Arturo Alvarez-Buylla and Erica L. Jackson, of the University of California, San Francisco, and colleagues reported their findings in a paper in the July 20, 2006, Neuron, published by Cell Press. In their studies, they sought to discover whether neural stem cells in the brain called B cells carry a receptor--known as platelet-derived growth factor receptor á (PDGFRá)--for the signaling molecule PDGF.
Neural stem cells are immature cells that serve as the continual source of new brain cells in adults, and PDGF is known as an important regulator of such cells. Also, PDGF has been implicated as a key signaling molecule underlying the formation of brain tumors. PDGF triggers such cell response by plugging into the target receptor on the stem cell, like a key inserting into a lock.
There had been indirect evidence that neural stem cells give rise to brain tumors. "However, it has not been shown in vivo that tumor stem cells are derived from normal stem cells or that a specific population of cells with demonstrated stem cell properties is capable of initiating tumor formation," wrote the researchers.
Using tracers, the researchers discovered that PDGFRá is, indeed, found on the stem cells in both mouse and human brain tissue. They also found that the receptor is triggered by PDGF in the stem cells to regulate their production of mature brain cells. The researchers located the PDGFRá-containing cells in the subventricular zone (SVZ) of the brain, which is the center for production of new brain cells in adults.
The researchers also found that infusing PDGF into mouse brain caused abnormal growth--called hyperplasia--of tumor-like nodules that invaded surrounding brain tissue. Their analysis indicated that the PDGF infusion caused the stem cells to halt their normal production of mature brain cells and launch into the abnormal proliferation pathway. Importantly, the researchers found that stopping the PDGF infusion caused a complete regression of the nodules.
The researchers wrote that "these findings are significant due to our limited knowledge of surface markers for neural stem cells. Our data also provide evidence of a link between these PDGFRá B cells and the early changes associated with tumor initiation, suggesting they may be targets of neoplastic transformation. The regression of atypical hyperplasia after PDGF removal described here suggests that inhibition of PDGF signaling could provide a useful therapy for those gliomas in which the pathway is upregulated, especially given the recovery of the normal architecture after regression of the hyperplasia."
In a preview of the paper in the same issue of Neuron, Santosh Kesari and Charles D. Stiles wrote that the new findings "lend weight" to the argument that the stem cells identified by Alvarez-Buylla and his colleagues are the cells or origin for malignant gliomas. They wrote that such work offers "therapeutic opportunities," emphasizing that "the people that matter the most do not have the luxury of time to watch this work unfold. The median interval from diagnosis to death for patients with malignant glioma is currently only 14 months."
Transforming plant cells from generalists to specialists
07.12.2016 | Duke University
What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
07.12.2016 | Earth Sciences
07.12.2016 | Earth Sciences
07.12.2016 | Materials Sciences