Project description:This SuperSeries is composed of the following subset Series: GSE35311: Integrative array-based approach identifies MZB1 as a frequently methylated putative tumor-suppressor in hepatocellular carcinoma (expression) GSE35312: Integrative array-based approach identifies MZB1 as a frequently methylated putative tumor-suppressor in hepatocellular carcinoma (MeDIP) Refer to individual Series
| E-GEOD-35313 | biostudies-arrayexpress
Project description:Integrative array-based approach identifies MZB1 as a frequently methylated putative tumor-suppressor in hepatocellular carcinoma
Project description:Silencing of tumor suppressor genes plays a vital role in head and neck carcinogenesis. Aberrant hypermethylation in the promoter region of some known or putative tumor suppressor genes (TSGs) occurs frequently during the development of various cancers including head and neck squamous cell carcinoma (HNSCC). In this study we used an expanded mRNA expression profiling approach followed by microarray expression analysis to identify epigenetically inactivated genes in HNSCC. Two HNSCC cell lines were treated with 5-aza-2’-deoxycytidine followed by microarray analysis to identify epigenetically silenced genes in HNSCC. 1960, 614, and 427 genes were upregulated in HNSCC cell lines JHU-012, JHU-011 and the combination of both cell lines, respectively. HNSCC tumor and normal mucosal samples were used for gene profiling by a 47K mRNA gene expression array and we found, 7140 genes were downregulated in HNSCC tumors compared to normal mucosa as determined by microarray analysis and were integrated with cell line data. Integrative analysis defined 126 candidate genes, of which only seven genes showed differentially methylation in tumors and no methylation in normal mucosa after bisulfite sequencing. After validation by QMSP, one gene, GNG7, was confirmed as being highly methylated in tumors and unmethylated in normal mucosal and salivary rinse samples demonstrating cancer-specific methylation in HNSCC tissues. TXNIP and TUSC2 were partially methylated in tumors and normal salivary rinses but unmethylated in normal mucosa. We concluded GNG7 as a highly specific promoter methylated gene associated with HNSCC. In addition, TXNIP and TUSC2 are also potential biomarkers for HNSCC.
Project description:The newly discovered 5-hydroxymethylcytosine (5hmC) may complicate previous observations of abnormal cytosine methylation statuses used for the identification of new tumor suppressor gene candidates relevant to human hepatocarcinogenesis. The simultaneous detection of 5mC and 5hmC will stimulate the discovery of aberrantly methylated genes with increased accuracy in human hepatocellular carcinoma (HCC). Here, we performed a newly developed single-base high-throughput sequencing approach (hydroxymethylation and methylation Sensitive Tag sequencing, HMST-seq) to synchronously measure these two modifications in HCC samples. After identifying the differentially methylated and hydroxymethylated genes in HCC, we integrated the DNA copy-number alterations as determined using array-based comparative genomic hybridization (aCGH) data with gene expression to identify genes potentially silenced by promoter hypermethylation. As a result, we report a high enrichment of genes with epigenetic aberrations in cancer signaling pathways. Six genes were selected as tumor suppressor gene (TSG) candidates, among which, ECM1, ATF5 and EOMES were confirmed to have potential anti-cancer function via siRNA experiments. To fully examine 5mC and 5hmC status in HCC, we used a newly developed single-base high-throughput sequencing approach (hydroxymethylation and methylation sensitive tag sequencing, HMST-seq) to synchronously measure these two modifications in HCC samples and their adjacent non-cancerous liver tissues (non-HCCs).
Project description:The newly discovered 5-hydroxymethylcytosine (5hmC) may complicate previous observations of abnormal cytosine methylation statuses used for the identification of new tumor suppressor gene candidates relevant to human hepatocarcinogenesis. The simultaneous detection of 5mC and 5hmC will stimulate the discovery of aberrantly methylated genes with increased accuracy in human hepatocellular carcinoma (HCC). Here, we performed a newly developed single-base high-throughput sequencing approach (hydroxymethylation and methylation Sensitive Tag sequencing, HMST-seq) to synchronously measure these two modifications in HCC samples. After identifying the differentially methylated and hydroxymethylated genes in HCC, we integrated the DNA copy-number alterations as determined using array-based comparative genomic hybridization (aCGH) data with gene expression to identify genes potentially silenced by promoter hypermethylation. As a result, we report a high enrichment of genes with epigenetic aberrations in cancer signaling pathways. Six genes were selected as tumor suppressor gene (TSG) candidates, among which, ECM1, ATF5 and EOMES were confirmed to have potential anti-cancer function via siRNA experiments.
Project description:Two major genetic pathways leading to colorectal carcinoma can well be distinguished; the ‘suppressor pathway’, which is characterized by inactivation of tumor-suppressor genes and the ‘mutator pathway’, which is characterized by microsatellite instability. The purpose of this study is to explore a third putative pathway; microsatellite and chromosome stable colorectal cancer where an alternative cancer-causative mechanism might play a role.
Project description:Genome wide expression profiling of 20 PDAC cell lines and an immortalized non-malignant pancreatic duct cell line (HPDE) to facilitate identification of novel tumor suppressor genes using an integrative genomics approach Genome wide expression profiling of 20 PDAC cell lines and an immortalized non-malignant pancreatic duct cell line (HPDE) to facilitate identification of novel tumor suppressor genes using an integrative genomics approach RNA from the 21 samples was converted to Cy3 labeled cRNA and hybridized to the array; arrays were processed with GenePix software and median array normalization was performed
Project description:BRCA-1 Associated Protein (BAP1) is a deubiquitinating enzyme that acts as a tumour suppressor. Inactivating mutations in the BAP1 gene have been identified in many cancers including cholangiocarcinoma, hepatocellular carcinoma, mesothelioma, uveal melanoma and renal cell carcinoma. Current standard therapeutic approaches for BAP1-deficient tumours are not particularly promising, contributing to poor overall survival and disease-free survival rates. Here, we found BAP1 to mediate the turnover of the key proteins in the DNA nucleotide excision repair (NER) pathway, and therefore promotes DNA repair. Importantly, we demonstrate that the loss of functional BAP1 sensitise tumour cells to LSD1 inhibitor, SP2509, in vitro and in vivo, through further impairment of NER efficiency. When used in combination with PARP1 inhibitor, Olaparib, we show that a synergistic drug combination response is achieved. Overall, our study identifies a drug combination approach that has the potential to be exploited clinically to target BAP1 deficient tumours.
Project description:Genomic and gene expression profiling identifies two major gene/genomic circuits operating in urothelial carcinoma 146 primary bladder cancer tumor samples were analyzed on BAC array containing ~32 000 BAC clones. Arrays were produced at the Swegene Centre for Integrative Biology at Lund University (SCIBLU).