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Jiang M, Salari A, Stock C, Nikolovska K, Boedtkjer E, Amiri M, Seidler UE. The electroneutral Na +-HCO 3- cotransporter NBCn1 (SLC4A7) modulates colonic enterocyte pH i, proliferation, and migration. Am J Physiol Cell Physiol 2024; 326:C1625-C1636. [PMID: 38646790 DOI: 10.1152/ajpcell.00079.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/05/2024] [Accepted: 04/06/2024] [Indexed: 04/23/2024]
Abstract
NBCn1 (SLC4A7) is one of the two major Na+-HCO3- cotransporters in the human colonic epithelium, expressed predominantly in the highly proliferating colonocytes at the cryptal base. Increased NBCn1 expression levels are reported in tumors, including colorectal cancer. The study explores its importance for maintenance of the intracellular pH (pHi), as well as the proliferative, adhesive, and migratory behavior of the self-differentiating Caco2BBe colonic tumor cell line. In the self-differentiating Caco2BBe cells, NBCn1 mRNA was highly expressed from the proliferative stage until full differentiation. The downregulation of NBCn1 expression by RNA interference affected proliferation and differentiation and decreased intracellular pH (pHi) of the cells in correlation with the degree of knockdown. In addition, a disturbed cell adhesion and reduced migratory speed were associated with NBCn1 knockdown. Murine colonic Nbcn1-/- enteroids also displayed reduced proliferative activity. In the migrating Caco2BBe cells, NBCn1 was found at the leading edge and in colocalization with the focal adhesion markers vinculin and paxillin, which suggests that NBCn1 is involved in the establishment of cell-matrix adhesion. Our data highlight the physiological significance of NBCn1 in modulating epithelial pH homeostasis and cell-matrix interactions in the proliferative region of the colonic epithelium and unravel the molecular mechanism behind pathological overexpression of this transporter in human colorectal cancers.NEW & NOTEWORTHY The transporter NBCn1 plays a central role in maintaining homeostasis within Caco2BBe colonic epithelial cells through its regulation of intracellular pH, matrix adhesion, migration, and proliferation. These observations yield valuable insights into the molecular mechanism of the aberrant upregulation of this transporter in human colorectal cancers.
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Affiliation(s)
- Min Jiang
- Department of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Azam Salari
- Department of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Christian Stock
- Department of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Katerina Nikolovska
- Department of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Mahdi Amiri
- Department of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Ursula E Seidler
- Department of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology, Hannover Medical School, Hannover, Germany
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Axelsen TV, Olesen C, Khan D, Mohammadi A, Bouzinova EV, Nielsen CJF, Mele M, Hauerslev KR, Pedersen HL, Balling E, Vahl P, Tramm T, Christiansen PM, Boedtkjer E. Antibodies toward Na +,HCO 3--cotransporter NBCn1/SLC4A7 block net acid extrusion and cause pH-dependent growth inhibition and apoptosis in breast cancer. Br J Cancer 2024; 130:1206-1220. [PMID: 38310186 PMCID: PMC10991555 DOI: 10.1038/s41416-024-02591-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 01/09/2024] [Accepted: 01/17/2024] [Indexed: 02/05/2024] Open
Abstract
BACKGROUND Na+,HCO3--cotransporter NBCn1/Slc4a7 accelerates murine breast carcinogenesis. Lack of specific pharmacological tools previously restricted therapeutic targeting of NBCn1 and identification of NBCn1-dependent functions in human breast cancer. METHODS We develop extracellularly-targeted anti-NBCn1 antibodies, screen for functional activity on cells, and evaluate (a) mechanisms of intracellular pH regulation in human primary breast carcinomas, (b) proliferation, cell death, and tumor growth consequences of NBCn1 in triple-negative breast cancer, and (c) association of NBCn1-mediated Na+,HCO3--cotransport with human breast cancer metastasis. RESULTS We identify high-affinity (KD ≈ 0.14 nM) anti-NBCn1 antibodies that block human NBCn1-mediated Na+,HCO3--cotransport in cells, without cross-reactivity towards human NBCe1 or murine NBCn1. These anti-NBCn1 antibodies abolish Na+,HCO3--cotransport activity in freshly isolated primary organoids from human breast carcinomas and lower net acid extrusion effectively in primary breast cancer tissue from patients with macrometastases in axillary lymph nodes. Inhibitory anti-NBCn1 antibodies decelerate tumor growth in vivo by ~50% in a patient-derived xenograft model of triple-negative breast cancer and pH-dependently reduce colony formation, cause G2/M-phase cell cycle accumulation, and increase apoptosis of metastatic triple-negative breast cancer cells in vitro. CONCLUSIONS Inhibitory anti-NBCn1 antibodies block net acid extrusion in human breast cancer tissue, particularly from patients with disseminated disease, and pH-dependently limit triple-negative breast cancer growth.
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Affiliation(s)
- Trine V Axelsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Claus Olesen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Danish Khan
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Ali Mohammadi
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | | | - Marco Mele
- Department of Surgery, Randers Regional Hospital, Randers, Denmark
| | - Katrine R Hauerslev
- Department of Plastic and Breast Surgery, Aarhus University Hospital, Aarhus, Denmark
| | - Helene L Pedersen
- Department of Pathology, Randers Regional Hospital, Randers, Denmark
| | - Eva Balling
- Department of Surgery, Randers Regional Hospital, Randers, Denmark
| | - Pernille Vahl
- Department of Pathology, Aarhus University Hospital, Aarhus, Denmark
| | - Trine Tramm
- Department of Pathology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Peer M Christiansen
- Department of Surgery, Randers Regional Hospital, Randers, Denmark
- Department of Plastic and Breast Surgery, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.
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Pedersen SHF. Acid-base transporters in the context of tumor heterogeneity. Pflugers Arch 2024; 476:689-701. [PMID: 38332178 DOI: 10.1007/s00424-024-02918-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/20/2024] [Accepted: 01/29/2024] [Indexed: 02/10/2024]
Abstract
The copious metabolic acid production and -extrusion by cancer cells render poorly vascularized regions of solid tumors highly acidic. A growing list of proton - and bicarbonate transporters has been suggested to contribute to net acid extrusion from cancer cells, and/or been shown to be dysregulated and favor malignant development in various cancers. The great majority of these roles have been studied at the level of the cancer cells. However, recent advances in understanding of the cellular and physicochemical heterogeneity of solid tumors both enable and necessitate a reexamination of the regulation and roles of acid-base transporters in such malignancies. This review will briefly summarize the state-of-the-art, with a focus on the SLC9A and SLC4A families, for which most evidence is available. This is followed by a discussion of key concepts and open questions arising from recent insights and of the challenges that need to be tackled to address them. Finally, opportunities and challenges in therapeutic targeting of the acid-base transportome in cancers will be addressed.
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Affiliation(s)
- Stine Helene Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen, Denmark.
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4
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Abstract
Cancers undergo sequential changes to proton (H+) concentration and sensing that are consequences of the disease and facilitate its further progression. The impact of protonation state on protein activity can arise from alterations to amino acids or their titration. Indeed, many cancer-initiating mutations influence pH balance, regulation or sensing in a manner that enables growth and invasion outside normal constraints as part of oncogenic transformation. These cancer-supporting effects become more prominent when tumours develop an acidic microenvironment owing to metabolic reprogramming and disordered perfusion. The ensuing intracellular and extracellular pH disturbances affect multiple aspects of tumour biology, ranging from proliferation to immune surveillance, and can even facilitate further mutagenesis. As a selection pressure, extracellular acidosis accelerates disease progression by favouring acid-resistant cancer cells, which are typically associated with aggressive phenotypes. Although acid-base disturbances in tumours often occur alongside hypoxia and lactate accumulation, there is now ample evidence for a distinct role of H+-operated responses in key events underpinning cancer. The breadth of these actions presents therapeutic opportunities to change the trajectory of disease.
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Affiliation(s)
- Pawel Swietach
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
| | - Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.
| | - Stine Falsig Pedersen
- Department of Biology, University of Copenhagen, University of Copenhagen, Faculty of Science, København, Denmark.
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5
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Lee S, Toft NJ, Axelsen TV, Espejo MS, Pedersen TM, Mele M, Pedersen HL, Balling E, Johansen T, Burton M, Thomassen M, Vahl P, Christiansen P, Boedtkjer E. Carbonic anhydrases reduce the acidity of the tumor microenvironment, promote immune infiltration, decelerate tumor growth, and improve survival in ErbB2/HER2-enriched breast cancer. Breast Cancer Res 2023; 25:46. [PMID: 37098526 PMCID: PMC10127511 DOI: 10.1186/s13058-023-01644-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 03/30/2023] [Indexed: 04/27/2023] Open
Abstract
BACKGROUND Carbonic anhydrases catalyze CO2/HCO3- buffer reactions with implications for effective H+ mobility, pH dynamics, and cellular acid-base sensing. Yet, the integrated consequences of carbonic anhydrases for cancer and stromal cell functions, their interactions, and patient prognosis are not yet clear. METHODS We combine (a) bioinformatic analyses of human proteomic data and bulk and single-cell transcriptomic data coupled to clinicopathologic and prognostic information; (b) ex vivo experimental studies of gene expression in breast tissue based on quantitative reverse transcription and polymerase chain reactions, intracellular and extracellular pH recordings based on fluorescence confocal microscopy, and immunohistochemical protein identification in human and murine breast cancer biopsies; and (c) in vivo tumor size measurements, pH-sensitive microelectrode recordings, and microdialysis-based metabolite analyses in mice with experimentally induced breast carcinomas. RESULTS Carbonic anhydrases-particularly the extracellular isoforms CA4, CA6, CA9, CA12, and CA14-undergo potent expression changes during human and murine breast carcinogenesis. In patients with basal-like/triple-negative breast cancer, elevated expression of the extracellular carbonic anhydrases negatively predicts survival, whereas, surprisingly, the extracellular carbonic anhydrases positively predict patient survival in HER2/ErbB2-enriched breast cancer. Carbonic anhydrase inhibition attenuates cellular net acid extrusion and extracellular H+ elimination from diffusion-restricted to peripheral and well-perfused regions of human and murine breast cancer tissue. Supplied in vivo, the carbonic anhydrase inhibitor acetazolamide acidifies the microenvironment of ErbB2-induced murine breast carcinomas, limits tumor immune infiltration (CD3+ T cells, CD19+ B cells, F4/80+ macrophages), lowers inflammatory cytokine (Il1a, Il1b, Il6) and transcription factor (Nfkb1) expression, and accelerates tumor growth. Supporting the immunomodulatory influences of carbonic anhydrases, patient survival benefits associated with high extracellular carbonic anhydrase expression in HER2-enriched breast carcinomas depend on the tumor inflammatory profile. Acetazolamide lowers lactate levels in breast tissue and blood without influencing breast tumor perfusion, suggesting that carbonic anhydrase inhibition lowers fermentative glycolysis. CONCLUSIONS We conclude that carbonic anhydrases (a) elevate pH in breast carcinomas by accelerating net H+ elimination from cancer cells and across the interstitial space and (b) raise immune infiltration and inflammation in ErbB2/HER2-driven breast carcinomas, restricting tumor growth and improving patient survival.
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Affiliation(s)
- Soojung Lee
- Department of Biomedicine, Aarhus University, Hoegh-Guldbergs Gade 10, Building 1115, DK-8000, Aarhus C, Denmark
| | - Nicolai J Toft
- Department of Biomedicine, Aarhus University, Hoegh-Guldbergs Gade 10, Building 1115, DK-8000, Aarhus C, Denmark
| | - Trine V Axelsen
- Department of Biomedicine, Aarhus University, Hoegh-Guldbergs Gade 10, Building 1115, DK-8000, Aarhus C, Denmark
| | - Maria Sofia Espejo
- Department of Biomedicine, Aarhus University, Hoegh-Guldbergs Gade 10, Building 1115, DK-8000, Aarhus C, Denmark
| | - Tina M Pedersen
- Department of Biomedicine, Aarhus University, Hoegh-Guldbergs Gade 10, Building 1115, DK-8000, Aarhus C, Denmark
| | - Marco Mele
- Department of Surgery, Randers Regional Hospital, Randers, Denmark
| | - Helene L Pedersen
- Department of Pathology, Randers Regional Hospital, Randers, Denmark
| | - Eva Balling
- Department of Surgery, Randers Regional Hospital, Randers, Denmark
| | - Tonje Johansen
- Department of Pathology, Randers Regional Hospital, Randers, Denmark
| | - Mark Burton
- Department of Clinical Genetics, University of Southern Denmark, Odense, Denmark
- Clinical Genome Center, University and Region of Southern Denmark, Odense, Denmark
- Department of Clinical Medicine, University of Southern Denmark, Odense, Denmark
| | - Mads Thomassen
- Department of Clinical Genetics, University of Southern Denmark, Odense, Denmark
- Clinical Genome Center, University and Region of Southern Denmark, Odense, Denmark
| | - Pernille Vahl
- Department of Pathology, Aarhus University Hospital, Aarhus, Denmark
| | - Peer Christiansen
- Department of Surgery, Randers Regional Hospital, Randers, Denmark
- Department of Plastic and Breast Surgery, Aarhus University Hospital, Aarhus, Denmark
| | - Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Hoegh-Guldbergs Gade 10, Building 1115, DK-8000, Aarhus C, Denmark.
