kns42

Pediatric high-grade gliomas (pHGG) are brain tumors occurring in children and adolescents associated with a dismal prognosis despite existing treatments. Therapeutic failure in both adult and pHGG has been partially imputed to glioma stem cells (GSC), a subset of cancer cells endowed with stem-like cell potential and malignant, invasive, adaptative, and treatment-resistant capabilities. Whereas GSC have largely been portrayed in adult tumors, less information has been provided in pHGG. The aim of our study was to comprehensively document the stem-like capacities of seven in-use pediatric glioma cell cultures (Res259, UW479, SF188, KNS42, SF8628, HJSD-DIPG-007 and HJSD-DIPG-012) using parallel in vitro assays assessing stem cell-related protein expression, multipotency, self-renewal and proliferation/quiescence, and in vivo investigation of their tumorigenicity and invasiveness...

PURPOSE: While pediatric glioblastomas are molecularly distinct from adult counterparts, the activation of NF-kB is partially shared by both subsets, playing key roles in tumor propagation and treatment response. RESULTS: We show that, in vitro, dehydroxymethylepoxyquinomicin (DHMEQ) impairs growth and invasiveness. Xenograft response to the drug alone varied according to the model, being more effective in KNS42-derived tumors. In combination, SF188-derived tumors were more sensitive to temozolomide while KNS42-derived tumors responded better to the combination with radiotherapy, with continued tumor regression...

Poor outcomes associated with diffuse high-grade gliomas occur in both adults and children, despite substantial progress made in the molecular characterisation of the disease. Targeting the metabolic requirements of cancer cells represents an alternative therapeutic strategy to overcome the redundancy associated with cell signalling. Cholesterol is an integral component of cell membranes and is required by cancer cells to maintain growth and may also drive transformation. Here, we show that removal of exogenous cholesterol in the form of lipoproteins from culture medium was detrimental to the growth of two paediatric diffuse glioma cell lines, KNS42 and SF188, in association with S-phase elongation and a transcriptomic program, indicating dysregulated cholesterol homeostasis...

Paediatric glioblastomas are rapidly growing, devastating brain neoplasms with an invasive phenotype. Radiotherapy and chemotherapy, which are the current therapeutic adjuvant to surgical resection, are still associated with various toxicity profiles and only marginally improve the course of the disease and life expectancy. A considerable body of evidence supports the antitumour and apoptotic effects of certain cannabinoids, such as WIN55,212-2, against a wide spectrum of cancer cells, including gliomas. In fact, we previously highlighted the potent cytotoxic activity of the cannabinoid ligand 5 against glioblastoma KNS42 cells...

High-grade gliomas represent the most lethal class of pediatric tumors, and their resistance to both radio- and chemotherapy is associated with a poor prognosis. Recurrent mutations affecting histone genes drive the tumorigenesis of some pediatric high-grade gliomas, and H3K27M mutations are notably characteristic of a subtype of gliomas called DMG (Diffuse Midline Gliomas). This dominant negative mutation impairs H3K27 trimethylation, leading to profound epigenetic modifications of genes expression. Even though this mutation was described as a driver event in tumorigenesis, its role in tumor cell resistance to treatments has not been deciphered so far...

BACKGROUND/AIM: Both pediatric glioblastoma (pGB) and adult glioblastoma (aGB) are clinically devastating, and are known to have different molecular pathogenesis. Here, we focused on the role of ZEB2 in pGB and aGB. MATERIALS AND METHODS: Following transfection with ZEB2 siRNA into pGB cells (KNS42) and aGB cells (U87 and U373), cell proliferation, migration and invasion, and cell cycle progression were evaluated. RESULTS: Targeted inhibition of ZEB2 induced up-regulation of E-cadherin expression and down-regulation of vimentin expression...

The histone H3 variant H3.3 is a highly conserved and dynamic regulator of chromatin organization. Therefore, fully elucidating its nucleosome incorporation mechanisms is essential to understanding its functions in epigenetic inheritance. We previously identified the RNase P protein subunit, Rpp29, as a repressor of H3.3 chromatin assembly. Here, we use a biochemical assay to show that Rpp29 interacts with H3.3 through a sequence element in its own N terminus, and we identify a novel interaction with histone H2B at an adjacent site...

INTRODUCTION: Glioblastoma (GBM) is the most common malignant primary brain tumor affecting adults. In pediatric patients, GBM exhibits genetic variations distinct from those identified in the adult GBM phenotype. This tumor exhibits complex genetic changes leading to malignant progression and resistance to standard therapies including radiotherapy and temozolomide treatment. The GDF15 gene codes for a growth factor whose expression is altered in the presence of inflammations and malignancies...

The mechanisms by which microRNAs control pediatric high-grade gliomas (pHGGs) have yet to be fully elucidated. Our studies of patient-derived pHGG tissues and of the pHGG cell line KNS42 revealed down-regulation in these tumors of three microRNAs, specifically miR-107, miR-181c, and miR-29a-3p. This down-regulation increases the proliferation of KNS42 cells by de-repressing expression of the Notch2 receptor (Notch2), a validated target of miR-107 and miR-181c and a putative target of miR-29a-3p. Inhibition (either pharmacologic or genetic) of Notch2 or re-expression of the implicated microRNAs (all three combined but also individually) significantly reduced KNS42 cell proliferation...

Recent experimental data showed that the PI3K pathway contributes to resistance to temozolomide (TMZ) in paediatric glioblastoma and that this effect is reversed by combination treatment of TMZ with a PI3K inhibitor. Our aim is to assess whether this combination results in metabolic changes that are detectable by nuclear magnetic resonance (NMR) spectroscopy, potentially providing metabolic biomarkers for PI3K inhibition and TMZ combination treatment. Using two genetically distinct paediatric glioblastoma cell lines, SF188 and KNS42, in vitro 1H-NMR analysis following treatment with the dual pan-Class I PI3K/mTOR inhibitor PI-103 resulted in a decrease in lactate and phosphocholine (PC) levels (P<0...

