Genomic analysis of the thymine-DNA glycosylase (TDG) gene on 12q22-q24.1 in human pancreatic ductal adenocarcinoma.

Conclusion: Abnormality of the thymine-DNA glycosylase (TDG) gene on 12q22-q24.1 appears to play a limited role in pancreatic ductal carcinogenesis.

Background: Recently, a human G/T-specific TDG gene was identified. This protein acts in a system correcting G/T mispairs to G/C pairs. TDG was mapped to chromosome bands 12q22-q24.1, one of the regions frequently lost in pancreatic cancer. Therefore, there is the possibility that the TDG gene on 12q is one of the genes responsible for pancreatic ductal carcinogenesis.

Methods: Nucleotide sequences of the entire coding region of the TDG gene were analyzed in 21 human pancreatic cancer cell lines. mRNA expression of the TDG gene was also analyzed by Northern hybridization in several human tissues and 21 human pancreatic cancer cell lines.

Results: Decreased levels of mRNA expression were detected in the pancreatic cancer cell lines, but no somatic mutations were observed.