Alteration of Cadherin 3 Expression and DNA Methylation in Association with Aggressive Renal Cell Carcinoma.

Cadherins (calcium-dependent adhesion proteins) are important in cellular adhesion and may play a role in the development and progression of renal cell carcinoma (RCC). This study investigated changes in cadherin 3 (CDH3; P-cadherin) mRNA expression, DNA methylation, and protein expression in RCC and compared the results with the histopathological and clinical characteristics of patients. The possible contribution of CDH3 to tumor cell invasiveness was tested in a functional assay using siRNA-based suppression of CDH3 expression and subsequent real-time impedance analysis using a Matrigel invasion model. Our analyses revealed a tumor-specific loss of CDH3 mRNA expression, CDH3 DNA hypermethylation, and loss of distal tubular and collecting duct CDH3 protein expression in RCC. A relatively higher methylation level in tumors was associated with a loss of cell differentiation and higher clinical stage. siRNA-induced suppression of CDH3 expression modulated the invasion characteristics of tumor cells in the impedance-based real-time cellular analysis. Our results indicate that loss of CDH3 expression is common in RCC and may contribute to the pathogenesis of a subset of RCC. Further studies to reveal the mechanisms of loss of expression and its effects on the invasive behavior of renal tumor cells are required.

Age-Related DNA Methylation in Normal Kidney Tissue Identifies Epigenetic Cancer Risk Susceptibility Loci in the ANKRD34B and ZIC1 Genes.

Both age-dependent and age-independent alteration of DNA methylation in human tissues are functionally associated with the development of many malignant and non-malignant human diseases. TCGA-KIRC data were biometrically analyzed to identify new loci with age-dependent DNA methylation that may contribute to tumor risk in normal kidney tissue. ANKRD34B and ZIC1 were evaluated as candidate genes by pyrosequencing of 539 tissues, including 239 normal autopsy, 157 histopathologically tumor-adjacent normal, and 143 paired tumor kidney samples. All candidate CpG loci demonstrated a strong correlation between relative methylation levels and age (R = 0.70−0.88, p < 2 × 10−16) and seven out of 10 loci were capable of predicting chronological age in normal kidney tissues, explaining 84% of the variance (R = 0.92). Moreover, significantly increased age-independent methylation was found for 9 out of 10 CpG loci in tumor-adjacent tissues, compared to normal autopsy tissues (p = 0.001−0.028). Comparing tumor and paired tumor-adjacent tissues revealed two patient clusters showing hypermethylation, one cluster without significant changes in methylation, and a smaller cluster demonstrating hypomethylation in the tumors (p < 1 × 10−10). Taken together, our results show the presence of additional methylation risk factors besides age for renal cancer in normal kidney tissue. Concurrent tumor-specific hypermethylation suggests a subset of these loci are candidates for epigenetic renal cancer susceptibility.

Identification of a Novel Renal Metastasis Associated CpG-Based DNA Methylation Signature (RMAMS).

Approximately 21% of patients with renal cell cancer (RCC) present with synchronous metastatic disease at the time of diagnosis, and metachronous metastatic disease occurs in 20-50% of cases within 5 years. Recent advances in adjuvant treatment of aggressive RCC following surgery suggest that biomarker-based prediction of risk for distant metastasis could improve patient selection. Biometrical analysis of TCGA-KIRC data identified candidate loci in the NK6 homeobox 2 gene (NKX6-2) that are hypermethylated in primary metastatic RCC. Analyses of NKX6-2 DNA methylation in three gene regions including a total of 16 CpG sites in 154 tumor-adjacent normal tissue, 189 RCC, and 194 metastatic tissue samples from 95 metastasized RCC patients revealed highly significant tumor-specific, primary metastatic-specific, and metastatic tissue-specific hypermethylation of NKX6-2. Combined CpG site methylation data for NKX6-2 and metastasis-associated genes (INA, NHLH2, and THBS4) demonstrated similarity between metastatic tissues and metastatic primary RCC tissues. The random forest method and evaluation of an unknown test cohort of tissues using receiver operator characteristic curve analysis revealed that metastatic tissues can be differentiated by a median area under the curve of 0.86 (p = 1.7 × 10-8-7.5 × 10-3) in 1000 random runs. Analysis of variable importance demonstrated an above median contribution for decision-making of at least one CpG site in each of the genes, suggesting superior informativity for sites annotated to NHLH2 and NKX6-2. Thus, DNA methylation of NKX6-2 is associated with the metastatic state of RCC tissues and contributes to a four-gene-based statistical predictor of tumoral and metastatic renal tissues.

