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Hansen DT, Rueb NJ, Levinzon ND, Cheatham TE, Gaston R, Tanvir Ahmed K, Osburn-Staker S, Cox JE, Dudley GB, Barrios AM. The mechanism of covalent inhibition of LAR phosphatase by illudalic acid. Bioorg Med Chem Lett 2024; 104:129740. [PMID: 38599294 PMCID: PMC11057956 DOI: 10.1016/j.bmcl.2024.129740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 04/05/2024] [Accepted: 04/07/2024] [Indexed: 04/12/2024]
Abstract
Leukocyte antigen-related (LAR) phosphatase is a receptor-type protein tyrosine phosphatase involved in cellular signaling and associated with human disease including cancer and metabolic disorders. Selective inhibition of LAR phosphatase activity by well characterized and well validated small molecules would provide key insights into the roles of LAR phosphatase in health and disease, but identifying selective inhibitors of LAR phosphatase activity has been challenging. Recently, we described potent and selective inhibition of LAR phosphatase activity by the fungal natural product illudalic acid. Here we provide a detailed biochemical characterization of the adduct formed between LAR phosphatase and illudalic acid. A mass spectrometric analysis indicates that two cysteine residues are covalently labeled by illudalic acid and a related analog. Mutational analysis supports the hypothesis that inhibition of LAR phosphatase activity is due primarily to the adduct with the catalytic cysteine residue. A computational study suggests potential interactions between the illudalic acid moiety and the enzyme active site. Taken together, these data offer novel insights into the mechanism of inhibition of LAR phosphatase activity by illudalic acid.
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Affiliation(s)
- Daniel T Hansen
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Nicole J Rueb
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Nathan D Levinzon
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Thomas E Cheatham
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Robert Gaston
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506, USA
| | - Kh Tanvir Ahmed
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506, USA
| | - Sandra Osburn-Staker
- Mass Spectrometry and Proteomics Facility, University of Utah, Salt Lake City, UT 84112, USA
| | - James E Cox
- Mass Spectrometry and Proteomics Facility, University of Utah, Salt Lake City, UT 84112, USA
| | - Gregory B Dudley
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506, USA
| | - Amy M Barrios
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, UT 84112, USA.
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2
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Liprins in oncogenic signaling and cancer cell adhesion. Oncogene 2021; 40:6406-6416. [PMID: 34654889 PMCID: PMC8602034 DOI: 10.1038/s41388-021-02048-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/21/2021] [Accepted: 09/28/2021] [Indexed: 12/30/2022]
Abstract
Liprins are a multifunctional family of scaffold proteins, identified by their involvement in several important neuronal functions related to signaling and organization of synaptic structures. More recently, the knowledge on the liprin family has expanded from neuronal functions to processes relevant to cancer progression, including cell adhesion, cell motility, cancer cell invasion, and signaling. These proteins consist of regions, which by prediction are intrinsically disordered, and may be involved in the assembly of supramolecular structures relevant for their functions. This review summarizes the current understanding of the functions of liprins in different cellular processes, with special emphasis on liprins in tumor progression. The available data indicate that liprins may be potential biomarkers for cancer progression and may have therapeutic importance.
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3
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Wang Y, Shan A, Zhou Z, Li W, Xie L, Du B, Lei B. LncRNA TCONS_00004099-derived microRNA regulates oncogenesis through PTPRF in gliomas. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1023. [PMID: 34277823 PMCID: PMC8267291 DOI: 10.21037/atm-21-2442] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 06/17/2021] [Indexed: 01/25/2023]
Abstract
Background Glioblastoma is the most common and aggressive primary tumor in the central nervous system (CNS). Patients with glioblastomas have poor prognosis due to its aggressive clinical behavior and resistance to the chemotherapeutic agent temozolomide (TMZ). Aberrant long non-coding RNAs (lncRNAs) are involved in glioma progression and its regulatory mechanisms. Analysis of sequencing data identified a new lncRNA, named lncRNA TCONS_00004099, which could derive a new microRNA and was highly expressed in glioma. Methods To elucidate the role of lncRNA TCONS_00004099 in gliomas, Quantitative Real-time PCR (qPCR) was used to assess the differential expression of lncRNA TCONS_00004099 and its related miRNA in glioma tissues, normal brain tissues, glioma cell lines (U87 and U251 cells), and a normal human embryonic brain cell line (HEB). Cell Counting Kit-8 (CCK8) assays to assess cell proliferation, flow cytometry assays examining apoptosis and the cell cycle, colony formation assays, wound healing assay, transwell assays, and zebrafish xenograft models were performed to further clarify the effects of the lncRNA and the related miRNA. Finally, Western blots were carried out to verify the mechanisms related to PTPRF (Protein Tyrosine Phosphatase Receptor Type F). Results LncRNA TCONS_00004099 was significantly increased in glioma tissues and glioma cell lines. A novel miRNA (miRNA TCONS_00004099) derived from the lncRNA was identified by qPCR. Knockdown of this lncRNA suppressed cell proliferation, migration, invasion and enhanced TMZ-induced apoptosis in U87 and U251 cell lines in vitro and in vivo. The miRNA mimics or inhibitor of miRNA TCONS_00004099 was used to reverse the effects of knockdown or overexpression of lncRNA TCONS_00004099, respectively. Western Blot analyses verified that PTPRF is one of the downstream targets of lncRNA TCONS_00004099. Conclusions These results demonstrated that lncRNA TCONS_00004099 promoted malignant behaviors in gliomas, including proliferation, metastasis, and anti-apoptosis. The effect of lncRNA TCONS_00004099 was mediated through miRNA TCONS_00004099 and its target PTPRF. Thus, the lncRNA TCONS_00004099/miRNA/PTPRF axis may be a potential therapeutic target for gliomas.
