Pharmacological disruption of the Notch transcription factor complex

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Notch pathway signaling is crucial in human cancers, with aberrant activation linked to tumor development and therapy resistance.
• Current therapies target Notch receptor activation, but downstream mediators remain largely unexplored.
• Targeting the Notch transcription activation complex presents a novel therapeutic strategy.

Purpose of the Study:

• To discover and characterize a novel small-molecule inhibitor targeting the Notch transcription activation complex.
• To evaluate the efficacy of this inhibitor in preclinical cancer models, including GSI-resistant tumors.
• To assess the safety and toxicity profile of the novel inhibitor.

Main Methods:

• Discovery of an orally active small-molecule inhibitor, CB-103, targeting the Notch transcription activation complex.
• In vitro testing in human T cell acute lymphoblastic leukemia and other Notch-dependent cancer cell lines.
• In vivo studies using fly and mouse models, and human xenografts (breast cancer, leukemia).

Main Results:

• CB-103 effectively inhibits Notch signaling, inducing cell cycle arrest and apoptosis in Notch-dependent cancer cells.
• The inhibitor demonstrates efficacy against GSI-resistant human tumor cell lines.
• CB-103 shows therapeutic potential in preclinical models, inhibiting tumor xenograft growth without dose-limiting intestinal toxicity.

Conclusions:

• CB-103 represents a new pharmacological strategy by disrupting the Notch transcription complex.
• This orally active small molecule shows significant therapeutic potential for Notch-driven cancers.
• CB-103 offers a promising alternative to existing Notch inhibitors due to its distinct mechanism and improved safety profile.