Background: Numerous experiments have shown that alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are present in cells of various cancer and can play role in carcinogenesis. In previous investigations we have found elevated levels of alcohol dehydrogenase class III activity in pancreatic cancer cells. It can suggest that these changes may be reflected by enzyme activity in the serum.
Aim: In this paper we have measured the activity of alcohol dehydrogenase isoenzymes, and aldehyde dehydrogenase in the sera of patients with pancreatic cancer.
Methods: Serum samples were taken for routine biochemical investigation from 56 patients with pancreatic cancer before treatment. Total ADH activity was measured by photometric method with p-nitrosodimethylaniline (NDMA) as a substrate, and ALDH activity by the fluorometric method with 6-methoxy-2-naphtaldehyde as a substrate. For the measurement of the activity of class I isoenzymes, we employed the fluorometric methods, with class-specific fluorogenic substrates. The activity of class III alcohol dehydrogenase was measured by the photometric method with n-octanol and class IV with m-nitrobenzaldehyde as a substrate.
Results: A statistically significant increase of class III alcohol dehydrogenase isoenzymes was found in the sera of cancer patients. The median activity of this class isoenzyme in the total cancer group increased about 22% (13.52 mU/l) in the comparison with the control level (11.08 mU/l). The total alcohol dehydrogenase activity was significantly higher (19.7%) among patients with cancer than healthy ones. The activities of other tested ADH isoenzymes and total ALDH were unchanged. The activity of the class I ADH isoenzyme was significantly higher in the sera of drinkers with pancreatic cancer than non-drinkers.
Conclusion: The increased total activity of alcohol dehydrogenase and class III isoenzyme in the sera of patients with pancreatic cancer can be caused by release of this isoenzyme from cancer cells.