Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Breast cancer can be reversed in laboratory mice, scientists report

04.11.2003


Findings provide new molecular drug targets, validate transgenic mouse models



Breast cancer researchers have demonstrated for the first time that it is possible to block genetic switches in mice that turn cancer on and off — thus preventing and even reversing breast cancer in the animals. The findings, reported Sunday morning at the 24th Congress of the International Association for Breast Cancer Research, suggest potential new molecular targets for drugs to prevent and potentially eradicate breast cancer in humans.

“It’s enormously gratifying,” said conference director Robert Cardiff, professor of pathology at UC Davis School of Medicine and Medical Center and an author of the research. “Our findings suggest paths forward that may help us alter the biological path of breast cancer and more successfully treat — and even potentially prevent — this cancer in humans.”


In new research reported by a team of scientists from Canada, Switzerland and UC Davis, investigators demonstrated that removing a single gene known as beta-1 integrin prevented or halted breast cancer growth in laboratory mice. Beta-1 integrin is a principal regulator of normal breast tissue growth and survival, but if the gene malfunctions, it can directly initiate breast tumors. The new work demonstrates that knocking out the beta-1 integrin gene prevents cancer-prone mice from developing breast tumors, and halts further tumor growth in mice that have already developed breast cancer.

“This study shows that it is absolutely essential to have the beta-1 integrin gene present in order for mammary gland tumors to develop. We now have a good target for biological drug development, and the challenge is to develop an agent that can block its activity,” said William J. Muller, professor of biochemistry at McGill University in Montreal and a lead investigator of the study.

In a related presentation, researchers from the University of Pennsylvania reported on a series of experiments using a novel mouse model of human breast cancer, one that enables scientists to turn oncogenes — genes that can cause cancer — on or off at will. A triggering agent, in this case the antibiotic doxycycline, throws the switch on or off. Scientists used the approach to test four oncogenes: c-myc, Neu, Wnt1, and v-Ha-Ras. When any one of the oncogenes was turned on, the transgenic mice developed extremely aggressive mammary tumors; in many cases, the tumors metastasized to the lungs. When the gene was turned off, many of the breast tumors — including many of the most aggressive and advanced cancers — regressed to the point that they no longer could be detected by physical examination, magnetic resonance imaging (MRI) or positron emission tomography (PET) scans.

“We’re extremely encouraged that we have been able to demonstrate in laboratory animals that we can make mammary cancers essentially disappear by reversing just one mutation,” said Lewis A. Chodosh, associate professor at the Abramson Family Cancer Research Center at the University of Pennsylvania and lead author of the study.
“This suggests that, with appropriate therapies that target the genes used in this study, we might be able to cause tumors to regress and improve substantially, even those that are quite advanced.”

However, even though many of the tumors in the transgenic mice went into complete remission, a substantial number of the cancers spontaneously recurred over periods of up to a year, Chodosh reported.

This finding is important since it replicates the natural history of human breast cancer — many women, after apparently successful treatment, harbor residual tumor cells that eventually give rise to tumor recurrences that ultimately may result in death. Some of these residual cells can remain for decades. No previous laboratory mouse model has successfully replicated this feature of human breast cancer cells.

“The next critical step is to figure out the mechanisms that some tumors use to escape these treatments,” Chodosh said. “We believe these mouse models will help us to do exactly that.”

Founded in the mid 1950s, the International Association for Breast Cancer Research is an international community of scientists focused on the important issues in modern breast cancer research. The 24th IABCR Congress, focused on preclinical research using mouse models of human breast cancer, is sponsored by UC Davis Cancer Center, the Office of Women’s Health of the U.S. Department of Health and Human Services, the California Breast Cancer Research Program, and the National Cancer Institute’s Mouse Models of Human Cancers Consortium and Specialized Programs of Research Excellence.

Claudia Morain | UC Davis Health System
Further information:
http://cme.ucdmc.ucdavis.edu/iabcr.htm
http://news.ucdmc.ucdavis.edu
http://cme.ucdmc.ucdavis.edu/Confrnce/IABCR/reversed.html

More articles from Health and Medicine:

nachricht Investigators may unlock mystery of how staph cells dodge the body's immune system
22.09.2017 | Cedars-Sinai Medical Center

nachricht Monitoring the heart's mitochondria to predict cardiac arrest?
21.09.2017 | Boston Children's Hospital

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: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>