Wu Xiaoli, Feng Shuo, Chang Tse-Shao, Zhang Ruoliu, Jaiswal Sangeeta, Choi Eun-Young K, Duan Yuting, Jiang Hui, Wang Thomas D
Department of Internal Medicine, Division of Gastroenterology, University of Michigan, Ann Arbor, MI 48109, USA.
Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
Cancers (Basel). 2024 Aug 10;16(16):2818. doi: 10.3390/cancers16162818.
Hepatocellular carcinoma (HCC) has emerged as a major contributor to the worldwide cancer burden. Improved methods are needed for early cancer detection and image-guided surgery. Peptides have small dimensions that can overcome delivery challenges to achieve high tumor concentrations and deep penetration. We used phage display methods to biopan against the extra-cellular domain of the purified EpCAM protein, and used IRDye800 as a near-infrared (NIR) fluorophore. The 12-mer sequence HPDMFTRTHSHN was identified, and specific binding to EpCAM was validated with HCC cells in vitro. A binding affinity of k = 67 nM and onset of k = 0.136 min (7.35 min) were determined. Serum stability was measured with a half-life of T = 2.6 h. NIR fluorescence images showed peak uptake in vivo by human HCC patient-derived xenograft (PDX) tumors at 1.5 h post-injection. Also, the peptide was able to bind to foci of local and distant metastases in liver and lung. Peptide biodistribution showed high uptake in tumor versus other organs. No signs of acute toxicity were detected during animal necropsy. Immunofluorescence staining of human liver showed specific binding to HCC compared with cirrhosis, adenoma, and normal specimens.
肝细胞癌（HCC）已成为全球癌症负担的主要贡献因素。早期癌症检测和图像引导手术需要改进方法。肽具有小尺寸，能够克服递送挑战以实现高肿瘤浓度和深度渗透。我们使用噬菌体展示方法针对纯化的EpCAM蛋白的细胞外结构域进行生物淘选，并使用IRDye800作为近红外（NIR）荧光团。鉴定出12聚体序列HPDMFTRTHSHN，并在体外用人肝癌细胞验证了其与EpCAM的特异性结合。确定结合亲和力k = 67 nM，起始k = 0.136分钟（7.35分钟）。测量血清稳定性，半衰期T = 2.6小时。近红外荧光图像显示，在注射后1.5小时，人肝癌患者来源的异种移植（PDX）肿瘤在体内摄取达到峰值。此外，该肽能够与肝脏和肺中的局部和远处转移灶结合。肽的生物分布显示肿瘤相对于其他器官的摄取较高。在动物尸检期间未检测到急性毒性迹象。人肝脏的免疫荧光染色显示与肝硬化、腺瘤和正常标本相比，该肽与肝癌具有特异性结合。
