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Hou L, Fu Y, Zhao C, Fan L, Hu H, Yin S. Ciprofloxacin and enrofloxacin can cause reproductive toxicity via endocrine signaling pathways. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 244:114049. [PMID: 36063617 DOI: 10.1016/j.ecoenv.2022.114049] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 08/16/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
Ciprofloxacin (CIP) and enrofloxacin (ENR) are veterinary antibiotics commonly utilized to treat and prevent animal diseases. Environmental and dietary antibiotic residues can directly and indirectly affect the reproductive development of animals and humans. This article investigated the reproductive toxicity of CIP in male zebrafish, showing that it could decrease the spermatogonial weight and damage the spermatogonial tissue. The sex hormone assays showed that CIP decreased fshb and lhb gene expression and plasma testosterone (T). In addition, transcriptome analysis indicated that the effect of CIP on zebrafish might be related to the endocrine signaling pathways. ENR, which was selected for further study, inhibited mouse Leydig (TM3) and Sertoli (TM4) cell proliferation and caused cell cycle arrest. The sperm concentration, serum luteotropic hormone (LH) and follicle-stimulating hormone (FSH), and T levels decreased in adolescent mice after ENR treatment for 30d in vivo. Hematoxylin and eosin (H&E) staining showed that ENR exposure potentially induced testicular injury, while the real-time quantitative PCR (qPCR) results indicated that ENR inhibited the mRNA expression of key genes in the Leydig cells (cyp11a1, 3β-HSD, and 17β-HSD), Sertoli cells (Inhbβ and Gdnf) and spermatogenic cells (Plzf, Stra8 and Dmc1). In conclusion, these findings indicated that ENR exposure might influence the development of the testes of pubescent mice.
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Affiliation(s)
- Lirui Hou
- Department of Nutrition and Health, College of Food Science and Nutritional Engineering, China Agricultural University, 17 Qinghua East Road, Haidian District, Beijing 100083, China
| | - Yuhan Fu
- Department of Nutrition and Health, College of Food Science and Nutritional Engineering, China Agricultural University, 17 Qinghua East Road, Haidian District, Beijing 100083, China
| | - Chong Zhao
- Department of Nutrition and Health, College of Food Science and Nutritional Engineering, China Agricultural University, 17 Qinghua East Road, Haidian District, Beijing 100083, China
| | - Lihong Fan
- College of Veterinary Medicine, China Agricultural University, Yunamingyuan West Road, Haidian District, Beijing 100193, China
| | - Hongbo Hu
- Department of Nutrition and Health, College of Food Science and Nutritional Engineering, China Agricultural University, 17 Qinghua East Road, Haidian District, Beijing 100083, China
| | - Shutao Yin
- Department of Nutrition and Health, College of Food Science and Nutritional Engineering, China Agricultural University, 17 Qinghua East Road, Haidian District, Beijing 100083, China.
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2
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Lohmüller M, Roeck BF, Szabo TG, Schapfl MA, Pegka F, Herzog S, Villunger A, Schuler F. The SKP2-p27 axis defines susceptibility to cell death upon CHK1 inhibition. Mol Oncol 2022; 16:2771-2787. [PMID: 35673965 PMCID: PMC9348596 DOI: 10.1002/1878-0261.13264] [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: 01/19/2022] [Revised: 05/05/2022] [Accepted: 06/07/2022] [Indexed: 11/07/2022] Open
Abstract
Checkpoint kinase 1 (CHK1; encoded by CHEK1) is an essential gene that monitors DNA replication fidelity and prevents mitotic entry in the presence of under-replicated DNA or exogenous DNA damage. Cancer cells deficient in p53 tumor suppressor function reportedly develop a strong dependency on CHK1 for proper cell cycle progression and maintenance of genome integrity, sparking interest in developing kinase inhibitors. Pharmacological inhibition of CHK1 triggers B-Cell CLL/Lymphoma 2 (BCL2)-regulated cell death in malignant cells largely independently of p53, and has been suggested to kill p53-deficient cancer cells even more effectively. Next to p53 status, our knowledge about factors predicting cancer cell responsiveness to CHK1 inhibitors is limited. Here, we conducted a genome-wide CRISPR/Cas9-based loss-of-function screen to identify genes defining sensitivity to chemical CHK1 inhibitors. Next to the proapoptotic BCL2 family member, BCL2 Binding Component 3 (BBC3; also known as PUMA), the F-box protein S-phase Kinase-Associated Protein 2 (SKP2) was validated to tune the cellular response to CHK1 inhibition. SKP2 is best known for degradation of the Cyclin-dependent Kinase Inhibitor 1B (CDKN1B; also known as p27), thereby promoting G1-S transition and cell cycle progression in response to mitogens. Loss of SKP2 resulted in the predicted increase in p27 protein levels, coinciding with reduced DNA damage upon CHK1-inhibitor treatment and reduced cell death in S-phase. Conversely, overexpression of SKP2, which consequently results in reduced p27 protein levels, enhanced cell death susceptibility to CHK1 inhibition. We propose that assessing SKP2 and p27 expression levels in human malignancies will help to predict the responsiveness to CHK1-inhibitor treatment.
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Affiliation(s)
- Michael Lohmüller
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Austria
| | - Bernhard F Roeck
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Austria
| | - Tamas G Szabo
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Austria
| | - Marina A Schapfl
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Austria
| | - Fragka Pegka
- Institute for Medical Biochemistry, Biocenter, Medical University of Innsbruck, Austria
| | - Sebastian Herzog
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Austria
| | - Andreas Villunger
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Austria
| | - Fabian Schuler
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Austria
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3
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Zaveri L, Dhawan J. Inducible expression of Oct-3/4 reveals synergy with Klf4 in targeting Cyclin A2 to enhance proliferation during early reprogramming. Biochem Biophys Res Commun 2022; 587:29-35. [PMID: 34864392 DOI: 10.1016/j.bbrc.2021.11.058] [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: 09/27/2021] [Revised: 11/02/2021] [Accepted: 11/15/2021] [Indexed: 11/18/2022]
Abstract
During reprogramming of somatic cells, heightened proliferation is one of the earliest changes observed. While other early events such as mesenchymal-to-epithelial transition have been well studied, the mechanisms by which the cell cycle switches from a slow cycling state to a faster cycling state are still incompletely understood. To investigate the role of Oct-3/4 in this early transition, we created a 4-Hydroxytamoxifen (OHT) dependent Oct-3/4 Estrogen Receptor fusion (OctER). We confirmed that OctER can substitute for Oct-3/4 to reprogram mouse embryonic fibroblasts to a pluripotent state. During the early stages of reprograming, Oct-3/4 and Klf4 individually did not affect cell proliferation but in combination hastened the cell cycle. Using OctER + Klf4, we found that proliferative enhancement is OHT dose-dependent, suggesting that OctER is the driver of this transition. We identified Cyclin A2 as a likely target of Oct-3/4 + Klf4. In mESC, Klf4 and Oct-3/4 bind ∼100bp upstream of Cyclin A2 CCRE, suggesting a potential regulatory role. Using inducible OctER, we show a dose-dependent induction of Cyclin A2 promoter-reporter activity. Taken together, our results suggest that Cyclin A2 is a key early target during reprogramming, and support the view that a rapid cell cycle assists the transition to pluripotency.
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Affiliation(s)
- Lamuk Zaveri
- Institute for Stem Cell Science and Regenerative Medicine, Bengaluru, 560068, India; CSIR-Centre for Cellular and Molecular Biology, Hyderabad, 500007, India; Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Jyotsna Dhawan
- Institute for Stem Cell Science and Regenerative Medicine, Bengaluru, 560068, India; CSIR-Centre for Cellular and Molecular Biology, Hyderabad, 500007, India.
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4
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Effect of Actin Alpha Cardiac Muscle 1 on the Proliferation and Differentiation of Bovine Myoblasts and Preadipocytes. Animals (Basel) 2021; 11:ani11123468. [PMID: 34944244 PMCID: PMC8698029 DOI: 10.3390/ani11123468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/02/2021] [Accepted: 12/02/2021] [Indexed: 12/23/2022] Open
Abstract
Simple Summary Marbling is an important factor affecting the quality of beef. The co-culture (myoblast-preadipocytes) system was successfully established in our lab in the early stage to simulate the internal environment of marbling. Within this environment, ACTC1 gene was a differentially expressed gene screened from the co-culture system. The gene was not expressed in monocultured adipocytes but was expressed in co-cultured adipocytes. Therefore, we hypothesize that the ACTC1 gene plays a role in the development of bovine myoblasts and preadipocytes. In this study, we explored the effect of ACTC1 gene on the proliferation and differentiation of bovine myoblasts and preadipocytes, aiming to discover the potential biological function of ACTC1 gene in muscle development and fat deposition. The results showed that ACTC1 could regulate the development of bovine myoblasts and preadipocytes, and ACTC1 could be used as an important target for improving beef quality in the future. Abstract Actin Alpha Cardiac Muscle 1 (ACTC1) gene is a differentially expressed gene screened through the co-culture system of myoblasts-preadipocytes. In order to study the role of this gene in the process of proliferation and differentiation of bovine myoblasts and preadipocytes, the methods of the knockdown, overexpression, and ectopic expression of ACTC1 were used in this study. After ACTC1 knockdown in bovine myoblasts and inducing differentiation, the sizes and numbers of myotube formation were significantly reduced compared to the control group, and myogenic marker genes—MYOD1, MYOG, MYH3, MRF4, MYF5, CKM and MEF2A—were significantly decreased (p < 0.05, p < 0.01) at both the mRNA and protein levels of myoblasts at different differentiation stages (D0, D2, D4, D6 and D8). Conversely, ACTC1 overexpression induced the inverse result. After ectopic expression of ACTC1 in bovine preadipocytes and induced differentiation, the number and size of lipid droplets were significantly higher than those of the control group, and the expression of adipogenic marker genes—FABP4, SCD1, PPARγ and FASN—were significantly increased (p < 0.05, p < 0.01) at the mRNA and protein levels of preadipocytes at different differentiation stages. Flow cytometry results showed that both the knockdown and overexpression of ACTC1 inhibited the normal cell cycle of myoblasts; however, ectopic expression of ACTC1 in adipocytes induced no significant cell cycle changes. This study is the first to explore the role of ACTC1 in bovine myogenesis and lipogenesis and demonstrates that ACTC1 promotes the differentiation of bovine myoblasts and preadipocytes, affecting the proliferation of myoblasts.
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Li H, Weng Y, Wang S, Wang F, Wang Y, Kong P, Zhang L, Cheng C, Cui H, Xu E, Wei S, Guo D, Chen F, Bi Y, Meng Y, Cheng X, Cui Y. CDCA7 Facilitates Tumor Progression by Directly Regulating CCNA2 Expression in Esophageal Squamous Cell Carcinoma. Front Oncol 2021; 11:734655. [PMID: 34737951 PMCID: PMC8561731 DOI: 10.3389/fonc.2021.734655] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/27/2021] [Indexed: 01/14/2023] Open
Abstract
Background CDCA7 is a copy number amplified gene identified not only in esophageal squamous cell carcinoma (ESCC) but also in various cancer types. Its clinical relevance and underlying mechanisms in ESCC have remained unknown. Methods Tissue microarray data was used to analyze its expression in 179 ESCC samples. The effects of CDCA7 on proliferation, colony formation, and cell cycle were tested in ESCC cells. Real-time PCR and Western blot were used to detect the expression of its target genes. Correlation of CDCA7 with its target genes in ESCC and various SCC types was analyzed using GSE53625 and TCGA data. The mechanism of CDCA7 was studied by chromatin immunoprecipitation (ChIP), luciferase reporter assays, and rescue assay. Results The overexpression of CDCA7 promoted proliferation, colony formation, and cell cycle in ESCC cells. CDCA7 affected the expression of cyclins in different cell phases. GSE53625 and TCGA data showed CCNA2 expression was positively correlated with CDCA7. The knockdown of CCNA2 reversed the malignant phenotype induced by CDCA7 overexpression. Furthermore, CDCA7 was found to directly bind to CCNA2, thus promoting its expression. Conclusions Our results reveal a novel mechanism of CDCA7 that it may act as an oncogene by directly upregulating CCNA2 to facilitate tumor progression in ESCC.
