Project description:WHO classification for tumors of the central nervous system strongly endorses molecular tests for the precise diagnosis of diffuse gliomas. While alterations in the DNA methylation status of gliomas are already well documented and used in specialised clinical centers to distinguish between brain tumor entities, changes to the epigenetic layer at the level of histone modifications are only poorly characterised. Here, we applied a recently developed data-independent acquisition (DIA) - mass spectrometry method to generate a comprehensive histone epi-proteomic map that documents the abundance of almost all characterized and many uncharacterized histone modifications to a series of IDH-mutant oligodendroglioma and astrocytoma samples. Our analysis documented significant abundance differences in almost one-third of the 144 quantified histone peptides. Among them are lower abundance levels of the polycomb repressive mark H3K27me3 in oligodendroglioma samples compared to astrocytomas. We validated this finding by immunohistochemistry using the C36B11 antibody. Surprisingly, we observed inconsistencies with another widely applied H3K27me3 antibody (07-449), providing a warning flag for immunohistochemistry of brain cancers. An unbiased unsupervised clustering analysis of the proteomic dataset separated the two IDH-mutant glioma subtypes in full accordance to the EPIC DNA methylation classifier and the 1p/19q status. The clustering also revealed at least two histone epi-proteomic subgroups of oligodendroglioma, a feature not observable in the DNA methylation dataset. Our results indicate that histone epi-proteomic profiling at the depth of the current method has the capacity to identify clinically-relevant glioma sub-groups. In addition to being of use for diagnostic purposes, this could also provide novel insights in glioma biology and may identify new therapeutic targets.
Project description:In human, the 39 coding HOX genes and 18 referenced non-coding antisense transcripts are arranged in four genomic clusters named HOXA, B, C, and D. This highly conserved family belongs to the homeobox class of genes that encode transcription factors required for normal development. Therefore, HOX gene deregulation might contribute to the development of many cancer types. Here, we study HOX gene deregulation in adult glioma, a common type of primary brain tumor. We performed extensive molecular analysis of tumor samples, classified according to their isocitrate dehydrogenase (IDH1) gene mutation status, and of glioma stem cells. We found widespread expression of sense and antisense HOX transcripts only in aggressive (IDHwt) glioma samples, although the four HOX clusters displayed DNA hypermethylation. Integrative analysis of expression-, DNA methylation- and histone modification signatures along the clusters revealed that HOX gene upregulation relies on canonical and alternative bivalent CpG island promoters that escape hypermethylation. H3K27me3 loss at these promoters emerges as the main cause of widespread HOX gene upregulation in IDHwt glioma cell lines and tumors. Our study provides the first comprehensive description of the epigenetic changes at HOX clusters and their contribution to the transcriptional changes observed in adult glioma. It also identified putative "master" HOX proteins that might contribute to the tumorigenic potential of glioma stem cells.
Project description:CTCF ChIP-seq of 39 primary samples derived from human acute leukemias, namely AML, T-ALL and mixed myeloid/lymphoid leukemias with CpG Island Methylator Phenotype (CIMP). Due to patient confidentiality considerations, the raw data files for this dataset have been deposited to the EGA controlled-access archive under the accession numbers EGAS00001007094 (study); EGAD00001011059 (dataset).
Project description:Canine mammary gland tumors (CMTs) have been suggested as promising cancer models to human breast cancer due to their many biological and clinical similarities. Here, we collected 222 samples consist of 158 tumor samples and 64 matched normal samples of CMTs. Fresh tissue samples were transferred in to RNAlater, and refrigerated overnight at 4°C and then stored at -80°C. Total RNA was extracted from tissues using RNeasy mini kit. We aligned RNA-Seq raw data from 222 samples to canine reference genome CanFam3.1 using Tophat. We assembled transcript and calculated FPKM values using Cufflinks. All tumor samples were evaluated by histopathological characteristics including histopathological subtype, grade, and lymphatic invasion, and annotated with corresponding sequencing data. The histopathological classification and the histological grading system of CMTs were adopted from those of human breast cancer. In addition, immunohistochemical evaluation was performed in samples for estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) status. DISCLAIMER: Using this dataset became freely available on Jul 22, 2019. On the other hand, we are now preparing a key paper about comparative analysis of canine and human breast cancer based on this dataset. If you plan to submit a similar paper using this dataset before the main paper is published, please feel free to contact the submitter (swkim@yuhs.ac) to coordinate submission.
Project description:H3K27ac ChIP-seq of 79 primary samples derived from human acute leukemias, namely AML, T-ALL and mixed myeloid/lymphoid leukemias with CpG Island Methylator Phenotype (CIMP). In addition, 4 samples derived from CD34+ cord blood cells of healthy donors were included. Due to patient confidentiality considerations, the raw data files for this dataset have been deposited to the EGA controlled-access archive under the accession numbers EGAS00001007094 (study); EGAD00001011060 (dataset).