Genome-wide promoter methylation analysis of human melanocytes and melanoma cell lines
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Christina Dahl
PROVIDER: E-GEOD-53801 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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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:All cancers are diseases of the genome. A combination of somatic point mutations, focal amplifications and deletions, and chromosome level aberrations conspire to disrupt gene expression and the interplay between signaling pathways that control normal growth and tissue homeostasis. Here we investigate somatic copy number abberations in metastatic melanomas. A metastatic melanoma was assayed on Affymetrix SNP arrays to detect copy number abberations. 7 cutaneous melanomas as well as their matched control ( peripheral blood lymphocytes (PBL) or Epstein-Barr virus transformed lymphoblastoid cell lines ) and 2 control melanocytes were assayed on Illumina SNP arrays. 7 metastatic melanomas were hybridized on Agilent CGH arrays using donor matched control as reference.
2011-04-07 | E-GEOD-22928 | biostudies-arrayexpress
Project description:Epigenetic regulation of tumor suppressor genes (TSGs) has been shown to play a central role in melanomagenesis. Integrating gene expression and methylation array analysis we identified novel candidate TSGs frequently methylated in melanoma. We validated the methylation status of the most promising TSGs using the highly sensitive, specific and comprehensive Sequenom Epityper assay in a large panel of melanoma cell lines and resected melanomas, and compared the findings with that from cultured melanocytes. We found transcript levels of UCHL1, COL1A2, THBS1 and TNFRSF10D were inversely correlated with promoter methylation. The effect of this methylation on expression was confirmed at the protein level. Identification of these candidate TSGs and how their silencing is related to melanoma development will increase our understanding of the etiology of this cancer and may provide tools for its early diagnosis. Analysed samples consisted of 11 melanoma cell lines and 1 neonatal foreskin melanocyte pool as a reference. Melanoma cell lines overlap with members of the DNA copy number analysis series GSE9003 and expression profiling series GSE7127 . The matching copy number data GEO samples IDs are noted in characteristics: Matching CN Sample ID and characteristics: Matching expn Sample ID columns respectively.
2011-10-24 | E-GEOD-28356 | biostudies-arrayexpress
Project description:Oncogenic alterations to DNA are not transforming in all cellular contexts. This may be due to pre-existing transcriptional programs in the cell of origin. Here, we define anatomic position as a major determinant of why cells respond to specific oncogenes. Cutaneous melanoma arises throughout the body, whereas the acral subtype arises on the palms of the hands, soles of the feet, or under the nails. We sequenced the DNA of cutaneous and acral melanomas from a large cohort of human patients and found a specific enrichment for BRAF mutations in cutaneous melanoma but CRKL amplifications in acral melanoma. We modeled these changes in transgenic zebrafish models and found that CRKL-driven tumors predominantly formed in the fins of the fish. The fins are the evolutionary precursors to tetrapod limbs, indicating that melanocytes in these acral locations may be uniquely susceptible to CRKL. RNA profiling of these fin/limb melanocytes, compared to body melanocytes, revealed a positional identity gene program typified by posterior HOX13 genes. This positional gene program synergized with CRKL to drive tumors at acral sites. Abrogation of this CRKL-driven program eliminated the anatomic specificity of acral melanoma. These data suggest that the anatomic position of the cell of origin endows it with a unique transcriptional state that makes it susceptible to only certain oncogenic insults.
2022-01-12 | PXD027968 | Pride
Project description:Purpose: Epigenetic mechanisms and alterations in uveal melanoma (UM) development are still not well understood. In this pilot study, histone posttranslational modifications (PTMs), which are epigenetic mechanisms regulating gene expression, were analyzed in UM formalin-fixed paraffin-embedded (FFPE) tissues and control tissue as well as in UM cell lines and healthy melanocytes to provide a deeper insight into the pathogenesis of UM and the potentially prognostic relevance of these molecular markers. Methods: FFPE tissue of UM (n=24) and normal choroid (n=4) as well as human UM cell lines (n=7), human skin melanocytes (n=6) and uveal melanocytes (n=2), were analyzed by a quantitative mass spectrometry (MS) approach.
