Enzymatically Formed Peptide Assemblies Sequestrate Proteins and Relocate Inhibitors to Selectively Kill Cancer Cells

Area of Science:

• Biochemistry
• Molecular Biology
• Cancer Therapeutics

Background:

• Inhibitors of apoptotic proteins (IAPs) are crucial regulators of cell death pathways.
• Targeting IAPs offers a potential strategy for cancer therapy.
• Developing selective drug delivery systems remains a challenge in cancer treatment.

Purpose of the Study:

• To develop a novel peptide-based therapeutic system for selective cancer cell killing.
• To investigate the role of enzymatic peptide assembly in drug delivery.
• To leverage differences in cellular uptake mechanisms for targeted therapy.

Main Methods:

• Synthesis of a phosphopeptide containing the AVPI motif.
• Formation of peptide assemblies via enzymatic reaction.
• Investigation of cellular uptake mechanisms (caveolin-dependent endocytosis and macropinocytosis).
• Assessment of IAP sequestration and bortezomib (BTZ) release.
• Evaluation of alkaline phosphatase (ALP) as a signaling molecule for targeted trafficking.
• Analysis of proteolytic resistance of peptide assemblies.

Main Results:

• Enzymatically formed peptide assemblies effectively sequester IAPs and release BTZ in cancer cells.
• Normal cells (HS-5) are rescued by lysosomal trafficking of BTZ.
• Alkaline phosphatase (ALP) acts as a context-dependent signal for selective cancer cell death.
• AVPI peptide assemblies demonstrate enhanced proteolytic resistance.
• Differential endocytic uptake pathways are exploited for selective targeting.

Conclusions:

• Enzymatically formed peptide assemblies offer a promising platform for targeted cancer therapy.
• Exploiting differences in cellular uptake and enzymatic signaling enables selective killing of cancer cells.
• This approach provides a novel strategy for developing selective and effective cancer therapeutics.