MiRNAs play a number of roles in biological regulation, including development and cell differentiation, helping to determine what type a cell ultimately becomes. But when damaged, they can contribute to cancer by either turning on cancer-causing genes or by inhibiting tumor-blocking genes. The ways that MiRNAs are expressed have been used to profile tumor types in humans.
To see if miRNAs could affect cancer risk, Linda Siracusa, Ph.D., associate professor of microbiology and immunology at Jefferson Medical College of Thomas Jefferson University, research associate Cinzia Sevignani, Ph.D., and co-workers George Calin, M.D., Ph.D., and Carlo M. Croce, M.D., at Ohio State University in Columbus and Peter Demant, M.D., Ph.D., at Roswell Park Cancer Institute in Buffalo compared the mouse chromosome locations of genes known to affect cancer susceptibility – or "susceptibility loci" – in eight different types of tumors to the locations of mouse miRNAs.
Reporting in the journal Proceedings of the National Academy of Sciences, the team showed that overall, miRNAs were found 1.5 times more likely to be in susceptibility regions than in non-susceptibility regions. "MiRNAs appear to be frequently located near places in the mouse genome that affect cancer susceptibility," the researchers say, suggesting that miRNAs could be "a new family of cancer tumor susceptibility genes."
Susceptibility loci are forms of the same gene. While one form may give a person a higher risk of developing a cancer, an alternate form may confer resistance to that particular type of cancer.
The researchers identified changes in the DNA sequences surrounding several miRNAs that were located at or near the susceptibility areas in mouse strains with a variety of tumor types. The team also looked at which mouse strains were cancer-resistant and which were susceptible to cancer, uncovering seven miRNAs that had genetic sequence differences between the two groups. Five of these miRNAs had changes within their predicted promoter regions, which turn on and potentially regulate the genes' expression levels.
"We have hypothesized that changes in the promoter regions could affect the levels of miRNAs, which could influence a person's lifetime risk of cancer," Dr. Siracusa notes.
Dr. Siracusa and her collaborators plan to examine miRNA expression levels among inbred mice strains. "Could the level of a particular miRNA affect the expression of other genes and regulate the stability of the RNA transcript" she asks. "Having a slightly lower level of a particular miRNA could make a person more susceptible to a particular cancer or the reverse, or a slightly increased level might protect that person."
Steve Benowitz | EurekAlert!
New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg
Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
24.02.2017 | Life Sciences
24.02.2017 | Life Sciences
24.02.2017 | Trade Fair News