Colorado State University researchers are finding new ways to treat cancers in humans and pets, but they are doing it with a specimen not of those species: mice.

Researchers at CSU’s Laboratory Animal Resources are injecting mice with tumors to study how different cancer treatments can be effectively be used in humans.

“What we are trying to do is increase efficiency,” said Dr. Daniel Gustafson, the director of research and professor of pharmacology and biomedical engineering. “(We want to) increase the time of remission and time of cancer treatment and number of cures and try to increase how well a treatment works, but also decrease the toxic effect of these long term drugs.”

“A lot of what we do is not only how to make drug treatment better in regards to outcomes for the patients but also making the treatments less morbid in regards to less toxicity associated with the drug itself,” Gustafson said.

The tumor models are typically created by injecting tumor cells under the skin with a syringe and needle similar to a vaccination you might get from your physician, wrote Dr. Lon Kendall, director of the Laboratory Animal Resources, in an email to the Collegian.

“Several of the tumor cell lines are labeled with a fluorescent marker that can be seen with a special imaging machine so that the tumor progression can be easily monitored for each animal,” Kendall said.

The researchers use mice instead of rats or other rodents because the mice are smaller, easier to manipulate genetically, and are more similar the humans and dogs genetically.

The mice used, a mutant species called nude mice, have no immune system, which makes them useful for research because their immune system will not attack the cancer, allowing researchers to study the cancer and treatment.

“They look like the ugly nude hairless cat from the Austin Powers movie,” Gustafson said. “But they are good to grow the tumor in because the responses you are looking at are true of the human disease.”

“We are very careful about that in terms of the doses that we give the mice are appropriate and reflective of what you can give a human or a dog being treated with cancer so a lot of what I have done is comparative to make sure what they are given is reflective of what you can get of humans or dogs,” added Gustafson.

Though cancer treatment in mice isn’t a surefire way to treat cancer in humans or pets, having some success in the mice gives researchers a good idea of what will work well in humans.

“Studies have been done that mouse models for human cancer may not be good in humans, but if you can’t make it work in the mouse, it virtually isn’t going to work in the human or dog,” said Douglas Thamm, associate professor of oncology and a veterinarian working on the research with Gustafson.

Thamm said that one of the biggest problems with the mouse model research is the lack of variability in the mice.

“The mice are genetically identical, and that’s not the way humans and dogs are,” Thamm said. “Mice are likely to behave the same way, with no variability [in their genetics].”

“We need to take [the research] we get with a grain of salt,” added Thamm.

However, both Thamm and Gustafson agreed that the mice models are useful for research.

“It is a means to an end,” Thamm said. “We get the answer with the mice and we save a lot of time, money and resources, you can impact that. I think doing responsible science and getting good answers in the most appropriate model is what is most satisfying to me.”

Collegian Reporter Taylor Pettaway can be reached at news@collegian.com.