Apoptosis, proliferation and p53, cyclin D1, and retinoblastoma gene expression in relation to radiation response in transitional cell carcinoma of the bladder

Exogenous C₈-Ceramide Induces Apoptosis by Overproduction of ROS and the Switch of Superoxide Dismutases SOD1 to SOD2 in Human Lung Cancer Cells

Ceramides, abundant sphingolipids on the cell membrane, can act as signaling molecules to regulate cellular functions including cell viability. Exogenous ceramide has been shown to exert potent anti-proliferative effects against cancer cells, but little is known about how it affects reactive oxygen species (ROS) in lung cancer cells. In this study, we investigated the effect of N-octanoyl-D-erythro-sphingosine (C₈-ceramide) on human non-small-cell lung cancer H1299 cells. Flow cytometry-based assays indicated that C₈-ceramide increased the level of endogenous ROS in H1299 cells. Interestingly, the ratio of superoxide dismutases (SODs) SOD1 and SOD2 seem to be regulated by C₈-ceramide treatment. Furthermore, the accumulation of cell cycle G1 phase and apoptotic populations in C₈-ceramide-treated H1299 cells was observed. The results of the Western blot showed that C₈-ceramide causes a dramatically increased protein level of cyclin D1, a critical regulator of cell cycle G1/S transition. These results suggest that C₈-ceramide acts as a potent chemotherapeutic agent and may increase the endogenous ROS level by regulating the switch of SOD1 and SOD2, causing the anti-proliferation, and consequently triggering the apoptosis of NSCLC H1299 cells. Accordingly, our works may give a promising strategy for lung cancer treatment in the future.

Comparison between whole mount tissue preparations and virtual tissue microarray samples for measuring Ki-67 and apoptosis indices in human bladder cancer: A cross-sectional study

Recent tissue microarray (TMA)-based studies have shown that cell proliferation- and apoptosis-related biomarkers are associated with clinical outcomes in patients with bladder urothelial carcinoma. However, little is known about the differences in these biomarker measurements between whole mount tissue preparations and TMAs. This study aimed to elucidate the discrepancy in the measurements of Ki-67 indices (KIs) and apoptosis indices (AIs) between whole mount tissue preparations and TMAs of bladder urothelial carcinoma samples.Whole mount tissue preparations for Ki-67 immunohistochemistry and terminal deoxynucleotidyl transferase dUTP nick end labeling were made from 30 patients who underwent transurethral resection of bladder urothelial carcinoma. Digital microscopy-assisted virtual TMAs, consisting of 3 small round areas (1 or 0.6 mm in diameter), were generated from the same whole mount tissue preparations. The measurement results in highly reactive areas of biomarkers were compared between the whole mount tissue preparation- and the TMA-based methods. Bland-Altman plot analysis, regression analysis, and Kendall τ were performed to investigate differences in the measurement results, systematic biases, and correlations between biomarkers.Although the Bland-Altman plot analysis demonstrated that almost all the plots were within the limits of agreement, fixed biases were detected in the 1- and 0.6-mm TMAs for the KI (0.181 and 0.222, respectively) and the AI (0.055 and 0.063, respectively). Proportional biases were also detected in the 1- and 0.6-mm TMAs for the AI (P < 0.001 and P < 0.001, respectively). Furthermore, positive correlations between KIs and AIs were observed in whole mount tissue preparations (r = 0.260, P = 0.044) and in the 1 mm TMAs (r = 0.375, P = 0.004); however, no such correlation was observed in the 0.6 mm TMAs.Our study suggests that the measurement results for certain biomarkers of bladder urothelial carcinoma obtained from TMA-based samples can be susceptible to systematic bias, and the lack of correlation between biomarkers cannot be avoided as it is in whole mount tissue preparations. Virtual TMAs can help identify systematic bias and establish a better sampling strategy prior to performing high-throughput TMAs for biomarker studies.

High Ki-67 Immunohistochemical Reactivity Correlates With Poor Prognosis in Bladder Carcinoma: A Comprehensive Meta-Analysis with 13,053 Patients Involved

