Experimental models indicate that activated ras genes and HPV oncogenic sequences may cooperate in inducing a completely transformed phenotype in epithelial cells. We searched for K-ras gene mutations and HPV type-16 and -18 sequences in 67 primary adenocarcinomas of the uterine cervix by analyzing DNAs from formalin-fixed, paraffin-embedded tissue samples. Target sequences were amplified by PCR and analyzed by denaturing gradient gel electrophoresis (DGGE) and sequencing for the detection of K-ras gene mutations and by Southern blotting for the detection of HPV infection. We found 16 mutations in 15 cases; 14 were at codon 12 and 2 at codon 13; 11 were base transitions and 5 were transversions. Mutations were more frequent in mucin-secreting than in non-mucinous tumors. HPV oncogenic sequences were detected in 58 cases with no signifcant difference between K-ras-mutated and wild-type tumors. HPV oncogenic sequences were also more frequent in mucin-secreting than in non-mucinous tumors. Both molecular events were present simultaneously in 13 out of 58 cases, all of which had histologically grade-2 and grade-3 tumors. Clinicopathological parameters of the disease and the overall survival however, were independent of K-ras mutations and of HPV-16 and -18 infection, as shown by univariate and multivariate analysis. In contrast, stage of disease, lymph-node metastases, deep infiltration, clear-cell histology and low grade of differentiation were risk factors for tumor-related death.
ASJC Scopus subject areas
- Cancer Research