The high mobility group protein AT-hook 2 (HMGA2) is an architectonic transcription factor abundantly expressed during embryonic and fetal development and is associated with the progression of malignant tumors. In this thesis, chromatin immunoprecipitation (ChIP) experiments and bioinformatic methods were used to analyze and characterize DNA-binding sites of the HMGA2 protein. The results show that artificially generated SELEX sequences and short BLAST alignments of the ChIP fragments from living cells possess similarities in their structural organization. In further experiments the expression of HMGB1 and HMGA2 in different body fluids from cancer patients and pregnant women was determined to provide valuable data for further use in tumor and prenatal diagnosis. HMGB1, a so-called danger signaling protein, as well as the protooncogene HMGA2 were found to be highly expressed in human pleural and peritoneal effusions due to cancer and inflammation. The results underline these proteins as possible targets for treatment in advanced cancer as well as in inflammatory diseases. Additionally an improved protocol of the chromatin immunoprecipitation was established, to select and enrich cell-free, fetal DNA from amniotic fluid. The fact that HMGA2 apparently remains to be attached to cell-free DNA suggests interesting new approaches in noninvasive prenatal diagnosis.
