Engineered Exosomes for Targeted Transfer of siRNA to HER2 Positive Breast Cancer Cells

Abstract

Exosomes are the best options for gene targeting, because of their natural, nontoxic, non-immunogenic, biodegradable, and targetable properties. By engineering exosome-producing cells, ligands can be expressed fusing with exosomal surface proteins for targeting cancer cell receptors. In the present study, HER2-positive breast cancer cells were targeted with a modified exosome producing engineered HEK293T cell. For this purpose, the HEK293T cells were transduced by a lentiviral vector bearing-LAMP2b-DARPin G3 chimeric gene. Stable cells expressing the fusion protein were selected, and the exosomes produced by these cells were isolated from the culture medium, characterized, and then loaded with siRNA for subsequent delivery to the SKBR3 cells. Our results showed that stable HEK293T cells produced DARPin G3 on the surface of exosomes. These exosomes can bind specifically to HER2/Neu and are capable of delivering siRNA molecules against TPD52 gene into SKBR3 cell line down-regulating the gene expression up to 70%. Present approach is envisaged to facilitate genes and drugs transfer to HER2 cancer cells providing additional option for gene therapy and drug delivery.

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

“…In short, although there are significant challenges and difficulties in the application of EV-based drug delivery, this endogenous vesicle shows great potential in the biomedical field as the next generation of nanomaterials for advanced drug delivery and treatment. (Ohno et al, 2013), siRNA (Steinman, 2012), protein (Limoni et al, 2019) Widely used but uncontrollable in quantity of cargo loading…”

“…So far, three methods have been tried to modify EVs: (1) binding of receptor-ligand; (2) binding of antibody-antigen; (3) binding of microenvironment specific molecules. An example of receptor-ligand manner was that bioengineered EVs can specifically bind to HER2/Neu by expressing designed ankyrin repeat proteins (DARPins) on the membrane surface (Limoni et al, 2019). Brain and muscle targeting was achieved by bioengineering a fusion protein of Lamp2b with neuron-specific rabies viral glycoprotein (RVG) peptide and muscle-specific peptide on the surface of EVs, respectively (Alvarez-Erviti et al, 2011).…”

Tumor microenvironment complexity and therapeutic implications at a glance

“…To this, the transduction of HEK293T cells was performed by a lentiviral vector carrying-LAMP2b-DARPin G3 chimeric gene, where lysosomal associated membrane protein (LAMP) was served as anchoring chimerization with the ligand (DAR-Pin for Her2 targeting) [189]. These exosomes delivered therapeutic siRNA into the targeted breast cancer cell lines resulting in 70% decrease in TPD52 gene expression in SKBR3 cells [190]. More recently, exosomes have also been targeted to deliver DOX to HER2+ cancer cells to evaluate the anticancer effects of DOX-loaded targeted exosomes in a murine tumor model.…”

Engineered Extracellular Vesicles as a Reliable Tool in Cancer Nanomedicine

“…Lentiviral vector bearing LAMP2b-Designed ankyrin repeat protein (DARPin) G3 chimeric gene or herpes simplex virus with plasmid pACgp67B-HER2m, containing the anti-human epidermal growth factor receptor 2 (HER2) scFv (ML39) antibody DNA sequence, are used to engineer HEK-293T cells. EVs isolated from transfected cells can bind specifically to HER2/Neu in adenocarcinoma cell lines [139,140]. Human carcinoembryonic antigen or human HER2/neu can be also inserted into the mouse lactadherin expression plasmid p6mLC1C2 and transfected into dendritic cells, enhancing the production of functionalized EVs to target breast cancer cells [141].…”