Tumor-penetrating peptide for systemic targeting of Tenascin-C

Prakash Lingasamy,Allan Tobi,Toomas Asser,Markko Salumäe,Kaarel Kurm,Tõnu Rätsep,Rolf Bjerkvig,Sergei Kopanchuk,Tambet Teesalu,Aleksander Sudakov

doi:10.1038/s41598-020-62760-y

Abstract

Extracellular matrix in solid tumors has emerged as a specific, stable, and abundant target for affinity-guided delivery of anticancer drugs. Here we describe the homing peptide that interacts with the C-isoform of Tenascin-C (TNC-C) upregulated in malignant tissues. TNC-C binding PL3 peptide (amino acid sequence: AGRGRLVR) was identified by in vitro biopanning on recombinant TNC-C. Besides TNC-C, PL3 interacts via its C-end Rule (CendR) motif with cell-and tissue penetration receptor neuropilin-1 (NRP-1). Functionalization of iron oxide nanoworms (NWs) and metallic silver nanoparticles (AgNPs) with PL3 peptide increased tropism of systemic nanoparticles towards glioblastoma (GBM) and prostate carcinoma xenograft lesions in nude mice (eight and five-fold respectively). Treatment of glioma-bearing mice with proapoptotic PL3-guided NWs improved the survival of the mice, whereas treatment with untargeted particles had no effect. PL3-coated nanoparticles were found to accumulate in TNC-C and NRP-1-positive areas in clinical tumor samples, suggesting a translational relevance. The systemic tumor-targeting properties and binding of PL3-NPs to the clinical tumor sections, suggest that the PL3 peptide may have applications as a targeting moiety for the selective delivery of imaging and therapeutic agents to solid tumors.

Highlights

Extracellular matrix in solid tumors has emerged as a specific, stable, and abundant target for affinityguided delivery of anticancer drugs
Tenascin C (TNC)-C was expressed in E. coli and purified using affinity chromatography on Ni-NTA matrix (Fig. S1)
For identification of TNC-C–interacting peptides, 5-round biopanning with of T7 CX7C peptide phage libraries was performed, using as the target his-tagged TNC-C coated on polystyrene multiwell plates in rounds 1 and 4, and TNC-C immobilized on Ni-NTA magnetic beads in rounds 2, 3 and 5 (Fig. S2)

Summary

Introduction

Extracellular matrix in solid tumors has emerged as a specific, stable, and abundant target for affinityguided delivery of anticancer drugs. We describe the homing peptide that interacts with the C-isoform of Tenascin-C (TNC-C) upregulated in malignant tissues. The microenvironment in solid tumors is shaped by concerted actions of tumor cells and cells in tumor stroma (endothelial cells, immune cells, and fibroblasts) All these cells deposit and remodel tumor extracellular matrix (ECM) – a complex meshwork of structural proteins and bioactive compounds. Several affinity ligands of TNC have been developed for targeting payloads to solid tumors, such as G11 single-chain antibody[5], aptamers[6], FH peptide[7], and PL1 peptide[8]. Systemic PL3-guided nanoparticles accumulated in tumor xenografts implanted in mice These nanoparticles were useful for tumor detection, imaging and served as a tumor-seeking carrier for a proapoptotic peptide anticancer payload. Our study suggests applications for PL3-targeted compounds and nanoparticles for improved detection and therapy of solid tumors

Methods

Results

Conclusion