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Affiliation(s)
- Yuhao Wang
- Nosocomial Infection Control Center, People's Hospital of Shenzhen Baoan District, Shenzhen, China
| | - Aijun Shan
- Department of Emergency, Shenzhen People's Hospital, The Second Clinical Medical College of Jinan University, The First Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
| | - Zhiwei Zhou
- Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Department of Neurosurgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Faculty of Health Sciences, University of Macau, Macau, China
| | - Wenpeng Li
- Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Department of Neurosurgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Lin Xie
- Department of Neurosurgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Bo Du
- Department of Emergency, Shenzhen People's Hospital, The Second Clinical Medical College of Jinan University, The First Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
| | - Bingxi Lei
- Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.,Department of Neurosurgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
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4
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Inhibition of protein tyrosine phosphatase receptor type F suppresses Wnt signaling in colorectal cancer. Oncogene 2020; 39:6789-6801. [PMID: 32973331 PMCID: PMC7606795 DOI: 10.1038/s41388-020-01472-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 09/15/2020] [Indexed: 02/05/2023]
Abstract
Wnt signaling dysregulation promotes tumorigenesis in colorectal cancer (CRC). We investigated the role of PTPRF, a receptor-type tyrosine phosphatase, in regulating Wnt signaling in CRC. Knockdown of PTPRF decreased cell proliferation in patient-derived primary colon cancer cells and established CRC cell lines. In addition, the rate of proliferation as well as colony formation ability were significantly decreased cells in tumor organoids grown in 3D, whereas the number of differentiated tumor organoids were markedly increased. Consistently, knockdown of PTPRF resulted in a decrease in the expression of genes associated cancer stem cells downstream of Wnt/β-catenin signaling. Treating PTPRF knockdown cells with GSK3 inhibitor rescued the expression of Wnt target genes suggesting that PTPRF functions upstream of the β-catenin destruction complex. PTPRF was found to interact with LRP6 and silencing PTPRF largely decreased the activation of LRP6. Interestingly, this PTPRF-mediated activation of Wnt signaling was blocked in cells treated with clathrin endocytosis inhibitor. Furthermore, knockdown of PTPRF inhibited xenograft tumor growth in vivo and decreased the expression of Wnt target genes. Taken together, our studies identify a novel role of PTPRF as an oncogenic protein phosphatase in supporting the activation of Wnt signaling in CRC.
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5
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McCullough BS, Batsomboon P, Hutchinson KB, Dudley GB, Barrios AM. Synthesis and PTP Inhibitory Activity of Illudalic Acid and Its Methyl Ether, with Insights into Selectivity for LAR PTP over Other Tyrosine Phosphatases under Physiologically Relevant Conditions. JOURNAL OF NATURAL PRODUCTS 2019; 82:3386-3393. [PMID: 31809044 DOI: 10.1021/acs.jnatprod.9b00663] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The protein tyrosine phosphatase (PTP) family of enzymes includes many attractive therapeutic targets, such as those in the leukocyte common antigen-related (LAR) subfamily of receptor PTPs. Synthesis and PTP inhibitory activity of illudalic acid and its methyl ether are described, with a focus on selective inhibition of LAR PTP relative to a small collection of other representative PTPs. The synthesis comprises 16 steps and provides illudalic acid in up to 12% overall yield from neopentylene-fused benzoate 1 (20 steps from commercial materials). Illudalic acid dose-dependently (measured IC50 = 2.1 ± 0.2 μM) and time-dependently inhibits LAR consistent with previous reports of covalent binding. The kinetics of LAR inhibition by illudalic acid are consistent with a two-step mechanism in which the inhibitor and enzyme first interact noncovalently (KI = 130 ± 50 μM), followed by covalent ligation at a rate kinact = 1.3 ± 0.4 min-1. The kinact/KI ratio of 104 corresponds to a t∞1/2 of 0.5 min, as discussed herein. The phenol methyl ether of illudalic acid was found to be less potent in our dose-response assays (measured IC50 = 55 ± 6 μM) but more selective for LAR, with a weaker initial noncovalent interaction and faster covalent ligation of LAR as compared to illudalic acid itself. A truncated analogue of illudalic acid that lacks the neopentylene ring fusion was found to be devoid of significant activity under our assay conditions, in contrast to previous reports. These observations collectively help inform further development of illudalic acid analogues as potent and selective inhibitors of the LAR subfamily of tyrosine phosphatases.
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Affiliation(s)
- Brandon S McCullough
- Department of Medicinal Chemistry , University of Utah , Salt Lake City , Utah 84112 , United States
| | - Paratchata Batsomboon
- C. Eugene Bennett Department of Chemistry , West Virginia University , Morgantown , West Virginia 26506 , United States
| | - Kacey B Hutchinson
- Department of Medicinal Chemistry , University of Utah , Salt Lake City , Utah 84112 , United States
| | - Gregory B Dudley
- C. Eugene Bennett Department of Chemistry , West Virginia University , Morgantown , West Virginia 26506 , United States
| | - Amy M Barrios
- Department of Medicinal Chemistry , University of Utah , Salt Lake City , Utah 84112 , United States
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6
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Ruckert MT, de Andrade PV, Santos VS, Silveira VS. Protein tyrosine phosphatases: promising targets in pancreatic ductal adenocarcinoma. Cell Mol Life Sci 2019; 76:2571-2592. [PMID: 30982078 PMCID: PMC11105579 DOI: 10.1007/s00018-019-03095-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 03/25/2019] [Accepted: 04/08/2019] [Indexed: 12/21/2022]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer. It is the fourth leading cause of cancer-related death and is associated with a very poor prognosis. KRAS driver mutations occur in approximately 95% of PDAC cases and cause the activation of several signaling pathways such as mitogen-activated protein kinase (MAPK) pathways. Regulation of these signaling pathways is orchestrated by feedback loops mediated by the balance between protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs), leading to activation or inhibition of its downstream targets. The human PTPome comprises 125 members, and these proteins are classified into three distinct families according to their structure. Since PTP activity description, it has become clear that they have both inhibitory and stimulatory effects on cancer-associated signaling processes and that deregulation of PTP function is closely associated with tumorigenesis. Several PTPs have displayed either tumor suppressor or oncogenic characteristics during the development and progression of PDAC. In this sense, PTPs have been presented as promising candidates for the treatment of human pancreatic cancer, and many PTP inhibitors have been developed since these proteins were first associated with cancer. Nevertheless, some challenges persist regarding the development of effective and safe methods to target these molecules and deliver these drugs. In this review, we discuss the role of PTPs in tumorigenesis as tumor suppressor and oncogenic proteins. We have focused on the differential expression of these proteins in PDAC, as well as their clinical implications and possible targeting for pharmacological inhibition in cancer therapy.
