Tumor heterogeneity of fibroblast growth factor receptor 3 (FGFR3) mutations in invasive bladder cancer: implications for perioperative anti-FGFR3 treatment

Molecular Urothelial Tumor Cell Subtypes Remain Stable During Metastatic Evolution

Urothelial cancer (UC) care is moving toward precision oncology. For tumor biology-driven treatment of metastatic UC (mUC), molecular subtypes play a crucial role. However, it is not known whether subtypes change during metastatic evolution. To address this, we analyzed a UC progression cohort (N = 154 patients) with 138 matched primary tumors (PRIM) and synchronous or metachronous distant metastasis (MET) by immunohistochemistry, and mRNA sequencing in a subgroup of 20 matched pairs. Protein-based tumor cell subtypes and histomorphology remained stable during metastatic progression (concordance: 94%, 95% confidence interval [CI] 88-97%). In comparison, transcriptome-based molecular consensus subtypes exhibited higher heterogeneity between PRIM and MET (concordance: 45%, 95% CI 23-69%), with switches particularly occurring between luminal and stroma-rich tumors. Of note, all tumors classified as stroma rich showed luminal tumor cell differentiation. By an in-depth analysis, we found a negative correlation of luminal gene and protein expression with increasing desmoplastic stroma content, suggesting that luminal tumor cell differentiation of "stroma-rich tumors" is superimposed by gene expression signals stemming from the stromal compartment. Immunohistochemistry allows tumor cell subtyping into luminal, basal, or neuroendocrine classes that remain stable during metastatic progression. These findings expand our biological understanding of UC MET and have implications for future subtype-stratified clinical trials in patients with mUC. PATIENT SUMMARY: Urothelial carcinomas (UCs) occur in different appearances, the so-called molecular subtypes. These molecular subtypes will gain importance for the therapy of metastatic UCs in the future. We could demonstrate that the subtype remains stable during metastasis, which is highly relevant for future studies.

Intratumoral Heterogeneity of Molecular Subtypes in Muscle-invasive Bladder Cancer-An Extensive Multiregional Immunohistochemical Analysis

BACKGROUND

Molecular bladder cancer (BC) subtypes define distinct biological entities and were shown to predict treatment response in neoadjuvant and adjuvant settings. The extent of intratumoral heterogeneity (ITH) might affect subtyping of individual patients.

OBJECTIVE

To comprehensively assess the ITH of molecular subtypes in a cohort of muscle-invasive BC.

DESIGN, SETTING, AND PARTICIPANTS

A total of 251 patients undergoing radical cystectomy were screened. Three cores of the tumor center (TC) and three cores of the invasive tumor front (TF) of each patient were assembled in a tissue microarray. Molecular subtypes were determined employing 12 pre-evaluated immunohistochemical markers (FGFR3, CCND1, RB1, CDKN2A, KRT5, KRT14, FOXA1, GATA3, TUBB2B, EPCAM, CDH1, and vimentin). A total of 18 072 spots were evaluated, of which 15 002 spots were assessed based on intensity, distribution, or combination.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Allocation to one of five different molecular subtypes-urothelial like, genomically unstable, small-cell/neuroendocrine like, basal/squamous cell carcinoma like, and mesenchymal like-was conducted for each patient for the complete tumor, individual cores, TF, and TC separately. The primary objective was to assess the ITH between the TF and TC (n = 208 patients). The secondary objective was the evaluation of multiregion ITH (n = 191 patients). An analysis of the composition of ITH cases, association with clinicopathological parameters, and prognosis was conducted.

RESULTS AND LIMITATIONS

ITH between the TF and TC was seen in 12.5% (n = 26/208), and ITH defined by at least two different subtypes of any location was seen in 24.6% (n = 47/191). ITH was more frequent in locally confined (pT2) versus advanced (pT ≥3) BC stages (38.7% vs 21.9%, p = 0.046), and pT4 BC presented with significantly more basal subtypes than pT2 BC (26.2% vs 11.5%, p = 0.049). In our cohort, there was no association of subtype ITH with prognosis or accumulation of specific molecular subtypes in ITH cases. The key limitations were missing transcriptomic and mutational genetic validation as well as investigation of ITH beyond subtypes.

CONCLUSIONS

Several molecular subtypes can be found in nearly every fourth case of muscle-invasive BC, when using immunohistochemistry. ITH must be given due consideration for subtype-guided strategies in BC. Genomic validation of these results is needed.

PATIENT SUMMARY

Different molecular subtypes can be found in many cases of muscle-invasive bladder cancer. This might have implications for individualized, subtype-based therapeutic approaches.

FGFR3 mutation characterization identifies prognostic and immune-related gene signatures in bladder cancer

BACKGROUND

Immunotherapy and FGFR3-targeted therapy play an important role in the management of locally advanced and metastatic bladder cancer (BLCA). Previous studies indicated that FGFR3 mutation (mFGFR3) may be involved in the alterations of immune infiltration, which may affect the priority or combination of these two treatment regimes. However, the specific impact of mFGFR3 on the immunity and how FGFR3 regulates the immune response in BLCA to affect prognosis remain unclear. In this study, we aimed to elucidate the immune landscape associated with mFGFR3 status in BLCA, screen immune-related gene signatures with prognostic value, and construct and validate a prognostic model.

