1
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Kito H, Kawagishi R, Ryu T, Endo K, Kajikuri J, Giles WR, Ohya S. K Ca3.1 regulates cell cycle progression by modulating Ca 2+ signaling in murine preosteoblasts. J Pharmacol Sci 2023; 153:142-152. [PMID: 37770155 DOI: 10.1016/j.jphs.2023.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 08/28/2023] [Accepted: 09/04/2023] [Indexed: 10/03/2023] Open
Abstract
Osteoblasts synthesize and deposit essential components of the extracellular bone matrix and collagen scaffolds, leading to mineralized bone formation. Therefore, the proliferation of preosteoblasts (precursors of mature osteoblasts) helps in regulating skeletal homeostasis. This study demonstrated that the functional expression of KCa3.1, an intermediate-conductance Ca2+-activated K+ channel, is markedly upregulated in murine preosteoblastic MC3T3-E1 cells in the G0/G1 phase. The enhancement of KCa3.1 is involved in the establishment of more negative membrane potentials in MC3T3-E1 cells. This hyperpolarization can promote intracellular Ca2+ signaling because store-operated Ca2+ channels are activated. Treatment with TRAM-34, a specific KCa3.1 inhibitor, attenuated the cell cycle progression from the G0/G1 phase to the S/G2/M phases. In MC3T3-E1 cells, KCa3.1 significantly promoted the transition from the G1 phase to the S phase. KCa3.1 inhibition also caused G0 phase cell accumulation. Furthermore, TRAM-34 decreased the expression of alkaline phosphatase, bone sialoprotein, and osteocalcin, osteoblast differentiation markers in MC3T3-E1 cells, and inhibited the endochondral ossification of murine metatarsals. These results reveal novel ways by which KCa3.1 activity can strongly modulate osteoblast maturation during bone formation.
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Affiliation(s)
- Hiroaki Kito
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan.
| | - Reiko Kawagishi
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Takusei Ryu
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Kyoko Endo
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Junko Kajikuri
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Wayne R Giles
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Susumu Ohya
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
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2
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Eskandari N, Gentile S. Potassium channels activity unveils cancer vulnerability. CURRENT TOPICS IN MEMBRANES 2023; 92:1-14. [PMID: 38007264 DOI: 10.1016/bs.ctm.2023.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
"No cell could exist without ion channels" (Clay Armstrong; 1999). Since the discovery in the early 1950s, that ions move across biological membranes, the idea that changes of ionic gradients can generate biological signals has fascinated scientists in any fields. Soon later (1960s) it was found that ionic flows were controlled by a class of specific and selective proteins called ion channels. Thus, it became clear that the concerted activities of these proteins can initiate, arrest, and finely tune a variety of biochemical cascades which offered the opportunity to better understand both biology and pathology. Cancer is a disease that is notoriously difficult to treat due its heterogeneous nature which makes it the deadliest disease in the developed world. Recently, emerging evidence has established that potassium channels are critical modulators of several hallmarks of cancer including tumor growth, metastasis, and metabolism. Nevertheless, the role of potassium ion channels in cancer biology and the therapeutic potential offered by targeting these proteins has not been explored thoroughly. This chapter is addressed to both cancer biologists and ion channels scientists and it aims to shine a light on the established and potential roles of potassium ion channels in cancer biology and on the therapeutic benefit of targeting potassium channels with activator molecules.
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Affiliation(s)
- Najmeh Eskandari
- Department of Cell and Molecular Pharmacology & Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, United States
| | - Saverio Gentile
- Department of Cell and Molecular Pharmacology & Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, United States.
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3
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Xia C, Liu C, Ren S, Cai Y, Zhang Q, Xia C. Potassium channels, tumorigenesis and targeted drugs. Biomed Pharmacother 2023; 162:114673. [PMID: 37031494 DOI: 10.1016/j.biopha.2023.114673] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/03/2023] [Accepted: 04/06/2023] [Indexed: 04/11/2023] Open
Abstract
Potassium channels play an important role in human physiological function. Recently, various molecular mechanisms have implicated abnormal functioning of potassium channels in the proliferation, migration, invasion, apoptosis, and cancer stem cell phenotype formation. Potassium channels also mediate the association of tumor cells with the tumor microenvironment. Meanwhile, potassium channels are important targets for cancer chemotherapy. A variety of drugs exert anti-cancer effects by modulating potassium channels in tumor cells. Therefore, there is a need to understand how potassium channels participate in tumor development and progression, which could reveal new, novel targets for cancer diagnosis and treatment. This review summarizes the roles of voltage-gated potassium channels, calcium-activated potassium channels, inwardly rectifying potassium channels, and two-pore domain potassium channels in tumorigenesis and the underlying mechanism of potassium channel-targeted drugs. Therefore, the study lays the foundation for rational and effective drug design and individualized clinical therapeutics.
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Affiliation(s)
- Cong Xia
- Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning Province 116023, China
| | - Can Liu
- Affiliated Foshan Maternity and Child Healthcare Hospital, Southern Medical University, Foshan, Guangdong Province 528099, China; School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, China
| | - Shuangyi Ren
- Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning Province 116023, China
| | - Yantao Cai
- Affiliated Foshan Maternity and Child Healthcare Hospital, Southern Medical University, Foshan, Guangdong Province 528099, China
| | - Qianshi Zhang
- Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning Province 116023, China.
| | - Chenglai Xia
- Affiliated Foshan Maternity and Child Healthcare Hospital, Southern Medical University, Foshan, Guangdong Province 528099, China; School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, China.
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4
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Soret B, Hense J, Lüdtke S, Thale I, Schwab A, Düfer M. Pancreatic K Ca3.1 channels in health and disease. Biol Chem 2023; 404:339-353. [PMID: 36571487 DOI: 10.1515/hsz-2022-0232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 11/24/2022] [Indexed: 12/27/2022]
Abstract
Ion channels play an important role for regulation of the exocrine and the endocrine pancreas. This review focuses on the Ca2+-regulated K+ channel KCa3.1, encoded by the KCNN4 gene, which is present in both parts of the pancreas. In the islets of Langerhans, KCa3.1 channels are involved in the regulation of membrane potential oscillations characterizing nutrient-stimulated islet activity. Channel upregulation is induced by gluco- or lipotoxic conditions and might contribute to micro-inflammation and impaired insulin release in type 2 diabetes mellitus as well as to diabetes-associated renal and vascular complications. In the exocrine pancreas KCa3.1 channels are expressed in acinar and ductal cells. They are thought to play a role for anion secretion during digestion but their physiological role has not been fully elucidated yet. Pancreatic carcinoma, especially pancreatic ductal adenocarcinoma (PDAC), is associated with drastic overexpression of KCa3.1. For pharmacological targeting of KCa3.1 channels, we are discussing the possible benefits KCa3.1 channel inhibitors might provide in the context of diabetes mellitus and pancreatic cancer, respectively. We are also giving a perspective for the use of a fluorescently labeled derivative of the KCa3.1 blocker senicapoc as a tool to monitor channel distribution in pancreatic tissue. In summary, modulating KCa3.1 channel activity is a useful strategy for exo-and endocrine pancreatic disease but further studies are needed to evaluate its clinical suitability.
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Affiliation(s)
- Benjamin Soret
- University of Münster, Institute of Physiology II, Robert-Koch-Straße 27b, D-48149 Münster, Germany
| | - Jurek Hense
- University of Münster, Institute of Pharmaceutical and Medicinal Chemistry, Department of Pharmacology, Corrensstraße 48, D-48149 Münster, Germany
| | - Simon Lüdtke
- University of Münster, Institute of Pharmaceutical and Medicinal Chemistry, Department of Pharmacology, Corrensstraße 48, D-48149 Münster, Germany
| | - Insa Thale
- University of Münster, Institute of Pharmaceutical and Medicinal Chemistry, Corrensstraße 48, D-48149 Münster, Germany
| | - Albrecht Schwab
- University of Münster, Institute of Physiology II, Robert-Koch-Straße 27b, D-48149 Münster, Germany
| | - Martina Düfer
- University of Münster, Institute of Pharmaceutical and Medicinal Chemistry, Department of Pharmacology, Corrensstraße 48, D-48149 Münster, Germany
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5
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Zhao H, Wang X, Tang Y, Zhao Q, Huang C. Inhibition of intermittent calcium-activated potassium channel (SK4) attenuates Ang II-induced hypertrophy of human-induced stem cell-derived cardiomyocytes via targeting Ras-Raf-MEK1/2-ERK1/2 and CN-NFAT signaling pathways. Cell Biol Int 2023; 47:480-491. [PMID: 36273427 DOI: 10.1002/cbin.11948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/20/2022] [Accepted: 10/15/2022] [Indexed: 01/17/2023]
Abstract
Cardiac hypertrophy caused by angiotensin II (Ang II) is essential for the pathological process of heart failure. The intermediate calcium-activated potassium channel (SK4) has been shown to be involved in the process of the inflammatory response, cell proliferation, and apoptosis. However, the role of SK4 in cardiac hypertrophy has not been elucidated. Cardiac hypertrophy in human-induced pluripotent stem cells-derived cardiomyocytes (HiPSC-CMs) was induced by Ang II. Cells were transfected with SK4 adenovirus or treated with SK4 inhibitor (TRAM-34). TUNEL staining was used to assess the levels of apoptosis. Real-time polymerase chain reaction and Western blot analysis were used to measure messenger RNA (mRNA) and protein levels, respectively. The present results showed that SK4 expression was upregulated in HiPSC-CMs stimulated by Ang II. The downregulation of SK4 by a specific inhibitor TRAM-34 markedly ameliorated cardiac hypertrophy (reflected by the mRNA levels of atrial natriuretic peptide, brain natriuretic peptide, and β-myosin heavy chain) and apoptosis (reflected by the level of Caspase 3, Bax, and Bcl-2) induced by Ang II treatment. The action of SK4 in cardiac hypertrophy was mediated by Ras-Raf-mitogen-activated protein kinases 1/2 (MEK1/2)-extracellular-regulated protein kinases 1/2 (ERK1/2) and calcineurin (CN)-nuclear factors of activated T cells (NFAT) activation. Our studies demonstrated that inhibition of SK4 significantly alleviated cardiac hypertrophy induced by Ang II in hiPSC-CMs by targeting Ras-Raf-MEK1/2-ERK1/2 signaling and CN-NFAT signaling pathway. Our studies suggest that SK4 may serve as a potential therapeutic target that could delay hypertrophy.
