Abstract:
Breast cancer is the most frequent malignant neoplasia in women. The understanding of its genetic pathogenesis and progression during tumor growth is of essential importance for an improved diagnostic procedure with the aim of an effective and individualised therapy. Mutations of the oncogene HER/2neu, for example, indicate an aggressive tumor form, which can be favourably influenced by a treatment with monoclonal antibodies. In the same way, specific genetic aberrations for different stages of progression could be a step towards a tumor progression model similar to the one existing for colorectal cancer. Differential DNA-analysis like Comparative Genomic Hybridization (CGH) is a suitable tool for the exact investigation of the tumor-genome. This requires a high grade of purity of the extracted tumor-DNA. As tumor cells are embedded in heterogeneous tissue, special microdissection technologies are necessary to obtain pure tumor-DNA. Therefore, in the work presented here the new technology of Laser Capture Microdissection (LCM) was used. This technology was combined with a DOP-PCR (PCR with degenerated primers for amplification of the complete genome) in order to obtain sufficient concentrations of DNA for subsequent CGH-experiments. This thesis presents the establishment and optimizing steps of the separate methods LCM, DOP-PCR and CGH as well as their combination. Two primary cancers as well as one lymph node metastasis of invasive ductal breast cancer were intensively analysed and aberrations known from the literature could be confirmed. This shows the suitability of the chosen methods for cytogenetic analysis of breast cancer and provides an important basis for broad studies of genetic progression of breast cancer.