p53 gene mutation is rare in human cervical carcinomas with positive HPV sequences

Chromosome 17p allelic losses and concurrent p53 mutations have been demonstrated in various human cancers. We therefore investigated the presence of chromosome 17p allelic loss and possible concurrent p53 mutation in 29 Korean cases of cervical carcinoma by restriction fragment length polymorphism (RFLP) analysis and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) over the region from exon 4 to exon 9 of the p53 gene. We also examined the expression of p53 in paraffin tissues by immunohistochemical staining and determined the incidence of human papillomavirus (HPV) sequences in the same tissues by multitype PCR analysis to correlate them to the allelic loss on chromosome 17p13 and p53 mutation. In the analysis of 29 cases, loss of heterozygosity (LOH) was observed in eight (40%) cases out of 20 informative cases and p53 mutation was observed in only one case (3.4%) at exon 5. So in the majority of cases with LOH on 17p in this series, mutation of p53 gene appeared to be rare. But we obtained three cases (10.3%) of positive immunoreactivity from 29 cases. Those cases may carry mutations outside of the regions examined by PCR-SSCP. HPV DNA was detected in 27 of 29 cases (93.1%). HPV types 8, 11, 16, and 18 were detected in the samples we tested, while only two (7.4%) out of 27 HPV positive cases exhibited overexpression for p53 without any demonstrable p53 mutation upon PCR-SSCP. These results suggest that HPV infection may play a role in inactivating wild-type p53 protein in cervical carcinomas. In conclusion, mutation and overexpression of p53 gene appear to be rare, particularly in cases of cervical carcinoma associated with positive HPV sequence.