Impact of selenium content in fetal bovine serum on ferroptosis susceptibility and selenoprotein expression in cultured cells.

Ferroptosis, a mode of cell death involving iron-dependent lipid peroxidation, has attracted widespread attention in the development of anticancer drugs and toxicological studies as a potential mechanism of chemical-induced cytotoxicity. This process is regulated by several antioxidant enzymes, of which the selenium-containing glutathione peroxidase 4 (GPx4) is the prime regulator. However, accurately and reproducibly evaluating ferroptosis in cultured cells is challenging since numerous experimental factors in in vitro setting can influence the results. In the present study, we found that the expression levels of selenoproteins, such as GPx4 and GPx1, fluctuate across several cell lines depending on the selenium content of different origin of fetal bovine serum (FBS). Cells cultured in FBS containing higher selenium concentrations exhibited elevated GPx4 expression, and were resistant to ferroptosis induced by erastin and RSL3. These findings suggest that the variability of selenium content in different FBS batches can significantly influence the susceptibility of cells to ferroptosis, highlighting the importance of standardizing these factors to enhance the reproducibility of ferroptosis-related experiments.