Negative p53/positive p21 immunostaining is a predictor of favorable response to chemotherapy in patients with locally advanced bladder cancer

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.

Recent advances in treatment of advanced urothelial carcinoma

GC (cisplatin and gemcitabine) and MVAC (methotrexate, vinblastine, Adriamycin [doxorubicin], and cisplatin) have been the standard systemic chemotherapy in advanced urothelial carcinoma. These regimens have shown significant response rates in this patient population. Nevertheless, disease does recur with most patients who unfortunately do succumb to the disease. Research efforts are focused in several different areas of therapy, targeted therapy, and immunotherapy. Further efforts include those in improving understanding of the molecular biology of urothelial carcinoma which may lead development of biomarkers that may enhance therapeutic index. This paper reviews recent advances in the treatment and ongoing study of molecular biology of urothelial carcinoma.

Selective bladder preservation with curative intent for muscle-invasive bladder cancer: a contemporary review

Radical cystectomy plus urinary diversion, the reference standard treatment for muscle-invasive bladder cancer, associates with high complication rates and compromises quality of life as a result of long-term effects on urinary, gastrointestinal and sexual function, and changes in body image. As a society ages, the number of elderly patients unfit for radical cystectomy as a result of comorbidity will increase, and thus the demand for bladder-sparing approaches for muscle-invasive bladder cancer will also inevitably increase. Trimodality bladder-sparing approaches consisting of transurethral resection, chemotherapy and radiotherapy (Σ 55-65 Gy) yield overall survival rates comparable with those of radical cystectomy series (50-70% at 5 years), while preserving the native bladder in 40-60% of muscle-invasive bladder cancer patients, contributing to an improvement in quality of life for such patients. Limitations of the trimodality therapy include (i) muscle-invasive bladder cancer recurrence in the preserved bladder, which most often arises in the original muscle-invasive bladder cancer site; (ii) potential lack of curative intervention for regional lymph nodes; and (iii) increased morbidity in the event of salvage radical cystectomy for remaining or recurrent disease as a result of high-dose pelvic irradiation. Consolidative partial cystectomy with pelvic lymph node dissection followed by induction chemoradiotherapy at lower dose (e.g. 40 Gy) is a rational strategy for overcoming such limitations by strengthening locoregional control and reducing radiation dosage. Molecular profiling of the tumor and functional imaging might play important roles in optimal patient selection for bladder preservation. Refinement of radiation techniques, intensified concurrent or adjuvant chemotherapy, and novel sensitizers, including molecular targeting agent, are also expected to improve outcomes and consequently provide more muscle-invasive bladder cancer patients with favorable quality of life.

Role of diffusion-weighted magnetic resonance imaging in predicting sensitivity to chemoradiotherapy in muscle-invasive bladder cancer

PURPOSE

In chemoradiation (CRT)-based bladder-sparing approaches for muscle invasive bladder cancer (MIBC), patients who respond favorably to induction CRT enjoy the benefits of bladder preservation, whereas nonresponders do not. Thus, accurate prediction of CRT sensitivity would optimize patient selection for bladder-sparing protocols. Diffusion-weighted MRI (DW-MRI) is a functional imaging technique that quantifies the diffusion of water molecules in a noninvasive manner. We investigated whether DW-MRI predicts CRT sensitivity of MIBC.

METHODS AND MATERIALS

The study cohort consisted of 23 MIBC patients (cT2/T3 = 7/16) who underwent induction CRT consisting of radiotherapy to the small pelvis (40 Gy) with two cycles of cisplatin (20 mg/day for 5 days), followed by partial or radical cystectomy. All patients underwent DW-MRI before the initiation of treatment. Associations of apparent diffusion coefficient (ADC) values with CRT sensitivity were analyzed. The proliferative potential of MIBC was also assessed by analyzing the Ki-67 labeling index (LI) in pretherapeutic biopsy specimens.

RESULTS

Thirteen patients (57%) achieved pathologic complete response (pCR) to CRT. These CRT-sensitive MIBCs showed significantly lower ADC values (median, 0.63 × 10(-3) mm(2)/s; range, 0.43-0.77) than CRT-resistant (no pCR) MIBCs (median, 0.84 × 10(-3) mm(2)/s; range, 0.69-1.09; p = 0.0003). Multivariate analysis identified ADC value as the only significant and independent predictor of CRT sensitivity (p < 0.0001; odds ratio per 0.001 ×10(-3) mm(2)/s increase, 1.03; 95% confidence interval, 1.01-1.08). With a cutoff ADC value at 0.74 × 10(-3) mm(2)/s, sensitivity/specificity/accuracy in predicting CRT sensitivity was 92/90/91%. Ki-67 LI was significantly higher in CRT-sensitive MIBCs (p = 0.0005) and significantly and inversely correlated with ADC values (ρ = -0.67, p = 0.0007).

