Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA256979 | ENA |
REPOSITORIES: ENA
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Project description:Therapeutic targeting of BRAFV600E has shown a significant impact on progression-free and overall survival in advanced melanoma, but only a fraction of patients benefit from these treatments, suggesting that additional signaling pathways involved in melanoma growth/survival need to be identified. In fact MAPK and PI3K/mTOR signaling pathways are constituively activated in most cancers, including melanoma, to sustain the melanoma growth/survival. A large panel of melanoma were characterized for resistance/susceptibility to different inhibitors targeting MAPK and PI3K/mTOR signaling pathways and the synergistic effect of combinatorial treatments affecting both pathways. These effects were evaluated in terms of cell viability (MTT), apoptosis (Annexin V-PI), caspase 3/7 activity and subG1 cell fraction, highlighting a hierarchy in the combination effects. Further, a smaller panel of melanoma cell lines, were treated with inhibitors singularly and in combination to test the effects on the expression of principal proteins involved in these two pathways. Gene expression profile was performed to analyse the gene modulation induced by inhibitors to identify new strategies to fight melanoma resistance.
2016-12-31 | GSE59882 | GEO
Project description:Combining direct anti-tumor effects with targeting of tumor microenvironment is an attractive strategy that may lead to more effective therapies for advanced melanoma. Here, we tested whether association of TRAIL with co-targeting of MEK and PI3K/mTOR, or with MEK blockade, could have synergistic anti-melanoma activity mediated not only by induction of tumor cell death, but also by effects on the tumor microenvironment. Drug interaction analysis by the Chou-Talalay approach in a panel of 21 melanoma cell lines indicated that strong synergism could be achieved by association of the MEK1/2 inhibitor AZD6244, the PI3K/mTOR inhibitor NPV-BEZ235 and TRAIL, as well as by the AZD6244/TRAIL combination. Synergism was observed on most tumors including TRAIL- or inhibitor-resistant melanomas, irrespective of the BRAF, NRAS, p53 and PTEN status, and was explained by enhanced induction of caspase-dependent melanoma apoptosis. The AZD/BEZ/TRAIL and AZD/TRAIL combinatorial treatments induced strong modulation of key apoptosis regulators along the extrinsic and intrinsic cell death pathways, including c-FLIP down-regulation, caspase-8 cleavage, BIMs and BAXa upregulation, clusterin and Mcl-1 inhibition, enhanced mitochondrial depolarization, suppression of inhibitors of apoptosis c-IAP1, c-IAP2, XIAP and Apollon, and caspase 3/7 activation. In an in vivo model, the AZD6244/TRAIL combinatorial treatment induced highly significant growth inhibition of a TRAIL-resistant tumor associated not only with melanoma cell death, but even with suppression of pro-angiogenic molecules HIF1a, VEGFa, IL-8 and TGFb1, and with inhibition of tumor angiogenesis. These results provide a proof of principle supporting the rationale for combinatorial treatments with synergistic anti-melanoma activity based on direct and indirect anti-tumor effects. The human melanoma cell line Me13 was established in our laboratory from a surgical specimen. Cells were routinely maintained in RPMI medium 1640 (Lonza, Basel, Switzerland) supplemented with 10% FBS (Lonza) and 2 mM glutamine (Lonza). Cells were maintained at 37°C in a water-saturated atmosphere of 5% CO2 in air. 3x10^6 cells were seeded in 75 cm2 flasks; after 24 hours, cells were left untreated or treated with Selumetinib (Selleck Chemicals, Houston, TX) at 0.1 micromol/L, NVP-BEZ-235 (Selleck Chemicals, Houston, TX) at 0.1 micromol/L and sTRAIL (AdipoGen) at 25ng/ml as single drugs or in combination for 8 hours. Each treatment or combination was performed in triplicate. At the end of treatment, cells were collected and RNA extracted.
2014-10-08 | E-GEOD-55050 | biostudies-arrayexpress
Project description:Combining direct anti-tumor effects with targeting of tumor microenvironment is an attractive strategy that may lead to more effective therapies for advanced melanoma. Here, we tested whether association of TRAIL with co-targeting of MEK and PI3K/mTOR, or with MEK blockade, could have synergistic anti-melanoma activity mediated not only by induction of tumor cell death, but also by effects on the tumor microenvironment. Drug interaction analysis by the Chou-Talalay approach in a panel of 21 melanoma cell lines indicated that strong synergism could be achieved by association of the MEK1/2 inhibitor AZD6244, the PI3K/mTOR inhibitor NPV-BEZ235 and TRAIL, as well as by the AZD6244/TRAIL combination. Synergism was observed on most tumors including TRAIL- or inhibitor-resistant melanomas, irrespective of the BRAF, NRAS, p53 and PTEN status, and was explained by enhanced induction of caspase-dependent melanoma apoptosis. The AZD/BEZ/TRAIL and AZD/TRAIL combinatorial treatments induced strong modulation of key apoptosis regulators along the extrinsic and intrinsic cell death pathways, including c-FLIP down-regulation, caspase-8 cleavage, BIMs and BAXa upregulation, clusterin and Mcl-1 inhibition, enhanced mitochondrial depolarization, suppression of inhibitors of apoptosis c-IAP1, c-IAP2, XIAP and Apollon, and caspase 3/7 activation. In an in vivo model, the AZD6244/TRAIL combinatorial treatment induced highly significant growth inhibition of a TRAIL-resistant tumor associated not only with melanoma cell death, but even with suppression of pro-angiogenic molecules HIF1a, VEGFa, IL-8 and TGFb1, and with inhibition of tumor angiogenesis. These results provide a proof of principle supporting the rationale for combinatorial treatments with synergistic anti-melanoma activity based on direct and indirect anti-tumor effects.
