Studies of Jelski and Szmitkowski show that differences of a
Studies of Jelski and Szmitkowski show that differences of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activity between auz of many cancers and healthy tissue may be one of the factors intensifying carcinogenesis . Moreover, changes of ADH and ALDH activity in cancer cells are reflected in serum of patients because of releasing these enzymes from malignant tissue . Human alcohol dehydrogenase and aldehyde dehydrogenase exist in multiple molecular forms that have been grouped into several classes. The best characterized function of these enzymes is a metabolism of ethanol and the other alcohols, also role in protection against products of lipid peroxidation and some exogenous xenobiotics. It was also found that ADH and ALDH take part in biosynthesis of retinoic acid, an important factor for cell differentiation and regeneration , .
In our previous study we showed that normal and cancerous cells of kidney exhibit the activity of alcohol dehydrogenase and aldehyde dehydrogenase. Furthermore, the activity of class I ADH isoenzymes and total ADH were significantly higher in cancer tissue than in unchanged renal cells. Moreover, the activity of ADH seems to be disproportionately high compared to the activity of ALDH, what suggests an increased ability of cancer cells to form the highly toxic and mutagenic acetaldehyde and initiating disorders in metabolism of many biologically important substances .
Material and methods
Results The activities of total ADH, ALDH and ADH isoenzymes in the sera of patients with renal cell carcinoma are presented in Table 1. The total activity of alcohol dehydrogenase was significantly higher (about 26%) in the serum of patients with renal cancer than in healthy subjects. The median total activity of ADH was 1213.0 mIU/l in the RCC group and 895.0 mIU/l in the control group. The analysis of ALDH activity did not indicate significant differences between total tested group and healthy persons. The comparison of ADH isoenzymes activities showed that the highest difference was exhibited by class I ADH. The median activity of this class of isoenzymes in the cancer group increased by about 24% (1.785 mIU/l) in comparison to the control level (1.338 mIU/l). The increase of ADH I activity was statistically significant. The other tested classes of ADH isoenzymes had higher activities in the serum of patients with cancer but the differences were not statistically significant (p>0.05). The analysis of particular ADH isoenzymes activities depending on the progression stage of carcinoma, showed the tendency of ADH I activity to increase in accordance with the advance of disease (Fig. 1). Significantly higher ADH class I activity was found in every stage (from II to IV) of cancer compared to the control group. In the stage II of cancer advancement we observed about 20% increase of ADH I activity compared to the control group. In the stage III the increase in class I activity was above 23% and in the IV stage − 26% in comparison to healthy subjects. The activity of total ADH was found to be also significantly higher in patients with renal cancer without dependence on tumor stage. The other isoenzymes did not exhibit any characteristic changes of activity correlating with stage of disease. The total activity of ALDH also did not indicate significant differences between advancement stages.
Discussion Renal cell carcinoma is characterized by an abnormally high glycogen deposition caused by altered enzyme activities . Many studies reported decreased expression of glucose 6-phosphatase, aminoacylase-I and aldehyde dehydrogenase-1 in RCC , . ALDH catalyses an oxidation of aldehydes to carboxylic compounds and this reaction is considered as a general detoxification process. Sreerama at al revealed that ALDH-1 take part in the detoxification of chemotherapeutic agents such as cyclophosphamide, so decrease of this enzyme activity can be the reason of disturbances in this process .