Proteolytically Stable Cyclic Decapeptide for Breast Cancer Cell Targeting

Area of Science:

• Biochemistry
• Oncology
• Materials Science

Background:

• Linear peptides are being explored for targeted cancer therapies.
• Developing stable and selective cancer-targeting agents remains a challenge.

Purpose of the Study:

• To synthesize and evaluate a novel cyclic peptide analogue of a known breast cancer targeting decapeptide.
• To assess the cyclic peptide's efficacy in targeting breast cancer cells, its stability, and its potential for diagnostic applications.

Main Methods:

• Synthesis of a novel N- to C-terminus amide cyclized peptide analogue.
• In vitro assessment of cellular uptake in breast cancer versus noncancerous cells.
• Evaluation of proteolytic stability.
• Immobilization on a gold microcantilever for cell capture and sensing.
• In vivo studies in mice with orthotopic breast tumors (MDA-MB-231).

Main Results:

• The cyclic peptide demonstrated higher uptake by breast cancer cells and minimal uptake by noncancerous cells compared to the linear version.
• The cyclic peptide exhibited enhanced stability against proteolytic degradation.
• Immobilized cyclic peptide specifically captured breast cancer cells and sensed samples with as few as 25 cancer cells/mL.
• In vivo studies showed preferential tumor accumulation and rapid clearance from most organs.

Conclusions:

• A novel, proteolytically stable cyclic peptide WxEAAYQkFL analogue was successfully synthesized.
• This cyclic peptide exhibits high specificity and uptake for breast cancer cells.
• The findings suggest potential applications in targeted breast cancer drug delivery and circulating tumor cell enumeration.