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Holmes TR, Dindu S, Hansen LA. Aberrant localization of signaling proteins in skin cancer: Implications for treatment. Mol Carcinog 2019; 58:1631-1639. [PMID: 31062427 DOI: 10.1002/mc.23036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/15/2019] [Accepted: 04/17/2019] [Indexed: 01/01/2023]
Abstract
Aberrant subcellular localization of signaling proteins can provide cancer cells with advantages such as resistance to apoptotic cell death, increased invasiveness and more rapid proliferation. Nuclear to cytoplasmic shifts in tumor-promoting proteins can lead to worse patient outcomes, providing opportunities to target cancer-specific processes. Herein, we review the significance of dysregulated protein localization with a focus on skin cancer. Altered localization of signaling proteins controlling cell cycle progression or cell death is a common feature of cancer. In some instances, aberrant subcellular localization results in an acquired prosurvival function. Taking advantage of this knowledge reveals novel targets useful in the development of cancer therapeutics.
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Affiliation(s)
- Thomas R Holmes
- Department of Biomedical Sciences, Creighton University, Omaha, Nebraska
| | - Shravya Dindu
- Department of Biomedical Sciences, Creighton University, Omaha, Nebraska
| | - Laura A Hansen
- Department of Biomedical Sciences, Creighton University, Omaha, Nebraska
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2
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Accumulation of cytoplasmic CDC25A in cutaneous squamous cell carcinoma leads to a dependency on CDC25A for cancer cell survival and tumor growth. Cancer Lett 2017; 410:41-49. [DOI: 10.1016/j.canlet.2017.09.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/15/2017] [Accepted: 09/16/2017] [Indexed: 01/29/2023]
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3
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Barkeer S, Guha N, Hothpet V, Saligrama Adavigowda D, Hegde P, Padmanaban A, Yu LG, Swamy BM, Inamdar SR. Molecular mechanism of anticancer effect of Sclerotium rolfsii lectin in HT29 cells involves differential expression of genes associated with multiple signaling pathways: A microarray analysis. Glycobiology 2015; 25:1375-91. [PMID: 26347523 DOI: 10.1093/glycob/cwv067] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 08/17/2015] [Indexed: 12/16/2022] Open
Abstract
Sclerotium rolfsii lectin (SRL) is a lectin isolated from fungus S. rolfsii and has high binding specificity toward the oncofetal Thomsen-Friedenreich carbohydrate antigen (Galβ1-3GalNAc-α-O-Ser/Thr, T or TF), which is expressed in more than 90% of human cancers. Our previous studies have shown that binding of SRL to human colon, breast and ovarian cancer cells induces cell apoptosis in vitro and suppresses tumor growth in vivo. This study investigated the SRL-mediated cell signaling in human colon cancer HT29 cells by mRNA and miRNA microarrays. It was found that SRL treatment results in altered expression of several hundred molecules including mitogen-activated protein kinase (MAPK) and c-JUN-associated, apoptosis-associated and cell cycle and DNA replication-associated signaling molecules. Pathway analysis using GeneSpring 12.6.1 revealed that SRL treatment induces changes of MAPK and c-JUN-associated signaling pathways as early as 2 h while changes of cell cycle, DNA replication and apoptosis pathways were significantly affected only after 24 h. A significant change of cell miRNA expression was also observed after 12 h treatment of the cells with SRL. These changes were further validated by quantitative real time polymerase chain reaction and immunoblotting. This study thus suggests that the presence of SRL affects multiple signaling pathways in cancer cells with early effects on cell proliferation pathways associated with MAPK and c-JUN, followed by miRNA-associated cell activity and apoptosis. This provides insight information into the molecular mechanism of the anticancer activity of this fungal lectin.
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Affiliation(s)
- Srikanth Barkeer
- Department of Studies in Biochemistry, Karnatak University, Dharwad 580 003, India
| | - Nilanjan Guha
- Agilent Technologies India Pvt. Ltd, Bangalore 560048, India
| | | | | | - Prajna Hegde
- Department of Studies in Biochemistry, Karnatak University, Dharwad 580 003, India
| | | | - Lu-Gang Yu
- Department of Gastroenterology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
| | - Bale M Swamy
- Department of Studies in Biochemistry, Karnatak University, Dharwad 580 003, India Department of Gastroenterology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
| | - Shashikala R Inamdar
- Department of Studies in Biochemistry, Karnatak University, Dharwad 580 003, India Department of Gastroenterology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK
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Liu L, Zuo LF, Zuo J, Wang J. Artesunate induces apoptosis and inhibits growth of Eca109 and Ec9706 human esophageal cancer cell lines in vitro and in vivo. Mol Med Rep 2015; 12:1465-72. [PMID: 25816175 DOI: 10.3892/mmr.2015.3517] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 03/03/2015] [Indexed: 11/05/2022] Open
Abstract
Esophageal cancer is a common malignant tumor worldwide with a high incidence rate in China and it is a great threat to human health. Combined modality therapy is used for chemotherapeutic treatment of esophageal cancer; however, drug resistance and side effects of the drugs is a major barrier to the success of chemotherapy. As chemotherapy with common drugs is far from providing satisfactory clinical outcomes for patients with esophageal cancer, more efficient drugs are urgently required. Artesunate (Art) is the first-line treatment option for malaria; however, it was recently revealed that Art has remarkable anti-tumor activity, making it a novel candidate for cancer chemotherapy. Although the anti-cancer effects of Art have been well documented, its potential against esophageal cancer has rarely been explored. The present study aimed to investigate the significance and mechanism of the anti-proliferative activity of Art on esophageal cancer cells in vitro and in vivo. In the in vitro experiments, Art inhibited the growth as well as induced cell apoptosis and cell cycle arrest of esophageal cancer cell lines (Eca109 and Ec9706) in a concentration-dependent manner. Furthermore, downregulation of mitochondrial membrane potential, B-cell lymphoma-2 (BCL-2) and CDC25A, as well as upregulation of BCL-2‑associated X protein (Bax) and caspase-3 expression in Art-treated cells were identified. In addition, an in vivo study showed that Art produced a dose-dependent tumor regression in nude mice, while side effects were low. The anti-tumor activity of 200 mg/kg Art was similar to that of 3 mg/kg cisplatin. In conclusion, Art exerted concentration-dependent inhibitory activity against esophageal cancer in vivo and in vitro by inducing cell apoptosis and cell cycle arrest through affecting mitochondrial membrane potential, BCL-2, Bax, caspase-3 and CDC25A.
