[DNMT1 protein promotes retinoblastoma proliferation by silencing MEG3 gene].

OBJECTIVE: To investigate whether DNMT1 protein induces retinoblastoma proliferation by silencing MEG3 gene. METHODS: Two retinoblastoma cell lines (HXO-RB44 and SO-RB50) and a normal human retinal pigment epithelial (RPE) cell line were transfected with the plasmid pcDNA-DNMT1 or si-DNMT1 for up-regulating or interference of DNMT1 expression, and with pcDNA-MEG3 or si-MEG3 for up-regulating or interference of MEG3 expression. Western blotting was used to detect the changes in the expression of DNMT1 protein in the transfected cells, and CCK-8 and EdU assays were used to detect the changes in cell proliferation. Real-time quantitative PCR (qRT-PCR) was performed to detect MEG3 expression in SO-RB50 and HXO-RB44 cells after transfection, and the methylation level of MEG3 gene promoter after interference of DNMT1 expression was detected using methylation-specific PCR. RESULTS: < 0.05). CONCLUSIONS: In retinoblastoma cells, the up-regulation of DNMT1 protein induces promoter methylation and inactivation of MEG3 gene and eventually leads to abnormal cell proliferation.