<?xml version='1.0' encoding='UTF-8'?><xml><records><record><source-app name="HighWire" version="7.x">Drupal-HighWire</source-app><ref-type name="Journal Article">17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">ILIEV, ROBERT</style></author><author><style face="normal" font="default" size="100%">FEDORKO, MICHAL</style></author><author><style face="normal" font="default" size="100%">MACHACKOVA, TANA</style></author><author><style face="normal" font="default" size="100%">MLCOCHOVA, HANA</style></author><author><style face="normal" font="default" size="100%">SVOBODA, MAREK</style></author><author><style face="normal" font="default" size="100%">PACIK, DALIBOR</style></author><author><style face="normal" font="default" size="100%">DOLEZEL, JAN</style></author><author><style face="normal" font="default" size="100%">STANIK, MICHAL</style></author><author><style face="normal" font="default" size="100%">SLABY, ONDREJ</style></author></authors><secondary-authors></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Expression Levels of PIWI-interacting RNA, piR-823, Are Deregulated in Tumor Tissue, Blood Serum and Urine of Patients with Renal Cell Carcinoma</style></title><secondary-title><style face="normal" font="default" size="100%">Anticancer Research</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2016</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2016-12-01 00:00:00</style></date></pub-dates></dates><pages><style  face="normal" font="default" size="100%">6419-6423</style></pages><volume><style face="normal" font="default" size="100%">36</style></volume><issue><style face="normal" font="default" size="100%">12</style></issue><abstract><style  face="normal" font="default" size="100%">Background: Renal cell carcinoma (RCC) is the most common neoplasm of adult kidney accounting for about 3% of adult malignancies. P-Element induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are a new class of naturally occurring, short non-coding RNAs involved in silencing of transposable elements and in sequence-specific chromatin modifications. There were preliminary data published indicating that piR-823 expression is deregulated in circulating tumor cells and tumor tissue in gastric and kidney cancer, respectively. Patients and Methods: In our study, we analyzed piR-823 levels in 588 biological specimens: tumor tissue (N=153), adjacent renal parenchyma (N=121), blood serum (N=178) and urine (N=20) of patients undergoing nephrectomy for RCC; and in blood serum (N=101) and urine (N=15) of matched healthy controls. Expression levels of piR-823 were determined in all biological specimens by quantitative real-time polymerase chain reaction, compared in patients and controls, and correlated with clinicopathological features of RCC. Results: We identified a significant down-regulation of piR-823 in tumor tissue [p&lt;0.0001, area under the curve (AUC)=0.7945]. On the contrary in blood serum and urine, the expression of piR-823 was significantly higher in patients with RCC compared to healthy individuals (p=0.0005, AUC=0.6264 and p=0.0157, AUC=0.7433, respectively). We further observed higher levels of piR-823 in tumor tissue to be associated with shorter disease-free survival of patients (p=0.0186) and a trend for higher piR-823 levels in serum to be associated with advanced clinical stages of RCC (p=0.0691). There were no other significant associations of piR-823 levels in any type of biological specimen with clinicopathological features of RCC. Conclusion: piR-823 is down-regulated in tumor tissue, but positively correlated with worse outcome, indicating its complex role in RCC pathogenesis. In blood serum, piR-823 is up-regulated, but with unsatisfactory analytical performance. Preliminary data indicate the promising diagnostic utility of urinary piR-823 in patients with RCC.</style></abstract></record></records></xml>