Ubiquitin-independent pathway regulates the RIT1-MAPK pathway in chordoma progression

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Chordoma is a rare, slow-growing bone cancer originating from notochord remnants, often recurring locally due to its proximity to vital structures.
• The proteasome system regulates intracellular protein degradation, and REGγ, a proteasome activator, is implicated in various cancers but its role in chordoma is unknown.
• Ras GTPases like RIT1 are involved in cancer progression, presenting potential therapeutic avenues.

Purpose of the Study:

• To investigate the role of REGγ in chordoma pathogenesis and evaluate it as a potential therapeutic target.
• To explore the relationship between REGγ expression and clinical outcomes in chordoma patients.
• To elucidate the molecular mechanism by which REGγ influences chordoma progression.

Main Methods:

• Analysis of REGγ expression in chordoma tissues and correlation with clinical data.
• In vitro experiments assessing the effects of REGγ on chordoma cell proliferation, migration, and apoptosis.
• Investigation of the regulatory pathway involving REGγ, RIT1, and the MAPK signaling pathway.
• Validation in patient-derived organoid models.

Main Results:

• REGγ is upregulated in chordoma and associated with poor clinical outcomes.
• REGγ overexpression promotes chordoma cell proliferation and migration while inhibiting apoptosis and influencing osteoclast differentiation.
• REGγ drives chordoma progression via ubiquitin- and ATP-independent degradation of RIT1, modulating the RIT1-MAPK pathway.
• Targeting RIT1 in REGγ-knockdown models and organoids ameliorated disease progression.

Conclusions:

• REGγ is a key driver of chordoma progression and a potential therapeutic target.
• Targeting the REGγ-RIT1 axis offers a novel therapeutic strategy for chordoma treatment.
• Further research into REGγ inhibition may lead to improved clinical outcomes for chordoma patients.