Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Approved cancer drug potentially could help treat diabetes, Stanford researchers find

16.09.2013
A pair of studies by researchers at the Stanford University School of Medicine has identified a molecular pathway — a series of interaction among proteins — involved in the development of diabetes. Furthermore, they have found that a drug already approved for use in humans can regulate the pathway.

The findings will be published online Sept. 15 in two articles in Nature Medicine.

The studies, done in mice, identify a previously unexpected link between a low-oxygen condition called hypoxia and the ability of cells in the liver to respond to insulin. The drug, aflibercept (marketed as Eylea or Zaltrap), is used to treat metastatic colorectal cancer and a form of macular degeneration. Aflibercept is a member of a family of proteins that inhibit the vascular endothelial growth factor, or VEGF, pathway. It works by blocking the growth of the blood vessels into tumors and starving them of oxygen.

The lab of Calvin Kuo, MD, PhD, professor of medicine, identified a series of protein interactions that link VEGF inhibitors and blood glucose levels. "We were surprised to find that this drug currently used in patients for cancer treatment had beneficial effects on diabetes in laboratory mice and could, potentially, in humans," said Kuo, senior author of one of the Nature Medicine papers.

Amato Giaccia, PhD, the Jack, Lulu and Sam Willson Professor of Cancer Biology, is senior author of the other paper. "Proteins involved in this pathway could also be targeted for the development of new diabetes therapies," said Giaccia, who also is a professor and director of radiation oncology. His laboratory has identified a protein called PhD3 that could be a particularly attractive target.

The lead author of the Giaccia paper is Cullen Taniguchi MD, PhD, a radiation oncology resident at Stanford; former graduate students Kevin Wei, MD, PhD, and Lisa McGinnis, MD, PhD, and postdoctoral scholar Stephanie Piecewicz, PhD, are lead authors of the Kuo paper.

Together, the studies explain an observation made several years ago by Kuo and his lab members that VEGF inhibitors, such as aflibercept, could lower blood glucose levels in mice. There have been intriguing hints that these inhibitors could function in a similar way in humans, but human studies have not been formally conducted.

"Anecdotally, there have been reports that diabetic patients who have been prescribed VEGF inhibitors to treat their cancer are better able to control their diabetes," Kuo said.

The liver is commonly known as the organ responsible for removing toxins from our blood. But it also serves as the body's energy warehouse. After a meal, blood glucose levels rise and insulin triggers cells in the liver to squirrel away the glucose in long, branching chains of a substance called glycogen (imagine an ever-growing Lego structure, where each block is a glucose molecule). When we are asleep or fasting, the liver breaks down that Lego structure unit by unit to deliver glucose into the blood for cells to use as an energy source until the next meal.

When this process goes awry, blood glucose levels can become dangerously high. This can happen when the body either can't make insulin (in the case of type-1, or juvenile, diabetes) or when it can't respond appropriately to the insulin the body does make (type-2 diabetes).

The liver's critical function requires that most of its cells have ready access to blood, which carries both glucose and oxygen. Oxygen diffuses as a gradient outward from blood vessels; those cells that are more removed have less oxygen and can become hypoxic. Hypoxic cells naturally produce certain proteins to enable them to live and function under these more severe conditions.

Wei, McGinnis and Piecewicz, in Kuo's lab, found that one protein induced by hypoxia, HIF-2alpha, activates the expression of insulin receptor substrate 2. IRS2 enhances the ability of the cells to respond to insulin. Treatment of normal and diabetic laboratory mice with a variety of VEGF inhibitors, including aflibercept, causes regression of blood vessels and increases the number of hypoxic cells in the liver. As a result, HIF-2alpha levels increase, IRS2 expression rises and the animals become better able to tolerate increases in blood-glucose levels.

The researchers found that deletion of HIF-2alpha blocked the effect of the VEGF inhibitors, while liver-specific induction of HIF-2alpha expression also significantly improved the animals' glucose tolerance.

"Much work remains to translate these mouse studies to human patients, but it will be interesting to explore VEGF inhibitors or drugs that can stabilize HIF-2alpha, such as prolyl hydroxylase inhibitors, for diabetes treatment, possibly in combination with pre-existing therapies to minimize toxicities," Kuo said.

Taniguchi, in Giaccia's lab, focused on the biology of HIF-2alpha. He and his colleagues found that blocking the expression of a protein called Phd3 specifically taps into the pathway identified by the Kuo group, stabilizing the HIF-2alpha protein and prolonging its effect on IRS2 expression. Laboratory mice missing Phd3 are more sensitive to insulin and exhibit improved glucose tolerance.

The specificity of the effect of Phd3 on HIF-2alpha is important. Because it doesn't appear to regulate other proteins in the HIF family in the liver, it's possible a diabetes treatment could be designed that would avoid unwanted or dangerous side effects that could occur by blocking the production of a more broadly acting protein.

"Targeting the Phd3/HIF-2 pathway represents a new therapeutic approach for the treatment of diabetes with little toxicity," said Giaccia. "These studies indicate that Phd specific inhibitors, especially Phd3, should be more widely developed for clinical development."

Additional Stanford authors of the papers were research assistant David Kuo; basic life sciences research associates Jenny Yuan and Mario Vallon; assistant professor of medicine Justin Annes, MD, PhD; and postdoctoral scholars Elizabeth Finger, PhD, Colleen Wu, PhD, Anh Diep, VMD, and Edward LaGory, PhD.

Funding for the studies was provided by the National Institutes of Health (grants R01HL074267, R01NS064517, R01CA158528, 1R01HL074267, RO1DK043748, P60DK020593, U24DK059637 CA67166 and CA88480); the National Cancer Institute (grant CA121940); Radiological Society of North America Resident Research Grants; the Canadian Institutes of Health and Research; the National Institute of General Medical Sciences (grants GM104936 and GM007365); the Sydney Frank Foundation; Stanford's Medical Scientist Training Program; and Stanford training-program grants in comparative animal medicine, cardiovascular medicine, molecular and cellular immunobiology, and molecular endocrinology.

Regeneron Pharmaceuticals, Sanofi and Genentech provided reagents for the Kuo study. Three co-authors of the Kuo study are employees at Regeneron, which manufactures aflibercept.

The Stanford University School of Medicine consistently ranks among the nation's top medical schools, integrating research, medical education, patient care and community service. For more news about the school, please visit http://mednews.stanford.edu. The medical school is part of Stanford Medicine, which includes Stanford Hospital & Clinics and Lucile Packard Children's Hospital. For information about all three, please visit http://stanfordmedicine.org/about/news.html.

Print media contact: Krista Conger at (650) 725-5371 (kristac@stanford.edu)
Broadcast media contact: M.A. Malone at (650) 723-6912 (mamalone@stanford.edu)

Krista Conger | EurekAlert!
Further information:
http://www.stanford.edu

More articles from Health and Medicine:

nachricht Satellites, airport visibility readings shed light on troops' exposure to air pollution
09.12.2016 | Veterans Affairs Research Communications

nachricht Oxygen can wake up dormant bacteria for antibiotic attacks
08.12.2016 | Penn State

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>