• Measuring levels of intracellular glutathione (GSH) is not a new study, but NMR is new way of determining levels of GSH without opening the cell.



• Previous research has shown that cancer cells which are resistant to cancer treatment consistently show higher levels of intracellular GSH than those which are not.



• The two isotopes used were phosphorus-31 and carbon-13. Carbon is a common element found in cellular compounds such as GSH, and phosphorus is found in adenine triphosphate (ATP), a molecule which cells use to harness energy. The phosphorus-31 specta produced show clear resonances indicating that the cells were viable throughout the experiment.



• The figure below shows the carbon-13 spectra which results by performing the spectroscopy on a solution of GSH. The six noticable peaks are due to the six carbon atoms as labeled in the structural representation of GSH shown below the graph.







• The carbon-13 spectra produced by the MCF-7hc (treatment resistant) cells shows consistently higher peaks than that of the MCF-7wt (non-resistant) cells. Thus, NMR spectroscopy indicates that, as shown by previous studies, resistant cancer cells contain higher levels of GSH than non-resistant.



• After adding buthionine sulfoximine to the MCF-7hc cells, glutathione levels dropped dramatically over a period of 60 hours. This gives further evidence that the resonances seen in the carbon-13 NMR spectra correlate to the carbon atoms of glutathione.

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Group 13 - November 25, 1997