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Lagzian A, Askari M, Haeri MS, Sheikhi N, Banihashemi S, Nabi-Afjadi M, Malekzadegan Y. Increased V-ATPase activity can lead to chemo-resistance in oral squamous cell carcinoma via autophagy induction: new insights. Med Oncol 2024; 41:108. [PMID: 38592406 DOI: 10.1007/s12032-024-02313-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 01/23/2024] [Indexed: 04/10/2024]
Abstract
Oral squamous cell carcinoma (OSCC) is a cancer type with a high rate of recurrence and a poor prognosis. Tumor chemo-resistance remains an issue for OSCC patients despite the availability of multimodal therapy options, which causes an increase in tumor invasiveness. Vacuolar ATPase (V-ATPase), appears to be one of the most significant molecules implicated in MDR in tumors like OSCC. It is primarily responsible for controlling the acidity in the solid tumors' microenvironment, which interferes with the absorption of chemotherapeutic medications. However, the exact cellular and molecular mechanisms V-ATPase plays in OSCC chemo-resistance have not been understood. Uncovering these mechanisms can contribute to combating OSCC chemo-resistance and poor prognosis. Hence, in this review, we suggest that one of these underlying mechanisms is autophagy induced by V-ATPase which can potentially contribute to OSCC chemo-resistance. Finally, specialized autophagy and V-ATPase inhibitors may be beneficial as an approach to reduce drug resistance to anticancer therapies in addition to serving as coadjuvants in antitumor treatments. Also, V-ATPase could be a prognostic factor for OSCC patients. However, in the future, more investigations are required to demonstrate these suggestions and hypotheses.
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Affiliation(s)
- Ahmadreza Lagzian
- Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran
| | - Marziye Askari
- Department of Immunology, School of Medicine, Hamedan University of Medical Sciences, Hamedan, Iran
| | - Melika Sadat Haeri
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Nastaran Sheikhi
- Biotechnology Department, Biological Sciences Faculty, Alzahra University, Tehran, Iran
| | - Sara Banihashemi
- Department of Bioscience, School of Science and Technology, Nottingham Trend University, Nottingham, UK
| | - Mohsen Nabi-Afjadi
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Yalda Malekzadegan
- Department of Microbiology, Saveh University of Medical Sciences, Saveh, Iran.
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2
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Berg AL, Rowson-Hodel A, Wheeler MR, Hu M, Free SR, Carraway KL. Engaging the Lysosome and Lysosome-Dependent Cell Death in Cancer. Breast Cancer 2022. [DOI: 10.36255/exon-publications-breast-cancer-lysosome] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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3
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Iessi E, Vona R, Cittadini C, Matarrese P. Targeting the Interplay between Cancer Metabolic Reprogramming and Cell Death Pathways as a Viable Therapeutic Path. Biomedicines 2021; 9:biomedicines9121942. [PMID: 34944758 PMCID: PMC8698563 DOI: 10.3390/biomedicines9121942] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 12/12/2022] Open
Abstract
In cancer cells, metabolic adaptations are often observed in terms of nutrient absorption, biosynthesis of macromolecules, and production of energy necessary to meet the needs of the tumor cell such as uncontrolled proliferation, dissemination, and acquisition of resistance to death processes induced by both unfavorable environmental conditions and therapeutic drugs. Many oncogenes and tumor suppressor genes have a significant effect on cellular metabolism, as there is a close relationship between the pathways activated by these genes and the various metabolic options. The metabolic adaptations observed in cancer cells not only promote their proliferation and invasion, but also their survival by inducing intrinsic and acquired resistance to various anticancer agents and to various forms of cell death, such as apoptosis, necroptosis, autophagy, and ferroptosis. In this review we analyze the main metabolic differences between cancer and non-cancer cells and how these can affect the various cell death pathways, effectively determining the susceptibility of cancer cells to therapy-induced death. Targeting the metabolic peculiarities of cancer could represent in the near future an innovative therapeutic strategy for the treatment of those tumors whose metabolic characteristics are known.
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4
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Studying Proton Gradients Across the Nuclear Envelope. Methods Mol Biol 2021; 2175:47-63. [PMID: 32681483 DOI: 10.1007/978-1-0716-0763-3_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The existence of nuclear pore complexes in the nuclear envelope has led to the assumption that ions move freely from the cytosol into the nucleus, and that the molecular mechanisms at the plasma membrane that regulate cytosolic pH also regulate nuclear pH. Furthermore, studies to measure pH in the nucleus have produced contradictory results, since it has been found that the nuclear pH is either similar to the cytosol or more alkaline than the cytosol. However, most studies of nuclear pH have lacked the rigor needed to understand pH regulation in the nucleus. A major problem has been the lack of in situ titrations in the nucleus and cytosol, since the intracellular environment is different in the cytosol and nucleus and the behavior of fluorescent pH probes is different in these environments. Here we present a method that uses the fluorescence of SNARF-1 that labels both cytosol and nucleus. Using ratio imaging microscopy, regions of interest corresponding to the nucleus and cytosol to perform steady-state pH measurements followed by in situ titrations, to correctly assign pH in those cellular domains.
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Verma S, Ravichandiran V, Ranjan N, Flora SJS. Recent Advances in Therapeutic Applications of Bisbenzimidazoles. Med Chem 2021; 16:454-486. [PMID: 31038072 DOI: 10.2174/1573406415666190416120801] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 03/19/2019] [Accepted: 04/08/2019] [Indexed: 12/16/2022]
Abstract
Nitrogen-containing heterocycles are one of the most common structural motifs in approximately 80% of the marketed drugs. Of these, benzimidazoles analogues are known to elicit a wide spectrum of pharmaceutical activities such as anticancer, antibacterial, antiparasitic, antiviral, antifungal as well as chemosensor effect. Based on the benzimidazole core fused heterocyclic compounds, crescent-shaped bisbenzimidazoles were developed which provided an early breakthrough in the sequence-specific DNA recognition. Over the years, a number of functional variations in the bisbenzimidazole core have led to the emergence of their unique properties and established them as versatile ligands against several classes of pathogens. The present review provides an overview of diverse pharmacological activities of the bisbenzimidazole analogues in the past decade with a brief account of its development through the years.
