γδTDEs: An Efficient Delivery System for miR-138 with Anti-tumoral and Immunostimulatory Roles on Oral Squamous Cell Carcinoma

Abstract

In this study, we sought to investigate the potential application of γδ T cell-derived extracellular vesicles (γδTDEs) as drug delivery system (DDS) for miR-138 in the treatment of oral squamous cell carcinoma (OSCC). Our data showed that overexpression of miR-138 in γδ T cells obtained miR-138-rich γδTDEs accompanying increased expansion and cytotoxicity of γδ T cells. γδTDEs inherited the cytotoxic profile of γδ T cells and could efficiently deliver miR-138 to OSCC cells, resulting in synergetic inhibition on OSCC both in vitro and in vivo. The pre-immunization by miR-138-rich γδTDEs inhibited the growth of OSCC tumors in immunocompetent C3H mice, but not in nude mice, suggesting an immunomodulatory role by miR-13-rich γδTDEs. γδTDEs and miR-138 additively increased the proliferation, interferon-γ (IFN-γ) production, and cytotoxicity of CD8+ T cells against OSCC cells. Only delivered by γδTDEs can miR-138 efficiently target programmed cell death 1 (PD-1) and CTLA-4 in CD8+ T cells. We conclude that γδTDEs delivering miR-138 could achieve synergetic therapeutic effects on OSCC, which is benefited from the individual direct anti-tumoral effects on OSCC and immunostimulatory effects on T cells by both γδTDEs and miR-138; γδTDEs could serve as an efficient DDS for microRNAs (miRNAs) in the treatment of cancer.

Prospects and challenges of extracellular vesicle-based drug delivery system: considering cell source

“…Activated CD8þ T cells from healthy mice have been found to release cytotoxic EVs causing remarkable attenuation of tumor invasion and metastasis (Seo et al, 2018). We have recently showed that cd T cell-derived EVs load with miR-138 had direct anti-tumor and indirect tumor immune promoting effects on oral squamous cell carcinoma (Li et al, 2019c).…”

“…EVs are natural carriers of nucleic acids molecules and can be genetically engineered to deliver specific nucleic acid molecules such as siRNA (El-Andaloussi et al, 2012), miRNA (Li et al, 2019c), and gene editing system-CRISPER/Cas9 . SiRNA and miRNAs can target complementary mRNAs for degradation in a sequence-dependent manner, but the low bioavailability and inability to cross key biological barriers such as the BBB make them difficult to translate into clinical application.…”

“…Post-loading method Co-incubation Curcumin (Street et al, 2017) hsiRNA (Seo et al, 2018), porphyrins , catalase (Li et al, 2019c) A simplest way but uncontrollable in quantity of cargo loading Low loading efficiency Electroporation SiRNA (Steinman, 2012), TMP , DOX (Kantoff et al, 2010) Superior loading of siRNA over chemical transfection but disrupting integrity of exosomes…”

“…Sonication PTX (Cheng et al, 2017), catalase (Li et al, 2019c), small RNAs (Sun et al, 2010) High loading efficiency but not efficient for hydrophobic drugs High loading efficiency Extrusion Porphyrins , catalase (Li et al, 2019c) High drug loading efficiency but potential deformation of membrane High loading efficiency Freeze/thaw cycle Catalase (Li et al, 2019c), prepare hybrid exosomes (Li et al, 2019d) Exosomes may aggregate and the drugs loading efficiency is low Low loading efficiency…”

“…As 'molecule carrier', EVs may serve as novel tools for various therapeutic and diagnostic purpose (EL Andaloussi et al, 2013;Ohno et al, 2016), such as anti-tumor therapy (Poggio et al, 2019), immune-modulatory (Buzas et al, 2014), and drug delivery (Gudbergsson et al, 2019). As a drug delivery vesicle, EVs have been tested for the delivery of siRNAs (El-Andaloussi et al, 2012), miRNAs (Li et al, 2019c), proteins (Haney et al, 2015), small molecule drugs (Zhuang et al, 2011), nanoparticles (Jung et al, 2018), and CRISPR/Cas9 into animal models. Owing to their natural origin, EVs are born with high biocompatibility, enhanced stability, and limited immunogenicity, which provide potential advantages over traditional synthetic delivery vehicles, such as liposomes and nanoparticles.…”