Search results for "GLIOMA"

Endothelial Wnt/β-catenin signaling reduces vascularization, barrier breakdown and tumor growth in a mouse glioma model

2012

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…

Image Analysis of Proliferating Cells in Tumors of the Human Nervous System

1994

Obtaining growth fractions from immunohistological preparations by the commonly used cell count calculation method is time consuming. For the first time, we investigated and compared the detection of proliferating cells in immunohistologically labeled tissue from tumors of the nervous system using the monoclonal antibody Ki-67 by a new computerized image analysis system and by cell count calculation. The two methods showed a high correlation (correlation index, 0.98) in 37 gliomas (2 pilocytic astrocytomas, 10 Grade II astrocytomas, 5 Grade III astrocytomas, 20 Grade IV astrocytomas and glioblastoma multiforme) and a heterogenous group of 10 additional tumors of the nervous system, includin…

Intraoperative Scintigraphy With Portable Gamma Camera for the Localization of Interaortocaval Paraganglioma

2021

A 15-year-old adolescent girl diagnosed of interaortocaval paraganglioma with a positive 123I-MIGB SPECT/CT and 1 unsuccessful prior surgery was operated on with the assistance of a handheld gamma camera. Once the lesion was located and removed, 2 images were taken, one of the surgical field (without 123I-MIGB uptake) and another of the tumor ex vivo (with high 123I-MIGB uptake), confirming that the lesion had been satisfactorily excised. This case highlights the use of a portable gamma camera as a useful tool to locate this rare tumor, with a SPECT/CT positive for 123I-MIGB and a difficult anatomical location suspected.

Probabilistic classification of intracranial gliomas in digital microscope images based on EGFR quantity

2009

A glioma is a type of cancer occurring, in the majority of cases, in the brain. The World Health Organization (WHO) assigns a grade from I to IV to this tumor, with I being the least aggressive and IV being the most aggressive. In glioma cells of grade IV the Epidermal Growth Factor Receptors (EGFRs) are over expressed. In this paper we hypothesize that this overexpression occurs also for gliomas of grades I to III. Moreover, we present a medical study aiming to determine the correlation between the WHO classification and the EGFR quantity in glioma tissue. We define five quantity classes for EGFR. First, results of immunohistochemical staining on brain glioma slices, which visualize the EG…

Normalization of sphingomyelin levels by 2-hydroxyoleic acid induces autophagic cell death of SF767 cancer cells

2012

The very high mortality rate of gliomas reflects the unmet therapeutic need associated with this type of brain tumor. We have discovered that the plasma membrane fulfills a critical role in the propagation of tumorigenic signals, whereby changes in membrane lipid content can either activate or silence relevant pathways. We have designed a synthetic fatty acid, 2-hydroxyoleic acid (2OHOA), that specifically activates sphingomyelin synthase (SGMS), thereby modifying the lipid content of cancer cell membranes and restoring lipid levels to those found in normal cells. In reverting, the structure of the membrane by activating SGMS, 2OHOA inhibits the RAS-MAPK pathway, which in turn fails to acti…

PDGFRα-Positive B Cells Are Neural Stem Cells in the Adult SVZ that Form Glioma-like Growths in Response to Increased PDGF Signaling

2006

Neurons and oligodendrocytes are produced in the adult brain subventricular zone (SVZ) from neural stem cells (B cells), which express GFAP and have morphological properties of astrocytes. We report here on the identification B cells expressing the PDGFRalpha in the adult SVZ. Specifically labeled PDGFRalpha expressing B cells in vivo generate neurons and oligodendrocytes. Conditional ablation of PDGFRalpha in a subpopulation of postnatal stem cells showed that this receptor is required for oligodendrogenesis, but not neurogenesis. Infusion of PDGF alone was sufficient to arrest neuroblast production and induce SVZ B cell proliferation contributing to the generation of large hyperplasias wi…

Targeting of biotinylated compounds to its target tissue using a low-density lipoprotein receptor–avidin fusion protein

2003

The very high binding affinity of avidin to biotin is one of the highest to occur in nature. We constructed a fusion protein composed of avidin and the endocytotic LDL receptor in order to target biotinylated molecules to cells of the desired tissues. In addition to the native avidin, charge-mutated and nonglycosylated avidins were utilized as part of the fusion proteins, in order to modify its properties. All of the fusion protein versions retained the biotin-binding capacity. Although the specificity was not increased, however, fusion proteins composed of natural avidin and nonglycosylated avidin bound most efficiently to the biotinylated ligands. Fluorescence microscopy and atomic force …

Integrated approach to delineating molecular traits of recurrent glioblastoma using glioma stem cell models and tumor tissue profiling

2018

2015

To investigate the effect of nitric oxide on tumor development, we established a rat tumor xenograft model in zebrafish embryos. The injected tumor cells formed masses in which nitric oxide production could be detected by the use of the cell-permeant DAF-FM-DA (diaminofluorophore 4-amino-5-methylamino-2’-7’-difluorofluorescein diacetate) and DAR-4M-AM (diaminorhodamine-4M). This method revealed that nitric oxide production could be co-localized with the tumor xenograft in 46% of the embryos. In 85% of these embryos, tumors were vascularized and blood vessels were observed on day 4 post injection. Furthermore, we demonstrated by qRT-PCR that the transplanted glioma cells highly expressed Nos…