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Affiliation(s)
- Mariana Tannús Ruckert
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, São Paulo, Brazil
| | - Pamela Viani de Andrade
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, São Paulo, Brazil
| | - Verena Silva Santos
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, São Paulo, Brazil
| | - Vanessa Silva Silveira
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, São Paulo, Brazil.
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7
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Tian X, Yang C, Yang L, Sun Q, Liu N. PTPRF as a novel tumor suppressor through deactivation of ERK1/2 signaling in gastric adenocarcinoma. Onco Targets Ther 2018; 11:7795-7803. [PMID: 30464527 PMCID: PMC6223389 DOI: 10.2147/ott.s178152] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Background Protein tyrosine phosphatase, receptor type F (PTPRF) is an important phosphatase playing roles in regulating cell growth, differentiation and oncogenic transformation. Overexpression of PTPRF has been observed in non-small cell lung cancer, but its clinical significance in other malignancies is still unknown. Methods We explored the expression pattern of PTPRF in gastric adenocarcinoma by using RT-qPCR and immunohistochemistry staining. The clinical significance of PTPRF was evaluated by univariate and multivariate analyses. Furthermore, the signaling pathways downstream of PTPRF was investigated by knockdown and overexpression assays combined with cellular studies. Results We found a remarkable down-regulation of PTPRF in gastric adenocarcinomas, which was significantly associated with advanced tumor TNM stages. Survival analysis showed that lower PTPRF level indicated a poorer overall survival of gastric adenocarcinoma patients. By conducting knockdown and overexpression studies in gastric adenocarcinoma cells, we revealed the role of PTPRF on inhibiting extracellular signal-regulated kinase-1/2 (ERK1/2) phosphorylation and its downstream signaling. Consistent with clinical findings, cellular results demonstrated that overexpressing PTPRF can significantly inhibit tumor migration and invasion, while silencing PTPRF showed opposite effects. Conclusion In conclusion, patients with lower PTPRF expression in gastric adenocarcinoma tissues were more predisposed to advanced tumor stage and unfavorable prognosis.
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Affiliation(s)
- Xiang'an Tian
- First Department of General Surgery, Linyi Central Hospital, Linyi 276400, Shandong Province, China,
| | - Chengju Yang
- Second Department of Obstetrics, Linyi Central Hospital, Linyi 276400, Shandong Province, China
| | - Liguang Yang
- First Department of General Surgery, Linyi Central Hospital, Linyi 276400, Shandong Province, China,
| | - Qinli Sun
- First Department of General Surgery, Linyi Central Hospital, Linyi 276400, Shandong Province, China,
| | - Naiqing Liu
- First Department of General Surgery, Linyi Central Hospital, Linyi 276400, Shandong Province, China,
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8
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Zhang S, Fan G, Hao Y, Hammell M, Wilkinson JE, Tonks NK. Suppression of protein tyrosine phosphatase N23 predisposes to breast tumorigenesis via activation of FYN kinase. Genes Dev 2017; 31:1939-1957. [PMID: 29066500 PMCID: PMC5710140 DOI: 10.1101/gad.304261.117] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 10/06/2017] [Indexed: 12/18/2022]
Abstract
Zhang et al. identified PTPN23 as a suppressor of cell motility and invasion in mammary epithelial and breast cancer cells. They validated the underlying mechanism of PTPN23 function in breast tumorigenesis as that of a key phosphatase that normally suppresses the activity of FYN in two different models. Disruption of the balanced modulation of reversible tyrosine phosphorylation has been implicated in the etiology of various human cancers, including breast cancer. Protein Tyrosine Phosphatase N23 (PTPN23) resides in chromosomal region 3p21.3, which is hemizygously or homozygously lost in some breast cancer patients. In a loss-of-function PTPome screen, our laboratory identified PTPN23 as a suppressor of cell motility and invasion in mammary epithelial and breast cancer cells. Now, our TCGA (The Cancer Genome Atlas) database analyses illustrate a correlation between low PTPN23 expression and poor survival in breast cancers of various subtypes. Therefore, we investigated the tumor-suppressive function of PTPN23 in an orthotopic transplantation mouse model. Suppression of PTPN23 in Comma 1Dβ cells induced breast tumors within 56 wk. In PTPN23-depleted tumors, we detected hyperphosphorylation of the autophosphorylation site tyrosine in the SRC family kinase (SFK) FYN as well as Tyr142 in β-catenin. We validated the underlying mechanism of PTPN23 function in breast tumorigenesis as that of a key phosphatase that normally suppresses the activity of FYN in two different models. We demonstrated that tumor outgrowth from PTPN23-deficient BT474 cells was suppressed in a xenograft model in vivo upon treatment with AZD0530, an SFK inhibitor. Furthermore, double knockout of FYN and PTPN23 via CRISPR/CAS9 also attenuated tumor outgrowth from PTPN23 knockout Cal51 cells. Overall, this mechanistic analysis of the tumor-suppressive function of PTPN23 in breast cancer supports the identification of FYN as a therapeutic target for breast tumors with heterozygous or homozygous loss of PTPN23.
