101
|
Baldoli E, Maier JAM. Silencing TRPM7 mimics the effects of magnesium deficiency in human microvascular endothelial cells. Angiogenesis 2011; 15:47-57. [PMID: 22183257 DOI: 10.1007/s10456-011-9242-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 12/08/2011] [Indexed: 01/27/2023]
Abstract
Evidence has accumulated to suggest that magnesium might play a role in controlling angiogenesis. Since microvascular endothelial cells are protagonists in this process, we investigated the behavior of these cells cultured in low extracellular magnesium or silenced for its transporter Transient Receptor Potential Melastatin (TRPM)7, essential for cellular magnesium homeostasis. In particular, we focused on some crucial steps of the angiogenic process, i.e. proliferation, migration, protease production and organization in tridimensional structures. Silencing TRPM7 mimics the effects of low extracellular magnesium on human microvascular endothelial cells (HMEC). Indeed, while no effects were observed on the production of metalloproteases and on tridimensional organization on matrigel, both magnesium deficiency and silencing of TRPM7 impair cell migration and inhibit growth by arresting the cells in the G0/G1 and G2/M phases of the cell cycle. Since low extracellular magnesium markedly decreases TRPM7 in HMEC, we suggest that TRPM7 downregulation might mediate low magnesium-induced inhibition of cell growth and migration. Human endothelial cells from the umbilical vein are growth inhibited by low magnesium and growth stimulated after TRPM7 silencing. An impairment of ERK phosphorylation in HMEC silencing TRPM7 is responsible, in part, for the different proliferative behavior of these two cell types. We broadened our studies also to endothelial colony-forming cells and found that they are sensitive to fluctuations of the concentrations of extracellular magnesium, while their proliferation rate is not modulated by TRPM7 silencing. Our results point to magnesium and TRPM7 as a modulators of the angiogenic phenotype of microvascular endothelial cells.
Collapse
Affiliation(s)
- Erika Baldoli
- Dipartimento di Scienze Cliniche Luigi Sacco, Università di Milano, Via GB Grassi, 74, 20157 Milano, Italy
| | | |
Collapse
|
102
|
Gao H, Chen X, Du X, Guan B, Liu Y, Zhang H. EGF enhances the migration of cancer cells by up-regulation of TRPM7. Cell Calcium 2011; 50:559-68. [PMID: 21978419 DOI: 10.1016/j.ceca.2011.09.003] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 09/13/2011] [Accepted: 09/14/2011] [Indexed: 01/02/2023]
Abstract
Ion channels involved in the migration of tumor cells that is required for their invasion and metastasis. In this paper, we describe the interaction of TRPM7 channel and epidermal growth factor (EGF), an important player in cancer development in the migration of lung cancer cells. The TRPM7 currents in A549 cells were first characterized by means of electrophysiology, pharmacology and RNA interference. Removing Ca(2+) from the extracellular solution not only potentiated a large inward current, but also abolished the outward rectification. 200μM 2-APB inhibited the outward and the inward TRPM7 currents and at the same time restored the property of outward rectification. EGF greatly enhanced the migration of A549 cells, and also markedly up-regulated the membrane protein expression of TRPM7 and the amplitude of TRPM7 currents. Depressing the function of TRPM7 with RNA interference or pharmacological agents not only reversed the EGF-enhanced migration of A549 cells but also inhibited the basal migration of A549 cells in the absence of EGF. Thus it seems that TRPM7 plays a pivotal role in the migration of A549 cells induced by EGF and thus could be a potential therapeutic target in lung cancers.
