TY - JOUR
T1 - Effect of calcium electroporation in combination with metformin in vivo and correlation between viability and intracellular ATP level after calcium electroporation in vitro
AU - Frandsen, Stine Krog
AU - Gehl, Julie
PY - 2017/7
Y1 - 2017/7
N2 - Background: Calcium electroporation is a new experimental anti-cancer treatment where calcium is internalized into cells by application of short, high voltage pulses. Calcium electroporation has been shown to induce tumor necrosis associated with ATP depletion while the effect on normal fibroblasts was limited when investigated in a 3D in vitro spheroid model. We aimed to investigate the effect of calcium electroporation in combination with metformin, a drug that affects intracellular ATP level. We also aimed to study the relationship between the viability and intracellular ATP levels after calcium electroporation in vitro. Methods: In this study, we investigated the effect of calcium electroporation with metformin on NMRI-Foxn1nu mice in vivo on tumor size, survival, and intracellular ATP. We further investigated viability and intracellular ATP level in vitro after calcium electroporation in two human cancer cell lines: Breast (MDA-MB231) and colon (HT29), and in normal human fibroblasts (HDF-n), as well as investigating viability in human bladder cancer cells (SW780) and human small cell lung cancer cells (H69) where we have previously published intracellular ATP levels. Results: Calcium electroporation significantly reduced the size and ATP level of bladder cancer tumors treated in vivo but no increased effect of metformin combined with calcium electroporation was shown on neither tumor size, survival, nor ATP level. Calcium electroporation in vitro significantly decreased viability compared with calcium alone (p<0.0001 for calcium concentrations from 0.5 mM for H69, HDF-n, and MDA-MB231; p<0.0001 for calcium concentrations from 1 mM for HT29 and SW780). Intracellular ATP levels decreased significantly after calcium electroporation (p<0.05), however no correlation between intracellular ATP level and viability after treatment was observed. Conclusion: Calcium electroporation caused reduced tumor size, increased survival, and acute ATP depletion in vivo. This effect was not augmented by metformin. Calcium electroporation is a possible novel anti-cancer treatment that has been shown to cause cell death associated with acute ATP depletion in vitro and in vivo.
AB - Background: Calcium electroporation is a new experimental anti-cancer treatment where calcium is internalized into cells by application of short, high voltage pulses. Calcium electroporation has been shown to induce tumor necrosis associated with ATP depletion while the effect on normal fibroblasts was limited when investigated in a 3D in vitro spheroid model. We aimed to investigate the effect of calcium electroporation in combination with metformin, a drug that affects intracellular ATP level. We also aimed to study the relationship between the viability and intracellular ATP levels after calcium electroporation in vitro. Methods: In this study, we investigated the effect of calcium electroporation with metformin on NMRI-Foxn1nu mice in vivo on tumor size, survival, and intracellular ATP. We further investigated viability and intracellular ATP level in vitro after calcium electroporation in two human cancer cell lines: Breast (MDA-MB231) and colon (HT29), and in normal human fibroblasts (HDF-n), as well as investigating viability in human bladder cancer cells (SW780) and human small cell lung cancer cells (H69) where we have previously published intracellular ATP levels. Results: Calcium electroporation significantly reduced the size and ATP level of bladder cancer tumors treated in vivo but no increased effect of metformin combined with calcium electroporation was shown on neither tumor size, survival, nor ATP level. Calcium electroporation in vitro significantly decreased viability compared with calcium alone (p<0.0001 for calcium concentrations from 0.5 mM for H69, HDF-n, and MDA-MB231; p<0.0001 for calcium concentrations from 1 mM for HT29 and SW780). Intracellular ATP levels decreased significantly after calcium electroporation (p<0.05), however no correlation between intracellular ATP level and viability after treatment was observed. Conclusion: Calcium electroporation caused reduced tumor size, increased survival, and acute ATP depletion in vivo. This effect was not augmented by metformin. Calcium electroporation is a possible novel anti-cancer treatment that has been shown to cause cell death associated with acute ATP depletion in vitro and in vivo.
KW - Adenosine Triphosphate/analysis
KW - Animals
KW - Antineoplastic Agents/administration & dosage
KW - Calcium/administration & dosage
KW - Cell Line, Tumor
KW - Cell Survival
KW - Electrochemotherapy/methods
KW - Female
KW - HT29 Cells
KW - Humans
KW - In Vitro Techniques
KW - Male
KW - Metformin/administration & dosage
KW - Mice
KW - Neoplasms, Experimental/drug therapy
U2 - 10.1371/journal.pone.0181839
DO - 10.1371/journal.pone.0181839
M3 - Journal article
C2 - 28742810
SN - 1932-6203
VL - 12
JO - PLOS ONE
JF - PLOS ONE
IS - 7
M1 - e0181839
ER -
