Discipline: Biological Sciences
Subcategory: Cancer Research
Sojourna Ferguson - University of the Virgin Islands
Co-Author(s): Ana de la Cueva, Boston University School of Medicine, MA; Kathrin H. Kirsch, Boston University School of Medicine, MA; Matthew D. Layne, Boston University School of Medicine, MA;
Epithelial derived breast tumors often exhibit alterations in the microenvironment and pathologic stromal activation. These stromal cells are referred to as cancer associated fibroblasts, or CAFs, and are related to activated fibroblasts that expresses both α-smooth muscle actin (α-SMA) and collagen I. When these fibroblasts are activated, they are believed to support tumorigenesis by stimulating angiogenesis, and enhancing cancer cell proliferation and invasion. The mechanisms of how these cells become activated remains uncertain. Understanding the mechanisms of stromal activation in cancer and the role of their secreted proteins will impact our understanding of cancer. The goal of this project is to identify activated cells in the breast cancer stroma and target the stromal derived protein aortic carboxypeptidase-like protein (ACLP) to examine the effects this secreted protein has on tumor progression and the remodeling of the extracellular matrix. In this study, we generated a breast cancer model in mice by overexpressing the oncogene Her2 and crossing these animals with transgenic mice harboring fluorescent reporters to monitor both α-SMA and collagen I activation. We analyzed and quantified the expression by both histological analysis and fluorescent imaging. Using flow cytometry, we studied the expression of these reporters, α-SMA and collagen I by adding the EpCam antibody to accurately identify the different cell populations. Immunofluorescence imaging of the tumors showed an increase expression in α-SMA and collagen I. The FACS analysis of the normal tissues showed there was 5.74% α-SMA and 3.17% collagen I expression in the fibroblastic cells. Additional work is developing a conditional mouse model to understand the role of ACLP in breast cancer progression and epithelial changes. Administration of ACLP to primary epithelial cells induces an epithelial to mesenchymal-like phenotype. The characterization of activated stroma cells and how they contribute to breast tumor progression may lead to the ability to target secreted proteins such as ACLP. Targeting these proteins that are increase in the tumor stroma may also lead to the development of new breast cancer therapies.
Funder Acknowledgement(s): This study was supported by a grant from Department of Defense Breakthrough Awards 11652902 & 11652913, that was awarded to Matthew Layne, PhD, Biochemistry Department of Boston University Medical School. The research was also supported by David Rowe, PhD, by the usage of his Collagen-I and SMA mice. My participation in the research was supported by the Boston University Graduate Medical Sciences Summer Training as Research Scholars Program - NIH HL118693.
Faculty Advisor: Dr. Matthew Layne, firstname.lastname@example.org
Role: For a period of approximately two months, I worked under my advisors on investigating the alterations in the stromal microenvironment of epithelial derived breast tumors and the effects it has on carcinogenesis. Primarily, I was able to do histologic analysis and fluorescent imaging on the expression of α-SMA and collagen I reporters in normal mammary glands and cancerous tissues. Also, I conducted a FACS analysis to obtain the base line expression in normal tissues which will later help in developing a mouse model.