c-myc in bladder cancer. Clinical findings and analysis of mechanism

Targeting microRNA-145-mediated progressive phenotypes of early bladder cancer in a molecularly defined in vivo model

A progressive subclass of early-stage non-muscle-invasive bladder cancer (NMIBC) frequently recurs and progress into invasive carcinoma, thus decreasing the overall survival rate of NMIBC. However, therapeutic development for progressive NMIBC has been challenging due to the lack of molecularly validated in vivo models and agents targeting its genetic vulnerability. We herein molecularly characterized an interventional model of progressive NMIBC and revealed the principal functions and therapeutic potential of microRNA-145 (miR-145) in early bladder tumorigenesis. N-butyl-N-(4-hydroxybutyl)nitrosamine-induced premalignant lesions (BiPLs) in rats exhibited downregulated expression of miR-145 as well as highly similar mutation/expression profiles to those of the human progressive NMIBC subclass with the worst prognosis. The expression patterns of miR-145 inversely correlated with those of BC-related oncogenes in BiPLs. We also demonstrated that miR-145 dominantly regulated interferon pathways and c-Myc expression, which play a crucial role in the pathogenesis of progressive NMIBC. Furthermore, we demonstrated that miR-145 replacement with a novel miR-145-based intravesical agent (miR-145S1) significantly inhibited the progression of BiPLs in vivo. These results provide insights into the essential role of miR-145 as the earliest-acting oncogenic driver of bladder tumorigenesis as well as a validated interventional model and novel miR-145-based nucleic acid therapeutic agent for progressive NMIBC.

Systems Drug Design for Muscle Invasive Bladder Cancer and Advanced Bladder Cancer by Genome-Wide Microarray Data and Deep Learning Method with Drug Design Specifications

Bladder cancer is the 10th most common cancer worldwide. Due to the lack of understanding of the oncogenic mechanisms between muscle-invasive bladder cancer (MIBC) and advanced bladder cancer (ABC) and the limitations of current treatments, novel therapeutic approaches are urgently needed. In this study, we utilized the systems biology method via genome-wide microarray data to explore the oncogenic mechanisms of MIBC and ABC to identify their respective drug targets for systems drug discovery. First, we constructed the candidate genome-wide genetic and epigenetic networks (GWGEN) through big data mining. Second, we applied the system identification and system order detection method to delete false positives in candidate GWGENs to obtain the real GWGENs of MIBC and ABC from their genome-wide microarray data. Third, we extracted the core GWGENs from the real GWGENs by selecting the significant proteins, genes and epigenetics via the principal network projection (PNP) method. Finally, we obtained the core signaling pathways from the corresponding core GWGEN through the annotations of the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway to investigate the carcinogenic mechanisms of MIBC and ABC. Based on the carcinogenic mechanisms, we selected the significant drug targets NFKB1, LEF1 and MYC for MIBC, and LEF1, MYC, NOTCH1 and FOXO1 for ABC. To design molecular drug combinations for MIBC and ABC, we employed a deep neural network (DNN)-based drug-target interaction (DTI) model with drug specifications. The DNN-based DTI model was trained by drug-target interaction databases to predict the candidate drugs for MIBC and ABC, respectively. Subsequently, the drug design specifications based on regulation ability, sensitivity and toxicity were employed as filter criteria for screening the potential drug combinations of Embelin and Obatoclax for MIBC, and Obatoclax, Entinostat and Imiquimod for ABC from their candidate drugs. In conclusion, we not only investigated the oncogenic mechanisms of MIBC and ABC, but also provided promising therapeutic options for MIBC and ABC, respectively.

