DETECTION OF MAMMA-CARCINOMA-SPECIFIC PRO TEINS FROM THE SERUM OF XENOTRANSPLANTED NUDE-MICE BY MEANS OF DIFFERENTIAL 2-DIMENSIONAL ELECTROPHORESIS

Two-dimensional electrophoresis is the most advanced technique for sep aration of complex protein mixtures. The method represents a combinati on of isoelectric focusing (IEF), i.e. separation of proteins accordin g to isoelectric points (first dimension), with slab gel electrophores is (SDS-PAGE), i. e. separation of proteins according to molecular wei ghts (second dimension). After staining the proteins are visible as sp ots on the gel slab. The use of this method for investigation of serum proteins from tumor patients is restricted by several obstacles. The most prominent problem is the absence of a tumor-free control-serum fr om the same patient. To overcome this problem we designed the followin g experiment: Two mamma-carcinoma cell-lines were transplanted onto nu de mice. Serum samples were obtained prior to and after transplantatio n and investigated by two-dimensional electrophoresis. By comparison o f the two patterns 12 additional protein-spots with pHi 4.4-6.5 and mo lecular weights from 21 to 70 kD were detected. It could therefore be shown that the detection of proteins unique to the tumor-bearing serum is possible in this system. This provides the basis for investigation of these proteins from patients serum and for correlation of these pr oteins with histology and course of disease. Furthermore, analysis and identification of the proteins is currently under way.