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Black JD, Affandi T, Black AR, Reyland ME. PKCα and PKCδ: Friends and Rivals. J Biol Chem 2022; 298:102194. [PMID: 35760100 PMCID: PMC9352922 DOI: 10.1016/j.jbc.2022.102194] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 06/13/2022] [Accepted: 06/21/2022] [Indexed: 01/06/2023] Open
Abstract
PKC comprises a large family of serine/threonine kinases that share a requirement for allosteric activation by lipids. While PKC isoforms have significant homology, functional divergence is evident among subfamilies and between individual PKC isoforms within a subfamily. Here, we highlight these differences by comparing the regulation and function of representative PKC isoforms from the conventional (PKCα) and novel (PKCδ) subfamilies. We discuss how unique structural features of PKCα and PKCδ underlie differences in activation and highlight the similar, divergent, and even opposing biological functions of these kinases. We also consider how PKCα and PKCδ can contribute to pathophysiological conditions and discuss challenges to targeting these kinases therapeutically.
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Affiliation(s)
- Jennifer D Black
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE.
| | - Trisiani Affandi
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus
| | - Adrian R Black
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE
| | - Mary E Reyland
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus.
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2
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Folate Conjugated Polyethylene Glycol Probe for Tumor-Targeted Drug Delivery of 5-Fluorouracil. Molecules 2022; 27:molecules27061780. [PMID: 35335144 PMCID: PMC8954791 DOI: 10.3390/molecules27061780] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/25/2022] [Accepted: 03/04/2022] [Indexed: 01/01/2023] Open
Abstract
A targeted delivery system is primarily intended to carry a potent anticancer drug to specific tumor sites within the bodily tissues. In the present study, a carrier system has been designed using folic acid (FA), bis-amine polyethylene glycol (PEG), and an anticancer drug, 5-fluorouracil (5-FU). FA and PEG were joined via an amide bond, and the resulting FA-PEG-NH2 was coupled to 5-FU producing folate-polyethylene glycol conjugated 5-fluorouracil (FA-PEG-5-FU). Spectroscopic techniques (UV-Vis, 1HNMR, FTIR, and HPLC) were used for the characterization of products. Prodrug (FA-PEG-5-FU) was analyzed for drug release profile (in vitro) up to 10 days and compared to a standard anticancer drug (5-FU). Folate conjugate was also analyzed to study its folate receptors (FR) mediated transport and in vitro cytotoxicity assays using HeLa cancer cells/Vero cells, respectively, and antitumor activity in tumor-bearing mice models. Folate conjugate showed steady drug release patterns and improved uptake in the HeLa cancer cells than Vero cells. Folate conjugate treated mice group showed smaller tumor volumes; specifically after the 15th day post-treatment, tumor sizes were decreased significantly compared to the standard drug group (5-FU). Molecular docking findings demonstrated importance of Trp138, Trp140, and Lys136 in the stabilization of flexible loop flanking the active site. The folic acid conjugated probe has shown the potential of targeted drug delivery and sustained release of anticancer drug to tumor lesions with intact antitumor efficacy.
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3
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Black AR, Black JD. The complexities of PKCα signaling in cancer. Adv Biol Regul 2021; 80:100769. [PMID: 33307285 PMCID: PMC8141086 DOI: 10.1016/j.jbior.2020.100769] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 11/15/2020] [Indexed: 01/06/2023]
Abstract
Protein kinase C α (PKCα) is a ubiquitously expressed member of the PKC family of serine/threonine kinases with diverse functions in normal and neoplastic cells. Early studies identified anti-proliferative and differentiation-inducing functions for PKCα in some normal tissues (e.g., regenerating epithelia) and pro-proliferative effects in others (e.g., cells of the hematopoietic system, smooth muscle cells). Additional well documented roles of PKCα signaling in normal cells include regulation of the cytoskeleton, cell adhesion, and cell migration, and PKCα can function as a survival factor in many contexts. While a majority of tumors lose expression of PKCα, others display aberrant overexpression of the enzyme. Cancer-related mutations in PKCα are uncommon, but rare examples of driver mutations have been detected in certain cancer types (e. g., choroid gliomas). Here we review the role of PKCα in various cancers, describe mechanisms by which PKCα affects cancer-related cell functions, and discuss how the diverse functions of PKCα contribute to tumor suppressive and tumor promoting activities of the enzyme. We end the discussion by addressing mutations and expression of PKCα in tumors and the clinical relevance of these findings.