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Affiliation(s)
- Liang Liu
- Department of FCM Analysis, Tumor Institute, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Lian-Fu Zuo
- Department of FCM Analysis, Tumor Institute, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Jing Zuo
- Department of FCM Analysis, Tumor Institute, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
| | - Jing Wang
- Department of FCM Analysis, Tumor Institute, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China
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5
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Maness L, Goktepe I, Chen H, Ahmedna M, Sang S. Impact of Phytolacca americana
Extracts on Gene Expression of Colon Cancer Cells. Phytother Res 2013; 28:219-23. [DOI: 10.1002/ptr.4979] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 02/13/2013] [Accepted: 02/13/2013] [Indexed: 01/07/2023]
Affiliation(s)
- L. Maness
- North Carolina Agricultural and Technical State University; Department of Family and Consumer Sciences, Food and Nutritional Sciences Program; Greensboro NC 27411 USA
| | - I. Goktepe
- North Carolina Agricultural and Technical State University; Department of Family and Consumer Sciences, Food and Nutritional Sciences Program; Greensboro NC 27411 USA
| | - H. Chen
- North Carolina Agricultural and Technical State University; Center of Excellence in Post-Harvest Technologies, North Carolina Research Campus; Kannapolis NC 28081 USA
| | - M. Ahmedna
- North Carolina Agricultural and Technical State University; Center of Excellence in Post-Harvest Technologies, North Carolina Research Campus; Kannapolis NC 28081 USA
| | - S. Sang
- North Carolina Agricultural and Technical State University; Center of Excellence in Post-Harvest Technologies, North Carolina Research Campus; Kannapolis NC 28081 USA
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Shen T, Huang S. The Role of Cdc25A in the Regulation of Cell Proliferation and Apoptosis. Anticancer Agents Med Chem 2012; 12:631-9. [DOI: 10.2174/187152012800617678] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 12/22/2011] [Accepted: 12/31/2011] [Indexed: 12/11/2022]
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7
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Lavecchia A, Di Giovanni C, Novellino E. Inhibitors of Cdc25 phosphatases as anticancer agents: a patent review. Expert Opin Ther Pat 2010; 20:405-25. [PMID: 20166845 DOI: 10.1517/13543771003623232] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD The cell division cycle 25 (Cdc25) family of proteins are highly conserved dual specificity phosphatases that regulate cyclin-dependent kinases, the main gatekeepers of the eukaryotic cell division cycle. The three isoforms of Cdc25, including Cdc25A, Cdc25B and Cdc25C, appear to act on different cyclin-dependent kinase/cyclin complexes at different stages of the cell cycle. Overexpression of Cdc25A and/or Cdc25B, but not Cdc25C, has been detected in numerous cancers and is often correlated with a poor clinical prognosis. Thus, inhibition of these phosphatases may represent a promising therapeutic approach in oncology. AREAS COVERED IN THIS REVIEW The main focus of the present review is to describe the development of Cdc25 inhibitors over the years. We describe different compounds according to the decade of discovery and focus attention on molecules that were published in patents. WHAT THE READER WILL GAIN Insight into the most clinically relevant therapeutic Cdc25 analogues that have been published in over 40 patents over the past 19 years. TAKE HOME MESSAGE Some Cdc25 inhibitors have suppressed in vivo the growth of human tumor xenografts in animals; this confirmed the validity of using Cdc25 phosphatase inhibition as an anticancer strategy, but side effects and toxicity remain to be investigated.
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Affiliation(s)
- Antonio Lavecchia
- Università di Napoli Federico II, Facoltà di Farmacia, Dipartimento di Chimica Farmaceutica e Tossicologica, Drug Discovery Laboratory, Via D. Montesano 49, Napoli, 80131, Italy.
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9
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Song M, Park JE, Park SG, Lee DH, Choi HK, Park BC, Ryu SE, Kim JH, Cho S. NSC-87877, inhibitor of SHP-1/2 PTPs, inhibits dual-specificity phosphatase 26 (DUSP26). Biochem Biophys Res Commun 2009; 381:491-5. [PMID: 19233143 DOI: 10.1016/j.bbrc.2009.02.069] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Accepted: 02/17/2009] [Indexed: 11/19/2022]
Abstract
Protein phosphorylation plays critical roles in many regulatory mechanisms controlling cell activities and thus involved in various diseases. The cellular equilibrium of phosphorylation is regulated through the actions of protein kinases and phosphatases. Therefore, these regulatory proteins have emerged as promising targets for drug development. In this study, we screened protein tyrosine phosphatases (PTPs) by in vitro phosphatase assays to identify PTPs that are inhibited by 8-hydroxy-7-(6-sulfonaphthalen-2-yl)diazenyl-quinoline-5-sulfonic acid (NSC-87877), a potent inhibitor of SHP-1 and SHP-2 PTPs. Phosphatase activity of dual-specificity protein phosphatase 26 (DUSP26) was decreased by the inhibitor in a dose-dependent manner. Kinetic studies with NSC-87877 and DUSP26 revealed a competitive inhibition. NSC-87877 effectively inhibited DUSP26-mediated dephosphorylation of p38, a member of mitogen-activated protein kinase (MAPK) family. Since DUSP26 is involved in survival of anaplastic thyroid cancer (ATC) cells, NSC-87877 could be a therapeutic reagent for treating ATC.
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Affiliation(s)
- Mina Song
- Chung-Ang University, Dongjak-Gu, Heuk-suk Dong, Seoul, Republic of Korea
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11
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Boldrini L, Gisfredi S, Ursino S, Lucchi M, Mussi A, Fontanini G. CDC25B: relationship with angiogenesis and prognosis in non–small cell lung carcinoma. Hum Pathol 2007; 38:1563-8. [PMID: 17651784 DOI: 10.1016/j.humpath.2007.03.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Revised: 03/09/2007] [Accepted: 03/12/2007] [Indexed: 12/21/2022]
Abstract
The CDC25 phosphatases are cell cycle regulators known to play an important role in cancer cell growth. Increased expression of CDC25B has been reported in tumors of different tissue origins, including non-small cell lung carcinoma (NSCLC). We analyzed primary tumors and corresponding healthy lung tissues from 177 patients with NSCLC for relative expression levels of CDC25B by reverse transcription-polymerase chain reaction, with the dual aims of investigating the relationships between CDC25B expression and angiogenesis as well as prognosis. Eighty-one (45.76%) of the 177 patients with NSCLC overexpressed the CDC25B gene; there was no significant difference in CDC25B expression among sex, age, T or N status, or clinical stages of NSCLC. Concerning the possible involvement of CDC25B in angiogenesis, high expression of CDC25B correlated with positive expression of endothelin-1 (chi(2) test; P = .0002), one of the major angiogenic factors in NSCLC. A significant association was also found with the number of intratumoral microvessels (chi(2) test; P = .03). Statistical analysis of survival data revealed that elevated CDC25B expression was significantly associated with shorter survival in terms of both overall survival and disease-free interval (P = .04 for both), maintaining its independent prognostic role in a Cox proportional hazards model (P = .009). A rich and varied engagement of many cellular pathways could cause or maintain a cancer; our study may offer insights into these mechanisms in lung cancer, suggesting that CDC25B might play an important role in the angiogenic process and in determining the prognosis of patients with NSCLC.
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Affiliation(s)
- Laura Boldrini
- Department of Surgery, University of Pisa, 56126 Pisa, Italy.
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12
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Lavecchia A, Cosconati S, Limongelli V, Novellino E. Modeling of Cdc25B dual specifity protein phosphatase inhibitors: docking of ligands and enzymatic inhibition mechanism. ChemMedChem 2006; 1:540-50. [PMID: 16892390 DOI: 10.1002/cmdc.200500092] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The Cdc25 dual specificity phosphatases have central roles in coordinating cellular signalling processes and cell proliferation. It has been reported that an improper amplification or activation of these enzymes is a distinctive feature of a number of human cancers, including breast cancers. Thus, the inhibition of Cdc25 phosphatases might provide a novel approach for the discovery of new and selective antitumor agents. By using the crystal structure of the catalytic domain of Cdc25B, structural models for the interaction of various Cdc25B inhibitors (1-13) with the enzyme were generated by computational docking. The parallel use of two efficient and predictive docking programs, AutoDock and GOLD, allowed mutual validation of the predicted binding poses. To evaluate their quality, the models were validated with known structure-activity relationships and site-directed mutagenesis data. The results provide an improved basis for structure-based ligand design and suggest a possible explanation for the inhibition mechanism of the examined Cdc25B ligands. We suggest that the recurring motif of a tight interaction between the inhibitor and the two arginine residues, 482 and 544, is of prime importance for reversible enzyme inhibition. In contrast, the irreversible inhibition mechanism of 1-4 seems to be associated with the close vicinity of the quinone ring and the Cys473 catalytic thiolate. We believe that this extensive study might provide useful hints to guide the development of new potent Cdc25B inhibitors as novel anticancer drugs.
