1
|
Ganser K, Stransky N, Abed T, Quintanilla-Martinez L, Gonzalez-Menendez I, Naumann U, Koch P, Krueger M, Ruth P, Huber SM, Eckert F. K Ca channel targeting impairs DNA repair and invasiveness of patient-derived glioblastoma stem cells in culture and orthotopic mouse xenografts which only in part is predictable by K Ca expression levels. Int J Cancer 2024. [PMID: 38938062 DOI: 10.1002/ijc.35064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 05/07/2024] [Accepted: 05/21/2024] [Indexed: 06/29/2024]
Abstract
Prognosis of glioblastoma patients is still poor despite multimodal therapy. The highly brain-infiltrating growth in concert with a pronounced therapy resistance particularly of mesenchymal glioblastoma stem-like cells (GSCs) has been proposed to contribute to therapy failure. Recently, we have shown that a mesenchymal-to-proneural mRNA signature of patient derived GSC-enriched (pGSC) cultures associates with in vitro radioresistance and gel invasion. Importantly, this pGSC mRNA signature is prognostic for patients' tumor recurrence pattern and overall survival. Two mesenchymal markers of the mRNA signature encode for IKCa and BKCa Ca2+-activated K+ channels. Therefore, we analyzed here the effect of IKCa- and BKCa-targeting concomitant to (fractionated) irradiation on radioresistance and glioblastoma spreading in pGSC cultures and in pGSC-derived orthotopic xenograft glioma mouse models. To this end, in vitro gel invasion, clonogenic survival, in vitro and in vivo residual DNA double strand breaks (DSBs), tumor growth, and brain invasion were assessed in the dependence on tumor irradiation and K+ channel targeting. As a result, the IKCa- and BKCa-blocker TRAM-34 and paxilline, respectively, increased number of residual DSBs and (numerically) decreased clonogenic survival in some but not in all IKCa- and BKCa-expressing pGSC cultures, respectively. In addition, BKCa- but not IKCa-blockade slowed-down gel invasion in vitro. Moreover, systemic administration of TRAM-34 or paxilline concomitant to fractionated tumor irradiation increased in the xenograft model(s) residual number of DSBs and attenuated glioblastoma brain invasion and (numerically) tumor growth. We conclude, that KCa-blockade concomitant to fractionated radiotherapy might be a promising new strategy in glioblastoma therapy.
Collapse
Affiliation(s)
- Katrin Ganser
- Department of Radiation Oncology, University Hospital of Tübingen, Tübingen, Germany
| | - Nicolai Stransky
- Department of Radiation Oncology, University Hospital of Tübingen, Tübingen, Germany
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Tayeb Abed
- Department of Radiation Oncology, University Hospital of Tübingen, Tübingen, Germany
| | - Leticia Quintanilla-Martinez
- Institute of Pathology and Neuropathology, Comprehensive Cancer Center, Eberhard Karls University of Tübingen, Tübingen, Germany
- Cluster of Excellence iFIT (EXC 2180), Image-Guided and Functionally Instructed Tumor Therapies, Eberhard Karls University, Tuebingen, Germany
| | - Irene Gonzalez-Menendez
- Institute of Pathology and Neuropathology, Comprehensive Cancer Center, Eberhard Karls University of Tübingen, Tübingen, Germany
- Cluster of Excellence iFIT (EXC 2180), Image-Guided and Functionally Instructed Tumor Therapies, Eberhard Karls University, Tuebingen, Germany
| | - Ulrike Naumann
- Molecular Neurooncology, Hertie Institute for Clinical Brain Research and Center Neurology, University of Tübingen, Tübingen, Germany
| | - Pierre Koch
- Department of Pharmaceutical/Medicinal Chemistry II, Institute of Pharmacy, University of Regensburg, Regensburg, Germany
| | - Marcel Krueger
- Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, University of Tübingen, Tübingen, Germany
| | - Peter Ruth
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Stephan M Huber
- Department of Radiation Oncology, University Hospital of Tübingen, Tübingen, Germany
| | - Franziska Eckert
- Department of Radiation Oncology, University Hospital of Tübingen, Tübingen, Germany
- Department of Radiation Oncology, Medical University Vienna, AKH, Comprehensive Cancer Center, Vienna, Austria
| |
Collapse
|
2
|
Van NTH, Kim WK, Nam JH. Challenges in the Therapeutic Targeting of KCa Channels: From Basic Physiology to Clinical Applications. Int J Mol Sci 2024; 25:2965. [PMID: 38474212 PMCID: PMC10932353 DOI: 10.3390/ijms25052965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 03/14/2024] Open
Abstract
Calcium-activated potassium (KCa) channels are ubiquitously expressed throughout the body and are able to regulate membrane potential and intracellular calcium concentrations, thereby playing key roles in cellular physiology and signal transmission. Consequently, it is unsurprising that KCa channels have been implicated in various diseases, making them potential targets for pharmaceutical interventions. Over the past two decades, numerous studies have been conducted to develop KCa channel-targeting drugs, including those for disorders of the central and peripheral nervous, cardiovascular, and urinary systems and for cancer. In this review, we synthesize recent findings regarding the structure and activating mechanisms of KCa channels. We also discuss the role of KCa channel modulators in therapeutic medicine. Finally, we identify the major reasons behind the delay in bringing these modulators to the pharmaceutical market and propose new strategies to promote their application.
