Fig. 5

CpG island hypermethylation was associated with UPF1 downregulation. a Demethylation following treatment with 5-Aza-2′ -deoxycytidine induced UPF1 up-regulation in HCCLM9 and Huh7 cells, the protein and mRNA expression level of UPF1 was checked by western blotting and RT-qPCR respectively. **p < 0.01. (b) The CpG island enriched sites in the upstream region of UPF1 were analyzed using CpG islandsearcher. c The CpG island enriched sites in the upstream region of UPF1 were analyzed using Meth-Primer (d) Bisulfite sequencing of the putative promoter region. Each line represents one PCR product, and ten PCR products are shown for each sample. ●, methylated CpGs; ○, unmethylated CpGs. e The methylation status of each CpG in this region was quantified using the percentage of methylated CpGs among all PCR products. *p < 0.05, **p < 0.01