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Affiliation(s)
- Antonio Lavecchia
- Dipartimento di Chimica Farmaceutica e Tossicologica, Università di Napoli Federico II, Via D. Montesano, 49, 80131 Napoli, Italy.
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13
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Bhawal UK, Sugiyama M, Nomura Y, Sawajiri M, Tsukinoki K, Ikeda MA, Kuniyasu H. High-risk human papillomavirus type 16 E7 oncogene associates with Cdc25A over-expression in oral squamous cell carcinoma. Virchows Arch 2006; 450:65-71. [PMID: 17111124 DOI: 10.1007/s00428-006-0327-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Accepted: 10/11/2006] [Indexed: 01/26/2023]
Abstract
Cells expressing high-risk human papillomavirus (HPV) E7 protein display impaired checkpoint control after DNA damage and exhibit elevated rates of mutagenesis. Repression of HPV E7 expression results in the subsequent accumulation of hypophosphorylated retinoblastoma protein and repression of the Cdc25A genes. No study has been conducted to elucidate the role of Cdc25A in the development and progression of human oral carcinomas. To confirm Cdc25A protein expression together with HPV, immunohistochemistry, Western blotting, polymerase chain reaction (PCR), and reverse transcriptase (RT)-PCR were performed using various histological subtypes of oral carcinomas. Cdc25A protein was localized predominantly in the cell nuclei in carcinomas, and high expression was found in 54% of primary tumors. HPV-16 E7 was not found in non-neoplastic oral tissues, whereas it was observed in eight (36%) of 22 oral carcinomas. We found a significant correlation between Cdc25A over-expression and HPV-16 E7 positive carcinomas. There was a strong positive correlation between Cdc25A over-expression and tumor size and TNM stage. This study suggests that Cdc25A is likely to be an important mediator in the progression of oral tumors, and HPV-16 E7 may be a sensitive indicator of the involvement of viral oncogenes in oral carcinogenesis.
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Affiliation(s)
- Ujjal Kumar Bhawal
- Department of Dental and Medical Biochemistry, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8553, Japan.
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Laezza C, Pisanti S, Crescenzi E, Bifulco M. Anandamide inhibits Cdk2 and activates Chk1 leading to cell cycle arrest in human breast cancer cells. FEBS Lett 2006; 580:6076-82. [PMID: 17055492 DOI: 10.1016/j.febslet.2006.09.074] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Revised: 09/27/2006] [Accepted: 09/29/2006] [Indexed: 11/30/2022]
Abstract
This study was designed to determine the molecular mechanisms underlying the anti-proliferative effect of the endocannabinoid anandamide on highly invasive human breast cancer cells, MDA-MB-231. We show that a metabolically stable analogue of anandamide, Met-F-AEA, induces an S phase growth arrest correlated with Chk1 activation, Cdc25A degradation and suppression of Cdk2 activity. These findings demonstrate that Met-F-AEA induced cell cycle blockade relies on modulated expression and activity of key S phase regulatory proteins. The observed mechanism of action, already reported for well-known chemotherapeutic drugs, provides strong evidence for a direct role of anandamide related compounds in the activation of cell cycle checkpoints.
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Bialy L, Waldmann H. Inhibitors of protein tyrosine phosphatases: next-generation drugs? Angew Chem Int Ed Engl 2006; 44:3814-39. [PMID: 15900534 DOI: 10.1002/anie.200461517] [Citation(s) in RCA: 366] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The protein tyrosine phosphatases (PTPs) constitute a family of closely related key regulatory enzymes that dephosphorylate phosphotyrosine residues in their protein substrates. Malfunctions in PTP activity are linked to various diseases, ranging from cancer to neurological disorders and diabetes. Consequently, PTPs have emerged as promising targets for therapeutic intervention in recent years. In this review, general aspects of PTPs and the development of small-molecule inhibitors of PTPs by both academic research groups and pharmaceutical companies are discussed. Different strategies have been successfully applied to identify potent and selective inhibitors. These studies constitute the basis for the future development of PTP inhibitors as drugs.
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Affiliation(s)
- Laurent Bialy
- Max-Planck-Institut für molekulare Physiologie, Abteilung Chemische Biologie, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
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Yu W, Imoto I, Inoue J, Onda M, Emi M, Inazawa J. A novel amplification target, DUSP26, promotes anaplastic thyroid cancer cell growth by inhibiting p38 MAPK activity. Oncogene 2006; 26:1178-87. [PMID: 16924234 DOI: 10.1038/sj.onc.1209899] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Anaplastic thyroid cancer (ATC) is one of the most lethal of all human tumors, but cytogenetic information concerning ATC is extremely limited. Using our in-house array-based comparative genomic hybridization and 14 ATC cell lines with further fluorescence in situ hybridization analysis, we demonstrated amplification of the DUSP26 gene, known by another report as MAP kinase phosphatase-8. DUSP26 was overexpressed in ATC cell lines and primary ATC tumor samples. When overexpressed, either exogenously or endogenously, DUSP26 promoted growth of the ATC cells. DUSP26 encodes a protein containing a dual-specificity phosphatase domain that can dephosphorylate itself. DUSP26 effectively dephosphorylates p38 and has a little effect on extracellular signal-regulated kinase in ATC cells. DUSP26 protein formed a physical complex with p38, and promoted survival of ATC cells by inhibiting p38-mediated apoptosis. Our findings suggest that DUSP26 may act as an oncogene in ATC, and might be a useful diagnostic marker and therapeutic target of this disease.
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Affiliation(s)
- W Yu
- Department of Molecular Cytogenetics, Medical Research Institute and Graduate School of Biomedical Science, Tokyo, Japan
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17
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Weide T, Arve L, Prinz H, Waldmann H, Kessler H. 3-Substituted indolizine-1-carbonitrile derivatives as phosphatase inhibitors. Bioorg Med Chem Lett 2006; 16:59-63. [PMID: 16236508 DOI: 10.1016/j.bmcl.2005.09.051] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2005] [Revised: 09/19/2005] [Accepted: 09/20/2005] [Indexed: 11/24/2022]
Abstract
In the course of studies directed toward the discovery of novel scaffolds for medicinal application, we synthesized a series of 3-substituted indolizine-1-carbonitrile derivatives. Some of them displayed activity against MPtpA/MPtpB phosphatases which are involved in infectious diseases. We report here the solid-phase synthesis and antiphosphatase activity of a series of indolizines.
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Affiliation(s)
- Timo Weide
- Department Chemie, Lehrstuhl II für Organische Chemie, Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany
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Aoyagi Y, Masuko N, Ohkubo S, Kitade M, Nagai K, Okazaki S, Wierzba K, Terada T, Sugimoto Y, Yamada Y. A novel cinnamic acid derivative that inhibits Cdc25 dual-specificity phosphatase activity. Cancer Sci 2005; 96:614-9. [PMID: 16128747 PMCID: PMC11159474 DOI: 10.1111/j.1349-7006.2005.00086.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The Cdc25 dual-specificity phosphatases are key regulators of cell cycle progression through activation of cyclin-dependent kinases (Cdk). Three homologs exist in humans: Cdc25A, Cdc25B, and Cdc25C. Cdc25A and Cdc25B have oncogenic properties and are overexpressed in some types of tumors. Compounds that inhibit Cdc25 dual-specificity phosphatase activity might thus be potent anticancer agents. We screened several hundred compounds in a library using an in vitro phosphatase assay, with colorimetric measurement of the conversion of p-nitrophenyl phosphate (pNPP) to p-nitrophenol by the catalytic domain of recombinant human Cdc25, and discovered TPY-835, which inhibits Cdc25A and Cdc25B activity (IC50 = 5.1 and 5.7 microM, respectively). TPY-835 had mixed inhibition kinetics for Cdc25A and Cdc25B. TPY-835 caused cell cycle arrest in the G1 phase in human lung cancer cells (A549 and SBC-5) but not cell cycle arrest in the G2/M phase. After treatment with TPY-835, the activation of Cdk2 was suppressed and phosphorylation of the retinoblastoma (Rb) protein was decreased in SBC-5 cells. In addition, TPY-835 induced an increase of the sub-G1 phase cell population after 48-72 h treatment. The growth inhibitory effects of TPY-835 against cisplatin (CDDP)-, camptothecin- and 5-FU-resistant cell lines are comparable to the growth inhibitory effect on their parental lines, thus indicating that TPY-835 did not show cross-resistance to these cell lines. These results suggest that TPY-835 is a promising candidate for constructing a novel class of antitumor agents that can control the cell cycle progression of cancer cells.
