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Chen JLY, Chen JP, Huang YS, Tsai YC, Tsai MH, Jaw FS, Cheng JCH, Kuo SH, Shieh MJ. Radiosensitization in esophageal squamous cell carcinoma: Effect of polo-like kinase 1 inhibition. Strahlenther Onkol 2016; 192:260-8. [PMID: 26952039 DOI: 10.1007/s00066-016-0951-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 01/28/2016] [Indexed: 01/27/2023]
Abstract
PURPOSE This study examined the efficacy of polo-like kinase 1 (PLK1) inhibition on radiosensitivity in vitro and in vivo by a pharmacologic approach using the highly potent PLK1 inhibitor volasertib. METHODS AND MATERIALS Human esophageal squamous cell carcinoma (ESCC) cell lines KYSE 70 and KYSE 150 were used to evaluate the synergistic effect of volasertib and irradiation in vitro using cell viability assay, colony formation assay, cell cycle phase analysis, and western blot, and in vivo using ectopic tumor models. RESULTS Volasertib decreased ESCC cell proliferation in a dose- and time-dependent manner. Combination of volasertib and radiation caused G2/M cell cycle arrest, increased cyclin B levels, and induced apoptosis. Volasertib significantly enhanced radiation-induced death in ESCC cells by a mechanism involving the enhancement of histone H3 phosphorylation and significant cell cycle interruption. The combination of volasertib plus irradiation delayed the growth of ESCC tumor xenografts markedly compared with either treatment modality alone. CONCLUSIONS The in vitro results suggested that targeting PLK1 might be a viable approach to improve the effects of radiation in ESCC. In vivo studies showed that PLK1 inhibition with volasertib during irradiation significantly improved local tumor control when compared to irradiation or drug treatment alone.
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Affiliation(s)
- Jenny Ling-Yu Chen
- Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei, Taiwan
- Department of Radiation Oncology, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan
- Department of Oncology, National Taiwan University Hospital and National Taiwan University Cancer Center, Taipei, Taiwan
| | - Jo-Pai Chen
- Department of Oncology, National Taiwan University Hospital and National Taiwan University Cancer Center, Taipei, Taiwan
- Department of Oncology, National Taiwan University Hospital Yun-Lin Branch, Yun-Lin, Taiwan
| | - Yu-Sen Huang
- Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei, Taiwan.
- Department of Medical Imaging, National Taiwan University Hospital, No.7, Chung-Shan South Road, 100, Taipei, Taiwan.
- Department of Medical Imaging, National Taiwan University Hospital Yun-Lin Branch, Yun-Lin, Taiwan.
| | - Yuan-Chun Tsai
- Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei, Taiwan
| | - Ming-Hsien Tsai
- Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei, Taiwan
| | - Fu-Shan Jaw
- Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei, Taiwan
| | - Jason Chia-Hsien Cheng
- Department of Oncology, National Taiwan University Hospital and National Taiwan University Cancer Center, Taipei, Taiwan
- Graduate Institute of Oncology, National Taiwan University, Taipei, Taiwan
| | - Sung-Hsin Kuo
- Department of Oncology, National Taiwan University Hospital and National Taiwan University Cancer Center, Taipei, Taiwan
- Graduate Institute of Oncology, National Taiwan University, Taipei, Taiwan
| | - Ming-Jium Shieh
- Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei, Taiwan
- Department of Oncology, National Taiwan University Hospital and National Taiwan University Cancer Center, Taipei, Taiwan
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Kumar S, Sharma AR, Sharma G, Chakraborty C, Kim J. PLK-1: Angel or devil for cell cycle progression. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1865:190-203. [PMID: 26899266 DOI: 10.1016/j.bbcan.2016.02.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/01/2016] [Accepted: 02/16/2016] [Indexed: 12/31/2022]
Abstract
PLK-1 is a key player in the eukaryotic cell cycle. Cell cycle progression is precisely controlled by cell cycle regulatory kinases. PLK-1 is a mitotic kinase that actively regulates the G2/M transition, mitosis, mitotic exit, and cytokinesis. During cell cycle progression, PLK-1 controls various events related to the cell cycle maturation, directly and/or indirectly. On the contrary, aberrant expression of PLK-1 is strongly associated with tumorigenesis and its poor prognosis. The misexpression of PLK-1 causes the abnormalities including aneuploidy, mitotic defects, leading to tumorigenesis through inhibiting the p53 and pRB genes. Therefore, we reviewed the role of PLK-1 in the cell cycle progression and in the tumorigenesis either as a cell cycle regulator or on an attractive anti-cancer drug target.
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Affiliation(s)
- Shiv Kumar
- Department of Biochemistry, Institute of Cell Differentiation and Aging, Hallym University, College of Medicine, Chucheonsi, Gangwondo 200-704, Republic of Korea.
| | - Ashish Ranjan Sharma
- Institute For Skeletal Aging & Orthopedic Surgery, Hallym University, College of Medicine, Chucheonsi, Gangwondo 200-704, Republic of Korea.
| | - Garima Sharma
- Institute For Skeletal Aging & Orthopedic Surgery, Hallym University, College of Medicine, Chucheonsi, Gangwondo 200-704, Republic of Korea.
| | - Chiranjib Chakraborty
- Department of Bio-informatics, School of Computer and Information Sciences, Galgotias University, Greater Noida 203201, India.
| | - Jaebong Kim
- Department of Biochemistry, Institute of Cell Differentiation and Aging, Hallym University, College of Medicine, Chucheonsi, Gangwondo 200-704, Republic of Korea.
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53
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Wu J, Ivanov AI, Fisher PB, Fu Z. Polo-like kinase 1 induces epithelial-to-mesenchymal transition and promotes epithelial cell motility by activating CRAF/ERK signaling. eLife 2016; 5:e10734. [PMID: 27003818 PMCID: PMC4811775 DOI: 10.7554/elife.10734] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 03/03/2016] [Indexed: 12/22/2022] Open
Abstract
Polo-like kinase 1 (PLK1) is a key cell cycle regulator implicated in the development of various cancers, including prostate cancer. However, the functions of PLK1 beyond cell cycle regulation remain poorly characterized. Here, we report that PLK1 overexpression in prostate epithelial cells triggers oncogenic transformation. It also results in dramatic transcriptional reprogramming of the cells, leading to epithelial-to-mesenchymal transition (EMT) and stimulation of cell migration and invasion. Consistently, PLK1 downregulation in metastatic prostate cancer cells enhances epithelial characteristics and inhibits cell motility. The signaling mechanisms underlying the observed cellular effects of PLK1 involve direct PLK1-dependent phosphorylation of CRAF with subsequent stimulation of the MEK1/2-ERK1/2-Fra1-ZEB1/2 signaling pathway. Our findings highlight novel non-canonical functions of PLK1 as a key regulator of EMT and cell motility in normal prostate epithelium and prostate cancer. This study also uncovers a previously unanticipated role of PLK1 as a potent activator of MAPK signaling.
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Affiliation(s)
- Jianguo Wu
- Department of Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, United States
- VCU Institute of Molecular Medicine, Virginia Commonwealth University School of Medicine, Richmond, United States
- VCU Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, United States
| | - Andrei I Ivanov
- Department of Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, United States
- VCU Institute of Molecular Medicine, Virginia Commonwealth University School of Medicine, Richmond, United States
- VCU Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, United States
| | - Paul B Fisher
- Department of Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, United States
- VCU Institute of Molecular Medicine, Virginia Commonwealth University School of Medicine, Richmond, United States
- VCU Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, United States
| | - Zheng Fu
- Department of Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, United States
- VCU Institute of Molecular Medicine, Virginia Commonwealth University School of Medicine, Richmond, United States
- VCU Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, United States
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54
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Ebrahim HY, El Sayed KA. Discovery of Novel Antiangiogenic Marine Natural Product Scaffolds. Mar Drugs 2016; 14:md14030057. [PMID: 26978377 PMCID: PMC4820311 DOI: 10.3390/md14030057] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 02/27/2016] [Accepted: 03/03/2016] [Indexed: 01/05/2023] Open
Abstract
Marine natural products (MNPs) are recognized for their structural complexity, diversity, and novelty. The vast majority of MNPs are pharmacologically relevant through their ability to modulate macromolecular targets underlying human diseases. Angiogenesis is a fundamental process in cancer progression and metastasis. Targeting angiogenesis through selective modulation of linked protein kinases is a valid strategy to discover novel effective tumor growth and metastasis inhibitors. An in-house marine natural products mini-library, which comprises diverse MNP entities, was submitted to the Lilly’s Open Innovation Drug Discovery platform. Accepted structures were subjected to in vitro screening to discover mechanistically novel angiogenesis inhibitors. Active hits were subjected to additional angiogenesis-targeted kinase profiling. Some natural and semisynthetic MNPs, including multiple members of the macrolide latrunculins, the macrocyclic oxaquinolizidine alkaloid araguspongine C, and the sesquiterpene quinone puupehenone, showed promising results in primary and secondary angiogenesis screening modules. These hits inhibited vascular endothelial growth factor (VEGF)-mediated endothelial tube-like formation, with minimal cytotoxicity at relevant doses. Secondary kinase profiling identified six target protein kinases, all involved in angiogenesis signaling pathways. Molecular modeling and docking experiments aided the understanding of molecular binding interactions, identification of pharmacophoric epitopes, and deriving structure-activity relationships of active hits. Marine natural products are prolific resources for the discovery of chemically and mechanistically unique selective antiangiogenic scaffolds.
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Affiliation(s)
- Hassan Y Ebrahim
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, 1800 Bienville Drive, Monroe, LA 71201, USA.
| | - Khalid A El Sayed
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, 1800 Bienville Drive, Monroe, LA 71201, USA.
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Michel DR, Mun KS, Ho CC, Stambrook PJ. Cytoskeletal architecture and cell motility remain unperturbed in mouse embryonic fibroblasts from Plk3 knockout mice. Exp Biol Med (Maywood) 2016; 241:603-10. [PMID: 26843517 DOI: 10.1177/1535370216629010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 01/04/2016] [Indexed: 11/17/2022] Open
Abstract
Polo-like kinase 3 (Plk3) is best known for its involvement in cell cycle checkpoint regulation following exposure to cytotoxicants or induction of DNA damage. Yet, Plk3 has also been implicated in roles beyond those of cellular responses to DNA damage. Here, we have investigated the proposition, suggested by the Plk literature, that Plk3 regulates cytoskeletal architecture and cell functions mediated by the cytoskeleton. To this end, we have assayed mouse embryonic fibroblasts (MEFs) generated from both Plk3 knockout and wild-type mice. In particular, we asked whether Plk3 is involved in actin fiber and microtubule integrity, cell migration, cell attachment, and/or cell invasion. Our results demonstrate that functional Plk3 is not critical for the regulation of cytoskeletal integrity, cell morphology, cell adhesion, or motility in MEFs.
