Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Brain tumors may originate with neural stem cells


Researchers at UT Southwestern Medical Center have determined that stem cells in a certain region of the brain may be the source of a particular type of incurable brain tumor and may be implicated in other types of brain cancers as well.

The research, conducted in mice, appears in the August issue of the journal Cancer Cell. The findings support growing evidence that adult stem cells may play a role in the development of some forms of cancer, said Dr. Luis Parada, senior author on the paper and director of the Center for Developmental Biology and the Kent Waldrep Center for Basic Research on Nerve Growth and Regeneration at UT Southwestern.

"Continued research into the biology of adult stem cells will aid in the understanding of how cancers originate and develop and may lead to possible new therapies for treating aggressive, currently incurable brain tumors," said Dr. Parada.

Malignant astrocytoma, or glioma, is one of the most common types of brain tumor in adults. The tumors are thought to arise from glial cells, which are non-nerve cells that provide support and nutrition to cells of the nervous system.

Because these incurable cancers generally are not detected until they are advanced, when symptoms have begun to develop, scientists have been unsure where, or what, initiates the process of uncontrolled cell replication that leads to the formation of the tumors.

Dr. Parada and his research group, including former UT Southwestern postdoctoral researcher and lead author Dr. Yuan Zhu, now at the University of Michigan Medical School, developed a strain of genetically engineered mice that served as models for their human brain-cancer studies and allowed researchers to track down the origins of such tumors. The mice lacked a tumor suppressor gene called p53 and also had a mutated version of another tumor suppressor gene called NF1. The mutated NF1 resulted in an increase in a biochemical reaction called Ras signaling, which has been implicated in the initiation of some cancers.

As infants, the mutant mice showed no sign of cancer, but as they grew older, they all developed brain tumors. By observing and evaluating "snapshots" of changes in the mouse brains over time, Dr. Parada’s research team determined that the tumors originated in neural stem cells. Those cells that became cancerous then migrated to other areas of the brain and caused tumors.

Previous research has demonstrated that adult neural stem cells are isolated in only a few regions of the mammalian brain, with the highest densities of such cells occurring in the hippocampus, an area important for learning and memory, and the subventricular zone of the forebrain.

The UT Southwestern researchers found that stem cells in the subventricular zone gave rise to malignant astrocytoma in the genetically engineered mice.

"While our study cannot rule out alternative explanations for the initiation of astrocytoma, the identification of the subventricular zone as the site of tumor origin in our models may have implications on therapeutic strategies for preventing and treating a subset of human malignant astrocytomas," Dr. Parada said. "Our results challenge current dogma, which assumes that tumors of this type arise from glial cells located throughout the brain."

The results offer an explanation for why current treatment for malignant astrocytoma in humans ultimately fails. Strategies that focus only on treating localized lesions would not be sufficient to eradicate tumor cells because these cells may eventually be replenished from the cell pool within the subventricular zone, the researchers said.

They also determined that inactivation of both p53 and NF1 is sufficient to initiate the formation of the brain cancer, and that the timing of the inactivation of each gene is critical. For the malignant astrocytoma to begin forming, p53 inactivation must either precede or coincide with the increase in Ras signaling associated with the loss of NF1.

Stem cells are unspecialized cells, capable of dividing and renewing themselves for long periods of time. They can give rise to many types of specialized cells, such as blood, nerve and muscle cells. While embryonic stem cells, which are derived from very early embryos, are capable of generating all types of cells in the body during normal development, adult stem cells have lost this potential. Adult stem cells differentiate to produce cells from the tissue where they originate.

Amanda Siegfried | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>