PMID- 16094112
OWN - NLM
STAT- MEDLINE
DCOM- 20050901
LR  - 20131121
IS  - 0023-852X (Print)
IS  - 0023-852X (Linking)
VI  - 115
IP  - 8
DP  - 2005 Aug
TI  - Methylation-associated silencing of death-associated protein kinase gene in 
      laryngeal squamous cell cancer.
PG  - 1395-401
AB  - OBJECTIVES/HYPOTHESIS: Death-associated protein kinase (DAPK) is a 
      Ca/calmodulin-regulated Ser/Thr kinase that functions as a positive mediator of 
      programmed cell death. It has been found that DAPK gene is frequently inactivated 
      by its promoter hypermethylation in some cancers and tumor cell lines. However, 
      it is not clear whether promoter hypermethylation of DAPK gene exists in 
      laryngeal squamous cell cancer (LSCC). The aim of this study was to investigate 
      the promoter methylation status of the DAPK gene in LSCC and the effect of 
      5-Aza-2'-deoxycytidine (5-Aza-CdR), a demethylating agent, on Hep-2 cells, a 
      human laryngeal cancer cell line, and on xenografts of Hep-2. METHODS: 
      Methylation-specific polymerase chain reaction (PCR) and reverse-transcription 
      PCR techniques were used to determine the promoter methylation status and mRNA 
      expression of DAPK gene in LSCC. Furthermore, Hep-2 cells in vitro and in vivo 
      were treated by 5-Aza-CdR to explore the effect of demethylating agents on DAPK 
      mRNA expression and tumor growth. RESULTS: Hypermethylation of DAPK gene promoter 
      was found in 39 (67.2%) of 58 LSCC samples. There was no significant difference 
      in the promoter hypermethylation rate among the samples of different histologic 
      grades or samples from patients with different T stages. However, there was 
      significant difference in methylation status of DAPK gene between the samples 
      from patients in N0 stages and those from patients in N1 stages. No promoter 
      hypermethylation of DAPK gene was found in any of the five normal laryngeal 
      tissue samples. DAPK mRNA expression was not detected in tumor specimens with 
      promoter hypermethylation. On the contrary, DAPK mRNA expression was observed in 
      the unmethylated tumor specimens, specimens from tissues adjacent to the tumor, 
      and normal laryngeal tissues samples. Promoter hypermethylation of DAPK gene was 
      found, and no DAPK mRNA expression was detected in Hep-2 cells. DAPK mRNA 
      expression in Hep-2 cells and xenografts could be restored by treating cells and 
      xenografts with 5-Aza-CdR. The tumors' xenografts, induced by way of Hep-2 cell 
      injection in nude mice treated with 5-Aza-CdR, were obviously smaller than those 
      in nude mice treated with phosphate-buffered saline. CONCLUSIONS: Abnormal loss 
      of DAPK expression could be associated with aberrant promoter region methylation 
      in the LSCC. 5-Aza-CdR may slow the growth of Hep-2 cells in vitro and in vivo by 
      reactivating tumor suppressor gene DAPK silenced by de novo methylation.
FAU - Kong, Wei-Jia
AU  - Kong WJ
AD  - Department of Otolaryngology, Union Hospital of Tongji Medical College, Huazhong 
      University of Science and Technology, 1277 Jiefang Dadao Avenue, Wuhan, Hubei 
      430-022, China. wjkong888@yahoo.com
FAU - Zhang, Song
AU  - Zhang S
FAU - Guo, Changkai
AU  - Guo C
FAU - Zhang, Sulin
AU  - Zhang S
FAU - Wang, Yanjun
AU  - Wang Y
FAU - Zhang, Dan
AU  - Zhang D
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Laryngoscope
JT  - The Laryngoscope
JID - 8607378
RN  - 0 (RNA, Messenger)
RN  - EC 2.7.- (Protein Kinases)
RN  - M801H13NRU (Azacitidine)
SB  - IM
CIN - Laryngoscope. 2006 Jan;116(1):161-2; author reply 162-3. PMID: 16481834
MH  - Adult
MH  - Aged
MH  - Animals
MH  - Azacitidine/*pharmacology
MH  - Carcinoma, Squamous Cell/*genetics/pathology
MH  - Case-Control Studies
MH  - Cell Death/*drug effects
MH  - Cell Line, Tumor/cytology/*drug effects
MH  - DNA Methylation
MH  - Female
MH  - Gene Expression Regulation, Neoplastic
MH  - Gene Silencing
MH  - Humans
MH  - Laryngeal Neoplasms/*genetics/pathology
MH  - Male
MH  - Mice
MH  - Mice, Nude
MH  - Middle Aged
MH  - Polymerase Chain Reaction/methods
MH  - Promoter Regions, Genetic
MH  - Protein Kinases/*genetics
MH  - RNA, Messenger/analysis
MH  - Reference Values
MH  - Sampling Studies
MH  - Sensitivity and Specificity
MH  - Transplantation, Heterologous
EDAT- 2005/08/12 09:00
MHDA- 2005/09/02 09:00
CRDT- 2005/08/12 09:00
PHST- 2005/08/12 09:00 [pubmed]
PHST- 2005/09/02 09:00 [medline]
PHST- 2005/08/12 09:00 [entrez]
AID - 00005537-200508000-00012 [pii]
AID - 10.1097/01.MLG.0000166708.23673.3A [doi]
PST - ppublish
SO  - Laryngoscope. 2005 Aug;115(8):1395-401. doi: 10.1097/01.MLG.0000166708.23673.3A.