title: CK1epsilon is required for breast cancers dependent on beta-catenin activity.
abstract: BACKGROUND
  Aberrant beta-catenin signaling plays a key role in several cancer types, notably colon, liver and breast cancer. However approaches to modulate beta-catenin activity for therapeutic purposes have proven elusive to date.
  
  
  METHODS
  To uncover genetic dependencies in breast cancer cells that harbor active beta-catenin signaling, we performed RNAi-based loss-of-function screens in breast cancer cell lines in which we had characterized beta-catenin activity. Here we identify CSNK1E, the gene encoding casein kinase 1 epsilon (CK1epsilon) as required specifically for the proliferation of breast cancer cells with activated beta-catenin and confirm its role as a positive regulator of beta-catenin-driven transcription. Furthermore, we demonstrate that breast cancer cells that harbor activated beta-catenin activity exhibit enhanced sensitivity to pharmacological blockade of Wnt/beta-catenin signaling. We also find that expression of CK1epsilon is able to promote oncogenic transformation of human cells in a beta-catenin-dependent manner.
  
  
  CONCLUSIONS
  These studies identify CK1epsilon as a critical contributor to activated beta-catenin signaling in cancer and suggest it may provide a potential therapeutic target for cancers that harbor active beta-catenin. More generally, these observations delineate an approach that can be used to identify druggable synthetic lethal interactions with signaling pathways that are frequently activated in cancer but are difficult to target with the currently available small molecule inhibitors.
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America.
authors.forename: So Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Ian F
authors.initials: IF
authors.lastname: Dunn
authors.forename: Ron
authors.initials: R
authors.lastname: Firestein
authors.forename: Piyush
authors.initials: P
authors.lastname: Gupta
authors.forename: Leslie
authors.initials: L
authors.lastname: Wardwell
authors.forename: Kara
authors.initials: K
authors.lastname: Repich
authors.forename: Anna C
authors.initials: AC
authors.lastname: Schinzel
authors.forename: Ben
authors.initials: B
authors.lastname: Wittner
authors.forename: Serena J
authors.initials: SJ
authors.lastname: Silver
authors.forename: David E
authors.initials: DE
authors.lastname: Root
authors.forename: Jesse S
authors.initials: JS
authors.lastname: Boehm
authors.forename: Sridhar
authors.initials: S
authors.lastname: Ramaswamy
authors.forename: Eric S
authors.initials: ES
authors.lastname: Lander
authors.forename: William C
authors.initials: WC
authors.lastname: Hahn
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D048149:Casein Kinase 1 epsilon / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015151:Immunoblotting; D007211:Indoles / Q000494:pharmacology; D051379:Mice; D041681:NIH 3T3 Cells; D020411:Oligonucleotide Array Sequence Analysis; D010696:Phloroglucinol / Q000031:analogs & derivatives / Q000494:pharmacology; D034622:RNA Interference; D015398:Signal Transduction; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*
chemical_list: C411652:IC 261; D007211:Indoles; D051176:beta Catenin; D010696:Phloroglucinol; D048149:Casein Kinase 1 epsilon