Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2006-3-7
pubmed:abstractText
Death-associated protein kinase (DAPK) is a Ca/calmodulin-regulated serine/threonine kinase and a positive mediator of apoptosis. Loss of expression of the DAPK gene by aberrant promoter methylation may play an important role in cancer development and progression. The aim of this study was to investigate the frequency of gene promoter methylation of DAPK in nasopharyngeal carcinoma (NPC) and the effect of 5-Aza-2'-deoxycytidine (5-Aza-CdR), a demethylating agent, on CNE cells, a human nasopharyngeal carcinoma cell line, and on xenografts of CNE cells. Methylation-specific PCR and RT-PCR were used to determine the promoter methylation status and mRNA expression of the DAPK gene in NPC. Furthermore, CNE cells were treated in vitro and in vivo with 5-Aza-CdR to explore the effect of demethylating agents on DAPK mRNA expression and tumor growth. Hypermethylation of the DAPK gene promoter was found in 35 (76.1%) of 46 NPC samples. There was no significant difference in the promoter hypermethylation rate among samples from patients with different TNM stages. No promoter hypermethylation of the DAPK gene was found in all six chronic inflammatory nasopharyngeal tissue specimens. DAPK mRNA expression was not detected in NPC tumor specimens with promoter hypermethylation. However, DAPK mRNA expression was observed in unmethylated NPC tumors and in the chronic inflammatory nasopharyngeal tissue specimens. Promoter hypermethylation of the DAPK gene was found and no DAPK mRNA expression was detected in CNE cells. DAPK mRNA expression in CNE cells and xenografts could be restored by treatment with 5-Aza-CdR. The CNE cell xenografts of nude mice treated with 5-Aza-CdR were obviously smaller in tumor volume than those of nude mice treated with PBS. These results demonstrate that loss of DAPK expression could be associated with promoter region methylation in NPC. 5-Aza-CdR may slow the growth of CNE cells in vitro and in vivo by reactivating the DAPK gene silenced by de novo methylation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0959-4973
pubmed:author
pubmed:issnType
Print
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
251-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:16520653-Adult, pubmed-meshheading:16520653-Aged, pubmed-meshheading:16520653-Animals, pubmed-meshheading:16520653-Apoptosis Regulatory Proteins, pubmed-meshheading:16520653-Azacitidine, pubmed-meshheading:16520653-Base Sequence, pubmed-meshheading:16520653-Calcium-Calmodulin-Dependent Protein Kinases, pubmed-meshheading:16520653-Cell Cycle, pubmed-meshheading:16520653-Cell Growth Processes, pubmed-meshheading:16520653-Cell Line, Tumor, pubmed-meshheading:16520653-DNA Methylation, pubmed-meshheading:16520653-Female, pubmed-meshheading:16520653-Gene Silencing, pubmed-meshheading:16520653-Humans, pubmed-meshheading:16520653-Male, pubmed-meshheading:16520653-Mice, pubmed-meshheading:16520653-Mice, Inbred BALB C, pubmed-meshheading:16520653-Mice, Nude, pubmed-meshheading:16520653-Middle Aged, pubmed-meshheading:16520653-Molecular Sequence Data, pubmed-meshheading:16520653-Nasopharyngeal Neoplasms, pubmed-meshheading:16520653-Polymerase Chain Reaction, pubmed-meshheading:16520653-Promoter Regions, Genetic, pubmed-meshheading:16520653-RNA, Messenger, pubmed-meshheading:16520653-Xenograft Model Antitumor Assays
pubmed:year
2006
pubmed:articleTitle
Effect of methylation-associated silencing of the death-associated protein kinase gene on nasopharyngeal carcinoma.
pubmed:affiliation
Department of Otolaryngology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. wjkong666@yahoo.com
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't