Selenium Compounds, Apoptosis and Other Types of Cell Death: An Overview for Cancer Therapy

Abstract

Selenium (Se) is an essential trace element involved in different physiological functions of the human body and plays a role in cancer prevention and treatment. Induction of apoptosis is considered an important cellular event that can account for the cancer preventive effects of Se. The mechanisms of Se-induced apoptosis are associated with the chemical forms of Se and their metabolism as well as the type of cancer studied. So, some selenocompounds, such as SeO2 involve the activation of caspase-3 while sodium selenite induces apoptosis in the absence of the activation of caspases. Modulation of mitochondrial functions has been reported to play a key role in the regulation of apoptosis and also to be one of the targets of Se compounds. Other mechanisms for apoptosis induction are the modulation of glutathione and reactive oxygen species levels, which may function as intracellular messengers to regulate signaling pathways, or the regulation of kinase, among others. Emerging evidence indicates the overlaps between the apoptosis and other types of cell death such as autophagy. In this review we report different processes of cell death induced by Se compounds in cancer treatment and prevention.

Selenoesters and selenoanhydrides as novel multidrug resistance reversing agents: A confirmation study in a colon cancer MDR cell line

“…To determine the activity of these derivatives, the fluorescence intensity emitted by the treated cells was measured and the mean for the treated cells was calculated and compared with the untreated cells. Results were given in terms of the fluorescence activity ratio (FAR), as indicated in equation (1). Once the FAR values were determined, they are divided by the FAR of verapamil, as showed in equation (2), to calculate the FAR quotient.…”

Preparation of Selenium-enriched Bifidobacterium Longum and its Effect on Tumor Growth and Immune Function of Tumor-Bearing Mice

“…Yan Yin 1,3& , Rong-Rong Wang 1,3& , Yan Wang 1 , Jian-Jun Wang 1 *, Gen-Xing Xu 1,2 * 2007; Sanmartin et al, 2012). Although the mechanisms of the antitumor activities of Se are not fully understood, proposed mechanisms include antioxidant protection, metabolic alteration of some carcinogens, stimulation of the immune system, inhibition of tumor cell proliferation and induction of cell apoptosis (Jiang et al, 2001;Yazdi et al, 2012).…”

“…Epidemiological data suggest that there is an inverse relationship between Se status and the risk of tumorigenesis (Karimi et al, 2012;Yadav et al, 2012), and recent studies indicated that Se compounds inhibited the proliferation and invasion of tumor cells in a variety of tumor models (Menter et al, 2000;Zeng et al, 2008;Sanmartin et al, 2012). Some groups used mouse models to study the role of Se in cancer cells and their results showed that Se exhibited antitumor activity in several tumor-bearing mouse models (Chen et al, …”

Recent advances in the mechanism of selenoamino acids toxicity in eukaryotic cells

“…For the sake of comparison, current knowledge on the mechanism of inorganic selenium toxicity will also be briefly considered, although readers are invited to consult recent reviews on the subject (17)(18)(19)(20).…”