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Affiliation(s)
- Smita Verma
- National Institute of Pharmaceutical Education and Research, ITI Compound, Raebareli, 229010, India.,National Institute of Pharmaceutical Education and Research, Kolkata, Maniktala Main Road, Kolkata, 700054, India
| | - Vishnuvardh Ravichandiran
- National Institute of Pharmaceutical Education and Research, Kolkata, Maniktala Main Road, Kolkata, 700054, India
| | - Nihar Ranjan
- National Institute of Pharmaceutical Education and Research, ITI Compound, Raebareli, 229010, India
| | - Swaran J S Flora
- National Institute of Pharmaceutical Education and Research, ITI Compound, Raebareli, 229010, India
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6
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Pamarthy S, Kulshrestha A, Katara GK, Beaman KD. The curious case of vacuolar ATPase: regulation of signaling pathways. Mol Cancer 2018; 17:41. [PMID: 29448933 PMCID: PMC5815226 DOI: 10.1186/s12943-018-0811-3] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 02/07/2018] [Indexed: 02/06/2023] Open
Abstract
The Vacuolar ATPase (V-ATPase) is a proton pump responsible for controlling the intracellular and extracellular pH of cells. The structure of V-ATPase has been highly conserved among all eukaryotic cells and is involved in diverse functions across species. V-ATPase is best known for its acidification of endosomes and lysosomes and is also important for luminal acidification of specialized cells. Several reports have suggested the involvement of V-ATPase in maintaining an alkaline intracellular and acidic extracellular pH thereby aiding in proliferation and metastasis of cancer cells respectively. Increased expression of V-ATPase and relocation to the plasma membrane aids in cancer modulates key tumorigenic cell processes like autophagy, Warburg effect, immunomoduation, drug resistance and most importantly cancer cell signaling. In this review, we discuss the direct role of V-ATPase in acidification and indirect regulation of signaling pathways, particularly Notch Signaling.
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Affiliation(s)
- Sahithi Pamarthy
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL, 60064, USA
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, 60611, USA
| | - Arpita Kulshrestha
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL, 60064, USA
| | - Gajendra K Katara
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL, 60064, USA
| | - Kenneth D Beaman
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL, 60064, USA.
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Stock C, Pedersen SF. Roles of pH and the Na +/H + exchanger NHE1 in cancer: From cell biology and animal models to an emerging translational perspective? Semin Cancer Biol 2016; 43:5-16. [PMID: 28007556 DOI: 10.1016/j.semcancer.2016.12.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 12/10/2016] [Indexed: 01/30/2023]
Abstract
Acidosis is characteristic of the solid tumor microenvironment. Tumor cells, because they are highly proliferative and anabolic, have greatly elevated metabolic acid production. To sustain a normal cytosolic pH homeostasis they therefore need to either extrude excess protons or to neutralize them by importing HCO3-, in both cases causing extracellular acidification in the poorly perfused tissue microenvironment. The Na+/H+ exchanger isoform 1 (NHE1) is a ubiquitously expressed acid-extruding membrane transport protein, and upregulation of its expression and/or activity is commonly correlated with tumor malignancy. The present review discusses current evidence on how altered pH homeostasis, and in particular NHE1, contributes to tumor cell motility, invasion, proliferation, and growth and facilitates evasion of chemotherapeutic cell death. We summarize data from in vitro studies, 2D-, 3D- and organotypic cell culture, animal models and human tissue, which collectively point to pH-regulation in general, and NHE1 in particular, as potential targets in combination chemotherapy. Finally, we discuss the possible pitfalls, side effects and cellular escape mechanisms that need to be considered in the process of translating the plethora of basic research data into a clinical setting.
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Affiliation(s)
- Christian Stock
- Department of Gastroenterology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
| | - Stine Falsig Pedersen
- Department of Biology, Section for Cell Biology and Physiology, University of Copenhagen, Universitetsparken 13, 2100 Copenhagen, Denmark.
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8
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Pamarthy S, Jaiswal MK, Kulshreshtha A, Katara GK, Gilman-Sachs A, Beaman KD. The Vacuolar ATPase a2-subunit regulates Notch signaling in triple-negative breast cancer cells. Oncotarget 2016; 6:34206-20. [PMID: 26418877 PMCID: PMC4741446 DOI: 10.18632/oncotarget.5275] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 09/07/2015] [Indexed: 12/24/2022] Open
Abstract
Triple Negative Breast Cancer (TNBC) is a subtype of breast cancer with poor prognosis for which no targeted therapies are currently available. Notch signaling has been implicated in breast cancer but the factors that control Notch in TNBC are unknown. Because the Vacuolar ATPase has been shown to be important in breast cancer invasiveness, we investigated the role of a2-subunit isoform of Vacuolar ATPase (a2V) in regulating Notch signaling in TNBC. Confocal microscopy revealed that among all the ‘a’ subunit isoforms, a2V was uniquely expressed on the plasma membrane of breast cancer cells. Both a2V and NOTCH1 were elevated in TNBC tumors tissues and cell lines. a2V knockdown by siRNA as well as V-ATPase inhibition by Bafilomycin A1 (Baf A1) in TNBC cell lines enhanced Notch signaling by increasing the expression of Notch1 intracellular Domain (N1ICD). V-ATPase inhibition blocked NICD degradation by disrupting autophagy and lysosomal acidification as demonstrated by accumulation of LC3B and diminished expression of LAMP1 respectively. Importantly, treatment with Baf A1 or anti-a2V, a novel-neutralizing antibody against a2V hindered cell migration of TNBC cells. Our findings indicate that a2V regulates Notch signaling through its role in endolysosomal acidification and emerges as a potential target for TNBC.
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Affiliation(s)
- Sahithi Pamarthy
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Mukesh K Jaiswal
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Arpita Kulshreshtha
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Gajendra K Katara
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Alice Gilman-Sachs
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Kenneth D Beaman
- Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
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9
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Mazhab-Jafari MT, Rubinstein JL. Cryo-EM studies of the structure and dynamics of vacuolar-type ATPases. SCIENCE ADVANCES 2016; 2:e1600725. [PMID: 27532044 PMCID: PMC4985227 DOI: 10.1126/sciadv.1600725] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 06/15/2016] [Indexed: 06/06/2023]
Abstract
Electron cryomicroscopy (cryo-EM) has significantly advanced our understanding of molecular structure in biology. Recent innovations in both hardware and software have made cryo-EM a viable alternative for targets that are not amenable to x-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. Cryo-EM has even become the method of choice in some situations where x-ray crystallography and NMR spectroscopy are possible but where cryo-EM can determine structures at higher resolution or with less time or effort. Rotary adenosine triphosphatases (ATPases) are crucial to the maintenance of cellular homeostasis. These enzymes couple the synthesis or hydrolysis of adenosine triphosphate to the use or production of a transmembrane electrochemical ion gradient, respectively. However, the membrane-embedded nature and conformational heterogeneity of intact rotary ATPases have prevented their high-resolution structural analysis to date. Recent application of cryo-EM methods to the different types of rotary ATPase has led to sudden advances in understanding the structure and function of these enzymes, revealing significant conformational heterogeneity and characteristic transmembrane α helices that are highly tilted with respect to the membrane. In this Review, we will discuss what has been learned recently about rotary ATPase structure and function, with a particular focus on the vacuolar-type ATPases.
