The DNA methylation landscape of human melanoma [RNA-Seq]
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Xiwei Wu
PROVIDER: E-GEOD-71747 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Melanoma genomes are often characterized by large numbers of sunlight-induced mutations. However, epigenetic alterations, in the form of aberrant DNA methylation patterns, are also abundant. Using MIRA-seq, we have carried out a comprehensive characterization of the DNA methylome in a series of metastatic melanoma samples and catalogued the methylation changes relative to normal melanocytes, the presumed cells of origin for these tumors. Individual melanoma tumors contained up to several thousand hypermethylated regions. We discovered 179 tumor-specific methylation peaks that were present in all (27/27) melanomas and may lend themselves as effective disease biomarkers, and 3124 methylation peaks were present in >40% of the tumors. We specifically examined the relationship between presence of the Polycomb mark, H3K27me3 in melanocytes and tumor-specific DNA methylation in melanoma. We found that 150 of the approximately 1,200 tumor-associated methylation peaks near transcription start sites (TSS) were H3K27me3-marked in melanocytes. Notably, DNA methylation in melanoma was specific for distinct H3K27me3 peaks rather than for H3K27me3-enriched regions with broad genomic coverage. Yet, there were also numerous H3K27me3 peak-associated TSS regions that were completely resistant to DNA methylation in tumors. Furthermore, a rather large group of genes became methylated in melanoma but lacked H3K27me3 in melanocytes. There was no relationship between presence of BRAF V600 mutations and the number of methylation peaks in individual tumors. Gene expression analysis showed a strong signature of upregulated immune response genes in melanomas presumably as a result of lymphocyte infiltration. Genes down-regulated in tumors were enriched for melanocyte differentiation and pigmentation factors. Overall, there was limited correlation between tumor-associated DNA methylation changes and changes in gene expression although distinct melanocyte differentiation genes including KIT, PAX3 and SOX10 became methylated and downregulated in melanoma. Using MIRA-Seq, DNA methylation profiles of 27 malignant melanomas and 3 primary cultured melanocyte samples were determined
2016-03-31 | E-GEOD-71938 | biostudies-arrayexpress
Project description:Melanoma genomes are often characterized by large numbers of sunlight-induced mutations. However, epigenetic alterations, in the form of aberrant DNA methylation patterns, are also abundant. Using MIRA-seq, we have carried out a comprehensive characterization of the DNA methylome in a series of metastatic melanoma samples and catalogued the methylation changes relative to normal melanocytes, the presumed cells of origin for these tumors. Individual melanoma tumors contained up to several thousand hypermethylated regions. We discovered 179 tumor-specific methylation peaks that were present in all (27/27) melanomas and may lend themselves as effective disease biomarkers, and 3124 methylation peaks were present in >40% of the tumors. We specifically examined the relationship between presence of the Polycomb mark, H3K27me3 in melanocytes and tumor-specific DNA methylation in melanoma. We found that 150 of the approximately 1,200 tumor-associated methylation peaks near transcription start sites (TSS) were H3K27me3-marked in melanocytes. Notably, DNA methylation in melanoma was specific for distinct H3K27me3 peaks rather than for H3K27me3-enriched regions with broad genomic coverage. Yet, there were also numerous H3K27me3 peak-associated TSS regions that were completely resistant to DNA methylation in tumors. Furthermore, a rather large group of genes became methylated in melanoma but lacked H3K27me3 in melanocytes. There was no relationship between presence of BRAF V600 mutations and the number of methylation peaks in individual tumors. Gene expression analysis showed a strong signature of upregulated immune response genes in melanomas presumably as a result of lymphocyte infiltration. Genes down-regulated in tumors were enriched for melanocyte differentiation and pigmentation factors. Overall, there was limited correlation between tumor-associated DNA methylation changes and changes in gene expression although distinct melanocyte differentiation genes including KIT, PAX3 and SOX10 became methylated and downregulated in melanoma. Examination of H3K27me3 histone modification in human normal melanocytes.
