The jury is in: microRNAs can cause tumors to metastasize. These tiny molecules fine-tune protein production and play a powerful role in biological processes ranging from development to aging. Now scientists have proved that they can prompt otherwise sedentary cancer cells to move and invade other tissues.
Labs have been probing the relationship between aberrant microRNA levels and cancer for several years. They’ve shown that some microRNAs cause normal cells to divide rapidly and form tumors, but they’ve never demonstrated that microRNAs subsequently cause cancer cells to metastasize.
Now, working in the lab of Whitehead Member Robert Weinberg, postdoctoral fellow Li Ma has coaxed cancer cells to break away from a tumor and colonize distant tissues in mice by simply increasing the level of one microRNA. Her results appear online in Nature on September 26.
“Li has shown that a specific microRNA is able to cause profound changes in the behavior of cancer cells, which is striking considering that 10 years ago no one suspected microRNAs were involved in any biological process,” says Weinberg, who is also an MIT professor of biology.
Ma began with a list of 29 microRNAs expressed at different levels in tumors versus normal tissue. She examined their production in two groups of cancer cells—metastatic and non-metastatic. Metastatic cancer cells (including those taken directly from patients) contained much higher levels of one microRNA called microRNA-10b.
Next, Ma forced non-metastatic human breast cancer cells to produce lots of microRNA-10b by inserting extra copies of the gene. She injected the altered cancer cells into the mammary fat pads of mice, which soon developed breast tumors that metastasized.
So what caused this stunning metamorphosis?
MicroRNAs typically disrupt protein production by binding to the messenger RNAs that copy DNA instructions for proteins and carry them to “translators.” Ma used a program developed in the lab of Whitehead Member David Bartel to search for the target of microRNA-10b. She identified several candidates, including the messenger RNA for a gene called HoxD10.
Generally involved in development, Hox proteins control many genes active in an embryo. Some Hox proteins have also been implicated in cancer. HoxD10, for example, can block the expression of genes required for cancer cells to move—essentially applying the brakes to a migration process.
To test whether she had removed the brakes during her experiment, awakening the dormant migration process, Ma boosted the level of HoxD10 in the cancer cells with artificially high levels of microRNA-10b. The cells lost their newly acquired abilities to move and invade.
“I was able to fully reverse microRNA-10b induced migration and invasion, suggesting that HoxD10 is indeed a functional target,” Ma explains.
“During normal development, this microRNA probably enables cells to move from one part of the embryo to another,” adds Weinberg. “Its original function has been co-opted by carcinoma cells.”
Eric Bender | EurekAlert!
How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH
A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
23.06.2017 | Physics and Astronomy
23.06.2017 | Physics and Astronomy
23.06.2017 | Information Technology