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Affiliation(s)
- Hongyi Li
- Department of Pathology & Shanxi Key Laboratory of Carcinogenesis and Translational Research of Esophageal Cancer, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Yongjia Weng
- Department of Pathology & Shanxi Key Laboratory of Carcinogenesis and Translational Research of Esophageal Cancer, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Shaojie Wang
- Department of Pathology & Shanxi Key Laboratory of Carcinogenesis and Translational Research of Esophageal Cancer, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Fang Wang
- Department of Pathology & Shanxi Key Laboratory of Carcinogenesis and Translational Research of Esophageal Cancer, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Yanqiang Wang
- Department of Pathology & Shanxi Key Laboratory of Carcinogenesis and Translational Research of Esophageal Cancer, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Pengzhou Kong
- Department of Pathology & Shanxi Key Laboratory of Carcinogenesis and Translational Research of Esophageal Cancer, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Ling Zhang
- Department of Pathology & Shanxi Key Laboratory of Carcinogenesis and Translational Research of Esophageal Cancer, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Caixia Cheng
- Department of Pathology, the First Hospital, Shanxi Medical University, Taiyuan, China
| | - Heyang Cui
- Department of Pathology & Shanxi Key Laboratory of Carcinogenesis and Translational Research of Esophageal Cancer, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Enwei Xu
- Department of Pathology, Shanxi Province Cancer Hospital, Taiyuan, China
| | - Shuqing Wei
- Department of Thoracic Surgery (Ⅰ), Shanxi Province Cancer Hospital, Taiyuan, China
| | - Dinghe Guo
- Department of Pathology & Shanxi Key Laboratory of Carcinogenesis and Translational Research of Esophageal Cancer, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Fei Chen
- Department of Pathology & Shanxi Key Laboratory of Carcinogenesis and Translational Research of Esophageal Cancer, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Yanghui Bi
- The Science Research Center, Shanxi Bethone Hospital, Taiyuan, China
| | - Yongsheng Meng
- Tumor Biobank, Shanxi Province Cancer Hospital, Taiyuan, China
| | - Xiaolong Cheng
- Department of Pathology & Shanxi Key Laboratory of Carcinogenesis and Translational Research of Esophageal Cancer, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Yongping Cui
- Department of Pathology & Shanxi Key Laboratory of Carcinogenesis and Translational Research of Esophageal Cancer, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
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6
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Watanabe M, Saeki Y, Takahashi H, Ohtake F, Yoshida Y, Kasuga Y, Kondo T, Yaguchi H, Suzuki M, Ishida H, Tanaka K, Hatakeyama S. A substrate-trapping strategy to find E3 ubiquitin ligase substrates identifies Parkin and TRIM28 targets. Commun Biol 2020; 3:592. [PMID: 33082525 PMCID: PMC7576197 DOI: 10.1038/s42003-020-01328-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 09/28/2020] [Indexed: 02/06/2023] Open
Abstract
The identification of true substrates of an E3 ligase is biologically important but biochemically difficult. In recent years, several techniques for identifying substrates have been developed, but these approaches cannot exclude indirect ubiquitination or have other limitations. Here we develop an E3 ligase substrate-trapping strategy by fusing a tandem ubiquitin-binding entity (TUBE) with an anti-ubiquitin remnant antibody to effectively identify ubiquitinated substrates. We apply this method to one of the RBR-type ligases, Parkin, and to one of the RING-type ligases, TRIM28, and identify previously unknown substrates for TRIM28 including cyclin A2 and TFIIB. Furthermore, we find that TRIM28 promotes cyclin A2 ubiquitination and degradation at the G1/S phase and suppresses premature entry into S phase. Taken together, the results indicate that this method is a powerful tool for comprehensively identifying substrates of E3 ligases. Watanabe et al. combine two previously developed strategies to identify E3 ubiquitin ligase substrates into a method, TR-TUBE that is subsequently used to identify substrates of the Parkin and TRIM28 ligases. They identify known substrates, validating the utility of the approach, and find that TRIM28 targets Cyclin A and TFIIB for degradation.
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Affiliation(s)
- Masashi Watanabe
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-Ku, Sapporo, Hokkaido, 060-8638, Japan.
| | - Yasushi Saeki
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, Setagaya-Ku, Tokyo, 156-8506, Japan
| | - Hidehisa Takahashi
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-Ku, Sapporo, Hokkaido, 060-8638, Japan
| | - Fumiaki Ohtake
- Life Science Tokyo Advanced Research Center, Hoshi University, 2-4-41 Ebara, Shinagawa-Ku, Tokyo, 142-8501, Japan
| | - Yukiko Yoshida
- Ubiquitin Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-Ku, Tokyo, 156-8506, Japan
| | - Yusuke Kasuga
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-Ku, Sapporo, Hokkaido, 060-8638, Japan
| | - Takeshi Kondo
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-Ku, Sapporo, Hokkaido, 060-8638, Japan
| | - Hiroaki Yaguchi
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-Ku, Sapporo, Hokkaido, 060-8638, Japan
| | - Masanobu Suzuki
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-Ku, Sapporo, Hokkaido, 060-8638, Japan
| | - Hiroki Ishida
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-Ku, Sapporo, Hokkaido, 060-8638, Japan
| | - Keiji Tanaka
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, Setagaya-Ku, Tokyo, 156-8506, Japan
| | - Shigetsugu Hatakeyama
- Department of Biochemistry, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-Ku, Sapporo, Hokkaido, 060-8638, Japan.
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7
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Chotiner JY, Wolgemuth DJ, Wang PJ. Functions of cyclins and CDKs in mammalian gametogenesis†. Biol Reprod 2020; 101:591-601. [PMID: 31078132 DOI: 10.1093/biolre/ioz070] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/10/2019] [Accepted: 04/17/2019] [Indexed: 12/13/2022] Open
Abstract
Cyclins and cyclin-dependent kinases (CDKs) are key regulators of the cell cycle. Most of our understanding of their functions has been obtained from studies in single-cell organisms and mitotically proliferating cultured cells. In mammals, there are more than 20 cyclins and 20 CDKs. Although genetic ablation studies in mice have shown that most of these factors are dispensable for viability and fertility, uncovering their functional redundancy, CCNA2, CCNB1, and CDK1 are essential for embryonic development. Cyclin/CDK complexes are known to regulate both mitotic and meiotic cell cycles. While some mechanisms are common to both types of cell divisions, meiosis has unique characteristics and requirements. During meiosis, DNA replication is followed by two successive rounds of cell division. In addition, mammalian germ cells experience a prolonged prophase I in males or a long period of arrest in prophase I in females. Therefore, cyclins and CDKs may have functions in meiosis distinct from their mitotic functions and indeed, meiosis-specific cyclins, CCNA1 and CCNB3, have been identified. Here, we describe recent advances in the field of cyclins and CDKs with a focus on meiosis and early embryogenesis.
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Affiliation(s)
- Jessica Y Chotiner
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
- Cell and Molecular Biology Graduate Program, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Debra J Wolgemuth
- Department of Genetics & Development, Columbia University Medical Center, New York, New York, USA
| | - P Jeremy Wang
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
- Cell and Molecular Biology Graduate Program, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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8
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Tan J, Bai J, Yan Z. An Aligned Patterned Biomimetic Elastic Membrane Has a Potential as Vascular Tissue Engineering Material. Front Bioeng Biotechnol 2020; 8:704. [PMID: 32695769 PMCID: PMC7338373 DOI: 10.3389/fbioe.2020.00704] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/04/2020] [Indexed: 11/24/2022] Open
Abstract
Cardiovascular disease is the leading cause of death worldwide, with an annual mortality incidence predicted to rise to 23.3 million worldwide by 2030. Synthetic vascular grafts as an alternative to autologous vessels have shown satisfactory long-term results for replacement of large- and medium-diameter arteries, but have poor patency rates when applied to small-diameter vessels. Nanoparticles with low toxicity, contrasting agent properties, tailorable characteristics, targeted/stimuli- response delivery potential, and precise control over behavior (via external stimuli such as magnetic fields) have made possible their use for improving engineered tissues. Poly (styrene-block-butadiene-block-styrene) (SBS) is a kind of widely used thermoplastic elastomer with good mechanical properties and biocompatibility. Here, we synthesized anthracene-grafted SBS (SBS-An) by the method for the fabrication of a biomimetic elastic membrane with a switchable Janus structure, and formed the patterns on the surface of SBS-An under ultraviolet (UV) light irradiation. By irradiating the SBS-An film at different times (0, 10, 20, 30, 60, and 120 s), we obtained six well-ordered surface-patterned biomimetic elastic film with SBS-An at different heights in the thickness direction and the same distances of intervals (named sample-0, 10, 20, 30, 60, and 120 s). The structural effects of the SBS-An films on the adhesion and proliferation of human umbilical vein endothelial cells (HUVECs) were studied, and the possible mechanism was explored. When the HUVECs were cultured on the SBS-An films at different heights in the thickness direction, the sample-30 s with approximately 4 μm height significantly promoted adhesion of the HUVECs at the early stage and proliferation during the culture period compared with the samples of the lower (0, 10, and 20 s) and higher (60 and 120 s) heights. Consistent with this, the sample 30 s showed a higher stimulatory effect on the proliferation- and angiogenesis-related genes. These results suggest that SBS-An with appropriate height could efficiently control bioactivities of the biomimetic elastic membrane and might have great potential in vascular tissue engineering application.
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Affiliation(s)
- Juanjuan Tan
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composite Materials and Shanghai Key Lab of Electrical Insulation and Thermal Ageing, Shanghai Jiao Tong University, Shanghai, China
- Joint Research Center for Precision Medicine, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital South Campus, Shanghai, China
| | - Jing Bai
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composite Materials and Shanghai Key Lab of Electrical Insulation and Thermal Ageing, Shanghai Jiao Tong University, Shanghai, China
| | - Zhiqiang Yan
- Central Laboratory, Southern Medical University affiliated Fengxian Hospital, Shanghai, China
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9
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Akaike Y, Chibazakura T. Aberrant activation of cyclin A-CDK induces G2/M-phase checkpoint in human cells. Cell Cycle 2019; 19:84-96. [PMID: 31760882 DOI: 10.1080/15384101.2019.1693119] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cyclin A-cyclin dependent kinase (CDK) activity is regulated by cyclin A proteolysis and CDK inhibitors (CKIs) during M and G1 phases. Our previous work has shown that constitutive activation of cyclin A-CDK in mouse somatic cells, by ectopic expression of stabilized human cyclin A2 (lacking the destruction box: CycAΔ80) in triple CKI (p21, p27, and p107)-knocked-out mouse embryonic fibroblasts, induces rapid tetraploidization. However, effects of such cyclin A-CDK hyperactivation in human cells have been unknown. Here, we show hyperactivity of cyclin A-CDK induces G2/M-phase arrest in human cell lines with relatively low expression of p21 and p27. Moreover, adenovirus E1A protein promoted CycAΔ80-derived G2/M-phase arrest by increasing the amount of cyclin A and cyclin A-CDK2 complex. This response was suppressed by an addition of ATR or Chk1 inhibitor. The amount of repressive phosphorylation of CDK1 at tyrosine 15 (Y15) was decreased by Chk1 inhibitor treatment. Moreover, we observed that co-expressing CDK1AF mutant, which is resistant to the repressive phosphorylation at threonine 14 and Y15, or cdc25A, which dephosphorylates CDK1 at Y15, suppressed the G2/M-phase arrest by CycAΔ80 with E1A. These results suggest that G2/M-phase arrest in human cells by hyperactivity of cyclin A-CDK2 is caused by repression of CDK1 via the cell cycle checkpoint ATR-Chk1 pathway.
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Affiliation(s)
- Yasunori Akaike
- Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan
| | - Taku Chibazakura
- Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan
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10
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Dutta P, Islam S, Choppara S, Sengupta P, Kumar A, Kumar A, Wani MR, Chatterjee S, Santra MK. The tumor suppressor FBXO31 preserves genomic integrity by regulating DNA replication and segregation through precise control of cyclin A levels. J Biol Chem 2019; 294:14879-14895. [PMID: 31413110 DOI: 10.1074/jbc.ra118.007055] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 08/09/2019] [Indexed: 11/06/2022] Open
Abstract
F-box protein 31 (FBXO31) is a reported putative tumor suppressor, and its inactivation due to loss of heterozygosity is associated with cancers of different origins. An emerging body of literature has documented FBXO31's role in preserving genome integrity following DNA damage and in the cell cycle. However, knowledge regarding the role of FBXO31 during normal cell-cycle progression is restricted to its functions during the G2/M phase. Interestingly, FBXO31 levels remain high even during the early G1 phase, a crucial stage for preparing the cells for DNA replication. Therefore, we sought to investigate the functions of FBXO31 during the G1 phase of the cell cycle. Here, using flow cytometric, biochemical, and immunofluorescence techniques, we show that FBXO31 is essential for maintaining optimum expression of the cell-cycle protein cyclin A for efficient cell-cycle progression. Stable FBXO31 knockdown led to atypical accumulation of cyclin A during the G1 phase, driving premature DNA replication and compromised loading of the minichromosome maintenance complex, resulting in replication from fewer origins and DNA double-strand breaks. Because of these inherent defects in replication, FBXO31-knockdown cells were hypersensitive to replication stress-inducing agents and displayed pronounced genomic instability. Upon entering mitosis, the cells defective in DNA replication exhibited a delay in the prometaphase-to-metaphase transition and anaphase defects such as lagging and bridging chromosomes. In conclusion, our findings establish that FBXO31 plays a pivotal role in preserving genomic integrity by maintaining low cyclin A levels during the G1 phase for faithful genome duplication and segregation.
