1. The MDM2 inducible promoter folds into four-tetrad antiparallel G-quadruplexes targetable to fight malignant liposarcoma.
- Author
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Lago S, Nadai M, Ruggiero E, Tassinari M, Marušič M, Tosoni B, Frasson I, Cernilogar FM, Pirota V, Doria F, Plavec J, Schotta G, and Richter SN
- Subjects
- Apoptosis, Cell Cycle, Cell Line, Tumor, Computer Simulation, Humans, Ligands, Models, Genetic, Neoplasm Proteins metabolism, Nuclear Proteins metabolism, Protein Interaction Mapping, Proteolysis, Proto-Oncogene Proteins c-mdm2 biosynthesis, Tumor Suppressor Protein p53 metabolism, G-Quadruplexes, Gene Expression Regulation, Neoplastic genetics, Liposarcoma therapy, Molecular Targeted Therapy, Promoter Regions, Genetic genetics, Proto-Oncogene Proteins c-mdm2 genetics, Soft Tissue Neoplasms therapy
- Abstract
Well-differentiated liposarcoma (WDLPS) is a malignant neoplasia hard to diagnose and treat. Its main molecular signature is amplification of the MDM2-containing genomic region. The MDM2 oncogene is the master regulator of p53: its overexpression enhances p53 degradation and inhibits apoptosis, leading to the tumoral phenotype. Here, we show that the MDM2 inducible promoter G-rich region folds into stable G-quadruplexes both in vitro and in vivo and it is specifically recognized by cellular helicases. Cell treatment with G-quadruplex-ligands reduces MDM2 expression and p53 degradation, thus stimulating cancer cell cycle arrest and apoptosis. Structural characterization of the MDM2 G-quadruplex revealed an extraordinarily stable, unique four-tetrad antiparallel dynamic conformation, amenable to selective targeting. These data indicate the feasibility of an out-of-the-box G-quadruplex-targeting approach to defeat WDLPS and all tumours where restoration of wild-type p53 is sought. They also point to G-quadruplex-dependent genomic instability as possible cause of MDM2 expansion and WDLPS tumorigenesis., (© The Author(s) 2021. Published by Oxford University Press on behalf of Nucleic Acids Research.)
- Published
- 2021
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