September 21 Research Roundup: Zombie Cells, Pancreatic Cancer, Household Cleaners and Obesity, and Genetic Aspects of Laziness
Published: Sep 21, 2018 By Mark Terry
There are plenty of great scientific research stories out this week. Here’s a look at just a few of them.
Zombie Cells Precede Cognitive Loss
Senescent cells are cells that no longer function but are not yet dead. As they accumulate, they inhibit proper functioning of organs and tissues unless they can be eliminated. They are implicated in several age-related diseases. Researchers with the Mayo Clinic published research in Nature that found these “zombie” cells in mice appear to accumulate in some brain cells before cognitive loss.
“Senescent cells are known to accumulate with advancing natural age and at sites related to diseases of aging, including osteoarthritis; atherosclerosis; and neurodegenerative diseases, such as Alzheimer’s and Parkinson’s,” stated Darren Baker, a molecular biologist and senior author of the paper. “In prior studies, we have found that elimination of senescent cells from naturally aged mice extends their healthy lifespan.”
In the mouse model, the researchers prevented the accumulation of senescent cells, which decreased the aggregation of tau proteins, neuronal death and memory loss. Tau proteins are connected to Alzheimer’s disease, although they typically occur later in the disease. This finding has the potential for significant new approaches to preventing Alzheimer’s disease and other illnesses linked to senescent cells.
Blood Test for Early Detection of Pancreatic Cancer
Pancreatic cancer is notorious for being difficult to diagnose until it’s too late for effective treatment. Researchers at Lund University in Sweden, Herlev Hospital, Knight Cancer Center and Immunovia have developed a blood test that can detect early-stage pancreatic cancer. Their work has been published in the Journal of Clinical Oncology.
Pancreatic ductal adenocarcinoma (PDAC) has a 5-year survival rate of less than 10 percent, largely related to symptoms leading to late-stage diagnosis. If able to be detected earlier, the survival rate would increase significantly. Using data from a Scandinavian cohort of 16 patients with stage 1, 132 patients with stage II, 65 patients with stage III, and 230 patients with stage IV PDAC, and 888 controls, the team developed a test that could identify stage I and II.
“Our test can detect pancreatic cancer with 96 percent accuracy at stage I and II, while there is still the possibility of successful surgical intervention,” said Carl Borrebaeck, professor at the department of Immunotechnology at Lund University, in a statement. “There is currently no cure and few treatment options for advanced pancreatic cancer, which is the late stage when pancreatic cancer is usually diagnosed.”
It’s possible the test could be used to screen people at high risk for pancreatic cancer, such as people with a family history, newly onset diabetic patients, and individuals with chronic inflammation of the pancreas.
Do Household Cleaning Products Make Kids Fat?
No, the idea here isn’t if your kids are sniffing toilet bowl cleaner (or eating Tide Pods). Researchers from across Canada evaluated data from the Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort on microbes in infant fecal matter—baby poop, in other words. They found altered gut flora in babies three to four months old had the most frequent exposure to household disinfectants such as multisurface cleaners. They showed lower levels of Haemophilus and Clostridium bacteria, but higher levels of Lachnospiraceae. The research was published in the Canadian Medical Association Journal (CMAJ).
“We found that infants living in households with disinfectants being used at least weekly were twice as likely to have higher levels of the gut microbes Lachnospiraceae at age 3-4 months; when they were 3 years old, their body mass index was higher than children not exposed to heavy home use of disinfectants as an infant,” stated Anita Kozyrskyj, a professor of pediatrics at the University of Alberta and principal investigator of the SyMBIOTA projects “Those infants growing up in households with heavy use of eco cleaners had much lower levels of the gut microbes Enterobacteriaceae. However, we found no evidence that these gut microbiome changes caused the reduced obesity risk.”
The researchers call for more studies to further determine if changes in the microbiome in early childhood caused by exposure to environmental cleansers are causing obesity.
Stem Cell Characteristics Different in Epithelial Cancer Cells
Researchers with the UCLA Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research and Johnsson Comprehensive Cancer Center published research in the journal Cell Reports identifying similarities between adult stem cells and those that drive aggressive epithelial cancers. “Pinpointing the molecular and genetic features common among multiple cancer types is crucial because it reveals new targets for drugs that could work for a broad range of aggressive cancer types that do not respond to current therapies,” stated Owen Witte, founding director of the UCLA Broad Stem Cell Research Center.
Epithelial cancers include lung, prostate and bladder cancers. The new research identified genetic characteristics that are found not only in aggressive cancers, but in different epithelial tissues and in human adult stem cells that renew and regenerate epithelial tissues. “Our research suggests that some epithelial cancers, regardless of tissue of origin, possess stem-like genetic features and activate this program when becoming the more deadly small cell neuroendocrine type,” stated Bryan Smith, a postdoctoral fellow in Witte’s lab.
Bacteria and Stress Make Colon Cancer Worse
Scientists at the Technical University of Munich (TUM) were investigating triggering factors in colon cancer when they discovered that cell stress with a change in the colon microbiome drives tumor growth. They published their work in the journal Gastroenterology.
“With our study we originally wanted to study the role of bacteria in the intestines in the development of intestinal inflammation,” stated Dirk Haller, with the Department of Nutrition and Immunology at the Weihenstephan Science Centre of the TUM. “However, the surprising result for us was the discovery that bacteria together with stress in cells caused tumors (exclusively in the colon) and without the involvement of inflammation.”
A transcription factor called ATF6 regulates stress in cells and that intensity increases with disease. But it isn’t just cell stress that led to tumor growth, but a combination of cell stress and microbiota that favored cancer growth. ATF6 is increased in colon cancer patients. Haller stated, “In certain patients, the protein ATF6 could serve as a diagnostic marker for an increased risk of colon cancer and could indicate the start of therapy at an early stage. A microbial therapy is conceivable, when we know more about the composition of the bacterial flora. What now became clear, however: Chronic inflammation has no effect on cancer development in the colon.”
Your Brain Wants You to be a Couch Potato
Despite years of encouragement to exercise, fewer people do. Why? Researchers at the University of British Columbia say it’s because our brains are hard-wired for laziness. They published their research in the journal Neuropsychologia.
“Conserving energy has been essential for humans’ survival, as it allowed us to be more efficient in searching for food and shelter, competing for sexual partners, and avoiding predators,” stated Matthieu Boisgontier, postdoctoral researcher in UBC’s brain behavior laboratory at the department of physical therapy. “The failure of public policies to counteract the pandemic of physical inactivity may be due to brain processes that have been developed and reinforced across evolution.”
The study subjects were flashed small images that showed either physical activity or physical inactivity. They had to move an avatar as fast as possible toward pictures of physical activity and away from pictures of physical inactivity, and vice versa. Electrodes recorded brain activity as they did so. Study participants typically were faster at moving toward active pictures and away from “lazy” pictures, but electroencephalograms showed that the “away from lazy pictures” required brains to work harder.
“We knew from previous studies that people are faster at avoiding sedentary behaviors and moving toward active behaviors,” Boisgontier stated. “The exciting novelty of our study is that it shows this faster avoidance of physical inactivity comes at a cost — and that is an increased involvement of brain resources. These results suggest that our brain is innately attracted to sedentary behaviors.”