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Inhibition of Macropinocytosis Enhances the Sensitivity of Osteosarcoma Cells to Benzethonium Chloride. Cancers (Basel) 2023; 15:cancers15030961. [PMID: 36765917 PMCID: PMC9913482 DOI: 10.3390/cancers15030961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 01/28/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
Osteosarcoma (OS) is a primary malignant tumor of bone. Chemotherapy is one of the crucial approaches to prevent its metastasis and improve prognosis. Despite continuous improvements in the clinical treatment of OS, tumor resistance and metastasis remain dominant clinical challenges. Macropinocytosis, a form of non-selective nutrient endocytosis, has received increasing attention as a novel target for cancer therapy, yet its role in OS cells remains obscure. Benzethonium chloride (BZN) is an FDA-approved antiseptic and bactericide with broad-spectrum anticancer effects. Here, we described that BZN suppressed the proliferation, migration, and invasion of OS cells in vitro and in vivo, but simultaneously promoted the massive accumulation of cytoplasmic vacuoles as well. Mechanistically, BZN repressed the ERK1/2 signaling pathway, and the ERK1/2 activator partially neutralized the inhibitory effect of BZN on OS cells. Subsequently, we demonstrated that vacuoles originated from macropinocytosis and indicated that OS cells might employ macropinocytosis as a compensatory survival mechanism in response to BZN. Remarkably, macropinocytosis inhibitors enhanced the anti-OS effect of BZN in vitro and in vivo. In conclusion, our results suggest that BZN may inhibit OS cells by repressing the ERK1/2 signaling pathway and propose a potential strategy to enhance the BZN-induced inhibitory effect by suppressing macropinocytosis.
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7
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Targeting Na-H exchanger 1 overcomes nuclear factor kappa B-mediated tumor resistance to radiotherapy. Neoplasia 2022; 35:100862. [PMID: 36508876 PMCID: PMC9761853 DOI: 10.1016/j.neo.2022.100862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/30/2022] [Accepted: 11/30/2022] [Indexed: 12/13/2022] Open
Abstract
Intrinsic or acquired radioresistance often limits the efficacy of radiation therapy (RT), thereby leading to local control failure. Cancerous cells have abnormal pH dynamics due to high metabolic demands, but it is unclear how pH dynamics contribute to radioresistance. In this study, we investigated the role of Na-H exchange 1 (NHE1), the major intracellular pH (pHi) regulator, in RT response. We observed that RT increased NHE1 expression and modulated pHi in MDA-MB-231 human breast cancer cells. When combined with RT, pharmacological NHE1 inhibition by 5-(N-Ethyl-N-isopropyl)amiloride (EIPA) reduced pHi and clonogenic survival. EIPA attenuated radiation-damaged DNA repair, increasing G2/M cell cycle arrest. The combination of EIPA and RT increased apoptotic cell death while decreasing phosphorylation of NF-κB p65. Similarly, the knockdown of NHE1 increased radiosensitivity with lower pHi and increased apoptosis. Consistent with in vitro data, the EIPA plus RT inhibited the growth of MDA-MB-231 xenograft tumors in mice to a greater extent than either EIPA or RT alone. EIPA abrogated the RT-induced increase in NHE1 and phospho-NF-κB p65 expression in tumor tissues. Such coincidence of increased NHE1 level, pHi, and NF-κB activation was also found in radioresistant MDA-MB-231 cells, which were reversed by EIPA treatment. Bioinformatics analysis of RNA sequencing data revealed that inhibiting NHE1 reversed three core gene networks that were up-regulated in radioresistant cells and correlated with high NHE1 expression in patient samples: NF-κB, senescence, and extracellular matrix. Taken together, our findings suggest that NHE1 contributes to RT resistance via NF-κB-mediated signaling networks, and NHE1 may be a promising target for improving RT outcomes.
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Hammers DE, Donahue DL, Tucker Z, Ashfeld BL, Ploplis VA, Castellino FJ, Lee SW. Streptolysin S targets the sodium-bicarbonate cotransporter NBCn1 to induce inflammation and cytotoxicity in human keratinocytes during Group A Streptococcal infection. Front Cell Infect Microbiol 2022; 12:1002230. [PMID: 36389147 PMCID: PMC9663810 DOI: 10.3389/fcimb.2022.1002230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 09/29/2022] [Indexed: 11/30/2022] Open
Abstract
Group A <i>Streptococcus</i> (GAS, <i>Streptococcus pyogenes</i>) is a Gram-positive human pathogen that employs several secreted and surface-bound virulence factors to manipulate its environment, allowing it to cause a variety of disease outcomes. One such virulence factor is Streptolysin S (SLS), a ribosomally-produced peptide toxin that undergoes extensive post-translational modifications. The activity of SLS has been studied for over 100 years owing to its rapid and potent ability to lyse red blood cells, and the toxin has been shown to play a major role in GAS virulence <i>in vivo</i>. We have previously demonstrated that SLS induces hemolysis by targeting the chloride-bicarbonate exchanger Band 3 in erythrocytes, indicating that SLS is capable of targeting host proteins to promote cell lysis. However, the possibility that SLS has additional protein targets in other cell types, such as keratinocytes, has not been explored. Here, we use bioinformatics analysis and chemical inhibition studies to demonstrate that SLS targets the electroneutral sodium-bicarbonate cotransporter NBCn1 in keratinocytes during GAS infection. SLS induces NF-κB activation and host cytotoxicity in human keratinocytes, and these processes can be mitigated by treating keratinocytes with the sodium-bicarbonate cotransport inhibitor S0859. Furthermore, treating keratinocytes with SLS disrupts the ability of host cells to regulate their intracellular pH, and this can be monitored in real time using the pH-sensitive dye pHrodo Red AM in live imaging studies. These results demonstrate that SLS is a multifunctional bacterial toxin that GAS uses in numerous context-dependent ways to promote host cell cytotoxicity and increase disease severity. Studies to elucidate additional host targets of SLS have the potential to impact the development of therapeutics for severe GAS infections.
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Affiliation(s)
- Daniel E. Hammers
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States,Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States
| | - Deborah L. Donahue
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States
| | - Zachary D. Tucker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Brandon L. Ashfeld
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Victoria A. Ploplis
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States
| | - Francis J. Castellino
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States
| | - Shaun W. Lee
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States,Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States,*Correspondence: Shaun W. Lee,
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Wang J, Zahra A, Wang Y, Wu J. Understanding the Physiological Role of Electroneutral Na+-Coupled HCO3− Cotransporter and Its Therapeutic Implications. Pharmaceuticals (Basel) 2022; 15:ph15091082. [PMID: 36145304 PMCID: PMC9505461 DOI: 10.3390/ph15091082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/28/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
Acid–base homeostasis is critical for proper physiological function and pathology. The SLC4 family of HCO3− transmembrane cotransporters is one of the HCO3− transmembrane transport carriers responsible for cellular pH regulation and the uptake or secretion of HCO3− in epithelial cells. NBCn1 (SLC4A7), an electroneutral Na+/HCO3− cotransporter, is extensively expressed in several tissues and functions as a cotransporter for net acid extrusion after cellular acidification. However, the expression and activity level of NBCn1 remain elusive. In addition, NBCn1 has been involved in numerous other cellular processes such as cell volume, cell death/survival balance, transepithelial transport, as well as regulation of cell viability. This review aims to give an inclusive overview of the most recent advances in the research of NBCn1, emphasizing the basic features, regulation, and tissue-specific physiology as well as the development and application of potent inhibitors of NBCn1 transporter in cancer therapy. Research and development of targeted therapies should be carried out for NBCn1 and its associated pathways.
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Affiliation(s)
- Jingjing Wang
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
| | - Aqeela Zahra
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
| | - YunFu Wang
- Hubei Key Laboratory of Embryonic Stem Cell Research, Hubei University of Medicine, Shiyan 442000, China
| | - Jianping Wu
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China
- Hubei Key Laboratory of Embryonic Stem Cell Research, Hubei University of Medicine, Shiyan 442000, China
- Correspondence:
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10
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Laubitz D, Gurney MA, Midura-Kiela M, Clutter C, Besselsen DG, Chen H, Ghishan FK, Kiela PR. Decreased NHE3 expression in colon cancer is associated with DNA damage, increased inflammation and tumor growth. Sci Rep 2022; 12:14725. [PMID: 36042372 PMCID: PMC9427942 DOI: 10.1038/s41598-022-19091-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022] Open
Abstract
Dysregulation of intra- and extracellular pH in cancer contributes to extracellular matrix remodeling, favors cell migration, proliferation, and metastasis. Although the primary attention has been focused on the role of the ubiquitous Na+/H+ exchanger isoform NHE1, the role of NHE3, the predominant apical isoform in colonic surface epithelium in the pathogenesis of colon cancer has not been investigated. Here, we show that NHE3 mRNA expression is significantly reduced in colorectal cancer patients and that low NHE3 expression is associated with poorer survival. Deletion of NHE3 in ApcMin mice evaluated at 15 weeks of age (significant mortality was observed beyond this time) led to lower body weights, increased mucosal inflammation, increased colonic tumor numbers, evidence of enhanced DNA damage in tumor surface epithelium, and to significant alteration in the gut microbiota. In the absence of the inflammatory and microbial pressors, ca. 70% knockdown of NHE3 expression in SK-CO15 cells led to reduced intracellular pH, elevated apical pH, dramatic differences in their transcriptomic profile, increased susceptibility to DNA damage, increased proliferation, decreased apoptosis and reduced adhesion to extracellular matrix proteins. Our findings suggest that loss of NHE3 in the surface epithelium of colonic tumors has profound consequences for cancer progression and behavior.
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Affiliation(s)
- Daniel Laubitz
- Department of Pediatrics, Steele Children's Research Center, University of Arizona College of Medicine, 1501 N. Campbell Ave, Tucson, AZ, 85724, USA
| | - Michael A Gurney
- Department of Pediatrics, Steele Children's Research Center, University of Arizona College of Medicine, 1501 N. Campbell Ave, Tucson, AZ, 85724, USA
| | - Monica Midura-Kiela
- Department of Pediatrics, Steele Children's Research Center, University of Arizona College of Medicine, 1501 N. Campbell Ave, Tucson, AZ, 85724, USA
| | - Christy Clutter
- Department of Pediatrics, Steele Children's Research Center, University of Arizona College of Medicine, 1501 N. Campbell Ave, Tucson, AZ, 85724, USA
| | | | - Hao Chen
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Fayez K Ghishan
- Department of Pediatrics, Steele Children's Research Center, University of Arizona College of Medicine, 1501 N. Campbell Ave, Tucson, AZ, 85724, USA
| | - Pawel R Kiela
- Department of Pediatrics, Steele Children's Research Center, University of Arizona College of Medicine, 1501 N. Campbell Ave, Tucson, AZ, 85724, USA.
- Department of Immunobiology, University of Arizona College of Medicine, Tucson, AZ, USA.
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11
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Inhibition of c-MYC-miRNA 19 Pathway Sensitized CML K562 Cells to Etoposide via NHE1 Upregulation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:9306614. [PMID: 35915613 PMCID: PMC9338868 DOI: 10.1155/2022/9306614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 07/03/2022] [Indexed: 11/17/2022]
Abstract
As a previously discovered target of DNA damage, Na+/H+ exchanger 1 (NHE1) plays a role in regulation of intracellular pH (pHi) through the extrusion of intracellular proton (H+) in exchange for extracellular sodium (Na+). Its abnormal expression and dysfunction have been reported in solid tumor and hematopoietic malignancies. Here, we reported that suppression of NHE1 in BCR-ABL+ hematopoietic malignancies' K562 cells treated with Etoposide was manipulated by miR-19 and c-MYC. Inhibition of miR-19 or c-MYC enhanced the expression of NHE1 and sensitized K562 cells to Etoposide in vitro. The in vivo nude mouse transplantation model was also performed to confirm the enhanced sensitivity of K562 cells to Etoposide by inhibiting the miR-19 or c-MYC pathway. TCGA analysis conferred a negative correlation between miR-19 level and leukemia patients' survival. Thus, our results provided a potential management by which the c-MYC-miRNA 19 pathway might have a crucial impact on sensitizing K562 cells to Etoposide in the therapeutic approaches.
