Toward personalized management in bladder cancer: the promise of novel molecular taxonomy

Cytokeratin 5 and cytokeratin 20 inversely correlate with tumour grading in Ta non-muscle-invasive bladder cancer

Cytokeratin 5 is a marker of basal molecular subtypes of muscle‐invasive bladder cancer (MIBC), which correlates with worse overall survival compared to luminal subtypes. Our observations have not confirmed CK5 as a marker of high‐grade (HG) disease in Ta non‐muscle‐invasive bladder cancer (NMIBC). Therefore, to understand the basal‐luminal immunohistochemistry profile in Ta NMIBC, we performed immunohistochemistry for CK5, P40, P63 (basal), GATA3 and CK20 (luminal) and studied the correlation with HG and clinical outcome in 109 patients with Ta NMIBC. HG and low‐grade (LG) diseases were scored in each patient. Four different CK5 patterns were evaluated: absent (median 41.3%), normal (72.5%), rising (84.4%) and full thickness (23.9%). The median percentage of GATA3 was 100%. HG disease and CK5 expression and rising CK5 pattern had a significant inverse correlation, whereas HG disease and CK20 expression had a significant positive correlation. We also found a significant inverse correlation between CK5 expression and CK20 expression. Quantitative PCR confirmed that the presence of CK5 correlated with up‐regulation of CK5 RNA. None of the markers could differentiate patients with regard to clinical outcome. Our results suggest a role for CK5 and CK20 in differentiating between LG and HG disease in Ta NMIBC.

Molecular and immunohistochemical evaluation of BAP-1 antibody in bladder cancer and comparison with luminal-basal subtyping

AIM

Molecular subtyping has become increasingly important in bladder cancer, and it is mainly divided into "luminal" and "basal" types. Despite the large amount of studies about the molecular pathway of bladder cancer, there are few studies about BAP-1. The aim of this study is to evaluate the BAP-1 expression molecularly and immunohistochemically and compare it with GATA-3 and CK5/6 immunohistochemical stains.

MATERIALS AND METHOD

A BAP-1 antibody was applied by western blotting to the tumor and normal tissues of 11 patients with known primary bladder tumors. The paraffin blocks of 150 non-invasive and 150 invasive tumor tissues were selected from transurethral resection materials. BAP-1, GATA-3, and CK5/6 immunohistochemical stains were applied to them, and the results were evaluated.

RESULTS

The protein expression levels of BAP-1 increased more in the tumor tissues compared to the normal tissues. The immunohistochemical BAP-1 expression was strong in the muscle-invasive group. The immunohistochemical GATA-3 expression was higher in the non-invasive group, and the CK5/6 expression was higher in the muscle-invasive group. The GATA-3 and CK5/6 immunohistochemical stains had a negative correlation in the muscle-invasive group. The immunohistochemical expression of BAP-1 had no correlation with GATA-3 and CK5/6 in all groups.

CONCLUSIONS

Molecular subtyping has become increasingly important in bladder cancer and it is mainly divided into "luminal" and "basal" type. Despite the large amount of studies about molecular pathway of the bladder cancer, there are a few studies about BAP-1. The aim of this study is to evaluate the BAP-1 expression molecularly and immunohistochemically and compare it with GATA-3 and CK5/6 immunohistochemical stains.

Potential biomarkers and risk assessment models to enhance the tumor-node-metastasis (TNM) staging classification of urologic cancers

INTRODUCTION

The anatomic-based TNM classification is considered the benchmark in cancer staging and has been regularly updated since its inception. In the current era of precision medicine, the added intention for future TNM modifications is to heighten its impact in the more 'personalized' level of cancer care. In urologic cancers, this goal may be achieved by incorporating 'non-anatomic' factors into TNM, such as biomarkers (e.g. gene alterations, molecular subtypes, genomic classifiers) and risk assessment models (e.g. nomogram, look-up table), while maintaining the anatomic extent as the foundation of staging. These different prognosticators can be combined and integrated, may serve as substratifiers for T, N, or M categories, and perhaps, incorporated as elements in TNM stage groupings to enhance their prognostic capability in urologic cancers.