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Affiliation(s)
- Hongyi Zhao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, P. R. China.,Cardiovascular Research Institute, Wuhan University, Wuhan, P. R. China.,Hubei Key Laboratory of Cardiology, Wuhan, P. R. China
| | - Xi Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, P. R. China.,Cardiovascular Research Institute, Wuhan University, Wuhan, P. R. China.,Hubei Key Laboratory of Cardiology, Wuhan, P. R. China
| | - Yanhong Tang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, P. R. China.,Cardiovascular Research Institute, Wuhan University, Wuhan, P. R. China.,Hubei Key Laboratory of Cardiology, Wuhan, P. R. China
| | - Qingyan Zhao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, P. R. China.,Cardiovascular Research Institute, Wuhan University, Wuhan, P. R. China.,Hubei Key Laboratory of Cardiology, Wuhan, P. R. China
| | - Congxin Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, P. R. China.,Cardiovascular Research Institute, Wuhan University, Wuhan, P. R. China.,Hubei Key Laboratory of Cardiology, Wuhan, P. R. China
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6
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Tiffner A, Hopl V, Derler I. CRAC and SK Channels: Their Molecular Mechanisms Associated with Cancer Cell Development. Cancers (Basel) 2022; 15:cancers15010101. [PMID: 36612099 PMCID: PMC9817886 DOI: 10.3390/cancers15010101] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 12/28/2022] Open
Abstract
Cancer represents a major health burden worldwide. Several molecular targets have been discovered alongside treatments with positive clinical outcomes. However, the reoccurrence of cancer due to therapy resistance remains the primary cause of mortality. Endeavors in pinpointing new markers as molecular targets in cancer therapy are highly desired. The significance of the co-regulation of Ca2+-permeating and Ca2+-regulated ion channels in cancer cell development, proliferation, and migration make them promising molecular targets in cancer therapy. In particular, the co-regulation of the Orai1 and SK3 channels has been well-studied in breast and colon cancer cells, where it finally leads to an invasion-metastasis cascade. Nevertheless, many questions remain unanswered, such as which key molecular components determine and regulate their interplay. To provide a solid foundation for a better understanding of this ion channel co-regulation in cancer, we first shed light on the physiological role of Ca2+ and how this ion is linked to carcinogenesis. Then, we highlight the structure/function relationship of Orai1 and SK3, both individually and in concert, their role in the development of different types of cancer, and aspects that are not yet known in this context.
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7
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Pharmacological targeting of the mitochondrial calcium-dependent potassium channel KCa3.1 triggers cell death and reduces tumor growth and metastasis in vivo. Cell Death Dis 2022; 13:1055. [PMID: 36539400 PMCID: PMC9768205 DOI: 10.1038/s41419-022-05463-8] [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: 07/27/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 12/24/2022]
Abstract
Ion channels are non-conventional, druggable oncological targets. The intermediate-conductance calcium-dependent potassium channel (KCa3.1) is highly expressed in the plasma membrane and in the inner mitochondrial membrane (mitoKCa3.1) of various cancer cell lines. The role mitoKCa3.1 plays in cancer cells is still undefined. Here we report the synthesis and characterization of two mitochondria-targeted novel derivatives of a high-affinity KCa3.1 antagonist, TRAM-34, which retain the ability to block channel activity. The effects of these drugs were tested in melanoma, pancreatic ductal adenocarcinoma and breast cancer lines, as well as in vivo in two orthotopic models. We show that the mitochondria-targeted TRAM-34 derivatives induce release of mitochondrial reactive oxygen species, rapid depolarization of the mitochondrial membrane, fragmentation of the mitochondrial network. They trigger cancer cell death with an EC50 in the µM range, depending on channel expression. In contrast, inhibition of the plasma membrane KCa3.1 by membrane-impermeant Maurotoxin is without effect, indicating a specific role of mitoKCa3.1 in determining cell fate. At sub-lethal concentrations, pharmacological targeting of mitoKCa3.1 significantly reduced cancer cell migration by enhancing production of mitochondrial reactive oxygen species and nuclear factor-κB (NF-κB) activation, and by downregulating expression of Bcl-2 Nineteen kD-Interacting Protein (BNIP-3) and of Rho GTPase CDC-42. This signaling cascade finally leads to cytoskeletal reorganization and impaired migration. Overexpression of BNIP-3 or pharmacological modulation of NF-κB and CDC-42 prevented the migration-reducing effect of mitoTRAM-34. In orthotopic models of melanoma and pancreatic ductal adenocarcinoma, the tumors at sacrifice were 60% smaller in treated versus untreated animals. Metastasis of melanoma cells to lymph nodes was also drastically reduced. No signs of toxicity were observed. In summary, our results identify mitochondrial KCa3.1 as an unexpected player in cancer cell migration and show that its pharmacological targeting is efficient against both tumor growth and metastatic spread in vivo.
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8
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IK Ca channels control breast cancer metabolism including AMPK-driven autophagy. Cell Death Dis 2022; 13:902. [PMID: 36302750 PMCID: PMC9613901 DOI: 10.1038/s41419-022-05329-z] [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: 06/22/2022] [Revised: 09/28/2022] [Accepted: 10/07/2022] [Indexed: 11/30/2022]
Abstract
Ca2+-activated K+ channels of intermediate conductance (IK) are frequently overexpressed in breast cancer (BC) cells, while IK channel depletion reduces BC cell proliferation and tumorigenesis. This raises the question, of whether and mechanistically how IK activity interferes with the metabolic activity and energy consumption rates, which are fundamental for rapidly growing cells. Using BC cells obtained from MMTV-PyMT tumor-bearing mice, we show that both, glycolysis and mitochondrial ATP-production are reduced in cells derived from IK-deficient breast tumors. Loss of IK altered the sub-/cellular K+- and Ca2+- homeostasis and mitochondrial membrane potential, ultimately resulting in reduced ATP-production and metabolic activity. Consequently, we find that BC cells lacking IK upregulate AMP-activated protein kinase activity to induce autophagy compensating the glycolytic and mitochondrial energy shortage. Our results emphasize that IK by modulating cellular Ca2+- and K+-dynamics contributes to the remodeling of metabolic pathways in cancer. Thus, targeting IK channel might disturb the metabolic activity of BC cells and reduce malignancy.
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9
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Konken CP, Heßling K, Thale I, Schelhaas S, Dabel J, Maskri S, Bulk E, Budde T, Koch O, Schwab A, Schäfers M, Wünsch B. Imaging of the calcium activated potassium channel 3.1 (K Ca 3.1) in vivo using a senicapoc-derived positron emission tomography tracer. Arch Pharm (Weinheim) 2022; 355:e2200388. [PMID: 36161669 DOI: 10.1002/ardp.202200388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 09/05/2022] [Accepted: 09/06/2022] [Indexed: 11/10/2022]
Abstract
The calcium-activated potassium channel 3.1 (KCa 3.1) is overexpressed in many tumor entities and has predictive power concerning disease progression and outcome. Imaging of the KCa 3.1 channel in vivo using a radiotracer for positron emission tomography (PET) could therefore establish a potentially powerful diagnostic tool. Senicapoc shows high affinity and excellent selectivity toward the KCa 3.1 channel. We have successfully pursued the synthesis of the 18 F-labeled derivative [18 F]3 of senicapoc using the prosthetic group approach with 1-azido-2-[18 F]fluoroethane ([18 F]6) in a "click" reaction. The biological activity of the new PET tracer was evaluated in vitro and in vivo. Inhibition of the KCa 3.1 channel by 3 was demonstrated by patch clamp experiments and the binding pose was analyzed by docking studies. In mouse and human serum, [18 F]3 was stable for at least one half-life of [18 F]fluorine. Biodistribution experiments in wild-type mice were promising, showing rapid and predominantly renal excretion. An in vivo study using A549-based tumor-bearing mice was performed. The tumor signal could be delineated and image analysis showed a tumor-to-muscle ratio of 1.47 ± 0.24. The approach using 1-azido-2-[18 F]fluoroethane seems to be a good general strategy to achieve triarylacetamide-based fluorinated PET tracers for imaging of the KCa 3.1 channel in vivo.