METHODS

ESTIMATE and TIMER were used to assess the immune infiltration within tumors in the TCGA BLCA cohort based on transcriptome data. Further, the mFGFR3 status and mRNA expression profiles were analyzed to identify immune-related genes that were differentially expressed between patients with BLCA with wild-type FGFR3 or mFGFR3 in the TCGA training cohort. An FGFR3-related immune prognostic score (FIPS) model was established in the TCGA training cohort. Furthermore, we validated the prognostic value of FIPS with microarray data in the GEO database and tissue microarray from our center. Multiple fluorescence immunohistochemical analysis was performed to confirm the relationship between FIPS and immune infiltration.

RESULTS

mFGFR3 resulted in differential immunity in BLCA. In total, 359 immune-related biological processes were enriched in the wild-type FGFR3 group, whereas none were enriched in the mFGFR3 group. FIPS could effectively distinguish high-risk patients with poor prognosis from low-risk patients. The high-risk group was characterized by a higher abundance of neutrophils; macrophages; and follicular helper, CD4, and CD8 T-cells than the low-risk group. In addition, the high-risk group exhibited higher expression of PD-L1, PD-1, CTLA-4, LAG-3, and TIM-3 than the low-risk group, indicating an immune-infiltrated but functionally suppressed immune microenvironment. Furthermore, patients in the high-risk group exhibited a lower mutation rate of FGFR3 than those in the low-risk group.

CONCLUSIONS

FIPS effectively predicted survival in BLCA. Patients with different FIPS exhibited diverse immune infiltration and mFGFR3 status. FIPS might be a promising tool for selecting targeted therapy and immunotherapy for patients with BLCA.

Large, Nested Variant of Urothelial Carcinoma Is Enriched with Activating Mutations in Fibroblast Growth Factor Receptor-3 among Other Targetable Mutations

The large, nested variant of urothelial carcinoma (LNVUC) is characterized by bland histomorphology mimicking that of benign von Brunn nests. In the current study, we aimed to investigate the Fibroblast Growth Factor Receptor-3 (FGFR-3) activation and missense mutation in 38 cases, including 6 cases diagnosed with LNVUC and 32 with metastatic invasive urothelial carcinoma (UC). Initially, six formalin-fixed paraffin-embedded (FFPE) tissue samples of the LNVUC were subjected to whole-exome sequencing (WES), and then we performed targeted sequencing on 32 cases of metastatic invasive UC of various morphological subtypes, which were interrogated for the FGFR3. Our results revealed 3/6 (50%) LNVUC cases evaluated by WES in our study showed an activating mutation in FGFR-3, 33% showed an activating mutation in PIK3CA, and 17% showed activating mutation in GNAS or MRE11. Additionally, 33% of cases showed a truncating mutation in CDKN1B. All LNVUC in our study that harbored the FGFR-3 mutation showed additional activating or truncating mutations in other genes. Overall, 6/32 (18.75%) cases of random metastatic invasive UC showed missense mutations of the FGFR-3 gene. The LNVUC variant showed the higher incidence of FGFR-3 mutations compared to other types of mutations. Additionally, all LNVUC cases show additional activating or truncating mutations in other genes, thus being amenable to novel targeted therapy.

The Search for the Optimal cut-off Value of p53-Immunohistochemistry to Predict Prognosis of Invasive Bladder Cancer: A Multi-Center, Multi-Laboratory Analysis

Introduction: Mutations in the TP53 gene are indicative of worse outcome in bladder cancer and are usually assessed by immunohistochemistry. To define p53-overexpression, a threshold of >10% is most commonly used (cut-off1). Recently, a novel cut-off (aberrant = 0% or ≥50%) (cut-off2) showed better correlation to clinical outcome. In this study, we evaluate the association between p53-immunohistochemistry cut-offs, clinico-pathological variables and disease-specific survival (DSS). Methods: Seven-hundred-fifty chemotherapy-naïve patients who underwent radical cystectomy were included (92% muscle-invasive bladder cancer. In addition to cut-off1 and cut-off2, a third cut-off (cut-off3) was determined based on the highest Youden-index value. Cut-off values were associated with clinico-pathological variables and FGFR3 mutation status. The Kaplan-Meier method was used to estimate DSS. Results: Aberrant p53-expression was found in 489 (65%) (cut-off1) and 466 (62%) (cut-off2) tumors. Cut-off3 was determined at 25% and aberrant p53-expression in 410 cases (55%) (cutoff3). p53-expression levels were significantly associated with higher pT-stage (cut-off1/2/3: P = 0.047, P = 0.006 and P = 0.0002, respectively), higher grade (all, P < 0.0001), and FGFR3 wild-type (cut-off1: P = 0.02, cut-offs2&3: P = 0.001). Median follow-up was 5.3 years (interquartile range, 4.0-6.0 years). p53-expression was not associated with DSS for any of the three cut-offs (cut-off1/2/3: P-log-rank = 0.566, 0.77 and 0.50, respectively). If we only considered locally advanced bladder cancer, results on DSS remained non-significant. Conclusion: This multi-center, multi-laboratory study showed that, regardless of the cut-off used, p53-immunohistochemistry did not enable selection of patients with worse outcome. Our results suggest that p53-immunohistochemistry alone is not suitable to guide clinical decision making after radical cystectomy.