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12
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Sloth RA, Axelsen TV, Espejo MS, Toft NJ, Voss NCS, Burton M, Thomassen M, Vahl P, Boedtkjer E. Loss of RPTPγ primes breast tissue for acid extrusion, promotes malignant transformation and results in early tumour recurrence and shortened survival. Br J Cancer 2022; 127:1226-1238. [PMID: 35821297 DOI: 10.1038/s41416-022-01911-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/22/2022] [Accepted: 06/29/2022] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND While cellular metabolism and acidic waste handling accelerate during breast carcinogenesis, temporal patterns of acid-base regulation and underlying molecular mechanisms responding to the tumour microenvironment remain unclear. METHODS We explore data from human cohorts and experimentally investigate transgenic mice to evaluate the putative extracellular HCO3--sensor Receptor Protein Tyrosine Phosphatase (RPTP)γ during breast carcinogenesis. RESULTS RPTPγ expression declines during human breast carcinogenesis and particularly in high-malignancy grade breast cancer. Low RPTPγ expression associates with poor prognosis in women with Luminal A or Basal-like breast cancer. RPTPγ knockout in mice favours premalignant changes in macroscopically normal breast tissue, accelerates primary breast cancer development, promotes malignant breast cancer histopathologies, and shortens recurrence-free survival. In RPTPγ knockout mice, expression of Na+,HCO3--cotransporter NBCn1-a breast cancer susceptibility protein-is upregulated in normal breast tissue but, contrary to wild-type mice, shows no further increase during breast carcinogenesis. Associated augmentation of Na+,HCO3--cotransport in normal breast tissue from RPTPγ knockout mice elevates steady-state intracellular pH, which has known pro-proliferative effects. CONCLUSIONS Loss of RPTPγ accelerates cellular net acid extrusion and elevates NBCn1 expression in breast tissue. As these effects precede neoplastic manifestations in histopathology, we propose that RPTPγ-dependent enhancement of Na+,HCO3--cotransport primes breast tissue for cancer development.
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Affiliation(s)
- Rasmus A Sloth
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Trine V Axelsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Nicolai J Toft
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Ninna C S Voss
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Mark Burton
- Department of Clinical Genetics, University of Southern Denmark, Odense, Denmark.,Clinical Genome Center, University and Region of Southern Denmark, Odense, Denmark.,Department of Clinical Medicine, University of Southern Denmark, Odense, Denmark
| | - Mads Thomassen
- Department of Clinical Genetics, University of Southern Denmark, Odense, Denmark.,Clinical Genome Center, University and Region of Southern Denmark, Odense, Denmark
| | - Pernille Vahl
- Department of Pathology, Aarhus University Hospital, Aarhus, Denmark
| | - Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.
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13
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Zhou Z, Zhang C, Ma Z, Wang H, Tuo B, Cheng X, Liu X, Li T. Pathophysiological role of ion channels and transporters in HER2-positive breast cancer. Cancer Gene Ther 2022; 29:1097-1104. [PMID: 34997219 DOI: 10.1038/s41417-021-00407-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/21/2021] [Accepted: 11/08/2021] [Indexed: 11/09/2022]
Abstract
The incidence of breast cancer (BC) has been increasing each year, and BC is now the most common malignant tumor in women. Among the numerous BC subtypes, HER2-positive BC can be treated with a variety of strategies based on targeting HER2. Although there has been great progress in the treatment of HER2-positive BC, recurrence, metastasis and drug resistance remain considerable challenges. The dysfunction of ion channels and transporters can affect the development and progression of HER2-positive BC, so these entities are expected to be new therapeutic targets. This review summarizes various ion channels and transporters associated with HER2-positive BC and suggests potential targets for the development of new and effective therapies.
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Affiliation(s)
- Zhengxing Zhou
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, Guizhou Province, China
| | - Chengmin Zhang
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, Guizhou Province, China
| | - Zhiyuan Ma
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, Guizhou Province, China
| | - Hu Wang
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, Guizhou Province, China
| | - Biguang Tuo
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, Guizhou Province, China
| | - Xiaoming Cheng
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, Guizhou Province, China
| | - Xuemei Liu
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, Guizhou Province, China.
| | - Taolang Li
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, Guizhou Province, China.
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14
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Druzhkova I, Lukina M, Dudenkova V, Ignatova N, Snopova L, Gavrina A, Shimolina L, Belousov V, Zagaynova E, Shirmanova M. Tracing of intracellular pH in cancer cells in response to Taxol treatment. Cell Cycle 2021; 20:1540-1551. [PMID: 34308742 PMCID: PMC8409750 DOI: 10.1080/15384101.2021.1949106] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/15/2021] [Accepted: 06/24/2021] [Indexed: 01/21/2023] Open
Abstract
Genetically encoded pH-sensors are the promising instrument for intracellular pH (pHi) registration. In tumor tissue the reversed pH gradient is known to be the important hallmark of cancer and regulator of tumor response on chemotherapy. However the effect of chemotherapeutic drugs on the pHi of tumor cells is largely unknown. Here we using genetically encoded ratiometric pH-sensor SypHer2 were able to monitor pHi in vitro in cell monolayer and tumor spheroids and in vivo in tumor xenografts. In tumor cell monolayer different pHi dynamic was revealed in the dying cell and division-arrested surviving cells. The treatment effect of taxol varied in monolayer and tumor spheroids and pHi changes were able to reflect these difference. The tend to pHi decrease in respect to taxol in vivo matched with results obtained for the cell monolayer. Also in both cases the cell cycle-arrest was the main treatment effect in contrast to tumor spheroid, where the cell death was the primary result. These findings elucidate the significance of pHi in the mechanisms of taxol action on cervical cancer cells and will be valuable for development of new approaches for cancer treatment.
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Affiliation(s)
- Irina Druzhkova
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
| | - Maria Lukina
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
| | - Varvara Dudenkova
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
- Lobachevsky State University of Nizhni Novgorod, Nizhny Novgorod, Russian Federation
| | - Nadezhda Ignatova
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
| | - Ludmila Snopova
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
| | - Alena Gavrina
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
| | - Lyubov Shimolina
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
| | - Vsevolod Belousov
- Pirogov Russian National Research Medical University, Laboratory of Experimental Oncology, Moscow, Russia
- Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, Moscow, Russia
| | - Elena Zagaynova
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
- Lobachevsky State University of Nizhni Novgorod, Nizhny Novgorod, Russian Federation
| | - Marina Shirmanova
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
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15
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Ion Channels, Transporters, and Sensors Interact with the Acidic Tumor Microenvironment to Modify Cancer Progression. Rev Physiol Biochem Pharmacol 2021; 182:39-84. [PMID: 34291319 DOI: 10.1007/112_2021_63] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Solid tumors, including breast carcinomas, are heterogeneous but typically characterized by elevated cellular turnover and metabolism, diffusion limitations based on the complex tumor architecture, and abnormal intra- and extracellular ion compositions particularly as regards acid-base equivalents. Carcinogenesis-related alterations in expression and function of ion channels and transporters, cellular energy levels, and organellar H+ sequestration further modify the acid-base composition within tumors and influence cancer cell functions, including cell proliferation, migration, and survival. Cancer cells defend their cytosolic pH and HCO3- concentrations better than normal cells when challenged with the marked deviations in extracellular H+, HCO3-, and lactate concentrations typical of the tumor microenvironment. Ionic gradients determine the driving forces for ion transporters and channels and influence the membrane potential. Cancer and stromal cells also sense abnormal ion concentrations via intra- and extracellular receptors that modify cancer progression and prognosis. With emphasis on breast cancer, the current review first addresses the altered ion composition and the changes in expression and functional activity of ion channels and transporters in solid cancer tissue. It then discusses how ion channels, transporters, and cellular sensors under influence of the acidic tumor microenvironment shape cancer development and progression and affect the potential of cancer therapies.
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16
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Toft NJ, Axelsen TV, Pedersen HL, Mele M, Burton M, Balling E, Johansen T, Thomassen M, Christiansen PM, Boedtkjer E. Acid-base transporters and pH dynamics in human breast carcinomas predict proliferative activity, metastasis, and survival. eLife 2021; 10:68447. [PMID: 34219652 PMCID: PMC8282339 DOI: 10.7554/elife.68447] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/02/2021] [Indexed: 12/13/2022] Open
Abstract
Breast cancer heterogeneity in histology and molecular subtype influences metabolic and proliferative activity and hence the acid load on cancer cells. We hypothesized that acid-base transporters and intracellular pH (pHi) dynamics contribute inter-individual variability in breast cancer aggressiveness and prognosis. We show that Na+,HCO3- cotransport and Na+/H+ exchange dominate cellular net acid extrusion in human breast carcinomas. Na+/H+ exchange elevates pHi preferentially in estrogen receptor-negative breast carcinomas, whereas Na+,HCO3- cotransport raises pHi more in invasive lobular than ductal breast carcinomas and in higher malignancy grade breast cancer. HER2-positive breast carcinomas have elevated protein expression of Na+/H+ exchanger NHE1/SLC9A1 and Na+,HCO3- cotransporter NBCn1/SLC4A7. Increased dependency on Na+,HCO3- cotransport associates with severe breast cancer: enlarged CO2/HCO3--dependent rises in pHi predict accelerated cell proliferation, whereas enhanced CO2/HCO3--dependent net acid extrusion, elevated NBCn1 protein expression, and reduced NHE1 protein expression predict lymph node metastasis. Accordingly, we observe reduced survival for patients suffering from luminal A or basal-like/triple-negative breast cancer with high SLC4A7 and/or low SLC9A1 mRNA expression. We conclude that the molecular mechanisms of acid-base regulation depend on clinicopathological characteristics of breast cancer patients. NBCn1 expression and dependency on Na+,HCO3- cotransport for pHi regulation, measured in biopsies of human primary breast carcinomas, independently predict proliferative activity, lymph node metastasis, and patient survival.
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Affiliation(s)
- Nicolai J Toft
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Trine V Axelsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Helene L Pedersen
- Department of Pathology, Regionshospitalet Randers, Randers, Denmark
| | - Marco Mele
- Department of Surgery, Regionshospitalet Randers, Randers, Denmark
| | - Mark Burton
- Department of Clinical Genetics, University of Southern Denmark, Odense, Denmark.,Clinical Genome Center, University and Region of Southern Denmark, Odense, Denmark
| | - Eva Balling
- Department of Surgery, Regionshospitalet Randers, Randers, Denmark
| | - Tonje Johansen
- Department of Pathology, Regionshospitalet Randers, Randers, Denmark
| | - Mads Thomassen
- Department of Clinical Genetics, University of Southern Denmark, Odense, Denmark.,Clinical Genome Center, University and Region of Southern Denmark, Odense, Denmark
| | - Peer M Christiansen
- Department of Surgery, Regionshospitalet Randers, Randers, Denmark.,Department of Plastic and Breast Surgery, Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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17
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Hussein NA, Malla S, Pasternak MA, Terrero D, Brown NG, Ashby CR, Assaraf YG, Chen ZS, Tiwari AK. The role of endolysosomal trafficking in anticancer drug resistance. Drug Resist Updat 2021; 57:100769. [PMID: 34217999 DOI: 10.1016/j.drup.2021.100769] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/10/2021] [Accepted: 05/14/2021] [Indexed: 02/08/2023]
Abstract
Multidrug resistance (MDR) remains a major obstacle towards curative treatment of cancer. Despite considerable progress in delineating the basis of intrinsic and acquired MDR, the underlying molecular mechanisms remain to be elucidated. Emerging evidences suggest that dysregulation in endolysosomal compartments is involved in mediating MDR through multiple mechanisms, such as alterations in endosomes, lysosomes and autophagosomes, that traffic and biodegrade the molecular cargo through macropinocytosis, autophagy and endocytosis. For example, altered lysosomal pH, in combination with transcription factor EB (TFEB)-mediated lysosomal biogenesis, increases the sequestration of hydrophobic anti-cancer drugs that are weak bases, thereby producing an insufficient and off-target accumulation of anti-cancer drugs in MDR cancer cells. Thus, the use of well-tolerated, alkalinizing compounds that selectively block Vacuolar H⁺-ATPase (V-ATPase) may be an important strategy to overcome MDR in cancer cells and increase chemotherapeutic efficacy. Other mechanisms of endolysosomal-mediated drug resistance include increases in the expression of lysosomal proteases and cathepsins that are involved in mediating carcinogenesis and chemoresistance. Therefore, blocking the trafficking and maturation of lysosomal proteases or direct inhibition of cathepsin activity in the cytosol may represent novel therapeutic modalities to overcome MDR. Furthermore, endolysosomal compartments involved in catabolic pathways, such as macropinocytosis and autophagy, are also shown to be involved in the development of MDR. Here, we review the role of endolysosomal trafficking in MDR development and discuss how targeting endolysosomal pathways could emerge as a new therapeutic strategy to overcome chemoresistance in cancer.
