Subtraktiver Vergleich der Differenzierungsmuster menschlicher invasiver Trophoblastzellen und maligner Choriokarzinomzellen mit Hilfe von Choriokarzinom-, Trophoblast-Hybriden

摘要

Human cytotrophoblasts are a naturally occurring invasive cell population. They differ from their maligne counterpart, the choriocarcinoma cells mainly in regard of invasion depth and invasion timecourse. To analyse the molecular difference between normal and maligne invasion, normal invasive extravillous cytotrophoblasts from Chorion laeve were fused with AC1-1, a HGPRT-negative mutant of the choriocarcinoma cell line JEG-3. The resulting population of hybrid cells was called ACH1P. For this thesis 92 monoclonal cell lines were isolated from the hybrid population AC1-1. Five cell lines out of these 92 with the designations AC-1M32, AC-1M46, AC-1M59, AC-1M81 and AC-1M88 were chosen at random for further analysis. The diversity of the cell lines could be proven with the help of DNA fingerprints. In addition they showed that the cell lines contain genetic material from the one parental cell line AC1-1 and additional genetic material most likely from the other parental cell line, the extravillous cytotrophoblast. Moreover the clonal identity of the cell lines could be verified with the help of their cytogenetic, which also proved that the cells are true hybrids. The tumorigenicity of the five cell lines was assayed in nude mice. The cell line AC-1M59 is non-tumorigenic, the cell lines AC1-1, AC-1M32 and AC-1M46 are weak tumorigenic and the cell lines AC-1M81 and AC-1M88 are strong tumorigenic. The tumorigenicity thereby correlates positively with the absence of the altered X-chromosome addXq26 derived from the cell line AC1-1. Only cell lines without this altered X-chromosome are strong tumorigenic. The chromosome addXq26 harbours a translocation, which means it has lost all X-chromosomal genes distal of the translocation breakpoint Xq26. These deleted genes therefore could influence the phenotype of the cell lines. With the help of cDNA arrays and 2-D PAGE the tumorigenic cell lines were compared with the non i.e. weak tumorigenic cell lines. This comparison revealed 16 differentially expressed genes/geneproducts. Non of these genes has been discussed before in relation with human trophoblast invasion or transformation.