The Human Lung Adenocarcinoma Cell Line EKVX Produces an Infectious Xenotropic Murine Leukemia Virus

The cell lines of the NCI-60 panel represent different cancer types and have been widely utilized for drug screening and molecular target identification. Screening these cell lines for envelope proteins or gene sequences related to xenotropic murine leukemia viruses (X-MLVs) revealed that one cell line, EKVX, was a candidate for production of an infectious gammaretrovirus. The presence of a retrovirus infectious to human cells was confirmed by the cell-free transmission of infection to the human prostate cancer cell line LNCaP. Amplification and sequencing of additional proviral sequences from EKVX confirmed a high degree of similarity to X-MLV. The cell line EKVX was established following passage of the original tumor cells through nude mice, providing a possible source of the X-MLV found in the EKVX cells

Osteopontin regulates human glioma cell invasiveness and tumor growth in mice

Human malignant glioma cells are characterized by local invasion. In the present study, we investigated the role of osteopontin (OPN) in the invasiveness of human glioma cells isolated from grade IV tumors. We found that the expression levels of OPN in these cell lines paralleled matrix metalloproteinase-2 (MMP-2) expression and cell invasiveness potential. When U87MG glioma cells (with a high-OPN expression level) were stably transformed with specific small hairpin RNA to knock down OPN expression, MMP-2 secretion, cell invasiveness, and tumor growth in implanted brains were dramatically reduced. Conversely, forced expression of OPN in GBM-SKH glioma cells (which expressed OPN at a low level) increased MMP-2 secretion, enhanced cell invasiveness, and increased tumor growth in a rodent xenograft model. Expression of OPN was associated with increased expression of vimentin and decreased expression of glial fibrillary acidic protein. Treatment of glioma cells with 5-aza-2′-deoxycytidine (5-aza-dC) suppressed OPN expression in a concentration-dependent manner. Suppression of OPN expression by 5-aza-dC was associated with reductions in MMP-2 secretion, vimentin expression, cell invasion, intravasation, and tumor growth. These data suggest that OPN may play important roles in regulating cell invasion in glioma cells and that 5-aza-dC may serve as a therapeutic agent for human gliomas

Rapid, reliable, and reproducible molecular sub-grouping of clinical medulloblastoma samples

The diagnosis of medulloblastoma likely encompasses several distinct entities, with recent evidence for the existence of at least four unique molecular subgroups that exhibit distinct genetic, transcriptional, demographic, and clinical features. Assignment of molecular subgroup through routine profiling of high-quality RNA on expression microarrays is likely impractical in the clinical setting. The planning and execution of medulloblastoma clinical trials that stratify by subgroup, or which are targeted to a specific subgroup requires technologies that can be economically, rapidly, reliably, and reproducibly applied to formalin-fixed paraffin embedded (FFPE) specimens. In the current study, we have developed an assay that accurately measures the expression level of 22 medulloblastoma subgroup-specific signature genes (CodeSet) using nanoString nCounter Technology. Comparison of the nanoString assay with Affymetrix expression array data on a training series of 101 medulloblastomas of known subgroup demonstrated a high concordance (Pearson correlation r = 0.86). The assay was validated on a second set of 130 non-overlapping medulloblastomas of known subgroup, correctly assigning 98% (127/130) of tumors to the appropriate subgroup. Reproducibility was demonstrated by repeating the assay in three independent laboratories in Canada, the United States, and Switzerland. Finally, the nanoString assay could confidently predict subgroup in 88% of recent FFPE cases, of which 100% had accurate subgroup assignment. We present an assay based on nanoString technology that is capable of rapidly, reliably, and reproducibly assigning clinical FFPE medulloblastoma samples to their molecular subgroup, and which is highly suited for future medulloblastoma clinical trials

MicroRNA 128a Increases Intracellular ROS Level by Targeting Bmi-1 and Inhibits Medulloblastoma Cancer Cell Growth by Promoting Senescence

