The protective efficacy of basic fibroblast growth factor in radiation-induced salivary gland dysfunction in mice.
OBJECTIVE
Radiotherapy is one of the most effective treatments for head and neck cancer. However, in addition to the target tumor, normal salivary glands are also included in the irradiation field. This unavoidably results in dry mouth syndrome as a side effect. In this study, the protective efficacy of basic fibroblast growth factor (bFGF) was investigated in radiation-damaged salivary glands.


METHODS
Prospective animal experiment with control.


METHODS
Nine-week-old female C57BL/6 mice were divided into three groups. All mice in two of the three groups were irradiated (10 Gy) at the same time. In the bFGF-treated group, bFGF was administered to the submandibular glands for 3 consecutive days after neck irradiation. Mice in the untreated control group were administered distilled water. Mice in the third group were not irradiated and did not receive any additional treatments. Saliva flow rate and submandibular gland morphology were assessed, and the apoptotic response of irradiated submandibular glands was also evaluated.


RESULTS
Administration of bFGF improved hyposalivation 8 weeks after irradiation, and histologic analysis revealed that bFGF-treated glands contained more acinar cells compared to untreated glands. The apoptotic response to irradiation, examined 1 and 2 days after irradiation, was reduced, and quantitative real-time polymerase chain reaction revealed a paracrine effect for bFGF in the glands that received bFGF treatment.


CONCLUSIONS
Our study indicates that bFGF prevents salivary gland dysfunction after irradiation. The protective benefits of bFGF may be attributed to the inhibition of radiation-induced apoptosis as well as the paracrine effect it has in these tissues.
Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Tsuyoshi
T
Kojima
Shin-Ichi
S
Kanemaru
Shigeru
S
Hirano
Ichiro
I
Tateya
Atsushi
A
Suehiro
Yoshiharu
Y
Kitani
Yo
Y
Kishimoto
Satoshi
S
Ohno
Tatsuo
T
Nakamura
Juichi
J
Ito
D061354:Acinar Cells; D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D020287:In Situ Nick-End Labeling; D051379:Mice; D008810:Mice, Inbred C57BL; D011446:Prospective Studies; D011833:Radiation Injuries, Experimental / Q000473:pathology / Q000517:prevention & control*; D060888:Real-Time Polymerase Chain Reaction; D012469:Salivary Glands / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects*; D012472:Salivation / Q000502:physiology
D016222:Fibroblast Growth Factor 2