Intravesical BCG treatment causes a long-lasting reduction of recurrence and progression in patients with high-risk non-muscle-invasive bladder cancer.

PURPOSE: To analyse if BCG treatment leads to long-term reduction of recurrence, progression, and cancer-specific mortality (CSM) in patients with high-risk NMIBC. MATERIALS AND METHODS: 140 patients with high-risk NMIBC were drawn from a population-based cohort of 538 patients with newly diagnosed bladder cancer in the Stockholm County between 1995 and 1996. Data were collected prospectively, and a final follow-up for recurrence, progression, and CSM was performed after 15 years. Patients that received BCG were compared with patients who did not receive BCG. Survival analysis was done with Kaplan-Meier estimates and Mantel-Cox log-rank test. Multivariable Cox proportional regression with stepwise selection was performed to verify the statistical significance of clinicopathological factors of prognostic importance. Results were displayed in Hazard ratios and a p < 0.05 was considered to be statistically significant. RESULTS: With a median follow-up of 100 months (2-182), 76 patients recurred; 50 progressed to muscle invasion; and 92 died of whom 38 died from bladder cancer. After 15-year follow-up, there was a statistically significant reduction in rate for recurrence (HR 0.40, p < 0.0001) and progression (HR 0.52, p = 0.038), but not for CSM, in patients that received BCG compared to those who did not. CONCLUSIONS: In this group, BCG in high-risk NMIBC patients reduced the long-term risk of recurrence and progression. The effect on CSM is yet to be clarified.

Prostaglandin D2 effects and DP1 /DP2 receptor distribution in guinea pig urinary bladder out-flow region.

The proximal urethra and urinary bladder trigone play important roles in continence. We have previously shown that PGD2 is released from guinea pig bladder urothelium/suburothelium and can inhibit detrusor contractile responses. We presently wished to investigate PGD2 actions in guinea pig out-flow region and the distribution of DP1 /DP2 receptors. The effects of PGD2 on urothelium-intact trigone and proximal urethra contractility were studied in organ bath experiments. Expression of DP1 /DP2 receptor proteins was analysed by western blot. Immunohistochemistry was used to identify distribution of DP1 /DP2 receptors. PGD2 in a dose-dependent manner inhibited trigone contractions induced by electrical field stimulation (EFS) and inhibited spontaneous contractions of the proximal urethra. PGD2 was equally (trigone) or slightly less potent (urethra) compared with PGE2 . Expression of DP1 and DP2 receptors was found in male guinea pig bladder trigone, neck and proximal urethra. In the trigone and proximal urethra, DP1 receptors were found on the membrane of smooth muscle cells and weak immunoreactivty was observed in the urothelium. DP2 receptors were distributed more widespread, weakly and evenly in the urothelium and smooth muscles. Inhibitory effects by PGD2 on motor activity of guinea pig trigone and proximal urethra are consistent with finding DP1 and DP2 receptors located in the urothelium and smooth muscle cells of the trigone and proximal urethra, and PGD2 may therefore be a modulator of the bladder out-flow region, possibly having a function in regulation of micturition and a role in overactive bladder syndrome.

FTY720 (Fingolimod) sensitizes hepatocellular carcinoma cells to sorafenib-mediated cytotoxicity.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. The multityrosine kinase inhibitor sorafenib is used in the therapy of advanced disease. However, the effects of sorafenib are limited, and combination treatments aiming at improved survival are encouraged. The sphingosine analog FTY720 (Fingolimod), which is approved for treatment of multiple sclerosis, has shown tumor suppressive effects in cell lines and animal models of HCC. In the present study, we combined sorafenib with FTY720 in order to sensitize the HCC cell lines Huh7 and HepG2 to sorafenib treatment. Using the XTT assay we show that noncytotoxic doses of FTY720 synergistically enhanced the decrease in viability caused by treatment of both cell lines with increasing doses of sorafenib. Further studies in Huh7 revealed that combined treatment with FTY720 and sorafenib resulted in G1 arrest and enhanced cell death measured using flow cytometry analysis of cells labeled with propidium iodide (PI)/Annexin-V and PI and 4',6-diamidino-2-phenylindole-staining of nuclei. In addition, signs of both caspase-dependent and - independent apoptosis were observed, as cotreatment with FTY720 and sorafenib caused cytochrome c release and poly-ADP ribose polymerase-cleavage as well as translocation of Apoptosis-inducing factor into the cytosol. We also detected features of autophagy blockage, as the protein levels of LC3-II and p62 were affected by combined treatment with FTY720 and sorafenib. Together, our results suggest that FTY720 sensitizes HCC cells to cytotoxic effects induced by treatment with sorafenib alone. These findings warrant further investigations of combined treatment with sorafenib and FTY720 in vivo in order to develop more effective treatment of HCC.