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Affiliation(s)
- Noor A Hussein
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy & Pharmaceutical Sciences, University of Toledo, Toledo, 43614, OH, USA
| | - Saloni Malla
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy & Pharmaceutical Sciences, University of Toledo, Toledo, 43614, OH, USA
| | - Mariah A Pasternak
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy & Pharmaceutical Sciences, University of Toledo, Toledo, 43614, OH, USA
| | - David Terrero
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy & Pharmaceutical Sciences, University of Toledo, Toledo, 43614, OH, USA
| | - Noah G Brown
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy & Pharmaceutical Sciences, University of Toledo, Toledo, 43614, OH, USA
| | - Charles R Ashby
- Department of Pharmaceutical Sciences, College of Pharmacy & Pharmaceutical Sciences, St. John's University, Queens, NY, USA
| | - Yehuda G Assaraf
- The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Zhe-Sheng Chen
- Department of Pharmaceutical Sciences, College of Pharmacy & Pharmaceutical Sciences, St. John's University, Queens, NY, USA.
| | - Amit K Tiwari
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy & Pharmaceutical Sciences, University of Toledo, Toledo, 43614, OH, USA; Department of Cancer Biology, College of Medicine and Life Sciences, University of Toledo, Toledo, 43614, OH, USA.
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18
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Jia Z, Zhu H, Sun H, Hua Y, Zhang G, Jiang J, Wang X. Adipose Mesenchymal Stem Cell-Derived Exosomal microRNA-1236 Reduces Resistance of Breast Cancer Cells to Cisplatin by Suppressing SLC9A1 and the Wnt/β-Catenin Signaling. Cancer Manag Res 2020; 12:8733-8744. [PMID: 33061571 PMCID: PMC7519869 DOI: 10.2147/cmar.s270200] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/21/2020] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Emerging evidence has noted the versatile functions of mesenchymal stem cell-derived exosomes (MSC-Exos) in cancer control. This work aims to probe to function of adipose MSC-Exos (adMSC-Exos) in drug-resistance of breast cancer (BC) cells to cisplatin (DDP) and the molecules involved. METHODS Parental and DDP-resistant BC cell lines MCF-7 and MDA-MB-231 were used. All cells were pre-treated with adMSC-Exos. Then, the viability and apoptosis of cells after DDP treatment were determined. Differentially expressed miRNAs after adMSC-exo treatment were screened out. Rescue experiments were conducted by pre-transfecting miR-1236 inhibitor into adMSCs, and the role of miR-1236 in DDP sensitivity was determined. Targeting mRNAs of miR-1236 were predicted by bioinformatics analysis. Altered SLC9A1 expression was administrated to evaluate its function in DDP resistance. RESULTS The adMSC-Exos notably increased the sensitivity of either parental or DDP-resistant BC cells to DDP. SLC9A1 was notably highly expressed in DDP-resistant cells but inhibited following adMSC-exo administration. Importantly, miR-1236, which could directly bind to SLC9A1 and suppress its expression, was confirmed as an enriched miRNA in adMSC-Exos. Either inhibition of miR-1236 or upregulation of SLC9A1 blocked the pro-sensitize roles of adMSC-Exos. In addition, the Wnt/β-catenin pathway activity was suppressed by adMSC-Exos but recovered by SLC9A1. CONCLUSION This study evidenced that adMSC-Exos carry miR-1236 to increase sensitivity of BC cells to DDP with the involvement of SLC9A1 downregulation and Wnt/β-catenin inactivation. This finding may offer novel insights into treatment for drug-resistant BC.
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Affiliation(s)
- Zhongming Jia
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Binzhou Medical University, Binzhou256603, Shandong, People’s Republic of China
| | - Huamin Zhu
- Department of Medical Ultrasonics, Affiliated Hospital of Binzhou Medical University, Binzhou256603, Shandong, People’s Republic of China
| | - Hongguang Sun
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Binzhou Medical University, Binzhou256603, Shandong, People’s Republic of China
| | - Yitong Hua
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Binzhou Medical University, Binzhou256603, Shandong, People’s Republic of China
| | - Guoqiang Zhang
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Binzhou Medical University, Binzhou256603, Shandong, People’s Republic of China
| | - Jingru Jiang
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Binzhou Medical University, Binzhou256603, Shandong, People’s Republic of China
| | - Xiaohong Wang
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Binzhou Medical University, Binzhou256603, Shandong, People’s Republic of China
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19
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Role of pH Regulatory Proteins and Dysregulation of pH in Prostate Cancer. Rev Physiol Biochem Pharmacol 2020; 182:85-110. [PMID: 32776252 DOI: 10.1007/112_2020_18] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Prostate cancer is the fourth most commonly diagnosed cancer, and although it is often a slow-growing malignancy, it is the second leading cause of cancer-associated deaths in men and the first in Europe and North America. In many forms of cancer, when the disease is a solid tumor confined to one organ, it is often readily treated. However, when the cancer becomes an invasive metastatic carcinoma, it is more often fatal. It is therefore of great interest to identify mechanisms that contribute to the invasion of cells to identify possible targets for therapy. During prostate cancer progression, the epithelial cells undergo epithelial-mesenchymal transition that is characterized by morphological changes, a loss of cell-cell adhesion, and invasiveness. Dysregulation of pH has emerged as a hallmark of cancer with a reversed pH gradient and with a constitutively increased intracellular pH that is elevated above the extracellular pH. This phenomenon has been referred to as "a perfect storm" for cancer progression. Acid-extruding ion transporters include the Na+/H+ exchanger NHE1 (SLC9A1), the Na+HCO3- cotransporter NBCn1 (SLC4A7), anion exchangers, vacuolar-type adenosine triphosphatases, and the lactate-H+ cotransporters of the monocarboxylate family (MCT1 and MCT4 (SLC16A1 and 3)). Additionally, carbonic anhydrases contribute to acid transport. Of these, several have been shown to be upregulated in different human cancers including the NBCn1, MCTs, and NHE1. Here the role and contribution of acid-extruding transporters in prostate cancer growth and metastasis were examined. These proteins make significant contributions to prostate cancer progression.
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20
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Malinda RR, Zeeberg K, Sharku PC, Ludwig MQ, Pedersen LB, Christensen ST, Pedersen SF. TGFβ Signaling Increases Net Acid Extrusion, Proliferation and Invasion in Panc-1 Pancreatic Cancer Cells: SMAD4 Dependence and Link to Merlin/NF2 Signaling. Front Oncol 2020; 10:687. [PMID: 32457840 PMCID: PMC7221161 DOI: 10.3389/fonc.2020.00687] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 04/14/2020] [Indexed: 12/14/2022] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a major cause of cancer-related death, with a 5-year survival of <10% and severely limited treatment options. PDAC hallmarks include profound metabolic acid production and aggressive local proliferation and invasiveness. This phenotype is supported by upregulated net acid extrusion and epithelial-to-mesenchymal transition (EMT), the latter typically induced by aberrant transforming growth factor-β (TGFβ) signaling. It is, however, unknown whether TGFβ-induced EMT and upregulation of acid extrusion are causally related. Here, we show that mRNA and protein expression of the net acid extruding transporters Na+/H+ exchanger 1 (NHE1, SLC9A1) and Na+, HCO3- cotransporter 1 (NBCn1, SLC4A7) are increased in a panel of human PDAC cell lines compared to immortalized human pancreatic ductal epithelial (HPDE) cells. Treatment of Panc-1 cells (which express SMAD4, required for canonical TGFβ signaling) with TGFβ-1 for 48 h elicited classical EMT with down- and upregulation of epithelial and mesenchymal markers, respectively, in a manner inhibited by SMAD4 knockdown. Accordingly, less pronounced EMT was induced in BxPC-3 cells, which do not express SMAD4. TGFβ-1 treatment elicited a SMAD4-dependent increase in NHE1 expression, and a smaller, SMAD4-independent increase in NBCn1 in Panc-1 cells. Consistent with this, TGFβ-1 treatment led to elevated intracellular pH and increased net acid extrusion capacity in Panc-1 cells, but not in BxPC-3 cells, in an NHE1-dependent manner. Proliferation was increased in Panc-1 cells and decreased in BxPC-3 cells, upon TGFβ-1 treatment, and this, as well as EMT per se, was unaffected by NHE1- or NBCn1 inhibition. TGFβ-1-induced EMT was associated with a 4-fold increase in Panc-1 cell invasiveness, which further increased ~10-fold upon knockdown of the tumor suppressor Merlin (Neurofibromatosis type 2). Knockdown of NHE1 or NBCn1 abolished Merlin-induced invasiveness, but not that induced by TGFβ-1 alone. In conclusion, NHE1 and NBCn1 expression and NHE-dependent acid extrusion are upregulated during TGFβ-1-induced EMT of Panc-1 cells. NHE1 upregulation is SMAD4-dependent, and SMAD4-deficient BxPC-3 cells show no change in pHi regulation. NHE1 and NBCn1 are not required for EMT per se or EMT-associated proliferation changes, but are essential for the potentiation of invasiveness induced by Merlin knockdown.
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Affiliation(s)
- Raj R Malinda
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Zeeberg
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Patricia C Sharku
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Mette Q Ludwig
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Lotte B Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Søren T Christensen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Stine F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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21
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Ward C, Meehan J, Gray ME, Murray AF, Argyle DJ, Kunkler IH, Langdon SP. The impact of tumour pH on cancer progression: strategies for clinical intervention. EXPLORATION OF TARGETED ANTI-TUMOR THERAPY 2020; 1:71-100. [PMID: 36046070 PMCID: PMC9400736 DOI: 10.37349/etat.2020.00005] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 02/05/2020] [Indexed: 02/06/2023] Open
Abstract
Dysregulation of cellular pH is frequent in solid tumours and provides potential opportunities for therapeutic intervention. The acidic microenvironment within a tumour can promote migration, invasion and metastasis of cancer cells through a variety of mechanisms. Pathways associated with the control of intracellular pH that are under consideration for intervention include carbonic anhydrase IX, the monocarboxylate transporters (MCT, MCT1 and MCT4), the vacuolar-type H+-ATPase proton pump, and the sodium-hydrogen exchanger 1. This review will describe progress in the development of inhibitors to these targets.
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Affiliation(s)
- Carol Ward
- Cancer Research UK Edinburgh Centre and Edinburgh Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, EH4 2XU Edinburgh, UK
| | - James Meehan
- Cancer Research UK Edinburgh Centre and Edinburgh Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, EH4 2XU Edinburgh, UK
| | - Mark E Gray
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush, EH25 9RG Midlothian, UK
| | - Alan F Murray
- School of Engineering, Institute for Integrated Micro and Nano Systems, EH9 3JL Edinburgh, UK
| | - David J Argyle
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush, EH25 9RG Midlothian, UK
| | - Ian H Kunkler
- Cancer Research UK Edinburgh Centre and Edinburgh Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, EH4 2XU Edinburgh, UK
| | - Simon P Langdon
- Cancer Research UK Edinburgh Centre and Edinburgh Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, EH4 2XU Edinburgh, UK
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22
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Targeting the Acidic Tumor Microenvironment: Unexpected Pro-Neoplastic Effects of Oral NaHCO 3 Therapy in Murine Breast Tissue. Cancers (Basel) 2020; 12:cancers12040891. [PMID: 32268614 PMCID: PMC7226235 DOI: 10.3390/cancers12040891] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/31/2020] [Accepted: 03/31/2020] [Indexed: 11/16/2022] Open
Abstract
The acidic tumor microenvironment modifies malignant cell behavior. Here, we study consequences of the microenvironment in breast carcinomas. Beginning at carcinogen-based breast cancer induction, we supply either regular or NaHCO3-containing drinking water to female C57BL/6j mice. We evaluate urine and blood acid-base status, tumor metabolism (microdialysis sampling), and tumor pH (pH-sensitive microelectrodes) in vivo. Based on freshly isolated epithelial organoids from breast carcinomas and normal breast tissue, we assess protein expression (immunoblotting, mass spectrometry), intracellular pH (fluorescence microscopy), and cell proliferation (bromodeoxyuridine incorporation). Oral NaHCO3 therapy increases breast tumor pH in vivo from 6.68 ± 0.04 to 7.04 ± 0.09 and intracellular pH in breast epithelial organoids by ~0.15. Breast tumors develop with median latency of 85.5 ± 8.2 days in NaHCO3-treated mice vs. 82 ± 7.5 days in control mice. Oral NaHCO3 therapy does not affect tumor growth, histopathology or glycolytic metabolism. The capacity for cellular net acid extrusion is increased in NaHCO3-treated mice and correlates negatively with breast tumor latency. Oral NaHCO3 therapy elevates proliferative activity in organoids from breast carcinomas. Changes in protein expression patterns-observed by high-throughput proteomics analyses-between cancer and normal breast tissue and in response to oral NaHCO3 therapy reveal complex influences on metabolism, cytoskeleton, cell-cell and cell-matrix interaction, and cell signaling pathways. We conclude that oral NaHCO3 therapy neutralizes the microenvironment of breast carcinomas, elevates the cellular net acid extrusion capacity, and accelerates proliferation without net effect on breast cancer development or tumor growth. We demonstrate unexpected pro-neoplastic consequences of oral NaHCO3 therapy that in breast tissue cancel out previously reported anti-neoplastic effects.
