title: EGFR-targeted immunoliposomes derived from the monoclonal antibody EMD72000 mediate specific and efficient drug delivery to a variety of colorectal cancer cells.
abstract: We hypothesized that immunoliposomes (ILs) constructed using Fab' from the humanized anti-EGFR monoclonal antibody, EMD72000, can provide efficient intracellular drug delivery in EGFR-overexpressing colorectal tumor cells.ILs were constructed modularly with various MAb fragments, including Fab' from EMD72000 (matuzumab) or C225 (cetuximab, Erbitux) covalently linked to stabilized liposomes containing chemotherapeutic drugs or probes. Immunoliposome preparation was optimized, including Fab' reduction and linkage, and evaluated for specific binding and cytotoxicity in epidermal growth factor receptor (EGFR)--overexpressing colorectal cancer cell lines in vitro. Flow cytometry showed that EGFR-targeted ILs, but not non-targeted liposomes or irrelevant ILs, were efficiently bound and internalized by a variety of EGFR-overexpressing colorectal cancer cells. Linkage of the Fab' to a longer PEG chain (Mal-PEG3400-DSPE) resulted in an increased uptake of immunoliposomal constructs when compared to previously used materials (Mal-PEG2000-DSPE). ILs derived from EMD72000-Fab' were used to deliver doxorubicin to EGFR-overexpressing target cells in vitro. Immunoliposomal doxorubicin was significantly more cytotoxic than the corresponding non-targeted liposomal drug in target cells, such as HCT116, while equivalent in cells lacking EGFR-overexpression, such as Colo205. We conclude that EGFR-targeted ILs derived from the humanized MAb EMD72000 provide efficient and targeted delivery of anticancer drugs in colorectal cancer cells overexpressing EGFR.
authors.affiliation: Division of Oncology, Department of Internal Medicine, University Hospital of Basel, Petersgraben 4, CH-4031 Basel, Switzerland. mamotc@uhbs.ch
authors.forename: Christoph
authors.initials: C
authors.lastname: Mamot
authors.forename: Reto
authors.initials: R
authors.lastname: Ritschard
authors.forename: Willy
authors.initials: W
authors.lastname: Küng
authors.forename: John W
authors.initials: JW
authors.lastname: Park
authors.forename: Richard
authors.initials: R
authors.lastname: Herrmann
authors.forename: Christoph F
authors.initials: CF
authors.lastname: Rochlitz
mesh_terms: D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000737:chemistry / Q000276:immunology; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000276:immunology; D018938:Caco-2 Cells; D045744:Cell Line, Tumor; D000068818:Cetuximab; D015179:Colorectal Neoplasms / Q000378:metabolism; D004317:Doxorubicin / Q000008:administration & dosage*; D016503:Drug Delivery Systems; D066246:ErbB Receptors / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000008:administration & dosage* / Q000276:immunology; D008081:Liposomes / Q000008:administration & dosage* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D007140:Immunoglobulin Fab Fragments; D008081:Liposomes; D004317:Doxorubicin; D066246:ErbB Receptors; D000068818:Cetuximab