Michael A. Mancini, Ph.D.
Department of Molecular and Cellular Biology
Director, Integrated Microscopy Core
Ph.D.: University of Texas Health Science Center, San Antonio
Postdoctoral training: University of Texas Institute of Biotechnology
High Throughput Systems Biology of Gene Regulation
In general terms, a highly dynamic and complex set key regulators underly mechanisms of normal and aberrant gene regulation. Over two decades of reductionist biochemical/molecular studies of gene regulation have identified a great wealth of key factors and interactive pathways, often resulting in important transgenic animal models. Consideration of gene regulator mechanisms at the single cell level, however, have been lacking, largely due to technical hurdles. In the past few years, an increasingly powerful series of automated and quantitive imaging capabilities have come to the fore, providing an altogether new ability of generate and mine a wide series of mechanistic data on gene regulation, with the result being an improving cellular appreciation of how gene regulators function. Further, single cell approaches allow a heretofore impossible view of cellular heterogeneity, as numerous measurements can be made on individual cells that are inherently obscured by population analyses, which is typical in biochemical studies. The results from live or fixed cell studies have led to improved appreciation of the importance of spatiotemporal issues of gene regulators, and a rethinking of how well classically drawn static diagrams may reflect mechanistic cell biology.
Our laboratory has several single cell-based models of nuclear receptor gene regulation in progress, including estrogen and androgen receptors linked to both mechanistic study of wild type and clinical mutations. We have developed live imaging studies focusing upon intracellular dynamics (time lapse, photobleaching), and high throughput system biology level approaches using state of the art automated fluorescence microscopy and image analyses. Multiplexing of numerous quantitative readouts is an intensive effort, including current single cell analyses that capture hundreds of individual measurements per cell. For example, our current estrogen receptor studies generate quantitative data on NR/CoR trafficking, subnuclear organization, promoter occupancy, large scale chromatin modeling, transcription and the cell cycle---all on a per cell basis---and at 384 well plate speed. Single cell-based analyses of both engineered cell lines that allow quantitation of 'visual ChIP' and mRNA synthesis and, increasingly, use of highly sensitive/specific mRNA FISH probes to quantify expression of endogenous genes, are providing large scale data sets for extensive bioinformatic mining. The goal of these studies is to general sophisticated molecular, cytological, functional cellular response fingerprints for normal and mutant receptors, and how ligand and RNAi libraries on hand alter these measurements for, ultimately, predictive personalized medicine.
Baylor College of Medicine
One Baylor Plaza, 113A Cullen Building
Houston, TX 77030
Lab Web Site:
- Hartig SM, He B, Newberg JY, Ochsner SA, Loose DS, Lanz RB, McKenna NJ, Buehrer BM, McGuire SE, Marcelli M, Mancini MA. (2012).
Feed-forward inhibition of androgen receptor activity by glucocorticoid action in human adipocytes. Chemistry and Biology 19:1126-41
- Hartig SM, He B, Long W, Buehrer BM, Mancini MA. (2011). Homeostatic levels of SRC-2 and SRC-3 promote early human adipogenesis. J Cell Biol. 192:55-67.
- Ashcroft FJ, Newberg JY, Jones ED, Mikic I, Mancini MA. (2011). High content imaging-based assay to classify estrogen receptor-α ligands based on defined mechanistic outcomes. Gene. Jan 20. [Epub ahead of print]
- García-Becerra R, Berno V, Ordaz-Rosado D, Sharp ZD, Cooney AJ, Mancini MA, Larrea F. (2010). Ligand-induced large-scale chromatin dynamics as a biosensor for the detection of estrogen receptor subtype selective ligands. Gene. [Epub ahead of print]
- Szafran AT, Hartig S, Sun H, Uray IP, Szwarc M, Shen Y, Mediwala SN, Bell J, McPhaul MJ, Mancini MA, Marcelli M. (2009). Androgen receptor mutations associated with androgen insensitivity syndrome: a high content analysis approach leading to personalized medicine. PLoS One. 2009 4:e8179.
- Szafran AT, Szwarc M, Marcelli M, Mancini MA. (2008) Androgen Receptor Functional Analyses by High Throughput Imaging: Determination of Ligand, Cell Cycle, and Mutation-Specific Effects. PLoS ONE 3(11): e3605.
- Berno V, Amazit L, Hinojos CA, Zhong J, Mancini MG and Mancini MA. (2008). Estrogen receptor-α activated by estradiol or epidermal growth factor induces temporally distinct chromatin remodeling and transcription. PLoS ONE 3:e2286.
- Amazit L, Pasini L, AT Szafran, Mielke M, Wu RC, Mancini MG, Hinojos CA, Berno V, O’Malley BW and Mancini MA. (2007). SRC-3/AIB1 function is regulated by phosphocode-directed spatiotemporal dynamics. Mol Cell Biol 27:6913-32. Epub 2007 Jul 23.
- Sharp ZD, Mancini MG, Hinojos CA, Dai F, Berno V, Szafran AT, Smith KP, Lele T, Ingber D and Mancini MA. (2006). Estrogen-receptor-α exchange, and chromatin dynamics are ligand- and domain-dependent. J Cell Science 119:4101-16.
- Stenoien DL, Mielke M and Mancini MA. (2002). FRAP reveals that ataxin-1 inclusions contain both fast and slow exchanging components. Nature Cell Biol 4:806-10.