Nonviral nanoscale-based delivery of antisense oligonucleotides targeted to hypoxia-inducible factor 1α enhances the efficacy of chemotherapy in drug-resistant tumor

Purpose: To enhance the efficacy of cancer treatment, we propose a complex approach: simultaneous delivery to the tumor of a chemotherapeutic agent and a suppressor of hypoxia-inclucible factor alpha (HIF1A). Experimental Design: The novel complex liposomal drug delivery system was developed and evaluated in vitro and in vivo on nude mice bearing xenografts of multidrug-resistant human ovarian carcinoma. The proposed novel complex drug delivery system consists of liposomes as a nanocarrier, a traditional anticancer drug (doxorubicin) as a cell death inducer, and antisense oligonucleoticles targeted to HIF1A mRNA as a suppressor of cellular resistance and angiogenesis. Results: The system effectively delivers active ingredients into tumor cells, multiplies the cell death signal initiated by doxorubicin, and inhibits cellular defensive mechanisms and angiogenesis by down-regulating BCL2, HSP90, and vascular endothelial growth factor proteins. This, in turn, activates caspases, promotes apoptosis, necrosis, and tumor shrinkage. The proposed novel complex multipronged approach enhances the efficiency of chemotherapy. Conclusions: The proposed combination therapy prevents the development of resistance in cancer cells, and thus, increases the efficacy of chemotherapy to an extent that cannot be achieved by individual components applied separately. It could form the foundation for a novel type of cancer therapy based on simultaneous delivery of an anticancer drug and a suppressor of HIF1A.