title: [Reversal effect of 5-aza-2-deoxycytidine on the maternally expressed gene 3 promoter hypermethylation and its inhibitory effect on the proliferation of epithelial ovarian cancer cells].
abstract: OBJECTIVE
  To investigate the reversal effects of different concentrations of DNA methylation inhibitor, 5-aza-2-deoxycytidine, on the hypermethylation of maternally expressed gene 3 (MEG3) gene promoter, and then the inhibitory effect of restoration of MEG3 expression on the proliferation of ovarian cancer cells.
  
  
  METHODS
  Human ovarian cancer OVCAR3 cells were treated with various concentration of 5-aza-2-deoxycytidine (0, 1, 5, 10, 20 µmol/L, respectively) for 6 days. Then the methylation status of MEG3 promoter was detected by methylation specific PCR (MSP). The alteration of MEG3 gene expression was detected by RT-PCR. Cell proliferation was determined by MTT assay and EdU incorporation assay.
  
  
  RESULTS
  After treated with 5-aza-2-deoxycytidine, the methylation status of MEG3 in the 0, 1, 5, 10, 20 µmol/L 5-aza-2-deoxycytidine groups were 1.00 ± 0.00, 0.79 ± 0.00, 0.67 ± 0.00, 0.65 ± 0.03 and 0.61 ± 0.01 folds, respectively (P < 0.05 for all). The relative expressions of MEG3 mRNA in the 0, 1, 5, 10, 20 µmol/L 5-aza-2-deoxycytidine groups were 1.00 ± 0.00, 2.04 ± 0.16, 2.44 ± 0.17, 3.19 ± 0.34 and 5.34 ± 0.39, respectively (P < 0.05 for all). In contrast to the negative control, the inhibition rates of the OVCAR3 cell growth were increased significantly when treated with 1, 5, 10, 20 µmol/L 5-aza-2-deoxycytidine in 2, 4 and 6 days. There were (40.78 ± 0.80)%, (35.65 ± 0.33)%, (31.81 ± 0.66)%, (27.33 ± 1.27)% and (17.75 ± 1.85)% of EdU-positive cells in the 0, 1, 5, 10 and 20 µmol/L 5-aza-2-deoxycytidine groups (P < 0.01 for all).
  
  
  CONCLUSIONS
  Maternally expressed gene 3 promoter hypermethylation is reversed by 5-aza-2-deoxycytidine in ovarian cancer cells. The downregulation of MEG3 gene might be resulted from the methylation, and the re-expression of MEG3 partly contribute to the growth inhibition of epithelial ovarian cancer cells.
authors.affiliation: Department of Obstetrics and Gynecology, the Third Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutions, Guangzhou 510150, China.
authors.forename: Jianqi
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Obstetrics and Gynecology, the Third Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutions, Guangzhou 510150, China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Department of Obstetrics and Gynecology, the Third Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutions, Guangzhou 510150, China.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Obstetrics and Gynecology, the Third Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutions, Guangzhou 510150, China.
authors.forename: Linyu
authors.initials: L
authors.lastname: Tan
authors.affiliation: Department of Obstetrics and Gynecology, the Third Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutions, Guangzhou 510150, China.
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Obstetrics and Gynecology, the Third Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutions, Guangzhou 510150, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Obstetrics and Gynecology, the Third Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutions, Guangzhou 510150, China; Email: xjsheng@gzemail.cn.
authors.forename: Xiujie
authors.initials: X
authors.lastname: Sheng
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000077216:Carcinoma, Ovarian Epithelial; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019175:DNA Methylation; D000077209:Decitabine; D005260:Female; D006801:Humans; D009375:Neoplasms, Glandular and Epithelial; D010051:Ovarian Neoplasms; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger
chemical_list: D000964:Antimetabolites, Antineoplastic; D012333:RNA, Messenger; D000077209:Decitabine; D001374:Azacitidine