Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Transcription profiling of Renal Cell carcinoma cell lines following global de-methylation.

ABSTRACT: Promoter region hypermethylation and transcriptional silencing is a frequent cause of tumour suppressor gene (TSG) inactivation in many types of human cancers. Functional epigenetic studies, in which gene expression is induced by treatment with demethylating agents, may identify novel genes with tumour-specific methylation. We used high-density gene expression microarrays in a functional epigenetic study of 11 renal cell carcinoma (RCC) cell lines. Twenty eight genes were then selected for analysis of promoter methylation status in cell lines and primary RCC. Eight genes (BNC1, PDLIM4/RIL, REPRIMORPRM, CST6, SFRP1, GREM1, COL14A1 and COL15A1) demonstrated frequent (>30% of RCC tested) tumour-specific promoter region methylation. Hypermethylation was associated with transcriptional silencing. Re-expression of BNC1, CST6, RPRM, and SFRP1 suppressed the growth of RCC cell lines. Whereas, RNAi-knock-down of BNC1, SFRP1 and COL14A1 increased the growth potential of RCC cell lines. Methylation of BNC1 or COL14A1 was associated with a poorer prognosis independent of tumour size, stage or grade. The identification of these epigenetically inactivated candidate RCC tumour suppressor genes can provide insights into renal tumourigenesis and a basis for developing novel therapies and biomarkers for prognosis and detection. We used expression microarrays to identified genes that were frequently methylated and silenced in RCC by determining the globlal expression patterns of RCC-derived cell lines following de-methylation by treatment with 5-Aza-2'-deoxycytidine.

ORGANISM(S): Homo sapiens

SUBMITTER: Mark Morris

PROVIDER: E-GEOD-22563 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Publications

Identification of candidate tumour suppressor genes frequently methylated in renal cell carcinoma.

Morris M R MR Ricketts C C Gentle D D Abdulrahman M M Clarke N N Brown M M Kishida T T Yao M M Latif F F Maher E R ER

Oncogene 20100215 14

Promoter region hyermethylation and transcriptional silencing is a frequent cause of tumour suppressor gene (TSG) inactivation in many types of human cancers. Functional epigenetic studies, in which gene expression is induced by treatment with demethylating agents, may identify novel genes with tumour-specific methylation. We used high-density gene expression microarrays in a functional epigenetic study of 11 renal cell carcinoma (RCC) cell lines. Twenty-eight genes were then selected for analys ...[more]

PMID: 20154727

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Project description:Abstract; Background: Promoter hypermethylation coupled with loss of heterozygosity at the same locus results in loss of gene function in many tumor cells. The ârulesâ governing which genes are methylated during the pathogenesis of individual cancers, how specific methylation profiles are initially established, or what determines tumor-type specific methylation are unknown. However, DNA methylation markers that are highly specific and sensitive for common tumors would be useful for the early detection of cancer, and those required for the malignant phenotype identify pathways important as therapeutic targets. Methods and Findings: In an effort to identify new cancer-specific methylation markers, we employed a high throughput global expression profiling approach in lung cancer cells. We identified 132 genes that have 5â CpG islands, are induced from undetectable levels by 5-aza-2â-deoxycytidine (5-aza) in multiple non-small cell lung cancer cell lines, and are expressed in immortalized human bronchial epithelial cells. As expected, these genes were also expressed in normal lung, but often not in companion primary lung cancers. Methylation analysis of a subset (45/132) of these promoter regions in primary lung cancer (N=20) and adjacent non-malignant tissue showed that 31 genes had acquired methylation in the tumors, but did not show methylation in normal lung or lymphocytes. We studied the eight most frequently and specifically methylated genes from our lung cancer data set in breast cancer (N=37), colon cancer (N=24), and prostate cancer (N=24) along with counterpart non-malignant tissues. We found that seven loci were frequently methylated in both breast and lung cancers, with four showing extensive methylation in all four epithelial tumors. Conclusions: By using a systematic biological screen we identified multiple genes that are methylated with high penetrance in primary lung, breast, colon, and prostate cancers. The cross-tumor methylation pattern we observed for these novel markers suggests that we have identified a partial promoter hypermethylation signature for these common malignancies. These data suggest that while tumors in different tissues vary substantially with respect to gene expression, there may be commonalities in their promoter methylation profiles that represent potential targets for early detection screening or therapeutic intervention. Experiment Overall Design: Drug treatment: control, 100 nM, 1 uM Experiment Overall Design: Cancer vs. Normal Comparison: NSCLC vs. Normal

Project description:BACKGROUND: Promoter hypermethylation coupled with loss of heterozygosity at the same locus results in loss of gene function in many tumor cells. The "rules" governing which genes are methylated during the pathogenesis of individual cancers, how specific methylation profiles are initially established, or what determines tumor type-specific methylation are unknown. However, DNA methylation markers that are highly specific and sensitive for common tumors would be useful for the early detection of cancer, and those required for the malignant phenotype would identify pathways important as therapeutic targets. METHODS AND FINDINGS: In an effort to identify new cancer-specific methylation markers, we employed a high-throughput global expression profiling approach in lung cancer cells. We identified 132 genes that have 5' CpG islands, are induced from undetectable levels by 5-aza-2'-deoxycytidine in multiple non-small cell lung cancer cell lines, and are expressed in immortalized human bronchial epithelial cells. As expected, these genes were also expressed in normal lung, but often not in companion primary lung cancers. Methylation analysis of a subset (45/132) of these promoter regions in primary lung cancer (n = 20) and adjacent nonmalignant tissue (n = 20) showed that 31 genes had acquired methylation in the tumors, but did not show methylation in normal lung or peripheral blood cells. We studied the eight most frequently and specifically methylated genes from our lung cancer dataset in breast cancer (n = 37), colon cancer (n = 24), and prostate cancer (n = 24) along with counterpart nonmalignant tissues. We found that seven loci were frequently methylated in both breast and lung cancers, with four showing extensive methylation in all four epithelial tumors. CONCLUSIONS: By using a systematic biological screen we identified multiple genes that are methylated with high penetrance in primary lung, breast, colon, and prostate cancers. The cross-tumor methylation pattern we observed for these novel markers suggests that we have identified a partial promoter hypermethylation signature for these common malignancies. These data suggest that while tumors in different tissues vary substantially with respect to gene expression, there may be commonalities in their promoter methylation profiles that represent targets for early detection screening or therapeutic intervention. Experiment Overall Design: We compared the gene expression changes HBEC and NSCLC cells before and after treatment with 5-aza-2'deoxycytidine.