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Affiliation(s)
- Parul Dutta
- National Centre for Cell Science, NCCS Complex, Ganeshkhind Road, Pune, Maharashtra 411007, India.,Department of Biotechnology, Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Sehbanul Islam
- National Centre for Cell Science, NCCS Complex, Ganeshkhind Road, Pune, Maharashtra 411007, India.,Department of Biotechnology, Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Srinadh Choppara
- National Centre for Cell Science, NCCS Complex, Ganeshkhind Road, Pune, Maharashtra 411007, India.,Department of Biotechnology, Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra 411007, India
| | | | - Anil Kumar
- National Centre for Cell Science, NCCS Complex, Ganeshkhind Road, Pune, Maharashtra 411007, India.,Department of Biotechnology, Savitribai Phule Pune University, Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Avinash Kumar
- National Centre for Cell Science, NCCS Complex, Ganeshkhind Road, Pune, Maharashtra 411007, India.,Arnold and Marie Schwartz College of Pharmacy and Health Sciences, Long Island University, Brooklyn, New York 11201
| | - Mohan R Wani
- National Centre for Cell Science, NCCS Complex, Ganeshkhind Road, Pune, Maharashtra 411007, India
| | | | - Manas Kumar Santra
- National Centre for Cell Science, NCCS Complex, Ganeshkhind Road, Pune, Maharashtra 411007, India
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11
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Abstract
A complex network precisely regulates the cell cycle through the G1, S, G2, and M phases and is the basis for cell division under physiological and pathological conditions. On the one hand, the transition from one phase to another as well as the progression within each phase is driven by the specific cyclin-dependent kinases (CDKs; e.g., CDK1, CDK2, CDK4, CDK6, and CDK7), together with their exclusive partner cyclins (e.g., cyclin A1, B1, D1–3, and E1). On the other hand, these phases are negatively regulated by endogenous CDK inhibitors such as p16ink4a, p18ink4c, p19ink4d, p21cip1, and p27kip1. In addition, several checkpoints control the commitment of cells to replicate DNA and undergo mitosis, thereby avoiding the passage of genomic errors to daughter cells. CDKs are often constitutively activated in cancer, which is characterized by the uncontrolled proliferation of transformed cells, due to genetic and epigenetic abnormalities in the genes involved in the cell cycle. Moreover, several oncogenes and defective tumor suppressors promote malignant changes by stimulating cell cycle entry and progression or disrupting DNA damage responses, including the cell cycle checkpoints, DNA repair mechanisms, and apoptosis. Thus, genes or proteins related to cell cycle regulation remain the main targets of interest in the treatment of various cancer types, including hematologic malignancies. In this context, advances in the understanding of the cell cycle regulatory machinery provide a basis for the development of novel therapeutic approaches. The present article summarizes the pathways as well as their genetic and epigenetic alterations that regulate the cell cycle; moreover, it discusses the various approved or potential therapeutic targets associated with the cell cycle, focusing on hematologic malignancies.
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12
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Shekhar R, Priyanka P, Kumar P, Ghosh T, Khan MM, Nagarajan P, Saxena S. The microRNAs miR-449a and miR-424 suppress osteosarcoma by targeting cyclin A2 expression. J Biol Chem 2019; 294:4381-4400. [PMID: 30679313 DOI: 10.1074/jbc.ra118.005778] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 01/18/2019] [Indexed: 12/19/2022] Open
Abstract
MicroRNAs of the miR-16 and miR-34 families have been reported to inhibit cell cycle progression, and their loss has been linked to oncogenic transformation. Utilizing a high-throughput, genome-wide screen for miRNAs and mRNAs that are differentially regulated in osteosarcoma (OS) cell lines, we report that miR-449a and miR-424, belonging to the miR-34 and miR-16 families, respectively, target the major S/G2 phase cyclin, cyclin A2 (CCNA2), in a bipartite manner. We found that the 3'-UTR of CCNA2 is recognized by miR-449a, whereas the CCNA2 coding region is targeted by miR-424. Of note, we observed loss of both miR-449a and miR-424 in OS, resulting in derepression of CCNA2 and appearance of aggressive cancer phenotypes. Ectopic expression of miR-449a and miR-424 significantly decreased cyclin A2 levels and inhibited proliferation rate, migratory potential, and colony-forming ability of OS cells. To further probe the roles of miR-449a and miR-424 in OS, we developed an OS mouse model by intraosseous injection of U2OS cells into the tibia bone of NOD-scid mice, which indicated that miR-449a and miR-424 co-expression suppresses tumor growth. On the basis of this discovery, we analyzed the gene expression of human OS biopsy samples, revealing that miR-449a and miR-424 are both down-regulated, whereas cyclin A2 is significantly up-regulated in these OS samples. In summary, the findings in our study highlight that cyclin A2 repression by miRNAs of the miR-16 and miR-34 families is lost in aggressive OS.
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Affiliation(s)
- Ritu Shekhar
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi-110067, India
| | - Priyanka Priyanka
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi-110067, India
| | - Praveen Kumar
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi-110067, India
| | - Tanushree Ghosh
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi-110067, India
| | - Md Muntaz Khan
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi-110067, India
| | - Perumal Nagarajan
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi-110067, India
| | - Sandeep Saxena
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi-110067, India
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13
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Dong L, Yu L, Bai C, Liu L, Long H, Shi L, Lin Z. USP27-mediated Cyclin E stabilization drives cell cycle progression and hepatocellular tumorigenesis. Oncogene 2018; 37:2702-2713. [PMID: 29497124 PMCID: PMC5955865 DOI: 10.1038/s41388-018-0137-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 11/09/2017] [Accepted: 12/19/2017] [Indexed: 01/28/2023]
Abstract
Overexpression of Cyclin E has been seen in many types of cancers. However, the underlying mechanism remains enigmatic. Herein, we identified ubiquitin-specific peptidase 27 (USP27) as a Cyclin E interactor. We found that USP27 promoted Cyclin E stability by negatively regulating its ubiquitination. In addition, suppression of USP27 expression resulted in the inhibition of the growth, migration, and invasion of hepatocellular carcinoma. Furthermore, we detected a positive correlation between USP27 and Cyclin E expression in hepatocellular carcinoma tissues. Finally, we found that USP27 expression is inhibited by 5-fluorouracil (5-FU) treatment and USP27 depletion sensitizes Hep3B cells to 5-FU-induced apoptosis. USP27-mediated Cyclin E stabilization is involved in tumorigenesis, suggesting that targeting USP27 may represent a new therapeutic strategy to treat cancers with aberrant overexpression of Cyclin E protein.
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Affiliation(s)
- Ling Dong
- Laboratory of Pathology, School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Le Yu
- Laboratory of Pathology, School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Chunrong Bai
- Laboratory of Pathology, School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Liu Liu
- Laboratory of Pathology, School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Hua Long
- Laboratory of Pathology, School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Lei Shi
- Laboratory of Pathology, School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Zhenghong Lin
- Laboratory of Pathology, School of Life Sciences, Chongqing University, Chongqing, 401331, China.
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14
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Rausch JL, Boichuk S, Ali AA, Patil SS, Liu L, Lee DM, Brown MF, Makielski KR, Liu Y, Taguchi T, Kuan SF, Duensing A. Opposing roles of KIT and ABL1 in the therapeutic response of gastrointestinal stromal tumor (GIST) cells to imatinib mesylate. Oncotarget 2018; 8:4471-4483. [PMID: 27965460 PMCID: PMC5354847 DOI: 10.18632/oncotarget.13882] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 12/05/2016] [Indexed: 11/25/2022] Open
Abstract
Most gastrointestinal stromal tumors (GISTs) are caused by activating mutations of the KIT receptor tyrosine kinase. The small molecule inhibitor imatinib mesylate was initially developed to target the ABL1 kinase, which is constitutively activated through chromosomal translocation in BCR-ABL1-positive chronic myeloid leukemia. Because of cross-reactivity of imatinib against the KIT kinase, the drug is also successfully used for the treatment of GIST. Although inhibition of KIT clearly has a major role in the therapeutic response of GIST to imatinib, the contribution of concomitant inhibition of ABL in this context has never been explored. We show here that ABL1 is expressed in the majority of GISTs, including human GIST cell lines. Using siRNA-mediated knockdown, we demonstrate that depletion of KIT in conjunction with ABL1 – hence mimicking imatinib treatment – leads to reduced apoptosis induction and attenuated inhibition of cellular proliferation when compared to depletion of KIT alone. These results are explained by an increased activity of the AKT survival kinase, which is mediated by the cyclin-dependent kinase CDK2, likely through direct phosphorylation. Our results highlight that distinct inhibitory properties of targeted agents can impede antitumor effects and hence provide insights for rational drug development. Novel KIT-targeted agents to treat GIST should therefore comprise an increased specificity for KIT while at the same time displaying a reduced ability to inhibit ABL1.
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Affiliation(s)
- Jessica L Rausch
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA
| | - Sergei Boichuk
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA.,Current address: Department of Pathology, Kazan State Medical University, Kazan, Russia
| | - Areej A Ali
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA
| | - Sneha S Patil
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA
| | - Lijun Liu
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA
| | - Donna M Lee
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA
| | - Matthew F Brown
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA
| | - Kathleen R Makielski
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA
| | - Ying Liu
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA
| | - Takahiro Taguchi
- Department of Anatomy, Kochi Medical School, Nankoku Kochi, Japan
| | - Shih-Fan Kuan
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Anette Duensing
- Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA.,Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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15
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Wang X, Ha T, Liu L, Hu Y, Kao R, Kalbfleisch J, Williams D, Li C. TLR3 Mediates Repair and Regeneration of Damaged Neonatal Heart through Glycolysis Dependent YAP1 Regulated miR-152 Expression. Cell Death Differ 2018; 25:966-982. [PMID: 29358670 PMCID: PMC5943401 DOI: 10.1038/s41418-017-0036-9] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 10/16/2017] [Accepted: 11/03/2017] [Indexed: 12/20/2022] Open
Abstract
The present study investigated whether TLR3 is required for neonatal heart repair and regeneration following myocardial infarction (MI). TLR3 deficient neonatal mice exhibited impaired cardiac functional recovery and a larger infarct size, while wild type neonatal mice showed cardiac functional recovery and small infarct size after MI. The data suggest that TLR3 is essential for the regeneration and repair of damaged neonatal myocardium. In vitro treatment of neonatal cardiomyocytes with a TLR3 ligand, Poly (I:C), significantly enhances glycolytic metabolism, YAP1 activation and proliferation of cardiomyocytes which were prevented by a glycolysis inhibitor, 2-deoxyglucose (2-DG). Administration of 2-DG to neonatal mice abolished cardiac functional recovery and YAP activation after MI, suggesting that TLR3-mediated regeneration and repair of the damaged neonatal myocardium is through glycolytic-dependent YAP1 activation. Inhibition of YAP1 activation abolished Poly (I:C) induced proliferation of neonatal cardiomyocytes. Interestingly, activation of YAP1 increases the expression of miR-152 which represses the expression of cell cycle inhibitory proteins, P27kip1 and DNMT1, leading to cardiomyocyte proliferation. We conclude that TLR3 is required for neonatal heart regeneration and repair after MI. The mechanisms involve glycolytic-dependent YAP1 activation, resulting in miR-152 expression which targets DNMT1/p27kip1.
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Affiliation(s)
- Xiaohui Wang
- Departments of Surgery, East Tennessee State University, Johnson City, TN, USA.,Center of Excellence in Inflammation, Infectious Disease and Immunity, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Tuanzhu Ha
- Departments of Surgery, East Tennessee State University, Johnson City, TN, USA.,Center of Excellence in Inflammation, Infectious Disease and Immunity, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Li Liu
- Department of Geriatrics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yuanping Hu
- Departments of Surgery, East Tennessee State University, Johnson City, TN, USA.,Department of Pharmacy, the Binhu Hospital of Hefei, Anhui, China
| | - Race Kao
- Departments of Surgery, East Tennessee State University, Johnson City, TN, USA.,Center of Excellence in Inflammation, Infectious Disease and Immunity, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - John Kalbfleisch
- Center of Excellence in Inflammation, Infectious Disease and Immunity, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA.,Biometry and Medical Computing and East Tennessee State University, Johnson City, TN, USA
| | - David Williams
- Departments of Surgery, East Tennessee State University, Johnson City, TN, USA.,Center of Excellence in Inflammation, Infectious Disease and Immunity, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Chuanfu Li
- Departments of Surgery, East Tennessee State University, Johnson City, TN, USA. .,Center of Excellence in Inflammation, Infectious Disease and Immunity, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA.
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16
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Zhang HP, Wang YH, Ma SC, Zhang H, Yang AN, Yang XL, Zhang MH, Sun JM, Hao YJ, Jiang YD. Homocysteine inhibits endothelial progenitor cells proliferation via DNMT1-mediated hypomethylation of Cyclin A. Exp Cell Res 2017; 362:217-226. [PMID: 29155363 DOI: 10.1016/j.yexcr.2017.11.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 11/13/2017] [Accepted: 11/15/2017] [Indexed: 01/08/2023]
Abstract
Endothelial progenitor cells (EPCs) contribute to neovasculogenesis and reendothelialization of damaged blood vessels to maintain the endothelium. Dysfunction of EPCs is implicated in the pathogenesis of vascular injury induced by homocysteine (Hcy). We aimed to investigate the role of Cyclin A in Hcy-induced EPCs dysfunction and explore its molecular mechanism. In this study, by treatment of EPCs with Hcy, we found that the expression of Cyclin A mRNA and protein were significantly downregulated in a dose-dependent manner. Knockdown of Cyclin A prominently reduced proliferation of EPCs, while over-expression of Cyclin A significantly promoted the cell proliferation, suggesting that Hcy inhibits EPCs proliferation through downregulation of Cyclin A expression. In addition, epigenetic study also demonstrated that Hcy induces DNA hypomethylation of the Cyclin A promoter in EPCs through downregulated expression of DNMT1. Moreover, we found that Hcy treatment of EPCs leads to increased SAM, SAH and MeCP2, while the ratio of SAM/SAH and MBD expression decrease. In summary, our results indicate that Hcy inhibits Cyclin A expression through hypomethylation of Cyclin A and thereby suppress EPCs proliferation. These findings demonstrate a novel mechanism of DNA methylation mediated by DNMT1 in prevention of Hcy associated cardiovascular disease.