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Affiliation(s)
- Daniel R Michel
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Kyu-Shik Mun
- Department of Chemical and Materials Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Chia-Chi Ho
- Department of Chemical and Materials Engineering, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Peter J Stambrook
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA
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56
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Helmke C, Becker S, Strebhardt K. The role of Plk3 in oncogenesis. Oncogene 2016; 35:135-47. [PMID: 25915845 DOI: 10.1038/onc.2015.105] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 02/02/2015] [Accepted: 02/02/2015] [Indexed: 01/08/2023]
Abstract
The polo-like kinases (Plks) encompass a family of five serine/threonine protein kinases that play essential roles in many cellular processes involved in the control of the cell cycle, including entry into mitosis, DNA replication and the response to different types of stress. Plk1, which has been validated as a cancer target, came into the focus of many pharmaceutical companies for the development of small-molecule inhibitors as anticancer agents. Recently, FDA (Food and Drug Administration) has granted a breakthrough therapy designation to the Plk inhibitor BI 6727 (volasertib), which provided a survival benefit for patients suffering from acute myeloid leukemia. However, the various ATP-competitive inhibitors of Plk1 that are currently in clinical development also inhibit the activities of Plk2 and Plk3, which are considered as tumor suppressors. Plk3 contributes to the control and progression of the cell cycle while acting as a mediator of apoptosis and various types of cellular stress. The aberrant expression of Plk3 was found in different types of tumors. Recent progress has improved our understanding of Plk3 in regulating stress signaling and tumorigenesis. When using ATP-competitive Plk1 inhibitors, the biological roles of Plk1-related family members like Plk3 in cancer cells need to be considered carefully to improve treatment strategies against cancer.
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Affiliation(s)
- C Helmke
- Department of Obstetrics and Gynecology, School of Medicine, J.W. Goethe University, Frankfurt, Germany
| | - S Becker
- Department of Obstetrics and Gynecology, School of Medicine, J.W. Goethe University, Frankfurt, Germany
| | - K Strebhardt
- Department of Obstetrics and Gynecology, School of Medicine, J.W. Goethe University, Frankfurt, Germany
- German Cancer Consortium (DKTK), Heidelberg, Germany
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57
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Asteriti IA, De Mattia F, Guarguaglini G. Cross-Talk between AURKA and Plk1 in Mitotic Entry and Spindle Assembly. Front Oncol 2015; 5:283. [PMID: 26779436 PMCID: PMC4688340 DOI: 10.3389/fonc.2015.00283] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 11/30/2015] [Indexed: 12/21/2022] Open
Abstract
The Aurora kinase A (AURKA) is involved in different aspects of mitotic control, from mitotic entry to cytokinesis. Consistent with its pleiotropic roles, several AURKA interactors are able to modulate its activity, the best characterized being the microtubule-binding protein TPX2, the centrosomal protein Cep192, and Bora. Bora has been described as an essential cofactor of AURKA for phosphorylation-mediated activation of the mitotic kinase polo-like kinase 1 (Plk1) at the G2/M transition. A complex AURKA/Plk1 signaling axis is emerging, with multiple involved actors; recent data suggest that this control network is not restricted to mitotic entry only, but operates throughout mitosis. Here, we integrate available data from the literature to depict the complex interplay between AURKA and Plk1 in G2 and mitosis and how it contributes to their mitotic functions. We will particularly focus on how the activity of specifically localized AURKA/Plk1 pools is modulated in time and space by their reciprocal regulation to ensure the timely and coordinated unfolding of downstream mitotic events.
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Affiliation(s)
- Italia Anna Asteriti
- Institute of Molecular Biology and Pathology, National Research Council (CNR), c/o Department of Biology and Biotechnology, Sapienza University of Rome , Rome , Italy
| | - Fabiola De Mattia
- Institute of Molecular Biology and Pathology, National Research Council (CNR), c/o Department of Biology and Biotechnology, Sapienza University of Rome , Rome , Italy
| | - Giulia Guarguaglini
- Institute of Molecular Biology and Pathology, National Research Council (CNR), c/o Department of Biology and Biotechnology, Sapienza University of Rome , Rome , Italy
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58
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Hu ZB, Liao XH, Xu ZY, Yang X, Dong C, Jin AM, Lu H. PLK2 phosphorylates and inhibits enriched TAp73 in human osteosarcoma cells. Cancer Med 2015; 5:74-87. [PMID: 26625870 PMCID: PMC4708894 DOI: 10.1002/cam4.558] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 09/12/2015] [Accepted: 09/14/2015] [Indexed: 01/01/2023] Open
Abstract
TAp73, a member of the p53 tumor suppressor family, can substitute for p53 function, especially in p53‐null and p53‐mutant cells. However, TAp73 enrichment and phosphorylation change its transcriptional activity. Previously, we found that the antitumor function of TAp73 was reactivated by dephosphorylation. Polo‐like kinase 2 (PLK2) plays an important role in bone development. Using a biological information database and phosphorylation prediction software, we hypothesized that PLK2 phosphorylates TAp73 and inhibits TAp73 function in osteosarcomas. Actually,we determined that PLK2 physically binds to and phosphorylates TAp73 when TAp73 protein abundance is up‐regulated by cisplatin. PLK2‐phosphorylated TAp73 at residue Ser48 within the TA domain; phosphorylation of TAp73 was abolished by mutating this residue. Moreover, PLK2 inhibition combined with cisplatin treatment in osteosarcoma Saos2 cells up‐regulated p21 and puma mRNA expression to a greater extent than cisplatin treatment alone. Inhibiting PLK2 in TAp73‐enriched Saos2 cells resulted in inhibited cell proliferation, increased apoptosis, G1 phase arrest, and decreased cell invasion. However, these changes did not occur in TAp73 knockdown Saos2 cells. In conclusion, these findings reveal a novel PLK2 function in the phosphorylation of TAp73, which prevents TAp73 activity in osteosarcoma cells. Thereby, this research provides an insight into the clinical treatment of malignant tumors overexpressing TAp73.
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Affiliation(s)
- Zheng Bo Hu
- Department of Orthopedics, Zhu Jiang Hospital of Southern Medical University, Guangzhou, Guangdong, 510280, China
| | - Xiao Hong Liao
- The State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510280, China
| | - Zun Ying Xu
- Department of Orthopedics, Zhu Jiang Hospital of Southern Medical University, Guangzhou, Guangdong, 510280, China
| | - Xiao Yang
- Department of Orthopedics, Zhu Jiang Hospital of Southern Medical University, Guangzhou, Guangdong, 510280, China
| | - Chao Dong
- Department of Orthopedics, Zhu Jiang Hospital of Southern Medical University, Guangzhou, Guangdong, 510280, China
| | - An Min Jin
- Department of Orthopedics, Zhu Jiang Hospital of Southern Medical University, Guangzhou, Guangdong, 510280, China
| | - Hai Lu
- Department of Orthopaedics, The Third Affiliated Hospital of Southern Medical University, Academy of Orthopedics, Guangzhou, Guangdong, 510665, China
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Peng F, Zhao Y, Huang X, Chen C, Sun L, Zhuang L, Xue L. Loss of Polo ameliorates APP-induced Alzheimer's disease-like symptoms in Drosophila. Sci Rep 2015; 5:16816. [PMID: 26597721 PMCID: PMC4657023 DOI: 10.1038/srep16816] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 10/15/2015] [Indexed: 12/13/2022] Open
Abstract
The amyloid precursor protein (APP) has been implicated in the pathogenesis of Alzheimer’s disease (AD). Despite extensive studies, little is known about the regulation of APP’s functions in vivo. Here we report that expression of human APP in Drosophila, in the same temporal-spatial pattern as its homolog APPL, induced morphological defects in wings and larval NMJ, larva and adult locomotion dysfunctions, male choice disorder and lifespan shortening. To identify additional genes that modulate APP functions, we performed a genetic screen and found that loss of Polo, a key regulator of cell cycle, partially suppressed APP-induced morphological and behavioral defects in larval and adult stages. Finally, we showed that eye-specific expression of APP induced retina degeneration and cell cycle re-entry, both phenotypes were mildly ameliorated by loss of Polo. These results suggest Polo is an important in vivo regulator of the pathological functions of APP, and provide insight into the role of cell cycle re-entry in AD pathogenesis.
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Affiliation(s)
- Fei Peng
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Yu Zhao
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Xirui Huang
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Changyan Chen
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Lili Sun
- School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, P.R. China
| | - Luming Zhuang
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Lei Xue
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Science and Technology, Tongji University, 1239 Siping Road, Shanghai 200092, China
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60
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Hu Z, Xu Z, Liao X, Yang X, Dong C, Luk K, Jin A, Lu H. Polo-like kinase 2 acting as a promoter in human tumor cells with an abundance of TAp73. Onco Targets Ther 2015; 8:3475-88. [PMID: 26640387 PMCID: PMC4662374 DOI: 10.2147/ott.s90302] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Background TAp73, a member of the p53 tumor suppressor family, is frequently overexpressed in malignant tumors in humans. TAp73 abundance and phosphorylation modification result in variations in transcriptional activity. In a previous study, we found that the antitumor function of TAp73 was reactivated by dephosphorylation in head and neck squamous cell carcinomas. Polo-like kinase 2 (PLK2) displayed a close relationship with the p53 family in affecting the fate of cells. Herein, we investigate the hypothesis that PLK2 phosphorylates TAp73 and inhibits TAp73 function. Materials and methods Head and neck squamous cell carcinoma cell lines and osteosarcoma cell lines were used as natural models of the different expression levels of TAp73. Phosphorylation predictor software Scansite 3.0 and the predictor GPS-polo 1.0 were used to analyze the phosphorylation sites. Coimmunoprecipitation, phosphor-tag Western blot, metabolic labeling, and indirect immunofluorescence assays were used to determine the interactions between PLK2 and TAp73. TAp73 activity was assessed by Western blot and reverse transcription polymerase chain reaction, which we used to detect P21 and PUMA, both downstream genes of TAp73. The physiological effects of PLK2 cross talk with TAp73 on cell cycle progress and apoptosis were observed by flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling assays. Results PLK2 binds to and phosphorylates TAp73. PLK2 phosphorylates TAp73 at residue Ser48 and prohibits TAp73 translocation to the nucleus. Additionally, PLK2 inhibition combined with a DNA-damaging drug upregulated p21 and PUMA mRNA expression to a greater extent than DNA-damaging drug treatment alone. Inhibiting PLK2 in TAp73-enriched cells strengthened the effects of the DNA-damaging drug on both G1 phase arrest and apoptosis. Pretreatment with TAp73-siRNA weakened these effects. Conclusion These findings reveal a novel PLK2 function (catalyzed phosphorylation of TAp73) which suppresses TAp73 functions. PLK2 promotes the survival of human tumor cells, a novel insight into the workings of malignant tumors characterized by TAp73 overexpression, and one that could speed the development of therapies.
