STAT3 signaling protein is thought to promote oncogenesis by modulating the expression of genes that are required for tumor cell survival. Following translation STAT3 may undergo several modifications such as phosphorylation or acetylation which modulate its activity. These modifications are typically cytokine dependent but under unique conditions may be cytokine-independent and constitutive. In chronic lymphocytic leukemia (CLL) STAT3 is constitutively phosphorylated on serine residues. Serine pSTAT3 induces transcription of STAT3 targeted genes. The conserved bromodomain motif of p300 binds and acetylates lysine residues in several proteins including STAT3. Therefore, we wondered whether P300 also acetylates STAT3 in CLL cells.

Aim

Determine whether p-300-dependent acetylation of STAT3 increases STAT3-dependent transcriptional activity and provide CLL cells with a survival …