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Affiliation(s)
- Hui-Ping Zhang
- Department of Prenatal Diagnosis Center, General Hospital of Ningxia Medical University, Yinchuan 750004, China
| | - Yan-Hua Wang
- Department of Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan 750004, China; Ningxia Key Laboratory of Vascular Injury and Repair Research, Yinchuan 750004, China
| | - Sheng-Chao Ma
- Department of Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan 750004, China; Ningxia Key Laboratory of Vascular Injury and Repair Research, Yinchuan 750004, China
| | - Hui Zhang
- Department of Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan 750004, China; Ningxia Key Laboratory of Vascular Injury and Repair Research, Yinchuan 750004, China
| | - An-Ning Yang
- Department of Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan 750004, China; Ningxia Key Laboratory of Vascular Injury and Repair Research, Yinchuan 750004, China
| | - Xiao-Ling Yang
- Department of Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan 750004, China; Ningxia Key Laboratory of Vascular Injury and Repair Research, Yinchuan 750004, China
| | - Ming-Hao Zhang
- Department of Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan 750004, China; Ningxia Key Laboratory of Vascular Injury and Repair Research, Yinchuan 750004, China
| | - Jian-Min Sun
- Department of Pathogen Biology and Immunology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan 750004, China; Translational Cancer Research, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Yin-Ju Hao
- Department of Pharmacology, Ningxia Medical University, Yinchuan 750004, China
| | - Yi-Deng Jiang
- Department of Pathophysiology, School of Basic Medical Sciences, Ningxia Medical University, Yinchuan 750004, China; Ningxia Key Laboratory of Vascular Injury and Repair Research, Yinchuan 750004, China.
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17
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High-Risk Alphapapillomavirus Oncogenes Impair the Homologous Recombination Pathway. J Virol 2017; 91:JVI.01084-17. [PMID: 28768872 DOI: 10.1128/jvi.01084-17] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 07/28/2017] [Indexed: 01/25/2023] Open
Abstract
Persistent high-risk genus human Alphapapillomavirus (HPV) infections cause nearly every cervical carcinoma and a subset of tumors in the oropharyngeal tract. During the decades required for HPV-associated tumorigenesis, the cellular genome becomes significantly destabilized. Our analysis of cervical tumors from four separate data sets found a significant upregulation of the homologous-recombination (HR) pathway genes. The increased abundance of HR proteins can be replicated in primary cells by expression of the two HPV oncogenes (E6 and E7) required for HPV-associated transformation. HPV E6 and E7 also enhanced the ability of HR proteins to form repair foci, and yet both E6 and E7 reduce the ability of the HR pathway to complete double-strand break (DSB) repair by about 50%. The HPV oncogenes hinder HR by allowing the process to begin at points in the cell cycle when the lack of a sister chromatid to serve as a homologous template prevents completion of the repair. Further, HPV E6 attenuates repair by causing RAD51 to be mislocalized away from both transient and persistent DSBs, whereas HPV E7 is only capable of impairing RAD51 localization to transient lesions. Finally, we show that the inability to robustly repair DSBs causes some of these lesions to be more persistent, a phenotype that correlates with increased integration of episomal DNA. Together, these data support our hypothesis that HPV oncogenes contribute to the genomic instability observed in HPV-associated malignancies by attenuating the repair of damaged DNA.IMPORTANCE This study expands the understanding of HPV biology, establishing a direct role for both HPV E6 and E7 in the destabilization of the host genome by blocking the homologous repair of DSBs. To our knowledge, this is the first time that both viral oncogenes were shown to disrupt this DSB repair pathway. We show that HPV E6 and E7 allow HR to initiate at an inappropriate part of the cell cycle. The mislocalization of RAD51 away from DSBs in cells expressing HPV E6 and E7 hinders HR through a distinct mechanism. These observations have broad implications. The impairment of HR by HPV oncogenes may be targeted for treatment of HPV+ malignancies. Further, this attenuation of repair suggests HPV oncogenes may contribute to tumorigenesis by promoting the integration of the HPV genome, a common feature of HPV-transformed cells. Our data support this idea since HPV E6 stimulates the integration of episomes.
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18
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Liu Q, Xu C, Ji G, Liu H, Mo Y, Tollerud DJ, Gu A, Zhang Q. Sublethal effects of zinc oxide nanoparticles on male reproductive cells. Toxicol In Vitro 2016; 35:131-8. [DOI: 10.1016/j.tiv.2016.05.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 04/08/2016] [Accepted: 05/27/2016] [Indexed: 10/21/2022]
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19
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Trump BF. Mechanisms of Toxicity and Carcinogenesis. Toxicol Pathol 2016. [DOI: 10.1177/019262339502300616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Tantos A, Kalmar L, Tompa P. The role of structural disorder in cell cycle regulation, related clinical proteomics, disease development and drug targeting. Expert Rev Proteomics 2016; 12:221-33. [PMID: 25976105 DOI: 10.1586/14789450.2015.1042866] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Understanding the molecular mechanisms of the regulation of cell cycle is a central issue in molecular cell biology, due to its fundamental role in the existence of cells. The regulatory circuits that make decisions on when a cell should divide are very complex and particularly subtly balanced in eukaryotes, in which the harmony of many different cells in an organism is essential for life. Several hundred proteins are involved in these processes, and a great deal of studies attests that most of them have functionally relevant intrinsic structural disorder. Structural disorder imparts many functional advantages on these proteins, and we discuss it in detail that it is involved in all key steps from signaling through the cell membrane to regulating transcription of proteins that execute timely responses to an ever-changing environment.
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Affiliation(s)
- Agnes Tantos
- Institute of Enzymology, Research Centre for Natural Sciences of the Hungarian Academy of Sciences, Budapest, Hungary
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21
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Lee HJ, Dreyfus C, DiCicco-Bloom E. Valproic acid stimulates proliferation of glial precursors during cortical gliogenesis in developing rat. Dev Neurobiol 2015; 76:780-98. [PMID: 26505176 DOI: 10.1002/dneu.22359] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 10/16/2015] [Accepted: 10/23/2015] [Indexed: 11/06/2022]
Abstract
Valproic acid (VPA) is a neurotherapeutic drug prescribed for seizures, bipolar disorder, and migraine, including women of reproductive age. VPA is a well-known teratogen that produces congenital malformations in many organs including the nervous system, as well as later neurodevelopmental disorders, including mental retardation and autism. In developing brain, few studies have examined VPA effects on glial cells, particularly astrocytes. To investigate effects on primary glial precursors, we developed new cell culture and in vivo models using frontal cerebral cortex of postnatal day (P2) rat. In vitro, VPA exposure elicited dose-dependent, biphasic effects on DNA synthesis and proliferation. In vivo VPA (300 mg/kg) exposure from P2 to P4 increased both DNA synthesis and cell proliferation, affecting primarily astrocyte precursors, as >75% of mitotic cells expressed brain lipid-binding protein. Significantly, the consequence of early VPA exposure was increased astrocytes, as both S100-β+ cells and glial fibrillary acidic protein were increased in adolescent brain. Molecularly, VPA served as an HDAC inhibitor in vitro and in vivo as enhanced proliferation was accompanied by increased histone acetylation, whereas it elicited changes in culture in cell-cycle regulators, including cyclin D1 and E, and cyclin-dependent kinase (CDK) inhibitors, p21 and p27. Collectively, these data suggest clinically relevant VPA exposures stimulate glial precursor proliferation, though at higher doses can elicit inhibition through differential regulation of CDK inhibitors. Because changes in glial cell functions are proposed as mechanisms contributing to neuropsychiatric disorders, these observations suggest that VPA teratogenic actions may be mediated through changes in astrocyte generation during development. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 780-798, 2016.
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Affiliation(s)
- Hee Jae Lee
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, Piscataway, New Jersey.,Department of Pharmacology, School of Medicine, Kangwon National University, Chuncheon, Republic of Korea
| | - Cheryl Dreyfus
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, Piscataway, New Jersey
| | - Emanuel DiCicco-Bloom
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, Piscataway, New Jersey.,Department of Pediatrics, Rutgers Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, New Brunswick, New Jersey
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22
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PUL21a-Cyclin A2 interaction is required to protect human cytomegalovirus-infected cells from the deleterious consequences of mitotic entry. PLoS Pathog 2014; 10:e1004514. [PMID: 25393019 PMCID: PMC4231158 DOI: 10.1371/journal.ppat.1004514] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 10/11/2014] [Indexed: 12/02/2022] Open
Abstract
Entry into mitosis is accompanied by dramatic changes in cellular architecture, metabolism and gene expression. Many viruses have evolved cell cycle arrest strategies to prevent mitotic entry, presumably to ensure sustained, uninterrupted viral replication. Here we show for human cytomegalovirus (HCMV) what happens if the viral cell cycle arrest mechanism is disabled and cells engaged in viral replication enter into unscheduled mitosis. We made use of an HCMV mutant that, due to a defective Cyclin A2 binding motif in its UL21a gene product (pUL21a), has lost its ability to down-regulate Cyclin A2 and, therefore, to arrest cells at the G1/S transition. Cyclin A2 up-regulation in infected cells not only triggered the onset of cellular DNA synthesis, but also promoted the accumulation and nuclear translocation of Cyclin B1-CDK1, premature chromatin condensation and mitotic entry. The infected cells were able to enter metaphase as shown by nuclear lamina disassembly and, often irregular, metaphase spindle formation. However, anaphase onset was blocked by the still intact anaphase promoting complex/cyclosome (APC/C) inhibitory function of pUL21a. Remarkably, the essential viral IE2, but not the related chromosome-associated IE1 protein, disappeared upon mitotic entry, suggesting an inherent instability of IE2 under mitotic conditions. Viral DNA synthesis was impaired in mitosis, as demonstrated by the abnormal morphology and strongly reduced BrdU incorporation rates of viral replication compartments. The prolonged metaphase arrest in infected cells coincided with precocious sister chromatid separation and progressive fragmentation of the chromosomal material. We conclude that the Cyclin A2-binding function of pUL21a contributes to the maintenance of a cell cycle state conducive for the completion of the HCMV replication cycle. Unscheduled mitotic entry during the course of the HCMV replication has fatal consequences, leading to abortive infection and cell death. Cyclin A2 is a key regulator of the cell division cycle. Interactors of Cyclin A2 typically contain short sequence elements (RXL/Cy motifs) that bind with high affinity to a hydrophobic patch in the Cyclin A2 protein. Two types of RXL/Cy-containing factors are known: i) cyclin-dependent kinase (CDK) substrates, which are processed by the CDK subunit that complexes to Cyclin A2, and ii) CDK inhibitors, which stably associate to Cyclin A2-CDK due to the lack of CDK phosphorylation sites. Human cytomegalovirus (HCMV) has evolved a novel type of RXL/Cy-containing protein. Its UL21a gene product, a small and highly unstable protein, binds to Cyclin A2 via an RXL/Cy motif in its N-terminus, leading to efficient degradation of Cyclin A2 by the proteasome. Here, we show that this mechanism is not only essential for viral inhibition of cellular DNA synthesis, but also to prevent entry of infected cells into mitosis. Unscheduled mitotic entry is followed by aberrant spindle formation, metaphase arrest, precocious separation of sister chromatids, chromosomal fragmentation and cell death. Viral DNA replication and expression of the essential viral IE2 protein are abrogated in mitosis. Thus, pUL21a-Cyclin A2 interaction protects HCMV from a collapse of viral and cellular functions in mitosis.