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Affiliation(s)
- Christian P Konken
- Department of Nuclear Medicine, University Hospital Münster, Münster, Germany
| | - Kathrin Heßling
- Institute of Pharmaceutical and Medicinal Chemistry, Westphalian Wilhelms-University Münster, Münster, Germany
| | - Insa Thale
- Institute of Pharmaceutical and Medicinal Chemistry, Westphalian Wilhelms-University Münster, Münster, Germany.,GRK 2515, Chemical Biology of Ion Channels (Chembion), Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Sonja Schelhaas
- European Institute for Molecular Imaging (EIMI), Westphalian Wilhelms-University Münster, Münster, Germany.,Cells-in-Motion Interfaculty Center, Westphalian Wilhelms-University Münster, Münster, Germany
| | - Jennifer Dabel
- European Institute for Molecular Imaging (EIMI), Westphalian Wilhelms-University Münster, Münster, Germany
| | - Sarah Maskri
- Institute of Pharmaceutical and Medicinal Chemistry, Westphalian Wilhelms-University Münster, Münster, Germany.,GRK 2515, Chemical Biology of Ion Channels (Chembion), Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Etmar Bulk
- Institute for Physiology II, University Hospital Münster, Münster, Germany
| | - Thomas Budde
- GRK 2515, Chemical Biology of Ion Channels (Chembion), Westfälische Wilhelms-Universität Münster, Münster, Germany.,Institute for Physiology I, University Hospital Münster, Münster, Germany
| | - Oliver Koch
- Institute of Pharmaceutical and Medicinal Chemistry, Westphalian Wilhelms-University Münster, Münster, Germany.,GRK 2515, Chemical Biology of Ion Channels (Chembion), Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Albrecht Schwab
- GRK 2515, Chemical Biology of Ion Channels (Chembion), Westfälische Wilhelms-Universität Münster, Münster, Germany.,Institute for Physiology II, University Hospital Münster, Münster, Germany
| | - Michael Schäfers
- Department of Nuclear Medicine, University Hospital Münster, Münster, Germany.,European Institute for Molecular Imaging (EIMI), Westphalian Wilhelms-University Münster, Münster, Germany.,Cells-in-Motion Interfaculty Center, Westphalian Wilhelms-University Münster, Münster, Germany
| | - Bernhard Wünsch
- Institute of Pharmaceutical and Medicinal Chemistry, Westphalian Wilhelms-University Münster, Münster, Germany.,GRK 2515, Chemical Biology of Ion Channels (Chembion), Westfälische Wilhelms-Universität Münster, Münster, Germany.,Cells-in-Motion Interfaculty Center, Westphalian Wilhelms-University Münster, Münster, Germany
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10
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Zhang X, Yang M, Lv D, Xie Y, Sun Y, Zhang Y, He M, Liu H, Li F, Deng D. Effects of KCa channels on biological behavior of trophoblasts. Open Life Sci 2022; 17:1043-1052. [PMID: 36118166 PMCID: PMC9441684 DOI: 10.1515/biol-2022-0462] [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: 01/16/2022] [Revised: 05/12/2022] [Accepted: 06/14/2022] [Indexed: 11/29/2022] Open
Abstract
The Ca2+-activated potassium (KCa) channels are involved in many cellular functions, but their roles in trophoblasts are unclear. This study aimed to clarify the effects of KCa channels on the biological behavior of trophoblasts. The localization and expression of the three types of KCa channels, including large-conductance KCa channels (BKCa), intermediate-conductance KCa channels (IKCa), and small-conductance KCa channels (SKCa), were detected in human chorionic villi taken from pregnant women between 5 and 8 weeks of gestation (n = 15) and HTR-8/SVneo cells. The effects of KCa channels on proliferation, apoptosis, and migration of HTR-8/SVneo cells were examined by using the activators or inhibitors of KCa channels. Results showed that KCa channels were mainly localized on the membrane and in the cytoplasm of trophoblasts in human chorionic villi and HTR-8/SVneo cells. The proliferation and migration of HTR-8/SVneo cells were inhibited by activating KCa channels. Apoptosis of trophoblasts was promoted through activating BKCa channels but was not affected by neither activating nor inhibiting IKCa and SKCa channels. This study substantiated the abovementioned biological roles of KCa channels in trophoblast cells, which is fundamental to further research on whether dysfunction of KCa channels is involved in the pathogenesis of pregnancy-related complications.
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Affiliation(s)
- Xiaolei Zhang
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Meitao Yang
- Department of Gynecology and Obstetrics, Zhongnan Hospital, Wuhan University, Wuhan, 430071, China
| | - Dan Lv
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Yin Xie
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Yanan Sun
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Yanling Zhang
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Mengzhou He
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Haiyi Liu
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Fanfan Li
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
| | - Dongrui Deng
- Department of Gynecology and Obstetrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095, Jiefang Ave, Wuhan, Hubei, China
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11
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Burgstaller S, Wagner TR, Bischof H, Bueckle S, Padamsey A, Frecot D, Kaiser PD, Skrabak D, Malli R, Lukowski R, Rothbauer U. Monitoring extracellular ion and metabolite dynamics with recombinant nanobody-fused biosensors. iScience 2022; 25:104907. [PMID: 36046190 PMCID: PMC9421384 DOI: 10.1016/j.isci.2022.104907] [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: 04/13/2022] [Revised: 06/29/2022] [Accepted: 08/05/2022] [Indexed: 11/29/2022] Open
Abstract
Ion and analyte changes in the tumor microenvironment (TME) alter the metabolic activity of cancer cells, promote tumor cell growth, and impair anti-tumor immunity. Consequently, accurate determination and visualization of extracellular changes of analytes in real time is desired. In this study, we genetically combined FRET-based biosensors with nanobodies (Nbs) to specifically visualize and monitor extracellular changes in K+, pH, and glucose on cell surfaces. We demonstrated that these Nb-fused biosensors quantitatively visualized K+ alterations on cancer and non-cancer cell lines and primary neurons. By implementing a HER2-specific Nb, we generated functional K+ and pH sensors, which specifically stained HER2-positive breast cancer cells. Based on the successful development of several Nb-fused biosensor combinations, we anticipate that this approach can be readily extended to other biosensors and will open new opportunities for the study of extracellular analytes in advanced experimental settings. Generation of recombinant nanobody-fused FRET biosensors Nb-fused biosensors specifically bind targets on the outer surface of various cells Cellular bound Nb-biosensors visualize extracellular analyte changes in real time
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Affiliation(s)
- Sandra Burgstaller
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Markwiesenstrasse 55, 72770 Reutlingen, Germany.,Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
| | - Teresa R Wagner
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Markwiesenstrasse 55, 72770 Reutlingen, Germany.,NMI Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstrasse 55, 72770 Reutlingen, Germany
| | - Helmut Bischof
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
| | - Sarah Bueckle
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Markwiesenstrasse 55, 72770 Reutlingen, Germany
| | - Aman Padamsey
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Markwiesenstrasse 55, 72770 Reutlingen, Germany
| | - Desiree Frecot
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Markwiesenstrasse 55, 72770 Reutlingen, Germany.,NMI Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstrasse 55, 72770 Reutlingen, Germany
| | - Philipp D Kaiser
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstrasse 55, 72770 Reutlingen, Germany
| | - David Skrabak
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
| | - Roland Malli
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria.,BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Robert Lukowski
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
| | - Ulrich Rothbauer
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Markwiesenstrasse 55, 72770 Reutlingen, Germany.,NMI Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstrasse 55, 72770 Reutlingen, Germany
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12
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Zúñiga L, Cayo A, González W, Vilos C, Zúñiga R. Potassium Channels as a Target for Cancer Therapy: Current Perspectives. Onco Targets Ther 2022; 15:783-797. [PMID: 35899081 PMCID: PMC9309325 DOI: 10.2147/ott.s326614] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 07/08/2022] [Indexed: 12/18/2022] Open
Abstract
Potassium (K+) channels are highly regulated membrane proteins that control the potassium ion flux and respond to different cellular stimuli. These ion channels are grouped into three major families, Kv (voltage-gated K+ channel), Kir (inwardly rectifying K+ channel) and K2P (two-pore K+ channels), according to the structure, to mediate the K+ currents. In cancer, alterations in K+ channel function can promote the acquisition of the so-called hallmarks of cancer – cell proliferation, resistance to apoptosis, metabolic changes, angiogenesis, and migratory capabilities – emerging as targets for the development of new therapeutic drugs. In this review, we focus our attention on the different K+ channels associated with the most relevant and prevalent cancer types. We summarize our knowledge about the potassium channels structure and function, their cancer dysregulated expression and discuss the K+ channels modulator and the strategies for designing new drugs.
