Correlation between FUT4 expression and its promoter methylation in HaCaT cells

The expression level of fucosyltransferase Ⅳ (FUT4) is low in normal cells. The mechanism underlying regulation of FUT4 expression in normal cells remains elusive. In this study, Western blot, immunofluorescence and real-time PCR were used to analyze FUT4 expression in the immortalized human keratinocytes cells HaCaT. Methylated-specific PCR was used to investigate methylation status of FUT4 promoter. The results showed that the FUT4 expression level was significantly lower in HaCaT cells than squamous carcinoma cells A431 and SCC12. FUT4 mRNA expression was increased in HaCaT cells treated by 5-aza-dC (5 μmol/L), an inhibitor of DNA methyltransferase. Furthermore, using the primers to amplify the methylated fragment yielded PCR products and no products were yielded by the primers to amplify the unmethylated fragment in HaCaT cells. Unmethylated PCR products were obtained in HaCaT cells treated by 5-aza-dC, while methylated PCR products were not detected. These results suggest that the lower expression of FUT4 in HaCaT cells may be correlated with the methylation of CpG island in FUT4 promoter.