Identification of direct transcriptional targets of (V600E)BRAF/MEK signalling in melanoma.
Oncogenic mutations in BRAF are common in melanoma and drive constitutive activation of the MEK/ERK pathway. To elucidate the transcriptional events downstream of (V600E)BRAF/MEK signalling we performed gene expression profiling of A375 melanoma cells treated with potent and selective inhibitors of (V600E)BRAF and MEK (PLX4720 and PD184352 respectively). Using a stringent Bayesian approach, we identified 69 transcripts that appear to be direct transcriptional targets of this pathway and whose expression changed after 6 h of pathway inhibition. We also identified several additional genes whose expression changed after 24 h of pathway inhibition and which are likely to be indirect transcriptional targets of the pathway. Several of these were confirmed by demonstrating their expression to be similarly regulated when BRAF was depleted using RNA interference, and by using qRT-PCR in other BRAF mutated melanoma lines. Many of these genes are transcription factors and feedback inhibitors of the ERK pathway and are also regulated by MEK signalling in NRAS mutant cells. This study provides a basis for understanding the molecular processes that are regulated by (V600E)BRAF/MEK signalling in melanoma cells.
Packer
Leisl M
LM
Signal Transduction Team, Section of Cell and Molecular Biology, The Institute of Cancer Research, London, UK.
East
Philip
P
Reis-Filho
Jorge S
JS
Marais
Richard
R
D000818:Animals; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008545:Melanoma / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D015398:Signal Transduction / Q000502:physiology*; D014158:Transcription, Genetic
C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D048049:Extracellular Signal-Regulated MAP Kinases; D020929:Mitogen-Activated Protein Kinase Kinases