Background:The Pax8 transcription factor genes have a role in cell differentiation and cell growth, and silencing of Pax8 in cell cultures results in cell death. The aims of this study were to determine the expression and correlation of Pax8 protein with several clinicopathological variables in patients with endometrial cancer.Methods:The following clinical parameters from 229 patients were used for correlation with Pax8 expression; age, histological subtype, myometrial depth of invasion, lymphovascular invasion (LVI), the International Federation of Gynecology and Obstetrics grade, lymph nodes status, and disease status.Results:A positive association of Pax8+ expression was found with high tumour grade (P=0.002), LVI+(P=0.0186), and type II tumour subtype (P<0.0001) in univariate analysis. Survival analysis showed an association of Pax8 and 5-year overall survival probability (P=0.01486), 80.04% for patients with Pax8− and 55.59% for patients with Pax8+. There was also an association of Pax8 and 5-year disease-free survival probability (P=0.02028), 72.12% for patients with Pax8− vs 49.88% for patients with Pax8+. Finally, an association of Pax8+ and shorter recurrence-free survival was also found (P=0.00203), with 74.36% for Pax8− and 52.11% for Pax8+.Conclusion:Overexpression of Pax8 protein by endometrial cancer is associated with poor disease outcomes. Inhibition of Pax8 may be a very attractive targeted therapy for selective patients.

Recent studies have demonstrated that in clear cell renal cell carcinoma (ccRCC) several chromatin remodeling enzymes are genetically inactivated. Although, growing evidence in cancer models has demonstrated the importance of epigenetic changes, currently only changes in DNA methylation can be accurately determined from clinical samples. To address this limitation, we have applied formaldehyde-assisted isolation of regulatory elements (FAIREs) combined with next-generation sequencing (FAIRE-seq) to identify specific changes in chromatin accessibility in clinical samples of ccRCC. We modified the FAIRE procedure to allow us to examine chromatin accessibility for small samples of solid tumors. Our FAIRE results were compared with DNA-methylation analysis and show how chromatin accessibility decreases at many sites where DNA-methylation remains unchanged. In addition, our FAIRE-seq analysis allowed us to identify regulatory elements associated with both normal and tumor tissue. We have identified decreases in chromatin accessibility at key ccRCC-linked genes, including PBRM1, SETD2 and MLL2. Overall, our results demonstrate the power of examining multiple aspects of the epigenome.