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Archive - Feb 20, 2017

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Protein Once Thought Exclusive to Neurons Helps Aggressive Cancers Grow, Spread, Defy Death

How we think and fall in love are controlled by lightning-fast electrochemical signals across synapses, the dynamic spaces between nerve cells. Until now, nobody knew that cancer cells can repurpose tools of neuronal communication to fuel aggressive tumor growth and spread. University of Texas (UT) Southwestern Medical Center researchers report these findings in two recent studies, one in PNAS and the second in Developmental Cell. The PNAS article (online January 3, 2017) is titled “TRAIL-Death Receptor Endocytosis and Apoptosis Are Selectively Regulated by Dynamin-1 Activation,” and the Developmental Cell article (online February 6, 2017) is titled “Crosstalk Between CLCb/Dyn1-Mediated Adaptive Clathrin-Mediated Endocytosis and Epidermal Growth Factor Receptor Signaling Increases Metastasis.” “Many properties of aggressive cancer growth are driven by altered cell signaling,” said Dr. Sandra Schmid, senior author of both papers and Chair of Cell Biology at UT Southwestern. “We found that cancer cells are taking a page from the neuron’s signaling playbook to maintain certain beneficial signals and to squelch signals that would harm the cancer cells.” The two studies find that dynamin1 (Dyn1) – a protein once thought to be present only in nerve cells of the brain and spinal cord – is also found in aggressive cancer cells. In nerve cells, or neurons, Dyn1 helps sustain neural transmission by causing rapid endocytosis – the uptake of signaling molecules and receptors into the cell – and their recycling back to the cell surface. These processes ensure that the neurons keep healthy supplies at the ready to refire in rapid succession and also help to amplify or suppress important nerve signals as necessary, Dr. Schmid explained. “This role is what the cancer cells have figured out.

First Controllable Electronic Switch Within Single DNA Molecule

DNA, the stuff of life, may very well also pack quite the jolt for engineers trying to advance the development of tiny, low-cost electronic devices. Much like flipping your light switch at home---only on a scale 1,000 times smaller than that of a human hair---an Arizona Statte University (ASU)-led team has now developed the first controllable DNA switch to regulate the flow of electricity within a single, atomic-sized molecule. The new study, led by ASU Biodesign Institute researcher Dr. Nongjian Tao, was published online on February 20, 2017 in Nature Communications. The open-access article is titled “Gate-Controlled Conductance Switching in DNA.” "It has been established that charge transport is possible in DNA, but for a useful device, one wants to be able to turn the charge transport on and off. We achieved this goal by chemically modifying DNA," said Dr. Tao, who directs the Biodesign Center for Bioelectronics and Biosensors and is a professor in the Fulton Schools of Engineering. "Not only that, but we can also adapt the modified DNA as a probe to measure reactions at the single-molecule level. This provides a unique way for studying important reactions implicated in disease, or photosynthesis reactions for novel renewable energy applications." Engineers often think of electricity like water, and the research team's new DNA switch acts to control the flow of electrons on and off, just like water coming out of a faucet. Previously, Dr. Tao's research group had made several discoveries to understand and manipulate DNA to more finely tune the flow of electricity through it.