Collapse
Affiliation(s)
- Nhung Thi Hong Van
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Republic of Korea;
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, Goyang 10326, Republic of Korea
| | - Woo Kyung Kim
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, Goyang 10326, Republic of Korea
- Department of Internal Medicine, Graduate School of Medicine, Dongguk University, Goyang 10326, Republic of Korea
| | - Joo Hyun Nam
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Republic of Korea;
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, Goyang 10326, Republic of Korea
| |
Collapse
|
3
|
Drinkall S, Lawrence CB, Ossola B, Russell S, Bender C, Brice NB, Dawson LA, Harte M, Brough D. The two pore potassium channel THIK-1 regulates NLRP3 inflammasome activation. Glia 2022; 70:1301-1316. [PMID: 35353387 PMCID: PMC9314991 DOI: 10.1002/glia.24174] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/15/2022] [Accepted: 03/21/2022] [Indexed: 12/12/2022]
Abstract
The NLRP3 (NLR family, pyrin domain containing 3) inflammasome is a multi-protein complex responsible for the activation of caspase-1 and the subsequent cleavage and activation of the potent proinflammatory cytokines IL-1β and IL-18, and pyroptotic cell death. NLRP3 is implicated as a driver of inflammation in a range of disorders including neurodegenerative diseases, type 2 diabetes, and atherosclerosis. A commonly reported mechanism contributing to NLRP3 inflammasome activation is potassium ion (K+ ) efflux across the plasma membrane. Identification of K+ channels involved in NLRP3 activation remains incomplete. Here, we investigated the role of the K+ channel THIK-1 in NLRP3 activation. Both pharmacological inhibitors and cells from THIK-1 knockout (KO) mice were used to assess THIK-1 contribution to macrophage NLRP3 activation in vitro. Pharmacological inhibition of THIK-1 inhibited caspase-1 activation and IL-1β release from mouse bone-marrow-derived macrophages (BMDMs), mixed glia, and microglia in response to NLRP3 agonists. Similarly, BMDMs and microglia from THIK-1 KO mice had reduced NLRP3-dependent IL-1β release in response to P2X7 receptor activation with ATP. Overall, these data suggest that THIK-1 is a regulator of NLRP3 inflammasome activation in response to ATP and identify THIK-1 as a potential therapeutic target for inflammatory disease.
Collapse
Affiliation(s)
- Samuel Drinkall
- Division of Pharmacy & Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Catherine B Lawrence
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | | | | | | | | | | | - Michael Harte
- Division of Pharmacy & Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK.,The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, UK
| | - David Brough
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK.,The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, UK.,Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance NHS Group, University of Manchester, Manchester, UK
| |
Collapse
|
4
|
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.
