Ablation of Red Stable Transfected Claudin Expressing Canine Prostate Adenocarcinoma and Transitional Cell Carcinoma Cell Lines by C-CPE Gold-Nanoparticle-Mediated Laser Intervention.

Claudin (CLDN) proteins are commonly expressed in cancers and targeted in novel therapeutic approaches. The C-terminal of Clostridium perfringens enterotoxin (C-CPE) efficiently binds several claudins. In this study, recombinant C-CPE conjugated to gold nanoparticles (AuNPs) has been used for prostate adenocarcinoma (PAC) and transitional cell carcinoma (TCC) cell killing in vitro using gold-nanoparticle-mediated laser perforation (GNOME-LP). A PAC and TCC cell lines, as well as red fluorescence variants, allowing deep tissue imaging, were used. CLDN-3, -4, and -7 expression was confirmed by qPCR and immunofluorescences. The binding of C-CPE-AuNPs complexes on the cell surface was examined by scanning electron microscopy (SEM). Further, transcriptome analysis was carried out to evaluate the effect of C-CPE binder on the biological response of treated cells. Directed C-CPE-AuNP binding verified the capability to target CLDN receptors. Transcriptome analysis showed that C-CPE binding may activate immune and inflammatory responses but does not directly affect cell survival. Cancer cells ablation was demonstrated using a combination of GNOME-LP and C-CPE-AuNPs treatment reducing tumor cell viability to less than 10% depending on cell line. The fluorescent cell lines and the verified proof of concept in vitro provide the basis for perspective xenograft studies in an animal model.