Targeted Doxorubicin-Loaded Bacterially Derived Nano-Cells for the Treatment of Neuroblastoma.

Advanced stage neuroblastoma is an aggressive disease with limited treatment options for patients with drug-resistant tumors. Targeted delivery of chemotherapy for pediatric cancers offers promise to improve treatment efficacy and reduce toxicity associated with systemic chemotherapy. The EnGeneIC Dream Vector (EDV ^TM ) is a nanocell, which can package chemotherapeutic drugs and target tumors via attachment of bispecific proteins to the surface of the nanocell. Phase I trials in adults with refractory tumors have shown an acceptable safety profile. Herein we investigated the activity of EGFR-targeted and doxorubicin-loaded EDV ^TM ( ^EGFR EDV ^TM _Dox ) for the treatment of neuroblastoma. Two independent neuroblastoma cell lines with variable expression of EGFR protein [SK-N-BE(2), high; SH-SY-5Y, low] were used. ^EGFR EDV ^TM _Dox induced apoptosis in these cells compared to control, doxorubicin, or non-doxorubicin loaded ^EGFR EDV ^TM In three-dimensional tumor spheroids, imaging and fluorescence life-time microscopy revealed that ^EGFR EDV ^TM _Dox had a marked enhancement of doxorubicin penetration compared to doxorubicin alone, and improved penetration compared to non-EGFR-targeted EDV ^TM _Dox , with enhanced spheroid penetration leading to increased apoptosis. In two independent orthotopic human neuroblastoma xenograft models, short-term studies (28 days) of tumor-bearing mice led to a significant decrease in tumor size in ^EGFR EDV ^TM _Dox -treated animals compared to control, doxorubicin, or non-EGFR EDV ^TM _Dox There was increased TUNEL staining of tumors at day 28 compared to control, doxorubicin, or non-EGFR EDV ^TM _Dox Moreover, overall survival was increased in neuroblastoma mice treated with ^EGFR EDV ^TM _Dox ( P < 0007) compared to control. Drug-loaded bispecific-antibody targeted EDVs ^TM offer a highly promising approach for the treatment of aggressive pediatric malignancies such as neuroblastoma. Mol Cancer Ther; 17(5); 1012-23. ©2018 AACR .
(©2018 American Association for Cancer Research.)