title: Cinacalcet HCl suppresses Cyclin D1 oncogene-derived parathyroid cell proliferation in a murine model for primary hyperparathyroidism.
abstract: Cinacalcet HCl (cinacalcet) is a calcimimetic compound, which suppresses parathyroid (PTH) hormone secretion from parathyroid glands in both primary hyperparathyroidism (PHPT) and secondary hyperparathyroidism (SHPT). We previously reported the suppressive effect of cinacalcet on PTH secretion in vivo in a PHPT model mouse, in which parathyroid-targeted overexpression of the cyclin D1 oncogene caused chronic biochemical hyperparathyroidism and parathyroid cell hyperplasia. Although cinacalcet suppressed parathyroid cell proliferation in SHPT in 5/6-nephrectomized uremic rats, its effect on PHPT has not yet been determined. In this study, the effect of cinacalcet on parathyroid cell proliferation was analyzed in PHPT mice. Cinacalcet (1 mg/g) was mixed into the rodent diet and orally administrated to 80-week-old PHPT mice for 10 days before death. 5-Bromo-2'-deoxyuridine (BrdU, 6 mg/day) was infused by an osmotic pump for 5 days before death, followed by immunostaining of the thyroid-parathyroid complex using an anti-BrdU antibody to estimate parathyroid cell proliferation. Compared to untreated PHPT mice, cinacalcet significantly suppressed both serum calcium and PTH. The proportion of BrdU-positive cells to the total cell number in the parathyroid glands increased considerably in untreated PHPT mice (9.5 ± 3.1%) compared to wild-type mice (0.7 ± 0.1%) and was significantly suppressed by cinacalcet (1.2 ± 0.2%). Cinacalcet did not affect apoptosis in the parathyroid cells of PHPT mice. These data suggest that cinacalcet suppressed both serum PTH levels and parathyroid cell proliferation in vivo in PHPT.
authors.affiliation: Department of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, 1-4-3, Asahi-machi, Abeno-ku, Osaka, 545-8585, Japan. imanishi@med.osaka-cu.ac.jp
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Imanishi
authors.forename: Takehisa
authors.initials: T
authors.lastname: Kawata
authors.forename: Takao
authors.initials: T
authors.lastname: Kenko
authors.forename: Michihito
authors.initials: M
authors.lastname: Wada
authors.forename: Nobuo
authors.initials: N
authors.lastname: Nagano
authors.forename: Takami
authors.initials: T
authors.lastname: Miki
authors.forename: Andrew
authors.initials: A
authors.lastname: Arnold
authors.forename: Masaaki
authors.initials: M
authors.lastname: Inaba
mesh_terms: D000818:Animals; D017209:Apoptosis; D049109:Cell Proliferation / Q000187:drug effects; D000069449:Cinacalcet; D019938:Cyclin D1 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D049950:Hyperparathyroidism, Primary / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D023421:Models, Animal; D009281:Naphthalenes / Q000627:therapeutic use*; D009857:Oncogenes / Q000235:genetics; D010280:Parathyroid Glands / Q000187:drug effects* / Q000378:metabolism; D010281:Parathyroid Hormone / Q000378:metabolism
chemical_list: D009281:Naphthalenes; D010281:Parathyroid Hormone; D019938:Cyclin D1; D000069449:Cinacalcet