Project description:Affimetrix Human Gene 1.1 ST Array profiling of 13 normal human cerebellum samples. Total RNA from 8 fetal brains and 5 adult brains was obtained from the Biochain company.
Project description:Pilocytic astrocytomas (PA) are the most common brain tumor in pediatric patients and can cause significant morbidity, including chronic neurological deficiencies. They are characterized by activating alterations in the mitogen-activated protein kinase (MAPK) pathway, but little else is known about their development. To further define their molecular development, we analysed the global DNA methylation profiles of 61 PAs and 6 normal cerebellum samples and integrated this data with transcriptome profiling. These data revealed two subgroups of PA that separate according to tumor location (infratentorial versus supratentorial), and identified key neural developmental genes that are differentially methylated between the two groups. Significant expression differences were identified for the majority of differentially methylated genes, and these were unexpectedly associated with a strong positive correlation between methylation and expression. We also identified a large number of differentially methylated/expressed genes between cerebellar PAs and normal cerebellum, which included additional developmental genes.
Project description:Pilocytic astrocytomas (PA) are the most common brain tumor in pediatric patients and can cause significant morbidity, including chronic neurological deficiencies. They are characterized by activating alterations in the mitogen-activated protein kinase (MAPK) pathway, but little else is known about their development. To further define their molecular development, we analysed the global DNA methylation profiles of 61 PAs and 6 normal cerebellum samples and integrated this data with transcriptome profiling. These data revealed two subgroups of PA that separate according to tumor location (infratentorial versus supratentorial), and identified key neural developmental genes that are differentially methylated between the two groups. Significant expression differences were identified for the majority of differentially methylated genes, and these were unexpectedly associated with a strong positive correlation between methylation and expression. We also identified a large number of differentially methylated/expressed genes between cerebellar PAs and normal cerebellum, which included additional developmental genes. Total RNA from 49 PA tumour samples and 9 normal cerebellum samples (from commercial sources) were hybridised to the Affymetrix HG U133 Plus 2.0 microarrays.
Project description:Pilocytic astrocytomas (PA) are the most common brain tumor in pediatric patients and can cause significant morbidity, including chronic neurological deficiencies. They are characterized by activating alterations in the mitogen-activated protein kinase (MAPK) pathway, but little else is known about their development. To map the global DNA methylation profiles of these tumors, we analysed 61 PAs and 6 normal cerebellum samples using Illumina's Infinium HumanMethylation450 BeadChips. These data revealed two subgroups of PA that separate according to tumor location (infratentorial versus supratentorial), and identified key neural developmental genes that are differentially methylated between the two groups. Integration with transcriptome microarray data highlighted significant expression differences, which were unexpectedly associated with a strong positive correlation between methylation and expression. Differentially methylated probes were often identified within the gene body and/or regions up- or downstream of the gene, rather than at the transcription start site. We also identified a large number of differentially methylated genes between cerebellar PAs and normal cerebellum, which included additional developmental genes.
Project description:Pilocytic astrocytomas (PA) are the most common brain tumor in pediatric patients and can cause significant morbidity, including chronic neurological deficiencies. They are characterized by activating alterations in the mitogen-activated protein kinase (MAPK) pathway, but little else is known about their development. To map the global DNA methylation profiles of these tumors, we analysed 61 PAs and 6 normal cerebellum samples using Illumina's Infinium HumanMethylation450 BeadChips. These data revealed two subgroups of PA that separate according to tumor location (infratentorial versus supratentorial), and identified key neural developmental genes that are differentially methylated between the two groups. Integration with transcriptome microarray data highlighted significant expression differences, which were unexpectedly associated with a strong positive correlation between methylation and expression. Differentially methylated probes were often identified within the gene body and/or regions up- or downstream of the gene, rather than at the transcription start site. We also identified a large number of differentially methylated genes between cerebellar PAs and normal cerebellum, which included additional developmental genes. Bisulphite converted DNA from 61 PA tumours (fresh frozen) and 6 normal cerebellum (from commerical sources) were hybridised to the Illumina Infinium HumanMethylation450 BeadChips.
Project description:We generated chimeric mice with livers that were predominantly repopulated with human hepatocytes. Hepatocytes were isolated from the chimeric mouse livers and their gene expressions were compared with hepatocytes isolated from normal human livers . Cluster and principal components analyses showed that gene expression profiles of hepatocytes from the chimeric mice and those from normal human livers were extremely closed. Additionally, we performed microarray experiments to examine gene expression in human tissues. This data was used for comparison with hepatocytes. A total of 22 tissues (bone marrow, cerebellum, colon, cortex, fetal brain, heart, kidney, liver, lung, pancreas, prostate, salivary gland, skeletal muscle, small intestine, spinal cord, spleen, stomach, testes, thymus, thyroid, trachea and uterus) were examined.