Near-Infrared Fluorescent Labeled CGRRAGGSC Peptides for Optical Imaging of IL-11 Receptor Subunit α in Athymic Mice Bearing Tumor Xenografts
- Available Online: 2019-05-29
Abstract: The interleukin-11(IL-11) and the IL-11 receptor subunit αhave been demonstrated to regulate the invasion and proliferation of tumor cells. This study was initiated to evaluate an noninvasive imaging of IL-11Rαexpression in breast tumors using near-infrared (NIR) fluorescent dye Cy7-labeled IL-11 mimic CGRRAGGSC. This work evaluated the IL-11Rα expression of breast tumor cells and the binding status of CGRRAGGSC peptide to IL-11Rα in vitro and in vivo by using western blots, immunofluorescence staining and near-infrared fluorescence imaging. Western blot and immunohistochemistry analysis showed that IL-11Rα was overexpressed in breast tumor cells (MCF-7). The cell-binding assay demonstrated specific binding of c(CGRRAGGSC) to MCF-7 cells in vitro. In vivo imaging results showed that NIR fluorescent signals of Cy7-CGRRAGGSC were selectively accumulated in tumor and metabolic organs. While in the blocking experiment, free CGRRAGGSC obviously blocked the concentration of the Cy7-CGRRAGGSC in the tumors. These results suggested that IL-11Rα may be used as a potential target for noninvasive imaging in IL-11Rα overexpressed tumors. Furthermore, the imaging agent of near-infrared fluorescent dye Cy7 labeled c(CGRRAGGSC) is suitable for IL-11Rα expression imaging study in vivo.