Development of a tool for reversed-phase protein microarrays (RPMA) and use in immunoproteomics of breast cancer

Abstract

e22186 Background: Breast cancer is the most commonly diagnosed cancer type in women and one of the most frequent types of cancer which leads to death. It´s early detection is a key factor for successful treatment of patients. Besides, most of the current biomarkers are still lacking of specificity. In the past decade cancer immunogenicity has been described. A development of a new non-invasive method for the detection of humoral response to cancer would be of great benefit. Methods: The proteins from healthy breast tissue and carcinoma were extracted and separated via sodium dodecylsulfate polyacrylamide gel electrophoresis. The non-stained proteins were cut out of gel, digested with trypsin and spotted on nitrocellulose microarray slides. Each sub array was incubated either with different sera of breast cancer patient or with control sera and afterwards labelled with a cyanine 5-labelled human anti-immunoglobulin G antibody (IgG). Results: The extracted and digested protein fractions from both tissue types showed reproducible antibody profiles after the incubation with sera and labelling with anti-IgG antibody. The intensity of the detected signals varied within different protein fractions. Conclusions: This method provides a stable, simple and reproducible visualization of specific antibody profiles. Further upgrading of this method could facilitate a development of a fast, non-invasive and cost- efficient tool for immunoproteomics of cancer. Moreover, the following subsequent identification of the involved tumor associated antigens (TAA´s) is crucial for an understanding of their role in pathogenesis and cancer development, possibly leading to design of new cancer therapies. No significant financial relationships to disclose.