CGH analysis of melanomas and germline samples from Braf mutant mouse model
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ABSTRACT: We investigated copy number alterations in melanomas from two cohorts of Braf mutant mice (UV exposed and no UV exposure) by comparing tumour DNA to germline DNA by array CGH There were 15 tumour samples in each cohort (UV exposed and no UV exposure)
Project description:We investigated copy number alterations in melanomas from two cohorts of Braf mutant mice (UV exposed and no UV exposure) by comparing tumour DNA to germline DNA by array CGH
Project description:Investigating genome-wide characteristics of CNVs in 6 horses representing 6 distinct breeds by using the aCGH method and performed GO and KEGG analysis for the CNVs genes.This result is an important complement to the mapping of horse whole-genome CNVs and helpful to study plateau horsesM-bM-^@M-^Y adaption to the plateauM-bM-^@M-^Ys environment. Comparison Mongolia horse , Abaga horse, Hequ horse, Kazakh horse, Debao pony, Thoroughbred with Thoroughbred
Project description:Comparative genomic hybridization (CGH) analysis of androgenetic haploid embryonic stem cells was done with 129/Sv male mouse kidney genomic DNA as reference. The results revealed no consistent copy number variations (CNVs) among the examined cell lines (AH129-5, AH129-N1 and AH129-NC1), except for the global difference on the X chromosome to the male control. Genomic DNA of FACS sorted G0/G1 stage ahES cells was compared with 129/Sv male mouse kidney genomic DNA reference by the NimbleGen Mouse CGH 3x720K Whole-Genome Tiling Array (Build MM9) [100718_MM9_WG_CGH_HX3]
Project description:The genomic DNA sample of AG-haESCs were compared to the C57BL/6J male mouse kidney by comparative genomic hybridization. The data confirmed that the haploid cells sustained genome integrity. The analysis was performed on a NimbleGen Mouse CGH 3x720K Whole-Genome Tiling Array to analyse the copy number variations in AG-haESCs, and the genomic DNA of C57BL/6J male mouse kidney was used as control, which had the same background with haploid ESCs.
Project description:The purpose of this study was to investigate the presence of a gene expression signature in BRAF V600E melanomas compared to wild type ones, all derived from sun-exposed sites. Microdissected tissues from excisional biopsies of 18 cutaneous melanomas were analyzed to detect the presence of BRAF and NRAS mutations and to profile whole genome expression by means of oligonucleotide microarrays. Class comparison methods were used to select differentially expressed genes between wild type and mutated lesions. Real Time RT-PCR and immunohistochemistry were applied to validate differences at the mRNA and protein levels on an independent cohort of samples. BRAF mutations were evidenced in 67% of melanomas. All of them consisted of the oncogenic change V600E (and the mutation event was independent of Clark's level). Data indicate that in V600E melanomas there is an over-expression of cancer stem cell markers and an upregulation of important oncogenes, like KRAS. This, together with the downregulation of genes involved in oxidative UV stress response and immuno system defense, confers an advantage to V600E melanomas compared to wt lesions. Moreover, the downregulation of topoisomerase I and CDKN2A results in an increased replicative potential associated with a decrease in senescence markers and a diminished DNA damage response. As far as the wild-type lesions, we interestingly pointed out the overexpression of PML, PIK3CA and the downregulation of two tumour suppressor genes (BRCA1 and TP73) relevant to DNA repair.
Project description:This SuperSeries is composed of the following subset Series: GSE35785: mRNA expression data from AG-haESC, E14 and MEF GSE35786: CGH analysis of AG-haESCs (androgenetic haploid embryonic stem cells) Refer to individual Series
Project description:We designed a microarray to test at exonic resolution for genomic imbalance for genes representative of all known chromosomal microdeletion/microduplication syndromes, all known causative genes for ID, all known genes encoding glutamate receptors and their known encoding proteins and all known genes encoding proteins with epigenetic regulatory function. We found 36 de novo copy number variants affecting 35 children in this study. 167 trios, each comprising an affected child and both its normal parents were analyzed by conducting two comparative hybridizations; child vs. mother and child vs. father, and only selecting a CNV if it appeared in both hybridizations, i.e., was de novo. De novo CNVs were independantly validated using quantitative PCR.