BACKGROUND: MicroRNAs (miRNAs) are a class of short non-coding RNAs that regulate cell homeostasis by inhibiting translation or degrading mRNA of target genes, and thereby can act as tumor suppressor genes or oncogenes. The role of microRNAs in medulloblastoma has only recently been addressed. We hypothesized that microRNAs differentially expressed during normal CNS development might be abnormally regulated in medulloblastoma and are functionally important for medulloblastoma cell growth. METHODOLOGY AND PRINCIPAL FINDINGS: We examined the expression of microRNAs in medulloblastoma and then investigated the functional role of one specific one, miR-128a, in regulating medulloblastoma cell growth. We found that many microRNAs associated with normal neuronal differentiation are significantly down regulated in medulloblastoma. One of these, miR-128a, inhibits growth of medulloblastoma cells by targeting the Bmi-1 oncogene. In addition, miR-128a alters the intracellular redox state of the tumor cells and promotes cellular senescence. CONCLUSIONS AND SIGNIFICANCE: Here we report the novel regulation of reactive oxygen species (ROS) by microRNA 128a via the specific inhibition of the Bmi-1 oncogene. We demonstrate that miR-128a has growth suppressive activity in medulloblastoma and that this activity is partially mediated by targeting Bmi-1. This data has implications for the modulation of redox states in cancer stem cells, which are thought to be resistant to therapy due to their low ROS states

Telomerase inhibition abolishes the tumorigenicity of pediatric ependymoma tumor-initiating cells

Pediatric ependymomas are highly recurrent tumors resistant to conventional chemotherapy. Telomerase, a ribonucleoprotein critical in permitting limitless replication, has been found to be critically important for the maintenance of tumor-initiating cells (TICs). These TICs are chemoresistant, repopulate the tumor from which they are identified, and are drivers of recurrence in numerous cancers. In this study, telomerase enzymatic activity was directly measured and inhibited to assess the therapeutic potential of targeting telomerase. Telomerase repeat amplification protocol (TRAP) (n = 36) and C-circle assay/telomere FISH/ATRX staining (n = 76) were performed on primary ependymomas to determine the prevalence and prognostic potential of telomerase activity or alternative lengthening of telomeres (ALT) as telomere maintenance mechanisms, respectively. Imetelstat, a phase 2 telomerase inhibitor, was used to elucidate the effect of telomerase inhibition on proliferation and tumorigenicity in established cell lines (BXD-1425EPN, R254), a primary TIC line (E520) and xenograft models of pediatric ependymoma. Over 60 % of pediatric ependymomas were found to rely on telomerase activity to maintain telomeres, while no ependymomas showed evidence of ALT. Children with telomerase-active tumors had reduced 5-year progression-free survival (29 +/- A 11 vs 64 +/- A 18 %; p = 0.03) and overall survival (58 +/- A 12 vs 83 +/- A 15 %; p = 0.05) rates compared to those with tumors lacking telomerase activity. Imetelstat inhibited proliferation and self-renewal by shortening telomeres and inducing senescence in vitro. In vivo, Imetelstat significantly reduced subcutaneous xenograft growth by 40 % (p = 0.03) and completely abolished the tumorigenicity of pediatric ependymoma TICs in an orthotopic xenograft model. Telomerase inhibition represents a promising therapeutic approach for telomerase-active pediatric ependymomas found to characterize high-risk ependymomas.Canadian Institutes of Health Research [MOP 82727]info:eu-repo/semantics/publishedVersio

Differential expression and localization of TIMP-1 and TIMP-4 in human gliomas

Studies have suggested that an imbalance of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) may contribute to the malignant phenotype of gliomas. In this study, we have undertaken a detailed analysis of expression of the TIMP family in normal human brain and malignant gliomas at both the mRNA and protein level. Reverse transcription-PCR (RT-PCR) analyses of total RNA from surgical tumour specimens revealed unique expression patterns for the 4 members of the TIMP family, with TIMP-1 and -4 showing positive and negative correlations, respectively, with glioma malignancy. By RT-PCR, TIMP-2 and TIMP-3 expression did not change with tumour grade. In situ hybridization localized TIMP-1 to glial tumour cells and also to the surrounding tumour vasculature. TIMP-4 transcripts were predominantly localized to tumour cells, though minor expression was found in vessels. Recombinant TIMP-4 reduced invasion of U251 glioma cells through Matrigel, and U87 clones overexpressing TIMP-4 showed reduced invasive capacity in vitro. TIMP-4, but not TIMP-1, blocked Membrane Type-1-MMP-mediated progelatinase-A (MMP-2) activation in human umbilical vein endothelial cells. The differential expression and localization of individual TIMPs may contribute to the pathophysiology of human malignant gliomas, particularly with regard to tumour vascularization. © 2001 Cancer Research Campaign http://www.bjcancer.co