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Affiliation(s)
- Mohammad T. Mazhab-Jafari
- Molecular Structure and Function Program, The Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, Ontario M5G 0A4, Canada
| | - John L. Rubinstein
- Molecular Structure and Function Program, The Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, Ontario M5G 0A4, Canada
- Department of Biochemistry, The University of Toronto, 1 King’s College Circle, Toronto, Ontario M5S 1A8, Canada
- Department of Medical Biophysics, The University of Toronto, 101 College Street, Toronto, Ontario M5G 1L7, Canada
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10
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Smith GA, Howell GJ, Phillips C, Muench SP, Ponnambalam S, Harrison MA. Extracellular and Luminal pH Regulation by Vacuolar H+-ATPase Isoform Expression and Targeting to the Plasma Membrane and Endosomes. J Biol Chem 2016; 291:8500-15. [PMID: 26912656 PMCID: PMC4861423 DOI: 10.1074/jbc.m116.723395] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Indexed: 01/02/2023] Open
Abstract
Plasma membrane vacuolar H+-ATPase (V-ATPase) activity of tumor cells is a major factor in control of cytoplasmic and extracellular pH and metastatic potential, but the isoforms involved and the factors governing plasma membrane recruitment remain uncertain. Here, we examined expression, distribution, and activity of V-ATPase isoforms in invasive prostate adenocarcinoma (PC-3) cells. Isoforms 1 and 3 were the most highly expressed forms of membrane subunit a, with a1 and a3 the dominant plasma membrane isoforms. Correlation between plasma membrane V-ATPase activity and invasiveness was limited, but RNAi knockdown of either a isoform did slow cell proliferation and inhibit invasion in vitro. Isoform a1 was recruited to the cell surface from the early endosome-recycling complex pathway, its knockdown arresting transferrin receptor recycling. Isoform a3 was associated with the late endosomal/lysosomal compartment. Both a isoforms associated with accessory protein Ac45, knockdown of which stalled transit of a1 and transferrin-transferrin receptor, decreased proton efflux, and reduced cell growth and invasiveness; this latter effect was at least partly due to decreased delivery of the membrane-bound matrix metalloproteinase MMP-14 to the plasma membrane. These data indicate that in prostatic carcinoma cells, a1 and a3 isoform populations predominate in different compartments where they maintain different luminal pH. Ac45 plays a central role in navigating the V-ATPase to the plasma membrane, and hence it is an important factor in expression of the invasive phenotype.
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Affiliation(s)
- Gina A Smith
- From the Endothelial Cell Biology Unit, School of Molecular and Cellular Biology and
| | - Gareth J Howell
- From the Endothelial Cell Biology Unit, School of Molecular and Cellular Biology and
| | - Clair Phillips
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Stephen P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | | | - Michael A Harrison
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
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11
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Fais S, Venturi G, Gatenby B. Microenvironmental acidosis in carcinogenesis and metastases: new strategies in prevention and therapy. Cancer Metastasis Rev 2015; 33:1095-108. [PMID: 25376898 PMCID: PMC4244550 DOI: 10.1007/s10555-014-9531-3] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Much effort is currently devoted to developing patient-specific cancer therapy based on molecular characterization of tumors. In particular, this approach seeks to identify driver mutations that can be blocked through small molecular inhibitors. However, this approach is limited by extensive intratumoral genetic heterogeneity, and, not surprisingly, even dramatic initial responses are typically of limited duration as resistant tumor clones rapidly emerge and proliferate. We propose an alternative approach based on observations that while tumor evolution produces genetic divergence, it is also associated with striking phenotypic convergence that loosely correspond to the well-known cancer “hallmarks”. These convergent properties can be described as driver phenotypes and may be more consistently and robustly expressed than genetic targets. To this purpose, it is necessary to identify strategies that are critical for cancer progression and metastases, and it is likely that these driver phenotypes will be closely related to cancer “hallmarks”. It appears that an antiacidic approach, by targetting a driver phenotype in tumors, may be thought as a future strategy against tumors in either preventing the occurrence of cancer or treating tumor patients with multiple aims, including the improvement of efficacy of existing therapies, possibly reducing their systemic side effects, and controlling tumor growth, progression, and metastasis. This may be achieved with existing molecules such as proton pump inhibitors (PPIs) and buffers such as sodium bicarbonate, citrate, or TRIS.
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Affiliation(s)
- Stefano Fais
- Department of Therapeutic Research and Medicines Evaluation, Unit of Antitumor Drugs, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome, Italy
- Department of Drug Research and Medicines Evaluation, Istituto Superiore di Sanità (National Institute of Health), Viale Regina Elena 299, 00161 Rome, Italy
| | - Giulietta Venturi
- Department of Therapeutic Research and Medicines Evaluation, Unit of Antitumor Drugs, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome, Italy
| | - Bob Gatenby
- Radiology Department, Cancer Biology and Evolution Program Moffitt Cancer Center, 12902 Magnolia Drive, Tampa, FL 33612 USA
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12
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Sun-Wada GH, Wada Y. Role of vacuolar-type proton ATPase in signal transduction. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1166-72. [PMID: 26072192 DOI: 10.1016/j.bbabio.2015.06.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 06/01/2015] [Accepted: 06/03/2015] [Indexed: 12/21/2022]
Abstract
The vacuolar H(+)-ATPase (V-ATPase) was first identified as an electrogenic proton pump that acidifies the lumen of intra- and extracellular compartments. The acidic pH generated by V-ATPase is important for a wide range of cellular processes as well as acidification-independent processes such as secretion and membrane fusion. In addition to these housekeeping functions, recent studies implicate V-ATPase in the direct regulation and function of signaling pathways. In this review, we describe recent findings on the functions of V-ATPase in growth regulation and tissue physiology.
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Affiliation(s)
- Ge-Hong Sun-Wada
- Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts, Kohdo, Kyotanabe, Kyoto 610-0395, Japan.
| | - Yoh Wada
- Division of Biological Science, Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
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Grillon E, Farion R, Reuveni M, Glidle A, Rémy C, Coles JA. Spatial profiles of markers of glycolysis, mitochondria, and proton pumps in a rat glioma suggest coordinated programming for proliferation. BMC Res Notes 2015; 8:207. [PMID: 26032618 PMCID: PMC4467611 DOI: 10.1186/s13104-015-1191-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 05/20/2015] [Indexed: 02/07/2023] Open
Abstract
Background In cancer cells in vitro, the glycolytic pathway and the mitochondrial tricarboxylic acid (TCA) cycle are programmed to produce more precursor molecules, and relatively less ATP, than in differentiated cells. We address the questions of whether and where these changes occur in vivo in glioblastomas grown from C6 cells in rat brain. These gliomas show some spatial organization, notably in the upregulation of membrane proton transporters near the rim. Results We immunolabeled pairs of proteins (as well as DNA) on sections of rat brains containing gliomas, measured the profiles of fluorescence intensity on strips 200 µm wide and at least 3 mm long running perpendicular to the tumor rim, and expressed the intensity in the glioma relative to that outside. On averaged profiles, labeling of a marker of the glycolytic pathway, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), was, as expected, greater in the glioma. Over distances up to 2.5 mm into the glioma, expression of a marker of the TCA cycle, Tom20, a pre-protein receptor on the translocation complex of the mitochondrial outer membrane, was also upregulated. The ratio of upregulation of Tom20 to upregulation of GAPDH was, on average, slightly greater than one. Near the rim (0.4–0.8 mm), GAPDH was expressed less and there was a peak in the mean ratio of 1.16, SEM = 0.001, N = 16 pairs of profiles. An antibody to V-ATPase, which, by pumping protons into vacuoles contributes to cell growth, also indicated upregulation by about 40%. When compared directly with GAPDH, upregulation of V-ATPase was only 0.764, SD = 0.016 of GAPDH upregulation. Conclusions Although there was considerable variation between individual measured profiles, on average, markers of the glycolytic pathway, of mitochondria, and of cell proliferation showed coherent upregulation in C6 gliomas. There is a zone, close to the rim, where mitochondrial presence is upregulated more than the glycolytic pathway, in agreement with earlier suggestions that lactate is taken up by cells near the rim. Electronic supplementary material The online version of this article (doi:10.1186/s13104-015-1191-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Emmanuelle Grillon
- Université Grenoble Alpes, IRMaGe, 3800, Grenoble, France. .,Inserm, US 17, 3800, Grenoble, France. .,CNRS, UMS 3552, 3800, Grenoble, France. .,CHU de Grenoble, Hopital Michallon, IRMaGe, 3800, Grenoble, France.