DNA methylation of tumor associated calcium signal transducer 2 (TACSTD2) loci shows association with clinically aggressive renal cell cancers.

BACKGROUND: DNA methylation is frequently observed in the development and progression of many human tumors as well as renal cell cancer (RCC). Tumor Associated Calcium Signal Transducer 2 (TACSTD2) participates in cell cycle progression through MAPK signalling pathway activation. Moreover, tumor-specific hypermethylation and association with aggressive cancer characteristics has been found for lung adenocarcinoma, hepatocellular carcinoma and cholangiocarcinoma. Whether TACSTD2 is tumor specifically hypermethylated in RCC or shows association of methylation with adverse clinicopathological parameters and survival of patients has not been investigated at yet. METHODS: Quantitative methylation-specific PCR (qMSP) analysis of a locus in the intron 1 region of TACSTD2 gene was carried out in a cross-sectional study of 127 paired RCC and normal samples. In silico analysis of TACSTD2 methylation in the TCGA Kidney Renal Clear Cell Carcinoma (KIRC) dataset of 280 patients served as validation cohort. Statistical analyses were carried out using the two-sided paired t-test for matched tumor and normal sample comparisons, logistic regression for subgroup comparisons, Cox regression for analysis of recurrence free survival (RFS) and Pearson correlation analysis for correlation of TACSTD2 methylation and TACSTD2 mRNA in KIRC data. RESULTS: Higher methylation levels in RCC were significantly associated with advanced disease (p < 0.001), high tumor stage (p = 0.003), tumor differentiation (p = 0.033) and presence of lymph node (p = 0.021) or distant metastases (p = 0.008). TACSTD2 hypermethylation was associated with a shorter RFS of patients and demonstrate statistical independency from clinical parameters as state of metastasis, tumor stage, grade and state of advanced disease. In silico validation using TCGA KIRC data also demonstrated association of TACSTD2 loci with adverse clinicopathology and shortened RFS of patients. In addition, in silico analyses of TCGA KIRC data showed an inverse correlation between DNA methylation levels of TACSTD2 and mRNA expression. CONCLUSIONS: Our results suggest an association between TACSTD2 methylation and disease progression and clinical course of RCC.

Decreased GATA5 mRNA expression associates with CpG island methylation and shortened recurrence-free survival in clear cell renal cell carcinoma.

BACKGROUND: GATA-5, a zinc-finger transcription factor and member of the GATA family proteins 1-6, is known to be involved in cellular differentiation. We recently found that tumor-specific hypermethylation of the GATA5 CpG island (CGI) occurs in renal cell carcinoma (RCC) and is associated with an adverse clinical outcome. In this study, we investigated whether epigenetic GATA5 alterations may result in changes in GATA5 mRNA expression levels and correlate with the observed prognostic impact of epigenetic changes in GATA5 in RCC. METHODS: Quantitative real-time reverse-transcribed polymerase chain reaction was applied to measure relative GATA5 mRNA expression levels in 135 kidney tissue samples, including 77 clear cell RCC (ccRCC) tissues and 58 paired adjacent normal renal tissue samples. Relative GATA5 expression levels were determined using the ΔΔCt method and detection of three endogenous control genes then compared to previously measured values of relative methylation. RESULTS: The mean relative GATA5 mRNA expression level exhibited an approximately 31-fold reduction in tumor specimens compared with corresponding normal tissues (p < 0.001, paired t-test). Decreased GATA5 mRNA expression was inversely correlated with increased GATA5 CGI methylation (p < 0.001) and was associated with shortened recurrence-free survival in ccRCC patients (p = 0.023, hazard ratio = 0.25). CONCLUSION: GATA5 mRNA expression is decreased in ccRCC, likely due to gene silencing by methylation of the GATA5 CGI. Moreover, reduced GATA5 mRNA levels were associated with a poor clinical outcome, indicating a possible role of GATA5 for the development of aggressive ccRCC phenotypes.

Reduced mRNA expression level of corticotropin-releasing hormone-binding protein is associated with aggressive human kidney cancer.

