Biomarker model for cancer: Development of fast LC-MS/MS method for reduced and oxidized glutathione

In recent years, there have been significant efforts devoted to countering the challenge of detecting cancer in early stages. Reduced glutathione (GSH) plays an important role in the antioxidant system and is required for the maintenance of the redox status of the cell, defense against free radicals and detoxification of toxic compounds. GSH may be converted to oxidized glutathione (GSSG) during the oxidative stress that it regularly undergoes when combating cancer cells. Therefore, the ratio of GSH to the total amount of glutathione can be an extremely useful biomarker for detecting cancer. However, there has yet to be an effective method of detecting and quantifying glutathione in cells, making it extremely difficult to use as a biomarker. In this study, we have created an effective method of detecting both forms of glutathione, utilizing high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The analysis time took less than 1 minute, and we were able to quantify both GSH and GSSG in one method. The limit of quantitation is 1 ng/mL, and we ran three trials, each examining a range of concentrations, from 1 to 500 ng/ml of GSH and GSSG. Results were calculated using peak area ratios, using HPLC-MS/MS technology, we were able to determine both the amounts of GSH and GSSG in a single method, creating a fast, reliable, non-invasive, and cost-effective method of testing early stages of cancer.