| | - Régine Farion
- Université Grenoble Alpes, IRMaGe, 3800, Grenoble, France. .,Inserm, US 17, 3800, Grenoble, France. .,CNRS, UMS 3552, 3800, Grenoble, France. .,CHU de Grenoble, Hopital Michallon, IRMaGe, 3800, Grenoble, France.
| | - Moshe Reuveni
- Institute of Plant Sciences, The Volcan Center, Bet Dagan, Israel.
| | - Andrew Glidle
- Department of Engineering, University of Glasgow, Glasgow, UK.
| | - Chantal Rémy
- Université Grenoble Alpes, IRMaGe, 3800, Grenoble, France. .,Inserm, U 836, 3800, Grenoble, France.
| | - Jonathan A Coles
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow, G12 8TA, UK.
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Graham RM, Thompson JW, Webster KA. Inhibition of the vacuolar ATPase induces Bnip3-dependent death of cancer cells and a reduction in tumor burden and metastasis. Oncotarget 2015; 5:1162-73. [PMID: 24811485 PMCID: PMC4012732 DOI: 10.18632/oncotarget.1699] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The pro-apoptotic protein Bnip3 is induced by hypoxia and is present in the core regions of most solid tumors. Bnip3 induces programmed necrosis by an intrinsic caspase independent mitochondrial pathway. Many tumor cells have evolved pathways to evade Bnip3-mediated death attesting to the physiological relevance of the survival threat imposed by Bnip3. We have reported that acidosis can trigger the Bnip3 death pathway in hypoxic cells therefore we hypothesized that manipulation of intracellular pH by pharmacological inhibition of the vacuolar (v)ATPase proton pump, a significant pH control pathway, may activate Bnip3 and promote death of hypoxic cells within the tumor. Here we confirm that bafilomycin A1 (BafA1), a selective vATPase inhibitor, significantly increased death of breast cancer cells in a hypoxia and Bnip3-dependent manner and significantly reduced tumor growth in MCF7 and MDA-MB-231 mouse xenografts. Combined treatment of cells with BafA1 and the ERK1/2 inhibitor U0126 further augmented cell death. Combined treatment of mice containing MDA-MB-231 xenografts with BafA1 and the ERK1/2 inhibitor sorafenib was superior to either treatment alone and supported tumor regression. BafA1 and sorafenib treatments alone reduced MDA-MB-231 cell metastasis and again the combination was significantly more effective than either treatment alone and was without apparent side effects. These results present a novel mechanism to destroy hypoxic tumor cells that may help reverse the resistance of hypoxic tumors to radiation and chemotherapy and perhaps target tumor stem cells.
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15
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Polarization of the vacuolar adenosine triphosphatase delineates a transition to high-grade pancreatic intraepithelial neoplasm lesions. Pancreas 2014; 43:1256-63. [PMID: 25072283 PMCID: PMC4519037 DOI: 10.1097/mpa.0000000000000201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
OBJECTIVES A functional vacuolar adenosine triphosphatase (v-ATPase) complex regulates canonical Wnt/β-catenin signaling. The goal of this study was to identify the distribution of the v-ATPase in human and murine models of pancreatic intraepithelial neoplasms (PanINs) and assess its role in Wnt/β-catenin signaling. METHODS We evaluated the immunolabeling pattern of the v-ATPase in human PanIN specimens and murine PanIN-1 and PanIN-2 lesions obtained from Ptf1a(Cre/+); LSL-Kras(G12D) mice. Wnt/β-catenin signaling was interrogated in primary PanIN cells by examining the phosphorylated levels of its surface coreceptor, low-density lipoprotein receptor-related protein-6 (LRP6), and its intracellular effector, nonphosphorylated β-catenin. The response of primary PanIN cells to epidermal growth factor (EGF) was assessed in the absence and presence of the v-ATPase inhibitor, concanamycin. RESULTS In advanced (PanIN-2), but not early (PanIN-1), lesions, the v-ATPase assumed a polarized phenotype. Blocking the v-ATPase disrupted Wnt/β-catenin signaling in primary PanIN cells despite significantly higher levels of the total and activated Wnt cell surface coreceptor, LRP6. Vacuolar adenosine triphosphatase blockade significantly decreased the total and activated levels of EGF receptor, a determinant of PanIN progression. The activation of EGF receptor and its intracellular mediator, p44/42 mitogen-activated protein kinase, was also reduced by v-ATPase blockade. This led to diminished proliferation in response to EGF ligand. CONCLUSIONS The v-ATPase regulates Wnt/β-catenin and EGF receptor signaling in PanINs.
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16
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Muench SP, Rawson S, Eyraud V, Delmas AF, Da Silva P, Phillips C, Trinick J, Harrison MA, Gressent F, Huss M. PA1b inhibitor binding to subunits c and e of the vacuolar ATPase reveals its insecticidal mechanism. J Biol Chem 2014; 289:16399-408. [PMID: 24795045 PMCID: PMC4047407 DOI: 10.1074/jbc.m113.541250] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 04/14/2014] [Indexed: 12/03/2022] Open
Abstract
The vacuolar ATPase (V-ATPase) is a 1MDa transmembrane proton pump that operates via a rotary mechanism fuelled by ATP. Essential for eukaryotic cell homeostasis, it plays central roles in bone remodeling and tumor invasiveness, making it a key therapeutic target. Its importance in arthropod physiology also makes it a promising pesticide target. The major challenge in designing lead compounds against the V-ATPase is its ubiquitous nature, such that any therapeutic must be capable of targeting particular isoforms. Here, we have characterized the binding site on the V-ATPase of pea albumin 1b (PA1b), a small cystine knot protein that shows exquisitely selective inhibition of insect V-ATPases. Electron microscopy shows that PA1b binding occurs across a range of equivalent sites on the c ring of the membrane domain. In the presence of Mg·ATP, PA1b localizes to a single site, distant from subunit a, which is predicted to be the interface for other inhibitors. Photoaffinity labeling studies show radiolabeling of subunits c and e. In addition, weevil resistance to PA1b is correlated with bafilomycin resistance, caused by mutation of subunit c. The data indicate a binding site to which both subunits c and e contribute and inhibition that involves locking the c ring rotor to a static subunit e and not subunit a. This has implications for understanding the V-ATPase mechanism and that of inhibitors with therapeutic or pesticidal potential. It also provides the first evidence for the position of subunit e within the complex.
