Vitexin targets USP49-GRPR deubiquitination axis in medullary thyroid carcinoma therapy

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Medullary thyroid carcinoma (MTC) is an aggressive neuroendocrine cancer with limited treatment options and frequent therapeutic resistance.
• The gastrin-releasing peptide receptor (GRPR) drives tumor growth in neuroendocrine cancers, promoting survival through the PI3K/AKT pathway.
• Targeting post-translational modifications, like deubiquitination, offers novel therapeutic strategies for MTC.

Purpose of the Study:

• To investigate the role of the deubiquitination axis involving USP49 and GRPR in MTC progression.
• To evaluate the therapeutic potential of the natural flavonoid vitexin in suppressing MTC.
• To elucidate the mechanism by which vitexin affects GRPR stability and MTC cell behavior.

Main Methods:

• Identification of USP49 as a regulator of GRPR protein stability in MTC.
• In vitro experiments assessing vitexin's effects on MTC cell proliferation, apoptosis, migration, and invasion.
• In vivo studies using nude mouse xenograft models to evaluate vitexin's anti-tumor efficacy.
• Analysis of molecular markers including Ki67 and Tunel staining.

Main Results:

• Vitexin inhibits USP49, leading to GRPR destabilization and degradation.
• Vitexin significantly reduced MTC cell proliferation, enhanced apoptosis, and inhibited migration and invasion in vitro.
• Vitexin markedly suppressed tumor growth in vivo, correlating with decreased proliferation and increased apoptosis.
• USP49 was identified as a key stabilizer of GRPR in MTC.

Conclusions:

• Vitexin effectively suppresses MTC progression by disrupting the USP49-GRPR deubiquitination axis.
• Targeting deubiquitination pathways with natural compounds like vitexin shows promise for overcoming therapeutic resistance in MTC.
• Vitexin represents a potential therapeutic agent for aggressive neuroendocrine cancers by modulating GPCR stability.