Department of Cell Biology

Kristy R. Stengel, Ph. D. - Research Interest

Kristy


Assistant Professor, Department of Cell Biology
Chanin Bldg., Room 403

kristy.stengel@einsteinmed.org

Research Interest 
Selected Publications 
Biosketch

 

  

Using CRISPR-mediated Chemical Genetics to Define Oncogenic Transcription Networks

 

fig1
 
The disruption of normal gene expression programs is a hallmark of all cancers. One common way in which this occurs is through chromosomal translocation that results in the generation of gain-of-function transcription factor fusion proteins. For example, PAX3-FOXO1, arises from the t(2;13) translocation, and is the defining feature of a subset of highly aggressive, pediatric rhabdomyosarcoma (RMS), while AML1-ETO arises from the t(8;21) translocation in acute myeloid leukemia (AML). Both of these translocations target transcription factors that regulate critical cell fate decisions, and both are thought to be the initiating event and an ideal therapeutic target in the cancer in which they arise. Thus, it is essential to understand how these oncogenic transcription factors alter transcriptional programs to drive cancer development.
Historically, our ability to understand how sequence-specific transcription factors rapidly and specifically alter transcriptional programs has been limited by a toolbox of very slow genetic and knockdown strategies that take days to weeks before transcription factor activity can be assayed. Therefore, while direct transcriptional effects occur within minutes to hours, these models take days to establish, which results in the detection of secondary and/or compensatory transcriptional changes that often mask the direct/immediate effects of transcription factor disruption. In order to overcome these technical limitations, we use CRISPR-mediated genome editing to introduce degron tags into endogenous transcription factor loci. This chemical-genetic approach allows rapid transcription factor degradation (minutes to hours) following PROTAC (e.g. dTAG-47, see figure above) treatment, and effectively collapses the timeframe for assaying transcriptional changes, chromatin states, and genome-wide transcription factor occupancy from days to hours. We also incorporate proteomics-based methods to identify associated protein complexes and cooperating transcription factors. Combined, these approaches are allowing us to define the mechanism of action of specific oncogenic transcription factors (e.g. AML1-ETO and PAX3-FOXO1). Moreover, we aim to address fundamental questions in the transcription field including how oncogenic transcription factors are influenced by and exert influence over the chromatin landscape, how multiple sequence-specific transcription factors cooperate to fine-tune gene expression, and how enhancer activity functions to control gene transcription.

 

 
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