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Affiliation(s)
- ZhengBo Hu
- Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - ZunYing Xu
- Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - XiaoHong Liao
- The State Key Laboratory of Respiratory Diseases, the First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Xiao Yang
- Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Cao Dong
- Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - KuaDi Luk
- Department of Orthopedics and Traumatology, The University of Hong Kong, Hong Kong, SAR, People's Republic of China
| | - AnMin Jin
- Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Hai Lu
- Department of Orthopedics, the Third Affiliated Hospital of the Southern Medical University, Guangzhou, Guangdong, People's Republic of China ; Academy of Orthopedics, Guangdong Province, People's Republic of China
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Aspinall CF, Zheleva D, Tighe A, Taylor SS. Mitotic entry: Non-genetic heterogeneity exposes the requirement for Plk1. Oncotarget 2015; 6:36472-88. [PMID: 26472023 PMCID: PMC4742190 DOI: 10.18632/oncotarget.5507] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 09/30/2015] [Indexed: 12/02/2022] Open
Abstract
The quest to develop novel antimitotic chemotherapy agents has led to the generation of several small molecule inhibitors targeting Plk1, a protein kinase required for multiple aspects of cell division. Previous studies have shown that upon exposure to Plk1 inhibitors, cells enter mitosis, delay briefly in prophase and then arrest in mitosis due to an inability to undergo centrosome separation. Here, we show that four different classes of Plk1 inhibitor block mitotic entry in several cancer cell lines and non-transformed RPE-1 cells. The proportion of cells that arrest in G2 is cell line and concentration dependent, and is subject to non-genetic heterogeneity. Following inhibitor washout, the G2 block is alleviated and cells enter mitosis but then fail to complete cell division indicating that most Plk1 inhibitors are not fully reversible. An exception is CYC140844; in contrast to five other inhibitors examined here, this novel Plk1 inhibitor is fully reversible. We discuss the implications for developing Plk1 inhibitors as chemotherapy agents and research tools.
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Affiliation(s)
- Claire F. Aspinall
- Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom
| | | | - Anthony Tighe
- Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Stephen S. Taylor
- Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom
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Archambault V, Lépine G, Kachaner D. Understanding the Polo Kinase machine. Oncogene 2015; 34:4799-807. [PMID: 25619835 DOI: 10.1038/onc.2014.451] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 11/27/2014] [Accepted: 11/28/2014] [Indexed: 12/26/2022]
Abstract
The Polo Kinase is a central regulator of cell division required for several events of mitosis and cytokinesis. In addition to a kinase domain (KD), Polo-like kinases (Plks) comprise a Polo-Box domain (PBD), which mediates protein interactions with targets and regulators of Plks. In all organisms that contain Plks, one Plk family member fulfills several essential functions in the regulation of cell division, and here we refer to this conserved protein as Polo Kinase (Plk1 in humans). The PBD and the KD are capable of both cooperation and mutual inhibition in their functions. Crystal structures of the PBD, the KD and, recently, a PBD-KD complex have helped understanding the inner workings of the Polo Kinase. In parallel, an impressive array of molecular mechanisms has been found to mediate the regulation of the protein. Moreover, the targeting of Polo Kinase in the development of anti-cancer drugs has yielded several molecules with which to chemically modulate Polo Kinase to study its biological functions. Here we review our current understanding of the protein function and regulation of Polo Kinase as a fascinating molecular device in control of cell division.
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Affiliation(s)
- V Archambault
- Institut de recherche en immunologie et en cancérologie, Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, Québec, Canada
| | - G Lépine
- Institut de recherche en immunologie et en cancérologie, Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, Québec, Canada
| | - D Kachaner
- Institut de recherche en immunologie et en cancérologie, Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, Québec, Canada
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Singh L, Pushker N, Sen S, Singh MK, Chauhan FA, Kashyap S. Prognostic significance of polo-like kinases in retinoblastoma: correlation with patient outcome, clinical and histopathological parameters. Clin Exp Ophthalmol 2015; 43:550-7. [PMID: 25754767 DOI: 10.1111/ceo.12517] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 02/14/2015] [Indexed: 01/27/2023]
Abstract
BACKGROUND Retinoblastoma is evolving, but it is still a therapeutic challenge for pediatric oncologists. Polo-like kinases (PLKs) plays an important role in cell cycle events. They play a crucial role in cell proliferation which may lead to tumour formation. The objective of this study is to investigate the role of PLK1 and PLK3 proteins in human retinoblastoma tissues. DESIGN Non-randomized, prospective study was performed in the Dr R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India. PARTICIPANTS This study included 74 primary enucleated retinoblastoma tissues. METHODS Expression of PLK1 and PLK3 protein were assessed in primary enucleated retinoblastoma tissues by immunohistochemistry and western blotting. MAIN OUTCOME MEASURES Expression of PLK1 and PLK3 protein were correlated with clinical and histopathological parameters, tumour staging and overall survival of patients. RESULTS Immunohistochemical results revealed expression of PLK1 in 47/74 (63.51%) cases and PLK3 in 31/74 (41.89%) cases. Western blotting confirmed the immunoreactivity results. Expression of PLK1 showed correlation with poor differentiation and tumour invasion. In addition, PLK1 was statistically significant with massive choroidal invasion, whereas PLK3 did not correlate with any of the clinical or histopathological parameters. There was no statistical correlation in the overall survival of patients with PLK1 and PLK3 expression. CONCLUSIONS PLK1 expression was associated with poor tumour differentiation and histopathological high-risk factors. These proteins may be involved in tumorigenesis and progression of disease. These results suggest that PLK1 may act as a potential therapeutic target and a promising marker for developing potent small molecule inhibitors of PLK isoforms in retinoblastoma.
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Affiliation(s)
- Lata Singh
- Department of Ocular Pathology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Neelam Pushker
- Department of Ophthalmology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Seema Sen
- Department of Ocular Pathology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Mithalesh K Singh
- Department of Ocular Pathology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Feeroj A Chauhan
- Department of Ocular Pathology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Seema Kashyap
- Department of Ocular Pathology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
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Abstract
Acute myeloid leukemia (AML) is a disease diagnosed mostly in patients >65 years of age. Despite its heterogeneous nature, the different types of AMLs are still managed by standard induction chemotherapy for those who can tolerate it in the beginning. For the elderly and infirm patients, however, this approach leads to unacceptably high induction mortality rate. This article reviews past and current efforts searching for low-intensiveness treatments for the elderly and infirm patients who cannot tolerate the standard induction regimen. Volasertib, currently in Phase III clinical trials in combination with cytarabine, is reviewed as a promising agent for this patient population with AML, from the viewpoints of potential compliance and efficacy.
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Affiliation(s)
- Zhonglin Hao
- Cancer Center, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA
| | - Vamsi Kota
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, USA
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65
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Jin HY, Qiu XG, Yang B. The MicroRNA3686 Inhibits the Proliferation of Pancreas Carcinoma Cell Line by Targeting the Polo-Like Kinase 1. BIOMED RESEARCH INTERNATIONAL 2015; 2015:954870. [PMID: 26090465 PMCID: PMC4454736 DOI: 10.1155/2015/954870] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 04/04/2015] [Accepted: 04/06/2015] [Indexed: 12/18/2022]
Abstract
The Polo-like kinase 1 (PLK1) is one member of the so-called Polo-like kinase family which plays an important role in tumorigenesis. By analyzing the potential complementary microRNA (miRNA) targeting sequence of PLK1, we identified that miRNA-3686 (hereby and thereafter mir3696) could be the potential regulator for PLK1. Real-time PCR demonstrated that the mir3686 has a relatively higher expression in the immortalized pancreas cell HPDE6C7 than pancreas carcinoma derived cell line PANC1. The upregulation of mir3686 in HPDE6C7 cell corresponded with the low expression of PLK1 as well. Both luciferase based reporter assay and evaluation of endogenous PLK1 expression demonstrated that mir3686 regulated PLK1, which confirms our speculation. Moreover, we found that transfection of mir3686 in PANC1 cell could lead to proliferation inhibition and promote apoptosis. Further analysis demonstrated that mir3686 transfection in PANC1 cell also inhibited cell invasion, and clone formation in cell invasion assay and clonogenic cell survival assay, respectively. In contrast, inhibition of mir3686 expression in HPDE6C7 cell enhanced the capability of proliferation, cell invasion and clone formation. Taken together, our results indicated that mir3686 could target PLK1 to inhibit the cell proliferation in pancreas cancer derived cell line and mir3686 could be a new therapeutic target for pancreas cancer treatment.
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Affiliation(s)
- Hong-Yi Jin
- Department of General Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou 450052, China
- Department of Emergency, Chinese PLA General Hospital, Beijing 100853, China
| | - Xin-Guang Qiu
- Department of General Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou 450052, China
| | - Bo Yang
- Department of Thoracic Surgery, Anyang Tumor Hospital, Anyang 455000, China
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66
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Reina J, Gonzalez C. When fate follows age: unequal centrosomes in asymmetric cell division. Philos Trans R Soc Lond B Biol Sci 2015; 369:rstb.2013.0466. [PMID: 25047620 PMCID: PMC4113110 DOI: 10.1098/rstb.2013.0466] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A strong correlation between centrosome age and fate has been reported in some stem cells and progenitors that divide asymmetrically. In some cases, such stereotyped centrosome behaviour is essential to endow stemness to only one of the two daughters, whereas in other cases causality is still uncertain. Here, we present the different cell types in which correlated centrosome age and fate has been documented, review current knowledge on the underlying molecular mechanisms and discuss possible functional implications of this process.
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Affiliation(s)
- Jose Reina
- Institute for Research in Biomedicine (IRB-Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain
| | - Cayetano Gonzalez
- Institute for Research in Biomedicine (IRB-Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, Barcelona 08010, Spain
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67
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Roccuzzo M, Visintin C, Tili F, Visintin R. FEAR-mediated activation of Cdc14 is the limiting step for spindle elongation and anaphase progression. Nat Cell Biol 2015; 17:251-61. [PMID: 25706236 DOI: 10.1038/ncb3105] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 01/09/2015] [Indexed: 01/01/2023]
Abstract
Cleavage of cohesins and cyclin-dependent kinase (CDK) inhibition are thought to be sufficient for triggering chromosome segregation. Here we identify an essential requirement for anaphase chromosome movement. We show that, at anaphase onset, the phosphatase Cdc14 and the polo-like kinase Cdc5 are redundantly required to drive spindle elongation. This role of Cdc14 is mediated by the FEAR network, a group of proteins that activates Cdc14 at anaphase onset, and we suggest that Cdc5 facilitates both Cdc14 activation and CDK inhibition. We further identify the kinesin-5 motor protein Cin8 as a key target of Cdc14. Indeed, Cin8 mutants lacking critical CDK phosphorylation sites suppress the requirement for Cdc14 and Cdc5 in anaphase spindle elongation. Our results indicate that cohesin dissolution and CDK inhibition per se are not sufficient to drive sister chromatid segregation but that the motor protein Cin8 must be activated to elongate the spindle.
