Hypermethylation in the p16 promoter region in the carcinogenesis of endometrial cancer in Japanese patients.
BACKGROUND
p16 has been reported to disappear by hypermethylation in various cancers. However, the relationship between the frequency of hypermethylation of p16 and the mechanism of its inactivation has not been completely elucidated in endometrial cancer.


METHODS
Hypermethylation in the promoter region of the p16 gene and the expression of the p16 protein in 51 specimens, including 8 endometrial cancer cell lines, 7 normal endometrial tissues, 12 atypical endometrial hyperplasia tissues and 32 endometrial cancer tissues were analyzed.


RESULTS
Five out of 8 endometrial cancer cell lines showed hypermethylation with high frequency, although only 1 showed loss of gene expression. However, no endometrial cancer tissue of the 32 specimens showed hypermethylation. Furthermore, loss of expression was immunohistochemically observed in 3 out of the 20 specimens.


CONCLUSIONS
These results suggest that hypermethylation of p16 rarely occurs and, thus, has no significant effect on the carcinogenesis of endometrial cancer in Japanese patients.
Yanokura
Megumi
M
Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, Japan.
Banno
Kouji
K
Susumu
Nobuyuki
N
Kawaguchi
Makiko
M
Kuwabara
Yoshiko
Y
Tsukazaki
Kastumi
K
Aoki
Daisuke
D
D018269:Carcinoma, Endometrioid / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D016889:Endometrial Neoplasms / Q000235:genetics* / Q000473:pathology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D019942:Genes, p16; D006801:Humans; D007564:Japan; D009367:Neoplasm Staging; D011401:Promoter Regions, Genetic
D004273:DNA, Neoplasm