Ki-67 is considered as one of prime biomarkers to reflect cell proliferation and immunohistochemical Ki-67 staining has been widely applied in clinical pathology. To solve the widespread controversy whether Ki-67 reactivity significantly predicts clinical prognosis of bladder carcinoma (BC), we performed a comprehensive meta-analysis by combining results from different literature. A comprehensive search was conducted in the Chinese databases of WanFang, China National Knowledge Infrastructure and Chinese VIP as well as English databases of PubMed, ISI web of science, EMBASE, Science Direct, and Wiley online library. Independent studies linking Ki-67 to cancer-specific survival (CSS), disease-free survival (DFS), overall survival (OS), progression-free survival (PFS), and recurrence-free survival (RFS) were included in our meta-analysis. With the cut-off values literature provided, hazard ratio (HR) values between the survival distributions were extracted and later combined with STATA 12.0. In total, 76 studies (n = 13,053 patients) were eligible for the meta-analysis. It was indicated in either univariate or multivariate analysis for survival that high Ki-67 reactivity significantly predicted poor prognosis. In the univariate analysis, the combined HR for CSS, DFS, OS, PFS, and RFS were 2.588 (95% confidence interval [CI]: 1.623-4.127, P < 0.001), 2.697 (95%CI: 1.874-3.883, P < 0.001), 2.649 (95%CI: 1.632-4.300, P < 0.001), 3.506 (95%CI: 2.231-5.508, P < 0.001), and 1.792 (95%CI: 1.409-2.279, P < 0.001), respectively. The pooled HR of multivariate analysis for CSS, DFS, OS, PFS, and RFS were 1.868 (95%CI: 1.343-2.597, P < 0.001), 2.626 (95%CI: 2.089-3.301, P < 0.001), 1.104 (95%CI: 1.008-1.209, P = 0.032), 1.518 (95%CI: 1.299-1.773, P < 0.001), and 1.294 (95%CI: 1.203-1.392, P < 0.001), respectively. Subgroup analysis of univariate analysis by origin showed that Ki-67 reactivity significantly correlated with all 5 clinical outcome in Asian and European-American patients (P < 0.05). For multivariate analysis, however, the pooled results were only significant for DFS, OS, and RFS in Asian patients, for CSS, DFS, PFS, and RFS in European-American patients (P < 0.05). In the subgroup with low cut-off value (<20%), our meta-analysis indicated that high Ki-67 reactivity was significantly correlated with worsened CSS, DFS, OS, PFS, and RFS on univariate analysis (P < 0.05). For multivariate analysis, the meta-analysis of literature with low cut-off value (<20%) demonstrated that high Ki-67 reactivity predicted shorter DFS, PFS, and RFS in BC patients (P < 0.05). In the subgroup analysis of high cut-off value (≥20%), our meta-analysis indicated that high Ki-67 reactivity, in either univariate or multivariate analysis, significantly correlated with all five clinical outcomes in BC patients (P < 0.05). The meta-analysis indicates that high Ki-67 reactivity significantly correlates with deteriorated clinical outcomes in BC patients and that Ki-67 can be considered as an independent indicator for the prognosis by the meta-analyses of multivariate analysis.

Critical analysis of bladder sparing with trimodal therapy in muscle-invasive bladder cancer: a systematic review

CONTEXT

Aims of bladder preservation in muscle-invasive bladder cancer (MIBC) are to offer a quality-of-life advantage and avoid potential morbidity or mortality of radical cystectomy (RC) without compromising oncologic outcomes. Because of the lack of a completed randomised controlled trial, oncologic equivalence of bladder preservation modality treatments compared with RC remains unknown.

OBJECTIVE

This systematic review sought to assess the modern bladder-preservation treatment modalities, focusing on trimodal therapy (TMT) in MIBC.

EVIDENCE ACQUISITION

A systematic literature search in the PubMed and Cochrane databases was performed from 1980 to July 2013.

EVIDENCE SYNTHESIS

Optimal bladder-preservation treatment includes a safe transurethral resection of the bladder tumour as complete as possible followed by radiation therapy (RT) with concurrent radiosensitising chemotherapy. A standard radiation schedule includes external-beam RT to the bladder and limited pelvic lymph nodes to an initial dose of 40 Gy, with a boost to the whole bladder to 54 Gy and a further tumour boost to a total dose of 64-65 Gy. Radiosensitising chemotherapy with phase 3 trial evidence in support exists for cisplatin and mitomycin C plus 5-fluorouracil. A cystoscopic assessment with systematic rebiopsy should be performed at TMT completion or early after TMT induction. Thus, nonresponders are identified early to promptly offer salvage RC. The 5-yr cancer-specific survival and overall survival rates range from 50% to 82% and from 36% to 74%, respectively, with salvage cystectomy rates of 25-30%. There are no definitive data to support the benefit of using of neoadjuvant or adjuvant chemotherapy. Critical to good outcomes is proper patient selection. The best cancers eligible for bladder preservation are those with low-volume T2 disease without hydronephrosis or extensive carcinoma in situ.

CONCLUSIONS

A growing body of accumulated data suggests that bladder preservation with TMT leads to acceptable outcomes and therefore may be considered a reasonable treatment option in well-selected patients.

PATIENT SUMMARY

Treatment based on a combination of resection, chemotherapy, and radiotherapy as bladder-sparing strategies may be considered as a reasonable treatment option in properly selected patients.

Expression of TIP60 (tat-interactive protein) and MRE11 (meiotic recombination 11 homolog) predict treatment-specific outcome of localised invasive bladder cancer

What's known on the subject? and What does the study add? Several studies have shown that defects in DNA-damage response are associated with good survival after chemotherapy and radiotherapy. Furthermore, loss of cell cycle regulators may be prognostic indicators of poor survival after cystectomy. However, the potential clinical impact of previous findings is hampered by insufficient validation of significant results in suitable cystectomy and radiotherapy cohorts. Here we use a large cohort of patients receiving radiotherapy to successfully validate the importance of MRE11 as a predictive marker of disease-specific survival (DSS). Furthermore, using two independent patient cohorts we show for the first time that TIP60 is a predictive marker of DSS after cystectomy. We show that combined use of TIP60 and MRE11 may hold the potential to guide treatment decisions.

OBJECTIVE

• To determine the association between the proteins: tat-interactive protein 60 kDa (TIP60), p16, meiotic recombination 11 homolog (MRE11), phosphorylated ataxia telangiectasia mutated (ATM), retinoblastoma protein (Rb), Ki67, and p53 and clinical outcome in invasive lymph node-negative bladder cancer.

PATIENTS AND METHODS

• Protein expression was measured by immunohistochemistry in cancer specimens from two independent cohorts of patients with bladder cancer treated with cystectomy (162 patients and 273) and one cohort of patients receiving radiotherapy (148). • Disease-specific survival (DSS) was used as the outcome measure, and patients with no disease-specific death were followed for a minimum of 36 months.

