Autologous extracellular vesicles derived from conjunctival squamous cell carcinoma deliver therapeutic microRNAs to induce apoptosis in originating cancer

Abstract

There are significant challenges in treating advanced and recurrent conjunctival squamous cell carcinoma (cSCC). Therapeutic miRNAs directed at cSCC may have anticancer potential, but questions remain regarding efficiency of their targeted delivery. In this study, we address limitations of miRNA delivery by engineering autologous extracellular vesicles (EVs) of ∼130 nm sizes derived from cSCC UMSCC9 cells and tumors (cSCC-EVs) using a microfluidic based reconstruction system. We ICG-labelled these cSCC-EVs to enable subsequent tracking of miRNA delivery to tumors in vivo, and loaded them with Cy5-labelled antimiR-10b to monitor delivery efficiency of miRNA-ICG-EVs in vitro and in vivo using optical imaging. We characterized miRNA-ICG-EVs and confirmed their successful internalization into UMSCC9 cells in culture using confocal microscopy and FACS analysis. In an orthotopic subconjunctival implantation mouse model of cSCC, fluorescence signals in miRNA-ICG-EV-treated mice remained strong at tumor locations even 96 h after in vivo administration. We found in mice treated with miRNA-ICG-EVs that there were significantly higher levels of both intracellular Cy5-antimiR-10b on ex vivo tumor histological analysis, and antimiR-10b-induced apoptotic cells in tumors on TUNEL assay, as well as a significant reduction in tumor growth on in vivo optical coherence tomography and ex vivo H&E staining. Taken together, we show that targeted delivery of therapeutic miRNAs encapsulated within autologously-derived EVs may have substantial potential in future adjunctive clinical treatment for cSCC. This novel approach may provide a minimally invasive and personalized strategy that could be combined with topical chemotherapy in future clinical applications.