Chicken Chorioallantoic Membrane-based Cancer Modeling: An In Ovo Model to Study Cancer Cell Tumorigenesis and Metastasis

The chicken chorioallantoic membrane, or CAM, is a highly vascularized membrane found in the eggs of certain vertebrates like chickens. This extra-embryonic membrane lines a non-vascular shell membrane and functions as the site of exchange of gaseous oxygen and carbon dioxide between the embryo and the environment.

To generate a CAM cancer model, begin with a viable, fertilized chicken egg bearing a fully developed CAM with a partially opened shell that exposes its branching vasculature. Confirm that the CAM is detached from the shell membrane.

Place a sterile non-stick ring over a blood vessel branch point. Using a glass rod, gently rub the membrane inside the ring to scrape its outer epithelial layer and expose the underlying mesodermal layer carrying the vasculature. Pipet a chilled suspension of cancer cells mixed with a suitable extracellular matrix into the ring. The ring restricts cellular dispersal.

Allow the matrix to solidify to secure the cells within. Seal the eggshell opening and incubate the egg under appropriate conditions. The dense vasculature within the mesodermal layer supplies oxygen and essential nutrients to the cancer cells, thus providing a suitable microenvironment for their growth and expansion.