Lactoferrin modifies apoptosis-related gene expression in the colon of the azoxymethane-treated rat

Lactoferrin, an iron-binding glycoprotein, exhibits suppressive effects on development of azoxymethane (AOM)-induced tumors in the rat colon, but the mechanisms are largely unknown. In this study, we investigated the effect of lactoferrin on the gene expression of 10 apoptosis-related molecules in colon mucosa of AOM-treated rats during early and late stages of colon carcinogenesis by reverse transcription PCR. Here we document that a death-inducing receptor, Fas, and a pro-apoptotic Bcl-2 family member, Bid, are increased in the colon mucosa in proportion to decreases in AOM-induced aberrant crypt foci by lactoferrin. Similarly, increased expression of the pro-apoptotic Bcl-2 family member, Bax, was also observed in AOM-induced tumors in rats fed by lactoferrin. These results indicate that Fas and pro-apoptotic Bcl-2 members participate in the lactoferrin action and may contribute to suppressive effects on tumor development in the rat colon.