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Affiliation(s)
- Yoshimi Aoyagi
- Cancer Research Laboratory, Hanno Research Center, Taiho Pharmaceutical Company, 1-27 Misugidai, Hanno-shi, Saitama 357-8527, Japan.
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Bialy L, Waldmann H. Inhibitoren der Proteintyrosinphosphatasen: Kandidaten für zukünftige Wirkstoffe? Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200461517] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Vasudevan SA, Skoko J, Wang K, Burlingame SM, Patel PN, Lazo JS, Nuchtern JG, Yang J. MKP-8, a novel MAPK phosphatase that inhibits p38 kinase. Biochem Biophys Res Commun 2005; 330:511-8. [PMID: 15796912 DOI: 10.1016/j.bbrc.2005.03.028] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2005] [Indexed: 11/22/2022]
Abstract
Intracellular signaling pathways and their relationship to malignant progression have become a major focus of cancer biology. The dual-specificity phosphatase (DSP) family is a more recently identified family of intracellular signaling modulators. We have identified a novel protein phosphatase with a well-conserved DSP catalytic domain containing the DSP catalytic motif, xHCxxGxSRS, and mitogen-activated protein kinase phosphatase (MKP) motif, AYLM. Because of these unique characteristics, the protein was named mitogen-activated protein kinase phosphatase-8 (MKP-8). This protein is approximately 20kDa in size and mainly localizes to the nuclear compartment of the cell. MKP-8 is expressed in embryonal cancers (retinoblastoma, neuroepithelioma, and neuroblastoma) and has limited expression in normal tissues. MKP-8 displays significant phosphatase activity that is inhibited by a cysteine to serine substitution in the catalytic domain. When co-expressed with activated MAPKs, MKP-8 is able to inhibit p38 kinase phosphorylation and downstream activity.
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Affiliation(s)
- Sanjeev A Vasudevan
- Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
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Ray D, Terao Y, Nimbalkar D, Chu LH, Donzelli M, Tsutsui T, Zou X, Ghosh AK, Varga J, Draetta GF, Kiyokawa H. Transforming growth factor beta facilitates beta-TrCP-mediated degradation of Cdc25A in a Smad3-dependent manner. Mol Cell Biol 2005; 25:3338-47. [PMID: 15798217 PMCID: PMC1069597 DOI: 10.1128/mcb.25.8.3338-3347.2005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Ubiquitin-dependent degradation of Cdc25A is a major mechanism for damage-induced S-phase checkpoint. Two ubiquitin ligases, the Skp1-cullin-beta-TrCP (SCFbeta-TrCP) complex and the anaphase-promoting complex (APCCdh1), are involved in Cdc25A degradation. Here we demonstrate that the transforming growth factor beta (TGF-beta)-Smad3 pathway promotes SCF(beta-TrCP)-mediated Cdc25A ubiquitination. Cells treated with TGF-beta, as well as cells transfected with Smad3 or a constitutively active type I TGF-beta receptor, exhibit increased ubiquitination and markedly shortened half-lives of Cdc25A. Furthermore, Cdc25A is stabilized in cells transfected with Smad3 small interfering RNA (siRNA) and cells from Smad3-null mice. TGF-beta-induced ubiquitination is associated with Cdc25A phosphorylation at the beta-TrCP docking site (DS82G motif) and physical association of Cdc25A with Smad3 and beta-TrCP. Cdc25A mutant proteins deficient in DS82G phosphorylation are resistant to TGF-beta-Smad3-induced degradation, whereas a Cdc25A mutant protein defective in APCCdh1 recognition undergoes efficient degradation. Smad3 siRNA inhibits beta-TrCP-Cdc25A interaction and Cdc25A degradation in response to TGF-beta. beta-TrCP2 siRNA also inhibits Smad3-induced Cdc25A degradation. In contrast, Cdh1 siRNA had no effect on Cdc25A down-regulation by Smad3. These data suggest that Smad3 plays a key role in the regulation of Cdc25A ubiquitination by SCFbeta-TrCP and that Cdc25A stabilization observed in various cancers could be associated with defects in the TGF-beta-Smad3 pathway.
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Affiliation(s)
- Dipankar Ray
- Department of Biochemistry and Molecular Genetics, University of Illinois College of Medicine, Chicago, IL 60607, USA
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22
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Abstract
The Cdc25 phosphatases are essential for cell-cycle control in eukaryotes under normal conditions and in response to DNA damage via checkpoint controls. Recent evidence indicates direct control of the Cdc25s, and therefore the cell cycle, in response to changes in cellular redox status. These redox changes may originate intracellularly from mitochondrial leakage or in response to specific external triggers leading to production of reactive oxygen species (ROS). This review shows that the known chemistry and biology of the Cdc25s favor a direct role for these phosphatases in temporarily blocking cell-cycle progression until favorable reducing conditions are restored. First, the Cdc25s contain a highly reactive cysteine at the active site that can react directly with ROS, leading to enzyme inactivation. Second, the ROS-inactivated form of Cdc25 is expected to prevent cell-cycle progression based on precedent from cellular responses to DNA damage. Third, ROS-mediated oxidation of the Cdc25s leads to an intramolecular disulfide that is readily reversible by the cellular reductant thioredoxin. Finally, in vivo data supporting a direct role for the Cdc25s in redox regulation are considered.
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Affiliation(s)
- Johannes Rudolph
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
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23
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Shimbashi A, Tsuchiya A, Imoto M, Nishiyama S. Synthesis of the naphthalene-derived inhibitors against Cdc25A dual-specificity protein phosphatase and their biological activity. Bioorg Med Chem Lett 2005; 15:61-5. [PMID: 15582411 DOI: 10.1016/j.bmcl.2004.10.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Revised: 09/11/2004] [Accepted: 10/12/2004] [Indexed: 10/26/2022]
Abstract
The novel naphthalene-type analogues 14 and 18 and the naphthoquinone-type analogues, 8, 9, 15, 16, 19, 21, 22, and 23-28 have been synthesized, and their in vitro Cdc25A phosphatase-inhibitory activity was examined. In assessment of the inhibitory activity, it was revealed that the naphthoquinone core is contributed to the activity, rather than the alkyl side chain.
