Abstract 661: Identification of the novel tissue biomarker for breast cancer cells ZR-75-1 using combination of bacterial display and modified affinity chromatography methods

Abstract

Abstract Identification of the novel tissue biomarker for breast cancer cells ZR-75-1 using combination of bacterial display and modified affinity chromatography methods Introduction: Recognition of biomarkers for cancers is very important for the diagnosis, therapy and prognosis of these kinds of diseases. The study of identifying those novel cancer biomarkers is difficult although people have already tried lots of methods, the numbers and types of effective biomarkers could not meet the needs of medical practices yet. Setting up new methods and identifying novel biomarkers for cancers are working aims for many researchers. Breast cancer is one of the most malignant and common cancer types for women. Even some biomarkers have been identified and prove to play a role in the diagnosis and treatment of cancers, such as estrogen and HER-2, but they cannot be applied to all breast cancer types. The purpose of this work is to combine the bacterial display and modified affinity chromatography methods to identify novel biomarkers for breast cancer cells ZR-75-1. Methods: 1. Bacteria display methods have been used to identify the specific binding peptides for ZR-75-1 cells; 2. Bacteria which express specific binding peptides have been used as the matrix for affinity chromatography; 3. The membrane fraction of cells has been extracted and biotinylated cell membrane lysates have been used to bait the peptide binding receptors; 4. Protein identification has been performed using Nano-LC followed by mass spectrometry; 5. Newly identified membrane receptors for specific peptides need to be justified as novel biomarkers for this kind of cancer by checking the protein membrane localization, interactive proteins and affected possible signaling pathway. Summary and conclusion: Peptides which can interact with breast cancer ZR-75-1 cells have been identified and published in the lab previous paper, but the targeted receptor groups for those peptides have not been established. Glycolytic enzyme aldolase is supposed to be the cytosolic protein which is involved in the cell glycolysis procedure, but our experiment proved that it could be the binding partner for the one of the most specific peptides published before by modified affinity chromatography method. Furthermore, it has also been proved that both aldolase and calveolin-1 can co-locate on the membrane of these non-muscle cells. Therefore, we can predict that this over-expressed membrane localized glycolytic enzyme may be involved in some signal transduction pathways which can initiate tumorigenesis or proliferation besides its original glycolysis activity. Meanwhile, combination of identification of specific binding peptides using bacteria display with modified affinity chromatography methods could be used as the novel methods to identify the tissue biomarkers for cancers. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 661.