title: Inhibition of metalloproteinases enhances the internalization of anti-CD30 antibody Ki-3 and the cytotoxic activity of Ki-3 immunotoxin.
abstract: CD30 is selectively expressed on the tumor cells of a variety of malignant disorders of the immune system and can therefore be used as a target for an anti-CD30 antibody-based immunotherapy. However, CD30 is cleaved at the cell surface by tumor necrosis factor-alpha converting enzyme (TACE). This metalloproteinase releases the soluble ectodomain of CD30 (sCD30), which is able to neutralize immunotherapeutic agents before these reach their target cells. Such constitutive CD30 cleavage is enhanced after binding of most anti-CD30 antibodies, leading to a downregulation of CD30 and an increase of sCD30 in the cell environment. Here, we demonstrate that CD30 shedding from the cell line Karpas 299 could effectively be blocked by the hydroxamic acid-based metalloproteinase inhibitors BB-3644 (IC50 = 180 nM), BB-2116 (IC50 = 230 nM), BB-94 (batimastat, IC50 = 230 nM) and BB-2516 (marimastat, IC50 = 1 microM). This inhibition reduced the concentration of sCD30 in the cell environment to the background level, prolonged the persistence of the anti-CD30 antibody Ki-3 on Karpas 299 cells and favored its internalization. Moreover, a nontoxic concentration of the inhibitor BB-3644 significantly increased the cytotoxic activity of the anti-CD30 ricin A-chain immunotoxin Ki-3.dgA towards the CD30(+) Hodgkin-derived cell line L540. Hence, the metalloproteinase inhibitor BB-3644 may be a promising compound to improve the immunotherapy of CD30(+) malignancies.
authors.affiliation: Department of Biochemistry, University of Kiel, Kiel, Germany. hhansen48@gmx.net
authors.forename: Hinrich P
authors.initials: HP
authors.lastname: Hansen
authors.forename: Bärbel
authors.initials: B
authors.lastname: Matthey
authors.forename: Stefan
authors.initials: S
authors.lastname: Barth
authors.forename: Tatiana
authors.initials: T
authors.lastname: Kisseleva
authors.forename: Thilo
authors.initials: T
authors.lastname: Mokros
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Davies
authors.forename: R Paul
authors.initials: RP
authors.lastname: Beckett
authors.forename: Regina
authors.initials: R
authors.lastname: Foelster-Holst
authors.forename: Hans H
authors.initials: HH
authors.lastname: Lange
authors.forename: Andreas
authors.initials: A
authors.lastname: Engert
authors.forename: Hilmar
authors.initials: H
authors.lastname: Lemke
mesh_terms: D000631:Aminopyridines / Q000737:chemistry / Q000494:pharmacology*; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000378:metabolism*; D002470:Cell Survival; D004305:Dose-Response Relationship, Drug; D004705:Endocytosis; D006801:Humans; D006877:Hydroxamic Acids / Q000737:chemistry / Q000494:pharmacology*; D000922:Immunotoxins / Q000494:pharmacology*; D017730:Ki-1 Antigen / Q000276:immunology* / Q000378:metabolism; D007700:Kinetics; D008223:Lymphoma / Q000378:metabolism / Q000628:therapy; D017728:Lymphoma, Large-Cell, Anaplastic / Q000378:metabolism / Q000628:therapy; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors*; D011480:Protease Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D000631:Aminopyridines; D000911:Antibodies, Monoclonal; C448637:BB 3644; D006877:Hydroxamic Acids; D000922:Immunotoxins; D017730:Ki-1 Antigen; D011480:Protease Inhibitors; D008666:Metalloendopeptidases