As I walked in I was in awe, I imagined a research lab to be filled with beakers and microscopes with scientists walking around in lab coats but it wasn’t any of those things. But none of that is what caught my attention, instead, it was the back wall lined with 5 shelves, each shelf held 8-12 cages of mice, something close to 50 in total! 

While they might look cute and harmless, I would eventually learn that those tiny creatures were actually costing the US hundreds of millions of dollars every year in wasted research.

In recent decades there has been an increasing problem with reproducing results in humans from research done on rodents. The hundreds of millions being spent on this research produces no useful results in the end and is essentially wasted.

The wall filled with cages upon cages of mice isn’t an unfamiliar one in a biomedical lab. According to the National Association for Biomedical Research, 95% of the animals used by biomedical researchers are rodents, which translates to roughly 20,000,000 rodents being used annually for animal models in the United States alone! One would assume that if they are being used this often, they must be a very accurate model; however, after doing some research, to my surprise, the answer is no. 

The truth is that this is how it’s always been done and once people are set in their ways, it’s hard to change it.

The Animal Welfare Act of 1966, the only federal law in the United States that regulates the treatment of animals in research, doesn’t cover birds or rodents that were bred for the specific purpose of research. This basically means we can and have done anything and everything to mice in the quest for knowledge. We’ve developed technology to be able to modify mice’s genome to add or remove anything we want. We can make mice that glow in the dark, ones without an immune system, ones that have specific diseases or ones with tumors and the list goes on and on. 

Mice are very unique in the number of different options it gives researchers, but the problem is that the conclusions made from mice research don’t translate well into humans; after all, that is the end goal.

Mice share 97% of the same DNA as humans – this was one of the original reasons why mice were chosen as models for human biomedical research. However, we are starting to realize that 3% makes a whole lot of difference. Dr. Perlman compared the metabolic rates of humans and mice and found that a 30g mouse has a metabolic rate 7 times that of a 70kg human! Our metabolisms have a huge impact on how our bodies respond to different drug treatments and such a drastic difference between humans and mice leads to drastic differences as to the effectiveness of drugs.

Dr. Seok, a researcher studying human inflammatory disease, found that prior to 2013, 150 clinical trials had been conducted looking at different drugs to prevent inflammatory response in humans and none were found to be successful, even though all had passed animal testing.   

The problem has surpassed simply a waste of money and time; it has begun to threaten the lives of humans. 

In an extreme case, Dr. Attarwala reviewed a clinical trial conducted in 2006 looking at a new drug that showed promising results in animal models of increasing antibody function. The drug could have been used in the treatment of autoimmune diseases, a class of diseases in which one’s own immune system attacks itself. The drug was tested on mice and was found to be effective and showed no signs of adverse effects. Once the drug got to human clinical trials, a dose of the drug 1/500 of the amount given to mice was given to 6 volunteers. However, unlike the mice within a few hours, the volunteers were all in multi-organ failure and had to be rushed to the hospital. 

Most people would think that obviously the researchers had messed something up or done this intentionally, but after the incident, the United Kingdom’s Medicines and Healthcare Products Regulatory Agency led an investigation into the clinical trial’s procedures and ethics and found no flaws or malicious intent. The problem was that mice and humans just aren’t the same and we can’t be expected to react the same to medications either. The drug should have been tested on chimpanzees or another animal who’s reaction would have been similar to that of humans rather than rodents.   

Well, if we know there’s a problem, then why don’t we stop using mice? This is a tricky position that many researchers find themselves in nowadays. Many know that using mice for their research might make their findings irrelevant or flawed, especially when trying to make conclusions about humans. On the other hand, many researchers have been using mice their entire lives and it’s difficult to switch to other animal models when your expertise is already in mice. Since the majority of the scientific community also tests on mice, they can compare finding something that isn’t possible across species. 

However, the tipping factor comes down to money. Not only are mice cheaper to buy as well as to maintain, many times researchers aren’t able to obtain grants in order to fund their research unless the research is on mice. So if the research isn’t done on mice, it might not ever get done at all. Imagine how much knowledge we’ve lost out simply because we are afraid to branch out and try something new, even if it was more expensive. Some time ago research funded by the government is what leads to innovations that have since brought us: smartphones, GPS, supercomputers, Google Search Engine, MRIs, lactose-free milk, etc. things we now take for granted, but none would have been possible if at the time people were more concerned with saving money over innovation.

In the search for new medicines, the solution is as simple as funding better projects, even if it means funding less, quality or quantity. We know that what we are doing now isn’t working – we haven’t seen breakthroughs in discovering new treatments in decades. According to the CDC, our most effective treatment for Tuberculosis, a bacterial infection of the lungs, is Isonicotinic acid hydrazide, a treatment that we have been using since 1945. Who knows – maybe one of the projects that weren’t funded because testing on chimpanzees was too expensive might have been the one that discovered a cure for cancer.

By: K Patel

References

Attarwala, H. “TGN1412: from discovery to disaster.” Journal of Young Pharmacists 2.3 (2010): 332-336, https://www.sciencedirect.com/science/article/abs/pii/S0975148310230248.

“Treatment for TB Disease.” Centers for Disease Control and Prevention, 5 Apr. 2016, www.cdc.gov/tb/topic/treatment/tbdisease.htm.

“Laboratory Animals.” NABR, www.nabr.org/biomedical-research/laboratory-animals/species-in-research/.

Perlman, Robert L. “Mouse models of human disease “An evolutionary perspective.” Evolution, medicine, and public health 2016.1 (2016): 170-176, https://academic.oup.com/emph/article/2016/1/170/2802638.

Seok, Junhee, et al. “Genomic responses in mouse models poorly mimic human inflammatory diseases.” Proceedings of the National Academy of Sciences 110.9 (2013): 3507-3512, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3587220/?tool=pmcentrez&report=abstract.

Image Credit

Black and White Mouse 51340, Pexels, https://www.pexels.com/photo/black-and-white-mouse-51340/