Monovalent ions control proliferation of Ehrlich Lettre ascites cells
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Monovalent ions control proliferation of Ehrlich Lettre ascites cells. / Klausen, Thomas Kjaer; Preisler, Sarah; Pedersen, Stine Helene Falsig; Hoffmann, Else Kay.
In: American Journal of Physiology (Consolidated), Vol. 299, No. 3, 01.09.2010, p. C714-25.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Monovalent ions control proliferation of Ehrlich Lettre ascites cells
AU - Klausen, Thomas Kjaer
AU - Preisler, Sarah
AU - Pedersen, Stine Helene Falsig
AU - Hoffmann, Else Kay
PY - 2010/9/1
Y1 - 2010/9/1
N2 - Channels and transporters of monovalent ions are increasingly suggested as putative anticarcinogenic targets. However, the mechanisms involved in modulation of proliferation by monovalent ions are poorly understood. Here, we investigated the role of K+, Na+, and Cl(-) ions for the proliferation of Ehrlich Lettre ascites (ELA) cells. We measured the intracellular concentration of each ion in G(0), G(1), and S phases of the cell cycle following synchronization by serum starvation and release. We show that intracellular concentrations and content of Na+ and Cl(-) were reduced in the G(0)-G(1) phase transition, followed by an increased content of both ions in S phase concomitant with water uptake. The effect of substituting extracellular monovalent ions was investigated by bromodeoxyuridine incorporation and showed marked reduction after Na+ and Cl(-) substitution. In spectrofluorometric measurements with the pH-sensitive dye BCECF, substitution of Na+ was observed to upregulate the activity of the Na+/H+ exchanger NHE1 as well as of Na+-independent acid extrusion mechanisms, facilitating intracellular pH (pH(i)) recovery after acid loading and increasing pH(i). Results using the potential sensitive dye DiBaC4(3) showed a reduced Cl(-) conductance in S compared with G(1) followed by transmembrane potential (E(m)) hyperpolarization in S. Cl(-) substitution by impermeable anions strongly inhibited proliferation and increased free, intracellular Ca2+ ([Ca2+]i), whereas a more permeable anion had little effect. Western blots showed reduced chloride intracellular channel CLIC1 and chloride channel ClC-2 expression in the plasma membrane in S compared with G(1). Our results suggest that Na+ regulates ELA cell proliferation by regulating intracellular pH while Cl(-) may regulate proliferation by fine-tuning of E(m) in S phase and altered Ca2+ signaling.
AB - Channels and transporters of monovalent ions are increasingly suggested as putative anticarcinogenic targets. However, the mechanisms involved in modulation of proliferation by monovalent ions are poorly understood. Here, we investigated the role of K+, Na+, and Cl(-) ions for the proliferation of Ehrlich Lettre ascites (ELA) cells. We measured the intracellular concentration of each ion in G(0), G(1), and S phases of the cell cycle following synchronization by serum starvation and release. We show that intracellular concentrations and content of Na+ and Cl(-) were reduced in the G(0)-G(1) phase transition, followed by an increased content of both ions in S phase concomitant with water uptake. The effect of substituting extracellular monovalent ions was investigated by bromodeoxyuridine incorporation and showed marked reduction after Na+ and Cl(-) substitution. In spectrofluorometric measurements with the pH-sensitive dye BCECF, substitution of Na+ was observed to upregulate the activity of the Na+/H+ exchanger NHE1 as well as of Na+-independent acid extrusion mechanisms, facilitating intracellular pH (pH(i)) recovery after acid loading and increasing pH(i). Results using the potential sensitive dye DiBaC4(3) showed a reduced Cl(-) conductance in S compared with G(1) followed by transmembrane potential (E(m)) hyperpolarization in S. Cl(-) substitution by impermeable anions strongly inhibited proliferation and increased free, intracellular Ca2+ ([Ca2+]i), whereas a more permeable anion had little effect. Western blots showed reduced chloride intracellular channel CLIC1 and chloride channel ClC-2 expression in the plasma membrane in S compared with G(1). Our results suggest that Na+ regulates ELA cell proliferation by regulating intracellular pH while Cl(-) may regulate proliferation by fine-tuning of E(m) in S phase and altered Ca2+ signaling.
KW - Animals
KW - Anions
KW - Calcium
KW - Carcinoma, Ehrlich Tumor
KW - Cations, Monovalent
KW - Cell Membrane
KW - Cell Membrane Permeability
KW - Cell Proliferation
KW - Cells, Cultured
KW - Chloride Channels
KW - Chlorides
KW - G0 Phase
KW - G1 Phase
KW - Hydrogen-Ion Concentration
KW - Meglumine
KW - Potassium
KW - Protein Transport
KW - S Phase
KW - Sodium
KW - Sodium-Hydrogen Antiporter
KW - Water
U2 - 10.1152/ajpcell.00445.2009
DO - 10.1152/ajpcell.00445.2009
M3 - Journal article
C2 - 20592244
VL - 299
SP - C714-25
JO - American Journal of Physiology - Cell Physiology
JF - American Journal of Physiology - Cell Physiology
SN - 0363-6143
IS - 3
ER -
ID: 33345512