RESULTS

• TIP60 was significantly correlated with DSS in both cystectomy cohorts (hazard ratio [HR] 0.42, 95% confidence interval [CI] 0.26-0.68, P < 0.001 and HR 0.45, 95% CI 0.28-0.72, P = 0.001). • MRE11 was significantly correlated with DSS in the cohort receiving radiotherapy (HR 0.64, 95% CI 0.47-0.86, P = 0.005). • P16 was significantly correlated with DSS in all three cohorts (HR 0.46, 95% CI 0.30-0.75, P = 0.032; HR 0.60, 95% CI 0.37-0.97, P = 0.032; HR 0.52, 95% CI 0.28-0.96, P = 0.001). • Rb was significantly correlated with DSS in one cystectomy cohort (HR 1.71, 95% CI 1.13-2.75, P = 0.017). • Ki67, p53, and pATM were not significantly correlated with DSS in any of the cohorts.

CONCLUSIONS

• TIP60 protein expression was a predictive marker for DSS after cystectomy in two independent cohorts. This novel marker was the strongest predictive factor in multivariate analysis in patients receiving cystectomy. • MRE11 was shown to be a predictive marker for DSS after radiotherapy. • We have shown that TIP60 and MRE11 hold the potential to guide patients with invasive bladder cancer to either cystectomy or radiotherapy. This study was based on retrospective material and consequently we suggest that these markers should be validated in a prospective study.

Mechanism-based screen establishes signalling framework for DNA damage-associated G1 checkpoint response

DNA damage activates checkpoint controls which block progression of cells through the division cycle. Several different checkpoints exist that control transit at different positions in the cell cycle. A role for checkpoint activation in providing resistance of cells to genotoxic anticancer therapy, including chemotherapy and ionizing radiation, is widely recognized. Although the core molecular functions that execute different damage activated checkpoints are known, the signals that control checkpoint activation are far from understood. We used a kinome-spanning RNA interference screen to delineate signalling required for radiation-mediated retinoblastoma protein activation, the recognized executor of G₁ checkpoint control. Our results corroborate the involvement of the p53 tumour suppressor (TP53) and its downstream targets p21^CIP1/WAF1 but infer lack of involvement of canonical double strand break (DSB) recognition known for its role in activating TP53 in damaged cells. Instead our results predict signalling involving the known TP53 phosphorylating kinase PRPK/TP53RK and the JNK/p38MAPK activating kinase STK4/MST1, both hitherto unrecognised for their contribution to DNA damage G1 checkpoint signalling. Our results further predict a network topology whereby induction of p21^CIP1/WAF1 is required but not sufficient to elicit checkpoint activation. Our experiments document a role of the kinases identified in radiation protection proposing their pharmacological inhibition as a potential strategy to increase radiation sensitivity in proliferating cancer cells.

ErbB2 and NFκB overexpression as predictors of chemoradiation resistance and putative targets to overcome resistance in muscle-invasive bladder cancer

Radical cystectomy for muscle-invasive bladder cancer (MIBC) patients frequently impairs their quality of life (QOL) due to urinary diversion. To improve their QOL, a bladder-sparing alternative strategy using chemoradiation has been developed. In bladder-sparing protocols, complete response (CR) to induction chemoradiation is a prerequisite for bladder preservation and favorable survival. Thus predicting chemoradiation resistance and overcoming it would increase individual MIBC patients' chances of bladder preservation. The aim of this study is to investigate putative molecular targets for treatment aimed at improving chemoradiation response. Expression levels of erbB2, NFκB, p53, and survivin were evaluated immunohistochemically in pretreatment biopsy samples from 35 MIBC patients in whom chemoradiation sensitivity had been pathologically evaluated in cystectomy specimens, and associations of these expression levels with chemoradiation sensitivity and cancer-specific survival (CSS) were investigated. Of the 35 patients, 11 (31%) achieved pathological CR, while tumors in the remaining 24 patients (69%) were chemoradiation-resistant. Multivariate analysis identified erbB2 and NFκB overexpression and hydronephrosis as significant and independent risk factors for chemoradiation resistance with respective relative risks of 11.8 (P = 0.014), 15.4 (P = 0.024) and 14.3 (P = 0.038). The chemoradiation resistance rate was 88.5% for tumors overexpressing erbB2 and/or NFκB, but only 11.1% for those negative for both (P <0.0001). The 5-year CSS rate was 74% overall. Through multivariate analysis, overexpression of erbB2 and/or NFκB was identified as an independent risk factor for bladder cancer death with marginal significance (hazard ratio 21.5, P = 0.056) along with chemoradiation resistance (P = 0.003) and hydronephrosis (P = 0.018). The 5-year CSS rate for the 11 patients achieving pathological CR was 100%, while that for the 24 with chemoradiation-resistant disease was 61% (P = 0.018). Thus, erbB2 and NFκB overexpression are relevant to chemoradiation resistance and are putative targets aimed at overcoming chemoradiation resistance in MIBC.

Association between cyclin D1 polymorphism with CpG island promoter methylation status of tumor suppressor genes in gastric cancer

BACKGROUND

CpG island hypermethylation of tumor suppressor genes is highly involved in gastric carcinogenesis, and enhanced cell proliferation could accelerate this process. Cyclin D1 regulates cell cycle function and may play a role in methylation-related carcinogenesis.

AIMS

We investigated the association between Cyclin D1 gene G870A polymorphism and the methylation status of tumor suppressor genes in gastric cancer.