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Nakagawa S, Sakamoto Y, Okabe H, Hayashi H, Hashimoto D, Yokoyama N, Tokunaga R, Sakamoto K, Kuroki H, Mima K, Beppu T, Baba H. Epigenetic therapy with the histone methyltransferase EZH2 inhibitor 3-deazaneplanocin A inhibits the growth of cholangiocarcinoma cells. Oncol Rep 2014; 31:983-8. [PMID: 24337160 DOI: 10.3892/or.2013.2922] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 11/25/2013] [Indexed: 02/05/2023] Open
Abstract
Enhancer of zeste homolog 2 (EZH2) is involved in malignant transformation and the biological aggressiveness of several human malignancies. Growing evidence indicates that EZH2 may be an appropriate therapeutic target for malignancies, including cholangiocarcinoma. Recently, an S-adenosyl-L-homocysteine hydrolase inhibitor, 3-deazaneplanocin A (DZNep) was shown to deplete and inhibit EZH2. The aim of this study was to determine the effect of DZNep and the combination of gemcitabine and DZNep in cholangiocarcinoma cells. The effects of DZNep and its combination with gemcitabine were assessed in the cholangiocarcinoma cell lines RBE and TFK-1. DZNep depleted the cellular levels of EZH2 and inhibited the associated histone H3 lysine 27 trimethylation. DZNep treatment resulted in the inhibition of proliferation in the cholangiocarcinoma cell lines, and the combination of DZNep and gemcitabine showed synergistic inhibition of cell proliferation. DZNep induced apoptosis and G1 phase cell cycle arrest in cholangiocarcinoma cells, and the combination of DZNep and gemcitabine enhanced the induced apoptosis and G1 arrest when compared with gemcitabine alone. Inhibition of cell proliferation by DZNep was partially associated with upregulation of p16INK4a and p17KIP1. The present study shows that DZNep inhibits cell proliferation by inducing G1 arrest and apoptosis. These results indicate that an epigenetic therapy that pharmacologically targets EZH2 via DZNep may constitute a novel approach for the treatment of cholangiocarcinoma.
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Affiliation(s)
- Shigeki Nakagawa
- Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto 860-0811, Japan
| | - Yasuo Sakamoto
- Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto 860-0811, Japan
| | - Hirohisa Okabe
- Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto 860-0811, Japan
| | - Hiromitsu Hayashi
- Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto 860-0811, Japan
| | - Daisuke Hashimoto
- Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto 860-0811, Japan
| | - Naomi Yokoyama
- Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto 860-0811, Japan
| | - Ryuma Tokunaga
- Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto 860-0811, Japan
| | - Keita Sakamoto
- Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto 860-0811, Japan
| | - Hideyuki Kuroki
- Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto 860-0811, Japan
| | - Kosuke Mima
- Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto 860-0811, Japan
| | - Toru Beppu
- Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto 860-0811, Japan
| | - Hideo Baba
- Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto 860-0811, Japan
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Kaposi's sarcoma-associated herpesvirus transactivator Rta induces cell cycle arrest in G0/G1 phase by stabilizing and promoting nuclear localization of p27kip. J Virol 2013; 87:13226-38. [PMID: 24067984 DOI: 10.1128/jvi.02540-13] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The Kaposi's sarcoma-associated herpesvirus (KSHV) immediate-early gene, replication, and transcription activator (K-Rta) is a key viral protein that serves as the master regulator for viral lytic replication. In this study, we investigated the role of K-Rta in cell cycle regulation and found that the expression of K-Rta in doxycycline (Dox)-inducible BJAB cells induced cell cycle arrest in G0/G1 phase. Western blot analysis of key cell cycle regulators revealed that K-Rta-mediated cell cycle arrest was associated with a decrease in cyclin A and phosphorylated Rb (pS807/pS811) protein levels, both markers of S phase progression, and an increase in protein levels for p27, a cyclin-dependent kinase inhibitor. Further, we found that K-Rta does not affect the transcription of p27 but regulates p27 at the posttranslational level by inhibiting its proteosomal degradation. Immunofluorescence staining and cell fractionation experiments revealed largely nuclear compartmentalization of p27 in K-Rta-expressing cells, demonstrating that K-Rta not only stabilizes p27 but also modulates its cellular localization. Finally, short hairpin RNA knockdown of p27 significantly abrogates cell cycle arrest in K-Rta-expressing cells, supporting its key role in K-Rta-mediated cell cycle arrest. Our findings are consistent with previous studies which showed that expression of immediate-early genes of several herpesviruses, including herpes simplex virus, Epstein-Barr virus, and cytomegalovirus, results in cell cycle arrest at the G0/G1 phase, possibly to avoid competition for resources needed for host cell replication during the S phase.
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25
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Wang L, Wang G, Yang D, Guo X, Xu Y, Feng B, Kang J. Euphol arrests breast cancer cells at the G1 phase through the modulation of cyclin D1, p21 and p27 expression. Mol Med Rep 2013; 8:1279-85. [PMID: 23969579 DOI: 10.3892/mmr.2013.1650] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 08/12/2013] [Indexed: 11/05/2022] Open
Abstract
Euphorbia tirucalli is a long‑established treatment for a wide variety of cancers. However, the mechanism of its anticancer effect is yet to be elucidated. In the present study, we examined the anticancer effect of euphol, a tetracyclic triterpene alcohol isolated from the sap of Euphorbia tirucalli, in T47D human breast cancer cells. Following the treatment of cells with different doses of euphol for 24, 48 and 72 h, the cell proliferation, cell cycle, and mRNA and protein levels of cell cycle regulatory molecules were analyzed, respectively. Treatment of the cells with euphol resulted in decreased cell viability, which was accompanied by an accumulation of cells in the G1 phase. Further studies demonstrated that euphol treatment downregulated cyclin D1 expression and the hypophosphorylation of Rb. Furthermore, this effect was correlated with the downregulation of cyclin‑dependent kinase 2 (CDK2) expression and the upregulation of the CDK inhibitors p21 and p27. Reduced expression levels of cyclin A and B1 were also observed, corresponding to the decreased distribution of cells in the S and G2/M phases, respectively. These findings indicated that euphol is an active agent in Euphorbia tirucalli that exerts anticancer activity by arresting the cell cycle of cancer cells.
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Affiliation(s)
- Lin Wang
- Department of Endocrinology, East Hospital, Tongji University School of Medicine, Yangpu, Shanghai 200092, P.R. China
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26
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Yan KH, Lee LM, Hsieh MC, Yan MD, Yao CJ, Chang PY, Chen TL, Chang HY, Cheng AL, Lai GM, Chuang SE. Aspirin antagonizes the cytotoxic effect of methotrexate in lung cancer cells. Oncol Rep 2013; 30:1497-505. [PMID: 23799623 DOI: 10.3892/or.2013.2561] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 05/09/2013] [Indexed: 11/06/2022] Open
Abstract
Methotrexate (MTX) has been widely used for the treatment of cancer and rheumatoid arthritis (RA). Aspirin (ASA) is a non-selective cyclooxygenase (COX) inhibitor that contributes to the treatment of inflammatory conditions such as RA. It has been observed that the antitumor effect of ASA can be attributed to inhibition of cell cycle progression, induction of apoptosis and inhibition of angiogenesis. In the present study, we revealed that the treatment with a combination of MTX and ASA resulted in antagonism of the cytotoxic effect as demonstrated by SRB and colony formation assays. ASA alleviated the MTX-mediated S phase accumulation and recovered the G1 phase. MTX-mediated accumulation of the S phase marker cyclin A was also alleviated by ASA. Notably, FAS protein levels were upregulated by MTX in A549 cells. The antagonism of MTX efficacy caused by ASA was accompanied by altered expression of caspase-3, Bcl-2 and FAS but not dihydrofolate reductase (DHFR). This suggests that the alteration of caspase-3, Bcl-2 and FAS was involved in the antagonism between ASA and MTX. Exogenously added folic acid reversed the MTX-mediated DHFR inhibition following either MTX or MTX + ASA treatments. Most importantly, we demonstrated for the first time that the commonly used non-steroidal anti-inflammatory drug for headache ASA and possibly other COX-1/2 inhibitors can produce a strong antagonistic effect on the growth inhibition of lung cancer cells when administered in combination with MTX. The clinical implication of our finding is obvious, i.e., the clinical efficacy of MTX therapy can be compromised by ASA and their concomitant use should be avoided.
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Affiliation(s)
- Kun-Huang Yan
- Department of Urology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan, R.O.C
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27
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Vidal-Laliena M, Gallastegui E, Mateo F, Martínez-Balbás M, Pujol MJ, Bachs O. Histone deacetylase 3 regulates cyclin A stability. J Biol Chem 2013; 288:21096-21104. [PMID: 23760262 DOI: 10.1074/jbc.m113.458323] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
PCAF and GCN5 acetylate cyclin A at specific lysine residues targeting it for degradation at mitosis. We report here that histone deacetylase 3 (HDAC3) directly interacts with and deacetylates cyclin A. HDAC3 interacts with a domain included in the first 171 aa of cyclin A, a region involved in the regulation of its stability. In cells, overexpression of HDAC3 reduced cyclin A acetylation whereas the knocking down of HDAC3 increased its acetylation. Moreover, reduction of HDAC3 levels induced a decrease of cyclin A that can be reversed by proteasome inhibitors. These results indicate that HDAC3 is able to regulate cyclin A degradation during mitosis via proteasome. Interestingly, HDAC3 is abruptly degraded at mitosis also via proteasome thus facilitating cyclin A acetylation by PCAF/GCN5, which will target cyclin A for degradation. Because cyclin A is crucial for S phase progression and mitosis entry, the knock down of HDAC3 affects cell cycle progression specifically at both, S phase and G2/M transition. In summary we propose here that HDAC3 regulates cyclin A stability by counteracting the action of the acetylases PCAF/GCN5.
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Affiliation(s)
- Miriam Vidal-Laliena
- From the Department of Cell Biology, Immunology and Neurosciences, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, 08036 Barcelona, Spain and
| | - Edurne Gallastegui
- From the Department of Cell Biology, Immunology and Neurosciences, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, 08036 Barcelona, Spain and
| | | | - Marian Martínez-Balbás
- Molecular Biology, Barcelona Institute of Molecular Biology, Consejo Superior de Investigaciones Científicas (CSIC), 08028 Barcelona, Spain
| | - Maria Jesús Pujol
- From the Department of Cell Biology, Immunology and Neurosciences, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, 08036 Barcelona, Spain and
| | - Oriol Bachs
- From the Department of Cell Biology, Immunology and Neurosciences, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), University of Barcelona, 08036 Barcelona, Spain and.
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28
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Kikuchi J, Takashina T, Kinoshita I, Kikuchi E, Shimizu Y, Sakakibara-Konishi J, Oizumi S, Marquez VE, Nishimura M, Dosaka-Akita H. Epigenetic therapy with 3-deazaneplanocin A, an inhibitor of the histone methyltransferase EZH2, inhibits growth of non-small cell lung cancer cells. Lung Cancer 2012; 78:138-43. [PMID: 22925699 PMCID: PMC3472089 DOI: 10.1016/j.lungcan.2012.08.003] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 07/13/2012] [Accepted: 08/05/2012] [Indexed: 12/31/2022]
Abstract
EZH2 (enhancer of zeste homolog 2) is the catalytic subunit of PRC2 (polycomb repressive complex 2), which mediates histone methyltransferase activity and functions as transcriptional repressor involved in gene silencing. EZH2 is involved in malignant transformation and biological aggressiveness of several human malignancies. We previously demonstrated that non-small cell lung cancers (NSCLCs) also overexpress EZH2 and that high expression of EZH2 correlates with poor prognosis. Growing evidence indicates that EZH2 may be an appropriate therapeutic target in malignancies, including NSCLCs. Recently, an S-adenosyl-l-homocysteine hydrolase inhibitor, 3-Deazaneplanocin A (DZNep), has been shown to deplete and inhibit EZH2. The aim of this study was to determine the effect of DZNep in NSCLC cells. Knockdown of EZH2 by small-interfering RNA (siRNA) resulted in decreased growth of four NSCLC cell lines. MTT assays demonstrated that DZNep treatment resulted in dose-dependent inhibition of proliferation in the NSCLC cell lines with a half maximal inhibitory concentration (IC50) ranging from 0.08 to 0.24 μM. Immortalized but non-cancerous bronchial epithelial and fibroblast cell lines were less sensitive to DZNep than the NSCLC cell lines. Soft agarose assays demonstrated that anchorage-independent growth was also reduced in all three NSCLC cell lines that were evaluated using this assay. Flow cytometry analysis demonstrated that DZNep induced apoptosis and G1 cell cycle arrest in NSCLC cells, which was partially associated with cyclin A decrease and p27(Kip1) accumulation. DZNep depleted cellular levels of EZH2 and inhibited the associated histone H3 lysine 27 trimethylation. These results indicated that an epigenetic therapy that pharmacologically targets EZH2 via DZNep may constitute a novel approach to treatment of NSCLCs.
