Abstract
Background: Exosomes are small, cellular membrane-derived vesicles with a diameter of 50-150 nm. Exosomes are considered ideal drug delivery systems with a wide range of applications in various diseases, including cancer. However, nonspecific delivery of therapeutic agents by exosomes in vivo remains challenging. H uman epidermal growth factor receptor 2 (HER2) is an epidermal growth factor receptor tyrosine kinase, and its overexpression is usually associated with cell survival and tumor progression in various cancers. In this study, we aim to develop novel exosomes with dual HER2-targeting ability as a nanoparticle delivery vehicle to enhance antitumor efficacy in vivo . Results: Here, we report the generation of two kinds of exosomes carrying miRNAs designed to block HER2 synthesis and consequently kill tumor cells. 293-miR-HER2 exosomes package and deliver designed miRNAs to cells to block HER2 synthesis. These exosomes kill cancer cells dependent on HER2 for survival but do not affect cells that lack HER2 or that are engineered to express HER2 but are not dependent on it for survival. In contrast, 293-miR-XS-HER2 exosomes carry an additional peptide, which enables them to adhere to HER2 on the surface of cancer cells. Consequently, these exosomes preferentially enter and kill cells with surface expression of HER2. 293-miR-XS-HER2 exosomes are significantly more effective than the 293-miR-HER2 exosomes in shrinking HER2-positive tumors implanted in mice. Conclusions: Collectively, as novel antitumor drug delivery vehicles, HER2 dual-targeting exosomes exhibit increased target-specific delivery efficiency and can be further utilized to develop new nanoparticle-based targeted therapies.
Affibody Molecules for Epidermal Growth Factor Receptor Targeting In Vivo: Aspects of Dimerization and Labeling Chemistry