Collapse
|
5
|
Steudel FA, Mohr CJ, Stegen B, Nguyen HY, Barnert A, Steinle M, Beer‐Hammer S, Koch P, Lo W, Schroth W, Hoppe R, Brauch H, Ruth P, Huber SM, Lukowski R. SK4 channels modulate Ca 2+ signalling and cell cycle progression in murine breast cancer. Mol Oncol 2017; 11:1172-1188. [PMID: 28557306 PMCID: PMC5579333 DOI: 10.1002/1878-0261.12087] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 04/27/2017] [Accepted: 05/16/2017] [Indexed: 01/08/2023] Open
Abstract
Oncogenic signalling via Ca2+ -activated K+ channels of intermediate conductance (SK4, also known as KCa 3.1 or IK) has been implicated in different cancer entities including breast cancer. Yet, the role of endogenous SK4 channels for tumorigenesis is unclear. Herein, we generated SK4-negative tumours by crossing SK4-deficient (SK4 KO) mice to the polyoma middle T-antigen (PyMT) and epidermal growth factor receptor 2 (cNeu) breast cancer models in which oncogene expression is driven by the retroviral promoter MMTV. Survival parameters and tumour progression were studied in cancer-prone SK4 KO in comparison with wild-type (WT) mice and in a syngeneic orthotopic mouse model following transplantation of SK4-negative or WT tumour cells. SK4 activity was modulated by genetic or pharmacological means using the SK4 inhibitor TRAM-34 in order to establish the role of breast tumour SK4 for cell growth, electrophysiological signalling, and [Ca2+ ]i oscillations. Ablation of SK4 and TRAM-34 treatment reduced the SK4-generated current fraction, growth factor-dependent Ca2+ entry, cell cycle progression and the proliferation rate of MMTV-PyMT tumour cells. In vivo, PyMT oncogene-driven tumorigenesis was only marginally affected by the global lack of SK4, whereas tumour progression was significantly delayed after orthotopic implantation of MMTV-PyMT SK4 KO breast tumour cells. However, overall survival and progression-free survival time in the MMTV-cNeu mouse model were significantly extended in the absence of SK4. Collectively, our data from murine breast cancer models indicate that SK4 activity is crucial for cell cycle control. Thus, the modulation of this channel should be further investigated towards a potential improvement of existing antitumour strategies in human breast cancer.
Collapse
Affiliation(s)
- Friederike A. Steudel
- Department of Pharmacology, Toxicology and Clinical PharmacyInstitute of PharmacyUniversity of TuebingenGermany
| | - Corinna J. Mohr
- Department of Pharmacology, Toxicology and Clinical PharmacyInstitute of PharmacyUniversity of TuebingenGermany
- Dr. Margarete Fischer‐Bosch‐Institute of Clinical PharmacologyStuttgart and University of TuebingenGermany
| | - Benjamin Stegen
- Department of Radiation OncologyUniversity of TuebingenGermany
| | - Hoang Y. Nguyen
- Department of Pharmacology, Toxicology and Clinical PharmacyInstitute of PharmacyUniversity of TuebingenGermany
| | - Andrea Barnert
- Department of Pharmacology, Toxicology and Clinical PharmacyInstitute of PharmacyUniversity of TuebingenGermany
| | - Marc Steinle
- Department of Pharmacology, Toxicology and Clinical PharmacyInstitute of PharmacyUniversity of TuebingenGermany
| | - Sandra Beer‐Hammer
- Department of Pharmacology and Experimental TherapyInstitute of Experimental and Clinical Pharmacology and ToxicologyUniversity Hospital TuebingenGermany
| | - Pierre Koch
- Pharmaceutical and Medicinal ChemistryInstitute of PharmacyUniversity of TuebingenGermany
| | - Wing‐Yee Lo
- Dr. Margarete Fischer‐Bosch‐Institute of Clinical PharmacologyStuttgart and University of TuebingenGermany
| | - Werner Schroth
- Dr. Margarete Fischer‐Bosch‐Institute of Clinical PharmacologyStuttgart and University of TuebingenGermany
| | - Reiner Hoppe
- Dr. Margarete Fischer‐Bosch‐Institute of Clinical PharmacologyStuttgart and University of TuebingenGermany
| | - Hiltrud Brauch
- Dr. Margarete Fischer‐Bosch‐Institute of Clinical PharmacologyStuttgart and University of TuebingenGermany
- German Cancer Consortium (DKTK)German Cancer Research Center (DKFZ)HeidelbergGermany
| | - Peter Ruth
- Department of Pharmacology, Toxicology and Clinical PharmacyInstitute of PharmacyUniversity of TuebingenGermany
| | | | - Robert Lukowski
- Department of Pharmacology, Toxicology and Clinical PharmacyInstitute of PharmacyUniversity of TuebingenGermany
| |
Collapse
|
6
|
Zhang P, Yang X, Yin Q, Yi J, Shen W, Zhao L, Zhu Z, Liu J. Inhibition of SK4 Potassium Channels Suppresses Cell Proliferation, Migration and the Epithelial-Mesenchymal Transition in Triple-Negative Breast Cancer Cells. PLoS One 2016; 11:e0154471. [PMID: 27124117 PMCID: PMC4849628 DOI: 10.1371/journal.pone.0154471] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 04/14/2016] [Indexed: 11/21/2022] Open
Abstract
