ATM and the Catalytic Subunit of DNA-Dependent Protein Kinase Activate NF-κB through a Common MEK/Extracellular Signal-Regulated Kinase/p90rsk Signaling Pathway in Response to Distinct Forms of DNA Damage

Abstract
We have identified a novel pathway of ataxia telangiectasia mutated (ATM) and DNA-dependent protein kinase (DNA-PK) signaling that results in nuclear factor κB (NF-κB) activation and chemoresistance in response to DNA damage. We show that the anthracycline doxorubicin (DOX) and its congener N-benzyladriamycin (AD 288) selectively activate ATM and DNA-PK, respectively. Both ATM and DNA-PK promote sequential activation of the mitogen-activated protein kinase (MAPK)/p90rsk signaling cascade in a p53-independent fashion. In turn, p90rsk interacts with the IκB kinase 2 (IKK-2) catalytic subunit of IKK, thereby inducing NF-κB activity and cell survival. Collectively, our findings suggest that distinct members of the phosphatidylinositol kinase family activate a common prosurvival MAPK/IKK/NF-κB pathway that opposes the apoptotic response following DNA damage.