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
Project description:DNA methylation profiling of human melanocytes and melanoma cell lines. Goal was to identify hypermethylated gene promoters in melanoma Genomic DNA from 4 human melanoma cell lines and normal human epidermal melanocytes was subjected to methylated DNA immunoprecipitation (MeDIP) and hybridized to Agilent's G4489A Human Promoter ChIP-on-Chip Set 244K
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.
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
Project description:DNA methylation profiling of human melanocytes and melanoma cell lines. Goal was to identify hypermethylated gene promoters in melanoma
Project description:Tumor suppressor genes (TSGs) are sometimes inactivated by transcriptional silencing through promoter hypermethylation. To identify novel methylated TSGs in melanoma, we carried out global mRNA expression profiling on a panel of 12 melanoma cell lines treated with a combination of 5-Aza-2-deoxycytidine (5AzadC) and an inhibitor of histone deacetylase, Trichostatin A. Reactivation of gene expression after drug treatment was assessed using Illumina whole-genome microarrays. After qRT-PCR confirmation, we followed up 8 genes (AKAP12, ARHGEF16, ARHGAP27, ENC1, PPP1R3C, PPP1R14C, RARRES1, and TP53INP1) by quantitative DNA methylation analysis using mass spectrometry of base-specific cleaved amplification products in panels of melanoma cell lines and fresh tumors. PPP1R3C, ENC1, RARRES1, and TP53INP1, showed reduced mRNA expression in 35–59% of the melanoma cell lines compared to melanocytes and which was correlated with a high proportion of promoter methylation (>40–60%). The same genes also showed extensive promoter methylation in 6–25% of the tumor samples, thus confirming them as novel candidate TSGs in melanoma. We sought to identify melanoma TSGs silenced by promoter methylation by carrying out an array-based analysis in a well-annotated panel of 12 cell lines after combined treatment with 5AzadC and an inhibitor of histone deacetylase, Trichostatin A (TSA). Expression profiles were generated for each cell line before and after drug treatment using Illumina Sentrix Human-6 Expression version 2 BeadChips. Genes reactivated in all 12 cell lines were removed from further analysis since they are likely responding to drug treatment as part of the ‘‘cellular stress response,’’ or due to promoter demethylation of genes normally silenced in the melanocytic lineage. Genes were further filtered to identify those with an average of >4-fold increased expression in at least four samples in the panel of 12 lines and >10-fold increase in at least one of the cell lines.
Project description:Aberrant DNA methylation and histone modifications both contribute to carcinogenesis, but how these two epigenetic factors interact to impact gene expression remain unclear. To address this issue, we studied gene expression profiles, DNA methylation and two key histone modifications (H3K4me3 and H3K27me3), in two normal melanocytes (HEMn and HEMa) and two melanoma cell lines SK-MEL-28 and LOXIMVI. Using these data, we analyzed the relationship between epigenetic factors and gene expression status in both normal and melanoma cells, and the impact of epigenetic switches on gene expression change during melanomagenesis. Each of the two normal melanocytes (HEMn and HEMa) and the two melanoma cell lines SK-MEL-28 and LOXIMVI was cultured in triplicate. For each cell line, the same culture conditions and cell density were applied to the triplicates. Total RNA was extracted and microarray analysis was performed for genome-wide gene expression profiling. Using the Sentrix Human-HT12 v4 Beadchip, all four cell samples, each in triplicate, were examined in 12 individual arrays on a same beadchip. Thus, together with the data on DNA methylation and histone modifications, we could not only analyze the epigenetic regulation of gene expression in each cell sample, but also investigate the expression change associated with epigenetic changes in melanoma when compared to normal melanocytes.
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
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.