| Alterations of p16INK4A and p18INK4C, Human Papillomavirus infections and Expression of the Cell Cycle Associated Proteins in Cervical Carcinomas. |
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Kyung Ik Kwon, Sang Pyo Kim, Seong Il Suh, Mi Yeul Hwang, Won Ki Baek, Kun Young Kwon, Sang Sook Lee, Chi Heum Cho, Soon Do Cha |
1Departments of Obstetrics and Gynecology, Keimyung University School of Medicine, Taegu, Korea.
2Departments of Pathology, Keimyung University School of Medicine, Taegu, Korea.
3Departments of Microbiology, Keimyung University School of Medicine, Taegu, Korea. |
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| Abstract |
OBJECTIVE
We analyzed the gene status of p16INK4A, p18INK4C, the expression of cell cycle associated proteins (p16INK4A, p18INK4C, cyclin D1, CDK4, pRb, and p53), and human papillomavirus (HPV) infection to investigate whether the inactivation of these genes participated in carcinogenesis, and to evaluated the expression of cell cycle associated proteins and HPV infections. METHODS: We examined forty-one primary cervical carcinomas (17 adenocarcinomas, 13 keratinizing squamous cell carcinomas, and 11 nonkeratinizing squamous cell carcinomas) using PCR, comparative multiplex PCR, PCR-SSCP, methylation-specific PCR, and immunohistochemistry. RESULTS: Ninety percent of cervical carcinomas showed HPV infection. HPV type 16 was detected in 41% and HPV type 18 was found in 44%. Homozygous deletions at p16INK4A gene were observed in 2 cases, but the mutation of p16INK4A and alterations of p18INK4C gene were not detected. The promoter hypermethylation for p16INK4A in nine cases (31%) of 29 cervical carcinomas was found. Expression of p16INK4A protein was observed in 93% and p18INK4C protein expression was noted in 78%. Positive immunostaining for cyclin D1 was only identified in 5%, whereas positive immunostaining for CDK4 was observed in 95%. Expression of pRb protein was found in 93% and p53 protein in 24% of cervical carcinomas. CONCLUSION: These results suggest that high risk HPV infections and methylation of the p16INK4A promoter region seem to play an important role in the pathogenesis of cervical carcinomas. Alterations of p18INK4C gene and cyclin D1-CDK4 pathway does not contribute significantly in the cervical carcinogenesis. |
| Key Words:
p16INK4A, p18INK4C, Human papillomavirus infection, Cell cycle associated protein, Cervical carcinoma |
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