166 research outputs found
CD56 expression in breast cancer induces sensitivity to natural killer-mediated cytotoxicity by enhancing the formation of cytotoxic immunological synapse
We examined the potential value of the natural killer (NK) cell line; NK-92, as immunotherapy tool for breast cancer (BC) treatment and searched for biomarker(s) of sensitivity to NK-92-mediated cytotoxicity. The cytotoxic activity of NK-92 cells towards one breast precancerous and nine BC cell lines was analyzed using calcein-AM and degranulation assays. The molecules associated with NK-92-responsiveness were determined by differential gene expression analysis using RNA-sequencing and validated by RT-PCR, immunostaining and flow cytometry. NK-target interactions and immunological synapse formation were assessed by fluorescence microscopy. Potential biomarker expression was determined by IHC in 99 patient-derived BC tissues and 10 normal mammary epithelial tissues. Most (8/9) BC cell lines were resistant while only one BC and the precancerous cell lines were effectively killed by NK-92 lymphocytes. NK-92-sensitive target cells specifically expressed CD56, which ectopic expression in CD56-negative BC cells induced their sensitivity to NK-92-mediated killing, suggesting that CD56 is not only a biomarker of responsiveness but actively regulates NK function. CD56 adhesion molecules which are also expressed on NK cells accumulate at the immunological synapse enhancing NK-target interactions, cytotoxic granzyme B transfer from NK-92 to CD56-expressing target cells and induction of caspase 3 activation in targets. Interestingly, CD56 expression was found to be reduced in breast tumor tissues (36%) with strong inter- and intratumoral heterogeneity in comparison to normal breast tissues (80%). CD56 is a potential predictive biomarker for BC responsiveness to NK-92-cell based immunotherapy and loss of CD56 expression might be a mechanism of escape from NK-immunity. - 2019, The Author(s).We would like to thank Ms Khaoula Errafii, Dr Kumaran Mande and Dr Richard Thompson for technical support in RNA sequencing. This work was supported by the Qatar Biomedical Research Institute (QBRI), Qatar Foundation.Scopu
TMEM106B is a genetic modifier of frontotemporal lobar degeneration with C9orf72 hexanucleotide repeat expansions
Hexanucleotide repeat expansions in chromosome 9 open reading frame 72 (C9orf72) have recently been linked to frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis, and may be the most common genetic cause of both neurodegenerative diseases. Genetic variants at TMEM106B influence risk for the most common neuropathological subtype of FTLD, characterized by inclusions of TAR DNA-binding protein of 43 kDa (FTLD-TDP). Previous reports have shown that TMEM106B is a genetic modifier of FTLD-TDP caused by progranulin (GRN) mutations, with the major (risk) allele of rs1990622 associating with earlier age at onset of disease. Here, we report that rs1990622 genotype affects age at death in a single-site discovery cohort of FTLD patients with C9orf72 expansions (n = 14), with the major allele correlated with later age at death (p = 0.024). We replicate this modifier effect in a 30-site international neuropathological cohort of FTLD-TDP patients with C9orf72 expansions (n = 75), again finding that the major allele associates with later age at death (p = 0.016), as well as later age at onset (p = 0.019). In contrast, TMEM106B genotype does not affect age at onset or death in 241 FTLD-TDP cases negative for GRN mutations or C9orf72 expansions. Thus, TMEM106B is a genetic modifier of FTLD with C9orf72 expansions. Intriguingly, the genotype that confers increased risk for developing FTLD-TDP (major, or T, allele of rs1990622) is associated with later age at onset and death in C9orf72 expansion carriers, providing an example of sign epistasis in human neurodegenerative disease
EGFRvIII deletion mutations in pediatric high-grade glioma and response to targeted therapy in pediatric glioma cell lines
Purpose: The epidermal growth factor receptor (EGFR) is amplified and overexpressed
in adult glioblastoma, with response to targeted inhibition dependent on the underlying
biology of the disease. EGFR has thus far been considered to play a less important role
in pediatric glioma, although extensive data are lacking. We have sought to clarify the
role of EGFR in pediatric high-grade glioma (HGG).
