骨肉瘤组织中ephrinB2和EphB4蛋白表达与临床病理及血管生成的关系

Expressions of ephrinB2 and its receptor EphB4 in human osteosarcoma and their relationship between clincial pathology and angiogenesis

目的:探讨ephrinB2 及其受体EphB4在骨肉瘤中的表达及其与肿瘤发生、发展以及血管生成的关系。方法:采用免疫组化SP法检测三种骨肉瘤细胞株(SAOS、U2 OS、HOS)、10例正常骨、10 例良性骨肿瘤和80例骨肉瘤组织中EphB4、ephrinB2、CD34和FⅧRag 等蛋白表达,并根据CD34和FⅧRag染色结果计数微血管密度。结果:EphB4 及ephrinB2 在骨肉瘤细胞株中呈阳性表达,骨肉瘤中EphB4 及ephrinB2显著高于正常骨,P=0 .000 6。EphB4 及ephrinB2的蛋白表达定位于肿瘤细胞和血管内皮细胞胞质, 呈异质性分布;两种蛋白在Ⅲ级骨肉瘤中的表达均明显高于Ⅰ、Ⅱ级,P=0. 003和P=0 .013。EphB4 和eph rinB2强表达组中的MVD 分别为44. 4±14 .7和46. 8±16. 0,均显著高于EphB4 和ephrinB2 弱表达组相应的MVD . 32. 3±22. 2 和31 .0 ±15. 5, P = 0 .008 和P=0 .000 7。结论: EphB4/ephrinB2 在骨肉瘤发生、演进过程中起着重要作用,并与肿瘤血管生成密切相关。

OBJECTIVE: To investigate the expressions of ephrinB2 protein and its EphB4 receptor in human osteosarcoma, and also evaluate their role in tumor initiation, development and angiogenesis. METHODS: The expressions of ephrinB2 and EphB4 proteins were detected immunohistochemically in three osteosarcoma cell lines (SAOS, U2-OS, HOS), 10 normal human bone samples, 10 cases of human bone benign tumor and 80 cases of human osteosarcoma. Intratumor microvessel density (MVD) was counted according to the results of CD 34 and FⅧ-RAg protein staining. RESULTS: Both ephrinB2 and EphB4 proteins were positive staining in three osteosarcoma cell lines. The protein levels of the two genes in osteosarcoma were significantly higher than those in the bone. The positive staining of both ephrinB2 and EphB4 proteins mainly localized in cytoplasm of tumor cells and endothelial cells and showed obvious heterogeneity fashion. The protein levels of the two genes in Grade Ⅰ,Ⅱ osteosarcoma were significantly lower than those in Grade Ⅲ osteosarcoma specimens. The MVDs of the cases of ephrinB2 and EphB4 high level expression groups were 46.8±16.0 and 44.4±14.7 respectively, both of which were significantly higher than those of the low level expression groups, P=0.008 and P=0.000 7.CONSLUSION: Both EphB4 and ephrinB2 genes might be of much importance in carcinogenesis and progression of osteosarcoma. They might also play critical roles in neoangiogenesis.