Expression of Neutrophil Gelatinase-Associated Lipocalin and Kidney Injury Molecule-1 in Wilms Tumor

Neutrophil gelatinase-associated lipocalin (NGAL) and Kidney injury molecule-1 (KIM-1) play important roles in both immunity and cell proliferation. It was reported previously that they are overexpressed in various human cancers. The present study was undertaken to examine the expressions of NGAL and KIM-1 in Wilms Tumors. Tissue samples of 50 Wilms Tumors were evaluated and underwent immunhistochemical staining for NGAL and KIM-1 protein expressions. The correlations between them, and some clinical prognostic factors such as tumor weight, stage and histological features were also evaluated. Twenty-three (46%) of the cases were male while 27 (54%) were female. The mean age was found to be 3.26±2 years. The average tumor size was 9.16 ± 2.9 cm in diameter and the average weight of the kidney was 478±312 gr. Thirteen (26%) cases were stage I, 18 (36%) cases were stage II, 7 (14%) cases were stage III, and 6 (12%) cases were stage IV. Thirty-nine cases were alive (78%), while 11 cases (22%) were deceased. Mean overall survival time was 68.2±39.5 (2-148) months. NGAL expression was negative in all tumors except the neutrophils within the tumors. KIM-1 expression was positive in 37 tumors (74%), while it was absent in 13 tumors (26%). Using Mann-Whitney U Analysis, KIM-1 expression was found to be associated with the stage of the tumor (p=0.027). The preliminary data indicates that KIM-1 expression may be associated with stage in Wilms Tumor. However, further studies are needed to validate these pilot observations and to clarify the functional and mechanistic significance of this relevance.