Die tissue microarray-technik als neues "high throughput-tool" für den nachweis differentieller proteinexpression

The attempt to accurately determine the clinical prognosis of patients suffering from malignant disease has indicated the need for the availability of new biological variables that help to better predict the biological aggressiveness of the individual tumor in addition to established histopathological characteristics, e.g. tumor stage and grade. For this purpose, the tissue microarray technique, a high throughput-tool for the cost- and time-effective immunohistochemical analysis of large number of tumor specimens has been recently introduced. This technical approach has the potential to greatly facilitate analysis of alterations in multiple tumor types and histologically heterogeneous areas. In this technique, 0.6 mm diameter tumor biopsy cores are retrieved from selected regions of archival tissue blocks, and hundreds of such cylindrical samples are subsequently arrayed in a new paraffin block. This provides a method for the high throughput-analysis of multiple targets, aiming at the identification of prognostically important parameters either on the DNA/RNA or protein level. Therefore, in comparison with conventional immunohistochemical approaches, for example, the tissue microarray-technique is a powerful tool to study the multifocal and heterogeneous nature of cancer.