Downregulation of HINFP induces senescence-associated secretory phenotype to promote metastasis in a non-cell-autonomous manner in bladder cancer

Transcription dysregulation is a salient characteristic of bladder cancer (BC), but no appropriate therapeutic target for it has been established. Here, we found that heterogeneous downregulation of histone H4 transcription factor (HINFP) was associated with senescence in BC tissues and that lower HINFP expression could predict an unfavorable outcome in BC patients. Knockout of HINFP transcriptionally inhibited H1F0 and H1FX to trigger DNA damage, consequently inducing cell senescence to repress the proliferation and growth of BC cells. However, the senescence-associated secretory phenotype, characterized by increases in MMP1/3, enhances the invasion and metastasis of non-senescent BC cells. Histone deacetylase inhibitors (HDACis) could efficiently eliminate the senescent cells induced by HINFP knockout to suppress the invasion and metastasis of BC cells. Our study suggests that HDACis, widely used in multiple cancer types in a clinical context, may also benefit BC patients with metastases induced by cell senescence.

PRMT5-activated c-Myc promote bladder cancer proliferation and invasion through up-regulating NF-κB pathway

AIM

PRMT5 and c-Myc were considered as oncogene of bladder cancer. Nevertheless, whether the interaction between of PRMT5 and c-Myc affect bladder cancer progress is unknown. Herein, we explore the above points and discuss deeply its' potential mechanism.

METHOD

5637 and T24 cells were study subjects in vitro. Western blot was used to examined the protein expression. CCK8 and transwell assay were used to analyze proliferation and invasion ability. Additionally, xenograft tumor model was established. Mice imaging experiment, Immunochemistry assay and western blot were carried out.

RESULT

Western blot result showed successful transfection of PRMT5-siRNA and c-Myc-siRNA. PRMT5-siRNA could inhibit c-Myc expression, and decrease the proliferation and invasion of bladder cells. And c-Myc overexpression could reverse inhibitory action caused by PRMT5 silence. And in vitro studies found low-expression of c-Myc reduced proliferation and invasion of tumor cells and make the NF-κB pathway inactivation. In vivo studies also demonstrated that inhibiting PRMT5 could downregulate c-Myc expression and inhibit the bladder cancer progress, and the potential mechanism was likely to be related to NF-κB signaling pathway.

CONCLUSION

In a word, low-expression of PRMT5 suppressed c-Myc, and thus inhibited proliferation and invasion ability of 5637 and T24 cells through NF-κB pathway.

Prognostic Value of c-Myc Immunohistochemical Expression in Muscle Invasive Urothelial Carcinoma of the Urinary Bladder: A Retrospective Study

Objective:

This study aimed to investigate the immunohistochemical expression of c-Myc in muscle invasive urothelial carcinoma (MIUC) of the urinary bladder and to evaluate the correlation of c-Myc expression with different clinicopathological parameters and outcome, including a relatively new histopathological tumor characteristic that is the growth pattern of tumor invasion.

Methods:

A total of 66 formalin-fixed and paraffin-embedded sections of MIUC obtained from radical cystectomy specimens were enrolled. The sections were stained with c-Myc antibody using immunohistochemistry technique.

Results:

Tumor cells showed variability in nuclear c-Myc expression according to the growth pattern of invasion. The median H-score of nuclear expression of infiltrative pattern was significantly higher than that of non-infiltrative pattern (p<0.001). Nuclear expression of c-Myc in tumor tissue had a significant association with poor prognostic factors (sarcomatoid variant (p<0.001), perineural invasion (p=0.037), lymphovascular invasion (p<0.001), lymph node metastasis (p<0.001), distant metastasis (p=0.042) and advanced stage grouping (p=0.001). Kaplan Meier survival analysis demonstrated that c-Myc expression could not be significantly correlated with overall survival or disease free survival rates.

Conclusion:

Nuclear c-Myc seems to have a prominent role in epithelial to mesenchymal transition with consequential in tumor progression and metastasis, while it is not as much useful to predict the clinical behavior of patients with MIUC.

