Erschienen in:
01.06.2005 | Original Paper
The hypermethylation and protein expression of p16
INK4A
and DNA repair gene O
6
-methylguanine-DNA methyltransferase in various uterine cervical lesions
verfasst von:
Zhenhua Lin, Meihua Gao, Xianglan Zhang, Young-Sik Kim, Eung-Seok Lee, Han-Kyeom Kim, Insun Kim
Erschienen in:
Journal of Cancer Research and Clinical Oncology
|
Ausgabe 6/2005
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Abstract
Purpose
This study is aimed at investigating the significance of gene promoter methylation status and protein expression of p16 INK4A and O6-methylguanine-DNA methyltransferase (MGMT) in the various uterine cervical lesions.
Materials and methods
Methylation status by using methylation-specific polymerase chain reaction (MS-PCR) and protein expression by using immunohistochemistry for p16
INK4A
and MGMT genes were performed in cervical squamous intraepithelial neoplasms (CIN), invasive squamous cell carcinomas (SCC), adenocarcinomas and non-neoplastic cervices.
Results
None of 20 non-neoplastic cervices showed p16
INK4A
and MGMT gene hypermethylation, whereas at least one of these genes was hypermethylated with 50.0% (5/10) of CIN I, 65.0% (13/20) of CIN II–III, 70.2% (33/47) of SCC and 85.0% (17/20) of adenocarcinoma. p16 INK4A protein was totally negative in non-neoplastic cervices, but positive with 90.0% of CIN I, 100% of CIN II–III and adenocarcinoma, and 78.7% of SCC. MGMT protein was expressed in 10% of non-neoplastic cervices, but significantly increased in SCC (42.5%) and adenocarcinoma (70.0%). The protein expression of p16 INK4A and MGMT was not related to their gene promoter methylation status.
Conclusions
The hypermethylation of p16
INK4A
and MGMT genes in the uterine cervix may indicate the presence of malignant cells, and p16 INK4A immunostaining is useful in grading CIN and diagnosing invasive SCC and adenocarcinoma.