Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.1.1.37 (DNA methyltransferase)
 4,983 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The DNA methylation status of the metastasis-associated S100A4 gene in S100A4-positive and -negative human colon adenocarcinoma cell lines was examined. Northern and Western blot analyses revealed that HT-29, SW480, SW620, WiDr and Colo201 cells expressed S100A4, whereas SW837, LoVo and DLD-1 cells expressed little S100A4. Using CpG methylation-sensitive and -insensitive restriction enzymes and PCR-based methylation assay, it was found that the S100A4 gene in HT-29, SW480, SW620, WiDr and Colo201 cells, but not in SW837, LoVo and DLD-1 cells, was hypomethylated and that the hypomethylation of the second intron was correlated well with the expression of S100A4. 5-Aza-2'-deoxycytidine, an inhibitor of the eukaryotic DNA methyltransferase, induced the expression of the S100A4 gene in SW837, LoVo and DLD-1 cells, while it showed no effect on the expression of the gene in WiDr cells. These results indicate that hypomethylation of the S100A4 gene results in the expression of the gene in colon adenocarcinoma cells.
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PMID:Hypomethylation of the metastasis-associated S100A4 gene correlates with gene activation in human colon adenocarcinoma cell lines. 1009 42

Deregulated expression of genes encoding members of the S100 family of calcium-binding proteins has been associated with the malignant progression of multiple tumour types. Using a pharmacological expression reactivation approach, we screened 16 S100 genes for evidence of epigenetic regulation in medulloblastoma, the most common malignant brain tumour of childhood. Four family members (S100A2, S100A4, S100A6 and S100A10) demonstrated evidence of upregulated expression in multiple medulloblastoma cell lines, following treatment with the DNA methyltransferase inhibitor, 5'-aza-2'-deoxycytidine. Subsequent analysis revealed methylation of critical CpG sites located within these four genes in an extended cell line panel. Assessment of these genes in the non-neoplastic cerebellum (from which medulloblastomas develop) revealed strong somatic methylation affecting S100A2 and S100A4, whereas S100A6 and S100A10 were unmethylated. Assessed against these normal tissue-specific methylation states, S100A6 and S100A10 demonstrated tumour-specific hypermethylation in medulloblastoma primary tumours (5 out of 40 and 4 out of 35, respectively, both 12%) and cell lines (both 7 out of 9, 78%), which was associated with their transcriptional silencing. Moreover, S100A6 hypermethylation was significantly associated with the aggressive large cell/anaplastic morphophenotype (P=0.026). In contrast, pro-metastatic S100A4 displayed evidence of hypomethylation relative to the normal cerebellum in a significant proportion primary tumours (7 out of 41, 17%) and cell lines (3 out of 9, 33%), which was associated with its elevated expression. In summary, these data characterise complex patterns of somatic methylation affecting S100 genes in the normal cerebellum and demonstrate their disruption causing epigenetic deregulation of multiple S100 family members in medulloblastoma development. Epigenetic events affecting S100 genes have potential clinical utility and merit further investigation as molecular biomarkers for this disease.
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PMID:Epigenetic deregulation of multiple S100 gene family members by differential hypomethylation and hypermethylation events in medulloblastoma. 1757 22

Microarray analysis of paired cultures of normal and cancerous urothelial cells revealed differences in cytokeratin and adhesion gene expression. Normal cells expressed autocrine growth factor genes more strongly whereas carcinoma cells were distinguished by concomitant expression of urothelial and epidermal differentiation markers. Expression of SNCG, S100A9 and LCN2 was also enhanced. In other cancers, overexpression of SNCG, LCN2 and S100A4 has been ascribed to DNA hypomethylation. We therefore investigated expression and methylation of SNCG, S100A4, S100A9 and LCN2 in urothelial cancer cell lines and tissues. SNCG and S100A4 were overexpressed in some cancer tissues and cell lines, but downregulated in others, whereas LCN2 and S100A9 were upregulated in few cancer cell lines, but regularly in tissues. Normal and cancerous urothelial cells expressing SNCG lacked promoter methylation. SNCG downregulation was associated with hypermethylation and could be reversed by the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine. S100A4 methylation at regulatory intronic sites and in the promoter region was lowest in leukocytes and fibroblasts, and denser in urothelial cells. Gene expression responded to 5-aza-2'-deoxycytidine. LCN2 promoter methylation was variable and even less consistently related to expression. The S100A9 promoter was partially methylated in nonexpressing cells, but 5-aza-2'-deoxycytidine had no effect. Our data indicate that SNCG methylation is cell type-specific and the gene is hypermethylated in some urothelial cancers. S100A4, S100A9 and LCN2 are genes with moderate CpG-density that show a less stringent relationship between DNA methylation and gene expression. Therefore, changes in methylation of these genes in cancer should be interpreted cautiously.
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PMID:Relationship of SNCG, S100A4, S100A9 and LCN2 gene expression and DNA methylation in bladder cancer. 1880 90

