According to estimates by the American Skin Cancer Foundation today suffer more people together to skin cancer than from breast, prostate, lung and colon cancer. Although only about 5% of all skin cancers are associated with the black skin cancer (malignant melanoma), but these instances are the most dangerous and can lead to death. Approximately half of all patients who get melanoma, has a specific genetic variation. It involves a mutation of the gene BRAF (B genes for Rapid Acceleration of fibrosarcoma), which results in an uncontrolled multiplication of cells.
There are now drugs that exploit these specific mutations to fight the cancer and thus significantly increase the life expectancy of patients. However, they are only effective if the corresponding gene mutation is actually present. Otherwise occur massive side effects, without the desired effect begins. “It is therefore essential to identify the mutations in tissue samples reliably.Only in this way the patient can be treated properly and successfully, “explains co-author Prof. Katharina Glatz from the Institute of Pathology at the University Hospital Basel.
Coated micro cantilever
The team led by Prof. Ernst Meyer and Prof. Christoph Gerber from the Swiss Nanoscience Institute and the Department of Physics at the University of Basel for the first time used in a pilot clinical trial nanosensors to detect in tissue samples from patients with malignant melanoma mutations. The researchers used this tiny cantilever (cantilever) that have been coated in different ways. On some there was a recognition sequence for the desired mutation.
From the tissue sample of the patient’s genetic material (RNA) has now been isolated and deposited on this cantilever. If the genetic variation present, binds the RNA of the patient to the recognition sequence on the cantilever. Because of the resulting surface stress to the cantilever, which can be measured bend. If the mutation is not in the RNA sample, it does not occur the bending – in other words only a specific binding leads to a signal. The use of the nano-cantilever has the advantage that no time-consuming methods are needed, and not even a day goes by withdrawal of the biopsy to diagnosis.
30 years ago, unthinkable
With this work, the Basel research teams showed that nanomechanical microcantilever are able to identify mutations in complex mixtures of total RNA was isolated from tissue samples. Originally cantilevers were used in atomic force microscopes. Prof Christoph Gerber, the 6 September in Oslo together with Gerd Binnig and Cal Quate the Kavli Prize for the development of the atomic force microscope is awarded, states: “We can not foresee 30 years ago that our technology even in hospital could be used for personalized medicine – so to speak, from the bench to bedside “.