The study, which appears in the advance online edition of the journal Molecular and Cellular Biology, indicates that two proteins, named Timeless and Tipin, form a complex that regulates the rate at which DNA is replicated after exposure to ultraviolet radiation.
Ultraviolet radiation in sunlight damages the DNA in skin cells. If left unrepaired by the cell, this damage can turn into mutations that lead to cancer. Before cells divide, they must replicate, or copy, their DNA to form new daughter cells. If damage in the DNA is discovered even after the cell has given a "go-ahead" to replicate its DNA, the Timeless/Tipin complex sends a signal throughout the nucleus of the cell to slow the rate of replication. This slowdown may give the cell additional time to repair its DNA and potentially save itself from becoming cancerous or from dying in response to ultraviolet radiation.
"What we discovered here was that the cell can send out an additional SOS and slow DNA replication even after it has begun," said Dr. William Kaufmann, a professor of pathology and laboratory medicine and a member of the UNC Lineberger Comprehensive Cancer Center and Center for Environmental Health and Susceptibility.
"We've known for 25 years that a cell can stop DNA replication from even starting when it detects damage in its own DNA – this gives the DNA repair mechanisms in the cell the time to find and repair the damage," he said.
Using an innovative new technique to visualize the replication of DNA strands exposed to ultraviolet radiation, Kaufmann and his co-authors noted a slowdown in DNA replication when Timeless and Tipin were present in the cell. Building blocks for DNA were labeled with fluorescent molecules so that tracks of newly synthesized DNA could be observed under the microscope and their lengths measured.
Though the study specifically examined only the Timless/Tipin response to ultraviolet radiation, Kaufmann speculates that this response may be relevant to other types of DNA damage as well – including those used as treatments for cancer.
"This protective response may make some cells more resistant to certain types of cancer therapies which work by inducing the cancer cell to die. If the cell, even if it is a cancer cell, is given this additional time to recover from treatment, it may be able to survive it, much to the detriment of the patient." Kaufmann said.
Ultraviolet radiation in sunlight causes at least one million cases of skin cancer in the U.S. annually and greater than fifty thousand cases of melanoma.
Leslie Lang | EurekAlert!
Rutgers scientists discover 'Legos of life'
23.01.2018 | Rutgers University
Researchers identify a protein that keeps metastatic breast cancer cells dormant
23.01.2018 | Institute for Research in Biomedicine (IRB Barcelona)
Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together with colleagues from the University of Bochum, scientists from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute reported the findings in the journal Nature Photonics.
Microscopes allow us to see structures that are otherwise invisible to the human eye. However, conventional optical microscopes cannot be used to image...
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
23.01.2018 | Life Sciences
23.01.2018 | Earth Sciences
23.01.2018 | Physics and Astronomy