METHODS

Polymorphisms at G870A in the Cyclin D1 gene were genotyped, and methylation status of the p14, p16, DAP-kinase, and CDH1 genes were determined by methylation-specific-polymerase chain reaction in 139 gastric cancer tissues. CIHM high was defined as three or more methylated CpG islands.

RESULTS

Although no association was found between methylation status and different stages and Lauren's subtypes, patients with CIHM of DAP-kinase showed significantly worse survival than those without (p = 0.017). In addition, the number of methylated sites was also associated with survival curves (p = 0.0397). The 870G carrier a significantly lower prevalence of CIHM high compared to the AA genotype in advanced-stage gastric cancer (adjusted OR = 0.32, p = 0.047). A weak correlation between the same genotypes and CIHM of p14 were found in the same subtype (adjusted OR = 0.32, p = 0.052). The mean methylation number was significantly lower in G carriers than in AA genotypes in advanced-stage gastric cancer (p = 0.017).

CONCLUSIONS

Genetic polymorphism of CCND1 is associated with CIHM status in gastric cancer, especially in the advanced stage, but is independent of clinico-pathological features.

MRE11 expression is predictive of cause-specific survival following radical radiotherapy for muscle-invasive bladder cancer

Radical radiotherapy and surgery achieve similar cure rates in muscle-invasive bladder cancer, but the choice of which treatment would be most beneficial cannot currently be predicted for individual patients. The primary aim of this study was to assess whether expression of any of a panel of DNA damage signaling proteins in tumor samples taken before irradiation could be used as a predictive marker of radiotherapy response, or rather was prognostic. Protein expression of MRE11, RAD50, NBS1, ATM, and H2AX was studied by immunohistochemistry in pretreatment tumor specimens from two cohorts of bladder cancer patients (validation cohort prospectively acquired) treated with radical radiotherapy and one cohort of cystectomy patients. In the radiotherapy test cohort (n = 86), low tumor MRE11 expression was associated with worse cancer-specific survival compared with high expression [43.1% versus 68.7% 3-year cause-specific survival (CSS), P = 0.012] by Kaplan-Meier analysis. This was confirmed in the radiotherapy validation cohort (n = 93; 43.0% versus 71.2%, P = 0.020). However, in the cystectomy cohort (n = 88), MRE11 expression was not associated with cancer-specific survival, commensurate with MRE11 being a predictive marker. High MRE11 expression in the combined radiotherapy cohort had a significantly better cancer-specific survival compared with the high-expression cystectomy cohort (69.9% versus 53.8% 3-year CSS, P = 0.021). In this validated immunohistochemistry study, MRE11 protein expression was shown and confirmed as a predictive factor associated with survival following bladder cancer radiotherapy, justifying its inclusion in subsequent trial designs. MRE11 expression may ultimately allow patient selection for radiotherapy or cystectomy, thus improving overall cure rates.

Effect of cyclin D1 (CCND1) polymorphism on gastric premalignant condition

BACKGROUND

Cyclin D1 (CCND1) is known to regulate function in G1 arrest and therefore may play an important role in carcinogenesis. The aim of this study was to investigate the effect of G870A polymorphism of the CCND1 gene on gastric precancerous condition, on histological chronic gastritis, and on the risk of peptic ulcer diseases.

METHODS

Restriction fragment length polymorphism analysis was performed for polymorphisms at 870GA in the CCND1 gene in 524 cancer-free subjects, including 111 gastric and 54 duodenal ulcers, and 359 non-ulcer subjects. Gastritis scores of antral gastric mucosa were assessed according to the updated Sydney system in 384 subjects.

RESULTS

CCND1 genotype was significantly associated with the severity of intestinal metaplasia by the Kruskal-Wallis test, and this tendency was especially stronger among older subjects of 61 years or older (overall subjects: p=0.035, 61 years approximately : p=0.007). We also found that the 870AA genotype held a significant high risk of intestinal metaplasia [Helicobacter pylori infection adjusted odds ratio (OR)=1.8, 95% confidence interval (CI)=1.03-3.15, p=0.04]. The same genotype was more closely associated with the risk of intestinal metaplasia in older subjects of 61 years or older (H. pylori infection adjusted OR=3.45, 95% CI=1.48-8.08, p=0.004). A non-significant association was found between CCND1 G870A genotypes and the risk of peptic ulcer diseases as well as histological severity of acute or chronic inflammation.

CONCLUSIONS

It appears that the G870A polymorphism of CCND1 is associated with gastric premalignant condition especially in older subjects.

Cyclin D1 expression is induced by viral BARF1 and is overexpressed in EBV-associated gastric cancer

Approximately 10% of gastric carcinomas (GC) worldwide are associated with Epstein-Barr virus (EBV). GC is one of the most frequent human malignancies associated with EBV. The latent expression of the EBV-oncogene BARF1 is restricted to epithelial malignancies. To investigate the underlying BARF1-related mechanisms of oncogenic epithelial transformation, we analyzed gene expression profiles of a BARF1-transfected epithelial (HaCaT+) and the corresponding BARF1-negative (HaCaT-) cell line by cDNA microarray analysis. Real-time PCR was performed to confirm the cDNA microarray results. In addition, immunohistochemistry and fluorescence in situ hybridization were performed on a tissue microarray of 181 GC including 11 EBV-associated GC. Among other genes cyclin D1 expression was significantly upregulated in HaCaT+ on the transcriptional and protein level. Cyclin D1 protein expression in GC revealed a significant overexpression of cyclin D1 in EBV-associated GC (p<0.012) but not in EBV-negative GC. Cyclin D1 FISH showed that cyclin D1 overexpression was not due to gene amplification in EBV-associated GC. Cyclin D1 is induced in HaCaT+ by BARF1 and is overexpressed in EBV-associated GC indicating an interaction of viral BARF1 and cyclin D1.