AREAS COVERED

This review highlights candidate biomarkers and risk assessment models that can be explored to potentially improve TNM prognostication of bladder, prostate, kidney, and testicular cancers.

EXPERT OPINION

Recent advances in molecular analysis have increased the understanding of the genomic, transcriptomic, and epigenetic features for biomarker use in prognostication of urologic cancers, which together with the available risk assessment models, may complement and overcome the limitations of the traditional TNM staging.

CDCA5 functions as a tumor promoter in bladder cancer by dysregulating mitochondria-mediated apoptosis, cell cycle regulation and PI3k/AKT/mTOR pathway activation

Bladder cancer (BC) is one of the most prevalent cancers worldwide and has high rates of relapse and progression. Cell division cycle associated 5 (CDCA5), a substrate of the anaphase-promoting complex, was reported to be upregulated in several types of cancer; however, the function of CDCA5 in BC remains unclear. In this study, we observed that BC tissues had higher levels of CDCA5 expression than adjacent normal tissues. We also found that high CDCA5 expression in patients was associated with poor survival rates. An in vitro study showed that knockdown of CDCA5 in T24 and 5637 cells reduced cell proliferation and induced apoptosis in T24 and 5637 cells, while overexpression of CDCA5 in UMUC3 cells caused the opposite effects. In an additional experiment, we found that CDCA5 promoted cell proliferation by upregulating two key cell cycle factors, cell division cycle protein 2 (CDC2) and cyclin B1, and by activating the PI3K/AKT/mTOR pathway. Furthermore, CDCA5 regulate cancer cell apoptosis through the mitochondrial apoptosis pathway. In conclusion, CDCA5 plays a pivotal role in the proliferation of BC cells. A better understanding of CDCA5 may provide new insights into its role as a therapeutic target for BC.

Collagen stiffness promoted non-muscle-invasive bladder cancer progression to muscle-invasive bladder cancer

Purpose: Bladder cancer (BCa) is generally considered one of the most prevalent deadly diseases worldwide. Patients suffering from muscle-invasive bladder cancer (MIBC) possess dismal prognoses, while those with non-muscle-invasive bladder cancer (NMIBC) generally have a favorable outcome after local treatment. However, some NMIBCs relapse and progress to MIBC, with an unclarified mechanism. Hence, insight into the genetic drivers of BCa progression has tremendous potential benefits for precision therapeutics, risk stratification, and molecular diagnosis. Methods: In this study, three cohorts profile datasets (GSE13507, GSE32584, and GSE89) consisting of NMIBC and MIBC samples were integrated to address the differently expressed genes (DEGs). Subsequently, the protein-protein interaction (PPI) network and pathway enrichment analysis of DGEs were performed. Results: Six collagen members (COL1A1, COL1A2, COL5A2, COL6A1, COL6A2, and COL6A3) were up-regulated and gathered in the ECM-receptor interaction signal pathway identified by KEGG pathway analysis and GSEA. Evidence derived from the Oncomine and TCGA databases indicated that the 6 collagen genes promote the progression of BCa and are negatively associated with patient prognosis. Moreover, taking COL1A1 as a further research object, the results showed that COL1A1 was up-regulated in MIBC and its knockdown significantly inhibited the proliferation, migration, and invasion of 5637 and T24 cells by inhibiting epithelial-mesenchymal transition (EMT) process and the TGF-β signaling pathway. Conclusion: With integrated bioinformatic analysis and cell experiments, we showed that 6 collagen family members are high progression risk factors and that they can be used as independent effective diagnostic and prognostic biomarkers for BCa.

