Publications by authors named "Kevin Ashelford"

Background: Combined inhibition of phosphatidylinositol 3-kinase (PI3K) and the mammalian target of rapamycin (mTOR) complexes may be an efficient treatment for acute leukemia. The primary objective of this phase I single center open label study was to determine the maximum tolerated dose (MTD) and recommended phase II dose (RP2D) of the dual pan-class I PI3K and mTOR inhibitor BEZ235 in patients with advanced leukemia.

Methods: Herein patients > 18 years of age who had relapsed or showed refractory leukemia were treated with BEZ235 (orally at 300-400 mg BID (cohort - 1/1)) to assess safety, tolerability, preliminary efficacy and pharmacokinetic (PK).

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Aberrant activation of the Wnt signalling pathway is required for tumour initiation and survival in the majority of colorectal cancers. The development of inhibitors of Wnt signalling has been the focus of multiple drug discovery programs targeting colorectal cancer and other malignancies associated with aberrant pathway activation. However, progression of new clinical entities targeting the Wnt pathway has been slow.

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Chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) are incurable hematological malignancies that are pathologically linked with aberrant NF-κB activation. In this study, we identified a group of novel C8-linked benzofused Pyrrolo[2,1-c][1,4]benzodiazepines (PBD) monomeric hybrids capable of sequence-selective inhibition of NF-κB with low nanomolar LD50 values in CLL (n=46) and MM cell lines (n=5). The lead compound, DC-1-192, significantly inhibited NF-κB DNA binding after just 4h exposure and demonstrating inhibitory effects on both canonical and non-canonical NF-κB subunits.

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Purpose: Broadly expressed, highly differentiated tumor-associated antigens (TAA) can elicit antitumor immunity. However, vaccines targeting TAAs have demonstrated disappointing clinical results, reflecting poor antigen selection and/or immunosuppressive mechanisms.

Experimental Design: Here, a panel of widely expressed, novel colorectal TAAs were identified by performing RNA sequencing of highly purified colorectal tumor cells in comparison with patient-matched colonic epithelial cells; tumor cell purification was essential to reveal these genes.

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Fusion of critically short or damaged telomeres is associated with the genomic rearrangements that support malignant transformation. We have demonstrated the fundamental contribution of DNA ligase 4-dependent classical non-homologous end-joining to long-range inter-chromosomal telomere fusions. In contrast, localized genomic recombinations initiated by sister chromatid fusion are predominantly mediated by alternative non-homologous end-joining activity that may employ either DNA ligase 3 or DNA ligase 1.

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Duodenal polyposis and cancer are important causes of morbidity and mortality in familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP). This study aimed to comprehensively characterize somatic genetic changes in FAP and MAP duodenal adenomas to better understand duodenal tumorigenesis in these disorders. Sixty-nine adenomas were biopsied during endoscopy in 16 FAP and 10 MAP patients with duodenal polyposis.

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The commonest tumors associated with neurofibromatosis type 1 (NF1) are benign peripheral nerve sheath tumors, called neurofibromas. Malignant transformation of neurofibromas into aggressive MPNSTs may occur with a poor patient prognosis. A cooperative role of SUZ12 or EED inactivation, along with NF1, TP53, and CDKN2A loss-of-function, has been proposed to drive progression to MPNSTs.

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Background: The Rhynchosporium species complex consists of hemibiotrophic fungal pathogens specialized to different sweet grass species including the cereal crops barley and rye. A sexual stage has not been described, but several lines of evidence suggest the occurrence of sexual reproduction. Therefore, a comparative genomics approach was carried out to disclose the evolutionary relationship of the species and to identify genes demonstrating the potential for a sexual cycle.

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Telomeres shorten with each cell division and can ultimately become substrates for nonhomologous end-joining repair, leading to large-scale genomic rearrangements of the kind frequently observed in human cancers. We have characterized more than 1400 telomere fusion events at the single-molecule level, using a combination of high-throughput sequence analysis together with experimentally induced telomeric double-stranded DNA breaks. We show that a single chromosomal dysfunctional telomere can fuse with diverse nontelomeric genomic loci, even in the presence of an otherwise stable genome, and that fusion predominates in coding regions.

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Short dysfunctional telomeres are capable of fusion, generating dicentric chromosomes and initiating breakage-fusion-bridge cycles. Cells that escape the ensuing cellular crisis exhibit large-scale genomic rearrangements that drive clonal evolution and malignant progression. We demonstrate that there is an absolute requirement for fully functional DNA ligase III (LIG3), but not ligase IV (LIG4), to facilitate the escape from a telomere-driven crisis.

