Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers discover a possible reason for drug resistance in breast tumors

20.07.2015

HER2 membrane proteins play a special role in certain types of breast cancer: amplified levels of HER2 drive unrestricted cell growth. HER2-tailored antibody-based therapeutics aim to prevent cancer cell growth. However, two-thirds of HER2 positive breast cancer patients develop resistance against HER2-targeting drugs. The reason for this is not yet understood. Researchers now found out, that HER2 dimers appeared to be absent from a small sub-population of resting SKBR3 breast cancer cells. This small subpopulation may have self-renewing properties that are resistant to HER2-antibody therapy and thus able to seed new tumor growth.

For their studies researchers from the INM – Leibniz-Institute for New Materials, Saarbrücken and from the German Cancer Research Center (DKFZ) in Heidelberg used a new electron microscopy method called Liquid STEM. It allows nanoscale studies of intact cells in their native liquid environment.

The scientists have studied the local variations of HER2 membrane protein and of its dimers. HER2 is a member of the human epidermal growth factor receptor (EGFR) family. These family members trigger cell growth signals, when two of the membrane proteins are bound into a protein complex (dimerization).

This happens usually after the binding of a small protein, the epidermal growth factor, which circulates in the blood stream and serves as communicator to transmit signals that regulate cell growth. HER2 is special in the sense that it does not need the growth factor protein in order to form dimers. It is thus capable of triggering cell growth without external regulation.

In certain types of breast cancer, amplified levels of HER2 and its dimerization are known to drive unrestricted cell growth. HER2-tailored antibody-based therapeutics entered clinical practice more than a decade ago. These drugs aim to prevent cell growth triggered by HER2 homo- and/or heterodimerization.

“We found out, that HER2 dimers appeared to be absent from a small sub-population of resting SKBR3 cells. Could such cells survive the therapy and then develop into a drug resistant cancer at a later stage? It thus seems to be of key significance to study this sub-population of cells with exceptional phenotype,” says Niels de Jonge, head of the Innovative Electron Microscopy group.

HER2 dimerization processes were thus far mostly studied on the basis of cell population averages, for example, with biochemical methods using pooled cell material, and information about the localization of HER2 dimerization was lacking. Therefore, the researchers around de Jonge pioneered the electron microscopy method Liquid STEM to imaging these receptors on cancer cells. The cells were examined on a microchip placed in the electron microscope, and remained intact and in liquid.

“Specimens cannot be studied in liquid with traditional electron microscopy”, explains Professor de Jonge. “Cells are typically studied in dry state via thin sectioning of solid dried plastic embedded or frozen material. The role of HER proteins is a "hot" topic in cancer research but despite large research efforts using a wide range of techniques over the past decades this important information was not unveiled before. Our novel findings were obtained as a direct consequence of the high spatial resolution of Liquid STEM combined with its capability to study many intact cells in liquid,” says de Jonge.

Original Publication:
“Local variations of HER2 dimerization in breast cancer cells discovered by correlative fluorescence and liquid electron microscopy” was published in the new online journal Science Advances Sci. Adv. 1, e1500165 (2015) by D. B. Peckys, U. Korf, N. de Jonge.

The research was conducted by Prof. Dr. Niels de Jonge, Dr. Diana B. Peckys of the INM – Leibniz-Institute for New Materials in Saarbrücken together with the group of Dr. Ulrike Korf, Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ) in Heidelberg, Germany.

Your expert:
Prof. Niels de Jonge
INM – Leibniz Institute for New Materials
Head Innovative Electron Microscopy
Phone: +49681-9300-313
niels.dejonge(at)leibniz-inm.de

INM conducts research and development to create new materials – for today, tomorrow and beyond. Chemists, physicists, biologists, materials scientists and engineers team up to focus on these essential questions: Which material properties are new, how can they be investigated and how can they be tailored for industrial applications in the future? Four research thrusts determine the current developments at INM: New materials for energy application, new concepts for medical surfaces, new surface materials for tribological systems and nano safety and nano bio. Research at INM is performed in three fields: Nanocomposite Technology, Interface Materials, and Bio Interfaces.
INM – Leibniz Institute for New Materials, situated in Saarbrücken, is an internationally leading centre for materials research. It is an institute of the Leibniz Association and has about 210 employees.

Weitere Informationen:

http://www.leibniz-inm.de/en
http://www.leibniz-gemeinschaft.de

Dr. Carola Jung | idw - Informationsdienst Wissenschaft

More articles from Life Sciences:

nachricht Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

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 >>>