Collapse
Affiliation(s)
- Haixia Gao
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, PR China
| | | | | | | | | | | |
Collapse
|
103
|
Zierler S, Yao G, Zhang Z, Kuo WC, Pörzgen P, Penner R, Horgen FD, Fleig A. Waixenicin A inhibits cell proliferation through magnesium-dependent block of transient receptor potential melastatin 7 (TRPM7) channels. J Biol Chem 2011; 286:39328-35. [PMID: 21926172 DOI: 10.1074/jbc.m111.264341] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Transient receptor potential melastatin 7 (TRPM7) channels represent the major magnesium-uptake mechanism in mammalian cells and are key regulators of cell growth and proliferation. They are expressed abundantly in a variety of human carcinoma cells controlling survival, growth, and migration. These characteristics are the basis for recent interest in the channel as a target for cancer therapeutics. We screened a chemical library of marine organism-derived extracts and identified waixenicin A from the soft coral Sarcothelia edmondsoni as a strong inhibitor of overexpressed and native TRPM7. Waixenicin A activity was cytosolic and potentiated by intracellular free magnesium (Mg(2+)) concentration. Mutating a Mg(2+) binding site on the TRPM7 kinase domain reduced the potency of the compound, whereas kinase deletion enhanced its efficacy independent of Mg(2+). Waixenicin A failed to inhibit the closely homologous TRPM6 channel and did not significantly affect TRPM2, TRPM4, and Ca(2+) release-activated Ca(2+) current channels. Therefore, waixenicin A represents the first potent and relatively specific inhibitor of TRPM7 ion channels. Consistent with TRPM7 inhibition, the compound blocked cell proliferation in human Jurkat T-cells and rat basophilic leukemia cells. Based on the ability of the compound to inhibit cell proliferation through Mg(2+)-dependent block of TRPM7, waixenicin A, or structural analogs may have cancer-specific therapeutic potential, particularly because certain cancers accumulate cytosolic Mg(2+).
Collapse
Affiliation(s)
- Susanna Zierler
- The Queen's Medical Center and John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96813, USA
| | | | | | | | | | | | | | | |
Collapse
|
104
|
Runnels LW. TRPM6 and TRPM7: A Mul-TRP-PLIK-cation of channel functions. Curr Pharm Biotechnol 2011; 12:42-53. [PMID: 20932259 DOI: 10.2174/138920111793937880] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 05/07/2010] [Indexed: 12/31/2022]
Abstract
Unique among ion channels, TRPM6 and TRPM7 garnered much interest upon their discovery as the first ion channels to possess their own kinase domain. Soon after their identification, the two proteins were quickly linked to the regulation of magnesium homeostasis. However, study of their physiological functions in mouse and zebrafish have revealed expanding roles for these channel-kinases that include skeletogenesis and melanopore formation, thymopoiesis, cell adhesion, and neural fold closure during early development. In addition, mutations in the TRPM6 gene constitute the underlying genetic defect in hypomagnesemia with secondary hypocalcemia, a rare autosomal-recessive disease characterized by low serum magnesium accompanied by hypocalcemia. Depletion of TRPM7 expression in brain, on the other hand, proved successful in mitigating much of the cellular devastation that accompanies oxygen-glucose deprivation during ischemia. The aim of this review is to summarize the data emerging from molecular genetic, biochemical, electrophysiological, and pharmacological studies of these unique channel-kinases.
Collapse
Affiliation(s)
- Loren W Runnels
- Department of Pharmacology, UMDNJ-Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854, USA.
| |
Collapse
|
105
|
Abstract
In most cases, metastasis, not the primary tumour per se, is the main cause of mortality in cancer patients. In order to effectively escape the tumour, enter the circulation and establish secondary growth in distant organs cancer cells must develop an enhanced propensity to migrate. The ubiquitous second messenger Ca²⁺ is a crucial regulator of cell migration. Recently, a number of known molecular players in cellular Ca²⁺ homeostasis, including calcium release-activated calcium channel protein 1 (ORAI1), stromal interaction molecule 1 (STIM1) and transient receptor potential (TRP) channels, have been implicated in tumour cell migration and the metastatic cell phenotype. We discuss how these developments have increased our understanding of the Ca²⁺ dependence of pro-metastatic behaviours.
Collapse
Affiliation(s)
- Natalia Prevarskaya
- INSERM, U1003, Laboratoire de Physiologie Cellulaire, Equipe labellise par la Ligue contre le cancer, Villeneuve dAscq, F59650, France.