The hepatitis B virus-encoded X (HBx) protein coactivates transcription of a variety of viral and cellular genes and it is believed to play essential roles in viral replication and hepatocarcinogenesis. To examine the pleiotropic effects of HBx protein on host cell protein expression, we utilized 2-DE and MS analysis to compare and identify differentially expressed proteins between a stable HBx-transfected cell line (HepG2-HBx), constitutively expressing HBx, and vector control cells. Of the 60 spots identified as differentially expressed (+/- over 2-fold, p < 0.05) between the two cell lines, 54 spots were positively identified by MS/MS analysis. Several recent studies suggested that HBx was involved in regional hypermethylation of tumor suppressor genes and global hypomethylation of satellite 2 repeats during hepatocarcinogenesis; however, no specific gene has been reported as hypomethylated by HBx. Promoter methylation analysis was examined for those protein spots showing significant alterations, and our results revealed that specific genes, such as aldehyde dehydrogenase 1 (ALDH1), can be hypomethylated by HBx, and two calcium ion-binding proteins, S100A6 and S100A4, were hypermethylated by HBx and could be re-expressed by AZA (DNA methylase inhibitor) treatment. Moreover, via cluster and pathway analysis, we proposed a hypothetical model for the HBx regulatory circuit involving aberrant methylation of retinol metabolism-related genes and calcium homeostasis-related genes. In summary, we profiled proteome alterations between HepG2-HBx and control cells, and found that HBx not only induces regional hypermethylation but also specific hypomethylation of host cell genes.
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PMID:Proteomic profiling identifies aberrant epigenetic modifications induced by hepatitis B virus X protein. 1911 5

The present study aimed to identify genes related to 5AZA-CdR in laryngeal squamous cell carcinoma (LSCC) and to investigate the role of S100A4 in the development and aggression of LSCC. Differentially expressed proteins were identified in Hep-2 cells treated with 5AZA-CdR by two-dimensional gel electrophoresis combined with MALDI-TOF-MS. mRNA, protein levels and DNA methylation status of S100A4 were assessed by RT-PCR, Western blotting and methylation-specific PCR, respectively. The invasiveness of Hep-2 cells transfected by siRNA S100A4 was determined by transwell migration assay. Protein profiles from Hep-2 cells treated with 5AZA-CdR were obtained, and several differentially expressed proteins such as S100 calcium-binding protein A4 (S100A4) were identified. Results of RT-PCR and Western blotting revealed that both mRNA and protein levels of S100A4 were significantly higher in the metastatic lymph nodes than those in paired adjacent normal laryngeal (PANL) or tumor tissues. The DNA methylation status displayed significant differences between the LSCC and the PANL tissues. The expression level of S100A4 decreased in Hep-2 cells undergoing RNA interference of S100A4. The number of cells which crossed the basement membrane filter was significantly lower in the RNAi S100A4 group when compared with the number in the control group. The abnormal expression of S100A4 identified in Hep-2 cells treated with an inhibitor of DNA methyltransferase appeared to result from the aberrant DNA methylation status of S100A4. The abnormal expression of S100A4 altered the invasiveness of LSCC.
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PMID:Hypomethylation-induced expression of S100A4 increases the invasiveness of laryngeal squamous cell carcinoma. 2020 97

A hallmark of cancer is aberrant DNA methylation, consisting of global hypomethylation and regional hypermethylation of tumor suppressor genes. DNA methyltransferase inhibitors have been recognized as promising candidate anticancer drugs. Drug development has focused on DNA methylation inhibitors with the goal of activating tumor suppressor genes silenced by DNA methylation. 5-azacytidine (5-AC; Vidaza), a global DNA methyltransferase inhibitor, was Food and Drug Administration approved to treat myelodysplastic syndromes and is clinically tested for solid tumors. In this paper, it was demonstrated that 5'-aza-2'-deoxycytidine (5-azaCdR) activated both silenced tumor suppressor genes and pro-metastatic genes by demethylation, raising the concern that it would promote metastasis. 5-AzaCdR treatment increased the invasiveness of non-invasive breast cancer cell lines MCF-7 cells and ZR-75-1 and dramatically induced pro-metastatic genes; Urokinase plasminogen activator (uPA), matrix metalloproteinase 2 (MMP2), metastasis-associated gene (H-MTS1; S100A4) and C-X-C chemokine receptor 4 (CXCR4). The hypothesis that the blocking of cellular transformation activity of DNA methyltransferase inhibitor could be separated from the pro-metastatic activity was tested using short interfering RNA (siRNA) targeted to the different DNA methyltransferase (DNMT) genes. Although depletion of DNMT1 had the strongest effect on colony growth suppression in cellular transformation assays, it did not result in demethylation and activation of uPA, S100A4, MMP2 and CXCR4 in MCF-7 cells. Depletion of DNMT1 did not induce cellular invasion in MCF-7 and ZR-75-1 non-invasive breast cancer cell lines. These data have implications on the design of new DNA methyltransferase inhibitor and on the proper utilization of current inhibitors.
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PMID:Effects of specific DNMT gene depletion on cancer cell transformation and breast cancer cell invasion; toward selective DNMT inhibitors. 2098 Mar 50