Feasibility of SH2 Binding as a Prognostic and Diagnostic Indicator: 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 of breast cancer treatments. The overall goal of this project is 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 is to use and existing SH2 profiling method, based on far- Western blotting, to analyze fresh surgical breast cancer samples. The second aim is to develop a more high-throughput quantitative reversed-phase SH2 profiling format, and test its usefulness in classifying breast cancer sample. The third aim is 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 value. In the past year we have begun analysis of clinical breast cancer samples by both far-Western and reverse-phase protein array. In particular we have optimized and validated a robust reverse-phase array platform for SH2 profiling with throughput and reproducibility suitable for analysis of clinical tumor samples, and generated 45 new SH2 domain proves for use in SH2 profiling. We have performed SH2 profiling on eight clinical breast cancer samples, and performed hierarchical clustering analysis of these tumors based on their Sh2 binding patterns. We have also found an intriguing correlation between SH2 binding pattern and the presence of inflammation in the tumor.