CARLo-7-A plausible biomarker for bladder cancer

Cancer is defined as undifferentiated and unchecked growth of cells damaging the surrounding tissue. Cancers manifest altered gene expression. Gene expression is regulated by a diverse array of non-protein-coding RNA. Aberrant expression of long non-coding RNAs (lncRNAs) has been recently found to have functional consequences in cancers. In the current study, we report CARLo-7 as the only bladder cancer-specific lncRNA from the CARLos cluster. The expression of this lncRNA correlates with bladder cancer grade. We propose that CARLo-7 has an oncogenic potential and might be regulator of cell proliferation. Furthermore, by comparison the expression of proto-oncogene MYC, which is the only well-annotated gene close to the cancer - associated linkage disequilibrium blocks of this region, does not show a pronounced change in expression between the low- and high-grade tumours. Our results indicate that CARlo-7 can act as a prognostic marker for bladder cancer.

Long non-coding RNA SNHG20 promotes bladder cancer via activating the Wnt/β-catenin signalling pathway

The long non‑coding RNA, small nucleolar RNA host gene 20 (SNHG20), is involved in promoting several common types of human cancer, however, the exact function of SNHG20 in the pathogenesis of bladder cancer remains to be elucidated. The present study aimed to examine the regulatory mechanism of SNHG20 underlying the malignant progression of bladder cancer. Reverse transcription‑quantitative polymerase chain reaction and western blotting were used to examine mRNA and protein expression. Cell survival, proliferation, apoptosis, colony formation, migration and invasion were also studied. The resulting data indicated that SNHG20 was significantly upregulated in bladder cancer tissues and cell lines, compared with its expression in adjacent non‑tumour tissues and the SV‑HUC‑1 normal urinary tract epithelial cell line, respectively. In addition, the high expression of SNHG20 was associated with advanced clinical stage, lymph node metastasis, and reduced patient survival rate. The knockdown of SNHG20 caused a significant reduction in cancer cell survival, proliferation, colony formation, migration and invasion, and induced cell apoptosis. Additionally, the inhibition of SNHG20 reduced tumour growth in vivo. Investigations into the mechanism revealed that the inhibition of SNHG20 suppressed the activation of Wnt/β‑catenin signalling and the expression of certain key genes in bladder cancer cells. Taken together, these results indicated that SNHG20 is involved in promoting bladder cancer and may be used as a potential therapeutic target for the treatment of this disease.

Biomarkers in Bladder Cancer: Present Status and Perspectives

Bladder cancers are a mixture of heterogeneous cell populations, and numerous factors are likely to be involved in dictating their recurrence, progression and the patient's survival. For any candidate prognostic marker to have considerable clinical relevance, it must add some predictive capacity beyond that offered by conventional clinical and pathologic parameters. Here, the current situation in bladder cancer research with respect to identification of suitable prognostic markers is reviewed. A number of individual molecular markers that might predict bladder cancer recurrence and progression have been identified but many are not sufficiently sensitive or specific for the whole spectrum of bladder cancer diseases seen in routine clinical practice. These limitations have led to interest in other molecular parameters that could enable more accurate prognosis for bladder cancer patients. Of particular interest is the epigenetic silencing of tumor suppressor genes. Since the methylation of these genes can correlate with a poor prognosis, the methylation profile may represent a new biomarker that indicates the risk of transitional cell carcinoma development. In addition, bladder cancer research is likely to be revolutionized by high-throughput molecular technologies, which allow rapid and global gene expression analysis of thousands of tumor samples. Initial studies employing these technologies have considerably expanded our ability to classify bladder cancers with respect to their survivability. Future microarray analyses are likely to reveal particular gene expression signatures that predict the likelihood of bladder cancer progression and recurrence, as well as patient's survival and responsiveness to different anti-cancer therapies, with great specificity and sensitivity.

