkel
- Mikrobiologisches Institut, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Myriam Jeninga
- Mikrobiologisches Institut, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jan Schulze-Luehrmann
- Mikrobiologisches Institut, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Martha Ölke
- Mikrobiologisches Institut, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Benedikt Schmid
- Lehrstuhl für Biotechnik, Department Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Daniele Hasler
- Biochemistry Center Regensburg (BZR), Laboratory for RNA Biology, University of Regensburg, Regensburg, Germany
| | - Gunter Meister
- Biochemistry Center Regensburg (BZR), Laboratory for RNA Biology, University of Regensburg, Regensburg, Germany
| | - Georg Häcker
- Faculty of Medicine, Institute of Medical Microbiology and Hygiene, Medical Center-University of Freiburg, Freiburg, Germany
| | - Michaela Petter
- Mikrobiologisches Institut, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Paul A. Beare
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Anja Lührmann
- Mikrobiologisches Institut, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- * E-mail:
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14
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Huang F, Nguyen TT, Echeverria I, Rakesh R, Cary DC, Paculova H, Sali A, Weiss A, Peterlin BM, Fujinaga K. Reversible phosphorylation of cyclin T1 promotes assembly and stability of P-TEFb. eLife 2021; 10:68473. [PMID: 34821217 PMCID: PMC8648303 DOI: 10.7554/elife.68473] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 11/19/2021] [Indexed: 01/06/2023] Open
Abstract
The positive transcription elongation factor b (P-TEFb) is a critical coactivator for transcription of most cellular and viral genes, including those of HIV. While P-TEFb is regulated by 7SK snRNA in proliferating cells, P-TEFb is absent due to diminished levels of CycT1 in quiescent and terminally differentiated cells, which has remained unexplored. In these cells, we found that CycT1 not bound to CDK9 is rapidly degraded. Moreover, productive CycT1:CDK9 interactions are increased by PKC-mediated phosphorylation of CycT1 in human cells. Conversely, dephosphorylation of CycT1 by PP1 reverses this process. Thus, PKC inhibitors or removal of PKC by chronic activation results in P-TEFb disassembly and CycT1 degradation. This finding not only recapitulates P-TEFb depletion in resting CD4+ T cells but also in anergic T cells. Importantly, our studies reveal mechanisms of P-TEFb inactivation underlying T cell quiescence, anergy, and exhaustion as well as proviral latency and terminally differentiated cells.
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Affiliation(s)
- Fang Huang
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States.,Department of Medicine, San Francisco, United States
| | - Trang Tt Nguyen
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States.,Department of Medicine, San Francisco, United States.,The Howard Hughes Medical Institute, San Francisco, United States
| | - Ignacia Echeverria
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States.,Departmentof Cellular Molecular Pharmacology, California Institute for Quantitative Biosciences (QBI), and Department of Bioengineering and Therapeutic Sciences, San Francisco, United States
| | - Ramachandran Rakesh
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States.,Departmentof Cellular Molecular Pharmacology, California Institute for Quantitative Biosciences (QBI), and Department of Bioengineering and Therapeutic Sciences, San Francisco, United States
| | - Daniele C Cary
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States.,Department of Medicine, San Francisco, United States
| | - Hana Paculova
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States
| | - Andrej Sali
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States.,Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, and California Institute for Quantitative Biosciences (QBI), San Francisco, United States
| | - Arthur Weiss
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States.,Department of Medicine, San Francisco, United States.,The Howard Hughes Medical Institute, San Francisco, United States
| | - Boris Matija Peterlin
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States.,Department of Medicine, San Francisco, United States
| | - Koh Fujinaga
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, San Francisco, United States.,Department of Medicine, San Francisco, United States
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15
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Zhou Y, Gao X, Yuan M, Yang B, He Q, Cao J. Targeting Myc Interacting Proteins as a Winding Path in Cancer Therapy. Front Pharmacol 2021; 12:748852. [PMID: 34658888 PMCID: PMC8511624 DOI: 10.3389/fphar.2021.748852] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/10/2021] [Indexed: 12/26/2022] Open
Abstract
MYC, as a well-known oncogene, plays essential roles in promoting tumor occurrence, development, invasion and metastasis in many kinds of solid tumors and hematologic neoplasms. In tumors, the low expression and the short half-life of Myc are reversed, cause tumorigenesis. And proteins that directly interact with different Myc domains have exerted a significant impact in the process of Myc-driven carcinogenesis. Apart from affecting the transcription of Myc target genes, Myc interaction proteins also regulate the stability of Myc through acetylation, methylation, phosphorylation and other post-translational modifications, as well as competitive combination with Myc. In this review, we summarize a series of Myc interacting proteins and recent advances in the related inhibitors, hoping that can provide new opportunities for Myc-driven cancer treatment.
