A sumoylation-dependent transcriptional subprogram is required for Myc-driven tumorigenesis

Myc is an oncogenic transcription factor frequently dysregulated in human cancer. To identify pathways supporting the Myc oncogenic program, we employed a genome-wide RNAi screen for Myc-synthetic-lethal (MySL) genes and uncovered a role for the SUMO-activating-enzyme (SAE1/2). Loss of SAE1/2 enzymatic activity drives synthetic lethality with Myc. Mechanistically, SAE2 inhibition switches a transcriptional subprogram of Myc from activated to repressed. A subset of these SUMOylation-dependent Myc-switchers (SMS genes) governs mitotic spindle function and is required to support the Myc oncogenic program. comparison of 4 treatments: normal HMEC, High Myc in HMEC, SUMO depleted in HMEC, High Myc+Sumo Depleted in HMEC