27 research outputs found
Do NO, N2O, N2 and CO2 fluxes differ in soils sourced from cropland and varying riparian buffer vegetation? An incubation study
DATA AVAILABILITY STATEMENT : Data available from authors upon reasonable request.Please read abstract in the article.Biotechnology and Biological Sciences
Research Council and National
Research Foundation South Africa.http://www.wileyonlinelibrary.com/journal/sumhj2024Plant Production and Soil ScienceSDG-06:Clean water and sanitatio
Estimativa de áreas com culturas de verão no Paraná, por meio de imagens multitemporais EVI/Modis
The Evaluation Method for Enterprise Group Information Planning and Implementation Based on PDCA Cycle
Recommended from our members
Cell-cycling status of mammary epithelial cells predicts p53 responsiveness to gamma-radiation
The tumor suppressor gene, TP53, plays a major role in surveillance and repair of radiation-induced DNA damage. In multiple cell types, including mammary epithelial cells, abrogation of p53 (encoded by Trp53) function is associated with increased tumorigenesis. We examined gamma-irradiated BALB/c-Trp53(+/+) and -Trp53(-/-) female mice at five stages of post-natal mammary gland development to determine whether radiation-induced p53 activity is developmentally regulated. Our results show that p53-mediated responses are attenuated in glands from irradiated virgin and lactating mice, as measured by induction of p21/WAF1 (encoded by Cdkn1a) and apoptosis, while irradiated early- and mid-pregnancy glands exhibit robust p53 activity. There is a strong correlation between p53-mediated apoptosis and the degree of cellular proliferation, independent of the level of differentiation. In vivo, proliferation is intimately influenced by steroid hormones. To determine whether steroid hormones directly modulate p53 activity, whole organ cultures of mammary glands were induced to proliferate using estrogen plus progesterone or epidermal growth factor plus transforming growth factor-alpha and p53 responses to gamma-irradiation were measured. Regardless of mitogens used, proliferating mammary epithelial cells show comparable p53 responses to gamma-irradiation, including expression of nuclear p53 and p21/WAF1 and increased levels of apoptosis, compared to non-proliferating irradiated control cultures. Our study suggests that differences in radiation-induced p53 activity during post-natal mammary gland development are influenced by the proliferative state of the gland, and may be mediated indirectly by the mitogenic actions of steroid hormones in vivo