Growth hormone gene expression in canine normal growth plates and spontaneous osteosarcoma.
The indirect growth-promoting action of pituitary-derived growth hormone (GH) on skeletal growth is thought to be mediated by systemically released insulin-like growth factor-I (IGF-I) and by locally produced IGF-I. The aim of the present study was to document whether GH is expressed locally in canine bone and spontaneous osteosarcoma. Using RT-PCR the expression of GH mRNA was demonstrated in the metaphyseal, but not in the majority of epiphyseal ends of the canine growth plate. GH mRNA was also present in 25% of the canine osteosarcoma specimens. The expression of GH mRNA in predominantly active osteoid forming areas was associated with the presence of immunoreactive GH in osteoblasts, as shown by immunohistochemistry. It is concluded that locally produced GH is involved in osteoid formation and may play a role in the growth of neoplastic bone lesions in the dog.
Kirpensteijn
Jolle
J
Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, University of Utrecht, P.O. Box 80.154, NL-3508 TD Utrecht, The Netherlands. j.kirpensteijn@vet.uu.nl
Timmermans-Sprang
Elpetra P M
EP
van Garderen
Evert
E
Rutteman
Gerard R
GR
Lantinga-van Leeuwen
Irma S
IS
Mol
Jan A
JA
D000818:Animals; D001846:Bone Development; D001859:Bone Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000235:genetics* / Q000378:metabolism; D004285:Dogs / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D013006:Growth Hormone / Q000235:genetics* / Q000378:metabolism; D006132:Growth Plate / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D012516:Osteosarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D012333:RNA, Messenger / Q000378:metabolism
D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone