Patient-derived Xenograft Modeling: A Technique to Generate Melanoma Mouse Models

- In patient-derived xenograft or PDX models, tumor cells or fragments from human patients get implanted into immunodeficient recipient mice. PDX models simulate the biological and molecular characteristics of the human tumor microenvironment. To develop a melanoma PDX model, first, harvest tumor tissue from a melanoma patient. Remove the necrotic tissue from the tumor. Mince the tumor to obtain a slurry. Next, prep an anesthetized recipient mouse in a prone position. Make a small surgical incision on the dorsal skin. Gently cut the fascial membrane or the layer of loose connective tissue just underneath the skin. This separates the skin from the underlying muscle layers and helps create a pocket for tumor implantation.

Gently transfer the tumor slurry into the pocket. Now, administer an artificial extracellular matrix into the pocket to stabilize and secure the implanted tumor cells. Surgically staple the wound and allow the mouse to recover. Monitor the recipient mouse weekly to observe the growth of xenograft tumor. In the following protocol, we will demonstrate the subcutaneous implantation of patient-derived melanoma tumor cells into an immunodeficient NSG mouse to generate me