Inhibition of adipocyte differentiation by cMyc is not accompanied by alterations in cell cycle control

Using a preadipocyte cell Line constitutively expressing cMyc, we set out t o determine if the ability of cMyc to inhibit adipogenic differentiation wa s functionally distinct from its role in cell cycle progression and transfo rmation. We now report that in this system differentiation control and cell ular transformation are separable functions of cMyc. Furthermore, the Myc-i nduced inhibition of adipocyte differentiation appears to be mediated via s uppression of C/EBP-alpha and p21 gene expression late in the adipogenic di fferentiation programme, without deregulation of either cell cycle control or gene expression during the early stages of the process. (C) 2000 Academi c Press.