Bohn Kaci A, Adkins Chris E, Nounou Mohamed I, Lockman Paul R
Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, AmarilloTX, USA.
Department of Pharmaceutical Sciences, College of Pharmacy, Harding University, SearcyAR, USA.
Front Pharmacol. 2017 Apr 11;8:193. doi: 10.3389/fphar.2017.00193. eCollection 2017.
For metastases in the central nervous system, angiogenesis enhances metastatic potential and promotes progression. Primary factors which drive vessel growth are vascular endothelial growth factor (VEGF) and angiopoietin-2. Preclinical models show inhibition of either factor reduces metastases spread and inhibits growth. This work sets out to answer two questions in a preclinical mouse model. First, whether the combined inhibition of VEGF and angiopoietin-2, reduces passive permeability and limits drug uptake into brain metastases; and second, whether this inhibition reduces metastases burden in brain. We observed combinatorial inhibition of VEGF and angiopoietin-2, decreased ( < 0.05) angiogenesis and vascular branching in an aortic ring assay and decreased ( < 0.05) endothelial wound closure times. Using a brain metastases of breast cancer model (induced by intracardiac injections of brain seeking MDA-MB-231Br cells or 4T1Br cells), we observed, similar to VEGF, angiopoetin-2 expression correlates to increased angiogenesis ( < 0.05) and increased lesion permeability. To determine efficacy, animals were administered bevacizumab plus L1-10 (angiopoietin inhibitor) twice per week until neurological symptoms developed. Lesion permeability significantly decreased by ∼50% ( < 0.05) compared to untreated lesions, but remained ∼25% greater ( < 0.0%) than brain. In subsequent experiments, animals were administered similar regimens but sacrificed on day 32. The number of metastatic lesions developed was significantly ( < 0.001) reduced in the bevacizumab group (56%) and combination group (86%). Lesions' size was reduced in bevacizumab treated lesions (∼67%) and bevacizumab and L1-10 treated lesions (∼78%) developing area < 0.5 mm. In summary, combinatorial inhibition of VEGF and angiopoietin reduces lesion permeability and brain metastatic burden.
对于中枢神经系统的转移瘤,血管生成增强了转移潜能并促进其进展。驱动血管生长的主要因素是血管内皮生长因子(VEGF)和血管生成素-2。临床前模型显示,抑制这两种因子中的任何一种都可减少转移灶的扩散并抑制其生长。这项研究旨在在临床前小鼠模型中回答两个问题。第一,联合抑制VEGF和血管生成素-2是否能降低被动通透性并限制药物进入脑转移瘤;第二,这种抑制是否能减轻脑内转移瘤的负担。我们观察到,在主动脉环实验中,联合抑制VEGF和血管生成素-2可使血管生成和血管分支减少(<0.05),并使内皮伤口闭合时间缩短(<0.05)。使用乳腺癌脑转移模型(通过心内注射脑靶向MDA-MB-231Br细胞或4T1Br细胞诱导),我们观察到,与VEGF类似,血管生成素-2的表达与血管生成增加(<0.05)和病变通透性增加相关。为了确定疗效,每周给动物注射两次贝伐单抗加L1-10(血管生成素抑制剂),直至出现神经症状。与未治疗的病变相比,病变通透性显著降低约50%(<0.05),但仍比脑实质高约25%(<0.0%)。在随后的实验中,给动物使用类似的给药方案,但在第32天处死。贝伐单抗组(56%)和联合治疗组(86%)发生的转移瘤数量显著减少(<0.001)。在贝伐单抗治疗的病变(约67%)以及贝伐单抗和L1-10治疗的病变(约78%)中,病变面积<0.5 mm的病变大小减小。总之,联合抑制VEGF和血管生成素可降低病变通透性和脑转移瘤负担。