Project description:This SuperSeries is composed of the following subset Series: GSE25035: The role of p53 in the regulation of miRNA expression profiling GSE25036: miRNA expression profiling in human mammary epithelial cell (HMEC) CD24-CD44+ and non-CD24-CD44+ cell populations Refer to individual Series
Project description:To understand the role of p53 in regulating stem cell population (CD24-CD44+) and stemness-associated miRNAs, we first compared miRNA expression profiles between human mammary epithelial cells knocked-down p53 and control cells. We then cross-referenced p53-regulated miRNAs with stemness-associated miRNAs analyzed from expression profiling of sorted CD24-CD44+ and non-CD24-CD44+ cell populations. Further biological experiments were performed with the miRNAs that are altered in CD24-CD44+ stem cell populations and also regulated by p53.
Project description:To understand the role of p53 in regulating stem cell population (CD24-CD44+) and stemness-associated miRNAs, we first compared miRNA expression profiles between human mammary epithelial cells knocked-down p53 and control cells. We then cross-referenced p53-regulated miRNAs with stemness-associated miRNAs analyzed from expression profiling of sorted CD24-CD44+ and non-CD24-CD44+ cell populations. Further biological experiments were performed with the miRNAs that are altered in CD24-CD44+ stem cell populations and also regulated by p53. Total RNAs, including miRNAs, were extracted from cells infected with retrovirus expressing shp53 (labeled in Hy3) and vector control (labeled in Hy5). miRNAs were hybridized on Exiqon miRCURY LNA arrays according to the manufacturer's protocol.
Project description:To understand the role of p53 in regulating stem cell population (CD24-CD44+) and stemness-associated miRNAs, we first compared miRNA expression profiles between human mammary epithelical cells knocked-down p53 and control cells. We then cross-referenced p53-regulated miRNAs with stemness-associated miRNAs analyzed from expression profiling of sorted CD24-CD44+ and non-CD24-CD44+ cell populations. Further biological experiments were performed with the miRNAs that are altered in CD24-CD44+ stem cell populations and also regulated by p53.
Project description:To understand the role of p53 in regulating stem cell population (CD24-CD44+) and stemness-associated miRNAs, we first compared miRNA expression profiles between human mammary epithelical cells knocked-down p53 and control cells. We then cross-referenced p53-regulated miRNAs with stemness-associated miRNAs analyzed from expression profiling of sorted CD24-CD44+ and non-CD24-CD44+ cell populations. Further biological experiments were performed with the miRNAs that are altered in CD24-CD44+ stem cell populations and also regulated by p53. Total RNAs, including miRNAs, extracted from CD24-CD44+ cells (labeled in Hy3) and non-CD24-CD44+ cells (labeled in Hy5) were hybridized on Exiqon miRCURY LNA arrays according to the manufacturer's protocol.
Project description:Molecular distinctions between the stasis and telomere attrition senescence barriers in cultured human mammary epithelial cells Normal human epithelial cells in culture have generally shown a limited proliferative potential of ~10-40 population doublings before encountering a stress-associated senescence barrier (stasis) associated with elevated levels of cyclin-dependent kinase inhibitors p16 and/or p21. We now show that simple changes in media composition can expand the proliferative potential of human mammary epithelial cells (HMEC) initiated as primary cultures to 50-60 population doublings, followed by p16(+), senescence-associated b-galactosidase(+) stasis. We compared the properties of growing and senescent pre-stasis HMEC with growing and senescent post-selection HMEC, i.e., cells grown in a serum-free medium that overcame stasis via silencing of p16 expression and that display senescence associated with telomere dysfunction. Cultured pre-stasis populations contained cells expressing markers associated with luminal and myoepithelial HMEC lineages in vivo, in contrast to the basal-like phenotype of the post-selection HMEC. Gene transcript and protein expression, DNA damage-associated markers, mean TRF length, and genomic stability, differed significantly between HMEC populations at the stasis vs. telomere attrition senescence barriers. Senescent isogenic fibroblasts showed greater similarity to HMEC at stasis than at telomere attrition, although their gene transcript profile was distinct from HMEC at both senescence barriers. These studies support our model of the senescence barriers encountered by cultured HMEC in which the first barrier, stasis, is Rb-mediated and independent of telomere length, while a second barrier (agonescence or crisis) results from telomere attrition leading to telomere dysfunction. Additionally, the ability to maintain long-term growth of genomically stable multi-lineage pre-stasis HMEC populations can greatly enhance experimentation with normal HMEC. 48 samples from Human Mammary Epithelial cells which includes samples from four different individuals at different passage levels which includes prestasis,intermediate,post selection and agonesence stages of cell cycle.
Project description:Microarrays were used to examine gene expression differences in four different sub-populations of mammary epithelial cells obtained through flow cytometry of stem cell markers for H2BGFP, CD24, and CD29. The present study aims to find the specific differences between these populations that influence their ability to repopulate mammary structures in vivo during transplantation assays. H2GFP+/CD24+/CD29lo cells were found to be multipotent and able to give rise to mammary structures capable of lactation, and this ability increased dramatically if the recipient mice were pregnant. Total RNA obtained from sorted sub-populations of mammary epithelial cells.
Project description:It has been suggested that breast cancers are driven and maintained by a cellular subpopulation with stem cell properties. These breast cancer stem cells (BCSCs) mediate metastasis and by virtue of their resistance to radiation and chemotherapy, contribute to relapse. Although several BCSC markers have been described, it is unclear whether these markers identify the same or independent BCSC populations. Based on established breast cancer cell lines, as well as primary tumor xenografts, we show that BCSCs exist in distinct mesenchymal-like (epithelial-mesenchymal transition, EMT) and epithelial-like (mesenchymal-epithelial transition, MET) states characterized by expression of distinct markers, proliferative capacity and invasive characteristics. The gene expression profiles of mesenchymal-like and epithelial-like BCSCs are remarkably similar across the different molecular subtypes of breast cancer and resemble those of distinct basal and luminal stem cells found in the normal breast. We propose that the plasticity of BCSCs allowing them to transition between EMT- and MET-like states endows these cells with the capacity for tissue invasion, dissemination and growth at metastatic sites. Breast cancer cell lines, primary xenografts and normal breast cells from patient were sorted using flow cytometry to select for cells that were CD24-,CD44+ and ALDH+. Gene expression profiles of CD24-CD44+ cells were compared with non-CD24-CD44+ cells. Gene expression profiles of ALDH+ cells were compared with ALDH- cells.