S100 calcium-binding
protein A7 (S100A7)

Psoriasin
Psoriasin 1 (PSOR1)
S100A7 (gene locus)

Gene: S100A7 maps to 1q21 (Schafer B. et al., 1995). It is organised in three exons and two introns, spanning 2.7 kb. The 5' flanking region contains AP1- and Sp1-binding motifs and a TATA box. Functional assays by using the beta-galactosidase gene as a reporter have indicated that this region has strong promoter activity (Semprini S. et al., 1999).
mRNA: size:
Protein:

Cell lines:

Tumors:
- The S100A7 gene was found to be expressed in breast cancer cell lines and in cancer cells of some breast carcinomas but not in any non-cancerous tissues examined, except skin (Moog-Lutz C. et al., 1995).

- Persistence of S100A7 mRNA and protein expression in relation to prognostic factors was examined in a cohort of 57 invasive breast tumors, comprising 34 invasive ductal carcinomas and 23 other invasive tumor types (lobular, mucinous, medullary, tubular). The protein was localized by immunohistochemistry predominantly to epithelial cells, with both nuclear and cytoplasmic staining, as well as occasional stromal cells in psoriatic skin and breast tumors; however, in situ hybridization showed that S100A7 mRNA expression was restricted to epithelial cells. In breast tumors, higher levels of S100A7 measured by RT-PCR and Western blot (93% concordance) were significantly associated with estrogen and progesterone receptor-negative status, and with nodal metastasis in invasive ductal tumors, but not with tumor type or grade. S100A7 expression also correlated with inflammatory infiltrates (Al-Haddad S. et al., 1999).

Al-Haddad S. et al. (1999) Psoriasin (S100A7) expression and invasive breast cancer. Am. J. Pathol. 155, 2057-2066. (PubMed)
Moog-Lutz C. et al. (1995) Comparative expression of the psoriasin (S100A7) and S100C genes in breast carcinoma and co-localization to human chromosome 1q21-q22. Int. J. Cancer 63, 297-303. (PubMed)
Schafer B. et al. (1995) Isolation of a YAC clone covering a cluster of nine S100 genes on human chromosome 1q21: rationale for a new nomenclature of the S100 calcium-binding protein family. Genomics 25, 638-643. (PubMed)
Semprini S. et al. (1999) Genomic structure, promoter characterisation and mutational analysis of the S100A7 gene: exclusion of a candidate for familial psoriasis susceptibility. Hum. Genet. 104, 130-134. (PubMed)
Watson P.H. et al. (1998) Psoriasin (S100A7). Int. J. Biochem. Cell. Biol. 30, 567-571 (Review). (PubMed)

UniGene data (Hs.112408)