Environment and bladder cancer: molecular analysis by interaction networks

Bladder cancer (BC) is the 9th most common cancer worldwide, and the 6th most common cancer in men. Its development is linked to chronic inflammation, genetic susceptibility, smoking, occupational exposures and environmental pollutants. Aim of this work was to identify a sub-network of genes/proteins modulated by environmental or arsenic exposure in BC by computational network approaches. Our studies evidenced the presence of HUB nodes both in "BC and environment" and "BC and arsenicals" networks. These HUB nodes resulted to be correlated to circadian genes and targeted by some miRNAs already reported as involved in BC, thus suggesting how they play an important role in BC development due to environmental or arsenic exposure. Through data-mining analysis related to putative effect of the identified HUB nodes on survival we identified genes/proteins and their mutations on which it will be useful to focus further experimental studies related to the evaluation of their expression in biological matrices and to their utility as biomarkers of BC development.

ASP5878, a selective FGFR inhibitor, to treat FGFR3-dependent urothelial cancer with or without chemoresistance

FGF/FGFR gene aberrations such as amplification, mutation and fusion are associated with many types of human cancers including urothelial cancer. FGFR kinase inhibitors are expected to be a targeted therapy for urothelial cancer harboring FGFR3 gene alternations. ASP5878, a selective inhibitor of FGFR1, 2, 3 and 4 under clinical investigation, selectively inhibited cell proliferation of urothelial cancer cell lines harboring FGFR3 point mutation or fusion (UM-UC-14, RT-112, RT4 and SW 780) among 23 urothelial cancer cell lines. Furthermore, ASP5878 inhibited cell proliferation of adriamycin-resistant UM-UC-14 cell line harboring MDR1 overexpression and gemcitabine-resistant RT-112 cell line. The protein expression of c-MYC, an oncoprotein, in gemcitabine-resistant RT-112 cell line was higher than that in RT-112 parental cell line and ASP5878 decreased the c-MYC expression in both RT-112 parental and gemcitabine-resistant RT-112 cell lines. Once-daily oral administration of ASP5878 exerted potent antitumor activities in UM-UC-14, RT-112 and gemcitabine-resistant RT-112 xenograft models without affecting body weight. These findings suggest that ASP5878 has the potential to be an oral targeted therapy against urothelial cancer harboring FGFR3 fusion or FGFR3 point mutation after the acquisition of gemcitabine- or adriamycin-resistance.

MicroRNA-92 promotes invasion and chemoresistance by targeting GSK3β and activating Wnt signaling in bladder cancer cells

miR-92 has been reported to be upregulated in several human cancers. Until now, its expression pattern and biological roles in human bladder cancer still remains unexplored. The present study aims to clarify its expression, function, and potential molecular mechanisms in bladder cancer. Using real-time PCR, we found that miR-92 was upregulated in bladder cancer tissues compared with normal bladder tissues. We transfected miR-92 mimic and inhibitor in T24 and 5637 bladder cancer cells separately. We found that miR-92 mimic promoted T24 proliferation and invasion, with increased expression of cyclin D1, c-myc, and MMP7 at both mRNA and protein levels. Further investigation found that miR-92 could also promote epithelial-mesenchymal transition by downregulating E-cadherin protein and upregulating vimentin. In addition, miR-92 mimic also promoted activation of Wnt signaling. Meanwhile, miR-92 inhibitor displayed the opposite effects in 5637 cell line. By use of bioinformatic prediction software and luciferase reporter assay, we discovered that GSK3β acted as a direct target of miR-92. Additionally, GSK3β siRNA abrogated the effects of miR-92 mimic on cyclin D1 and MMP7. Moreover, we observed a negative correlation between GSK3β and miR-92 in bladder cancer tissues. In conclusion, our study demonstrated that upregulation of miR-92 is closely related with malignant progression of bladder cancer and miR-92 promotes proliferation, invasion, and Wnt/c-myc/MMP7 signaling by targeting GSK3β.

