Immunohistochemical detection of a specific receptor for lipocalin2 (solute carrier family 22 member 17, SLC22A17) and its prognostic significance in endometrial carcinoma.

BACKGROUND: We previously reported the overexpression of lipocalin2 (LCN2), a 25kDa secretory protein involved in iron-transportation, in endometrial carcinoma and its possible contribution to endometrial carcinogenesis. Recently, a specific receptor for LCN2, solute carrier family 22 member 17 (SLC22A17), was identified. The present study was undertaken to investigate the expression of SLC22A17 in endometrial carcinoma. METHODS: The expression of the SLC22A17 and LCN2 proteins was examined immunohistochemically using 69 cases of endometrial carcinoma and adjacent normal endometrial tissues. Immunoreactivity was evaluated according to the percentage of positive cells and described as a positivity index (PI, full score 100). RESULTS: The expression of SLC22A17 was negligible in normal endometria, but positive staining for SLC22A17 (PI≧1) was observed in 35 cases of endometrial carcinoma. The PI for SLC22A17 was significantly higher in cases with histological grade 3 (P<0.0005), advanced FIGO stage (P=0.002), deep myometrial invasion (P=0.029), positive lymph-vascular space invasion (P=0.029), positive intraperitoneal cytology (P=0.020) and adnexal metastasis (P=0.029). The expression of SLC22A17 and LCN2 was positively correlated with a significant difference (P=0.002), and the patients who overexpressed both SLC22A17 and LCN2 showed poorer survival than those without the expression of SLC22A17 or LCN2 (P=0.002). Moreover, the overexpression of both SLC22A17 and LCN2 was indicated to be an independent prognostic factor by multivariable analysis. CONCLUSIONS: These results suggested that SLC22A17, in cooperation with LCN2, to be involved in the acquisition of aggressive behavior among endometrial carcinoma cells.

Immunohistochemical expression of keratan sulfate: a possible diagnostic marker for carcinomas of the female genital tract.

AIMS: The authors previously reported the expression of keratan sulfate (KS), a glycosaminoglycan, in the epithelium of normal and neoplastic endometria. The aim of this study was to evaluate its potential use as a diagnostic marker, and the expression of KS was investigated in other human epithelial tissues. METHODS: Expression was examined immunohistochemically using 102 samples of normal epithelia and 110 samples of carcinomas from the female genital tract (FGT; cervix, endometrium, ovary, fallopian tube), digestive organs (gastrointestinal tract, pancreas, liver), urinary tract, lung, mammary gland, thyroid and mesothelium. RESULTS: In normal tissues, KS was consistently detected in the FGT and ectopic endometrium (25/26), but was not found in the digestive organs (1/42) and urinary tract (0/6), and was only partly detected in the lung (7/10), mammary gland (3/9) and thyroid (4/4). In malignant tissues, KS was consistently observed in carcinomas of the endometrium, ovary and fallopian tube (29/32), and was partly detected in carcinomas of the lung, mammary gland, thyroid, pancreas and mesothelium, but was absent in carcinomas of the gastrointestinal tract (0/17), liver (0/5) and urinary tract (0/11). Among carcinomas of the FGT, digestive organs and urinary tract, KS positivity suggested the possibility of FGT carcinomas, with 79.5% (31/39) sensitivity and 92.9% (39/42) specificity. CONCLUSIONS: KS is a potentially useful marker for the supportive diagnosis of the primary site of metastatic carcinomas or unknown primary carcinomas, especially in the abdominal cavity.