Yanokura Megumi, Banno Kouji, Susumu Nobuyuki, Kawaguchi Makiko, Kuwabara Yoshiko, Tsukazaki Kastumi, Aoki Daisuke
Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, Japan.
Anticancer Res. 2006 Mar-Apr;26(2A):851-6.
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.
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.
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.
These results suggest that hypermethylation of p16 rarely occurs and, thus, has no significant effect on the carcinogenesis of endometrial cancer in Japanese patients.
据报道，p16在多种癌症中会因高甲基化而消失。然而，在子宫内膜癌中，p16高甲基化频率与其失活机制之间的关系尚未完全阐明。
分析了51份标本中p16基因启动子区域的高甲基化及p16蛋白的表达情况，其中包括8种子宫内膜癌细胞系、7份正常子宫内膜组织、12份非典型子宫内膜增生组织和32份子宫内膜癌组织。
8种子宫内膜癌细胞系中有5种显示出高频率的高甲基化，尽管只有1种显示基因表达缺失。然而，32份标本中的子宫内膜癌组织均未显示高甲基化。此外，在20份标本中有3份通过免疫组化观察到表达缺失。
这些结果表明，p16的高甲基化很少发生，因此对日本患者子宫内膜癌的致癌作用没有显著影响。
