Fig. 3. Myoblast differentiation can occur in the presence of TNFα-mediated NFκB activation. EMSA performed with a radiolabeled oligonucleotide containing a NFκB binding site on nuclear extracts from: (A) proliferating C2 (GM) and differentiating C2 (DM12) cells with or without TNFα treatment; and (B) differentiating F3 cells with or without TNFα treatment. NFκB binding activity (b) decreases during differentiation and is stimulated upon TNFα treatment in both C2 and F3 cells. The presence of the p65 subunit in NFκB complexes is demonstrated by a super-shift (a), performed by incubating the nuclear extract with an antibody against p65 (+Ab). An aspecific band (c) and the unbound probe (d) are shown. As controls, samples with no nuclear extract (no sample) or reacted in the presence of excess of unlabeled competitor are shown (+cold).