Related Experiment Video
Updated: May 20, 2026
Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death
Published on: December 27, 2016
Evaluation of phosphatidylserine-binding peptides targeting apoptotic cells
Janice Kapty1, Shanna Banman, Ing Swie Goping
1Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Alberta, Canada.
Abstract:
The inhibition or dysregulation of apoptosis plays an intimate role in the initiation and progression of cancer by confounding normal tissue homeostasis. We currently do not have a clinical method to assess apoptosis induced by cancer therapies. Phosphatidylserine (PS) is an attractive target for imaging apoptosis because it is on the exterior of the apoptotic cells and PS externalization is an early marker of apoptosis. PS-binding peptides are an attractive option for developing an imaging probe to detect apoptosis using positron emission tomography. In this study, four peptides were evaluated for PS-binding characteristics using a plate-based assay system, a liposome mimic of cell membrane PS presentation, and a cell assay of apoptosis. This work also describes two screening techniques to enable researchers to identify and optimize compounds that bind to PS. The results of our study indicate that all four peptides bind to PS and are specific to apoptotic cells. Two of the peptides in particular that have an additional cysteine residue are good potential candidates for development into imaging probes because they bind to PS with high affinity and specificity and they can be easily radiolabelled with (18)F.
Insights
Researchers developed new peptides to detect cancer cell apoptosis, a key process in cancer progression. These peptides bind specifically to apoptotic cells, offering a promising method for developing new cancer imaging agents.
Area of Science:
- Biochemistry
- Molecular Biology
- Oncology
Background:
- Apoptosis (programmed cell death) dysregulation is crucial in cancer development and progression.
- Current clinical methods to assess therapy-induced apoptosis are lacking.
- Phosphatidylserine (PS) externalization is an early, accessible marker of apoptosis.
Purpose of the Study:
- To evaluate PS-binding peptides for detecting apoptosis.
- To develop novel positron emission tomography (PET) imaging probes for apoptosis.
- To establish screening techniques for identifying and optimizing PS-binding compounds.
Main Methods:
- Utilized a plate-based assay system to assess peptide binding.
- Employed a liposome mimic to simulate cell membrane PS presentation.
- Conducted cell-based assays to evaluate peptide specificity in apoptotic cells.
Main Results:
- All four evaluated peptides demonstrated binding to PS.
- Peptides showed specificity for apoptotic cells.
- Two peptides with an additional cysteine residue exhibited high affinity and specificity for PS, suitable for radiolabeling with Fluorine-18 ((18)F).
Conclusions:
- PS-binding peptides are effective for detecting apoptosis.
- The identified peptides are promising candidates for developing targeted PET imaging agents for cancer.
- The developed screening techniques can aid in optimizing future apoptosis-targeting compounds.