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Affiliation(s)
- Stephen P Muench
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom,
| | - Shaun Rawson
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom
| | - Vanessa Eyraud
- Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées-Lyon, Université de Lyon, IFR 41, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, Batiment Louis-Pasteur 20, avenue Albert Einstein, F-69621 Villeurbanne, France
| | - Agnès F Delmas
- the Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique Unité Propre de Recherche 4301, Rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Pedro Da Silva
- Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées-Lyon, Université de Lyon, IFR 41, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, Batiment Louis-Pasteur 20, avenue Albert Einstein, F-69621 Villeurbanne, France
| | - Clair Phillips
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom
| | - John Trinick
- the School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom, and
| | - Michael A Harrison
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom
| | - Frédéric Gressent
- Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées-Lyon, Université de Lyon, IFR 41, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, Batiment Louis-Pasteur 20, avenue Albert Einstein, F-69621 Villeurbanne, France
| | - Markus Huss
- Abteilung Tierphysiologie, Fachbereich Biologie/Chemie Universität Osnabrück, 49069 Osnabrück, Germany
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17
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Acidic pH via NF-κB favours VEGF-C expression in human melanoma cells. Clin Exp Metastasis 2013; 30:957-67. [PMID: 23784694 DOI: 10.1007/s10585-013-9595-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 06/03/2013] [Indexed: 12/19/2022]
Abstract
Malignant melanomas are characterized by the ability of early metastatic dissemination to regional lymph nodes and the detection of sentinel lymph node metastases serves as an important prognostic parameter. There is clear evidence that melanoma cells and stromal cells of tumor environment can induce lymphangiogenesis, e.g. growth of lymphatic vessels, and this phenomenon is correlated with lymph node metastases. Vascular endothelial growth factor (VEGF) C represents the most potent and well-recognized lymphangiogenic growth factor secreted in tumor milieu by melanoma cells and tumor-associated macrophages, however the mechanism underlying VEGF-C secretion is not completely understood. We demonstrate that an acidic extracellular pH promotes the expression of VEGF-C in A375P melanoma cells and in melanoma cells isolated from a human spontaneous metastatic lesion, through the NF-κB transcription factor. We also demonstrate that esomeprazole, a proton pump inhibitor which requires acidosis to be activated, is able to prevent VEGF-C expression in acidic melanoma cells by interfering with NF-κB activation. Furthermore, we show that esomeprazole abrogates the enhanced VEGF-C expression in tumor cells grown in a acidic medium and stimulated by IL-1β. On the whole, the present study reveals that acidity may be considered a strong promoter of VEGF-C expression in melanoma cells and provides a new pharmacological target to limit the development of tumor lymphangiogenesis.
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18
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Rahman S, Yamato I, Saijo S, Mizutani K, Ishizuka-Katsura Y, Ohsawa N, Terada T, Shirouzu M, Yokoyama S, Iwata S, Murata T. Biochemical and biophysical properties of interactions between subunits of the peripheral stalk region of human V-ATPase. PLoS One 2013; 8:e55704. [PMID: 23409023 PMCID: PMC3569449 DOI: 10.1371/journal.pone.0055704] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 12/28/2012] [Indexed: 11/18/2022] Open
Abstract
Peripheral stalk subunits of eukaryotic or mammalian vacuolar ATPases (V-ATPases) play key roles in regulating its assembly and disassembly. In a previous study, we purified several subunits and their isoforms of the peripheral stalk region of Homo sapiens (human) V-ATPase; such as C1, E1G1, H, and the N-terminal cytoplasmic region of V(o), a1. Here, we investigated the in vitro binding interactions of the subunits at the stalk region and measured their specific affinities. Surface plasmon resonance experiments revealed that the subunit C1 binds the E1G1 heterodimer with both high and low affinities (2.8 nM and 1.9 µM, respectively). In addition, an E1G1-H complex can be formed with high affinity (48 nM), whereas affinities of other subunit pairs appeared to be low (∼0.21-3.0 µM). The putative ternary complex of C1-H-E1G1 was not much strong on co-incubation of these subunits, indicating that the two strong complexes of C1-E1G1 and H-E1G1 in cooperation with many other weak interactions may be sufficiently strong enough to withstand the torque of rotation during catalysis. We observed a partially stable quaternary complex (consisting of E1G1, C1, a1(NT), and H subunits) resulting from discrete peripheral subunit interactions stabilizing the complex through their intrinsic affinities. No binding was observed in the absence of E1G1 (using only H, C1, and a1(NT)); therefore, it is likely that, in vivo, the E1G1 heterodimer has a significant role in the initiation of subunit assembly. Multiple interactions of variable affinity in the stalk region may be important to the mechanism of reversible dissociation of the intact V-ATPase.
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Affiliation(s)
- Suhaila Rahman
- Department of Biological Science and Technology, Tokyo University of Science, Chiba, Japan.
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19
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Vishvakarma NK, Singh SM. Augmentation of myelopoiesis in a murine host bearing a T cell lymphoma following in vivo administration of proton pump inhibitor pantoprazole. Biochimie 2011; 93:1786-96. [DOI: 10.1016/j.biochi.2011.06.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 06/16/2011] [Indexed: 01/13/2023]
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20
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Chung C, Mader CC, Schmitz J, Atladottir J, Fitchev P, Cornwell M, Koleske AJ, Crawford SE, Gorelick F. The vacuolar-ATPase modulates matrix metalloproteinase isoforms in human pancreatic cancer. J Transl Med 2011; 91:732-43. [PMID: 21339745 PMCID: PMC3084324 DOI: 10.1038/labinvest.2011.8] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The vacuolar-ATPase (v-ATPase) is a proton transporter found on many intracellular organelles and the plasma membrane (PM). The v-ATPase on PMs of cancer cells may contribute to their invasive properties in vitro. Its relevance to human cancer tissues remains unclear. We investigated whether the expression and cellular localization of v-ATPase corresponded to the stage of human pancreatic cancer, and its effect on matrix metalloproteinase (MMP) activation in vitro. The intensity of v-ATPase staining increased significantly across the range of pancreatic histology from normal ducts to pancreatic intraepithelial neoplasms (PanIN), and finally pancreatic ductal adenocarcinoma (PDAC). Low-grade PanIN lesions displayed polarized staining confined to the basal aspect of the cell in the majority (86%) of fields examined. High-grade PanIN lesions and PDAC showed intense and diffuse v-ATPase localization. In pancreatic cancer cells, PM-associated v-ATPase colocalized with cortactin, a component of the leading edge that helps direct MMP release. Blockade of the v-ATPase with concanamycin or short-hairpin RNA targeting the V₁E subunit reduced MMP-9 activity; this effect was greatest in cells with prominent PM-associated v-ATPase. In cells with detectable MMP-2 activities, however, treatment with concanamycin markedly increased MMP-2's most activated forms. V-ATPase blockade inhibited functional migration and invasion in those cells with predominantly MMP-9 activity. These results indicate that human PDAC specimens show loss of v-ATPase polarity and increased expression that correlates with increasing invasive potential. Thus, v-ATPase selectively modulates specific MMPs that may be linked to an invasive cancer phenotype.