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Affiliation(s)
- Yihui Zhou
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Xiaomeng Gao
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Meng Yuan
- Cancer Center of Zhejiang University, Hangzhou, China
| | - Bo Yang
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,The Innovation Institute for Artificial Intelligence in Medicine, Zhejiang University, Hangzhou, China
| | - Qiaojun He
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Cancer Center of Zhejiang University, Hangzhou, China.,The Innovation Institute for Artificial Intelligence in Medicine, Zhejiang University, Hangzhou, China
| | - Ji Cao
- Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Cancer Center of Zhejiang University, Hangzhou, China.,The Innovation Institute for Artificial Intelligence in Medicine, Zhejiang University, Hangzhou, China
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16
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Parrello D, Vlasenok M, Kranz L, Nechaev S. Targeting the Transcriptome Through Globally Acting Components. Front Genet 2021; 12:749850. [PMID: 34603400 PMCID: PMC8481634 DOI: 10.3389/fgene.2021.749850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 09/02/2021] [Indexed: 11/13/2022] Open
Abstract
Transcription is a step in gene expression that defines the identity of cells and its dysregulation is associated with diseases. With advancing technologies revealing molecular underpinnings of the cell with ever-higher precision, our ability to view the transcriptomes may have surpassed our knowledge of the principles behind their organization. The human RNA polymerase II (Pol II) machinery comprises thousands of components that, in conjunction with epigenetic and other mechanisms, drive specialized programs of development, differentiation, and responses to the environment. Parts of these programs are repurposed in oncogenic transformation. Targeting of cancers is commonly done by inhibiting general or broadly acting components of the cellular machinery. The critical unanswered question is how globally acting or general factors exert cell type specific effects on transcription. One solution, which is discussed here, may be among the events that take place at genes during early Pol II transcription elongation. This essay turns the spotlight on the well-known phenomenon of promoter-proximal Pol II pausing as a step that separates signals that establish pausing genome-wide from those that release the paused Pol II into the gene. Concepts generated in this rapidly developing field will enhance our understanding of basic principles behind transcriptome organization and hopefully translate into better therapies at the bedside.
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Affiliation(s)
- Damien Parrello
- Department of Biomedical Sciences, University of North Dakota School of Medicine, Grand Forks, ND, United States
| | - Maria Vlasenok
- Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Lincoln Kranz
- Department of Biomedical Sciences, University of North Dakota School of Medicine, Grand Forks, ND, United States
| | - Sergei Nechaev
- Department of Biomedical Sciences, University of North Dakota School of Medicine, Grand Forks, ND, United States
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17
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Russi M, Marson D, Fermeglia A, Aulic S, Fermeglia M, Laurini E, Pricl S. The fellowship of the RING: BRCA1, its partner BARD1 and their liaison in DNA repair and cancer. Pharmacol Ther 2021; 232:108009. [PMID: 34619284 DOI: 10.1016/j.pharmthera.2021.108009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 08/22/2021] [Accepted: 09/20/2021] [Indexed: 12/12/2022]
Abstract
The breast cancer type 1 susceptibility protein (BRCA1) and its partner - the BRCA1-associated RING domain protein 1 (BARD1) - are key players in a plethora of fundamental biological functions including, among others, DNA repair, replication fork protection, cell cycle progression, telomere maintenance, chromatin remodeling, apoptosis and tumor suppression. However, mutations in their encoding genes transform them into dangerous threats, and substantially increase the risk of developing cancer and other malignancies during the lifetime of the affected individuals. Understanding how BRCA1 and BARD1 perform their biological activities therefore not only provides a powerful mean to prevent such fatal occurrences but can also pave the way to the development of new targeted therapeutics. Thus, through this review work we aim at presenting the major efforts focused on the functional characterization and structural insights of BRCA1 and BARD1, per se and in combination with all their principal mediators and regulators, and on the multifaceted roles these proteins play in the maintenance of human genome integrity.
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Affiliation(s)
- Maria Russi
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy
| | - Domenico Marson
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy
| | - Alice Fermeglia
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy
| | - Suzana Aulic
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy
| | - Maurizio Fermeglia
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy
| | - Erik Laurini
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy
| | - Sabrina Pricl
- Molecular Biology and Nanotechnology Laboratory (MolBNL@UniTs), DEA, University of Trieste, Trieste, Italy; Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.
