Cy5.5-labeled Affibody molecule for near-infrared fluorescent optical imaging of epidermal growth factor receptor positive tumors
Cy5.5-labeled Affibody molecule for near-infrared fluorescent optical imaging of epidermal growth factor receptor positive tumors
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DOI：
10.1117/1.3432738
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发表时间：
2010-05-01
影响因子：
3.5
通讯作者：
Cheng, Zhen
中科院分区：
文献类型：
--
作者：
Miao, Zheng;Ren, Gang;Cheng, Zhen
粘附体蛋白是一种具有三螺旋束结构的工程蛋白支架。小尺寸（7kd）的附着体分子在体内靶向过表达的癌症生物标志物方面具有很大的潜力。为了开发一种基于附着体的分子探针，用于表皮生长因子受体（EGFR）阳性肿瘤的体内光学成像，研究人员将一种抗表皮生长因子受体的附着体分子Ac-Cys-Z(EGFR:1907) （7 kD）与近红外荧光染料cy5.5 -单马来酰亚胺位点特异性偶联。利用荧光显微镜，用高表达EGFR的A431细胞和低表达EGFR的MCF7细胞检测探针Cy5.5-Z（EGFR:1907）的结合特异性。通过流式细胞术检测，Cy5.5-Z(EGFR:1907) （K-D）与EGFR的结合亲和力为43.6 +/- 8.4 nM。在一项体内成像研究中，A431肿瘤的探针在注射后0.5 h （p.i）就显示出快速的肿瘤靶向性和良好的肿瘤对比，而MCF7肿瘤几乎不可见。一项离体成像研究也表明，cyp5.5 - z （EGFR:1907）在24小时内具有较高的肿瘤、肝脏和肾脏摄取。综上所述，Cy5.5-Z（EGFR:1907）对EGFR具有良好的亲和力和高特异性。Cy5.5-Z(EGFR): 1907快速实现了良好的肿瘤与正常组织对比，从而证明了其在EGFR靶向肿瘤分子成像方面的潜力。(C) 2010光学仪器工程师学会。(DOI: 10.1117/1.3432738)
Affibody protein is an engineered protein scaffold with a three-helical bundle structure. Affibody molecules of small size (7 kD) have great potential for targeting overexpressed cancer biomarkers in vivo. To develop an Affibody-based molecular probe for in vivo optical imaging of epidermal growth factor receptor (EGFR) positive tumors, an anti-EGFR Affibody molecule, Ac-Cys-Z(EGFR:1907) (7 kD), is site-specifically conjugated with a near-IR fluorescence dye, Cy5.5-mono-maleimide. Using fluorescent microscopy, the binding specificity of the probe Cy5.5-Z(EGFR:1907) is checked by a high-EGFR-expressing A431 cell and low-EGFR-expressing MCF7 cells. The binding affinity of Cy5.5-Z(EGFR:1907) (K-D) to EGFR is 43.6 +/- 8.4 nM, as determined by flow cytometry. For an in vivo imaging study, the probe shows fast tumor targeting and good tumor contrast as early as 0.5 h postinjection (p.i.) for A431 tumors, while MCF7 tumors are barely visible. An ex vivo imaging study also demonstrates that Cy5.5-Z(EGFR:1907) has high tumor, liver, and kidney uptakes at 24 h p.i.. In conclusion, Cy5.5-Z(EGFR:1907) shows good affinity and high specificity to the EGFR. There is rapid achievement of good tumor-to-normal-tissue contrasts of Cy5.5-Z(EGFR): 1907, thus demonstrating its potential for EGFR-targeted molecular imaging of cancers. (C) 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3432738]