TGF-beta in neural stem cells and in tumors of the central nervous system
Ludwig Aigner1, Ulrich Bogdahn
1Department of Neurology, University of Regensburg, Universitätsstrasse 84, 93053, Regensburg, Germany. ludwig.aigner@klinik.uni-regensburg.de
Abstract:
Mechanisms that regulate neural stem cell activity in the adult brain are tightly coordinated. They provide new neurons and glia in regions associated with high cellular and functional plasticity, after injury, or during neurodegeneration. Because of the proliferative and plastic potential of neural stem cells, they are currently thought to escape their physiological control mechanisms and transform to cancer stem cells. Signals provided by proteins of the transforming growth factor (TGF)-beta family might represent a system by which neural stem cells are controlled under physiological conditions but released from this control after transformation to cancer stem cells. TGF-beta is a multifunctional cytokine involved in various physiological and patho-physiological processes of the brain. It is induced in the adult brain after injury or hypoxia and during neurodegeneration when it modulates and dampens inflammatory responses. After injury, although TGF-beta is neuroprotective, it may limit the self-repair of the brain by inhibiting neural stem cell proliferation. Similar to its effect on neural stem cells, TGF-beta reveals anti-proliferative control on most cell types; however, paradoxically, many brain tumors escape from TGF-beta control. Moreover, brain tumors develop mechanisms that change the anti-proliferative influence of TGF-beta into oncogenic cues, mainly by orchestrating a multitude of TGF-beta-mediated effects upon matrix, migration and invasion, angiogenesis, and, most importantly, immune escape mechanisms. Thus, TGF-beta is involved in tumor progression. This review focuses on TGF-beta and its role in the regulation and control of neural and of brain-cancer stem cells.
Insights
Transforming growth factor-beta (TGF-β) regulates neural stem cells but is subverted by brain tumors. This cytokine
Area of Science:
- Neuroscience
- Cancer Biology
- Molecular Signaling
Background:
- Adult neural stem cells (NSCs) generate neurons and glia in specific brain regions.
- NSCs possess plasticity, but can transform into cancer stem cells (CSCs).
- Transforming growth factor-beta (TGF-β) is a key regulator in the brain.
Purpose of the Study:
- To review the role of TGF-β in regulating normal neural stem cells.
- To examine how TGF-β signaling is altered in brain cancer stem cells.
- To understand TGF-β's dual role in neuroprotection and tumor progression.
Main Methods:
- Literature review of studies on TGF-β signaling in the brain.
- Analysis of TGF-β's effects on neural stem cell proliferation and differentiation.
- Investigation of TGF-β pathway manipulation in brain tumor development and progression.
Main Results:
- TGF-β normally inhibits NSC proliferation, potentially limiting self-repair after injury.
- Brain tumors evade TGF-β's anti-proliferative effects.
- Cancer cells reprogram TGF-β signals to promote invasion, angiogenesis, and immune escape.
Conclusions:
- TGF-β plays a critical role in controlling neural stem cell fate.
- Dysregulation of TGF-β signaling is a hallmark of brain cancer stem cells.
- Understanding TGF-β's complex roles is crucial for developing brain cancer therapies.