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Affiliation(s)
- Siwei Zhang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA.,Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York 11794, USA
| | - Gaofeng Fan
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA.,School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yuan Hao
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Molly Hammell
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - John Erby Wilkinson
- Unit for Laboratory Animal Medicine, Department of Pathology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Nicholas K Tonks
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
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9
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Meeusen B, Janssens V. Tumor suppressive protein phosphatases in human cancer: Emerging targets for therapeutic intervention and tumor stratification. Int J Biochem Cell Biol 2017; 96:98-134. [PMID: 29031806 DOI: 10.1016/j.biocel.2017.10.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 02/06/2023]
Abstract
Aberrant protein phosphorylation is one of the hallmarks of cancer cells, and in many cases a prerequisite to sustain tumor development and progression. Like protein kinases, protein phosphatases are key regulators of cell signaling. However, their contribution to aberrant signaling in cancer cells is overall less well appreciated, and therefore, their clinical potential remains largely unexploited. In this review, we provide an overview of tumor suppressive protein phosphatases in human cancer. Along their mechanisms of inactivation in defined cancer contexts, we give an overview of their functional roles in diverse signaling pathways that contribute to their tumor suppressive abilities. Finally, we discuss their emerging roles as predictive or prognostic markers, their potential as synthetic lethality targets, and the current feasibility of their reactivation with pharmacologic compounds as promising new cancer therapies. We conclude that their inclusion in clinical practice has obvious potential to significantly improve therapeutic outcome in various ways, and should now definitely be pushed forward.
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Affiliation(s)
- Bob Meeusen
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, Faculty of Medicine, KU Leuven & Leuven Cancer Institute (LKI), KU Leuven, Belgium
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, Faculty of Medicine, KU Leuven & Leuven Cancer Institute (LKI), KU Leuven, Belgium.
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10
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Elson A. Stepping out of the shadows: Oncogenic and tumor-promoting protein tyrosine phosphatases. Int J Biochem Cell Biol 2017; 96:135-147. [PMID: 28941747 DOI: 10.1016/j.biocel.2017.09.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 09/15/2017] [Accepted: 09/16/2017] [Indexed: 12/18/2022]
Abstract
Protein tyrosine phosphorylation is critical for proper function of cells and organisms. Phosphorylation is regulated by the concerted but generically opposing activities of tyrosine kinases (PTKs) and tyrosine phosphatases (PTPs), which ensure its proper regulation, reversibility, and ability to respond to changing physiological situations. Historically, PTKs have been associated mainly with oncogenic and pro-tumorigenic activities, leading to the generalization that protein dephosphorylation is anti-oncogenic and hence that PTPs are tumor-suppressors. In many cases PTPs do suppress tumorigenesis. However, a growing body of evidence indicates that PTPs act as dominant oncogenes and drive cell transformation in a number of contexts, while in others PTPs support transformation that is driven by other oncogenes. This review summarizes the known transforming and tumor-promoting activities of the classical, tyrosine specific PTPs and highlights their potential as drug targets for cancer therapy.
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Affiliation(s)
- Ari Elson
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, 76100, Israel.
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11
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Classification of 27 Tumor-Associated Antigens by Histochemical Analysis of 36 Freshly Resected Lung Cancer Tissues. Int J Mol Sci 2016; 17:ijms17111862. [PMID: 27834817 PMCID: PMC5133862 DOI: 10.3390/ijms17111862] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 10/26/2016] [Accepted: 11/01/2016] [Indexed: 12/21/2022] Open
Abstract
In previous studies, we identified 29 tumor-associated antigens (TAAs) and isolated 488 human monoclonal antibodies (mAbs) that specifically bind to one of the 29 TAAs. In the present study, we performed histochemical analysis of 36 freshly resected lung cancer tissues by using 60 mAbs against 27 TAAs. Comparison of the staining patterns of tumor cells, bronchial epithelial cells, and normal pulmonary alveolus cells and interalveolar septum allowed us to determine the type and location of cells that express target molecules, as well as the degree of expression. The patterns were classified into 7 categories. While multiple Abs were used against certain TAAs, the differences observed among them should be derived from differences in the binding activity and/or the epitope. Thus, such data indicate the versatility of respective clones as anti-cancer drugs. Although the information obtained was limited to the lung and bronchial tube, bronchial epithelial cells represent normal growing cells, and therefore, the data are informative. The results indicate that 9 of the 27 TAAs are suitable targets for therapeutic Abs. These 9 Ags include EGFR, HER2, TfR, and integrin α6β4. Based on our findings, a pharmaceutical company has started to develop anti-cancer drugs by using Abs to TfR and integrin α6β4. HGFR, PTP-LAR, CD147, CDCP1, and integrin αvβ3 are also appropriate targets for therapeutic purposes.