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Affiliation(s)
- Adrian R Black
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Jennifer D Black
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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4
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Balashova OA, Visina O, Borodinsky LN. Folate action in nervous system development and disease. Dev Neurobiol 2018; 78:391-402. [PMID: 29380544 DOI: 10.1002/dneu.22579] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 01/24/2018] [Accepted: 01/24/2018] [Indexed: 01/04/2023]
Abstract
The vitamin folic acid has been recognized as a crucial environmental factor for nervous system development. From the early fetal stages of the formation of the presumptive spinal cord and brain to the maturation and maintenance of the nervous system during infancy and childhood, folate levels and its supplementation have been considered influential in the clinical outcome of infants and children affected by neurological diseases. Despite the vast epidemiological information recorded on folate function and neural tube defects, neural development and neurodegenerative diseases, the mechanisms of folate action in the developing neural tissue have remained elusive. Here we compiled studies that argue for a unique role for folate in nervous system development and function and its consequences to neural disease and repair. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 78: 391-402, 2018.
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Affiliation(s)
- Olga A Balashova
- Department of Physiology & Membrane Biology and Institute for Pediatric Regenerative Medicine, Shriners Hospital for Children, University of California Davis School of Medicine, Sacramento, California
| | - Olesya Visina
- Department of Physiology & Membrane Biology and Institute for Pediatric Regenerative Medicine, Shriners Hospital for Children, University of California Davis School of Medicine, Sacramento, California
| | - Laura N Borodinsky
- Department of Physiology & Membrane Biology and Institute for Pediatric Regenerative Medicine, Shriners Hospital for Children, University of California Davis School of Medicine, Sacramento, California
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5
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Ginter PS, McIntire PJ, Cui X, Irshaid L, Liu Y, Chen Z, Shin SJ. Folate Receptor Alpha Expression Is Associated With Increased Risk of Recurrence in Triple-negative Breast Cancer. Clin Breast Cancer 2017; 17:544-549. [DOI: 10.1016/j.clbc.2017.03.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 03/14/2017] [Indexed: 12/27/2022]
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6
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Protein phosphorylation and its role in the regulation of Annexin A2 function. Biochim Biophys Acta Gen Subj 2017; 1861:2515-2529. [PMID: 28867585 DOI: 10.1016/j.bbagen.2017.08.024] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 08/17/2017] [Accepted: 08/30/2017] [Indexed: 02/08/2023]
Abstract
BACKGROUND Annexin A2 (AnxA2) is a multifunctional protein involved in endocytosis, exocytosis, membrane domain organisation, actin remodelling, signal transduction, protein assembly, transcription and mRNA transport, as well as DNA replication and repair. SCOPE OF REVIEW The current knowledge of the role of phosphorylation in the functional regulation of AnxA2 is reviewed. To provide a more comprehensive treatment of this topic, we also address in depth the phosphorylation process in general and discuss its possible conformational effects. Furthermore, we discuss the apparent limitations of the methods used to investigate phosphoproteins, as exemplified by the study of AnxA2. MAJOR CONCLUSIONS AnxA2 is subjected to complex regulation by post-translational modifications affecting its cellular functions, with Ser11, Ser25 and Tyr23 representing important phosphorylation sites. Thus, Ser phosphorylation of AnxA2 is involved in the recruitment and docking of secretory granules, the regulation of its association with S100A10, and sequestration of perinuclear, translationally inactive mRNP complexes. By contrast, Tyr phosphorylation of AnxA2 regulates its role in actin dynamics and increases its association with endosomal compartments. Modification of its three main phosphorylation sites is not sufficient to discriminate between its numerous functions. Thus, fine-tuning of AnxA2 function is mediated by the joint action of several post-translational modifications. GENERAL SIGNIFICANCE AnxA2 participates in malignant cell transformation, and its overexpression and/or phosphorylation is associated with cancer progression and metastasis. Thus, tight regulation of AnxA2 function is an integral aspect of cellular homeostasis. The presence of AnxA2 in cancer cell-derived exosomes, as well as the potential regulation of exosomal AnxA2 by phosphorylation or other PTMs, are topics of great interest.
