Chapter 4: Cross-talk between ubiquitin ligase and breast carcinogenesis

Ubiquitin Proteosome System (UPS) plays a pivotal role in keeping a check on protein stability and removal of misfolded or unwanted proteins in order to maintain homeostasis of the cell. Findings to date show majorly its proteolytic function and great diversity of non-proteolytic involvement in cell signaling, cell cycle, apoptosis, cell proliferation, development, cell migration, DNA repair, genome stability, inflammation, protein trafficking, etc. This diverse array of functions is being carried out due to the presence of various ubiquitin ligase E3s that confers the substrate specificity. It is noteworthy that scientific evidence related to carcinogenesis shows the central role of UPS in tumor development as most of the proteins responsible for cancer development i.e., oncogenes or tumor suppressor genes, belong to ubiquitin ligase E3. This chapter is a comprehensive summary of E3s that show either genetic or expression aberration specific to breast cancer. Primarily such E3s are involved in the cell cycle, apoptosis, cell proliferation, and DNA repair mechanism. Understanding these pathways pave the way to identifying and developing the E3s as a diagnostic marker and drug target for breast cancer.