Zhang Wen Biao, Zheng Li Wu, Chua Daniel Tsin Tien, Cheung Lim Kwong
Discipline of Oral and Maxillofacial Surgery, University of Hong Kong Faculty of Dentistry, Hong Kong, China.
J Oral Maxillofac Surg. 2011 Nov;69(11):2860-71. doi: 10.1016/j.joms.2010.12.037. Epub 2011 Jul 8.
The present study evaluated the expression of bone morphogenetic proteins (BMPs)-2, -4, -7, vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) in irradiated mandibles during distraction osteogenesis.
A total of 24 rabbits were randomly assigned to the control and experimental groups. Each rabbit in the experimental group underwent preoperative radiation to 9 Gy in 5 fractions. After 1 month, all rabbits underwent osteotomy and distraction osteogenesis with 7 days of latency. Three rabbits in the control and experimental groups were killed at day 7 (end of the latency period), day 12 (middle of active distraction), day 18 (end of active distraction), and day 25 (1 week after consolidation). The specimens were used for immunohistochemical staining and real-time polymerase chain reaction analysis.
Histologically, at day 25, cortical bone formation was much better in the control group than in the radiotherapy group. In the radiotherapy group, the bone spicules were aligned in the direction of tension stress. At day 12, the expression of BMP-2, -4, and -7 was elevated in the radiotherapy group compared with the control group. At day 25, the expression of BMP-2 was significantly greater in the radiotherapy group. At day 7, the expression of bFGF was significantly suppressed in the radiotherapy group. At day 12, the expression of bFGF and VEGF was significantly elevated in the radiotherapy group compared with the control group. At day 25, the expression of VEGF was significantly greater in the radiotherapy group.
The results of our study have shown that radiotherapy changes the expression pattern of BMPs, VEGF, and bFGF.
本研究评估了在牵张成骨过程中，辐射后下颌骨中骨形态发生蛋白（BMP）-2、-4、-7、血管内皮生长因子（VEGF）和碱性成纤维细胞生长因子（bFGF）的表达情况。
总共24只兔子被随机分为对照组和实验组。实验组的每只兔子术前接受5次分割、总量9 Gy的放疗。1个月后，所有兔子均接受截骨术，并在延迟7天后进行牵张成骨。对照组和实验组各有3只兔子分别在第7天（延迟期结束）、第12天（牵张活跃期中期）、第18天（牵张活跃期结束）和第25天（巩固1周后）处死。标本用于免疫组织化学染色和实时聚合酶链反应分析。
组织学上，在第25天时，对照组的皮质骨形成明显优于放疗组。在放疗组中，骨小梁沿张应力方向排列。在第12天时，放疗组中BMP-2、-4和-7的表达高于对照组。在第25天时，放疗组中BMP-2的表达明显更高。在第7天时，放疗组中bFGF的表达明显受到抑制。在第12天时，放疗组中bFGF和VEGF的表达高于对照组。在第25天时，放疗组中VEGF的表达明显更高。
我们的研究结果表明，放疗改变了BMP、VEGF和bFGF的表达模式。