2024-02-14 | PXD043551 | Pride
Project description:Epigenetic alterations play significant roles in the melanoma tumorigenesis and malignant progression. We profiled genome-wide promoter DNA methylation patterns of melanoma cells deribed from primary lesions of Radial Growrth phase (RGP) and Vertical Growth Phase (VGP), metastatic lesions, and primary normal melanocytes by interrogating 14,495 genes using Illumina bead chip technology. By comparative analysis of the promoter methylation profiles, we identified epigenetically silenced gene signatures that potentially associated with malignant melanoma progression. Bisulphite converted genomic DNA from a group of melanoma cells representing pathologic stages of melanoma progression (3 cell lines derived from RGP melanoma lesions, 4 cell lines derived from VGP lesions, and 3 melastatic melanomas) and normal human primary melanocytes isolated from lightly pigmented adult skin were hybridized to Illumina's Infinium HumanMethylation27 BeadChips
2013-12-20 | E-GEOD-53516 | biostudies-arrayexpress
Project description:Genome wide DNA methylation profiling of primary uveal melanoma cells, normal uveal melanocytes, neural crest stem cells, embryonic stem cells and uveal melanoma cell lines. The Illumina Infinium 27k Human DNA methylation Beadchip Rev B was used to obtain DNA methylation profiles across approximately 27,000 CpGs in the samples. Samples included 58 primary UM, 3 NUM and NCSC controls and 2 cell lines. Bisulphite converted DNA from the 63 samples were hybridised to the Illumina Infinium 27k Human Methylation Beadchip Rev B
2013-02-14 | E-GEOD-44296 | biostudies-arrayexpress
Project description:Post-partum uterine inflammation (endometritis) is associated with lower fertility at both the time of infection and after the inflammation has resolved. It was hypothesized that aberrant DNA methylation may be involved in the sub-fertility associated with post-partum uterine inflammation. The objective of this study was to characterize genome-wide DNA methylation and gene expression in the endometrium of dairy cows with sub-clinical endometritis. Endometrial tissues were obtained at 29 days post-partum (n=12) and Agilent two-colour microarrays were used to characterize transcription and DNA methylation profiles. Analyses revealed 1,856 probes to be differentially expressed in animals with subclinical endometritis (SUI, n=6) compared with control cows (NUI, n=6, P<0.05, Storey Multiple testing correction). No significant associations among DNA methylation and gene expression were detected. Further analysis of gene expression data using GeneGo Metacore and Gene Set Enrichment Analysis identified several pathways and processes enriched in the comparison. Several pathways that are involved in the innate immune response were enriched in SUI cows. Consistent with the presence of microorganisms in the uterus, there was enrichment for the Toll-like receptor (TLR) signaling pathway, including increased expression of the transcription factor NFKB1, the pro-inflammatory cytokines IL1A and IL1B, downstream chemokines, cytokines, and acute phase and antimicrobial proteins in the endometrium of SUI cows. Furthermore, the chemokine signaling pathway was enriched in SUI cows, with increased expression of genes that attract cells of the innate immune system. Increased expression of IL-8 and CXCL6, chemotactic factors for recruitment of neutrophils along with the immune cell surface marker PTPRC in SUI cows is consistent with the greater number of polymorphonuclear cells present in the uterus of these cows. Several antimicrobial peptides (LAP, TAP, DEFB1, DEFB10, DEFB103B, DEFB7) and acute phase proteins, including SAA3, LBP, and the complement gene CFB, had greater expression in SUI cows. Gene expression profiles in cows with subclinical endometritis in this study indicate that the immune response is activated, potentially resulting in a local pro-inflammatory environment in the uterus. If this period of inflammation is prolonged, it could result in tissue damage or failure to complete involution of the uterus, which may create a sub-optimal environment for future pregnancy. Agilent two-colour microarrays were used to characterize DNA methylation profiles in cows with subclinical endometritis (SUI, n=6) compared to control cows (NUI, n=6). Endometrial tissues (caruncular, intercaruncular) were obtained at 29 days post-partum.
2015-05-07 | E-GEOD-60831 | biostudies-arrayexpress
Project description:To pinpoint developmental pathways that are up-regulated both in neural crest stem cells (NCSC) and in melanoma cells but not in melanocytes, we carried out computational analyses to compare gene expression profiles of human skin-derived NCSC, epidermal melanocytes and melanoma cells. Our aim was to preselect genes that exhibit high mRNA expression levels both in melanoma cells and in NCSC but low levels in melanocytes.
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Project description:Melanoma is one of the most aggressive and treatment-resistant cancers. It represents the most life-threatening neoplasm of the skin, and its incidence has been increasing for the last three decades. Melanoma evolves from the local transformation of melanocytes to primary tumors, which can metastasize to multiple organs. Brain metastases represent one of the most significant causes of death in cutaneous melanoma patients. Despite aggressive multi-modality threapy, patients with melanoma brain metastasis have a median survival of less than a year, with a majority of these patients dying as a result of their intracranial disease. To identify alterations in gene expression related to brain metastasis, we used Affymetrix expression arrays to assess differentially expressed genes in melanocytes, lymph node metastases, and brain metastases. Total RNA from twenty-two specimens representing normal melanocytes (n=3), melanoma lymph node metastasis (n=12), and melanoma brain metastasis (n=7) was extracted and analyzed by Affymetrix expression arrays. Melanocytes specimens were used as control samples. Melanocytes were acquired from Invitrogen (LifeTechnologies). Metastatic melanoma specimens were taken from different patients, established as cell lines in the John Wayne Cancer Institute. Early passages (less than 6) were used to perform expression analysis.
2013-09-19 | E-GEOD-44660 | biostudies-arrayexpress