Rab23 is overexpressed in human bladder cancer and promotes cancer cell proliferation and invasion

Rab23 overexpression has been implicated in several human cancers. However, its expression pattern and biological roles in human bladder cancer have not been elucidated. In this study, we examined Rab23 expression in 93 bladder cancer specimens and analyzed its correlation with clinicopathological parameters. We found that Rab23 was overexpressed in 45 of 93 (48.3 %) cancer specimens. Significant association was found between Rab23 overexpression and tumor invasion depth (p = 0.0027). Rab23 overexpression also negatively correlated with FGFR3 protein expression (p = 0.021). We found that Rab23 expression was lower in normal bladder transitional cell line SV-HUC-1 than in bladder cancer cell lines BIU-87, 5637, and T24. We knocked down Rab23 expression in T24 cancer cells and transfected a Rab23 plasmid in the BIU-87 cell line. Rab23 depletion inhibited cell growth rate and invasion, while its overexpression resulted in increased cell growth and invasion. In addition, we demonstrated that Rab23 depletion decreased and its transfection upregulated expression of cyclin E, c-myc, and MMP-9. Furthermore, we showed that Rab23 knockdown inhibited NF-κB signaling and its overexpression upregulated NF-κB signaling. BAY 11-7082 (NF-κB inhibitor) partly inhibited the effect of Rab23 on cyclin E and MMP-9 expression. In conclusion, the present study demonstrated that Rab23 overexpression facilitates malignant cell growth and invasion in bladder cancer through the NF-κB pathway.

The emerging role of the androgen receptor in bladder cancer

Men are three to four times more likely to get bladder cancer than women. The gender disparity characterizing bladder cancer diagnoses has been investigated. One hypothesis is that androgen receptor (AR) signaling is involved in the etiology and progression of this disease. Although bladder cancer is not typically described as an endocrine-related malignancy, it has become increasingly clear that AR signaling plays a role in bladder tumors. This review summarizes current findings regarding the role of the AR in bladder cancer. We discuss work demonstrating AR expression in bladder cancer and its role in promoting formation and progression of tumors. Additionally, we discuss the therapeutic potential of targeting the AR in this disease.

MicroRNA-33b suppresses migration and invasion by targeting c-Myc in osteosarcoma cells

MicroRNAs have emerged as fundamental regulators in gene expression through silencing gene expression at the post-transcriptional and translational levels. Osteosarcoma is the most common type of primary malignant bone tumor and is characterized by complex genetic changes and resistance to conventional treatments. In our study, the role of miR-33b in the progression and metastasis of osteosarcoma was investigated. Our results showed that miR-33b was significantly downregulated in osteosarcoma tissue and cell lines. Overexpression of miR-33b significantly inhibited cell proliferation, migration, and invasion in the MG-63 osteosarcoma cell line. Moreover, we also showed that c-Myc was negatively regulated by miR-33b at the posttranscriptional level, via a specific target site within the 3′UTR. Overexpression of c-Myc impaired miR-33b-induced inhibition of proliferation and invasion in osteosarcoma cells. The expression of c-Myc was frequently downregulated in osteosarcoma tumors and cell lines and was inversely correlated with miR-33b expression. Thus, our findings suggest that miR-33b inhibits osteosarcoma cells migration and invasion by targeting the c-Myc gene, acting as tumor suppressor. The findings of this study contribute to current understanding of the functions of miR-33b in osteosarcoma.

