恶性胃间质瘤的血管生成拟态与恶性程度的关系

Vasculogenic mimicry in malignant gastric stromal tumors

目的探讨恶性胃间质瘤中是否存在血管生成拟态(VM),即肿瘤细胞变形并模仿正常血管结构形成的拟态血管。方法将36例恶性间质瘤分为低、中、高度3组,分别采用免疫组织化学和PAS染色双重染色测定微血管密度(MVD)、血管生成拟态密度(VMD),并分析肿瘤的恶性程度与VMD的关系。结果恶性胃间质瘤中有VM形成,含有VM的恶性胃间质瘤VEGF表达及MVD均低于无VM者(P均<0.05);随着胃间质瘤恶性程度的增高,VM肿瘤的比例逐渐增加,VMD逐渐增高,高度恶性与低或中度恶性肿瘤间差异具有统计学意义(P均<0.05),但后二者间差异无统计学意义(P>0.05)。结论恶性胃间质瘤细胞具有可塑性,能通过自身变形并分泌细胞外基质,模拟正常血管结构形成可输送血液的管道系统,即血管生成拟态。

Objective To investigate whether malignant gastric stromal tumors contain PAS-pesitive patterned matrix-associated vascular channels, that is vasculngenic mimicry（VM） independent of tumor angiogenesis. Methods 36 tissue samples were divided into three groups： the poorly, the moderately and the highly malignant gastric stromal tumors. Tissue sections were stained with VEGF, CD31 land periodic acid Sehiff （PAS）. The number of VEGF, microvascular density （MVD） or vaseulogenic mimicry density （VIVID） was calculated. Results PAS-positive patterned matrix-associated vascular channels were detected in 30.56% （11/36） of malignant gastric stromal tumors. The number of VEGF or MVD in tumors containing patterned channels was fewer than that in tumors not containing pattemed channels, and there was a significant difference between them（ P 〈 0.05）. Also, the malignant degree of gastric stromal tumors, and proportion of malignant gastric stromal tumors containing patterned channels and quantity of VMD were increased. Conclusion In malignant gastric stromal tinters, there is the VM mechanism underlying some tumor cells deforming themselves and secreting an extraeelluar metrix, thus the PAS-pasitive patterned matrix-associated vascular channels appear and bring a blood supply for tumors to sustain growth and metastasis.