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Affiliation(s)
- Chuhan Chung
- Department of Medicine, Section of Digestive Diseases, VA CT Research, VA CT Healthcare System, Yale University School of Medicine, West Haven, CT 06516, USA.
| | | | | | | | - Phillip Fitchev
- Department of Surgery, NorthShore Research Institute, University of Chicago Pritzker School of Medicine
| | - Mona Cornwell
- Department of Surgery, NorthShore Research Institute, University of Chicago Pritzker School of Medicine
| | | | - Susan E Crawford
- Department of Surgery, NorthShore Research Institute, University of Chicago Pritzker School of Medicine
| | - Fred Gorelick
- Section of Digestive Diseases, Department of Medicine, VA CT Healthcare System, Yale University School of Medicine
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21
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García-García A, Pérez-Sayáns M, Rodríguez MJ, Antúnez-López J, Barros-Angueira F, Somoza-Martín M, Gándara-Rey JM, Aguirre-Urízar JM. Immunohistochemical localization of C1 subunit of V-ATPase (ATPase C1) in oral squamous cell cancer and normal oral mucosa. Biotech Histochem 2011; 87:133-9. [DOI: 10.3109/10520295.2011.574647] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- A García-García
- Department of Stomatology, University of Santiago de Compostela, Santiago de Compostela
- University Hospital Complex of Santiago, Santiago de Compostela
| | - M Pérez-Sayáns
- Department of Stomatology, University of Santiago de Compostela, Santiago de Compostela
| | - MJ Rodríguez
- Department of Stomatology, University of the Basque Country EHU,
Leioa, Vizcaya
| | - J Antúnez-López
- Department of Stomatology, University of Santiago de Compostela, Santiago de Compostela
- University Hospital Complex of Santiago, Santiago de Compostela
| | - F Barros-Angueira
- Galician Public Foundation for Genomic Medicine, Santiago de Compostela, Spain
| | - M Somoza-Martín
- Department of Stomatology, University of Santiago de Compostela, Santiago de Compostela
| | - JM Gándara-Rey
- Department of Stomatology, University of Santiago de Compostela, Santiago de Compostela
| | - JM Aguirre-Urízar
- Department of Stomatology, University of the Basque Country EHU,
Leioa, Vizcaya
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22
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Abstract
AbstractThe rotary ATPase family of membrane protein complexes may have only three members, but each one plays a fundamental role in biological energy conversion. The F1Fo-ATPase (F-ATPase) couples ATP synthesis to the electrochemical membrane potential in bacteria, mitochondria and chloroplasts, while the vacuolar H+-ATPase (V-ATPase) operates as an ATP-driven proton pump in eukaryotic membranes. In different species of archaea and bacteria, the A1Ao-ATPase (A-ATPase) can function as either an ATP synthase or an ion pump. All three of these multi-subunit complexes are rotary molecular motors, sharing a fundamentally similar mechanism in which rotational movement drives the energy conversion process. By analogy to macroscopic systems, individual subunits can be assigned to rotor, axle or stator functions. Recently, three-dimensional reconstructions from electron microscopy and single particle image processing have led to a significant step forward in understanding of the overall architecture of all three forms of these complexes and have allowed the organisation of subunits within the rotor and stator parts of the motors to be more clearly mapped out. This review describes the emerging consensus regarding the organisation of the rotor and stator components of V-, A- and F-ATPases, examining core similarities that point to a common evolutionary origin, and highlighting key differences. In particular, it discusses how newly revealed variation in the complexity of the inter-domain connections may impact on the mechanics and regulation of these molecular machines.
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23
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Grillon E, Farion R, Fablet K, De Waard M, Tse CM, Donowitz M, Rémy C, Coles JA. The spatial organization of proton and lactate transport in a rat brain tumor. PLoS One 2011; 6:e17416. [PMID: 21390324 PMCID: PMC3044751 DOI: 10.1371/journal.pone.0017416] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 02/01/2011] [Indexed: 12/20/2022] Open
Abstract
Tumors create a heterogeneous acidic microenvironment which assists their growth and which must be taken into account in the design of drugs and their delivery. In addition, the acidic extracellular pH (pHe) is itself exploited in several experimental techniques for drug delivery. The way the acidity is created is not clear. We report here the spatial organization of key proton-handling proteins in C6 gliomas in rat brain. The mean profiles across the tumor rim of the Na+/H+ exchanger NHE1, and the lactate-H+ cotransporter MCT1, both showed peaks. NHE1, which is important for extension and migration of cells in vitro, showed a peak 1.55 times higher than in extratumoural tissue at 0.33 mm from the edge. MCT1 had a broader peak, further into the tumor (maximum 1.76 fold at 1.0 mm from the edge). In contrast, MCT4 and the carbonic anhydrase CAIX, which are associated with hypoxia, were not significantly upregulated in the rim. The spatial distribution of MCT4 was highly correlated with that of CAIX, suggesting that their expression is regulated by the same factors. Since protons extruded by NHE1 diffuse away through extracellular clefts, NHE1 requires a continuous source of intracellular protons. From the stoichiometries of metabolic pathways that produce or consume H+, and the greater availability of glucose compared to oxygen in most parts of a tumor, we support the classic view that most of the net proton efflux from C6 gliomas originates in glycolytic formation of lactate and H+ inside the tumor, but add that some lactate is taken up into cells in the rim on MCT1, and some lactate diffuses away, leaving its associated protons available to re-enter cells for extrusion on NHE1. Therapeutic inhibition of NHE1, MCT1 or CAIX is predicted to affect different parts of a tumor.