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Vulval intraepithelial neoplasia is a precursor of vulval cancer and is commonly caused by infection with Human Papillomavirus (HPV). Development of topical treatments for vulval intraepithelial neoplasia requires appropriate in vitro models. This study evaluated the feasibility of primary culture of vulval intraepithelial neoplasia biopsy tissue to produce cell lines for use as in vitro models.

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Background: Invasive Non-typhoidal Salmonella (iNTS) are an important cause of bacteraemia in children and HIV-infected adults in sub-Saharan Africa. Previous research has shown that iNTS strains exhibit a pattern of gene loss that resembles that of host adapted serovars such as Salmonella Typhi and Paratyphi A. Salmonella enterica serovar Bovismorbificans was a common serovar in Malawi between 1997 and 2004.

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Arcobacter butzleri is considered to be an emerging human foodborne pathogen. The completion of an A. butzleri genome sequence along with microarray analysis of 13 isolates in 2007 revealed a surprising amount of diversity amongst A.

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Anthropogenic endocrine disruptors now contaminate all environments globally, with concomitant deleterious effects across diverse taxa. While most studies on endocrine disruption (ED) have focused on vertebrates, the superimposition of male sexual characteristics in the female dogwhelk, Nucella lapillus (imposex), caused by organotins, provides one of the most clearcut ecological examples of anthropogenically induced ED in aquatic ecosystems. To identify the underpinning mechanisms of imposex for this 'nonmodel' species, we combined Roche 454 pyrosequencing with custom oligoarray fabrication inexpensively to both generate gene models and identify those responding to chronic tributyltin (TBT) treatment.

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Map based cloning in Arabidopsis thaliana can be a difficult and time-consuming process, specifically if the phenotype is subtle and scoring labour intensive. Here, we have re-sequenced the 120-Mb genome of a novel Arabidopsis clock mutant early bird (ebi-1) in Wassilewskija (Ws-2). We demonstrate the utility of sequencing a backcrossed line in limiting the number of SNPs considered.

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Although the major food-borne pathogen Campylobacter jejuni has been isolated from diverse animal, human and environmental sources, our knowledge of genomic diversity in C. jejuni is based exclusively on human or human food-chain-associated isolates. Studies employing multilocus sequence typing have indicated that some clonal complexes are more commonly associated with particular sources.

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Pseudomonas aeruginosa is a common opportunistic bacterial pathogen that causes a variety of infections in humans. Populations of P. aeruginosa are dominated by common clones that can be isolated from diverse clinical and environmental sources.

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Background: Mytilus species are important in marine ecology and in environmental quality assessment, yet their molecular biology is poorly understood. Molecular aspects of their reproduction, hybridisation between species, mitochondrial inheritance, skewed sex ratios of offspring and adaptation to climatic and pollution factors are priority areas.

Methodology/principal Findings: To start to address this situation, expressed genetic transcripts from M.

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Ostreococcus tauri virus (OtV-1) is a large double-stranded DNA virus and a prospective member of the family Phycodnaviridae, genus Prasinovirus. OtV-1 infects the unicellular marine green alga O. tauri, the smallest known free-living eukaryote.

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Background: Toxoplasma gondii is a zoonotic parasite of global importance. In common with many protozoan parasites it has the capacity for sexual recombination, but current evidence suggests this is rarely employed. The global population structure is dominated by a small number of clonal genotypes, which exhibit biallelic variation and limited intralineage divergence.

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A new computer program, called Mallard, is presented for screening entire 16S rRNA gene libraries of up to 1,000 sequences for chimeras and other artifacts. Written in the Java computer language and capable of running on all major operating systems, the program provides a novel graphical approach for visualizing phylogenetic relationships among 16S rRNA gene sequences. To illustrate its use, we analyzed most of the large libraries of cloned bacterial 16S rRNA gene sequences submitted to the public repository during 2005.

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A new method for detecting chimeras and other anomalies within 16S rRNA sequence records is presented. Using this method, we screened 1,399 sequences from 19 phyla, as defined by the Ribosomal Database Project, release 9, update 22, and found 5.0% to harbor substantial errors.

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Here we report the first direct counts of soil bacteriophage and show that substantial populations of these viruses exist in soil (grand mean = 1.5 x 10(7) g(-1)), at least 350-fold more than the highest numbers estimated from traditional viable plaque counts. Adding pure cultures of a Serratia phage to soil showed that the direct counting methods with electron microscopy developed here underestimated the added phage populations by at least eightfold.

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Eleven strains of Serratia were isolated from different soils and the guts of invertebrates and characterized by their sensitivity to eight indigenous bacteriophages. They were also classified according to bacteriocin production and sensitivity, BiOLOG plate and API 20E strip profiles and 16S rRNA sequence information. One strain was thus identified as Serratia plymuthica, another as Serratia fonticola.

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