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Affiliation(s)
- Michela Roccuzzo
- Department of Experimental Oncology, European Institute of Oncology, Milan 20139, Italy
| | - Clara Visintin
- Department of Experimental Oncology, European Institute of Oncology, Milan 20139, Italy
| | - Federico Tili
- Department of Experimental Oncology, European Institute of Oncology, Milan 20139, Italy
| | - Rosella Visintin
- Department of Experimental Oncology, European Institute of Oncology, Milan 20139, Italy
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68
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Bergman ZJ, Mclaurin JD, Eritano AS, Johnson BM, Sims AQ, Riggs B. Spatial reorganization of the endoplasmic reticulum during mitosis relies on mitotic kinase cyclin A in the early Drosophila embryo. PLoS One 2015; 10:e0117859. [PMID: 25689737 PMCID: PMC4331435 DOI: 10.1371/journal.pone.0117859] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 12/24/2014] [Indexed: 11/19/2022] Open
Abstract
Mitotic cyclin-dependent kinase with their cyclin partners (cyclin:Cdks) are the master regulators of cell cycle progression responsible for regulating a host of activities during mitosis. Nuclear mitotic events, including chromosome condensation and segregation have been directly linked to Cdk activity. However, the regulation and timing of cytoplasmic mitotic events by cyclin:Cdks is poorly understood. In order to examine these mitotic cytoplasmic events, we looked at the dramatic changes in the endoplasmic reticulum (ER) during mitosis in the early Drosophila embryo. The dynamic changes of the ER can be arrested in an interphase state by inhibition of either DNA or protein synthesis. Here we show that this block can be alleviated by micro-injection of Cyclin A (CycA) in which defined mitotic ER clusters gathered at the spindle poles. Conversely, micro-injection of Cyclin B (CycB) did not affect spatial reorganization of the ER, suggesting CycA possesses the ability to initiate mitotic ER events in the cytoplasm. Additionally, RNAi-mediated simultaneous inhibition of all 3 mitotic cyclins (A, B and B3) blocked spatial reorganization of the ER. Our results suggest that mitotic ER reorganization events rely on CycA and that control and timing of nuclear and cytoplasmic events during mitosis may be defined by release of CycA from the nucleus as a consequence of breakdown of the nuclear envelope.
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Affiliation(s)
- Zane J. Bergman
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, United States of America
| | - Justin D. Mclaurin
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, United States of America
| | - Anthony S. Eritano
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, United States of America
| | - Brittany M. Johnson
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, United States of America
| | - Amanda Q. Sims
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, United States of America
| | - Blake Riggs
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, United States of America
- * E-mail:
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69
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Schmucker S, Sumara I. Molecular dynamics of PLK1 during mitosis. Mol Cell Oncol 2014; 1:e954507. [PMID: 27308323 PMCID: PMC4905186 DOI: 10.1080/23723548.2014.954507] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/09/2014] [Accepted: 07/10/2014] [Indexed: 12/30/2022]
Abstract
Polo-like kinase 1 (PLK1) is a key regulator of eukaryotic cell division. During mitosis, dynamic regulation of PLK1 is crucial for its roles in centrosome maturation, spindle assembly, microtubule–kinetochore attachment, and cytokinesis. Similar to other members of the PLK family, the molecular architecture of PLK1 protein is characterized by 2 domains—the kinase domain and the regulatory substrate-binding domain (polo-box domain)—that cooperate and control PLK1 function during mitosis. Mitotic cells employ many layers of regulation to activate and target PLK1 to different cellular structures in a timely manner. During the last decade, numerous studies have shed light on the precise molecular mechanisms orchestrating the mitotic activity of PLK1 in time and space. This review aims to discuss available data and concepts related to regulation of the molecular dynamics of human PLK1 during mitotic progression.
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Affiliation(s)
- Stephane Schmucker
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC) ; Illkirch, France
| | - Izabela Sumara
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC) ; Illkirch, France
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70
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Moreira A. Integrating transcription kinetics with alternative polyadenylation and cell cycle control. Nucleus 2014; 2:556-61. [DOI: 10.4161/nucl.2.6.18064] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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71
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Giansanti MG, Sechi S, Frappaolo A, Belloni G, Piergentili R. Cytokinesis in Drosophila male meiosis. SPERMATOGENESIS 2014; 2:185-196. [PMID: 23094234 PMCID: PMC3469441 DOI: 10.4161/spmg.21711] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cytokinesis separates the cytoplasm and the duplicated genome into two daughter cells at the end of cell division. This process must be finely regulated to maintain ploidy and prevent tumor formation. Drosophila male meiosis provides an excellent cell system for investigating cytokinesis. Mutants affecting this process can be easily identified and spermatocytes are large cells particularly suitable for cytological analysis of cytokinetic structures. Over the past decade, the powerful tools of Drosophila genetics and the unique characteristics of this cell system have led researchers to identify molecular players of the cell cleavage machinery and to address important open questions. Although spermatocyte cytokinesis is incomplete, resulting in formation of stable intercellular bridges, the molecular mechanisms are largely conserved in somatic cells. Thus, studies of Drosophila male meiosis will shed new light on the complex cell circuits regulating furrow ingression and substantially further our knowledge of cancer and other human diseases.
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Affiliation(s)
- Maria Grazia Giansanti
- Istituto di Biologia e Patologia Molecolari del CNR; Dipartimento di Biologia e Biotecnologie Università Sapienza di Roma; Rome, Italy
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72
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Barth TK, Schade GOM, Schmidt A, Vetter I, Wirth M, Heun P, Thomae AW, Imhof A. Identification of novel Drosophila centromere-associated proteins. Proteomics 2014; 14:2167-78. [PMID: 24841622 DOI: 10.1002/pmic.201400052] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Revised: 04/03/2014] [Accepted: 05/15/2014] [Indexed: 12/16/2022]
Abstract
Centromeres are chromosomal regions crucial for correct chromosome segregation during mitosis and meiosis. They are epigenetically defined by centromeric proteins such as the centromere-specific histone H3-variant centromere protein A (CENP-A). In humans, 16 additional proteins have been described to be constitutively associated with centromeres throughout the cell cycle, known as the constitutive centromere-associated network (CCAN). In contrast, only one additional constitutive centromeric protein is known in Drosophila melanogaster (D.mel), the conserved CCAN member CENP-C. To gain further insights into D.mel centromere composition and biology, we analyzed affinity-purified chromatin prepared from D.mel cell lines expressing green fluorescent protein tagged histone three variants by MS. In addition to already-known centromeric proteins, we identified novel factors that were repeatedly enriched in affinity purification-MS experiments. We analyzed the cellular localization of selected candidates by immunocytochemistry and confirmed localization to the centromere and other genomic regions for ten factors. Furthermore, RNA interference mediated depletion of CG2051, CG14480, and hyperplastic discs, three of our strongest candidates, leads to elevated mitotic defects. Knockdowns of these candidates neither impair the localization of several known kinetochore proteins nor CENP-A(CID) loading, suggesting their involvement in alternative pathways that contribute to proper centromere function. In summary, we provide a comprehensive analysis of the proteomic composition of Drosophila centromeres. All MS data have been deposited in the ProteomeXchange with identifier PXD000758 (http://proteomecentral.proteomexchange.org/dataset/PXD000758).
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Affiliation(s)
- Teresa K Barth
- Munich Center of Integrated Protein Science, Adolf-Butenandt Institute, Ludwig Maximilians University of Munich, Munich, Germany
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73
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Wälde S, King MC. The KASH protein Kms2 coordinates mitotic remodeling of the spindle pole body. J Cell Sci 2014; 127:3625-40. [PMID: 24963130 DOI: 10.1242/jcs.154997] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Defects in the biogenesis of the spindle pole body (SPB), the yeast centrosome equivalent, can lead to monopolar spindles and mitotic catastrophe. The KASH domain protein Kms2 and the SUN domain protein Sad1 colocalize within the nuclear envelope at the site of SPB attachment during interphase and at the spindle poles during mitosis in Schizosaccharomyces pombe. We show that Kms2 interacts with the essential SPB components Cut12 and Pcp1 and the Polo kinase Plo1. Depletion of Kms2 delays mitotic entry and leads to defects in the insertion of the SPB into the nuclear envelope, disrupting stable bipolar spindle formation. These effects are mediated in part by a delay in the recruitment of Plo1 to the SPB at mitotic entry. Plo1 activity supports mitotic SPB remodeling by driving a burst of incorporation of Cut12 and Pcp1. Thus, a fission yeast SUN-KASH complex plays an important role in supporting the remodeling of the SPB at mitotic entry.
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Affiliation(s)
- Sarah Wälde
- Department of Cell Biology, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Megan C King
- Department of Cell Biology, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
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74
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Rizvi SMD, Shakil S, Zeeshan M, Khan MS, Shaikh S, Biswas D, Ahmad A, Kamal MA. An enzoinformatics study targeting polo-like kinases-1 enzyme: Comparative assessment of anticancer potential of compounds isolated from leaves of Ageratum houstonianum. Pharmacogn Mag 2014; 10:S14-21. [PMID: 24914294 PMCID: PMC4047579 DOI: 10.4103/0973-1296.127333] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 03/26/2013] [Accepted: 02/21/2014] [Indexed: 11/23/2022] Open
Abstract
Natural products from plant sources, embracing inherently ample structural diversity than synthetic ones are the major sources of anticancer agents and will constantly play as protagonists for discovering new drugs. Polo-like kinases (PLKs) play a leading role in the ordered execution of mitotic events and 4 mammalian PLK family members have been identified. PLK1 is an attractive target for anticancer drugs in mammalian cells, among the four members of PLKs. The present study expresses the molecular interaction of compounds (1,2-Benzenedicarboxylic acid bis (2 ethylhexyl) ester, squalene, 3,5-bis (1,1-dimethylethyl) phenol, Pentamethyl tetrahydro-5H-chromene, (1,4-Cyclohexylphenyl) ethanone and 6-Vinyl-7-methoxy-2,2-dimethylchromene) isolated from methanolic extract of leaves of Ageratum houstonianum with PLK1 enzyme. Docking between PLK1 and each of these compounds (separately) was performed using “Auto dock 4.2.” (1,4-Cyclohexylphenyl) ethanone showed the maximum potential as a promising inhibitor of PLK1 enzyme with reference to ∆G (−6.84 kcal/mol) and Ki (9.77 μM) values. This was sequentially followed by Pentamethyl tetrahydro-5H-chromene (∆G = −6.60 kcal/mol; Ki = 14.58 μM), squalene (∆G = −6.17 kcal/mol; Ki = 30.12 μM), 6-Vinyl-7-methoxy-2,2-dimethylchromene (∆G = −5.91 kcal/mol; Ki = 46.68 μM), 3, 5-bis (1,1-dimethylethyl) phenol (∆G = −5.70 kcal/mol; Ki = 66.68 μM) and 1,2-Benzenedicarboxylic acid bis (2 ethylhexyl) ester (∆G = −5.58 kcal/mol; Ki = 80.80 μM). These results suggest that (1,4-Cyclohexylphenyl) ethanone might be a potent PLK1 inhibitor. Further, in vitro and in vivo rumination are warranted to validate the anticancer potential of (1,4-Cyclohexylphenyl) ethanone.
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Affiliation(s)
| | - Shazi Shakil
- Department of Bioengineering, Integral University, Lucknow, Uttar Pradesh, India
| | - Mohd Zeeshan
- Department of Biosciences, Integral University, Lucknow, Uttar Pradesh, India
| | - Mohd Sajid Khan
- Department of Biosciences, Integral University, Lucknow, Uttar Pradesh, India
| | - Sibhghatulla Shaikh
- Department of Biosciences, Integral University, Lucknow, Uttar Pradesh, India
| | - Deboshree Biswas
- Department of Biosciences, Integral University, Lucknow, Uttar Pradesh, India
| | - Adnan Ahmad
- Department of Bioengineering, Integral University, Lucknow, Uttar Pradesh, India
| | - Mohammad Amjad Kamal
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
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75
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Riparbelli MG, Gottardo M, Glover DM, Callaini G. Inhibition of Polo kinase by BI2536 affects centriole separation during Drosophila male meiosis. Cell Cycle 2014; 13:2064-72. [PMID: 24802643 PMCID: PMC4111698 DOI: 10.4161/cc.29083] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 04/30/2014] [Accepted: 04/30/2014] [Indexed: 12/25/2022] Open
Abstract
Pharmacological inhibition of Drosophila Polo kinase with BI2536 has allowed us to re-examine the requirements for Polo during Drosophila male gametogenesis. BI2536-treated spermatocytes persisted in a pro-metaphase state without dividing and had condensed chromosomes that did not separate. Centrosomes failed to recruit γ-tubulin and centrosomin (Cnn) and were not associated with microtubule arrays that were abnormal and did not form proper bipolar spindles. Centrioles, which usually separate during the anaphase of the first meiosis, remained held together in a V-shaped configuration suggesting that Polo kinase regulates the proteolysis that breaks centriole linkage to ensure their disengagement. Despite these defects spermatid differentiation proceeds, leading to axoneme formation.
