The transcription cofactor c-JUN mediates phenotype switching and BRAF inhibitor resistance in melanoma.
Most patients with BRAF-mutant metastatic melanoma display remarkable but incomplete and short-lived responses to inhibitors of the BRAF kinase or the mitogen-activated protein kinase kinase (MEK), collectively BRAF/MEK inhibitors. We found that inherent resistance to these agents in BRAF(V600)-mutant melanoma cell lines was associated with high abundance of c-JUN and characteristics of a mesenchymal-like phenotype. Early drug adaptation in drug-sensitive cell lines grown in culture or as xenografts, and in patient samples during therapy, was consistently characterized by down-regulation of SPROUTY4 (a negative feedback regulator of receptor tyrosine kinases and the BRAF-MEK signaling pathway), increased expression of JUN and reduced expression of LEF1. This coincided with a switch in phenotype that resembled an epithelial-mesenchymal transition (EMT). In cultured cells, these BRAF inhibitor-induced changes were reversed upon removal of the drug. Knockdown of SPROUTY4 was sufficient to increase the abundance of c-JUN in the absence of drug treatment. Overexpressing c-JUN in drug-naïve melanoma cells induced similar EMT-like phenotypic changes to BRAF inhibitor treatment, whereas knocking down JUN abrogated the BRAF inhibitor-induced early adaptive changes associated with resistance and enhanced cell death. Combining the BRAF inhibitor with an inhibitor of c-JUN amino-terminal kinase (JNK) reduced c-JUN phosphorylation, decreased cell migration, and increased cell death in melanoma cells. Gene expression data from a panel of melanoma cell lines and a patient cohort showed that JUN expression correlated with a mesenchymal gene signature, implicating c-JUN as a key mediator of the mesenchymal-like phenotype associated with drug resistance.
Molecular Oncology Laboratory, Peter MacCallum Cancer Centre, St. Andrew's Place, East Melbourne, Victoria 3002, Australia. Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia.
Rachel
R
Ramsdale
Systems Biology and Personalised Medicine Division, Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, Victoria 3052, Australia. Department of Medical Biology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria 3010, Australia.
Robert N
RN
Jorissen
Molecular Oncology Laboratory, Peter MacCallum Cancer Centre, St. Andrew's Place, East Melbourne, Victoria 3002, Australia. Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia. Sir Peter MacCallum Department of Oncology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria 3010, Australia.
Frederic Z
FZ
Li
Molecular Oncology Laboratory, Peter MacCallum Cancer Centre, St. Andrew's Place, East Melbourne, Victoria 3002, Australia. Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia.
Sheren
S
Al-Obaidi
Molecular Oncology Laboratory, Peter MacCallum Cancer Centre, St. Andrew's Place, East Melbourne, Victoria 3002, Australia. Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia.
Teresa
T
Ward
Molecular Oncology Laboratory, Peter MacCallum Cancer Centre, St. Andrew's Place, East Melbourne, Victoria 3002, Australia. Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia. Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria 3010, Australia.
Karen E
KE
Sheppard
Molecular Therapeutics and Biomarkers Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia. Cancer Therapeutics Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia.
Patricia E
PE
Bukczynska
Molecular Therapeutics and Biomarkers Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia. Cancer Therapeutics Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia.
Richard J
RJ
Young
Cancer Therapeutics Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia. Cancer Development and Treatment Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia. Department of Pathology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria 3010, Australia.
Samantha E
SE
Boyle
Sir Peter MacCallum Department of Oncology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria 3010, Australia. Cancer Therapeutics Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia. Cancer Development and Treatment Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia. Department of Pathology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria 3010, Australia.
Mark
M
Shackleton
Plexxikon Inc., 91 Bolivar Drive, Berkeley, CA 94710, USA.
Gideon
G
Bollag
Melanoma Institute Australia, Sydney, New South Wales 2060, Australia. University of Sydney, Sydney, New South Wales 2006, Australia.
Georgina V
GV
Long
Department of Cancer Studies and Molecular Medicine, University of Leicester, Leicester LE2 7LX, UK.
Eugene
E
Tulchinsky
Melanoma Institute Australia, Sydney, New South Wales 2060, Australia. Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales 2109, Australia.
Helen
H
Rizos
Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia. Sir Peter MacCallum Department of Oncology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria 3010, Australia. Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria 3010, Australia. Cancer Signalling Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia.
Richard B
RB
Pearson
Molecular Oncology Laboratory, Peter MacCallum Cancer Centre, St. Andrew's Place, East Melbourne, Victoria 3002, Australia. Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia. Sir Peter MacCallum Department of Oncology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria 3010, Australia. Cancer Therapeutics Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia.
Grant A
GA
McArthur
Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia. Sir Peter MacCallum Department of Oncology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria 3010, Australia. Department of Pathology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria 3010, Australia.
Amardeep S
AS
Dhillon
Molecular Oncology Laboratory, Peter MacCallum Cancer Centre, St. Andrew's Place, East Melbourne, Victoria 3002, Australia. Oncogenic Signalling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia. Sir Peter MacCallum Department of Oncology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria 3010, Australia. Cancer Therapeutics Program, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia. Department of Pathology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria 3010, Australia. petranel.ferrao@petermac.org.
Petranel T
PT
Ferrao
D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects / Q000235:genetics; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D053631:Interleukin Receptor Common gamma Subunit / Q000172:deficiency / Q000235:genetics; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics* / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000235:genetics; D008545:Melanoma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D016688:Mice, Inbred NOD; D018345:Mice, Knockout; D016513:Mice, SCID; D008856:Microscopy, Fluorescence; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D048493:Proto-Oncogene Proteins B-raf / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D047368:Tumor Burden / Q000187:drug effects / Q000235:genetics; D023041:Xenograft Model Antitumor Assays
C507942:Il2rg protein, mouse; D053631:Interleukin Receptor Common gamma Subunit; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D047428:Protein Kinase Inhibitors; C485561:SPRY2 protein, human; C499038:SPRY4 protein, human; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D048031:JNK Mitogen-Activated Protein Kinases