Outcome after BCG treatment for urinary bladder cancer may be influenced by polymorphisms in the NOS2 and NOS3 genes.

PURPOSE: Bacillus Calmette-Guérin (BCG)-treatment is an established treatment for bladder cancer, but its mechanisms of action are not fully understood. High-risk non-muscle invasive bladder-cancer (NMIBC)-patients failing to respond to BCG-treatment have worse prognosis than those undergoing immediate radical cystectomy and identification of patients at risk for BCG-failure is of high priority. Several studies indicate a role for nitric oxide (NO) in the cytotoxic effect that BCG exerts on bladder cancer cells. In this study we investigated whether NO-synthase (NOS)-gene polymorphisms, NOS2-promoter microsatellite (CCTTT)n, and the NOS3-polymorphisms-786T>C (rs2070744) and Glu298Asp (rs1799983), can serve as possible molecular markers for outcome after BCG-treatment for NMIBC. MATERIALS AND METHODS: All NMIBC-patients from a well-characterized population based cohort were analyzed (n=88). Polymorphism data were combined with information from 15-years of clinical follow-up. The effect of BCG-treatment on cancer-specific death (CSD), recurrence and progression in patients with varying NOS-genotypes were studied using Cox proportional hazard-models and log rank tests. RESULTS: BCG-treatment resulted in significantly better survival in patients without (Log rank: p=0.006; HR: 0.12, p=0.048), but not in patients with a long version ((CCTTT)n ≧13 repeats) of the NOS2-promoter microsatellite. The NOS3-rs2070744(TT) and rs1799983(GG)-genotypes showed decreased risk for CSD (Log rank(TT): p=0.001; Log rank(GG): p=0.010, HR(GG): 0.16, p=0.030) and progression (Log rank(TT): p<0.001, HR(TT): 0.05, p=0.005; Log rank(GG): p<0.001, HR(GG): 0.10, p=0.003) after BCG-therapy compared to the other genotypes. There was also a reduction in recurrence in BCG-treated patients that was mostly genotype independent. Analysis of combined genotypes identified a subgroup of 30% of the BCG-treated patients that did not benefit from BCG-treatment. CONCLUSIONS: Our results suggest that the investigated polymorphisms influence patient response to BCG-treatment and thus may serve as possible markers for identification of BCG-failures.

Localization of P2X receptor subtypes 2, 3 and 7 in human urinary bladder.

BACKGROUND: Voiding dysfunctions are a common problem that has a severe negative impact on the quality of life. Today there is a need for new drug targets for these conditions. The role of ATP receptors in bladder physiology has been studied for some time, primarily in animal models. The aim of this work is to investigate the localization of the ATP receptors P2X2, P2X3 and P2X7 and their colocalization with vimentin and actin in the human urinary bladder. METHODS: Immunohistochemical analysis was conducted on full-thickness bladder tissues from fundus and trigonum collected from 15 patients undergoing open radical cystectomy due to chronic cystitis, bladder cancer or locally advanced prostate cancer. Colocalization analyses were performed between the three different P2X subtypes and the structural proteins vimentin and actin. Specimens were examined using epifluorescence microscopy and correlation coefficients were calculated for each costaining as well as the mean distance from the laminin positive basal side of the urothelium to the vimentin positive cells located in the suburothelium. RESULTS: P2X2 was expressed in vimentin positive cells located in the suburothelium. Less distinct labelling of P2X2 was also observed in actin positive smooth muscle cells and in the urothelium. P2X3 was expressed in vimentin positive cells surrounding the smooth muscle, and in vimentin positive cells located in the suburothelium. Weaker P2X3 labelling was seen in the urothelium. P2X7 was expressed in the smooth muscle cells and the urothelium. In the suburothelium, cells double positive for P2X2 and vimentin where located closer to the urothelium while cells double positive for P2X3 and vimentin where located further from the urothelium. CONCLUSION: The results from this study demonstrate that there is a significant difference in the expression of the purinergic P2X2, P2X3 and P2X7 receptors in the different histological layers of the human urinary bladder.

