The Role of Reductases in Cancer.

Only a small attention was paid for long time to reducing enzymes, but today it is clear that these are an important part of the endogenous metabolism and also the phase I biotransformation of xenobiotics. The significant group of reducing enzymes are carbonyl reductases that belong to two superfamilies - short chain dehydrogenases/reductases (SDR) and aldo-keto reductases (AKR). Their role in cancer is now intensively studied and their functions in cancer it is possible to divide into two main sections. It is known that carbonyl reductases play a substantial role in hormone-dependent cancers as prostate, breast or endometrial cancer. Active estrogens or androgens are important growth factors for these cancers because they evoke increasing of cell proliferation so that elevated possibility of mutations of important genes and development of cancer. Carbonyl reductases along with other enzymes (e.g. aromatase) participate in formation of these active sex hormones in extragonadal tissues, so an inhibition of such enzymes may be a target of anticancer therapy of hormone-dependent cancers. It is necessary to determine which enzymes are essential for the formation of active sex hormones in particular types of cancers. Besides hormone-dependent cancers, carbonyl reductases play also role in cancers that..