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Affiliation(s)
- Leandro Zúñiga
- Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Talca, Chile.,Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Escuela de Medicina, Universidad de Talca, Talca, Chile
| | - Angel Cayo
- Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Talca, Chile.,Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Escuela de Medicina, Universidad de Talca, Talca, Chile
| | - Wendy González
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca, Chile.,Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca, Chile
| | - Cristian Vilos
- Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Escuela de Medicina, Universidad de Talca, Talca, Chile.,Laboratory of Nanomedicine and Targeted Delivery, School of Medicine, Universidad de Talca, Talca, 3460000, Chile.,Center for The Development of Nanoscience & Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago, 8350709, Chile
| | - Rafael Zúñiga
- Laboratorio de Fisiología Molecular, Escuela de Medicina, Universidad de Talca, Talca, Chile.,Centro de Nanomedicina, Diagnóstico y Desarrollo de Fármacos (ND3), Escuela de Medicina, Universidad de Talca, Talca, Chile
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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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Brömmel K, Konken CP, Börgel F, Obeng-Darko H, Schelhaas S, Bulk E, Budde T, Schwab A, Schäfers M, Wünsch B. Synthesis and biological evaluation of PET tracers designed for imaging of calcium activated potassium channel 3.1 (K Ca3.1) channels in vivo. RSC Adv 2021; 11:30295-30304. [PMID: 35480282 PMCID: PMC9041111 DOI: 10.1039/d1ra03850h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 09/05/2021] [Indexed: 12/14/2022] Open
Abstract
Expression of the Ca2+ activated potassium channel 3.1 (KCa3.1) channel (also known as the Gàrdos channel) is dysregulated in many tumor entities and has predictive power with respect to patient survival. Therefore, a positron emission tomography (PET) tracer targeting this ion channel could serve as a potential diagnostic tool by imaging the KCa3.1 channel in vivo. It was envisaged to synthesize [18F]senicapoc ([18F]1) since senicapoc (1) shows high affinity and excellent selectivity towards the KCa3.1 channels. Because problems occurred during 18F-fluorination, the [18F]fluoroethoxy senicapoc derivative [18F]28 was synthesized to generate an alternative PET tracer targeting the KCa3.1 channel. Inhibition of the KCa3.1 channel by 28 was confirmed by patch clamp experiments. In vitro stability in mouse and human serum was shown for 28. Furthermore, biodistribution experiments in wild type mice were performed. Since [18F]fluoride was detected in vivo after application of [18F]28, an in vitro metabolism study was conducted. A potential degradation route of fluoroethoxy derivatives in vivo was found which in general should be taken into account when designing new PET tracers for different targets with a [18F]fluoroethoxy moiety as well as when using the popular prosthetic group [18F]fluoroethyl tosylate for the alkylation of phenols. Expression of the Ca2+ activated potassium channel 3.1 (KCa3.1) channel (also known as the Gàrdos channel) is dysregulated in many tumor entities and has predictive power with respect to patient survival.![]()
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Affiliation(s)
- Kathrin Brömmel
- Institute for Pharmaceutical and Medicinal Chemistry, Westphalian Wilhelms-University Münster Corrensstraße 48 D-48149 Münster Germany
| | - Christian Paul Konken
- Department of Nuclear Medicine, University Hospital Münster, Albert-Schweitzer-Campus 1 Building A1 D-48149 Münster Germany +49-8347363 +49-251-8344791
| | - Frederik Börgel
- Institute for Pharmaceutical and Medicinal Chemistry, Westphalian Wilhelms-University Münster Corrensstraße 48 D-48149 Münster Germany
| | - Henry Obeng-Darko
- Institute for Pharmaceutical and Medicinal Chemistry, Westphalian Wilhelms-University Münster Corrensstraße 48 D-48149 Münster Germany
| | - Sonja Schelhaas
- European Institute for Molecular Imaging (EIMI), Westphalian Wilhelms-University Münster Waldeyerstraße 15 D-48149 Münster Germany
| | - Etmar Bulk
- Institute for Physiology II, University Hospital Münster Robert-Koch-Straße 27b D-48149 Münster Germany
| | - Thomas Budde
- Institute for Physiology I, University Hospital Münster Robert-Koch-Straße 27a D-48149 Münster Germany.,Cells-in-Motion Interfaculty Center, Westphalian Wilhelms-University Münster Waldeyerstraße 15 D-84149 Münster Germany
| | - Albrecht Schwab
- Institute for Physiology II, University Hospital Münster Robert-Koch-Straße 27b D-48149 Münster Germany.,Cells-in-Motion Interfaculty Center, Westphalian Wilhelms-University Münster Waldeyerstraße 15 D-84149 Münster Germany
| | - Michael Schäfers
- Department of Nuclear Medicine, University Hospital Münster, Albert-Schweitzer-Campus 1 Building A1 D-48149 Münster Germany +49-8347363 +49-251-8344791.,European Institute for Molecular Imaging (EIMI), Westphalian Wilhelms-University Münster Waldeyerstraße 15 D-48149 Münster Germany.,Cells-in-Motion Interfaculty Center, Westphalian Wilhelms-University Münster Waldeyerstraße 15 D-84149 Münster Germany
| | - Bernhard Wünsch
- Institute for Pharmaceutical and Medicinal Chemistry, Westphalian Wilhelms-University Münster Corrensstraße 48 D-48149 Münster Germany.,Cells-in-Motion Interfaculty Center, Westphalian Wilhelms-University Münster Waldeyerstraße 15 D-84149 Münster Germany
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15
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Hou X, Tang L, Li X, Xiong F, Mo Y, Jiang X, Deng X, Peng M, Wu P, Zhao M, Ouyang J, Shi L, He Y, Yan Q, Zhang S, Gong Z, Li G, Zeng Z, Wang F, Guo C, Xiong W. Potassium Channel Protein KCNK6 Promotes Breast Cancer Cell Proliferation, Invasion, and Migration. Front Cell Dev Biol 2021; 9:616784. [PMID: 34195184 PMCID: PMC8237943 DOI: 10.3389/fcell.2021.616784] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 03/31/2021] [Indexed: 01/18/2023] Open
Abstract
Breast cancer is the most common malignant tumor in women, and its incidence is increasing each year. To effectively treat breast cancer, it is important to identify genes involved in its occurrence and development and to exploit them as potential drug therapy targets. Here, we found that potassium channel subfamily K member 6 (KCNK6) is significantly overexpressed in breast cancer, however, its function in tumors has not been reported. We further verified that KCNK6 expression is upregulated in breast cancer biopsies. Moreover, overexpressed KCNK6 was found to enhance the proliferation, invasion, and migration ability of breast cancer cells. These effects may occur by weakening cell adhesion and reducing cell hardness, thus affecting the malignant phenotype of breast cancer cells. Our study confirmed, for the first time, that increased KCNK6 expression in breast cancer cells may promote their proliferation, invasion, and migration. Moreover, considering that ion channels serve as therapeutic targets for many small molecular drugs in clinical treatment, targeting KCNK6 may represent a novel strategy for breast cancer therapies. Hence, the results of this study provide a theoretical basis for KCNK6 to become a potential molecular target for breast cancer treatment in the future.
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Affiliation(s)
- Xiangchan Hou
- NHC Key Laboratory of Carcinogenesis and Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Le Tang
- Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Xiayu Li
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Disease Genome Research Center, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Fang Xiong
- Department of Stomatology, Xiangya Hospital, Central South University, Changsha, China
| | - Yongzhen Mo
- Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Xianjie Jiang
- Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Xiangying Deng
- Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Miao Peng
- Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Pan Wu
- Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Mengyao Zhao
- Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Jiawei Ouyang
- Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Lei Shi
- Department of Oral and Maxillofacial Surgery, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Yi He
- NHC Key Laboratory of Carcinogenesis and Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Qijia Yan
- Department of Stomatology, Xiangya Hospital, Central South University, Changsha, China
| | - Shanshan Zhang
- Department of Stomatology, Xiangya Hospital, Central South University, Changsha, China
| | - Zhaojian Gong
- Department of Oral and Maxillofacial Surgery, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Guiyuan Li
- Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Zhaoyang Zeng
- Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Fuyan Wang
- Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Can Guo
- NHC Key Laboratory of Carcinogenesis and Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Wei Xiong
- NHC Key Laboratory of Carcinogenesis and Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Key Laboratory of Carcinogenesis and Cancer Invasion of The Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China.,Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Disease Genome Research Center, The Third Xiangya Hospital, Central South University, Changsha, China
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16
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Checchetto V, Leanza L, De Stefani D, Rizzuto R, Gulbins E, Szabo I. Mitochondrial K + channels and their implications for disease mechanisms. Pharmacol Ther 2021; 227:107874. [PMID: 33930454 DOI: 10.1016/j.pharmthera.2021.107874] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/12/2021] [Indexed: 02/06/2023]
Abstract
The field of mitochondrial ion channels underwent a rapid development during the last decade, thanks to the molecular identification of some of the nuclear-encoded organelle channels and to advances in strategies allowing specific pharmacological targeting of these proteins. Thereby, genetic tools and specific drugs aided definition of the relevance of several mitochondrial channels both in physiological as well as pathological conditions. Unfortunately, in the case of mitochondrial K+ channels, efforts of genetic manipulation provided only limited results, due to their dual localization to mitochondria and to plasma membrane in most cases. Although the impact of mitochondrial K+ channels on human diseases is still far from being genuinely understood, pre-clinical data strongly argue for their substantial role in the context of several pathologies, including cardiovascular and neurodegenerative diseases as well as cancer. Importantly, these channels are druggable targets, and their in-depth investigation could thus pave the way to the development of innovative small molecules with huge therapeutic potential. In the present review we summarize the available experimental evidence that mechanistically link mitochondrial potassium channels to the above pathologies and underline the possibility of exploiting them for therapy.
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Affiliation(s)
| | - Luigi Leanza
- Department of Biology, University of Padova, Italy
| | | | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Italy
| | - Erich Gulbins
- Department of Molecular Biology, University of Duisburg-Essen, Germany
| | - Ildiko Szabo
- Department of Biology, University of Padova, Italy; CNR Institute of Neurosciences, Italy.
