title: Synthetic Lethal Screens Identify Vulnerabilities in GPCR Signaling and Cytoskeletal Organization in E-Cadherin-Deficient Cells.
abstract: The CDH1 gene, which encodes the cell-to-cell adhesion protein E-cadherin, is frequently mutated in lobular breast cancer (LBC) and diffuse gastric cancer (DGC). However, because E-cadherin is a tumor suppressor protein and lost from the cancer cell, it is not a conventional drug target. To overcome this, we have taken a synthetic lethal approach to determine whether the loss of E-cadherin creates druggable vulnerabilities. We first conducted a genome-wide siRNA screen of isogenic MCF10A cells with and without CDH1 expression. Gene ontology analysis demonstrated that G-protein-coupled receptor (GPCR) signaling proteins were highly enriched among the synthetic lethal candidates. Diverse families of cytoskeletal proteins were also frequently represented. These broad classes of E-cadherin synthetic lethal hits were validated using both lentiviral-mediated shRNA knockdown and specific antagonists, including the JAK inhibitor LY2784544, Pertussis toxin, and the aurora kinase inhibitors alisertib and danusertib. Next, we conducted a 4,057 known drug screen and time course studies on the CDH1 isogenic MCF10A cell lines and identified additional drug classes with linkages to GPCR signaling and cytoskeletal function that showed evidence of E-cadherin synthetic lethality. These included multiple histone deacetylase inhibitors, including vorinostat and entinostat, PI3K inhibitors, and the tyrosine kinase inhibitors crizotinib and saracatinib. Together, these results demonstrate that E-cadherin loss creates druggable vulnerabilities that have the potential to improve the management of both sporadic and familial LBC and DGC.
authors.affiliation: Cancer Genetics Laboratory, Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Bryony J
authors.initials: BJ
authors.lastname: Telford
authors.affiliation: Cancer Genetics Laboratory, Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Augustine
authors.initials: A
authors.lastname: Chen
authors.affiliation: Cancer Genetics Laboratory, Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Henry
authors.initials: H
authors.lastname: Beetham
authors.affiliation: Cancer Genetics Laboratory, Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: James
authors.initials: J
authors.lastname: Frick
authors.affiliation: Cancer Genetics Laboratory, Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Tom P
authors.initials: TP
authors.lastname: Brew
authors.affiliation: Victorian Centre for Functional Genomics, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia.
authors.forename: Cathryn M
authors.initials: CM
authors.lastname: Gould
authors.affiliation: Cancer Genetics Laboratory, Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Andrew
authors.initials: A
authors.lastname: Single
authors.affiliation: Cancer Genetics Laboratory, Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Tanis
authors.initials: T
authors.lastname: Godwin
authors.affiliation: Victorian Centre for Functional Genomics, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia. The Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Kaylene J
authors.initials: KJ
authors.lastname: Simpson
authors.affiliation: Cancer Genetics Laboratory, Department of Biochemistry, University of Otago, Dunedin, New Zealand. parry.guilford@otago.ac.nz.
authors.forename: Parry
authors.initials: P
authors.lastname: Guilford
mesh_terms: D015703:Antigens, CD; D001381:Azepines / Q000494:pharmacology; D001549:Benzamides / Q000494:pharmacology; D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics*; D015820:Cadherins / Q000172:deficiency*; D045744:Cell Line, Tumor; D055808:Drug Discovery; D005260:Female; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D037342:Pertussis Toxin / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D011724:Pyridazines / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000494:pharmacology*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics*; D015398:Signal Transduction / Q000187:drug effects; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000235:genetics*
chemical_list: D015703:Antigens, CD; D001381:Azepines; D001549:Benzamides; C513384:CDH1 protein, human; D015820:Cadherins; D007093:Imidazoles; C581039:LY2784544; C550258:MLN 8237; D011720:Pyrazoles; D011724:Pyridazines; D011743:Pyrimidines; D034741:RNA, Small Interfering; D043562:Receptors, G-Protein-Coupled; D037342:Pertussis Toxin; C523797:danusertib