RESEARCH REPORT: UCSD team’s find could stem stem-cell loss
By Lynne Friedmann
Chemo and radiation therapy kills cancer cells but also depletes patients of their own adult stem cells, particularly those responsible for making new blood and intestine cells. The result: anemia, appetite suppression and significant weight loss. Biologists at UCSD report a discovery that may help stem this adult stem cell loss.
Scientists have long known that when normal cells accumulate significant DNA damage, such as during cancer therapy, the tumor suppressor p53 is activated, which leads cells to stop dividing, go into hibernation and undergo a programmed cell death called apoptosis. They also know that a gene called Puma (short for “p53-unregulated modulator of apoptosis”) is critical for p53 to initiate the cell death of DNA-damaged cells.
Suppressing p53 isn’t a treatment option, because to do so would induce cancer. But, the ability to target and suppress Puma function could rescue many adult stem cells that would otherwise be lost after the accumulation of DNA damage such as during cancer therapy. The research was conducted in animal models and the findings appear in the journal Nature Cell Biology. News release at bit.ly/9VmDpE.
Clearing harmful proteins
Scientists believe amyloid (an insoluble fibrous protein) plays a central role in the development of Alzheimer’s disease and that an imbalance between production and clearance of amyloid leads to the build up and formation of plaques. What remains a mystery is how amyloid is normally broken down and removed as debris from the brain.
Scientists have begun to suspect that amyloid disables a structure called a proteasome (found in every cell), which chops up a variety of proteins no longer need into pieces that can be reused or discarded by a cell. In Alzheimer’s patients, however, tagged proteins are not discarded but instead pile up in the brain.
Chemists at UCSD have demonstrated that proteasome has a greater affinity for amyloid. This helps explain why other proteins build up undigested. The findings appear in the journal ACS Chemical Neuroscience. More information at bit.ly/bpdFOy.
Sound and marine life
Because light penetrates so poorly in water, many marine organisms use sound to guide their movements. As human have increasingly introduced sound and noise into the oceans of the world, researchers have sought ways to better understand the potential harmful effects on marine mammals such as whales and dolphins.
An international team of researchers from San Diego State University, UCSD and the Kolmården Zoo in Sweden has integrated advanced computing, X-ray CT scanners and modern computational methods to create a 3D simulated look inside the head of a Cuvier’s beaked whale, a species known to have stranded on beaches and died in the presence of Navy sonar.
Within this thre-dimensional virtual environment scientists can simulate sounds propagated through the virtual specimen and reveal the interactions between the sound and the anatomy. By having a virtual “peek” inside the whale’s head, the scientists are able to better understand and see how sound may impact or potentially harm marine life. The research results are published in PLoS ONE. News release at bit.ly/cPbOKy.
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