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17
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Bischof H, Burgstaller S, Springer A, Matt L, Rauter T, Bachkönig OA, Schmidt T, Groschner K, Schindl R, Madl T, Plesnila N, Lukowski R, Graier WF, Malli R. Potassium ions promote hexokinase-II dependent glycolysis. iScience 2021; 24:102346. [PMID: 33870140 PMCID: PMC8047173 DOI: 10.1016/j.isci.2021.102346] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/22/2021] [Accepted: 03/18/2021] [Indexed: 02/06/2023] Open
Abstract
High expression levels of mitochondria-associated hexokinase-II (HKII) represent a hallmark of metabolically highly active cells such as fast proliferating cancer cells. Typically, the enzyme provides a crucial metabolic switch towards aerobic glycolysis. By imaging metabolic activities on the single-cell level with genetically encoded fluorescent biosensors, we here demonstrate that HKII activity requires intracellular K+. The K+ dependency of glycolysis in cells expressing HKII was confirmed in cell populations using extracellular flux analysis and nuclear magnetic resonance-based metabolomics. Reductions of intracellular K+ by gramicidin acutely disrupted HKII-dependent glycolysis and triggered energy stress pathways, while K+ re-addition promptly restored glycolysis-dependent adenosine-5'-triphosphate generation. Moreover, expression and activation of KV1.3, a voltage-gated K+ channel, lowered cellular K+ content and the glycolytic activity of HEK293 cells. Our findings unveil K+ as an essential cofactor of HKII and provide a mechanistic link between activities of distinct K+ channels and cell metabolism.
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Affiliation(s)
- Helmut Bischof
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
| | - Sandra Burgstaller
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- Department of Molecular Biology, Interfaculty Institute for Cell Biology, University of Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany
| | - Anna Springer
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Lucas Matt
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
| | - Thomas Rauter
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Olaf A. Bachkönig
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Tony Schmidt
- Gottfried Schatz Research Center, Biophysics, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Klaus Groschner
- Gottfried Schatz Research Center, Biophysics, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Rainer Schindl
- Gottfried Schatz Research Center, Biophysics, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Tobias Madl
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Nikolaus Plesnila
- Laboratory of Experimental Stroke Research, Institute for Stroke and Dementia Research, University of Munich Medical Center, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Robert Lukowski
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
| | - Wolfgang F. Graier
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Roland Malli
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
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18
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Abstract
Neoplastic transformation is reportedly associated with alterations of the potassium transport across plasma and intracellular membranes. These alterations have been identified as crucial elements of the tumourigenic reprogramming of cells. Potassium channels may contribute to cancer initiation, malignant progression and therapy resistance of tumour cells. The book chapter focusses on (oncogenic) potassium channels frequently upregulated in different tumour entities, upstream and downstream signalling of these channels, their contribution to the maintenance of cancer stemness and the formation of an immunosuppressive tumour microenvironment. In addition, their role in adaptation to tumour hypoxia, metabolic reprogramming, as well as tumour spreading and metastasis is discussed. Finally, we discuss how (oncogenic) potassium channels may confer treatment resistance of tumours against radiation and chemotherapy and thus might be harnessed for new therapy strategies, for instance, by repurposing approved drugs known to target potassium channels.
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19
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Hofschröer V, Najder K, Rugi M, Bouazzi R, Cozzolino M, Arcangeli A, Panyi G, Schwab A. Ion Channels Orchestrate Pancreatic Ductal Adenocarcinoma Progression and Therapy. Front Pharmacol 2021; 11:586599. [PMID: 33841132 PMCID: PMC8025202 DOI: 10.3389/fphar.2020.586599] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 10/30/2020] [Indexed: 02/06/2023] Open
Abstract
Pancreatic ductal adenocarcinoma is a devastating disease with a dismal prognosis. Therapeutic interventions are largely ineffective. A better understanding of the pathophysiology is required. Ion channels contribute substantially to the "hallmarks of cancer." Their expression is dysregulated in cancer, and they are "misused" to drive cancer progression, but the underlying mechanisms are unclear. Ion channels are located in the cell membrane at the interface between the intracellular and extracellular space. They sense and modify the tumor microenvironment which in itself is a driver of PDAC aggressiveness. Ion channels detect, for example, locally altered proton and electrolyte concentrations or mechanical stimuli and transduce signals triggered by these microenvironmental cues through association with intracellular signaling cascades. While these concepts have been firmly established for other cancers, evidence has emerged only recently that ion channels are drivers of PDAC aggressiveness. Particularly, they appear to contribute to two of the characteristic PDAC features: the massive fibrosis of the tumor stroma (desmoplasia) and the efficient immune evasion. Our critical review of the literature clearly shows that there is still a remarkable lack of knowledge with respect to the contribution of ion channels to these two typical PDAC properties. Yet, we can draw parallels from ion channel research in other fibrotic and inflammatory diseases. Evidence is accumulating that pancreatic stellate cells express the same "profibrotic" ion channels. Similarly, it is at least in part known which major ion channels are expressed in those innate and adaptive immune cells that populate the PDAC microenvironment. We explore potential therapeutic avenues derived thereof. Since drugs targeting PDAC-relevant ion channels are already in clinical use, we propose to repurpose those in PDAC. The quest for ion channel targets is both motivated and complicated by the fact that some of the relevant channels, for example, KCa3.1, are functionally expressed in the cancer, stroma, and immune cells. Only in vivo studies will reveal which arm of the balance we should put our weights on when developing channel-targeting PDAC therapies. The time is up to explore the efficacy of ion channel targeting in (transgenic) murine PDAC models before launching clinical trials with repurposed drugs.
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Affiliation(s)
| | - Karolina Najder
- Institute of Physiology II, University of Münster, Münster, Germany
| | - Micol Rugi
- Institute of Physiology II, University of Münster, Münster, Germany
| | - Rayhana Bouazzi
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Marco Cozzolino
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Annarosa Arcangeli
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Albrecht Schwab
- Institute of Physiology II, University of Münster, Münster, Germany
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20
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Brömmel K, Maskri S, Bulk E, Pethő Z, Rieke M, Budde T, Koch O, Schwab A, Wünsch B. Co-staining of K Ca 3.1 Channels in NSCLC Cells with a Small-Molecule Fluorescent Probe and Antibody-Based Indirect Immunofluorescence. ChemMedChem 2020; 15:2462-2469. [PMID: 33043595 PMCID: PMC7756743 DOI: 10.1002/cmdc.202000652] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/21/2020] [Indexed: 01/01/2023]
Abstract
The Ca2+ activated potassium channel 3.1 (KCa 3.1) is involved in critical steps of the metastatic cascade, such as proliferation, migration, invasion and extravasation. Therefore, a fast and efficient protocol for imaging of KCa 3.1 channels was envisaged. The novel fluorescently labeled small molecule imaging probes 1 and 2 were synthesized by connecting a dimethylpyrrole-based BODIPY dye with a derivative of the KCa 3.1 channel inhibitor senicapoc via linkers of different length. Patch-clamp experiments revealed the inhibition of KCa 3.1 channels by the probes confirming interaction with the channel. Both probes 1 and 2 were able to stain KCa 3.1 channels in non-small-cell lung cancer (NSCLC) cells following a simple, fast and efficient protocol. Pre-incubation with unlabeled senicapoc removed the punctate staining pattern showing the specificity of the new probes 1 and 2. Staining of the channel with the fluorescently labeled senicapoc derivatives 1 or 2 or with antibody-based indirect immunofluorescence yielded identical or very similar densities of stained KCa 3.1 channels. However, co-staining using both methods did not lead to the expected overlapping punctate staining pattern. This observation was explained by docking studies showing that the antibody used for indirect immunofluorescence and the probes 1 and 2 label different channel populations. Whereas the antibody binds at the closed channel conformation, the probes 1 and 2 bind within the open channel.
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Affiliation(s)
- Kathrin Brömmel
- Institute for Pharmaceutical and Medicinal ChemistryWestphalian Wilhelms-University MünsterCorrensstraße 4848149MünsterGermany
- Cells-in-Motion Interfaculty CenterWestphalian Wilhelms-University MünsterWaldeyerstraße 1584149MünsterGermany
| | - Sarah Maskri
- Institute for Pharmaceutical and Medicinal ChemistryWestphalian Wilhelms-University MünsterCorrensstraße 4848149MünsterGermany
| | - Etmar Bulk
- Institute for Physiology IIUniversity Hospital MünsterRobert-Koch-Straße 27b48149MünsterGermany
| | - Zoltan Pethő
- Institute for Physiology IIUniversity Hospital MünsterRobert-Koch-Straße 27b48149MünsterGermany
| | - Marius Rieke
- Institute for Physiology IIUniversity Hospital MünsterRobert-Koch-Straße 27b48149MünsterGermany
| | - Thomas Budde
- Institute for Physiology IUniversity Hospital MünsterRobert-Koch-Straße 27a48149MünsterGermany
- Cells-in-Motion Interfaculty CenterWestphalian Wilhelms-University MünsterWaldeyerstraße 1584149MünsterGermany
| | - Oliver Koch
- Institute for Pharmaceutical and Medicinal ChemistryWestphalian Wilhelms-University MünsterCorrensstraße 4848149MünsterGermany
| | - Albrecht Schwab
- Institute for Physiology IIUniversity Hospital MünsterRobert-Koch-Straße 27b48149MünsterGermany
- Cells-in-Motion Interfaculty CenterWestphalian Wilhelms-University MünsterWaldeyerstraße 1584149MünsterGermany
| | - Bernhard Wünsch
- Institute for Pharmaceutical and Medicinal ChemistryWestphalian Wilhelms-University MünsterCorrensstraße 4848149MünsterGermany
- Cells-in-Motion Interfaculty CenterWestphalian Wilhelms-University MünsterWaldeyerstraße 1584149MünsterGermany
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21
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Tiffner A, Derler I. Molecular Choreography and Structure of Ca 2+ Release-Activated Ca 2+ (CRAC) and K Ca2+ Channels and Their Relevance in Disease with Special Focus on Cancer. MEMBRANES 2020; 10:membranes10120425. [PMID: 33333945 PMCID: PMC7765462 DOI: 10.3390/membranes10120425] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022]
Abstract
Ca2+ ions play a variety of roles in the human body as well as within a single cell. Cellular Ca2+ signal transduction processes are governed by Ca2+ sensing and Ca2+ transporting proteins. In this review, we discuss the Ca2+ and the Ca2+-sensing ion channels with particular focus on the structure-function relationship of the Ca2+ release-activated Ca2+ (CRAC) ion channel, the Ca2+-activated K+ (KCa2+) ion channels, and their modulation via other cellular components. Moreover, we highlight their roles in healthy signaling processes as well as in disease with a special focus on cancer. As KCa2+ channels are activated via elevations of intracellular Ca2+ levels, we summarize the current knowledge on the action mechanisms of the interplay of CRAC and KCa2+ ion channels and their role in cancer cell development.