Androgen activates β-catenin signaling in bladder cancer cells

Androgen receptor (AR) signals have been implicated in bladder carcinogenesis and tumor progression. Activation of Wnt/β-catenin signaling has also been reported to correlate with bladder cancer progression and poor patients' outcomes. However, cross talk between AR and β-catenin pathways in bladder cancer remains uncharacterized. In radical cystectomy specimens, we immunohistochemically confirmed aberrant expression of β-catenin especially in aggressive tumors. There was a strong association between nuclear expressions of AR and β-catenin in bladder tumors (P=0.0215). Kaplan-Meier and log-rank tests further revealed that reduced membranous β-catenin expression (P=0.0276), nuclear β-catenin expression (P=0.0802), and co-expression of nuclear AR and β-catenin (P=0.0043) correlated with tumor progression after cystectomy. We then assessed the effects of androgen on β-catenin in AR-positive and AR-negative bladder cancer cell lines. A synthetic androgen R1881 increased the expression of an active form of β-catenin and its downstream target c-myc only in AR-positive lines. R1881 also enhanced the activity of β-catenin-mediated transcription, which was abolished by an AR antagonist hydroxyflutamide. Using western blotting and immunofluorescence, R1881 was found to induce nuclear translocation of β-catenin when co-localized with AR. Finally, co-immunoprecipitation revealed androgen-induced associations of AR with β-catenin or T-cell factor (TCF) in bladder cancer cells. Thus, it was likely that androgen was able to activate β-catenin signaling through the AR pathway in bladder cancer cells. Our results also suggest that activation of β-catenin signaling possibly via formation of AR/β-catenin/TCF complex contributes to the progression of bladder cancer, which may enhance the feasibility of androgen deprivation as a potential therapeutic approach.

Tumor markers of bladder cancer: the schistosomal bladder tumors versus non-schistosomal bladder tumors

Background

The aim of this study is to comparatively elucidate the underlying molecular pathways and clinicopathological criteria in schistosomal bladder tumor (SBT) versus non-schistosomal bladder tumor (NSBT).

Methods

This study explored the role of p53, p16, bcl-2, ki-67, c-myc, Rb and EGFR, by using Immunohistochemistry assay, in 45 SBT and 39 NSBT patients in comparison with 16 schistosomal chronic cystitis (SC), 28 non-schistosomal chronic cystitis (NSC), and 20 normal control (CTL) subjects. The studied markers in SBT and NSBT were correlated with different clinicopathological criteria namely, tumor histopathology, grading, invasiveness, stage, and presentation of the disease.

Results

SBT was associated with high grade invasive squamous cell carcinoma (SCC) while NSBT was associated with lower grade less invasive transitional cell carcinoma (TCC). The expression of p53, bcl-2, c-myc, and EGFR was higher in SBT than in NSBT while Rb was higher in NSBT than in SBT. However, p16 and ki-67 were not different between SBT and NSBT. The profile of molecular markers in SC was similar to NSC except for EGFR which was higher in SC than in NSC. Both SC and NSC showed higher level of p53, bcl-2, ki-67, and EGFR than in CTL group while p16, Rb, and c-myc were not different. p53 was associated with high grade SCC in both SBT and NSBT. Bcl-2 was associated with high grade invasive tumors in SBT and NSBT. P16 was associated with low grade, late stage, and recurrent SBT and high grade, invasive, late stage, and recurrent NSBT. Rb was associated with SCC in SBT, invasive tumors in NSBT, and late stage and recurrent presentation in both SBT and NSBT. C-myc was associated with high grade, invasive, and late stage SBT and SCC, high grade, invasive, and late stage NSBT. EGFR was associated with invasive SCC in SBT and invasive, high grade, and late stage TCC in NSBT. ki-67 was associated with invasive SBT and high grade late stage NSBT.

Conclusion

SBT and NSBT showed distinct molecular profile of tumor development and progression which can be taken into consideration in fine adjusting the anti-cancer therapy for SBT and NSBT.

Association between metabolic syndrome and nephrolithiasis in an inpatient population in southern Italy: role of gender, hypertension and abdominal obesity

BACKGROUND

Metabolic syndrome (MetS) and nephrolithiasis (NL) are quite common disorders. While some of the components of MetS have been proposed as precursors of NL in population studies, no data are available about the possible association between NL and MetS as such. The primary objective of the study was to evaluate the relationship between MetS and NL. The secondary outcome was to examine the relationship between MetS single constitutive elements and NL considering the strict correlation occurring among these factors.