Spatial Immunephenotypes of Distant Metastases but not Matched Primary Urothelial Carcinomas Predict Response to Immune Checkpoint Inhibition

BACKGROUND

The value of programmed cell death ligand-1 (PD-L1) to predict durable responses to immune checkpoint inhibitors (ICIs) in metastatic urothelial carcinoma (mUC) is inconsistent. We hypothesize that the use of archived primary tumor material (PRIM) for PD-L1 testing in clinical trials not properly reflecting the metastatic disease status (MET) contributes to this clinical issue.

OBJECTIVE

To analyze the predictive and prognostic value of PD-L1, spatial immunephenotypes, and major histocompatibility complex class I (MHC-I) determined in patient-matched PRIM/MET.

DESIGN, SETTING, AND PARTICIPANTS

PD-L1, spatial immunephenotypes, and MHC-I were examined in 154 mUC patients with at least one available pretreatment MET (138 patient-matched PRIM/MET pairs).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

PD-L1, spatial immunephenotype, and MHC-I status of (patient-matched PRIM and) pretreatment MET were correlated with chemotherapy and ICI response and outcomes.

RESULTS AND LIMITATIONS

Discordance rates in patient-matched PRIM/MET were 25/30%, 36%, and 49% for PD-L1 (CPS10/IC5%), immunephenotypes, and MHC-I (loss vs preserved), respectively. Correlations with chemotherapy and ICI responses were observed for immunephenotypes and MHC-I status determined in MET (not for PD-L1 alone), but not in PRIM. In case of ICIs, patients with cytotoxic tumor immune microenvironment (TIME) showed durable responses with disease control rates of 90% and a hazard ratio for disease progression/death of 0.05 (95% confidence interval: 0.01-0.65) versus patients with immunedepleted MET (disease control rate 29%). MET MHC-I status added an incremental value to predict durable ICI responses. Limitations include the partly retrospective design and the lack of MET multisampling on individual patient level.

CONCLUSIONS

The TIME is subject to substantial dynamics during metastatic evolution. MET immunephenotypes and MHC-I statuses show promising potential to predict chemotherapy and durable ICI responses, while the PRIM TIME does not. Thus, future clinical trials should rather rely on pretreatment MET biopsies reflecting the current immunological disease state than on PRIM.

PATIENT SUMMARY

Prediction of chemotherapy and responses to immune checkpoint inhibitors might be possible using representative pretreatment metastatic biopsies.

Genomic heterogeneity as a barrier to precision oncology in urothelial cancer

Precision oncology relies on the accurate molecular characterization of individual patients with cancer at the time of treatment initiation. However, tumor molecular profiles are not static, and cancers continually evolve because of ongoing mutagenesis and clonal selection. Here, we performed genomic analyses of primary tumors, metastases, and plasma collected from individual patients to define the concordance of actionable genomic alterations and to identify drivers of metastatic disease progression. We observed a high degree of discordance of actionable genomic alterations, with 23% discordant between primary and metastatic disease sites. Among chromatin-modifying genes, ARID1A mutations, when discordant, were exclusive to the metastatic tumor samples. Our findings indicate that the high degree of lesion-to-lesion genomic heterogeneity may be a barrier to precision oncology approaches for bladder cancer and that circulating tumor DNA profiling may be preferred to tumor sequencing for a subset of patients.

Adjuvant Systemic Therapy for High-risk Muscle-invasive Bladder Cancer After Radical Cystectomy: Current Options and Future Opportunities

We describe the case of a 71-yr-old woman with locally advanced muscle-invasive bladder cancer and stage III chronic kidney disease due to an obstructed nonfunctional left kidney. She was started on neoadjuvant immunotherapy, but had to stop treatment because of acute worsening of renal function. Radical cystectomy was then performed uneventfully, revealing pT3aN1 urothelial carcinoma of the bladder. Adjuvant chemotherapy in high-risk locally advanced bladder cancer after radical cystectomy currently poses several challenges, especially for cisplatin-ineligible candidates. Recent data on adjuvant immunotherapy trials suggest a disease-free survival advantage for this subgroup of patients. The current and future role of immuno-oncology agents in this setting is discussed. PATIENT SUMMARY: Patients with advanced bladder cancer might benefit from further chemotherapy or immunotherapy following bladder removal, but it is still unclear which patients benefit the most from this strategy. Measurement of biomarkers and scans to show urinary function will probably help in optimising patient selection for this treatment in the near future.