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22
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Rosendo-Pineda MJ, Moreno CM, Vaca L. Role of ion channels during cell division. Cell Calcium 2020; 91:102258. [PMID: 32736154 DOI: 10.1016/j.ceca.2020.102258] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/20/2020] [Accepted: 07/20/2020] [Indexed: 02/06/2023]
Abstract
Ion channels are transmembrane proteins whose canonical function is the transport of ions across the plasma membrane to regulate cell membrane potential and play an essential role in neural communication, nerve conduction, and muscle contraction. However, over the last few years, non-canonical functions have been identified for many channels, having active roles in phagocytosis, invasiveness, proliferation, among others. The participation of some channels in cell proliferation has raised the question of whether they may play an active role in mitosis. There are several reports showing the participation of channels during interphase, however, the direct participation of ion channels in mitosis has received less attention. In this article, we summarize the current evidence on the participation of ion channels in mitosis. We also summarize some tools that would allow the study of ion channels and cell cycle regulatory molecules in individual cells during mitosis.
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Affiliation(s)
| | - Claudia M Moreno
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Luis Vaca
- Instituto de Fisiología Celular. Universidad Nacional Autónoma de México. Ciudad Universitaria, Coyoacán, DF, 04510, Mexico; Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, 98195, USA.
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23
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Amador-Muñoz D, Gutiérrez ÁM, Payán-Gómez C, Matheus LM. In silico and in vitro analysis of cation-activated potassium channels in human corneal endothelial cells. Exp Eye Res 2020; 197:108114. [PMID: 32561484 DOI: 10.1016/j.exer.2020.108114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 06/02/2020] [Accepted: 06/07/2020] [Indexed: 12/31/2022]
Abstract
The corneal endothelium is the inner cell monolayer involved in the maintenance of corneal transparence by the generation of homeostatic dehydration. The glycosaminoglycans of the corneal stroma develop a continuous swelling pressure that should be counteracted by the corneal endothelial cells through active transport mechanisms to move the water to the anterior chamber. Protein transporters for sodium (Na+), potassium (K+), chloride (Cl-) and bicarbonate (HCO3-) are involved in this endothelial "pump function", however despite its physiological importance, the efflux mechanism is not completely understood. There is experimental evidence describing transendothelial diffusion of water in the absence of osmotic gradients. Therefore, it is important to get a deeper understanding of alternative models that drive the fluid transport across the endothelium such as the electrochemical gradients. Three transcriptomic datasets of the corneal endothelium were used in this study to analyze the expression of genes that encode proteins that participate in the transport and the reestablishment of the membrane potential across the semipermeable endothelium. Subsequently, the expression of the identified channels was validated in vitro both at mRNA and protein levels. The results of this study provide the first evidence of the expression of KCNN2, KCNN3 and KCNT2 genes in the corneal endothelium. Differences among the level of expression of KCNN2, KCNT2 and KCNN4 genes were found in a differentially expressed gene analysis of the dataset. Taken together these results underscore the potential importance of the ionic channels in the pathophysiology of corneal diseases. Moreover, we elucidate novel mechanisms that might be involved in the pivotal dehydrating function of the endothelium and in others physiologic functions of these cells using in silico pathways analysis.
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Affiliation(s)
- Diana Amador-Muñoz
- Neuroscience (NEUROS) Research Group, School of Medicine and Health Sciences, Universidad del Rosario, Carrera 24 No. 63 C 69, P.O 111221, Bogotá, Colombia.
| | - Ángela María Gutiérrez
- Escuela Superior de Oftalmología, Instituto Barraquer de América, Calle 100 No. 18 A 51, Bogotá, Colombia.
| | - César Payán-Gómez
- Department of Biology, Faculty of Natural Sciences, Universidad del Rosario, Carrera 24 No. 63 C 69, Bogotá, P.O 111221, Colombia.
| | - Luisa Marina Matheus
- Neuroscience (NEUROS) Research Group, School of Medicine and Health Sciences, Universidad del Rosario, Carrera 24 No. 63 C 69, P.O 111221, Bogotá, Colombia.
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24
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Mohr CJ, Schroth W, Mürdter TE, Gross D, Maier S, Stegen B, Dragoi A, Steudel FA, Stehling S, Hoppe R, Madden S, Ruth P, Huber SM, Brauch H, Lukowski R. Subunits of BK channels promote breast cancer development and modulate responses to endocrine treatment in preclinical models. Br J Pharmacol 2020; 179:2906-2924. [PMID: 32468618 DOI: 10.1111/bph.15147] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 03/20/2020] [Accepted: 05/13/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND AND PURPOSE Pore-forming α subunits of the voltage- and Ca2+ -activated K+ channel with large conductance (BKα) promote malignant phenotypes of breast tumour cells. Auxiliary subunits such as the leucine-rich repeat containing 26 (LRRC26) protein, also termed BKγ1, may be required to permit activation of BK currents at a depolarized resting membrane potential that frequently occur in non-excitable tumour cells. EXPERIMENTAL APPROACH Anti-tumour effects of BKα loss were investigated in breast tumour-bearing MMTV-PyMT transgenic BKα knockout (KO) mice, primary MMTV-PyMT cell cultures, and in a syngeneic transplantation model of breast cancer derived from these cells. The therapeutic relevance of BK channels in the context of endocrine treatment was assessed in human breast cancer cell lines expressing either low (MCF-7) or high (MDA-MB-453) levels of BKα and BKγ1, as well as in BKα-negative MDA-MB-157. KEY RESULTS BKα promoted breast cancer onset and overall survival in preclinical models. Conversely, lack of BKα and/or knockdown of BKγ1 attenuated proliferation of murine and human breast cancer cells in vitro. At low concentrations, tamoxifen and its major active metabolites stimulated proliferation of BKα/γ1-positive breast cancer cells, independent of the genomic signalling controlled by the oestrogen receptor. Finally, tamoxifen increased the relative survival time of BKα KO but not of wild-type tumour cell recipient mice. CONCLUSION AND IMPLICATIONS Breast cancer initiation, progression, and tamoxifen sensitivity depend on functional BK channels thereby providing a rationale for the future exploration of the oncogenic actions of BK channels in clinical outcomes with anti-oestrogen therapy.
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Affiliation(s)
- Corinna J Mohr
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Tuebingen, Germany.,Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart and University of Tuebingen, Germany
| | - Werner Schroth
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart and University of Tuebingen, Germany
| | - Thomas E Mürdter
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart and University of Tuebingen, Germany
| | - Dominic Gross
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Tuebingen, Germany
| | - Selina Maier
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Tuebingen, Germany.,Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart and University of Tuebingen, Germany
| | - Benjamin Stegen
- Department of Radiation Oncology, University of Tuebingen, Tuebingen, Germany
| | - Alice Dragoi
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Tuebingen, Germany
| | - Friederike A Steudel
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Tuebingen, Germany
| | - Severine Stehling
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Tuebingen, Germany
| | - Reiner Hoppe
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart and University of Tuebingen, Germany
| | - Stephen Madden
- RCSI Division of Population Health Sciences, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Peter Ruth
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Tuebingen, Germany
| | - Stephan M Huber
- Department of Radiation Oncology, University of Tuebingen, Tuebingen, Germany
| | - Hiltrud Brauch
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart and University of Tuebingen, Germany.,German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany.,iFIT-Cluster of Excellence, University of Tuebingen, Tuebingen, Germany
| | - Robert Lukowski
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Tuebingen, Germany
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25
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Chung CC, Lin YK, Chen YC, Kao YH, Lee TI, Chen YJ. Vascular endothelial growth factor enhances profibrotic activities through modulation of calcium homeostasis in human atrial fibroblasts. J Transl Med 2020; 100:285-296. [PMID: 31748680 DOI: 10.1038/s41374-019-0341-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 09/14/2019] [Accepted: 10/16/2019] [Indexed: 12/16/2022] Open
Abstract
Vascular endothelial growth factor (VEGF), a pivotal activator of angiogenesis and calcium (Ca2+) signaling in endothelial cells, was shown to increase collagen production in atrial fibroblasts. In this study, we evaluated whether VEGF may regulate Ca2+ homeostasis in atrial fibroblasts and contribute to its profibrogenesis. Migration, and proliferation analyses, patch-clamp assay, Ca2+ fluorescence imaging, and western blotting were performed using VEGF-treated (300 pg/mL or 1000 pg/mL) human atrial fibroblasts with or without coadministration of Ethylene glycol tetra-acetic acid (EGTA, 1 mmol/L), or KN93 (a Ca2+/calmodulin-dependent protein kinase II [CaMKII] inhibitor, 10 μmol/L). VEGF (1000 pg/mL) increased migration, myofibroblast differentiation, pro-collagen type I, pro-collagen type III production, and phosphorylated VEGF receptor 1 expression of fibroblasts. VEGF (1000 pg/mL) increased the nonselective cation current (INSC) of transient receptor potential (TRP) channels and potassium current of intermediate-conductance Ca2+-activated K+ (KCa3.1) channels thereby upregulating Ca2+ entry. VEGF upregulated phosphorylated ERK expression. An ERK inhibitor (PD98059, 50 μmol/L) attenuated VEGF-activated INSC of TRP channels. The presence of EGTA attenuated the profibrotic effects of VEGF on pro-collagen type I, pro-collagen type III production, myofibroblast differentiation, and migratory capabilities of fibroblasts. VEGF upregulated the expression of phosphorylated CaMKII in fibroblasts, which was attenuated by EGTA. In addition, KN93 reduced VEGF-increased pro-collagen type I, pro-collagen type III production, myofibroblast differentiation, and the migratory capabilities of fibroblasts. In conclusion, we found that VEGF increases atrial fibroblast activity through CaMKII signaling by enhancing Ca2+ entry. Our findings provide benchside evidence leading to a potential novel strategy targeting atrial myopathy and arrhythmofibrosis.
