Transmembrane serine protease TADG-15 (ST14/Matriptase/MT-SP1): expression and prognostic value in ovarian cancer

Tumour- associated differentially expressed gene- 15 ( TADG- 15/ ST14/ matriptase/ MT- SP1) is a novel member of the transmembrane serine proteases. Previous studies indicated that TADG- 15 is overexpressed in ovarian tumours; however, relationships between expression of TADG- 15 and clinical characteristics of ovarian cancer remain unclear. The purpose of this study was to examine TADG- 15 expression in ovarian cancers and determine any associations with clinicopathological characteristics or patient survival. Immunohistochemical study revealed that TADG- 15 was expressed in 50 ( 56.2%) of 89 ovarian carcinomas, whereas it was not detected in normal ovaries. TADG- 15 expression was significantly more common in patients with early stage disease compared with patients with advanced stage diseases ( namely, stage I, 24 out of 33: 72.7%; stage II/ III/ IV, 26 out of 56: 46.4%; P = 0.0157). Kaplan- Meier survival curves demonstrated that patients with TADG- 15- positive tumours have had substantially longer survival ( P = 0.0480). The mean value of relative TADG- 15 mRNA expression ratio was significantly higher in stage I tumours than in stage II/ III/ IV tumours ( P = 0.0053). Increased expression of TADG- 15 is frequently detected in early stage cancers, with expression level downregulated during progression of disease. TADG- 15 is associated with early stage ovarian cancer and longer patient survival; therefore, it may be a favourable prognostic marker for this malignancy.