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Affiliation(s)
| | - Marco Gottardo
- Department of Life Sciences; University of Siena; Siena, Italy
| | - David M Glover
- Department of Genetics; University of Cambridge; Cambridge, UK
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76
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Abstract
Polo-like kinase-1 (Plk1) belongs to a family of serine-threonine kinases and plays a critical role in mitotic progression. Plk1 involves in the initiation of mitosis, centrosome maturation, bipolar spindle formation, and cytokinesis, well-reported as traditional functions of Plk1. In this review, we discuss the role of Plk1 during DNA damage response beyond the functions in mitotsis. When DNA is damaged in cells under various stress conditions, the checkpoint mechanism is activated to allow cells to have enough time for repair. When damage is repaired, cells progress continuously their division, which is called checkpoint recovery. If damage is too severe to repair, cells undergo apoptotic pathway. If damage is not completely repaired, cells undergo a process called checkpoint adaptation, and resume cell division cycle with damaged DNA. Plk1 targets and regulates many key factors in the process of damage response, and we deal with these subjects in this review.
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Affiliation(s)
- Sun-Yi Hyun
- Department of Nanobiomedical Science & BK21 PLUS Global Research Center for Regenerative Medicine, Dankook University, Cheonan 330-714, Korea
| | - Hyo-In Hwan
- Department of Nanobiomedical Science & BK21 PLUS Global Research Center for Regenerative Medicine, Dankook University, Cheonan 330-714, Korea
| | - Young-Joo Jang
- Department of Nanobiomedical Science & BK21 PLUS Global Research Center for Regenerative Medicine, Dankook University, Cheonan 330-714, Korea
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77
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Suzuki MG, Ito H, Aoki F. Effects of RNAi-mediated knockdown of histone methyltransferases on the sex-specific mRNA expression of Imp in the silkworm Bombyx mori. Int J Mol Sci 2014; 15:6772-96. [PMID: 24758924 PMCID: PMC4013661 DOI: 10.3390/ijms15046772] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 03/25/2014] [Accepted: 04/10/2014] [Indexed: 12/11/2022] Open
Abstract
Sexual differentiation in Bombyx mori is controlled by sex-specific splicing of Bmdsx, which results in the omission of exons 3 and 4 in a male-specific manner. In B. mori, insulin-like growth factor II mRNA-binding protein (Imp) is a male-specific factor involved in male-specific splicing of Bmdsx. Male-specific Imp mRNA results from the male-specific inclusion of exon 8. To verify the link between histone methylation and alternative RNA processing in Imp, we examined the effects of RNAi-mediated knockdown of several histone methyltransferases on the sex-specific mRNA expression of Imp. As a result, male-specific expression of Imp mRNA was completely abolished when expression of the H3K79 methyltransferase DOT1L was repressed to <10% of that in control males. Chromatin immunoprecipitation-quantitative PCR analysis revealed a higher distribution of H3K79me2 in normal males than in normal females across Imp. RNA polymerase II (RNAP II) processivity assays indicated that RNAi knockdown of DOT1L in males caused a twofold decrease in RNAP II processivity compared to that in control males, with almost equivalent levels to those observed in normal females. Inhibition of RNAP II-mediated elongation in male cells repressed the male-specific splicing of Imp. Our data suggest the possibility that H3K79me2 accumulation along Imp is associated with the male-specific alternative processing of Imp mRNA that results from increased RNAP II processivity.
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Affiliation(s)
- Masataka G Suzuki
- Division of Biological Sciences, Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, 302 Bioscience-Bldg, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
| | - Haruka Ito
- Division of Biological Sciences, Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, 302 Bioscience-Bldg, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
| | - Fugaku Aoki
- Division of Biological Sciences, Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, 302 Bioscience-Bldg, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
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Wei X, Ai J, Deng Y, Guan X, Johnson DR, Ang CY, Zhang C, Perkins EJ. Identification of biomarkers that distinguish chemical contaminants based on gene expression profiles. BMC Genomics 2014; 15:248. [PMID: 24678894 PMCID: PMC4051169 DOI: 10.1186/1471-2164-15-248] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 03/11/2014] [Indexed: 11/29/2022] Open
Abstract
Background High throughput transcriptomics profiles such as those generated using microarrays have been useful in identifying biomarkers for different classification and toxicity prediction purposes. Here, we investigated the use of microarrays to predict chemical toxicants and their possible mechanisms of action. Results In this study, in vitro cultures of primary rat hepatocytes were exposed to 105 chemicals and vehicle controls, representing 14 compound classes. We comprehensively compared various normalization of gene expression profiles, feature selection and classification algorithms for the classification of these 105 chemicals into14 compound classes. We found that normalization had little effect on the averaged classification accuracy. Two support vector machine (SVM) methods, LibSVM and sequential minimal optimization, had better classification performance than other methods. SVM recursive feature selection (SVM-RFE) had the highest overfitting rate when an independent dataset was used for a prediction. Therefore, we developed a new feature selection algorithm called gradient method that had a relatively high training classification as well as prediction accuracy with the lowest overfitting rate of the methods tested. Analysis of biomarkers that distinguished the 14 classes of compounds identified a group of genes principally involved in cell cycle function that were significantly downregulated by metal and inflammatory compounds, but were induced by anti-microbial, cancer related drugs, pesticides, and PXR mediators. Conclusions Our results indicate that using microarrays and a supervised machine learning approach to predict chemical toxicants, their potential toxicity and mechanisms of action is practical and efficient. Choosing the right feature and classification algorithms for this multiple category classification and prediction is critical.
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Affiliation(s)
| | | | - Youping Deng
- Department of Internal Medicine, Rush University Cancer Center, Rush University Medical Center, Kidston House, 630 S, Hermitage Ave, Room 408, Chicago, IL 60612, USA.
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79
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Plk1-targeted therapies in TP53- or RAS-mutated cancer. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2014; 761:31-39. [PMID: 24630986 DOI: 10.1016/j.mrrev.2014.02.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 02/27/2014] [Accepted: 02/27/2014] [Indexed: 11/23/2022]
Abstract
Despite advances in treatment, prognosis for many types of carcinoma remains poor. Polo-like kinase 1 (Plk1) has been explored as a target for the development of anticancer drugs. As a mitotic master Ser/Thr kinase, Plk1 is involved in centrosomal maturation, microtubule nucleation, chromosomal segregation, and cytokinesis. Additional functions in interphase and in response to DNA damage have been revealed. The multiple locations of Plk1 correspond to distinct functions, mediated by phosphorylation of multiple substrates. Since it is highly expressed in several carcinomas, and expression of Plk1 is inversely correlated with the survival rate of patients in non-small cell lung, head and neck, and esophageal cancer, Plk1 is recognized as a valid prognostic marker. Connections between Plk1 and p53 or KRAS in carcinoma provide a rationale and several possible routes to the development of therapies. Tumors with both p53-deficiency and high Plk1 expression may be particularly sensitive to Plk1 inhibitors, although some controversial data exist. In KRAS-mutant cancers, on the other hand, Plk1 may be essential for tumor cell survival, but detailed studies as to whether Plk1 inhibitors are more effective in KRAS-mutant cancers must be performed in order to determine whether this is the case. Here, we present evidence for Plk1 as a prognostic marker and potentially effective target for the treatment of patients with carcinoma, to demonstrate the value of Plk1 as a target for the development of cancer treatment, especially for patients with solid tumors. In addition, the effects of Plk1 inhibition in p53- or KRAS-mutated cancer are discussed with respect to clinical implications. Structural specifics of Plk1 are presented, as well as current strategies for discovering new Plk1 inhibitors by targeting the conserved ATP binding site or polo-box domain of Plk1, in order to develop Plk1-specific anticancer drugs.
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80
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Kamaraj B, Rajendran V, Sethumadhavan R, Purohit R. In-silico screening of cancer associated mutation on PLK1 protein and its structural consequences. J Mol Model 2013; 19:5587-99. [PMID: 24271645 DOI: 10.1007/s00894-013-2044-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Accepted: 10/21/2013] [Indexed: 11/28/2022]
Abstract
The Polo-like kinases (Plks) are a conserved subfamily of serine-threonine protein kinases that have significant roles in cell proliferation. The serine/threonine protein kinases or polo-like kinase 1 (PLK1) exist in centrosome during interphase and is an important regulatory enzyme in cell cycle progression during M phase. Mutations in mammalian PLK1 were found to be over expressed in various human cancers and it is disrupting the binding ability of polo box domain with target peptide. In this analysis we implemented a computational approach to filter the most deleterious and cancer associated mutation on PLK1 protein. We found W414F as the most deleterious and cancer associated by Polyphen 2.0, SIFT, I-mutant 3.0, PANTHER, PhD-SNP, SNP&GO, Mutpred and Dr Cancer tools. Molecular docking and molecular dynamics simulation (MDS) approach was used to investigate the structural and functional behavior of PLK1 protein upon mutation. MDS and docking results showed stability loss in mutant PLK1 protein. Due to mutation, PLK1 protein became more flexible and alters the dynamic property of protein which might affect the interaction with target peptide and leads to cell proliferation. Our study provided a well designed computational methodology to examine the cancer associated nsSNPs and their molecular mechanism. It further helps scientists to develop a drug therapy against PLK1 cancer-associated diseases.
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Affiliation(s)
- Balu Kamaraj
- School of Bio Sciences and Technology (SBST), Bioinformatics Division, Vellore Institute of Technology University, Vellore, 632014, Tamil Nadu, India
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81
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Bibi N, Parveen Z, Rashid S. Identification of potential Plk1 targets in a cell-cycle specific proteome through structural dynamics of kinase and Polo box-mediated interactions. PLoS One 2013; 8:e70843. [PMID: 23967120 PMCID: PMC3744538 DOI: 10.1371/journal.pone.0070843] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 06/23/2013] [Indexed: 01/15/2023] Open
Abstract
Polo like kinase 1 (Plk1) is a key player in orchestrating the wide variety of cell-cycle events ranging from centrosome maturation, mitotic entry, checkpoint recovery, transcriptional control, spindle assembly, mitotic progression, cytokinesis and DNA damage checkpoints recovery. Due to its versatile nature, Plk1 is considered an imperative regulator to tightly control the diverse aspects of the cell cycle network. Interactions among Plk1 polo box domain (PBD) and its putative binding proteins are crucial for the activation of Plk1 kinase domain (KD). To date, only a few substrate candidates have been characterized through the inclusion of both polo box and kinase domain-mediated interactions. Thus it became compelling to explore precise and specific Plk1 substrates through reassessment and extension of the structure-function paradigm. To narrow this apparently wide gap in knowledge, here we employed a thorough sequence search of Plk1 phosphorylation signature containing proteins and explored their structure-based features like conceptual PBD-binding capabilities and subsequent recruitment of KD directed phosphorylation to dissect novel targets of Plk1. Collectively, we identified 4,521 phosphodependent proteins sharing similarity to the consensus phosphorylation and PBD recognition motifs. Subsequent application of filters including similarity index, Gene Ontology enrichment and protein localization resulted in stringent pre-filtering of irrelevant candidates and isolated unique targets with well-defined roles in cell-cycle machinery and carcinogenesis. These candidates were further refined structurally using molecular docking and dynamic simulation assays. Overall, our screening approach enables the identification of several undefined cell-cycle associated functions of Plk1 by uncovering novel phosphorylation targets.