2016-03-31 | E-GEOD-71692 | biostudies-arrayexpress
Project description:Melanoma genomes are often characterized by large numbers of sunlight-induced mutations. However, epigenetic alterations, in the form of aberrant DNA methylation patterns, are also abundant. Using MIRA-seq, we have carried out a comprehensive characterization of the DNA methylome in a series of metastatic melanoma samples and catalogued the methylation changes relative to normal melanocytes, the presumed cells of origin for these tumors. Individual melanoma tumors contained up to several thousand hypermethylated regions. We discovered 179 tumor-specific methylation peaks that were present in all (27/27) melanomas and may lend themselves as effective disease biomarkers, and 3124 methylation peaks were present in >40% of the tumors. We specifically examined the relationship between presence of the Polycomb mark, H3K27me3 in melanocytes and tumor-specific DNA methylation in melanoma. We found that 150 of the approximately 1,200 tumor-associated methylation peaks near transcription start sites (TSS) were H3K27me3-marked in melanocytes. Notably, DNA methylation in melanoma was specific for distinct H3K27me3 peaks rather than for H3K27me3-enriched regions with broad genomic coverage. Yet, there were also numerous H3K27me3 peak-associated TSS regions that were completely resistant to DNA methylation in tumors. Furthermore, a rather large group of genes became methylated in melanoma but lacked H3K27me3 in melanocytes. There was no relationship between presence of BRAF V600 mutations and the number of methylation peaks in individual tumors. Gene expression analysis showed a strong signature of upregulated immune response genes in melanomas presumably as a result of lymphocyte infiltration. Genes down-regulated in tumors were enriched for melanocyte differentiation and pigmentation factors. Overall, there was limited correlation between tumor-associated DNA methylation changes and changes in gene expression although distinct melanocyte differentiation genes including KIT, PAX3 and SOX10 became methylated and downregulated in melanoma.
2016-03-31 | GSE71938 | GEO
Project description:Melanoma genomes are often characterized by large numbers of sunlight-induced mutations. However, epigenetic alterations, in the form of aberrant DNA methylation patterns, are also abundant. Using MIRA-seq, we have carried out a comprehensive characterization of the DNA methylome in a series of metastatic melanoma samples and catalogued the methylation changes relative to normal melanocytes, the presumed cells of origin for these tumors. Individual melanoma tumors contained up to several thousand hypermethylated regions. We discovered 179 tumor-specific methylation peaks that were present in all (27/27) melanomas and may lend themselves as effective disease biomarkers, and 3124 methylation peaks were present in >40% of the tumors. We specifically examined the relationship between presence of the Polycomb mark, H3K27me3 in melanocytes and tumor-specific DNA methylation in melanoma. We found that 150 of the approximately 1,200 tumor-associated methylation peaks near transcription start sites (TSS) were H3K27me3-marked in melanocytes. Notably, DNA methylation in melanoma was specific for distinct H3K27me3 peaks rather than for H3K27me3-enriched regions with broad genomic coverage. Yet, there were also numerous H3K27me3 peak-associated TSS regions that were completely resistant to DNA methylation in tumors. Furthermore, a rather large group of genes became methylated in melanoma but lacked H3K27me3 in melanocytes. There was no relationship between presence of BRAF V600 mutations and the number of methylation peaks in individual tumors. Gene expression analysis showed a strong signature of upregulated immune response genes in melanomas presumably as a result of lymphocyte infiltration. Genes down-regulated in tumors were enriched for melanocyte differentiation and pigmentation factors. Overall, there was limited correlation between tumor-associated DNA methylation changes and changes in gene expression although distinct melanocyte differentiation genes including KIT, PAX3 and SOX10 became methylated and downregulated in melanoma.
