近红外荧光染料对胃癌细胞的特异性识别*

测试近红外荧光(near infrared fluorescence,NIRF)染料IR-783对胃癌细胞的特异性识别。将转染荧光素酶luciferase的人胃癌传代细胞SGC-7901皮下移植于裸鼠,7 d后分别使用NIRF染料IR-783和荧光素酶底物进行活体荧光成像和生物发光,测定肿瘤部位ROI(region of interest)值,连续检测并绘制NIRF强度与生物发光强度相关性曲线;选择前期建立的胃癌PDX(patient-derived tumor xenografs,PDX)模型免疫组织化学检测肿瘤组织中CEA与CK8/18的表达,确定移植瘤与原发肿瘤病理学一致性;将SGC-7901细胞和来自PDX模型的胃癌细胞分别培养24 h,分别加入线粒体示踪剂(mito-tracker)或溶酶体示踪剂(lyso-tracker),30 min后加入IR-783染料,在荧光显微镜下观察近IR-783染料在胃癌细胞中的结合部位;将正常胃上皮细胞分别与转染GFP的SGC-7901细胞和来自PDX模型的胃癌细胞共培养24 h后,加入IR-783染料,在荧光显微镜下观察近IR-783染料对胃癌细胞的特异性识别。活体成像结果显示,IR-783染料能够特异性的聚集于人胃癌裸鼠移植瘤部位;NIRF强度与luciferase强度的相关性达99%以上;PDX肿瘤与原发肿瘤中CEA与CK8/18表达均呈强阳性;荧光显微镜下检测到NIRF染料不仅能够特异性识别传代胃癌细胞,同时也能识别来自PDX模型的肿瘤细胞,并优先集聚在肿瘤细胞的线粒体与溶酶体中。近红外荧光染料IR-783能够特异性识别胃癌细胞,可用于胃癌模型的成像研究,是肿瘤治疗的一种潜在工具。

Near infrared fluorescent dye specific identification of gastric cancer cells

Objective To detect the specific identification of near infrared fluorescent (NIRF) dye by gastric cancer cells. Methods The gastric cancer cells SGC-7901 labeled with luciferase were transplanted into nude mice subcutaneously. Seven days later, the whole-body optical imaging was taken for mice bearing tumor by fluorescence and bioluminescent respectively, and the ROI (region of interest) value of the tumor sites were monitored constantly. The curve graph of the correction between the intensity of fluorescence and bioluminescent was drawn. The expression of CEA and CK8/18 in gastric cancer PDX (patient-derived tumor xenograft) model was detected by immunohistochemistry, to confirm the pathological consistency of transplantation tumor and primary tumor. After SGC -7901 and gastric cancer cells from PDX models cultured 24 hours respectively,mito-tracker orlyso-tracker was added,30minutes later, IR-783 was added to observe where it reached; Normal gastric epithelial cells were co-cultured with SGC -7901 labeled with GFP or gastric cancer cells from PDX models respectively. After 24 hours, NIRF dye IR-783 was added to observe the uptake of IR-783 dye by gastric cancer cells by a NIR fluorescence microscopy. Results The optical imaging results shown that NIRF dye can be specifically accumulated in the tumor site of the human gastric cancer xenograft model. The correlations between NIR fluorescence intensity and bioluminescent intensity are above 99%. The expression of CEA and CK8/18 in tumor tissues of PDX model demonstrated positive strongly. Both gastric cancer cell SGC-7901 and cultured gastric cancer cell from PDX model can be identified specifically by IR-783 dye. Conclusions NIRF dye IR-783 can be applied to distinguish gastric cancer cell excellently, and it is a promising tool for gastric cancer imaging and targeting.