Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA309132 | ENA |
REPOSITORIES: ENA
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Project description:The majority of human melanomas bears BRAF mutations and thus is treated with inhibitors of BRAF, such as vemurafenib. While patients with BRAF mutations often demonstrate an initial dramatic response to vemurafenib, relapse is extremely common. Thus, novel agents are needed for the treatment of these aggressive melanomas. Honokiol is a small molecule compound derived from Magnolia grandiflora that has activity against solid tumors and hematopoietic neoplasms. In order to increase the lipophilicity of honokiol, we have synthesized honokiol DCA, the dichloroacetate ester of honokiol. In addition, we synthesized a novel fluorinated honokiol analog, bis-trifluoromethyl-bis-(4-hydroxy-3-allylphenyl) methane (hexafluoro). Both compounds exhibited activity against A375 melanoma in vivo, but honokiol DCA was more active. Gene arrays comparing treated with vehicle control tumors demonstrated induction of the respiratory enzyme succinate dehydrogenase B (SDHB) by treatment, suggesting that our honokiol analogs induce respiration in vivo. We then examined its effect against a pair of melanomas, LM36 and LM36R, in which LM36R differs from LM36 in that LM36R has acquired vemurafenib resistance. Honokiol DCA demonstrated in vivo activity against LM36R (vemurafenib resistant) but not against parental LM36. Honokiol DCA and hexafluoro inhibited the phosphorylation of DRP1, thus stimulating a phenotype suggestive of respiration through mitochondrial normalization. Honokiol DCA may act in vemurafenib resistant melanomas to increase both respiration and reactive oxygen generation, leading to activity against aggressive melanoma in vivo. Tumors from animals treated with control vehicle, honokiol DCA, and hexafluoro were harvested and snapped-frozen in liquid nitrogen until RNA Extraction. RNA extraction was performed according to the Qiagen RNeasy kit. RNA samples were then submitted to Emory Universityâs Intergrated Genomics Core for RNA quality analysis and gene expression assay. Gene expression analysis was performed using an Illumina HumanHT-12 v3 Expression Bead Chip and Gene Expression Module of Illuminaâs GenomeStudio Software package (v2011.1, Illumina).
2016-01-20 | E-GEOD-76956 | biostudies-arrayexpress
Project description:The majority of human melanomas bears BRAF mutations and thus is treated with inhibitors of BRAF, such as vemurafenib. While patients with BRAF mutations often demonstrate an initial dramatic response to vemurafenib, relapse is extremely common. Thus, novel agents are needed for the treatment of these aggressive melanomas. Honokiol is a small molecule compound derived from Magnolia grandiflora that has activity against solid tumors and hematopoietic neoplasms. In order to increase the lipophilicity of honokiol, we have synthesized honokiol DCA, the dichloroacetate ester of honokiol. In addition, we synthesized a novel fluorinated honokiol analog, bis-trifluoromethyl-bis-(4-hydroxy-3-allylphenyl) methane (hexafluoro). Both compounds exhibited activity against A375 melanoma in vivo, but honokiol DCA was more active. Gene arrays comparing treated with vehicle control tumors demonstrated induction of the respiratory enzyme succinate dehydrogenase B (SDHB) by treatment, suggesting that our honokiol analogs induce respiration in vivo. We then examined its effect against a pair of melanomas, LM36 and LM36R, in which LM36R differs from LM36 in that LM36R has acquired vemurafenib resistance. Honokiol DCA demonstrated in vivo activity against LM36R (vemurafenib resistant) but not against parental LM36. Honokiol DCA and hexafluoro inhibited the phosphorylation of DRP1, thus stimulating a phenotype suggestive of respiration through mitochondrial normalization. Honokiol DCA may act in vemurafenib resistant melanomas to increase both respiration and reactive oxygen generation, leading to activity against aggressive melanoma in vivo.