Molecular Pathologic Subtyping of Urothelial Bladder Carcinoma in Young Patients

Urothelial cancer is a heterogeneous disease with different molecular pathways that produce distinct molecular subtypes with specific characteristics and patient survival outcomes that require different therapeutic methods. Urothelial tumors in young patients appear to have distinct genetic features compared with their counterparts in older patients. Using a Lund subtype-specific immunohistochemistry panel, we performed molecular subtype profiling of an urothelial carcinoma case series (n = 49) in patients younger than 45 years of age. We demonstrate that the urothelial carcinoma in young patients tends to be of molecular urothelial-like A subtype (80%) and is associated with favorable, recurrent-free survival (P = .022). In the urothelial-like cluster, we identified a portion of patients (10%) with high-grade non-muscle-invasive cancers (so-called urothelial-like D type) that showed significantly higher levels of squamous differentiation and p16, E2F3, and ki67 expression in addition to aberrant expression of Ck20 and a trend toward lower recurrent-free survival (P = .057). Segregation of the cohort according to the decade of occurrence revealed that all tumors (n = 8) of patients younger than 30 years were clearly classified as urothelial-like A subtype. Statistically more aggressive molecular subtypes, such as urothelial-like D and basal/squamous-like (6%) subtypes, were identified in patients older than 30 years of age. Genomically unstable (2%) and mesenchymal-like (2%) subtypes were classified in the 40- to 44-year age group only. These data suggest that more aggressive molecular subtypes of bladder carcinoma appear and become more frequent with age. Further investigations are needed to validate this hypothesis.

The papilla as a biomarker in the molecular era of bladder oncology

Background

Conventional optical microscopy has been fundamental in the diagnosis of cancer for over a century. Tumor morphology has prognostic value and impact on treatment choice, but integration with molecular knowledge can enhance the correlation with clinical behavior. A papillary structure implies that the proliferating epithelium has been able to interact with its microenvironment to conceive a fibrovascular core, suggesting a fair degree of differentiation.

Main body

In the bladder, a papillary architecture carries a favorable outcome and its presence is uniform in all non-invasive urothelial lesions, except for carcinoma in situ. Despite the increase in bladder cancer incidence, mortality has remained fairly stable for the last three decades, raising concern for overdiagnosis. Therefore, bladder cancer nomenclature has evolved to better communicate with the clinical scenario, including clinicians and patients. During this time, the need to incorporate new tools into morphology has raised a search for molecular biomarkers that grew exponentially with technology and scientific foment. Activating mutations in oncogenes like HRAS, PIK3 and FGFR3 are a hallmark of non-invasive papillary neoplasms, and their detection in advanced carcinomas is a favorable predictor of outcome. These alterations result in sustained proliferative stimuli and independent control of metabolism. Through the amplified interface of a papillary axis, the lamina propria can continue to supply nutrients, oxygen, hormones and other vital cellular needs to an increasing population of urothelial cells. mTOR regulates processes that require a substantial amount of matter and energy and alterations in this pathway are among the most frequent in urothelial tumors. Recent genomic landscape studies have provided data for molecularly subtyping urothelial cancers as luminal and basal. Within the luminal subtype, a p53-like signature is associated with chemoresistance. Luminal tumors, which phenotype is reminiscent of mature differentiated superficial cells, are enriched for papillary morphology and downregulation of miRNA involved in mTOR pathway regulation.

Conclusion

Because the papillary structure is the result of a transcriptional program and its post-transcriptional modifications, it is likely that its presence will be maintained in classification schemes as a powerful tool for clinical translation.

