Figure 1.

The expression of ASZ1 is regulated by DNA methylation. A) Asz1 promoter contains multiple CpG-rich sites. B) Transcript levels of ASZ1 in MEF and NIH3T3 cells in the absence or presence of 5′-Aza by RT-PCR. C) RT-PCR of Asz1 and β-actin on total RNAs or MSRE-PCR on the promoter region of Asz1 (pAsz1) from various tissues. The deduction of methylation status and expression level of Asz1 was summarized in Table 1. No expression of Asz1 was detected when its promoter was methylated, which was indicated by a band present with prior treatment with HpaII. D) Bisulfate sequencing of the Asz1 promoter on genomic DNA. White circles: unmethylated CpG; black circles: methylated CpGs.