When primary tumor cells are grown in vitro, they are exposed to an environment that is vastly different from the tumor environment they originate from. The in vitro environment can lack the three-dimensional structure of the tumor, other cell types present within the tumor microenvironment, and important growth factors. Humanized mouse models allow researchers to study primary tumor cells in a more natural environment. With further development of several strains of immune-deficient mice, the mouse model allows for observation of the patient-derived tumor xenograft (PDTX) growth alone as well as in the presence of a human immune system. We describe how this can be accomplished with injection of single cell suspension of melanoma tumor cells into immune-deficient NOD-scid IL2Rγnull (NSG) mice. We also describe how tumor cells and immune cells can be co-injected, using Winn assay, and the possibility to use that method to study immune therapies for cancer.
Keywords: Immune deficiency; Melanoma; NSG mice; Tumor-infiltrating lymphocytes; Xenograft.