Receptors involved in the modulation of guinea pig urinary bladder motility by prostaglandin D2.

BACKGROUND AND PURPOSE: We have described a urothelium-dependent release of PGD2 -like activity which had inhibitory effects on the motility of guinea pig urinary bladder. Here, we have pharmacologically characterized the receptors involved and localized the sites of PGD2 formation and of its receptors. EXPERIMENTAL APPROACH: In the presence of selective DP and TP receptor antagonists alone or combined, PGD2 was applied to urothelium-denuded diclofenac-treated urinary bladder strips mounted in organ baths. Antibodies against PGD2 synthase and DP1 receptors were used with Western blots and for histochemistry. KEY RESULTS: PGD2 inhibited nerve stimulation -induced contractions in strips of guinea pig urinary bladder with estimated pIC50 of 7.55 ± 0.15 (n = 13), an effect blocked by the DP1 receptor antagonist BW-A868C. After blockade of DP1 receptors, PGD2 enhanced the contractions, an effect abolished by the TP receptor antagonist SQ-29548. Histochemistry revealed strong immunoreactivity for PGD synthase in the urothelium/suburothelium with strongest reaction in the suburothelium. Immunoreactive DP1 receptors were found in the smooth muscle of the bladder wall with a dominant localization to smooth muscle membranes. CONCLUSIONS AND IMPLICATIONS: In guinea pig urinary bladder, the main effect of PGD2 is an inhibitory action via DP1 receptors localized to the smooth muscle, but an excitatory effect via TP receptors can also be evoked. The urothelium with its suburothelium might signal to the smooth muscle which is rich in PGD2 receptors of the DP1 type. The results are important for our understanding of regulation of bladder motility.

Mutations in TERT promoter and FGFR3 and telomere length in bladder cancer.

Mutations in the promoter of the telomerase reverse transcriptase (TERT) and fibroblast growth factor receptor 3 (FGFR3) genes constitute the most recurrent somatic alterations in urothelial carcinoma of bladder. In this study, we screened DNA from 327 urothelial bladder carcinomas from well-documented patients, with different stages and grades and known TERT promoter mutational status, for FGFR3 alterations and measured relative telomere length (RTL). Although, the frequency of the TERT promoter mutations was higher than those in FGFR3; however, the alterations at the two loci occurred together more frequently than per chance [Odds ratio (OR) = 4.93, 95% CI = 2.72-8.92, p < 0.0001]. While tumors with TERT promoter and FGFR3 mutations had shorter RTL than those without mutations (p < 0.0001), the TERT promoter mutations in conjunction with the common allele of the rs2853669 polymorphism defined sub-group of patients with an observed decreased overall survival (OR = 2.15, 95% CI = 1.00-4.61) and increased recurrence in patients with TaG1+TaG2 disease categories (OR = 3.68, 95%CI = 1.12-12.05). The finding of shorter telomeres in tumors with TERT promoter and/or FGFR3 mutations than without mutations implies mechanistic relevance of telomere biology in cancer progression. The observed association with recurrence and survival shows that the TERT promoter mutations can potentially be used as markers to refine selection of patients for different treatments. The overwhelming frequency of the TERT promoter mutations also represents a case for development of an eventual therapeutic target.

Polymorphisms In The Nitric-Oxide Synthase 2 Gene And Prostate Cancer Pathogenesis.

BACKGROUND: Nitric-oxide synthase (NOS)-polymorphisms influence the cellular amount of NO, and are associated with disease-risk in many disorders. We investigated 145 SNP-polymorphisms and a (CCTTT)n-microsatellite in the NOS2-gene in 3161 prostate-cancer patients and 2149 controls from a Swedish population-based GWAS-study. AIM: To analyze possible associations between NOS2-polymorphisms, prostate cancer, and prostate cancer pathogenesis. METHODS: Two groups were analyzed, those with advanced tumours (Gleason≥6), and those with tumours of mixed Gleason-statues. Affymetrix 5.0-chip (SNP-polymorphisms), DNA Fragment-analysis and Sequencing ((CCTTT)n-microsatellite) were used for genotyping. Genotypes were combined with information on tumour stage, Gleason, PSA, metastases and cancer-specific death, using clinical follow-up. RESULTS: We divided the (CCTTT)n-alleles into short (S, n≤10), intermediate (M, n=11-12) and long (L, n≥13). Patients homozygous for longer repeats (LL) had decreased risk of highly aggressive (Gleason ≥7;PSA>20;T3+) tumours (OR:0.40;CI:0.14-1.08;p=0.071), but, once ill they showed a threefold increased risk of dying in prostate cancer (HR:3.31;CI:0.85-12.85;p=0.084), compared to SS-homozygotes. The SNP-alleles that co-varied with the (CCTTT)l-allele also had lower risk of aggressive tumours, as well as, once ill, a 2-4 times higher risk of dying (p=0.009). Also the proportion of patients with lymph node metastases increased with length of the (CCTTT)n-alleles of the patients (SS

