Melanoma therapeutic strategies that select against resistance by exploiting MYC-driven evolutionary convergence
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE99923 | GEO | 2017/11/16
SECONDARY ACCESSION(S): PRJNA390137
REPOSITORIES: GEO
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Project description:The majority of BRAFV600 mutant melanomas regress in response to BRAF/MEK inhibitors (BRAFi/MEKi). Yet nearly all relapse within the first two years. Most BRAFi/MEKi-resistant tumors are cross-resistant to immunotherapies, highlighting the need to prevent and circumvent resistance. We recently showed that androgen receptor (AR) activity is required for sustained melanoma cells proliferation and tumorigenesis. Here we find that AR expression is markedly increased in BRAFi resistant melanoma cells as well as in sensitive cells already at very early times of BRAFi exposure. Proliferation and tumorigenicity of BRAFi resistant melanoma cells are blunted by genetic or pharmacologic suppression of AR activity, while AR overexpression is by itself sufficient to rendersmelanoma cells BRAFi/MEKi-resistant. Increased AR elicits transcriptional changes linked with AXL-positive BRAFi resistant subpopulations and induces expression of PAI-1 and EGFR, two determinants of melanoma progression that associate with elevated AR expression in clinical cohorts. Our results point to increased AR signaling as a determinant of melanoma BRAFi resistance, which can be counteracted by AR as well as PAI-1 and EGFR inhibitors.
2023-08-03 | GSE199405 | GEO
Project description:The majority of BRAFV600 mutant melanomas regress in response to BRAF/MEK inhibitors (BRAFi/MEKi). Yet nearly all relapse within the first two years. Most BRAFi/MEKi-resistant tumors are cross-resistant to immunotherapies, highlighting the need to prevent and circumvent resistance. We recently showed that androgen receptor (AR) activity is required for sustained melanoma cells proliferation and tumorigenesis. Here we find that AR expression is markedly increased in BRAFi resistant melanoma cells as well as in sensitive cells already at very early times of BRAFi exposure. Proliferation and tumorigenicity of BRAFi resistant melanoma cells are blunted by genetic or pharmacologic suppression of AR activity, while AR overexpression is by itself sufficient to rendersmelanoma cells BRAFi/MEKi-resistant. Increased AR elicits transcriptional changes linked with AXL-positive BRAFi resistant subpopulations and induces expression of PAI-1 and EGFR, two determinants of melanoma progression that associate with elevated AR expression in clinical cohorts. Our results point to increased AR signaling as a determinant of melanoma BRAFi resistance, which can be counteracted by AR as well as PAI-1 and EGFR inhibitors.
2023-08-03 | GSE232693 | GEO
Project description:The majority of BRAFV600 mutant melanomas regress in response to BRAF/MEK inhibitors (BRAFi/MEKi). Yet nearly all relapse within the first two years. Most BRAFi/MEKi-resistant tumors are cross-resistant to immunotherapies, highlighting the need to prevent and circumvent resistance. We recently showed that androgen receptor (AR) activity is required for sustained melanoma cells proliferation and tumorigenesis. Here we find that AR expression is markedly increased in BRAFi resistant melanoma cells as well as in sensitive cells already at very early times of BRAFi exposure. Proliferation and tumorigenicity of BRAFi resistant melanoma cells are blunted by genetic or pharmacologic suppression of AR activity, while AR overexpression is by itself sufficient to rendersmelanoma cells BRAFi/MEKi-resistant. Increased AR elicits transcriptional changes linked with AXL-positive BRAFi resistant subpopulations and induces expression of PAI-1 and EGFR, two determinants of melanoma progression that associate with elevated AR expression in clinical cohorts. Our results point to increased AR signaling as a determinant of melanoma BRAFi resistance, which can be counteracted by AR as well as PAI-1 and EGFR inhibitors.
