急性白血病患者血管内皮生长因子及其受体表达的动态观察

目的探讨急性白血病(AL)患者治疗前后骨髓中血管内皮生长因子(VEGF)及其受体的表达差异以及这种表达与血管生成的相关性.方法应用EnVision免疫组织化学二步法,检测122例次成人AL患者骨髓中造血细胞VEGF及其两种特异性受体fms-样酪氨酸激酶受体(Flt-1)、激酶插入嵌合受体(KDR)蛋白的表达情况.结果化疗后获得完全缓解(CR)的患者,其VEGF、KDR蛋白的表达在治疗前为6.0(3.3～12.0)和5.3(3.3～8.0),获CR后为5.3(3.3～9.0)和2.0(1.0～4.0)差异有显著性(P<0.05;P<0.01),而在化疗后未获得CR患者中的表达差异无显著性.在缓解后复发患者中的表达又升高到初发时的水平.各组初发患者Flt-1的表达水平与对照组之间差异无显著性,但CR期Flt-1的表达水平在CR组为3.3(1.7～5.3),复发组为3.3(2.0～5.3)与初发及对照组差异有显著性(P<0.01).微血管数处于高水平组的VEGF及KDR表达显著高于微血管处于低水平组者(P<0.01).骨髓原始细胞与急性髓系白血病(AML)初发患者VEGF和KDR的表达之间成正相关(r=0.429,0.359;P=0.005,0.02);与急性淋巴细胞白血病(ALL)初发患者VEGF的表达之间成正相关(r=0.522,P=0.03).结论 VEGF及其两种特异性细胞受体Flt-1, KDR在造血细胞及血管内皮细胞中表达.提示VEGF可能是白血病细胞的一种自分泌因子,同时作为一种旁分泌因子调控患者骨髓中的血管新生反应.VEGF及其细胞受体KDR可能构成抗血管新生和抗白血病治疗的新靶点.

Dynamic observation of vascular endothelial growth factor (VEGF)/VEGF-receptors expression in acute leukemia

OBJECTIVE: To investigate the expression of vascular endothelial growth factor (VEGF)/VEGF-receptors and its relation to bone marrow angiogenesis in acute leukemia patients before and after chemotherapy. METHODS: Bone marrow biopsies from 122 cases with different stages of human acute leukemia were immunostained with anti-vascular endothelial growth factor, anti-fms-like tyrosine kinase (Flt-1) and anti- kinase-domain insert containing receptor (KDR) antibodies with envision two-step immunohistochemical staining method. RESULTS: The expression of VEGF and KDR protein in remission patients was 5.3 (3.3 - 9.0) and 2.0 (1.0 - 4.0) being significantly lower than newly diagnosed untreated patients 6.0 (3.3 - 12.0) and 5.3 (3.3 - 8.0) (P < 0.05, 0.01). However nonsignificant decrease was shown among non-remission patients. In relapsed patients the expression of VEGF and KDR was significantly increased as compared with that in newly diagnosed patients. Flt-1 staining levels were in the same range between the newly diagnosed untreated patients and control group (P > 0.05), but significantly increased in remission or relapse patients, being 3.3 (1.7 - 5.3) in the remission group and 3.3 (2.0 - 5.3) in the relapse group (P < 0.01). Expression of VEGF and KDR protein was significantly higher in patients with a high degree of bone marrow microvessel counts as compared with those with a low degree and the expression correlated well with microvessel counts (P < 0.01). There was a positive correlation of the percentage of bone marrow blasts with VEGF and KDR expression in AML patients (r = 0.429, 0.359; P = 0.005, 0.02), and with VEGF expression in ALL patients (r = 0.522; P = 0.03). CONCLUSION: VEGF and its two specific cellular receptors are expressed in both haematopoietic cells and endothelial cells. VEGF may be a autocrine factor and modulates the angiogenic reaction in bone marrow as a paracrine factor. VEGF and its cellular receptor KDR may constitute promising targets for antiangiogenic and antileukemic treatment strategies.