In Vitro Differentiation of Mouse Embryonic Stem Cells into Neurons of the Dorsal Forebrain

Pluripotent embryonic stem cells (ESCs) are able to differentiate into all cell types in the organism including cortical neurons. To follow the dynamic generation of progenitors of the dorsal forebrain in vitro, we generated ESCs from D6-GFP mice in which GFP marks neocortical progenitors and neurons after embryonic day (E) 10.5. We used several cell culture protocols for differentiation of ESCs into progenitors and neurons of the dorsal forebrain. In cell culture, GFP-positive cells were induced under differentiation conditions in quickly formed embryoid bodies (qEBs) after 10–12 day incubation. Activation of Wnt signaling during ESC differentiation further stimulated generation of D6-GFP-positive cortical cells. In contrast, differentiation protocols using normal embryoid bodies (nEBs) yielded only a few D6-GFP-positive cells. Gene expression analysis revealed that multiple components of the canonical Wnt signaling pathway were expressed during the development of embryoid bodies. As shown by immunohistochemistry and quantitative qRT-PCR, D6-GFP-positive cells from qEBs expressed genes that are characteristic for the dorsal forebrain such as Pax6, Dach1, Tbr1, Tbr2, or Sox5. qEBs culture allowed the formation of a D6-GFP positive pseudo-polarized neuroepithelium with the characteristic presence of N-cadherin at the apical pole resembling the structure of the developing neocortex

Abstract P3-07-12: Risk Factors for Breast Cancer in Women Served in Odete Valadares Maternity, Belo Horizonte-MG

Abstract With changes in lifestyle of the population and changes in women reproductive patterns in the last century, the profile of mortality among women has changed, today the prevailing non-infectious chronic diseases, like cancer, including breast cancer. This paper is a case-control population-based, with the objective of evaluating the risk factors and their association with breast cancer in a population of women seen in Odete Valadares Maternity, in the Hospital Foundation of the State of Minas Gerais, in Belo Horizonte, between January and July 2006. Inclusion criteria were age over 18 years and referral for mammography service. Women with abnormal mammography and confirmation of malignancy of the breast were invited to participate in the study, and those with normal mammography were invited to compose the control group. We evaluated 710 women and 456 selected to participate in the study, 261 with breast cancer and 195 healthy controls. The participants were interviewed, answered a questionnaire on reproductive aspects and lifestyle habits (smoking, alcohol consumption, physical activity, children, age at menarche and menopause, oral contraceptive use and hormone replacement therapy and breast-feeding) and was measured anthropometric data. The association between several independent variables and the presence of breast cancer was evaluated by Student's t test, Mann-Whitney and chi square test. We estimated odds ratio and their respective confidence intervals. This study found a positive association between physical inactivity, menopause, nulliparity, lack of breastfeeding and family history of breast cancer and the diagnosis of breast cancer, and alcohol conferred a protective effect in this population. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-07-12.</jats:p