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18
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Zheng T, Chen P, Huang Y, Qiu J, Zhou C, Wu Z, Li L. CPI-637 as a Potential Bifunctional Latency-Reversing Agent That Targets Both the BRD4 and TIP60 Proteins. Front Cell Infect Microbiol 2021; 11:686035. [PMID: 34350133 PMCID: PMC8326664 DOI: 10.3389/fcimb.2021.686035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 06/28/2021] [Indexed: 11/13/2022] Open
Abstract
The failure of highly active antiretroviral therapy (HAART) has been largely responsible for the existence of latent human immunodeficiency virus type 1 (HIV-1) reservoirs. The “shock and kill” strategy was confirmed to reactivate HIV-1 latent reservoirs by latency-reversing agents (LRAs) for accelerated HIV-1 clearance. However, a single LRA might be insufficient to induce HIV-1 reactivation from latency due to the complexity of the multiple signaling regulatory pathways that establish the HIV-1 latent reservoir. Therefore, combinations of LRAs or dual-mechanism LRAs are urgently needed to purge the latent reservoirs. We demonstrate here for the first time that a dual-target inhibitor with a specific suppressive effect on both BRD4 and TIP60, CPI-637, could reactivate latent HIV-1 in vitro by permitting Tat to bind positive transcription elongation factor b (P-TEFb) and assembling Tat-super-elongation complex (SEC) formation. In addition, CPI-637-mediated TIP60 downregulation further stimulated BRD4 dissociation from the HIV-1 long terminal repeat (LTR) promoter, allowing Tat to more effectively bind P-TEFb compared to BRD4 inhibition alone. Much more importantly, CPI-637 exerted a potent synergistic effect but alleviated global T cell activation and blocked viral spread to uninfected bystander CD4+ T cells with minimal cytotoxicity. Our results indicate that CPI-637 opens up the prospect of novel dual-target inhibitors for antagonizing HIV-1 latency and deserves further investigation for development as a promising LRA with a “shock and kill” strategy.
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Affiliation(s)
- Tengyi Zheng
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Pei Chen
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Yifan Huang
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Jiayin Qiu
- School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Chenliang Zhou
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Ziyao Wu
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Lin Li
- Guangdong Provincial Key Laboratory of New Drug Screening, Guangzhou Key Laboratory of Drug Research for Emerging Virus Prevention and Treatment, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
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19
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Lücking U, Kosemund D, Böhnke N, Lienau P, Siemeister G, Denner K, Bohlmann R, Briem H, Terebesi I, Bömer U, Schäfer M, Ince S, Mumberg D, Scholz A, Izumi R, Hwang S, von Nussbaum F. Changing for the Better: Discovery of the Highly Potent and Selective CDK9 Inhibitor VIP152 Suitable for Once Weekly Intravenous Dosing for the Treatment of Cancer. J Med Chem 2021; 64:11651-11674. [PMID: 34264057 DOI: 10.1021/acs.jmedchem.1c01000] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Selective inhibition of exclusively transcription-regulating positive transcription elongation factor b/CDK9 is a promising new approach in cancer therapy. Starting from atuveciclib, the first selective CDK9 inhibitor to enter clinical development, lead optimization efforts aimed at identifying intravenously (iv) applicable CDK9 inhibitors with an improved therapeutic index led to the discovery of the highly potent and selective clinical candidate VIP152. The evaluation of various scaffold hops was instrumental in the identification of VIP152, which is characterized by the underexplored benzyl sulfoximine group. VIP152 exhibited the best preclinical overall profile in vitro and in vivo, including high efficacy and good tolerability in xenograft models in mice and rats upon once weekly iv administration. VIP152 has entered clinical trials for the treatment of cancer with promising longterm, durable monotherapy activity in double-hit diffuse large B-cell lymphoma patients.
