荧光内镜靶向黏膜内皮素 A 受体表达可检测和特征分析结肠炎相关癌症在小鼠中的情况。

Targeting Mucosal Endothelin-A-Receptor Expression by Fluorescence Endoscopy is Feasible to Detect and Characterize Colitis-Associated Cancer in Mice.

机构信息

University Hospital Frankfurt, Department of Internal Medicine 1, Frankfurt a. M., Germany.

University of Münster, Department of Medicine B, Münster, Germany.

出版信息

Inflamm Bowel Dis. 2017 Dec 19;24(1):111-122. doi: 10.1093/ibd/izx032.

DOI:10.1093/ibd/izx032

PMID:29272493

Abstract

BACKGROUND

To facilitate onsite decision-making during endoscopy, both accurate detection and in vivo characterization of preneoplasia are prerequisites. However, no endoscopy technique is available that meets both demands satisfactorily. We evaluated endothelin-receptor A (ETAR)-guided fluorescence endoscopy (FE) in vivo and fluorescence reflectance imaging (FRI) ex vivo for detection and characterization of early dysplastic colitis-associated colonic lesions.

METHODS

Colorectal cancerogenesis was investigated in the inflammatory driven AOM-DSS model and spontaneous adenoma development in ApcMin mice. A Cy5.5-labeled nonpeptidic ETAR-specific imaging probe was injected intravenously to assess tumor development in vivo by white light endoscopy (WLE) and FE. Ex vivo tumors were evaluated by FRI, histological examination, and western blot analysis. In addition, tissue samples from patients with colitis-associated malignant and nonmalignant mucosal alterations were analyzed. Specificity experiments were performed using an unspecific Cy3.5-glycine tracer.

RESULTS

Overall, 62 adenomas were observed. FE was able to detect and quantify ETAR expression targeting the ETAR-specific photoprobe. A significantly higher fluorescent contrast was detected in colonic adenomas compared to adjacent nonmalignant mucosa by FE (64.3 ± 7.9 vs. 56.6. ± 7.0; P < 0.001). These results were confirmed by FRI examination, immunochemistry, and western blot analysis. Additionally, ETAR expression in samples from human patients with colitis-associated cancer was highly elevated compared to nonmalignant alterations. Specificity experiments indicated a high binding-specificity of the applied ETAR photoprobe (1.4 ± 0.3 vs. 2.5 ± 0.7; P < 0.001).

CONCLUSIONS

We introduced ETAR guided FE in mice for successful in vivo detection and characterization of colorectal neoplasia on a molecular level.

摘要

背景

为了便于内镜检查时现场决策，准确检测和体内鉴定癌前病变都是前提条件。然而，目前还没有一种内镜技术能够同时满足这两个要求。我们评估了内皮素受体 A（ETAR）指导的荧光内镜（FE）体内和荧光反射成像（FRI）体外检测和鉴定早期发育不良性结肠炎相关结肠病变的能力。

方法

在炎症驱动的 AOM-DSS 模型中研究了大肠癌的发生，在 ApcMin 小鼠中研究了自发性腺瘤的发展。静脉注射 Cy5.5 标记的非肽 ETAR 特异性成像探针，通过白光内镜（WLE）和 FE 评估体内肿瘤的发展。通过 FRI、组织学检查和 Western blot 分析评估离体肿瘤。此外，还分析了伴有恶性和非恶性黏膜改变的结肠炎患者的组织样本。使用非特异性 Cy3.5-甘氨酸示踪剂进行特异性实验。

结果

共观察到 62 个腺瘤。FE 能够检测和定量靶向 ETAR 特异性光探针的 ETAR 表达。FE 检测到的结肠腺瘤中 ETAR 表达的荧光对比度明显高于相邻非恶性黏膜（64.3 ± 7.9 比 56.6. ± 7.0；P < 0.001）。FRI 检查、免疫化学和 Western blot 分析证实了这一结果。此外，与非恶性改变相比，来自伴有结肠炎的癌症患者的样本中 ETAR 表达显著升高。特异性实验表明，应用的 ETAR 光探针具有较高的结合特异性（1.4 ± 0.3 比 2.5 ± 0.7；P < 0.001）。