BACKGROUND: Significance of Urocortin (Ucn or UcnI), Ucn2, Ucn3 and their receptors, Corticotropin Releasing Factor Receptor 1 and 2 (CRFR1 and CRFR2), and the binding protein, Corticotropin-Releasing Hormone-Binding Protein (CRHBP) in oncology is growing rapidly. The objective of our study was to assess the expression of the CRHBP mRNA and protein in renal cancer. METHODS: Tumoral tissues of 78 patients with clear cell renal cell cancer and their corresponding normal tissues were analyzed using quantitative mRNA expression analysis for detection of mRNA expression level. Protein expression and tissue localization of CRHBP protein in renal specimens was evaluated using western blotting, immunohistochemistry and double immunofluorescence, respectively. RESULTS: We found an approx. 33 fold decrease of average CRHBP mRNA level in tumoral tissues compared to paired normal tissues (p<0.001). Diminished CRHBP mRNA expression was positively correlated with advanced, metastasized and higher stage of disease (p<0.001, p=0.026, p=0.028 respectively). CRHBP protein was detected in glomeruli and proximal tubules of normal kidney while none or weak immunopositivity was found in cc-RCC (p<0.001). CONCLUSIONS: The expression analysis of CRHBP shows that cc-RCC is characterized by a significant loss of CRHBP mRNA expression that furthermore is associated with a more aggressive state of tumors. Depletion of CRHBP proteins also indicate that the protein as part of the UCN system may be involved in renal carcinogenesis.

GATA5 CpG island methylation in renal cell cancer: a potential biomarker for metastasis and disease progression.

UNLABELLED: GATA5 CpG island (CGI) methylation and transcriptional inactivation is involved in colorectal and gastric cancer. Whether DNA methylation of GATA5 affects clinical pathology is still unclear. In the present study, we analysed, for the first time, CGI methylation in RCC and its association with clinicopathological parameters and progression-free survival of patients. We show for the first time GATA5 CGI hypermethylation in RCC. Moreover, we found out that increased methylation is statistically associated with status of metastasis, progressive disease and shortened progression-free survival. The present study underline the necessity for further functional investigations as well as prospective survival analyses to clarify whether GATA5 promoter methylation can provide independent information for future clinical management of patients with RCC. OBJECTIVE: To investigate whether GATA5 CpG island (CGI) methylation occurs in renal cell carcinoma (RCC) and is associated with clinical, histopathological characteristics or progression-free survival of patients. PATIENTS AND METHODS: Methylation was quantified in 117 RCC samples and 89 paired adjacent normal tissues using quantitative combined bisulphite restriction analysis (COBRA). COBRA was evaluated in advance by pyrosequencing analyses of control RCC cell lines (coefficient of correlation, R = 0.95). Statistical analyses were carried out using the paired t-test for matched tumour tissue (TU) and adjacent normal tissue (adN) samples, logistic regression for comparisons of independent sample groups and Cox regression for analysis of progression-free survival. RESULTS: In the present study, we found a significant higher mean relative methylation in TU (20.4%) than in adN (7.9%, P < 0.001) in paired samples of all RCCs. Increased GATA5 methylation in tumours was associated with metastasis (P = 0.005) and decreased progression-free survival (P = 0.005, HR = 4.59) in the clear-cell RCC (ccRCC) group. CGI methylation in advanced ccRCCs (pT ≥3 and/or N1, M1 or G2-3/G3) exceeds those detected in localized tumours (pT ≤2, N0, M0, G1/G1-2) (27.8% vs 11.0%, P < 0.001). CONCLUSIONS: The association of GATA5 hypermethylation with metastasis and progression-free survival of patients indicates that epigenetic alterations of GATA5 participate in renal cell carcinogenesis. Moreover, GATA5 CGI methylation could serve as a biomarker for tumour progression, although prospective and functional investigations are necessary to clarify whether independent information for future clinical management of patients with RCC can be obtained.

Caveolin 1 protein expression in renal cell carcinoma predicts survival.

