37P - P14ARF-p53-p21 alters the metabolic pathway in breast cancer – a novel proteomic global approach

Date 07 May 2015
Event IMPAKT 2015
Session Welcome reception and Poster Walk
Topics Breast Cancer
Translational Research
Presenter Diana Hatoum
Citation Annals of Oncology (2015) 26 (suppl_3): 10-14. 10.1093/annonc/mdv116
Authors D. Hatoum1, D. Yagoub2, S. Brennan1, N. Nassif1, E.M. McGowan1
  • 1School Of Medical And Molecular Biosciences, University of Technology Sydney, 2007 - Sydney/AU
  • 2School Of Biotechnology And Biomolecular Sciences, University of New South Wales, 2052 - Sydney/AU

Abstract

Body

One of the least understood hallmarks of cancer is the alteration in cellular metabolism. Cancer cells show a shift in energy production from oxidative phosphorylation (aerobic), occurring in the mitochondria, to glycolysis (anaerobic) in the cytoplasm. The reason for this shift is unclear as glucose metabolism is energy deficient compared to mitochondrial energy production. Our laboratory has recently demonstrated that reactivation of p53 via p14ARF rapidly stops cell proliferation and shifts metabolism back in favour of aerobic respiration concomitant with an increase in viable mitochondrial biomass and distribution.

Aim: To investigate the proteins involved in the p14ARF-p53 metabolic switch from anaerobic to aerobic respiration.

Methods: SILAC MS/MS analysis and MaxQuant software were employed to study the proteomic changes associated with p14ARF-p53 expression at 24h and 72h post-activation. MS/MS spectral data were further analysed with the MASCOT search engine against the decoy IPI-human database. Cytoscape 3 software was used to analyse global protein function and interactions. MTS assays and TMRM flow cytometry measured mitochondria viability and function.

Results: Over 1270 differentially regulated proteins were identified using SILAC MS/MS with a protein false discovery rate (FDR) of 0.01. Activation of the p14ARF-p53 pathway identified novel protein changes in the mitochondrial network system. Using Cytoscape software, proteins involved in alteration of mitochondria function were mapped and several novel signalling pathways were highlighted. Mitochondria were viable, as measured by MTS assays, and membrane potentiality was intact as verified by TMRM flow cytometry.

Discussion: Changes in metabolism have been listed as one of the key hallmarks of cancer. However we still do not fully appreciate the importance of these metabolic changes in normal and cancer cells and how these changes may lead to tumorigenesis. Understanding the p53 paradigm demonstrating a shift from an inefficient anaerobic glycolytic pathway to a predominantly energy efficient mitochondrial aerobic metabolic process will be important to understanding tumorigenesis and cancer cell metabolism.

Disclosure: All authors have declared no conflicts of interest.