title: Targeted and intracellular triggered delivery of therapeutics to cancer cells and the tumor microenvironment: impact on the treatment of breast cancer.
abstract: Limiting tumor invasion to the surrounding healthy tissues has proven to be clinically relevant for anticancer treatment options. We have demonstrated that, within a solid tumor, it is possible to achieve such a goal with the same nanoparticle by intracellular and triggered targeted drug delivery to more than one cell population. We have identified the nucleolin receptor in endothelial and cancer cells in tissue samples from breast cancer patients, which enabled the design of a F3-peptide-targeted sterically stabilized pH-sensitive liposome. The clinical potential of such strategy was demonstrated by the successful specific cellular association by breast cancer cells harvested from tumors of patients submitted to mastectomy. In vitro, the nanoparticle targeted the nucleolin receptor on a cell and ligand-specific manner and improved cytotoxicity of doxorubicin (used as a model drug) towards breast cancer and endothelial cells by 177- and 162-fold, respectively, relative to the commercially available non-targeted non-pH-sensitive liposomes. Moreover, active accumulation of F3-targeted pH-sensitive liposomes into human orthotopic tumors, implanted in the mammary fat pad of nude mice, was registered for a time point as short as 4 h, reaching 48% of the injected dose/g of tissue. Twenty-four hours post-injection the accumulation of the dual-targeted pH-sensitive nanoparticle in the tumor tissue was 33-fold higher than the non-targeted non-pH-sensitive counterpart. In mice treated with the developed targeted nanoparticle significant decrease of the tumor viable rim area and microvascular density, as well as limited invasion to surrounding healthy tissues were observed (as opposed to other tested controls), which may increase the probability of tumors falling in the category of "negative margins" with reduced risk of relapse.
authors.affiliation: Center for Neuroscience and Cell Biology, University of Coimbra, Largo Marquês de Pombal, 3004-517 Coimbra, Portugal.
authors.forename: Vera
authors.initials: V
authors.lastname: Moura
authors.forename: Manuela
authors.initials: M
authors.lastname: Lacerda
authors.forename: Paulo
authors.initials: P
authors.lastname: Figueiredo
authors.forename: Maria L
authors.initials: ML
authors.lastname: Corvo
authors.forename: Maria E M
authors.initials: ME
authors.lastname: Cruz
authors.forename: Raquel
authors.initials: R
authors.lastname: Soares
authors.forename: Maria C Pedroso
authors.initials: MC
authors.lastname: de Lima
authors.forename: Sérgio
authors.initials: S
authors.lastname: Simões
authors.forename: João N
authors.initials: JN
authors.lastname: Moreira
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage* / Q000493:pharmacokinetics; D001943:Breast Neoplasms / Q000098:blood supply / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D004317:Doxorubicin / Q000008:administration & dosage* / Q000493:pharmacokinetics; D016503:Drug Delivery Systems; D042783:Endothelial Cells / Q000187:drug effects; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008081:Liposomes; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008875:Middle Aged; D008969:Molecular Sequence Data; D058990:Molecular Targeted Therapy; D053769:Nanocapsules; D009389:Neovascularization, Pathologic / Q000188:drug therapy / Q000473:pathology; D010455:Peptides; D010750:Phosphoproteins / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D014018:Tissue Distribution; D059016:Tumor Microenvironment / Q000187:drug effects*; D023041:Xenograft Model Antitumor Assays; D000097796:Nucleolin
chemical_list: D000903:Antibiotics, Antineoplastic; D004317:Doxorubicin; D008081:Liposomes; D053769:Nanocapsules; D010455:Peptides; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; D000097796:Nucleolin