Transcription promoter activity of the human S100A7 gene in oral squamous cell carcinoma cell lines

The S100A7 (psoriasin) gene has been shown to be markedly over-expressed in squamous cell carcinomas (SCCs) as well as in psoriasis. We herein examined the S100A7 gene promoter activity in human oral SCC cell lines to identify the putative SCC-specific regulatory regions for the S100A7 transcription. Functional deletion assays of 5′-flanking region demonstrated that the segments, (−1513 to −988), (−1954 to −1513) and (−3040 to −2578), play important roles in the transcription activity in the oral SCCs. The internal deletion of the short segments, (−1248 to −1110), (−1109 to −988) and (−1248 to −988), decreased this activity. These segments cloned upstream of the heterologous promoter increased the promoter activity in oral SCC cell line. Electrophoretic mobility shift assays, using the sequence segmental probes, (−1248 to −1110) and (−1109 to −988), showed different DNA-protein complex patterns depending on the types of used cell lines. One of the complexes was only observed in the oral SCCs. These data suggested that the segment from −1513 to −988 contains up-regulatory elements for the transcription activity of the S100A7 gene in oral SCCs.