Scientists at the Netherlands Cancer Institute research the causes and treatments of cancer, in addition to developing new treatment methods. They often study (cancer) cells that grow in lab dishes (2D), or conduct analyses on 3D structures called organoids. Because cancer is a very complex disease that often involves different cell types, tissues and organs, 2D and 3D culture models fall short in certain stages of the research. That is why they also perform research with mice and rats at the Animal Facility.
These animal tests are strongly regulated and require specialized knowledge. Europe has very strict rules: only if there are no other ways to answer a research question, scientists are allowed to use animals. In addition to this rule, various permits are required, as well as protocols and instructions on handling animals in research.
Concerning that last factor, Els Hermans, head of the facility, has now bundled all existing knowledge and experience together with her colleagues throughout Europe in a clear guideline that offers tools for anyone working with lab animals in cancer research. “With this step-by-step plan, everyone has all the information required to track animals very accurately,” she says. “This allows them to see which effects they can expect from the tumor growth in advance, how they can detect them, and what they should do next.”
Researcher studying cancer in a mouse always have to keep an eye on how the animal feels and how the tumor develops. The symptoms you can expect, and how you should deal with them, varies enormously depending on the mouse model and the tumor type. Is a mouse with ovarian cancer not feeling well? You can tell by the fact that the animal no longer takes good care of itself, and develops a rough and somewhat messy coat. If that's the case, the animal needs more supervision. The same happens when the mouse suddenly displays less activity and has a thick belly. Then it may suffer from abdominal fluid and the researcher can decide to drain it.
“We previously had to sift through a huge pile of scientific publications before starting new animal research on, for example, brain cancer,” says Hermans. “You would eventually find the required information, but it would be spread out across dozens of articles, and it was rarely complete or applicable in practice. That is why we have bundled these existing publications, supplemented with practical experience.”
For this collaboration, Hermans and her colleague Stéphanie De Vleeschauwer of KU Leuven in Belgium brought together many international experts, including academics from Spain, Ireland, and Austria, as well as pharmaceutical companies and the international consortia EurOPDX and INFRAFRONTIER.
Hermans: “This guideline will form the basis for a renewed code of practice this year, which indicates how we treat rats and mice in cancer research in the Netherlands. We are already speaking with the NCAD, the National Committee for Animal Testing Policy of the government.”