目的:观察到糖尿病视网膜病变(DR)的病理性血管生成和血管不稳定性,糖尿病性黄斑水肿(DME),和湿性年龄相关性黄斑变性(wAMD)。许多受体酪氨酸激酶(RTKs)包括血管内皮生长因子受体(VEGFRs)有助于血管生成,而RTKTIE2对血管稳定性很重要。Pan-VEGFR酪氨酸激酶抑制剂(TKIs),如vorolanib,舒尼替尼,和阿西替尼比目前仅靶向一种或两种配体的抗体治疗具有治疗意义。这项研究比较了这些TKIs的抗血管生成潜力。
方法:进行激酶HotSpot™测定以鉴定TKI抑制与血管生成和血管稳定性相关的RTK。测定每个TKI的VEGFRs和TIE2的半数最大抑制浓度(IC50)。使用人脐静脉内皮细胞发芽测定法研究了体外血管生成抑制,并使用绒毛尿囊膜测定法研究了体内血管生成。使用黑色素结合测定法评估黑色素结合。进行计算机建模以了解TIE2-阿西替尼复合物以及vorolanib和VEGFRs之间的相互作用。
结果:沃罗拉尼,舒尼替尼,和阿西替尼抑制血管生成中感兴趣的RTK并表现出泛-VEGFR抑制。HotSpot™测定和TIE2IC50值显示只有阿西替尼有效抑制TIE2(高达89%)。所有三种TKIs均在体外有效抑制血管生成。在体内,TKI在抑制VEGF诱导的血管生成方面比抗VEGF抗体贝伐单抗更有效。在三个TKIs中,只有舒尼替尼结合黑色素。TKIs的分类和与VEGFR的结合不同,这很重要,因为II型抑制剂比I型TKIs具有更大的选择性。
结论:沃罗拉尼,舒尼替尼,和阿西替尼表现出泛VEGFR抑制作用,并抑制与病理性血管生成相关的RTK。在三个TKIs中,只有阿西替尼才能有效抑制TIE2,这是一种不希望的性状,因为TIE2对血管稳定性至关重要。研究结果支持使用vorolanib治疗性抑制DR中观察到的血管生成,DME,WAMD。
OBJECTIVE: Pathological angiogenesis and vascular instability are observed in diabetic retinopathy (DR), diabetic macular edema (DME), and wet age-related macular degeneration (wAMD). Many receptor tyrosine kinases (RTKs) including vascular endothelial growth factor receptors (VEGFRs) contribute to angiogenesis, whereas the RTK TIE2 is important for vascular stability. Pan-VEGFR tyrosine kinase inhibitors (TKIs) such as vorolanib, sunitinib, and
axitinib are of therapeutic interest over current antibody treatments that target only one or two ligands. This study compared the anti-angiogenic potential of these TKIs.
METHODS: A kinase HotSpot™ assay was conducted to identify TKIs inhibiting RTKs associated with angiogenesis and vascular stability. Half-maximal inhibitory concentration (IC50) for VEGFRs and TIE2 was determined for each TKI. In vitro angiogenesis inhibition was investigated using a human umbilical vein endothelial cell sprouting assay, and in vivo angiogenesis was studied using the chorioallantoic membrane assay. Melanin binding was assessed using a melanin-binding assay. Computer modeling was conducted to understand the TIE2-
axitinib complex as well as interactions between vorolanib and VEGFRs.
RESULTS: Vorolanib, sunitinib, and
axitinib inhibited RTKs of interest in angiogenesis and exhibited pan-VEGFR inhibition. HotSpot™ assay and TIE2 IC50 values showed that only
axitinib potently inhibited TIE2 (up to 89%). All three TKIs effectively inhibited angiogenesis in vitro. In vivo, TKIs were more effective at inhibiting VEGF-induced angiogenesis than the anti-VEGF antibody bevacizumab. Of the three TKIs, only sunitinib bound melanin. TKIs differ in their classification and binding to VEGFRs, which is important because type II inhibitors have greater selectivity than type I TKIs.
CONCLUSIONS: Vorolanib, sunitinib, and
axitinib exhibited pan-VEGFR inhibition and inhibited RTKs associated with pathological angiogenesis. Of the three TKIs, only axitinib potently inhibited TIE2 which is an undesired trait as TIE2 is essential for vascular stability. The findings support the use of vorolanib for therapeutic inhibition of angiogenesis observed in DR, DME, and wAMD.