title: FAM129B is a novel regulator of Wnt/β-catenin signal transduction in melanoma cells.
abstract: The inability of targeted BRAF inhibitors to produce long-lasting improvement in the clinical outcome of melanoma highlights a need to identify additional approaches to inhibit melanoma growth. Recent studies have shown that activation of the Wnt/β-catenin pathway decreases tumor growth and cooperates with ERK/MAPK pathway inhibitors to promote apoptosis in melanoma. Therefore, the identification of Wnt/β-catenin regulators may advance the development of new approaches to treat this disease. In order to move towards this goal we performed a large scale small-interfering RNA (siRNA) screen for regulators of β-catenin activated reporter activity in human HT1080 fibrosarcoma cells. Integrating large scale siRNA screen data with phosphoproteomic data and bioinformatics enrichment identified a protein, FAM129B, as a potential regulator of Wnt/β-catenin signaling.  Functionally, we demonstrated that siRNA-mediated knockdown of FAM129B in A375 and A2058 melanoma cell lines inhibits WNT3A-mediated activation of a β-catenin-responsive luciferase reporter and inhibits expression of the endogenous Wnt/β-catenin target gene, AXIN2. We also demonstrate that FAM129B knockdown inhibits apoptosis in melanoma cells treated with WNT3A. These experiments support a role for FAM129B in linking Wnt/β-catenin signaling to apoptosis in melanoma.
authors.affiliation: The Howard Hughes Medical Institute, Seattle WA, 98195, USA ; Department of Pharmacology, University of Washington School of Medicine, Seattle WA, 98195, USA.
authors.forename: Willliam
authors.initials: W
authors.lastname: Conrad
authors.affiliation: The Howard Hughes Medical Institute, Seattle WA, 98195, USA ; Department of Cell Biology and Physiology, UNC Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill NC, 27599-7295, USA.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Major
authors.affiliation: Rosetta Inpharmatics, LLC, Merck & Co Inc., Seattle WA, 98109, USA ; Merck & Co., Inc., West Point PA, 19486, USA.
authors.forename: Michele A
authors.initials: MA
authors.lastname: Cleary
authors.affiliation: Department of Automated Biotechnology, Merck, North Wales PA, 19454, USA ; NCATS/NIH, Rockville MD, 20850, USA.
authors.forename: Marc
authors.initials: M
authors.lastname: Ferrer
authors.affiliation: Rosetta Inpharmatics, LLC, Merck & Co Inc., Seattle WA, 98109, USA ; Hudson Alpha Institute for Biotechnology, Huntsville AL, 35806, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Roberts
authors.affiliation: Department of Screening and Protein Sciences, Merck Research Laboratories, North Wales PA, 19454, USA.
authors.forename: Shane
authors.initials: S
authors.lastname: Marine
authors.affiliation: Rosetta Inpharmatics, LLC, Merck & Co Inc., Seattle WA, 98109, USA ; Bristol-Myers Squibb Company, Applied Genomics, Princeton NJ, 08543, USA.
authors.forename: Namjin
authors.initials: N
authors.lastname: Chung
authors.affiliation: Rosetta Inpharmatics, LLC, Merck & Co Inc., Seattle WA, 98109, USA ; Seattle Genetics, Bothell WA, 98021, USA.
authors.forename: William T
authors.initials: WT
authors.lastname: Arthur
authors.affiliation: The Howard Hughes Medical Institute, Seattle WA, 98195, USA ; Department of Pharmacology, University of Washington School of Medicine, Seattle WA, 98195, USA ; The Institute for Stem Cell and Regenerative Medicine, Seattle WA, 98109, USA.
authors.forename: Randall T
authors.initials: RT
authors.lastname: Moon
authors.affiliation: The Howard Hughes Medical Institute, Seattle WA, 98195, USA ; Department of Pharmacology, University of Washington School of Medicine, Seattle WA, 98195, USA ; The Institute for Stem Cell and Regenerative Medicine, Seattle WA, 98109, USA.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Berndt
authors.affiliation: Division of Dermatology, Department of Medicine, University of Washington, Seattle WA, 98195, USA ; The Institute for Stem Cell and Regenerative Medicine, Seattle WA, 98109, USA.
authors.forename: Andy J
authors.initials: AJ
authors.lastname: Chien