A novel recurrent mutation in MITF predisposes to familial and sporadic melanoma
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE31269 | GEO | 2011/12/01
SECONDARY ACCESSION(S): PRJNA146135
REPOSITORIES: GEO
Similar Datasets
Project description:We identified a novel germline mutation of the microphthalmia-associated transcription factor (MITF - E318K). This mutation was found to be present in numerous melanoma families, as well as the general population, where its association with melanoma has a significant effect. We determined the effect of the E318K mutation on global MITF target gene transcription. We developed a tetracycline-inducible system for expression of wild type MITF or the E318K variant in melanoma cell lines with constitutively low or undetectable levels of endogenous MITF (HT144 and C32). We examined whole-genome expression profiles in these cells following induction of either wild-type or E318K MITF for 48 hours. Analysis suggests that the MITF E318K mutant exhibits differential transcriptional activity against some, though not all, target genes. Expression profiling by array
2011-12-01 | E-GEOD-31269 | biostudies-arrayexpress
Project description:A novel recurrent mutation in MITF predisposes to familial and sporadic melanoma
| PRJNA76045 | ENA
Project description:Canonical Wnt signaling plays an important role in development and disease, regulating transcription of target genes and stabilizing many proteins phosphorylated by Glycogen Synthase Kinase 3 (GSK3). We observed that the MiT family of transcription factors, which includes the melanoma oncogene MITF and the lysosomal master regulator TFEB, had the highest phylogenetic conservation of three consecutive putative GSK3 phosphorylation sites in animal proteomes. This prompted us to examine the relationship between MITF, endolysosomal biogenesis and Wnt signaling. Here we report that MITF expression levels correlated with the expression of a large subset of lysosomal genes in melanoma cell lines. MITF expression in the Tetracycline-inducible C32 melanoma model caused a marked increase in vesicular structures, and increased expression of late endosomal proteins such as Rab7, LAMP1, and CD63. These late endosomes were not functional lysosomes as they were less active in proteolysis, yet were able to concentrate Axin1, phospho-LRP6, phospho-β-Catenin, and GSK3 in the presence of Wnt ligands. This relocalization significantly enhanced Wnt signaling by increasing the number of multivesicular bodies (MVBs) into which the Wnt signalosome/destruction complex becomes localized upon Wnt signaling. We also show that the MITF protein was stabilized by Wnt signaling, through the novel C-terminal GSK3 phosphorylations identified here. MITF stabilization caused an increase in MVB biosynthesis, which in turn increased Wnt signaling, generating a positive feed-back loop that may function during the proliferative stages of melanoma. The results underscore the importance of misregulated endolysosomal biogenesis in Wnt signaling and cancer. Expression of selected Lysosomal genes and CLEAR element plus MITF were compared in 51 melanoma cell lines to a mixed reference pool containing equal amounts of 47 melanoma cell lines.
2014-12-24 | E-GEOD-64497 | biostudies-arrayexpress
Project description:Canonical Wnt signaling plays an important role in development and disease, regulating transcription of target genes and stabilizing many proteins phosphorylated by Glycogen Synthase Kinase 3 (GSK3). We observed that the MiT family of transcription factors, which includes the melanoma oncogene MITF and the lysosomal master regulator TFEB, had the highest phylogenetic conservation of three consecutive putative GSK3 phosphorylation sites in animal proteomes. This prompted us to examine the relationship between MITF, endolysosomal biogenesis and Wnt signaling. Here we report that MITF expression levels correlated with the expression of a large subset of lysosomal genes in melanoma cell lines. MITF expression in the Tetracycline-inducible C32 melanoma model caused a marked increase in vesicular structures, and increased expression of late endosomal proteins such as Rab7, LAMP1, and CD63. These late endosomes were not functional lysosomes as they were less active in proteolysis, yet were able to concentrate Axin1, phospho-LRP6, phospho-β-Catenin, and GSK3 in the presence of Wnt ligands. This relocalization significantly enhanced Wnt signaling by increasing the number of multivesicular bodies (MVBs) into which the Wnt signalosome/destruction complex becomes localized upon Wnt signaling. We also show that the MITF protein was stabilized by Wnt signaling, through the novel C-terminal GSK3 phosphorylations identified here. MITF stabilization caused an increase in MVB biosynthesis, which in turn increased Wnt signaling, generating a positive feed-back loop that may function during the proliferative stages of melanoma. The results underscore the importance of misregulated endolysosomal biogenesis in Wnt signaling and cancer.
2014-12-24 | GSE64497 | GEO
Project description:The ability of cancer cells to switch phenotype in response to a dynamic intra-tumor microenvironment is a major barrier to effective therapy. In melanoma, down-regulation of the lineage addiction oncogene MITF (Microphthalmia-associated transcription factor) is a hallmark of the proliferative-to-invasive phenotype switch. Yet how MITF promotes proliferation and suppresses invasion is poorly understood. Here we show that expression of the key lipogenic enzyme stearoyl-CoA desaturase (SCD) is activated by MITF, but suppressed by the stress-responsive transcription factor ATF4. SCD expression is required for MITF-positive melanoma cell proliferation,. By contrast, MITF-low cells express reduced levels of SCD and are insensitive to its inhibition, indicating that cell phenotype dictates response to drugs targeting lipid metabolism. Since SCD suppresses inflammatory signalling and ATF4 expression, the results identify a positive feedback-loop that can maintain an invasive phenotype, uncover a key role for MITF and ATF4 in metabolic reprograming, and reveal fatty acid composition as a driver of melanoma phenotype-switching.
