Ang—2和VEGF在肾细胞癌患者外周血中的表达及其意义
2017-11-14韩晖王永刚刘尚莹
韩晖 王永刚 刘尚莹
【摘要】 目的:检测促血管生成素-2(Angiopoietin-2,Ang-2)和血管内皮生长因子(vascular endothelial growth factor,VEGF)在肾细胞癌患者外周血中的表达,探讨两者的变化及其相互关系。方法:收集56例肾细胞癌患者按肿瘤分期分为实验1、2、3组,30例健康人为对照组,采用ELISA方法分别检测标本Ang-2、VEGF的水平,对以上数据进行比较。结果:四组的VEGF两两比较,差异均有统计学意义(P<0.05);实验3组的Ang-2高于实验1组、实验2组、对照组,对照组的Ang-2低于实验1、2、3组,差异均有统计学意义(P<0.05)。肾细胞癌患者血清VEGF和Ang-2呈正相关(r=0.732,P<0.05)。结论:Ang-2、VEGF在肾细胞癌患者外周血中呈高表达,且与临床分期关系密切,Ang-2和VEGF在肾细胞癌血管生成中可能相互影响。
【关键词】 肾细胞癌; 促血管生成素-2; 血管内皮生长因子
The Expression and Significance of Ang-2 and VEGF in Peripheral Blood of Renal Cell Carcinoma Patient/HAN Hui,WANG Yong-gang,LIU Shang-ying.//Medical Innovation of China,2017,14(27):110-112
【Abstract】 Objective:To investigate the expression of angiopoietin-2 and vascular endothelial growth factor in peripheral blood of patients with renal cell carcinoma,and to explore the changes and their relationship.Method:56 renal cell carcinoma patients were selected,according to the tumor stage were divided into experimental group 1,2,3,30 healthy people were selected as the control group,specimens was detected by ELISA method Ang-2,the levels of VEGF,the above data were compared.Result:The differences between the four groups of VEGF compsred were statistically significant(P<0.05);the Ang-2 of experimental group 3 was higher than the experimental group 1,experimental group 2,control group,the Ang-2 of the control group was lower than the experimental group 1,2,3,the differences have the statistical significance(P<0.05).Serum VEGF and Ang-2 were positively correlated in patients with renal cell carcinoma(r=0.732,P<0.05).Conclusion:Ang-2 and VEGF are highly expressed in peripheral blood of patients with renal cell carcinoma and are closely related to clinical stages, and Ang-2 and VEGF may interact with each other in the angiogenesis of renal cell carcinoma.
【Key words】 Renal cell carcinoma; Angiopoietin-2; Vascular endothelial growth factor
First-authors address:Shanxi Medical University,Taiyuan 030001,China
doi:10.3969/j.issn.1674-4985.2017.27.031