Evidence of Compromised Blood-Spinal Cord Barrier in Early and Late Symptomatic SOD1 Mice Modeling ALS

Background: The blood-brain barrier (BBB), blood-spinal cord barrier (BSCB), and blood-cerebrospinal fluid barrier (BCSFB) control cerebral/spinal cord homeostasis by selective transport of molecules and cells from the systemic compartment. In the spinal cord and brain of both ALS patients and animal models, infiltration of T-cell lymphocytes, monocyte-derived macrophages and dendritic cells, and IgG deposits have been observed that may have a critical role in motor neuron damage. Additionally, increased levels of albumin and IgG have been found in the cerebrospinal fluid in ALS patients. These findings suggest altered barrier permeability in ALS. Recently, we showed disruption of the BBB and BSCB in areas of motor neuron degeneration in the brain and spinal cord in G93A SOD1 mice modeling ALS at both early and late stages of disease using electron microscopy. Examination of capillary ultrastructure revealed endothelial cell degeneration, which, along with astrocyte alteration, compromised the BBB and BSCB. However, the effect of these alterations upon barrier function in ALS is still unclear. The aim of this study was to determine the functional competence of the BSCB in G93A mice at different stages of disease. Methodology/Principal Findings: Evans Blue (EB) dye was intravenously injected into ALS mice at early or late stage disease. Vascular leakage and the condition of basement membranes, endothelial cells, and astrocytes were investigated in cervical and lumbar spinal cords using immunohistochemistry. Results showed EB leakage in spinal cord microvessels from all G93A mice, indicating dysfunction in endothelia and basement membranes and confirming our previous ultrastructural findings on BSCB disruption. Additionally, downregulation of Glut-1 and CD146 expressions in the endothelial cells of the BSCB were found which may relate to vascular leakage. Conclusions/Significance: Results suggest that the BSCB is compromised in areas of motor neuron degeneration in ALS mice at both early and late stages of the disease

Az adalimumab hatékonysága és biztonságossága hagyományos kezelésre refrakter colitis ulcerosában

INTRODUCTION: Adalimumab was approved for the treatment of ulcerative colitis refractory to conventional therapy several years later than infliximab in Europe. Due to the relatively low remission rate observed in Ultra trials, data on the efficacy of adalimumab in ulcerative colitis are really helpful in the daily practice. AIM: The aim of this study was to prospectively collect data on induction and maintenance adalimumab therapy in patients with ulcerative colitis treated in Hungarian centres. METHOD: This prospective study collected data of all patients with ulcerative colitis treated with adalimumab in 10 Hungarian centres. The primary endpoints of the study were rates of remission, response and primary failure at week 12, and the rate of continuous clinical response, remission and loss of response at weeks 30, and 52. Secondary endpoints were endoscopic outcome at week 52 and comparison of the efficacy of adalimumab between treatment naive and infliximab-experienced patients. RESULTS: 73 patients with active ulcerative colitis were enrolled in the study. 75.3% of the patients exhibited clinical response after the induction at week 12. The probability of maintaining adalimumab treatment was 48.6% at week 52 with a continuous clinical response in 92% of these patients. Mucosal healing was achieved in 48.1% of the patients at week 52. Dose intensification was performed in 17.6% of the patients. Minor side effects developed in 4% of the patients and 5.4% of the patients underwent colectomy during the 1-year treatment period. CONCLUSIONS: These results coming from the real clinical setting demonstrate a favourable efficacy of adalimumab induction and maintenance therapy in patients with ulcerative colitis. Orv. Hetil., 2016, 157(18), 706-711