METHODS

We studied 2132 Caucasian inpatients of the 'Spinelli' Hospital in southern Italy (males/females = 0.95; mean age 63.8 +/- 15.8 years; body mass index 26.1 +/- 3.9 kg/m(2)). The MetS diagnosis was performed according to the Heart Association/National Heart, Lung, and Blood Institute criteria. The presence of NL was assessed by ultrasound examination of the kidneys and upper urinary tract.

RESULTS

Seven hundred twenty-five subjects (34.0%) had a positive diagnosis of MetS. Two hundred twenty subjects (10.3%) had echographic evidence of NL, while 199 subjects reported a past history of NL (9.3%). The presence of MetS, as well as the male sex, and the occurrence of a previous episode of NL (in male subjects only) were each independently related to echographic evidence of NL. Among the individual components of MetS, high blood pressure and abdominal obesity (in female individuals only) were also independently related to echographic evidence of NL.

CONCLUSIONS

MetS is significantly associated with echographic evidence of NL. A gender-related difference in the clinical expression of NL was also observed.

Prognostic and functional significance of thromboxane synthase gene overexpression in invasive bladder cancer

Thromboxane synthase (TXAS) is one of the enzymes downstream from cyclooxygenase-2 and catalyzes the synthesis of thromboxane A(2) (TXA(2)). TXAS was among the genes we identified based on its overexpression in invasive bladder tumors. TXAS is overexpressed in common forms of bladder tumors: 69 of 97 (71.1%) transitional cell carcinoma (TCC), 38 of 53 (71.6%) squamous cell carcinoma, and 5 of 11 (45.5%) adenocarcinoma relative to nontumor tissue. Overall, 112 of 161 (69.5%) invasive tumors exhibited elevated expression. Significantly, patients with tumors having >4-fold levels of TXAS expression showed significant statistical evidence of lower overall survival expressed by the estimated hazard ratio of 2.74 with P = 0.009 in Cox's regression analysis. TXAS mRNA expression was found to be an independent prognostic marker for patients with bladder cancer. Treatment of bladder cancer cell lines (T24 and TCC-SUP) with TXAS inhibitors and TXA(2) (TP) receptor antagonists reduced cell growth, migration, and invasion, whereas TP agonists stimulated cell migration and invasion. The positive correlation between elevated TXAS expression and shorter patient survival supports a potential role for TXAS-regulated pathways in tumor invasion and metastases and suggests that modulation of the TXAS pathway may offer a novel therapeutic approach.

Molecular subtypes of bladder cancer: Jekyll and Hyde or chalk and cheese?

Cancer of the bladder shows divergent clinical behaviour following diagnosis and it has been proposed that two major groups of tumours exist that develop via different molecular pathways. Low-grade, non-invasive papillary tumours recur frequently, but patients with these tumours do not often suffer progression of disease to muscle invasion. In contrast, tumours that are invading muscle at diagnosis are aggressive and associated with significant mortality. Molecular studies have identified distinct genetic, epigenetic and expression changes in these groups. However, it is not yet clear whether there is direct progression of low-grade superficial tumours to become invasive (a Jeckell and Hyde scenario) or whether in those patients who apparently progress from one form of the disease to the other, different tumour clones are involved and that the two tumour groups are mutually exclusive ('chalk and cheese'). If the latter is true, then attempts to identify molecular markers to predict progression of low-grade superficial bladder tumours may be fruitless. Similarly, it is not clear whether other subgroups of tumours exist that arise via different molecular pathways. There is now a large amount of molecular information about bladder cancer that facilitates examination of these possibilities. Some recent studies provide evidence for the existence of at least one further group of tumours, high-grade superficial papillary tumours, which may develop via a distinct molecular pathway. Patients with such tumours do show increased risk of disease progression and for these there may exist a real progression continuum from non-invasive to invasive. If this is the case, definition of the molecular signature of this pathway and improved understanding of the biological consequences of the events involved will be pivotal in disease management.

