MDM2 suppresses c-Myc synthesis by binding to the 5' mRNA translation regulatory sequence
- Proc Natl Acad Sci U S A. 2026 Jun 30;123(26):e2611131123. doi: 10.1073/pnas.2611131123.
- 1. Institut de Recherche Saint Louis, Unité Mixte de Recherches 1342, Université Paris Cité, Hôpital St. Louis, Paris 75010, France.
- 2. Department of Medical Biosciences, Umeå University, Umeå 901 85, Sweden.
- 3. Department of Biological Sciences and Engineering, Indian Institute of Technology Palakkad, Palakkad 678 623, India.
- 4. Department of Diagnostics and Intervention, Umeå University, Umeå 901 85, Sweden.
- 5. Department of Urology, New York University Grossman School of Medicine, New York, NY 10016.
- 6. Research Center for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Brno 65653, Czech Republic.
- 7. Institute of Experimental Botany, Laboratory of Growth Regulators, The Czech Academy of Sciences, Olomouc 779 00, Czech Republic.
- # Contributed equally.
The p53 tumor suppressor and the c-Myc oncogene are among the most frequently deregulated genes in human cancers, yet the molecular cross talk between these pathways remains poorly understood. MDM2 is a key negative regulator of p53 and a target for emerging Cancer therapies designed to activate p53. Likewise, targeting c-Myc is a long-standing but challenging goal in Cancer therapy. Here, we report that the small MDM2-binding drug Milademetan promotes an interaction between MDM2 and the 5' untranslated region of the c-Myc mRNA, causing a suppression of c-Myc mRNA translation without affecting c-Myc RNA levels. The interaction also occurs under nonproliferative conditions in the absence of drug. Milademetan-mediated c-Myc depletion is accompanied by the induction of Apoptosis and suppression of cell proliferation and prevents tumor growth, independently of p53 status. These findings reveal an unexpected mechanism by which MDM2 coordinates two of the most frequently altered pathways in Cancer and provide a rationale for targeting c-Myc-driven tumors, including those lacking functional p53, through MDM2 modulators.