TY - JOUR
T1 - Quiescence and γH2AX in neuroblastoma are regulated by ouabain/Na,K-ATPase
AU - Hiyoshi, H.
AU - Abdelhady, S.
AU - Segerström, L.
AU - Sveinbjörnsson, B.
AU - Nuriya, M.
AU - Lundgren, T. K.
AU - Desfrere, L.
AU - Miyakawa, A.
AU - Yasui, M.
AU - Kogner, P.
AU - Johnsen, J. I.
AU - Andäng, M.
AU - Uhlén, P.
N1 - Funding Information:
This study was supported by the Swedish Research Council (Dnr 2005-6682, 2008-2760, 2009-3364, 2010-4392, 2011-4567 and DBRM), Foundation for Strategic Research (CEDB), Knut and Alice Wallenberg Foundation (CLICK and Research Fellow to PU), Royal Swedish Academy of Sciences (PU), Swedish Children’s
PY - 2012/5/22
Y1 - 2012/5/22
N2 - Background: Cellular quiescence is a state of reversible proliferation arrest that is induced by anti-mitogenic signals. The endogenous cardiac glycoside ouabain is a specific ligand of the ubiquitous sodium pump, Na,K-ATPase, also known to regulate cell growth through unknown signalling pathways. Methods: To investigate the role of ouabain/Na,K-ATPase in uncontrolled neuroblastoma growth we used xenografts, flow cytometry, immunostaining, comet assay, real-time PCR, and electrophysiology after various treatment strategies. Results: The ouabain/Na,K-ATPase complex induced quiescence in malignant neuroblastoma. Tumour growth was reduced by >50% when neuroblastoma cells were xenografted into immune-deficient mice that were fed with ouabain. Ouabain-induced S-G2 phase arrest, activated the DNA-damage response (DDR) pathway marker γH2AX, increased the cell cycle regulator p21 Waf1/Cip1 and upregulated the quiescence-specific transcription factor hairy and enhancer of split1 (HES1), causing neuroblastoma cells to ultimately enter G0. Cells re-entered the cell cycle and resumed proliferation, without showing DNA damage, when ouabain was removed. Conclusion: These findings demonstrate a novel action of ouabain/Na,K-ATPase as a regulator of quiescence in neuroblastoma, suggesting that ouabain can be used in chemotherapies to suppress tumour growth and/or arrest cells to increase the therapeutic index in combination therapies.
AB - Background: Cellular quiescence is a state of reversible proliferation arrest that is induced by anti-mitogenic signals. The endogenous cardiac glycoside ouabain is a specific ligand of the ubiquitous sodium pump, Na,K-ATPase, also known to regulate cell growth through unknown signalling pathways. Methods: To investigate the role of ouabain/Na,K-ATPase in uncontrolled neuroblastoma growth we used xenografts, flow cytometry, immunostaining, comet assay, real-time PCR, and electrophysiology after various treatment strategies. Results: The ouabain/Na,K-ATPase complex induced quiescence in malignant neuroblastoma. Tumour growth was reduced by >50% when neuroblastoma cells were xenografted into immune-deficient mice that were fed with ouabain. Ouabain-induced S-G2 phase arrest, activated the DNA-damage response (DDR) pathway marker γH2AX, increased the cell cycle regulator p21 Waf1/Cip1 and upregulated the quiescence-specific transcription factor hairy and enhancer of split1 (HES1), causing neuroblastoma cells to ultimately enter G0. Cells re-entered the cell cycle and resumed proliferation, without showing DNA damage, when ouabain was removed. Conclusion: These findings demonstrate a novel action of ouabain/Na,K-ATPase as a regulator of quiescence in neuroblastoma, suggesting that ouabain can be used in chemotherapies to suppress tumour growth and/or arrest cells to increase the therapeutic index in combination therapies.
KW - Na,K-ATPase
KW - neuroblastoma
KW - ouabain
KW - quiescence
KW - γH2AX
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U2 - 10.1038/bjc.2012.159
DO - 10.1038/bjc.2012.159
M3 - Article
C2 - 22531632
AN - SCOPUS:84861461292
SN - 0007-0920
VL - 106
SP - 1807
EP - 1815
JO - British Journal of Cancer
JF - British Journal of Cancer
IS - 11
ER -