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Affiliation(s)
- Junko Kikuchi
- First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan
| | - Taichi Takashina
- First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan
| | - Ichiro Kinoshita
- Department of Medical Oncology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Eiki Kikuchi
- First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan
| | - Yasushi Shimizu
- Department of Medical Oncology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | | | - Satoshi Oizumi
- First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan
| | - Victor E. Marquez
- Chemical Biology Laboratory; Frederick National Laboratory for Cancer Research (FNLCR), National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Masaharu Nishimura
- First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan
| | - Hirotoshi Dosaka-Akita
- Department of Medical Oncology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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Honda A, Valogne Y, Bou Nader M, Bréchot C, Faivre J. An intron-retaining splice variant of human cyclin A2, expressed in adult differentiated tissues, induces a G1/S cell cycle arrest in vitro. PLoS One 2012; 7:e39249. [PMID: 22745723 PMCID: PMC3379989 DOI: 10.1371/journal.pone.0039249] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Accepted: 05/21/2012] [Indexed: 11/18/2022] Open
Abstract
Background Human cyclin A2 is a key regulator of S phase progression and entry into mitosis. Alternative splice variants of the G1 and mitotic cyclins have been shown to interfere with full-length cyclin functions to modulate cell cycle progression and are therefore likely to play a role in differentiation or oncogenesis. The alternative splicing of human cyclin A2 has not yet been studied. Methodology/Principal Findings Sequence-specific primers were designed to amplify various exon–intron regions of cyclin A2 mRNA in cell lines and human tissues. Intron retaining PCR products were cloned and sequenced and then overexpressed in HeLa cells. The subcellular localization of the splice variants was studied using confocal and time-lapse microscopy, and their impact on the cell cycle by flow cytometry, immunoblotting and histone H1 kinase activity. We found a splice variant of cyclin A2 mRNA called A2V6 that partly retains Intron 6. The gene expression pattern of A2V6 mRNA in human tissues was noticeably different from that of wild-type cyclin A2 (A2WT) mRNA. It was lower in proliferating fetal tissues and stronger in some differentiated adult tissues, especially, heart. In transfected HeLa cells, A2V6 localized exclusively in the cytoplasm whereas A2WT accumulated in the nucleus. We show that A2V6 induced a clear G1/S cell cycle arrest associated with a p21 and p27 upregulation and an inhibition of retinoblastoma protein phosphorylation. Like A2WT, A2V6 bound CDK2, but the A2V6/CDK2 complex did not phosphorylate histone H1. Conclusion/Significance This study has revealed that some highly differentiated human tissues express an intron-retaining cyclin A2 mRNA that induced a G1/S block in vitro. Contrary to full-length cyclin A2, which regulates cell proliferation, the A2V6 splice variant might play a role in regulating nondividing cell states such as terminal differentiation or senescence.
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Affiliation(s)
- Arata Honda
- Tokyo Metropolitan Health and Medical Treatment Corporation, Ebara Hospital, Tokyo, Japan
- INSERM, U785, Centre Hépatobiliaire, Villejuif, France
- Université Paris-Sud, Faculté de Médecine, Villejuif, France
| | - Yannick Valogne
- INSERM, U785, Centre Hépatobiliaire, Villejuif, France
- Université Paris-Sud, Faculté de Médecine, Villejuif, France
| | - Myriam Bou Nader
- INSERM, U785, Centre Hépatobiliaire, Villejuif, France
- Université Paris-Sud, Faculté de Médecine, Villejuif, France
| | - Christian Bréchot
- INSERM, U785, Centre Hépatobiliaire, Villejuif, France
- Université Paris-Sud, Faculté de Médecine, Villejuif, France
| | - Jamila Faivre
- INSERM, U785, Centre Hépatobiliaire, Villejuif, France
- Université Paris-Sud, Faculté de Médecine, Villejuif, France
- * E-mail:
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30
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Liu J, Shen M, Yue Z, Yang Z, Wang M, Li C, Xin C, Wang Y, Mei Q, Wang Z. Triptolide inhibits colon-rectal cancer cells proliferation by induction of G1 phase arrest through upregulation of p21. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2012; 19:756-762. [PMID: 22464014 DOI: 10.1016/j.phymed.2012.02.014] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 02/18/2012] [Indexed: 05/31/2023]
Abstract
Triptolide, a diterpene triepoxide compound extracted from the traditional Chinese medicine herb Tripterygium wilfordii Hook F., is a potential cancer chemotherapeutic for tumors. However, the mechanism of anti-proliferative mechanism of triptolide in colon cancer cells is not entirely clear. Triptolide markedly inhibited HT29 and SW480 cells proliferation in a dose- and time-dependent manner. Triptolide decreased ERK and AKT phosphorylation, and GABPα expression in colon cancer cells. Beta-catenin expression and phosphorylation were not altered by incubation of triptolide. However, we found that triptolide repressed expression of LEF/TCF. Although it did not significantly affect cells apoptosis, triptolide induced G1 phase arrest dose-dependently. Further detection for the expression of cell cycle-related proteins suggesting that triptolide stimulate expression of p21 and repress cyclin A1. Increased p21 binded to CDK4/CDK6, therefore blocked function of CDK4/CDK6, and subsequently contribute to the G1 arrest. These data suggested that triptolide is a potential agent for treatment of colon cancer, and its anti-proliferation effect mainly occur through G1 phase arrest.
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Affiliation(s)
- Juanjuan Liu
- Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi'an, China
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31
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Valcourt JR, Lemons JMS, Haley EM, Kojima M, Demuren OO, Coller HA. Staying alive: metabolic adaptations to quiescence. Cell Cycle 2012; 11:1680-96. [PMID: 22510571 DOI: 10.4161/cc.19879] [Citation(s) in RCA: 166] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Quiescence is a state of reversible cell cycle arrest that can grant protection against many environmental insults. In some systems, cellular quiescence is associated with a low metabolic state characterized by a decrease in glucose uptake and glycolysis, reduced translation rates and activation of autophagy as a means to provide nutrients for survival. For cells in multiple different quiescence model systems, including Saccharomyces cerevisiae, mammalian lymphocytes and hematopoietic stem cells, the PI3Kinase/TOR signaling pathway helps to integrate information about nutrient availability with cell growth rates. Quiescence signals often inactivate the TOR kinase, resulting in reduced cell growth and biosynthesis. However, quiescence is not always associated with reduced metabolism; it is also possible to achieve a state of cellular quiescence in which glucose uptake, glycolysis and flux through central carbon metabolism are not reduced. In this review, we compare and contrast the metabolic changes that occur with quiescence in different model systems.
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Affiliation(s)
- James R Valcourt
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
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32
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Engler DA, Gupta S, Growdon WB, Drapkin RI, Nitta M, Sergent PA, Allred SF, Gross J, Deavers MT, Kuo WL, Karlan BY, Rueda BR, Orsulic S, Gershenson DM, Birrer MJ, Gray JW, Mohapatra G. Genome wide DNA copy number analysis of serous type ovarian carcinomas identifies genetic markers predictive of clinical outcome. PLoS One 2012; 7:e30996. [PMID: 22355333 PMCID: PMC3280266 DOI: 10.1371/journal.pone.0030996] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 12/28/2011] [Indexed: 01/09/2023] Open
Abstract
Ovarian cancer is the fifth leading cause of cancer death in women. Ovarian cancers display a high degree of complex genetic alterations involving many oncogenes and tumor suppressor genes. Analysis of the association between genetic alterations and clinical endpoints such as survival will lead to improved patient management via genetic stratification of patients into clinically relevant subgroups. In this study, we aim to define subgroups of high-grade serous ovarian carcinomas that differ with respect to prognosis and overall survival. Genome-wide DNA copy number alterations (CNAs) were measured in 72 clinically annotated, high-grade serous tumors using high-resolution oligonucleotide arrays. Two clinically annotated, independent cohorts were used for validation. Unsupervised hierarchical clustering of copy number data derived from the 72 patient cohort resulted in two clusters with significant difference in progression free survival (PFS) and a marginal difference in overall survival (OS). GISTIC analysis of the two clusters identified altered regions unique to each cluster. Supervised clustering of two independent large cohorts of high-grade serous tumors using the classification scheme derived from the two initial clusters validated our results and identified 8 genomic regions that are distinctly different among the subgroups. These 8 regions map to 8p21.3, 8p23.2, 12p12.1, 17p11.2, 17p12, 19q12, 20q11.21 and 20q13.12; and harbor potential oncogenes and tumor suppressor genes that are likely to be involved in the pathogenesis of ovarian carcinoma. We have identified a set of genetic alterations that could be used for stratification of high-grade serous tumors into clinically relevant treatment subgroups.
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Affiliation(s)
- David A. Engler
- Department of Statistics, Brigham Young University, Provo, Utah, United States of America
| | - Sumeet Gupta
- Whitehead Institute of Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Whitfield B. Growdon
- Department of Vincent Obstetrics and Gynecology, Vincent Center for Reproductive Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Ronny I. Drapkin
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Mai Nitta
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Petra A. Sergent
- Department of Vincent Obstetrics and Gynecology, Vincent Center for Reproductive Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Serena F. Allred
- Department of Statistics, Brigham Young University, Provo, Utah, United States of America
| | - Jenny Gross
- Women's Cancer Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Michael T. Deavers
- Department of Pathology and Gynecology Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Wen-Lin Kuo
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Beth Y. Karlan
- Women's Cancer Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Bo R. Rueda
- Department of Vincent Obstetrics and Gynecology, Vincent Center for Reproductive Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Sandra Orsulic
- Women's Cancer Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - David M. Gershenson
- Department of Pathology and Gynecology Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Michael J. Birrer
- Center for Cancer Research, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Joe W. Gray
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Gayatry Mohapatra
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- * E-mail:
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Zhao X, Mirza S, Alshareeda A, Zhang Y, Gurumurthy CB, Bele A, Kim JH, Mohibi S, Goswami M, Lele SM, West W, Qiu F, Ellis IO, Rakha EA, Green AR, Band H, Band V. Overexpression of a novel cell cycle regulator ecdysoneless in breast cancer: a marker of poor prognosis in HER2/neu-overexpressing breast cancer patients. Breast Cancer Res Treat 2012; 134:171-80. [PMID: 22270930 PMCID: PMC3397230 DOI: 10.1007/s10549-011-1946-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 12/26/2011] [Indexed: 01/16/2023]
Abstract
Uncontrolled proliferation is one of the hallmarks of breast cancer. We have previously identified the human Ecd protein (human ortholog of Drosophila Ecdysoneless, hereafter called Ecd) as a novel promoter of mammalian cell cycle progression, a function related to its ability to remove the repressive effects of Rb-family tumor suppressors on E2F transcription factors. Given the frequent dysregulation of cell cycle regulatory components in human cancer, we used immunohistochemistry of paraffin-embedded tissues to examine Ecd expression in normal breast tissue versus tissues representing increasing breast cancer progression. Initial studies of a smaller cohort without outcomes information showed that Ecd expression was barely detectable in normal breast tissue and in hyperplasia of breast, but high levels of Ecd were detected in benign breast hyperplasia, ductal carcinoma in situ (DCIS) and infiltrating ductal carcinoma (IDCs) of the breast. In this cohort of 104 IDC patients, Ecd expression levels showed a positive correlation with higher grade (P = 0.04). Further analyses of Ecd expression using a larger, independent cohort (954) confirmed these results, with a strong positive correlation of elevated Ecd expression with higher histological grade (P = 0.013), mitotic index (P = 0.032), and Nottingham Prognostic Index score (P = 0.014). Ecd expression was positively associated with HER2/neu (P = 0.002) overexpression, a known marker of poor prognosis in breast cancer. Significantly, increased Ecd expression showed a strong positive association with shorter breast cancer specific survival (BCSS) (P = 0.008) and disease-free survival (DFS) (P = 0.003) in HER2/neu overexpressing patients. Taken together, our results reveal Ecd as a novel marker for breast cancer progression and show that levels of Ecd expression predict poorer survival in Her2/neu overexpressing breast cancer patients.