Project description:Through the analysis of mouse liver tumours promoted by distinct routes (DEN exposure alone, DEN exposure plus non-genotoxic insult with phenobarbital and non-alcoholic fatty liver disease); we report that the cancer associated hyper-methylated CGI events in mice are also predicated by silent promoters that are enriched for both the DNA modification 5-hydroxymethylcytosine (5hmC) and the histone modification H3K27me3 in normal liver. During cancer progression these CGIs undergo hypo-hydroxymethylation, prior to subsequent hyper-methylation; whilst retaining H3K27me3. A similar loss of promoter-core 5hmC is observed in Tet1 deficient mouse livers indicating that reduced Tet1 binding at CGIs may be responsible for the epigenetic dysregulation observed during hepatocarcinogenesis. Consistent with this reduced Tet1 protein levels are observed in mouse liver tumour lesions. As in human, DNA methylation changes at CGIs do not appear to be direct drivers of hepatocellular carcinoma progression in mice. Instead dynamic changes in H3K27me3 promoter deposition are strongly associated with tumour-specific activation and repression of transcription. Our data suggests that loss of promoter associated 5hmC in diverse liver tumours licences DNA methylation reprogramming at silent CGIs during cancer progression. 5-mc is a well establisehd epigenetic mark typically related to gene silencing events. Phenobarbital (PB) is a well studied non-genotoxic carcinogen with roles in epigenetic perturbation. We profile 5mC in both control mouse livers as well as in the livers of 12 week PB treated mice. We also profile 5mC in liver tumours arising in the presence of long term PB exposure (35 week: resulting in Ctnnb1 mutated tumours) to a Ha-Ras liver tumour which arose without PB. Samples: 2 control and 2 PB exposed mouse livers, 3 liver tumours resulting from long term PB exposrue and 1 liver tumour arising without PB
Project description:Through the analysis of mouse liver tumours promoted by distinct routes (DEN exposure alone, DEN exposure plus non-genotoxic insult with phenobarbital and non-alcoholic fatty liver disease); we report that the cancer associated hyper-methylated CGI events in mice are also predicated by silent promoters that are enriched for both the DNA modification 5-hydroxymethylcytosine (5hmC) and the histone modification H3K27me3 in normal liver. During cancer progression these CGIs undergo hypo-hydroxymethylation, prior to subsequent hyper-methylation; whilst retaining H3K27me3. A similar loss of promoter-core 5hmC is observed in Tet1 deficient mouse livers indicating that reduced Tet1 binding at CGIs may be responsible for the epigenetic dysregulation observed during hepatocarcinogenesis. Consistent with this reduced Tet1 protein levels are observed in mouse liver tumour lesions. As in human, DNA methylation changes at CGIs do not appear to be direct drivers of hepatocellular carcinoma progression in mice. Instead dynamic changes in H3K27me3 promoter deposition are strongly associated with tumour-specific activation and repression of transcription. Our data suggests that loss of promoter associated 5hmC in diverse liver tumours licences DNA methylation reprogramming at silent CGIs during cancer progression. 5-hmC is a novel epigenetic mark derived from oxidation of methylcytosine. Phenobarbital (PB) is a well studied non-genotoxic carcinogen with roles in epigenetic perturbation. We profile 5hmC in both control mouse livers as well as in the livers of 12 week PB treated mice. We also profile 5hmC in liver tumours arising in the presence of long term PB exposure (35 week: resulting in Ctnnb1 mutated tumours) to a Ha-Ras liver tumour which arose without PB. Samples: 5hmC profiles in 2 control and 2 PB exposed mouse livers, 3 liver tumours resulting from long term PB exposrue and 1 liver tumour arising without PB