The Limitations of Collagen/CPP Hybrid Peptides as Carriers for Cancer Drugs to FaDu Cells.

Kevin Ho,Katarzyna Slowinska,Cristobal Morfin

doi:10.3390/molecules24040676

Kevin Ho, Katarzyna Slowinska + Show 1 more

Open Access

https://doi.org/10.3390/molecules24040676

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Abstract

The in vitro efficacy of cancer prodrugs varies significantly between malignant cell lines. The most commonly identified problems relate to delivery: uptake mechanism, endosomal entrapment, and drug release. Here we present the study of collagen/cell penetrating hybrid (COL/CPP) peptide carriers intended to deliver paclitaxel to the hypopharyngeal carcinoma (FaDu) cells. Confocal microscopy imaging revealed the surprising response of FaDu cell to COL/CPP in comparison to previously studied cancer cell lines: hybrid peptides that carry both COL and CPP domain adsorb on the FaDu cell surface. While the CPP domain was design to facilitate the cellular uptake, in the case of FaDu cells, it also induced detrimental interactions with the cell membrane. Despite surface adsorption, the colocalization study with endosomal markers EEA1 and LAMP1 reveals that COL/CPP is internalized via endosomal pathway, peptides are able to escape before lysosome formation and release paclitaxel. Therefore, the main obstacle for paclitaxel delivery to FaDu cells appears to be related to cell surface properties. This behavior seems specific to FaDu cells, and could be linked to previously reported overexpression of T5, heparanase splice variants that produces protein lacking enzymatic activity of heparanase. This results in increased concentration of HSPG on FaDu cell surface, and possibly creates a barrier for cellular uptake of highly charged COL/CPP.

Highlights

Despite numerous oncological advancements, cancer is the second leading cause of death in the United States [1]
The colocalization study with endosomal markers Endosome Antigen 1 antibodies (EEA1) and LAMP1 reveals that collagen-cell penetrating peptide (COL/Cell penetrating peptides (CPP)) is internalized via endosomal pathway, peptides are able to escape before lysosome formation and release paclitaxel
We considered two proteins that are known to be upregulated and present at the FaDu cell surface that are not overexpressed in other cancer cell lines that we have studied in the past: junctional adhesion molecule A (JAM-A), expressed in tight junctions (TJ), and heparan sulfate proteoglycans (HSPG), which result from the downregulation of heparanase

Summary

Introduction

Cancer is the second leading cause of death in the United States [1]. Chemotherapy together with surgery, radiation, immuno-, and hormonal therapy are among the available treatment options today [2]. The localization of the cancer determines the course of therapy. In head and neck cancers (HNCs) that affect the pharynx—an organ essential to the ability to swallow and to speak—surgery is often problematic, particularity in the late stages of the cancer [3,4]. Due to the significant patient morbidity associated with surgical treatment and an increasing trend towards organ preservation strategies, treatments with an emphasis on organ preservation and restoration have become more common [5,6].

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