Retinoid regulation of target gene transcription and antitumor activity of retinoid related molecules
Retionidy regulovaná transkripce genu a protinádorová aktivita retinoidům podobných molekul
dissertation thesis (DEFENDED)
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http://hdl.handle.net/20.500.11956/9828Identifiers
Study Information System: 133291
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- Kvalifikační práce [4497]
Author
Advisor
Referee
Kostrouch, Zdeněk
Pokorný, Jaroslav
Faculty / Institute
First Faculty of Medicine
Discipline
-
Department
3rd Medical Department - Clinical Department of Endocrinology and Metabolism
Date of defense
24. 5. 2007
Publisher
Univerzita Karlova, 1. lékařská fakultaLanguage
English
Grade
Pass
Nuclear Retinoic Acid (RA) Receptors (RARs) activate gene expression through dynamic interactions with coregulators in coordination with the ligand and phosphorylation processes. In the first part of this work, we showed that during RA-dependent activation of the RARq isotype, the pi 60 coactivator pCIP/ACTR/AIВ-1 /RAC-3/TRAM-1 /SRC-3 was phosphorylated by p38MAPK. SRC-3 phosphorylation was correlated to an initial facilitation of RARa-target genes activation, via the control of the dynamics of the interactions of the coactivator with RARa. Then phosphorylation inhibited transcription via promoting the degradation of SRC-3. In line with this, inhibition of p38MAPK markedly enhanced RARa-mediated transcription and RA-dependent induction of cell differentiation. SRC-3 phosphorylation and degradation occurred only within the context of RARa complexes, suggesting that the RAR isotype defined a phosphorylation code through dictating the accessibility of the coactivator to p38MAPK. We proposed a model in which RARa transcriptional activity was regulated by SRC-3 through coordinated events that are fine- tuned by RA and p38MAPK. The retinoid related molecules (RRMs), ST1926 and CD437, are promising anti-cancer agents. In the second part of this work, we compared the RAR trans-activating properties of the two RRMs...