The majority of cancer deaths are caused by blood-borne metastasis from a primary epithelial tumor, but our understanding of this process is limited. Epithelial-to-Mesenchymal Transition (EMT) is a fundamental developmentally regulated change in cell fate, whose aberrant activation in cancer has been proposed as contributing to the invasiveness and motility of cancer cells. However, given the difficulty in studying human cancer metastasis, most studies have relied on cell line and mouse models, and the relevance of EMT in human cancer is not well established. New technologies enabling the isolation and molecular analysis of circulating tumor cells (CTCs), rare cancer cells that are in transit through the bloodstream, now provide a unique opportunity to define mechanisms involved in human cancer metastasis. We propose a molecular analysis of CTCs to validate the prevalence of EMT in human breast cancer, use a carefully titrated in vitro model of EMT to identify key effectors that could constitute potential drug targets, and test their effectiveness using a mouse model in which CTC quantitation provides a rapid readout for the metastatic potential of human breast cancer cells. Our approach has three aims:
in Aim 1, we will determine whether EMT is a consistent feature of different histological subtypes of breast cancer and whether these markers evolve dynamically during response or resistance to therapy. This will be accomplished using RNA-in-situ probes that we have developed, capable of scoring quantitative epithelial and mesenchymal markers within individual cells. RNA sequencing will then be applied to identify EMT associated transcripts within breast circulating tumor cells, thus providing insight into the relevant biological pathways.
In Aim 2, we will study an inducible in vitro model of EMT, which effectively mediates a regulated epigenetic switch. We have generated timelines of both transcriptionaland chromatin immuno-precipitation profiles, which will be used to identify candidate effectors of EMT, seeking potential drugable targets.
In Aim 3, we will establish a robust mouse assay to monitor the ability of breast cancer cells to metastasize and thus test potential suppressors of EMT-related phenotypes. CTC enumeration in the mouse model will be used as a rapid and quantifiable readout for vascular invasiveness. Together, these experiments aim to combine novel molecular and bioengineering technologies to address the relevance of EMT as a therapeutic target in suppressing human cancer metastasis.

Public Health Relevance

Most cancer deaths are caused by metastastic spread of tumor cells from the primary to distant sites, yet our understanding of this process is limited and there are no specific therapeutic approaches to suppress cancer metastasis. Epithelial-to-Mesenchymal Transition (EMT) is a developmentally regulated change in cell fate, which has been proposed as contributing to the invasiveness and motility of cancer cells, but whose clinical relevance is not well established. We propose to first test the clinical relevance of EMT in breast cancer by analyzing circulating tumor cells (CTCs) using a microfluidic device that we have established, identify potential drug targets that modulate EMT using an in vitro model that we have developed, and finally test their potential relevance by developing a mouse model to screen for metastatic potential in breast cancer cells.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA129933-07
Application #
8627132
Study Section
Special Emphasis Panel (ZRG1-BMCT-C (01))
Program Officer
Song, Min-Kyung H
Project Start
2007-07-01
Project End
2018-03-31
Budget Start
2014-04-01
Budget End
2015-03-31
Support Year
7
Fiscal Year
2014
Total Cost
$347,240
Indirect Cost
$145,965
Name
Massachusetts General Hospital
Department
Type
DUNS #
073130411
City
Boston
State
MA
Country
United States
Zip Code
02199
Bhan, Irun; Mosesso, Kelly; Goyal, Lipika et al. (2018) Detection and Analysis of Circulating Epithelial Cells in Liquid Biopsies From Patients With Liver Disease. Gastroenterology 155:2016-2018.e11
Aceto, Nicola; Bardia, Aditya; Wittner, Ben S et al. (2018) AR Expression in Breast Cancer CTCs Associates with Bone Metastases. Mol Cancer Res 16:720-727
Franses, Joseph W; Basar, Omer; Kadayifci, Abdurrahman et al. (2018) Improved Detection of Circulating Epithelial Cells in Patients with Intraductal Papillary Mucinous Neoplasms. Oncologist 23:121-127
Kwan, Tanya T; Bardia, Aditya; Spring, Laura M et al. (2018) A Digital RNA Signature of Circulating Tumor Cells Predicting Early Therapeutic Response in Localized and Metastatic Breast Cancer. Cancer Discov 8:1286-1299
Hong, Xin; Sullivan, Ryan J; Kalinich, Mark et al. (2018) Molecular signatures of circulating melanoma cells for monitoring early response to immune checkpoint therapy. Proc Natl Acad Sci U S A 115:2467-2472
Viswanathan, Vasanthi S; Ryan, Matthew J; Dhruv, Harshil D et al. (2017) Dependency of a therapy-resistant state of cancer cells on a lipid peroxidase pathway. Nature 547:453-457
Yazinski, Stephanie A; Comaills, Valentine; Buisson, RĂ©mi et al. (2017) ATR inhibition disrupts rewired homologous recombination and fork protection pathways in PARP inhibitor-resistant BRCA-deficient cancer cells. Genes Dev 31:318-332
Micalizzi, Douglas S; Haber, Daniel A; Maheswaran, Shyamala (2017) Cancer metastasis through the prism of epithelial-to-mesenchymal transition in circulating tumor cells. Mol Oncol 11:770-780
Micalizzi, Douglas S; Maheswaran, Shyamala; Haber, Daniel A (2017) A conduit to metastasis: circulating tumor cell biology. Genes Dev 31:1827-1840
Zheng, Yu; Miyamoto, David T; Wittner, Ben S et al. (2017) Expression of ?-globin by cancer cells promotes cell survival during blood-borne dissemination. Nat Commun 8:14344

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