Figure 6. IF staining for Rbbp5 and DNMT1 expression and ChIP-PCR analysis of Rbbp5 binding to the DNMT1 promoter in pancreatic endocrine and exocrine tissues.

Rbbp5 protein was seen in both endocrine and exocrine tissues of the pancreas from Men1 WT (A) and KO (B) mice by IF staining. Rbbp5 bound the DNMT1 promoter in the pancreatic endocrine tissue, but not in the pancreatic exocrine tissue, from Men1 WT and KO mice (C). The Rbbp5-IP products were amplified using quantitative real-time RT-PCR with primers corresponding to the promoter regions of the DNMT1 gene. The relative amount of DNA in the ChIP product was calculated using the input for normalization. IgG was used as a control. The mRNA, protein expression, and enzymatic activity of DNMT1 were increased in the pancreatic endocrine tumor tissues from Men1 KO mice compared to normal endocrine tissues from control mice (D and E). No increases were observed in pancreatic exocrine tissues from Men1 KO mice compared to normal exocrine tissues from control mice (D, E, and F).