Increased expression of EZH2 indicates aggressive potential of urothelial carcinoma of the bladder in a Chinese population

Here, we attempt to better define the long-term outcomes of radical cystectomy (RC) for urothelial carcinoma (UC) in a Chinese population and to investigate the relationship between EZH2 protein expression levels and the clinicopathological parameters and outcomes in patients with UC. We detected the relative EZH2 protein expression levels by immunohistochemistry in tumour specimens from a cohort of 189 Chinese UC patients. In patients who underwent RC, the 5-year cancer-specific survival (CSS) and overall survival (OS) were 69% and 61% respectively. EZH2 expression was increased in UC compared with normal urothelium. The expression levels of EZH2 were elevated in parallel with tumour stage (p = 0.001) and tumour grade (p = 0.001) and were increased in cases with lymph node metastasis compared with node-negative cases (p = 0.018). Kaplan-Meier analyses showed that higher EZH2 expression was related to significantly shorter CSS and OS in patients who underwent RC. High EZH2 expression was associated with worse CSS (HR = 3.51; p = 0.037) and OS (HR = 2.15; p = 0.047) in the univariate analysis, but only lymph node invasion maintained its predictive value for CSS in a multivariate model. This contemporary and homogeneous single-centre series found acceptable outcomes for Chinese UC patients who underwent RC. Clinically, our retrospective studies suggest that EZH2 levels can be used to identify more aggressive phenotypes in UC patients, thereby improving our prognostic knowledge.

Overexpression of high mobility group box 1 contributes to progressive clinicopathological features and poor prognosis of human bladder urothelial carcinoma

Background

High mobility group box 1 (HMGB1), a versatile protein with intranuclear and extracellular functions, plays an important role in a variety of human cancers. However, the clinical/prognostic significance of HMGB1 expression in human bladder urothelial carcinoma (BUC) remains unclear. The aim of this study was to investigate the HMGB1 expression in human BUC with regard to its clinical and prognostic significance.

Patients and methods

HMGB1 mRNA and protein expressions in tumor and paired normal bladder tissues were detected in 20 BUC cases by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. HMGB1 protein expression in 165 primary BUC tissues was evaluated by immunohistochemistry (IHC), and its correlations with clinicopathological characteristics and prognosis were also analyzed. Student’s t-test, χ² test, Kaplan–Meier plots, and Cox proportional hazard regression model were performed to analyze the data.

Results

By using qRT-PCR and Western blot, the upregulated expression of HMGB1 mRNA and protein was detected in BUC, compared with paired normal tissue (P<0.05). By using IHC, high HMGB1 expression was examined in 84 of 165 (51.0%) BUC cases. High HMGB1 expression was significantly correlated with poorer differentiation and higher T and N classification (all P<0.05). Univariate analysis showed that high HMGB1 expression was significantly associated with a shortened patients’ overall survival (OS) and disease-free survival (DFS; both P<0.001). In different subgroups of BUC patients, HMGB1 expression was a prognostic factor in patients with different histological grades or T classification (all P<0.05), pN− (both P<0.001) for OS and DFS, and pT1/pN− (P<0.05) for OS. HMGB1 expression, as well as pT and pN status, was an independent prognostic factor for both OS (P=0.001, hazard ratio [HR] =2.973, 95% confidence interval [CI] =1.550–5.704) and DFS (P<0.001, HR =3.019, 95% CI =1.902–4.792) in multivariate analysis.

Conclusion

Overexpression of HMGB1 may be a new independent molecular marker for the poor prognosis of patients with BUC.

Bladder Cancer: New Insights into Its Molecular Pathology

Bladder cancer is one of the most prevalent cancers worldwide. Unfortunately, there have been few advances in its clinical management due to a poor understanding of the correlations between its molecular and clinical features. Mounting evidence suggests that bladder cancer comprises a group of molecularly heterogeneous diseases that undergo a variety of clinical courses and possess diverse therapeutic responses. Owing to the close association between its molecular subtypes and clinicopathological features, specific therapeutic strategies have recently been suggested. This review summarizes the current understanding of the molecular pathology of bladder cancer, including its molecular biomarkers/pathways and molecular subtypes that have been newly identified using high-throughput technologies. It also discusses advances in our understanding of personalized treatments for specific molecular subtypes.