The role of the HIF-1α transcription factor in increased cell division at physiological oxygen tensions.

HIF-1 is a transcription factor that mediates the cellular responses to low oxygen environments, mainly as a result of having an oxygen-labile subunit, HIF-1α. HIF-1α has been carefully studied in the context of severe hypoxic stresses (<1% O2), but it is also known to be present at oxygen tensions commonly found in normal tissues in vivo (∼1-13% O2), albeit at much lower levels. Its role under these physiological conditions is not fully understood. Here, we show that a transcriptionally active HIF-1α was up-regulated at 5% O2, both in normal and cancer cells, but only some of its target genes were elevated as a result. HIF-1α induction was in part dependent on the activation of the ERK1/2 MAPK signalling pathway, which we have previously shown is active at 5% O2. We also found that HIF-1α does not contribute to the protection against DNA damage that can be observed in low oxygen environments, and that there are certain DNA damaging agents, such as doxorubicin and actinomycin D, that prevent HIF-1α induction independently of p53. Moreover, absence of HIF-1α significantly reduced the growth advantage of cells cultured at 5% O2. In view of these data, we conclude that HIF-1α can be induced and activated at physiological oxygen tensions in a MAPK-dependent manner and that, although this does not lead to pro-survival responses to stress, it determines the increased cell proliferation rates that are common under these conditions.

Genome-wide association study yields variants at 20p12.2 that associate with urinary bladder cancer.

Genome-wide association studies (GWAS) of urinary bladder cancer (UBC) have yielded common variants at 12 loci that associate with risk of the disease. We report here the results of a GWAS of UBC including 1670 UBC cases and 90 180 controls, followed by replication analysis in additional 5266 UBC cases and 10 456 controls. We tested a dataset containing 34.2 million variants, generated by imputation based on whole-genome sequencing of 2230 Icelanders. Several correlated variants at 20p12, represented by rs62185668, show genome-wide significant association with UBC after combining discovery and replication results (OR = 1.19, P = 1.5 × 10(-11) for rs62185668-A, minor allele frequency = 23.6%). The variants are located in a non-coding region approximately 300 kb upstream from the JAG1 gene, an important component of the Notch signaling pathways that may be oncogenic or tumor suppressive in several forms of cancer. Our results add to the growing number of UBC risk variants discovered through GWAS.

Secondary stimulation from Bacillus Calmette-Guérin induced macrophages induce nitric oxide independent cell-death in bladder cancer cells.

The anti-tumour mechanisms following Bacillus Calmette-Guérin (BCG) treatment of bladder-cancer remain largely unknown. Previous studies have shown involvement of nitric-oxide (NO) formation in the BCG-mediated effect. We analyzed the effects of macrophage secreted factors (MSFs) from BCG-stimulated RAW264.7 cells on the bladder-cancer cell line MBT2. Direct treatment with BCG did not induce NO in MBT2-cells whereas supernatant from BCG-stimulated macrophages increased NOS2 mRNA and protein expression, NO concentrations and cell-death. Blocking NO-synthesis with the NOS-inhibitor L-NAME did not affect levels of cell-death suggesting cytotoxic pathways involving other signalling molecules than NO. Several such candidate genes were identified in a microarray.

The (CCTTT)n microsatellite polymorphism in the NOS2 gene may influence lung cancer risk and long-term survival, especially in non-smokers.