Treatments for triple-negative breast cancer (TNBC) are limited; intermediate-conductance calcium-activated potassium (SK4) channels are closely involved in tumor progression, but little is known about these channels in TNBC. We aimed to investigate whether SK4 channels affect TNBC. First, by immunohistochemistry (IHC) and western blotting (WB), increased SK4 protein expression in breast tumor tissues was detected relative to that in non-tumor breast tissues, but there was no apparent expression difference between various subtypes of breast cancer (p>0.05). Next, functional SK4 channels were detected in the TNBC cell line MDA-MB-231 using WB, real-time PCR, immunofluorescence and patch-clamp recording. By employing SK4 specific siRNAs and blockers, including TRAM-34 and clotrimazole, in combination with an MTT assay, a colony-formation assay, flow cytometry and a cell motility assay, we found that the suppression of SK4 channels significantly inhibited cell proliferation and migration and promoted apoptosis in MDA-MB-231 cells (p<0.05). Further investigation revealed that treatment with epidermal growth factor (EGF)/basic fibroblast growth factor (bFGF) caused MDA-MB-231 cells to undergo the epithelial-mesenchymal transition (EMT) and to show increased SK4 mRNA expression. In addition, the down-regulation of SK4 expression inhibited the EMT markers Vimentin and Snail1. Collectively, our findings suggest that SK4 channels are expressed in TNBC and are involved in the proliferation, apoptosis, migration and EMT processes of TNBC cells.
Collapse
Affiliation(s)
- Panshi Zhang
- Department of Thyroid and Breast Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaowei Yang
- Department of General Surgery, the First Affiliated Hospital, Anhui Medical University, Hefei, China
| | - Qian Yin
- Department of Thyroid and Breast Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jilin Yi
- Department of Thyroid and Breast Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wenzhuang Shen
- Department of Thyroid and Breast Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lu Zhao
- Department of Thyroid and Breast Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhi Zhu
- Department of Thyroid and Breast Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jinwen Liu
- Department of Thyroid and Breast Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- * E-mail:
| |
Collapse
|
7
|
Abstract
The metabolism of cancer cells differs substantially from normal cells, including ion transport. Although this phenomenon has been long recognized, ion transporters have not been viewed as suitable therapeutic targets. However, the acidic pH values present in tumours which are well outside of normal limits are now becoming recognized as an important therapeutic target. Carbonic anhydrase IX (CAIX) is fundamental to tumour pH regulation. CAIX is commonly expressed in cancer, but lowly expressed in normal tissues and that presents an attractive target. Here, we discuss the possibilities of exploiting the acidic, hypoxic tumour environment as possible target for therapy. Additionally, clinical experience with CAIX targeting in cancer patients is discussed.
Collapse
Affiliation(s)
- E Oosterwijk
- Department of Urology, 267 Experimental Urology, Radboud University Medical Center, , PO Box 9101, Nijmegen 6500 HB, The Netherlands
| | | |
Collapse
|
8
|
Agarwal JJ, Zhu Y, Zhang QY, Mongin AA, Hough LB. TRAM-34, a putatively selective blocker of intermediate-conductance, calcium-activated potassium channels, inhibits cytochrome P450 activity. PLoS One 2013; 8:e63028. [PMID: 23667566 PMCID: PMC3646888 DOI: 10.1371/journal.pone.0063028] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 03/27/2013] [Indexed: 11/25/2022] Open
Abstract
TRAM-34, a clotrimazole analog characterized as a potent and selective inhibitor of intermediate-conductance, calcium-activated K+ (IKCa) channels, has been used extensively in vitro and in vivo to study the biological roles of these channels. The major advantage of TRAM-34 over clotrimazole is the reported lack of inhibition of the former drug on cytochrome P450 (CYP) activity. CYPs, a large family of heme-containing oxidases, play essential roles in endogenous signaling and metabolic pathways, as well as in xenobiotic metabolism. However, previously published work has only characterized the effects of TRAM-34 on a single CYP isoform. To test the hypothesis that TRAM-34 may inhibit some CYP isoforms, the effects of this compound were presently studied on the activities of four rat and five human CYP isoforms. TRAM-34 inhibited recombinant rat CYP2B1, CYP2C6 and CYP2C11 and human CYP2B6, CYP2C19 and CYP3A4 with IC50 values ranging from 0.9 µM to 12.6 µM, but had no inhibitory effects (up to 80 µM) on recombinant rat CYP1A2, human CYP1A2, or human CYP19A1. TRAM-34 also had both stimulatory and inhibitory effects on human CYP3A4 activity, depending on the substrate used. These results show that low micromolar concentrations of TRAM-34 can inhibit several rat and human CYP isoforms, and suggest caution in the use of high concentrations of this drug as a selective IKCa channel blocker. In addition, in vivo use of TRAM-34 could lead to CYP-related drug-drug interactions.
