Semirigid ureteroscopy prior retrograde intrarenal surgery (RIRS) helps to select the right ureteral access sheath.

OBJECTIVE: To evaluate ureteral compliance through semirigid ureteroscopy (sURS) in order to select the proper ureteral access sheath (UAS) size for retrograde intrarenal surgery (RIRS). PATIENTS AND METHODS: In a prospective study, 100 consecutive patients selected for elective sURS or RIRS were recruited. Each patient, initially underwent 9.5 Fr sURS with a safety guidewire 3Fr, in order to estimate ureteral compliance. If the ureter was compliant, a gently passage of a 12/14Fr UAS was attempted. If the ureter was not deemed compliant, passage of either a smaller UAS or a smaller semirigid 7Fr or a flexible 7.5Fr or a digital 8.5Fr scope with and without safety guidewire, was attempted. Age, gender, disease location, prestenting, previous RIRS and/or stone elimination, hydronephrosis, ureteral strictures, unsuccessful procedures, and complications, were analyzed as possible correlated factors of ureteral compliance. RESULTS: In 77 patients the ureter was deemed compliant ≥ 14Fr. Of the preoperative factors that were examined, stent placement before RIRS (P < 0.002), previous RIRS (P = 0.000) and previous stone elimination (P = 0.004), correlated with ureter ≥ 14Fr. Ureteral lithiasis (P < 0.001), ureteral strictures (P < 0.05), unsuccessful procedures (P < 0.005) and complications (P = 0.01) correlated with ureter < 14Fr. The complication rate was 10% (10 patients) with ureteral injuries grade I in 9 patients and grade III in 1 patient according to the endoscopic grading system. Age, gender, hydronephrosis and urothelial carcinoma (UC) had no influence. CONCLUSIONS: sURS performed before RIRS allows selection of the right ureteral access sheath (UAS) and avoidance of major complications. Pre-stenting, previous RIRS and stone elimination history are all factors correlating with a compliant ureter.

Identification of common differentially expressed genes in urinary bladder cancer.

BACKGROUND: Current diagnosis and treatment of urinary bladder cancer (BC) has shown great progress with the utilization of microarrays. PURPOSE: Our goal was to identify common differentially expressed (DE) genes among clinically relevant subclasses of BC using microarrays. METHODOLOGY/PRINCIPAL FINDINGS: BC samples and controls, both experimental and publicly available datasets, were analyzed by whole genome microarrays. We grouped the samples according to their histology and defined the DE genes in each sample individually, as well as in each tumor group. A dual analysis strategy was followed. First, experimental samples were analyzed and conclusions were formulated; and second, experimental sets were combined with publicly available microarray datasets and were further analyzed in search of common DE genes. The experimental dataset identified 831 genes that were DE in all tumor samples, simultaneously. Moreover, 33 genes were up-regulated and 85 genes were down-regulated in all 10 BC samples compared to the 5 normal tissues, simultaneously. Hierarchical clustering partitioned tumor groups in accordance to their histology. K-means clustering of all genes and all samples, as well as clustering of tumor groups, presented 49 clusters. K-means clustering of common DE genes in all samples revealed 24 clusters. Genes manifested various differential patterns of expression, based on PCA. YY1 and NFκB were among the most common transcription factors that regulated the expression of the identified DE genes. Chromosome 1 contained 32 DE genes, followed by chromosomes 2 and 11, which contained 25 and 23 DE genes, respectively. Chromosome 21 had the least number of DE genes. GO analysis revealed the prevalence of transport and binding genes in the common down-regulated DE genes; the prevalence of RNA metabolism and processing genes in the up-regulated DE genes; as well as the prevalence of genes responsible for cell communication and signal transduction in the DE genes that were down-regulated in T1-Grade III tumors and up-regulated in T2/T3-Grade III tumors. Combination of samples from all microarray platforms revealed 17 common DE genes, (BMP4, CRYGD, DBH, GJB1, KRT83, MPZ, NHLH1, TACR3, ACTC1, MFAP4, SPARCL1, TAGLN, TPM2, CDC20, LHCGR, TM9SF1 and HCCS) 4 of which participate in numerous pathways. CONCLUSIONS/SIGNIFICANCE: The identification of the common DE genes among BC samples of different histology can provide further insight into the discovery of new putative markers.

Implication of RAF and RKIP genes in urinary bladder cancer.

RKIP has been shown to regulate the RAS-RAF-MEK-ERK kinase cascade acting as modulator of apoptosis and metastasis in prostate cancer. Our goal was to examine the expression of the RAF (A-RAF, B-RAF and RAF-1) and RKIP genes in urinary bladder cancer. Microarray analysis and qPCR was employed to investigate the expression of RAF and RKIP, in 30 patients with transitional cell carcinoma (TCC) of the urinary bladder vs. the corresponding levels of adjacent normal tissue. Computational analysis was also performed on Gene Expression Omnibus (GEO) datasets, to unravel differences in the expression of RAF or RKIP between tumor and control samples, and between superficial and muscle invasive tumors. Microarray analysis revealed >2-fold expression of BRAF and RKIP in T2, T3, grade III tumors vs. controls. B-RAF over-expression was verified by qPCR in pT1, grade III tumors vs. their normal counterparts (p = 0.016). qPCR revealed a significant RKIP reduction in TCC vs. normal tissue (p = 0.002 and p < 0.001 for T1, grade II and Ta-T1, grade III, respectively); All RAF genes were positively correlated among each other (A-RAF/B-RAF, p = 0.003; A-RAF/RAF-1, p < 0.001; B-RAF/RAF-1, p = 0.050), whereas B-RAF was negatively correlated with RKIP in TCC (p = 0.050). Further computational analysis revealed different expression profiles for the genes of interest, among muscle invasive carcinomas, superficial TCCs, cystectomy specimens and normal tissue. The reduced RKIP mRNA levels in TCC and the elevated levels of B-RAF in pT1, grade III tumors vs. normal tissue, corroborate that these genes are involved in the pathogenesis of urinary bladder cancer.

Mutational analysis of the BRAF gene in transitional cell carcinoma of the bladder.

PURPOSE: Mutational activation of the MAP kinase pathway is frequently found in many types of cancer. Recently, activating mutations in the BRAF gene, an important activator of this pathway, have been described in several tumor types including melanoma, colorectal and papillary thyroid cancer. The most frequent mutation in exon 15 (V600E) as well as several other mutations within exons 11 and 15 result in constitutive activation of the oncoprotein. MATERIALS AND METHODS: Our study aimed to investigate BRAF mutations in 30 human bladder tumors and their adjacent normal tissues. The V600E mutation was screened by PCR/RFLP and exons 11, 14 and 15 of BRAF including intron-exon boundaries were sequenced. RESULTS: We detected two tumor specimens bearing two different mutations, both of which were found in exon 15. One sample showed the T1799A (V600E) and the other the G1798T (V600L) mutation. The first specimen was stage pT1a and grade II, whereas the second was stage pT2b and grade III. No mutations within the coding region of exons 11, 14, 15 and the intron-exon junctions for the remaining samples were found. CONCLUSIONS: Our results suggest that involvement of BRAF mutations in the development of transitional cell carcinoma of the bladder is infrequent.