Experimental Design: We retrospectively studied a total of 90 archival pediatric HGG
specimens for EGFR protein overexpression, gene amplification, and mutation and assessed the in vitro sensitivity of pediatric glioma cell line models to the small-molecule
EGFR inhibitor erlotinib.
Results: Amplification was detected in 11% of cases, with corresponding overexpression of the receptor. No kinase or extracellular domain mutations were observed; however, 6 of 35 (17%) cases harbored the EGFRvIII deletion, including two anaplastic
oligodendrogliomas and a gliosarcoma overexpressing EGFRvIII in the absence of gene
amplification and coexpressing platelet-derived growth factor receptor α. Pediatric glioblastoma cells transduced with wild-type or deletion mutant EGFRvIII were not rendered
more sensitive to erlotinib despite expressing wild-type PTEN. Phosphorylated receptor
tyrosine kinase profiling showed a specific activation of platelet-derived growth factor
receptor α/β in EGFRvIII-transduced pediatric glioblastoma cells, and targeted coinhibition with erlotinib and imatinib leads to enhanced efficacy in this model.
Conclusions: These data identify an elevated frequency of EGFR gene amplification and
EGFRvIII mutation in pediatric HGG than previously recognized and show the likely
necessity of targeting multiple genetic alterations in the tumors of these children.Cancer Research UK grants C1178/A10294, C309/A2187, and
C309/A8274; Oak Foundation (L. Marshall); La Fondation de France (N. Gaspar);
and Breakthrough Breast Cancer (J.S. Reis-Filho). We acknowledge NHS funding to the National Institute for Health Research Biomedical Research Centre
Synthesis of novel Fe3O4 nanostructures surrounded by Ti-MOF nanostructures as bioactive and efficient catalysts in three-component synthesis of new pyrazole derivatives
Synthesis and reporting of new nanoparticles with diverse properties is important in chemistry. A one-step, rapid and controllable synthesis of the new Fe3O4 surrounded in Ti-MOF nanostructures was carried out with microwave technology. After identifying and confirming the structure, Fe3O4 surrounded in Ti-MOF nanostructures was used as a suitable catalyst with high thermal resistance and recyclable in a three-component reaction of phenylhydrazine, malononitrile and aldehyde to synthesis novel pyrazole derivatives. Continuing investigations on Fe3O4 surrounded in Ti-MOF nanostructures, its antimicrobial properties were tested on Gram-positive bacterial species, Gram-negative bacterial species and fungi bacterial. Identification of Fe3O4 surrounded in Ti-MOF nanostructures with morphology and size distribution technique (SEM), surface area technique (BET), Infrared spectroscopy (FT-IR), Energy-Dispersive X-ray spectroscopy (EDX/EDX mapping), and Vibrating Sample Magnetometer (VSM) were performed. Synthesized pyrazole derivatives with Fe3O4 surrounded in Ti-MOF nanostructures than previously reported methods have less synthesis time and high efficiency. In antimicrobial properties high effects were observed based on MIC, MBC, and MFC values
Distribution patterns of tau pathology in progressive supranuclear palsy
Progressive supranuclear palsy (PSP) is a 4R-tauopathy predominated by subcortical pathology in neurons, astrocytes, and oligodendroglia associated with various clinical phenotypes. In the present international study, we addressed the question of whether or not sequential distribution patterns can be recognized for PSP pathology. We evaluated heat maps and distribution patterns of neuronal, astroglial, and oligodendroglial tau pathologies and their combinations in different clinical subtypes of PSP in postmortem brains. W
Proliferation and aneusomy predict survival of young patients with astrocytoma grade II
