[Study on promoter methylation status of E-cadherin gene in nasopharyngeal carcinoma cell lines].
OBJECTIVE
To investigate the role of methylation on E-cadherin inactivation in nasopharyngeal carcinoma (NPC) cell line HNE1 and CNE2, as well as evaluate the inhibitory effect of 5-aza-2'-deoxycytidine (5-Aza-dC) on cell abilities of proliferation and invasion.


METHODS
The expression level of E-cadherin was measured by RT-PCR, Western blot and immunohistochemistry (polymer method), the methyaltion status was analyzed by methylation-specific PCR (MSP), and cell proliferation and invasion were examined by MTT and invasion assay, separately before and after treatment with demethylating agent 5-Aza-dC.


RESULTS
The expression level of E-cadherin was down-regulated compared with the normal tissue, simultaneously partially methylated in gene promoter. Treatment with 20 µmol/L 5-Aza-dC increased the expression of E-cadherin and reduced the methylation degree. Moreover, it also significantly suppressed cell growth (27.6% for HNE1 cells and 34.3% for CNE2 cells, P < 0.05) and invasiveness (37.2% for HNE1 cells and 29.7% for CNE2 cells, P < 0.05).


CONCLUSIONS
Aberrant methylation around gene promoter region may play an important part in down regulation of E-cadherin in NPC, suggesting a potential therapeutic strategy for demethylating agents such as 5-Aza-dC.
Department of Tumor Research Lab, Cancer Hospital of Shantou University Medical College, China.
Chao-qun
CQ
Hong
Yong-gang
YG
Ran
Jiong-yu
JY
Chen
Xiao
X
Wu
Yan-jie
YJ
You
D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D019175:DNA Methylation; D000077209:Decitabine; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009303:Nasopharyngeal Neoplasms / Q000378:metabolism / Q000473:pathology; D009361:Neoplasm Invasiveness; D011401:Promoter Regions, Genetic
D000964:Antimetabolites, Antineoplastic; D015820:Cadherins; D000077209:Decitabine; D001374:Azacitidine