We analyzed the associations of the NOS2 (CCTTT)n promoter polymorphism to lung cancer risk and tumor histology in smokers and non-smokers. We also investigated lung cancer long-term survival in relation to the polymorphism, smoking data, histology, age at diagnosis, and gender. One hundred eighty-five lung-cancer patients and 164 matched controls, where non-smokers were enriched among the lung cancer cases, were genotyped by fragment analysis and sequencing. Genotypes were combined with information on histology, patient smoking status, and cancer-specific death, using a 20-year follow-up. We divided the (CCTTT)n alleles into short (n ≤ 10), intermediate (n = 11-12), and long (n ≥ 13). Patients homozygous for short repeats had significantly increased risk of lung cancer (p = 0.030) compared to carriers of two long alleles (LL). Lack of long allele was associated with a significantly increased lung cancer risk overall (p = 0.011), especially among non-smokers (p = 0.001). A significantly higher lung cancer survival was seen in non-smokers compared to smokers (p = 0.046) and in low-dose smokers compared to high-dose smokers at the time of diagnosis (p = 0.028). Moreover, non-smoking patients with squamous cell carcinoma (p = 0.015) or adenocarcinoma (p = 0.024) showed a significantly lower survival compared to other lung carcinomas. Nitric oxide can induce proliferation as well as apoptosis depending on cellular context. Our results suggest that the (CCTTT)n NOS2 microsatellite may influence the risk of developing lung cancer, especially in non-smokers, possibly by affecting intracellular nitric oxide levels. Our results also give additional information about the yet poorly understood etiological and prognostic differences between lung cancer in non-smokers and smokers.

TERT promoter mutations in bladder cancer affect patient survival and disease recurrence through modification by a common polymorphism.

The telomerase reverse transcriptase (TERT) promoter, an important element of telomerase expression, has emerged as a target of cancer-specific mutations. Originally described in melanoma, the mutations in TERT promoter have been shown to be common in certain other tumor types that include glioblastoma, hepatocellular carcinoma, and bladder cancer. To fully define the occurrence and effect of the TERT promoter mutations, we investigated tumors from a well-characterized series of 327 patients with urothelial cell carcinoma of bladder. The somatic mutations, mainly at positions -124 and -146 bp from ATG start site that create binding motifs for E-twenty six/ternary complex factors (Ets/TCF), affected 65.4% of the tumors, with even distribution across different stages and grades. Our data showed that a common polymorphism rs2853669, within a preexisting Ets2 binding site in the TERT promoter, acts as a modifier of the effect of the mutations on survival and tumor recurrence. The patients with the mutations showed poor survival in the absence [hazard ratio (HR) 2.19, 95% confidence interval (CI) 1.02-4.70] but not in the presence (HR 0.42, 95% CI 0.18-1.01) of the variant allele of the polymorphism. The mutations in the absence of the variant allele were highly associated with the disease recurrence in patients with Tis, Ta, and T1 tumors (HR 1.85, 95% CI 1.11-3.08). The TERT promoter mutations are the most common somatic lesions in bladder cancer with clinical implications. The association of the mutations with patient survival and disease recurrence, subject to modification by a common polymorphism, can be a unique putative marker with individualized prognostic potential.

Localization and expression of inducible nitric oxide synthase in patients after BCG treatment for bladder cancer.

Treatment with Bacillus Calmette Guerin (BCG) bladder instillations is an established treatment modality for superficial urinary bladder cancer and carcinoma in situ (CIS), but the anti-tumor mechanisms following BCG instillations remain largely unknown. Previous data show increased nitric oxide (NO) concentrations in the urinary bladder from patients treated with BCG suggesting that NO-formation may be involved in the BCG mediated effect. In the present study we evaluated 11 patients with urinary bladder cancer who had received BCG treatment and 11 tumor free control subjects. We performed immunohistochemistry, Western blot and real-time polymerase chain reaction (PCR) on bladder biopsies to establish inducible nitric oxide synthase (iNOS) protein levels and localization as well as iNOS mRNA expression. Endogenous NO formation in the bladder was also measured. In patients with bladder cancer who had received BCG treatment iNOS-like immunoreactivity was found in the urothelial cells but also in macrophages in the submucosa. Furthermore, endogenously formed NO was significantly increased (p<0.001) in the BCG treated patients and they had a ten-fold increase in mRNA expression for iNOS compared to healthy controls (p=0.003). In conclusion iNOS was found to be localized to the urothelium and macrophages underlying it. Our study also confirms elevated levels of endogenously formed NO and increased mRNA expression and protein levels for iNOS in patients with BCG treated bladder cancer. These data further support the notion that NO may be involved in the anti-tumor mechanism that BCG exerts on bladder cancer cells.

