Research Roundup: Skin bacteria may protect against cancer, rats used to detect TB and more!

Welcome to this week’s Research Roundup. These Friday posts aim to inform our readers about the many stories that relate to animal research each week. Do you have an animal research story we should include in next week’s Research Roundup? You can send it to us via our Facebook page or through the contact form on the website.

  • Bovine embryos as a model system. A new study from Ludwig-Maximillians University (LMU) in Munich shows the advantages of studying multiple types of mammals to understand early mammalian (e.g. human) development. For many years scientists utilized advanced genetic techniques developed with mice to study early development in mammals. Now with the CRISPR-Cas9 technique, scientists can manipulate the genetics of many other mammals. In this new study, scientists compared bovine, mouse, and human blastocyst model systems that delete the OCT4 gene, which is critically involved in the self-renewal of undifferentiated embryonic stem cells. Comparing these systems, they determined that the bovine model worked similarly to the human model and in sharp contrast to the mouse model. Thus, bovine embryos are an ideal alternative model for understanding mammalian development, and should be considered when comparing studies from mice and humans. Published in PNAS.
Tupanvirus – Image: Microscopy Center of UFMG, Brazil
  • Gene therapy in dogs treats macular degeneration. Researchers at the University of Pennsylvania were able to reverse a type of macular degeneration in dogs by correcting a version of the BEST1 gene, which is mutated in the disease. Best disease is strikingly similar between humans and dogs and results in vision loss in the central portion of the eye. By delivering a healthy version of the BEST1 gene to canines, researchers were able to correct both mild and severe eye lesions that result due to the mutated gene. This correction lasted for five years. Dr. Guziewicz, lead research, stated that “we have demonstrated that there is a therapy that is working in a large animal model. Following safety studies, a human clinical trial could be less than two years away.” Published in PNAS.
  • Rats could be used to reduce global TB burden. Tuberculosis (TB) can be prevented and cured, but it is difficult to detect. Because of this, researchers in Tanzania are developing a new method where rats can be used to “sniff out” samples that are infected with TB bacteria — similar to how dogs have been used to “sniff out” drugs. So far, the rats are able to screen 100 samples in 20 minutes with an accuracy of 70%. This is in contrast to resource-stretched labs that can test 15-20 samples daily and with many cases undetected — in 2016, 40% of new TB cases were undetected. While more research is needed to refine this method, it is a promising first step.
Nonprofit APOPO is researching the use of rats to sniff out tuberculosis. Photo by: Briana Marie
  • Skin bacteria may protect against cancer. Skin cancer is the most common form of cancer in the United States, with an estimated 9,500 Americans diagnosed every day. Researchers have discovered a new strain of skin bacteria that kills several types of cancer cells, but does not harm normal cells. The strain S. epidermidis produces the chemical compound 6-N-hydroxyaminopurine (6-HAP), that, when absent in mice, resulted in the development of tumors after exposure to cancer-causing ultraviolet rays. Additionally, mice injected with 6-HAP every 48 hours over a two-week period showed no toxic effects. When transplanted with melanoma cells, the 6-HAP-injected mice showed a 50% reduction in tumor size compared to control mice. Published in Science Advances.