2014-10-08 | GSE55050 | GEO
Project description:The close integration of the MAPK, PI3K and WNT signaling pathways underpins much of development and is deregulated in cancer. In principle, combinatorial post-translational modification of key lineage–specific transcription factors would be an effective means to integrate critical signaling events. Understanding how this might be achieved is central to deciphering the impact of microenvironmental cues in development and disease. The microphthalmia associated transcription factor, MITF, plays a crucial role in the development of melanocytes, the retinal pigment epithelium, osteoclasts and mast cells, and acts as a lineage survival oncogene in melanoma. MITF coordinates survival, differentiation, cell cycle progression, cell migration, metabolism and lysosome biogenesis. Yet how the activity of this key transcription factor is controlled remains poorly understood. Here we show that GSK3b, downstream from both the PI3K and Wnt pathways, and BRAF/MAPK signaling converge to control MITF nuclear export. Phosphorylation of the melanocyte MITF-M isoform in response to BRAF/MAPK signaling primes for phosphorylation by GSK3b, a kinase inhibited by both PI3K and Wnt signaling. Dual phosphorylation, but not monophosphorylation, then promotes MITF nuclear export by activating a previously unrecognized hydrophobic export signal. Nonmelanocyte MITF isoforms exhibit poor regulation by MAPK signaling, but instead their export is controlled by mTOR. We uncover here an unanticipated mode of MITF regulation that integrates the output of key developmental and cancer-associated signaling pathways to gate MITF flux through the import-export cycle. The results have significant implications for our understanding of melanoma progression and stem cell renewal
2022-02-28 | PXD010665 | Pride
Project description:The close integration of the MAPK, PI3K, and WNT signaling pathways underpins much of development and is deregulatedin cancer. In principle, combinatorial posttranslational modification of key lineage specific transcription factors would be an effective mean stointegrate critical signaling events. Understanding how this might be achieved is central to deciphering the impact of microenvironmental cues in development and disease. The microphthalmia-associated transcription factor MITF plays a crucial role in the development of melanocytes, the retinal pigment epithelium, osteoclasts, and mast cells and acts as a lineage survival oncogene in melanoma. MITF coordinates survival, differentiation, cell-cycle progression, cell migration, metabolism, and lysosome biogenesis. However, how the activity of this key transcriptionfactoriscontrolledremainspoorlyunderstood.Here,we showthatGSK3,downstreamfromboththePI3KandWntpathways, and BRAF/MAPK signaling converge to control MITF nuclear export. Phosphorylation of the melanocyte MITF-M isoform in response to BRAF/MAPK signaling primes for phosphorylation by GSK3, a kinase inhibited by both PI3K and Wnt signaling. Dual phosphorylation, but not monophosphorylation, then promotes MITF nuclear export by activatinga previously unrecognizedhydrophobic exportsignal. NonmelanocyteMITFisoformsexhibitpoorregulationbyMAPKsignaling, but instead their export is controlled by mTOR. We uncover here an unanticipated mode of MITF regulation that integrates the output of key developmental and cancer-associated signaling pathways to gate MITF flux through the import–export cycle. The results have significant implications for our understanding of melanoma progression and stem cell renewal.
2019-11-12 | PXD010782 | Pride
Project description:Dataset containing multiple Hyptis and Artemisia spp. used for the discovery of natural products inhibiting aberrant signaling, namely MAPK/ERK and PI3K/AKT, in melanoma
2021-12-22 | MSV000088606 | GNPS
Project description:Metastatic melanoma is either intrinsically resistant or rapidly acquires resistance to targeted therapy treatments, such as MAPK inhibitors. A leading cause of resistance to targeted therapy is a dynamic transition of melanoma cells from a proliferative to a highly invasive state, a phenomenon called phenotype switching. Mechanisms regulating phenotype switching represent potential targets for improving treatment of melanoma patients. Using a drug screen targeting chromatin regulators in patient-derived 3D MAPK inhibitor-resistant melanoma cell cultures, we discovered that PARP inhibitors restore sensitivity to MAPK inhibitors, independent of DNA damage repair pathways. Integrated transcriptomic, proteomic, and epigenomic analyses demonstrated that PARP inhibitors induce lysosomal autophagic cell death, accompanied by enhanced mitochondrial lipid metabolism that ultimately increases antigen presentation and sensitivity to T-cell cytotoxicity. Moreover, transcriptomic and epigenetic rearrangements induced by PARP inhibition reversed EMT-like phenotype switching, which redirected melanoma cells toward a proliferative and MAPK inhibitor-sensitive state. The combination of PARP and MAPK inhibitors synergistically induced cancer cell death both in vitro and in vivo in patient-derived xenograft models. Therefore, this study provides a scientific rationale for treating melanoma patients with PARP inhibitors in combination with MAPK inhibitors to abrogate acquired therapy resistance.
