Fig. 1

Downregulated DNMT1 inhibits progression of breast cancer cells through promoting MEG3. The A DNMT1 and B MEG3 expression levels in breast cancer cell lines (MDA-MB-231, SUM 149) and normal breast epithelial cell line MCF10A were detected by western blot and qRT-PCR; C ChIP assay was used to determine whether DNMT1 could bind to MEG3; D MEG3 methylation was determined by MethPrimer software; E Western blot was used to detect interference efficiency of the shRNAs targeting DNMT1; F MEG3 methylation level was tested by MSP (U, unmethylated reaction; M, methylated reaction; In control group, cells were not transfected with any plasmids); G MEG3 expression was detected after DNMT1 was silenced; H interference efficiency of the shRNAs targeting MEG3 was detected by qRT-PCR; I DNMT1 and MEG3 levels were detected by qRT-PCR in four groups (sh-NC, sh-DNMT1  +  sh-NC, sh-DNMT1  +  sh-MEG3-1, sh-DNMT1  +  sh-MEG3-2); J cell proliferation, K migration and L invasion were tested. *p  < 0.05