A Functional Proteomics Perspective of DBC1 as a Regulator of Transcription.

The past few years have seen significant advances in the use of modern proteomics approaches for biological discoveries. Among the fields impacted by proteomics is that of epigenetics, as mass spectrometry-based approaches have allowed the identification and characterization of transcriptional regulators, epigenetic marks, and the constantly evolving epigenetic landscape of a cell in health and disease states. These studies have substantially expanded our understanding of critical genes that mediate cell processes, such as differentiation, cell cycle regulation, and apoptosis. Not surprisingly, a great emphasis has been placed on defining factors that are de-regulated in cancers, in an attempt to define new and specific targets for therapeutic design. Differential gene expression observed during carcinogenesis can be induced by aberrant activities of transcription factors and chromatin remodeling enzymes. Through a series of recent mass spectrometry studies of histone deacetylases and nuclear receptors, Deleted in Breast Cancer 1 (DBC1) has emerged as a master regulator of transcriptional processes. DBC1 acts as a modulator of cellular epigenetic mechanisms and is frequently associated with human metastasis. Through its negative regulation of SIRT1 and HDAC3 deacetylation activities, DBC1 has a broad impact on gene expression, downstream cellular pathways, and associated human diseases. Here, we review the identified roles of DBC1, highlighting the critical contribution of mass spectrometry to these findings. Additionally, we provide a perspective of integrative proteomics approaches that can continue to shed light on the interplay between DBC1 and its protein targets, helping to further define its role in epigenetic modifications and to identify novel targets for cancer therapy.