Loss of the SIN3 transcriptional corepressor results in aberrant mitochondrial function

<p>Abstract</p> <p>Background</p> <p>SIN3 is a transcriptional repressor protein known to regulate many genes, including a number of those that encode mitochondrial components.</p> <p>Results</p> <p>By monitoring RNA levels, we find that loss of SIN3 in <it>Drosophila </it>cultured cells results in up-regulation of not only nuclear encoded mitochondrial genes, but also those encoded by the mitochondrial genome. The up-regulation of gene expression is accompanied by a perturbation in ATP levels in SIN3-deficient cells, suggesting that the changes in mitochondrial gene expression result in altered mitochondrial activity. In support of the hypothesis that SIN3 is necessary for normal mitochondrial function, yeast <it>sin3 </it>null mutants exhibit very poor growth on non-fermentable carbon sources and show lower levels of ATP and reduced respiration rates.</p> <p>Conclusions</p> <p>The findings that both yeast and <it>Drosophila </it>SIN3 affect mitochondrial activity suggest an evolutionarily conserved role for SIN3 in the control of cellular energy production.</p

The impact of using computer decision-support software in primary care nurse-led telephone triage:Interactional dilemmas and conversational consequences

Telephone triage represents one strategy to manage demand for face-to-face GP appointments in primary care. Although computer decision-support software (CDSS) is increasingly used by nurses to triage patients, little is understood about how interaction is organized in this setting. Specifically any interactional dilemmas this computer-mediated setting invokes; and how these may be consequential for communication with patients. Using conversation analytic methods we undertook a multi-modal analysis of 22 audio-recorded telephone triage nurse-caller interactions from one GP practice in England, including 10 video-recordings of nurses' use of CDSS during triage. We draw on Goffman's theoretical notion of participation frameworks to make sense of these interactions, presenting 'telling cases' of interactional dilemmas nurses faced in meeting patient's needs and accurately documenting the patient's condition within the CDSS. Our findings highlight troubles in the 'interactional workability' of telephone triage exposing difficulties faced in aligning the proximal and wider distal context that structures CDSS-mediated interactions. Patients present with diverse symptoms, understanding of triage consultations, and communication skills which nurses need to negotiate turn-by-turn with CDSS requirements. Nurses therefore need to have sophisticated communication, technological and clinical skills to ensure patients' presenting problems are accurately captured within the CDSS to determine safe triage outcomes. Dilemmas around how nurses manage and record information, and the issues of professional accountability that may ensue, raise questions about the impact of CDSS and its use in supporting nurses to deliver safe and effective patient care

Integrin-mediated traction force enhances paxillin molecular associations and adhesion dynamics that increase the invasiveness of tumor cells into a three-dimensional extracellular matrix.

Metastasis requires tumor cells to navigate through a stiff stroma and squeeze through confined microenvironments. Whether tumors exploit unique biophysical properties to metastasize remains unclear. Data show that invading mammary tumor cells, when cultured in a stiffened three-dimensional extracellular matrix that recapitulates the primary tumor stroma, adopt a basal-like phenotype. Metastatic tumor cells and basal-like tumor cells exert higher integrin-mediated traction forces at the bulk and molecular levels, consistent with a motor-clutch model in which motors and clutches are both increased. Basal-like nonmalignant mammary epithelial cells also display an altered integrin adhesion molecular organization at the nanoscale and recruit a suite of paxillin-associated proteins implicated in invasion and metastasis. Phosphorylation of paxillin by Src family kinases, which regulates adhesion turnover, is similarly enhanced in the metastatic and basal-like tumor cells, fostered by a stiff matrix, and critical for tumor cell invasion in our assays. Bioinformatics reveals an unappreciated relationship between Src kinases, paxillin, and survival of breast cancer patients. Thus adoption of the basal-like adhesion phenotype may favor the recruitment of molecules that facilitate tumor metastasis to integrin-based adhesions. Analysis of the physical properties of tumor cells and integrin adhesion composition in biopsies may be predictive of patient outcome