Reactive oxygen species and mitochondrial sensitivity to oxidative stress determine induction of cancer cell death by p21.

p21(Waf1/Cip1/Sdi1) is a cyclin-dependent kinase inhibitor that mediates cell cycle arrest. Prolonged p21 up-regulation induces a senescent phenotype in normal and cancer cells, accompanied by an increase in intracellular reactive oxygen species (ROS). However, it has been shown recently that p21 expression can also lead to cell death in certain models. The mechanisms involved in this process are not fully understood. Here, we describe an induction of apoptosis by p21 in sarcoma cell lines that is p53-independent and can be ameliorated with antioxidants. Similar levels of p21 and ROS caused senescence in the absence of significant death in other cancer cell lines, suggesting a cell-specific response. We also found that cells undergoing p21-dependent cell death had higher sensitivity to oxidants and a specific pattern of mitochondrial polarization changes. Consistent with this, apoptosis could be blocked with targeted expression of catalase in the mitochondria of these cells. We propose that the balance between cancer cell death and arrest after p21 up-regulation depends on the specific effects of p21-induced ROS on the mitochondria. This suggests that selective up-regulation of p21 in cancer cells could be a successful therapeutic intervention for sarcomas and tumors with lower resistance to mitochondrial oxidative damage, regardless of p53 status.

European genome-wide association study identifies SLC14A1 as a new urinary bladder cancer susceptibility gene.

Three genome-wide association studies in Europe and the USA have reported eight urinary bladder cancer (UBC) susceptibility loci. Using extended case and control series and 1000 Genomes imputations of 5 340 737 single-nucleotide polymorphisms (SNPs), we searched for additional loci in the European GWAS. The discovery sample set consisted of 1631 cases and 3822 controls from the Netherlands and 603 cases and 37 781 controls from Iceland. For follow-up, we used 3790 cases and 7507 controls from 13 sample sets of European and Iranian ancestry. Based on the discovery analysis, we followed up signals in the urea transporter (UT) gene SLC14A. The strongest signal at this locus was represented by a SNP in intron 3, rs17674580, that reached genome-wide significance in the overall analysis of the discovery and follow-up groups: odds ratio = 1.17, P = 7.6 × 10(-11). SLC14A1 codes for UTs that define the Kidd blood group and are crucial for the maintenance of a constant urea concentration gradient in the renal medulla and, through this, the kidney's ability to concentrate urine. It is speculated that rs17674580, or other sequence variants in LD with it, indirectly modifies UBC risk by affecting urine production. If confirmed, this would support the 'urogenous contact hypothesis' that urine production and voiding frequency modify the risk of UBC.

Polymorphisms in nitric-oxide synthase 3 may influence the risk of urinary-bladder cancer.

Nitric oxide (NO) is an important biological messenger known to influence several types of human cancers. NO formation is catalyzed by three different nitric oxide synthase (NOS) enzymes. In this study we analyzed if the NOS3 promoter polymorphism -786T>C (rs2070744) and the NOS3 Glu298Asp polymorphism in exon 7 (rs1799983) influence risk and pathogenesis of urinary-bladder cancer. Allelic discrimination and DNA sequencing were used to determine the -786T>C and the Glu298Asp NOS3 genotypes in 359 urinary-bladder cancer patients, from a population-based patient material, and 164 population controls. Patient genotypes were combined with information on tumor stage, grade, stage and grade progression and cancer-specific death, using a 5-year clinical follow-up. A threefold increased odds ratio for bladder cancer was found in homozygous carriers of the C allele of the -786T>C promoter polymorphism (p=0.017). No increased bladder cancer risk was found for the Glu298Asp polymorphism, but there was an association between the Glu298Asp and tumor grade (p=0.040). Our results suggest that the NOS3 promoter polymorphism -786T>C may influence bladder cancer risk.

Ser608Leu polymorphisms in the nitric oxide synthase-2 gene may influence urinary bladder cancer pathogenesis.

