Abstract
The Hedgehog (Hh) pathway regulates proliferation in a variety of tissues, however its specific effects on the cell cycle are unclear. During retinal proliferation in particular, the role of Hh has been controversial, with studies variably suggesting a stimulatory or an inhibitory effect on proliferation. Our recent data provide an underlying mechanism, which reconciles these different views. We showed that Hh signaling in the retina accelerates the G1 and G2 phases of the cell cycle and then pushes these rapidly dividing cells out of the cell cycle prematurely. From this and other evidence, we propose that Hh converts quiescent retinal stem cells into fast-cycling transient amplifying progenitors that are closer to cell cycle exit and differentiation. This is, we suggest, likely to be a general role of Hh in the nervous system and other tissues. This function of Hh in cell cycle kinetics and cell cycle exit may have implications for tumorigenesis and brain evolution.
Original language | English (US) |
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Pages (from-to) | 156-159 |
Number of pages | 4 |
Journal | Cell Cycle |
Volume | 6 |
Issue number | 2 |
DOIs | |
State | Published - Jan 15 2007 |
Keywords
- Cancer stem cells
- Cell cycle
- Hedgehog signaling
- Neural stem cells
- Retina
- Transient amplifying progenitors
ASJC Scopus subject areas
- Molecular Biology
- Developmental Biology
- Cell Biology