Molecular markers for bladder cancer: the road to a multimarker approach

Bladder cancer is the seventh most common malignancy worldwide, with almost 14,000 patients dying from this disease in the USA alone. Because of the need for long-term and frequent follow-up, as well as the paucity of sensitive and specific noninvasive tests, bladder cancer management has the highest cost per patient among all cancer types. Several molecular markers, especially members of the cell cycle regulation and apoptosis pathways, have been investigated. However, no individual marker has been prognostically powerful enough to change clinical management. The combined analysis of a panel of markers spanning different pathways is the most promising approach. We give an overview of the most important molecular markers functioning in crucial pathways and focus on their role in multimarker analysis.

Radiotherapy for Bladder Cancer

The radiotherapy panel met to develop international consensus about the optimal use of radiotherapy, alone or in combination with surgery and chemotherapy, in the radical treatment of patients with bladder cancer. A consensus meeting of experts in the treatment of bladder cancer was convened by the Société Internationale d'Urologie (SIU). The radiotherapy committee, which had international representation from 6 countries, performed a critical review of the English-language literature and developed evidence-based guidelines for the use of radiotherapy in the treatment of patients with bladder cancer. The strength of the evidence supporting each recommendation was ranked according to a 4-point scale. Consensus statements were developed that address (1) the effectiveness of radiotherapy in the treatment of bladder cancer, (2) the most appropriate patients for curative treatment with radiotherapy, (3) the optimal method of delivery of radiotherapy, (4) the best radiation prescription for treating bladder cancer, and (5) optimal management of the patient's condition after radiotherapy has been provided. Radiotherapy is effective treatment for selected patients with bladder cancer; it produces long-term disease control with preservation of normal bladder function. Modern radiotherapy treatment techniques offer the potential to improve cure rates and reduce adverse effects. All patients in whom the condition is newly diagnosed should be assessed in a multidisciplinary setting, where the relative merits of surgery, radiotherapy, and chemotherapy can be considered on an individual basis with the aim of optimizing overall outcomes.

Trimodality Treatment and Selective Organ Preservation for Bladder Cancer

Standard treatment for muscle-invasive bladder cancer is cystectomy. Trimodality treatment, including transurethral resection of the bladder tumor (TURBT), radiation therapy and chemotherapy, has been shown to produce survival rates comparable to those of cystectomy. With these programs, cystectomy has been reserved for patients with incomplete response or local relapse. During the past 15 years, organ preservation by trimodality treatment has been investigated in prospective series from single centers and cooperative groups, with more than 1,000 patients included. Five-year overall survival rates in the range of 50% to 60% have been reported, and approximately three quarters of the surviving patients maintained their bladder. Clinical criteria helpful in determining ideal patients for bladder preservation include early tumor stage (including high-risk T1 disease), a visibly complete TURBT, and absence of ureteral obstruction. Close coordination among all disciplines is required to achieve optimal results. Future investigations will focus on (1) optimizing radiation techniques and incorporating more effective systemic chemotherapy, and (2) the proper selection of patients based on molecular makers.

Apoptotic and proliferation indexes in primary superficial bladder tumors

Whether apoptotic index [AI] and/or Ki-67 labeling index [Ki-67LI] add prognostic information in bladder cancer remains unclear. Mean AI and Ki-67 LI increased with grade and stage in 147 superficial bladder tumors. AI (>1.7%) correlated with tumor size, grade and proliferation. Ki-67 LI (>10%) correlated with higher grade and stage. Tumor size and Ki-67 LI were independent predictors of disease-free and progression-free survival, respectively. Tumor size, patient's age and tumor's recurrence predicted overall survival. We conclude that conventional clinical parameters and Ki-67 LI define risk groups of bladder tumors, while AI has limited value.

Molecular biology of bladder cancer: prognostic and clinical implications

The role of various molecular determinants involved in the genesis, progression, and outcome of bladder cancer has been the focus of investigations for the past 2 decades. Increasingly, the analysis of the interplay between these molecular factors is taking center stage. We review herein the studies examining the effects of deregulation of the various molecules implicated in the cell cycle, apoptosis, and angiogenesis pathways and analyze the central role of p53 in regulating these pathways. Technological advancements enable detection and quantification of gene transcripts and protein products, helping us move toward achieving the goal of establishing diagnostic, prognostic, and therapeutic marker panels. Recent studies have therefore focused on multiple-marker analyses to generate informative panels that can have greater clinical value for bladder cancer management. The use of molecular marker panels can provide a more objective alternative to clinical parameters for diagnosis and treatment decisions. Clinical trials aimed at treating urothelial carcinoma based on a patient's molecular profile can be predicted to empower clinicians to personalize patient management through increased therapeutic efficacy.

Establishment and characterization of human urothelial cancer xenografts in severe combined immunodeficient mice

AIM

To establish and characterize a murine xenograft model of human urothelial cancer in severe combined immunodeficient (SCID) mice for therapeutic simulation.