The clinical course of astrocytoma grade II (AII) is highly variable and not reflected by histological characteristics. As one of the best prognostic factors, higher age identifies rapid progressive A II. For patients over 35 years of age, an aggressive treatment is normally propagated. For patients under 35 years, there is no clear guidance for treatment choices, and therefore also the necessity of histopathological diagnosis is often questioned. We studied the additional prognostic value of the proliferation index and the detection of genetic aberrations for patients with A II. The tumour samples were obtained by stereotactic biopsy or tumour resection and divided into two age groups, that is 18–34 years (n=19) and 35 years (n=28). Factors tested included the proliferation (Ki-67) index, and numerical aberrations for chromosomes 1, 7, and 10, as detected by in situ hybridisation (ISH). The results show that age is a prognostic indicator when studied in the total patient group, with patients above 35 years showing a relatively poor prognosis. Increased proliferation index in the presence of aneusomy appears to identify a subgroup of patients with poor prognosis more accurately than predicted by proliferation index alone. We conclude that histologically classified cases of A II comprise a heterogeneous group of tumours with different biological and genetic constitution, which exhibit a highly variable clinical course. Immunostaining for Ki-67 in combination with the detection of aneusomy by ISH allows the identification of a subgroup of patients with rapidly progressive A II. This is an extra argument not to defer stereotactic biopsy in young patients with radiological suspicion of A II
USF-1 Is Critical for Maintaining Genome Integrity in Response to UV-Induced DNA Photolesions
An important function of all organisms is to ensure that their genetic material remains intact and unaltered through generations. This is an extremely challenging task since the cell's DNA is constantly under assault by endogenous and environmental agents. To protect against this, cells have evolved effective mechanisms to recognize DNA damage, signal its presence, and mediate its repair. While these responses are expected to be highly regulated because they are critical to avoid human diseases, very little is known about the regulation of the expression of genes involved in mediating their effects. The Nucleotide Excision Repair (NER) is the major DNA–repair process involved in the recognition and removal of UV-mediated DNA damage. Here we use a combination of in vitro and in vivo assays with an intermittent UV-irradiation protocol to investigate the regulation of key players in the DNA–damage recognition step of NER sub-pathways (TCR and GGR). We show an up-regulation in gene expression of CSA and HR23A, which are involved in TCR and GGR, respectively. Importantly, we show that this occurs through a p53 independent mechanism and that it is coordinated by the stress-responsive transcription factor USF-1. Furthermore, using a mouse model we show that the loss of USF-1 compromises DNA repair, which suggests that USF-1 plays an important role in maintaining genomic stability
Early growth response-1 is a regulator of DR5-induced apoptosis in colon cancer cells
BACKGROUND: Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) induces tumour cell apoptosis by binding to death receptor 4 (DR4) and DR5. DR4 and DR5 activation however can also induce inflammatory and pro-survival signalling. It is not known how these different cellular responses are regulated and what the individual role of DR4 vs DR5 is in these processes.METHODS: DNA microarray study was carried out to identify genes differentially expressed after DR4 and DR5 activation. RT-PCR and western blotting was used to examine the expression of early growth response gene-1 (Egr-1) and the proteins of the TRAIL signalling pathway. The function of Egr-1 was studied by siRNA-mediated knockdown and overexpression of a dominant-negative version of Egr-1.RESULTS: We show that the immediate early gene, Egr-1, regulates TRAIL sensitivity. Egr-1 is constitutively expressed in colon cancer cells and further induced upon activation of DR4 or DR5. Our results also show that DR4 mediates a type II, mitochondrion-dependent apoptotic pathway, whereas DR5 induces a mitochondrion-independent, type I apoptosis in HCT15 colon carcinoma cells. Egr-1 drives c-FLIP expression and the short splice variant of c-FLIP (c-FLIPS) specifically inhibits DR5 activation.CONCLUSION: Selective knockdown of c-FLIPS sensitises cells to DR5-induced but not DR4-induced apoptosis and Egr-1 exerts an effect as an inhibitor of the DR5-induced apoptotic pathway, possibly by regulating the expression of c-FLIPS. British Journal of Cancer (2010) 102, 754-764. doi:10.1038/sj.bjc.6605545 www.bjcancer.com Published online 19 January 2010 (C) 2010 Cancer Research U
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