Abstract
Native human mammary MCF-7 adenocarcinoma cells and a subline displaying resistance to 4-hydroperoxycyclophosphamide, the chemically activated form of cyclophosphamide, were grown as multicellular spheroids or on a collagen sponge matrix and perfused for study by 31P and 13C nuclear magnetic resonance spectroscopy. The natural abundance 13C spectrum of the perfused cells exhibits well-resolved resonances due to the intracellular glutathione (GSH). The resistant cell line shows a higher intensity of the GSH 13C resonances, consistent with the increased GSH concentration determined from biochemical assays of extracts. Treatment of the resistant cell line with buthionine sulfoximine selectively diminishes the intensity of the GSH resonances in the 13C nuclear magnetic resonance spectrum.
Footnotes
-
↵1 This work was supported by NIH Grants CA51229 (to M. P. G.) and CA16783 (to O. M. C.).
-
↵2 To whom requests for reprints should be addressed, at Division of NMR Research, 340 Traylor Building, 720 Rutland Avenue, Baltimore, MD 21205-2196.
- Received February 16, 1995.
- Accepted April 5, 1995.
- ©1995 American Association for Cancer Research.
Volume 55, Issue 10