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MESH Headings
- Adolescent
- Adult
- Aged
- Antibody Specificity
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Breast/metabolism
- Breast/pathology
- Breast Neoplasms/metabolism
- Breast Neoplasms/mortality
- Breast Neoplasms/pathology
- Carcinoma, Ductal, Breast/metabolism
- Carcinoma, Ductal, Breast/mortality
- Carcinoma, Ductal, Breast/pathology
- Carcinoma, Intraductal, Noninfiltrating/metabolism
- Carcinoma, Intraductal, Noninfiltrating/mortality
- Carcinoma, Intraductal, Noninfiltrating/pathology
- Carrier Proteins/genetics
- Carrier Proteins/immunology
- Carrier Proteins/metabolism
- Cohort Studies
- Disease-Free Survival
- Female
- Gene Expression
- Humans
- Hyperplasia/metabolism
- Kaplan-Meier Estimate
- Middle Aged
- Prognosis
- Receptor, ErbB-2/genetics
- Receptor, ErbB-2/metabolism
- Receptors, Estrogen/metabolism
- Receptors, Progesterone/metabolism
- Young Adult
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Affiliation(s)
- Xiangshan Zhao
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198-5805 USA
| | - Sameer Mirza
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198-5805 USA
| | - Alaa Alshareeda
- School of Molecular Medical Sciences and Cellular Pathology, University of Nottingham and Nottingham University Hospital, Nottingham City Hospital, Hucknall Road, Nottingham, NG5 1PB UK
| | - Ying Zhang
- Abbott Molecular, 1300 E. Touhy Avenue, Des Plaines, IL 60018 USA
| | | | - Aditya Bele
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198-5805 USA
| | - Jun Hyun Kim
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198-5805 USA
| | - Shakur Mohibi
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198-5805 USA
| | - Monica Goswami
- Department of Pathology and Laboratory Medicine, Tulane University Health Sciences, 1430 Tulane Avenue, SL79, New Orleans, LA 70112 USA
| | - Subodh M. Lele
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-3135 USA
| | - William West
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-3135 USA
| | - Fang Qiu
- Department of Biostatistics, University of Nebraska Medical Center, Omaha, NE 68198-5805 USA
| | - Ian O. Ellis
- School of Molecular Medical Sciences and Cellular Pathology, University of Nottingham and Nottingham University Hospital, Nottingham City Hospital, Hucknall Road, Nottingham, NG5 1PB UK
| | - Emad A. Rakha
- School of Molecular Medical Sciences and Cellular Pathology, University of Nottingham and Nottingham University Hospital, Nottingham City Hospital, Hucknall Road, Nottingham, NG5 1PB UK
| | - Andrew R. Green
- School of Molecular Medical Sciences and Cellular Pathology, University of Nottingham and Nottingham University Hospital, Nottingham City Hospital, Hucknall Road, Nottingham, NG5 1PB UK
| | - Hamid Band
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198-5805 USA
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-3135 USA
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5805 USA
- Department of Pharmacology and Experimental Neuroscience, College of Medicine, University of Nebraska Medical Center, Omaha, NE 68198-5805 USA
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198-5805 USA
| | - Vimla Band
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198-5805 USA
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198-5805 USA
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Chu J, Loughlin EA, Gaur NA, SenBanerjee S, Jacob V, Monson C, Kent B, Oranu A, Ding Y, Ukomadu C, Sadler KC. UHRF1 phosphorylation by cyclin A2/cyclin-dependent kinase 2 is required for zebrafish embryogenesis. Mol Biol Cell 2011; 23:59-70. [PMID: 22072796 PMCID: PMC3248904 DOI: 10.1091/mbc.e11-06-0487] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Although UHRF1 is essential for many epigenetic marks, the mechanism that regulates UHRF1 is not understood. This study shows that a key component of the cell cycle machinery—cyclin-dependent kinase 2/cyclin A2—phosphorylates UHRF1 and that this phosphorylation is essential for early zebrafish development. Ubiquitin-like, containing PHD and RING finger domains 1 (uhrf1) is regulated at the transcriptional level during the cell cycle and in developing zebrafish embryos. We identify phosphorylation as a novel means of regulating UHRF1 and demonstrate that Uhrf1 phosphorylation is required for gastrulation in zebrafish. Human UHRF1 contains a conserved cyclin-dependent kinase 2 (CDK2) phosphorylation site at Ser-661 that is phosphorylated in vitro by CDK2 partnered with cyclin A2 (CCNA2), but not cyclin E. An antibody specific for phospho-Ser-661 recognizes UHRF1 in both mammalian cancer cells and in nontransformed zebrafish cells, but not in zebrafish bearing a mutation in ccna2. Depleting Uhrf1 from zebrafish embryos by morpholino injection causes arrest before gastrulation and early embryonic death. This phenotype is rescued by wild-type UHRF1, but not by UHRF1 in which the phospho-acceptor site is mutated, demonstrating that UHRF1 phosphorylation is essential for embryogenesis. UHRF1 was detected in the nucleus and cytoplasm, whereas nonphosphorylatable UHRF1 is unable to localize to the cytoplasm, suggesting the importance of localization in UHRF1 function. Together, these data point to an essential role for UHRF1 phosphorylation by CDK/CCNA2 during early vertebrate development.
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Affiliation(s)
- Jaime Chu
- Division of Pediatric Hepatology, Department of Pediatrics, Mount Sinai School of Medicine, New York, NY 10029, USA
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35
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Gordon GM, Du W. Targeting Rb inactivation in cancers by synthetic lethality. Am J Cancer Res 2011; 1:773-786. [PMID: 21814623 PMCID: PMC3147291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 05/15/2011] [Indexed: 05/31/2023] Open
Abstract
The retinoblastoma protein, pRb, is a key regulator of cell proliferation, differentiation, apoptosis, as well as checkpoint and stress responses. The function of Rb is often inactivated in many types of cancers, a feature that can potentially be used to target this specific subset of cancers. However little is known about how the loss of Rb function can be exploited in cancer therapies. In this review, we overview the functions of Rb, and discuss a genetic screen that led to the finding that inactivation of TSC2 and Rb induces synergistic cell death in both Drosophila developing tissues and human cancer cells. The mechanisms for synergistic cell death involve the accumulation of cellular stress, suggesting that inactivation of TSC2 and chemotherapeutic agents that result in induction of cellular stress can potentially be combined to treat cancers harboring inactivated Rb.
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36
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Zhang B, Shi Z, Duncan DT, Prodduturi N, Marnett LJ, Liebler DC. Relating protein adduction to gene expression changes: a systems approach. MOLECULAR BIOSYSTEMS 2011; 7:2118-27. [PMID: 21594272 DOI: 10.1039/c1mb05014a] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Modification of proteins by reactive electrophiles such as the 4-hydroxy-2-nonenal (HNE) plays a critical role in oxidant-associated human diseases. However, little is known about protein adduction and the mechanism by which protein damage elicits adaptive effects and toxicity. We developed a systems approach for relating protein adduction to gene expression changes through the integration of protein adduction, gene expression, protein-DNA interaction, and protein-protein interaction data. Using a random walk strategy, we expanded a list of responsive transcription factors inferred from gene expression studies to upstream signaling networks, which in turn allowed overlaying protein adduction data on the network for the prediction of stress sensors and their associated regulatory mechanisms. We demonstrated the general applicability of transcription factor-based signaling network inference using 103 known pathways. Applying our workflow on gene expression and protein adduction data from HNE-treatment not only rediscovered known mechanisms of electrophile stress but also generated novel hypotheses regarding protein damage sensors. Although developed for analyzing protein adduction data, the framework can be easily adapted for phosphoproteomics and other types of protein modification data.
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Affiliation(s)
- Bing Zhang
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
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37
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Noda N, Honma S, Ohmiya Y. Hes1 is required for contact inhibition of cell proliferation in 3T3-L1 preadipocytes. Genes Cells 2011; 16:704-13. [PMID: 21481105 DOI: 10.1111/j.1365-2443.2011.01518.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cell-cell contact causes the growth arrest of cells in culture, which is referred to as contact inhibition of cell proliferation. Notch signaling is involved in the growth arrest of cells represented by contact inhibition of cell proliferation. The Notch effector, Hes1 (Hairy and enhancer of split 1), promotes or inhibits cell proliferation by repressing the expression of cyclin-dependent kinase inhibitors. However, it is still unclear whether Hes1 is involved in the mechanisms responsible for contact inhibition of cell proliferation. Here, we examined the involvement of Hes1 in contact inhibition of cell proliferation using a γ-secretase inhibitor and a stable 3T3-L1 preadipocyte cell line expressing Hes1-shRNA as a model cell. The cell cycle was not arrested in Hes1-knockdown cells even after the cells reached confluence. Reduced Hes1 levels failed to repress the expression of E2F-1, a transcription factor required for the progression of the cell cycle. The expression of Myc, cyclin E1, and cyclin A2 in E2F-1 target genes was also higher in Hes1-knockdown cells compared with the negative control. These results suggest that Hes1 plays essential roles in contact inhibition of cell proliferation in 3T3-L1 cells by repressing E2F-1 expression.
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Affiliation(s)
- Natsumi Noda
- Department of Physiology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
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38
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Chung YJ, Lee JI, Chong S, Seok JW, Park SJ, Jang HW, Kim SW, Chung JH. Anti-proliferative effect and action mechanism of dexamethasone in human medullary thyroid cancer cell line. Endocr Res 2011; 36:149-57. [PMID: 21973234 DOI: 10.3109/07435800.2011.593012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Dexamethasone is known to inhibit the cell proliferation of certain transformed cell lines. In this study, the effect and action mechanism of dexamethasone were examined in the human medullary thyroid cancer cell line, TT cells. METHODS TT cells were treated with or without dexamethasone. 5-Bromo-2'-deoxyuridine uptake assay was used to evaluate cell proliferation. Cell cycle and its regulatory proteins were assessed by flow cytometry and western blot analysis, respectively. Apoptosis was analyzed by Hoechst staining and Annexin V assay. RESULTS Dexamethasone significantly reduced TT cell proliferation by 60% (p < 0.01). A substantial portion of cells was arrested at the G1 phase. The expression levels of cyclin D1, cyclin-dependent kinase (CDK)4, and CDK2 were decreased. In addition, the phosphorylation of retinoblastoma protein, which is a critical checkpoint protein in the transition of G1 to S phase, was decreased. On the other hand, the expression level of p27(Kip1), which is a cyclin/CDK inhibitor, was enhanced. Hoechst staining showed many fragmented nuclei in the dexamethasone-treated cells. The proportion of early apoptotic cells was also increased in the Annexin V assay. CONCLUSION Dexamethasone inhibited the proliferation of TT cells through cell cycle arrest at the G1 phase and increased apoptosis.
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Affiliation(s)
- Yun Jae Chung
- Department of Internal Medicine, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea
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39
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IL-1β-driven neutrophilia preserves antibacterial defense in the absence of the kinase IKKβ. Nat Immunol 2010. [PMID: 21170027 DOI: 10.1038/ni.1976.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Transcription factor NF-κB and its activating kinase IKKβ are associated with inflammation and are believed to be critical for innate immunity. Despite the likelihood of immune suppression, pharmacological blockade of IKKβ-NF-κB has been considered as a therapeutic strategy. However, we found neutrophilia in mice with inducible deletion of IKKβ (Ikkβ(Δ) mice). These mice had hyperproliferative granulocyte-macrophage progenitors and pregranulocytes and a prolonged lifespan of mature neutrophils that correlated with the induction of genes encoding prosurvival molecules. Deletion of interleukin 1 receptor 1 (IL-1R1) in Ikkβ(Δ) mice normalized blood cellularity and prevented neutrophil-driven inflammation. However, Ikkβ(Δ)Il1r1(-/-) mice, unlike Ikkβ(Δ) mice, were highly susceptible to bacterial infection, which indicated that signaling via IKKβ-NF-κB or IL-1R1 can maintain antimicrobial defenses in each other's absence, whereas inactivation of both pathways severely compromises innate immunity.
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40
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IL-1β-driven neutrophilia preserves antibacterial defense in the absence of the kinase IKKβ. Nat Immunol 2010; 12:144-50. [PMID: 21170027 DOI: 10.1038/ni.1976] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Accepted: 11/19/2010] [Indexed: 12/13/2022]
Abstract
Transcription factor NF-κB and its activating kinase IKKβ are associated with inflammation and are believed to be critical for innate immunity. Despite the likelihood of immune suppression, pharmacological blockade of IKKβ-NF-κB has been considered as a therapeutic strategy. However, we found neutrophilia in mice with inducible deletion of IKKβ (Ikkβ(Δ) mice). These mice had hyperproliferative granulocyte-macrophage progenitors and pregranulocytes and a prolonged lifespan of mature neutrophils that correlated with the induction of genes encoding prosurvival molecules. Deletion of interleukin 1 receptor 1 (IL-1R1) in Ikkβ(Δ) mice normalized blood cellularity and prevented neutrophil-driven inflammation. However, Ikkβ(Δ)Il1r1(-/-) mice, unlike Ikkβ(Δ) mice, were highly susceptible to bacterial infection, which indicated that signaling via IKKβ-NF-κB or IL-1R1 can maintain antimicrobial defenses in each other's absence, whereas inactivation of both pathways severely compromises innate immunity.
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41
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Cyclin A promotes S-phase entry via interaction with the replication licensing factor Mcm7. Mol Cell Biol 2010; 31:248-55. [PMID: 21078875 DOI: 10.1128/mcb.00630-10] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cyclin A is known to promote S-phase entry in mammals, but its critical targets in this process have not been defined. We derived a novel human cyclin A mutant (CycA-C1), which can activate cyclin-dependent kinase but cannot promote S-phase entry, and isolated replication licensing factor Mcm7 as a factor that interacts with the wild-type cyclin A but not with the mutant. We demonstrated that human cyclin A and Mcm7 interact in the chromatin fraction. To address the physiological significance of the cyclin A-Mcm7 interaction, we isolated an Mcm7 mutant (Mcm7-3) that is capable of association with CycA-C1 and found that it can also suppress the deficiency of CycA-C1 in promoting S-phase entry. Finally, RNA interference experiments showed that the CycA-C1 mutant is defective for the endogenous cyclin A function in S-phase entry and that this defect can be suppressed by the Mcm7-3 mutant. Our findings demonstrate that interaction with Mcm7 is essential for the function of cyclin A in promoting S-phase entry.
