Humanization of the mouse mammary gland.

Although mouse models have provided invaluable information on the mechanisms of mammary gland development, anatomical and developmental differences between human and mice limit full understanding of this fundamental process. Humanization of the mouse mammary gland by injecting immortalized human breast stromal cells into the cleared murine mammary fat pad enables the growth and development of human mammary epithelial cells or tissue. This facilitates the characterization of human mammary gland development or tumorigenesis by utilizing the mouse mammary fat pad. Here we describe the process of isolating human mammary stromal and epithelial cells as well as their introduction into the mammary fat pads of immunocompromised mice.