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Affiliation(s)
- Ulrich Lücking
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Dirk Kosemund
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Niels Böhnke
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Philip Lienau
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Gerhard Siemeister
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Karsten Denner
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Rolf Bohlmann
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Hans Briem
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Ildiko Terebesi
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Ulf Bömer
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Martina Schäfer
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Stuart Ince
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Dominik Mumberg
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Arne Scholz
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
| | - Raquel Izumi
- Vincerx Pharma, Inc., 260 Sheridan Avenue, Suite 400, Palo Alto, California 94306, United States
| | - Stuart Hwang
- Vincerx Pharma, Inc., 260 Sheridan Avenue, Suite 400, Palo Alto, California 94306, United States
| | - Franz von Nussbaum
- Pharmaceuticals, Research and Development, Bayer Pharma AG, Müllerstr. 178, Berlin 13353, Germany
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20
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Vervoort SJ, Welsh SA, Devlin JR, Barbieri E, Knight DA, Offley S, Bjelosevic S, Costacurta M, Todorovski I, Kearney CJ, Sandow JJ, Fan Z, Blyth B, McLeod V, Vissers JHA, Pavic K, Martin BP, Gregory G, Demosthenous E, Zethoven M, Kong IY, Hawkins ED, Hogg SJ, Kelly MJ, Newbold A, Simpson KJ, Kauko O, Harvey KF, Ohlmeyer M, Westermarck J, Gray N, Gardini A, Johnstone RW. The PP2A-Integrator-CDK9 axis fine-tunes transcription and can be targeted therapeutically in cancer. Cell 2021; 184:3143-3162.e32. [PMID: 34004147 PMCID: PMC8567840 DOI: 10.1016/j.cell.2021.04.022] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 11/27/2020] [Accepted: 04/14/2021] [Indexed: 12/18/2022]
Abstract
Gene expression by RNA polymerase II (RNAPII) is tightly controlled by cyclin-dependent kinases (CDKs) at discrete checkpoints during the transcription cycle. The pausing checkpoint following transcription initiation is primarily controlled by CDK9. We discovered that CDK9-mediated, RNAPII-driven transcription is functionally opposed by a protein phosphatase 2A (PP2A) complex that is recruited to transcription sites by the Integrator complex subunit INTS6. PP2A dynamically antagonizes phosphorylation of key CDK9 substrates including DSIF and RNAPII-CTD. Loss of INTS6 results in resistance to tumor cell death mediated by CDK9 inhibition, decreased turnover of CDK9 phospho-substrates, and amplification of acute oncogenic transcriptional responses. Pharmacological PP2A activation synergizes with CDK9 inhibition to kill both leukemic and solid tumor cells, providing therapeutic benefit in vivo. These data demonstrate that fine control of gene expression relies on the balance between kinase and phosphatase activity throughout the transcription cycle, a process dysregulated in cancer that can be exploited therapeutically.
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Affiliation(s)
- Stephin J Vervoort
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia.
| | - Sarah A Welsh
- The Wistar Institute, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jennifer R Devlin
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia
| | | | - Deborah A Knight
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia
| | - Sarah Offley
- The Wistar Institute, Philadelphia, PA 19104, USA; Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Stefan Bjelosevic
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia
| | - Matteo Costacurta
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia
| | - Izabela Todorovski
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia
| | - Conor J Kearney
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia
| | - Jarrod J Sandow
- The Walter and Eliza Hall Institute, Parkville 3010, VIC, Australia; Department of Medical Biology, University of Melbourne, Parkville 3010, VIC, Australia
| | - Zheng Fan
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia
| | - Benjamin Blyth
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia
| | - Victoria McLeod
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia
| | - Joseph H A Vissers
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia; Centre for Cancer Research and Department of Clinical Pathology, University of Melbourne, Parkville 3010, VIC, Australia
| | - Karolina Pavic
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku FI-20014, Finland; Institute of Biomedicine, University of Turku, Turku FI-20014, Finland
| | - Ben P Martin
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia
| | - Gareth Gregory
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia; School of Clinical Sciences at Monash Health, Monash University, Clayton 3168, VIC, Australia
| | | | - Magnus Zethoven
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia
| | - Isabella Y Kong
- The Walter and Eliza Hall Institute, Parkville 3010, VIC, Australia; Department of Medical Biology, University of Melbourne, Parkville 3010, VIC, Australia
| | - Edwin D Hawkins
- The Walter and Eliza Hall Institute, Parkville 3010, VIC, Australia; Department of Medical Biology, University of Melbourne, Parkville 3010, VIC, Australia
| | - Simon J Hogg
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia
| | - Madison J Kelly
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia
| | - Andrea Newbold
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia
| | | | - Otto Kauko
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku FI-20014, Finland; Institute of Biomedicine, University of Turku, Turku FI-20014, Finland
| | - Kieran F Harvey
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia; Department of Anatomy and Developmental Biology, and Biomedicine Discovery Institute, Monash University, Clayton 3168, VIC, Australia
| | - Michael Ohlmeyer
- Mount Sinai School of Medicine, New York, NY 10029, USA; Atux Iskay LLC, Plainsboro, NJ 08536, USA
| | - Jukka Westermarck
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku FI-20014, Finland; Institute of Biomedicine, University of Turku, Turku FI-20014, Finland
| | | | | | - Ricky W Johnstone
- Peter MacCallum Cancer Centre, Melbourne 3000, VIC, Australia; The Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville 3010, VIC, Australia.
