Levels of protein carbonyl groups at patients with breast cancer

The relationship among protein oxidation, protein dysfonction and diseases remain largely unclear, however, it is known that oxidative modification of enzymes and structural proteins may play a significant role in the aetiology of diseases. The aim of this study was to investigate the relation between oxidative stress and protein carbonyl group in patients with breast cancer. The assay for detection of protein carbonyl groups involve derivatisation of the carbonyl group with 2,4-dinitrophenylhydrazine (DNPH), which leads to formation of a stable dinitrophenyl (DNP) hydrazone product. This product was detected by a spectrophotometric assay. The result presented here show that the serum level of 2,4-dinitrophenylhydrazone- reactive carbonyl derivates, as a marker of oxidative modification of proteins, increased in plasma of patients with breast cancer before treatment compared to patients with breast cancer after treatment with chemotherapy. The results presented support the statement that in breast cancer accumulation of free radical species and an oxidation of susceptible protein injury occurs. Serum protein carbonyl groups level corralates with the treatment of breast cancer.