How and Why Rat Cancer Models are Used

Early research studies

Early in the previous century it was observed that rats exposed to a tapeworm would characteristically develop a certain cancer.  Efforts to further investigate this phenomenon led researchers to reproduce the sarcomas using various strains of rats. It was observed that differences in the rates of the disease among the rats might provide useful insights.  This led the researchers to develop a number of inbred rats to use in their experiments.

With this model system in hand, the process of the development of these cancers began to yield results. The success of this work, combined with advances in husbandry and breeding of rats, enabled research on other aspects of cancer using rats as a model system to ensue.

Advantages of rats

Researchers worldwide have since made remarkable progress on understanding cancer triggers, mechanisms, and therapeutics using rat model systems.  In the last several years, they have integrated genetic mapping, gene expression, and computational analysis to discover the genetic bases of a number of polygenic traits in rats, including breast cancer.  The gene associations in rats were closely related to human breast cancer.  With continued international investment in the research infrastructure for rat experimentation, the pace of discovery will increase further.

Examining similarities and differences in cancer development between rats and mice, and among human, mice, and rats provides even more evidence for the importance of an observation about cancer than does investigation of a single species.  Many advances in rat genomics, strain distribution, databases and other community resources makes the cross-species comparative medicine approach far more feasible, especially now that the rat germline is accessible to manipulation.  Until recently, researchers lacked some of the most useful tools to alter the genes of rats as they are able to in mice.  Thus the laboratory mouse emerged as the leading mammal for experimental genetics, but now rat models with similar genetic alterations as mice and human will become available.

To learn more about the foundations and utilities of these different types of models you can explore the navigation links at the left.