消化道双向分化肿瘤的血管生成拟态研究

目的 探讨在消化道双向分化恶性肿瘤中是否存在血管生成拟态（VM）。方法采用免疫组化和PAS染色技术研究消化道双向分化恶性肿瘤的血管生成模式,收集消化道双向分化恶性肿瘤111例,包括恶性胃肠间质瘤80例;恶性黑色素瘤18例;癌肉瘤13例。分别进行血管内皮生长因子（VEGF）、CD31及PAS染色,通过体视学网格计数法计算VEGF的表达量、显微图像分析仪下分别计算CD31和PAS阳性图案围成的管道面积即微血管密度（MVD）与VM密度（VMD）,根据三者的表达量研究VM并比较分析三者之间的关系以及与肿瘤恶性程度的关系。结果消化道双向分化恶性肿瘤有VM形成,其内存在红细胞,含有VM的肿瘤其VEGF表达（89±20）及MVD（47±12）均低于无VM者（126±18,78±13,均P〈0．05）;随着肿瘤恶性程度的增高,VM肿瘤的比例逐渐增高,VM肿瘤VEGF的表达、MVD、VMD均逐渐增高,上述指标在各肿瘤的低度恶性（45±19,15±8,38±25）与高度恶性（128±42,81±17,122±39）之间差异均有统计学意义（均P〈0．05）。结论 消化道双向分化恶性肿瘤细胞具有可塑性,存在VM。肿瘤细胞通过VM可进一步获得血液供应和血道转移。

Vasculogenic mimicry in the bi-directional differentiation malignant tumors of digestive tract

OBJECTIVE: To investigate whether vasculogenic mimicry (VM) exists in the bi-directional differentiation malignant tumors of digestive tract. METHODS: 111 specimens of bi-directional differentiation malignant tumors of digestive tract. including malignant gastrointestinal stromal tumors (GIST, n = 80), malignant melanoma (n = 18), and carcinosarcoma (n = 13), underwent periodic acid Schiff (PAS) staining and microscopy. Immunohistochemistry was used to examine the expression of vascular endothelial growth factor (VEGF), and CD31. Microvascular density (MVD) and vasculogenic mimicry density (VMD) were calculated. RESULTS: PAS-positive patterned matrix-associated vascular channels with red blood cells therein were detected in 39.1% (31.5/111) of the tumor samples. (89 +/- 20) and MVD (47 +/- 12) both lower than without VM (76, 126 +/- 18, 78 +/- 13, all P < 0.05) the expression levels of VEGF and MVD in the tumors containing patterned channels were (89 +/- 20) and MVD (47 +/- 12) respectively, both significantly lower than those in the tumors without VM (126 +/- 18) and (78 +/- 13) respectively, both P < 0. 05]. The higher the malignant degree of tumor, the higher the proportion of the tumor with VM. The levels of MVD and VMD of the GIST, malignant melanoma, and carcinosarcoma with low malignancy were 45 +/- 19, 15 +/- 8, and 38 +/- 25 respectively, all significantly lower than those of the GIST, malignant melanoma, and carcinosarcoma with high malignancy (128 +/- 42, 81 +/- 17, 122 +/- 39, all P < 0.05). CONCLUSION: VM exists in the bi-directional differentiation malignant tumors of digestive tract. The tumor cells obtain blood supply and become metastatic via the mechanism of VM.