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Affiliation(s)
- Nousheen Bibi
- National Center for Bioinformatics, Quaid-i-Azam University, Islamabad, Pakistan
| | - Zahida Parveen
- National Center for Bioinformatics, Quaid-i-Azam University, Islamabad, Pakistan
| | - Sajid Rashid
- National Center for Bioinformatics, Quaid-i-Azam University, Islamabad, Pakistan
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82
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Noatynska A, Tavernier N, Gotta M, Pintard L. Coordinating cell polarity and cell cycle progression: what can we learn from flies and worms? Open Biol 2013; 3:130083. [PMID: 23926048 PMCID: PMC3758543 DOI: 10.1098/rsob.130083] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Spatio-temporal coordination of events during cell division is crucial for animal development. In recent years, emerging data have strengthened the notion that tight coupling of cell cycle progression and cell polarity in dividing cells is crucial for asymmetric cell division and ultimately for metazoan development. Although it is acknowledged that such coupling exists, the molecular mechanisms linking the cell cycle and cell polarity machineries are still under investigation. Key cell cycle regulators control cell polarity, and thus influence cell fate determination and/or differentiation, whereas some factors involved in cell polarity regulate cell cycle timing and proliferation potential. The scope of this review is to discuss the data linking cell polarity and cell cycle progression, and the importance of such coupling for asymmetric cell division. Because studies in model organisms such as Caenorhabditis elegans and Drosophila melanogaster have started to reveal the molecular mechanisms of this coordination, we will concentrate on these two systems. We review examples of molecular mechanisms suggesting a coupling between cell polarity and cell cycle progression.
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Affiliation(s)
- Anna Noatynska
- Department of Physiology and Metabolism, Faculty of Medicine, University of Geneva, 1 rue Michel Servet, 1211 Geneva, Switzerland
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83
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Nie Z, Feher V, Natala S, McBride C, Kiryanov A, Jones B, Lam B, Liu Y, Kaldor S, Stafford J, Hikami K, Uchiyama N, Kawamoto T, Hikichi Y, Matsumoto SI, Amano N, Zhang L, Hosfield D, Skene R, Zou H, Cao X, Ichikawa T. Discovery of TAK-960: an orally available small molecule inhibitor of polo-like kinase 1 (PLK1). Bioorg Med Chem Lett 2013; 23:3662-6. [PMID: 23664874 DOI: 10.1016/j.bmcl.2013.02.083] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 02/14/2013] [Accepted: 02/19/2013] [Indexed: 11/28/2022]
Abstract
Using structure-based drug design, we identified and optimized a novel series of pyrimidodiazepinone PLK1 inhibitors resulting in the selection of the development candidate TAK-960. TAK-960 is currently undergoing Phase I evaluation in adult patients with advanced solid malignancies.
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Affiliation(s)
- Zhe Nie
- Takeda California, 10410 Science Center Drive, San Diego, CA 92121, USA
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84
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Lu J, Xin S, Meng H, Veldman M, Schoenfeld D, Che C, Yan R, Zhong H, Li S, Lin S. A novel anti-tumor inhibitor identified by virtual screen with PLK1 structure and zebrafish assay. PLoS One 2013; 8:e53317. [PMID: 23658603 PMCID: PMC3637257 DOI: 10.1371/journal.pone.0053317] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 11/30/2012] [Indexed: 11/19/2022] Open
Abstract
Polo-like kinase 1 (PLK1), one of the key regulators of mitosis, is a target for cancer therapy due to its abnormally high activity in several tumors. Plk1 is highly conserved and shares a nearly identical 3-D structure between zebrafish and humans. The initial 10 mitoses of zebrafish embryonic cleavages occur every∼30 minutes, and therefore provide a rapid assay to evaluate mitosis inhibitors including those targeting Plk1. To increase efficiency and specificity, we first performed a computational virtual screen of∼60000 compounds against the human Plk1 3-D structure docked to both its kinase and Polo box domain. 370 candidates with the top free-energy scores were subjected to zebrafish assay and 3 were shown to inhibit cell division. Compared to general screen for compounds inhibiting zebrafish embryonic cleavage, computation increased the efficiency by 11 folds. One of the 3 compounds, named I2, was further demonstrated to effectively inhibit multiple tumor cell proliferation in vitro and PC3 prostate cancer growth in Xenograft mouse model in vivo. Furthermore, I2 inhibited Plk1 enzyme activity in a dose dependent manner. The IC50 values of I2 in these assays are compatible to those of ON-01910, a Plk1 inhibitor currently in Phase III clinic trials. Our studies demonstrate that zebrafish assays coupled with computational screening significantly improves the efficiency of identifying specific regulators of biological targets. The PLK1 inhibitor I2, and its analogs, may have potential in cancer therapeutics.
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Affiliation(s)
- Jing Lu
- Shenzhen Graduate School of Peking University, Shenzhen, China
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Shengchang Xin
- Shenzhen Graduate School of Peking University, Shenzhen, China
| | - Huan Meng
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Matt Veldman
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - David Schoenfeld
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
| | - Chao Che
- Shenzhen Graduate School of Peking University, Shenzhen, China
| | - Ruibin Yan
- Shenzhen Graduate School of Peking University, Shenzhen, China
| | - Hanbing Zhong
- Shenzhen Graduate School of Peking University, Shenzhen, China
| | - Song Li
- Shenzhen Graduate School of Peking University, Shenzhen, China
| | - Shuo Lin
- Shenzhen Graduate School of Peking University, Shenzhen, China
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California, United States of America
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85
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Affiliation(s)
- Conrad von Schubert
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland
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86
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Henriques T, Ji Z, Tan-Wong SM, Carmo AM, Tian B, Proudfoot NJ, Moreira A. Transcription termination between polo and snap, two closely spaced tandem genes of D. melanogaster. Transcription 2013; 3:198-212. [PMID: 22992452 PMCID: PMC3654770 DOI: 10.4161/trns.21967] [Citation(s) in RCA: 11] [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
Transcription termination of RNA polymerase II between closely spaced genes is an important, though poorly understood, mechanism. This is true, in particular, in the Drosophila genome, where approximately 52% of tandem genes are separated by less than 1 kb. We show that a set of Drosophila tandem genes has a negative correlation of gene expression and display several molecular marks indicative of promoter pausing. We find that an intergenic spacing of 168 bp is sufficient for efficient transcription termination between the polo-snap tandem gene pair, by a mechanism that is independent of Pcf11 and Xrn2. In contrast, analysis of a tandem gene pair containing a longer intergenic region reveals that termination occurs farther downstream of the poly(A) signal and is, in this case, dependent on Pcf11 and Xrn2. For polo-snap, displacement of poised polymerase from the snap promoter by depletion of the initiation factor TFIIB results in an increase of polo transcriptional read-through. This suggests that poised polymerase is necessary for transcription termination. Interestingly, we observe that polo forms a TFIIB dependent gene loop between its promoter and terminator regions. Furthermore, in a plasmid containing the polo-snap locus, deletion of the polo promoter causes an increase in snap expression, as does deletion of polo poly(A) signals. Taken together, our results indicate that polo forms a gene loop and polo transcription termination occurs by an Xrn2 and Pcf11 independent mechanism that requires TFIIB.
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Affiliation(s)
- Telmo Henriques
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
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87
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Centrobin controls mother-daughter centriole asymmetry in Drosophila neuroblasts. Nat Cell Biol 2013; 15:241-8. [PMID: 23354166 DOI: 10.1038/ncb2671] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 12/07/2012] [Indexed: 12/23/2022]
Abstract
During interphase in Drosophila neuroblasts, the Centrobin (CNB)-positive daughter centriole retains pericentriolar material (PCM) and organizes an aster that is a key determinant of the orientation of cell division. Here we show that daughter centrioles depleted of CNB cannot fulfil this function whereas mother centrioles that carry ectopic CNB can. CNB co-precipitates with a set of centrosomal proteins that include γ-TUB, ANA2, CNN, SAS-4, ASL, DGRIP71, POLO and SAS-6. Following chemical inhibition of POLO or removal of three POLO phosphorylation sites present in CNB, the interphase microtubule aster is lost. These results demonstrate that centriolar CNB localization is both necessary and sufficient to enable centrioles to retain PCM and organize the interphase aster in Drosophila neuroblasts. They also reveal an interphase function for POLO in this process that seems to have co-opted part of the protein network involved in mitotic centrosome maturation.
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88
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Pek JW, Ng BF, Kai T. Polo-mediated phosphorylation of Maelstrom regulates oocyte determination during oogenesis in Drosophila. Development 2012; 139:4505-13. [DOI: 10.1242/dev.082867] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In Drosophila, Maelstrom is a conserved component of the perinuclear nuage, a germline-unique structure that appears to serve as a site for Piwi-interacting RNA (piRNA) production to repress deleterious transposons. Maelstrom also functions in the nucleus as a transcriptional regulator to repress the expression of microRNA-7, a process that is essential for the proper differentiation of germline stem cells. In this paper, we report another function of Maelstrom in regulating oocyte determination independently of its transposon silencing and germline stem cell differentiation activities. In Drosophila, the conserved serine 138 residue in Maelstrom is required for its phosphorylation, an event that promotes oocyte determination. Phosphorylation of Maelstrom is required for the repression of the pachytene checkpoint protein Sir2, but not for transposon silencing or for germline stem cell differentiation. We identify Polo as a kinase that mediates the phosphorylation of Maelstrom. Our results suggest that the Polo-mediated phosphorylation of Maelstrom may be a mechanism that controls oocyte determination by inactivating the pachytene checkpoint via the repression of Sir2 in Drosophila ovaries.
