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.
- Researchers at Johns Hopkins University (JHU) have identified a gene that encourages the growth of intestinal stem cells. This gene, HMGA1, also encourages the growth of the cells that support these stem cells, and previously has been identified as essential for tumor growth in many human cancers. This discovery came about somewhat serendipitously, when Dr. Linda M.S. Resar, Professor of Medicine, Oncology, and Pathology at the Institute for Cellular Engineering at JHU, and her team were studying genetically engineered mice that express high levels of HMGA1. Resar’s group also noticed that these animals’ intestines were much larger and heavier than wild-type (control) mice, and further exploration revealed that their intestines were also riddled with polyps, which are abnormal growths projecting from the intestinal lining that can develop into cancer. Resar and her colleagues isolated stem cells from both transgenic and wild-type mice, and found that those carrying the HMGA1 transgene multiplied far more quickly, and that the HMGA1 gene was able to turn on several genes in another pathway involved in developing proteins required for stem cell activity. Because stem cells need a “niche” to survive and maintain their undifferentiated state, the researchers also studied HMGA1’s role in niche cells, and found that the gene was also increasing the number of niches cells, called Paneth cells, that are known to support intestinal stem cells. Because of its known role in tumor growth, Resar says that studying HGMA1’s role in both cancer and stem cells could eventually lead to clinical applications. Turning down its overexpression in cancer could disrupt cancer growth and prevent tumor progression, while turning up its expression could help researchers grow new intestinal tissue for patients suffering from, for example, irritable bowel syndrome. The study was published April 28 in Nature Communications.
- Pittsburgh polio vaccine pioneer dies at 96
Dr. Julius S. Youngner, like many scientists, pursued a passion to help people. His interest in infectious disease led him to join Dr. Jonas Salk’s vaccine team in the quest to fight polio. Polio crippled an average of 1,000 children every day in more than 125 countries during its peak. The polio vaccine ended this serious illness that plagued the United States from the late 1800s to the mid-20th century. This life saving work could not have been possible without research animals including mice and monkeys.
- California National Primate Research Center (CNPRC) Successfully Demonstrates Gene Editing in Nonhuman Primates
Collaborating scientists at the CNPRC efficiently used CRISPR/Cas9 to move one step closer to the development of gene-edited monkeys for study of human disease. A recent publication in Human Molecular Genetics described the successful editing of the genes of monkey embryos with 85 percent efficiency. CRISPR is a DNA segment that scientists can manipulate using a system known as CRISPR/Cas9 to edit the genes within organisms. CRISPR/Cas9 targets specific genes that are linked to particular diseases by utilizing a single strand of ribonucleic acid (RNA), which is present in all living cells, as a guide to find the specific genes for editing. Although this technology has been successful in mice, a gene-edited monkey has not yet been fully developed. Future studies will implant the edited embryos into monkey surrogate mothers, with the goal of creating a gene-edited monkey. This new advancement offers hope in developing better models for new therapies, because nonhuman primates share more similarities with humans than do mice in terms of anatomy, physiology, genetics, and behavior.
- CRISPR Eliminates HIV in Live Animals
Another studying relying on CRISPR technology, this time in mice, showed that HIV can be eliminated in live animals. Researchers from the University of Pittsburgh were the first to perform this feat in “humanized” animals models, in which mice were transplanted with human immune cells, then infected with HIV. Dr. Kamel Khalili, Professor of the Department of Neuroscience at the Lewis Katz School of Medicine at Pitt, and his team tested whether CRISPR/Cas9 could treat mice both acutely and chronically infected with a mouse equivalent of HIV. They found that CRISPR/Cas9 blocked viral replication and prevented systemic infection, resulting in 96% efficiency, in the acutely infected mice. In the chronically infected mice, a single treatment of CRISPR/Cas9 was effective in excising viral fragments of the virus from latently infected human cells that were embedded in mouse tissues and organs. The next steps, the researchers said, “would be to repeat the study in primates, a more suitable model where HIV infection induces disease,” in order to further demonstrate the efficacy of this technique. “Our eventual goal is a clinical trial in human patients.” The study was published May 3 in Molecular Therapy.
- Controversial Italian scientist, Sergio Canavero, has carried out a “head transplant” – stitching the head of a mouse onto the body of a rat. This is the latest in a series of questionable “proof of concept” animal studies, including those on dogs and monkeys. Canavero has stated his intention to conduct the procedure on humans by late 2017. The subject of his latest studies lived only several days and, as of yet, none of this work has been published in peer-reviewed journals. The research was conducted in China, and would almost certainly not be approved by regulators in Western countries given the unlikeliness of success.