Collapse
Affiliation(s)
- Jay J. Agarwal
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
| | - Yi Zhu
- Wadsworth Center, New York State Department of Health, and School of Public Health, State University of New York at Albany, Albany, New York, United States of America
| | - Qing-Yu Zhang
- Wadsworth Center, New York State Department of Health, and School of Public Health, State University of New York at Albany, Albany, New York, United States of America
| | - Alexander A. Mongin
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
| | - Lindsay B. Hough
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
- * E-mail:
| |
Collapse
|
9
|
The inhibitor of Ca(2+)-dependent K+ channels TRAM-34 blocks growth of hepatocellular carcinoma cells via downregulation of estrogen receptor alpha mRNA and nuclear factor-kappaB. Invest New Drugs 2012; 31:452-7. [PMID: 23054207 DOI: 10.1007/s10637-012-9879-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 09/16/2012] [Indexed: 01/03/2023]
Abstract
Hepatocellular carcinoma (HCC) is the most common liver malignancy still demanding for novel therapeutic options. Since the ion channel inhibitor TRAM-34 (1-[(2-chlorophenyl) diphenylmethyl]-1H-pyrazole) was shown to block growth in various cancer cells, we investigated anti-tumor effects of TRAM-34 in human HCC cell lines. We found that TRAM-34 reduced HCC cell proliferation without induction of apoptosis. This was due to a decreased mRNA expression of estrogen receptor alpha (ESR1) and a reduced activation of NF-kappaB, which both are implicated in the development of HCC. Therefore, TRAM-34 might represent a novel therapeutic target for the treatment of HCC.
Collapse
|
10
|
Yamamoto T, Ohara A, Nishikawa M, Yamamoto G, Saeki Y. Dexamethasone-induced up-regulation of two-pore domain K+ channel genes, TASK-1 and TWIK-2, in cultured human periodontal ligament fibroblasts. In Vitro Cell Dev Biol Anim 2011; 47:273-9. [PMID: 21359819 DOI: 10.1007/s11626-011-9388-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Accepted: 01/26/2011] [Indexed: 12/25/2022]
Abstract
Two-pore domain K(+) channels are widely expressed in many types of cells, and have various important functions, especially maintaining the resting membrane potential. In the previous report, we have confirmed the presence of several kinds of two-pore domain K(+) channels in the periodontal ligament (PDL) fibroblasts. It is well known that dexamethasone (Dex) regulates the functions of various kinds of ion channels. In this work, we investigate if Dex affects the gene expressions of the two-pore domain K(+) channels in the PDL fibroblasts. We also examined the effects of other steroid hormones on the K(+) channels gene expression. The mRNA levels of two-pore domain K(+) channels in human PDL fibroblasts were examined in the presence or absence of Dex by RT-PCR. The effects of other steroid hormones (aldosterone, estrogen, 1α,25-dihydroxyvitamin D(3) [1,25-(OH)(2)D(3)], and retinoic acid) were also examined. Dex significantly induced the expression of TASK-1 and TWIK-2 in mRNA levels in both a dose- and a time-dependent manner. The stimulatory effects of Dex were completely abolished by a glucocorticoid receptor antagonist. 1,25-(OH)(2)D(3) also increased the TASK-1 mRNA levels but had no effect on TWIK-2 expression. Dex, one of the potent glucocorticoid, probably have a protective role against external stimuli by maintaining the membrane potential of PDL fibroblasts through the up-regulation of TASK-1 and TWIK-2 K(+) channels.
Collapse
Affiliation(s)
- Takahiro Yamamoto
- Department of Oral and Maxillofacial Surgery, Shiga University of Medical Science, Otsu, Shiga 520-2192, Japan.
| | | | | | | | | |
Collapse
|