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Identification and functional characterization of murine prostate epithelial stem cells
Lawson, Devon Ann University of California, Los Angeles 2008 해외박사(DDOD)
The ability to isolate prostate stem cells is critical to explore their roles in both prostate development and prostate cancer. Prostate epithelial stem cells possess several key properties, including the capacity to self-renew, differentiate to produce both basal and luminal cell types, and to generate prostatic ducts in vivo. Previous studies also suggest they possess a basal cell phenotype and reside within the region of the gland that is proximal to the urethra where they are largely replication quiescent (1). Our approach in this study was to screen for cell surface markers that could positively or negatively select for cells with these characteristics using Fluorescence Activated Cell Sorting (FACS) technology. A dissociated cell prostate regeneration assay based on a tissue recombination procedure developed by Cunha and Lung (1978) was developed to measure stem cell activity in sorted cell fractions (2). In this assay, dissociated prostate epithelial cells from adult mice form prostate tubules de novo when combined with dissociated fetal urogenital sinus mesenchymal cells (UGSM) and implanted under the kidney capsule of immune deficient mice (3). We found that Stem cell antigen-1 (Sca-1), a member of the Ly-6 family of GPI-linked proteins, is present on cells with enhanced capacity for ductal morphogenesis in this in vivo assay (4). Sca-1 + fractions are also enriched for replication quiescent cells in the G0 stage of the cell cycle, and Sca-1+ cells cluster in the putative prostate stem cell niche. We further found that castration resulted in enrichment for Sca-1+ cells, indicating these cells are androgen independent. For further purification of prostate stem cells, we developed an in vitro sphere-forming assay for rapid and quantitative screening for markers that could subfractionate the Sca-1+ cell fraction. In this system, prostate cells are suspended in an extracellular matrix compound called Matrigel where they grow to generate clonogenic spheroid structures that can be serially passaged (5,6). Using this assay, we found that depletion of hematopoietic (CD45+, Ter119+) and endothelial (CD31 +) lineages coupled with positive selection for basal cells (CD49f +) within the Sca-1+ fraction results in a 60-fold enrichment for sphere-forming cells (6). These Lin(CD31/CD45/Ter119) -Sca-1+CD49f+ cells can self-renew and expand to form spheres for many generations, and differentiate to produce prostatic ductal structures containing both basal and luminal cells in vivo. These cells also localize to the basal cell layer within the proximal region of the prostate gland. In sum, prostate stem cells can be isolated to a purity of 1 in 35 using this cell surface paradigm. References (1) Tsujimura, A., Koikawa, Y., Salm, S., Takao, T., Coetzee, S., Moscatelli, D., Shapiro, E., Lepor, H., Sun, T. T., and Wilson, E. L. (2002) J Cell Biol 157(7), 1257-1265; (2) Cunha, G. R., and Lung, B. (1978) J Exp Zool 205(2), 181-193; (3) Xin, L., Ide, H., Kim, Y., Dubey, P., and Witte, O. N. (2003) Proc Natl Acad Sci U S A 100 Suppl 1, 11896-11903; (4) Xin, L., Lawson, D. A., and Witte, O. N. (2005) Proc Natl Acad Sci U S A 102(19), 6942-6947; (5) Xin, L., Lukacs, R. U., Lawson, D. A., Cheng, D., and Witte, O. N. (2007) Stem cells (Dayton, Ohio) 25(11), 2760-2769; (6) Lawson, D. A., Xin, L., Lukacs, R. U., Cheng, D., and Witte, O. N. (2007) Proceedings of the National Academy of Sciences of the United States of America 104(1), 181-186.
Subject Matter: Feminism, Interiority, and Literary Embodiment After 1980
Lawson, Jessica Lynn ProQuest Dissertations & Theses The University of 2015 해외박사(DDOD)
I argue that literary texts after 1980 use the fluid relationship between the physical world and the world of writing in order to present alternate versions of the body's relationship to the mind. Examining works by Toni Morrison, William Gibson. I emphasize the political implications of the kinds of bodies employed in these metaphors, setting this against the background of late twentieth century feminism. I read my primary texts alongside the work of Julia Kristeva, Helene Cixous, Luce.