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Rolver MG, Elingaard-Larsen LO, Andersen AP, Counillon L, Pedersen SF. Pyrazine ring-based Na +/H + exchanger (NHE) inhibitors potently inhibit cancer cell growth in 3D culture, independent of NHE1. Sci Rep 2020; 10:5800. [PMID: 32242030 PMCID: PMC7118118 DOI: 10.1038/s41598-020-62430-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 03/12/2020] [Indexed: 12/24/2022] Open
Abstract
The Na+/H+ exchanger-1 (NHE1) supports tumour growth, making NHE1 inhibitors of interest in anticancer therapy, yet their molecular effects are incompletely characterized. Here, we demonstrate that widely used pyrazinoylguanidine-type NHE1 inhibitors potently inhibit growth and survival of cancer cell spheroids, in a manner unrelated to NHE1 inhibition. Cancer and non-cancer cells were grown as 3-dimensional (3D) spheroids and treated with pyrazinoylguanidine-type (amiloride, 5-(N-ethyl-N-isopropyl)-amiloride (EIPA), 5-(N,N-dimethyl)-amiloride (DMA), and 5-(N,N-hexamethylene)-amiloride (HMA)) or benzoylguanidine-type (eniporide, cariporide) NHE1 inhibitors for 2-7 days, followed by analyses of viability, compound accumulation, and stress- and death-associated signalling. EIPA, DMA and HMA dose-dependently reduced breast cancer spheroid viability while cariporide and eniporide had no effect. Although both compound types inhibited NHE1, the toxic effects were NHE1-independent, as inhibitor-induced viability loss was unaffected by NHE1 CRISPR/Cas9 knockout. EIPA and HMA accumulated extensively in spheroids, and this was associated with marked vacuolization, apparent autophagic arrest, ER stress, mitochondrial- and DNA damage and poly-ADP-ribose-polymerase (PARP) cleavage, indicative of severe stress and paraptosis-like cell death. Pyrazinoylguanidine-induced cell death was partially additive to that induced by conventional anticancer therapies and strongly additive to extracellular-signal-regulated-kinase (ERK) pathway inhibition. Thus, in addition to inhibiting NHE1, pyrazinoylguanidines exert potent, NHE1-independent cancer cell death, pointing to a novel relevance for these compounds in anticancer therapy.
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Affiliation(s)
- Michala G Rolver
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Line O Elingaard-Larsen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Anne P Andersen
- Center for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Laurent Counillon
- Université Côte d'Azur, CNRS, France LP2M, 28 Avenue de Valombrose, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
| | - Stine F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
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24
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Flinck M, Hagelund S, Gorbatenko A, Severin M, Pedraz-Cuesta E, Novak I, Stock C, Pedersen SF. The Vacuolar H + ATPase α3 Subunit Negatively Regulates Migration and Invasion of Human Pancreatic Ductal Adenocarcinoma Cells. Cells 2020; 9:E465. [PMID: 32085585 PMCID: PMC7072798 DOI: 10.3390/cells9020465] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/10/2020] [Accepted: 02/13/2020] [Indexed: 12/12/2022] Open
Abstract
Increased metabolic acid production and upregulation of net acid extrusion render pH homeostasis profoundly dysregulated in many cancers. Plasma membrane activity of vacuolar H+ ATPases (V-ATPases) has been implicated in acid extrusion and invasiveness of some cancers, yet often on the basis of unspecific inhibitors. Serving as a membrane anchor directing V-ATPase localization, the a subunit of the V0 domain of the V-ATPase (ATP6V0a1-4) is particularly interesting in this regard. Here, we map the regulation and roles of ATP6V0a3 in migration, invasion, and growth in pancreatic ductal adenocarcinoma (PDAC) cells. a3 mRNA and protein levels were upregulated in PDAC cell lines compared to non-cancer pancreatic epithelial cells. Under control conditions, a3 localization was mainly endo-/lysosomal, and its knockdown had no detectable effect on pHi regulation after acid loading. V-ATPase inhibition, but not a3 knockdown, increased HIF-1 expression and decreased proliferation and autophagic flux under both starved and non-starved conditions, and spheroid growth of PDAC cells was also unaffected by a3 knockdown. Strikingly, a3 knockdown increased migration and transwell invasion of Panc-1 and BxPC-3 PDAC cells, and increased gelatin degradation in BxPC-3 cells yet decreased it in Panc-1 cells. We conclude that in these PDAC cells, a3 is upregulated and negatively regulates migration and invasion, likely in part via effects on extracellular matrix degradation.
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Affiliation(s)
- Mette Flinck
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark; (M.F.); (S.H.); (M.S.); (E.P.-C.); (I.N.)
| | - Sofie Hagelund
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark; (M.F.); (S.H.); (M.S.); (E.P.-C.); (I.N.)
| | - Andrej Gorbatenko
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
| | - Marc Severin
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark; (M.F.); (S.H.); (M.S.); (E.P.-C.); (I.N.)
| | - Elena Pedraz-Cuesta
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark; (M.F.); (S.H.); (M.S.); (E.P.-C.); (I.N.)
| | - Ivana Novak
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark; (M.F.); (S.H.); (M.S.); (E.P.-C.); (I.N.)
| | - Christian Stock
- Department of Gastroentero-, Hepato- and Endocrinology, Hannover Medical School, D-30625 Hannover, Germany;
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark; (M.F.); (S.H.); (M.S.); (E.P.-C.); (I.N.)
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25
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Lee D, Hong JH. The Fundamental Role of Bicarbonate Transporters and Associated Carbonic Anhydrase Enzymes in Maintaining Ion and pH Homeostasis in Non-Secretory Organs. Int J Mol Sci 2020; 21:ijms21010339. [PMID: 31947992 PMCID: PMC6981687 DOI: 10.3390/ijms21010339] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/02/2020] [Accepted: 01/03/2020] [Indexed: 12/18/2022] Open
Abstract
The bicarbonate ion has a fundamental role in vital systems. Impaired bicarbonate transport leads to various diseases, including immune disorders, cystic fibrosis, tumorigenesis, kidney diseases, brain dysfunction, tooth fracture, ischemic reperfusion injury, hypertension, impaired reproductive system, and systemic acidosis. Carbonic anhydrases are involved in the mechanism of bicarbonate movement and consist of complex of bicarbonate transport systems including bicarbonate transporters. This review focused on the convergent regulation of ion homeostasis through various ion transporters including bicarbonate transporters, their regulatory enzymes, such as carbonic anhydrases, pH regulatory role, and the expression pattern of ion transporters in non-secretory systems throughout the body. Understanding the correlation between these systems will be helpful in order to obtain new insights and design potential therapeutic strategies for the treatment of pH-related disorders. In this review, we have discussed the broad prospects and challenges that remain in elucidation of bicarbonate-transport-related biological and developmental systems.
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Affiliation(s)
| | - Jeong Hee Hong
- Correspondence: ; Tel.: +82-32-899-6682; Fax: +82-32-899-6039
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26
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Elingaard-Larsen LO, Rolver MG, Sørensen EE, Pedersen SF. How Reciprocal Interactions Between the Tumor Microenvironment and Ion Transport Proteins Drive Cancer Progression. Rev Physiol Biochem Pharmacol 2020; 182:1-38. [PMID: 32737753 DOI: 10.1007/112_2020_23] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Solid tumors comprise two major components: the cancer cells and the tumor stroma. The stroma is a mixture of cellular and acellular components including fibroblasts, mesenchymal and cancer stem cells, endothelial cells, immune cells, extracellular matrix, and tumor interstitial fluid. The insufficient tumor perfusion and the highly proliferative state and dysregulated metabolism of the cancer cells collectively create a physicochemical microenvironment characterized by altered nutrient concentrations and varying degrees of hypoxia and acidosis. Furthermore, both cancer and stromal cells secrete numerous growth factors, cytokines, and extracellular matrix proteins which further shape the tumor microenvironment (TME), favoring cancer progression.Transport proteins expressed by cancer and stromal cells localize at the interface between the cells and the TME and are in a reciprocal relationship with it, as both sensors and modulators of TME properties. It has been amply demonstrated how acid-base and nutrient transporters of cancer cells enable their growth, presumably by contributing both to the extracellular acidosis and the exchange of metabolic substrates and waste products between cells and TME. However, the TME also impacts other transport proteins important for cancer progression, such as multidrug resistance proteins. In this review, we summarize current knowledge of the cellular and acellular components of solid tumors and their interrelationship with key ion transport proteins. We focus in particular on acid-base transport proteins with known or proposed roles in cancer development, and we discuss their relevance for novel therapeutic strategies.
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Affiliation(s)
- Line O Elingaard-Larsen
- Translational Type 2 Diabetes Research, Department of Clinical Research, Steno Diabetes Center Copenhagen, Gentofte, Denmark
| | - Michala G Rolver
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Ester E Sørensen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Stine F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
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27
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Pedersen SF, Counillon L. The SLC9A-C Mammalian Na +/H + Exchanger Family: Molecules, Mechanisms, and Physiology. Physiol Rev 2019; 99:2015-2113. [PMID: 31507243 DOI: 10.1152/physrev.00028.2018] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Na+/H+ exchangers play pivotal roles in the control of cell and tissue pH by mediating the electroneutral exchange of Na+ and H+ across cellular membranes. They belong to an ancient family of highly evolutionarily conserved proteins, and they play essential physiological roles in all phyla. In this review, we focus on the mammalian Na+/H+ exchangers (NHEs), the solute carrier (SLC) 9 family. This family of electroneutral transporters constitutes three branches: SLC9A, -B, and -C. Within these, each isoform exhibits distinct tissue expression profiles, regulation, and physiological roles. Some of these transporters are highly studied, with hundreds of original articles, and some are still only rudimentarily understood. In this review, we present and discuss the pioneering original work as well as the current state-of-the-art research on mammalian NHEs. We aim to provide the reader with a comprehensive view of core knowledge and recent insights into each family member, from gene organization over protein structure and regulation to physiological and pathophysiological roles. Particular attention is given to the integrated physiology of NHEs in the main organ systems. We provide several novel analyses and useful overviews, and we pinpoint main remaining enigmas, which we hope will inspire novel research on these highly versatile proteins.
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Affiliation(s)
- S F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
| | - L Counillon
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
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28
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Ma Z, Yuan D, Cheng X, Tuo B, Liu X, Li T. Function of ion transporters in maintaining acid-base homeostasis of the mammary gland and the pathophysiological role in breast cancer. Am J Physiol Regul Integr Comp Physiol 2019; 318:R98-R111. [PMID: 31553634 DOI: 10.1152/ajpregu.00202.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The incidence of breast cancer is increasing year by year, and the pathogenesis is still unclear. Studies have shown that the high metabolism of solid tumors leads to an increase in hypoxia, glycolysis, production of lactic acid and carbonic acid, and extracellular acidification; a harsh microenvironment; and ultimately to tumor cell death. Approximately 50% of locally advanced breast cancers exhibit hypoxia and/or local hypoxia, and acid-base regulatory proteins play an important role in regulating milk secretion and maintaining mammary gland physiological function. Therefore, ion transporters have gradually become a hot topic in mammary gland and breast cancer research. This review focuses on the research progress of ion transporters in mammary glands and breast cancer. We hope to provide new targets for the treatment and prognosis of breast cancer.