OBJECTIVE: The aim of this study was to analyse whether the exonic Ser608Leu (rs2297518) polymorphism in nitric oxide synthase-2 (NOS2) influences urinarybladder cancer risk and pathogenesis. MATERIAL AND METHODS: Genotyping of 359 bladder cancer patients from a population-based cohort and 164 population controls was carried out by allelic discrimination and sequencing. Genotypes were combined with information on tumour stage, grade, stage progression and cancer-specific death, from a 5-year clinical follow-up. RESULTS: For the Ser608Leu polymorphism, TT homozygotes had three-fold higher odds for bladder cancer (p = 0.081), but once ill, a lower risk for stage progression (p = 0.031) and a better prognosis. CONCLUSIONS: The data indicate that the Tallele of the NOS2 Ser608Leu polymorphism is an initial risk factor for developing urinary bladder cancer. Among bladder cancer patients, however, individuals who are TT homozygous have a lower risk of developing muscle-invasive disease and a higher cancer-specific survival. Depending on the cellular context, nitric oxide can induce proliferation as well as apoptosis. The results from this and previous studies suggest that NOS2 polymorphisms may influence both the risk of contracting bladder cancer and the aggressiveness of the disease.

Genotypes, haplotypes and diplotypes of three XPC polymorphisms in urinary-bladder cancer patients.

PURPOSE: The XPC gene is involved in DNA damage recognition in the nucleotide excision repair pathway (NER). We investigated the additive effects of single nucleotide polymorphisms (SNPs) in bladder-cancer patients and population controls for three XPC polymorphisms: A499V (C>T), K939Q (A>C), and poly AT (PAT, -/+). EXPERIMENTAL DESIGN: 311 bladder-cancer patients from a population-based cohort and 337 population controls were genotyped using the PCR-restriction fragment length polymorphism (RFLP) technique. RESULTS: We found complete linkage between the K939Q (A>C) and PAT (-/+) polymorphisms and therefore only the K939Q (A>C) polymorphism was included in analyses. The over all estimated odds ratio was 1.7 (95% CI 1.3-2.4) for A499V (C>T) and 1.4 (95% CI 1.0-2.0) for K939Q (A>C). The associated odds ratio increase with the variant allele homozygotes was six-fold for the A499V (C>T) and three-fold for the K939Q (A>C) polymorphism (OR=5.7, 95% CI 3.4-9.5 and OR=2.6, 95% CI 1.3-5.6, respectively). The variant allele haplotype of the two polymorphisms (T499C939) was associated with a nearly four fold increased odds ratio compared to the common allele haplotype (C499A939) (OR=3.6, 95% CI:1.9-6.9). Combined genotype analysis showed an increased disease association with increasing number of variant alleles (p<0.0001), with a dominant effect of the A499V polymorphism. In addition we observed association of the disease with increasing number of variant alleles for the A499V polymorphism and an early age at diagnosis (p=0.004). CONCLUSIONS: Our results suggest an association between the XPC genotypes of the A499V, K939Q and PAT polymorphisms and urinary-bladder cancer. We propose a poly-allelic effect of these polymorphisms where the cumulative effect on disease becomes higher than the individual allelic effects.

The (CCTTT)n microsatellite polymorphism in the nitric oxide synthase 2 gene may influence bladder cancer pathogenesis.

PURPOSE: We analyzed whether the NOS2 promoter microsatellite (CCTTT)n polymorphism influences bladder cancer pathogenesis. MATERIALS AND METHODS: We genotyped 359 patients with bladder cancer in a population based cohort and 164 population controls by DNA fragment analysis and sequencing. Genotypes were combined with information on tumor stage, grade and stage, grade progression and cancer specific death. Clinical followup was 5 years. RESULTS: We divided (CCTTT)n alleles into short-10 or fewer, intermediate-11 or 12 and long-13 or greater repeats. Patients homozygous for 13 or longer (CCTTT)n repeats were at decreased odds ratio for bladder cancer (p = 0.010). However, after illness developed they were at 3-fold increased hazard ratio for stage progression (p = 0.062) and 4-fold increased hazard ratio for death from bladder cancer (p = 0.056). We discovered what is to our knowledge a previously undescribed polymorphism at position 23105343 (C/T). There was no difference in frequency between bladder cancer cases and population controls for this polymorphism. No associations were found between tumor stage, grade or stage and grade progression. However, patients with bladder cancer with the heterozygous CT genotype were at 3-fold increased hazard ratio of death from cancer (p = 0.011). CONCLUSIONS: Nitric oxide can induce proliferation or apoptosis depending on the cellular context. Results suggest that the (CCTTT)n NOS2 microsatellite may influence bladder cancer risk and aggressiveness. This polymorphism may have an impact on disease pathogenesis, possibly by affecting intracellular nitric oxide levels.