CONCLUSIONS

DW-MRI is a potential biomarker for predicting CRT sensitivity in MIBC. DW-MRI may be useful to optimize patient selection for CRT-based bladder-sparing approaches.

Low-dose chemoradiotherapy followed by partial or radical cystectomy against muscle-invasive bladder cancer: an intent-to-treat survival analysis

OBJECTIVES

To evaluate the clinical outcomes of patients with muscle-invasive bladder cancer treated with a prospective institutional protocol composed of induction low-dose chemoradiotherapy (LCRT) plus partial or radical cystectomy.

METHODS

From March 1997 to March 2006, 102 patients with Stage T2-T4aN0M0 bladder urothelial carcinoma consecutively underwent transurethral resection of the bladder tumor followed by LCRT consisting of radiotherapy to the bladder (radiation dose 40 Gy) concurrent with two cycles of intravenous (20 mg/d for 5 days) or intra-arterial (100 mg) cisplatin. Depending to their post-LCRT tumor status, patients were recommended to undergo partial or radical cystectomy with curative intent.

RESULTS

LCRT-related toxicity of grade 3 or greater was rare (3%). Of 97 eligible patients, 41 (42%) had a complete response, 29 (30%) a partial response, 24 (25%) had stable disease, and 3 (4%) progressive disease. Of the 97 patients, 19, underwent partial cystectomy, and 58 underwent radical cystectomy, 2 underwent transurethral resection of the bladder tumor, and 18 did not undergo surgery. The 5-year overall survival and cancer-specific survival (CSS) rate was 66% and 74%, respectively. The median follow-up was 43 months (range 3-126). On multivariate analysis, the response to LCRT had the strongest effect on CSS, and CSS was clearly stratified by the response to LCRT (P < .0001), with a 5-year CSS rate of 100% for the 41 patients with a complete response.

CONCLUSIONS

The results of our study have shown that LCRT is an effective and less-toxic induction therapy against muscle-invasive bladder cancer. Our therapeutic protocol with LCRT plus partial or radical cystectomy yielded favorable survival outcomes. The response to LCRT was the strongest prognostic factor for CSS.

C-reactive protein level predicts prognosis in patients with muscle-invasive bladder cancer treated with chemoradiotherapy

OBJECTIVE

To investigate the effect of C-reactive protein (CRP) level on the prognosis of patients with muscle-invasive bladder cancer treated with chemoradiotherapy (ChRT), as it is increasingly recognized that the presence of a systemic inflammatory response is associated with poor survival in various malignancies.

PATIENTS AND METHODS

The clinical records of 88 patients with bladder urothelial carcinoma (cT2-4 N0M0) treated with ChRT were reviewed retrospectively. ChRT comprised external beam radiotherapy to the bladder (40 Gy) with two cycles of cisplatin (50-100 mg) at 3-week intervals. Elevated CRP was defined as > 0.5 mg/dL. The survival rate was calculated using the Kaplan-Meier method, and a multivariate analysis was used to identify significant factors associated with prognosis, using a Cox proportional hazards model.

RESULTS

During the median (range) follow-up of 33 (3-117) months, 19 patients died from bladder cancer; the 5-year cancer-specific survival (CSS) rate was 73%. Ten patients had a high CRP level before ChRT (> or = 0.5 mg/dL) and their CSS rate was significantly worse than that in the remaining patients (P = 0.003). Multivariate analysis showed that CRP and cT stage were independent prognostic indicators for CSS, with a hazard ratio of 1.80 (95% confidence interval 1.01-2.97; P = 0.046). Among 10 patients in those with elevated CRP the CRP levels became normal after ChRT in six, of whom all but one was alive with no evidence of recurrence or metastasis during the follow-up. By contrast, all four with no CRP normalization after ChRT died within 2 years.

CONCLUSIONS

To our knowledge this is the first study to report that elevation of CRP before treatment predicts a poor prognosis in patients with muscle-invasive bladder cancer who are receiving ChRT. Furthermore, failure of CRP levels to normalize after ChRT was associated with extremely poor survival.

[The role of tumor markers in prognosing transitional bladder cancer]

PURPOSE

Review the literature on tumor markers used for prognosis of transitional bladder cancer. The existing problems regarding grading and local staging of these tumors are also discussed.

METHODS

The published literature on transitional bladder cancer markers was identified using a Medline search and critically analysed.

