Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The most aggressive forms of breast cancer elude cellular control mechanisms in order to expand

25.11.2010
Scientists at IRB Barcelona have provided new data on how certain types of aggressive breast cancer bypass tumour suppression mechanisms.

About 30% of breast cancer patients have tumours that show rapid growth and invasion through the body. A common denominator in all of these cases is the presence of a large number of Her2 proteins in tumour cellular membranes.

Consequently, these aggressive tumours are referred to as HER2+. Scientists working in the Metastasis Laboratory (MetLab) at IRB Barcelona headed by ICREA researcher Roger Gomis, have described the molecular mechanism that induces HER2+ tumours to ignore the signals that protect cells from excessive growth. The study is published this week in the specialized journal Cancer Research.

Certain external molecules bind to the Her family proteins, thus instructing the cell to divide. However, when cells have multiple copies of the Her2 gene, as is the case of HER2+ patients, they show uncontrolled division and do not respect the signals from their milieu. The prospects for HER2+ patients changed dramatically about ten years ago when the drug Herceptin came onto the market. This agent binds to Her2 to inhibit its proliferative activity, thereby leading to an improved prognosis and greater survival.

LIP disobeys the body¡¯s defense system
When cells detect potential harm, they activate a series of protective responses which often lead to cell death or senescence (no growth). All these mechanisms are systems through which the cell can avoid the irreversible errors that lead them to generate tumours. This explains why tumour cells are removed from the body and replaced by healthy ones. In this context, tumour suppression mechanisms are of particular relevance, among these that induced by the hormone TGF-¦Â and the senescence caused by genes that contribute to the development of malignant cells (OIS).

Through experiments using metastatic cells from patients and animal models, the researchers have discovered that Her2 not only accelerates cell division but also evades these cell arrest systems. Her2 stimulates the production of the protein Lip, which deactivates the mechanisms that prevent cell division mediated by TGF-¦Â and the senescence mediated by OIS, thereby leading to accelerated division. ¡°Lip is the baddie in the film. It affects TGF-¦Â and OIS function, both tumour suppression mechanisms¡±, explains Gomis.

Towards more rational drug administration
One of the problems associated with Herceptin is that after long periods of treatment patients begin to develop drug resistance. This study shows that tumour cells that produce an excess of Lip continue to grow in the presence of the drug. This observation indicates that part of the resistance derives from the increase in Lip shown by these individuals.

"In patients that have an alteration in Her2 plus an increase in Lip, treatment with Herceptin may not be as effective. It should be remembered that this drug acts only against the membrane protein Her2", explains Gomis. These discoveries highlight the need to rationalise drug administration, from patient to patient, and to provide new data for the design of novel pharmaceutical agents against cancer that improve its diagnosis and treatment.

This study has involved the collaboration of Joan Massagu¨¦, Chairman of the Cancer Biology and Genetics Program at the Memorial Sloan-Kettering Cancer Center, New York City, assessor to the MetLab at IRB Barcelona, and adjunct director of the same institute, and has been supported by funding from the BBVA Foundation and the Ministry of Science and Innovation.

Reference article:
HER2 Silences Tumor Suppression in Breast Cancer Cells by Switching Expression of C/EBPb Isoforms
Anna Arnal-Estap¨¦, Maria Tarragona, M¨°nica Morales, Marc Guiu, Cristina Nadal, Joan Massagu¨¦ and Roger R. Gomis.

Cancer Research (2010) [DOI: 10.1158/0008-5472.CAN-10-0869]

Nuria Noriega | EurekAlert!
Further information:
http://www.irbbarcelona.org

More articles from Health and Medicine:

nachricht Cholesterol-lowering drugs may fight infectious disease
22.08.2017 | Duke University

nachricht Once invincible superbug squashed by 'superteam' of antibiotics
22.08.2017 | University at Buffalo

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>