Morlandt Anthony B, Moore Lindsay S, Johnson Aubrey O, Smith Caris M, Stevens Todd M, Warram Jason M, MacDougall Mary, Rosenthal Eben L, Amm Hope M
Associate Professor and Section Chief, Division of Oral Oncology, Department of Oral and Maxillofacial Surgery, University of Alabama at Birmingham, Birmingham, AL.
Resident, Department of Otolaryngology, University of Alabama at Birmingham, Birmingham, AL.
J Oral Maxillofac Surg. 2020 Oct;78(10):1736-1747. doi: 10.1016/j.joms.2020.05.022. Epub 2020 May 19.
Fluorescently labeled epidermal growth factor receptor (EGFR) antibodies have successfully identified microscopic tumors in multiple in vivo models of human cancers with limited toxicity. The present study sought to demonstrate the ability of fluorescently labeled anti-EGFR, cetuximab-IRDye800, to localize to ameloblastoma (AB) tumor cells in vitro and in vivo.
EGFR expression in AB cells was confirmed by quantitative real-time polymerase chain reaction and immunohistochemistry. Primary AB cells were labeled in vitro with cetuximab-IRDye800 or nonspecific IgG-IRDye800. An in vivo patient-derived xenograft (PDX) model of AB was developed. The tumor tissue from 3 patients was implanted subcutaneously into immunocompromised mice. The mice received an intravenous injection of cetuximab-IRDye800 or IgG-IRDye800 and underwent imaging to detect infrared fluorescence using a Pearl imaging system (LI-COR Biosciences, Lincoln, NE). After resection of the overlying skin, the tumor/background ratios (TBRs) were calculated and statistically analyzed using a paired t test.
EGFR expression was seen in all AB samples. Tumor-specific labeling was achieved, as evidenced by a positive fluorescence signal from cetuximab-IRDye800 binding to AB cells, with little staining seen in the negative controls treated with IgG-IRDye800. In the animal PDX model, imaging revealed that the TBRs produced by cetuximab were significantly greater than those produced by IgG on days 7 to 14 for AB-20 tumors. After skin flap removal to simulate a preresection state, the TBRs increased with cetuximab and were significantly greater than the TBRs with the IgG control for PDX tumors derived from the 3 patients with AB. The excised tissues were embedded in paraffin and examined to confirm the presence of tumor.
Fluorescently labeled anti-EGFR demonstrated specificity for AB cells and PDX tumors. The present study is the first report of tumor-specific, antibody-based imaging of odontogenic tumors, of which AB is one of the most clinically aggressive. We expect this technology will ultimately assist surgeons treating AB by helping to accurately assess the tumor margins during surgery, leading to improved long-term local tumor control and less surgical morbidity.
荧光标记的表皮生长因子受体（EGFR）抗体已在多种人类癌症体内模型中成功识别出微小肿瘤，且毒性有限。本研究旨在证明荧光标记的抗EGFR西妥昔单抗 - IRDye800在体外和体内定位于成釉细胞瘤（AB）肿瘤细胞的能力。
通过定量实时聚合酶链反应和免疫组织化学确认AB细胞中的EGFR表达。原代AB细胞在体外用西妥昔单抗 - IRDye800或非特异性IgG - IRDye800进行标记。建立了AB的体内患者来源异种移植（PDX）模型。将3例患者的肿瘤组织皮下植入免疫缺陷小鼠体内。小鼠接受静脉注射西妥昔单抗 - IRDye800或IgG - IRDye800，并使用Pearl成像系统（LI - COR Biosciences，林肯，内布拉斯加州）进行成像以检测红外荧光。切除覆盖皮肤后，计算肿瘤/背景比（TBR），并使用配对t检验进行统计分析。
在所有AB样本中均观察到EGFR表达。实现了肿瘤特异性标记，西妥昔单抗 - IRDye800与AB细胞结合产生的阳性荧光信号证明了这一点，而用IgG - IRDye800处理的阴性对照中几乎没有染色。在动物PDX模型中，成像显示，对于AB - 20肿瘤，在第7至14天，西妥昔单抗产生的TBR显著高于IgG产生的TBR。在去除皮瓣以模拟切除前状态后，对于源自3例AB患者的PDX肿瘤，西妥昔单抗处理后的TBR增加，且显著高于IgG对照的TBR。将切除的组织包埋在石蜡中并检查以确认肿瘤的存在。
荧光标记的抗EGFR对AB细胞和PDX肿瘤具有特异性。本研究是牙源性肿瘤基于抗体的肿瘤特异性成像的首次报道，AB是临床上侵袭性最强的牙源性肿瘤之一。我们预计这项技术最终将有助于外科医生治疗AB，通过在手术期间帮助准确评估肿瘤边缘，从而改善长期局部肿瘤控制并减少手术发病率。
