Mouse cancer models
One of the most widely used systems of models to study cancers is the mouse. Decades of breeding to develop and identify characteristic strains, combined with more recent technologies to alter the genome structure or individual genes, enable researchers to precisely target genes and pathways of interest for investigation.
For example, one of the early applications of genetic modifications in mice was to create “oncomice” that were intended to develop cancer. It was first shown that introduction and expression of oncogenes in normal tissues initiated tumor development. Later the creation of knockout mice lacking tumor suppressor genes also demonstrated that cancer ensued. These strategies firmly established mice as a means to generate model systems for the study of cancer, and subsequent generations of mice, technology, and scientists continue to make progress in our understanding of the mechanisms of cancer.
Transplants of cells or tissues also provide a means of understanding tumor biology, and have for decades. Early use of these types of models in mice was pursued by the National Cancer Institute in groundbreaking projects that included 60 types of tumor transplants. When it was determined that transplantation of human tumors into various immune-compromised mice (xenograft techniques) could be valuable and effective, many investigations explored that path as well. Researchers also use defined mouse tumors into mouse models, and sometimes other species’ tumors as well. There are both benefits and drawbacks to all of these techniques, and we are learning a great deal from these methods.
Many strains of inbred mice are also available for the study of cancer biology. Some strains have been established that may characteristically develop cancers in certain tissues or stages; others are used as a defined background for exposure to carcinogenic agents.
Many existing models would provide a suitable foundation to study the onset of cancer, aspects of tumor biology, or therapeutic interventions. To find these useful models, explore the section about Acquiring Models. If the research directions demand development of new models of this nature, examine the navigation option in the left sidebar to consider various strategies and tools. Researchers are always eager to build better mice.