Background: Human papilloma virus (HPV) is the most important factor in the oncogenic mechanism of cervical tumor. Furthermore, in a separate multi-stage process, abnormality in cell cycle kinetics has been demonstrated. In order to elucidate the oncogenic mechanism, we examined the relationship between cervical carcinoma and HPV infection, and also investigated the expression of p53 and p21 proteins as well as the cell proliferation capability by detecting Ki-67, and analyzed the correlations of these factors.
Materials and methods: We studied the biopsy specimens from 107 patients of chronic cervicitis, cervical intraepithelial neoplasia and squamous cell carcinoma (SCC). HPV DNA was detected by the hybrid capture method. Immunostaining by LSAB procedures were performed using antibodies to p53 protein, p21 and MIB-1. The PCR-denaturing gradient gel electrophoresis (DGGE) method was used to search for mutation in exons 5, 6, 7 and 8 of p53.
Results: Of 107 cases studied, high-oncogenic HPV was detected in 80 cases (74.8%) with a particularly high prevalence in SCC. No correlation was observed between HPV infection and expression of p53, p21 or Ki-67. The degree of positivity of Ki-67 expression tended to be higher with disease progression. Cases strongly positive (2+) for p53 and p21 proteins were weakly positive for Ki-67, and cases positive (1+) or negative for p53 and p21 were strongly positive for Ki-67.
Conclusion: In oncogenesis of cervical carcinoma, p53 protein, p21 protein and HPV may act separately as independent factors in some cases, and there is a strong possibility that other factors are involved.