Targeting the FGFR Pathway in Urothelial Carcinoma: the Future Is Now

OPINION STATEMENT

As we come to better understand cancer genomics, we are increasingly shifting towards precision medicine. FGFR has been elucidated as one of the oncogenic driver pathways in urothelial carcinoma, leading to exciting targeted drug development. Although many agents are being investigated, erdafitinib is the only FGFR inhibitor currently approved by the FDA for treating platinum-refractory metastatic urothelial carcinoma harboring susceptible FGFR2/3 alterations, with seemingly higher response rates than second-line chemotherapy or immunotherapy. In this review, we summarize the clinical data supporting FGFR inhibition, ways to optimize its use in routine clinical practice including FGFR testing, dosing, and toxicity management. We also highlight ongoing efforts evaluating combination strategies and testing in earlier treatment settings to further expand this targeted therapeutic approach in urothelial carcinoma.

Non-muscle invasive bladder cancer biomarkers beyond morphology

Non-muscle invasive bladder cancer (NMIBC) still represents a challenge in decision-making and clinical management since prognostic and predictive biomarkers of response to treatment are still under investigation. In addition to the risk factors defined by EORTC guidelines, histological features have also been considered key variables able to impact on recurrence and progression in bladder cancer. Conversely, the role of genomic rearrangements or expression of specific proteins at tissue level need further assessment in NMIBC. As with muscle-invasive cancer, NMIBC is a heterogeneous disease, characterized by genomic instability, varying rates of mutation and a wide range of protein tissue expression. In this Review, we summarized the recent evidence on prognostic and predictive tissue biomarkers in NMIBC, beyond morphological parameters, outlining how they could affect tumor biology and consequently its behavior during clinical care. Our aim was to facilitate clinical evaluation of promising biomarkers that may be employed to better stratify patients. We described the most common molecular events and immunohistochemical protein expressions linked to recurrence and progression. Moreover, we discussed the link between available treatments and molecular drivers that could be predictive of clinical response. In conclusion, we foster further investigations with particular focus on immunohistochemical evaluation of tissue biomarkers, a promising and cost-effective tool for daily practice.

Profiling the Biological Characteristics and Transitions through Upper Tract Tumor Origin, Bladder Recurrence, and Muscle-Invasive Bladder Progression in Upper Tract Urothelial Carcinoma

To evaluate biological characteristics and transitions of upper tract urothelial carcinoma (UTUC) through metachronous bladder tumors after radical nephroureterectomy (RNU), we conducted immunohistochemical (IHC) staining of tumor specimens of UTUC tumor origin, non-muscle-invasive bladder cancer (NMIBC) and MIBC progressed after intravesical recurrence (IVR), and bladder primary MIBC. Fibroblast growth factor receptor 3 (FGFR3), p53, cytokeratin 5/6 (CK5/6), and CK20 were stained to examine expression rates. After expression assessment with heatmap clustering, the overexpression of four biomarkers from UTUC origin to metachronous MIBC progression was analyzed with clinicopathological variables. We found that high CK20 and low CK5/6 expression were both observed in UTUC tumor origin and subsequent NMIBC after RNU. By investigating molecular expression in the IVR specimen, we observed that low pT stage bladder recurrence occupied the majority of CK20 high CK5/6 low expression, but would change to CK20 low CK5/6 high expression as it progressed to MIBC. UTUC metachronous MIBC has different characteristics compared with bladder primary MIBC, which comprises favorable biological features such as high FGFR3 expression, and follows favorable prognosis compared to those without FGFR3 expression. The present study demonstrated that the biological characteristics of UTUC tumor origin shifts from luminal to basal-like features with progression to MIBC, but FGFR3 expression taken over from UTUC origin may comprise a favorable entity compared to primary MIBC.

New Directions and Challenges in Targeted Therapies of Advanced Bladder Cancer: The Role of FGFR Inhibitors

Simple Summary

The aim of this study was to present and analyze the up-to-date literature describing the epidemiology, genetics, and histopathology of bladder cancer, as well as the latest methods of bladder cancer treatment. The treatment of urothelial cancer was divided depending on its stage and advancement. FGFR3 mutations and overexpression occur more frequently in bladder cancer than any other malignancy, occurring in nearly 80% of the tumors. Closer acknowledgement of targeted therapy will help physicians to navigate specific groups of patients for whom this treatment strategy can be beneficial. To that end, intense clinical research was conducted, bringing evidence for effectiveness and safety of FGFR inhibitors. Recent years of research have truly set a positive perspective for the better understanding of the complex issue of urothelial carcinoma pathology and management.

Abstract

Bladder neoplasms, including the most common urothelial carcinoma, have been an escalating problem for years, especially in highly developed countries. Recent decades have brought us a steadily growing share of this cancer in terms of both morbidity and mortality statistics. Bladder neoplasms are not only a therapeutic challenge but also an economical one due to the demanding, costly diagnostics and treatment. The treatment of urothelial cancer can be divided depending on the stage and advancement; thus, we can distinguish three main categories: non-muscle invasive bladder cancer, conventionally treated by surgical interventions; muscle invasive bladder cancer, conventionally treated with chemotherapeutics; and advanced bladder cancer with distant metastases, conventionally treated with the intensive chemotherapy in the MVAC scheme (methotrexate, vinblastine, doxorubicin, and cisplatin). Recent years have brought a breakthrough: immunotherapy and targeted therapy were discovered to be beneficial for patients disqualified from chemotherapy or patients who progressed despite treatment. This literature review summarizes the latest research into the use of targeted therapy in the treatment of advanced bladder cancer, its benefits, and its limitations.