| | | | | |
Collapse
|
106
|
Cross-talk between calcium and protein kinase A in the regulation of cell migration. Curr Opin Cell Biol 2011; 23:554-61. [PMID: 21665456 DOI: 10.1016/j.ceb.2011.05.006] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 05/16/2011] [Accepted: 05/17/2011] [Indexed: 12/31/2022]
Abstract
Calcium (Ca(2+)) and the cAMP-dependent protein kinase (PKA) are pleiotropic cellular regulators and both exert powerful, diverse effects on cytoskeletal dynamics, cell adhesion, and cell migration. Localization, by A-kinase-anchoring proteins (AKAPs), of PKA activity to the protrusive leading edge, integrins, and other regulators of cytoskeletal dynamics has emerged as an important facet of its role in cell migration. Additional recent work has firmly established the importance of Ca(2+) influx through mechanosensitive transient receptor potential (TRP) channels and through store-operated Ca(2+) entry (SOCE) in cell migration. Finally, there is considerable evidence showing that these mechanisms of Ca(2+) influx and PKA regulation intersect--and often interact--and thus may work in concert to translate complex extracellular cues into the intracellular biochemical anisotropy required for directional cell migration.
Collapse
|
107
|
Current world literature. Curr Opin Otolaryngol Head Neck Surg 2011; 19:138-41. [PMID: 21637039 DOI: 10.1097/moo.0b013e328345326d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
108
|
Dhennin-Duthille I, Gautier M, Faouzi M, Guilbert A, Brevet M, Vaudry D, Ahidouch A, Sevestre H, Ouadid-Ahidouch H. High Expression of Transient Receptor Potential Channels in Human Breast Cancer Epithelial Cells and Tissues: Correlation with Pathological Parameters. Cell Physiol Biochem 2011; 28:813-22. [DOI: 10.1159/000335795] [Citation(s) in RCA: 184] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/26/2011] [Indexed: 01/19/2023] Open
|
109
|
Svensson L, McDowall A, Giles KM, Stanley P, Feske S, Hogg N. Calpain 2 controls turnover of LFA-1 adhesions on migrating T lymphocytes. PLoS One 2010; 5:e15090. [PMID: 21152086 PMCID: PMC2994845 DOI: 10.1371/journal.pone.0015090] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 10/19/2010] [Indexed: 11/19/2022] Open
Abstract
The immune cells named T lymphocytes circulate around the body fulfilling their role in immunosurveillance by monitoring the tissues for injury or infection. To migrate from the blood into the tissues, they make use of the integrin LFA-1 which is exclusively expressed by immune cells. These highly motile cells attach and migrate on substrates expressing the LFA-1 ligand ICAM-1. The molecular events signaling LFA-1 activation and adhesion are now reasonably well identified, but the process of detaching LFA-1 adhesions is less understood. The cysteine protease calpain is involved in turnover of integrin-mediated adhesions in less motile cell types. In this study we have explored the involvement of calpain in turnover of LFA-1-mediated adhesions of T lymphocytes. Using live cell imaging and immunohistochemistry, we demonstrate that turnover of adhesions depends on the Ca2+-dependent enzyme, calpain 2. Inhibition of calpain activity by means of siRNA silencing or pharmacological inhibition results in inefficient disassembly of LFA-1 adhesions causing T lymphocyte elongation and shedding of LFA-1 clusters behind the migrating T lymphocytes. We show that calpain 2 is distributed throughout the T lymphocyte, but is most active at the trailing edge as detected by expression of its fluorescent substrate CMAC,t-BOC-Leu-Met. Extracellular Ca2+ entry is essential for the activity of calpain 2 that is constantly maintained as the T lymphocytes migrate. Use of T cells from a patient with mutation in ORAI1 revealed that the major calcium-release-activated-calcium channel is not the ion channel delivering the Ca2+. We propose a model whereby Ca2+ influx, potentially through stretch activated channels, is sufficient to activate calpain 2 at the trailing edge of a migrating T cell and this activity is essential for the turnover of LFA-1 adhesions.
Collapse
Affiliation(s)
- Lena Svensson
- Leukocyte Adhesion Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
| | - Alison McDowall
- Leukocyte Adhesion Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
| | - Katherine M. Giles
- Leukocyte Adhesion Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
| | - Paula Stanley
- Leukocyte Adhesion Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
| | - Stefan Feske
- Department of Pathology, Langone Medical Center, New York University, New York, New York, United States of America
| | - Nancy Hogg
- Leukocyte Adhesion Laboratory, Cancer Research UK London Research Institute, London, United Kingdom
- * E-mail:
| |
Collapse
|