METHODS

Pieces of 30 freshly resected urothelial tumors (24 obtained from bladder and 6 from ureter or pelvis) were implanted subcutaneously into SCID mice, and xenograft tumors were passed in tumorigenic cases. At each passage, histopathology, TP53 mutational status assessed by yeast p53 functional assay, and the Ki-67 labeling index (LI) were examined to evaluate the preservation of original features. A growth delay assay after single-dose irradiation was performed in four representative xenografts.

RESULTS

Tumor growth was observed in 18 mice (60%, 18/30). Histologically, 15 of the 18 were epithelial carcinomas similar to the original tumors, whereas the other 3 were Epstein-Barr virus-associated lymphoproliferative disease, resulting in a 50% (15/30) take rate. No correlation was found between the tumor take rate and the clinicopathologic features, TP53 mutational status, or Ki-67 LI of the patients' tumors. Of these 15 xenografts, 11 xenografts were passed from 3 to 10 generations. TP53 mutational status remained stable during the passages, and the Ki-67 LI of eight xenografts was within a range of 50% of the LI of the original tumors, although the other three xenografts increased by over 50%. Specific growth delay after irradiation, independent of the original tumor growth speed and Ki-67 LI, was observed in four xenografts.

CONCLUSIONS

SCID mice are useful recipients for investigations of human urothelial cancer with a wide biological range. This easy-to-handle xenograft system can help to develop a better in vivo preclinical evaluation system for therapeutic agents as well as the investigation of tumor pathophysiology.

Experimental models of human bladder carcinogenesis

Bladder cancer is the fifth most common cancer in the UK, yet human bladder carcinogenesis remains poorly understood and the response of bladder tumours to radio- and chemo-therapy is unpredictable. The aims of this article are to review human bladder carcinogenesis and appraise the different in vitro and in vivo approaches that have been developed to study the process. The review considers how in vitro models based on normal human urothelial (NHU) cells can be applied to human bladder cancer research. We conclude that recent advances in NHU cell culture offer novel approaches for defining urothelial tissue-specific responses to genotoxic and non-genotoxic carcinogens and elucidating the role of specific genes involved in the mechanisms of bladder carcinogenesis and malignant progression.

The retinoblastoma protein--from bench to bedside

The retinoblastoma tumour suppressor protein (Rb) has come a long way since its initial discovery in 1986. Encoded by the first candidate tumour suppressor gene it has emerged a versatile and context-dependent modulator of cell behaviour. Its activity is managed by signalling networks sensing intra- and extracellular cues. These cues are relayed to hold or permit inactivation of Rb by phosphorylation. Loss or mutation of the retinoblastoma gene is rare in sporadic cancers but defects in the pathways that license inactivation of Rb are found in the majority of them, suggesting that loss of Rb control is central to tumour development and arguing that its reinstatement might reverse tumour formation. Furthermore, mouse models with engineered defects in the Rb-phosphorylating kinases provide evidence that moderation of Rb inactivation may be a strategy for the prevention of tumour formation. The rationale behind these arguments, their underlying molecular concepts and strategies towards therapeutic application will be discussed.

Heat stress induces different forms of cell death in sea anemones and their endosymbiotic algae depending on temperature and duration

Bleaching of reef building corals and other symbiotic cnidarians due to the loss of their dinoflagellate algal symbionts (=zooxanthellae), and/or their photosynthetic pigments, is a common sign of environmental stress. Mass bleaching events are becoming an increasingly important cause of mortality and reef degradation on a global scale, linked by many to global climate change. However, the cellular mechanisms of stress-induced bleaching remain largely unresolved. In this study, the frequency of apoptosis-like and necrosis-like cell death was determined in the symbiotic sea anemone Aiptasia sp. using criteria that had previously been validated for this symbiosis as indicators of programmed cell death (PCD) and necrosis. Results indicate that PCD and necrosis occur simultaneously in both host tissues and zooxanthellae subject to environmentally relevant doses of heat stress. Frequency of PCD in the anemone endoderm increased within minutes of treatment. Peak rates of apoptosis-like cell death in the host were coincident with the timing of loss of zooxanthellae during bleaching. The proportion of apoptosis-like host cells subsequently declined while cell necrosis increased. In the zooxanthellae, both apoptosis-like and necrosis-like activity increased throughout the duration of the experiment (6 days), dependent on temperature dose. A stress-mediated PCD pathway is an important part of the thermal stress response in the sea anemone symbiosis and this study suggests that PCD may play different roles in different components of the symbiosis during bleaching.

p53, p16 and cyclin D1: Molecular determinants of radiotherapy treatment response in oral carcinoma

Management of oral cancer by radiotherapy has witnessed promising advances in the past few years, with patient-tailored radio fractionation regimens. Different fractionation schedules, conventional and altered regimes, have been used in curative radiotherapy. Although contribution of biological markers on radio response has been evaluated, its unique influence on various radio fractionation schemes has not been accounted so far. Our study analyses a set of proteins that previously demonstrated radio response influence for their possible prognostic value in decision-making process between the respective fractionation schemes. Expression patterns of regulatory proteins such as p53, cyclin D1, p16, Cdk4, p21, Rb, bcl-2 and PCNA were determined by immunohistochemistry utilizing monoclonal antibodies in 125 patients who received curative radiotherapy dose. Among these 125 patients, 90 (72%) received altered fractionation, whereas 35 (28%) received conventional fractionation. p53 over-expression correlated with local treatment failure among the patients treated with conventional fractionation whereas cyclin D1 over-expression and p16 underexpression were associated with local treatment failure as well as overall survival in altered fractionation treated cases. Our findings suggest that wild-type p53 status may be an important parameter for achieving high local control in those patients undergoing conventional fractionation, where as intact p16 and cyclin D1 status may be beneficial for effective local control in patients who are treated with altered fractionation. Furthermore, it can be assumed that conventional fractionation employs p53-mediated apoptosis, whereas altered fractionation activates the functional G1 cell-cycle checkpoint for tumor growth suppression.

