In vitro coculture models to study heterotypic interactions in breast cancer microenvironments Public Deposited

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  • March 21, 2019
  • Casbas-Hernandez, Patricia
    • Affiliation: School of Medicine, Department of Pathology and Laboratory Medicine
  • Epithelial-stromal interactions are fundamental to tissue homeostasis and may alter breast cancer (BC) initiation and progression. Co-evolution of the neoplastic epithelium and the stroma implies that these compartments maintain an active dialogue with functional consequences for both parts. To study epithelial-stromal interactions and elucidate the role of stromal variation in tumor phenotypes, in vitro cocultures can be used. Gene expression data and cell-based assays from cocultures can identify cellular phenotypes and biomarkers with possible relevance in human studies. This research hypothesizes that stromal-epithelial interactions are altered from early in carcinogenesis (Chapter2) and that the different subtypes of invasive BC have distinct heterotypic interactions (Chapter3). Epithelial-stroma interactions change during progression from benign disease to ductal-carcinoma in-situ (DCIS) in invasive Basal-like BC (BLBC). We cocultured fibroblasts with an isogenic series of cell lines (the MCF10 series) that represent premalignant stages of BC. The MCF10DCIS:fibroblasts cocultures have similar gene expression responses to those observed when invasive BLBC lines are cocultured with fibroblasts. Compared to MCF10A (benign) and MCF10AT1 (atypical-hyperplasia), MCF10DCIS cocultures showed high HGF secretion/activation and complimentary MET IV upregulation. The morphogenic development of MCF10DCIS in 3D cocultures was slowed when the HGF-pathway was blocked. A novel HGF genomic signature was identified and was highly expressed in 86% of BLBCs. High expression of this HGF signature predicted worse overall survival among BLBC patients. These results show that HGF secretion and complementary MET overexpression occurs early in BLBC carcinogenesis with important consequences in invasive tumors. Heterotypic interactions in cancer-adjacent tissue also differ by BC subtypes. We studied gene expression data of cancer-adjacent tissue from 158 BC patients and performed in-vitro cocultures. Gene expression analysis shows triple-negative BCs are associated with upregulated immune response and cytokine gene expression and Luminal BCs are associated with estrogen-response in cancer-adjacent tissues. Intrinsic tumor subtypes are reflected in the histologically normal cancer-adjacent tissue. This research furthers our understanding on how BC interacts with surrounding tissues and how epithelial-stromal interactions play a role in BC progression.. Biomarkers derived from these studies may be helpful in earlier detection of aggressive lesions, in defining personalized surgical strategies or in predicting recurrence risk.
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  • In Copyright
  • Troester, Melissa
  • Doctor of Philosophy
Degree granting institution
  • University of North Carolina at Chapel Hill
Graduation year
  • 2013

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