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Affiliation(s)
- Zhiyuan Ma
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Dumin Yuan
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,Digestive Disease Institute of Guizhou Province, Zunyi, China
| | - Xiaoming Cheng
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Biguang Tuo
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,Digestive Disease Institute of Guizhou Province, Zunyi, China
| | - Xuemei Liu
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,Digestive Disease Institute of Guizhou Province, Zunyi, China
| | - Taolang Li
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, China
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29
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Ergün S. Cross-Kingdom Gene regulation via miRNAs of Hypericum perforatum (St. John's wort) flower dietetically absorbed: An in silico approach to define potential biomarkers for prostate cancer. Comput Biol Chem 2019; 80:16-22. [PMID: 30861403 DOI: 10.1016/j.compbiolchem.2019.02.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 02/05/2019] [Accepted: 02/27/2019] [Indexed: 01/04/2023]
Abstract
Prostate cancer (PCa) is the most frequent type of cancer in men. Hypericum perforatum (H. Perforatum) extract (HPE) administration provides remarkable decrease of PCa development. H. perforatum contains 7 conserved miRNAs (Hyp-miR-156a, Hyp-miR-156b, Hyp-miR-166, Hyp-miR-390, Hyp-miR-394, Hyp-miR-396 and Hyp-miR-414) with different targets. In this study, we aimed to investigate cross-kingdom gene regulation via miRNAs of H. perforatum flower dietetically absorbed in manner of an in silico approach to define potential biomarkers for PCa. psRNATarget database was used to find human genes targeted by 7 pre-defined H. perforatum miRNAs. We defined the mostly affected gene families from these miRNAs as ZNF, TMEM, SLC and FAM gene families. GeneMANIA database was used to define the most affected genes (TMEM41B and SLC4A7) from these 7 miRNAs. cBioPortal database was used to define alteration frequencies of TMEM41B and SLC4A7 on different types of PCa and to measure the mutual interaction potency and significance of co-occurence in PCa. This analysis showed that neuroendocrine prostate cancer (NEPC) had the highest total mutation frequency (22%) of TMEM41B and SLC4A7 genes. Also, TMEM41B and SLC4A7 genes had an average 2.1% pathway change potential among all different types of PCa. Moreover, TMEM41B and SLC4A7 gene pair was found significantly co-occurrent in PCa (p < 0.001). Finally, via GEPIA database, we used Spearman correlation analysis to measure the correlation degree of TMEM41B and SLC4A7 genes in PCa and found their significant correlation with PCa (p = 1.2 × 10-12, R = 0.28). All in all, it was proved in silico and supported with previously known clinical data that SLC4A7 and TMEM41B potentially have a significant and critical tumor suppressive role for PCa, and show this effect combinatorily working together. This is the first study correlating SLC4A7 and TMEM41B with PCa significantly.
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Affiliation(s)
- Sercan Ergün
- Department of Medical Biology, Bacis Sciences Division, Faculty of Medicine, Ordu University, 52200, Ordu, Turkey.
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30
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31
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Jensen HH, Pedersen GA, Morgen JJ, Parsons M, Pedersen SF, Nejsum LN. The Na + /H + exchanger NHE1 localizes as clusters to cryptic lamellipodia and accelerates collective epithelial cell migration. J Physiol 2018; 597:849-867. [PMID: 30471113 DOI: 10.1113/jp277383] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 11/16/2018] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS Exogenous Na+ /H+ exchanger 1 (NHE1) expression stimulated the collective migration of epithelial cell sheets Stimulation with epidermal growth factor, a key morphogen, primarily increased migration of the front row of cells, whereas NHE1 increased that of submarginal cell rows, and the two stimuli were additive Accordingly, NHE1 localized not only to the leading edges of leader cells, but also in cryptic lamellipodia in submarginal cell rows NHE1 expression disrupted the morphology of epithelial cell sheets and three-dimensional cysts ABSTRACT: Collective cell migration plays essential roles in embryonic development, in normal epithelial repair processes, and in many diseases including cancer. The Na+ /H+ exchanger 1 (NHE1, SLC9A1) is an important regulator of motility in many cells and has been widely studied for its roles in cancer, although its possible role in collective migration of normal epithelial cells has remained unresolved. In the present study, we show that NHE1 expression in MDCK-II kidney epithelial cells accelerated collective cell migration. NHE1 localized to the leading edges of leader cells, as well as to cryptic lamellipodia in submarginal cell rows. Epidermal growth factor, a kidney morphogen, increased displacement of the front row of collectively migrating cells and reduced the number of migration fingers. NHE1 expression increased the number of migration fingers and increased displacement of submarginal cell rows, resulting in additive effects of NHE1 and epidermal growth factor. Finally, NHE1 expression resulted in disorganized development of MDCK-II cell cysts. Thus, NHE1 contributes to collective migration and epithelial morphogenesis, suggesting roles for the transporter in embryonic and early postnatal development.
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Affiliation(s)
- Helene H Jensen
- Department of Clinical Medicine, Aarhus University, Denmark.,Department of Molecular Biology and Genetics, Aarhus University, Denmark.,Department of Chemistry and Bioscience, Aalborg University, Denmark
| | | | - Jeanette J Morgen
- Department of Clinical Medicine, Aarhus University, Denmark.,Department of Molecular Biology and Genetics, Aarhus University, Denmark
| | - Maddy Parsons
- Randall Division of Cell and Molecular Biophysics, King's College London, UK
| | - Stine F Pedersen
- Department of Biology, Section for Cell Biology and Physiology, University of Copenhagen, Denmark
| | - Lene N Nejsum
- Department of Clinical Medicine, Aarhus University, Denmark
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Flinck M, Kramer SH, Schnipper J, Andersen AP, Pedersen SF. The acid-base transport proteins NHE1 and NBCn1 regulate cell cycle progression in human breast cancer cells. Cell Cycle 2018; 17:1056-1067. [PMID: 29895196 DOI: 10.1080/15384101.2018.1464850] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Precise acid-base homeostasis is essential for maintaining normal cell proliferation and growth. Conversely, dysregulated acid-base homeostasis, with increased acid extrusion and marked extracellular acidification, is an enabling feature of solid tumors, yet the mechanisms through which intra- and extracellular pH (pHi, pHe) impact proliferation and growth are incompletely understood. The aim of this study was to determine the impact of pH, and specifically of the Na+/H+ exchanger NHE1 and Na+, HCO3- transporter NBCn1, on cell cycle progression and its regulators in human breast cancer cells. Reduction of pHe to 6.5, a common condition in tumors, significantly delayed cell cycle progression in MCF-7 human breast cancer cells. The NHE1 protein level peaked in S phase and that of NBCn1 in G2/M. Steady state pHi changed through the cell cycle, from 7.1 in early S phase to 6.8 in G2, recovering again in M phase. This pattern, as well as net acid extrusion capacity, was dependent on NHE1 and NBCn1. Accordingly, knockdown of either NHE1 or NBCn1 reduced proliferation, prolonged cell cycle progression in a manner involving S phase prolongation and delayed G2/M transition, and altered the expression pattern and phosphorylation of cell cycle regulatory proteins. Our work demonstrates, for the first time, that both NHE1 and NBCn1 regulate cell cycle progression in breast cancer cells, and we propose that this involves cell cycle phase-specific pHi regulation by the two transporters.
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Affiliation(s)
- Mette Flinck
- a Section for Cell Biology and Physiology, Department of Biology , University of Copenhagen , Copenhagen Ø , Denmark
| | - Signe Hoejland Kramer
- a Section for Cell Biology and Physiology, Department of Biology , University of Copenhagen , Copenhagen Ø , Denmark
| | - Julie Schnipper
- a Section for Cell Biology and Physiology, Department of Biology , University of Copenhagen , Copenhagen Ø , Denmark
| | - Anne Poder Andersen
- a Section for Cell Biology and Physiology, Department of Biology , University of Copenhagen , Copenhagen Ø , Denmark
| | - Stine Falsig Pedersen
- a Section for Cell Biology and Physiology, Department of Biology , University of Copenhagen , Copenhagen Ø , Denmark
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33
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Flinck M, Kramer SH, Pedersen SF. Roles of pH in control of cell proliferation. Acta Physiol (Oxf) 2018; 223:e13068. [PMID: 29575508 DOI: 10.1111/apha.13068] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 02/17/2018] [Accepted: 03/19/2018] [Indexed: 02/06/2023]
Abstract
Precise spatiotemporal regulation of intracellular pH (pHi ) is a prerequisite for normal cell function, and changes in pHi or pericellular pH (pHe ) exert important signalling functions. It is well established that proliferation of mammalian cells is dependent on a permissive pHi in the slightly alkaline range (7.0-7.2). It is also clear that mitogen signalling in nominal absence of HCO3- is associated with an intracellular alkalinization (~0.3 pH unit above steady-state pHi ), which is secondary to activation of Na+ /H+ exchange. However, it remains controversial whether this increase in pHi is part of the mitogenic signal cascade leading to cell cycle entry and progression, and whether it is relevant under physiological conditions. Furthermore, essentially all studies of pHi in mammalian cell proliferation have focused on the mitogen-induced G0-G1 transition, and the regulation and roles of pHi during the cell cycle remain poorly understood. The aim of this review is to summarize and critically discuss the possible roles of pHi and pHe in cell cycle progression. While the focus is on the mammalian cell cycle, important insights from studies in lower eukaryotes are also discussed. We summarize current evidence of links between cell cycle progression and pHi and discuss possible pHi - and pHe sensors and signalling pathways relevant to mammalian proliferation control. The possibility that changes in pHi during cell cycle progression may be an integral part of the checkpoint control machinery is explored. Finally, we discuss the relevance of links between pH and proliferation in the context of the perturbed pH homoeostasis and acidic microenvironment of solid tumours.
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Affiliation(s)
- M. Flinck
- Section for Cell Biology and Physiology; Department of Biology; Faculty of Science; University of Copenhagen; Copenhagen Denmark
| | - S. H. Kramer
- Section for Cell Biology and Physiology; Department of Biology; Faculty of Science; University of Copenhagen; Copenhagen Denmark
| | - S. F. Pedersen
- Section for Cell Biology and Physiology; Department of Biology; Faculty of Science; University of Copenhagen; Copenhagen Denmark
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34
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Na+,HCO3–-cotransporter NBCn1 (Slc4a7) accelerates ErbB2-induced breast cancer development and tumor growth in mice. Oncogene 2018; 37:5569-5584. [DOI: 10.1038/s41388-018-0353-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 05/07/2018] [Accepted: 05/13/2018] [Indexed: 12/20/2022]
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35
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Olesen CW, Vogensen J, Axholm I, Severin M, Schnipper J, Pedersen IS, von Stemann JH, Schrøder JM, Christensen DP, Pedersen SF. Trafficking, localization and degradation of the Na +,HCO 3- co-transporter NBCn1 in kidney and breast epithelial cells. Sci Rep 2018; 8:7435. [PMID: 29743600 PMCID: PMC5943355 DOI: 10.1038/s41598-018-25059-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 04/13/2018] [Indexed: 01/28/2023] Open
Abstract
The Na+;HCO3− co-transporter NBCn1 (SLC4A7) is a major regulator of intracellular pH yet its trafficking and turnover are essentially unstudied. Here, we used MDCK-II and MCF-7 cells to investigate these processes in epithelial cells. GFP-NBCn1 membrane localization was abolished by truncation of the full NBCn1 C-terminal tail (C-tail) yet did not require the C-terminal PDZ-binding motif (ETSL). Glutathione-S-Transferase-pulldown of the C-tail followed by mass spectrometry analysis revealed putative interactions with multiple sorting-, degradation- and retention factors, including the scaffolding protein RACK1. Pulldown of FLAG-tagged deletion constructs mapped the RACK1 interaction to the proximal NBCn1 C-tail. Proximity Ligation Assay and co-immunoprecipitation confirmed that native NBCn1 interacts with RACK1 in a cellular context. Consistent with a functional role of this complex, RACK1 knockdown reduced NBCn1 membrane localization without affecting total NBCn1 expression. Notably, only non-confluent cells exhibited detectable NBCn1-RACK1 plasma membrane co-localization, suggesting that RACK1 regulates the trafficking of NBCn1 to the membrane. Whereas total NBCn1 degradation was slow, with a half-life of more than 24 h, one-third of surface NBCn1 was constitutively endocytosed from the basolateral membrane within 60 min. This suggests that a fraction of NBCn1 exhibits recycling between the basolateral membrane and intracellular compartment(s). Our findings have important implications for understanding NBCn1 regulation as well as its dysregulation in disease.
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Affiliation(s)
- Christina Wilkens Olesen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Jens Vogensen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Ida Axholm
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Marc Severin
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Julie Schnipper
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Isabella Skandorff Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Jakob Hjorth von Stemann
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Jacob Morville Schrøder
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Dan Ploug Christensen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark.
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark.
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Na+/H+ exchanger 1 has tumor suppressive activity and prognostic value in esophageal squamous cell carcinoma. Oncotarget 2018; 8:2209-2223. [PMID: 27902974 PMCID: PMC5356793 DOI: 10.18632/oncotarget.13645] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 10/21/2016] [Indexed: 12/30/2022] Open
Abstract
Na+/H+ exchanger 1 (NHE1) is a plasma membrane transporter that controls intracellular pH and regulates apoptosis and invasion in various cancer cells. However, the function of NHE1 in esophageal squamous cell carcinoma (ESCC) cells and the relationship between the expression of NHE1 and prognosis of ESCC remain unclear. We found that the knockdown of NHE1 in ESCC cells inhibited apoptosis and promoted cell proliferation, migration, and invasion and showed increases in Snail, β-catenin, and activation of PI3K-AKT signaling, which was consistent with the results obtained from microarrays. Microarrays results suggested that the knockdown of NHE1 suppressed Notch signaling pathway. An immunohistochemical investigation of 61 primary ESCC samples revealed that NHE1 was expressed at higher levels in well-differentiated tumors. The 5-year survival rate was poorer in the NHE1 low group (57.0%) than in the NHE1 high group (82.8%). Multivariate analyses revealed that the weak expression of NHE1 was associated with shorter postoperative survival (hazard ratio 3.570, 95% CI 1.291-11.484, p = 0.0135).We herein demonstrated that the suppression of NHE1 in ESCC may enhance malignant potential by mediating PI3K-AKT signaling and EMT via Notch signaling, and may be related to a poor prognosis in patients with ESCC.