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Affiliation(s)
- Cheng-Chih Chung
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Ting-I Lee
- Department of General Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan. .,Division of Endocrinology and Metabolism, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
| | - Yi-Jen Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan. .,Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan. .,Cardiovascular Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
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26
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Barrera P, Skorka C, Boktor M, Dave N, Jimenez V. A Novel Calcium-Activated Potassium Channel Controls Membrane Potential and Intracellular pH in Trypanosoma cruzi. Front Cell Infect Microbiol 2020; 9:464. [PMID: 32010643 PMCID: PMC6974456 DOI: 10.3389/fcimb.2019.00464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 12/16/2019] [Indexed: 12/13/2022] Open
Abstract
Trypanosoma cruzi develops in environments where nutrient availability, osmolarity, ionic concentrations, and pH undergo significant changes. The ability to adapt and respond to such conditions determines the survival and successful transmission of T. cruzi. Ion channels play fundamental roles in controlling physiological parameters that ensure cell homeostasis by rapidly triggering compensatory mechanisms. Combining molecular, cellular and electrophysiological approaches we have identified and characterized the expression and function of a novel calcium-activated potassium channel (TcCAKC). This channel resides in the plasma membrane of all 3 life stages of T. cruzi and shares structural features with other potassium channels. We expressed TcCAKC in Xenopus laevis oocytes and established its biophysical properties by two-electrode voltage clamp. Oocytes expressing TcCAKC showed a significant increase in inward currents after addition of calcium ionophore ionomycin or thapsigargin. These responses were abolished by EGTA suggesting that TcCAKC activation is dependent of extracellular calcium. This activation causes an increase in current and a negative shift in reversal potential that is blocked by barium. As predicted, a single point mutation in the selectivity filter (Y313A) completely abolished the activity of the channels, confirming its potassium selective nature. We have generated knockout parasites deleting one or both alleles of TcCAKC. These parasite strains showed impaired growth, decreased production of trypomastigotes and slower intracellular replication, pointing to an important role of TcCAKC in regulating infectivity. To understand the cellular mechanisms underlying these phenotypic defects, we used fluorescent probes to evaluate intracellular membrane potential, pH, and intracellular calcium. Epimastigotes lacking the channel had significantly lower cytosolic calcium, hyperpolarization, changes in intracellular pH, and increased rate of proton extrusion. These results are in agreement with previous reports indicating that, in trypanosomatids, membrane potential and intracellular pH maintenance are linked. Our work shows TcCAKC is a novel potassium channel that contributes to homeostatic regulation of important physiological processes in T. cruzi and provides new avenues to explore the potential of ion channels as targets for drug development against protozoan parasites.
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Affiliation(s)
- Patricia Barrera
- Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, United States
| | - Christopher Skorka
- Departmento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Histologia y Embriologia IHEM-CONICET, Facultad de Medicina, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Michael Boktor
- Departmento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Histologia y Embriologia IHEM-CONICET, Facultad de Medicina, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Noopur Dave
- Departmento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Histologia y Embriologia IHEM-CONICET, Facultad de Medicina, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Veronica Jimenez
- Departmento de Biología, Facultad de Ciencias Exactas y Naturales, Instituto de Histologia y Embriologia IHEM-CONICET, Facultad de Medicina, Universidad Nacional de Cuyo, Mendoza, Argentina
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Sawicka D, Maciak S, Kozłowska H, Kasacka I, Kloza M, Sadowska A, Sokołowska E, Konarzewski M, Car H. Functional and structural changes in aorta of mice divergently selected for basal metabolic rate. J Comp Physiol B 2019; 190:101-112. [PMID: 31873784 DOI: 10.1007/s00360-019-01252-6] [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: 08/30/2019] [Revised: 11/29/2019] [Accepted: 12/08/2019] [Indexed: 12/20/2022]
Abstract
Cardiovascular diseases (CVD) are one of the most common causes of mortality likely genetically linked to the variation in basal metabolic rate (BMR). A robust test of the significance of such association may be provided by artificial selection experiments on animals selected for diversification of BMR. Here we asked whether genetically determined differences in BMR correlate with anatomical shift in endothelium structure and if so, the relaxation and contraction responses of the aorta in mice from two lines of Swiss-Webster laboratory mice (Mus musculus) divergently selected for high or low BMR (HBMR and LBMR lines, respectively). Functional and structural study of aorta showed that a selection for divergent BMR resulted in the between-line difference in diastolic aortic capacity. The relaxation was stronger in aorta of the HBMR mice, which may stem from greater flexibility of aorta mediated by higher activity of Ca2+-activated K+ channels. Structural examination also indicated that HBMR mice had significantly thicker aorta's middle layer compared to LBMR animals. Such changes may promote arterial stiffness predisposing to cardiovascular diseases. BMR-related differences in the structure and relaxation ability of aortas in studied animals may be reminiscent of potential risk factors in the development of CVD in humans.
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Affiliation(s)
- Diana Sawicka
- Department of Experimental Pharmacology, Medical University of Bialystok, ul. Szpitalna 37, 15-295, Białystok, Poland.
| | - Sebastian Maciak
- Department of Evolutionary and Physiological Ecology, Faculty of Biology, University of Bialystok, ul. Ciołkowskiego 1J, 15-245, Białystok, Poland
| | - Hanna Kozłowska
- Department of Experimental Physiology and Pathophysiology, Medical University of Bialystok, ul. Mickiewicza 2A, 15-089, Białystok, Poland
| | - Irena Kasacka
- Department of Histology and Cytophysiology, Medical University of Bialystok, ul. Mickiewicza 2C, 15-222, Białystok, Poland
| | - Monika Kloza
- Department of Experimental Physiology and Pathophysiology, Medical University of Bialystok, ul. Mickiewicza 2A, 15-089, Białystok, Poland
| | - Anna Sadowska
- Department of Experimental Pharmacology, Medical University of Bialystok, ul. Szpitalna 37, 15-295, Białystok, Poland
| | - Emilia Sokołowska
- Department of Experimental Pharmacology, Medical University of Bialystok, ul. Szpitalna 37, 15-295, Białystok, Poland
| | - Marek Konarzewski
- Department of Evolutionary and Physiological Ecology, Faculty of Biology, University of Bialystok, ul. Ciołkowskiego 1J, 15-245, Białystok, Poland
| | - Halina Car
- Department of Experimental Pharmacology, Medical University of Bialystok, ul. Szpitalna 37, 15-295, Białystok, Poland
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29
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Kersting D, Fasbender S, Pilch R, Kurth J, Franken A, Ludescher M, Naskou J, Hallenberger A, Gall CV, Mohr CJ, Lukowski R, Raba K, Jaschinski S, Esposito I, Fischer JC, Fehm T, Niederacher D, Neubauer H, Heinzel T. From in vitro to ex vivo: subcellular localization and uptake of graphene quantum dots into solid tumors. NANOTECHNOLOGY 2019; 30:395101. [PMID: 31239418 DOI: 10.1088/1361-6528/ab2cb4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Among various nanoparticles tested for pharmacological applications over the recent years, graphene quantum dots (GQDs) seem to be promising candidates for the construction of drug delivery systems due to their superior biophysical and biochemical properties. The subcellular fate of incorporated nanomaterial is decisive for transporting pharmaceuticals into target cells. Therefore a detailed characterization of the uptake of GQDs into different breast cancer models was performed. The demonstrated accumulation inside the endolysosomal system might be the reason for the particles' low toxicity, but has to be overcome for cytosolic or nuclear drug delivery. Furthermore, the penetration of GQDs into precision-cut mammary tumor slices was studied. These constitute a far closer to reality model system than monoclonal cell lines. The constant uptake into the depth of the tissue slices underlines the systems' potential for drug delivery into solid tumors.
