Visualizing the antivascular effect of bortezomib on the hypoxic tumor microenvironment.
Visualizing the antivascular effect of bortezomib on the hypoxic tumor microenvironment.
复制标题
可视化硼替佐米对缺氧肿瘤微环境的抗血管作用。
DOI：
10.18632/oncotarget.5300
复制
发表时间：
2015-10-27
期刊：
影响因子：
--
通讯作者：
Li GC
中科院分区：
文献类型：
--
作者：
Sun X;Ackerstaff E;He F;Xing L;Hsiao HT;Koutcher JA;Ling CC;Li GC
硼替佐米是一种新型蛋白酶体抑制剂，已被批准用于治疗多发性骨髓瘤和套细胞淋巴瘤，并在临床前和临床上研究了实体瘤。硼替佐米在体外对缺氧的肿瘤细胞和内皮细胞具有优先的细胞毒性。本研究的目的是研究预处理低氧肿瘤微环境对硼替佐米体外和离体效应的作用，并探讨动态对比增强磁共振成像（DCE MRI）无创评估硼替佐米生物学效应的可行性。体外Western blot、流式细胞术和ELISA显示，硼替佐米以非功能形式积累HIF-1α，并阻断其在人结直肠癌细胞系中的缺氧反应。使用多种内源性和外源性标志物，用荧光免疫组织化学染色技术进行离体实验，以鉴定缺氧（哌莫硝唑，HRE-TKeGFP）、血流/渗透性（Hoechst 33342）、微血管（CD 31和SMA）、细胞凋亡（切割的半胱天冬酶3）和缺氧反应（CA 9）。硼替佐米给药后，肿瘤异种移植物的总体凋亡指数显著增加，血液灌注显著减少。更重要的是，凋亡信号被发现优先位于中度和重度预处理缺氧区域的肿瘤和内皮细胞。同时，DCE MRI检查显示硼替佐米给药后肿瘤血流量和通透性明显降低。目前的研究表明，硼替佐米减少肿瘤缺氧反应和血液灌注，因此，呈现抗血管特性。在进一步的转化研究中，确定治疗前和治疗期间的缺氧/灌注状态非常重要。
Bortezomib, a novel proteasome inhibitor, has been approved for treating multiple myeloma and mantle cell lymphoma and studied pre-clinically and clinically for solid tumors. Preferential cytotoxicity of bortezomib was found toward hypoxic tumor cells and endothelial cells in vitro. The purpose of this study is to investigate the role of a pretreatment hypoxic tumor microenvironment on the effects of bortezomib in vitro and ex vivo, and explore the feasibility of dynamic contrast enhanced magnetic resonance imaging (DCE MRI) to noninvasively evaluate the biological effects of bortezomib. It was shown in vitro by Western blot, flow cytometry, and ELISA that bortezomib accumulated HIF-1α in non-functional forms and blocks its hypoxia response in human colorectal cancer cell lines. Ex vivo experiments were performed with fluorescent immunohistochemical staining techniques using multiple endogenous and exogenous markers to identify hypoxia (pimonidazole, HRE-TKeGFP), blood flow/permeability (Hoechst 33342), micro-vessels (CD31 and SMA), apoptosis (cleaved caspase 3) and hypoxia response (CA9). After bortezomib administration, overall apoptosis index was significantly increased and blood perfusion was dramatically decreased in tumor xenografts. More importantly, apoptosis signals were found preferentially located in moderate and severe pretreatment hypoxic regions in both tumor and endothelial cells. Meanwhile, DCE MRI examinations showed that the tumor blood flow and permeability decreased significantly after bortezomib administration. The present study revealed that bortezomib reduces tumor hypoxia response and blood perfusion, thus, presenting antivascular properties. It will be important to determine the hypoxic/perfusion status pre- and during treatment at further translational studies.