B-MYB Delays Cell Aging by Repressing P16 INK4α Transcription

p16 INK4α , an inhibitor of cyclin-dependent kinase 4 and 6, has been proposed to play an important role in cellular aging and in premature senescence. The expression of the p16INK4α is primarily under transcriptional control. Our previous data showed that a negative regulation element lies in its promoter. In that element, a MYB-binding site (MBS) was uncovered by transcription analysis. Here, we report that MBS is a negative regulation element and B-MYB binds to this site in vivo. In human embryonic lung fibroblast cells, B-MYB downregulated p16 INK4α expression, whereas knocking down of B-MYB upregulated it. Evidence also showed that overexpression of B-MYB in cells could increase the number of utmost passage and decrease G1 block, whereas knocking down of B-MYB could impair their replicative ability. This study provides evidence of the capacity of B-MYB not only to regulate p16 INK4α expression but also the phenotypic consequence on cellular senescence.