Altered chemotherapeutic response of primary human breast cancer epithelial cells (HBCEC) and breast cancer cell lines

11506 Background: A novel technique to obtain individual primary cultures of human breast cancer biopsies was filed for patent (PCT/DE 2006/000608). The different individualized HBCEC (human breast cancer epithelial cell) cultures will be characterized and chemotherapeutic effects will be compared to established breast cancer cell lines. Methods: Primary HBCEC from 20 different breast cancer patients were characterized for epithelial cell and tumor markers by immunofluorescence and PCR. Following treatment with 1μM epirubicin for 1h up to 72h differences in protein expression patterns were compared to the similarly treated MCF-7 cell line by 2D gel electrophoresis. Differentially expressed protein spots were identified by mass spectrometry and confirmed by appropriate Western blot analysis. Results: Characterization of primary HBCEC revealed continuous mitosis and cell cycle progression for more than one year in culture with no significant contamination by fibroblasts or other cell types. Whereby HBCEC underwent cell death within 72h of epirubicin treatment analysis by 2D gel and subsequent protein identification by MALDI-TOF/TOF mass spectrometry exhibited a variety of differences compared to MCF-7 cells including HSP27 and prohibitin. Appropriate Western blots confirmed these differences and revealed altered expression levels for HSP27 and prohibitin in the course of epirubicin exposure in HBCEC and MCF-7 cells, respectively, suggesting altered signalling pathways in either primary breast cancer cells or the tumor cell line. Conclusions: Individualized primary HBCEC from various patients could provide a cellular platform beyond breast cancer cell lines, which eventually meet the requirements for an appropriate breast cancer testing system including the characterization of biomarkers and the identification of potential molecular targets. No significant financial relationships to disclose.