Cumate-inducible models of MYC-driven neuroblastoma identify mitoribosomal synthetic lethality as a precision oncology vulnerability in MYC(N)-amplified tumors

Abstract

Oncogenic MYC transcription factors profoundly rewire cellular programs, imposing therapeutically exploitable dependencies in MYC-driven cancers such as high-risk neuroblastoma. However, dissecting these synthetic lethal vulnerabilities using tunable gene expression remains challenging. Widely used tetracycline-regulated systems rely on inducers known to perturb mitochondrial function, introducing confounding off-target effects. To overcome this limitation, we established novel cumate (p-isopropylbenzoate)-inducible neuroblastoma models that enable physiologically unbiased regulation of MYC/MYCN expression. Functional validation demonstrated that cumate alone has no off-target effects on neuroblastoma cell viability, mitochondrial function, morphology, proteostasis, or stress signaling. The developed SHEP-CuO-MYC and -MYCN models show efficient, titratable, and reversible upregulation of c-MYC and N-MYC, respectively, recapitulating protein levels observed in MYC(N)-amplified neuroblastoma. As a proof-of-concept, we applied these models to mechanistically validate the recently proposed mitoribosomal synthetic lethality, providing clear evidence that MYC(N) activation sensitizes neuroblastoma cells to mitochondrial ribosome inhibitors. While impairing mitochondrial translation activated mitochondrial integrated stress response in both MYC-on and MYC-off states, it induced marked MYC downregulation coupled with enhanced caspase-dependent cell death only in MYC-on cells. Importantly, these MYC-selective effects were reproduced in patient-derived neuroblastoma cell lines, demonstrating the translational potential of mitoribosomal synthetic lethality. Together, our findings reveal that MYC(N) activation confers a clinically relevant mitochondrial vulnerability that can be selectively targeted by repurposing doxycycline or other well-tolerated mitoribosome-targeting antibiotics. This study establishes mitoribosomal synthetic lethality as an actionable precision oncology strategy and provides a robust, scalable platform to identify MYC-synthetic lethal candidates for rapid translation into therapies for refractory MYC-driven neuroblastoma.