Monitoring Intracellular Oxygen Concentration: Implications for Hypoxia Studies and Real-Time Oxygen Monitoring
The metabolic properties of cancer cells have been widely accepted as a hallmark of cancer for a number of years and have shown to be of critical importance in tumour development. It is generally accepted that tumour cells exhibit a more glycolytic phenotype than normal cells. In this study, we investigate the bioenergetic phenotype of two widely used cancer cell lines, RD and U87MG, by monitoring intracellular oxygen concentrations using phosphorescent Pt-porphyrin based intracellular probes. Our study demonstrates that cancer cell lines do not always exhibit an exclusively glycolytic phenotype. RD demonstrates a reliance on oxidative phosphorylation whilst U87MG display a more glycolytic phenotype. Using the intracellular oxygen sensing probe we generate an immediate readout of intracellular oxygen levels, with the glycolytic lines reflecting the oxygen concentration of the environment, and cells with an oxidative phenotype having significantly lower levels of intracellular oxygen. Inhibition of oxygen consumption in lines with high oxygen consumption increases intracellular oxygen levels towards environmental levels. We conclude that the use of intracellular oxygen probes provides a quantitative assessment of intracellular oxygen levels, allowing the manipulation of cellular bioenergetics to be studied in real time.
KeywordsIntracellular oxygen Mitochondria Oxidative phosphorylation Oxygen probe Aerobic glycolysis
MP and YH were supported by Williams Fund and LB by Luxcel Biosciences. We would also like to thank Dr James Hynes and Conn Carey (Luxcel Biosciences) and Jasmin Loo and Catherine Wark (BMG Labtech) for technical support.
- 1.Baynes JW (2009) Chapter 37 “oxygen and life”. In: Baynes JW, Dominiczak MH (eds) Medical biochemistry, 3rd edn. MOSBY Elsevier, Philadelphia. http://www.us.elsevierhealth.com/biochemistry/medical-biochemistry-paperback/9780323053716/