2016-03-31 | GSE71747 | GEO
Project description:Melanoma genomes are often characterized by large numbers of sunlight-induced mutations. However, epigenetic alterations, in the form of aberrant DNA methylation patterns, are also abundant. Using MIRA-seq, we have carried out a comprehensive characterization of the DNA methylome in a series of metastatic melanoma samples and catalogued the methylation changes relative to normal melanocytes, the presumed cells of origin for these tumors. Individual melanoma tumors contained up to several thousand hypermethylated regions. We discovered 179 tumor-specific methylation peaks that were present in all (27/27) melanomas and may lend themselves as effective disease biomarkers, and 3124 methylation peaks were present in >40% of the tumors. We specifically examined the relationship between presence of the Polycomb mark, H3K27me3 in melanocytes and tumor-specific DNA methylation in melanoma. We found that 150 of the approximately 1,200 tumor-associated methylation peaks near transcription start sites (TSS) were H3K27me3-marked in melanocytes. Notably, DNA methylation in melanoma was specific for distinct H3K27me3 peaks rather than for H3K27me3-enriched regions with broad genomic coverage. Yet, there were also numerous H3K27me3 peak-associated TSS regions that were completely resistant to DNA methylation in tumors. Furthermore, a rather large group of genes became methylated in melanoma but lacked H3K27me3 in melanocytes. There was no relationship between presence of BRAF V600 mutations and the number of methylation peaks in individual tumors. Gene expression analysis showed a strong signature of upregulated immune response genes in melanomas presumably as a result of lymphocyte infiltration. Genes down-regulated in tumors were enriched for melanocyte differentiation and pigmentation factors. Overall, there was limited correlation between tumor-associated DNA methylation changes and changes in gene expression although distinct melanocyte differentiation genes including KIT, PAX3 and SOX10 became methylated and downregulated in melanoma.
2016-03-31 | GSE71692 | GEO
Project description:DNA methylation is considered the primary epigenetic mechanism underlying the development of malignant melanoma. Since DNA methylation can be influenced by environmental factors, it is preferable to compare cancer and normal cells from the same patient. Here, we employed a novel epidermal sheet cultivation technique to isolate normal melanocytes from unaffected sites of melanoma patients and compared the methylation status with melanoma tissues from the same individuals. We also analyzed primary and metastatic melanoma samples, three commercially available melanocytes, and four melanoma cell lines. Cluster analysis of DNA methylation data classified freshly isolated melanomas and melanocytes into the same group, whereas the four melanoma cell lines were clustered together in a distant clade. Moreover, our analysis discovered methylation at several novel loci (KRTCAP3, AGAP2, ZNF490), in addition to those identified in previous studies (COL1A2, GPX3); however, the latter two were not observed in fresh melanoma samples. Subsequent studies revealed that NPM2 was hypermethylated and downregulated in melanomas, which was consistent with previous reports and indicated that NPM2 immunoreactivity could be used to differentiate melanomas from normal melanocytes or benign disease. Our results highlight the importance of using matched fresh melanoma and melanocyte samples in epigenetic studies. Illumina Infinium 450k Human Methylation Beadchip
2018-11-29 | GSE122909 | GEO
Project description:DNA methylation is considered the primary epigenetic mechanism underlying the development of malignant melanoma. Since DNA methylation can be influenced by environmental factors, it is preferable to compare cancer and normal cells from the same patient. Here, we employed a novel epidermal sheet cultivation technique to isolate normal melanocytes from unaffected sites of melanoma patients and compared the methylation status with melanoma tissues from the same individuals. We also analyzed primary and metastatic melanoma samples, three commercially available melanocytes, and four melanoma cell lines. Cluster analysis of DNA methylation data classified freshly isolated melanomas and melanocytes into the same group, whereas the four melanoma cell lines were clustered together in a distant clade. Moreover, our analysis discovered methylation at several novel loci (KRTCAP3, AGAP2, ZNF490), in addition to those identified in previous studies (COL1A2, GPX3); however, the latter two were not observed in fresh melanoma samples. Subsequent studies revealed that NPM2 was hypermethylated and downregulated in melanomas, which was consistent with previous reports and indicated that NPM2 immunoreactivity could be used to differentiate melanomas from normal melanocytes or benign disease. Our results highlight the importance of using matched fresh melanoma and melanocyte samples in epigenetic studies. illumina HumanHT-12_v4 BeadChip
2018-11-29 | GSE122907 | GEO