2016-01-20 | GSE76956 | GEO
Project description:Indolium 1 Exerts Activity against Vemurafenib-Resistant Melanoma In Vivo
| PRJNA827137 | ENA
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
Project description:The development of targeted therapies (Braf/MEK inhibitors) and immunotherapy have had a major impact on the treatment of melanoma. However, the majority of patients with advanced melanomas succumb to their disease. The mechanisms of resistance to both targeted therapies and immunotherapies are numerous and have been well-described. These include the alternative acti-vation of Braf/MEK signaling, novel compensating mutations in additional oncogenes, and loss of neoantigens. There has been limited development of small molecules that target alternative path-ways in melanoma in the last two decades. We have previously identified triphenylmethanes as a class that shows activity against a wide variety of tumors. We have synthesized a novel triphenyl-methane, indolium 1, and demonstrated its efficacy against an aggressive vemurafenib-resistant melanoma in vivo. Indolium 1 has a novel mechanism of action against melanoma, in that it results in induction of the tumor-suppressor EphA3. We believe that pre-IND studies are warranted for this novel compound, given its mechanism of action and ability to inhibit the growth of vemurafenib resistant melanoma in vivo
2022-06-01 | GSE200882 | GEO
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.
2018-10-20 | E-MTAB-7248 | biostudies-arrayexpress
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
Project description:Targeted inhibition of mutated kinases using selective MAP kinase inhibitors in malignant melanoma often results in temporary improvement of the metastatic disease followed by rapid development of resistance. To gain insights in molecular processes that govern resistance, we performed SILAC-based quantitative proteomics profiling of vemurafenib-resistant and -sensitive melanoma cells. Among downregulated proteins in vemurafenib-resistant cell lines we detected multiple proteins involved in cytoskeletal organization and signaling, including the intermediate filament nestin, which was one of the most down-regulated proteins. Previous studies showed that nestin is expressed in various types of solid tumors and its abundance correlates with malignant phenotype of transformed cells. However, the role of nestin in cancer cells with regard to acquired resistance is still poorly understood. We performed CRISPR/Cas9 knockout of the nestin gene (NES) in vemurafenib-sensitive cells and showed that loss of nestin leads to increased cellular proliferation and colony formation upon treatment with BRAF and MEK inhibitors. Moreover, nestin depletion led to increased invasiveness and metalloproteinase activity similar to resistant phenotype of melanoma cells. Finally, phosphoproteome analysis revealed that nestin depletion influenced signaling through integrin and PI3K-Akt-mTOR pathways and led to increased focal adhesion kinase expression and phosphorylation. Taken together, our results reveal that nestin is associated with acquired vemurafenib resistance in melanoma cell lines.
2019-05-14 | PXD010683 | Pride
Project description:Most BRAF-mutant melanoma tumors respond initially to BRAFi/MEKi therapy, although few patients have durable long-term responses to these agents. The goal of this study was to utilize an unbiased computational approach to identify inhibitors which reverse an experimentally derived BRAFi resistance gene expression signature. Using this approach, we predicted that ibrutinib, a BTK inhibitor, effectively reverses this signature, and we demonstrate experimentally that ibrutinib re-sensitizes a subset of BRAFi-resistant melanoma cells to vemurafenib. Ibrutinib is used clinically as a BTK inhibitor; however, neither BTK deletion nor treatment with acalabrutinib, an analog of ibrutinib with reduced off-target activity, re-sensitized cells to vemurafenib. These data suggest that ibrutinib acts through a BTK-independent mechanism in vemurafenib re-sensitization. To better understand this mechanism, we analyzed the transcriptional profile of ibrutinib-treated BRAFi-resistant melanoma cells and found that the transcriptional profile of ibrutinib was highly similar to that of multiple SRC kinase inhibitors. Since ibrutinib, but not acalabrutinib, has significant off-target activity against multiple SRC family kinases, it suggests that ibrutinib may be acting through this mechanism. Furthermore, genes either upregulated or downregulated by ibrutinib treatment are enriched with YAP1 target genes and we experimentally demonstrate that ibrutinib, but not acalabrutinib, reduces YAP1 activity in BRAFi-resistant melanoma cells. Taken together, these data suggest that ibrutinib, or other SRC family kinase inhibitors, may be useful for treating some BRAFi/MEKi-refractory melanoma tumors.
2020-02-27 | GSE145990 | GEO
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