Hoffman Robert M
AntiCancer, Inc., San Diego, CA 92111, USA.
Curr Top Dev Biol. 2005;70:121-44. doi: 10.1016/S0070-2153(05)70006-5.
This chapter describes a new cell biology where the behavior of individual cells can be visualized in the living animal. Previously it has been demonstrated that fluorescent proteins can be used for whole-body imaging of metastatic tumor growth, bacterial infection, and gene expression. An example of the new cell biology is dual-color fluorescence imaging using red fluorescent protein (RFP)-expressing tumors transplanted in green fluorescent protein (GFP)-expressing transgenic mice. These models show with great clarity the details of tumor-stroma interactions and especially tumor-induced angiogenesis, tumor-infiltrating lymphocytes, stromal fibroblasts, and macrophages. Another example is the color coding of cells with RFP or GFP such that both cell types can be simultaneously visualized in vivo. Stem cells can also be visualized and tracked in vivo. Mice in which the regulatory elements of the stem cell marker nestin drive GFP expression enable nascent vasculature to be visualized interacting with transplanted RFP-expressing cancer cells. Nestin-driven GFP expression can also be used to visualize hair follicle stem cells. Dual-color cells expressing GFP in the nucleus and RFP in the cytoplasm enable real-time visualization of nuclear-cytoplasm dynamics including cell cycle events and apoptosis. Highly elongated cancer cells in capillaries in living mice were observed within skin flaps. The migration velocities of the cancer cells in the capillaries were measured by capturing images of the dual-color fluorescent cells over time. The cells in the capillaries elongated to fit the width of these vessels. The use of the dual-color cancer cells differentially labeled in the cytoplasm and nucleus and associated fluorescent imaging provide a powerful tool to understand the mechanism of cancer cell migration and deformation in small vessels.
本章描述了一种新的细胞生物学，其中单个细胞的行为能够在活体动物中可视化。此前已经证明，荧光蛋白可用于转移性肿瘤生长、细菌感染和基因表达的全身成像。新细胞生物学的一个例子是双色荧光成像，即将表达红色荧光蛋白（RFP）的肿瘤移植到表达绿色荧光蛋白（GFP）的转基因小鼠中。这些模型非常清晰地展示了肿瘤与基质相互作用的细节，特别是肿瘤诱导的血管生成、肿瘤浸润淋巴细胞、基质成纤维细胞和巨噬细胞。另一个例子是用RFP或GFP对细胞进行颜色编码，这样两种细胞类型都能在体内同时可视化。干细胞也能在体内可视化并追踪。在干细胞标志物巢蛋白的调控元件驱动GFP表达的小鼠中，新生血管与移植的表达RFP的癌细胞相互作用的过程得以可视化。巢蛋白驱动的GFP表达还可用于可视化毛囊干细胞。在细胞核中表达GFP而在细胞质中表达RFP的双色细胞能够实时可视化核质动态，包括细胞周期事件和细胞凋亡。在活体小鼠的皮瓣内观察到了高度细长的癌细胞位于毛细血管中。通过随时间捕捉双色荧光细胞的图像，测量了癌细胞在毛细血管中的迁移速度。毛细血管中的细胞会伸长以适应这些血管的宽度。使用在细胞质和细胞核中进行差异标记的双色癌细胞以及相关的荧光成像，为理解癌细胞在小血管中的迁移和变形机制提供了一个强大的工具。
