Search results for "Sox2"

Multiple Pluripotent Stem Cell Markers in Human Anaplastic Thyroid Cancer: The Putative Upstream Role of SOX2

2013

Anaplastic thyroid carcinoma (ATC) is a rare and aggressive endocrine tumor with highly undifferentiated morphology. It has been suggested that cancer stem cells (CSCs) might play a central role in ATC. The objectives of this study were (i) to characterize CSCs from ex vivo ATC specimens by investigating the expression of several pluripotent stem cell markers, and (ii) to evaluate in vitro drug resistance modifications after specific CSC transcription factor switch-off.In ex vivo experiments, eight formalin-fixed, paraffin-embedded ATC specimens were analyzed by reverse-transcription and real-time quantitative PCR and immunohistochemistry. In in vitro experiments using ATC SW1736 cells, the…

Osteogenic commitment and differentiation of human mesenchymal stem cells by low‐intensity pulsed ultrasound stimulation

2018

Low-intensity pulsed ultrasound (LIPUS) as an adjuvant therapy in in vitro and in vivo bone engineering has proven to be extremely useful. The present study aimed at investigating the effect of 30 mW/cm(2) LIPUS stimulation on commercially available human mesenchymal stem cells (hMSCs) cultured in basal or osteogenic medium at different experimental time points (7d, 14d, 21d). The hypothesis was that LIPUS would improve the osteogenic differentiation of hMSC and guarantying the maintenance of osteogenic committed fraction, as demonstrated by cell vitality and proteomic analysis. LIPUS stimulation (a) regulated the balance between osteoblast commitment and differentiation by specific network…

2013

MicroRNAs of the miR-302 cluster are involved in early embryonic development and somatic cell reprogramming. Expression of the miR-302 gene is regulated by the binding of the pluripotency factors Oct4, Sox2 and Nanog to the miR-302 promoter. The specific expression pattern of the miR-302 gene suggested that additional transcription factors might be involved in its regulation. Here, we show that the miR-302 promoter is a direct target of the Wnt/β-catenin signaling pathway. We found that the miR-302 promoter contains three different functional Tcf/Lef binding sites. Two of the three sites were located within the cluster of Oct4/Sox2/Nanog binding sites and were essential for Wnt/β-catenin-me…

The importance of culturing primary cells under physiological conditions: proliferation, senescence, pluripotency

2017

Mesenchymal stem cells (MSCs), such as human dental pulp stem cells (hDPSCs), are currently a source for cell therapy. However, cell therapy protocols require 10–400 million cells per treatment, and consequently, they need to be expanded in vitro before implantation, with the inconvenience that MSCs undergo senescence following a certain number of cell expansion passages, loosing their stem cell qualities. Ambient oxygen tension (21% pO2) is normally used for in vitro culture, but physiological levels in vivo range between 3% and 6% pO2. We previously demonstrated that hDPSC proliferation rate is significantly lowered at 21% pO2 due to enhanced oxidative stress, which led to the activation …

The mitotic kinase Aurora-A promotes distant metastases by inducing epithelial-to-mesenchymal transition in ERα+ breast cancer cells

2013

In this study, we demonstrate that constitutive activation of Raf-1 oncogenic signaling induces stabilization and accumulation of Aurora-A mitotic kinase that ultimately drives the transition from an epithelial to a highly invasive mesenchymal phenotype in estrogen receptor α-positive (ERα(+)) breast cancer cells. The transition from an epithelial- to a mesenchymal-like phenotype was characterized by reduced expression of ERα, HER-2/Neu overexpression and loss of CD24 surface receptor (CD24(-/low)). Importantly, expression of key epithelial-to-mesenchymal transition (EMT) markers and upregulation of the stemness gene SOX2 was linked to acquisition of stem cell-like properties such as the ab…

Evidence for differential and redundant function of the Sox genes Dichaete and SoxN during CNS development in Drosophila.

2002

Group B Sox-domain proteins encompass a class of conserved DNA-binding proteins expressed from the earliest stages of metazoan CNS development. In all higher organisms studied to date, related Group B Sox proteins are co-expressed in the developing CNS; in vertebrates there are three (Sox1, Sox2 and Sox3) and in Drosophila there are two (SoxNeuro and Dichaete). It has been suggested there may be a degree of functional redundancy in Sox function during CNS development. We describe the CNS phenotype of a null mutation in the Drosophila SoxNeuro gene and provide the first direct evidence for both redundant and differential Sox function during CNS development in Drosophila. In the lateral neuro…

MicroRNA-29b-1 impairs in vitro cell proliferation, self‑renewal and chemoresistance of human osteosarcoma 3AB-OS cancer stem cells

2014

Osteosarcoma (OS) is the most common type of bone cancer, with a peak incidence in the early childhood. Emerging evidence suggests that treatments targeting cancer stem cells (CSCs) within a tumor can halt cancer and improve patient survival. MicroRNAs (miRNAs) have been implicated in the maintenance of the CSC phenotype, thus, identification of CSC-related miRNAs would provide information for a better understanding of CSCs. Downregulation of miRNA-29 family members (miR-29a/b/c; miR‑29s) was observed in human OS, however, little is known about the functions of miR-29s in human OS CSCs. Previously, during the characterization of 3AB-OS cells, a CSC line selected from human OS MG63 cells, we…

Identification Of Mitotically Competent SOX2+ Cells In White Matter Of Normal Human Adult Brain

2011

AbstractSOX2 expression is linked to the undifferentiated state of stem cells in mammalian neurogenic niches. While its expression has been reported in the adult human subventricular zone (SVZ), to date it has not been detected in adult human white matter. Here we describe a population of SOX2+ cells from the white matter of the adult human temporal lobe, which proliferate and express glial markers in vitro.