PLX4032, a selective BRAFV600E kinase inhibitor,activates the ERK pathway and enhances cell migration and proliferation of BRAFWT melanoma cells |
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| Authors: | Ruth Halaban Wengeng Zhang Antonella Bacchiocchi Elaine Cheng Fabio Parisi Stephan Ariyan Michael Krauthammer James P McCusker Yuval Kluger Mario Sznol |
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| Institution: | 1. Department of Dermatology, Yale University School of Medicine, New Haven, CT, USA;2. Department of Cell Biology, New York University Center for Health Informatics and Bioinformatics, New York University School of Medicine and Cancer Institute, New York, NY, USA;3. Department of Surgery, Yale University School of Medicine, New Haven, CT, USA;4. Department of Pathology, Yale University School of Medicine, New Haven, CT, USA;5. Comprehensive Cancer Center Section of Medical Oncology, Yale University School of Medicine, New Haven, CT, USA |
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| Abstract: | BRAFV600E/K is a frequent mutationally active tumor-specific kinase in melanomas that is currently targeted for therapy by the specific inhibitor PLX4032. Our studies with melanoma tumor cells that are BRAFV600E/K and BRAFWT showed that, paradoxically, while PLX4032 inhibited ERK1/2 in the highly sensitive BRAFV600E/K, it activated the pathway in the resistant BRAFWT cells, via RAF1 activation, regardless of the status of mutations in NRAS or PTEN. The persistently active ERK1/2 triggered downstream effectors in BRAFWT melanoma cells and induced changes in the expression of a wide-spectrum of genes associated with cell cycle control. Furthermore, PLX4032 increased the rate of proliferation of growth factor-dependent NRAS Q61L mutant primary melanoma cells, reduced cell adherence and increased mobility of cells from advanced lesions. The results suggest that the drug can confer an advantage to BRAFWT primary and metastatic tumor cells in vivo and provide markers for monitoring clinical responses. |
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| Keywords: | BRAF cell migration drug response ERK pathway melanoma RAF1 serum markers |
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