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Andersen AP, Samsøe-Petersen J, Oernbo EK, Boedtkjer E, Moreira JMA, Kveiborg M, Pedersen SF. The net acid extruders NHE1, NBCn1 and MCT4 promote mammary tumor growth through distinct but overlapping mechanisms. Int J Cancer 2018; 142:2529-2542. [PMID: 29363134 DOI: 10.1002/ijc.31276] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 12/16/2017] [Accepted: 01/17/2018] [Indexed: 01/01/2023]
Abstract
High metabolic and proliferative rates in cancer cells lead to production of large amounts of H+ and CO2 , and as a result, net acid extruding transporters are essential for the function and survival of cancer cells. We assessed protein expression of the Na+ /H+ exchanger NHE1, the Na+ - HCO3- cotransporter NBCn1, and the lactate-H+ cotransporters MCT1 and -4 by immunohistochemical analysis of a large cohort of breast cancer samples. We found robust expression of these transporters in 20, 10, 4 and 11% of samples, respectively. NHE1 and NBCn1 expression both correlated positively with progesterone receptor status, NHE1 correlated negatively and NBCn1 positively with HER2 status, whereas MCT4 expression correlated with lymph node status. Stable shRNA-mediated knockdown (KD) of either NHE1 or NBCn1 in the MDA-MB-231 triple-negative breast cancer (TNBC) cell line significantly reduced steady-state intracellular pH (pHi ) and capacity for pHi recovery after an acid load. Importantly, KD of any of the three transporters reduced in vivo primary tumor growth of MDA-MB-231 xenografts. However, whereas KD of NBCn1 or MCT4 increased tumor-free survival and decreased in vitro proliferation rate and colony growth in soft agar, KD of NHE1 did not have these effects. Moreover, only MCT4 KD reduced Akt kinase activity, PARP and CD147 expression and cell motility. This work reveals that different types of net acid extruding transporters, NHE1, NBCn1 and MCT4, are frequently expressed in patient mammary tumor tissue and demonstrates for the first time that they promote growth of TNBC human mammary tumors in vivo via distinct but overlapping mechanisms.
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Affiliation(s)
- Anne Poder Andersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jacob Samsøe-Petersen
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Eva Kjer Oernbo
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - José M A Moreira
- Section for Molecular Disease Biology, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marie Kveiborg
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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Pedersen AK, Mendes Lopes de Melo J, Mørup N, Tritsaris K, Pedersen SF. Tumor microenvironment conditions alter Akt and Na +/H + exchanger NHE1 expression in endothelial cells more than hypoxia alone: implications for endothelial cell function in cancer. BMC Cancer 2017; 17:542. [PMID: 28806945 PMCID: PMC5556346 DOI: 10.1186/s12885-017-3532-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 08/03/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Chronic angiogenesis is a hallmark of most tumors and takes place in a hostile tumor microenvironment (TME) characterized by hypoxia, low nutrient and glucose levels, elevated lactate and low pH. Despite this, most studies addressing angiogenic signaling use hypoxia as a proxy for tumor conditions. Here, we compared the effects of hypoxia and TME conditions on regulation of the Na+/H+ exchanger NHE1, Ser/Thr kinases Akt1-3, and downstream effectors in endothelial cells. METHODS Human umbilical vein endothelial cells (HUVEC) and Ea.hy926 endothelial cells were exposed to simulated TME (1% hypoxia, low serum, glucose, pH, high lactate) or 1% hypoxia for 24 or 48 h, with or without NHE1 inhibition or siRNA-mediated knockdown. mRNA and protein levels of NHE1, Akt1-3, and downstream effectors were assessed by qPCR and Western blotting, vascular endothelial growth factor (VEGF) release by ELISA, and motility by scratch assay. RESULTS Within 24 h, HIF-1α level and VEGF mRNA level were increased robustly by TME and modestly by hypoxia alone. The NHE1 mRNA level was decreased by both hypoxia and TME, and NHE1 protein was reduced by TME in Ea.hy926 cells. Akt1-3 mRNA was detected in HUVEC and Ea.hy926 cells, Akt1 most abundantly. Akt1 protein expression was reduced by TME yet unaffected by hypoxia, while Akt phosphorylation was increased by TME. The Akt loss was partly reversed by MCF-7 human breast cancer cell conditioned medium, suggesting that in vivo, the cancer cell secretome may compensate for adverse effects of TME on endothelial cells. TME, yet not hypoxia, reduced p70S6 kinase activity and ribosomal protein S6 phosphorylation and increased eIF2α phosphorylation, consistent with inhibition of protein translation. Finally, TME reduced Retinoblastoma protein phosphorylation and induced poly-ADP-ribose polymerase (PARP) cleavage consistent with inhibition of proliferation and induction of apoptosis. NHE1 knockdown, mimicking the effect of TME on NHE1 expression, reduced Ea.hy926 migration. TME effects on HIF-1α, VEGF, Akt, translation, proliferation or apoptosis markers were unaffected by NHE1 knockdown/inhibition. CONCLUSIONS NHE1 and Akt are downregulated by TME conditions, more potently than by hypoxia alone. This inhibits endothelial cell migration and growth in a manner likely modulated by the cancer cell secretome.
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Affiliation(s)
- A K Pedersen
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - J Mendes Lopes de Melo
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - N Mørup
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - K Tritsaris
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
| | - S F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen, Denmark.
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Dumas JF, Brisson L, Chevalier S, Mahéo K, Fromont G, Moussata D, Besson P, Roger S. Metabolic reprogramming in cancer cells, consequences on pH and tumour progression: Integrated therapeutic perspectives with dietary lipids as adjuvant to anticancer treatment. Semin Cancer Biol 2017; 43:90-110. [DOI: 10.1016/j.semcancer.2017.03.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 03/10/2017] [Accepted: 03/13/2017] [Indexed: 02/07/2023]
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Parks SK, Cormerais Y, Pouysségur J. Hypoxia and cellular metabolism in tumour pathophysiology. J Physiol 2017; 595:2439-2450. [PMID: 28074546 DOI: 10.1113/jp273309] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 12/01/2016] [Indexed: 12/17/2022] Open
Abstract
Cancer cells are optimised for growth and survival via an ability to outcompete normal cells in their microenvironment. Many of these advantageous cellular adaptations are promoted by the pathophysiological hypoxia that arises in solid tumours due to incomplete vascularisation. Tumour cells are thus faced with the challenge of an increased need for nutrients to support the drive for proliferation in the face of a diminished extracellular supply. Among the many modifications occurring in tumour cells, hypoxia inducible factors (HIFs) act as essential drivers of key pro-survival pathways via the promotion of numerous membrane and cytosolic proteins. Here we focus our attention on two areas: the role of amino acid uptake and the handling of metabolic acid (CO2 /H+ ) production. We provide evidence for a number of hypoxia-induced proteins that promote cellular anabolism and regulation of metabolic acid-base levels in tumour cells including amino-acid transporters (LAT1), monocarboxylate transporters, and acid-base regulating carbonic anhydrases (CAs) and bicarbonate transporters (NBCs). Emphasis is placed on current work manipulating multiple CA isoforms and NBCs, which is at an interesting crossroads of gas physiology as they are regulated by hypoxia to contribute to the cellular handling of CO2 and pHi regulation. Our research combined with others indicates that targeting of HIF-regulated membrane proteins in tumour cells will provide promising future anti-cancer therapeutic approaches and we suggest strategies that could be potentially used to enhance these tactics.
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Affiliation(s)
- Scott K Parks
- Medical Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, MC-98000, Monaco, Principality of Monaco
| | - Yann Cormerais
- Medical Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, MC-98000, Monaco, Principality of Monaco
| | - Jacques Pouysségur
- Medical Biology Department, Centre Scientifique de Monaco, 8 Quai Antoine 1er, MC-98000, Monaco, Principality of Monaco.,Institute for Research on Cancer and Aging (IRCAN), CNRS, INSERM, Centre A. Lacassagne, University of Nice-Sophia Antipolis, Nice, France
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White KA, Grillo-Hill BK, Barber DL. Cancer cell behaviors mediated by dysregulated pH dynamics at a glance. J Cell Sci 2017; 130:663-669. [PMID: 28202602 PMCID: PMC5339414 DOI: 10.1242/jcs.195297] [Citation(s) in RCA: 225] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Dysregulated pH is a common characteristic of cancer cells, as they have an increased intracellular pH (pHi) and a decreased extracellular pH (pHe) compared with normal cells. Recent work has expanded our knowledge of how dysregulated pH dynamics influences cancer cell behaviors, including proliferation, metastasis, metabolic adaptation and tumorigenesis. Emerging data suggest that the dysregulated pH of cancers enables these specific cell behaviors by altering the structure and function of selective pH-sensitive proteins, termed pH sensors. Recent findings also show that, by blocking pHi increases, cancer cell behaviors can be attenuated. This suggests ion transporter inhibition as an effective therapeutic approach, either singly or in combination with targeted therapies. In this Cell Science at a Glance article and accompanying poster, we highlight the interconnected roles of dysregulated pH dynamics in cancer initiation, progression and adaptation.
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Affiliation(s)
- Katharine A White
- Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Bree K Grillo-Hill
- Department of Biological Sciences, San José State University, San José, CA 95192, USA
| | - Diane L Barber
- Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, CA 94143, USA
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42
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Targeting pH regulating proteins for cancer therapy-Progress and limitations. Semin Cancer Biol 2017; 43:66-73. [PMID: 28137473 DOI: 10.1016/j.semcancer.2017.01.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 01/24/2017] [Indexed: 12/21/2022]
Abstract
Tumour acidity induced by metabolic alterations and incomplete vascularisation sets cancer cells apart from normal cellular physiology. This distinguishing tumour characteristic has been an area of intense study, as cellular pH (pHi) disturbances disrupt protein function and therefore multiple cellular processes. Tumour cells effectively utilise pHi regulating machinery present in normal cells with enhancements provided by additional oncogenic or hypoxia induced protein modifications. This overall improvement of pH regulation enables maintenance of an alkaline pHi in the continued presence of external acidification (pHe). Considerable experimentation has revealed targets that successfully disrupt tumour pHi regulation in efforts to develop novel means to weaken or kill tumour cells. However, redundancy in these pH-regulating proteins, which include Na+/H+ exchangers (NHEs), carbonic anhydrases (CAs), Na+/HCO3- co-transporters (NBCs) and monocarboxylate transporters (MCTs) has prevented effective disruption of tumour pHi when individual protein targeting is performed. Here we synthesise recent advances in understanding both normoxic and hypoxic pH regulating mechanisms in tumour cells with an ultimate focus on the disruption of tumour growth, survival and metastasis. Interactions between tumour acidity and other cell types are also proving to be important in understanding therapeutic applications such as immune therapy. Promising therapeutic developments regarding pH manipulation along with current limitations are highlighted to provide a framework for future research directives.
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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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Oncogenic p95HER2 regulates Na+-HCO3- cotransporter NBCn1 mRNA stability in breast cancer cells via 3'UTR-dependent processes. Biochem J 2016; 473:4027-4044. [PMID: 27609814 DOI: 10.1042/bcj20160054] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 09/08/2016] [Indexed: 02/08/2023]
Abstract
The Na+-HCO3- cotransporter NBCn1 (SLC4A7) is up-regulated in breast cancer, important for tumor growth, and a single nucleotide polymorphism (SNP), rs4973768, in its 3' untranslated region (3'UTR) correlates with increased breast cancer risk. We previously demonstrated that NBCn1 expression and promoter activity are strongly increased in breast cancer cells expressing a constitutively active oncogenic human epidermal growth factor receptor 2 (HER2) (p95HER2). Here, we address the roles of p95HER2 in regulating NBCn1 expression via post-transcriptional mechanisms. p95HER2 expression in MCF-7 cells reduced the rate of NBCn1 mRNA degradation. The NBCn1 3'UTR down-regulated luciferase reporter expression in control cells, and this was reversed by p95HER2, suggesting that p95HER2 counteracts 3'UTR-mediated suppression of NBCn1 expression. Truncation analyses identified three NBCn1 3'UTR regions of regulatory importance. Mutation of putative miRNA-binding sites (miR-374a/b, miR-200b/c, miR-29a/b/c, miR-488) in these regions did not have significant impact on 3'UTR activity. The NBCn1 3'UTR interacted directly with the RNA-binding protein human antigen R (HuR), and HuR knockdown reduced NBCn1 expression. Conversely, ablation of a distal AU-rich element increased 3'UTR-driven reporter activity, suggesting complex regulatory roles of these sites. The cancer-associated SNP variant decreased reporter expression in T-47D breast cancer cells, yet not in MCF-7, MDA-MB-231 and SK-BR-3 cells, arguing against a general role in regulating NBCn1 expression. Finally, p95HER2 expression increased total and plasma membrane NBCn1 protein levels and decreased the rate of NBCn1 protein degradation. Collectively, this is the first work to demonstrate 3'UTR-mediated NBCn1 regulation, shows that p95HER2 regulates NBCn1 expression at multiple levels, and substantiates the central position of p95HER2-NBCn1 signaling in breast cancer.
