Nanosensor detects cancer cells
27 February 2013
A nanosensor that can detect cancerous skin cells by identifying
mutated RNA has been developed by the Swiss Nanoscience Institute of
the University of Basel and the Ludwig Institute for Cancer Research
in Lausanne, Switzerland.
The sensor uses microscopically small cantilevers coated with a
layer of DNA molecules which can bind mutated RNA from cancerous
cells. When the RNA binds to the DNA the cantilever is bent, and
this is detected using a laser beam. In contrast to other methods,
this cantilever approach is so sensitive that DNA needs to be
neither amplified nor labelled with other molecules.
Malignant melanoma is the most aggressive type of skin cancer. In
more than 50% percent of affected patients a particular mutation
plays an important role. As the life span of the patients carrying
the mutation can be significantly extended by novel drugs, it is
very important to identify those reliably.
In Switzerland, every year about 2100 persons are affected by
malignant melanoma, which makes it one of the most frequent tumours.
While early detected the prospects of recovery are very good, in
contrast at later stages the chances of survival are reduced
In the past few years, several novel drugs have been developed
that take advantage of the presence of particular genetic mutations
related to fast cell growth in tissue. In case of melanoma, the
so-called BRAF gene is of importance, which leads in its mutated
state to uncontrolled cell growth. Since only about 50 percent of
patients with malignant melanoma show this mutation, it is important
to identify those patients who respond to the novel therapy. Taking
into account the negative side effects of the drug, it would not be
appropriate to apply the drug to all patients.
Nanosensor: Eight cantilevers of 500 μm in
length are applied
for detection of the genetic mutation.
(Photo: University of Basel)
Detection of other types of cancer
In experiments the researchers could show that cells carrying
this genetic mutation can be distinguished from others lacking the
mutation. RNA of cells from a cell culture was tested in
concentrations similar to those in tissue samples. Since the
researchers could detect the mutation in RNA stemming from different
cell lines, the method actually works independent of the origin of
The research has been published in Nature Nanotechnology. Dr
François Huber, first author of the paper, explains: "The technique
can also be applied to other types of cancer that depend on
mutations in individual genes, for example in gastrointestinal
tumours and lung cancer. This shows the wide application potential
in cancer diagnostics and personalized health care."
Co-author Dr. Donata Rimoldi adds: "Only the interdisciplinary
approach in medicine, biology and physics allows the application of
novel nanotechnology methods in medicine for the benefit of
Huber F, et al. Direct detection of a BRAF mutation in
total RNA from melanoma cells using cantilever arrays. Nature
Nanotechnology 8, 125-129 (2013) | doi 10.1038/NNANO.2012.263