POU3f2 in human gliomas - Expression pattern and functional role

Gliomas are tumors of the central nervous system (CNS). They are responsible for about 28% of all central nervous system tumors and for 80% of all malignant brain tumors. The most commonly used classification and grading of CNS tumors is the World Health organization (WHO) classification: According to the WHO classification, gliomas are divided into four grades, from grade I to IV. Furthermore, different grade tumors are characterised by different genetic aberrations and phenotypes. Tumor and fetal development display a resemblance due to the fast increase in biomass and extensive cell migration that characterised both processes. Thus the early embryo and tumors may share a common genetic basis. POU domain transcription factors have a critical role in embryo development, and reexpression/overexpression of these transcription factors have been reported in many cancers. POU3f2 is an intronless member of class III POU domain transcription factors. Its expression is confined to the CNS where it is involved in differentiation of neuronal and glial cell lineages in the embryo. Re-expression of POU3f2 has been reported in melanoma cancer by several independent groups. Although POU3f2 expression in gliomas has been sporadically reported, it has not been systematically characterised in a larger panel of gliomas of different grades and histologies. Since melanocytes and the main CNS cell types share a common neuroectodermal origin therefore, we hypothesized that POU3f2 is expressed in human gliomas. In order to assess the expression of POU3f2 in glioma patients, and its possible correlation with malignancy grade, 51 formalin fixed paraffin embedded patient biopsies (grade II-IV) were stained by immunohistochemistry. Secondly, to confirm IHC results, western blotting and qRT-PCR were performed on about 40 human glioma biopsies. In addition, we conducted a series of experiments in vitro and in vivo to investigate how POU3f2 impacted on various aspects of glioma cell behavior. We found that, POU3f2 is expressed in all grades of glioma of both astrocytic and oligodendroglial lineages. Moreover, expression was higher in grade IV than grade II tumors, whereas over-expression of POU3f2 in the U251cell line increased both glioma cell proliferation and colony formation. Conversely, down-regulation of POU3f2 decreased colony formation. Finally, over-expression of POU3f2 in the U251cell line promoted tumor growth in nude mice, compared to U251 glioma cells with down-regulation of POU3f2 or expression of scrambled RNA sequences. My plan for future studies will be to expand the present data to include additional glioma cell lines. In addition, my goal is to establish which signaling pathway mediates the effects of POU3f2.Master i Medisinsk biologiMAMD-MEDBIBMED39

Incremental View Maintenance For Collection Programming

In the context of incremental view maintenance (IVM), delta query derivation is an essential technique for speeding up the processing of large, dynamic datasets. The goal is to generate delta queries that, given a small change in the input, can update the materialized view more efficiently than via recomputation. In this work we propose the first solution for the efficient incrementalization of positive nested relational calculus (NRC+) on bags (with integer multiplicities). More precisely, we model the cost of NRC+ operators and classify queries as efficiently incrementalizable if their delta has a strictly lower cost than full re-evaluation. Then, we identify IncNRC+; a large fragment of NRC+ that is efficiently incrementalizable and we provide a semantics-preserving translation that takes any NRC+ query to a collection of IncNRC+ queries. Furthermore, we prove that incremental maintenance for NRC+ is within the complexity class NC0 and we showcase how recursive IVM, a technique that has provided significant speedups over traditional IVM in the case of flat queries [25], can also be applied to IncNRC+.Comment: 24 pages (12 pages plus appendix

GM-CSF, Flt3-L and IL-4 affect viability and function of conventional dendritic cell types 1 and 2

Conventional type 1 dendritic cells (cDC1) and conventional type 2 dendritic cells (cDC2) have attracted increasing attention as alternatives to monocyte-derived dendritic cells (moDCs) in cancer immunotherapy. Use of cDCs for therapy has been hindered by their low numbers in peripheral blood. In the present study, we found that extensive spontaneous apoptosis and cDC death in culture within 24hrs represent an additional challenge. Different media conditions that maintain cDC viability and function were investigated. CD141+ cDC1 and CD1c+ cDC2 were isolated from healthy blood donor buffy coats. Low viabilities were found with CellGenix DC, RPMI-1640, and X-VIVO 15 standard culture media and with several supplements at 24hrs and 48hrs. Among multiple factors it was found that GM-CSF improved both cDC1 and cDC2 viability, whereas Flt3-L and IL-4 only increased viability of cDC1 and cDC2, respectively. Combinations of these three cytokines improved viability of both cDCs further, both at 24hrs and 48hrs time points. Although these cytokines have been extensively investigated for their role in myeloid cell differentiation, and are also used clinically, their effects on mature cDCs remain incompletely known, in particular effects on pro-inflammatory or tolerogenic cDC features. HLA-DR, CD80, CD83, CD86, PD-L1 and PD-L2 cDC membrane expressions were relatively little affected by GM-CSF, IL-4 and Flt3-L cytokine supplements compared to the strong induction following Toll-like receptor (TLR) stimulation for 24hrs. With minor exceptions the three cytokines appeared to be permissive to the TLR-induced marker expression. Allogeneic mixed leukocyte reaction showed that the cytokines promoted T-cell proliferation and revealed a potential to boost both Th1 and Th2 polarizing cytokines. GM-CSF and Flt3-L and their combination improved the capability of cDC1 for dextran uptake, while in cDC2, dextran capture was improved by GM-CSF. The data suggest that GM-CSF, IL-4 and Flt3-L and combinations might be beneficial for DC viability and function in vitro. Limited viability of cDCs could be a confounding variable experimentally and in immunotherapy.publishedVersio

Stress granules regulate stress-induced paraspeckle assembly

Eukaryotic cells contain a variety of RNA-protein macrocomplexes termed RNP granules. Different types of granules share multiple protein components; however, the crosstalk between spatially separated granules remains unaddressed. Paraspeckles and stress granules (SGs) are prototypical RNP granules localized exclusively in the nucleus and cytoplasm, respectively. Both granules are implicated in human diseases, such as amyotrophic lateral sclerosis. We characterized the composition of affinity-purified paraspeckle-like structures and found a significant overlap between the proteomes of paraspeckles and SGs. We further show that paraspeckle hyperassembly is typical for cells subjected to SG-inducing stresses. Using chemical and genetic disruption of SGs, we demonstrate that formation of microscopically visible SGs is required to trigger and maintain stress-induced paraspeckle assembly. Mechanistically, SGs may sequester negative regulators of paraspeckle formation, such as UBAP2L, alleviating their inhibitory effect on paraspeckles. Our study reveals a novel function for SGs as positive regulators of nuclear RNP granule assembly and suggests a role for disturbed SG-paraspeckle crosstalk in human disease