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12
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Kiflemariam S, Ljungström V, Pontén F, Sjöblom T. Tumor vessel up-regulation of INSR revealed by single-cell expression analysis of the tyrosine kinome and phosphatome in human cancers. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:1600-9. [PMID: 25864925 DOI: 10.1016/j.ajpath.2015.02.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 02/08/2015] [Accepted: 02/18/2015] [Indexed: 01/16/2023]
Abstract
The tyrosine kinome and phosphatome harbor oncogenes and tumor suppressor genes and important regulators of angiogenesis and tumor stroma formation. To provide a better understanding of their potential roles in cancer, we analyzed the expression of 85 tyrosine kinases and 42 tyrosine phosphatases by in situ hybridization 48 human normal and 24 tumor tissue specimens. Nine-tenths of the assessed transcripts had tumor cell expression concordant with expression array databases. Further, pan-cancer expression of AATK, PTPRK, and PTPRU and expression of PTPRS in a subset of tumors were observed. To demonstrate tumor subcompartment resolution, we validated the predicted tumor stroma-specific markers HTRA1, HTRA3, MXRA5, MXRA8, and SERPING1 in situ. In addition to known vascular and stromal markers such as PDGFRB, we observed stromal expression of PTK6 and TNS1 and vascular expression of INSR, PTPRF, PTPRG, PTPRU, and TNS1, of which INSR emerged as a tumor-specific vessel marker. This study demonstrates the feasibility of large-scale analyses to chart the transcriptome in situ in human cancers and their ability to identify novel cancer biomarkers.
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Affiliation(s)
- Sara Kiflemariam
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Viktor Ljungström
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Fredrik Pontén
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Tobias Sjöblom
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
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Liu PJ, Chen CD, Wang CL, Wu YC, Hsu CW, Lee CW, Huang LH, Yu JS, Chang YS, Wu CC, Yu CJ. In-depth proteomic analysis of six types of exudative pleural effusions for nonsmall cell lung cancer biomarker discovery. Mol Cell Proteomics 2015; 14:917-32. [PMID: 25638566 DOI: 10.1074/mcp.m114.045914] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Indexed: 01/21/2023] Open
Abstract
Pleural effusion (PE), a tumor-proximal body fluid, may be a promising source for biomarker discovery in human cancers. Because a variety of pathological conditions can lead to PE, characterization of the relative PE proteomic profiles from different types of PEs would accelerate discovery of potential PE biomarkers specifically used to diagnose pulmonary disorders. Using quantitative proteomic approaches, we identified 772 nonredundant proteins from six types of exudative PEs, including three malignant PEs (MPE, from lung, breast, and gastric cancers), one lung cancer paramalignant PE, and two benign diseases (tuberculosis and pneumonia). Spectral counting was utilized to semiquantify PE protein levels. Principal component analysis, hierarchical clustering, and Gene Ontology of cellular process analyses revealed differential levels and functional profiling of proteins in each type of PE. We identified 30 candidate proteins with twofold higher levels (q<0.05) in lung cancer MPEs than in the two benign PEs. Three potential markers, MET, DPP4, and PTPRF, were further verified by ELISA using 345 PE samples. The protein levels of these potential biomarkers were significantly higher in lung cancer MPE than in benign diseases or lung cancer paramalignant PE. The area under the receiver-operator characteristic curve for three combined biomarkers in discriminating lung cancer MPE from benign diseases was 0.903. We also observed that the PE protein levels were more clearly discriminated in effusions in which the cytological examination was positive and that they would be useful in rescuing the false negative of cytological examination in diagnosis of nonsmall cell lung cancer-MPE. Western blotting analysis further demonstrated that MET overexpression in lung cancer cells would contribute to the elevation of soluble MET in MPE. Our results collectively demonstrate the utility of label-free quantitative proteomic approaches in establishing differential PE proteomes and provide a new database of proteins that can be used to facilitate identification of pulmonary disorder-related biomarkers.
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Affiliation(s)
- Pei-Jun Liu
- From the ‡Graduate Institute of Biomedical Sciences
| | - Chi-De Chen
- From the ‡Graduate Institute of Biomedical Sciences, **Molecular Medicine Research Center, Chang Gung University, Tao-Yuan, Taiwan
| | - Chih-Liang Wang
- §School of Medicine, ‡‡Division of Pulmonary Oncology and Interventional Bronchoscopy, Department of Thoracic Medicine
| | - Yi-Cheng Wu
- §§Department of Thoracic Surgery, Chang Gung Memorial Hospital, Linkou, Tao-Yuan, Taiwan
| | - Chia-Wei Hsu
- From the ‡Graduate Institute of Biomedical Sciences, **Molecular Medicine Research Center, Chang Gung University, Tao-Yuan, Taiwan
| | | | | | - Jau-Song Yu
- From the ‡Graduate Institute of Biomedical Sciences, ¶Department of Cell and Molecular Biology, and **Molecular Medicine Research Center, Chang Gung University, Tao-Yuan, Taiwan
| | - Yu-Sun Chang
- From the ‡Graduate Institute of Biomedical Sciences, **Molecular Medicine Research Center, Chang Gung University, Tao-Yuan, Taiwan
| | - Chih-Ching Wu
- **Molecular Medicine Research Center, Chang Gung University, Tao-Yuan, Taiwan;
| | - Chia-Jung Yu
- From the ‡Graduate Institute of Biomedical Sciences, ¶Department of Cell and Molecular Biology, and
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14
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Nunes-Xavier CE, Martín-Pérez J, Elson A, Pulido R. Protein tyrosine phosphatases as novel targets in breast cancer therapy. Biochim Biophys Acta Rev Cancer 2013; 1836:211-26. [PMID: 23756181 DOI: 10.1016/j.bbcan.2013.06.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Accepted: 06/01/2013] [Indexed: 02/07/2023]
Abstract
Breast cancer is linked to hyperactivation of protein tyrosine kinases (PTKs), and recent studies have unveiled that selective tyrosine dephosphorylation by protein tyrosine phosphatases (PTPs) of specific substrates, including PTKs, may activate or inactivate oncogenic pathways in human breast cancer cell growth-related processes. Here, we review the current knowledge on the involvement of PTPs in breast cancer, as major regulators of breast cancer therapy-targeted PTKs, such as HER1/EGFR, HER2/Neu, and Src. The functional interplay between PTKs and PTK-activating or -inactivating PTPs, and its implications in novel breast cancer therapies based on targeting of specific PTPs, are discussed.