Prognostic markers in invasive bladder cancer: FGFR3 mutation status versus P53 and KI-67 expression: a multi-center, multi-laboratory analysis in 1058 radical cystectomy patients

OBJECTIVES

To determine the association between the FGFR3 mutation status and immuno-histochemistry (IHC) markers (p53 and Ki-67) in invasive bladder cancer (BC), and to analyze their prognostic value in a multicenter, multi-laboratory radical cystectomy (RC) cohort.

PATIENTS AND METHODS

We included 1058 cN0M0, chemotherapy-naive BC patients who underwent RC with pelvic lymph-node dissection at 8 hospitals. The specimens were reviewed by uro-pathologists. Mutations in the FGFR3 gene were examined using PCR-SNaPshot; p53 and Ki-67 expression were determined by standard IHC. FGFR3 mutation status as well as p53 (cut-off>10%) and Ki-67 (cut-off>20%) expression were correlated to clinicopathological parameters and disease specific survival (DSS).

RESULTS

pT-stage was <pT2 in 80, pT2 in 266, pT3 in 513 and pT4 in 199 patients, respectively. Cancer-positive nodes were found in 410 (39%) patients. An FGFR3 mutation was detected in 107 (10%) and aberrant p53 and Ki-67 expression in 718 (68%) and 581(55%) tumors, respectively. The FGFR3 mutation was associated with lower pT-stage (P<0.001), lower grade (P<0.001), pN0 (P=0.001) and prolonged DSS (P<0.001). Aberrant Ki-67 and p53 expression were associated with higher pT-stage and G3-tumors, but not with pN-stage or worse DSS, even if these IHC-biomarkers were combined (P=0.81). Significant predictors for DSS in multivariable analysis were pT-stage (HR1.5, 95%CI:1.3-1.6; P<0.001), lympho-vascular invasion (LVI) (HR1.4, 95%CI:1.2-1.7; P=0.001), pN-stage (HR1.9, 95%CI:1.6-2.4; P<0.001) and FGFR3 mutation status (HR1.6, 95%CI:1.1-2.2; P=0.011).

CONCLUSION

The FGFR3 mutation selectively identified patients with favorable BC at RC while p53 and Ki-67 were only associated with adverse tumor characteristics. Our results suggest that, besides tumor-stage, nodal-status and LVI, the oncogenic FGFR3 mutation may represent a valuable tool to guide adjuvant treatment and follow-up strategies after RC.

Analysis of differentially expressed long non‑coding RNAs revealed a pro‑tumor role of MIR205HG in cervical cancer

Cervical cancer is the fourth most common female malignancy for both incidence and mortality worldwide and is one of the major threats to women's health. The role of long non‑coding RNAs (lncRNAs) in cervical cancer remains largely unknown. In the present study, the differentially expressed lncRNAs in cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) tissues were retrieved form The Cancer Genome Atlas (TCGA) and were analyzed. The expression analysis of related genes was performed with GEPIA. The proliferation and migratory and invasive abilities of MIR205HG knockdown CESC cells were analyzed using Cell Counting Kit‑8 and transwell assays. The expression of Ki‑67 and p16 was detected by immunofluorescence. A total of 203 differentially expressed lncRNAs were identified. The results demonstrated that MIR205HG was overexpressed in CESC tissues. Furthermore, the genes related to MIR205HG were enriched in cancer‑related pathways. MIR205HG knockdown significantly decreased the proliferation and migratory and invasive abilities of CESC cells. In addition, silencing of MIR205HG significantly decreased the expression of p16 in C‑33 A cells. The expression of fibroblast growth factor receptor 3, thymidine phosphorylase and GTPase HRas was downregulated in MIR205HG knockdown CESC cells. These findings revealed some potential lncRNA candidates for cervical cancer research and suggested that MIR205HG may have a pro‑tumor role in CESC.

Tumor Heterogeneity and Consequences for Bladder Cancer Treatment

Simple Summary

Bladder cancer is a heterogeneous disease that is composed of epithelia with varying transcriptional, mutational and lineage signatures. The epithelia of bladder tumors can also undergo pronounced changes in transcriptional and phenotypical qualities in response to progression, treatment related stresses and cues from the tumor microenvironment (TME). We hypothesize that changes in epithelial tumor heterogeneity (EpTH) occur due to the evolving content of epithelial subpopulations through both Darwinian and Lamarckian-like natural selection processes. We further conjecture that lineage-defined subpopulations can change through nongenomic and genomic cellular mechanisms that include cellular plasticity and acquired driver mutations, respectively. We propose that such processes are dynamic and contribute towards clinical treatment challenges including progression to drug resistance. In this article, we assess mechanisms that may support dynamic tumor heterogeneity with the overall goal of emphasizing the application of these concepts to the clinical setting.