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Project description:Nearly 50% of cutaneous melanomas carry activating mutations on the BRAF oncogene, and the combination of BRAF- and MEK-inhibitors (BRAF/MEKi) is frequently used for their clinical management. One major drawback of BRAF/MEKi targeted therapy is the rapid development of therapeutic resistance, which can occur via multiple mechanisms, including the metabolic rewiring of cancer cells that often involves the upregulation of mitochondrial bionergetics and NAD+ biosynthetic pathways. mTORC2 is a signaling complex that requires the presence of its essential RICTOR subunit to play its regulatory functions in cell growth and metabolism. mTORC2 is believed to play mostly pro-oncogenic roles in several tumor types, including melanoma. However, bioinformatics analysis of TCGA melanoma patients’ database revealed that low RICTOR levels in tumors correlate with an overall worse clinical outcome. GSEA analysis of low-RICTOR tumors evidenced also a gene expression signature suggestive of activation of mitochondrial energy producing pathways. On these bases, we have hypothesized that inhibition of mTORC2 activity may render BRAFV600E melanoma cells resistant to BRAFi/MEKi. We show here that RICTOR/mTORC2-deficient cells are intrinsically tolerant to BRAFi/MEKi, and anticipate the onset of resistance to BRAFi after sustained drug exposure both in vitro and in vivo, indicating that mTORC2 activity normally opposes the acquisition of targeted therapy resistance in BRAFV600E melanomas. Mechanistically, RICTOR-deficient cells show an enhanced mitochondrial respiratory potential and increased expression of nicotinamide phosphoribosyltransferase (NAMPT) protein, the rate-limiting enzyme of NAD+ salvage pathway, and pharmacological inhibition of these processes in RICTOR-deficient cells is sufficient to restore sensitivity to BRAFi. Thus, our work identifies a novel role for mTORC2 in favoring the responses of BRAF-mutated melanoma cells to targeted therapy, and suggest that the evaluation of the intratumor level of RICTOR may help to predict the responses of melanoma patients to these treatments.
2024-05-23 | PXD045346 | Pride
Project description:About 25% of melanoma harbor activating NRAS mutations, which are associated with aggressive disease therefore requiring a rapid anti-tumor intervention. However, no efficient targeted therapy options are currently available for patients with NRAS-mutant melanoma. MEK inhibitors (MEKi) appear to display a moderate anti-tumor activity and also immunological effects in NRAS-mutant melanoma, providing an ideal backbone for combination treatments. In this study, the MEKi binimetinib, cobimetinib, and trametinib combined with the BRAF inhibitors (BRAFi) encorafenib, vemurafenib, and dabrafenib were investigated for their ability to inhibit proliferation, induce apoptosis and alter the expression of immune modulatory molecules in sensitive NRAS-mutant melanoma cells using 2D and 3D cell culture models and transcriptome analyses. Furthermore, NRAS-mutant melanoma cells resistant to the three BRAFi/MEKi combinations were established to characterize the mechanisms contributing to their resistance. All BRAFi induced a stress response in the sensitive NRAS-mutant melanoma cells thereby significantly enhancing the anti-proliferative and pro-apoptotic activity of the MEKi analyzed. Furthermore, BRAFi/MEKi combinations upregulated immune relevant molecules, such as ICOS-L, components of antigen-presenting machinery and the “don’t eat me signal” molecule CD47 in the melanoma cells. The BRAFi/MEKi-resistant, NRAS-mutant melanoma cells counteracted the molecular and immunological effects of BRAFi/MEKi by upregulating downstream mitogen-activated protein kinase pathway molecules, inhibiting apoptosis and promoting immune escape mechanisms. Together, this study reveals potent molecular and immunological effects of BRAFi/MEKi in sensitive NRAS-mutant melanoma cells that may be exploited in new combinational treatment strategies for patients with NRAS-mutant melanoma.
2023-11-14 | GSE245262 | GEO
Project description:Targeted therapies against mutant BRAF are effectively used in combination with MEK inhibitors (MEKi) to treat advanced melanoma. However, treatment success is affected by resistance and adverse events (AEs). Approved BRAF inhibitors (BRAFi) show high levels of target promiscuity, which can contribute to these effects. Blood vessels are in direct contact with high plasma concentrations of BRAFi, but effects of the inhibitors in this cell type are unknown. Hence, we aimed to characterize responses to clinically relevant BRAF kinase inhibitors in the vascular endothelium. A mass spectrometry-based analysis of the phosphoproteome of dermal microvascular endothelial cells revealed distinct sets of off-targets of the used BRAFi. Meanwhile, there were only negligible changes to the proteome after 1 h of treatment. Together with our published functional data, these findings provide insights on the surprisingly distinct side effects of BRAFi on endothelial signaling and functionality.
