Carboplatin AUC and gamma-glutamylcysteine synthetase gene expression in peripheral mononuclear cells of lung cancer patients.

ABSTRACT

BACKGROUND: To investigate the association between glutathione-related enzymes and carboplatin (CBDCA) dose, we examined gene expression levels for both subunits of gamma-glutamylcysteine synthetase (heavy; gamma-GCSh, light; gamma-GCS1) in peripheral mononuclear cells (PMN) of lung cancer patients before and after CBDCA administration. MATERIALS AND METHODS: PMN and plasma samples were obtained from 10 advanced non-small lung cancer patients before and after CBDCA administration. We analyzed the gene expression levels by reverse transcription-polymerase chain reaction. RESULTS: Gamma-GCSh expression levels in PMN increased within 24 hours after CBDCA administration, whereas gamma-GCS1 expression levels did not. However, the actual area under the concentration curve (AUC) of CBDCA did not correlate with gamma-GCSh expression at 24 hours or the increased ratio of gamma-GCSh expression in PMN. CONCLUSION: Expression of gamma-GCSh is induced by CBDCA, however, CBDCA AUC is not a determinant for the increased expression levels of gamma-GCSh in PMN.