Targeting liposomal chemotherapy via both tumor cell-specific and tumor vasculature-specific ligands potentiates therapeutic efficacy.

Abstract

Neuroblastoma, the most common solid tumor of infancy derived from the sympathetic nervous system, continues to present a formidable clinical challenge. Sterically stabilized immunoliposomes (SIL) have been shown to enhance the selective localization of entrapped drugs to solid tumors, with improvements in therapeutic indices. We showed that SIL loaded with doxorubicin (DXR) and targeted to the disialoganglioside receptor GD(2) [aGD(2)-SIL(DXR)] led to a selective inhibition of the metastatic growth of experimental models of human neuroblastoma. By coupling NGR peptides that target the angiogenic endothelial cell marker aminopeptidase N to the surface of DXR-loaded liposomes [NGR-SL(DXR)], we obtained tumor regression, pronounced destruction of the tumor vasculature, and prolonged survival of orthotopic neuroblastoma xenografts. Here, we showed good liposome stability, long circulation times, and enhanced time-dependent tumor accumulation of both the carrier and the drug. Antivascular effects against animal models of lung and ovarian cancer were shown for formulations of NGR-SL(DXR). In the chick embryo chorioallantoic assay, NGR-SL(DXR) substantially reduced the angiogenic potential of various neuroblastoma xenografts, with synergistic inhibition observed for the combination of NGR-SL(DXR) with aGD(2)-SIL(DXR). A significant improvement in antitumor effects was seen in neuroblastoma-bearing animal models when treated with the combined formulations compared with control mice or mice treated with either tumor- or vascular-targeted liposomal formulations, administered separately. The combined treatment resulted in a dramatic inhibition of tumor endothelial cell density. Long-term survivors were obtained only in animals treated with the combined tumor- and vascular-targeted formulations, confirming the pivotal role of combination therapies in treating aggressive metastatic neuroblastoma.

• Authors: Fabio Pastorino, Chiara Brignole, Daniela Di Paolo, Bice Nico, Annalisa Pezzolo, Danilo Marimpietri, Gabriella Pagnan, Federica Piccardi, Michele Cilli, Renato Longhi, Domenico Ribatti, Angelo Corti, Theresa M Allen, Mirco Ponzoni
• Journal: Cancer research (Cancer Res) Vol. 66 Issue 20 Pg. 10073-82 (Oct 15 2006) ISSN: 0008-5472 [Print] United States
• PMID: 17047071 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• GPI-Linked Proteins
• Gangliosides
• Myelin Proteins
• Nogo Receptor 1
• Peptide Fragments
• RTN4R protein, human
• Receptors, Cell Surface
• ganglioside, GD2
• Doxorubicin

Topics

• Animals
• Apoptosis (drug effects)
• Cell Growth Processes (drug effects)
• Cell Line, Tumor
• Doxorubicin (administration & dosage, pharmacokinetics)
• Female
• GPI-Linked Proteins
• Gangliosides (administration & dosage, metabolism)
• Humans
• Lung Neoplasms (blood supply, drug therapy, metabolism)
• Mice
• Mice, Nude
• Mice, SCID
• Myelin Proteins (administration & dosage, metabolism)
• Neovascularization, Pathologic (drug therapy, metabolism)
• Neuroblastoma (blood supply, drug therapy, metabolism)
• Nogo Receptor 1
• Ovarian Neoplasms (blood supply, drug therapy, metabolism)
• Peptide Fragments (administration & dosage, pharmacokinetics)
• Receptors, Cell Surface (administration & dosage, metabolism)
• Tissue Distribution
• Xenograft Model Antitumor Assays