22 - NMR metabolic studies of human breast cancer cells

Abstract

The use of nuclear magnetic resonance spectroscopy as a non-invasive method for characterizing the metabolism of perfused mammalian cells is demonstrated in studies of the human breast cancer T47D cell line. Three methods of cell immobilization were employed: embedding cells in agarose gel threads, growing cells on agarose polyacrolein microcarriers and on ‘filters’ made of non woven polyester fabric. Scanning electron microscopy showed distinct differences in the cell morphology and growth pattern while 31P NMR showed differences in the cell energetics between the three methods. The rate of lactate production, measured on line by 13C NMR upon adding labeled glucose (1- 13C) to the perfusate, was 0.18 mM/s in cells in gel threads and 0.09 mM/s in cells on microcarriers. Modulations in the concentration of the phosphate metabolites and their interconversion rates at steady state, due to changes in medium oxygen content and in carbon source were monitored on line. The signal intensity of ATP and PCr were found to correlate with cell density. Thus NMR can be employed to study cell metabolism under various growth conditions and to investigate the response of cells to environmental changes.