BACKGROUND: Caveolae play a significant role in disease phenotypes such as cancer, diabetes, bladder dysfunction, and muscular dystrophy. The aim of this study was to elucidate the caveolin-1 (CAV1) protein expression in renal cell cancer (RCC) and to determine its potential prognostic relevance. METHODS: 289 clear cell RCC tissue specimens were collected from patients undergoing surgery for renal tumors. Both cytoplasmic and membranous CAV1 expression were determined by immunohistochemistry and correlated with clinical variables. Survival analysis was carried out for 169 evaluable patients with a median follow up of 80.5 months (interquartile range (IQR), 24.5-131.7 months). RESULTS: A high CAV1 expression in the tumor cell cytoplasm was significantly associated with male sex (p = 0.04), a positive nodal status (p = 0.04), and poor tumor differentiation (p = 0.04). In contrast, a higher than average (i.e. > median) CAV1 expression in tumor cell membranes was only linked to male sex (p = 0.03). Kaplan-Meier analysis disclosed significant differences in 5-year overall (51.4 vs. 75.2%, p = 0.001) and tumor specific survival (55.3 vs. 80.1%, p = 0.001) for patients with higher and lower than average cytoplasmic CAV1 expression levels, respectively. Applying multivariable Cox regression analysis a high CAV1 protein expression level in the tumor cell cytoplasm could be identified as an independent poor prognostic marker of both overall (p = 0.02) and tumor specific survival (p = 0.03) in clear cell RCC patients. CONCLUSION: Over expression of caveolin-1 in the tumour cell cytoplasm predicts a poor prognosis of patients with clear cell RCC. CAV1 is likely to be a useful prognostic marker and may play an important role in tumour progression. Therefore, our data encourage further investigations to enlighten the role of CAV1 and its function as diagnostic and prognostic marker in serum and/or urine of RCC patients.

Decreased galectin-8 is a strong marker for recurrence in urothelial carcinoma of the bladder.

OBJECTIVE: To investigate galectin-8 expression patterns in normal urothelium and bladder cancer specimens and to elucidate its prognostic value. MATERIALS AND METHODS: 162 samples of non-muscle-invasive transitional cell carcinoma, 25 samples of muscle-invasive transitional cell carcinoma and 10 samples of normal urothelium were investigated by immunohistochemistry using tissue microarrays. Complete patient and tumor characteristics were compared with galectin-8 staining patterns. The likelihood of tumor recurrence and progression was analyzed based on a 3-year follow-up. RESULTS: Loss of galectin-8 was associated with the likelihood of tumor recurrence in univariate (p < 0.05) and multivariate analyses (p < 0.01). No significance was observed for tumor progression. Patients whose specimens showed weak galectin-8 expression had a shorter recurrence-free interval (42 vs. 12 months; p < 0.01, log-rank test). All of the 10 normal urothelium samples showed high galectin-8 expression. Decreased staining was found to be associated with higher tumor stages and grades (p < 0.0001, one-way ANOVA). A significant difference was found comparing normal urothelium with any tumor stage (p < 0.01), pTa vs. pT1 tumors (p < 0.05) and non-muscle-invasive vs. muscle-invasive tumors (p < 0.0001). CONCLUSIONS: Loss of galectin-8 might be an early step in the development of malignant lesions of the bladder and is a significant independent predictor of recurrence.

DNA Methylation in INA, NHLH2, and THBS4 Is Associated with Metastatic Disease in Renal Cell Carcinoma.

The detection of DNA methylation in primary tumor tissues could be relevant for early stratification of aggressive renal cell carcinomas (RCCs) as a basis for future personalized adjuvant therapy. Methylated TCGA KIRC based candidate CpG loci in INA, NHLH2, and THBS4 that are possibly associated with RCC metastasis were evaluated by pyrosequencing in 154 paired normal adjacent and primary tumor tissues, as well as in 202 metastatic tissues. Statistical analysis was carried out by bivariate logistic regression for group comparisons, log rank survival analysis, and unsupervised and supervised analysis for the classification of tumors. Increased methylation of INA, NHLH2, and THBS4 loci were significantly associated with distant metastasis in primary tumors (p < 0.05), tissue-specific hypermethylation in metastatic (p = 7.88 × 10-8, 5.57 × 10-10, 2.06 × 10-7) and tumor tissues (p = 3.72 × 10-24, 3.17 × 10-13, 1.58 × 10-19), and shortened progression free survival in patients (p = 0.03). Combined use of CpG site-specific methylation permits the discrimination of tissues with metastatic disease and reveals a significant contribution of CpG sites in all genes to the statistical classification model. Thus, metastasis in RCC is significantly associated with methylation alterations in INA, NHLH2, and THBS4 loci, providing independent information for the potential early detection of aggressive renal cancers as a rationale for stratifying patients to adjuvant therapies.

