Project description:This study used microarray expression analysis to identify global changes in transcript alteration in response to MEK inhibition. Genes under ERK control were identified in a panel of V600E BRAF and RTK-activated tumor cells and xenografts, using short-term inhibition of ERK activity using the MEK inhibitor PD0325901 (Pfizer). Experiment Overall Design: Cell lines growing in culture (n=12) and murine xenografts (n=2) were treated with the MEK inhibitor PD0325901 or vehicle alone as control. Paired analysis of MEK inhibited to control samples was performed for two groups of tumor cells, V600E BRAF and RTK.
Project description:This study used microarray expression analysis to identify global changes in transcript alteration in response to MEK inhibition. Genes under ERK control were identified in a panel of V600E BRAF and RTK-activated tumor cells and xenografts, using short-term inhibition of ERK activity using the MEK inhibitor PD0325901 (Pfizer). Experiment Overall Design: Cell lines growing in culture (n=12) and murine xenografts (n=2) were treated with the MEK inhibitor PD0325901 or vehicle alone as control. Paired analysis of MEK inhibited to control samples was performed for two groups of tumor cells, V600E BRAF and RTK. Time course analysis was performed on one representative cell line in order to first determine the optimal time point to detect changes in all cell lines.
Project description:This study used microarray expression analysis to identify global changes in transcript alteration in response to MEK inhibition. Genes under ERK control were identified in a panel of V600E BRAF and RTK-activated tumor cells and xenografts, using short-term inhibition of ERK activity using the MEK inhibitor PD0325901 (Pfizer). Keywords: paired treatment and control
Project description:This study used microarray expression analysis to identify global changes in transcript alteration in response to MEK inhibition. Genes under ERK control were identified in a panel of V600E BRAF and RTK-activated tumor cells and xenografts, using short-term inhibition of ERK activity using the MEK inhibitor PD0325901 (Pfizer). This SuperSeries is composed of the SubSeries listed below.
Project description:Hairy cell leukemia (HCL) shows unique clinico-pathological and biological features. HCL responds well to purine analogues but relapses are frequent and novel therapies are required. BRAF-V600E is the key driver mutation in HCL and distinguishes it from other B-cell lymphomas, including HCL-like leukemias/lymphomas (HCL-variant and splenic marginal zone lymphoma). The kinase-activating BRAF-V600E mutation also represents an ideal therapeutic target in HCL. Here, we investigated the biological and therapeutic importance of the activated BRAF-MEK-ERK pathway in HCL by exposing in vitro primary leukemic cells purified from 26 patients to clinically available BRAF (Vemurafenib; Dabrafenib) or MEK (Trametinib) inhibitors. Results were validated in vivo in samples from Vemurafenib-treated HCL patients within a phase-2 clinical trial. BRAF and MEK inhibitors caused, specifically in HCL (but not HCL-like) cells, marked MEK/ERK dephosphorylation, silencing of the BRAF-MEK-ERK pathway transcriptional output, loss of the HCL-specific gene expression signature, downregulation of the HCL markers CD25, TRAP and cyclin-D1, smoothening of leukemic cells' hairy surface, and, eventually, apoptosis. Apoptosis was partially blunted by co-culture with bone marrow stromal cells antagonizing MEK-ERK dephosphorylation. This protective effect could be counteracted by combined BRAF and MEK inhibition. Our results strongly support and inform the clinical use of BRAF and MEK inhibitors in HCL. Analysis of differential gene expression in primary leukemic cells purified from peripheral blood of 6 HCL patients (from A to F), treated with Vemurafenib 1000 nM, in comparison with vehicle-treated (DMSO) HCL cells, for 48 hours or/and 72 hours. 24 gene expression profiles were analysed.
Project description:Hairy cell leukemia (HCL) shows unique clinico-pathological and biological features. HCL responds well to purine analogues but relapses are frequent and novel therapies are required. BRAF-V600E is the key driver mutation in HCL and distinguishes it from other B-cell lymphomas, including HCL-like leukemias/lymphomas (HCL-variant and splenic marginal zone lymphoma). The kinase-activating BRAF-V600E mutation also represents an ideal therapeutic target in HCL. Here, we investigated the biological and therapeutic importance of the activated BRAF-MEK-ERK pathway in HCL by exposing in vitro primary leukemic cells purified from 26 patients to clinically available BRAF (Vemurafenib; Dabrafenib) or MEK (Trametinib) inhibitors. Results were validated in vivo in samples from Vemurafenib-treated HCL patients within a phase-2 clinical trial. BRAF and MEK inhibitors caused, specifically in HCL (but not HCL-like) cells, marked MEK/ERK dephosphorylation, silencing of the BRAF-MEK-ERK pathway transcriptional output, loss of the HCL-specific gene expression signature, downregulation of the HCL markers CD25, TRAP and cyclin-D1, smoothening of leukemic cells' hairy surface, and, eventually, apoptosis. Apoptosis was partially blunted by co-culture with bone marrow stromal cells antagonizing MEK-ERK dephosphorylation. This protective effect could be counteracted by combined BRAF and MEK inhibition. Our results strongly support and inform the clinical use of BRAF and MEK inhibitors in HCL.
Project description:This study used microarray expression analysis to identify global changes in transcript alteration in response to MEK inhibition. Genes under ERK control were identified in a representative V600E BRAF cell line as a function of time following exposure to a small molecule inhibitor of MEK. Keywords: Time course
Project description:This study used microarray expression analysis to identify global changes in transcript alteration in response to MEK inhibition. Genes under ERK control were identified in a representative V600E BRAF cell line as a function of time following exposure to a small molecule inhibitor of MEK. Experiment Overall Design: SkMel-28 cells growing in culture were treated with the MEK inhibitor PD0325901 for 2, 8, or 24 hours. Changes in RNA compared to reference (time =0) were measured using microarray analysis.
Project description:BRAF, one of three RAF serine/threonine kinases (ARAF, BRAF and CRAF), plays a major role in the RAS-RAF-MEK-ERK mitogen-activated protein kinase (MAPK) signaling pathway, which mediates cellular responses to growth signals. Recently a high frequency (~60%-70%) of activating BRAF mutations (predominantly V600E) has been reported in malignant melanoma. In order to identify the downstream effects of BRAF signaling on melanoma cell growth and gene expression, cDNA microarray analysis was carried out following BRAF siRNA or MEK1/2 inhibitor (U0126) treatment. Keywords: time series, siRNA time series, siRNA, drug treatment
Project description:Using a chromatin regulator-focused shRNA library, we found that suppression of sex determining region Y-box 10 (SOX10) in melanoma causes resistance to BRAF and MEK inhibitors. To investigate how SOX10 loss leads to drug resistance, we performed transcriptome sequencing (RNAseq) of both parental A375 (Ctrl. PLKO) and A375-SOX10KD (shSOX10-1, shSOX10-2) cells. To ask directly whether SOX10 is involved indrug resistance in BRAF(V600E) melanoma patients, we isolated RNA from paired biopsies from melanoma patients (pre- and post- treatment) , that had gained BRAF or MEK inhibitor resistance . We performed RNAseq analysis to determine changes in transcriptome upon drug resistance.