RESULTS

There are significant interobserver differences in grading. There is a new grading system. There are also problems in local staging and low correlation between clinic stage and pathologic stage. Major tumor markers studied for prognosis of transitional bladder cancer are: flow cytometry, kariocytometric study, oncogenes (p53, bcl-2, Her2/Neu or c-erbB2), chromosomic alterations (chromosomes 9, 7 and 17), proliferation markers (Ki-67, MIB-1), cyclin-dependent kinases and its inhibitors (cyclin D1, cyclin E, p21Wafl, p27Kipl), vascular endothelial growth factor, other growth factors (fibroblastic, epidermal, hepatocyte, platelet-derived), metalloproteinases, cell adhesion molecules, and others.

CONCLUSIONS

At present, there are no prognostic markers for bladder cancer that are superior to conventional grading and staging, despite its imperfections. Standarization of assay methods in bladder tumor markers is needed to permit more conclusive and reproducible results and become a clinic tool. Controversy resulting from several studies make the meaning of some putative prognostic markers in transitional bladder cancer questionable.

[Perspectives for molecular diagnostics exemplified by urothelial bladder carcinoma]

The rapidly growing knowledge of molecular mechanisms will change the daily routine of clinicians in the near future. Regarding urothelial bladder carcinoma, one may expect that molecular diagnostics will identify patients susceptible to disease development by screening their genotype. Furthermore, in addition to histopathologic findings, prognostic markers will be used for disease management. In an ongoing multicenter trial, the decision on whether or not to treat patients with adjuvant chemotherapy after cystectomy is based on their p53 status. In the near future, cytostatic medications are expected to be chosen according to genetic profiles of the tumor or patient. New medications, which target tumor-specific alterations of cell-signaling cascades in bladder or other cancers, prominently inhibitors of the ERBB membrane receptor family, are currently under clinical investigation and will undoubtedly form an important part of therapeutic oncologic regimens. In conclusion, evaluation of gene profiles of tumors and patients will gain importance for clinicians.

Impaired Delta Np63 expression associates with reduced beta-catenin and aggressive phenotypes of urothelial neoplasms

p63, a homologue of the p53 gene, is considered to be essential for the normal development of stratified epithelia including urothelium. To examine possible roles of p63 in urothelial tumorigenesis, p63 expression was systematically examined in normal urothelium, low-grade papillary noninvasive (LPN) urothelial tumours, and high-grade or invasive carcinomas, using either an isoform-nonspecific or a Delta N-isoform-specific antibody. Expression profiles of p63 were also analysed in cultured cells. Immunoreactivity with the two antibodies was virtually identical in tissue samples examined. Basal and intermediate cell layers of normal urothelium showed intense nuclear p63 immunostaining. This normal staining pattern was preserved in a majority of LPN tumours, whereas it was frequently impaired in high-grade or muscle-invasive carcinomas. At the mRNA level, Delta Np63 expression predominated over TAp63, and amounts of Delta Np63 mRNA correlated with p63 immunoreactivity, confirming that Delta Np63 accounts for p63 expressed in urothelial tissues. In cultured cells, Delta Np63 was also expressed in low-grade tumour cells as well as normal urothelial cells, but undetectable in high-grade aggressive carcinoma cells. Interestingly, impaired Delta Np63 expression significantly associated with reduced beta-catenin expression that was possibly related to progression of urothelial neoplasms. Thus, impaired Delta Np63 expression characterises aggressive phenotypes of urothelial neoplasms.

Role of p53 in the responses of human urothelial cells to genotoxic damage

Loss of p53 function is a feature of many types of malignancy, including transitional-cell carcinoma (TCC), where it is associated with high-grade lesions and the development of muscle-invasive disease. Genotoxic agents used as part of the treatment strategy may contribute to tumour progression by inducing further non-lethal DNA damage in surviving cells. To determine the role of p53 in cellular responses to genotoxic agents, we used cultured normal human urothelial (NHU) cells and NHU cells with disabled p53 function. Mitomycin C and gamma-radiation caused normal cells to undergo an extended period of cell-cycle arrest, followed by complete recovery of proliferative potential. In contrast, cells with disabled p53 function, whether karyotypically normal (HU-E6 cells) or post-crisis with karyotypic abnormalities (HU-E6P cells), underwent extensive apoptosis. Overall survival was dose-dependent, and surviving HU-E6 cells from low-dose treatments showed clonal karyotypic abnormalities. These findings demonstrate that p53 status is a crucial factor in determining the ability of urothelial cells to survive DNA damage and suggest caution in the use of genotoxic treatments for low-grade tumours as our data imply that malignancies that have not yet lost p53 function will show the same "repair-and-recovery" response as normal cells.