Advantages of the Phosphatidylserine-Recognizing Peptide PSP1 for Molecular Imaging of Tumor Apoptosis Compared with Annexin V

Abstract

A number of peptide-based indicators have been identified and reported as potential apoptosis probes, offering great promise for early assessment of therapeutic efficacy in several types of cancer. Direct comparison of the newly developed probes with previously used ones would be an important step in assessing possible applications. Here, we compared the newly identified peptide-based phosphatidylserine (PS) indicator PSP1 (CLSYYPSYC) with annexin V, a common probe for molecular imaging of apoptotic cells, with respect to PS binding kinetics, apoptotic cell-targeting ability, and the efficacy of homing to apoptotic tumor cells in a mouse model after treatment with the anticancer agent camptothecin. Our results indicate that PSP1 efficiently targeted apoptotic cells and generated apoptosis/tumor-specific signals after cancer treatment in the animal model, whereas a similar dose of annexin V showed weak signals. The formation of a stable complex of PSP1 with PS might be one reason for the efficient in vivo targeting. We suggest that PSP1 has potential advantages for in vivo apoptotic cell imaging and could serve as a platform for the development of de novo peptide-based probes for apoptosis.

Design and synthesis of a novel peptide for selective detection of cancer cells

“…Peptide 2 is similar to peptide 1 in terms of chain length, amino acid composition, charge and hydrophobicity. The indiscriminate binding of peptide 2 with both normal cells (NIH3T3 and L132) and cancer cells (HT29 and A549) is similar to the non‐specific interaction of antimicrobial peptides (Bieke et al, 2009; Kim et al, 2015; Li & Cho, 2012; Mäe et al, 2009; Myrberg et al, 2008; Vrettos et al, 2018). Thus, the observed cancer cell selectivity of peptide 1 appears to stem from the RGD and NGR motifs.…”

“…The observed cancer cell‐selective binding of peptide 1 is similar to the binding behavior of antimicrobial and tumor‐homing peptides to specific cell types at lower concentrations. Binding of antimicrobial and tumor‐homing peptides to normal cells is mainly attributed to non‐specific peptide‐membrane interactions at higher concentrations of peptide (Bieke et al, 2009; Kim et al, 2015; Li & Cho, 2012; Mäe, Myrberg, Andaloussi, & Langel, 2009; Myrberg, Zhang, Mäe, & Langel, 2008; Vrettos, Mező, & Tzakos, 2018). Peptide 2 is similar to peptide 1 in terms of chain length, amino acid composition, charge and hydrophobicity.…”

Influenza A matrix protein M1 is sufficient to induce lipid membrane deformation

“…A-B: Bleaching/recovery experiment for GUVs composed of DOPC:DOPS 70:30 molar ratio, in the presence of 20 µM FITC-Annexin V. It is worth noting that the affinity of Annexin V for PS-containing membrane (50,51) is similar or even higher than that of M1 (8,52). Panel A shows a typical vesicle before bleaching the fluorescent protein in the region enclosed in the red rectangle.…”

Detection of acetaminophen-induced liver damage by fluorescence bioimaging, serum biochemistry and histopathological examination

“…Practically, cell death cannot be observed by the naked eye in live animals, nor by stereomicroscope during necropsy. As estimating cell death is a critical step in the evaluation of disease progression [2], many tools and techniques have been developed to study it [3][4][5][6][7][8]. Among them, histopathological techniques, such as general staining or specific immunohistochemical staining, have a strong advantage for the detection of cell death that occurs in a cell specific manner [9].…”