Project description:In an effort to understand the mechanisms of acquired resistance to BRAF inhibitors, we isolated clones that acquired resistance to the BRAF inhibitor GSK2118436 derived from the A375 BRAF V600E mutant melanoma cell line. This resistance clones acquired mutations in NRAS and MEK1. One clones, 16R6-4, acquired two mutations in NRAS – Q61K and A146T. Proliferation and western blot analyses demonstrated that these clones were insensitive to single agent GSK2118436 or GSK1120212 (an allosteric MEK inhibitor) but were sensitive to the combination of GSK2118436 and GSK1120212. To further characterize this combination, global transcriptomic analysis was performed in A375 and 16R6-4 after 24 hour treatment with GSK2118436, GSK1120212 or the combination of GSK2118436 and GSK1120212. This data set was published in Molecular Cancer Therapeutics with the title “Combined inhibition of BRAF and MEK, BRAF and PI3K/mTOR, or MEK and PI3K/mTOR overcomes acquired resistance to the BRAF inhibitor GSK2118436, mediated by NRAS or MEK mutations” by Greger, J.G., et.al. A375 and 16R6-4 (an A375 derived GSK2118436 resistance clone) were treated for 24 hours with 0.1 micromolar GSK2118436, 1 micromolar GSK2118436, 0.01 micromolar GSK1120212, 0.1 micromolar GSK2118436 + 0.01 micromolar GSK1120212, or 1 micromolar GSK2118436 + 0.01 micromolar GSK1120212.
Project description:The A375, human BRAFV600E mutant melanoma, cell line (wildtype), two PTEN-null, BRAFV600E cell lines (KO5 and KO11), and PI3K overexpression cells (WT and PI3K H1047R mutant) were treated with small molecule inhibitors (dabrafenib, BRAF inhibitor; trametinib, MEK inhibitor alone and in combination for 0, 1 and 7 days
Project description:In an effort to understand the mechanisms of acquired resistance to BRAF inhibitors, we isolated clones that acquired resistance to the BRAF inhibitor GSK2118436 derived from the A375 BRAF V600E mutant melanoma cell line. This resistance clones acquired mutations in NRAS and MEK1. One clones, 16R6-4, acquired two mutations in NRAS – Q61K and A146T. Proliferation and western blot analyses demonstrated that these clones were insensitive to single agent GSK2118436 or GSK1120212 (an allosteric MEK inhibitor) but were sensitive to the combination of GSK2118436 and GSK1120212. To further characterize this combination, global transcriptomic analysis was performed in A375 and 16R6-4 after 24 hour treatment with GSK2118436, GSK1120212 or the combination of GSK2118436 and GSK1120212. This data set was published in Molecular Cancer Therapeutics with the title “Combined inhibition of BRAF and MEK, BRAF and PI3K/mTOR, or MEK and PI3K/mTOR overcomes acquired resistance to the BRAF inhibitor GSK2118436, mediated by NRAS or MEK mutations” by Greger, J.G., et.al.
Project description:We treated for 24 hours the BRAF-V600E melanoma cell line A375 with 7 doses of the RAF inhibitor Vemurafenib and, in a second experimental desing, we treated for 24 hours the BRAF-V600E melanoma cell line A375 with Vemurafenib (1 uM) alone or in combination with the MEK inhibitor Cobimetinib (1 uM) and subsequently stimulated with EGF in a time-course of 7 time points for up to 8 hours (0, 0.5, 1, 2, 3, 4, 8 hours).
Project description:Identify transcriptionnally and translationally regulated mRNA in melanoma parental and persister cells In this dataset, we include expression data of A375 melanoma drug-naïve parental cells and A375 melanoma persister cells that survived from BRAF and MEK inhibition. The expression data are studied in both total RNA and polysome-bounded RNA.
