184 research outputs found
Canyons and Ice: The Wilderness Travel of Dick Griffith
No full textDick Griffith journeyed across Alaska, Canada, Mexico, and the American West. According to Jon Krakauer, "Griffith is simply afflicted with an irresistible inclination to attempt what others say can't be done. When asked what possesses a man to repeatedly strike out alone across hundreds of miles of rugged, lonely country, he replies, 'Every so often, it's just time to walk.'" Kaylene Johnson is author of five books about Alaska including her memoir A Tender Distance: Adventures Raising My Son in Alaska
Phosphorylation of NS5A Serine-235 is essential to hepatitis C virus RNA replication and normal replication compartment formation
No full textData source: Appendix A: supplementary material, http://www.sciencedirect.com/science/article/pii/S0042682216000210#appd002Abstract not availableNicholas S. Eyre, Rachel J. Hampton-Smith, Amanda L. Aloia, James S. Eddes, Kaylene J. Simpson, Peter Hoffmann, Michael R. Bear
Strategies and challenges for systematically mapping biologically significant molecular pathways regulating carcinoma epithelial-mesenchymal transition
No full textEnormous progress has been made towards understanding the role of specific factors in the process of epithelial-mesenchymal transition (EMT); however, the complex underlying pathways and the transient nature of the transition continues to present significant challenges. Targeting tumour cell plasticity underpinning EMT is an attractive strategy to combat metastasis. Global gene expression profiling and high-content analyses are among the strategies employed to identify novel EMT regulators. In this review, we highlight several approaches to systematically interrogate key pathways involved in EMT, with particular emphasis on the features of multiparametric, high-content imaging screening strategies that lend themselves to the systematic discovery of highly significant modulators of tumour cell plasticity
Systematic screening identifies dual PI3K and mTOR Inhibition as a conserved therapeutic vulnerability in osteosarcoma
No full textDisclosure of Potential Conflicts of Interest J. Desai is a consultant/advisory board member for GlaxoSmithKline, Novartis, and Roche. No potential conflicts of interest were disclosed by the other authors.Abstract not availableAnkita Gupte, Emma K. Baker, Soo-San Wan, Elizabeth Stewart, Amos Loh, Anang A. Shelat, Cathryn M. Gould, Alistair M. Chalk, Scott Taylor, Kurt Lackovic, Åsa Karlstr, om, Anthony J. Mutsaers, Jayesh Desai, Piyush B. Madhamshettiwar, Andrew C.W. Zannettino, Chris Burns, David C.S. Huang, Michael A. Dyer, Kaylene J. Simpson, and Carl R.Walkle
Whole-genome multiparametric screening to identify modulators of epithelial-to-mesenchymal transition
No full textMetastasis accounts for the poor prognosis of the majority of solid tumors. The phenotypic transition of nonmotile epithelial tumor cells to migratory and invasive “mesenchymal” cells (epithelial-to-mesenchymal transition [EMT]) enables the transit of cancer cells from the primary tumor to distant sites. There is no single marker of EMT; rather, multiple measures are required to define cell state. Thus, the multiparametric capability of high-content screening is ideally suited for the comprehensive analysis of EMT regulators. The aim of this study was to generate a platform to systematically identify functional modulators of tumor cell plasticity using the bladder cancer cell line TSU-Pr1-B1 as a model system. A platform enabling the quantification of key EMT characteristics, cell morphology and mesenchymal intermediate filament vimentin, was developed using the fluorescent whole-cell-tracking reagent CMFDA and a fluorescent promoter reporter construct, respectively. The functional effect of genome-wide modulation of protein-coding genes and miRNAs coupled with those of a collection of small-molecule kinase inhibitors on EMT was assessed using the Target Activation Bioapplication integrated in the Cellomics ArrayScan platform. Data from each of the three screens were integrated to identify a cohort of targets that were subsequently examined in a validation assay using siRNA duplexes. Identification of established regulators of EMT supports the utility of this screening approach and indicated capacity to identify novel regulators of this plasticity program. Pathway analysis coupled with interrogation of cancer-related expression profile databases and other EMT-related screens provided key evidence to prioritize further experimental investigation into the molecular regulators of EMT in cancer cells
Abstract A24: A genome-wide RNAi screen identifies synthetic lethality of CX-5461 with homologous recombination repair deficiency in ovarian cancer
No full textAbstract
Cancer is characterized by deregulated cell growth and proliferation, both of which are associated with hyperactivation of ribosome biogenesis. Inhibition of ribosome biogenesis using CX-5461, a specific inhibitor of RNA polymerase I-dependent transcription, has shown therapeutic efficacy in a MYC driven B-cell lymphoma mouse model, which is enhanced when used in combination with the mTORC1 inhibitor Everolimus. However, the therapeutic potential of CX-5461 in solid cancers is yet to be determined.
