Sirt1, p53 and p38MAPK are crucial regulators of detrimental phenotypes of ESCs with Max expression ablation

Ablation of expression of the Max gene encoding a Myc protein partner in ES cells provoked two major phenomena, i.e. loss of pluripotency and apoptotic cell death. We found that nicotinamide (Nam) significantly alleviates these Max expression ablation-coupled phenotypes in ES cells. To see the alleviation effect of Nam on the overall expression profile of Max-null ES cells whose Max expression is controlled by the tet-off system, we eliminated Max expression by adding doxycycline (Dox) in the presence of Nam. DNA microarray analyses were performed using total RNAs from Nam (4 mM)-treated Max-null ES cells that were cultured in the presence or absence of doxycycline for 6 days.