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Affiliation(s)
- Caroline E Nunes-Xavier
- BioCruces Health Research Institute, Hospital de Cruces, Plaza Cruces s/n, 48903 Barakaldo, Spain
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15
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Wang W, Huang J, Wang X, Yuan J, Li X, Feng L, Park JI, Chen J. PTPN14 is required for the density-dependent control of YAP1. Genes Dev 2012; 26:1959-71. [PMID: 22948661 DOI: 10.1101/gad.192955.112] [Citation(s) in RCA: 151] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Through an shRNA-mediated loss-of-function screen, we identified PTPN14 as a potential tumor suppressor. PTPN14 interacts with yes-associated protein 1 (YAP1), a member of the hippo signaling pathway. We showed that PTPN14 promotes the nucleus-to-cytoplasm translocation of YAP1 during contact inhibition and thus inhibits YAP1 transactivation activity. Interestingly, PTPN14 protein stability was positively controlled by cell density. We identified the CRL2(LRR1) (cullin2 RING ubiquitin ligase complex/leucine-rich repeat protein 1) complex as the E3 ligase that targets PTPN14 for degradation at low cell density. Collectively, these data suggest that PTPN14 acts to suppress cell proliferation by promoting cell density-dependent cytoplasmic translocation of YAP1.
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Affiliation(s)
- Wenqi Wang
- Department of Experimental Radiation Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA
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16
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Receptor type protein tyrosine phosphatases (RPTPs) - roles in signal transduction and human disease. J Cell Commun Signal 2012; 6:125-38. [PMID: 22851429 DOI: 10.1007/s12079-012-0171-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 07/12/2012] [Indexed: 01/06/2023] Open
Abstract
Protein tyrosine phosphorylation is a fundamental regulatory mechanism controlling cell proliferation, differentiation, communication, and adhesion. Disruption of this key regulatory mechanism contributes to a variety of human diseases including cancer, diabetes, and auto-immune diseases. Net protein tyrosine phosphorylation is determined by the dynamic balance of the activity of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Mammals express many distinct PTKs and PTPs. Both of these families can be sub-divided into non-receptor and receptor subtypes. Receptor protein tyrosine kinases (RPTKs) comprise a large family of cell surface proteins that initiate intracellular tyrosine phosphorylation-dependent signal transduction in response to binding of extracellular ligands, such as growth factors and cytokines. Receptor-type protein tyrosine phosphatases (RPTPs) are enzymatic and functional counterparts of RPTKs. RPTPs are a family of integral cell surface proteins that possess intracellular PTP activity, and extracellular domains that have sequence homology to cell adhesion molecules. In comparison to extensively studied RPTKs, much less is known about RPTPs, especially regarding their substrate specificities, regulatory mechanisms, biological functions, and their roles in human diseases. Based on the structure of their extracellular domains, the RPTP family can be grouped into eight sub-families. This article will review one representative member from each RPTP sub-family.
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17
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Whitmore TE, Peterson A, Holzman T, Eastham A, Amon L, McIntosh M, Ozinsky A, Nelson PS, Martin DB. Integrative Analysis of N-Linked Human Glycoproteomic Data Sets Reveals PTPRF Ectodomain as a Novel Plasma Biomarker Candidate for Prostate Cancer. J Proteome Res 2012; 11:2653-65. [DOI: 10.1021/pr201200n] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Theodore E. Whitmore
- Institute for Systems Biology, 1441 N. 34th St., Seattle, Washington 98103,
United States
| | - Amelia Peterson
- Department
of Chemistry, University of Wisconsin,
Madison, Wisconsin, United States
| | | | - Ashley Eastham
- Analytical & Formulation Sciences, Amgen Inc., Seattle, Washington 98119, United States
| | | | | | - Adrian Ozinsky
- Institute for Systems Biology, 1441 N. 34th St., Seattle, Washington 98103,
United States
| | | | - Daniel B. Martin
- Seattle Cancer Care Alliance,
825 Eastlake Avenue East, P.O. Box 19023, Seattle, Washington 98109,
United States
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18
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Lin G, Aranda V, Muthuswamy SK, Tonks NK. Identification of PTPN23 as a novel regulator of cell invasion in mammary epithelial cells from a loss-of-function screen of the 'PTP-ome'. Genes Dev 2011; 25:1412-25. [PMID: 21724833 DOI: 10.1101/gad.2018911] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We used an RNAi-mediated loss-of-function screen to study systematically the role of the protein tyrosine phosphatase (PTP) superfamily of enzymes in mammary epithelial cell motility in the absence or presence of the oncoprotein tyrosine kinase ERBB2. We report that although shRNAs directed against most of the PTP family were without effect, suppression of three PTPs-PRPN23, PTPRG, and PTPRR-enhanced cell motility. Furthermore, we found that suppression of PTPN23, but not PTPRG or PTPRR, induced cell invasion. Suppression of PTPN23 increased E-cadherin internalization, impaired early endosome trafficking of E-cadherin, induced the expression of mesenchymal proteins, and caused cell scattering. The activity of SRC and β-catenin was elevated when PTPN23 was suppressed. Moreover, we identified SRC, E-cadherin, and β-catenin as direct substrates of PTPN23. Inhibition of SRC with the small molecular inhibitor SU6656 blocked the effects of PTPN23 depletion. These findings suggest that loss of PTPN23 may increase the activity of SRC and the phosphorylation status of the E-cadherin/β-catenin signaling complex to promote tumor growth and invasive behavior in breast cancer. In addition, our studies highlight functional specificity among PTPs and reveal new roles for PTPs in mammary epithelial cell biology.
