血管内皮生长因子及其受体在子宫内膜癌中的表达

目的探讨血管内皮生长因子(VEGF)及其受体fms样酪氨酸受体-1 (flt-1)和含插入区的激酶受体(KDR)在子宫内膜癌血管生成中的作用及其与内膜癌分化程度的关系.方法采用免疫组织化学及原位杂交方法对23例子宫内膜癌及6例正常绝经期子宫内膜中VEGF、flt-1、KDR蛋白质及其mRNA进行检测,并对少数病例行Western印迹分析,以检测VEGF亚型在内膜癌组织的分布,用内皮细胞标志Ⅷ因子标记内膜癌组织中的微血管密度.结果 VEGF、flt-1、KDR蛋白质及其mRNA主要分布在子宫内膜癌组织血管内皮细胞及癌细胞胞质内.VEGF蛋白质在中分化(G2)、低分化(G3)内膜癌血管内皮细胞及癌细胞上的表达高于高分化内膜癌(G1)及正常绝经期子宫内膜(P<0.05), VEGF mRNA在不同分化程度内膜癌组织的表达差异无显著性意义(P>0.05),但均大于正常绝经期子宫内膜(P<0.05);flt-1蛋白质及flt-1mRNA在G3内膜癌血管内皮细胞的表达高于G1、G2及正常绝经期子宫内膜(P<0.05),在癌细胞的表达差异无显著性意义(P>0.05) ,但均高于正常绝经期子宫内膜(P<0.05);KDR蛋白质在子宫内膜癌组织血管内皮细胞及癌细胞上的表达较强,但不随分化程度发生变化,其mRNA在中分化(G2)、低分化(G3)内膜癌血管内皮细胞及癌细胞上的表达高于正常绝经期子宫内膜(P<0.05).G3子宫内膜癌组织的血管密度(48个±12个)高于G1(27个±14个)、G2(26个±16个)及正常绝经期子宫内膜(26个±11个,P<0.05).结论 VEGF、flt-1、KDR及mRNA在子宫内膜癌中的表达形式提示其与癌组织血管生成及血管通透性相关,VEGF及其受体是与子宫内膜癌旺盛生长相关的因子之一.

Expression of vascular endothelial growth factor and its receptors in endometrial carcinoma

OBJECTIVE: To study the expression of vascular endothelial growth factor (VEGF) and its receptors, the fms-like tyrosine-1 (flt-1) and kinase insert domain-containing receptor (KDR) in endometrial carcinoma and investigate the functions of VEGF and its receptors for endometrial carcinoma angiogenesis and its relation to the grade of tumor. METHODS: Immunocytochemistry and in situ hybridization technique were used to measure the level of VEGF, flt-1, KDR protein and mRNA in endometrial carcinoma tissue from 23 patients and endometrial samples from 6 normal menopausal women. A few endometrial carcinoma samples were homogenized for Western blot analysis. The blood vessel density was estimated by counting blood vessels stained with endothelial marker VIII factor. RESULTS: The VEGF and its receptors were widely expressed in the cytoplasm of endothelial cells and tumor cells of endometrial carcinoma. The level of VEGF protein in endothelial cells and endometrial cancer cells of grade II and III tumor tissues was higher than that in grade I and normal menopausal endometrium (P < 0.05). VEGF mRNA did not show higher expression with the increase of tumor grade but its expression in normal tissue was lower than that in cancer (P < 0.05). The expression of flt-1 protein and mRNA in endothelial cells got higher in III than in grade II and I (P < 0.05), but invariable in cancer cells (P > 0.05), flt-1 expression in cancer was higher than that in normal menopausal endometrium either in endothelial cells or in cancer cells (P < 0.05). The expression of KDR protein in endothelial and cancer cell was high but did not alter with the increase of tumor grade (P > 0.05), the level of its mRNA was higher in cancer than that in normal tissue (P < 0.05). The microvascular density in grade III (48 +/- 12) was higher than that in grade II (26 +/- 16), grade I (27 +/- 14) and normal menopausal tissue (26 +/- 11, P < 0.05). CONCLUSIONS: The expression pattern of VEGF, flt-1 and KDR protein and mRNA increased with the increase of tumor grade in endometrial carcinoma indicates that VEGF and its receptors contribute to the neovascularization of tumors and is one of the factors that relate to rapid tumor growth of endometrial carcinoma.