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Wang T, Fei HJ, Yang Y, Jiang XS, Yan M, Zeng Z, Wu J, Song LJ, Tian H, Fu GH. Expression of AE1/p16 promoted degradation of AE2 in gastric cancer cells. BMC Cancer 2016; 16:716. [PMID: 27595783 PMCID: PMC5011918 DOI: 10.1186/s12885-016-2751-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Accepted: 08/26/2016] [Indexed: 12/19/2022] Open
Abstract
Background Human anion exchanger 1 and 2 (AE1 and AE2) mediate the exchange of Cl−/HCO3− across the plasma membrane and regulate intracellular pH (pHi). AE1 is specifically expressed on the surface of erythrocytes, while AE2 is widely expressed in most tissues, and is particularly abundant in parietal cells. Previous studies showed that an interaction between AE1 and p16 is a key event in gastric cancer (GC) progression, but the importance of AE2 in GC is unclear. Methods The relationship among AE1, AE2 and p16 in GC cells was characterized by molecular and cellular experiments. AE2 expression and pHi were measured after knockdown or forced expression of AE1 or p16 in GC cells. The effect of AE2 on GC growth and the correlation of AE2 expression with differentiation and prognosis of GC were also evaluated. The effect of gastrin on AE2 expression and GC growth was investigated in cellular experiments and mouse xenograft models. Results p16 binds to both AE1 and AE2 simultaneously. AE1 or p16 silencing elevated AE2 expression on the plasma membrane where it plays a role in pHi regulation and GC suppression. AE2 expression was decreased in GC tissue, and these decreased levels were correlated with poor differentiation and prognosis of GC. The low AE2 protein levels are due to rapid ubiquitin-mediated degradation that was facilitated in the presence of p16. Gastrin inhibited the growth of GC cells at least partially through up-regulation of AE2 expression. Conclusion AE1/p16 expression promoted AE2 degradation in GC cells. Gastrin is a potential candidate drug for targeted therapies for AE1- and p16-positive GC.
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Affiliation(s)
- Ting Wang
- Pathology Center, Shanghai General Hospital/Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, No.280, South Chong-Qing Road, Shanghai, 200025, People's Republic of China
| | - Hong-Jun Fei
- Pathology Center, Shanghai General Hospital/Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, No.280, South Chong-Qing Road, Shanghai, 200025, People's Republic of China
| | - Ye Yang
- Department of Digestive Medicine, Ningbo No. 2 Hospital, Ningbo, 315010, People's Republic of China
| | - Xiao-Shu Jiang
- Department of Pathophysiology, Harbin Medical University, Harbin, 150081, People's Republic of China
| | - Min Yan
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, People's Republic of China
| | - Zhi Zeng
- Pathology Center, Shanghai General Hospital/Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, No.280, South Chong-Qing Road, Shanghai, 200025, People's Republic of China
| | - Jun Wu
- Pathology Center, Shanghai General Hospital/Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, No.280, South Chong-Qing Road, Shanghai, 200025, People's Republic of China
| | - Ling-Jun Song
- Pathology Center, Shanghai General Hospital/Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, No.280, South Chong-Qing Road, Shanghai, 200025, People's Republic of China
| | - Hua Tian
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200032, People's Republic of China
| | - Guo-Hui Fu
- Pathology Center, Shanghai General Hospital/Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, No.280, South Chong-Qing Road, Shanghai, 200025, People's Republic of China.
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Epi-reevesioside F inhibits Na+/K+-ATPase, causing cytosolic acidification, Bak activation and apoptosis in glioblastoma. Oncotarget 2016; 6:24032-46. [PMID: 26125228 PMCID: PMC4695168 DOI: 10.18632/oncotarget.4429] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 06/04/2015] [Indexed: 12/17/2022] Open
Abstract
Epi-reevesioside F, a new cardiac glycoside isolated from the root of Reevesia formosana, displayed potent activity against glioblastoma cells. Epi-reevesioside F was more potent than ouabain with IC50 values of 27.3±1.7 vs. 48.7±1.8 nM (P < 0.001) and 45.0±3.4 vs. 81.3±4.3 nM (P < 0.001) in glioblastoma T98 and U87 cells, respectively. However, both Epi-reevesioside F and ouabain were ineffective in A172 cells, a glioblastoma cell line with low Na+/K+-ATPase α3 subunit expression. Epi-reevesioside F induced cell cycle arrest at S and G2 phases and apoptosis. It also induced an increase of intracellular concentration of Na+ but not Ca2+, cleavage and exposure of N-terminus of Bak, loss of mitochondrial membrane potential, inhibition of Akt activity and induction of caspase cascades. Potassium supplements significantly inhibited Epi-reevesioside F-induced effects. Notably, Epi-reevesioside F caused cytosolic acidification that was highly correlated with the anti-proliferative activity. In summary, the data suggest that Epi-reevesioside F inhibits Na+/K+-ATPase, leading to overload of intracellular Na+ and cytosolic acidification, Bak activation and loss of mitochondrial membrane potential. The PI3-kinase/Akt pathway is inhibited and caspase-dependent apoptosis is ultimately triggered in Epi-reevesioside F-treated glioblastoma cells.
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Andersen AP, Flinck M, Oernbo EK, Pedersen NB, Viuff BM, Pedersen SF. Roles of acid-extruding ion transporters in regulation of breast cancer cell growth in a 3-dimensional microenvironment. Mol Cancer 2016; 15:45. [PMID: 27266704 PMCID: PMC4896021 DOI: 10.1186/s12943-016-0528-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Accepted: 05/20/2016] [Indexed: 12/20/2022] Open
Abstract
Background The 3-dimensional (3D) microenvironment of breast carcinomas is characterized by profoundly altered pH homeostasis, reflecting increased metabolic acid production and a confined extracellular space characterized by poor diffusion, yet the relative contributions of specific pH-regulatory transporters to 3D growth are poorly understood. The aim of this work was to determine how 3D spheroid growth of breast cancer cells impacts the expression and spatial organization of major acid extruding proteins, and how these proteins in turn are required for spheroid growth. Methods MCF-7 (Luminal-A) and MDA-MB-231 (Triple-negative) human breast cancer cells were grown as ~700-950 μm diameter spheroids, which were subjected to Western blotting for relevant transporters (2- and 3D growth), quantitative immunohistochemical analysis, and spheroid growth assays. Individual transporter contributions were assessed (i) pharmacologically, (ii) by stable shRNA- and transient siRNA-mediated knockdown, and (iii) by CRISPR/Cas9 knockout. Results In MCF-7 spheroids, expression of the lactate-H+ cotransporter MCT1 (SLC16A1) increased from the spheroid periphery to its core, the Na+,HCO3− cotransporter NBCn1 (SLC4A7) was most highly expressed at the periphery, and the Na+/H+ exchanger NHE1 (SLC9A1) and MCT4 (SLC16A3) were evenly distributed. A similar pattern was seen in MDA-MB-231 spheroids, except that these cells do not express MCT1. The relative total expression of NBCn1 and NHE1 was decreased in 3D compared to 2D, while that of MCT1 and MCT4 was unaltered. Inhibition of MCT1 (AR-C155858) attenuated MCF-7 spheroid growth and this was exacerbated by addition of S0859, an inhibitor of Na+,HCO3− cotransporters and MCTs. The pharmacological data was recapitulated by stable knockdown of MCT1 or NBCn1, whereas knockdown of MCT4 had no effect. CRISPR/Cas9 knockout of NHE1, but neither partial NHE1 knockdown nor the NHE1 inhibitor cariporide, inhibited MCF-7 spheroid growth. In contrast, growth of MDA-MB-231 spheroids was inhibited by stable or transient NHE1 knockdown and by NHE1 knockout, but not by knockdown of NBCn1 or MCT4. Conclusions This work demonstrates the distinct expression and localization patterns of four major acid-extruding transporters in 3D spheroids of human breast cancer cells and reveals that 3D growth is dependent on these transporters in a cell type-dependent manner, with potentially important implications for breast cancer therapy. Electronic supplementary material The online version of this article (doi:10.1186/s12943-016-0528-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anne Poder Andersen
- Department of Biology, Section for Cell Biology and Physiology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark
| | - Mette Flinck
- Department of Biology, Section for Cell Biology and Physiology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark
| | - Eva Kjer Oernbo
- Department of Biology, Section for Cell Biology and Physiology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark
| | - Nis Borbye Pedersen
- Department of Biology, Section for Cell Biology and Physiology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark
| | - Birgitte Martine Viuff
- Department of Veterinary Disease Biology, Section for Molecular Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Strandboulevarden 49, DK-2100, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Department of Biology, Section for Cell Biology and Physiology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark.
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48
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Pedraz-Cuesta E, Fredsted J, Jensen HH, Bornebusch A, Nejsum LN, Kragelund BB, Pedersen SF. Prolactin Signaling Stimulates Invasion via Na(+)/H(+) Exchanger NHE1 in T47D Human Breast Cancer Cells. Mol Endocrinol 2016; 30:693-708. [PMID: 27176613 DOI: 10.1210/me.2015-1299] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Prolactin (PRL) and its receptor (PRLR) are implicated in breast cancer invasiveness, although their exact roles remain controversial. The Na(+)/H(+) exchanger (NHE1) plays essential roles in cancer cell motility and invasiveness, but the PRLR and NHE1 have not previously been linked. Here we show that in T47D human breast cancer cells, which express high levels of PRLR and NHE1, exposure to PRL led to the activation of Janus kinase-2 (JAK2)/signal transducer and activator of transcription-5 (STAT5), Akt, and ERK1/2 signaling and the rapid formation of peripheral membrane ruffles, known to be associated with cell motility. NHE1 was present in small ruffles prior to PRL treatment and was further recruited to the larger, more dynamic ruffles induced by PRL exposure. In PRL-induced ruffles, NHE1 colocalized with activated Akt, ERK1/2, and the ERK effector p90Ribosomal S kinase (p90RSK), known regulators of NHE1 activity. Stimulation of T47D cells with PRL augmented p90RSK activation, Ser703-phosphorylation of NHE1, NHE1-dependent intracellular pH recovery, pericellular acidification, and NHE1-dependent invasiveness. NHE1 activity and localization to ruffles were attenuated by the inhibition of Akt and/or ERK1/2. In contrast, noncancerous MCF10A breast epithelial cells expressed NHE1 and PRLR at lower levels than T47D cells, and their stimulation with PRL induced neither NHE1 activation nor NHE1-dependent invasiveness. In conclusion, we show for the first time that PRLR activation stimulates breast cancer cell invasiveness via the activation of NHE1. We propose that PRL-induced NHE1 activation and the resulting NHE1-dependent invasiveness may contribute to the metastatic behavior of human breast cancer cells.
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Affiliation(s)
- Elena Pedraz-Cuesta
- Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark
| | - Jacob Fredsted
- Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark
| | - Helene H Jensen
- Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark
| | - Annika Bornebusch
- Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark
| | - Lene N Nejsum
- Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark
| | - Birthe B Kragelund
- Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark
| | - Stine F Pedersen
- Section for Cell Biology and Physiology (E.P.-C., J.F., A.B., S.F.P.), Department of Biology, and Structural Biology and NMR laboratory (B.B.K.), Department of Biology, University of Copenhagen, DK-2200 Copenhagen, Denmark; and Department of Molecular Biology and Genetics (H.H.J.) and Department of Clinical Medicine and Interdisciplinary Nanoscience Center (H.H.J., L.N.N.), Aarhus University, DK-8000 Aarhus C, Denmark
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Haining AWM, Lieberthal TJ, Hernández ADR. Talin: a mechanosensitive molecule in health and disease. FASEB J 2016; 30:2073-85. [DOI: 10.1096/fj.201500080r] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/09/2016] [Indexed: 12/22/2022]
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50
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Hypoxia optimises tumour growth by controlling nutrient import and acidic metabolite export. Mol Aspects Med 2016; 47-48:3-14. [DOI: 10.1016/j.mam.2015.12.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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