TY - JOUR
T1 - Therapeutic concentrations of digitoxin inhibit endothelial focal adhesion kinase and angiogenesis induced by different growth factors
AU - Trenti, Annalisa
AU - Zulato, Elisabetta
AU - Pasqualini, Lorenza
AU - Indraccolo, Stefano
AU - Bolego, Chiara
AU - Trevisi, Lucia
PY - 2017/1/1
Y1 - 2017/1/1
N2 - Background and Purpose: Cardiac glycosides are Na+/K+-ATPases inhibitors used to treat congestive heart failure and cardiac arrhythmias. Epidemiological studies indicate that patients on digitalis therapy are more protected from cancer. Evidence of a selective cytotoxicity against cancer cells has suggested their potential use as anticancer drugs. The effect on angiogenesis of clinically used cardiac glycosides has not been extensively explored. Experimental Approach: We studied the effect of digoxin, digitoxin and ouabain on early events of the angiogenic process in HUVECs. We determined HUVEC viability, proliferation, migration and differentiation into capillary tube-like structures. We also tested drug activity using an in vivo angiogenesis model. Activation of protein tyrosine kinase 2 (FAK) and signalling proteins associated with the Na+/K+-ATPase signalosome was determined by Western blotting. Key Results: Digitoxin and ouabain (1–100 nM) inhibited HUVEC migration, concentration-dependently, without affecting cell viability, while digoxin induced apoptosis at the same concentrations. Digitoxin antagonized growth factor-induced migration and tubularization at concentrations (1–25 nM) within its plasma therapeutic range. The anti-angiogenic effect of digitoxin was confirmed also by in vivo studies. Digitoxin induced Src, Akt and ERK1/2 phosphorylation but did not affect FAK autophosphorylation at Tyr397. However, it significantly inhibited growth factor-induced FAK phosphorylation at Tyr576/577. Conclusions and Implications: Therapeutic concentrations of digitoxin inhibited angiogenesis and FAK activation by several pro-angiogenic stimuli. These novel findings suggest a potential repositioning of digitoxin as a broad-spectrum anti-angiogenic drug for diseases where pathological angiogenesis is involved.
AB - Background and Purpose: Cardiac glycosides are Na+/K+-ATPases inhibitors used to treat congestive heart failure and cardiac arrhythmias. Epidemiological studies indicate that patients on digitalis therapy are more protected from cancer. Evidence of a selective cytotoxicity against cancer cells has suggested their potential use as anticancer drugs. The effect on angiogenesis of clinically used cardiac glycosides has not been extensively explored. Experimental Approach: We studied the effect of digoxin, digitoxin and ouabain on early events of the angiogenic process in HUVECs. We determined HUVEC viability, proliferation, migration and differentiation into capillary tube-like structures. We also tested drug activity using an in vivo angiogenesis model. Activation of protein tyrosine kinase 2 (FAK) and signalling proteins associated with the Na+/K+-ATPase signalosome was determined by Western blotting. Key Results: Digitoxin and ouabain (1–100 nM) inhibited HUVEC migration, concentration-dependently, without affecting cell viability, while digoxin induced apoptosis at the same concentrations. Digitoxin antagonized growth factor-induced migration and tubularization at concentrations (1–25 nM) within its plasma therapeutic range. The anti-angiogenic effect of digitoxin was confirmed also by in vivo studies. Digitoxin induced Src, Akt and ERK1/2 phosphorylation but did not affect FAK autophosphorylation at Tyr397. However, it significantly inhibited growth factor-induced FAK phosphorylation at Tyr576/577. Conclusions and Implications: Therapeutic concentrations of digitoxin inhibited angiogenesis and FAK activation by several pro-angiogenic stimuli. These novel findings suggest a potential repositioning of digitoxin as a broad-spectrum anti-angiogenic drug for diseases where pathological angiogenesis is involved.
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U2 - 10.1111/bph.13944
DO - 10.1111/bph.13944
M3 - Article
AN - SCOPUS:85028351610
VL - 174
SP - 3094
EP - 3106
JO - British Journal of Pharmacology
JF - British Journal of Pharmacology
SN - 0007-1188
IS - 18
ER -