title: Anti-ganglioside antibody-induced tumor cell death by loss of membrane integrity.
abstract: Gangliosides have been involved in multiple cellular processes such as growth, differentiation and adhesion, and more recently as regulators of cell death signaling pathways. Some of these molecules can be considered as tumor-associated antigens, in particular, N-glycolyl sialic acid-containing gangliosides, which are promising candidates for cancer-targeted therapy because of their low expression in normal human tissues. In this study, we provided the molecular and cellular characterization of a novel cell death mechanism induced by the anti-NGcGM3 14F7 monoclonal antibody (mAb) in L1210 murine tumor cell line but not in mouse normal cells (B and CD4(+) T lymphocytes) that expressed the antigen. Impairment of ganglioside synthesis in tumor cells abrogated the 14F7 mAb cytotoxic effect; however, exogenous reincorporation of the ganglioside did not restore tumor cell sensitivity to 14F7 mAb-induced cytotoxicity. 14F7 F(ab')(2) but not Fab fragments retained the cytotoxic capacity of the whole mAb. By contrary, other mAb, which recognizes N-glycolylated gangliosides, did not show any cytotoxic effect. These mAbs showed quite different capacities to bind NGcGM3-positive cell lines measured by binding inhibition experiments. Interestingly, this complement-independent cell death mechanism did not resemble apoptosis, because no DNA fragmentation, caspase activation, or Fas mediation were observed. However, NGcGM3 ganglioside-mediated 14F7 mAb-induced cell death was accompanied by cellular swelling, membrane lesion formation, and cytoskeleton activation, suggesting an oncosis-like phenomenon. This novel mechanism of cell death lets us to support further therapeutic approaches using NGcGM3 as a molecular target for antibody-based cancer immunotherapy.
authors.affiliation: Antibody Engineering Department, Centre of Molecular Immunology, 216 Street and 15th Avenue, Atabey, Playa, Havana, 11600 Cuba.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Roque-Navarro
authors.forename: Krittalak
authors.initials: K
authors.lastname: Chakrabandhu
authors.forename: Joel
authors.initials: J
authors.lastname: de León
authors.forename: Sandra
authors.initials: S
authors.lastname: Rodríguez
authors.forename: Carlos
authors.initials: C
authors.lastname: Toledo
authors.forename: Adriana
authors.initials: A
authors.lastname: Carr
authors.forename: Cristina Mateo
authors.initials: CM
authors.lastname: de Acosta
authors.forename: Anne-Odile
authors.initials: AO
authors.lastname: Hueber
authors.forename: Rolando
authors.initials: R
authors.lastname: Pérez
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D000912:Antibodies, Neoplasm / Q000494:pharmacology*; D000915:Antibody Affinity / Q000187:drug effects; D000918:Antibody Specificity / Q000187:drug effects; D001665:Binding Sites; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism*; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D005679:G(M3) Ganglioside / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009369:Neoplasms / Q000473:pathology*
chemical_list: D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D005679:G(M3) Ganglioside