Tandem activated caged galactoside prodrugs: advancing beyond single galactosidase dependence

Area of Science:

• Medicinal Chemistry
• Carbohydrate Chemistry
• Cancer Therapeutics

Background:

• β-Galactoside prodrugs leverage β-galactosidase (β-gal) for cancer cell-specific activation.
• Limited β-gal distribution necessitates improved specificity for precise drug release.
• Existing prodrug strategies require enhancement for controlled, on-demand activation.

Purpose of the Study:

• To develop a novel class of tandem activated caged galactoside (TACG) prodrugs.
• To achieve dual-stimulus (β-gal and light) controlled drug release for enhanced anticancer activity.
• To explore the impact of masking group position on prodrug efficacy and selectivity.

Main Methods:

• Synthesis of galactosides with masking groups at the 6-hydroxyl position to prevent β-gal hydrolysis.
• Incorporation of photosensitive 4,5-dimethoxy-2-nitrobenzyl (DMNB) mask for UV-dependent activation.
• Establishment of synthetic routes for O2-, O3-, and O4-DMNB modified TACGs.
• Comparative intracellular studies to evaluate positional isomer efficacy.

Main Results:

• Masking groups at the 6-hydroxyl position conferred resistance to β-gal hydrolysis.
• UV/β-gal-dependent anticancer activities were observed for O6-DMNB modified galactosides.
• The O2-DMNB modified TACG demonstrated superior light-dependent selectivity.
• The O2-DMNB modified galactoside of combretastatin A4 was identified as a potent UV-dependent microtubule assembly inhibitor.

Conclusions:

• A straightforward and universally applicable strategy for dual-stimulus responsive galactoside prodrugs was established.
• The O2-DMNB modified TACG offers enhanced control and selectivity for targeted drug delivery.
• This approach advances carbohydrate-based drug discovery for improved cancer therapeutics.