Project description:Melanoma cell lines were assessed for differences in gene expression patterns between the lines sensitive and resistant to BRAF and MEK inhibitor drugs. 22 BRAF-mutant melanoma cell lines were assessed for response to BRAF and MEK inhibitors in a 3 day drug treatment dose response assay. Based on the IC50, 18 lines were found to be responsive to BRAF or MEK inhibition and 4 were resistant. Normalised gene expression data generated from experimental replicate affymetrix arrays was assessed to identify differential patterns of inherent gene expression between the cell lines grouped as drug-responsive or drug-resistant. This were used to idenify specific candidate genes and pathways associated with inherent BRAF/MEK inhibitor drug resistance in melanoma cells.
Project description:Given the heterogeneous expression of SOX10 in naïve melanoma, we sought to characterize SOX10 deficient population. To this end, we generated SOX10 CRISPR/Cas9 knockouts using two different guide RNAs (gRNA, #2 and #4) in the A375 (BRAF mutant) metastatic cell line. Using this approach, we identified multiple clones with loss of SOX10 expression. RNA-seq was performed to characterize the SOX10-regulated transcriptome. We used GSEA analysis to evaluate significant pathway changes in SOX10 knockout cells when compared to parental cells. We observed an enrichment in pathways associated with the tumor microenvironment (epithelial-mesenchymal transition; TGF beta signaling; extracellular structure organization; apical junction; hypoxia; angiogenesis), alterations in metabolic pathways (increase in the glycolysis pathway), a reduction in MYC and E2F targets and upregulation in p53 pathway and TNFA signaling via NFkB in the SOX10 knockout cells compared to parental cells. SOX10 negative clones have been identified in the minimal residual disease in BRAF mutant PDX models following BRAF and MEK inhibition and in patient samples while on treatment and SOX10 loss has been described as a resistant mechanism in BRAF mutant melanoma patients following vemurafenib treatment. Thus, we also analyzed the transcriptome profile of SOX10 low/deficient cells that arose following BRAFi+MEKi treatment in vivo. We performed GSEA analysis on RNA-seq data of CRT34 and CRT35 cells compared to parental A375 cells. CRT34 and CRT35 showed a very similar transcriptome profile to SOX10 KO cells when compared to A375 parental cells
Project description:Vemurafenib is a BRAF inhibitor with specificity for the most common BRAF mutant encountered in melanomas (BRAFV600E). Vemurafenib suppresses the proliferation of BRAF mutant human melanoma cells by suppressing downstream activation of the MEK/ERK mitogen activated protein kinases. We used microarrays to examine the transcriptional response of a vemurafenib-sensitive BRAFV600E human melanoma cell line (A375) to vemurafenib in order to further delineate the mechanisms by which BRAFV600E drives cell proliferation and energy metabolism in human melanoma.
Project description:Vemurafenib is a BRAF inhibitor with specificity for the most common BRAF mutant encountered in melanomas (BRAFV600E). Vemurafenib suppresses the proliferation of BRAF mutant human melanoma cells by suppressing downstream activation of the MEK/ERK mitogen activated protein kinases. We used microarrays to examine the transcriptional response of a vemurafenib-sensitive BRAFV600E human melanoma cell line (A375) to vemurafenib in order to further delineate the mechanisms by which BRAFV600E drives cell proliferation and energy metabolism in human melanoma. BRAFV600E A375 human melanoma cells were treated with vehicle (0.1% DMSO) or 10 uM vemurafenib for 24 h after which total RNA was extracted. Cells were prepared and RNA was extracted in 3 separate batches (three different cell stocks on three separate days) providing three independent replicates (n=3). Paired replicates (prepared from the same stock of cells on the same day) are denoted by A, B and C.
Project description:BRAF-inhibitor (BRAFi)-resistance compromises long term survivorship of malignant melanoma patients, and mutant NRAS is a major mediator of BRAFi-resistance. We have employed NanoString nCounterTM transcriptomic analysis of isogenic human malignant melanoma cells that differ only by NRAS mutational status (BRAFi-sensitive A375-BRAFV600E/NRASQ61 versus BRAFi-resistant A375-BRAFV600E/NRASQ61K), identifying modulation of specific gene expression networks as a function of NRASQ61K-status.
