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:Using our computational method SynGeNet to evaluate genomic and transcriptomic data characterizing four major genomic subtypes of melanoma, we selected the top ranked drug combination for BRAF-mutation melanoma for subsequent validaiton. Here we present drug-induced gene expression data from the BRAF-mutant A375 melanoma cell line in response to four treatment conditions: vehicle control (DMSO), vemurafenib alone, tretinoin (ATRA) alone and vemurafenib+tretinoin combination.
Project description:Melanoma is a rare but deadly form of skin cancer, which is often treated with BRAF inhibitors such as Vemurafenib (referred to as PLX4032). Whilst Vemurafenib prolongs the survival of patients, BRAF inhibitor resistance inevitably occurs in most cases. Previous studies demonstrated that metabolic rewiring occurs in BRAF inhibitor resistance and causes dependence on glutamine. To investigate whether this vulnerability could be exploited with clinically relevant drugs, we used the BRAF inhibitor, Vemurafenib, and the glutaminase imhibitor, CB839 to treat A375-derived melanoma xenografted tumors. We showed that whilst CB839 did not significantly affect the growth of A375-derived tumors compared to those given a vehicle, the addition of CB839 to Vemurafenib treatment had a significant anti-tumor effect. Tumors were taken at the endpoint (Max tumor length 15mm) from the 6 mice in each treatment group and cut into fragments and stored in RNAlater for RNAseq analysis. RNA extraction was performed on 1-3 fragments per tumor to make up 200-300mg of tissue.
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:Melanoma is an aggressive skin cancer with increasing incidence worldwide. The development of BRAF kinase inhibitors as targeted treatments for patients with BRAF-mutant tumours contributed profoundly to an improved overall survival of patients with metastatic melanoma. Despite these promising results, the emergence of rapid resistance to targeted therapy remains a serious clinical issue. To investigate the impact of BRAF inhibitors on miRNomes and transcriptomes, we used in vitro melanoma models consisting of BRAF inhibitor-sensitive and -resistant cell lines generated in our laboratory. miRNA and gene expression were assessed by microarray analyses of the BRAF inhibitor sensitive melanoma cells A375, IGR37, and 501Mel, as well as on the vemurafenib (PLX4032) - resistant cells A375_XP, IGR37_XP, 501Mel_XP, and dabrafenib (GSK2118436) - resistant cells A375_GP, IGR37_GP, 501Mel_GP. For each cell line the microarray experiment was performed in duplicates.
Project description:Melanoma is an aggressive skin cancer with increasing incidence worldwide. The development of BRAF kinase inhibitors as targeted treatments for patients with BRAF-mutant tumours contributed profoundly to an improved overall survival of patients with metastatic melanoma. Despite these promising results, the emergence of rapid resistance to targeted therapy remains a serious clinical issue. To investigate the impact of BRAF inhibitors on miRNomes and transcriptomes, we used in vitro melanoma models consisting of BRAF inhibitor-sensitive and -resistant cell lines generated in our laboratory. miRNA and gene expression were assessed by microarray analyses of the BRAF inhibitor sensitive melanoma cells A375, IGR37, and 501Mel, as well as on the vemurafenib (PLX4032) - resistant cells A375_XP, IGR37_XP, 501Mel_XP, and dabrafenib (GSK2118436) - resistant cells A375_GP, IGR37_GP, 501Mel_GP. For each cell line the microarray experiment was performed in duplicates.
Project description:Three cell lines were derived from the A375 human melanoma (harbouring the BRAF v600e mutation; ATCC) after treatment with vemurafenib during a period of 4-5 weeks in the absence (MAPKi-resist Rep1/Rep2) or presence of the fatty acid oxidation inhibitors etomoxir (Etomoxir Rep1/Rep2) or ranolazine (Ranolazine Rep1/Rep2).
Project description:Purpose: Identification of miRNAs that enable resistance to BRAF inhibitors in melanoma suggests a mechanism-based strategy to limit resistance and improve clinical outcomes. Methods: We generated A375 melanoma cells resistant to Vemurafenib (VMF) with the goal of investigating changes in miRNA expression patterns that might contribute to resistance. Results: Increased expression of miR-204-5p and miR-211-5p occurring in VMF-resistant cells was determined to impact VMF response.
Project description:BRAF is the most frequently mutated gene in melanoma. Constitutive activation of mutant BRAFV600E leads to aberrant Ras-independent MAPK signaling and cell transformation. Inhibition of mutant BRAF is a current front-line therapy for such cases, with improved survival compared with chemotherapy. Unfortunately, reactivation of MAPK signaling by several mechanisms has been shown to cause drug resistance and disease recurrence. In this work, we describe the co-occurrence of an in-frame deletion within an amplified BRAFV600E locus, and a missense point mutation of the transcriptional repressor BCORL1, in vemurafenib-resistant A375 melanoma cells. Functional data confirmed that truncated p47BRAFV600E and mutant BCORL1Q1076H both contribute to resistance. Interestingly, either endogenous BCORL1 silencing or ectopic BCORL1Q1076H expression mimicked the effects of a CRISPR/Cas9-edited BCORL1Q1076H locus, suggesting a change-of-function mutation. Transcriptomic data confirmed this hypothesis. Finally, we show that the pan-RAF inhibitor sorafenib is not affected by expression of BRAF deletion variant and effectively synergizes with vemurafenib to block resistant cells, suggesting a possible intervention for this class of mutants.