Our preliminary data utilizing a panel of 36 ovarian cancer (OVCA) cell lines suggest that acute CX-5461 treatment results in cell cycle arrest and does not induce apoptosis. We hypothesize that the identification of genes that can be targeted to cooperate with CX-5461 will define novel drug combinations for the improved treatment of OVCA. Therefore, we performed a genome-wide RNAi screen to identify synthetic lethal genes with CX-5461 in the high-grade serous ovarian cancer (HGSOC) cell line OVCAR4. Pathway enrichment analysis of the candidate hits showed significant enrichment in the homologous recombination DNA repair (HR) pathway. Synergy with CX-5461 was validated in multiple HGSOC cell lines by both genetic and pharmacological inhibition of HR pathway components. We are currently investigating the mechanism of this synergy and will further assess efficacy in vivo.
As HR deficiency is observed in 20% of OVCA patients, we suggest that future application of our studies will lead to new therapeutic options to improve the survival of this cohort of patients.
Citation Format: Shunfei Yan, Keefe T. Chan, Kaylene J. Simpson, Elaine Sanij, Karen E. Sheppard, Katherine M. Hannan, Ross D. Hannan, Richard B. Pearson. A genome-wide RNAi screen identifies synthetic lethality of CX-5461 with homologous recombination repair deficiency in ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on DNA Repair: Tumor Development and Therapeutic Response; 2016 Nov 2-5; Montreal, QC, Canada. Philadelphia (PA): AACR; Mol Cancer Res 2017;15(4_Suppl):Abstract nr A24.</jats:p
High content multiparametric functional screen for regulators of epithelial-mesenchymal transition identifies genes associated with chemoresistance
No full textAbstract
Metastasis accounts for the majority of treatment-refractory cancers and poor prognosis of the disease. The phenotypic transition of non-motile epithelial tumor cells to migratory and invasive ‘mesenchymal’ cells enables the escape of cancer cells from the primary tumor into the circulation. Morphological changes from cobblestone epithelial cells to elongated and spindle-shaped cells is a key feature of this process. This transition is also marked by upregulation of vimentin, an intermediate filament found in mesenchymal cells. We have previously developed a bladder cancer model with a step-wise enhancement in the metastatic cascade that we have used to interrogate the role of tumor cell plasticity in metastasis (1). Given the need to elucidate pathways and assign functions to particular genes involved in this process, we conducted a high content screening assay across genome wide siRNA, miRNA and kinase inhibitor (131 compounds) libraries to systematically identify modulators of EMT/MET. We identified candidate gene regulators of EMT in TSU-Pr1-B1 bladder cancer cells using the readouts of morphological change (cells stained with CMFDA) and a vimentin promoter activity (dsRed reporter construct). Following integration of the predicted target genes for miRNA hits and kinase inhibitors with siRNA hits, initial validation using a siRNA deconvolution strategy was performed for 400 targets. 221 siRNAs were classified as inducing statistically significant effects on cell shape and/or vimentin promoter reporter activity (defined as at least 2/4 duplexes inducing the effect for a given target). Gene ontology and pathway analyses feature cell cycle and various developmental pathways. Furthermore, the validated gene list was associated with bladder cancer histology and drug sensitivity in clinical specimens in multiple cancer types (Oncomine). Molecules identified in this assay will be further analysed using functional assays to determine their role in maintaining the epithelial phenotype and as regulators of chemoresistance.
(1) Chaffer et al. (2005) Clin Exp Metastasis 22: 115-25.
Citation Format: Elizabeth D. Williams, Nur Akmarina Said, Cathryn M. Gould, Erik W. Thompson, Kaylene J. Simpson. High content multiparametric functional screen for regulators of epithelial-mesenchymal transition identifies genes associated with chemoresistance. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4282. doi:10.1158/1538-7445.AM2014-428
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