title: Herceptin conjugates linked by EDC boost direct tumor cell death via programmed tumor cell necrosis.
abstract: Tumor-targeted antibody therapy is one of the safest biological therapeutics for cancer patients, but it is often ineffective at inducing direct tumor cell death and is ineffective against resistant tumor cells. Currently, the antitumor efficacy of antibody therapy is primarily achieved by inducing indirect tumor cell death, such as antibody-dependent cell cytotoxicity. Our study reveals that Herceptin conjugates, if generated via the crosslinker EDC (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride), are capable of engendering human epidermal growth factor receptor 2 (Her2) positive tumor cells death. Using a high-performance liquid chromatography (HPLC) system, three peaks with estimated molecular weights of antibody monomer, dimer, and trimer were isolated. Both Herceptin trimer and dimer separated by HPLC induced significant levels of necrotic tumor cell death, although the trimer was more effective than the dimer. Notably, the Herceptin trimer also induced Herceptin-resistant tumor cell death. Surprisingly different from the known cell death mechanism that often results from antibody treatment, the Herceptin trimer elicited effective and direct tumor cell death via a novel mechanism: programmed cell necrosis. In Her2-positive cells, inhibition of necrosis pathways significantly reversed Herceptin trimer-induced cell death. In summary, the Herceptin trimer reported herein harbors great potential for overcoming tumor cell resistance to Herceptin treatment.
authors.affiliation: Department of Pediatric Research, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
authors.forename: Jiemiao
authors.initials: J
authors.lastname: Hu
authors.forename: Xinli
authors.initials: X
authors.lastname: Liu
authors.forename: Dennis
authors.initials: D
authors.lastname: Hughes
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Esteva
authors.forename: Bolin
authors.initials: B
authors.lastname: Liu
authors.forename: Joya
authors.initials: J
authors.lastname: Chandra
authors.forename: Shulin
authors.initials: S
authors.lastname: Li
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D005022:Ethyldimethylaminopropyl Carbodiimide / Q000494:pharmacology*; D006801:Humans; D009336:Necrosis / Q000473:pathology*; D009369:Neoplasms / Q000473:pathology*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000378:metabolism; D000068878:Trastuzumab
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D005022:Ethyldimethylaminopropyl Carbodiimide; D018719:Erb-b2 Receptor Tyrosine Kinases; D053422:Receptor-Interacting Protein Serine-Threonine Kinases; D000068878:Trastuzumab