title: A novel approach for targeted elimination of CSPG4-positive triple-negative breast cancer cells using a MAP tau-based fusion protein.
abstract: Chondroitin sulfate proteoglycan 4 (CSPG4) has been identified as a highly promising target antigen for immunotherapy of triple-negative breast cancer (TNBC). TNBC represents a highly aggressive heterogeneous group of tumors lacking expression of estrogen, progesterone and human epidermal growth factor receptor 2. TNBC is particularly prevalent among young premenopausal women. No suitable targeted therapies are currently available and therefore, novel agents for the targeted elimination of TNBC are urgently needed. Here, we present a novel cytolytic fusion protein (CFP), designated αCSPG4(scFv)-MAP, that consists of a high affinity CSPG4-specific single-chain antibody fragment (scFv) genetically fused to a functionally enhanced form of the human microtubule-associated protein (MAP) tau. Our data indicate that αCSPG4(scFv)-MAP efficiently targets CSPG4(+) TNBC-derived cell lines MDA-MB-231 and Hs 578T and potently inhibits their growth with IC50 values of ∼200 nM. Treatment with αCSPG(scFv)-MAP resulted in induction of the mitochondrial stress pathway by activation of caspase-9 as well as endonuclease G translocation to the nucleus, while induction of the caspase-3 apoptosis pathway was not detectable. Importantly, in vivo studies in mice bearing human breast cancer xenografts revealed efficient targeting to and accumulation of αCSPG4(scFv)-MAP at tumor sites resulting in prominent tumor regression. Taken together, this preclinical proof of concept study confirms the potential clinical value of αCSPG4(scFv)-MAP as a novel targeted approach for the elimination of CSPG4-positive TNBC.
authors.affiliation: Department of Experimental Medicine and Immunotherapy, Institute for Applied Medical Engineering, University Hospital RWTH Aachen, Germany.
authors.forename: Manal
authors.initials: M
authors.lastname: Amoury
authors.affiliation: Department of Experimental Medicine and Immunotherapy, Institute for Applied Medical Engineering, University Hospital RWTH Aachen, Germany.
authors.forename: Radoslav
authors.initials: R
authors.lastname: Mladenov
authors.affiliation: Department of Experimental Medicine and Immunotherapy, Institute for Applied Medical Engineering, University Hospital RWTH Aachen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Nachreiner
authors.affiliation: Department of Experimental Medicine and Immunotherapy, Institute for Applied Medical Engineering, University Hospital RWTH Aachen, Germany.
authors.forename: Anh-Tuan
authors.initials: AT
authors.lastname: Pham
authors.affiliation: Department of Experimental Medicine and Immunotherapy, Institute for Applied Medical Engineering, University Hospital RWTH Aachen, Germany.
authors.forename: Dmitrij
authors.initials: D
authors.lastname: Hristodorov
authors.affiliation: Department of Pharmaceutical Product Development, Fraunhofer Institute for Molecular Biology and Applied Ecology, Aachen, Germany.
authors.forename: Stefano
authors.initials: S
authors.lastname: Di Fiore
authors.affiliation: Department of Surgery, Laboratory for Translational Surgical Oncology, University of Groningen, University Medical Center Groningen, The Netherlands.
authors.forename: Wijnand
authors.initials: W
authors.lastname: Helfrich
authors.affiliation: Department of Experimental Medicine and Immunotherapy, Institute for Applied Medical Engineering, University Hospital RWTH Aachen, Germany.
authors.forename: Alessa
authors.initials: A
authors.lastname: Pardo
authors.affiliation: Department of Biology, Friedrich Alexander University Erlangen-Nuremberg, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Fey
authors.affiliation: Bio-Rad AbD Serotec GmbH, Puchheim, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schwenkert
authors.affiliation: Department of Pharmaceutical Product Development, Fraunhofer Institute for Molecular Biology and Applied Ecology, Aachen, Germany.
authors.forename: Theophilus
authors.initials: T
authors.lastname: Thepen
authors.affiliation: Institute for Experimental Molecular Imaging, University Hospital RWTH Aachen, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Kiessling
authors.affiliation: Department of Gynecology and Obstetrics, University Hospital RWTH Aachen, Germany.
authors.forename: Ahmad F
authors.initials: AF
authors.lastname: Hussain
authors.affiliation: Department of Pharmaceutical Product Development, Fraunhofer Institute for Molecular Biology and Applied Ecology, Aachen, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Fischer
authors.affiliation: Department of Experimental Medicine and Immunotherapy, Institute for Applied Medical Engineering, University Hospital RWTH Aachen, Germany.|Department of Pharmaceutical Product Development, Fraunhofer Institute for Molecular Biology and Applied Ecology, Aachen, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Kolberg
authors.affiliation: South African Research Chair in Cancer Biotechnology, Institute of Infectious Disease and Molecular Medicine (IDM), Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Observatory, South Africa.
authors.forename: Stefan
authors.initials: S
authors.lastname: Barth
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics*; D015415:Biomarkers; D014408:Biomarkers, Tumor; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D011508:Chondroitin Sulfate Proteoglycans / Q000235:genetics / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D015870:Gene Expression; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D058990:Molecular Targeted Therapy; D011485:Protein Binding; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D057127:Single-Chain Antibodies / Q000235:genetics*; D064726:Triple Negative Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D014404:Tubulin / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays; D016875:tau Proteins / Q000235:genetics / Q000378:metabolism*; D000099216:Chondroitin Sulfate Proteoglycan 4
chemical_list: D000911:Antibodies, Monoclonal; D015415:Biomarkers; D014408:Biomarkers, Tumor; D053148:Caspase 3; D053453:Caspase 9; D011508:Chondroitin Sulfate Proteoglycans; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D057127:Single-Chain Antibodies; D014404:Tubulin; D016875:tau Proteins; C101390:CSPG4 protein, human; D000099216:Chondroitin Sulfate Proteoglycan 4
keywords: human cytolytic fusion protein; immunotherapy; medical biotechnology; microtubule-associated protein tau; triple negative breast cancer