2024-06-01 | PXD052251 | Pride
Project description:Targeted therapies against mutant BRAF are effectively used in combination with MEK inhibitors (MEKi) to treat advanced melanoma. However, treatment success is affected by resistance and adverse events (AEs). Approved BRAF inhibitors (BRAFi) show high levels of target promiscuity, which can contribute to these effects. Blood vessels are in direct contact with high plasma concentrations of BRAFi, but effects of the inhibitors in this cell type are unknown. Hence, we aimed to characterize responses to clinically relevant BRAF kinase inhibitors in the vascular endothelium. A mass spectrometry-based analysis of the phosphoproteome of dermal microvascular endothelial cells revealed distinct sets of off-targets of the used BRAFi. Meanwhile, there were only negligible changes to the proteome after 1 h of treatment. Together with our published functional data, these findings provide insights on the surprisingly distinct side effects of BRAFi on endothelial signaling and functionality.
2024-06-01 | PXD052259 | 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:About half of all melanomas harbor a constitutively active mutant BRAFV600E/K kinase that can be selectively inhibited by targeted BRAF inhibitors (BRAFi). While patients treated with BRAFi initially exhibit measurable clinical improvement, the majority of patients eventually develop drug resistance and relapse. We observe significant elevation of WNT5A in a subset of tumors from patients exhibiting disease progression on BRAFi therapy. WNT5A transcript and protein are also elevated in BRAFi-resistant melanoma cell lines generated by long-term in vitro treatment with BRAFi. RNAi-mediated reduction in levels of endogenous WNT5A in melanoma decreases cell growth, increases apoptosis in response to BRAFi challenge, and decreases the activity of pro-survival AKT signaling. Overexpression of WNT5A conversely promotes melanoma growth and tumorigenesis and activates AKT signaling. Similar to WNT5A knockdown, knockdown of the WNT receptors FZD7 and RYK inhibits growth, sensitizes melanoma cells to BRAFi, and reduces AKT activation. Together, these findings suggest that chronic BRAF inhibition elevates WNT5A expression, which then acts through FZD7 and RYK to promote AKT signaling, leading to increased growth and therapeutic resistance. Increased WNT5A expression in BRAFi-resistant melanomas also correlates with an associated transcriptional signature, which identifies potential therapeutic targets to reduce clinical resistance to BRAFi. Expression of WNT5A-correlated genes was compared in melanoma cell lines generated to be resistant to PLX4032 and the their associated naïve parental line Basal expression of the WNT5A-correlated genes was also measured in experiments comparing each naïve line to a mixed reference pool containing equal amounts of 47 melanoma cell lines.
2014-03-06 | E-GEOD-55583 | biostudies-arrayexpress
Project description:Although treatment of melanoma patients with BRAF and MEK inhibitors has demonstrated impressive clinical outcomes, innate or acquired resistance to targeted therapy remains a major challenge. To uncover resistance mechanisms in patients, we performed single cell RNA sequencing of longitudinal biopsies of the same tumors from four consenting melanoma patients before the start of BRAFi/MEKi treatment and at different time points during treatment. Among the genes most differentially expressed between malignant cells from resistant vs. responding patients was POSTN encoding the secreted factor periostin. POSTN was predicted to predominantly signal to a macrophage population associated with targeted therapy resistance (TTR) in patients and was able to polarize macrophages towards a TTR phenotype. Finally, polarized TTR macrophages protected melanoma cells from MEKi-induced killing, which involved CD44 receptor expression on melanoma cells. Thus, interfering with the protective activity of TTR macrophages might represent a strategy to overcome targeted therapy resistance in melanoma.
2023-12-01 | GSE229908 | GEO