Biology Reference
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Figure 11.1 Carcinoma cells in the primary tumour are concentrated around blood vessels
as a polarized cell layer. Rat mammary carcinoma cells (MTLn3) that stably express GFP
to define the cell volume were injected into the mammary fat pad of a rat to form a tumour.
Blood vessels were labeled by IV rhodamine-dextran. Imaging of the primary tumour near
blood vessels demonstrates that the carcinoma cells (brackets) have accumulated around a
blood vessel (dashed lines mark vessel walls) with their pseudopods pointing toward the
vessel (arrows). Carcinoma cells more distant from the vessel are not polarized toward the
vessel (arrowheads). These results suggest that a chemotactic signal such as EGF is
associated with blood vessels in the primary tumour. (This figure has been modified from
Wyckoff et al., 2000) (A colour reproduction of this figure can be found in the colour plate
section)
(Kaufmann et al., 1994), and experimental expression of the EGF receptor in
MTC cells increases chemotactic responses to EGF in vitro and metastatic
ability in vivo (Kaufmann et al., 1994; Wyckoff et al., 1998, 2000). Therefore,
chemotaxis to blood vessels, mediated by the EGF receptor, is important in