Abstract

Acquired therapeutic resistance remains a major challenge in cancer management and associates with poor oncological outcomes in most solid tumor types. A major contributor is tumor heterogeneity (TH) which can be influenced by the stromal; immune and epithelial tumor compartments. We hypothesize that heterogeneity in tumor epithelial subpopulations—whether de novo or newly acquired—closely regulate the clinical course of bladder cancer. Changes in these subpopulations impact the tumor microenvironment including the extent of immune cell infiltration and response to immunotherapeutics. Mechanisms driving epithelial tumor heterogeneity (EpTH) can be broadly categorized as mutational and non-mutational. Mechanisms regulating lineage plasticity; acquired cellular mutations and changes in lineage-defined subpopulations regulate stress responses to clinical therapies. If tumor heterogeneity is a dynamic process; an increased understanding of how EpTH is regulated is critical in order for clinical therapies to be more sustained and durable. In this review and analysis, we assess the importance and regulatory mechanisms governing EpTH in bladder cancer and the impact on treatment response.

A hypoxia related long non-coding RNA signature could accurately predict survival outcomes in patients with bladder cancer

Hypoxia plays a significant role in tumor progression. This study aimed to develop a hypoxia-related long noncoding RNA (lncRNA) signature for predicting survival outcomes of patients with bladder cancer (BC). The transcriptome and clinicopathologic data were downloaded from The Cancer Genome Atlas (TCGA) database. Univariate Cox regression analysis and Lasso regression analysis were used to screened lncRNAs. Ten lncRNAs were screened out and included into the hypoxia lncRNA signature. The risk score based on hypoxia lncRNA signature could accurately predict the survival outcomes of BC patients. Immune infiltration analysis showed that six types of immune cells had significant different infiltration. Tumor mutation burden (TMB) analysis showed that the risk scores between the wild types and the mutation types of TP53, FGFR3, and RB1 were significantly different. Gene Set Enrichment Analysis (GSEA) showed that cancer-associated pathways belonged to the high risk groups and immune-related signal pathways were enriched into the low risk group. Then, we constructed a predictive model with the risk score, age, and clinical stage, which showed a robust prognostic performance. An lncRNA-mRNA coexpression network was constructed, which contained 62 lncRNA-mRNA links among 10 lncRNAs and 40 related mRNAs. In summary, the hypoxia lncRNA signature could accurately predict prognosis, chemotherapy and immunotherapy response in patients with BC and was relevant to clinicopathologic parameters and immune cell infiltration.

Development and Validation of a Hypoxia-Related Signature for Predicting Survival Outcomes in Patients With Bladder Cancer

Objectives

This study aimed to develop and validate a hypoxia signature for predicting survival outcomes in patients with bladder cancer.

Methods

We downloaded the RNA sequence and the clinicopathologic data of the patients with bladder cancer from The Cancer Genome Atlas (TCGA) (https://portal.gdc.cancer.gov/repository?facetTab=files) and the Gene Expression Omnibus (GEO) (https://www.ncbi.nlm.nih.gov/geo/) databases. Hypoxia genes were retrieved from the Molecular Signatures Database (https://www.gsea-msigdb.org/gsea/msigdb/index.jsp). Differentially expressed hypoxia-related genes were screened by univariate Cox regression analysis and Lasso regression analysis. Then, the selected genes constituted the hypoxia signature and were included in multivariate Cox regression to generate the risk scores. After that, we evaluate the predictive performance of this signature by multiple receiver operating characteristic (ROC) curves. The CIBERSORT tool was applied to investigate the relationship between the hypoxia signature and the immune cell infiltration, and the maftool was used to summarize and analyze the mutational data. Gene-set enrichment analysis (GSEA) was used to investigate the related signaling pathways of differentially expressed genes in both risk groups. Furthermore, we developed a model and presented it with a nomogram to predict survival outcomes in patients with bladder cancer.

Results

Eight genes (AKAP12, ALDOB, CASP6, DTNA, HS3ST1, JUN, KDELR3, and STC1) were included in the hypoxia signature. The patients with higher risk scores showed worse overall survival time than the ones with lower risk scores in the training set (TCGA) and two external validation sets (GSE13507 and GSE32548). Immune infiltration analysis showed that two types of immune cells (M0 and M1 macrophages) had a significant infiltration in the high-risk group. Tumor mutation burden (TMB) analysis showed that the risk scores between the wild types and the mutation types of TP53, MUC16, RB1, and FGFR3 were significantly different. Gene-Set Enrichment Analysis (GSEA) showed that immune or cancer-associated pathways belonged to the high-risk groups and metabolism-related signal pathways were enriched into the low-risk group. Finally, we constructed a predictive model with risk score, age, and stage and validated its performance in GEO datasets.

Conclusion

We successfully constructed and validated a novel hypoxia signature in bladder cancer, which could accurately predict patients’ prognosis.

Artificial Intelligence-based Detection of FGFR3 Mutational Status Directly from Routine Histology in Bladder Cancer: A Possible Preselection for Molecular Testing?

BACKGROUND

Fibroblast growth factor receptor (FGFR) inhibitor treatment has become the first clinically approved targeted therapy in bladder cancer. However, it requires previous molecular testing of each patient, which is costly and not ubiquitously available.