2019-11-19 | PXD010254 | Pride
Project description:<p>We conducted whole-genome sequencing of probands from several melanoma families, identifying one individual carrying a novel germline variant (c.G1075A, NM_000248.3; p.E318K, NP_000239.1; rs149617956) in the melanoma lineage-specific oncogene MITF. While the variant cosegregated with melanoma in some, but not all cases in the family, linkage analysis of 31 families subsequently identified to carry the variant generated a LOD score of 2.7 under a dominant model, suggesting E318K as a possible intermediate risk variant. Consistent with this, E318K was significantly associated with melanoma in a large Australian case-control sample, giving an odds ratio (OR) of 2.33, 95% CI 1.21-4.70 (case and control carrier frequency, 0.0165 and 0.0072, respectively; P=0.008). Likewise, it was similarly associated in an independent case-control sample from the United Kingdom (UK P=0.012; combined P=0.0003, OR 2.19, 95% CI 1.41-3.45). In the Australian sample, the variant allele was significantly over-represented in cases with a family history of melanoma (OR 2.95, 95% CI 1.23-6.92), multiple primary melanomas (OR 4.22, 95% CI 1.52-10.91), or both (OR 8.37, 95% CI 2.58-23.80). The variant allele was also associated with increased nevus count (combined P=0.002, OR 2.54, 95% CI 1.42-4.55) and non-blue eye color (combined P=0.008, OR 2.01, 95% CI 1.11-3.81). Functional analysis of E318K showed that MITF encoded by the variant allele had impaired sumoylation and differentially regulated several MITF targets. These data indicate that MITF is a melanoma predisposition gene and highlights the utility of whole-genome sequencing to identify novel rare variants associated with disease susceptibility.</p>
| phs000419.v1.p1 | EGA
Project description:We analyzed the transcriptional response of the human melanoma cell line MZ7 to TNF-alpha (24 hours) in a dose-dependent manner (TNF-alpha 10U/ml, 100U/ml, 1000U/ml) either transfected with control siRNA (siNT = non-targeting siRNA) or transfected with siRNAs (pool of 4 active and independent siRNAs) against the melanocytic transcription factor and lineage oncogene MITF. (Microphthalmia-associated transcription factor). The experiment was performed as biological duplicate. As MITF is critical for melanoma cell state control, we aimed to explore how MITF expression intersects with inflammation-induced plasticity pathways in melanoma. Total RNA was obtained from siRNA/TNF-treated MZ7 melanoma cell lines at various conditions and global gene expression profiling was done using the Illumina Human HT12 v4 platform.
2015-10-29 | E-GEOD-71798 | biostudies-arrayexpress
Project description:Key to effective gene regulation in development and homeostasis is the ability of transcription factors to discriminate between different classes of binding sites. Yet how this is achieved is poorly understood. The microphthalmia-associated transcription factor MITF is a lineage-survival oncogene that plays a crucial role in melanoma and melanocyte development where it suppresses invasion but promotes both proliferation and differentiation. How MITF distinguishes between differentiation and proliferation-associated targets is unknown. Unexpectedly we show here that differentiation-associated target genes are characterized by low affinity MITF binding sites. MAPK signaling, a key driver of melanomagenesis downstream from BRAF and NRAS, promotes p300/CBP-mediated MITF acetylation at K206 to reduce preferentially DNA binding affinity at differentiation-associated targets. The results reveal a MAPK-driven acetylation switch that can trigger de-differentiation of melanocytes and provide a mechanistic explanation of why a human K206Q MITF mutation is associated with Waardenburg’s syndrome characterized by pigmentation abnormalities.
2023-08-07 | GSE137776 | GEO
Project description:We analyzed the transcriptional response of the human melanoma cell line MZ7 to TNF-alpha (24 hours) in a dose-dependent manner (TNF-alpha 10U/ml, 100U/ml, 1000U/ml) either transfected with control siRNA (siNT = non-targeting siRNA) or transfected with siRNAs (pool of 4 active and independent siRNAs) against the melanocytic transcription factor and lineage oncogene MITF. (Microphthalmia-associated transcription factor). The experiment was performed as biological duplicate. As MITF is critical for melanoma cell state control, we aimed to explore how MITF expression intersects with inflammation-induced plasticity pathways in melanoma.
2015-10-29 | GSE71798 | GEO
Project description:So far, two genes associated with familial melanoma have been identified, accounting for a minority of genetic risk in families. Mutations in CDKN2A account for approximately 40% of familial cases, and predisposing mutations in CDK4 have been reported in a very small number of melanoma kindreds. Here we report the whole-genome sequencing of probands from several melanoma families, which we performed in order to identify other genes associated with familial melanoma. We identify one individual carrying a novel germline variant (coding DNA sequence c.G1075A; protein sequence p.E318K; rs149617956) in the melanoma-lineage-specific oncogene microphthalmia-associated transcription factor (MITF). Although the variant co-segregated with melanoma in some but not all cases in the family, linkage analysis of 31 families subsequently identified to carry the variant generated a log of odds (lod) score of 2.7 under a dominant model, indicating E318K as a possible intermediate risk variant. Consistent with this, the E318K variant was significantly associated with melanoma in a large Australian case-control sample. Likewise, it was similarly associated in an independent case-control sample from the United Kingdom. In the Australian sample, the variant allele was significantly over-represented in cases with a family history of melanoma, multiple primary melanomas, or both. The variant allele was also associated with increased naevus count and non-blue eye colour. Functional analysis of E318K showed that MITF encoded by the variant allele had impaired sumoylation and differentially regulated several MITF targets. These data indicate that MITF is a melanoma-predisposition gene and highlight the utility of whole-genome sequencing to identify novel rare variants associated with disease susceptibility.
| S-EPMC3266855 | biostudies-literature