Fibronectin 1 mRNA expression correlates with advanced disease in renal cancer.

BACKGROUND: Fibronectin 1 (FN1) is a glycoprotein involved in cellular adhesion and migration processes. The aim of this study was to elucidate the role of FN1 in development of renal cell cancer (RCC) and to determine a prognostic relevance for optimal clinical management. METHODS: 212 renal tissue samples (109 RCC, 86 corresponding tissues from adjacent normal renal tissue and 17 oncocytomas) were collected from patients undergoing surgery for renal tumors and subjected to total RNA extraction. Detection of FN1 mRNA expression was performed using quantitative real time PCR, three endogenous controls, renal proximal tubular epithelial cells (RPTEC) as biological control and the ΔΔCt method for calculation of relative quantities. RESULTS: Mean tissue specific FN1 mRNA expression was found to be increased approximately seven fold comparing RCC and corresponding kidney control tissues (p < 0.001; ANOVA). Furthermore, tissue specific mean FN1 expression was increased approx. 11 fold in clear cell compared to papillary RCC (p = 9×10-5; Wilcoxon rank sum test). Patients with advanced disease had higher FN1 expression when compared to organ-confined disease (p < 0.001; Wilcoxon rank sum test). Applying subgroup analysis we found a significantly higher FN1 mRNA expression between organ-confined and advanced disease in the papillary and not in the clear cell RCC group (p = 0.02 vs. p = 0.2; Wilcoxon rank sum test). There was an increased expression in RCC compared to oncocytoma (p = 0.016; ANOVA). CONCLUSIONS: To our knowledge, this is the first study to show that FN1 mRNA expression is higher in RCC compared to normal renal tissue. FN1 mRNA expression might serve as a marker for RCC aggressiveness, indicating early systemic progression particularly for patients with papillary RCC.

Cancer-Specific Loss of Urocortin 3 in Human Renal Cancer.

INTRODUCTION: The corticotropin-releasing hormone (CRH) system, its receptors corticotropin-releasing hormone receptor 1 (CRHR1) and 2 (CRHR2), and its corresponding binding protein corticotropin-releasing hormone-binding protein (CRHBP) as well as the urocortin proteins-structural homologues to CRH, which are included in this peptide family-have become interesting oncological targets recently. Carcinogenesis of various human tumors has been reported with an altered presence of members of this system. The aim of the present study was to examine the role of urocortin 3 (UCN3) in renal cell carcinoma (RCC). METHODS: Therefore, tumoral tissues of 106 patients with RCC and available corresponding normal tissues were analyzed using qPCR for quantitative mRNA expression analysis. Tissue localization and protein signals of UCN3 in normal and tumoral renal specimens were evaluated using western blot and immunohistochemistry. In addition, correlation studies of UCN3 mRNA expression with clinicopathological parameters of patients with RCC and different histological subtypes were evaluated. RESULTS: UCN3 mRNA was significantly downregulated in nearly all tumoral tissues (p = 7.92 × 10-13). The same effect was observed at protein level using immunohistochemistry. Level of UCN3 mRNA expression was not directly correlated with clinicopathological parameters. CONCLUSION: We report for the first time the significant downregulation of UCN3 in RCC. These results demonstrate a possible involvement of the CRH system and its significance in carcinogenesis of RCC.

Age-, tumor-, and metastatic tissue-associated DNA hypermethylation of a T-box brain 1 locus in human kidney tissue.

