Probing the Tyrosine Phosphorylation State in Breast Cancer by Src Homology 2 Domain Binding

摘要

Improved molecular diagnostic methods that can classify tumors and predict their response to therapy have enormous potential to improve the effectiveness breast cancer treatments. The overall goal of this project was to develop a novel molecular diagnostic method, termed SH2 profiling, that can classify cell samples based on their global protein tyrosine phosphorylation state. The first aim was to use an existing SH2 profiling method, based on far- Western blotting, to analyze fresh surgical breast cancer samples. The second aim was to develop a more high-throughput quantitative reversed-phase SH2 profiling format, and test its usefulness in classifying breast cancer samples. The third aim was to develop histochemical SH2 profiling methods that can be used to analyze archived, formalin-fixed tissue sections, and perform pilot retrospective studies to determine whether SH2 binding patterns have potential prognostic value. Over the course of this study we have made great progress in developing a robust, quantitative, high-throughput SH2 profiling method. We have constructed a nearly complete set of human SH2 domain probes. We have used these tools to profile 20 human breast cancer surgical specimens. We find that SH2 profiles differ among different breast cancer samples, and provide information beyond that provided by standard clinical-pathological staging. Thus we have demonstrated the feasibility of SH2 profiling as a novel molecular diagnostic tool for classifying cancer and potentially predicting clinical outcomes.