MICE STUDIES ARE A PRECURSOR (PRE CLINICAL STUDIES) IN BRINGING NEW DRUGS INTO HUMAN CLINICAL STUDIES
Mice fill a special and important role in medical research. Like humans, mice are mammals, and their bodies undergo many similar processes, such as ageing, and have similar immune responses to infection and disease. Their hormone (endocrine) systems are a lot like ours, too. They’re also one of the first species — along with humans — to have had their complete genome sequenced. From this, we’ve learned they share approximately 80 per cent of their genes with us.
Many important breakthroughs in medical science have come from studies carried out in mice. These include treatment for acute promyelocytic leukemia — a form of blood cancer that affects young adults and is now one of the most treatable forms of the disease — as well as gene transfer protocols for cystic fibrosis, which are currently being tested.
Nobel-winning scientific achievements such as the discovery of vitamin K, the development of the polio vaccine, the invention of monoclonal antibody technology now used for cancer treatment, and the unravelling of how neurons talk with each other in the brain all would not have occurred without mice.
Researchers use many other systems for clinical investigation — such as cell culture, explants, spheroids, in silico modeling and organ culture—but a mouse offers what these alternatives cannot: a whole, living organism in which to investigate disease, response to treatment, development of cancer and other basic research questions.
Physiologically, mice are very like humans, albeit around 3,000 times smaller (Partridge, 2013) but with similar basic body functions such as blood cell production (haematopoiesis), digestion, respiration and the cardiovascular system. Although differences do exist, mice respond similarly to humans when they are sick or undergo treatment.
Mice also breed easily, with short pregnancies and large litter sizes that are important in helping researchers create their own modified mice. However, most laboratories in Canada source non-specialized mice from commercial breeders, receiving purpose-bred animals with a full breeding history. For researchers, this is very important: Working with animals that show very little difference among individuals increases the value of experimental results, since all the animals respond the same. For even more consistency, we've also been able to clone mice since 1997.
Mice are also extremely diverse, meaning that commercial breeders can select for individual traits to create inbred strains with unique characteristics. For example, the CBA mouse has a low incidence of mammary tumour (breast cancer) development, whereas the BALB/c nude mouse is immunodeficient, since it lacks a thymus. These kinds of breed-specific properties are useful, as they allow scientists to focus on specific diseases. Researchers choose mdx mice, lacking mature dystrophin muscle protein, as models for studying Duchenne Muscular Dystrophy, while others choose non-obese diabetic (or NOD) mice as good models to study new treatments for autoimmunity
In addition to breeding strategies based on natural variations, researchers also have a number of genetic modification tools available. Since mice share approximately 80 per cent of their genes with humans, modifying mouse DNA is a powerful method for creating animal models of human disease
Even though there are key differences between the mouse and human genomes, those differences aren’t enough to discount the value of mice to the study of human disease. Although regulatory elements might be in different places, shuffled around in the 75 million years since mouse and human evolution parted, their basic functions are preserved.
Penicillin, originally discovered by Alexander Fleming in 1928, did not appear as a lifesaving medical treatment until the work of Howard Florey, who tested its safety and efficacy in mice over ten years later. Without mice (and other animals) in research, human and animal medicine would be without penicillin, vaccines for polio and meningitis, monoclonal antibody therapy, a cure for acute promyelocytic leukemia, and gene transfer for cystic fibrosis.
Scientists are always looking for alternatives to the use of animals in clinical reseAarch, but the role of mice as experimental models for human disease is, as yet, irreplaceable. Even with differences between the two species, carrying out basic research in humanized mouse models of disease gives scientists valuable information. Using mice as surrogates allows researchers to first see how patients might respond to treatment before giving them the drug — a vital step in ensuring patient safety.
SPL Price at posting:
45.0¢ Sentiment: Buy Disclosure: Held
A personalised tool to help users track selected stocks. Delivering real-time notifications on price updates, announcements, and performance stats on each to help make informed investment decisions.
(20min delay)