Neutrophil Elastase Promotes Linker Cleavage and Paclitaxel Release from an Integrin-Targeted Conjugate

Area of Science:

• Oncology
• Drug Delivery
• Bioconjugation

Background:

• Cancer cells express specific integrins (αvβ3) targeted by immune cells.
• Tumor microenvironments contain leukocyte-secreted enzymes that can be leveraged for drug activation.
• Paclitaxel is a potent anticancer drug with limitations in targeted delivery.

Purpose of the Study:

• To design and evaluate a tumor-targeting drug conjugate activated by tumor-infiltrating immune cells.
• To investigate the efficacy of a novel conjugate system for renal cell carcinoma treatment.

Main Methods:

• Conjugation of a peptidomimetic integrin ligand (cyclo(DKP-RGD)) to paclitaxel via an elastase-cleavable tripeptide linker (Asn-Pro-Val).
• In vitro assessment of linker cleavage by neutrophil elastase.
• Evaluation of the conjugate's antiproliferative activity against αvβ3 integrin-expressing renal cell carcinoma cells (786-O).

Main Results:

• The cyclo(DKP-RGD) ligand selectively accumulated on αvβ3 integrin-expressing 786-O cells.
• The Asn-Pro-Val linker was efficiently cleaved by neutrophil elastase in vitro.
• The drug conjugate demonstrated significant antiproliferative effects on cancer cells, confirming its efficacy.

Conclusions:

• The developed drug conjugate effectively targets tumors and is activated by tumor-associated enzymes.
• This approach shows promise for localized anticancer drug activation and improved therapeutic outcomes.
• The study opens avenues for developing enzyme-activated prodrugs for cancer therapy.