Molecular markers in clinical radiation oncology

Radiation therapy plays a critical role in the management of a majority of patients diagnosed with cancer. Identification of factors that help predict which patients are at risk for relapse within the irradiated field remains an active area of investigation. Although conventional clinical and pathologic factors have been helpful in identifying risk and guiding clinical decision-making for both local and systemic management, there is clearly a need to identify additional prognostic markers, which can aid in refining our treatment strategies and improving outcomes. A substantial amount of research efforts have been devoted to identifying molecular markers for prognostic and therapeutic strategies. The recent emergence of a powerful armamentarium of molecular tools has resulted in rapid expansion of our fund of knowledge and understanding of the molecular biology underlying tumor behavior and response. While a majority of these efforts have been focused on risk factors for metastatic disease and survival, there is a rapidly growing body of literature focused on molecular factors associated with radiation resistance and locoregional failure. In this review, we summarize recent advances and the available literature evaluating molecular markers as they relate to radiation sensitivity of solid tumors. Literature regarding the potential application of expression of genes related to apoptosis, angiogenesis, cell cycle, DNA repair and growth factors will be reviewed. Some of the basic biology and laboratory evidence demonstrating how the marker relates to radiation response and available correlative clinical studies employing these markers as prognostic tools are presented. The majority of molecular markers that have potential clinical significance with respect to radiation sensitivity and local control will be highlighted.

Retinoblastoma protein expression is an independent predictor of both radiation response and survival in muscle-invasive bladder cancer

The objective of the study was to investigate the predictive value of various clinical, biochemical, and histopathological parameters, with special emphasis on the expression of the retinoblastoma protein (pRB), on the radiation response in bladder cancer. In order to obtain a truly objective response measure, patients receiving preoperative radiotherapy followed by cystectomy were studied. Pretreatment tumour samples and clinical data from 108 consecutive patients were collected. End points were complete response (CR) to radiotherapy, relapse-free survival time and overall survival time. Expression of pRB was assessed by immunohistochemical staining as present or absent. Complete response to radiotherapy was obtained in 42 of 106 evaluable patients (40%). Predictive for CR to radiotherapy, in univariate analysis, was transurethral resection (as opposed to biopsy), B-haemoglobin, no upper urinary retention, and loss of pRB staining. Loss of pRB staining was the strongest independent predictor of radiation response in multivariate logistic regression analysis and absence of upper urinary retention was the only other significant factor. Loss of pRB was the only parameter showing statistically significant, independent association with relapse-free survival, whereas B-haemoglobin was also independently associated with overall survival. Loss of pRB expression seems to indicate a phenotype displaying enhanced radiosensivity and may be of benefit by denoting patients who would selectively benefit from a treatment schedule containing radiotherapy.

Association of cyclin D1 (G870A) polymorphism with susceptibility to esophageal and gastric cardiac carcinoma in a northern Chinese population

Our aim was to investigate the association of cyclin D1 (G870A) single nucleotide polymorphism with susceptibility to esophageal and cardiac carcinoma in a northern Chinese population. By polymerase chain reaction-single strand conformation polymorphism analysis, cyclin D1 (G870A) genotyping was carried out among 120 patients with esophageal squamous cell carcinoma (ESCC), 87 patients with gastric cardiac adenocarcinoma (CAC), and 183 age- and gender-matched controls. The cyclin D1 genotype distribution among ESCC patients was significantly different from that among healthy controls (chi(2) = 7.372, p = 0.025). The G/G genotype was significantly less frequent among ESCC patients (9.2%) than among healthy controls (20.8%) (chi(2) = 7.192, p = 0.007). The G/G genotype significantly reduced risk for the development of ESCC compared to the combination of G/A and A/A genotypes (adjusted odds ratio [OR] = 0.37, 95% confidence interval [CI] = 0.16-0.83). After stratification according to smoking status, the A/A frequency among smoking ESCC (34.3%) and CAC patients (35.7%) was significantly higher than that among smoking healthy controls (18.6%) (chi(2) = 5.426 and 5.599, p = 0.020 and 0.018, respectively). Smokers with the A/A genotype had an about 2-fold increased risk for both of ESCC and CAC compared to the G/A and G/G genotypes, with an adjusted OR of 2.26 in ESCC (95% CI = 1.14-4.49) and of 2.42 in CAC (95% CI = 1.17-4.98). No correlation between the cyclin D1 genotype and development of ESCC or CAC was found among nonsmokers. Determination of the cyclin D1 (G870A) single nucleotide polymorphism may be suitable to identify individuals with increased risk for ESCC or CAC in the northern Chinese population.

Preclinical evaluation of a radiosensitizing effect of gemcitabine in p53 mutant and p53 wild type bladder cancer cells

OBJECTIVES

Despite clinical use, the radiosensitizing effect of gemcitabine (2'2'-difluorodeoxycytidine) in human transitional cell carcinoma (TCC) has not been shown to date. We investigated gemcitabine as a radiosensitizer for human TCC cells.

