Reverse phase protein array based protein profiling of breast cancer specimens (2)

Expression levels of proteins and phosphoproteins, covering major cancer signaling pathways with a special focus on breast cancer biology, were obtained for a series of 164 breast cancer tumor specimens with positive estrogen receptor status. Tumor specimens from patients diagnosed with primary invasive breast carcinoma were collected at the time of surgery between 2005 and 2011 and provided by the NCT Tissue Bank Heidelberg as well as by the Department of Gynecology and Obstetrics / National Center for Tumor Diseases Heidelberg. None of the patients had received neoadjuvant therapy.Tumor specimens were processed within 20 min after surgery. Samples were stored snap frozen at -80°C until further use. Only tumor samples with > 70% tumour cells and positive estrogen receptor status (immunoreactive score ≥ 3) as assessed by routine immunohistochemistry were selected for this study (n = 164). Tumor lysates were printed on a series of nitrocellulose coated glass slides and probed with with differnt primary antibodies directed against proteins and phosphoproteins of interest. Primary antibodies were selected to recognize proteins involved in major cancer signaling pathways with a special focus on breast cancer biology.