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Affiliation(s)
- Akiko Shimbashi
- Department of Chemistry, Faculty of Science and Technology, Keio University, Hiyoshi 3-14-1, Kohoku-ku, Yokohama 223-8522, Japan
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24
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Shimbashi A, Tsuchiya A, Imoto M, Nishiyama S. The Synthesis and Biological Activity of Pyranonaphthoquione Derivatives fromStreptomycessp. and Their Related Substances. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2004. [DOI: 10.1246/bcsj.77.1925] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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25
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Fürstner A, Feyen F, Prinz H, Waldmann H. Synthesis and evaluation of the antitumor agent TMC-69-6H and a focused library of analogs. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.06.139] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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26
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Bova MP, Mattson MN, Vasile S, Tam D, Holsinger L, Bremer M, Hui T, McMahon G, Rice A, Fukuto JM. The oxidative mechanism of action of ortho-quinone inhibitors of protein-tyrosine phosphatase α is mediated by hydrogen peroxide. Arch Biochem Biophys 2004; 429:30-41. [PMID: 15288807 DOI: 10.1016/j.abb.2004.05.010] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2004] [Revised: 05/11/2004] [Indexed: 01/06/2023]
Abstract
Here, we report the identification and characterization of five ortho-quinone inhibitors of PTPalpha. We observed that the potency of these compounds in biochemical assays was markedly enhanced by the presence of DTT. A kinetic analysis suggested that they were functioning as irreversible inhibitors and that the inhibition was targeted to the catalytic site of PTPalpha. The inhibition observed by these compounds was sensitive to superoxide dismutase and catalase, suggesting that reactive oxygen species may be mediators of their inhibition. We observed that in the presence of DTT, these compounds would produce up to 2.5mM hydrogen peroxide (H(2)O(2)). The levels of H(2)O(2) produced were sufficient to completely inactivate PTPalpha. In contrast, without a reducing agent the compounds did not generate H(2)O(2) and showed little activity towards PTPalpha. In addition, these compounds inhibited PTPalpha-dependent cell spreading in NIH 3T3 cells at concentrations that were similar to their activity in biochemical assays. The biological implications of these results are discussed as they support growing evidence that H(2)O(2) is a key regulator of PTPs.
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Affiliation(s)
- Michael P Bova
- Drug Discovery, SUGEN Inc., 230 East Grand Avenue, South San Francisco, CA 94080, USA.
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27
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Lam MH, Liu Q, Elledge SJ, Rosen JM. Chk1 is haploinsufficient for multiple functions critical to tumor suppression. Cancer Cell 2004; 6:45-59. [PMID: 15261141 DOI: 10.1016/j.ccr.2004.06.015] [Citation(s) in RCA: 257] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2003] [Revised: 04/29/2004] [Accepted: 05/21/2004] [Indexed: 11/20/2022]
Abstract
The haploinsufficient tumor suppressor Chk1 is essential for embryonic cells, but the consequences of Chk1 loss in adult tissues are unknown. Using conditional Chk1 mice, we find that proliferating mammary cells lacking Chk1 undergo apoptosis leading to developmental defects. Conditional Chk1 heterozygosity increased the number of S phase cells and caused spontaneous DNA damage. Chk1+/- epithelia also exhibit a miscoordinated cell cycle in which S phase cells display an early mitotic phenotype. These cells maintain high levels of Cdc25A, which can promote inappropriate cell cycle transitions. Thus, Chk1 heterozygosity results in three distinct haploinsufficient phenotypes that can contribute to tumorigenesis: inappropriate S phase entry, accumulation of DNA damage during replication, and failure to restrain mitotic entry.
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Affiliation(s)
- Michael H Lam
- Baylor College of Medicine, Department of Molecular and Cellular Biology, Interdepartmental Program in Cellular and Molecular Biology, Houston, Texas 77030, USA
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28
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Cho SH, Lee CH, Ahn Y, Kim H, Kim H, Ahn CY, Yang KS, Lee SR. Redox regulation of PTEN and protein tyrosine phosphatases in H(2)O(2) mediated cell signaling. FEBS Lett 2004; 560:7-13. [PMID: 15017976 DOI: 10.1016/s0014-5793(04)00112-7] [Citation(s) in RCA: 152] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Protein tyrosine phosphatase (PTP) is a family of enzymes important for regulating cellular phosphorylation state. The oxidation and consequent inactivation of several PTPs by H(2)O(2) are well demonstrated. It is also shown that recovery of enzymatic activity depends on the availability of cellular reductants. Among these redox-regulated PTPs, PTEN, Cdc25 and low molecular weight PTP are known to form a disulfide bond between two cysteines, one in the active site and the other nearby, during oxidation by H(2)O(2). The disulfide bond likely confers efficiency in the redox regulation of the PTPs and protects cysteine-sulfenic acid of PTPs from further oxidation. In this review, through a comparative analysis of the oxidation process of Yap1 and PTPs, we propose the mechanism of disulfide bond formation in the PTPs.
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Affiliation(s)
- Seung-Hyun Cho
- Center for Cell Signaling Research, Department of Biological Sciences, Ewha Women's University, Seoul, South Korea
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29
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Sohn J, Kiburz B, Li Z, Deng L, Safi A, Pirrung MC, Rudolph J. Inhibition of Cdc25 phosphatases by indolyldihydroxyquinones. J Med Chem 2003; 46:2580-8. [PMID: 12801222 DOI: 10.1021/jm0300835] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Overexpression of the Cdc25A and Cdc25B dual-specificity phosphatases correlates with a wide variety of cancers, making the Cdc25s attractive drug targets for anticancer therapies. However, the search for good lead molecules has been hampered by the reactivity of the active site thiolate anion and the flat solvent-exposed active site region. We describe here the indolyldihydroxyquinones, a new class of inhibitors of Cdc25 that bind reversibly to the active site with submicromolar potency. Structure-activity relationships in the 50 derivatives of the lead molecule 2,5-dihydroxy-3-(1H-indol-3-yl)[1,4]benzoquinone show interesting and consistent trends identifying features required for inhibition of all three isoforms of Cdc25. The compounds do not show time-dependent inhibition, indicating that they form neither covalent adducts with nor oxidize the active site thiol. Our best compounds, 2,5-dihydroxy-3-(7-farnesyl-1H-indol-3-yl)[1,4]benzoquinone and 2,5-dihydroxy-3-(4,6-dichloro-7-farnesyl-1H-indol-3-yl)[1,4]benzoquinone, are competitive with substrate for the active site and yield K(i)s of 640 and 470 nM, respectively. Binding of the indolylhydroxyquinones is diminished by three, but not by six other, specific mutations in the active site region. Additionally, the flexible C-terminal tail required for binding of protein substrate is also required for binding derivatives with hydrophobic modifications at the 7-position. The indolyldihydroxyquinones compete effectively with the protein substrate for Cdc25 in vitro and lead to rapid cell death in vivo. Thus, the indolyldihydroxyquinones will serve as useful lead molecules for drug discovery and further cell-based studies on the role of Cdc25s in cell cycle control.
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Affiliation(s)
- Jungsan Sohn
- Department of Biochemistry, Duke University, and Duke University Medical Center, Durham, North Carolina 27710, USA
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30
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Xiao Z, Chen Z, Gunasekera AH, Sowin TJ, Rosenberg SH, Fesik S, Zhang H. Chk1 mediates S and G2 arrests through Cdc25A degradation in response to DNA-damaging agents. J Biol Chem 2003; 278:21767-73. [PMID: 12676925 DOI: 10.1074/jbc.m300229200] [Citation(s) in RCA: 272] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
UV and ionizing radiation (IR) activate DNA damage checkpoints and induce Cdc25A degradation (Mailand, N., Falck, J., Lukas, C., Syljuasen, R. G., Welcker, M., Bartek, J., and Lukas, J. (2000) Science 288, 1425-1429; Falck, J., Mailand, N., Syljuasen, R. G., Bartek, J., and Lukas J. (2001) Nature 410, 842-847). The degradation of Cdc25A is abrogated by caffeine, which implicates Chk1 as the potential mediator (Mailand, N., Falck, J., Lukas, C., Syljuasen, R. G., Welcker, M., Bartek, J., and Lukas, J. (2000) Science 288, 1425-1429). However, the involvement of Chk1 is far from clear, because caffeine is a rather nonspecific inhibitor of the ATR/Chk1 signaling pathway. Additionally, it is not known whether DNA-damaging drugs commonly used in chemotherapy, which may activate different signal transduction pathways than UV or IR, also confer Cdc25A degradation. Herein, we show that camptothecin and doxorubicin, two widely used topoisomerase inhibitors conferring S and G2 arrest, respectively, cause the degradation of Cdc25A. Using a small interfering RNA that enables the specific elimination of Chk1 expression, we show that the observed proteolysis of Cdc25A is mediated through Chk1. Moreover, Cdc25A overexpression abrogates the Chk1-mediated degradation and overcomes the doxorubicin-induced G2 arrest through dephosphorylation and activation of Cdc2/Cdk1 in a dose-dependent manner. These results suggest that: (a) Cdc25A is involved in the G2/M transition in addition to its commonly accepted effect on G1/S progression, and (b) Chk1 mediates both S and G2 checkpoint and is thus a more ubiquitous cell cycle checkpoint mediator than previously thought.