METHODS

Monolayer cultures of RT112 (G1, p53 wild type), RT4 (G1-G2, p53 wild type), T24 (G3, p53, mutant type), and SUP (G4, p53 mutant type) cells were incubated in medium with gemcitabine. Electron beam radiation was applied alone, simultaneous, or 3, 6, 12, and 24 hours after gemcitabine. Jurkat leukemia cells were used as controls for radiation toxicity. Cell survival was determined 6, 12, 24, 48, and 72 hours after radiation by microculture tetrazolium assay. DNA damage was evaluated by flow cytometric assessment of poly(ADP-ribose) polymerase, and apoptosis was determined by terminal-deoxynucleotidyltransferase-mediated dUTP nick-end labeling and flow cytometric assessment after annexin-V and propidium iodide labeling.

RESULTS

In all TCC cell lines, radiation alone caused only little and insignificant growth inhibitory effects at 10 Gy. Gemcitabine alone had a dose-dependent cytotoxic and apoptosis inducing effect on all TCC cell lines independent of p53 status. Assays combining radiation with gemcitabine in different dose and time schedules demonstrated no radiosensitizing effect in TCC cells.

CONCLUSIONS

Gemcitabine is effective in TCC cell lines independent of p53 status. A radiosensitizing effect could not be demonstrated. Again, p53 status was not predictive of the radioresponse in the bladder cancer cell lines. Clinical studies with gemcitabine and radiotherapy might nevertheless yield different results but should be performed with utmost caution.

Combined-modality treatment and selective organ preservation in invasive bladder cancer: long-term results

PURPOSE

To evaluate our long-term experience with combined modality treatment and selective bladder preservation and to identify factors that may predict treatment response, risk of relapse, and survival.

PATIENTS AND METHODS

Between 1982 and 2000, 415 patients with bladder cancer (high-risk T1, n = 89; T2 to T4, n = 326) were treated with radiotherapy (RT; n = 126) or radiochemotherapy (RCT; n = 289) after transurethral resection (TUR) of the tumor. Six weeks after RT/RCT, response was evaluated by restaging-TUR. In case of complete response (CR), patients were observed at regular intervals. In case of persistent or recurrent invasive tumor, salvage-cystectomy was recommended. Median follow-up was 60 months (range, 6 to 199 months).

RESULTS

CR was achieved in 72% of patients. Local control after CR without muscle-invasive relapse was maintained in 64% of patients at 10 years. Distant metastases were diagnosed in 98 patients with an actuarial rate of 35% at 10 years. Ten-year disease-specific survival was 42%, and more than 80% of survivors preserved their bladder. Early tumor stage and a complete TUR were the most important factors predicting CR and survival. RCT was more effective than RT alone in terms of CR and survival. Salvage cystectomy for local failure was associated with a 45% disease-specific survival rate at 10 years. Cystectomy because of a contracted bladder was restricted to 2% of patients.

CONCLUSION

TUR with RCT is a reasonable option for patients seeking an alternative to radical cystectomy. Ideal candidates are those with early-stage and unifocal tumors, in whom a complete TUR is accomplished.

Prognostic factors in transitional cell cancer of the bladder: an emerging role for Bcl-2 and p53

BACKGROUND AND PURPOSE

In a recent study on patients with transitional cell cancer of the bladder treated with curative radiotherapy following TUR-T, we demonstrated that a low apoptotic index and p53 positivity were associated with poor local control. The purpose of this study was to assess the prognostic significance of additional markers implicated in regulation of cell cycle and apoptosis.

PATIENTS AND METHODS

Bcl-2, Bax and p21 positivity were detected immunohistochemically on paraffin-embedded pre-treatment biopsies from 83 patients with invasive transitional cell cancer (TCC) of the bladder, treated with radiotherapy. In addition, markers determined in an earlier analysis, i.e.: p53, apoptotic index, cyclin D1, retinoblastoma protein and Ki-67 were included in the multivariate analysis. A stepwise proportional hazard analysis was performed, adjusting for classic prognostic factors (T-stage, grade, multifocality and macroscopic completeness of the TUR). Positivity was defined as >10% of tumor cells staining positive for Bcl-2, Bax and p21, and >20% for p53.

RESULTS

Bcl-2 positivity was found in 63%, Bax was positive in 52% and p21 in 55% of cases. In the PH analysis Bcl-2 positivity was found to be related to poor local control (36 vs. 72% at 3 years; P=0.003), as well as to shorter disease-specific survival (74 vs. 94% at 3 years; P=0.017). Evidence for an adverse effect of p53 positivity was also found (local control: 32 vs. 69% at 3 years;P=0.037, disease-specific survival: 76 vs. 92% at 3 years; P=0.043). In an additional PH analysis, we found poor local control rates for bladder cancers with combined Bcl-2 and p53 positivity (17 vs. 65% at 3 years; P=0.0017), and lower disease specific survival (60 vs. 92%; P=0.0024), disease-free survival (7 vs.35%, P=0.0023) and overall survival (39 vs. 80%; P=0.0018).

CONCLUSION

This study provides evidence for a poor outcome in patients treated with radiotherapy for TCC of the bladder expressing both Bcl-2 and p53. This relationship was found for local control and disease-free, disease-specific and overall survival.

New chemotherapy combinations for advanced bladder cancer

Transitional cell carcinoma of the urothelium is considered a chemosensitive malignancy. Until recently, the methotrexate, vinblastine, doxorubicin and cisplatin combination has been considered the standard for treating this disease. The development of new chemotherapeutic agents such as gemcitabine and the taxanes has opened up promising new perspectives in the treatment of this disease. However, the preliminary phase II data must be confirmed in adequately conducted phase III trials.