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21
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Gondkar K, Sathe G, Joshi N, Nair B, Pandey A, Kumar P. Integrated Proteomic and Phosphoproteomics Analysis of DKK3 Signaling Reveals Activated Kinase in the Most Aggressive Gallbladder Cancer. Cells 2021; 10:cells10030511. [PMID: 33670899 PMCID: PMC7997438 DOI: 10.3390/cells10030511] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 12/31/2022] Open
Abstract
DKK3 is a secreted protein, which belongs to a family of Wnt antagonists and acts as a potential tumor suppressor in gallbladder cancer. To further understand its tumor suppressor functions, we overexpressed DKK3 in 3 GBC cell lines. We have employed high-resolution mass spectrometry and tandem mass tag (TMT) multiplexing technology along with immobilized metal affinity chromatography to enrich phosphopeptides to check the downstream regulators. In this study, we reported for the first time the alteration in the phosphorylation of 14 kinases upon DKK3 overexpression. In addition, we observed DKK3 induced hyper phosphorylation of 2 phosphatases: PPP1R12A and PTPRA, which have not been reported previously. Canonical pathway analysis of altered molecules indicated differential enrichment of signaling cascades upon DKK3 overexpression in all the 3 cell lines. Protein kinase A signaling, Sirtuin signaling pathway, and Cell Cycle Control of Chromosomal Replication were observed to be differentially activated in the GBC cell lines. Our study revealed, DKK3 overexpression has differential effect based on the aggressive behavior of the cell lines. This study expands the understanding of DKK3-mediated signaling events and can be used as a primary factor for understanding the complex nature of this molecule.
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Affiliation(s)
- Kirti Gondkar
- Institute of Bioinformatics, International Tech Park, Bangalore 560066, India; (K.G.); (G.S.); (N.J.)
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam 690525, India;
| | - Gajanan Sathe
- Institute of Bioinformatics, International Tech Park, Bangalore 560066, India; (K.G.); (G.S.); (N.J.)
- Center for Molecular Medicine, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore 560029, India;
- Manipal Academy of Higher Education (MAHE), Manipal 576104, India
| | - Neha Joshi
- Institute of Bioinformatics, International Tech Park, Bangalore 560066, India; (K.G.); (G.S.); (N.J.)
- Manipal Academy of Higher Education (MAHE), Manipal 576104, India
| | - Bipin Nair
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam 690525, India;
| | - Akhilesh Pandey
- Center for Molecular Medicine, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore 560029, India;
- Manipal Academy of Higher Education (MAHE), Manipal 576104, India
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Prashant Kumar
- Institute of Bioinformatics, International Tech Park, Bangalore 560066, India; (K.G.); (G.S.); (N.J.)
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam 690525, India;
- Manipal Academy of Higher Education (MAHE), Manipal 576104, India
- Correspondence:
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22
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MNDA controls the expression of MCL-1 and BCL-2 in chronic lymphocytic leukemia cells. Exp Hematol 2020; 88:68-82.e5. [PMID: 32682001 DOI: 10.1016/j.exphem.2020.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/23/2020] [Accepted: 07/03/2020] [Indexed: 02/06/2023]
Abstract
The myeloid nuclear differentiation antigen (MNDA) is a stress-induced protein that promotes degradation of the anti-apoptotic factor MCL-1 and apoptosis in myeloid cells. MNDA is also expressed in normal lymphoid cells and in B-cell clones isolated from individuals with chronic lymphocytic leukemia (CLL), a disease characterized by abnormal apoptosis control. We found that MNDA expression levels inversely correlate with the amount of the anti-apoptotic proteins MCL-1 and BCL-2 in human CLL samples. We report that in response to chemotherapeutic agents that induce genotoxic stress, MNDA exits its typical nucleolar localization and accumulates in the nucleoplasm of CLL and lymphoid cells. Then, MNDA binds chromatin at Mcl1 and Bcl2 genes and affects the transcriptional competence of RNA polymerase II. Our data also reveal that MNDA specifically associates with Mcl1 and Bcl2 (pre-) mRNAs and favors their rapid turnover as a prompt response to genotoxic stress. We propose that this rapid dynamic tuning of RNA levels, which leads to the destabilization of Mcl1 and Bcl2 transcripts, represents a post-transcriptional mechanism of apoptosis control in CLL cells. These results provide an explanation of previous clinical data and corroborate the finding that higher MNDA expression levels in CLL are associated with a better clinical course.
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