Proteomics of breast cancer for marker discovery and signal pathway profiling

Breast cancer is the most common form of cancer among women and the identif ication of markers to discriminate tumorigenic from normal cells, as well a s the different stages of this pathology, is of critical importance. Two-di mensional electrophoresis has been used before for studying breast cancer, but the progressive completion of human genomic sequencing and the introduc tion of mass spectrometry, combined with advanced bioinformatics for protei n identification, have considerably increased the possibilities for charact erizing new markers and therapeutic targets. Breast cancer proteomics has a lready identified markers of potential clinical interest (such as the molec ular chaperone 14-3-3 sigma) and technological innovations such as large sc ale and high throughput analysis are now driving the field. Methods in func tional proteomics have also been developed to study the intracellular signa ling pathways that underlie the development of breast cancer. As illustrate d with fibroblast growth factor-2, a mitogen and motogen factor for breast cancer cells, proteomics is a powerful approach to identify signaling prote ins and to decipher the complex signaling circuitry involved in tumor growt h. Together with genomics, proteomics is well on the way to molecularly cha racterizing the different types of breast tumor, and thus defining new ther apeutic targets for future treatment.