BACKGROUND: While a considerable number of tumor-specific hypermethylated loci have been identified in renal cell cancer (RCC), DNA methylation of loci showing successive increases in normal, tumoral, and metastatic tissues could point to genes with high relevance both for the process of tumor development and progression. Here, we report that DNA methylation of a locus in a genomic region corresponding to the 3'UTR of the transcription factor T-box brain 1 (TBR1) mRNA accumulates in normal renal tissues with age and possibly increased body mass index. Moreover, a further tissue-specific increase of methylation was observed for tumor and metastatic tissue samples. RESULTS: Biometric analyses of the TCGA KIRC methylation data revealed candidate loci for age-dependent and tumor-specific DNA methylation within the last exon and in a genomic region corresponding to the 3'UTR TBR1 mRNA. To evaluate whether methylation of TBR1 shows association with RCC carcinogenesis, we measured 15 tumor cell lines and 907 renal tissue samples including 355 normal tissues, 175 tissue pairs of normal tumor adjacent and corresponding tumor tissue as well 202 metastatic tissues samples of lung, bone, and brain metastases by the use of pyrosequencing. Statistical evaluation demonstrated age-dependent methylation in normal tissue (R = 0.72, p < 2 × 10-16), association with adiposity (P = 0.019) and tumor-specific hypermethylation (P = 6.1 × 10-19) for RCC tissues. Comparison of tumor and metastatic tissues revealed higher methylation in renal cancer metastases (P = 2.65 × 10-6). CONCLUSIONS: Our analyses provide statistical evidence of association between methylation of TBR1 and RCC development and disease progression.

Notch signalling in the paraxial mesoderm is most sensitive to reduced Pofut1 levels during early mouse development.

BACKGROUND: The evolutionarily conserved Notch signalling pathway regulates multiple developmental processes in a wide variety of organisms. One critical posttranslational modification of Notch for its function in vivo is the addition of O-linked fucose residues by protein O-fucosyltransferase 1 (POFUT1). In addition, POFUT1 acts as a chaperone and is required for Notch trafficking. Mouse embryos lacking POFUT1 function die with a phenotype indicative of global inactivation of Notch signalling. O-linked fucose residues on Notch can serve as substrates for further sugar modification by Fringe (FNG) proteins. Notch modification by Fringe differently affects the ability of ligands to activate Notch receptors in a context-dependent manner indicating a complex modulation of Notch activity by differential glycosylation. Whether the context-dependent effects of Notch receptor glycosylation by FNG reflect different requirements of distinct developmental processes for O-fucosylation by POFUT1 is unclear. RESULTS: We have identified and characterized a spontaneous mutation in the mouse Pofut1 gene, referred to as "compact axial skeleton" (cax). Cax carries an insertion of an intracisternal A particle retrotransposon into the fourth intron of the Pofut1 gene and represents a hypomorphic Pofut1 allele that reduces transcription and leads to reduced Notch signalling. Cax mutant embryos have somites of variable size, showed partly abnormal Lfng expression and, consistently defective anterior-posterior somite patterning and axial skeleton development but had virtually no defects in several other Notch-regulated early developmental processes outside the paraxial mesoderm that we analyzed. CONCLUSION: Notch-dependent processes apparently differ with respect to their requirement for levels of POFUT1. Normal Lfng expression and anterior-posterior somite patterning is highly sensitive to reduced POFUT1 levels in early mammalian embryos, whereas other early Notch-dependent processes such as establishment of left-right asymmetry or neurogenesis are not. Thus, it appears that in the presomitic mesoderm (PSM) Notch signalling is particularly sensitive to POFUT1 levels. Reduced POFUT1 levels might affect Notch trafficking or overall O-fucosylation. Alternatively, reduced O-fucosylation might preferentially affect sites that are substrates for LFNG and thus important for somite formation and patterning.

The involvement of altered corticotropin releasing factor receptor 2 expression in prostate cancer due to alteration of anti-angiogenic signaling pathways.

BACKGROUND: Expression of urocortin (Ucn) in the human benign prostate and prostate cancer has been reported recently. Ucn binds and activates corticotropin releasing factor (CRF) receptor 1 (CRFR1) and 2 (CRFR2). Activation of CRFR2 has been shown to inhibit tumor growth by regulation of proliferation and apoptosis as well as suppression of vascularization. However, there is no report demonstrating expression profile of CRFR2 in normal prostate versus prostate cancer. METHODS: CRFR2 mRNA expression was assessed in human normal prostate and prostate cancer by reverse transcriptase PCR. CRFR2 expression on protein level has been performed using double staining immunofluorescence (IF) of tissue microarrays of 32 cases of prostatic adenocarcioma with corresponding normal tissues. Confocal microscopy was carried out to visualize the immunostaining. RESULTS: PCR of normal prostate lysates exhibited specific signals for CRFR2 mRNA. However PCR of lysates of prostate cancer exhibited no signal for CRFR2 mRNA. IF study exhibited that smooth muscle components of the stroma and endothelial cells of blood vessels express an extensive staining for CRFR2. In a lesser extend vascular smooth muscle cells expressed CRFR2. The tumoral neovascular system and stroma exhibited no immunopositivity for CRFR2. CONCLUSIONS: The present study demonstrates for the first time that human benign prostate tissue and prostate cancer specimen differentially express CRFR2. While Ucn expression in prostate cancer has been shown to be identical to non-malignant prostate tissues, we hypothesize that expression loss of CRFR2 in prostate cancer and its neovascularization contributes to prostate tumorigenesis, progression, and neoangiogenesis.

