Linker structure-activity relationships in fluorodeoxyglucose chlorambucil conjugates for tumor-targeted chemotherapy

Area of Science:

• Medicinal Chemistry
• Cancer Biology
• Drug Delivery

Background:

• Nitrogen mustards like chlorambucil (CLB) cause side effects due to distribution in non-target organs.
• Tumor-targeting drug delivery links cytotoxic agents to tumor-specific ligands.
• Malignant cells' high glucose uptake (Warburg effect) offers a cancer targeting strategy.

Purpose of the Study:

• To synthesize and evaluate new chlorambucil (CLB) glucoconjugates for tumor targeting.
• To investigate the impact of different linker structures on the cytotoxicity of CLB-FDG conjugates.
• To identify optimal linkers for enhanced in vitro antitumor activity.

Main Methods:

• Chemical synthesis of 16 new CLB glucoconjugates with varying linkages at the C-1 position of 2-fluoro-2-deoxyglucose (FDG).
• In vitro cytotoxicity evaluation of synthesized compounds against a panel of human tumor cell lines and human fibroblasts.
• Structure-activity relationship analysis focusing on the linker's chemical properties.

Main Results:

• The study identified a positive correlation between aromatic linkers and in vitro cytotoxicity.
• Compound 51, featuring a bis-aromatic spacer linked via an amide function, demonstrated the highest activity.
• The developed glucoconjugates showed promising potential for targeted cancer therapy.

Conclusions:

• Linker structure significantly influences the efficacy of glucose-based CLB conjugates.
• Aromatic linkers, particularly the bis-aromatic amide linker in compound 51, enhance cytotoxicity.
• This approach holds promise for developing more effective and less toxic cancer therapeutics exploiting the Warburg effect.