AMPK Is Essential to Balance Glycolysis and Mitochondrial Metabolism to Control T-ALL Cell Stress and Survival

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy associated with Notch pathway mutations. While both normal activated and leukemic T cells can utilize aerobic glycolysis to support proliferation, it is unclear to what extent these cell populations are metabolically similar and if differences reveal T-ALL vulnerabilities. Here we show that aerobic glycolysis is surprisingly less active in T-ALL cells than proliferating normal T cells and that T-ALL cells are metabolically distinct. Oncogenic Notch promoted glycolysis but also induced metabolic stress that activated 5' AMP-activated kinase (AMPK). Unlike stimulated T cells, AMPK actively restrained aerobic glycolysis in T-ALL cells through inhibition of mTORC1 while promoting oxidative metabolism and mitochondrial Complex I activity. Importantly, AMPK deficiency or inhibition of Complex I led to T-ALL cell death and reduced disease burden. Thus, AMPK simultaneously inhibits anabolic growth signaling and is essential to promote mitochondrial pathways that mitigate metabolic stress and apoptosis in T-ALL

Translational pharmacology of an inhaled small molecule αvβ6 integrin inhibitor for idiopathic pulmonary fibrosis

The αvβ6 integrin plays a key role in the activation of transforming growth factor-β (TGFβ), a pro-fibrotic mediator that is pivotal to the development of idiopathic pulmonary fibrosis (IPF). We identified a selective small molecule αvβ6 RGD-mimetic, GSK3008348, and profiled it in a range of disease relevant pre-clinical systems. To understand the relationship between target engagement and inhibition of fibrosis, we measured pharmacodynamic and diseaserelated end points. Here we report, GSK3008348 binds to αvβ6 with high affinity in human IPF lung and reduces downstream pro-fibrotic TGFβ signaling to normal levels. In human lung epithelial cells, GSK3008348 induces rapid internalization and lysosomal degradation of the αvβ6 integrin. In the murine bleomycin-induced lung fibrosis model, GSK3008348 engages αvβ6, induces prolonged inhibition of TGFβ signaling and reduces lung collagen deposition and serum C3M, a marker of IPF disease progression. These studies highlight the potential of inhaled GSK3008348 as an anti-fibrotic therapy

Phyto-oestrogens and breast cancer chemoprevention

Phytoestrogens are polyphenol compounds of plant origin that exhibit a structural similarity to the mammalian steroid hormone 17β-oestradiol. In Asian nations the staple consumption of phyto-oestrogen-rich foodstuffs correlates with a reduced incidence of breast cancer. Human dietary intervention trials have noted a direct relationship between phyto-oestrogen ingestion and a favourable hormonal profile associated with decreased breast cancer risk. However, these studies failed to ascertain the precise effect of dietary phyto-oestrogens on the proliferation of mammary tissue. Epidemiological and rodent studies crucially suggest that breast cancer chemoprevention by dietary phyto-oestrogen compounds is dependent on ingestion before puberty, when the mammary gland is relatively immature. Phyto-oestrogen supplements are commercially marketed for use by postmenopausal women as natural and safe alternatives to hormone replacement therapy. Of current concern is the effect of phyto-oestrogen compounds on the growth of pre-existing breast tumours. Data are contradictory, with cell culture studies reporting both the oestrogenic stimulation of oestrogen receptor-positive breast cancer cell lines and the antagonism of tamoxifen activity at physiological phyto-oestrogen concentrations. Conversely, phyto-oestrogen ingestion by rodents is associated with the development of less aggressive breast tumours with reduced metastatic potential. Despite the present ambiguity, current data do suggest a potential benefit from use of phyto-oestrogens in breast cancer chemoprevention and therapy. These aspects are discussed

Identification of six new susceptibility loci for invasive epithelial ovarian cancer.