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Affiliation(s)
- David Kersting
- Condensed Matter Physics Laboratory, Heinrich-Heine-University, D-40204 Düsseldorf, Germany
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30
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K Ca3.1 Channels Confer Radioresistance to Breast Cancer Cells. Cancers (Basel) 2019; 11:cancers11091285. [PMID: 31480522 PMCID: PMC6770875 DOI: 10.3390/cancers11091285] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 08/09/2019] [Accepted: 08/21/2019] [Indexed: 12/14/2022] Open
Abstract
KCa3.1 K+ channels reportedly contribute to the proliferation of breast tumor cells and may serve pro-tumor functions in the microenvironment. The putative interaction of KCa3.1 with major anti-cancer treatment strategies, which are based on cytotoxic drugs or radiotherapy, remains largely unexplored. We employed KCa3.1-proficient and -deficient breast cancer cells derived from breast cancer-prone MMTV-PyMT mice, pharmacological KCa3.1 inhibition, and a syngeneic orthotopic mouse model to study the relevance of functional KCa3.1 for therapy response. The KCa3.1 status of MMTV-PyMT cells did not determine tumor cell proliferation after treatment with different concentrations of docetaxel, doxorubicin, 5-fluorouracil, or cyclophosphamide. KCa3.1 activation by ionizing radiation (IR) in breast tumor cells in vitro, however, enhanced radioresistance, probably via an involvement of the channel in IR-stimulated Ca2+ signals and DNA repair pathways. Consistently, KCa3.1 knockout increased survival time of wildtype mice upon syngeneic orthotopic transplantation of MMTV-PyMT tumors followed by fractionated radiotherapy. Combined, our results imply that KCa3.1 confers resistance to radio- but not to chemotherapy in the MMTV-PyMT breast cancer model. Since KCa3.1 is druggable, KCa3.1 targeting concomitant to radiotherapy seems to be a promising strategy to radiosensitize breast tumors.
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31
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Brown BM, Shim H, Christophersen P, Wulff H. Pharmacology of Small- and Intermediate-Conductance Calcium-Activated Potassium Channels. Annu Rev Pharmacol Toxicol 2019; 60:219-240. [PMID: 31337271 DOI: 10.1146/annurev-pharmtox-010919-023420] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The three small-conductance calcium-activated potassium (KCa2) channels and the related intermediate-conductance KCa3.1 channel are voltage-independent K+ channels that mediate calcium-induced membrane hyperpolarization. When intracellular calcium increases in the channel vicinity, it calcifies the flexible N lobe of the channel-bound calmodulin, which then swings over to the S4-S5 linker and opens the channel. KCa2 and KCa3.1 channels are highly druggable and offer multiple binding sites for venom peptides and small-molecule blockers as well as for positive- and negative-gating modulators. In this review, we briefly summarize the physiological role of KCa channels and then discuss the pharmacophores and the mechanism of action of the most commonly used peptidic and small-molecule KCa2 and KCa3.1 modulators. Finally, we describe the progress that has been made in advancing KCa3.1 blockers and KCa2.2 negative- and positive-gating modulators toward the clinic for neurological and cardiovascular diseases and discuss the remaining challenges.
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Affiliation(s)
- Brandon M Brown
- Department of Pharmacology, University of California, Davis, California 95616, USA;
| | - Heesung Shim
- Department of Pharmacology, University of California, Davis, California 95616, USA;
| | | | - Heike Wulff
- Department of Pharmacology, University of California, Davis, California 95616, USA;
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Cancer-Associated Intermediate Conductance Ca 2+-Activated K⁺ Channel K Ca3.1. Cancers (Basel) 2019; 11:cancers11010109. [PMID: 30658505 PMCID: PMC6357066 DOI: 10.3390/cancers11010109] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/10/2019] [Accepted: 01/13/2019] [Indexed: 12/14/2022] Open
Abstract
Several tumor entities have been reported to overexpress KCa3.1 potassium channels due to epigenetic, transcriptional, or post-translational modifications. By modulating membrane potential, cell volume, or Ca2+ signaling, KCa3.1 has been proposed to exert pivotal oncogenic functions in tumorigenesis, malignant progression, metastasis, and therapy resistance. Moreover, KCa3.1 is expressed by tumor-promoting stroma cells such as fibroblasts and the tumor vasculature suggesting a role of KCa3.1 in the adaptation of the tumor microenvironment. Combined, this features KCa3.1 as a candidate target for innovative anti-cancer therapy. However, immune cells also express KCa3.1 thereby contributing to T cell activation. Thus, any strategy targeting KCa3.1 in anti-cancer therapy may also modulate anti-tumor immune activity and/or immunosuppression. The present review article highlights the potential of KCa3.1 as an anti-tumor target providing an overview of the current knowledge on its function in tumor pathogenesis with emphasis on vasculo- and angiogenesis as well as anti-cancer immune responses.
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Khatun A, Shimozawa M, Kito H, Kawaguchi M, Fujimoto M, Ri M, Kajikuri J, Niwa S, Fujii M, Ohya S. Transcriptional Repression and Protein Degradation of the Ca 2+-Activated K + Channel K Ca1.1 by Androgen Receptor Inhibition in Human Breast Cancer Cells. Front Physiol 2018; 9:312. [PMID: 29713287 PMCID: PMC5911984 DOI: 10.3389/fphys.2018.00312] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 03/14/2018] [Indexed: 01/14/2023] Open
Abstract
The large-conductance Ca2+-activated K+ channel KCa1.1 plays an important role in the promotion of breast cancer cell proliferation and metastasis. The androgen receptor (AR) is proposed as a therapeutic target for AR-positive advanced triple-negative breast cancer. We herein investigated the effects of a treatment with antiandrogens on the functional activity, activation kinetics, transcriptional expression, and protein degradation of KCa1.1 in human breast cancer MDA-MB-453 cells using real-time PCR, Western blotting, voltage-sensitive dye imaging, and whole-cell patch clamp recording. A treatment with the antiandrogen bicalutamide or enzalutamide for 48 h significantly suppressed (1) depolarization responses induced by paxilline (PAX), a specific KCa1.1 blocker and (2) PAX-sensitive outward currents induced by the depolarizing voltage step. The expression levels of KCa1.1 transcripts and proteins were significantly decreased in MDA-MB-453 cells, and the protein degradation of KCa1.1 mainly contributed to reductions in KCa1.1 activity. Among the eight regulatory β and γ subunits, LRRC26 alone was expressed at high levels in MDA-MB-453 cells and primary and metastatic breast cancer tissues, whereas no significant changes were observed in the expression levels of LRRC26 and activation kinetics of PAX-sensitive outward currents in MDA-MB-453 cells by the treatment with antiandrogens. The treatment with antiandrogens up-regulated the expression of the ubiquitin E3 ligases, FBW7, MDM2, and MDM4 in MDA-MB-453 cells, and the protein degradation of KCa1.1 was significantly inhibited by the respective siRNA-mediated blockade of FBW7 and MDM2. Based on these results, we concluded that KCa1.1 is an androgen-responsive gene in AR-positive breast cancer cells, and its down-regulation through enhancements in its protein degradation by FBW7 and/or MDM2 may contribute, at least in part, to the antiproliferative and antimetastatic effects of antiandrogens in breast cancer cells.
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Affiliation(s)
- Anowara Khatun
- Division of Pathological Sciences, Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Motoki Shimozawa
- Division of Pathological Sciences, Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Hiroaki Kito
- Division of Pathological Sciences, Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Mayu Kawaguchi
- Division of Pathological Sciences, Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Mayu Fujimoto
- Division of Pathological Sciences, Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Moe Ri
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Junko Kajikuri
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Satomi Niwa
- Division of Pathological Sciences, Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Masanori Fujii
- Division of Pathological Sciences, Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Susumu Ohya
- Division of Pathological Sciences, Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto, Japan.,Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
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Klumpp L, Sezgin EC, Skardelly M, Eckert F, Huber SM. KCa3.1 Channels and Glioblastoma: In Vitro Studies. Curr Neuropharmacol 2018; 16:627-635. [PMID: 28786347 PMCID: PMC5997865 DOI: 10.2174/1570159x15666170808115821] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 06/29/2017] [Accepted: 07/12/2017] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Several tumor entities including brain tumors aberrantly overexpress intermediate conductance Ca2+ activated KCa3.1 K+ channels. These channels contribute significantly to the transformed phenotype of the tumor cells. METHOD PubMed was searched in order to summarize our current knowledge on the molecular signaling upstream and downstream and the effector functions of KCa3.1 channel activity in tumor cells in general and in glioblastoma cells in particular. In addition, KCa3.1 expression and function for repair of DNA double strand breaks was determined experimentally in primary glioblastoma cultures in dependence on the abundance of proneural and mesenchymal stem cell markers. RESULTS By modulating membrane potential, cell volume, Ca2+ signals and the respiratory chain, KCa3.1 channels in both, plasma and inner mitochondrial membrane, have been demonstrated to regulate many cellular processes such as migration and tissue invasion, metastasis, cell cycle progression, oxygen consumption and metabolism, DNA damage response and cell death of cancer cells. Moreover, KCa3.1 channels have been shown to crucially contribute to resistance against radiotherapy. Futhermore, the original in vitro data on KCa3.1 channel expression in subtypes of glioblastoma stem(-like) cells propose KCa3.1 as marker for the mesenchymal subgroup of cancer stem cells and suggest that KCa3.1 contributes to the therapy resistance of mesenchymal glioblastoma stem cells. CONCLUSION The data suggest KCa3.1 channel targeting in combination with radiotherapy as promising new tool to eradicate therapy-resistant mesenchymal glioblastoma stem cells.
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Affiliation(s)
| | | | | | | | - Stephan M. Huber
- Address correspondence to this author at the Department of Radiation Oncology, University of Tübingen, Tübingen, Germany; Tel: +49-(0)7071-29-82183; E-mail:
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