Radiation effects on osteoblasts in vitro: a potential role in osteoradionecrosis.
OBJECTIVE
To evaluate the factors involved in bone remodeling and wound healing that may be altered by radiation therapy.


METHODS
A prospective, controlled study of biochemical activity in vitro.


METHODS
MC3T3-E1 mouse osteoblasts.


METHODS
Cells were irradiated at 0, 2, 4, or 6 Gy. Specimens were harvested at 1, 7, 14, 28, and 42 days following irradiation for immunohistochemical analysis of transforming growth factor beta(1) expression and transforming growth factor beta(1) type I and II receptor expression. Collagen production was measured at 1, 7, 28, 35, and 49 days after irradiation. The effects of dexamethasone on collagen production and cell proliferation were also examined.


RESULTS
Irradiated cells demonstrated decreased cell proliferation and a dose-dependent, sustained reduction in collagen production when compared with control cells. An increase in transforming growth factor beta(1) type I and II receptor expression was noted in irradiated cells when compared with controls.


CONCLUSIONS
Radiation-induced alterations of factors related to bone remodeling and wound healing have a potential role in the pathogenesis of osteoradionecrosis.
Gal
T J
TJ
Division of Otolaryngology, 74th Medical Operation Squadron/SGOSL, Medical Corps, US Air Force, 4881 Sugar Maple, Wright-Patterson Air Force Base, OH 45433, USA. tj_gal@ameritech.net.
Munoz-Antonia
T
T
Muro-Cacho
C A
CA
Klotch
D W
DW
D000818:Animals; D001847:Bone Diseases / Q000209:etiology*; D016723:Bone Remodeling / Q000502:physiology; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis; D003907:Dexamethasone / Q000494:pharmacology; D005938:Glucocorticoids / Q000494:pharmacology; D007150:Immunohistochemistry; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D010025:Osteoradionecrosis / Q000209:etiology*; D011446:Prospective Studies; D018125:Receptors, Transforming Growth Factor beta / Q000032:analysis
D005938:Glucocorticoids; D018125:Receptors, Transforming Growth Factor beta; D003907:Dexamethasone; D003094:Collagen