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7
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Hansen MF, Jensen SØ, Füchtbauer EM, Martensen PM. High folic acid diet enhances tumour growth in PyMT-induced breast cancer. Br J Cancer 2017; 116:752-761. [PMID: 28152548 PMCID: PMC5355920 DOI: 10.1038/bjc.2017.11] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 12/20/2016] [Accepted: 01/05/2017] [Indexed: 12/25/2022] Open
Abstract
Background: The B-vitamin folate is among the most studied bioactive food compound, and a dietary intake meeting the daily requirements has been found to reduce the risk of cancer and cardiovascular diseases as well as preventing neural tube defects during fetal development. Several countries have therefore introduced dietary fortification with folic acid. However, clinical and animal studies suggest that folic acid has a dual role in cancer development. Methods: During the period of initial tumour progression, MMTV-PyMT (MMTV-polyoma virus middle T) transgenic mice were fed with normal diet and high folic acid diet. Results: We found that PyMT-induced breast tumours highly express the cancer-specific folate receptor (FR), a feature they share with several human epithelial cancers in which expression of FRα correlates with tumour grade. Mice receiving a high folic acid diet displayed a significantly increased tumour volume compared with mice receiving normal diet. In the largest tumours, only found in mice on high folic acid diet, STAT3 was activated. In primary cells from PyMT tumours, STAT3 was activated upon treatment with folic acid in culture. Conclusions: Our results offer a novel molecular explanation for folic acid-induced growth of existing tumours.
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Affiliation(s)
| | - Sarah Østrup Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C 8000, Denmark
| | | | - Pia M Martensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C 8000, Denmark
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8
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Hou Z, Gattoc L, O'Connor C, Yang S, Wallace-Povirk A, George C, Orr S, Polin L, White K, Kushner J, Morris RT, Gangjee A, Matherly LH. Dual Targeting of Epithelial Ovarian Cancer Via Folate Receptor α and the Proton-Coupled Folate Transporter with 6-Substituted Pyrrolo[2,3- d]pyrimidine Antifolates. Mol Cancer Ther 2017; 16:819-830. [PMID: 28138029 DOI: 10.1158/1535-7163.mct-16-0444] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 01/06/2017] [Accepted: 01/19/2017] [Indexed: 02/04/2023]
Abstract
Folate uptake in epithelial ovarian cancer (EOC) involves the reduced folate carrier (RFC) and the proton-coupled folate transporter (PCFT), both facilitative transporters and folate receptor (FR) α. Although in primary EOC specimens, FRα is widely expressed and increases with tumor stage, PCFT was expressed independent of tumor stage (by real-time RT-PCR and IHC). EOC cell line models, including cisplatin sensitive (IGROV1 and A2780) and resistant (SKOV3 and TOV112D) cells, expressed a 17-fold range of FRα and similar amounts (within ∼2-fold) of PCFT. Novel 6-substituted pyrrolo[2,3-d]pyrimidine thienoyl antifolates AGF94 and AGF154 exhibited potent antiproliferative activities toward all of the EOC cell lines, reflecting selective cellular uptake by FRα and/or PCFT over RFC. When IGROV1 cells were pretreated with AGF94 at pH 6.8, clonogenicity was potently inhibited, confirming cell killing. FRα was knocked down in IGROV1 cells with lentiviral shRNAs. Two FRα knockdown clones (KD-4 and KD-10) showed markedly reduced binding and uptake of [3H]folic acid and [3H]AGF154 by FRα, but maintained high levels of [3H]AGF154 uptake by PCFT compared to nontargeted control cells. In proliferation assays, KD-4 and KD-10 cells preserved in vitro inhibition by AGF94 and AGF154, compared to a nontargeted control, attributable to residual FRα- and substantial PCFT-mediated uptake. KD-10 tumor xenografts in severe-compromised immune-deficient mice were likewise sensitive to AGF94 Collectively, our results demonstrate the substantial therapeutic potential of novel 6-substituted pyrrolo[2,3-d]pyrimidine antifolates with dual targeting of PCFT and FRα toward EOCs that express a range of FRα, along with PCFT, as well as cisplatin resistance. Mol Cancer Ther; 16(5); 819-30. ©2017 AACR.
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Affiliation(s)
- Zhanjun Hou
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan. .,Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan
| | - Leda Gattoc
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan
| | - Carrie O'Connor
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan
| | - Si Yang
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Science, Duquesne University, Pittsburgh, Pennsylvania
| | | | - Christina George
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan
| | - Steve Orr
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan
| | - Lisa Polin
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan.,Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan
| | - Kathryn White
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan
| | - Juiwanna Kushner
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan
| | - Robert T Morris
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan.,Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan
| | - Aleem Gangjee
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Science, Duquesne University, Pittsburgh, Pennsylvania.
| | - Larry H Matherly
- Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan. .,Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan.,Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan
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9
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Aukrust I, Rosenberg LA, Ankerud MM, Bertelsen V, Hollås H, Saraste J, Grindheim AK, Vedeler A. Post-translational modifications of Annexin A2 are linked to its association with perinuclear nonpolysomal mRNP complexes. FEBS Open Bio 2017; 7:160-173. [PMID: 28174683 PMCID: PMC5292671 DOI: 10.1002/2211-5463.12173] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 11/03/2016] [Accepted: 11/23/2016] [Indexed: 01/20/2023] Open
Abstract
Various post‐translational modifications (PTMs) regulate the localisation and function of the multifunctional protein Annexin A2 (AnxA2). In addition to its various tasks as a cytoskeletal‐ and membrane‐associated protein, AnxA2 can function as a trans‐acting protein binding to cis‐acting sequences of specific mRNAs. In the present study, we have examined the role of Ser25 phosphorylation in subcellular localisation of AnxA2 and its interaction with mRNP complexes. Subcellular fractionation and confocal microscopy of rat neuroendocrine PC12 cells showed that Ser25‐phosphorylated AnxA2 (pSer25AnxA2) is absent from the nucleus and mainly localised to the perinuclear region, evidently associating with both membranes and cytoskeletal elements. Perinuclear targeting of AnxA2 was abolished by inhibition of protein kinase C activity, which resulted in cortical enrichment of the protein. Although oligo(dT)‐affinity purification of mRNAs revealed that pSer25AnxA2 associates with nonpolysomal, translationally inactive mRNP complexes, it displayed only partial overlap with a marker of P‐bodies. The phosphorylated protein is present as high‐molecular‐mass forms, indicating that it contains additional covalent PTMs, apparently triggered by its Ser25 phosphorylation. The subcellular distributions of these forms clearly differ from the main form of AnxA2 and are also distinct from that of Tyr23‐phosphorylated AnxA2. Immunoprecipitation verified that these high‐molecular‐mass forms are due to ubiquitination and/or sumoylation. Moreover, these results indicate that Ser25 phosphorylation and ubiquitin/SUMO1 conjugation of AnxA2 promote its association with nonpolysomal mRNAs, providing evidence of a possible mechanism to sequester a subpopulation of mRNAs in a translationally inactive and transport competent form at a distinct subcellular localisation.
