Selenium and Cancer

Abstract

Selenium (Se), an essential trace element and an important part of many enzymatic activations, has come into prominence importance since 1957. Its metabolism is organized according to various requirements. Selenium is incorporated into protein structures as a structural component. Its level is affected by serum selenium and serum glutathione peroxidase activity. It exists in two forms as “selenomethionine” and “selenocysteine” in animal tissues. In general, protein-rich foods are good sources of selenium. When there is a deficiency, the absorption of selenium increases. There is a total of 13-20 mg of selenium in the body. The amount of selenium in erythrocytes is an indicator of long-term selenium intake; It is known that serum selenium levels decrease in malnutrition and cancer. It is in the structure of glutathione peroxidase, which is protective against oxidative injuries in the organism. Selenium intake levels and serum selenium levels have been associated with many types of cancer. As a result of the studies, the serum level of selenium was found low in some cancer types. A connection has been established between the function of selenium in the antioxidant enzyme system and most of the degenerative conditions. It has been reported that selenium have many potential mechanisms such as increasing immune functions, inducing apoptosis, inhibiting cell proliferation, and changing carcinogen metabolism. Epidemiological studies show an inverse relationship between dietary selenium intake and colorectal cancer risk. It shows that different selenium compounds provide the antiproliferative response in prostate cancer cells by apoptosis, changing the intracellular redox state and blocking the NF-κB signaling pathway. Animal experiments, epidemiological studies and intervention studies; reported that selenium compounds may have antimutagenic effects both in the prevention of specific cancers and in end-phase cancers. Selenium can acts as an anticarcinogenic and strengthens immune functions. Although some studies report that there is a negative correlation between the level of selenium in the body and the risk of cancer, conflicting results are also found in the literature. More clinical studies are needed to determine its effectiveness in cancer and cancer treatment. In this review, the metabolism and functions of selenium, which is an essential element for the body, will be mentioned and studies examining its relationship with cancer will be emphasized.