1. A chemical biology approach identifies AMPK as a modulator of melanoma oncogene MITF
- Author
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Giulio Superti-Furga, Uwe Rix, Keiryn L. Bennett, Manuela Gridling, Georg E. Winter, Jacques Colinge, Christine Wagner, Florian P. Breitwieser, André C. Müller, Viola Borgdorff, Stephan N. Wagner, Institut de recherche en cancérologie de Montpellier (IRCM - U896 Inserm - UM1), and Université Montpellier 1 (UM1)-CRLCC Val d'Aurelle - Paul Lamarque-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)
- Subjects
MAPK/ERK pathway ,Cancer Research ,Indoles ,Fluorescent Antibody Technique ,AMP-Activated Protein Kinases ,Mass Spectrometry ,Sunitinib ,Enzyme Inhibitors ,RNA, Small Interfering ,Melanoma ,Enzyme Inhibitors/pharmacology ,Chromatography ,Liquid ,integumentary system ,Indoles/pharmacology ,Blotting ,Staurosporine/analogs & derivatives/pharmacology ,Microphthalmia-associated transcription factor ,Cell biology ,AMP-Activated Protein Kinases/genetics/*metabolism ,Pyrroles/pharmacology ,Melanocytes ,RNA Interference ,Western ,Cell Survival/drug effects ,Cell Survival ,Blotting, Western ,[SDV.CAN]Life Sciences [q-bio]/Cancer ,Biology ,Transfection ,Small Interfering ,Cell Line ,Downregulation and upregulation ,Genetics ,medicine ,Humans ,Pyrroles ,Molecular Biology ,Transcription factor ,Microphthalmia-Associated Transcription Factor ,Oncogene ,Microphthalmia-Associated Transcription Factor/genetics/*metabolism ,AMPK ,Oncogenes ,medicine.disease ,Staurosporine ,Molecular biology ,body regions ,Melanocytes/drug effects/*metabolism ,Melanoma/genetics/*metabolism ,RNA ,BCL2-related protein A1 ,Chromatography, Liquid - Abstract
International audience; The microphthalmia-associated transcription factor (MITF) is indispensable for the viability of melanocytic cells, is an oncogene in melanoma and has a cell type-specific expression pattern. As the modulation of MITF activity by direct chemical targeting remains a challenge, we assessed a panel of drugs for their ability to downregulate MITF expression or activity by targeting its upstream modulators. We found that the multi-kinase inhibitors midostaurin and sunitinib downregulate MITF protein levels. To identify the target molecules shared by both the drugs in melanocytic cells, a chemical proteomic approach was applied and AMP-activated kinase (AMPK) was identified as the relevant target for the observed phenotype. RNA interference and chemical inhibition of AMPK led to a decrease in MITF protein levels. Reduction of MITF protein levels was the result of proteasomal degradation, which was preceded by enhanced phosphorylation of MITF mediated by ERK. As expected, downregulation of MITF protein levels by AMPK inhibition was associated with decreased viability. Together, these results identify AMPK as an important regulator for the maintenance of MITF protein levels in melanocytic cells.
- Published
- 2014
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