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Affiliation(s)
- Zhan Xiao
- Cancer Research, Abbott Laboratories, Abbott Park, Illinois 60064-6101, USA.
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31
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Pu L, Amoscato AA, Bier ME, Lazo JS. Dual G1 and G2 phase inhibition by a novel, selective Cdc25 inhibitor 6-chloro-7-[corrected](2-morpholin-4-ylethylamino)-quinoline-5,8-dione. J Biol Chem 2002; 277:46877-85. [PMID: 12356752 DOI: 10.1074/jbc.m207902200] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Cdc25 dual specificity phosphatases coordinate cell cycle progression, but potent and selective inhibitors have generally been unavailable. In the present study, we have examined one potential inhibitor, 6-chloro-7-(2-morpholin-4-ylethylamino)-quinoline-5,8-dione (NSC 663284), that was identified in the compound library of the National Cancer Institute [corrected]. We found that NSC 663284 arrested synchronized cells at both G(1) and G(2)/M phase, and blocked dephosphorylation and activation of Cdk2 and Cdk1 in vivo, as predicted for a Cdc25 inhibitor. Using the natural Cdc25A substrate, Tyr(15)-phosphorylated Cdk2/cyclin A, we demonstrated that NSC 663284 blocked reactivation of Cdk2/cyclin A kinase by Cdc25A catalytic domain in vitro. In-gel trypsin digestion followed by capillary liquid chromatography-electrospray ionization mass spectrometry and tandem mass spectrometry revealed the direct binding of NSC 663284 to one of the two serine residues in the active site loop HCEFSSER of the Cdc25A catalytic domain. Cdc25 binding and inhibition could contribute to the anti-proliferative activity of NSC 663284 and its ability to arrest cell cycle progression. Moreover, NSC 663284 should be a valuable reagent to probe the actions of Cdc25 phosphatases within cells and may also be useful structure for the design of more potent and selective antiproliferative agents.
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Affiliation(s)
- Lixia Pu
- Department of Pharmacology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
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32
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Lyon MA, Ducruet AP, Wipf P, Lazo JS. Dual-specificity phosphatases as targets for antineoplastic agents. Nat Rev Drug Discov 2002; 1:961-76. [PMID: 12461518 DOI: 10.1038/nrd963] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dual-specificity protein phosphatases are a subclass of protein tyrosine phosphatases that are uniquely able to hydrolyse the phosphate ester bond on both a tyrosine and a threonine or serine residue on the same protein. Dual-specificity phosphatases have a central role in the complex regulation of signalling pathways that are involved in cell stress responses, proliferation and death. Although this enzyme family is increasingly the target of drug discovery efforts in pharmaceutical companies, a summary of the salient developments in the biology and medicinal chemistry of dual-specificity phosphatases has been lacking. We hope that this comprehensive overview will stimulate further progress in the development of small-molecule inhibitors that could form the basis for a new class of target-directed therapeutic agents.
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Affiliation(s)
- Michael A Lyon
- Department of Chemistry, Chevron Science Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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33
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Melkun E, Pilione M, Paulson RF. A naturally occurring point substitution in Cdc25A, and not Fv2/Stk, is associated with altered cell-cycle status of early erythroid progenitor cells. Blood 2002; 100:3804-11. [PMID: 12411323 DOI: 10.1182/blood.v100.10.3804] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The Friend virus susceptibility gene 2 (Fv2) controls the polyclonal expansion of infected cells that occurs early during Friend erythroleukemia virus infection. Fv2 has recently been shown to encode a truncated form of the Stk receptor tyrosine kinase (Sf-Stk). This observation, coupled with earlier work, suggested that Sf-Stk drives the expansion of infected cells by forming a complex with the Friend virus envelope glycoprotein, gp55, and the erythropoietin receptor. Fv2 has also been implicated in the control of cell cycling in early erythroid progenitors (erythroid blast-forming units [BFU-Es]). Mouse strains that are homozygous for the resistant allele of Fv2 (Fv2(rr)) have few actively cycling BFU-Es. In this report, we demonstrate that the control of BFU-E cycling is encoded by a gene linked to, but distinct from, Fv2, and suggest that this gene is the dual-specific protein phosphatase Cdc25A, which regulates the G1- to S-phase transition of the cell cycle. We show that a naturally occurring allele of Cdc25A, which increases Cdc25A phosphatase activity and promotes cell-cycle progression, segregates in mouse strains that exhibit high levels of BFU-E cell cycling. In wild-type mice, this allele of Cdc25A does not overtly affect erythropoiesis; however, when this allele is combined with a mutation of the Kit receptor (Kit(WV)), the anemia of the mice is enhanced. Furthermore, overexpression of Cdc25A in bone marrow cells causes a defect in the BFU-E colony formation. These results suggest that proper regulation of the cell cycle through Cdc25A is required for normal erythropoiesis.
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Affiliation(s)
- Edward Melkun
- Department of Veterinary Science, The Schreyer's Honors College, and the Graduate Program in Biochemistry, Microbiology and Molecular Biology, Pennsylvania State University, University Park 16802, USA
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34
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Ito Y, Yoshida H, Nakano K, Kobayashi K, Yokozawa T, Hirai K, Matsuzuka F, Matsuura N, Kakudo K, Kuma K, Miyauchi A. Expression of cdc25A and cdc25B proteins in thyroid neoplasms. Br J Cancer 2002; 86:1909-13. [PMID: 12085185 PMCID: PMC2375432 DOI: 10.1038/sj.bjc.6600364] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2001] [Revised: 04/09/2002] [Accepted: 04/11/2002] [Indexed: 11/09/2022] Open
Abstract
Cdc25B and cdc25A phosphates are prominent stimulators of cell cycle progression and recent studies have also suggested their oncogenic roles. To elucidate the role of these proteins in thyroid neoplasms, we immunohistochemically investigated their expression, and neither protein was expressed in normal follicular cells. Cdc25B was frequently overexpressed in follicular adenoma and minimally invasive follicular carcinoma, but the incidence was significantly lower in widely invasive follicular carcinoma. Furthermore, the cdc25B expression level significantly decreased with the dedifferentiation of thyroid carcinoma. Cdc25A overexpression was observed in high incidences in all types of thyroid neoplasms. These results suggest that cdc25B and cdc25A play oncogenic roles in thyroid follicules and that cdc25B works predominantly in the early phase of the progression of thyroid carcinoma, whereas cdc25A plays a fundamental role in the development of thyroid neoplasms.
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Affiliation(s)
- Y Ito
- Department of Surgery, Kuma Hospital, 8-2-35, Shimoyamate-dori, Chuo-ku, Kobe City 650-0011, Japan.
