Mesenchymal stem cells (MSCs) are promising vehicles for the delivery of anticancer agents in cancer therapy. However, the tumor targeting of loaded therapeutics is essential. Here, we explored a dual-targeting strategy to incorporate tumor-tropic MSC delivery with HER2-specific killing by the immunoapoptotin e23sFv-Fdt-tBid generated in our previous studies. The MSC engineering allowed simultaneous immunoapoptotin secretion and bioluminescence detection of the modified MSCs. Systemic administration of the immunoapoptotin-engineered MSCs was investigated in human HER2-reconstituted syngeneic mouse models of orthotopic and metastatic breast cancer, as well as in a xenograft nude mouse model of orthotopic gastric cancer. In vivo dual tumor targeting was confirmed by local accumulation of the bioluminescence-imaged MSCs and persistence of His-immunostained immunoapoptotins in tumor sites. The added tumor preference of MSC-secreted immunoapoptotins resulted in a significantly stronger antitumor effect compared with purified immunoapoptotins and Jurkat-delivered immunoapoptotins. This immunoapoptotin-armored MSC strategy provides a rationale for its use in extended malignancies by combining MSC mobility with redirected immunoapoptotins against a given tumor antigen.
Keywords: Dual tumor targeting; Gene transduction; HER2-positive tumors; Immunoapoptotin; Mesenchymal stem cells.
Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.