OBJECTIVE

To determine whether an artificial intelligence system is able to predict mutations of the FGFR3 gene directly from routine histology slides of bladder cancer.

DESIGN, SETTING, AND PARTICIPANTS

We trained a deep learning network to detect FGFR3 mutations on digitized slides of muscle-invasive bladder cancers stained with hematoxylin and eosin from the Cancer Genome Atlas (TCGA) cohort (n = 327) and validated the algorithm on the "Aachen" cohort (n = 182; n = 121 pT2-4, n = 34 stroma-invasive pT1, and n = 27 noninvasive pTa tumors).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was the area under the receiver operating curve (AUROC) for mutation detection. Performance of the deep learning system was compared with visual scoring by an uropathologist.

RESULTS AND LIMITATIONS

In the TCGA cohort, FGFR3 mutations were detected with an AUROC of 0.701 (p < 0.0001). In the Aachen cohort, FGFR3 mutants were found with an AUROC of 0.725 (p < 0.0001). When trained on TCGA, the network generalized to the Aachen cohort, and detected FGFR3 mutants with an AUROC of 0.625 (p = 0.0112). A subgroup analysis and histological evaluation found highest accuracy in papillary growth, luminal gene expression subtypes, females, and American Joint Committee on Cancer (AJCC) stage II tumors. In a head-to-head comparison, the deep learning system outperformed the uropathologist in detecting FGFR3 mutants.

CONCLUSIONS

Our computer-based artificial intelligence system was able to detect genetic alterations of the FGFR3 gene of bladder cancer patients directly from histological slides. In the future, this system could be used to preselect patients for further molecular testing. However, analyses of larger, multicenter, muscle-invasive bladder cancer cohorts are now needed in order to validate and extend our findings.

PATIENT SUMMARY

In this report, a computer-based artificial intelligence (AI) system was applied to histological slides to predict genetic alterations of the FGFR3 gene in bladder cancer. We found that the AI system was able to find the alteration with high accuracy. In the future, this system could be used to preselect patients for further molecular testing.

Therapeutic and prognostic implications of NOTCH and MAPK signaling in bladder cancer

Signaling pathways that drive bladder cancer (BC) progression may be promising and specific targets for systemic therapy. Here, we investigated the clinical significance and targetability of NOTCH and mitogen-activated protein kinase (MAPK) signaling for this aggressive malignancy. We assessed NOTCH1 and MAPK activity in 222 stage III and IV BC specimens of patients that had undergone radical cystectomy, and tested for clinical associations including cancer-specific and overall survival. We examined therapeutic effects of NOTCH and MAPK repression in a murine xenograft model of human bladder cancer cells and evaluated tumor growth and tumor cell plasticity. In BC, NOTCH1 and MAPK signaling marked two distinct tumor cell subpopulations. The combination of high NOTCH1 and high MAPK activity indicated poor cancer-specific and overall survival in univariate and multivariate analyses. Inhibition of NOTCH and MAPK in BC xenografts in vivo depleted targeted tumor cell subpopulations and revealed strong plasticity in signaling pathway activity. Combinatorial inhibition of NOTCH and MAPK signaling most strongly suppressed tumor growth. Our findings indicate that tumor cell subpopulations with high NOTCH and MAPK activity both contribute to tumor progression. Furthermore, we propose a new concept for BC therapy, which advocates specific and simultaneous targeting of these different tumor cell subpopulations through combined NOTCH and MAPK inhibition.

Plasma ctDNA is a tumor tissue surrogate and enables clinical-genomic stratification of metastatic bladder cancer

Molecular stratification can improve the management of advanced cancers, but requires relevant tumor samples. Metastatic urothelial carcinoma (mUC) is poised to benefit given a recent expansion of treatment options and its high genomic heterogeneity. We profile minimally-invasive plasma circulating tumor DNA (ctDNA) samples from 104 mUC patients, and compare to same-patient tumor tissue obtained during invasive surgery. Patient ctDNA abundance is independently prognostic for overall survival in patients initiating first-line systemic therapy. Importantly, ctDNA analysis reproduces the somatic driver genome as described from tissue-based cohorts. Furthermore, mutation concordance between ctDNA and matched tumor tissue is 83.4%, enabling benchmarking of proposed clinical biomarkers. While 90% of mutations are identified across serial ctDNA samples, concordance for serial tumor tissue is significantly lower. Overall, our exploratory analysis demonstrates that genomic profiling of ctDNA in mUC is reliable and practical, and mitigates against disease undersampling inherent to studying archival primary tumor foci. We urge the incorporation of cell-free DNA profiling into molecularly-guided clinical trials for mUC.

FGFR3 – a Central Player in Bladder Cancer Pathogenesis?

