Basement membrane is a dense, highly cross-linked form of extracellular matrix that surrounds most tissues. During development and immune surveillance, specialized cells acquire the ability to breach basement membrane to disperse and traffic to sites of infection and injury. The cell invasion program is also co-opted or misregulate during many diseases, including asthma, arthritis, the pregnancy disorder pre-eclampsia, and cancer. Understanding how cells invade through basement membrane is thus of great importance to human health. Cell invasion involves dynamic interactions between the invading cell, the tissue being invaded, and the basement membrane separating them. Owing to an inability to recapitulate these complex interactions in vitro, and the challenge of experimentally examining invasion in vivo, the key mechanisms underlying cell invasive behavior remain poorly understood. Anchor cell invasion in C. elegans is an experimentally accessible in vivo model of cell invasion that uniquely combines single cell visual analysis with powerful genetic and genomic approaches. Using these strengths, we have identified two conserved transcription factors that regulate distinct steps in acquiring an invasive cell fate. NHR-67, an ortholog of the vertebrate Tailless protein, maintains the anchor cell in a post-mitotic state. Exit from the cell cycle appears necessary to then permit the C. elegans Fos family transcription factor ortholog FOS-1A to initiate the invasion program. Preliminary data indicate that FOS-1A regulates the expression of three matrix metalloproteinases (MMPs) in the anchor cell, implicating a specific pathway that controls basement membrane removal. Finally, we have found that elevated levels of the extracellular matrix protein SPARC, which is overexpressed in most advanced cancer malignancies, decreases type IV collagen levels in basement membrane, and dramatically enhances anchor cell invasion. The goal of this proposal is to use live-cell imaging with genetic and molecular analysis to determine: (1) How NHR-67 maintains the anchor cell in a post-mitotic state and allows the cell invasion program to initiate, (2) the role of FOS-1A in regulatin MMP expression and the function of MMPs in breaching the BM, (3) the role of SPARC in enhancing cell invasion. These studies are relevant to NIH's mission as they will lead to new insights into the importance of cell cycle exit for invasion, the specific role of MMPs in breachin basement membrane and the role of SPARC in facilitating the invasive process, thus allowing the development of better therapeutic strategies to limit invasive behavior in human diseases such as cancer.
Cell invasion through basement membrane plays pivotal roles in numerous cell migrations in development and immune cell trafficking. This behavior is also co-opted in many human diseases, most notably during the spread of cancer. Our proposed work will elucidate the function of a specific genetic program that shuts down cell proliferation t allow cell invasion to occur and a key pathway that promotes the ability of invasive cells to penetrate through basement membrane barriers. These studies will advance our understanding of the fundamental mechanisms underlying cell invasion and generate new therapeutic strategies to regulate cell invasive behavior in human diseases such as cancer.
|Lacroix, Benjamin; Bourdages, Karine G; Dorn, Jonas F et al. (2014) In situ imaging in C. elegans reveals developmental regulation of microtubule dynamics. Dev Cell 29:203-16|
|Kelley, Laura C; Lohmer, Lauren L; Hagedorn, Elliott J et al. (2014) Traversing the basement membrane in vivo: a diversity of strategies. J Cell Biol 204:291-302|
|Morrissey, Meghan A; Keeley, Daniel P; Hagedorn, Elliott J et al. (2014) B-LINK: a hemicentin, plakin, and integrin-dependent adhesion system that links tissues by connecting adjacent basement membranes. Dev Cell 31:319-31|
|Schindler, Adam J; Baugh, L Ryan; Sherwood, David R (2014) Identification of late larval stage developmental checkpoints in Caenorhabditis elegans regulated by insulin/IGF and steroid hormone signaling pathways. PLoS Genet 10:e1004426|
|Matus, David Q; Chang, Emily; Makohon-Moore, Sasha C et al. (2014) Cell division and targeted cell cycle arrest opens and stabilizes basement membrane gaps. Nat Commun 5:4184|
|Lohmer, Lauren L; Kelley, Laura C; Hagedorn, Elliott J et al. (2014) Invadopodia and basement membrane invasion in vivo. Cell Adh Migr 8:246-55|
|Hagedorn, Elliott J; Ziel, Joshua W; Morrissey, Meghan A et al. (2013) The netrin receptor DCC focuses invadopodia-driven basement membrane transmigration in vivo. J Cell Biol 201:903-13|
|Schindler, Adam J; Sherwood, David R (2013) Morphogenesis of the caenorhabditis elegans vulva. Wiley Interdiscip Rev Dev Biol 2:75-95|
|Hagedorn, Elliott J; Sherwood, David R (2011) Cell invasion through basement membrane: the anchor cell breaches the barrier. Curr Opin Cell Biol 23:589-96|
|Wang, Zheng; Sherwood, David R (2011) Dissection of genetic pathways in C. elegans. Methods Cell Biol 106:113-57|
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