[E-cadherin promoter methylation and demethylation in epithelial ovarian carcinoma cells].
OBJECTIVE
To investigate the cytidylyl phosphate guanosine (CpG) islands methylation status of E-cadherin (E-cad) promoter region in human ovarian carcinoma cell lines (ES-2,3AO,SKOV3), and the effect of 5-azacytidine-2'-deoxycytidines (5-Aza-CdR) on the cell proliferative ability, invasion and the expression of E-cad protein.


METHODS
Methylation specific PCR (MSP) was used to detect CpG islands methylation status of E-cad promoter region in ES-2,3AO and SKOV3 cell lines. After treated with different concentrations of 5-Aza-CdR, morphological changes of cell lines were observed under microscope. The proliferative ability was evaluated by methyl thiazolyl tetrazolium (MTT) assay. E-cad protein expression was detected by western-blot and cellular invasion was investigated by 24-well matrigel invasion chambers.


RESULTS
Hypermethylation status of CpG islands of E-cad promoter region was observed in ES-2 and SKOV3 cell lines, but not in 3AO cell lines. After treated with 5-Aza-CdR (0.1, 1.0, 10.0 micromol/L), ES-2 and SKOV3 cell lines displayed morphological evidence of differentiation. 5-Aza-CdR was found to decrease proliferation as evidenced by cell growth curve , to increase the level of E-cad protein expression (P < 0.01), and effectively inhibit the ability of cell invasion (P < 0.01).


CONCLUSIONS
CpG hypermethylation is an important mechanism of E-cad gene inactivation in ES-2 and SKOV3 cell lines. 5-Aza-CdR be found to inhibit proliferation and invasion, and increase the expression of E-cad probably by the inhibition of hypermethylation.
Qu
Peng-peng
PP
Department of Gynecology, Oncology, Tianjin Central Hospital of Obstetrics and Gynecology, Tianjin, China. likqupp@yahoo.com
Shi
Zheng
Z
Li
Na
N
D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D015820:Cadherins / Q000235:genetics* / Q000378:metabolism; D000077216:Carcinoma, Ovarian Epithelial; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D018899:CpG Islands; D019175:DNA Methylation; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D009361:Neoplasm Invasiveness; D009375:Neoplasms, Glandular and Epithelial / Q000235:genetics* / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic / Q000235:genetics*
D015820:Cadherins; D004791:Enzyme Inhibitors; D001374:Azacitidine