Prognostic markers for bladder cancer: International Consensus Panel on bladder tumor markers

The International Consensus Panel on cytology and bladder tumor markers evaluated markers that have the ability to predict tumor recurrence, progression, development of metastases, or response to therapy or patient survival. This article summarizes those findings. The panel mainly reviewed articles listed in PubMed on various prognostic indicators for bladder cancer. Based on these studies, most of which were case-control retrospective studies, various prognostic indicators were classified into 6 groups: (1) microsatellite-associated markers, (2) proto-oncogenes/oncogenes, (3) tumor suppressor genes, (4) cell cycle regulators, (5) angiogenesis-related factors, and (6) extracellular matrix adhesion molecules. The panel concluded that although certain markers, such as Ki-67 and p53, appear to be promising in predicting recurrence and progression of bladder cancer, the data are still heterogeneous. The panel recommends that identifying definitive criteria for test positivity, a clearly defined patient population, standardization of techniques used to evaluate markers, and clearly specified endpoints and statistical methods will help to bring accurate independent prognostic indicators into the clinical management of patients with bladder cancer.

High-throughput tissue microarray analysis ofCMYC amplificationin urinary bladder cancer

Alterations of chromosome 8, preferentially deletions of 8p and gains of 8q, belong to the most frequent cytogenetic changes in bladder cancer. CMYC on 8q24 is a candidate oncogene in this region. Little is known about the clinical significance of CMYC copy number changes in urinary bladder cancer because its frequency is low and a limited numbers of tumors were analyzed so far. To investigate the impact of CMYC alterations on tumor progression and patient prognosis in bladder cancer, we applied FISH to a tissue microarray containing 2317 bladder cancer samples. Presence of CMYC copy number increase was associated with advanced stage and high grade. CMYC amplifications were seen in 3 of 467 pTa (0.6%), 10 of 247 pT1 (4%) and 11 of 201 pT2-4 urothelial carcinomas (5.5%; p < 0.0001), as well as in 1 of 123 G1 (0.8%), 8 of 470 G2 (1.7%) and 17 of 365 G3 urothelial carcinomas (4.7%; p < 0.0001). CMYC gains were present in 49 of 467 pTa (10.5%), 39 of 247 pT1 (15.8%) and 43 of 201 pT2-4 urothelial carcinoma (21.4%; p < 0.0001), as well as in 7 of 123 G1 (5.7%), 56 of 470 G2 (11.9%) and 72 of 365 G3 urothelial carcinomas (19.7%; p < 0.0001). CMYC copy number changes were unrelated to prognosis of bladder cancer patients. We conclude that alterations of the CMYC gene, including copy number gains and amplifications, are linked to genetically unstable bladder cancers that are characterized by a high histologic grade and/or invasive growth. Patient prognosis was not affected by CMYC gene copy number changes.

Genetic instability in superficial bladder cancer and adjacent mucosa: an interphase cytogenetic study

A systematic analysis of both tumors and the surrounding urothelium to help identify what lies behind the mechanism of multifocal tumor development has not yet been performed. In this study we investigated chromosome 1, 7, 9, and 17 aneusomy in 25 superficial papillary carcinomas and in 51 tissue samples taken from sites of macroscopically uninvolved urothelium surrounding the tumors, using the fluorescence in situ hybridization method. Our data demonstrated a close genetic relationship between all examined tumors and normal-appearing mucosa. Numeric aberrations of chromosomes 1, 7, 9, and 17 were found to exhibit similar patterns in all analyzed specimens, although with different frequencies.

Angiogenesis in bladder cancer--prognostic marker and target for future therapy

Angiogenesis is the process by which tumours induce a blood supply, crucial for growth and metastasis. Evidence for its role in bladder carcinogenesis, its usefulness as a marker of patient prognosis, and potential anti-angiogenic therapies for future development are discussed in this chapter.