2009 ABSTRACTS - Universität Leipzig

non-coding RNAs as Regulators and tools
1 STAT3 regulated non-coding RNAs in tumor cells
Friedemann Horn
Recent analyses of the human genome revealed the existence of a high number of noncoding
(nc)RNA transcripts. It is increasingly being recognised that these ncRNAs now constitute
an important and complex layer of cellular regulation. In addition, a growing number of
ncRNAs prove to be disease-associated. However, data on how cellular signalling networks
interact with the ncRNA layer are still sparse.
The transcription factor Stat3 was discovered by our group as a central component of
interleukin-6 signalling. Stat3 is involved in differentiation, proliferation and apoptosis
control of many cell types during embryogenesis as well as in adult tissues. In addition, Stat3
is now regarded a highly oncogenic protein, being constitutively active in >70% of human
tumours.
We currently address the question whether in addition to its known functions, the Stat3
pathway is involved in the transcriptional regulation of ncRNAs. We could demonstrate
that Stat3 controls the expression of the anti-apoptotic microRNA miR-21 through a
phylogenetically conserved enhancer. This microRNA is highly expressed in many cancers.
Our results suggest that the oncogenic potential of Stat3 relies at least in part on the induction
of the miR-21 gene.
Furthermore, genome-wide expression analyses provided evidence that Stat3 regulates many
novel ncRNA genes, suggesting an intimate cross-talk between the Stat3 signal pathway and
the unfolding „RNA world“.
Prof. Dr. Friedemann Horn
Universitöt Leipzig
Faculty of Medicine
Institute of clinical immunology
friedemann.horn@medizin.uni-leipzig.de
http://ikit.uniklinikum-leipzig.de/
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