March: Animal Models

THE Role of animal models in cancer research

Sawyer Badiuk MSc.
March 15, 2021

Disclaimer: The following blog contains information about the use of animal models in research that some readers may find disturbing. 

Cancer affects most of the world in one way or another. As cancer researchers, we understand the importance of knowing as much as possible about the disease in order to develop treatments and help patients. However, cancer is not a simple disease and identifying causes, diagnoses, and treatments can take years of investigation by scientists and medical professionals. Medical research has, and continues to impact our greatest medical problems, and animal models are an essential part of this research. 

An animal model by definition is a non-human species used in medical research because it either has the disease under investigation or a similar disease that mimics aspects of the disease found in humans. These models are crucial for studying disease development, progression and diagnosis and for evaluating new treatments before being given to humans. The main reasons that animal models are used in research are shown in Figure 1.

Figure 1: Highlighting the role of animal models used in research

Animal models offer an accelerated timeline compared to humans since they have shorter lifespans, they reproduce more quickly, and mimic faster disease progression. This means results can be obtained more quickly compared to a similar analysis conducted in humans. Furthermore, animal models allow for control of more variables than with humans. For instance, in a laboratory setting the animal’s diet and environment can be controlled. Ultimately, the main reason that animal models are beneficial to medical research is because they represent actual living systems and will ideally deliver a better prediction of what will occur in people, as opposed to cells in a petri dish or computer models. 

Animal models are a valuable tool in research both for learning more about the biology and genetics of human cancers as well as in preclinical studies of cancer prevention and treatment. There are many discoveries and advances that have been made with cancer that are attributed to the use of animal models; immunotherapy is a prime example. Immunotherapy is a type of cancer treatment that boosts the body’s immune system to help fight cancer. Immunotherapy relies on the response of the immune system, and therefore researchers need an active immune system in order to fully understand its interaction with cancer and within the body. Over the years, animal models have allowed for ground-breaking work on the immune system and immunotherapy. 

In 2018, James Allison and Tasuku Honjo were awarded the Nobel Prize in Medicine for their scientific discovery of immunotherapy. Both researchers discovered proteins that function similar to a brake for the immune system. They saw and investigated the potential of releasing this brake and unleashing the body’s natural defense against cancer. This work has been said to have revolutionized cancer treatment and would not have been possible without the use of animal models. Immunotherapy has changed how cancer treatments are approached, and currently there are numerous clinical trials evaluating its combined effect with other therapies such as radiation and chemotherapy. Clinical trials are research studies that are performed with patient volunteers that let researchers know if a new drug, medical device, or treatment is safe and effective in humans. 

It is important to note that animal models are never the first step in research. For medicines and treatments to be considered for investigation with animal models, researchers must have an understanding of the treatments’ potential effects on an organism. Researchers achieve this understanding by performing initial testing on non-living patient substitutes or in vitro using tissues and cells. Throughout medical research, the use of animal research is regulated and requires approval by Animal Ethics Committees responsible for the protection of the animals used in research. Researchers that use animal models realize that this work is privileged and ensure they treat animals with the respect and care the animals deserve, performing their work in an ethical manner. 

To sum up the main points, cancer is an incredibly complex disease and animal models provide researchers the ability to learn more about it. Overall, the use of animal models can be the key to discovering new treatment approaches to enhance patient outcomes, improve disease detection to provide a more accurate prognosis or allow for earlier treatment, and to determine the cause of different tumour types to help discover new ways to prevent cancers.