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.
- Mouse study suggests a high-fat diet may exacerbate prostate cancer. Prostate cancer often starts when the gene PTEN shuts down, however, when a second gene, PML, also shuts down then the prostate cancer is more likely to spread. The rodent study at Beth Israel Deaconess Medical Center in Boston found that without PML, the cancerous cells of the mice (and petri dishes) started rapidly producing fat, which they believe is fuelling the spread of the cancer. Furthermore, they found that an anti-obesity drug caused the cancer to regress in mice, offering hope for new treatments. The Published in Nature Genetics.
- High salt linked to dementia in the absence of hypertension. In this study mice were fed either a 8x or 16x increase in salt in their diet and compared to mice fed a normal diet. Then mice were examined using MRI and were observed to have marked reductions in blood flow to brain areas associated with learning and memory — two functions impaired in dementia. Notably, when these animals were fed a normal diet, blood flow returned to normal. Behavioral indicators of these two cognitive functions were also impaired. Follow up experiments looking at the mechanism underlying these deficits implicated the the role of the gut and, in particular, a subset of white blood cells, TH17 and IL-17, which regulate the production of nitric acid in endothelial cells. When mice were treated with a drug that suppressed nitric acid activity, behavioral deficits were improved. The results are surprising because in humans, the risk associated with the consumption of a high salt diet on cognitive function have previously been attributed to hypertension. Published in Nature Neuroscience.
- Gene variant linked to deadly form of prostate cancer. Men with a gene variant, HSD17B4, may be more susceptible to castration resistant prostate cancer (CRPC). Based on previous research, the researchers studied, HSD17B4, because it encodes for enzymes that inactivate male hormones. As these hormones also promote cancer growth, inactivating them may decrease/prevent cancer growth. When looking at tissue from men with CRPC, these researchers found that expression of the HSD17B4 gene was decreased compared to local and benign prostate cancer tissue. These researchers found and validated in mice that that only one specific isoform of HSD17B4—isoform 2—enzymatically inactivated androgens and prevented tumor growth. Published in Cell Reports.
- Enlisting Dogs in the War on Cancer. Dogs get many of the same types of cancer as humans and have benefitted from human cancer drugs. Mice have long been essential models for developing cancer drugs as they provide an effective way to closely study the cancer and its mechanisms as well as the genes that may be related to it. As with every model, mice have limitations which led researchers to dogs as candidates for clinical trials. Veterinarians have long noted similarities in human and canine cancers. Canine cancer patients experience the same environment as their human counterparts. Their cancers are also spontaneous, as in the human, spread the same and respond similarly to therapeutics. Alternatively, dogs get cancer at a rate that is ten times more than humans. Dr. Matthew Breen, professor of comparative oncology genetics at North Carolina State University College of Veterinary Medicine said, “If there’s a silver lining, it’s the opportunity for investigators to study cancers that are relatively common in dogs but rare in humans. Researchers hope that studying these canine patients will accelerate the development of more effective treatments for both people and dogs.
- Oregon scientist develops promising vaccine against tuberculosis. Tuberculosis is highly contagious and caused illness in more than 10 million people across the world in 2016. Dr. Louis Picker, a researcher at Oregon Health & Science University said, “TB is actually the biggest infectious killer now – it’s surpassed HIV.” In monkeys, the disease is deadly. In the study, Picker and his colleagues vaccinated 34 rhesus macaques and then later exposed them to a virulent strain of tuberculosis, along with 17 control monkeys. The results showed that the vaccine was effective. Picker based the approach on his work with developing an HIV vaccine. The HIV vaccine study resulted in protection for the monkeys so human trials are expected to begin in 2019 with anticipated trials for the TB vaccine to follow. This study was published in Nature Medicine.