Engineered exosomes delivering specific tumor-suppressive RNAi attenuate oral cancer progression

Yutaro Kase,Dai Nakashima,Tomoaki Saito,Manabu Iyoda,Yuriko Toeda,Megumi Okubo,Katsuhiro Uzawa,Sho Wagai,Toshiaki Ando,Jun-Ichiro Yamamoto,Keitaro Eizuka,Shusaku Yoshimura,Takafumi Nobuchi,Kohei Kawasaki,Hideki Tanzawa,Atsushi Kasamatsu

doi:10.1038/s41598-021-85242-1

Abstract

Exosomes are involved in a wide range of biological processes in human cells. Considerable evidence suggests that engineered exosomes (eExosomes) containing therapeutic agents can attenuate the oncogenic activity of human cancer cells. Despite its biomedical relevance, no information has been available for oral squamous cell carcinoma (OSCC), and therefore the development of specific OSCC-targeting eExosomes (octExosomes) is urgently needed. We demonstrated that exosomes from normal fibroblasts transfected with Epstein–Barr Virus Induced-3 (EBI3) cDNA were electroporated with siRNA of lymphocyte cytoplasmic protein 1 (LCP1), as octExosomes, and a series of experiments were performed to evaluate the loading specificity/effectiveness and their anti-oral cancer cell activities after administration of octExosomes. These experiments revealed that octExosomes were stable, effective for transferring siLCP1 into OSCC cells and LCP1 was downregulated in OSCC cells with octExosomes as compared with their counterparts, leading to a significant tumor-suppressive effect in vitro and in vivo. Here we report the development of a new valuable tool for inhibiting tumor cells. By engineering exosomes, siLCP1 was transferred to specifically suppress oncogenic activity of OSCC cells. Inhibition of other types of human malignant cells merits further study.

Highlights

Exosomes are involved in a wide range of biological processes in human cells
Epstein–Barr Virus Induced-3 (EBI3) protein was significantly upregulated in EBI3-transfected NB1RGB cells and was incorporated into the NB1RGB cell–derived exosomes according to Western blots (Fig. 1F)
Accumulating evidence has suggested that exosomes released from human cells could be ideal nanocarriers of therapeutic agents for clinical u se[22,23,24]

Summary

Introduction

Exosomes are involved in a wide range of biological processes in human cells. Considerable evidence suggests that engineered exosomes (eExosomes) containing therapeutic agents can attenuate the oncogenic activity of human cancer cells. We demonstrated that exosomes from normal fibroblasts transfected with Epstein–Barr Virus Induced-3 (EBI3) cDNA were electroporated with siRNA of lymphocyte cytoplasmic protein 1 (LCP1), as octExosomes, and a series of experiments were performed to evaluate the loading specificity/effectiveness and their anti-oral cancer cell activities after administration of octExosomes These experiments revealed that octExosomes were stable, effective for transferring siLCP1 into OSCC cells and LCP1 was downregulated in OSCC cells with octExosomes as compared with their counterparts, leading to a significant tumor-suppressive effect in vitro and in vivo. Exosomes escape degradation or clearance in the blood by biological barrier permeability, low immunogenicity and low toxicity[6,7,8] They could be promising vehicles to deliver therapeutic RNAs. In murine pancreatic cancer cells, exosomes carrying a specific siRNA have been functionally modified to target oncogenic KRAS9, suggesting that these modified exosomes have therapeutic potential for malignant tumors whose molecular target has been identified. The potential therapeutic efficacy of the octExosomes containing therapeutic RNAi was evaluated in vitro and in vivo

Methods

Results

Conclusion