Hypermethylation in the p16 Promoter Region in the Carcinogenesis of Endometrial Cancer in Japanese Patients

• Published in: Anticancer research Vol. 26; no. 2A; pp. 851 - 856
• Main Authors: YANOKURA, Megumi, BANNO, Kouji, SUSUMU, Nobuyuki, KAWAGUCHI, Makiko, KUWABARA, Yoshiko, TSUKAZAKI, Kastumi, AOKI, Daisuke
• Format: Journal Article
• Language: English
• Published: Attiki International Institute of Anticancer Research 01-03-2006
• Subjects: Biological and medical sciences; Carcinoma, Endometrioid - genetics; Carcinoma, Endometrioid - pathology; Cell Line, Tumor; DNA Methylation; DNA, Neoplasm - genetics; DNA, Neoplasm - metabolism; Endometrial Neoplasms - genetics; Endometrial Neoplasms - pathology; Female; Female genital diseases; Gene Expression Regulation, Neoplastic; Gene Silencing; Genes, p16; Gynecology. Andrology. Obstetrics; Humans; Japan; Medical sciences; Neoplasm Staging; Promoter Regions, Genetic; Tumors; Asia; Japan; Human; Endometrium cancer; Cancerology; p16; Transcription promoter; hypermethylation; Uterine diseases; endometrial cancer; Malignant tumor; Methylation; Carcinogenesis; Female genital diseases
• ISSN: 0250-7005; 1791-7530

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. Materials and 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.
Conclusion: These results suggest that hypermethylation of p16 rarely occurs and, thus, has no significant effect on the carcinogenesis
of endometrial cancer in Japanese patients.