Carcinogenic chromium(Vl)-induced protein oxidation and lipid peroxidation: implications in DNA-protein crosslinking.

The article examines the hypothesis that hexavalent chromium Cr(VI)-induced DNA-protein crosslinks (DPCs) could be formed via generation of protein carbonyls and malonaldehyde (MDA) through protein oxidation and lipid peroxidation respectively. Treatment of human leukemic T-lymphocyte MOLT4 cells with potassium chromate induced the formation of protein carbonyls and DPC within 2 h. However, the increased level of MDA only after 4 h in a dose-dependent manner. Chromate treatment of MOLT4 cell homogenates also resulted in augmented formation of MDA and protein carbonyls in a dose-dependent manner. Electron paramagnetic resonance (EPR) spectrometry in combination with spin trapping techniques showed that reaction of Cr(VI) with biological reductants.