Project description:Genome wide CRISPR screen was performed to find resistance to targeted drugs for melanoma and lung .
This dataset contains all the data available for this study on 2019-08-28.
Project description:Despite recent therapeutic advances in the management of BRAFV600-mutant melanoma, there is still a compelling need for more effective treatments for patients who developed BRAF/NRAS wild type disease. Since the activity of single targeted agents is limited by innate and acquired resistance, we performed a high-throughput drug screen using 180 drug combinations to generate over 17,000 viability curves, with the aim of identifying agents that synergise to kill BRAF/NRAS wild type melanoma cells. From this screen we identified a promising drug combination that efficiency kills 30% of melanoma cell lines. We validated in vivo the synergy of the drug combination and found a potential marker to identify sensitive tumors. We applied a genome-wide CRISPR screening which revealed that resistance mechanisms to the drug combination. In order to investigate the mechanism of drug synergy, we treated sensitive and resistance melanoma cell lines with the single drugs and the drug combination and performed proteome analyses to investigate the changes in total proteins and protein phosphorylation. These analysis highlighted specific pathway deregulations associated to the drug synergy that allowed to get a better understanding of the drug interaction and their efficacy in killing melanoma cell lines.
Project description:Preclinical and clinical data implicate the transcriptional co-activator YAP1 in resistance to multiple targeted therapies, including BRAF and MEK inhibitors. However, tumor subtypes driven by YAP1 activity and associated vulnerabilities are poorly defined. Here, we show particularly high YAP1 activity in the MITFlow/AXLhigh subset of melanoma cell lines and patient tumors characterized by resistance to MAPK pathway inhibition and broad receptor tyrosine kinase activity. To uncover genetic dependencies of melanoma cells with high YAP1 activity, we used a genome-wide CRISPR/Cas9 functional screen and identified SLC35B2, the 3′-phosphoadenosine-5′-phosphosulfate transporter of the Golgi apparatus, as an essential gene for YAP1-mediated drug resistance. SLC35B2 expression correlates with tumor progression, and its loss decreases heparan sulfate expression, reduces receptor tyrosine kinase activity, and sensitizes resistant melanoma cells to BRAF inhibition in vitro and in vivo. Thus, SLC35B2 is a target in YAP1-driven BRAF mutant melanoma for overcoming drug resistance to MAPK pathway inhibitors.
Project description:The aim of this study is to analyze the change in genome wide expression levels in HAP1 cells upon loss of SMARCB1, SMARCA4 or both these genes together. The SMARCB1 and SMARCA4 genes were the hits from a genome wide screen involving genetrap mutagenesis to find new players that are involved in sensitivity to Doxorubicin (Dox). It was found that loss of SMARCB1 and SMARCA4 genes impart resistance in HAP1 cells to Dox. To validate this, the genes were knocked out in HAP1 cells with CRISPR-Cas9 technology. Gene expression levels in SMARCB1 null, SMARCA4 null and SMARCB1-SMARCA4 double null cells were compared to wildtype HAP1 cells using RNAseq. From these experiments it was found that SMARCB1 loss caused several fold increase in ABCB1 gene levels. ABCB1 is an efflux pump in cells responsible for flushing out many small-molecule drugs. Further analysis of this gene confirmed that ABCB1 was the main factor responsible for Dox resistance upon SMARCB1 loss. In total there are four different cell types with two replicates for each cell type. Therefore, 8 samples in total.
Project description:To identify genes driving encephalitogenic CD4+ T cell migration into the CNS, we performed a genome-wide CRISPR screen and a subsequent validation screen For the genome-wide CRISPR screen, up to 4 sgRNA per gene and 800 non targeted controls were included, for a total of 87690 individual sgRNAs, and for the validation screen, up to 6 sgRNA per gene and 241 non targeted controls for a total of 12000 individual sgRNAs
Project description:In a genome-wide CRISPR-Cas9 resistance drug screen, we identified the master osmostress regulator WNK1 kinase as a modulator of the response to the mitotic drug rigosertib. Osmotic stress and WNK1 inactivation lead to an altered response not only to rigosertib but also to other microtubule-related drugs, minimizing the prototypical mitotic arrest produced by these drugs. This effect is due to an alteration in microtubule stability and polymerization dynamics, likely maintained by fluctuations in intracellular molecular crowding upon WNK1 inactivation. This promotes resistance to microtubule depolymerizing drugs, and increased sensitivity to microtubule stabilizing drugs. In summary, our data proposes WNK1 osmoregulation activity as a biomarker for microtubule-associated chemotherapy response.
Project description:Most genetic events that drive melanoma development and resistance to targeted therapy have been uncovered. In contrast, and despite their increasingly recognized contribution, little is known about the non-genetic mechanisms that drive these processes. Here, we performed in vivo gain-of-function CRISPR screens and identified SMAD3, BIRC3 and SLC9A5 as key drivers of BRAFi-resistance and the tumor growth capability of persister cells. We show that their expression levels increase during acquisition of BRAFi-resistance, and remain high in persister cells and during relapse. Critically, chemical inhibition of SMAD3 or BIRC3 efficiently abrogates melanoma tumor growth and persister cells proliferation. Genetic inhibition of these targets efficiently restored the sensitivity of persister cells to BRAFi. Our work expands our understanding of the biology of persister cells and highlight novel drug vulnerabilities that can be exploited to develop long-lasting anti-melanoma therapies.
Project description:Small cell lung cancer (SCLC) is an aggressive disease with high mortality. The identification of effective pharmacological strategies to target SCLC biology represents an urgent need. Using a high-throughput cellular screen of a diverse chemical library we observe that SCLC is sensitive to transcription-targeting drugs, and in particular to THZ1, a newly identified covalent inhibitor of cyclin-dependent kinase 7 (CDK7). We find that expression of super-enhancer associated transcription factor genes including MYC family proto-oncogenes and neuroendocrine lineage-specific factors are highly vulnerability to THZ1 treatment. We propose that downregulation of these transcription factors contributes, in part, to SCLC sensitivity to transcriptional inhibitors and that THZ1 represents a novel treatment paradigm for targeted SCLC therapy. ChIP-Seq for H3K27ac in small cell lung cancer lines