The MDM2 inducible promoter folds into four-tetrad antiparallel G-quadruplexes targetable to fight malignant liposarcoma

Lago, Sara; Nadai, Matteo; Ruggiero, Emanuela; Tassinari, Martina; Marusic, Maja; Tosoni, Beatrice; Frasson, Ilaria; Cernilogar, Filippo M.; Pirota, Valentina; Doria, Filippo; Plavec, Janez; Schotta, Gunnar and Richter, Sara N. (2021): The MDM2 inducible promoter folds into four-tetrad antiparallel G-quadruplexes targetable to fight malignant liposarcoma. In: Nucleic Acids Research, Vol. 49, No. 2

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.

• Item Type: Journal article
• Faculties: Medicine
• Subjects: 600 Technology > 610 Medicine and health
• ISSN: 0305-1048
• Language: English