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42
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Lu GD, Leung CHW, Yan B, Tan CMY, Low SY, Aung MO, Salto-Tellez M, Lim SG, Hooi SC. C/EBPalpha is up-regulated in a subset of hepatocellular carcinomas and plays a role in cell growth and proliferation. Gastroenterology 2010; 139:632-43, 643.e1-4. [PMID: 20347819 DOI: 10.1053/j.gastro.2010.03.051] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 03/12/2010] [Accepted: 03/18/2010] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS C/EBPalpha (cebpa) is a putative tumor suppressor. However, initial results indicated that cebpa was up-regulated in a subset of human hepatocellular carcinomas (HCCs). The regulation and function of C/EBPalpha was investigated in HCC cell lines to clarify its role in liver carcinogenesis. METHODS The regulation of C/EBPalpha expression was studied by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), Western blotting, immunohistochemistry, methylation-specific PCR, and chromatin immunoprecipitation assays. C/EBPalpha expression was knocked-down by small interfering RNA or short hairpin RNA. Functional assays included colony formation, methylthiotetrazole, bromodeoxyuridine incorporation, and luciferase-reporter assays. RESULTS Cebpa was up-regulated at least 2-fold in a subset (approximately 55%) of human HCCs compared with adjacent nontumor tissues. None of the up-regulated samples were positive for hepatitis C infection. The HCC cell lines Hep3B and Huh7 expressed high, PLC/PRF/5 intermediate, HepG2 and HCC-M low levels of C/EBPalpha, recapitulating the pattern of expression observed in HCCs. No mutations were detected in the CEBPA gene in HCCs and cell lines. C/EBPalpha was localized to the nucleus and functional in Hep3B and Huh7 cells; knocking-down its expression reduced target-gene expression, colony formation, and cell growth, associated with a decrease in cyclin A and CDK4 concentrations and E2F transcriptional activity. Epigenetic mechanisms including DNA methylation, and the binding of acetylated histone H3 to the CEBPA promoter-regulated cebpa expression in the HCC cells. CONCLUSIONS C/EBPalpha is up-regulated in a subset of HCCs and has growth-promoting activities in HCC cells. Novel oncogenic mechanisms involving C/EBPalpha may be amenable to epigenetic regulation to improve treatment outcomes.
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Affiliation(s)
- Guo-Dong Lu
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, and Department of Medicine, National University Hospital Health Systems, Singapore
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43
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Abstract
Cyclin A must be degraded at prometaphase in order to allow mitosis progression. Nevertheless, the signals that trigger cyclin A degradation at mitosis have been largely elusive. In the present paper, we review the status of cyclin A degradation in the light of recent evidence indicating that acetylation plays a role in cyclin A stability. The emerging model proposes that the acetyltransferase PCAF [p300/CREB (cAMP-response-element-binding protein)-binding protein-associated factor] [perhaps also its homologue GCN5 (general control non-derepressible 5)] acetylates cyclin A at Lys(54), Lys(68), Lys(95) and Lys(112) during mitosis, leading to its ubiquitylation by the anaphase-promoting factor/cyclosome and its subsequent degradation via proteasome. Interestingly, these four lysine residues in cyclin A also participate in the regulation of cyclin A-Cdk (cyclin-dependent kinase) activity by modulating its interaction with Cdks.
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44
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Abstract
The retinoblastoma gene, Rb, was originally identified as the tumor suppressor gene mutated in a rare childhood cancer called retinoblastoma (reviewed in [1]). Subsequent studies showed that Rb functions in a pathway that is often functionally inactivated in a large majority of human cancers. Interestingly, recent studies showed that in certain types of cancers, Rb function is actually required for cancer development. The intimate link between the Rb pathway and cancer development suggests that the status of Rb activity can potentially be used to develop targeted therapy. However, a prerequisite will be to understand the role of Rb and its interaction with other signaling pathways in cancer development. In this review, we will discuss the roles of Rb in proliferation, apoptosis and differentiation by reviewing the recent findings in both mammalian systems and different model organisms. In addition, we will discuss strategies that can be employed that specifically target cancer cells based on the status of the Rb pathway.
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Affiliation(s)
- W Du
- Ben May Department for Cancer Research, The University of Chicago, 929 E. 57th Street, Chicago, IL 60637, USA.
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45
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Wang Q, Li W, Zhang Y, Yuan X, Xu K, Yu J, Chen Z, Beroukhim R, Wang H, Lupien M, Wu T, Regan MM, Meyer CA, Carroll JS, Manrai AK, Jänne OA, Balk SP, Mehra R, Han B, Chinnaiyan AM, Rubin MA, True L, Fiorentino M, Fiore C, Loda M, Kantoff PW, Liu XS, Brown M. Androgen receptor regulates a distinct transcription program in androgen-independent prostate cancer. Cell 2009; 138:245-56. [PMID: 19632176 DOI: 10.1016/j.cell.2009.04.056] [Citation(s) in RCA: 704] [Impact Index Per Article: 46.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 12/04/2008] [Accepted: 04/22/2009] [Indexed: 10/20/2022]
Abstract
The evolution of prostate cancer from an androgen-dependent state to one that is androgen-independent marks its lethal progression. The androgen receptor (AR) is essential in both, though its function in androgen-independent cancers is poorly understood. We have defined the direct AR-dependent target genes in both androgen-dependent and -independent cancer cells by generating AR-dependent gene expression profiles and AR cistromes. In contrast to what is found in androgen-dependent cells, AR selectively upregulates M-phase cell-cycle genes in androgen-independent cells, including UBE2C, a gene that inactivates the M-phase checkpoint. We find that epigenetic marks at the UBE2C enhancer, notably histone H3K4 methylation and FoxA1 transcription factor binding, are present in androgen-independent cells and direct AR-enhancer binding and UBE2C activation. Thus, the role of AR in androgen-independent cancer cells is not to direct the androgen-dependent gene expression program without androgen, but rather to execute a distinct program resulting in androgen-independent growth.
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Affiliation(s)
- Qianben Wang
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02115, USA
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Satyanarayana A, Kaldis P. Mammalian cell-cycle regulation: several Cdks, numerous cyclins and diverse compensatory mechanisms. Oncogene 2009; 28:2925-39. [PMID: 19561645 DOI: 10.1038/onc.2009.170] [Citation(s) in RCA: 530] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
After a decade of extensive work on gene knockout mouse models of cell-cycle regulators, the classical model of cell-cycle regulation was seriously challenged. Several unexpected compensatory mechanisms were uncovered among cyclins and Cdks in these studies. The most astonishing observation is that Cdk2 is dispensable for the regulation of the mitotic cell cycle with both Cdk4 and Cdk1 covering for Cdk2's functions. Similar to yeast, it was recently discovered that Cdk1 alone can drive the mammalian cell cycle, indicating that the regulation of the mammalian cell cycle is highly conserved. Nevertheless, cell-cycle-independent functions of Cdks and cyclins such as in DNA damage repair are still under investigation. Here we review the compensatory mechanisms among major cyclins and Cdks in mammalian cell-cycle regulation.
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Affiliation(s)
- A Satyanarayana
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, MD 21702-1201, USA.
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47
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Mateo F, Vidal-Laliena M, Canela N, Busino L, Martinez-Balbas MA, Pagano M, Agell N, Bachs O. Degradation of cyclin A is regulated by acetylation. Oncogene 2009; 28:2654-66. [PMID: 19483727 DOI: 10.1038/onc.2009.127] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cyclin A accumulates at the onset of S phase, remains high during G(2) and early mitosis and is degraded at prometaphase. Here, we report that the acetyltransferase P/CAF directly interacts with cyclin A that as a consequence becomes acetylated at lysines 54, 68, 95 and 112. Maximal acetylation occurs simultaneously to ubiquitylation at mitosis, indicating importance of acetylation on cyclin A stability. This was further confirmed by the observation that the pseudoacetylated cyclin A mutant can be ubiquitylated whereas the nonacetylatable mutant cannot. The nonacetylatable mutant is more stable than cyclin A WT (cycA WT) and arrests cell cycle at mitosis. Moreover, in cells treated with histone deacetylase inhibitors cyclin A acetylation increases and its stability decreases, thus supporting the function of acetylation on cyclin A degradation. Although the nonacetylatable mutant cannot be ubiquitylated, it interacts with the proteins needed for its degradation (cdks, Cks, Cdc20, Cdh1 and APC/C). In fact, its association with cdks is increased and its complexes with these kinases display higher activity than control cycA WT-cdk complexes. All these results indicate that cyclin A acetylation at specific lysines is crucial for cyclin A stability and also has a function in the regulation of cycA-cdk activity.
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Affiliation(s)
- F Mateo
- Faculty of Medicine, Department of Cell Biology and Pathology, University of Barcelona, Barcelona, Spain
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Kikuchi J, Kinoshita I, Shimizu Y, Oizumi S, Nishimura M, Birrer MJ, Dosaka-Akita H. Simultaneous blockade of AP-1 and phosphatidylinositol 3-kinase pathway in non-small cell lung cancer cells. Br J Cancer 2008; 99:2013-9. [PMID: 19018257 PMCID: PMC2607224 DOI: 10.1038/sj.bjc.6604782] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
c-Jun is a major constituent of AP-1 transcription factor that transduces multiple mitogen growth signals, and it is frequently overexpressed in non-small cell lung cancers (NSCLCs). Earlier, we showed that blocking AP-1 by the overexpression of a c-Jun dominant-negative mutant, TAM67, inhibited NSCLC cell growth. The phosphatidylinositol 3-kinase (PI3K)/Akt signal transduction pathway is important in transformation, proliferation, survival and metastasis of NSCLC cells. In this study, we used NCI-H1299 Tet-on clone cells that express TAM67 under the control of inducible promoter to determine the effects of inhibition of AP-1 and PI3K on cell growth. The PI3K inhibitor, LY294002, produced a dose-dependent inhibition of growth in H1299 cells and that inhibition was enhanced by TAM67. TAM67 increased dephosphorylation of Akt induced by LY294002 and reduced the TPA response element DNA-binding of phosphorylated c-Jun. TAM67 increased G1 cell cycle blockade induced by LY294002, which was partially associated with cyclin A decrease and p27Kip1 accumulation. Furthermore, TAM67 and LY294002 act, at least additively, to inhibit anchorage-independent growth of the H1299 cells. These results suggest that AP-1 and PI3K/Akt pathways play an essential role in the growth of some NSCLC cells.
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Affiliation(s)
- J Kikuchi
- First Department of Medicine, Hokkaido University School of Medicine, Sapporo, Japan
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Shimura T, Kataoka H, Ogasawara N, Kubota E, Sasaki M, Tanida S, Joh T. Suppression of proHB-EGF carboxy-terminal fragment nuclear translocation: a new molecular target therapy for gastric cancer. Clin Cancer Res 2008; 14:3956-65. [PMID: 18559618 DOI: 10.1158/1078-0432.ccr-07-4794] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Inactivation of epidermal growth factor (EGF) receptor (EGFR) represents a promising strategy for the development of selective therapies against epithelial cancers and has been extensively studied as a molecular target for cancer therapy. However, little attention has been paid to remnant cell-associated domains created by cleavage of EGFR ligands. The present study focused on recent findings that cleavage of membrane-anchored heparin-binding EGF-like growth factor (proHB-EGF), an EGFR ligand, induces translocation of the carboxyl-terminal fragment (CTF) of HB-EGF from the plasma membrane to the nucleus and regulates cell cycle. EXPERIMENTAL DESIGN Two gastric cancer cell lines, MKN28 and NUGC4, were used. KB-R7785, an inhibitor of proHB-EGF shedding, was used to suppress HB-EGF-CTF nuclear translocation with cetuximab, which inhibits EGFR phosphorylation. Cell growth was analyzed using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt assay, apoptosis was evaluated by assay of caspase-3 and caspase-7, and cell cycle was investigated by flow cytometry. RESULTS Immunofluorescence study confirmed that KB-R7785 inhibited HB-EGF-CTF nuclear translocation under conditions of proHB-EGF shedding induction by 12-O-tetradecanoylphorbol-13-acetate in gastric cancer cells. KB-R7785 inhibited cell growth in a dose-dependent manner and high-dose KB-R7785 induced apoptosis. Moreover, KB-R7785 induced cell cycle arrest and increased sub-G1 DNA content. KB-R7785 suppressed cyclin A and c-Myc expression. All effects of KB-R7785 were reinforced by combination with cetuximab. CONCLUSIONS These results suggest that both inhibition of EGFR phosphorylation and inhibition of HB-EGF-CTF nuclear translocation play crucial roles in inhibitory regulation of cancer cell growth. Suppression of HB-EGF-CTF nuclear translocation might offer a new strategy for treating gastric cancer.
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Affiliation(s)
- Takaya Shimura
- Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
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Walker A, Acquaviva C, Matsusaka T, Koop L, Pines J. UbcH10 has a rate-limiting role in G1 phase but might not act in the spindle checkpoint or as part of an autonomous oscillator. J Cell Sci 2008; 121:2319-26. [PMID: 18559889 DOI: 10.1242/jcs.031591] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Ubiquitin-dependent proteolysis mediated by the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase lies at the heart of the cell cycle. The APC/C targets mitotic cyclins for destruction in mitosis and G1 phase and is then inactivated at S phase, thereby generating the alternating states of high and low cyclin-Cdk activity required for the alternation of mitosis and DNA replication. Two key questions are how the APC/C is held in check by the spindle-assembly checkpoint to delay cells in mitosis in the presence of improperly attached chromosomes, and how the APC/C is inactivated once cells exit mitosis. The ubiquitin-conjugating protein UbcH10 has been proposed to be crucial in the answers to both questions. However, here we show that the behaviour of UbcH10 is inconsistent with both a crucial role in the spindle checkpoint and in inactivating the APC/C as part of an autonomous oscillator. Instead, we find that the rate-limiting role of UbcH10 is only at the end of G1 phase, just before DNA replication begins.
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Affiliation(s)
- Adam Walker
- Wellcome Trust/Cancer Research UK Gurdon Institute and Department of Zoology, University of Cambridge, Cambridge CB2 1QN, UK
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