Expression analysis and mutational screening of the epithelium-specific ets gene-1 (ESE-1) in patients with squamous anal cancer

To investigate whether ESE-1 gene abnormalities are involved in alterations of epithelial cell differentiation in squamous anal cancer ESE-1 expressio n and structure were screened in six patients by reverse transcriptase-poly merase chain reaction (RT-PCR) and automated sequence analysis. The complet e cDNA of isoform ESE-1b was always expressed and correctly spliced, with s ingle nucleotide polymorphism being observed in two cases. Presence of ESE- 1b point mutations was excluded. Expression of SPRR2A and ENDOA/CK8, two ep ithelium-specific ESE-1 target genes, were revealed by RT-PCR in all cases. This first report of expression of ESE-1, and of SPRR2A and ENDOA/CK8 (bot h related to terminal differentiation in different types of epithelia linin g) in anal cancer excludes the hypothesis that these genes influenced carci nogenesis in our patients. Despite selecting of patients without clinical e vidence of HPV infection, PCR consistently revealed HPV-16 DNA, highlightin g the importance of HPV infection in anal cancer.