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Affiliation(s)
- Guang Lin
- Graduate Program in Molecular and Cellular Biology, Stony Brook University, Stony Brook, New York 11794, USA
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19
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Roussos ET, Balsamo M, Alford SK, Wyckoff JB, Gligorijevic B, Wang Y, Pozzuto M, Stobezki R, Goswami S, Segall JE, Lauffenburger DA, Bresnick AR, Gertler FB, Condeelis JS. Mena invasive (MenaINV) promotes multicellular streaming motility and transendothelial migration in a mouse model of breast cancer. J Cell Sci 2011; 124:2120-31. [PMID: 21670198 PMCID: PMC3113666 DOI: 10.1242/jcs.086231] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2011] [Indexed: 12/20/2022] Open
Abstract
We have shown previously that distinct Mena isoforms are expressed in invasive and migratory tumor cells in vivo and that the invasion isoform (Mena(INV)) potentiates carcinoma cell metastasis in murine models of breast cancer. However, the specific step of metastatic progression affected by this isoform and the effects on metastasis of the Mena11a isoform, expressed in primary tumor cells, are largely unknown. Here, we provide evidence that elevated Mena(INV) increases coordinated streaming motility, and enhances transendothelial migration and intravasation of tumor cells. We demonstrate that promotion of these early stages of metastasis by Mena(INV) is dependent on a macrophage-tumor cell paracrine loop. Our studies also show that increased Mena11a expression correlates with decreased expression of colony-stimulating factor 1 and a dramatically decreased ability to participate in paracrine-mediated invasion and intravasation. Our results illustrate the importance of paracrine-mediated cell streaming and intravasation on tumor cell dissemination, and demonstrate that the relative abundance of Mena(INV) and Mena11a helps to regulate these key stages of metastatic progression in breast cancer cells.
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Affiliation(s)
- Evanthia T. Roussos
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Michele Balsamo
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Shannon K. Alford
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jeffrey B. Wyckoff
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Gruss Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Bojana Gligorijevic
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Yarong Wang
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Maria Pozzuto
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Robert Stobezki
- Department of Biology, Yeshiva University, New York, NY 10033, USA
| | - Sumanta Goswami
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Biology, Yeshiva University, New York, NY 10033, USA
| | - Jeffrey E. Segall
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Douglas A. Lauffenburger
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Anne R. Bresnick
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Frank B. Gertler
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - John S. Condeelis
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Gruss Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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20
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Abstract
Members of the protein tyrosine phosphatase (Ptp) family dephosphorylate target proteins and counter the activities of protein tyrosine kinases that are involved in cellular phosphorylation and signalling. As such, certain PTPs might be tumour suppressors. Indeed, PTPs play an important part in the inhibition or control of growth, but accumulating evidence indicates that some PTPs may exert oncogenic functions. Recent large-scale genetic analyses of various human tumours have highlighted the relevance of PTPs either as putative tumour suppressors or as candidate oncoproteins. Progress in understanding the regulation and function of PTPs has provided insights into which PTPs might be potential therapeutic targets in human cancer.
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Affiliation(s)
- Sofi G Julien
- Goodman Cancer Research Centre, Department of Biochemistry, McGill University, Montreal, Quebec, Canada
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21
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Dabbous MK, Margaret Jefferson M, Haney L, Thomas EL. Biomarkers of metastatic potential in cultured adenocarcinoma clones. Clin Exp Metastasis 2010; 28:101-11. [DOI: 10.1007/s10585-010-9362-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Accepted: 11/09/2010] [Indexed: 12/19/2022]
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22
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Affiliation(s)
- Tasneem Motiwala
- Department of Molecular and Cellular Biochemistry, The Ohio State University, College of Medicine, Columbus, Ohio 43210, USA
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23
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Abstract
Tyrosine phosphorylation is an important signalling mechanism in eukaryotic cells. In cancer, oncogenic activation of tyrosine kinases is a common feature, and novel anticancer drugs have been introduced that target these enzymes. Tyrosine phosphorylation is also controlled by protein-tyrosine phosphatases (PTPs). Recent evidence has shown that PTPs can function as tumour suppressors. In addition, some PTPs, including SHP2, positively regulate the signalling of growth-factor receptors, and can be oncogenic. An improved understanding of how these enzymes function and how they are regulated might aid the development of new anticancer agents.
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Affiliation(s)
- Arne Ostman
- Cancer Center Karolinska, Department of Pathology and Oncology, Karolinska Institutet, Stockholm, Sweden
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24
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Yang X, Li J, Zhou Y, Shen Q, Chen J, Li J. Discovery of novel inhibitor of human leukocyte common antigen-related phosphatase. Biochim Biophys Acta Gen Subj 2005; 1726:34-41. [PMID: 16198483 DOI: 10.1016/j.bbagen.2005.07.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Revised: 06/23/2005] [Accepted: 07/08/2005] [Indexed: 11/18/2022]
Abstract
Human leukocyte common antigen-related phosphatase (LAR) may play a role in type 2 diabetes and cancer, and in the development of the nervous system, and it may be an attractive target for the treatment of diabetes and cancer. We identified eight hits from the random screening of LAR D1 with a high-throughput screening assay. Further validation of the eight hits showed that the meD insertion was associated with inhibition of LAR D1D2 and LAR D1Q. These data suggest that the inserted meD peptide influences the interaction of the enzyme and inhibitor, which is consistent with the kinetic catalysis constants of the substrate pNPP. Our data showed that Hit 1, the first published novel inhibitor of LAR, is a competitive inhibitor with a K(i) of 330 nM that displays obvious selectivity for LAR and mouse PTPsigma, but not for other protein tyrosine phosphatases.