Low-grade (WHO I-II) gliomas and glioneuronal tumors represent the most frequent primary tumors of the central nervous system in children. They often have a good prognosis following total resection, however they can create many neurological complications due to mass effect, and may be difficult to resect depending on anatomic location. MicroRNAs have been identified as molecular regulators of protein expression/translation that can repress multiple mRNAs concurrently through base pairing, and have an important role in cancer, including brain tumors...

BACKGROUND: Glioblastoma (GBM) is considered to be one of the most aggressive tumors of the central nervous system (CNS). Even with the use of modern treatment protocols, the prognosis remains reserved, with children with GBM having a mean survival of 12-15 months. METHODS: In the present study we investigated the potential radiosensitizing effect of PCI-24781, a potent pan-histone deacetylase inhibitor (HDACi), on the SF188 and KNS42 cell lines of pediatric GBM...

BACKGROUND: Paediatric high grade glioma (pHGG) and diffuse intrinsic pontine glioma (DIPG) are highly aggressive brain tumours. Their invasive phenotype contributes to their limited therapeutic response, and novel treatments that block brain tumour invasion are needed. METHODS: Here, we examine the migratory characteristics and treatment effect of small molecule glycogen synthase kinase-3 inhibitors, lithium chloride (LiCl) and the indirubin derivative 6-bromoindirubin-oxime (BIO), previously shown to inhibit the migration of adult glioma cells, on two pHGG cell lines (SF188 and KNS42) and one patient-derived DIPG line (HSJD-DIPG-007) using 2D (transwell membrane, immunofluorescence, live cell imaging) and 3D (migration on nanofibre plates and spheroid invasion in collagen) assays...

The phosphoinositide 3-kinase (PI3K) pathway is believed to be of key importance in pediatric glioblastoma. Novel inhibitors of the PI3K pathway are being developed and are entering clinical trials. Our aim is to identify potential non-invasive biomarkers of PI3K signaling pathway inhibition in pediatric glioblastoma using in vitro nuclear magnetic resonance (NMR) spectroscopy, to aid identification of target inhibition and therapeutic response in early phase clinical trials of PI3K inhibitors in childhood cancer...

BACKGROUND: The factors affecting glioblastoma progression are of great clinical importance since dismal outcomes have been observed for glioblastoma patients. The Snail gene is known to coordinate the regulation of tumor progression in diverse tumors through induction of epithelial mesenchymal transition (EMT); however, its role in glioblastoma is still uncertain. Therefore, we aimed to further define its role in vitro. METHODS AND RESULTS: The small interfering RNA (siRNA) technique was employed to knock down Snail expression in three glioblastoma cell lines (KNS42, U87, and U373)...

BACKGROUND: Telomeric 3' overhangs can fold into a four-stranded DNA structure termed G-quadruplex (G4), a formation which inhibits telomerase. As telomerase activation is crucial for telomere maintenance in most cancer cells, several classes of G4 ligands have been designed to directly disrupt telomeric structure. METHODS: We exposed brain tumor cells to the G4 ligand 3,11-difluoro-6,8,13-trimethyl-8H-quino[4,3,2-kl]acridinium methosulfate (RHPS4) and investigated proliferation, cell cycle dynamics, telomere length, telomerase activity and activated c-Myc levels...

Pediatric high grade glioma is refractory to conventional multimodal treatment, highlighting a need to develop novel efficacious therapies. We investigated tumor metabolism as a potential therapeutic target in a panel of diverse pediatric glioma cell lines (SF188, KNS42, UW479 and RES186) using metformin and 2-deoxyglucose. As a single agent, metformin had little effect on cell viability overall. SF188 cells were highly sensitive to 2-deoxyglucose however, combination of metformin with 2-deoxyglucose significantly reduced cell proliferation compared to either drug alone in all cell lines tested...

INTRODUCTION: Physiologically relevant pre-clinical ex vivo models recapitulating CNS tumor micro-environmental complexity will aid development of biologically-targeted agents. We present comprehensive characterization of tumor aggregates generated using the 3D Rotary Cell Culture System (RCCS). METHODS: CNS cancer cell lines were grown in conventional 2D cultures and the RCCS and comparison with a cohort of 53 pediatric high grade gliomas conducted by genome wide gene expression and microRNA arrays, coupled with immunohistochemistry, ex vivo magnetic resonance spectroscopy and drug sensitivity evaluation using the histone deacetylase inhibitor, Vorinostat...

BACKGROUND: Urocortin and corticotropin-releasing factors (CRFs) and their receptors are expressed in many organs, including the central nervous system. In this study, the expression of mRNAs of urocortin 1, 2, 3, and CRF and CRF receptors 1 and 2 in malignant glioma, was examined. MATERIALS AND METHODS: The RNAs of human and rat glioma cell lines were isolated. Transcripts in these cells were analyzed using cDNA. In addition, the effects of proliferative and cytotoxic stimulation by serum supplementation, ionizing radiation, and the antineoplastic agent temozolomide were investigated...

BACKGROUND: Malignant glioma is an invasive disease of the central nervous system. One of the factors that regulate growth of these tumors is expression of epidermal growth factor receptor (EGFR) in the cells. This study investigated the effects of down-regulation of EGFR on cell proliferation, cell cycle and cytotoxicity to antineoplastic agent. MATERIALS AND METHODS: A short hairpin RNA transcription vector targeting EGFR was transfected into KNS42 cells. Growth curve, cell cycle and sensitivity to temozolomide of the cells were assessed...