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35
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Nguyen DX, Westbrook TF, McCance DJ. Human papillomavirus type 16 E7 maintains elevated levels of the cdc25A tyrosine phosphatase during deregulation of cell cycle arrest. J Virol 2002; 76:619-32. [PMID: 11752153 PMCID: PMC136809 DOI: 10.1128/jvi.76.2.619-632.2002] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Essential to the oncogenic properties of human papillomavirus type 16 (HPV-16) are the activities encoded by the early gene product E7. HPV-16 E7 (E7.16) binds to cellular factors involved in cell cycle regulation and differentiation. These include the retinoblastoma tumor suppressor protein (Rb) and histone deacetylase (HDAC) complexes. While the biological significance of these interactions remains unclear, E7 is believed to help maintain cells in a proliferative state, thus establishing an environment that is conducive to viral replication. Most pathways that govern cell growth converge on downstream effectors. Among these is the cdc25A tyrosine phosphatase. cdc25A is required for G(1)/S transition, and its deregulation is associated with carcinogenesis. Considering the importance of cdc25A in cell cycle progression, it represents a relevant target for viral oncoproteins. Accordingly, the present study focuses on the putative deregulation of cdc25A by E7.16. Our results indicate that E7.16 can impede growth arrest induced during serum starvation and keratinocyte differentiation. Importantly, these E7-specific phenotypes correlate with elevated cdc25A steady-state levels. Reporter assays performed with NIH 3T3 cell lines and human keratinocytes indicate that E7 can transactivate the cdc25A promoter. In addition, transcriptional activation by E7.16 requires the distal E2F site within the cdc25A promoter. We further demonstrate that the ability of E7 to abrogate cell cycle arrest, activate cdc25A transcription, and increase cdc25A protein levels requires intact Rb and HDAC-1 binding domains. Finally, by using the cdk inhibitor roscovitine, we reveal that E7 activates the cdc25A promoter independently of cell cycle progression and cdk activity. Consequently, we propose that E7.16 can directly target cdc25A transcription and maintains cdc25A gene expression by disrupting Rb/E2F/HDAC-1 repressor complexes.
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Affiliation(s)
- Don X Nguyen
- Department of Microbiology and Immunology, The Cancer Center, University of Rochester, Rochester, New York 14642, USA
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36
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Nishioka K, Doki Y, Shiozaki H, Yamamoto H, Tamura S, Yasuda T, Fujiwara Y, Yano M, Miyata H, Kishi K, Nakagawa H, Shamma A, Monden M. Clinical significance of CDC25A and CDC25B expression in squamous cell carcinomas of the oesophagus. Br J Cancer 2001; 85:412-21. [PMID: 11487274 PMCID: PMC2364065 DOI: 10.1054/bjoc.2001.1934] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
CDC25A, CDC25B and CDC25C belong to a family of protein phosphatases which activate the cyclin-dependent kinase at different points of the cell cycle. According to accumulating evidence, CDC25A and CDC25B seem to possess oncogenic properties. We have analysed these expressions by immunohistochemistry, western blot and RT-PCR in a series of 100 patients with squamous cell carcinoma of the oesophagus. When compared with non-cancerous cells, CDC25A and CDC25B were strongly expressed in the cytoplasm of cancer cells, with positive (+) classification in 46% (46 cases) and 48% (48 cases), respectively. There was no significant correlation between CDC25A and CDC25B expression, nor was there any association with the expression of other cell cycle-regulating molecules, including cyclin D1, Rb, p16(INK4), p27(KIP1)and PCNA (proliferating cell nuclear antigen). CDC25A (+), as well as CDC25B (+), was more frequently found in patients with deeper tumour invasion and lymph node metastasis, while tumour size was correlated only with CDC25A expression. Postoperative survival was significantly poorer for CDC25A (+) patients than CDC25A (-) patients, but was not affected by the CDC25B status. Nuclear localization of CDC25A was observed in 51 cases (51%), regardless of its cytoplasmic expression, and was not associated with clinico-pathological factors or prognosis. Multivariate analysis revealed only the CDC25A status to be an independent significant prognostic factor among these biological and clinico-pathological factors. CDC25A but not CDC25B may be a new prognostic factor for squamous cell carcinoma of the oesophagus. Thus, regulation of the G1 checkpoint in the cell cycle may be important in oesophageal carcinogenesis, which may also involve many other oncogenes.
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Affiliation(s)
- K Nishioka
- Department of Surgery and Clinical Oncology, Graduate School of Medicine, Osaka University, 2-2-E2, Yamadaoka Suita, Osaka, 565-0871, Japan
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37
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Peng H, Xie W, Otterness DM, Cogswell JP, McConnell RT, Carter HL, Powis G, Abraham RT, Zalkow LH. Syntheses and biological activities of a novel group of steroidal derived inhibitors for human Cdc25A protein phosphatase. J Med Chem 2001; 44:834-48. [PMID: 11262093 DOI: 10.1021/jm0004401] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Silica gel supported pyrolysis of an azido-homo-oxa steroid led to rearrangement, presumably by a mechanism similar to that of solution phase Schmidt fragmentation, to produce a group of novel inhibitors for the oncogenic cell cycle regulator Cdc25A phosphatase. Cyano-containing acid 17, one of the best inhibitors in this group, inhibited the activity of Cdc25A protein phosphatase reversibly and noncompetitively with an IC(50) value of 2.2 microM. Structure-activity relationships revealed that a phosphate surrogate such as a carboxyl or a xanthate group is required for inhibitory activity, and a hydrophobic alkyl chain, such as the cholesteryl side chain, contributes greatly to the potency. Without the cyano group, acid 26 and xanthate 27 were found to be more selective over Cdc25A (IC(50) = 5.1 microM and 1.1 microM, respectively) than toward CD45 (IC(50) > 100 microM, in each case), a receptor protein tyrosine phosphatase. Several of these inhibitors showed antiproliferative activities in the NCI 60-human tumor cell line screen. These steroidal derived Cdc25 inhibitors provide unique leads for the development of dual-specificity protein phosphatase inhibitors.
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Affiliation(s)
- H Peng
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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Peng H, Otterness DM, Abraham RT, Zalkow LH. Cdc25A Protein phosphatase inhibitors from anomalous ozonolysis of 5,6- seco -5-oxo-3-cholesten-6-oic acid. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(01)00043-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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39
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Rudolph J, Epstein DM, Parker L, Eckstein J. Specificity of natural and artificial substrates for human Cdc25A. Anal Biochem 2001; 289:43-51. [PMID: 11161293 DOI: 10.1006/abio.2000.4906] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cdc25A is a dual-specific protein phosphatase involved in the regulation of the kinase activity of Cdk-cyclin complexes in the eukaryotic cell cycle. To understand the mechanism of this important regulator, we have generated highly purified biochemical reagents to determine the kinetic constants for human Cdc25A with respect to a set of peptidic, artificial, and natural substrates. Cdc25A and its catalytic domain (dN25A) demonstrate very similar kinetics toward the artificial substrates p-nitrophenyl phosphate (k(cat)/K(m) = 15-25 M(-1) s(-1)) and 3-O-methylfluorescein phosphate (k(cat)/K(m) = 1.1-1.3 x 10(4) M(-1) s(-1)). Phospho-peptide substrates exhibit extremely low second-order rate constants and a flat specificity profile toward Cdc25A and dN25A (k(cat)/K(m) = 1 to 10 M(-1) s(-1)). In contrast to peptidic substrates, Cdc25A and dN25A are highly active phosphatases toward the natural substrate, T14- and Y15-bis-phosphorylated Cdk2/CycA complex (Cdk2-pTpY/CycA) with k(cat)/K(m) values of 1.0-1.1 x 10(6) M(-1) s(-1). In the context of the Cdk2-pTpY/CycA complex, phospho-threonine is preferred over phospho-tyrosine by more than 10-fold. The highly homologous catalytic domain of Cdc25c is essentially inactive toward Cdk2-pTpY/CycA. Taken together these data indicate that a significant degree of the specificity of Cdc25 toward its Cdk substrate resides within the catalytic domain itself and yet is in a region(s) that is outside the phosphate binding site of the enzyme.
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Affiliation(s)
- J Rudolph
- Mitotix, Inc., Cambridge, Massachusetts, USA.