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Affiliation(s)
- Ingvild Aukrust
- Department of Biomedicine University of Bergen Norway; Present address: Centre for Medical Genetics and Molecular Medicine Haukeland University Hospital Bergen Norway
| | | | | | - Vibeke Bertelsen
- Department of Biomedicine University of Bergen Norway; Present address: Department of Pathology Oslo University Hospital University of Oslo Oslo Norway
| | - Hanne Hollås
- Department of Biomedicine University of Bergen Norway
| | - Jaakko Saraste
- Department of Biomedicine University of Bergen Norway; Molecular Imaging Centre (MIC) University of Bergen Norway
| | - Ann Kari Grindheim
- Department of Biomedicine University of Bergen Norway; Molecular Imaging Centre (MIC) University of Bergen Norway
| | - Anni Vedeler
- Department of Biomedicine University of Bergen Norway
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10
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Wang L, Wallace A, Raghavan S, Deis SM, Wilson MR, Yang S, Polin L, White K, Kushner J, Orr S, George C, O'Connor C, Hou Z, Mitchell-Ryan S, Dann CE, Matherly LH, Gangjee A. 6-Substituted Pyrrolo[2,3-d]pyrimidine Thienoyl Regioisomers as Targeted Antifolates for Folate Receptor α and the Proton-Coupled Folate Transporter in Human Tumors. J Med Chem 2015; 58:6938-59. [PMID: 26317331 DOI: 10.1021/acs.jmedchem.5b00801] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
2-Amino-4-oxo-6-substituted-pyrrolo[2,3-d]pyrimidine antifolate thiophene regioisomers of AGF94 (4) with a thienoyl side chain and three-carbon bridge lengths [AGF150 (5) and AGF154 (7)] were synthesized as potential antitumor agents. These analogues inhibited proliferation of Chinese hamster ovary (CHO) sublines expressing folate receptors (FRs) α or β (IC50s < 1 nM) or the proton-coupled folate transporter (PCFT) (IC50 < 7 nM). Compounds 5 and 7 inhibited KB, IGROV1, and SKOV3 human tumor cells at subnanomolar concentrations, reflecting both FRα and PCFT uptake. AGF152 (6) and AGF163 (8), 2,4-diamino-5-substituted-furo[2,3-d]pyrimidine thiophene regioisomers, also inhibited growth of FR-expressing CHO and KB cells. All four analogues inhibited glycinamide ribonucleotide formyltransferase (GARFTase). Crystal structures of human GARFTase complexed with 5 and 7 were reported. In severe combined immunodeficient mice bearing SKOV3 tumors, 7 was efficacious. The selectivity of these compounds for PCFT and for FRα and β over the ubiquitously expressed reduced folate carrier is a paradigm for selective tumor targeting.
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Affiliation(s)
- Lei Wang
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences, Duquesne University , 600 Forbes Avenue, Pittsburgh, Pennsylvania 15282, United States
| | - Adrianne Wallace
- Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute , 110 East Warren Avenue, Detroit, Michigan 48201, United States
| | - Sudhir Raghavan
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences, Duquesne University , 600 Forbes Avenue, Pittsburgh, Pennsylvania 15282, United States
| | - Siobhan M Deis
- Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States
| | - Mike R Wilson
- Department of Oncology, Wayne State University School of Medicine , Detroit, Michigan 48201, United States
| | - Si Yang
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences, Duquesne University , 600 Forbes Avenue, Pittsburgh, Pennsylvania 15282, United States
| | - Lisa Polin
- Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute , 110 East Warren Avenue, Detroit, Michigan 48201, United States.,Department of Oncology, Wayne State University School of Medicine , Detroit, Michigan 48201, United States
| | - Kathryn White
- Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute , 110 East Warren Avenue, Detroit, Michigan 48201, United States.,Department of Oncology, Wayne State University School of Medicine , Detroit, Michigan 48201, United States
| | - Juiwanna Kushner
- Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute , 110 East Warren Avenue, Detroit, Michigan 48201, United States.,Department of Oncology, Wayne State University School of Medicine , Detroit, Michigan 48201, United States
| | - Steven Orr
- Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute , 110 East Warren Avenue, Detroit, Michigan 48201, United States
| | - Christina George
- Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute , 110 East Warren Avenue, Detroit, Michigan 48201, United States
| | - Carrie O'Connor
- Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute , 110 East Warren Avenue, Detroit, Michigan 48201, United States
| | - Zhanjun Hou
- Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute , 110 East Warren Avenue, Detroit, Michigan 48201, United States.,Department of Oncology, Wayne State University School of Medicine , Detroit, Michigan 48201, United States
| | - Shermaine Mitchell-Ryan
- Department of Oncology, Wayne State University School of Medicine , Detroit, Michigan 48201, United States
| | - Charles E Dann
- Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States
