posted on 2016-05-02, 00:00authored byP.C. Hart, M. Mao, A.L. de Abreu, Kristine Ansenberger-Fricano, D.N. Ekoue, D. Ganini, K. Kajdacsy-Balla, A.M. Diamond, R.D. Minshall, M.E. Consolaro, J.H. Santos, M.G. Bonini
Manganese superoxide dismutase (MnSOD/SOD2) is a mitochondria-resident enzyme that governs the types of reactive oxygen species egressing from the organelle to affect cellular signalling. Here we demonstrate that MnSOD upregulation in cancer cells establishes a steady flow of H2O2 originating from mitochondria that sustains AMP-activated kinase (AMPK) activation and the metabolic shift to glycolysis. Restricting MnSOD expression or inhibiting AMPK suppresses the metabolic switch and dampens the viability of transformed cells indicating that the MnSOD/AMPK axis is critical to support cancer cell bioenergetics. Recapitulating in vitro findings, clinical and epidemiologic analyses of MnSOD expression and AMPK activation indicated that the MnSOD/AMPK pathway is most active in advanced stage and aggressive breast cancer subtypes. Taken together, our results indicate that MnSOD serves as a biomarker of cancer progression and acts as critical regulator of tumour cell.
Funding
We are indebted to Drs Larry W. Oberley (in memoriam) and Frederick Domann
(University of Iowa) for the generous gift of cell lines stably overexpressing MnSOD,
Dr Kevin P. Claffey (University of Connecticut) for the generous gift of MCF-7-AMPKa1
/ cells, Dr Kevin Struhl (Harvard University) for the gift of the MCF10A lines
expressing v-Src under ER induction, Patricia Mavrogianis, Andrew Hall and Emily
Ionetz at the Research Histology Core at the University of Illinois at Chicago for providing
histology services, Dr Soumen Bera, Emmanuel Ansong, Paula Green, Alyssa
Master and M. Saqib Baig for technical assistance, and for funding provided by the US
Department of Defense (ARO no. 61758-LS) to M.G.B, the NCRR/NIH (S10RR027848)
to M.G.B., 1R21CA182103-01 to A.M.D. and M.G.B. K.A.-F. and P.C.H. were supported
by NIH T32 (HL072742). We also acknowledge gifts from RO1 CA101053 to A.M.D.,
NIH P01 HL60678 to R.D.M., CAPES—Coordenac¸a˜o de Aperfeic¸oamento Pessoal,
Ministe´rio da Cieˆncia e Tecnologia/Brazil—A109/2013 to M.G.B. and M.E.L.C.