Search results for "Progenitor cell"

Transplantation of prodrug-converting neural progenitor cells for brain tumor therapy

2003

Since neural progenitor cells can engraft stably into brain tumors and differentiate along the neuronal and glial line, we tested the hypothesis that transplanted cytosine deaminase (CD)-expressing ST14A cells (an immortalized neural progenitor cell line) can convert locally 5-fluorocytosine (5-FC) into 5-fluorouracil (5-FU) and produce a regression of glioma tumors. ST14A, retrovirally transduced with the E. coli CD gene, showed a strong bystander effect on glioma cells as assessed by in vitro assay. Intracerebral injection of C6 glioma cells generated a rapidly growing tumoral mass. DiI prelabeled ST14A, coinjected into the rat brain with C6 glioma cells, survived in the tumoral mass up t…

Mesenchymal stromal-cell transplants induce oligodendrocyte progenitor migration and remyelination in a chronic demyelination model.

2013

Demyelinating disorders such as leukodystrophies and multiple sclerosis are neurodegenerative diseases characterized by the progressive loss of myelin that may lead toward a chronic demyelination of the brain’s white matter, impairing normal axonal conduction velocity and ultimately causing neurodegeneration. Current treatments modifying the pathological mechanisms are capable of ameliorating the disease; however, frequently, these therapies are not sufficient to repress the progressive demyelination into a chronic condition and permanent loss of function. To this end, we analyzed the effect that bone marrow-derived mesenchymal stromal cell (BM-MSC) grafts exert in a chronically demyelinate…

2015

Notch receptors play an essential role in the regulation of central cellular processes during embryonic and postnatal development. The mammalian genome encodes for four Notch paralogs (Notch 1-4), which are activated by three Delta-like (Dll1/3/4) and two Serrate-like (Jagged1/2) ligands. Further, non-canonical Notch ligands such as EGFL7 have been identified and serve mostly as antagonists of Notch signaling. The Notch pathway prevents neuronal differentiation in the central nervous system by driving neural stem cell maintenance and commitment of neural progenitor cells into the glial lineage. Notch is therefore often implicated in the development of brain tumors, as tumor cells share vari…

HER2 regulates the mammary stem/progenitor cell population driving tumorigenesis and invasion.

2008

The cancer stem cell hypothesis proposes that cancers arise in stem/progenitor cells through disregulation of self-renewal pathways generating tumors, which are driven by a component of 'tumor-initiating cells' retaining stem cell properties. The HER2 gene is amplified in 20-30% of human breast cancers and has been implicated in mammary tumorigenesis as well as in mediating aggressive tumor growth and metastasis. We demonstrate that HER2 overexpression drives mammary carcinogenesis, tumor growth and invasion through its effects on normal and malignant mammary stem cells. HER2 overexpression in normal mammary epithelial cells (NMEC) increases the proportion of stem/progenitor cells as demons…

Influence of interferon-alpha on cytokine expression by the bone marrow microenvironment--impact on treatment of myeloproliferative disorders.

1996

Myeloproliferative disorders (MPD) are characterized by several common clinical and biological features, although at the molecular level, each disease entity exhibits distinct abnormalities. IFN-alpha exerts beneficial therapeutic effects in chronic myelogenous leukemia, polycythemia vera and essential thrombocythemia, resulting in control of hematopoietic hyperplasia and, in a minority of patients, in induction of cytogenetic remission. The mechanism of action of IFN-alpha in MPD is poorly defined. Recently published in vitro findings suggest that IFN-alpha interacts with the regulation of hematopoiesis by multiple ways. Its antiproliferative activity is well known for more than a decade, …

Abstract 3015: Precise investigation of cancer stem cells in mouse glioblastoma

2018

Abstract In this study, we employ mouse models to investigate features and roles of cancer stem cells (CSCs) in glioblastoma (GBM). A nestin-TK-GFP transgene is firstly used to label CSCs in a fully penetrant mouse model of GBM (M7: hGFAP-Cre; Nf1fl/+; p53fl/fl; Ptenfl/+). Food-mediated ganciclovir (GCV) delivery kills proliferative transgene positive cells and significantly prolongs the lives of the transgene bearing mice. Isolation and transplantation of the tumor cells indicates the GFP+ cells are more tumorigenic than the GFP- cells. We then generate and characterize a novel transgene (CGD: nestin-CreERT2-H2BeGFP-hDTR) that labels all the neural stem/progenitor cells in the subventricul…

The Endocannabinoid System Promotes Astroglial Differentiation by Acting on Neural Progenitor Cells

2006

Endocannabinoids exert an important neuromodulatory role via presynaptic cannabinoid CB1receptors and may also participate in the control of neural cell death and survival. The function of the endocannabinoid system has been extensively studied in differentiated neurons, but its potential role in neural progenitor cells remains to be elucidated. Here we show that the CB1receptor and the endocannabinoid-inactivating enzyme fatty acid amide hydrolase are expressed, bothin vitroandin vivo, in postnatal radial glia (RC2+cells) and in adult nestin type I (nestin+GFAP+) neural progenitor cells. Cell culture experiments show that CB1receptor activation increases progenitor proliferation and differ…

Degenerative and regenerative processes involved in midgut pseudotumor formation in the stick insect (Carausius morosus)

2009

Spontaneous and experimentally induced pseudotumor formation in Carausius morosus impairs the midgut tissue homeostasis. Spontaneous pseudotumor formation begins by the break down of a single or a small group of columnar cells (CCs) and is followed by the degeneration of neighboring CCs. There are not only marked similarities but also decisive differences between normal dying CCs in healthy specimens and the degeneration of CCs leading to pseudotumors: in both cases, the apical cell parts with the nucleus are extruded into the midgut lumen, but only during of pseudotumor formation an "amorphous substance" originates from the basal parts of the CCs. Hemocytes are attracted to this substance …

Collecting evidence for a stem cell hypothesis in HCC.

2010

Ever since Ernest McCulloch and James E Till defined essential stem cell properties, the field of stem cell biology has attracted increasing interest.1 Manipulating embryonic stem cells has resulted in advanced genetic technologies such as knock-out and transgenic animals, providing valuable models to study genetic influence on a wide variety of diseases.2 The success in manipulating stem cells and the ability to differentiate them into diverse tissues brought with them countless concepts of utilising stem cells in medicine. The idea of perpetually dividing pluripotent cells, capable of differentiating into nearly every possible cell or tissue type, seems like an inexhaustible resource for …

An affordable method to obtain cultured endothelial cells from peripheral blood

2013

The culture of endothelial progenitor cells (EPC) provides an excellent tool to research on EPC biology and vascular regeneration and vasculogenesis. The use of different protocols to obtain EPC cultures makes it difficult to obtain comparable results in different groups. This work offers a systematic comparison of the main variables of most commonly used protocols for EPC isolation, culture and functional evaluation. Peripheral blood samples from healthy individuals were recovered and mononuclear cells were cultured. Different recovery and culture conditions were tested: blood volume, blood anticoagulant, coating matrix and percentage of foetal bovine serum (FBS) in culture media. The succ…