Potential of selenium compounds as new anticancer agents for cholangiocarcinoma

We examined the in vitro effects of the selenium compounds sodium selenite (Se) and selenomethionine (SeMet) on cholangiocarcima (CCA) cell growth and migration to determine their potential usefulness as anticancer agents. The effect of both compounds on the selenoprotein M level was investigated, as well as the association between the expression level of selenoprotein M and the patients' clinicopathological data. Se and SeMet inhibited CCA cell growth with half-maximal inhibitory concentration values of 1.7-2.1 μM and 18.8-37.9 μM, respectively. Both compounds increased the ratio of B-cell lymphoma 2 (BCL2) to BCL2-associated X (BAX), triggering apoptotic cell death, and inhibited cell migration by reducing the ratio of N-cadherin to E-cadherin, an epithelial-mesenchymal transition marker. In addition, Se and SeMet increased selenoprotein M protein in CCA cells. Low expression of selenoprotein M in CCA tissues was significantly associated with shorter patient survival. In conclusion, selenium may potentially be an alternative anticancer agent that might lead to a better prognosis in patients with CCA.