结直肠肿瘤中血管生成素的表达及其与微血管密度的关系

目的:探讨结直肠肿瘤中血管生成素(ang iopo ietin,A ng)的表达及其与微血管密度(m icrovessel density,MVD)的关系。方法:采用免疫组化法,检测91例结直肠腺癌、20例结直肠腺瘤、24例正常结直肠组织中A ng-1和A ng-2的蛋白表达,以F-Ⅷ单克隆抗体标记血管内皮细胞,并计数MVD。结果:A ng-1在正常组织(7.07±2.00)的表达明显高于结直肠腺瘤(1.75±1.98)和腺癌(1.40±1.22),P<0.01;结直肠腺癌的A ng-2阳性表达率高于结直肠腺瘤、正常组织(P<0.01)。A ng-2的表达与结直肠腺癌的分化程度、有无脉管侵犯密切相关;在135例组织中,A ng-1表达与A ng-2表达(r=-0.338,P<0.01)、A ng-1表达与MVD(r=-0.388,P<0.01)、A ng-2表达与MVD(r=0.594,P<0.01)均有相关性。结论:A ng-2在结直肠腺癌中的过度表达对血管新生起重要作用,可能是评估结直肠腺癌恶性程度和预后的可靠指标。

Relationship of angiopoietins expression with microvessel density (MVD) in human colorectal tumors

OBJECTIVE: To investigate the expression of angiopoietin (Ang)-1 and Ang-2 in colorectal tumors and its relations to microvessel density (MVD) in tumor tissue. METHODS: Ang-1, Ang-2 and factor VIII-related antigen were stained immunohistochemically in 91 cases of primary colorectal adenocarcinoma, 20 cases of colorectal adenoma and 24 cases of normal colorectal mucosal tissue, and MVD was also assayed in above tissue specimens. RESULT: (1) A significantly higher Ang-1 (7.07+/-2.00) was observed in normal tissue compared with 1.75 +/-1.98 in the adenoma and 1.40 +/- 1.22 in the adenocarcinoma (P<0.01). (2) Ang-2 protein positive rate in adenocarcinoma was significantly higher than that in normal tissue and adenoma (P<0.01). The expression of Ang-2 in adenocarcinoma was closely associated with poor differentiation and vessel invasion. (3) There were significant correlations between Ang-1 and Ang-2 (r=-0.338, P<0.01), Ang-1 and MVD (r=-0.388, P<0.01), Ang-2 and MVD (r=0.594, P<0.01) in the 135 cases. CONCLUSION: The overexpression of Ang-2 may play an important role in angiogenesis of colorectal adenocarcinoma. It can be regarded as an index for malignancy and prognosis in colorectal adenocarcinoma.