Project description:Subpopulations of primary Human Mammary Epithelial Cells (HMEC) have the unique ability to escape a period of growth arrest and continue to proliferate. These cells, called post-selection or variant cells (vHMEC), share features with premalignant breast cancer lesions, including p16INK4A promoter hypermethylation. Epigenetic silencing of tumour suppressor genes through DNA methylation and histone modification is an early event in tumorigenesis. One of the main challenges is to find genes or gene pathways that are commonly silenced to provide early epigenetic diagnostic and therapeutic cancer targets. To identify very early epigenetic events that occur in breast cancer, we used microarrays to screen for gene pathways that were suppressed in post-selection HMECs, but reactivated after treatment with the demethylation agent 5-Aza-2â-deoxycytidine (5-Aza-dC). We found several members of the Transforming Growth Factor Beta (TGFb) signalling pathway (THBS1, TGFb2, TGFb R1 & TGFb R2) were consistently down-regulated in the post-selection HMEC population. Gene suppression was not associated with DNA methylation but was associated with chromatin remodelling, involving a decrease in histone H3 lysine 27 (H3K27) tri-methylation and an increase in histone H3 lysine 9 (H3K9) di-methylation and H3K9 de-acetylation. Similar epigenetic repression was also identified MDAMB453 breast cancer cells and in breast tumour samples. These results demonstrate for the first time that TGFb2, its receptors TGFb R1 & TGFb R2 and activator THBS1 are concordantly suppressed early in breast carcinogenesis by repressive histone modifications and indicate that the TGFb signalling pathway is a novel target for gene activation by epigenetic therapy. Keywords: cell differentiation, breast cancer, gene silencing, epigenetics Two-colour reference design was used. Two biological replicates were included in the study - Bre60 and Bre-80. Each cell line was sampled at pre-selection stage, post-selection stage and post AZA treatment. The post-selection stage was chosen as the reference sample, and a control post-post hybridisation included to assess variability across the assay.

Project description:Mantle cell lymphoma (MCL) is an aggressive B-cell non-HodgkinM-bM-^@M-^Ys lymphoma (NHL). In cancers, tumour suppressive microRNAs may be silenced by DNA hypermethylation. By microRNA profiling, miR-155-3p was significantly upregulated upon demethylation treatment of MCL cell lines with 5-aza-2M-bM-^@M-^Y-deoxycytidine (5-azadC). Methylation-specific PCR, verified by pyrosequencing, showed complete methylation of miR-155-3p in one MCL cell line (REC-1). 5-azadC treatment of REC-1 led to demethylation and re-expression of miR-155-3p. Over-expression of miR-155-3p led to increased sub-G1 apoptotic cells and reduced cellular viability, demonstrating its tumour suppressive properties. By luciferase assay, lymphotoxin-beta (LT-M-NM-2) was validated as a miR-155-3p target. In 31 primary MCL, miR-155-3p was found hypermethylated in 6(19%) cases. To test if methylation of miR-155-3p was MCL-specific, miR-155-3p methylation was tested in an additional 191 B-cell, T-cell and NK-cell NHLs, yielding miR-155-3p methylation in 66(34.6%) including 36(27%) non-MCL B-cell, 24(53%) T-cell and 6(46%) of NK-cell lymphoma. Moreover, in 72 primary NHL samples with RNA, miR-155-3p methylation correlated with miR-155-3p downregulation (p=0.030), and LT-M-NM-2 upregulation (p=0.004). Collectively, miR-155-3p is tumour suppressive microRNA hypermethylated in MCL and other NHL subtypes. As miR-155-3p targets LT-M-NM-2, which is an upstream activator of the non-canonical NF-kB signalling, miR-155-3p methylation is potentially important in lymphomagenesis Total RNA isolated from MINO and JEKO-1 before and after 5-azadC treatment were converted into cDNA by MegaplexTM RT Primers and TaqManM-BM-. MicroRNA Reverse Transcription Kit. cDNA was pre-amplified using MegaplexTM PreAmp Primer and loaded onto 384-well format TaqmanM-BM-. human microRNA array A V2.0 & B V3.0. Real-time PCR was performed on 7900HT Real-Time PCR system and raw data were analyzed normalizing to mean of three endogenous controls (U6snRNA, RNU44 and RNU48). Relative microRNA levels were determined by M-NM-^TM-NM-^TCt using endogenous controls and untreated controls using SDS 2.4 and RQ manager 1.2. All experimental procedures and analyses were performed according to manufacturerM-bM-^@M-^Ys instruction, using reagents, system and softwares acquired from Applied Biosystems (Foster City, USA).

Dataset Information

Transcription profiling of Renal Cell carcinoma cell lines following global de-methylation.

Publications

Identification of candidate tumour suppressor genes frequently methylated in renal cell carcinoma.

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