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Affiliation(s)
- Emmanuelle Grillon
- Unit 836, Institut National de la Santé et de la Recherche Médicale, La Tronche, Isère, France
- Grenoble Institut des Neurosciences, Université Joseph Fourier, Grenoble, France
| | - Régine Farion
- Unit 836, Institut National de la Santé et de la Recherche Médicale, La Tronche, Isère, France
- Grenoble Institut des Neurosciences, Université Joseph Fourier, Grenoble, France
| | - Katell Fablet
- Unit 836, Institut National de la Santé et de la Recherche Médicale, La Tronche, Isère, France
- Grenoble Institut des Neurosciences, Université Joseph Fourier, Grenoble, France
| | - Michel De Waard
- Unit 836, Institut National de la Santé et de la Recherche Médicale, La Tronche, Isère, France
- Grenoble Institut des Neurosciences, Université Joseph Fourier, Grenoble, France
| | - Chung Ming Tse
- Gastroenterology Division, Departments of Physiology and Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Mark Donowitz
- Gastroenterology Division, Departments of Physiology and Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Chantal Rémy
- Unit 836, Institut National de la Santé et de la Recherche Médicale, La Tronche, Isère, France
- Grenoble Institut des Neurosciences, Université Joseph Fourier, Grenoble, France
| | - Jonathan A. Coles
- Unit 836, Institut National de la Santé et de la Recherche Médicale, La Tronche, Isère, France
- Grenoble Institut des Neurosciences, Université Joseph Fourier, Grenoble, France
- Centre for Biophotonics, University of Strathclyde, Glasgow, United Kingdom
- * E-mail:
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24
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Vishvakarma NK, Singh SM. Immunopotentiating effect of proton pump inhibitor pantoprazole in a lymphoma-bearing murine host: Implication in antitumor activation of tumor-associated macrophages. Immunol Lett 2010; 134:83-92. [PMID: 20837061 DOI: 10.1016/j.imlet.2010.09.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 08/28/2010] [Accepted: 09/05/2010] [Indexed: 01/20/2023]
Abstract
Proton pump inhibitors (PPI) are being considered for antineoplastic therapeutic regimens due to their ability to reverse H(+) homeostasis in tumor microenvironment and induce tumor cell death. In order to explore additional mechanism(s) underlying antitumor action of PPI, the present investigation was undertaken to investigate the effect of a PPI pantoprazole (PPZ) on the activation of tumor-associated macrophages (TAM) to tumoricidal state in a murine model of a transplantable T cell lymphoma of spontaneous origin growing in ascitic form. In vivo administration of PPZ to tumor-bearing mice resulted in an enhanced TAM recruitment in tumor microenvironment with M1 macrophage phenotype and augmented activation of TAM to tumoricidal state along with expression of tumor cytotoxic molecules. The study also demonstrates that TAM activating action of PPZ is of indirect nature mediated via its antitumor activity, reversal of tumor-induced immunosuppression and a consequent shift of cytokine balance in the tumor microenvironment favoring polarization of macrophages to M1 type. The study further shows that adoptive transfer of TAM harvested from PPZ-administered tumor-bearing hosts causes an efficient retardation of tumor growth. Possible mechanisms and significance of these observations with respect to the designing of antitumor therapy using PPI are discussed.
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MESH Headings
- 2-Pyridinylmethylsulfinylbenzimidazoles/pharmacology
- Animals
- Ascitic Fluid/drug effects
- Ascitic Fluid/immunology
- Ascitic Fluid/pathology
- Blotting, Western
- Cell Survival/immunology
- Cells, Cultured
- Coculture Techniques
- Cytotoxicity, Immunologic/immunology
- Female
- Immunotherapy, Adoptive
- Interleukin-1/metabolism
- Lymphoma, T-Cell/immunology
- Lymphoma, T-Cell/pathology
- Lymphoma, T-Cell/therapy
- Macrophage Activation/drug effects
- Macrophage Activation/immunology
- Macrophages/immunology
- Macrophages/metabolism
- Macrophages/transplantation
- Male
- Mice
- Mice, Inbred BALB C
- Microscopy, Fluorescence
- Pantoprazole
- Phagocytosis/immunology
- Proton Pump Inhibitors/pharmacology
- Receptors, Interleukin-2/metabolism
- Tumor Cells, Cultured
- Tumor Microenvironment/drug effects
- Tumor Microenvironment/immunology
- Tumor Necrosis Factor-alpha/metabolism
- Vascular Endothelial Growth Factor A/metabolism
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Hildenbrand ZL, Molugu SK, Stock D, Bernal RA. The C-H peripheral stalk base: a novel component in V1-ATPase assembly. PLoS One 2010; 5:e12588. [PMID: 20838636 PMCID: PMC2933246 DOI: 10.1371/journal.pone.0012588] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Accepted: 08/10/2010] [Indexed: 11/18/2022] Open
Abstract
Vacuolar ATPases (V-ATPases) are molecular machines responsible for creating electrochemical gradients and preserving pH-dependent cellular compartments by way of proton translocation across the membrane. V-ATPases employ a dynamic rotary mechanism that is driven by ATP hydrolysis and the central rotor stalk. Regulation of this rotational catalysis is the result of a reversible V1Vo-domain dissociation that is required to preserve ATP during instances of cellular starvation. Recently the method by which the free V1-ATPase abrogates the hydrolytic breakdown of ATP upon dissociating from the membrane has become increasingly clear. In this instance the central stalk subunit F adopts an extended conformation to engage in a bridging interaction tethering the rotor and stator components together. However, the architecture by which this mechanism is stabilized has remained ambiguous despite previous work. In an effort to elucidate the method by which the rotational catalysis is maintained, the architecture of the peripheral stalks and their respective binding interactions was investigated using cryo-electron microscopy. In addition to confirming the bridging interaction exuded by subunit F for the first time in a eukaryotic V-ATPase, subunits C and H are seen interacting with one another in a tight interaction that provides a base for the three EG peripheral stalks. The formation of a CE3G3H sub-assembly appears to be unique to the dissociated V-ATPase and highlights the stator architecture in addition to revealing a possible intermediate in the assembly mechanism of the free V1-ATPase.
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Affiliation(s)
- Zacariah L. Hildenbrand
- Department of Chemistry, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Sudheer K. Molugu
- Department of Chemistry, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Daniela Stock
- Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
- Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Ricardo A. Bernal
- Department of Chemistry, University of Texas at El Paso, El Paso, Texas, United States of America
- * E-mail:
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26
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Vishvakarma NK, Singh SM. Mechanisms of tumor growth retardation by modulation of pH regulation in the tumor-microenvironment of a murine T cell lymphoma. Biomed Pharmacother 2010; 65:27-39. [PMID: 20685069 DOI: 10.1016/j.biopha.2010.06.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 06/21/2010] [Indexed: 12/15/2022] Open
Abstract
Mechanisms underlying tumor growth retarding effect of proton pump inhibitor pantoprazole (PPZ) on a murine T cell lymphoma, designated as Dalton's lymphoma (DL), were investigated. In vivo administration of PPZ to tumor-bearing mice resulted in retardation of tumor progression owing to an inhibition of tumor cell survival and augmented apoptosis. An alteration in the parameters of tumor microenvironment and modulation in the expression of cell growth regulatory molecules is indicated to be involved in PPZ-dependent tumor growth retardation. These findings will help in optimizing therapeutic strategies against cancer using PPZ.
