This happens because too many receptors for the growth factor EGF which are found on the surface of the cell join together to form pairs. These pairs start a signal chain into the cell, culminating in unrestricted growth.
Labeling of the EGFR with gold nanoparticles vizualizes its dimerisation
Now, scientists at the INM – Leibniz Institute for New Materials have for the first time been able to show this pairing in human cancer cells on individual receptors using gold nanoparticles.
The results were recently published in the online journal Scientific Reports.
“It has never before been possible to show the mechanism of pairing in individual receptors in whole cells”, explains Diana Peckys, a human biologist at the INM. “Up to now, biochemical methods in which the cells are either in principle destroyed or only ever receive calculated mean values from the observation of many receptors have been used”, she goes on. “We examined the arrangements of individual receptors in pairs and in smaller groups. This was possible because we were able to show the individual receptors on the intact cell under an electron microscope.”
To do this, researchers marked the growth factor EGF using gold nanoparticles with a diameter of around ten nanometers. At the same time, they worked with a special measuring and preparation technique that makes it possible to examine whole cells in their natural fluid state in the nanometer range under a scanning electron microscope. They used these combined methods with a resolution of three nanometers to for the first time show on a one to one basis that EGF binds to the receptor and form pairs and clusters.
In addition to experimentally proving previous theoretical calculations, the team from the Innovative Electron Microscopy Program Area is now stepping up its work with German cancer researchers. “With our new measuring method, we are keen to focus in the future on investigating how different cancer drugs influence pairing and grouping of the EGFR and similar related receptors. Observing these processes in terms of individual molecules on intact cells opens up new prospects for cancer research”, the electron microscope expert sums up.
INM – Leibniz Institute for New Materials, situated in Saarbruecken, is an internationally leading centre for materials research. It is an institute of the Leibniz Association and has about 190 employees.
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Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.
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