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EFS shows biallelic methylation in uveal melanoma with poor prognosis as well as tissue-specific methylation.

ABSTRACT: BACKGROUND: Uveal melanoma (UM) is a rare eye tumor. There are two classes of UM, which can be discriminated by the chromosome 3 status or global mRNA expression profile. Metastatic progression is predominantly originated from class II tumors or from tumors showing loss of an entire chromosome 3 (monosomy 3). We performed detailed EFS (embryonal Fyn-associated substrate) methylation analyses in UM, cultured uveal melanocytes and normal tissues, to explore the role of the differentially methylated EFS promoter region CpG island in tumor classification and metastatic progression. METHODS: EFS methylation was determined by direct sequencing of PCR products from bisulfite-treated DNA or by sequence analysis of individual cloned PCR products. The results were associated with clinical features of tumors and tumor-related death of patients. RESULTS: Analysis of 16 UM showed full methylation of the EFS CpG island in 8 (50%), no methylation in 5 (31%) and partial methylation in 3 (19%) tumors. Kaplan-Meier analysis revealed a higher risk of metastatic progression for tumors with EFS methylation (p = 0.02). This correlation was confirmed in an independent set of 24 randomly chosen tumors. Notably, only UM with EFS methylation gave rise to metastases. Real-time quantitative RT-PCR expression analysis revealed a significant inverse correlation of EFS mRNA expression with EFS methylation in UM. We further found that EFS methylation is tissue-specific with full methylation in peripheral blood cells, and no methylation in sperm, cultured primary fibroblasts and fetal muscle, kidney and brain. Adult brain samples, cultured melanocytes from the uveal tract, fetal liver and 3 of 4 buccal swab samples showed partial methylation. EFS methylation always affects both alleles in normal and tumor samples. CONCLUSIONS: Biallelic EFS methylation is likely to be the result of a site-directed methylation mechanism. Based on partial methylation as observed in cultured melanocytes we hypothesize that there might be methylated and unmethylated precursor cells located in the uveal tract. The EFS methylation of a UM may depend on which type of precursor cell the tumor originated from.

SUBMITTER: Neumann LC

PROVIDER: S-EPMC3175225 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature

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EFS shows biallelic methylation in uveal melanoma with poor prognosis as well as tissue-specific methylation.

Neumann Lisa C LC Weinhäusel Andreas A Thomas Stefanie S Horsthemke Bernhard B Lohmann Dietmar R DR Zeschnigk Michael M

BMC cancer 20110826

<h4>Background</h4>Uveal melanoma (UM) is a rare eye tumor. There are two classes of UM, which can be discriminated by the chromosome 3 status or global mRNA expression profile. Metastatic progression is predominantly originated from class II tumors or from tumors showing loss of an entire chromosome 3 (monosomy 3). We performed detailed EFS (embryonal Fyn-associated substrate) methylation analyses in UM, cultured uveal melanocytes and normal tissues, to explore the role of the differentially me ...[more]

PMID: 21871071

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Project description:Fatty acid-binding protein 5 (FABP5), which participates in mediating the biological properties of tumor cells, has been recognized in several neoplasms. The present study aims to investigate FABP5 transcriptional expression profiles, reveal its underlying biological interaction networks and define its prognostic value in uveal melanoma (UVM). A total of 80 patients with UVM and their RNA-sequence data, available from The Cancer Genome Atlas (TCGA) database, was analyzed. A differential transcriptional expression profile was obtained from TCGA and the Oncomine databases. The survival benefits were analyzed using the Kaplan-Meier method and log-rank test. The correlation between FABP5 expression and immune infiltration level was analyzed using the Tumor Immune Estimation Resource database. Functional enrichment analyses using Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and signaling hallmarks were utilized to describe the biological process, molecular functions, cellular component and significantly involved pathways. The elevated transcriptional expression of FABP5 was significantly associated with shorter overall survival (OS) and worse progression-free survival (PFS) times in patients with UVM (P<0.001). Moreover, FABP5 expression was significantly and positively correlated with tumor purity and CD8+ T cells and was negatively correlated with the infiltrating levels of CD4+ T cells and neutrophils. Gene Set Enrichment Analysis was performed to obtain 100 significantly associated genes of FABP5 and FABP5 was found to be critical in several hallmark pathways, including allograft rejection, complement, interleukin-6/Janus kinase-STAT3 signaling, interferon γ response, inflammatory response and tumor necrosis factor α signaling via NFκB. The present study is the first to demonstrate that FABP5 expression was positively associated with progression-associated clinicopathological factors and poor prognosis in UVM, which suggests its likely function as an oncogene and prognostic marker in patients with UVM.

Dataset Information

EFS shows biallelic methylation in uveal melanoma with poor prognosis as well as tissue-specific methylation.

Publications

EFS shows biallelic methylation in uveal melanoma with poor prognosis as well as tissue-specific methylation.

Similar Datasets

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