Targeting XBP1-mediated β-catenin expression associated with bladder cancer with newly synthetic Oridonin analogues

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Transitional cell carcinoma (TCC) and muscle invasive bladder cancer (MIBC) show poor response to chemotherapy and develop resistance.
• β-catenin, a key Wnt pathway effector, is implicated in TCC progression and chemo-resistance.
• Existing treatments for advanced TCC have limited efficacy and significant side effects.

Purpose of the Study:

• To identify novel therapeutic agents for chemo-resistant TCC and MIBC.
• To elucidate the mechanism of action of a new compound, CYD 6-17.
• To explore the role of β-catenin regulation in TCC chemo-resistance.

Main Methods:

• Screening of natural product analogues for anti-cancer activity.
• In vitro testing of CYD 6-17 on TCC cell lines, including drug-resistant models.
• In vivo efficacy studies using xenograft models.
• Mechanistic studies involving gene transcription, protein binding assays, and clinical correlation analysis.

Main Results:

• CYD 6-17 demonstrated potent inhibition of TCC cells with drug resistance (IC50 in nM range).
• CYD 6-17 significantly inhibited tumor growth in vivo without detectable side effects.
• The compound targets β-catenin gene transcription by disrupting XBP1 binding to its promoter region.
• XBP1 expression levels correlated with poor patient survival in advanced TCC.

Conclusions:

• CYD 6-17 is a novel, potent therapeutic agent for chemo-resistant TCC and MIBC.
• A new mechanism of β-catenin gene regulation involving XBP1 has been identified in TCC.
• This study provides a potential new therapeutic strategy for advanced bladder cancer.