Ha-ras and p53 gene mutations scanned by PCR-SSCP in human papillomavirus associated with premalignant and malignant lesions of the uterine cervix.

The aim of this study was to investigate the frequencies of human papilloma virus (HPV) and mutation in Ha-ras oncogene and tumour supressor p53 gene i n cervical cancer and precursor lesions. A total of 30 invasive carcinomas (IC), 36 cervical intraepithelial neoplasia grade III (CIN III) and 12 norm al tissues adjacent to the tumor (NT) were included. HPV typification and s canning of possible mutations in Ha-ras and p 53 genes were made by SSCP-PC R. The IC cases showed 93% HPV positivity, 41% having mobility shifts for H a-ras mutations and 17% for p53 mutations while in CIN III, these percentag es were 80%, 18% and 11%, respectively. In normal tissues HPV frequency was 17%. All Ha-ras mutated samples were HPV positive but 33% of p53 mutated c ases were HPV negative. All mutations were heterozygous. HPV 16 was more pr evalent (44%) than HPV 18 (15%) and the high rate ef undetermined HPV types (18%) would indicate the circulation in our country of other types differe nt from the assayed HPV controls (6, 11, 16, 18, 31 and 33), being variants or mixed infections. The low frequency of p53 mutations (17%) strengthens the view that wild type p53 inactivation by HPV probably plays a major role in the pathogenesis of cervical cancer. Because mutated Ha-ras was found i n HPV associated premalignant lesions, we speculate that it represents an e arly marker for progression. Our findings provide additional evidence for a n interactive effect between high risk types of HPV and oncogene activation in the development of uterine cervical cancer.