Department of Gastroenterology and Oncology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan.
Department of Molecular Medicinal Chemistry, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan.
J Gastroenterol Hepatol. 2021 May;36(5):1253-1262. doi: 10.1111/jgh.15281. Epub 2020 Oct 22.
It is difficult to differentiate gastrointestinal stromal tumors (GISTs) from other subepithelial lesions under gastrointestinal endoscopy. Because most GISTs express tyrosine kinase receptor c-KIT, fluorescence-labeled c-KIT-specific tyrosine kinase inhibitors seem to be useful agents for molecular imaging of GIST. We aimed to develop a near-infrared fluorescent imaging technology for GIST targeting c-KIT using the novel fluorescent probe indocyanine green-labeled dasatinib (ICG-dasatinib) and to investigate the antitumor effect of ICG-dasatinib on GIST cells.
Indocyanine green-labeled dasatinib was synthesized by labeling linker-induced dasatinib with ICG derivative 3-indocyanine-green-acyl-1,3-thiazolidine-2-thione. Human GIST cell lines GIST-T1 and GIST-882M were incubated with ICG-dasatinib and observed by fluorescent microscopy. GIST cells were incubated with ICG-dasatinib, unlabeled dasatinib, or imatinib, and cell viabilities were evaluated. Subcutaneous GIST model mice or orthotopic GIST model rats were intravenously injected with ICG-dasatinib and observed using an IVIS Spectrum.
Strong fluorescent signals of ICG-dasatinib were observed in both GIST cell lines in vitro. IC50 values for ICG-dasatinib, unlabeled dasatinib, and imatinib were 13.9, 1.17, and 16.2 nM in GIST-T1 and 26.6, 3.63, and 47.6 nM in GIST-882M cells, respectively. ICG-dasatinib accumulated in subcutaneous xenografts in mice. Fluorescent signals were also observed in liver and gallbladder, indicating biliary excretion; however, fluorescence intensity of tumors was significantly higher than that of intestine after washing. Strong fluorescent signals were observed in orthotopic xenografts through the covering normal mucosa in rats.
Indocyanine green-labeled dasatinib could visualize GIST cells and xenografted tumors. The antitumor effect of ICG-dasatinib was preserved to the same degree as imatinib.
在胃肠内窥镜下，胃肠道间质瘤（GIST）很难与其他黏膜下病变区分。由于大多数 GIST 表达酪氨酸激酶受体 c-KIT，荧光标记的 c-KIT 特异性酪氨酸激酶抑制剂似乎是 GIST 分子成像的有用药物。我们旨在使用新型荧光探针吲哚菁绿标记的达沙替尼（ICG-dasatinib）开发针对 c-KIT 的近红外荧光成像技术，并研究 ICG-dasatinib 对 GIST 细胞的抗肿瘤作用。
通过将连接子诱导的达沙替尼与吲哚菁绿衍生物 3-吲哚菁绿酰基-1,3-噻唑烷-2-硫酮标记，合成吲哚菁绿标记的达沙替尼。将人 GIST 细胞系 GIST-T1 和 GIST-882M 与 ICG-dasatinib 孵育，并通过荧光显微镜观察。将 GIST 细胞与 ICG-dasatinib、未标记的达沙替尼或伊马替尼孵育，并评估细胞活力。将 ICG-dasatinib 静脉内注射到皮下 GIST 模型小鼠或原位 GIST 模型大鼠中，并使用 IVIS Spectrum 观察。
在体外，两种 GIST 细胞系中均观察到 ICG-dasatinib 的强荧光信号。在 GIST-T1 细胞中，IC50 值分别为 ICG-dasatinib、未标记的达沙替尼和伊马替尼为 13.9、1.17 和 16.2 nM，在 GIST-882M 细胞中分别为 26.6、3.63 和 47.6 nM。ICG-dasatinib 在小鼠的皮下异种移植瘤中积聚。荧光信号也在肝脏和胆囊中观察到，表明胆汁排泄；然而，洗涤后肿瘤的荧光强度明显高于肠道。在大鼠中，通过覆盖正常黏膜，在原位异种移植瘤中观察到强荧光信号。
吲哚菁绿标记的达沙替尼可可视化 GIST 细胞和异种移植瘤。ICG-dasatinib 的抗肿瘤作用与伊马替尼相同。
