The use of fluorescent proteins for intravital imaging of cancer cell invasion

Abstract

The analysis of cancer cell behavior in the primary tumor in living animals provides an opportunity to explore the process of invasion and intravasation in the complex microenvironment that is present in vivo. In this chapter, we describe the methods that we have developed for performing intravital imaging of mammary tumors. We provide procedures for generating tumors through injection of tumor cell lines, and multiphoton imaging using a skin-flap tumor dissection and a mammary imaging window.

Fig. 1

Mammary imaging window design. (a) Overview of the construction with two spacer rings attached, with a coverslip mounted on the top. (b) Front view of the coverslip. (c) Alternative design of the window, where the bottom ring is curved to better accommodate a growing tumor. (d) Bottom view of a completed window ready for implantation. Adapted from (27).

Fig. 2

Imaging box used in combination with the mammary imaging window. (a) This general imaging box schematic can be optimized to fit any microscope stage. (b) A photograph of a currently-used version of the imaging box.

Fig. 3

Example of use of the mammary imaging window. When using the mammary imaging window and imaging box, multiple imaging sessions can be done using the same animal. Using expression of a photoconvertible protein, Dendra2, one can monitor the same cell population over 7 days (168 h).