Genome-wide association studies (GWAS) have identified 12 epithelial ovarian cancer (EOC) susceptibility alleles. The pattern of association at these loci is consistent in BRCA1 and BRCA2 mutation carriers who are at high risk of EOC. After imputation to 1000 Genomes Project data, we assessed associations of 11 million genetic variants with EOC risk from 15,437 cases unselected for family history and 30,845 controls and from 15,252 BRCA1 mutation carriers and 8,211 BRCA2 mutation carriers (3,096 with ovarian cancer), and we combined the results in a meta-analysis. This new study design yielded increased statistical power, leading to the discovery of six new EOC susceptibility loci. Variants at 1p36 (nearest gene, WNT4), 4q26 (SYNPO2), 9q34.2 (ABO) and 17q11.2 (ATAD5) were associated with EOC risk, and at 1p34.3 (RSPO1) and 6p22.1 (GPX6) variants were specifically associated with the serous EOC subtype, all with P < 5 × 10(-8). Incorporating these variants into risk assessment tools will improve clinical risk predictions for BRCA1 and BRCA2 mutation carriers.COGS project is funded through a European Commission's Seventh Framework Programme grant (agreement number 223175 ] HEALTH ]F2 ]2009 ]223175). The CIMBA data management and data analysis were supported by Cancer Research.UK grants 12292/A11174 and C1287/A10118. The Ovarian Cancer Association Consortium is supported by a grant from the Ovarian Cancer Research Fund thanks to donations by the family and friends of Kathryn Sladek Smith (PPD/RPCI.07). The scientific development and funding for this project were in part supported by the US National Cancer Institute GAME ]ON Post ]GWAS Initiative (U19 ]CA148112). This study made use of data generated by the Wellcome Trust Case Control consortium. Funding for the project was provided by the Wellcome Trust under award 076113. The results published here are in part based upon data generated by The Cancer Genome Atlas Pilot Project established by the National Cancer Institute and National Human Genome Research Institute (dbGap accession number phs000178.v8.p7). The cBio portal is developed and maintained by the Computational Biology Center at Memorial Sloan ] Kettering Cancer Center. SH is supported by an NHMRC Program Grant to GCT. Details of the funding of individual investigators and studies are provided in the Supplementary Note. This study made use of data generated by the Wellcome Trust Case Control consortium, funding for which was provided by the Wellcome Trust under award 076113. The results published here are, in part, based upon data generated by The Cancer Genome Atlas Pilot Project established by the National Cancerhttp://dx.doi.org/10.1038/ng.3185This is the Author Accepted Manuscript of 'Identification of six new susceptibility loci for invasive epithelial ovarian cancer' which was published in Nature Genetics 47, 164–171 (2015) © Nature Publishing Group - content may only be used for academic research

Characterizing the cancer genome in lung adenocarcinoma

Somatic alterations in cellular DNA underlie almost all human cancers(1). The prospect of targeted therapies(2) and the development of high-resolution, genome-wide approaches(3-8) are now spurring systematic efforts to characterize cancer genomes. Here we report a large-scale project to characterize copy-number alterations in primary lung adenocarcinomas. By analysis of a large collection of tumours ( n = 371) using dense single nucleotide polymorphism arrays, we identify a total of 57 significantly recurrent events. We find that 26 of 39 autosomal chromosome arms show consistent large-scale copy-number gain or loss, of which only a handful have been linked to a specific gene. We also identify 31 recurrent focal events, including 24 amplifications and 7 homozygous deletions. Only six of these focal events are currently associated with known mutations in lung carcinomas. The most common event, amplification of chromosome 14q13.3, is found in similar to 12% of samples. On the basis of genomic and functional analyses, we identify NKX2-1 ( NK2 homeobox 1, also called TITF1), which lies in the minimal 14q13.3 amplification interval and encodes a lineage-specific transcription factor, as a novel candidate proto-oncogene involved in a significant fraction of lung adenocarcinomas. More generally, our results indicate that many of the genes that are involved in lung adenocarcinoma remain to be discovered.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62944/1/nature06358.pd