Transforming growth factor-beta inhibits lactogenic hormone induction of beta-casein expression in HC11 mouse mammary epithelial cells.

HC11 mouse mammary epithelial cells can undergo a limited functional differentiation in terms of beta-casein synthesis in response to the combined action of dexamethasone and prolactin. Transforming growth factor-beta (TGF-beta) can inhibit beta-casein expression in HC11 cells in a dose-dependent manner. This effect is reversible and specific as shown by comparison with the effect of other growth factors. TGF-beta also inhibits DNA synthesis of HC11 cells. These findings suggest a possible role of TGF-beta as an inhibitor of functional differentiation in the mammary gland.