| | - Larry H Matherly
- Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute , 110 East Warren Avenue, Detroit, Michigan 48201, United States.,Department of Oncology, Wayne State University School of Medicine , Detroit, Michigan 48201, United States.,Department of Pharmacology, Wayne State University School of Medicine , Detroit, Michigan 48201, United States
| | - Aleem Gangjee
- Division of Medicinal Chemistry, Graduate School of Pharmaceutical Sciences, Duquesne University , 600 Forbes Avenue, Pittsburgh, Pennsylvania 15282, United States
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Hoque M, Rentero C, Cairns R, Tebar F, Enrich C, Grewal T. Annexins — Scaffolds modulating PKC localization and signaling. Cell Signal 2014; 26:1213-25. [DOI: 10.1016/j.cellsig.2014.02.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 02/22/2014] [Indexed: 12/15/2022]
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12
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Expression of folate receptor-α (FRA) in gynecologic malignancies and its relationship to the tumor type. Int J Gynecol Pathol 2013; 32:258-68. [PMID: 23518909 DOI: 10.1097/pgp.0b013e3182774562] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
An immunohistochemical evaluation for folate receptor-α (FRA) was undertaken to evaluate expression in gynecologic malignancies involving ovary, endometrium, and the fallopian tube. Commercial tissue microarrays were assessed using an optimized manual immunohistochemical method using MAb 26B3, a newly described monoclonal antibody. A positive result was defined as ≥5% of the sample demonstrating membranous staining. A semiquantitative staining algorithm, defined as the M-score, was used to analyze staining intensity between sample histotypes. MAb 26B3 showed uniform membranous staining and high levels of expression of FRA in ovarian, fallopian tube, and endometrial cancers. All serous ovarian cancers analyzed (70) were positive for FRA expression and no relationship to stage or grade was found. However, a significant difference for FRA expression, between serous and mucinous ovarian carcinomas, was demonstrated (P=0.014). In addition, approximately 90% of all endometrial adenocarcinomas were positive for FRA expression but, unlike ovarian serous carcinomas, a statistically significant relationship to grade was observed (P=0.0029). Although normal ovary is completely devoid of FRA immunoreactivity, normal fallopian tube and cortical serous/tubal inclusion cysts demonstrated uniform and intense FRA staining of columnar epithelium supporting the hypothesis that serous ovarian carcinoma is similar to the tubal epithelium. The data presented further support the hypothesis that FRA expression in gynecologic tumors is due to the cell of origin normally expressing this receptor. This is possibly due to an associated growth advantage, rather than the process of tumorigenesis resulting in aberrant expression of FRA per se.
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13
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O'Shannessy DJ, Somers EB, Maltzman J, Smale R, Fu YS. Folate receptor alpha (FRA) expression in breast cancer: identification of a new molecular subtype and association with triple negative disease. SPRINGERPLUS 2012; 1:22. [PMID: 23961352 PMCID: PMC3725886 DOI: 10.1186/2193-1801-1-22] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 08/29/2012] [Indexed: 12/22/2022]
Abstract
Given that several targeted therapies directed towards folate receptor alpha (FRA) are in late stage clinical development, the sensitive and robust detection of FRA in tissues is of paramount importance relative to patient selection, prognosis and prediction. In the present study we undertook an immunohistochemical evaluation of expression of FRA in breast cancer samples using formalin-fixed, paraffin-embedded (FFPE) tissues, primarily invasive ductal carcinomas, using a newly described monoclonal antibody, 26B3. Samples assessed included both tissue microarrays (TMA) and whole tissue sections from archival tissue blocks. Normal breast shows a highly restricted expression of FRA to luminal membrane staining of secretory ductal cells, consistent with FRA secretion into milk. In early stage (stages I-III) invasive ductal carcinomas, FRA staining was observed in approximately 30% of all samples, independent of molecular subtype (estrogen receptor (ER)/progesterone receptor (PR)/human epidermal growth factor receptor type 2 (Her2)). However, FRA expression was shown to associate with ER/PR negative tumors relative to ER/PR positive tumors (p = 0.012) and perhaps more importantly, with triple negative breast cancers (TNBC; p < 0.0001). FRA immunoreactivity was also shown to be retained in stage IV metastatic breast cancer samples from diverse anatomic sites including lymph node and bone. In metastatic breast cancer, FRA was shown to be expressed in 86% of TNBC patients. Taken together, these data suggest that FRA expressing breast cancer represents a novel molecular subtype and, further, may represent a new therapeutic target for this devastating disease.