DNA methylation biomarkers of prostate cancer: confirmation of candidates and evidence urine is the most sensitive body fluid for non-invasive detection.

BACKGROUND: A prostate cancer (PCa) biomarker with improved specificity relative to PSA is a public health priority. Hypermethylated DNA can be detected in body fluids from PCa patients and may be a useful biomarker, although clinical performance varies between studies. We investigated the performance of candidate PCa DNA methylation biomarkers identified through a genome-wide search. METHODS: Real-time PCR was used to measure four DNA methylation biomarkers: GSTP1 and three previously unreported candidates associated with the genes RASSF2, HIST1H4K, and TFAP2E in sodium bisulfite-modified DNA. Matched plasma and urine collected prospectively from 142 patients referred for prostate biopsy and 50 young asymptomatic males were analyzed. RESULTS: Analysis of all biomarkers in urine DNA significantly discriminated PCa from biopsy negative patients. The biomarkers discriminated PCa from biopsy negative patients with AUCs ranging from 0.64 for HIST1H4K (95% CI 0.55-0.72, P < 0.00001) to 0.69 for GSTP1 (95% CI 0.60-0.77, P < 0.00001). All biomarkers showed minimal correlation with PSA. Multivariate analysis did not yield a panel that significantly improved performance over that of single biomarkers. All biomarkers showed greater sensitivity for PCa in urine than in plasma DNA. CONCLUSIONS: Analysis of the biomarkers in urine DNA significantly discriminated PCa from biopsy negative patients. The biomarkers provided information independent of PSA and may warrant inclusion in nomograms for predicting prostate biopsy outcome. The biomarkers' PCa sensitivity was greater for urine than plasma DNA. The biomarker performances in urine DNA should next be validated in formal training and test studies.

Urocortin and corticotropin-releasing factor receptor 2 in human renal cell carcinoma: disruption of an endogenous inhibitor of angiogenesis and proliferation.

PURPOSE: Urocortin (Ucn) exerts its actions through activation of two corticotropin-releasing factor receptors (CRFRs), CRFR1 and CRFR2. Involvement of Ucn/CRFR2 system in pathophysiological conditions such as the regulation of angiogenesis and inhibition of proliferation has been already reported. Suppression of neovascularization through reduction of vascular endothelial growth factor and inhibition of tumor cell cycling is modulated mainly through activation of CRFR2. To find out a possible involvement of Ucn/CRFR2 in kidney tumor, we examined the expression of Ucn and CRFR2 in normal and tumoral kidney specimens. METHODS: We applied reverse transcriptase PCR (n=14), immunofluorescence (IF) on tissue microarrays (n=25) and confocal microscopy to examine the mRNA expression and peptide/protein localization of Ucn and CRFR2 in normal kidney versus clear cell renal cell carcinoma, respectively. RESULTS: Ucn and CRFR2 mRNAs are expressed in normal and tumor specimens. In normal tissue, IF showed a cytoplasmic staining of Ucn mainly in proximal tubules, whereas a diffuse nuclear staining with diverse intensity was observed in tumoral tissues. CRFR2 was detected in proximal tubules and vasculature of normal specimens. Intriguingly, an almost complete loss of CRFR2 was observed in epithelial cells and microvessels within tumor tissues. CONCLUSIONS: Here, and for the first time, we show the expression of Ucn and CRFR2 in human kidney and renal cell carcinoma. We propose that the nuclear translocation of Ucn along with the loss of CRFR2 in epithelial cells and microvasculature of tumoral specimens may be involved in the pathobiology of renal cell carcinoma.

TGFB1 gene polymorphism Leu10Pro (c.29T>C), prostate cancer incidence and quality of life in patients treated with brachytherapy.

