Development of PROTAC-Based Strategies for Cannabinoid Receptor Type 1 (CB₁R) Degradation in Cancer.

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Cannabinoid receptor type 1 (CB₁R) is implicated in cancer progression and metastasis.
• CB₁R overexpression in breast cancer drives tumor growth via cell cycle regulation.
• CB₁R is a potential therapeutic target for cancer treatment.

Purpose of the Study:

• To design and synthesize Proteolysis Targeting Chimeras (PROTACs) for selective CB₁R degradation in cancer cells.
• To develop peripherally restricted CB₁R-targeting therapeutics to minimize central nervous system (CNS) side effects.
• To evaluate the efficacy of novel PROTACs in reducing cancer cell proliferation and tumor growth.

Main Methods:

• Synthesis of bifunctional small molecules (PROTACs) designed for selective CB₁R degradation.
• Assessment of CB₁R degradation and downstream signaling inhibition in cancer cells.
• Evaluation of compound efficacy in 3D spheroid cancer models and in vivo studies for blood-brain barrier penetration.

Main Results:

• Several synthesized PROTACs effectively induced CB₁R degradation.
• The lead compound suppressed CB₁R signaling, reduced cancer cell proliferation, and promoted apoptosis.
• The lead compound significantly inhibited tumor growth in 3D spheroid models and demonstrated peripheral selectivity with minimal CNS penetration.

Conclusions:

• Targeted CB₁R degradation using PROTACs is a viable and innovative cancer therapy strategy.
• Peripherally selective PROTACs offer a promising approach for next-generation cancer therapeutics.
• This study validates PROTAC technology for developing precision-targeted cancer drugs.