Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

EGAS00001002366-sc-20180125 - samples

ABSTRACT: The discovery of the BRAF V600E mutation in almost all cases of hairy-cell leukemia has led to the widespread adoption of the BRAF inhibitor vemurafenib for treatment of chemotherapy-resistant cases. Impressive responses are reported; however, acquired resistance is common. Whilst diverse mechanisms of vemurafenib resistance have been elucidated in melanoma, the basis of resistance in HCL is unclear. Here we apply whole genome and deep targeted sequencing to investigate resistance mechanisms and potential therapeutic strategies in a patient with aquired resistance to vemurafenib.

PROVIDER: EGAD00001003924 | EGA |

REPOSITORIES: EGA

ACCESS DATA

Json Xml

Similar Datasets

EGAS00001002261-sc-20180125 - samples

Project description:The discovery of the BRAF V600E mutation in almost all cases of hairy-cell leukemia has led to the widespread adoption of the BRAF inhibitor vemurafenib for treatment of chemotherapy-resistant cases. Impressive responses are reported; however, acquired resistance is common. Whilst diverse mechanisms of vemurafenib resistance have been elucidated in melanoma, the basis of resistance in HCL is unclear. Here we apply whole genome and deep targeted sequencing to investigate resistance mechanisms and potential therapeutic strategies in a patient with aquired resistance to vemurafenib.

| EGAD00001003923 | EGA

A four-arm study of A375 melanoma cell line-derived xenograft tumors in NSG mice treated with Vemurafenib and CB839

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.

2023-04-07 | E-MTAB-12811 | biostudies-arrayexpress

Braf inhibitors reverse the unique molecular signature and phenotype of hairy cell leukemia, and exert anti-leukemic activity

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.

2014-12-12 | E-GEOD-63790 | biostudies-arrayexpress

Braf inhibitors reverse the unique molecular signature and phenotype of hairy cell leukemia, and exert anti-leukemic activity

2014-12-12 | GSE63790 | GEO

Polyamine and EIF5A hypusination downstream of c-Myc confers targeted therapy resistance in BRAF mutant melanoma

Project description:BRAF inhibitors are widely employed in the treatment of melanoma with the BRAF V600E mutation. However, the development of resistance greatly compromises their therapeutic efficacy. Here, we elucidate the role of polyamine biosynthesis and its regulatory mechanisms in promoting BRAF inhibitor resistance. Leveraging CRISPR-Cas9 screens, we identify AMD1 (S-adenosylmethionine decarboxylase 1), a critical enzyme for polyamine biosynthesis, as a druggable target whose inhibition reverses vemurafenib resistance. Metabolomic and proteomic analyses reveal that polyamine biosynthesis is upregulated in vemurafenib-resistant cancer, resulting in enhanced EIF5A hypusination, translation of mitochondrial proteins and oxidative phosphorylation. We also identify that sustained c-Myc levels in vemurafenib-resistant cancer are responsible for elevated polyamine biosynthesis. Finally, inhibition of polyamine biosynthesis or c-Myc reversed vemurafenib resistance both in vitro and in vivo in a xenograft model. With the polyamine biosynthesis signature correlated with poor prognosis in BRAF mutant melanoma patients, our findings reveal that the polyamine-hypusination-mitochondrial respiration pathway is an effective therapeutic target that can maximize the therapeutic efficacy of existing BRAF inhibitors.

2024-07-10 | GSE243344 | GEO

Vemurafenib resistance selects for highly malignant brain and lung-metastasizing melanoma cells

Project description:V600E being the most common mutation in BRAF, leads to constitutive activation of the MAPK signaling pathway. The majority of V600E BRAF positive melanoma patients treated with the BRAF inhibitor vemurafenib showed initial good clinical responses but relapsed due to acquired resistance to the drug. The aim of the present study was to identify possible biomarkers associated with the emergence of drug resistant melanoma cells. To this end we analyzed the differential gene expression of vemurafenib-sensitive and vemurafenib resistant brain and lung metastasizing melanoma cells. The major finding of this study is that the in vitro induction of vemurafenib resistance in melanoma cells is associated with an increased malignancy phenotype of these cells. Resistant cells expressed higher levels of genes coding for cancer stem cell markers (JARID1B, CD271 and Fibronectin) as well as genes involved in drug resistance (ABCG2), cell invasion and promotion of metastasis (MMP-1 and MMP-2). We also showed that drug-resistant melanoma cells adhere better to and transmigrate more efficiently through lung endothelial cells than drug-sensitive cells. The former cells also alter their microenvironment in a different manner from that of drug-sensitive cells. Biomarkers and molecular mechanisms associated with drug resistance may serve as targets for therapy of drug-resistant cancer.

2015-03-20 | GSE67088 | GEO

Gene expression of the A375 melanoma cell line treated with RAF inhibitors Vemurafenib and time-course with EGF stimulation during Vemurafenib RAF inhibitor treatment alone or with the MEK inhibitor Cobimetinib

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).

2020-10-19 | GSE127988 | GEO

Time-series RNA-seq experiment performed on 10 melanoma cell lines treated with BRAF inhibitor vemurafenib.

Project description:BRAF targeted drug vemurafenib have shown very good clinical benefit in melanoma patient containing BRAF V600E mutation. However, resistance always occurs in patient. Early stage of the resistance development require the tumor cell adapted to the targeted drug. We are trying to study the kinetic of melanoma cell adaptation towards vemurafenib. 10 melanoma cell lines with BRAF mutation are treated with targeted therapy vemurafenib. RNA-seq samples are collected after drug treatment for different time (day3 and day21) to compare with DMSO-treated control samples for each cell line. Except innate resistant cell line M381, all other cell lines shows inhibition of proliferation. However, a small cluster of cell lines (M397, M229 and M263) shows some other unique transcriptomic change. For cell line M397, M229 and M263, we also collected the RNA-seq data for long-term (73day/90day) drug treatment condition where the cells developed resistance to vemurafenib treatment. Dedifferentiation is enriched in these unique transcriptomic change within these 3 cell lines. Similar cell state dedifferentiation phenomenon is also reported to cause resistance towards immunotherpay where the resistant de-differentiated melanoma cells are induced by TNF which is secreted by tumor-infiltrating T cells. We also treat our cultured melanoma cells with TNF and collected the treated sample for RNA-seq experiment.

2019-06-22 | E-MTAB-5493 | biostudies-arrayexpress

Whole-exome sequencing of genomic DNA extracted from patient-derived melanoma cell lines resistant to vemurafenib (PLX).

Project description:Whole-exome sequencing was performed on DNA sample extracted from one melanoma cell line resistant to vemurafenib (BRAF V600E inhibitor). The aim of the experiment was to search for genetic alterations responsible for phenotypic diversity of melanoma cell lines reported at the level of cell morphology, activity of signaling pathways essential for melanoma development and progression, and resistance to targeted therapeutics.

2019-07-25 | E-MTAB-8150 | biostudies-arrayexpress

Whole-exome sequencing of genomic DNA from patient-derived melanoma cell lines resistant to either vemurafenib (PLX) or trametinib (TRA).

Project description:Whole-exome sequencing was performed on DNA samples extracted from seven melanoma cell lines resistant to either vemurafenib (BRAF V600E inhibitor) or trametinib (MEK1/2 inhibitor). The aim of the experiment was to search for genetic alterations responsible for phenotypic diversity of melanoma cell lines reported at the level of cell morphology, activity of signaling pathways essential for melanoma development and progression, and resistance to targeted therapeutics.

2019-06-15 | E-MTAB-7991 | biostudies-arrayexpress

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data