Project description:Melanoma is the deadliest form of skin cancer with rising incidence and mortality rates. Oncogenic mutation in BRAF gene is the single most frequent genetic alteration in human melanoma; however, this event per se is not sufficient to produce melanoma in vivo. We have investigated whether epigenetic changes, specifically aberrant DNA methylation and dysregulation of gene expression, alone or in combination with this genetic event, are involved in the genesis of human melanoma. We have constructed the whole M-bM-^@M-^XM-bM-^@M-^Xof primary human melanomas in relation to their BRAF mutational status. Our methylation profiling identified a large number of hyper- or hypomethylated genes in melanoma tumors, many of which being novel and having the potential to serve as biomarkers. Gene ontology analysis revealed that gene categories involved in neuronal cell morphology and development, and skin and neurological disorders were highly enriched. Frequently methylated targets included developmental regulatory transcription factors and homeobox genes, which are mostly subjected to bivalent histone marking and Polycomb occupancy in embryonic stem cells. Notably, several genes involved in the MEK-ERK and the PI3K pathways, two of the most frequently perturbed pathways in human melanoma, showed extensive methylation changes. Gene expression profiling identified a long list of dysregulated genes, many of which being involved in melanocytes development and differentiation, and showing concomitant aberrant DNA methylation. Sub-typing of the melanoma tumors based on BRAF mutational status revealed that tumors with a mutated BRAF had distinctive and more pronounced changes in both DNA methylation and gene expression profiles than tumors carrying the wildtype BRAF. The differentially compromised methylome and transcriptome of melanomas (dependent on BRAF mutation) deserves special attention because many epigenetic alterations, including DNA methylation-mediated regulation of gene expression, are potentially reversible. The dichotomous integrity of epigenome in human melanoma holds great promise for the field of personalized medicine. Methylome: Eleven primary human melanoma speciemens versus five normal human melanocyte samples. Transcriptome: Ten primary human melanoma speciemens versus four normal human melanocyte samples
2012-12-31 | E-GEOD-31879 | biostudies-arrayexpress
Project description:Cutaneous, ocular and mucosal melanomas are histologically indistinguishable tumors that are driven by different spectrum of genetic alterations. With current methods, identification of the site of origin of a melanoma metastasis is challenging, in particular when the metastasis is the first tumor manifestation. Genome wide DNA methylation profiling has shown promise for the identification of the site of tumor origin in various settings. Here we explore the DNA methylation landscape of melanomas from different sites and analyze if different melanoma origins can be distinguished by their epigenetic profile. We performed DNA methylation analysis, next generation DNA panel sequencing and copy number analysis of 82 non-cutaneous and 25 cutaneous melanoma samples. We further analyzed eight normal melanocyte cell culture preparations by DNA methylation profiling. DNA methylation analysis clearly separated uveal melanomas from melanomas of other primary sites while mucosal, conjunctival and cutaneous melanomas were epigenetically almost identical. Still, we observed DNA methylation differences in cancer-related genes, such as low frequencies of RARB and CDKN2A promoter methylation in mucosal melanomas, while conjunctival melanomas frequently harbored APC promoter methylation. Furthermore, all investigated melanomas of the paranasal sinus showed loss of PTEN expression, mainly caused by promoter methylation. This was less frequently seen in melanomas of other sites. Copy number analysis revealed recurrent amplifications in mucosal melanomas, including chromosome 4q, 5p, 11q and 12q. Most melanomas of the oral cavity showed gains of chromosome 5p with TERT amplification while 11q amplifications were enriched in melanomas of the nasal cavity. Mucosal, conjunctival and cutaneous melanomas show a surprisingly similar DNA methylation profile and identification of the site of origin by DNA methylation testing is likely not feasible. Still, our study shows that there are DNA methylation differences on the gene level in known tumor drivers, related to the anatomical primary site.
2021-09-21 | GSE178416 | GEO
Project description:Spotted oligonucleotide microarrays were used to assess global differential gene expression comparing normal human melanocytes with six independent melanoma cell strains from advanced lesions. The data, validated at the protein level for selected genes, confirmed the overexpression in melanoma cells relative to normal melanocytes of several genes in the growth factor/receptor family that confer growth advantage and metastasis. In addition, novel pathways and patterns of associated expression in melanoma cells not reported before emerged. Six melanoma cultures and two melanocyte cultures. The melanoma cultures are considered, for the purposes of this investigation, replicates from the point of view that they are all melanomas. Three of the melanomas were replicated once or twice in addition.
2010-07-01 | E-GEOD-4576 | biostudies-arrayexpress