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LemBix Journal Club. February 15 th , 2010 Robin Smith. Fun stuff?. 2000 . 2007 . “new”. High Throughput Screening Campaigns. PubChem: repository for HTS data. PubChem: description/protocol. Pubchem: data representation. Pubchem bioassays by date. @Time of grant proposal: 1500
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LemBix Journal Club February 15th, 2010 Robin Smith
Fun stuff? 2000 2007
Pubchem bioassays by date @Time of grant proposal: 1500 @Time of Robin start: 1885 @Last Month: 2029
The problems with Pubchem • Very generic data repository: Flexible to put data in, difficult to get data out • Few annotations of assay technologies and the underlying biology (e.g. no cell-based/biochemical distinction!) • No standardization of data • Difficult to search • Very compound-centric – no overexpression experiments, very few knockdown experiments
Example: Targets • Only protein targets allowed • Assay can have no target or 1 target (2 targets not allowed) • Links to redundant protein GI database
The BioAssay Ontology Project http://www.bioassayontology.org
BAO Objectives • Develop an ontology to describe high-throughput and high content bioassays • Annotate data from Pubchem and other sources using BAO concepts and store in a repository • Develop software tools to allow users to browse and visualize annotations in the repository
What is an ontology? • A formal, machine-readable, description of knowledge of a domain of interest Food is a Pizza is a is a Margherita Napoletana has topping is a Tomato Topping
Other biomedical ontologies - BioPortal http://bioportal.bioontology.org
ABA Adult Mouse Brain atlas http://bioportal.bioontology.org/visualize/40133#visualization
Automated annotation of an abstract http://bioportal.bioontology.org/annotator
What about HTS/HCS? • Currently no public ontology available for describing the domain of HTS and HCS bioassays • Can borrow ideas from related domains (e.g. microarray experiments), the cell line ontology, etc… • Need to describe biological targets, assay technologies, types of assays, types of results, etc…
Breaking down a BioAssay BioAssay Perturbagen Purpose • e.g.Primary screening, confirmatory • e.g. Counter assay, Alternate Technology e.g. Compound e.g. RNAi Measure Group Endpoint e.g. Activity linked measure For high content assays! Target 3 5 1 2 P 4 Technology e.g. Viability e.g. Binding Format e.g. Primary Cells e.g. Purified Proteins e.g. Activity at 10mM e.g. IC50
“Purpose” component • Why was this bioassay undertaken and how does it relate to other assays in the campaign? • Primary – one concentration • Confirmatory – multiple concentration response of hit series • Secondary – used to expand/subtract from hits • Counter – used to eliminate bad hits • Orthogonal – alternate technology to verify/add to results • qHTS assay – primary and confirmatory all at once • Further specifications: description, protocol, comments
“Format” component • What types of biological and chemical ingredients were present in each well of the bioassay? • Live cell – living dissociated cells • Primary cell • Cell Line • Biochemical – no intact live cells • Purified protein • Lysed cell (cells lysed before treatment) • Whole organism – includes bacteria, yeast, drosophila etc. • Ex vivo – intact tissues (slices, organs, etc) • Further specifications: cell line, cell type, assay plate, chemical additives
“Technology” component • What techniques and apparatus were used to measure the effect of the perturbagens on the target? • Binding reporter • Energy transfer, scintillation, luminescent proximity, etc. • Enzyme reporter • Modified substrate, coupled substrate • Protein conformation reporter • Viability reporter • ATP Luciferin, Caspase, NADH, etc. • Redistribution reporter • GFP/Calcium/cAMP/etc. • Inducible reporter • Luc, Bla, LacZ, GFP • Further specifications: detection technique, apparatus, signal direction
Text-Mining for Technology Concepts Protocol Enriched Description Enriched
“Perturbagen” component • What type of agent was used to perturb biological targets in the bioassay? • Chemical compounds – synthetic small molecules • Crude extracts – mixture of molecules derived from a natural source • RNA – siRNA/RNAi • DNA – cDNAs, oligos • Further specifications: database, reference, notes
“Meta Target” component • The biological identity that is the presumably affected by the action of the perturbagen. “Meta” = not just protein. • Cell component • Organelles, intracellular complexes • Interaction • Protein-protein, protein-RNA, protein-DNA • Biological Process, e.g. Neurite Outgrowth • Protein • Enzyme, TF, receptor, ion channel, etc. • Signaling Pathway • Further specifications: database, reference
“Endpoint” component • A measurement or parameter quantifying or qualifying a perturbation. • Pubchem Outcome • Pubchem Score • Concentration at defined response • IC50, EC80, AC50 • Response at defined concentration • E.g. Activity at 10um • Tested Concentration • Further specifications: unit, data type, attribute, attribute value, attribute unit
(web-based) Software in development • BAO Annotator • Allows domain experts to view original assay data (e.g. from Pubchem) and specify each component • Uses ontology rules to generate HTML forms • BAO Repository Search • Search annotation repository for: • A set of compounds, “luciferase” assays, “cell-based” assays, “transcription factor” targets, etc. • Browse the annotation repository using a treemap • Add assays to a work set that can be further filtered/manipulated for export to Excel/Spotfire • Visualize/download the ontology structure • View compound activities across multiple assays with comparable endpoints (e.g. IC50)
What should I be able to ask with a BAO? • Which compounds affect members of the STAT3 signaling pathway? • What technologies could be used to test whether my hit compound is acting non-specifically? • Which compounds have similar profiles to my compound but are less toxic? • What cell lines has my kinase been targeted in? • Which compounds are active with pAC50 < -5 in a set of related bioassays?
Ontology Team • Stephan Schürer • Vance Lemmon • Ubbo Visser • Robin Smith • Saminda Abeyruwan • Mitsunori Ogihara • Dusica Vidovic • Software Team • Chris Mader • Felimon Gayalino • Nakul Datar