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Affiliation(s)
- Jun Wei Pek
- Temasek Life Sciences Laboratory, 1 Research Link National University of Singapore, Singapore 117604
| | - Bing Fu Ng
- Department of Biological Sciences, National University of Singapore, Singapore 117604
| | - Toshie Kai
- Temasek Life Sciences Laboratory, 1 Research Link National University of Singapore, Singapore 117604
- Department of Biological Sciences, National University of Singapore, Singapore 117604
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89
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Han X, Zhang J, Guo L, Cao R, Li Y, Li N, Ma Q, Wu J, Wang Y, Si S. A series of beta-carboline derivatives inhibit the kinase activity of PLKs. PLoS One 2012; 7:e46546. [PMID: 23056340 PMCID: PMC3463587 DOI: 10.1371/journal.pone.0046546] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 09/03/2012] [Indexed: 12/05/2022] Open
Abstract
Polo-like kinases play an essential role in the ordered execution of mitotic events and 4 mammalian PLK family members have been identified. Accumulating evidence indicates that PLK1 is an attractive target for anticancer drugs. In this paper, a series of beta-carboline derivatives were synthesized and three compounds, DH281, DH285 and DH287, were identified as potent new PLK inhibitors. We employed various biochemical and cellular approaches to determine the effects of these compounds on the activity of PLK1 and other mitotic kinases and on cell cycle progression. We found that these three compounds could selectively inhibit the kinase activity of purified PLK1, PLK2 and PLK3 in vitro. They show strong antitumor activity against a number of cancer cell lines with relatively low micromolar IC(50)s, but are relatively less toxic to non-cancer cells (MRC5). Moreover, these compounds could induce obvious accumulation of HeLa cells in G(2)/M and S phases and trigger apoptosis. Although MRC5 cells show clear S-phase arrest after treatment with these compounds, the G2/M arrest and apoptosis are less insignificant, indicating the distinct sensitivity between normal and cancer cells. We also found that HeLa cells treated with these drugs exhibit monopolar spindles and increased Wee1 protein levels, the characteristics of cells treated with PLK1 inhibitors. Together, these results demonstrate that DH281, DH285 and DH287 beta-carboline compounds are new PLK inhibitors with potential for cancer treatment.
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Affiliation(s)
- Xiaomin Han
- Institute of Medicinal Biotechnology, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, People’s Republic of China
| | - Jing Zhang
- Institute of Medicinal Biotechnology, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, People’s Republic of China
| | - Liang Guo
- Xinjiang Huashidan Pharmaceutical Co., Urumqi, People’s Republic of China
| | - Rihui Cao
- Xinjiang Huashidan Pharmaceutical Co., Urumqi, People’s Republic of China
| | - Yongzhen Li
- Institute of Medicinal Biotechnology, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, People’s Republic of China
| | - Ni Li
- Institute of Medicinal Biotechnology, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, People’s Republic of China
| | - Qin Ma
- Xinjiang Huashidan Pharmaceutical Co., Urumqi, People’s Republic of China
| | - Jialin Wu
- Xinjiang Huashidan Pharmaceutical Co., Urumqi, People’s Republic of China
| | - Yanchang Wang
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America
| | - Shuyi Si
- Institute of Medicinal Biotechnology, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, People’s Republic of China
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90
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Zhang C, Sun X, Ren Y, Lou Y, Zhou J, Liu M, Li D. Validation of Polo-like kinase 1 as a therapeutic target in pancreatic cancer cells. Cancer Biol Ther 2012; 13:1214-20. [PMID: 22892842 PMCID: PMC3469479 DOI: 10.4161/cbt.21412] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Polo-like kinase 1 (PLK1) is a serine/threonine protein kinase and plays a critical role in mitosis. PLK1 has also been regarded as a valuable target for cancer treatment, and several PLK1 inhibitors are currently undergoing clinical investigations. In this study, our data show that the expression level of PLK1 is upregulated in human pancreatic cancer cells. Molecular modeling studies indicate that DMTC inhibits PLK1 activity through competitive displacement of ATP from its binding pocket. Our data further show that DMTC suppresses the proliferation of pancreatic cancer cells and induces the formation of multinucleated cells, ultimately resulting in apoptosis. In addition, combination index analysis demonstrates that DMTC acts synergistically with the chemotherapeutic drug gemcitabine in inhibiting the proliferation of pancreatic cancer cells. These results thus suggest a potential of using PLK1 inhibitors for the treatment of pancreatic cancer.
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Affiliation(s)
- Chao Zhang
- State Key Laboratory of Medicinal Chemical Biology; College of Life Sciences; Nankai University; Tianjin, China
| | - Xiaodong Sun
- State Key Laboratory of Medicinal Chemical Biology; College of Life Sciences; Nankai University; Tianjin, China
| | - Yuan Ren
- State Key Laboratory of Medicinal Chemical Biology; College of Life Sciences; Nankai University; Tianjin, China
| | - Yunbo Lou
- State Key Laboratory of Medicinal Chemical Biology; College of Life Sciences; Nankai University; Tianjin, China
| | - Jun Zhou
- State Key Laboratory of Medicinal Chemical Biology; College of Life Sciences; Nankai University; Tianjin, China
| | - Min Liu
- Key Laboratory of Immune Microenvironment and Disease of the Ministry of Education; Basic Medical College; Tianjin Medical University; Tianjin, China
| | - Dengwen Li
- State Key Laboratory of Medicinal Chemical Biology; College of Life Sciences; Nankai University; Tianjin, China
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91
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Giansanti MG, Fuller MT. What Drosophila spermatocytes tell us about the mechanisms underlying cytokinesis. Cytoskeleton (Hoboken) 2012; 69:869-81. [PMID: 22927345 DOI: 10.1002/cm.21063] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Revised: 08/13/2012] [Accepted: 08/17/2012] [Indexed: 12/21/2022]
Abstract
Cytokinesis separates the genomic material and organelles of a dividing cell equitably into two physically distinct daughter cells at the end of cell division. This highly choreographed process involves coordinated reorganization and regulated action of the actin and microtubule cytoskeletal systems, an assortment of motor proteins, and membrane trafficking components. Due to their large size, the ease with which exquisite cytological analysis may be performed on them, and the availability of numerous mutants and other genetic tools, Drosophila spermatocytes have provided an excellent system for exploring the mechanistic basis for the temporally programmed and precise spatially localized events of cytokinesis. Mutants defective in male meiotic cytokinesis can be easily identified in forward genetic screens by the production of multinucleate spermatids. In addition, the weak spindle assembly checkpoint in spermatocytes, which causes only a small delay of anaphase onset in the presence of unattached chromosomes, allows investigation of whether gene products required for spindle assembly and chromosome segregation are also involved in cytokinesis. Perhaps due to the large size of spermatocytes and the requirement for two rapid-fire rounds of division without intervening S or growth phases during meiosis, male meiotic mutants have also revealed much about molecular mechanisms underlying new membrane addition during cytokinesis. Finally, cell type-specific differences in the events that set up and complete cytokinesis are emerging from comparison of spermatocytes with cells undergoing mitosis either elsewhere in the organism or in tissue culture.
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Affiliation(s)
- Maria Grazia Giansanti
- Istituto di Biologia e Patologia Molecolari del CNR, Dipartimento di Biologia e Biotecnologie Università Sapienza di Roma, Piazzale A. Moro 5, Roma, Italy.
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92
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Moutinho-Santos T, Conde C, Sunkel CE. POLO ensures chromosome bi-orientation by preventing and correcting erroneous chromosome-spindle attachments. J Cell Sci 2012; 125:576-83. [PMID: 22389397 DOI: 10.1242/jcs.092445] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Correct chromosome segregation during cell division requires bi-orientation at the mitotic spindle. Cells possess mechanisms to prevent and correct inappropriate chromosome attachment. Sister kinetochores assume a 'back-to-back' geometry on chromosomes that favors amphitelic orientation but the regulation of this process and molecular components are unknown. Abnormal chromosome-spindle interactions do occur but are corrected through the activity of Aurora B, which destabilizes erroneous attachments. Here, we address the role of Drosophila POLO in chromosome-spindle interactions and show that, unlike inhibition of its activity, depletion of the protein results in bipolar spindles with most chromosomes forming stable attachments with both sister kinetochores bound to microtubules from the same pole in a syntelic orientation. This is partly the result of impaired localization and activity of Aurora B but also of an altered centromere organization with abnormal distribution of centromeric proteins and shorter interkinetochore distances. Our results suggests that POLO is required to promote amphitelic attachment and chromosome bi-orientation by regulating both the activity of the correction mechanism and the architecture of the centromere.
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93
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Shi JQ, Lasky K, Shinde V, Stringer B, Qian MG, Liao D, Liu R, Driscoll D, Nestor MT, Amidon BS, Rao Y, Duffey MO, Manfredi MG, Vos TJ, D' Amore N, Hyer ML. MLN0905, a small-molecule plk1 inhibitor, induces antitumor responses in human models of diffuse large B-cell lymphoma. Mol Cancer Ther 2012; 11:2045-53. [PMID: 22609854 DOI: 10.1158/1535-7163.mct-11-1036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Diffuse large B-cell lymphoma (DLBCL) is the most common of the non-Hodgkin lymphomas, accounting for up to 30% of all newly diagnosed lymphoma cases. Current treatment options for this disease are effective, but not always curative; therefore, experimental therapies continue to be investigated. We have discovered an experimental, potent, and selective small-molecule inhibitor of PLK1, MLN0905, which inhibits cell proliferation in a broad range of human tumor cells including DLBCL cell lines. In our report, we explored the pharmacokinetic, pharmacodynamic, and antitumor properties of MLN0905 in DLBCL xenograft models grown in mice. These studies indicate that MLN0905 modulates the pharmacodynamic biomarker phosphorylated histone H3 (pHisH3) in tumor tissue. The antitumor activity of MLN0905 was evaluated in three human subcutaneous DLBCL xenograft models, OCI LY-10, OCI LY-19, and PHTX-22L (primary lymphoma). In each model, MLN0905 yielded significant antitumor activity on both a continuous (daily) and intermittent dosing schedule, underscoring dosing flexibility. The antitumor activity of MLN0905 was also evaluated in a disseminated xenograft (OCI LY-19) model to better mimic human DLBCL disease. In the disseminated model, MLN0905 induced a highly significant survival advantage. Finally, MLN0905 was combined with a standard-of-care agent, rituximab, in the disseminated OCI LY-19 xenograft model. Combining rituximab and MLN0905 provided both a synergistic antitumor effect and a synergistic survival advantage. Our findings indicate that PLK1 inhibition leads to pharmacodynamic pHisH3 modulation and significant antitumor activity in multiple DLBCL models. These data strongly suggest evaluating PLK1 inhibitors as DLBCL anticancer agents in the clinic.
