PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Pathways activated in most K9 bone tumors not driving the worst bone tumors

2013-07-24
(Press-News.org) Many cancers show inappropriate activation of a cell signaling pathway called NOTCH. In the developing body, NOTCH tells brain cells to grow and proliferate. It should be quiet in the adult body, but cancers restart NOTCH to drive their own growth, far and beyond the rate of healthy tissues. A Colorado State University and University of Colorado Cancer Center study expected to find NOTCH signaling elevated in K9 osteosarcoma samples, gathered from patients at the CSU Flint Animal Cancer Center. What they found surprised the researchers: overall, NOTCH signaling was elevated in K9 osteosarcoma, but aspects of Notch signaling were noticeably deactivated in the worst cancers.

"We split the samples into two groups: poor responders who had gone less than 100 days after treatment before the progression of their disease, and strong responders who had made it more than 300 days after their treatment without disease progression. Then we could explore the genetic differences between these two groups," says Dawn Duval, PhD, CU Cancer Center investigator and associate professor of molecular oncology at Colorado State University.

Specifically, Duval and colleagues including first author Deanna Dailey, DVM, looked at the expression of a protein called HES1, which is used as a proxy to test for NOTCH activation. High HES1 means that upstream, NOTCH is firing. Low HES1 means it's not firing or that some other pathway is interfering. They expected to find a linear increase in HES1 as cancers and outcomes got worse – more HES1 would have meant more NOTCH signaling and results in other cancers imply that the more NOTCH, the worse the outcomes.

"What we found is that the poor responders had lower HES1. That fit nothing we expected," Duval says.

The osteosarcoma samples from dogs with disease progression in the shortest amount of time, also had the lowest levels of HES1.

"We had to go back and try to figure out what was happening, so we measured HES1 levels in normal bone samples and matched bone tumors. For good measure we also looked at several other Notch pathway markers. What we found was that, in general, Notch signaling was activated in the bone tumors, both good and bad, but that HES1 seemed to be disconnected from Notch signaling in the most aggressive tumors."

They validated the finding by examining HES1 protein expression in over 60 tumors and correlating it with cancer progression. This was the real deal: HES1 was down in the most aggressive K9 osteosarcomas.

"I have many hypotheses why. Here are a couple different ones, most of which have been worked out by Deanna," Duval says. "First, it may be that NOTCH is up due to the proliferation that occurs in most cancers, but that something else is driving the worst ones and this pathway interferes with HES1 expression. For example, another signaling pathway called Hedgehog, which can also affect the level of HES1 is deactivated in these aggressive osteosarcomas and so the level of HES1 may be down because Hedgehog was down. Maybe most interestingly, in the development of neurons, you can see an oscillation of HES1 – it has to go up and then down in order for cells to progress through their cycles. Maybe these osteosarcoma cells have overcome this regulatory pattern to progress?"

For now, the finding of low HES1 signaling in the worst K9 osteosarcomas remains a counterintuitive mystery. Dr. Duval's ongoing work hopes to provide answers to this surprising finding.



INFORMATION:



ELSE PRESS RELEASES FROM THIS DATE:

Researchers reveal the clearest new pictures of immune cells

2013-07-24
Scientists from The University of Manchester have revealed new images which provide the clearest picture yet of how white blood immune cells attack viral infections and tumours. They show how the cells, which are responsible for fighting infections and cancer in the human body, change the organisation of their surface molecules, when activated by a type of protein found on viral-infected or tumour cells. Professor Daniel Davis, who has been leading the investigation into the immune cells, known as natural killers, said the work could provide important clues for tackling ...

Hospital mammography recall rates higher

2013-07-24
OAK BROOK, Ill. – The rate at which women get called back for additional imaging after screening mammography may be higher at hospitals than at community office practices, mostly due to differences among the patients, according to a new study published online in the journal Radiology. The findings highlight the limitations of recall rates as a quality measure for breast cancer screening, the researchers said. Recall rates for mammography refer to the percentage of women who undergo screening and are called back for additional testing. Since recalls involve anxiety for ...

RI Hospital study finds differences in mammography recall rate between 2 centers

2013-07-24
PROVIDENCE, R.I. – A new study at Rhode Island Hospital has found that academic medical centers have higher rates of recall following mammography than community radiology centers. The recall rate is the frequency at which a radiologist interprets an examination as positive and the patient is instructed to return for more testing. The study is published online in advance of print in the journal Radiology. "Recalling a patient for a mammogram has an impact on both the patient, and on the hospital," said lead researcher and author Ana Lourenco, M.D., a radiologist at Rhode ...

New research findings highlight benefits of human-animal interaction

2013-07-23
Chicago, US (July 22, 2013) --- Positive results from three new studies on human-animal interaction (HAI) are being presented today at the triennial conference of the International Association of Human-Animal Interaction Organizations (IAHAIO) in Chicago, IL. The studies, supported by funding from Mars and the WALTHAM® Centre for Pet Nutrition (WALTHAM®), examined how pets impact our physical and emotional well-being and our social relationships and community connectedness. WALTHAM® is the state-of-the-art petcare science centre for Mars Petcare and provides the science ...