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Affiliation(s)
- Xiaoning Yang
- East China Normal University, Academy of Life Science, Shanghai 200062, P. R. China
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25
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Abstract
Protein tyrosine phosphatases (PTPs) consist of a large family of related enzymes, including the group of classical PTPs with its two main subgroups, the transmembrane receptor-type (RPTPs) and the intracellular or non-transmembrane PTPs. Published data on the expression and function of a panel of these enzymes in normal and cancerous breast tissues are discussed in this review. While most studies, albeit on different enzymes, have tended to agree on the evidence for an increased PTP expression in breast cancer, any connection between PTP expression and the enzymes' role in cancer development and progression remains largely open to interpretation. Concomitant increases of protein tyrosine kinase (PTK) and PTP activities in many cancers further indicate that a complex dysregulation in the balance of tyrosine phosphorylation could be responsible for major alterations in various cellular processes controlling tissue homeostasis. In particular, any relationship between the expression of PTPs and their specific diverse roles in the regulation of cell growth and apoptosis in breast cancer needs to be addressed in major fundamental, preclinical and clinical studies.
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Affiliation(s)
- Gilles Freiss
- Inserm Unit 540 on Molecular and Cellular Endocrinology of Cancers, 60, rue de Navacelles, 34090 Montpellier, France
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26
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Chagnon MJ, Uetani N, Tremblay ML. Functional significance of the LAR receptor protein tyrosine phosphatase family in development and diseases. Biochem Cell Biol 2004; 82:664-75. [PMID: 15674434 DOI: 10.1139/o04-120] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The protein tyrosine phosphatases (PTPs) have emerged as critical players in diverse cellular functions. The focus of this review is the leukocyte common antigen-related (LAR) subfamily of receptor PTPs (RPTPs). This subfamily is composed of three vertebrate homologs, LAR, RPTP-sigma, and RPTP-delta, as well as few invertebrates orthologs such as Dlar. LAR-RPTPs have a predominant function in nervous system development that is conserved throughout evolution. Proteolytic cleavage of LAR-RPTP proproteins results in the noncovalent association of an extracellular domain resembling cell adhesion molecules and intracellular tandem PTPs domains, which is likely regulated via dimerization. Their receptor-like structures allow them to sense the extracellular environment and transduce signals intracellularly via their cytosolic PTP domains. Although many interacting partners of the LAR-RPTPs have been identified and suggest a role for the LAR-RPTPs in actin remodeling, very little is known about the mechanisms of action of RPTPs. LAR-RPTPs recently raised a lot of interest when they were shown to regulate neurite growth and nerve regeneration in transgenic animal models. In addition, LAR-RPTPs have also been implicated in metabolic regulation and cancer. This RPTP subfamily is likely to become important as drug targets in these various human pathologies, but further understanding of their complex signal transduction cascades will be required.Key words: protein tyrosine phosphatase, LAR, signal transduction, nervous system development.
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Affiliation(s)
- Mélanie J Chagnon
- McGill Cancer Centre and Department of Biochemistry, McGill University, McIntyre Medical Sciences Building, 3655 Promenade Sir-William-Osler, Room 701, Montréal, QC H3G 1Y6, Canada
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27
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Kluza J, Marchetti P, Gallego MA, Lancel S, Fournier C, Loyens A, Beauvillain JC, Bailly C. Mitochondrial proliferation during apoptosis induced by anticancer agents: effects of doxorubicin and mitoxantrone on cancer and cardiac cells. Oncogene 2004; 23:7018-30. [PMID: 15273722 DOI: 10.1038/sj.onc.1207936] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Doxorubicin is one of the most largely prescribed antitumor drug for the treatment of breast, liver and colon cancers as well as leukemia, but the cardiotoxicity of this anthracycline derivative limits its clinical use. Although doxorubicin is toxic to both cancer and cardiac cells, there are evidences suggesting that the mechanism of cell death is different for the two cell types. To investigate further this issue, we have compared the proapoptotic effects of doxorubicin and the functionally related anthracenedione compound mitoxantrone, which is also used in the clinic for the treatment of cancer. After evaluating the toxicity of the two drugs to mammary adenocarcinoma MTLn3 cells and H9C2 cardiomyocytes, we dissected the drug-induced apoptotic machinery by measuring the effects on the cell cycle progression, DNA condensation and fragmentation, production of endogenous peroxides and caspase activation. Both doxorubicin and mitoxantrone are potent inducers of apoptosis in H9C2 cardiomyocytes and MTLn3 breast cancer cells, but there are significant differences between the two cell types in terms of kinetics and order of the events. In particular, flow cytometry measurements of drug-induced changes in mitochondrial transmembrane potential and mitochondrial mass with different fluorescent probes suggested that the two drugs induced a progressive increase in mitochondrial mass in the cancer cells but not in the cardiac cells. The hypothesis was validated by means of electron microscopy, which revealed a significant increase in the number of mitochondria in drug-treated MTLn3 but not in H9C2 cells. The mitochondrial proliferation precedes the nuclear apoptosis in doxorubicin-treated MTLn3 cells. The changes in the architecture and number of mitochondria are linked to the drug-induced perturbation of the cell cycle progression and apoptosis. The proliferation of mitochondria could explain the higher toxicity of doxorubicin to cancer cells compared to cardiac cells and this suggests novel therapeutic opportunities to better control the cardiotoxicity of anthracyclines.
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Affiliation(s)
- Jérôme Kluza
- INSERM U-524 and Laboratoire de Pharmacologie Antitumorale du Centre Oscar Lambret, IRCL, Place de Verdun, 59045 Lille, France
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