Effects of shRNA-mediated silence of metastasis-associated lung adenocarcinoma transcript 1 on the invasion and metastasis of ovarian carcinoma cell line OVCAR3 / 肿瘤研究与临床

Objective To evaluate the expression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1) in ovarian cancer cell lines, and to investigate the biological effects of down-regulated MALAT-1 on OVCAR3 cells.Methods qRT-PCR analysis was used to examine the expression level of MALAT-1 gene in ovarian cancer cells, including ES-2, A2780, SKOV3 and OVCAR3 cell lines.For functional research, four shRNA oligos specially targeting MALAT-1 and a empty vector were designed and constructed into pGPU6/GFP/Neo, then transfected into OVCAR3 cells.qRT-PCR was used to confirm the effective suppression of MALAT-1.Changes of proliferation and adhesion of cells were analyzed by CCK-8 and adhesion assays.Wound-healing, transwell migration and invasion assays were used to examine migration and invasion of MALAT-l-silencing cells in vitro.Results The expression of MALAT-1 gene in OVCAR3 cells was high, and qRT-PCR results confirmed successfully the knockdown of MALAT-1 after transient transfection.After successful suppression of MALAT-1, the proliferation, wound-healing and adhesion ability in vitro were inhibited to some degree.In transwell migration assay, the number of migration cells in MALAT-1-silencing group was 52.17±4.48, which is much less than that in the negative and control groups (286.50± 12.23 and 295.67±6.96, respectively).In invasion assay, the number of invasion cells passing the transwell membrane in MALAT-1-silencing group (37.33±2.40) was also decreased significantly, compared to that in the negative and control groups (239.00±15.72 and 222.67±20.85, P ＜ 0.05).Conclusions shRNA-mediated silence of MALAT-1 can effectively inhibit the proliferation, adhesion, migration and invasion abilities of ovarian cancer cell line OVCAR3 in vitro, indicating MALAT-1 is expected to be a target gene for the treatment of ovarian cancer.

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 / 中华肿瘤杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSIONS</b>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.</p>

Methylation state of MEG3 gene in epithelial ovarian cancer and its clinical significanc research / 实用医学杂志

Objective To study the relationship between the methylation status of CPG islands in MEG3 gene promoter region of epithelial ovarian cancer and its clinical and pathological features. Methods The promoter methylation status was evaluated by MSP (methylation-specific polymerase chain reaction ) in 47 cases of ovarian cancer tissue and 15 cases of normal control. Results The methylation ratio (42.6%) of the MEG3 genes in the ovarian cancer was statistically significantly higher (P = 0.035 ) than that (13.3%) in the normal control. The methyation rate of the group with an age > 60 years old was slightly higher than that of the group with an age≤60 years old, without statistically significant (P > 0.05), so was observed in ovarian cancers of stage Ⅰ andⅡ than that in stage Ⅲ and Ⅳ. There were also no significant differences in MEG3 gene methylation positive rate neither in different pathological grading nor in various ovarian cancer tissues (P > 0.05). Conclusion Abnormal methylation in MEG3 gene may be associated with epithelial ovarian cancer , but no relation to its clinical pathology.