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Pestell KE, Ducruet AP, Wipf P, Lazo JS. Small molecule inhibitors of dual specificity protein phosphatases. Oncogene 2000; 19:6607-12. [PMID: 11426646 DOI: 10.1038/sj.onc.1204084] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
One hallmark of neoplasia is the deregulation of cell cycle control mechanisms, which is secondary to altered protein phosphorylation. Dual specificity protein phosphatases uniquely dephosphorylate both phosphoserines/threonines and phosphotyrosines on the same protein substrate. As a class they regulate intracellular signaling through the mitogen activated and stress activated kinases and govern cellular movement through G1/S and G2/M cell cycle checkpoints by affecting the activity of cyclin-dependent kinases. In particular, the Cdc25 phosphatases, which dephosphorylate cyclin-dependent kinases, are overexpressed in many human tumors and this increased expression is associated with a poor prognosis. In addition to expression levels, the intracellular activity of Cdc25 phosphatases is determined by their subcellular distribution and physical proximity to substrates. Small molecules that either inhibit the catalytic activity or alter the subcellular distribution of these dual specificity protein phosphatases could provide effective tools to interrogate the role of phosphorylation pathways and may afford new approaches to the management of cancer.
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Affiliation(s)
- K E Pestell
- Department of Pharmacology, University of Pittsburgh, Pennsylvania 15261, USA
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41
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Molinari M, Mercurio C, Dominguez J, Goubin F, Draetta GF. Human Cdc25 A inactivation in response to S phase inhibition and its role in preventing premature mitosis. EMBO Rep 2000; 1:71-9. [PMID: 11256629 PMCID: PMC1083693 DOI: 10.1093/embo-reports/kvd018] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2000] [Revised: 05/31/2000] [Accepted: 06/07/2000] [Indexed: 11/14/2022] Open
Abstract
The Cdc25 A phosphatase is required for the G1-S transition of the cell cycle and is overexpressed in human cancers. We found that it is ubiquitylated and rapidly degraded by the proteasome and that its levels increase from G1 until mitosis. By treating cells with the DNA synthesis inhibitor hydroxyurea, Cdc25 A rapidly decreased in abundance, and this was accompanied by an increase in Cdk2 phosphotyrosine content and a decrease in Cdk2 kinase activity. Cdc25 A overexpression altered the ability of cells to arrest in the presence of hydroxyurea, and caused them to undergo premature chromosome condensation. Cdc25 A overexpression could render tumor cells less sensitive to DNA replication checkpoints, thereby contributing to their genomic instability.
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Affiliation(s)
- M Molinari
- European Institute of Oncology, Milan, Italy
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42
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Warabi M, Nemoto T, Ohashi K, Kitagawa M, Hirokawa K. Expression of protein tyrosine phosphatases and its significance in esophageal cancer. Exp Mol Pathol 2000; 68:187-95. [PMID: 10816386 DOI: 10.1006/exmp.2000.2303] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Expression of mRNA protein tyrosine phosphatases (PTPs) was surveyed in an esophageal cancer cell line by RT-PCR using degenerate primers. The mRNAs for eight kinds of PTPs were expressed in the cell line. We examined mRNA expression of these PTPs in 12 cases of esophageal cancer by Northern analysis. Significant signals were obtained for three kinds of PTPs, PTP1B, PTPH1, and PTPD1. The magnitude of expression of each PTP was measured as the ratio of the signal intensity of each PTP to that of a control gene (NADPH), and the ratio was then compared to normal mucosa around the cancer lesion. Among the three kinds of PTPs, the expression of PTP1B mRNA was significantly depressed in cancer lesions compared with that in the surrounding normal mucosa. In contrast, the expression of PTPH1 mRNA was significantly increased in cancer lesions compared with that in normal mucosa. PTPD1 did not show any significant trend in comparisons of cancer and surrounding normal mucosa. The results suggest that PTP1B and PTPH1 are engaged in opposing signaling pathways, the tumor-suppressive and tumor-promoting pathways, respectively, in esophageal carcinogenesis.
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MESH Headings
- Adult
- Aged
- Carcinoma, Squamous Cell/enzymology
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/pathology
- Cell Differentiation
- DNA, Complementary/genetics
- Enzyme Induction
- Esophageal Neoplasms/enzymology
- Esophageal Neoplasms/genetics
- Esophageal Neoplasms/pathology
- Female
- Gene Expression Regulation, Neoplastic
- Humans
- Lymphatic Metastasis
- Male
- Middle Aged
- Mucous Membrane/enzymology
- Neoplasm Invasiveness
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neoplasm Proteins/physiology
- Protein Tyrosine Phosphatase, Non-Receptor Type 1
- Protein Tyrosine Phosphatase, Non-Receptor Type 3
- Protein Tyrosine Phosphatases/biosynthesis
- Protein Tyrosine Phosphatases/deficiency
- Protein Tyrosine Phosphatases/genetics
- Protein Tyrosine Phosphatases/physiology
- Protein Tyrosine Phosphatases, Non-Receptor
- RNA, Messenger/biosynthesis
- RNA, Neoplasm/biosynthesis
- Tumor Cells, Cultured
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Affiliation(s)
- M Warabi
- Department of Pathology and Immunology, School of Medicine, Tokyo Medical and Dental University, Tokyo, 113-8519, Japan
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43
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Bernardi R, Liebermann DA, Hoffman B. Cdc25A stability is controlled by the ubiquitin-proteasome pathway during cell cycle progression and terminal differentiation. Oncogene 2000; 19:2447-54. [PMID: 10828887 DOI: 10.1038/sj.onc.1203564] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Members of the cdc25 family are protein phosphatases that play pivotal roles in cell cycle progression. Cdc25A has been shown to be a critical regulator of the G1/S transition of mammalian cells and to be a myc-target gene with oncongenic properties. We investigated the regulation of cdc25A during terminal differentiation using myeloblastic leukemia M1 cells, that can be induced to undergo differentiation into macrophages by interleukin-6 (IL-6) treatment. In this report it is shown that cdc25A protein is degraded by the ubiquitin-proteasome machinery in both terminally differentiating and cycling cells. Cdc25A was found to have two major peaks of accumulation during cell cycle progression, one in G1 and the other in S/G2. Evidence was obtained that degradation of cdc25A by the ubiquitin-proteasome machinery in terminally differentiating myeloid cells is accelerated compared to cycling cells. Moreover, deregulated expression of c-myc in M1 cells, which had been previously shown to block terminal differentiation, was also found to block IL-6 induced degradation of cdc25A.
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Affiliation(s)
- R Bernardi
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, 3307 N. Broad Street, Philadelphia, Pennsylvania, PA 19140, USA
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Peng H, Xie W, Kim DI, Zalkow LH, Powis G, Otterness DM, Abraham RT. Steroidal derived acids as inhibitors of human Cdc25A protein phosphatase. Bioorg Med Chem 2000; 8:299-306. [PMID: 10722152 DOI: 10.1016/s0968-0896(99)00284-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A group of steroidal derived acids were synthesized and found to be human Cdc25A inhibitors. Their potency ranged from 1.1 to > 100 microM; the best ones compare very favorably with that of the novel cyano-containing 5,6-seco-cholesteryl acid 1 (IC50=2.2microM) reported by us recently (Peng, H.; Zalkow, L. H.; Abraham, R. T.; Powis, G. J. Med. Chem. 1998, 41, 4677). Structure-activity relationships of these compounds revealed that a hydrophobic cholesteryl side chain and a free carboxyl group are crucial for activity. The distance between these two pharmacophores is also important for the potency of these compounds. Several of the compounds showed selective growth inhibition effects in the NCI in vitro cancer cell line panel.
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Affiliation(s)
- H Peng
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta 30332, USA
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