OBJECTIVES: Transforming growth factor beta1 gene (TGFB1) variant Leu10Pro (L10P) has previously been implicated in prostate cancer risk and radiation-induced side-effects. We investigated whether prevalence of this polymorphism is increased in prostate cancer patients and whether carriers are at increased risk for treatment-related side effects. METHODS: A series of 445 consecutive patients treated for early-stage prostate cancer receiving definitive I-125 brachytherapy (permanent seed implantation) between 10/2000 and 10/2007 at our institution and a comparison group of 457 healthy male control individuals were screened for TGFB1 L10P (869T>C) polymorphism. Morbidity was assessed prospectively and compared between carriers versus non-carriers using International Prostate Symptom Score (IPSS), disease-specific Quality-of-Life single question added to the IPSS and International Index of Erectile Function with its subgroups. RESULTS: The Leu/Leu genotype was found in 150 patients (34%) versus 180 controls (39%), the Pro/Pro genotype in 75 patients (17%) versus 65 controls (14%) and the Leu/Pro genotype in 220 patients (49%) versus 212 controls (46%) without any statistically significant differences between the two groups. There was a trend towards an increased prevalence of the L10P substitution among patients with a per allele odds ratio of 1.19 (95% CI 0.99-1.44; P = 0.08). After a median follow-up of 18 months (range 1-60 months) there were no statistically significant differences regarding morbidity. CONCLUSIONS: TGFB1 polymorphism L10P is not strongly associated with prostate cancer risk. After 18 months, there was no evidence for increased adverse radiotherapy responses in heterozygote or rare homozygote carriers. Longer follow-up may be necessary to detect a statistically significant difference.

DNA methylation of sarcosine dehydrogenase (SARDH) loci as a prognosticator for renal cell carcinoma.

DNA methylation plays an important role in the genesis and progression of tumor diseases. To identify new DNA methylation markers possibly associated with the clinical characteristics of renal cell carcinoma (RCC), we investigated loci in the sarcosine dehydrogenase (SARDH) gene. SARDH is involved in the metabolism of the glycine­derivative sarcosine and is closely linked through a functional control loop. Statistical evaluation of methylation data and clinical characteristics of patients showed that kidney tumors with clinically aggressive features such as a high tumor stage, positive lymph nodes, distant metastases or a previously advanced tumor status exhibited significantly lower methylation of a locus in the SARDH gene. Moreover, SARDH methylation was found to be a significant prognostic factor for recurrence­free survival in RCC patients showing statistical independence from the clinical prognosticators, grade, stage and state of metastasis. In conclusion, the methylation status of the SARDH­CGI was identified as an independent prognostic candidate marker for RCC.

Decreased expression of galectin-3 predicts tumour recurrence in pTa bladder cancer.

Galectin-3 (gal-3) is a glycoprotein involved in various physiological cellular processes. Altered expression/loss of function of gal-3 is suggested to be involved in the pathogenesis and further progression of various human cancer entities. The aim of the present investigation was to elucidate the role of galectin-3 in the development and/or progression of non-muscle invasive (pTa, pT1) transitional cell carcinoma (TCC) of the urinary bladder. Gal-3 was analyzed by immunohistochemistry in 162 randomly selected non-muscle invasive bladder cancer specimens (pTa, 91; pT1, 71) using tissue microarray technique. It was compared with various patient and tumour characteristics (t-test). In addition, the role of gal-3 in association with tumour recurrence and progression was investigated (Log-rank test, Cox regression analysis). Gal-3 was found to be negatively correlated with tumour grade (p<0.02). Within the group of non-muscle invasive TCC, gal-3 could not differentiate between pTa and pT1 tumours (p=0.50), and within the subgroup of pTa tumours, loss of gal-3 determined the likelihood for the development of recurrent disease (p<0.03; Student's t-test). Furthermore, as demonstrated by Kaplan-Meier analysis, the expression level of gal-3 was identified to predict the duration of recurrence-free survival (p=0.01). In the multivariate analysis, gal-3 was found as an independent prognostic marker for predicting recurrence among the cohort of bladder tumours classified as pTa. In conclusion, loss of galectin-3 appears to be involved in the carcinogenesis of TCC and to serve as a valuable biological variable to identify a subgroup of Ta bladder cancer patients at high risk for the development of recurrent disease.