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MESH Headings
- Administration, Oral
- Animals
- Antibodies, Monoclonal, Murine-Derived/administration & dosage
- Antibodies, Monoclonal, Murine-Derived/pharmacology
- Antineoplastic Agents/administration & dosage
- Antineoplastic Agents/pharmacokinetics
- Antineoplastic Agents/pharmacology
- Benzazepines/administration & dosage
- Benzazepines/pharmacokinetics
- Benzazepines/pharmacology
- Cell Cycle Proteins/antagonists & inhibitors
- Cell Cycle Proteins/genetics
- Cell Cycle Proteins/metabolism
- Cell Line, Tumor
- Cell Survival/drug effects
- Dose-Response Relationship, Drug
- Drug Administration Schedule
- Drug Synergism
- Female
- Gene Knockdown Techniques
- Histones/metabolism
- Lymphoma, Large B-Cell, Diffuse/drug therapy
- Mice
- Mice, Inbred NOD
- Mice, SCID
- Protein Serine-Threonine Kinases/antagonists & inhibitors
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Proto-Oncogene Proteins/antagonists & inhibitors
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- RNA Interference
- Rituximab
- Thiones/administration & dosage
- Thiones/pharmacokinetics
- Thiones/pharmacology
- Tumor Burden/drug effects
- Xenograft Model Antitumor Assays
- Polo-Like Kinase 1
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Affiliation(s)
- Judy Quiju Shi
- The Takeda Oncology Company, Cambridge, Massachusetts 02139, USA
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94
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Cabernard C. Cytokinesis in Drosophila melanogaster. Cytoskeleton (Hoboken) 2012; 69:791-809. [PMID: 22888045 DOI: 10.1002/cm.21060] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 07/31/2012] [Indexed: 12/22/2022]
Abstract
Cytokinesis is the process that physically separates two sibling cells, ensuring the proper partitioning of the nuclear and cytoplasmic contents at the end of cell division. Cytokinesis requires a fine-tuned molecular machinery that has to be assembled with high spatiotemporal precision. Drosophila melanogaster is an ideal model system to investigate this cellular process. Genetic screens performed in spermatocytes, neuroblasts, and Schneider cells revealed numerous evolutionary conserved components. These genetically amenable systems have proven to be very useful to further elucidate the cellular and molecular mechanism of cytokinesis, significantly contributing to our current understanding of this important cellular process. As in other organisms, cytokinesis is largely dependent on the mitotic spindle, providing positional cues for cleavage furrow placement and progression. However, spindle-independent mechanisms could also be important during special cases of cytokinesis, such as asymmetric cell division. Thus, powerful fly genetics combined with single-cell analysis, live imaging, and biochemical assays will continue to provide important insights into the mechanism of cytokinesis.
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95
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Schmit TL, Nihal M, Ndiaye M, Setaluri V, Spiegelman VS, Ahmad N. Numb regulates stability and localization of the mitotic kinase PLK1 and is required for transit through mitosis. Cancer Res 2012; 72:3864-72. [PMID: 22593191 PMCID: PMC3410979 DOI: 10.1158/0008-5472.can-12-0714] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Numb functions in progenitor cell fate determination and early development, but it is also expressed in postdevelopmental tissues and cancers where its role is unclear. In this study, we report that a targeted knockdown of Numb expression causes a G(2)-M arrest and reduced cell growth in human melanoma cells. Co-immunoprecipitation and colocalization studies showed that Numb interacts with the serine/threonine polo-like kinase Plk1 and Numb cycles in a cell-cycle-dependent fashion along with this mitotic regulator. Interestingly, Numb expression was required for Plk1 protein stability and localization to the spindle poles during mitosis. Reduction in Numb expression resulted in mislocalization of Plk1 at both metaphase and anaphase, leading to disorganized γ-tubulin recruitment in centrosomes. Together, our findings present a novel function for Numb during symmetric cell division. We suggest that dysregulation of Numb expression results in mislocalized Plk1 and poor centrosomal γ-tubulin recruitment, potentially contributing to mitotic errors, aneuploidy, and cancer development.
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Affiliation(s)
- Travis L. Schmit
- Department of Dermatology, University of Wisconsin, Madison, WI
- Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI
| | - Minakshi Nihal
- Department of Dermatology, University of Wisconsin, Madison, WI
- University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, University of Wisconsin, Madison, WI
| | - Mary Ndiaye
- Department of Dermatology, University of Wisconsin, Madison, WI
| | - Vijayasaradhi Setaluri
- Department of Dermatology, University of Wisconsin, Madison, WI
- Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI
- University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, University of Wisconsin, Madison, WI
| | - Vladimir S. Spiegelman
- Department of Dermatology, University of Wisconsin, Madison, WI
- Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI
- University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, University of Wisconsin, Madison, WI
| | - Nihal Ahmad
- Department of Dermatology, University of Wisconsin, Madison, WI
- Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI
- University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, University of Wisconsin, Madison, WI
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96
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Dynamic interactions between Bombyx mori nucleopolyhedrovirus and its host cells revealed by transcriptome analysis. J Virol 2012; 86:7345-59. [PMID: 22532689 DOI: 10.1128/jvi.07217-12] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although microarray and expressed sequence tag (EST)-based approaches have been used to profile gene expression during baculovirus infection, the response of host genes to baculovirus infection and the interaction between baculovirus and its host remain largely unknown. To determine the host response to Bombyx mori nucleopolyhedrovirus infection and the dynamic interaction between the virus and its host, eight digital gene expression libraries were examined in a Bm5 cell line before infection and at 1.5, 3, 6, 12, 24, 48, and 96 h postinfection. Gene set enrichment analysis of differentially expressed genes at each time point following infection showed that gene sets including cytoskeleton, transcription, translation, energy metabolism, iron ion metabolism, and the ubiquitin-proteasome pathway were altered after viral infection. In addition, a time course depicting protein-protein interaction networks between the baculovirus and the host were constructed and revealed that viral proteins interact with a multitude of cellular machineries, such as the proteasome, cytoskeleton, and spliceosome. Several viral proteins, including IE2, CG30, PE38, and PK-1/2, were predicted to play key roles in mediating virus-host interactions. Based on these results, we tested the role of the ubiquitin-proteasome pathway and iron ion metabolism in the viral infection cycle. Treatment with a proteasome inhibitor and deferoxamine mesylate in vitro and in vivo confirmed that these pathways regulate viral infection. Taken together, these findings provide new insights into the interaction between the baculovirus and its host and identify molecular mechanisms that can be used to block viral infection and improve baculovirus expression systems.
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97
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Abstract
The events of cell division are regulated by a complex interplay between kinases and phosphatases. Cyclin-dependent kinases (Cdks), polo-like kinases (Plks) and Aurora kinases play central roles in this process. Polo kinase (Plk1 in humans) regulates a wide range of events in mitosis and cytokinesis. To ensure the accuracy of these processes, polo activity itself is subject to complex regulation. Phosphorylation of polo in its T loop (or activation loop) increases its kinase activity several-fold. It has been shown that Aurora A kinase, with its co-factor Bora, activates Plk1 in G(2), and that this is essential for recovery from cell cycle arrest induced by DNA damage. In a recent article published in PLoS Biology, we report that Drosophila polo is activated by Aurora B kinase at centromeres, and that this is crucial for polo function in regulating chromosome dynamics in prometaphase. Our results suggest that this regulatory pathway is conserved in humans. Here, we propose a model for the collaboration between Aurora B and polo in the regulation of kinetochore attachment to microtubules in early mitosis. Moreover, we suggest that Aurora B could also function to activate Polo/Plk1 in cytokinesis. Finally, we discuss recent findings and open questions regarding the activation of polo and polo-like kinases by different kinases in mitosis, cytokinesis and other processes.
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Affiliation(s)
- Vincent Archambault
- Institut de Recherche en Immunologie et en Cancérologie and Département de Biochimie; Université de Montréal; Montréal, QC Canada
| | - Mar Carmena
- Wellcome Trust Centre for Cell Biology; University of Edinburgh; Edinburgh, Scotland UK
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98
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Luo J, Liu X. Polo-like kinase 1, on the rise from cell cycle regulation to prostate cancer development. Protein Cell 2012; 3:182-97. [PMID: 22447658 PMCID: PMC4875424 DOI: 10.1007/s13238-012-2020-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Accepted: 02/04/2012] [Indexed: 01/19/2023] Open
Abstract
Polo-like kinase 1 (Plk1), a well-characterized member of serine/threonine kinases Plk family, has been shown to play pivotal roles in mitosis and cytokinesis in eukaryotic cells. Recent studies suggest that Plk1 not only controls the process of mitosis and cytokinesis, but also, going beyond those previously described functions, plays critical roles in DNA replication and Pten null prostate cancer initiation. In this review, we briefly summarize the functions of Plk1 in mitosis and cytokinesis, and then mainly focus on newly discovered functions of Plk1 in DNA replication and in Pten-null prostate cancer initiation. Furthermore, we briefly introduce the architectures of human and mouse prostate glands and the possible roles of Plk1 in human prostate cancer development. And finally, the newly chemotherapeutic development of small-molecule Plk1 inhibitors to target Plk1 in cancer treatment and their translational studies are also briefly reviewed.
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Affiliation(s)
- Jijing Luo
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907 USA
| | - Xiaoqi Liu
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907 USA
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99
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Cizmecioglu O, Krause A, Bahtz R, Ehret L, Malek N, Hoffmann I. Plk2 regulates centriole duplication through phosphorylation-mediated degradation of Fbxw7 (human Cdc4). J Cell Sci 2012; 125:981-92. [DOI: 10.1242/jcs.095075] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Polo-like kinases (Plks) perform crucial functions during mitosis, cytokinesis and centriole duplication. Plk2 is activated in early G1 phase and is involved in the reproduction of centrosomes. However, the mechanisms underlying Plk2-induced centriole duplication are incompletely understood. Here, we show that Plk2 directly targets the F-box protein F-box/WD repeat-containing protein 7 (Fbxw7), which is a regulator of the ubiquitin-mediated degradation of cyclin E. Plk2 phosphorylates Fbxw7 on serine 176 and the two proteins form a complex in vitro and in vivo. Phosphorylation of Fbxw7 by Plk2 induces destabilization of the F-box protein resulting in accumulation of cyclin E and increased potential for centriole reproduction. In addition, loss of Fbxw7 in human cells leads to uncontrolled centriole duplication, highlighting the importance of Fbxw7 regulation by Plk2. These findings define a previously unknown Plk2-dependent pathway involved at the onset of S phase and in centrosome duplication.
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Affiliation(s)
- Onur Cizmecioglu
- Cell cycle Control and Carcinogenesis (F045), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
| | - Annekatrin Krause
- Cell cycle Control and Carcinogenesis (F045), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
| | - Ramona Bahtz
- Cell cycle Control and Carcinogenesis (F045), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
| | - Lena Ehret
- Cell cycle Control and Carcinogenesis (F045), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
| | - Nisar Malek
- University Hospital Tübingen, Department of Internal Medicine 1, Otfried-Müller-Str. 10, 72076 Tübingen, Germany
| | - Ingrid Hoffmann
- Cell cycle Control and Carcinogenesis (F045), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
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100
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Chen S, Bartkovitz D, Cai J, Chen Y, Chen Z, Chu XJ, Le K, Le NT, Luk KC, Mischke S, Naderi-Oboodi G, Boylan JF, Nevins T, Qing W, Chen Y, Wovkulich PM. Identification of novel, potent and selective inhibitors of Polo-like kinase 1. Bioorg Med Chem Lett 2012; 22:1247-50. [PMID: 22172702 DOI: 10.1016/j.bmcl.2011.11.052] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Revised: 11/09/2011] [Accepted: 11/14/2011] [Indexed: 10/14/2022]
Abstract
A series of pyrimidodiazepines was identified as potent Polo-like kinase 1 (PLK1) inhibitors. The synthesis and SAR are discussed. The lead compound 7 (RO3280) has potent inhibitory activity against PLK1, good selectivity against other kinases, and excellent in vitro cellular potency. It showed strong antitumor activity in xenograft mouse models.
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Affiliation(s)
- Shaoqing Chen
- Discovery Chemistry, Hoffmann-La Roche Inc., Pharma Research & Early Development, Small Molecule Research, 340 Kingsland Street, Nutley, NJ 07110, United States.
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