Abstract
Oral squamous cell carcinomas (SCCs) correlating histopathologic findings with different clinical features were studied. Further, types of HPVs, p53 status, and EIAF expression in SCCs were investigated.
First the prevalence rate of HPV DNAs in normal oral mucosa was investigated. The nested PCR method was utilized to detect target DNA sequences using the HPV-E6/E7 consensus primer pairs. Of 56 patients examined, HPV-6 and HPV-16 DNA sequences were detected in a 46-year-old male and a 35-year-old female, respectively. Seventy-seven oral SCCs were examined to detect HPV DNAS by PCR and dot blot hybridization. HPV-16 DNA was detected in 23 cases of oral SCC and both HPV-16 and HPV-18 DNA were detected in one case of tongue SCC. HPV is one of the causative factors of oral squamous cell carcinomas.
The p53 status is very important for tumorigenesis and was examined by SSCP analysis and the yeast functional assay. Mutated p53 was detected in 30 % of oral SCCs by SSCP, while almost 80 % of oral SCC had been shown to be mutant p53 by the yeast functional assay.
EIAF is a newly-identified ets-oncogene family transcription factor. Previous reports have noted that EIAF can up-regulate promoter activities of several matrix metalloproteinase (MMP) genes and showed that invasive potentials of oral squamous cell carcinoma-derived cell lines are correlated with expression of EIAF and MMPs. Twenty-seven oral SCC specimens were examined using RT-PCR. Southern blot hybridization and in situ hybridization (ISH) and compared to the clinico-pathological parameters. Among the 27 patients, E1AF was detected in 15 cases. E1AF mRNA was detected in 13 of 17 invasive SCCs, whereas the majority of SCCs not expressing EIAF showed an expansive growth pattern. Increased prevalence of EIAF-positive oral SCC was observed in cases with nodal metastasis. The results indicate that EIAF may be involved in cancer cell malignancies through its ability to promote invasive potential.
