Abstract: Cancer is a stochastic disease whose biology has been studied almost exclusively with deterministic approaches. Why? In this application, I propose to exploit the apparent randomness of cellular transformation to uncover new mechanisms involved in tumorigenesis. My focus is the ligandless receptor tyrosine kinase, ErbB2, which is overexpressed in 20-30% of breast cancers and is the target of anticancer drugs such as Herceptin(r) and Tykerb(r). In a 3D in vitro culture model of mammary-acinar morphogenesis, inducible activation of ErbB2 causes hyperproliferative multiacinar structures that in many ways are reminiscent of early-stage breast tumors. Importantly, the penetrance of the phenotype is incomplete-only a random fraction of the cultured acini exhibit the morphogenetic defect when ErbB2 is activated. How this fraction is specified and the mechanism by which a multiacinus initiates are unknown. My hypothesis is that acute differences (dichotomies) in gene expression develop among acini and give rise to the distinct 3D phenotypes induced by ErbB2. The transcriptional dichotomies that exist before the appearance of the multiacinar phenotype will be the ones most likely to control it. However, without seeing the phenotype, it is impossible to know which ErbB2 structures will go on to develop abnormally. To overcome this challenge, we will use a new technique, called """"""""stochastic profiling"""""""", that I developed for discovering transcriptional dichotomies in a seemingly uniform cell population. We will apply stochastic profiling to a series of conditional ErbB2 homo- and heterodimer pairs that have different penetrances for the multiacinar phenotype. By mapping the transcriptional dichotomies to the differences in penetrance among dimer pairs, we will link upstream acinus-specific expression programs to downstream morphogenetic heterogeneities. The results from this project could explain mechanistically why only a fraction of ErbB2- overexpressing breast cancers respond positively to ErbB2-targeted therapeutics. Public Health Relevance: Several modern cancer drugs target the ErbB2 protein, but these drugs are effective in only a fraction of cancers that express ErbB2. The research in this proposal combines novel experimental and statistical approaches in an attempt to identify new cancer genes that may be turned on only occasionally by ErbB2. Such genes could link ErbB2 to drug sensitivity, providing new avenues for more-effective anti-cancer therapeutics.

Agency
National Institute of Health (NIH)
Institute
Office of The Director, National Institutes of Health (OD)
Type
NIH Director’s New Innovator Awards (DP2)
Project #
1DP2OD006464-01
Application #
7848030
Study Section
Special Emphasis Panel (ZGM1-NDIA-O (02))
Program Officer
Basavappa, Ravi
Project Start
2009-09-30
Project End
2014-06-30
Budget Start
2009-09-30
Budget End
2014-06-30
Support Year
1
Fiscal Year
2009
Total Cost
$2,310,000
Indirect Cost
Name
University of Virginia
Department
Biomedical Engineering
Type
Schools of Engineering
DUNS #
065391526
City
Charlottesville
State
VA
Country
United States
Zip Code
22904
Bajikar, Sameer S; Wang, Chun-Chao; Borten, Michael A et al. (2017) Tumor-Suppressor Inactivation of GDF11 Occurs by Precursor Sequestration in Triple-Negative Breast Cancer. Dev Cell 43:418-435.e13
Jensen, Karin J; Moyer, Christian B; Janes, Kevin A (2016) Network Architecture Predisposes an Enzyme to Either Pharmacologic or Genetic Targeting. Cell Syst 2:112-121
Chitforoushzadeh, Zeinab; Ye, Zi; Sheng, Ziran et al. (2016) TNF-insulin crosstalk at the transcription factor GATA6 is revealed by a model that links signaling and transcriptomic data tensors. Sci Signal 9:ra59
Wang, Chun-Chao; Bajikar, Sameer S; Jamal, Leen et al. (2014) A time- and matrix-dependent TGFBR3-JUND-KRT5 regulatory circuit in single breast epithelial cells and basal-like premalignancies. Nat Cell Biol 16:345-56
Bajikar, Sameer S; Fuchs, Christiane; Roller, Andreas et al. (2014) Parameterizing cell-to-cell regulatory heterogeneities via stochastic transcriptional profiles. Proc Natl Acad Sci U S A 111:E626-35
Jensen, Karin J; Garmaroudi, Farshid S; Zhang, Jingchun et al. (2013) An ERK-p38 subnetwork coordinates host cell apoptosis and necrosis during coxsackievirus B3 infection. Cell Host Microbe 13:67-76
Wang, Lixin; Janes, Kevin A (2013) Stochastic profiling of transcriptional regulatory heterogeneities in tissues, tumors and cultured cells. Nat Protoc 8:282-301
Bose, Anjun K; Janes, Kevin A (2013) A high-throughput assay for phosphoprotein-specific phosphatase activity in cellular extracts. Mol Cell Proteomics 12:797-806
Kang, Byong H; Jensen, Karin J; Hatch, Jaime A et al. (2013) Simultaneous profiling of 194 distinct receptor transcripts in human cells. Sci Signal 6:rs13
Janes, Kevin A; Lauffenburger, Douglas A (2013) Models of signalling networks - what cell biologists can gain from them and give to them. J Cell Sci 126:1913-21

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