Figure 2

Hypermethylation-mediated downregulation of WWOX expression in intraductal papillary mucinous neoplasm of the pancreas (IPMN). (A) Results of bisulphite genomic sequence analysis at the WWOX regulatory site, including the promoter region, exon 1 and intron 1. Filled boxes indicate methylation; open boxes indicate absence of methylation. (B) Representative results of bisulphite genomic sequence analysis of BxPC-3 cells. Arrowheads indicate the CpG island that demonstrated cytosine–uracil transition. (C) The methylation status of the WWOX regulatory CpG site determined by the methylation-specific PCR (MSP) analysis. BxPC-3 cells were treated with trichostatin A (TSA), 5-aza-2′-deoxycytidine (5-aza-dC) and a combination of the two drugs. Restored WWOX expression was confirmed by western blot analysis. β-Actin was used as a loading control. (D) Representative results of MSP analysis. The status of WWOX expression detected by IHC was also exhibited. (E) Representative results of bisulphite genomic sequence analysis of IPMA and IPMC. Arrowheads indicate the CpG island that demonstrated cytosine–uracil transition. M, methylated; U, unmethylated.