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Affiliation(s)
- Daniel J O'Shannessy
- Department of Diagnostics Development, Morphotek, Inc, 210 Welsh Pool Road, Exton, PA 19341 USA
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14
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Knight SF, Kundu K, Joseph G, Dikalov S, Weiss D, Murthy N, Taylor WR. Folate receptor-targeted antioxidant therapy ameliorates renal ischemia-reperfusion injury. J Am Soc Nephrol 2012; 23:793-800. [PMID: 22282594 DOI: 10.1681/asn.2011070711] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Antioxidant therapy can protect against ischemic injury, but the inability to selectively target the kidney would require extremely high doses to achieve effective local concentrations of drug. Here, we developed a directed therapeutic that specifically targets an antioxidant to renal proximal tubule cells via the folate receptor. Because a local increase in superoxide contributes to renal ischemic injury, we created the folate-antioxidant conjugate 4-hydroxy-Tempo (tempol)-folate to target folate receptors, which are highly expressed in the proximal tubule. Dihydroethidium high-performance liquid chromatography demonstrated that conjugated tempol retained its efficacy to scavenge superoxide in proximal tubule cells. In a mouse model of renal ischemia-reperfusion injury, tempol-folate reduced renal superoxide levels more effectively than tempol alone. Furthermore, electron spin resonance revealed the successful targeting of the tempol-folate conjugate to the kidney and other tissues expressing folate receptors. Administration of tempol-folate protected the renal function of mice after ischemia-reperfusion injury and inhibited infiltration of macrophages. In conclusion, kidney-specific targeting of an antioxidant has therapeutic potential to prevent renal ischemic injury. Conjugation of other pharmaceuticals to folate may also facilitate the development of treatments for other kidney diseases.
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Affiliation(s)
- Sarah F Knight
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
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Zhou F, Lee AC, Krafczyk K, Zhu L, Murray M. Protein kinase C regulates the internalization and function of the human organic anion transporting polypeptide 1A2. Br J Pharmacol 2011; 162:1380-8. [PMID: 21133891 DOI: 10.1111/j.1476-5381.2010.01144.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND AND PURPOSE The human organic anion transporting polypeptide 1A2 (OATP1A2) is expressed in cells from several regions of the human body, including the kidney, cholangiocytes and the blood-brain barrier, and mediates the cellular flux of various anionic substances, including drugs in clinical use. Several related mammalian transporters have been shown to be subject to post-translational regulation, including kinase-induced internalization. In the present study the role of protein kinase C (PKC) in the regulation of OATP1A2 was investigated in an in vitro cell model. EXPERIMENTAL APPROACH COS-7 cells in which OATP1A2 was overexpressed were treated with the PKC-specific activator (phorbol 12-myristate 13-acetate; PMA) and the PKC-specific inhibitor (Go6976). The impact of these treatments on the function and regulation of OATP1A2 was determined. KEY RESULTS PKC activation decreased the transport function of OATP1A2 in a time- and concentration-dependent manner. PMA (0.1 µM) decreased the V(max) of oestrone-3-sulphate uptake and decreased the cell surface expression of OATP1A2 immunoreactive protein; these effects of PMA were prevented by the PKC specific inhibitor Go6976. In further studies, PMA treatment accelerated the internalization of OATP1A2 but did not affect its recycling. The disruption of clathrine-dependent endocytosis attenuated both the constitutive and PKC-modulated internalization of OATP1A2. In contrast, blocking the caveolin-dependent pathway was without effect. CONCLUSIONS AND IMPLICATIONS PKC regulates the transport function of OATP1A2 by modulating protein internalization; this effect of PKC is mediated in part by clathrine-dependent pathways.
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Affiliation(s)
- Fanfan Zhou
- Pharmacogenomics and Drug Development Laboratory, Faculty of Pharmacy, The University of Sydney, Australia.
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