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: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: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:To explore the characteristics of senescent melanoma cells induced by vemurafenib or cisplatin, melanoma A375 cells were treated with vemurafenib and cisplatin, respectively. The senescent phenotypes were verified by β-gal staining, EdU assay, cell morphology and the senescence-related pathways. RNA-seq was performed to explore the differentially expressed genes in the senescent cells induced by vemurafenib or cisplatin.
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:Both targeted inhibition of oncogenic driver mutations and immune-based therapies show efficacy in treatment of patients with metastatic cancer but responses are either short-lived or incompletely effective. Oncogene inhibition can augment the efficacy of immune-based therapy but mechanisms by which these two interventions might cooperate are incompletely resolved. Using a novel transplantable BRAFV600E-mutant murine melanoma model (SB-3123), we explore potential mechanisms of synergy between the selective BRAFV600E inhibitor vemurafenib and adoptive cell transfer (ACT)-based immunotherapy. We found that vemurafenib cooperated with ACT to delay melanoma progression but surprisingly did not enhance tumor infiltration or effector function of endogenous or adoptively transferred CD8+ T cells as previously observed. Instead, we found that the T cell cytokines IFN-gamma and TNF-alpha synergized with vemurafenib to induce cell cycle arrest of tumor cells in vitro. This was recapitulated in vivo as continuous vemurafenib administration was required to delay melanoma progression following ACT. The unexpected finding that immune cytokines synergize with oncogene inhibitors to induce growth arrest have major implications for understanding cancer biology at the intersection of oncogenic and immune signaling and provides a basis for design of combinatorial therapeutic approaches for patients with metastatic cancer. SB-3123p cells were treated in triplicate (biological replicates) under the following conditions for 96 hours: DMSO vehicle (control) (n=3); mouse IFNgamma (2.4 ng/ml) and mouse TNFalpha (0.24 ng/mL) (n=3); Vemurafenib (1uM) (n=3); and mouse IFNgamma (2.4 ng/ml), mouse TNFalpah (0.24 ng/mL) and Vemurafenib (1uM) (n=3).
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: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.