The activity of class I, II, III and IV alcohol dehydrogenase isoenzymes and aldehyde dehydrogenase in breast cancer.

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) play a significant role in the metabolism of many biological substances. ADH participates in the metabolism of ethanol, retinoic acid, lipid peroxidation products, leukotriene and glutathione metabolism. ALDH is responsible for oxidation of acetaldehyde and other aldehydes and metabolism of histamine and retinoic acid. The aim of this study was to compare the metabolism in breast cancer cells and normal breast parenchyma by measuring ADH isoenzymes and ALDH activities in these tissues. Total ADH activity was measured by a photometric method with p-nitrosodimethylaniline (NDMA) as a substrate. For the measurement of the activity of ALDH and class I and II isoenzymes of ADH we employed the fluorometric methods, with class-specific fluorogenic substrates. The activity of class III alcohol dehydrogenase was detected by the photometric method with n-octanol and class IV with m-nitrobenzaldehyde as substrates. The samples were taken surgically during resection of breast carcinoma from 75 women. The activity of the class I ADH isoenzyme was significantly lower in breast cancer cells than in healthy tissues. The other tested classes of ADH had a tendency for higher levels of activity in cancer cells than in normal mammary tissue. The activity of total ADH and ALDH was also not significantly lower in the cancer cells. The decrease of activity of class I ADH isoenzyme in breast cancer tissues may be a factor of some disorders in metabolic pathways with participation of these isoenzymes that can lead to carcinogenesis.