Determination of cellular glutathione:glutathione disulfide ratio in prostate cancer cells by high performance liquid chromatography with electrochemical detection

• The work illustrates the use of a validated method to analyse intracellular thiols in cancer cells.
• Electrochemical detection with diamond-doped electrode allows thiols and disulphide directly.
• Data indicates more aggressive cancers display adaptation to increased oxidative stress.
• In cancer cells, glutathione was only responsible for 60% and 79% respectively, of reduced thiol.
• Results indicate the presence of other biological thiols involved in oxidative stress.

A validated method has been developed for the simultaneous measurement of reduced and oxidized glutathione in de-proteinised cellular extracts. This has been used to compare models of malignant and non-malignant human prostate cell lines. Analysis of LNCaP and DU145 cells showed a glutathione to glutathione disulfide ratio of 8:1 and 32:1 respectively, whilst the control cell line, PZ-HPV7 displayed a ratio of 93:1. Results indicate that the more aggressive phenotype displays adaptation to increased oxidative stress via up regulation of glutathione turnover. It was also noted that in the LNCaP and DU145 cell line, glutathione was only responsible for ca. 60% and 79% respectively, of the total cellular reduced thiol; indicating the presence of other biological thiols.