Malonate as a ROS product is associated with pyruvate carboxylase activity in acute myeloid leukaemia cellsReportar como inadecuado




Malonate as a ROS product is associated with pyruvate carboxylase activity in acute myeloid leukaemia cells - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Cancer and Metabolism

, 4:15

First Online: 04 August 2016Received: 21 January 2016Accepted: 01 July 2016DOI: 10.1186-s40170-016-0155-7

Cite this article as: Reed, M.A.C., Ludwig, C., Bunce, C.M. et al. Cancer Metab 2016 4: 15. doi:10.1186-s40170-016-0155-7

Abstract

BackgroundThe role of anaplerotic nutrient entry into the Krebs cycle via pyruvate carboxylase has been the subject of increased scrutiny and in particular whether this is dysregulated in cancer. Here, we use a tracer-based NMR analysis involving high-resolution H-C-HSQC spectra to assess site-specific label incorporation into a range of metabolite pools, including malate, aspartate and glutamate in the acute myeloid leukaemia cell line K562. We also determine how this is affected following treatment with the redeployed drug combination of the lipid-regulating drug bezafibrate and medroxyprogesterone BaP.

ResultsUsing the tracer-based approach, we assessed the contribution of pyruvate carboxylase PC vs. pyruvate dehydrogenase PDH activity in the derivation of Krebs cycle intermediates. Our data show that PC activity is indeed high in K562 cells. We also demonstrate a branched entry to the Krebs cycle of K562 cells with one branch running counterclockwise using PC-derived oxaloacetate and the other clockwise from the PDH activity. Finally, we show that the PC activity of K562 cells exclusively fuels the ROS-induced decarboxylation of oxaloacetate to malonate in response to BaP treatment; resulting in further Krebs cycle disruption via depletion of oxaloacetate and malonate-mediated inhibition of succinate dehydrogenase SDH resulting in a twofold reduction of fumarate.

ConclusionsThis study extends the interest in the PC activity in solid cancers to include leukaemias and further demonstrates the value of tracer-based NMR approaches in generating a more accurate picture of the flow of carbons and metabolites within the increasingly inappropriately named Krebs cycle. Moreover, our studies indicate that the PC activity in cancer cells can be exploited as an Achilles heel by using treatments, such as BaP, that elevate ROS production.

KeywordsCancer metabolism Pyruvate carboxylase AML Malonate Electronic supplementary materialThe online version of this article doi:10.1186-s40170-016-0155-7 contains supplementary material, which is available to authorized users.

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Autor: Michelle A. C. Reed - Christian Ludwig - Christopher M. Bunce - Farhat L. Khanim - Ulrich L. Günther

Fuente: https://link.springer.com/







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