Targeting Transcriptional Addiction in MYCN-amplified Neuroblastoma via Super Elongation Complex Disruption

MYCN amplification in neuroblastoma predicts particular poor prognosis and directly targeting of MYCN remains a major challenge. We conducted a targeted screen of transcription elongation factors and identified the super elongation complex (SEC) as a unique vulnerability in MYCN-amplified neuroblastoma. Mechanistically, MYCN directly interacts with the SEC subunit EAF1 and recruits the complex to the target gene loci for ensuing processive transcription elongation, rendering MYCN-mediated transcriptional activation highly dependent on SEC. Pharmacological inhibition of SEC by KL-1 or KL-2 elicits selective cell death in MYCN-overexpressing neuroblastoma cells. Furthermore, drug combination screening identifies the BCL-2 inhibitor ABT-199 synergistic with KL-2. Pre-clinical studies manifest that KL-2 and ABT-199 co-treatment significantly suppresses tumorigenesis and shows therapeutic value in multiple neuroblastoma allograft and xenograft models. These findings highlight SEC as a targetable vulnerability, and simultaneous inhibition of SEC and BCL-2 holds great promise for the treatment of MYCN-driven neuroblastoma. We used human neuroblastoma as a model system, and performed multi-omics analysis including RNA-seq, TT-seq and ChIP-seq to study the regulatory mechanism and functional interplay between MYCN and SEC.