However, these studies were restricted to only one inflammatory marker, and none of the studies provided a comprehensive view of the inflammatory microenvironment in pediatric tumors or correlated the presence of these markers with inflammation in WT. To learn more about the role of the inflammatory microenvironment in the development of WT, we analyzed tumors for various inflammatory markers and inflammatory immune cells by immunohistochemical (IHC) staining. Overall, we found that WT exhibited infiltration of inflammatory

immune cells and overexpression of several inflammatory transcription factors and other inflammatory markers compared with normal kidneys. Our data suggest that a COX-2–mediated inflammatory microenvironment IWR-1 research buy may be important in WT tumorigenesis and that investigating the potential utility of therapeutic targeting of this environment is warranted. Pretreatment tumor tissues and autologous normal kidney specimens were obtained from 16 WT patients aged 7 to 66 months at the time of diagnosis. Informed consent was obtained from each patient’s parent or guardian. Studies were approved by the Institutional Review Board and in accordance with an assurance filed with and approved by the US Department CDK inhibitor of Health and Human Services. Eight of the patients were males and eight were females, and one patient had bilateral disease.

Of these 16 patients, 4 were at stage IV, 4 were at stage III, 3 were at stage II, and 5 were at stage I of WT disease. Tissues were fixed in formalin and embedded in paraffin (FFPE)

in preparation for analysis. A mouse model for the human WT has been generated in our laboratory [9] by Wt1 gene ablation and insulin-like growth factor 2 (IGF2) up-regulation by conditional knockout strategy (Wt1−/flH19+/−mCre-ERTM or Wt1-IGF2 mice). These mice developed tumors at the age of 3 months on an average. The tumors and normal kidneys from its littermate controls were collected at the similar age and processed as mentioned earlier for histology and IHC analysis. FFPE specimens were cut in 5-μm sections, which were stained with hematoxylin and eosin. For IHC analysis, FFPE sections Aprepitant were deparaffinized in xylene, rehydrated sequentially in ethanol (100%, 90%, and 70%), and placed into a 1% phosphate-buffered saline solution (PBS; pH 7.4). Tissues were analyzed for infiltration by T cells, B cells, macrophages, neutrophils, and mast cells (MCs). Inflammatory markers analyzed were COX-2, HIF-1, phosphorylated extracellular signal–related kinases 1 and 2 (p-ERK1/2), phosphorylated STAT3 (p-Stat3), inducible nitric oxide synthase (iNOS), nitrotyrosine (NT), and VEGF. Simultaneously, to prove the similar expression and infiltration pattern in the mouse model of WT, mouse tumor tissues and control kidneys were immunostained for inflammatory marker COX-2 and predominant inflammatory immune cells, macrophages (F4/80). Details of antibody staining and epitope retrieval are summarized in Table W1.