2023-08-24 | GSE221241 | GEO
Project description:Understanding the cancer stem-cell (CSC) landscape in diffuse intrinsic pontine glioma (DIPG) is desperately needed to address treatment resistance and identify novel therapeutic approaches. Patient derived DIPG cells demonstrated heterogeneous expression of aldehyde dehydrogenase (ALDH) and CD133 by flow cytometry. Transcriptome-level characterization identified elevated mRNA levels of MYC, E2F, DNA damage repair (DDR) genes, glycolytic metabolism and mTOR signaling in ALDH+ compared to ALDH- supporting a stem-like phenotype and indicating a druggable target. ALDH+ cells demonstrated increased proliferation and neurosphere formation and initiated tumors that resulted in decreased survival when orthotopically implanted. Pharmacological MAPK/PI3K/mTOR targeting downregulated MYC, E2F and DDR mRNAs and reduced glycolytic metabolism. In vivo PI3K/mTOR targeting inhibited tumor growth in both flank and an ALDH+ orthotopic tumor model likely by reducing cancer stemness. Characterization of DIPG CSCs coupled with targeting MAPK/PI3K/mTOR signaling provides an impetus for molecularly targeted therapy aimed at addressing the CSC phenotype in DIPG.
2020-11-03 | GSE149682 | GEO
Project description:Current therapeutic management of advanced melanoma patients largely depends on their BRAF mutation status. However, the vast heterogeneity of the tumors hampers the success of therapies targeting the MAPK/ERK pathway alone. Dissecting this heterogeneity will contribute to identifying key players in the oncogenic progression to tailor more effective therapies. We performed a comprehensive molecular and phenotypic characterization of a panel of patient-derived BRAFV600E-positive melanoma cell lines. Transcriptional profiling was used to identify groups of coregulated genes whose expression relates to an increased migratory potential and a higher resistance. A decrease in sensitivity to MAPK/ERK pathway inhibition with vemurafenib or trametinib corresponded with an increasing quiescence and migratory properties of the cells. This was accompanied by the loss of transcriptional signatures of melanocytic differentiation, and the gain of stem cell features that conferred highly-resistant/mesenchymal-like cells with increased xenobiotic efflux capacity. Nevertheless, targeting of the implicated ABC transporters did not improve the response to vemurafenib, indicating that incomplete BRAF inhibition due to reduced drug uptake is not a main driver of resistance. Rather, indifference to MAPK/ERK pathway inhibition arose from the activation of compensatory signaling cascades. The PI3K/AKT pathway in particular showed a higher activity in mesenchymal-like cells, conferring a lower dependency on MAPK/ERK signaling and supporting stem-like properties that could be reverted by dual PI3K/mTOR inhibition with dactolisib. In case of MAPK/ERK independency, therapeutic focus may be shifted to the PI3K/AKT pathway to overcome late-stage resistance in melanoma tumors that have acquired a mesenchymal phenotype.
2022-09-01 | GSE208004 | GEO
Project description:The emergence of effective inhibitors for BRAF-mutant melanoma has had major impact on clinical management of melanoma 1,2. The initial success of such treatments, however, has been limited due to the propensity of melanomas to develop resistance 3-5. In most cases, mechanisms underlying BRAFi-resistance include activation of genetic or epigenetic pathways that circumvent targeted BRAF and restore MAPK and related signaling to levels sufficient to encourage tumorigenesis 3-7. This outcome has led to development of combination therapies targeting both BRAF and associated pathways, such as MEK and PI3K 8,9, albeit, with limited success. Furthermore, 50% of melanomas, such as those harboring NRAS and NF1 mutations, lack BRAF mutations and are thus not amenable to BRAFi therapy 10,11. Thus tumor chemoresistance and the lack of therapies for BRAF wild-type (WT) tumors remains a major clinical challenge. Disrupting the eukaryotic translation initiation factor 4F (eIF4F) complex has been an appealing strategy to potentiate effectiveness of existing cancer therapies. We identify that the small molecule SBI-0640756 (SBI-756) binds to eIF4G1 and dissociates it from eIF4E, leading to disruption of the eIF4F complex. SBI-756 treatment also inhibited AKT, NF-κB and mTOR signaling. We detected the melanoma cell lines have different response to SBI-756. It important to invertigate genes and pathways in melanoma cells resistant to SBI-756.
2016-05-01 | GSE66401 | GEO