Role of iron chelators in growth-promoting effect on mouse hybridoma cells in a chemically defined medium

The role of various iron chelators on the multiplication of mouse hybridoma cells in an albumin-free, transferrin-deficient defined medium was investigated. Fe(III)-dihydroxyethylglycine, Fe(III)-glycylglycine, Fe(III)-ethylenediamine-N,N'-dipropionic acid, or Fe(III)-iminodiacetic acid supported the excellent growth of the cells. In addition, the growth of the iron-starved cells, which had been preincubated in a protein-, iron- and chelator-free defined medium, restored rapidly when the medium was supplemented with holotransferrin, ferric iron, and chelator compared to that when supplemented with holotransferrin, but without iron and chelator. The results suggest that such chelators modulate a progression of transferrin cycle in the presence of transferrin and ferric iron. An alternative explanation is that there is a decrease in generation of iron-catalyzed free radicals.