Model systems

Systems used to test hypotheses on what interventions may work with humans. In vitro (outside of a living being) systems are cultured cells, generally from humans. The more recent type of in vitro system is 3D cell cultures created from human cells, which are spherical in shape and thought to more closely resemble human tumours. In vivo models (models in living beings) are of two main types:

  • patient-derived or zenograft models, where human cancerous cells or tissues are implanted into a mouse or other animal to simulate human tumour biology
  • transgenic/genetically engineered models, where new or altered genes are inserted into the genome of a mouse or other animal by genetic engineering techniques, thereby making them more susceptible to cancer

Although mouse models are the mainstay of cancer research, zebrafish, a member of the minnow family, have become a popular model organism in cancer research and Canada has several leading experts. Zebrafish grow quickly, are nearly transparent allowing their internal structures to be easily examined, have had their genome fully sequenced, and share a similar genetic structure to humans. [From]