近年来泌尿系肿瘤的发病率逐年上升,其中肾细胞癌(renal cell carcinoma,RCC)是泌尿系统中恶性程度较高、血管丰富的实体肿瘤,其发病率和死亡率仅次于排名第一的膀胱癌[1]。有研究发现,促血管生成素-2(Angiopoietin,Ang-2)在肿瘤新生血管的调节中起着重要的作用,与肿瘤血管的形成有密切的关系[2],抑制Ang-2可促进血管的稳定性和减少血管形成[3]。此外,血管内皮生长因子(vascular endothelial growth factor,VEGF)能直接作用于血管內皮细胞促进细胞增殖,能影响血管的形成和肿瘤的生长,与肿瘤的增殖、转移密切相关[4]。本研究着重探讨Ang-2、血管内皮生长因子(VEGF)在肾细胞癌的发生发展中所扮演的角色,现报道如下。
1 材料与方法
1.1 标本 收集2016年2-10月本院符合纳入标准的肾细胞癌患者血清标本56例为实验组,纳入标准:(1)需经病理证实为肾细胞癌;(2)实验组患者在确诊前未行手术治疗、化疗、放疗及其他抗肿瘤治疗;(3)无其他系统肿瘤、严重感染及肿瘤家族史。参照2010年美国肿瘤联会委员会(AJCC)的肿瘤分期标准将实验组分为实验1组(Ⅰ期)30例、实验2组(Ⅱ期)15例、实验3组(Ⅲ、Ⅳ期)11例,并选取体检健康的血清标本30例为对照组。四组患者的一般资料比较,差异均无统计学意义(P>0.05),具有可比性。endprint
1.2 试剂与仪器 由武汉博士德生物工程有限公司提供Ang-2及VEGF的ELISA试剂盒。由山西医科大学第一医院病理科提供-80 ℃低温冰箱。恒温温育箱、分光光度计、恒温振荡器、离心机、酶标仪等实验仪器由山西医科大学分子生物实验室提供。
1.3 实验方法 采集血清标本:向所有受试抽血对象说明情况并取得知情同意后,于次日凌晨空腹抽血5 mL,常规分离血清冻存于-80 ℃低温冰箱保存待用,注意避免标本反复冻融。标本采集为同一个人,待所有标本收齐后,统一进行血清Ang-2和VEGF的浓度水平的检测,实验步骤严格按照ELISA试剂盒中的说明书进行操作。取3次测定值为均值,以标准物的质量浓度为横坐标,450 nm波长吸光度值(D)为纵坐标绘制标准曲线。样品的实际质量浓度(单位pg/mL)。
1.4 统计学处理 采用SPSS 18.0统计软件进行处理分析,符合正态分布的采用均数±标准差(x±s)表示。多组比较采用单因素方差分析(ANOVA),两两比较采用最小显著性差异法(LSD),相关分析采用Pearson检验,P<0.05为差异有统计学意义。
2 结果
四组的VEGF两两比较,差异均有统计学意义(P<0.05);实验3组的Ang-2高于实验1组、实验2组、对照组,对照组的Ang-2低于实验1、2、3组,差异均有统计学意义(P<0.05),见表1。肾细胞癌患者血清VEGF和Ang-2呈正相关(r=0.732,P<0.05)。
3 讨论
肿瘤是由肿瘤血管和肿瘤细胞两者构成的,其中肿瘤细胞对肿瘤血管的形成有促进作用,肿瘤血管的形成又可以营养肿瘤细胞,从而为肿瘤提供转移途径[5]。肿瘤血管生成过程复杂,是多种促进、抑制因子平衡后的结果,当促血管生成因子的作用强于抑制因子时,肿瘤血管便朝着生成这个方向启动[6]。
血管内皮生长因子(VEGF)为目前经典的调控血管生成物质,自2005年以来,通过抑制VEGF信号通路与哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)的七种新的靶向治疗药物已被批准用于治疗转移性肾细胞癌(mRCC)[7];Ang-2作为新的调控物质被发现表达在许多肿瘤中,例如:肝癌、乳腺癌、肺癌、胃癌等[8-11],该物质在正常人体呈低水平表达,但在以血管渗漏和炎症增加为特点的疾病中明显增高[12-13]。关于肿瘤的VEGF基因研究较多,多项研究均观察到VEGF与肿瘤分期相关[14]。本研究显示,Ang-2和VEGF在肾细胞癌患者血清中的表达均高于健康对照,且临床分期越晚的患者血清Ang-2和VEGF的表达水平越高,这与国内外多项研究结果相似[15-17]。
此外,本研究还发现,VEGF与Ang-2存在正相关(P<0.05),这提示Ang-2与VEGF在肿瘤血管的形成过程中可能存在相互协助的关系。Ang-2通过破坏血管的外基质与內皮细胞间的作用,从而强化部分受体对VEGF的敏感性,诱导增强血管重建相关物质产生;使得血管芽生增多,这对血管新生及维持、后期增生起重要作用,在肿瘤患者中这种过程变成了恶性循环[18]。
通过阻断肿瘤血管的生成从而抗肿瘤治疗成为一个研究热点[16],而由于肾细胞癌对化放疗均不是很敏感,且对免疫、瘤苗、基因等治疗方法的疗效还是很有限,因此以Ang-2家族作为肾细胞癌治疗的新靶点受到人们的关注[19]。临床研究表明,Ang-2的阻断剂可以阻断肿瘤生长及血管形成,特别是当结合VEGF的抗血管形成治疗时可以抑制随淋巴结转移、远处转移[20-21]。本实验受限于经费未就VEGF与Ang-2之间复杂的关系及相互作用方式展开研究,通过检测肾细胞癌血清中Ang-2和VEGF的含量希望揭示Ang-2的表达情况、影响因素以及其与经典的VEGF之间可能的相关作用,为肾细胞癌早发现、早诊断及新治疗机制提供方向。
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(收稿日期:2017-08-10) (本文編辑:张爽)endprint