近红外荧光染料IR-780在肾透明细胞癌中的成像特征

Imaging characteristics of near-infrared fluorescent dye IR-780 in clear cell renal cell carcinoma

背景:课题组研发了一组可以直接与肿瘤细胞结合的有机近红外荧光染料,IR-780是其中的优秀代表。目的:评估近红外荧光染料IR-780在肾透明细胞癌中的特异性成像效果。方法:取对数生长期的人肾透明细胞癌细胞786-O、ACHN和正常人胚肾细胞293T,分别与20μmol/L荧光染料IR-780共孵育30 min,激光共聚焦显微镜下观察染料在肾透明细胞癌细胞中的成像。取对数生长期的人肾透明细胞癌细胞786-O,与20μmol/L近红外荧光染IR-780共孵育30 min,激光共聚焦显微镜下观察染料在细胞线粒体与及溶酶体内的定位。在人血液样本中分别加入10,100,1 000,10 000个DAPI染色的人肾透明细胞癌细胞786-O,分离培养各组单个核细胞,再与20μmol/L近红外荧光染料IR-780共孵育30 min,激光共聚焦显微镜下观察DAPI和IR780双阳性染色细胞。结果与结论:(1)近红外荧光染料IR-780具备使多种肾透明细胞癌细胞显像的能力,对正常肾胚上皮细胞则无此能力;(2)近红外荧光染料IR-780与溶酶体或线粒体均有明显的染色重叠,验证了IR-780在膜性细胞器线粒体和溶酶体内的选择性聚集作用;(3)近红外荧光染料IR-780可检测到血液中微量的肾透明细胞癌细胞;(4)结果表明,近红外荧光染料IR-780能够在肾透明细胞癌细胞内特异性蓄积,可用于血液中肾透明细胞癌细胞的特异性诊断。

BACKGROUND： The near-infrared fluorescent dyes that directly bind to tumor cells have been developed, and IR-780 stands out. OBJECTIVE： To evaluate the specific imaging effect of near-infrared fluorescent dye IR-780 in clear cell renal cell carcinoma（ccRCC）. METHODS： Human ccRCC cells 786-O, ACHN and normal human embryonic kidney 293 T cells in logarithmic growth phase were incubated with 20 μmol/L IR-780 for 30 minutes. The localization of the dye in ccRCC was observed by laser confocal microscopy. Human ccRCC cells 786-O in logarithmic phase was incubated with 20 μmol/L IR-780 for 30 minutes. The localization of the dye in mitochondria and lysosomes was observed under confocal laser scanning microscope. 10, 100, 1 000 and 10 000 DAPI-stained human ccRCC cells 786-O were respectively added to human blood samples. The mononuclear cells in each group were isolated and cultured with 20 μmol/L IR-780 for 30 minutes. DAPI and IR-780 double positive cells were observed under confocal laser scanning microscope. RESULTS AND CONCLUSION： IR-780 possessed the ability to visualize a variety of ccRCC cells, but not for normal renal epithelial cells. IR-780 had obvious overlapping staining in lysosomes or mitochondria, indicating its selective accumulation in mitochondria and lysosomes in the organelles. IR-780 could detect a small amount of ccRCC in the blood. These results suggest that the near-infrared fluorescent dye IR-780 can specifically accumulate in ccRCC cells, which can be used for specific diagnosis of ccRCC.