Hunting pushing central African forests toward ecological collapse

2013-07-23
Scientists from the Universities of Stirling, Oxford, Queensland and the Wildlife Conservation Society warn that current hunting trends in Central African forests could result in complete ecological collapse. The authors maintain that the current rate of unsustainable hunting of forest elephants, gorillas and other seed-dispersing species threatens the ability of forest ecosystems to regenerate, and that landscape-wide hunting management plans are needed to avoid an environmental catastrophe. The study appears in the latest version of Philosophical Transactions of ...

University of Hawaii Cancer Center researchers report

2013-07-23
HONOLULU, HI – University of Hawaii Cancer Center Prevention and Control Program researchers Pallav Pokhrel, PhD and Thaddeus Herzog, PhD have found that smokers who use e-cigarettes as a tool to stop smoking tend to be younger and more motivated to quit smoking as compared to other smokers. Their study published online ahead of the print version in the American Journal of Public Health, found that approximately 13 percent of smokers had tried e-cigarettes as a means of quitting smoking. They also found that smokers who had tried e-cigarettes for smoking cessation help ...

Putting the brakes on inflammation

2013-07-23
A team led by a University of Arizona researcher has discovered a previously unknown mechanism that prevents the immune system from going into overdrive, shedding light not only on how our body controls its response to pathogens but on conditions such as autoimmune diseases, allergies and chronic inflammation as well. The group found a protein previously believed to only play a role in blood clotting acts as a negative feedback signal, telling defense cells to calm down, thereby preventing an immune reaction from spiraling out of control. The results, which could lead ...

Rapid upper ocean warming linked to declining aerosols

2013-07-23
Australian scientists have identified causes of a rapid warming in the upper subtropical oceans of the Southern Hemisphere. They partly attribute the observed warming, and preceding cooling trends to ocean circulation changes induced by global greenhouse gas emissions and aerosols predominantly generated in the Northern Hemisphere from human activity. The research, by scientists from CSIRO and the University of NSW, was published today in Scientific Reports. Mr Tim Cowan, lead author of the study, says his group was initially interested in the three decade long cooling ...

Tropical ecosystems regulate variations in Earth's carbon dioxide levels

2013-07-23
Rising temperatures, influenced by natural events such as El Niño, have a corresponding increase in the release of carbon dioxide from tropical forest ecosystems, according to a new study out today. The study, published in the journal Proceedings of the National Academy of Sciences, found that a temperature anomaly of just 1ºC (in near surface air temperatures in the tropics) leads to a 3.5-Petagram (billion tonnes of carbon) anomaly in the annual CO2 growth rate, on average. This is the equivalent of 1/3 of the annual global emissions from the combustion of fossil fuels ...

'Dead' gene comes to life, puts chill on inflammation, Stanford researchers find

2013-07-23
STANFORD, Calif. — A gene long presumed dead comes to life under the full moon of inflammation, Stanford University School of Medicine scientists have found. The discovery, described in a study to be published July 23 in eLife, may help explain how anti-inflammatory steroid drugs work. It also could someday lead to entirely new classes of anti-inflammatory treatments without some of steroids' damaging side effects. Chronic inflammation plays a role in cancer and in autoimmune, cardiovascular and neurodegenerative diseases, among others. Anti-inflammatory steroid drugs ...

LAST 30 PRESS RELEASES:

Pink skies

Monkeys are world’s best yodellers - new research

Key differences between visual- and memory-led Alzheimer’s discovered

% weight loss targets in obesity management – is this the wrong objective?

An app can change how you see yourself at work

NYC speed cameras take six months to change driver behavior, effects vary by neighborhood, new study reveals

New research shows that propaganda is on the rise in China

Even the richest Americans face shorter lifespans than their European counterparts, study finds

Novel genes linked to rare childhood diarrhea

New computer model reveals how Bronze Age Scandinavians could have crossed the sea

Novel point-of-care technology delivers accurate HIV results in minutes

Researchers reveal key brain differences to explain why Ritalin helps improve focus in some more than others

Study finds nearly five-fold increase in hospitalizations for common cause of stroke

Study reveals how alcohol abuse damages cognition

Medicinal cannabis is linked to long-term benefits in health-related quality of life

Microplastics detected in cat placentas and fetuses during early pregnancy

Ancient amphibians as big as alligators died in mass mortality event in Triassic Wyoming

Scientists uncover the first clear evidence of air sacs in the fossilized bones of alvarezsaurian dinosaurs: the "hollow bones" which help modern day birds to fly

Alcohol makes male flies sexy

TB patients globally often incur "catastrophic costs" of up to $11,329 USD, despite many countries offering free treatment, with predominant drivers of cost being hospitalization and loss of income

Study links teen girls’ screen time to sleep disruptions and depression

Scientists unveil starfish-inspired wearable tech for heart monitoring

Footprints reveal prehistoric Scottish lagoons were stomping grounds for giant Jurassic dinosaurs

AI effectively predicts dementia risk in American Indian/Alaska Native elders

First guideline on newborn screening for cystic fibrosis calls for changes in practice to improve outcomes

Existing international law can help secure peace and security in outer space, study shows

Pinning down the process of West Nile virus transmission

UTA-backed research tackles health challenges across ages

In pancreatic cancer, a race against time

Targeting FGFR2 may prevent or delay some KRAS-mutated pancreatic cancers

[Press-News.org] Pathways activated in most K9 bone tumors not driving the worst bone tumors