Experimental and translational breast cancer research is currently hampered
by the limited number of in vivo models available that accurately represent the full
spectrum of human breast disease. At least six unique classes of human breast cancers
have been identified based on gene expression analyses. While immortalized human
breast cancer cell lines as well as mouse in vivo models have been developed to
represent many of these classes, in vivo xenograft models are rapidly becoming a viable
preclinical experimental platform for both testing of experimental therapeutics and the
mechanistic studies of tumor cell regulators. These models include viral transductioninduced,
human cell line xenografts, and more recently, primary tumor xenografts
established directly from patients. Each model type is endowed with its own set of
advantages and limitations. However, as a collection, xenograft models of human breast
cancer represent powerful tools for preclinical analysis.
Keywords: Breast cancer, drug discovery, estrogen receptor, human cancer cell,
immunocompromised mice, in vitro model, in vivo model, progesterone receptor,
translational model, xenograft.
