Related Experiment Videos
STAT3 activation accompanies keratinocyte differentiation
P J Hauser1, D Agrawal, J Hackney
1Department of Cell Biology, Vanderbilt University, Nashville, Tennessee 37240, USA.
Cell Growth & Differentiation : the Molecular Biology Journal of the American Association for Cancer Research
|October 28, 1998
Summary
Signal transducers and activators of transcription 3 (STAT3) activation is crucial for keratinocyte differentiation and cell cycle exit. Its regulation is linked to cell cycle machinery, specifically p27kip1, impacting differentiation markers.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Signal transducers and activators of transcription (STAT) factors regulate cell differentiation and cell cycle.
- STAT3 plays roles in various cell types during differentiation and cell cycle exit.
Purpose of the Study:
- To investigate STAT3 activation during growth arrest and differentiation in primary murine keratinocytes.
- To explore the relationship between STAT3 activation and the cell cycle machinery, particularly p27kip1.
Main Methods:
- Studied STAT3 DNA binding activity in quiescent and mitogenically stimulated keratinocytes.
- Examined STAT3 activity in keratinocytes induced to differentiate by suspension culturing.
- Investigated the role of p27kip1 in STAT3 activation using antisense oligonucleotides and p27kip1-deficient keratinocytes.
Main Results:
- STAT3 activation was detected in quiescent keratinocytes, down-regulated by mitogens, and reaccumulated during re-quiescence.
- STAT3 activity was induced by suspension culturing, which promotes keratinocyte differentiation.
- STAT3 induction was absent in immortalized MK cells that do not differentiate.
- Inhibition of p27kip1 accumulation led to loss of STAT3 activation and delayed keratinocyte differentiation.
Conclusions:
- STAT3 activation is tightly linked to keratinocyte growth status and cell cycle withdrawal.
- Alterations in the cell cycle machinery, specifically involving p27kip1, are necessary for proper STAT3 up-regulation during keratinocyte differentiation.
- STAT3 activity is a key regulator of keratinocyte differentiation, influenced by cell cycle events.