Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genetic pathways to curable and incurable forms of pancreatic cancer identified

13.03.2007
Pancreatic ductal adenocarcinoma is an almost uniformly fatal disease regardless of the stage at time of diagnosis. However, a small percentage of patients develop a form of ductal adenocarcinoma associated with cystic lesions that can be detected earlier, is less aggressive and has a 50 percent long-term survival rate.

Why cystic ductal pancreatic cancer behaves differently, despite carrying the same basic genetic mutations as the more common and deadly type of ductal pancreatic cancer, has long been a mystery. Now researchers at Fred Hutchinson Cancer Research Center have unlocked the genetic reason why.

Using unique mouse models to mimic the progression of both forms of human pancreatic cancer, researchers have discovered that a specific sequence of otherwise common genetic mutations is responsible for sending cells down the less-traveled path toward cystic pancreatic cancer versus the well-traveled route to the more fatal form of ductal pancreatic cancer.

Sunil Hingorani, M.D., assistant member of the Hutchinson Center's Clinical Research and Public Health Sciences divisions, led a study to be published in the March 12 issue of the journal Cancer Cell that explains this sequence and details why the cells behave differently.

"Although at their end stage the two different routes to ductal pancreatic cancer can look very much the same under the microscope, involve the same constellation of genetic events, and culminate in invasive and metastatic disease that can ultimately kill patients, one route is 100 percent fatal while the other is 50 percent curable," Hingorani said. "Until now we didn't understand why. What these studies suggest is that it's not just the total complement of mutations that determines the behavior of these cancers but also the sequence in which the mutations arise."

About 5 percent of all primary tumors of the pancreas, out of 40,000 annual new cases in the United States, arise from cystic tumors.

The findings reported in the journal by Hingorani and colleagues represent an accidental discovery. The researchers started out studying the common genetic pathways to pancreatic ductal adenocarcinoma in hopes of finding clues to developing early detection biomarkers and possible treatments to halt the progression of the disease. The work involved activating the pancreatic cancer oncogene called Kras and then selectively mutating tumor-suppressor genes such as p53, p16 and Dpc4 in different combinations.

In the mouse model, which Hingorani first developed while at the University of Pennsylvania, the combination of Kras and p53 led to the more deadly form of pancreatic ductal adenocarcinoma. Earlier studies by researchers in Boston also found the same association between Kras and p16. From studies of human cancers, it is known that mutations in Dpc4 can also occur, but they do so late in the course of disease progression. The current study showed that the combination of Kras and an early mutation of Dcp4, in which one copy of the suppressor gene is eliminated, lead to cancer by a different path, beginning with the creation of a distinct class of precancerous lesions in the ductal epithelium called mucinous cystic neoplasms (MCN). This initiates a process that results in the rarer but far less deadly cystic pancreatic cancer.

MCN lesions often are large enough to be detected early by MRI or CT scan and also to cause symptoms. The cells in this cancer also react differently to a key signaling protein, TGFb, which can induce cancer cells to change shape and become more mobile and invasive. It turns out that the cystic pancreatic cancer cells are resistant to these effects of TGFb and these types of cancers are also less likely to invade surrounding tissues and to metastasize, or spread, to other organs. These properties likely contribute to the improved survival seen with this form of the cancer, Hingorani said.

Conversely, the initial lesions that lead to the more common and deadly form of pancreatic ductal adenocarcinoma, called pancreatic epithelial neoplasms, are tiny enough to be undetectable until the disease has progressed to the point where survival is almost nil. Moreover, these cells appear to be highly sensitive to the tumor-promoting properties of TGFb and thereby manifest a more aggressive behavior.

"With accurate animal models of both forms of pancreatic ductal cancers now in hand, it should be possible to unravel the detailed mechanisms behind their distinct behavior and hopefully identify points of vulnerability in the more fatal form to improve survival," Hingorani said.

Dean Forbes | EurekAlert!
Further information:
http://www.fhcrc.org

Further reports about: Hingorani KRAS adenocarcinoma cystic genetic mutation pancreatic pancreatic cancer

More articles from Life Sciences:

nachricht How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>