Search results for "glioma cell"

Molecular Determinants of Malignant Brain Cancers: From Intracellular Alterations to Invasion Mediated by Extracellular Vesicles

2017

Malignant glioma cells invade the surrounding brain parenchyma, by migrating along the blood vessels, thus promoting cancer growth. The biological bases of these activities are grounded in profound alterations of the metabolism and the structural organization of the cells, which consequently acquire the ability to modify the surrounding microenvironment, by altering the extracellular matrix and affecting the properties of the other cells present in the brain, such as normal glial-, endothelial- and immune-cells. Most of the effects on the surrounding environment are probably exerted through the release of a variety of extracellular vesicles (EVs), which contain many different classes of mol…

Oligodendroglioma cells synthesize the differentiation-specific linker histone H1˚ and release it into the extracellular environment through shed ves…

2013

Chromatin remodelling can be involved in some of the epigenetic modifications found in tumor cells. One of the mechanisms at the basis of chromatin dynamics is likely to be synthesis and incorporation of replacement histone variants, such as the H1° linker histone. Regulation of the expression of this protein can thus be critical in tumorigenesis. In developing brain, H1° expression is mainly regulated at the post-transcriptional level and RNA-binding proteins (RBPs) are involved. In the past, attention mainly focused on the whole brain or isolated neurons and little information is available on H1° expression in other brain cells. Even less is known relating to tumor glial cells. In this st…

Furostanol saponins and ecdysones with cytotoxic activity from Helleborus bocconei ssp. intermedius

2009

Two furostanol saponins helleboroside A (1) and helleboroside B (2) were isolated from the methanol extract of Helleborus bocconei Ten. subsp. intermedius (Guss.) Greuter and Burdet, along with the furospirostanol saponin 4 and two ecdysones: ecdysterone (5) and polypodyne B (6). Compound 2 was enzymatically hydrolysed to give product 3. The biological activity of all compounds was tested against rat C6 glioma cells showing a significant cytotoxicity for compounds 3, 4 and 6. Copyright © 2009 John Wiley & Sons, Ltd.

CD133 Expression Is Not Synonymous to Immunoreactivity for AC133 and Fluctuates throughout the Cell Cycle in Glioma Stem-Like Cells.

2015

A transmembrane protein CD133 has been implicated as a marker of stem-like glioma cells and predictor for therapeutic response in malignant brain tumours. CD133 expression is commonly evaluated by using antibodies specific for the AC133 epitope located in one of the extracellular domains of membrane-bound CD133. There is conflicting evidence regarding the significance of the AC133 epitope as a marker for identifying stem-like glioma cells and predicting the degree of malignancy in glioma cells. The reasons for discrepant results between different studies addressing the role of CD133/AC133 in gliomas are unclear. A possible source for controversies about CD133/AC133 is the widespread assumpt…

Melanoma cells release extracellular vesicles which contain H1° RNA and RNA-binding proteins

2015

G26/24 oligodendroglioma cells produce EVs that contain pro-apoptotic proteins, such as FasL and TRAIL, able to induce neuronal- [1] and astrocytic- [2] death. Cancer cells release EVs [3] through which transferring proteins, such as extracellular matrix remodelling proteases [4], and H1°, a differentiation-specific histone [5]. By releasing H1°, cells could escape differentiation cues [5]. To verify the role of EVs in releasing specific proteins and mRNAs, in this study we used A375 melanoma cells. EVs were purified from cell culture media as previously reported [1, 2]. T1 RNase-protection assays were performed on total cell lysates and EVs, as described elsewhere [6]. RNA-binding proteins…

COMPOSITION AND EFFECTS OF EXTRACELLULAR VESICLES SHED BY OLIGODENDROGLIOMA CELLS

2011

Guanine inhibits the growth of human glioma and melanoma cell lines by interacting with GPR23

2022

Guanine-based purines (GBPs) exert numerous biological effects at the central nervous system through putative membrane receptors, the existence of which is still elusive. To shed light on this question, we screened orphan and poorly characterized G protein-coupled receptors (GPRs), selecting those that showed a high purinoreceptor similarity and were expressed in glioma cells, where GBPs exerted a powerful antiproliferative effect. Of the GPRs chosen, only the silencing of GPR23, also known as lysophosphatidic acid (LPA) 4 receptor, counteracted GBP-induced growth inhibition in U87 cells. Guanine (GUA) was the most potent compound behind the GPR23-mediated effect, acting as the endpoint eff…

G26/24 extracellular microvesicles contain both H1° protein and RNA

2015

Extracellular vesicles (EVs) are released into the extracellular space from both tumor and normal brain cells. By releasing EVs which contain FGF2 and VEGF1-2, astrocytes and neurons, co-cultured with brain capillary endothelial cells, are for example able to induce them to form a blood-brain barrier-like monolayer. On the other hand, membrane microvesicles (MVs) shed from G26/24 oligodendro­glioma cells, when added to primary cultures of rat cortical neurons, induce neuronal damage; the damaging effects include a strong reduction of neurite outgrowth, and apoptosis in about 75% of the cells3. The same amount of shed MVs induce apoptosis in about 40% of astrocytes4. These effects are probab…

Melanoma cells release extracellular vesicle which contain H1° linker histone as well as RNA-binding proteins which bind to the H1° mRNA

2015

We previously demonstrated that G26/24 oligodendroglioma cells release EVs that contain proteins, such as FasL and TRAIL, which induce apoptosis in rat cortical neurons [1] and astrocytes [2]. We also reported that cancer cells use EVs for transferring, into the environment [3], proteins such as extracellular matrix remodelling proteases [4], and H1°, a differentiation-specific histone [5]. In particular, by releasing H1°, cells could escape differentiation cues [5]. To verify the role of EVs in releasing specific proteins and mRNAs, in this study we used as a model A375 melanoma cells. METHODS EVs were purified from cell culture media as previously reported [1, 2]. T1 RNase-protection assa…

Cancer cells can affect behaviour of neighbouring cells by transferring molecules through extracellular vesicles

2017

Most cells release into the extracellular space membrane-bound structures of different sizes, origin and composition, collectively called extracellular vesicles (EVs) [1]. Tumor cells are much more active than normal cells in producing EVs. Because of this property, they are able to transfer both nucleic acids and proteins to the surrounding normal cells, thus inducing in these latter at least some transformed behavior. We previously showed that EVs produced by G26/24 oligodendroglioma cells can horizontally transfer to their neighbours radioactive proteins [2]. In addition, EVs released by these cells contain pro-apoptotic proteins, such as TRAIL and Fas-Ligand, able to induce apoptosis in…