title: Generation of a humanized monoclonal antibody against human parathyroid hormone-related protein and its efficacy against humoral hypercalcemia of malignancy.
abstract: A humanized monoclonal antibody against parathyroid hormone-related protein (PTHrP) was generated from the mouse monoclonal antibody raised against the peptide corresponding to the N-terminal 34 amino acids of the human PTHrP [(PTHrP(1-34)]. The humanized antibody interacted with the PTHrP(1-34) with a kD value of 1.90 x 10(-10) M, and the epitope resides between the amino acids 20 and 30 of the PTHrP. PTHrP(1-34) significantly increased the intracellular cAMP levels in the rat osteosarcoma cells that expressed PTHR1, and the 5 microg/mL or higher concentrations of the humanized antibody almost completely blocked the PTHrP-induced cAMP production even in the presence of 2 microg/mL PTHrP(1-34), demonstrating its ability to fully neutralize PTHrP function. There was no significant difference in the potency of the mouse, chimera, or the humanized antibodies to suppress the PTHrP-induced increase in the intracellular cAMP in ROS cells. Furthermore, at the same doses, the administration of the chimera or the humanized antibody was equally effective in reducing the blood ionized calcium levels of hypercalcemic mice bearing the PAN-7-JCK human pancreatic cancer xenograft or the LC-6-JCK human lung cancer xenograft that secreted PTHrP. Thus, humanized anti-PTHrP may be useful for the treatment of the humoral hypercalcemia of malignancy in humans.
authors.affiliation: Chugai Research Laboratories, Chugai Pharmaceutical Co. Ltd., 200 Kajiwara, Kamakura, Kanagawa, Japan.
authors.forename: Etsuro
authors.initials: E
authors.lastname: Onuma
authors.forename: Koh
authors.initials: K
authors.lastname: Sato
authors.forename: Hidemi
authors.initials: H
authors.lastname: Saito
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Tsunenari
authors.forename: Kimie
authors.initials: K
authors.lastname: Ishii
authors.forename: Keiko
authors.initials: K
authors.lastname: Esaki
authors.forename: Naohiro
authors.initials: N
authors.lastname: Yabuta
authors.forename: Yuji
authors.initials: Y
authors.lastname: Wakahara
authors.forename: Hisafumi
authors.initials: H
authors.lastname: Yamada-Okabe
authors.forename: Etsuro
authors.initials: E
authors.lastname: Ogata
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D006801:Humans; D006934:Hypercalcemia / Q000097:blood / Q000209:etiology / Q000628:therapy*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007147:Immunoglobulin Light Chains / Q000235:genetics; D008175:Lung Neoplasms / Q000097:blood / Q000150:complications; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008969:Molecular Sequence Data; D010190:Pancreatic Neoplasms / Q000097:blood / Q000150:complications; D044162:Parathyroid Hormone-Related Protein / Q000037:antagonists & inhibitors* / Q000276:immunology*; D010446:Peptide Fragments / Q000276:immunology*; D051381:Rats; D011916:Rats, Inbred F344; D011923:Rats, Nude; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology / Q000494:pharmacology; D023041:Xenograft Model Antitumor Assays
chemical_list: D000911:Antibodies, Monoclonal; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D044162:Parathyroid Hormone-Related Protein; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; C054296:parathyroid hormone-related protein (1-34)