PROTAC-Mediated Targeted Degradation of MDM2 Induces Tumor-Suppressive Signaling in Osteosarcoma Cells

Area of Science:

• Oncology
• Molecular Biology
• Drug Discovery

Background:

• Osteosarcoma is a prevalent bone cancer in young people with poor prognosis.
• MDM2 protein suppresses the p53 tumor suppressor pathway, contributing to cancer progression.
• Conventional MDM2 inhibitors can lead to resistance through compensatory MDM2 upregulation.

Purpose of the Study:

• To evaluate the anticancer efficacy of novel MDM2-targeting PROTAC compounds, CL0144 and CL0174.
• To investigate the mechanism of action of these PROTACs in osteosarcoma models.
• To assess the therapeutic potential of MDM2-targeting PROTACs for osteosarcoma treatment.

Main Methods:

• Utilized osteosarcoma cell lines (Saos-2, U2OS) and in vivo xenograft models.
• Administered MDM2-targeting PROTAC compounds CL0144 and CL0174.
• Assessed MDM2 degradation, p53/p73 activation, reactive oxygen species (ROS) production, apoptosis, cell viability, proliferation, colony formation, sphere formation, migration, and invasion.

Main Results:

• Both PROTACs effectively induced MDM2 degradation in osteosarcoma cells.
• PROTAC treatment activated p53/p73 signaling, increased ROS, induced apoptosis, and reduced cell viability.
• Significant suppression of proliferation, colony formation, sphere formation, migration, and invasion was observed.
• In vivo studies showed robust inhibition of osteosarcoma tumor growth.

Conclusions:

• MDM2-targeting PROTACs demonstrate potent anticancer activity in osteosarcoma.
• These PROTACs function by degrading MDM2 and disrupting oncogenic signaling pathways.
• MDM2-targeting PROTACs represent a promising therapeutic strategy for osteosarcoma.