Gene-Directed Enzyme/Prodrug Therapy of Rat Brain Tumor Mediated by Human Mesenchymal Stem Cell Suicide Gene Extracellular Vesicles In Vitro and In Vivo

Abstract

MSC-driven, gene-directed enzyme prodrug therapy (GDEPT) mediated by extracellular vesicles (EV) represents a new paradigm—cell-free GDEPT tumor therapy. In this study, we tested the efficacy of yeast cytosine deaminase::uracilphosphoribosyl transferase (yCD::UPRT-MSC)-exosomes, in the form of conditioned medium (CM) to inhibit the growth of C6 glioblastoma cells both in vitro and in vivo. MSCs isolated from human adipose tissue, umbilical cord, or dental pulp engineered to express the yCD::UPRT gene secreted yCD::UPRT-MSC-exosomes that in the presence of the prodrug 5-fluorocytosine (5-FC), inhibited the growth of rat C6 glioblastoma cells and human primary glioblastoma cells in vitro in a dose-dependent manner. CM from these cells injected repeatedly either intraperitoneally (i.p.) or subcutaneously (s.c.), applied intranasally (i.n.), or infused continuously by an ALZET osmotic pump, inhibited the growth of cerebral C6 glioblastomas in rats. A significant number of rats were cured when CM containing yCD::UPRT-MSC-exosomes conjugated with 5-FC was repeatedly injected i.p. or applied i.n. Cured rats were subsequently resistant to challenges with higher doses of C6 cells. Our data have shown that cell-free GDEPT tumor therapy mediated by the yCD::UPRT-MSC suicide gene EVs for high-grade glioblastomas represents a safer and more practical approach that is worthy of further investigation.

Suicide-Gene-Modified Extracellular Vesicles of Human Primary Uveal Melanoma in Future Therapies

“…Recently, engineered tumor exosomes were found to act as a dendritic cell (DC)-primed vaccine, which boosted antitumor immunity in breast cancer [ 29 ]. Furthermore, MSC exosomes modified with the yCD::UPRT gene used for the experimental treatment of glioblastoma-carrying rats prevented the recurrence of glioblastoma in cured rats [ 27 ]. The prevention of UM metastases formation via the inhibition of premetastatic niche creation by yCD::UPRT -UM-sEVs seems to be possible.…”

Efficacy of HSV-TK/GCV system suicide gene therapy using SHED expressing modified HSV-TK against lung cancer brain metastases

“…It has been reported that extracellular vesicles (EVs) and exosomes secreted from stem cells are expected to be used as biological delivery vehicles for therapeutic agents. 48 , 49 EVs and exosomes can cross the blood-brain barrier and do not cause acute immune response and risk of tumor formation; thus, suicide gene therapy using EVs and exosomes could be a future therapeutic strategy for intracranial tumors. 50 …”

Nanotechnology and bioengineering approaches to improve the potency of mesenchymal stem cell as an off‐the‐shelf versatile tumor delivery vehicle

“…25,26 MSCs can be easily genetically engineered and used as biofactory for the local production of chemo and biological anticancer therapeutics at the tumor sites to overcome the challenges related to the systemic administration of anticancer therapeutics with a short half-life or high toxicity. [26][27][28] MSCs have been used for the delivery of chemotherapeutics and biological anticancer therapeutics such as genes encoding prodrug-activating enzymes, 29,30 cytokines, 31,32 oncolytic viruses, 9,33 among others. Therefore, MSCs emerged as a versatile tumor delivery vehicle in precision cancer treatment technologies for different cancers.…”