Year 2

STAT3 play a major role in controlling the fates of a variety of cell types including embryonic stem cells (ESCs). In this project, we proposed to investigate how STAT3 regulates ESC fate. In the past reporting period, we made the following progress:

1. Established and applied an inducible system in the mouse ESCs. This system allows us to tightly control the expression of different STAT3 mutants in mouse ESCs.
2. Discovered that phosphorylation of both Tyrosine 705 and Serine 727 is required for STAT3’s function in mouse ESCs.
3. Performed microarray analysis and identified 20 STAT3 target genes.
4. Further confirmed that STAT3 can enhance human ESC cell adhesion, but does not support human ESC self-renewal.

Based on the above results we have obtained and the tools we have developed, we are currently investigating the basic mechanisms how STAT3 regulates the fate of ESCs.