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27
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Pérez-Sayáns M, Somoza-Martín JM, Barros-Angueira F, Rey JMG, García-García A. V-ATPase inhibitors and implication in cancer treatment. Cancer Treat Rev 2009; 35:707-13. [PMID: 19758758 DOI: 10.1016/j.ctrv.2009.08.003] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Revised: 08/03/2009] [Accepted: 08/06/2009] [Indexed: 01/08/2023]
Abstract
Acidity is one of the main features of the tumors. The V-ATPase is the primary responsible for the control of tumor microenvironment by proton extrusion to the extracellular medium. The acid environment favors tissue damage, activation of destructive enzymes in the extracellular matrix, the acquisition of metastatic cell phenotypes as well as increasing the destructive capacity. The application of specific inhibitors of V-ATPases, can decrease the acidity of tumor and may allow the reduction of tumor metastasis, acting on the survival of tumor cells and prevent the phenomena of chemoresistance. Among the most important inhibitors can be distinguished benzolactone enamides (salicylihalamide), lobatamide A and B, apicularen, indolyls, oximidine, macrolactone archazolid, lobatamide C, and cruentaren. The latest generation of inhibitors includes NiK12192, FR202126, and PPI SB 242784. The purpose of this paper is to describe the latest advances in the field of V-ATPase inhibitors, describe further developments related to the classic inhibitors, and discuss new potential applications of these drugs in cancer treatment.
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28
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dos Santos SC, Sá-Correia I. Genome-Wide Identification of Genes Required for Yeast Growth Under Imatinib Stress: Vacuolar H+-ATPase Function Is an Important Target of This Anticancer Drug. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2009; 13:185-98. [DOI: 10.1089/omi.2008.0086] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Sandra C. dos Santos
- IBB—Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Lisboa, Portugal
| | - Isabel Sá-Correia
- IBB—Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Lisboa, Portugal
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Leiding T, Górecki K, Kjellman T, Vinogradov SA, Hägerhäll C, Arsköld SP. Precise detection of pH inside large unilamellar vesicles using membrane-impermeable dendritic porphyrin-based nanoprobes. Anal Biochem 2009; 388:296-305. [PMID: 19248752 DOI: 10.1016/j.ab.2009.02.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Accepted: 02/17/2009] [Indexed: 10/21/2022]
Abstract
Accurate real-time measurements of proton concentration gradients are pivotal to mechanistic studies of proton translocation by membrane-bound enzymes. Here we report a detailed characterization of the pH-sensitive fluorescent nanoprobe Glu(3), which is well suited for pH measurements in microcompartmentalized biological systems. The probe is a polyglutamic porphyrin dendrimer in which multiple carboxylate termini ensure its high water solubility and prevent its diffusion across phospholipid membranes. The probe's pK is in the physiological pH range, and its protonation can be followed ratiometrically by absorbance or fluorescence in the ultraviolet-visible spectral region. The usefulness of the probe was enhanced by using a semiautomatic titration system coupled to a charge-coupled device (CCD) spectrometer, enabling fast and accurate titrations and full spectral coverage of the system at millisecond time resolution. The probe's pK was measured in bulk solutions as well as inside large unilamellar vesicles in the presence of physiologically relevant ions. Glu(3) was found to be completely membrane impermeable, and its distinct spectroscopic features permit pH measurements inside closed membrane vesicles, enabling quantitative mechanistic studies of membrane-spanning proteins. Performance of the probe was demonstrated by monitoring the rate of proton leakage through the phospholipid bilayer in large vesicles with and without the uncoupler gramicidin present. Overall, as a probe for biological proton translocation measurements, Glu(3) was found to be superior to the commercially available pH indicators.
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Affiliation(s)
- Thom Leiding
- Department of Biochemistry, Center for Chemistry and Chemical Engineering, Lund University, 22100 Lund, Sweden
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Zhang Z, Zheng Y, Mazon H, Milgrom E, Kitagawa N, Kish-Trier E, Heck AJR, Kane PM, Wilkens S. Structure of the yeast vacuolar ATPase. J Biol Chem 2008; 283:35983-95. [PMID: 18955482 PMCID: PMC2602884 DOI: 10.1074/jbc.m805345200] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 10/15/2008] [Indexed: 01/01/2023] Open
Abstract
The subunit architecture of the yeast vacuolar ATPase (V-ATPase) was analyzed by single particle transmission electron microscopy and electrospray ionization (ESI) tandem mass spectrometry. A three-dimensional model of the intact V-ATPase was calculated from two-dimensional projections of the complex at a resolution of 25 angstroms. Images of yeast V-ATPase decorated with monoclonal antibodies against subunits A, E, and G position subunit A within the pseudo-hexagonal arrangement in the V1, the N terminus of subunit G in the V1-V0 interface, and the C terminus of subunit E at the top of the V1 domain. ESI tandem mass spectrometry of yeast V1-ATPase showed that subunits E and G are most easily lost in collision-induced dissociation, consistent with a peripheral location of the subunits. An atomic model of the yeast V-ATPase was generated by fitting of the available x-ray crystal structures into the electron microscopy-derived electron density map. The resulting atomic model of the yeast vacuolar ATPase serves as a framework to help understand the role the peripheral stalk subunits are playing in the regulation of the ATP hydrolysis driven proton pumping activity of the vacuolar ATPase.
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Affiliation(s)
- Zhenyu Zhang
- Department of Biochemistry, University of California, Riverside, California 92521, USA
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31
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Smith AN, Francis RW, Sorrell SL, Karet FE. The d subunit plays a central role in human vacuolar H(+)-ATPases. J Bioenerg Biomembr 2008; 40:371-80. [PMID: 18752060 PMCID: PMC2782108 DOI: 10.1007/s10863-008-9161-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Accepted: 07/16/2008] [Indexed: 12/27/2022]
Abstract
The multi-subunit vacuolar-type H(+)-ATPase consists of a V(1) domain (A-H subunits) catalyzing ATP hydrolysis and a V(0) domain (a, c, c', c", d, e) responsible for H(+) translocation. The mammalian V(0) d subunit is one of the least-well characterized, and its function and position within the pump are still unclear. It has two different forms encoded by separate genes, d1 being ubiquitous while d2 is predominantly expressed at the cell surface in kidney and osteoclast. To determine whether it forms part of the pump's central stalk as suggested by bacterial A-ATPase studies, or is peripheral as hypothesized from a yeast model, we investigated both human d subunit isoforms. In silico structural modelling demonstrated that human d1 and d2 are structural orthologues of bacterial subunit C, despite poor sequence identity. Expression studies of d1 and d2 showed that each can pull down the central stalk's D and F subunits from human kidney membrane, and in vitro studies using D and F further showed that the interactions between these proteins and the d subunit is direct. These data indicate that the d subunit in man is centrally located within the pump and is thus important in its rotary mechanism.
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Affiliation(s)
- Annabel N. Smith
- Department of Medical Genetics, University of Cambridge, Cambridge, UK
| | - Richard W. Francis
- Cambridge Institute for Medical Research, University of Cambridge, Box 139 Addenbrooke’s Hospital, Hills Road, Cambridge, CB2 0XY UK
| | - Sara L. Sorrell
- Department of Medical Genetics, University of Cambridge, Cambridge, UK
| | - Fiona E. Karet
- Department of Medical Genetics, University of Cambridge, Cambridge, UK
- Cambridge Institute for Medical Research, University of Cambridge, Box 139 Addenbrooke’s Hospital, Hills Road, Cambridge, CB2 0XY UK
- Division of Renal Medicine, University of Cambridge, Cambridge, UK
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