Willmann Jürgen K, Lutz Amelie M, Paulmurugan Ramasamy, Patel Manishkumar R, Chu Pauline, Rosenberg Jarrett, Gambhir Sanjiv S
Molecular Imaging Program at Stanford, Department of Radiology and Bio-X Program, Stanford University School of Medicine, the James H Clark Center, 318 Campus Dr, East Wing, 1st Floor, Stanford, CA 94305-5427, USA.
Radiology. 2008 Sep;248(3):936-44. doi: 10.1148/radiol.2483072231.
To develop and validate a dual-targeted ultrasonographic (US) imaging agent with microbubbles (MBs) that attaches to both vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) and alpha(v)beta(3) integrin and to compare the US imaging signal obtained from dual-targeted MBs (MB(D)) with that from single-targeted MBs (MB(S)) in a murine model of tumor angiogenesis.
Animal protocols were approved by the institutional Administrative Panel on Laboratory Animal Care. Single- and dual-targeted US imaging agents were prepared by attaching anti-VEGFR2, anti-alpha(v)beta(3) integrin, or both antibodies to the shell of perfluorocarbon-filled MBs. Binding specificities of targeted MBs compared with isotype-matched immunoglobulin G-labeled control MBs (MB(C)) and nontargeted nonlabeled MBs (MB(N)) were tested with VEGFR2-positive and alpha(v)beta(3) integrin-positive cells (mouse SVR cells) and control cells (mouse 4T1 cells). In vivo imaging signals of contrast material-enhanced US by using anti-VEGFR2-targeted MBs (MB(V)), anti-alpha(v)beta(3) integrin-targeted MBs (MB(I)), MB(D), and MB(C) were quantified in 49 mice bearing SK-OV-3 tumors (human ovarian cancer). Tumor tissue was stained for VEGFR2, alpha(v)beta(3) integrin, and CD31.
Attachment of MB(D) to SVR cells (mean, 0.74 MBs per cell +/- 0.05 [standard deviation]) was significantly higher than attachment to 4T1 cells (mean, 0.04 +/- 0.03), and attachment to SVR cells was higher for MB(D) than for MB(V) (mean, 0.58 +/- 0.09), MB(I) (mean, 0.42 +/- 0.21), MB(C) (mean, 0.11 +/- 0.13), and MB(N) (mean, 0.01 +/- 0.01) (P < .05). Imaging signal in the murine tumor angiogenesis model was significantly higher (P < .001) for MB(D) (mean, 16.7 +/- 7.2) than for MB(V) (mean, 11.3 +/- 5.7), MB(I) (mean, 7.8 +/- 5.3), MB(C) (mean, 2.8 +/- 0.9), and MB(N) (mean, 1.1 +/- 0.4). Immunofluorescence confirmed expression of VEGFR2 and alpha(v)beta(3) integrin on tumor vasculature.
Dual-targeted contrast-enhanced US directed at both VEGFR2 and alpha(v)beta(3) integrin improves in vivo visualization of tumor angiogenesis in a human ovarian cancer xenograft tumor model in mice.
http://radiology.rsnajnls.org/cgi/content/full/248/3/936/DC1.
研发并验证一种双靶点超声（US）成像剂，该成像剂为附着于血管内皮生长因子（VEGF）受体2（VEGFR2）和α(v)β3整合素的微泡（MBs），并在肿瘤血管生成的小鼠模型中比较双靶点微泡（MB(D)）与单靶点微泡（MB(S)）获得的US成像信号。
动物实验方案经机构实验动物护理管理小组批准。通过将抗VEGFR2、抗α(v)β3整合素或两种抗体附着于全氟化碳填充微泡的外壳来制备单靶点和双靶点US成像剂。用VEGFR2阳性和α(v)β3整合素阳性细胞（小鼠SVR细胞）及对照细胞（小鼠4T1细胞）检测靶向微泡与同型匹配免疫球蛋白G标记对照微泡（MB(C)）和非靶向未标记微泡（MB(N)）相比的结合特异性。在49只荷SK-OV-3肿瘤（人卵巢癌）的小鼠中，对使用抗VEGFR2靶向微泡（MB(V)）、抗α(v)β3整合素靶向微泡（MB(I)）、MB(D)和MB(C)的对比剂增强US的体内成像信号进行定量分析。对肿瘤组织进行VEGFR2、α(v)β3整合素和CD31染色。
MB(D)与SVR细胞的附着（平均每细胞0.74个微泡±0.05[标准差]）显著高于与4T1细胞的附着（平均0.04±0.03），且MB(D)与SVR细胞的附着高于MB(V)（平均0.58±0.09）、MB(I)（平均0.42±0.21）、MB(C)（平均0.11±0.13）和MB(N)（平均0.01±每细胞0.01）（P<.05）。在小鼠肿瘤血管生成模型中，MB(D)的成像信号（平均16.7±7.2）显著高于MB(V)（平均11.3±外5.7）、MB(I)（平均7.8±5.3）、MB(C)（平均2.8±0.9）和MB(N)（平均1.1±0.4）（P<.001）。免疫荧光证实VEGFR2和α(v)β3整合素在肿瘤血管上表达。
针对VEGFR2和α(v)β3整合素的双靶点对比增强US可改善小鼠人卵巢癌异种移植肿瘤模型中肿瘤血管生成的体内可视化。
http://radiology.rsnajnls.org/cgi/content/full/248/3/936/DC1
