Active N-Ras and B-Raf Inhibit Anoikis by Downregulating Bim Expression in Melanocytic Cells
doi: 10.1038/jid.2008.227
pmid: 18668139
Active N-Ras and B-Raf Inhibit Anoikis by Downregulating Bim Expression in Melanocytic Cells
B-Raf and N-Ras proteins are often activated in melanoma, yet their roles in producing inherent survival signals are not fully understood. In this study, we investigated how N-RAS(Q61K) and B-RAF(V600E) contribute to melanoma's resistance to apoptosis induced by detachment from the extracellular matrix (anoikis). We found that expression of constitutively active N-RAS(Q61K) and B-RAF(V600E) downregulated the proapoptotic Bim protein in an immortalized melanocyte cell line. Bim is one of the main proapoptotic mediators of anoikis. Western blot analysis showed that detachment increased Bim expression in melanocytes, and Annexin V staining indicated that detachment induced cell death significantly in melanocytes. Blocking Bim expression by using RNAi vectors or by expressing N-RAS(Q61K) significantly inhibited anoikis in melanocytes. In summary, this report indicates that N-RAS(Q61K) and B-RAF(V600E) contribute to melanoma's resistance to apoptosis in part by downregulating Bim expression, suggesting that Bim is a possible treatment target for overriding melanoma's inherent defenses against cell death.
- University of Colorado Denver United States
- United States Department of Veterans Affairs United States
Proto-Oncogene Proteins B-raf, Skin Neoplasms, Bcl-2-Like Protein 11, Down-Regulation, Membrane Proteins, Cell Biology, Dermatology, Anoikis, Transfection, Biochemistry, Gene Expression Regulation, Neoplastic, Genes, ras, Proto-Oncogene Proteins, Humans, Melanocytes, RNA Interference, Apoptosis Regulatory Proteins, Molecular Biology, Melanoma, Proto-Oncogene Proteins c-akt, Cell Line, Transformed
Proto-Oncogene Proteins B-raf, Skin Neoplasms, Bcl-2-Like Protein 11, Down-Regulation, Membrane Proteins, Cell Biology, Dermatology, Anoikis, Transfection, Biochemistry, Gene Expression Regulation, Neoplastic, Genes, ras, Proto-Oncogene Proteins, Humans, Melanocytes, RNA Interference, Apoptosis Regulatory Proteins, Molecular Biology, Melanoma, Proto-Oncogene Proteins c-akt, Cell Line, Transformed
17 Research products, page 1 of 2
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
chevron_left - 1
- 2
chevron_right
citations This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).27 popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.Top 10% influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).Average impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.Top 10%
