H. Kamiya et al., A METHYLENETETRAHYDROFOLATE REDUCTASE POLYMORPHISM IS ASSOCIATED WITHEXPRESSION OF P16 IN HUMAN LUNG-CANCER, Oncology Reports, 5(4), 1998, pp. 911-914
Methylenetetrahydrofolate reductase (MTHFR) is a critical enzyme in th
e folate cycle. Reduced MTHFR activity induces DNA hypomethylation and
stability, which may protect the tumor suppressor gene p16(INK4). We
examined the association between MTHFR polymorphism and expression of
p16(INK4). Th, frequency of the MTHFR genotypes were 21 Ala/Ala, 29 Al
a/Aal, and 7 Val/Val. Expression of p16(INK4) was 26.2+/-26.8% in the
Val/Val genotype and 11.21+/-16.6% in the other genotypes (p=0.46) as
examined by immunostaining, and excluding four specimens that were ove
rstained. These results suggest that folate metabolism can affect carc
inogenesis through the expression of p16(INK4).