Bifunctional ligands that target cells displaying the alpha v beta3 integrin

Area of Science:

• Bioconjugation Chemistry
• Immunology
• Oncology

Background:

• Targeting tumor cells for elimination is a key challenge in cancer therapy.
• Exploiting the immune system to target cancer cells offers a promising therapeutic avenue.
• Decorating tumor cells with immunogenic molecules can potentially trigger an immune response.

Purpose of the Study:

• To synthesize bifunctional ligands capable of targeting cancer cells and engaging the immune system.
• To develop a modular approach for creating conjugates that bind specific cell-surface proteins and antibodies.
• To evaluate the efficacy and selectivity of these novel ligands for potential cancer therapy.

Main Methods:

• Synthesis of RGD-based peptidomimetics and their conjugation with the alpha-Gal carbohydrate antigen.
• Utilizing dimethyl squarate as a linker for modular synthesis of bifunctional ligands.
• Employing cell-adhesion assays to assess the binding affinity and specificity of ligands for alpha v beta3 integrin.
• Evaluating the recruitment of human anti-Gal antibodies to targeted cells.

Main Results:

• Designed RGD mimetics and bifunctional ligands (1c, 2d) were successfully synthesized.
• The synthesized ligands effectively inhibit alpha v beta3-dependent cell adhesion.
• A high selectivity (4000-fold) for alpha v beta3 integrin over alpha v beta5 was achieved.
• Bifunctional ligands demonstrated simultaneous binding to alpha v beta3-positive cells and recruitment of anti-Gal antibodies.

Conclusions:

• Bifunctional conjugates can simultaneously target cancer cells via integrin binding and recruit endogenous antibodies.
• This strategy offers a novel approach for cancer cell targeting by leveraging the immune system.
• The developed modifiable ligands hold potential for applications in drug delivery and tumor targeting.