The identification of mutations in FGFR3 in bladder tumors in 1999 led to major interest in this receptor and during the subsequent 20 years much has been learnt about the mutational profiles found in bladder cancer, the phenotypes associated with these and the potential of this mutated protein as a target for therapy. Based on mutational and expression data, it is estimated that >80% of non-muscle-invasive bladder cancers (NMIBC) and ∼40% of muscle-invasive bladder cancers (MIBC) have upregulated FGFR3 signalling, and these frequencies are likely to be even higher if alternative splicing of the receptor, expression of ligands and changes in regulatory mechanisms are taken into account. Major efforts by the pharmaceutical industry have led to development of a range of agents targeting FGFR3 and other FGF receptors. Several of these have entered clinical trials, and some have presented very encouraging early results in advanced bladder cancer. Recent reviews have summarised the drugs and related clinical trials in this area. This review will summarise what is known about the effects of FGFR3 and its mutant forms in normal urothelium and bladder tumors, will suggest when and how this protein contributes to urothelial cancer pathogenesis and will highlight areas that may benefit from further study.

Reassessment of p53 immunohistochemistry thresholds in invasive high grade bladder cancer shows a better correlation with TP53 and FGFR3 mutations

FGFR3 mutations are frequently mutually exclusive of TP53 mutations in invasive high grade urothelial carcinoma (HGUC) and p53 immunohistochemistry is often used as a surrogate for TP53 mutations. A 10 % staining cut off has been used in HGUC for designation as p53 positive or negative however, a novel contemporary method we have previously proposed (0% or >50 % - abnormal vs. 1-49 % - wild type) has shown significant correlation with oncologic outcome as well. We aimed to compare how a ≥10 % vs. 0 % and ≥ 50 % cut off p53 assessment method correlates with TP53 and FGFR3 mutation status. Tissue microarrays created from three retrospective cohorts (two cystectomy cohorts (cohort A, n = 206 and cohort B, n = 91; one T1 transurethral resection cohort (cohort C, n = 47)) were stained with p53 and scored by two blinded reviewers using both p53 scoring schemes. 50 cases from cohort A were assessed for TP53 and FGFR3 mutation status using next generation sequencing and FGFR3 mutation status was separately assessed in cohorts B and C using SNaPshot methodology. 202 (58.7 %) and 142 (41.3 %) cases showed abnormal and wild type p53 staining, respectively. Using the 10 % cut off, 254 cases were positive (73.8 %) and 90 cases were negative (26.2 %). 27 (14.4 %) and 15 (30 %) assessed cases demonstrated FGFR3 and TP53 mutations, respectively; 19/27 FGFR3 mutated showed a wild type pattern of p53 expression while 15/15 TP53 mutated tumours showed an abnormal pattern of p53 expression. There was a significant correlation between the contemporary p53 scoring scheme and TP53 and FGFR3 mutations (p < 0.0001 and p = 0.002, respectively). Improved sensitivity, specificity, positive predictive value, and negative predictive value for TP53 mutation was also seen compared to the 10 % cut off; specifically, the sensitivity and negative predictive value were 100 %. These findings might be of clinical relevance in the era of precision medicine.

FGFR3 Mutation Status and FGFR3 Expression in a Large Bladder Cancer Cohort Treated by Radical Cystectomy: Implications for Anti-FGFR3 Treatment?†

Fibroblast growth factor receptor 3 (FGFR3) is an actionable target in bladder cancer (BC). FGFR3 mutations are common in noninvasive BC and associated with favorable BC prognosis. Overexpression was reported in up to 40% of FGFR3 wild-type muscle-invasive BC. We analyzed FGFR3 mutations, FGFR3, and p53 protein expression and assessed their prognostic value in a cohort of 1000 chemotherapy-naive radical cystectomy specimens. FGFR3 mutations were found in 11%, FGFR3 overexpression was found in 28%, and p53 overexpression was found in 69% of tumors. Among FGFR3 mutant tumors, 73% had FGFR3 overexpression versus 22% among FGFR3 wild-type tumors. FGFR3 mutations were significantly associated with lower pT stage, tumor grade, absence of carcinoma in situ, pN0, low-level p53, and longer disease-specific survival (DSS). FGFR3 overexpression was associated only with lower pT stage and tumor grade. Moreover, FGFR3 overexpression was not associated with DSS in patients with FGFR3 wild-type tumors. In conclusion, FGFR3 mutations identified patients with favorable BC at cystectomy. Our results suggest that FGFR3 mutations have a driver role and are functionally distinct from FGFR3 overexpression. Hence, patients with FGFR3 mutations would be more likely to benefit from anti-FGFR3 therapy. Ideally, further research is needed to test this hypothesis. PATIENT SUMMARY: Oncogenic fibroblast growth factor receptor 3 (FGFR3) mutations are very common in bladder cancer. In this report, we found that these FGFR3 mutations were associated with favorable features and prognosis of bladder cancer compared with patients with FGFR3 overexpressed tumors only. As a consequence, patients with FGFR3 mutant tumors would be more likely to benefit from anti-FGFR3 therapy than patients with FGFR3 protein overexpression only.

Genomic heterogeneity in bladder cancer: challenges and possible solutions to improve outcomes

Histological and molecular analyses of urothelial carcinoma often reveal intratumoural and intertumoural heterogeneity at the genomic, transcriptional and cellular levels. Despite the clonal initiation of the tumour, progression and metastasis often arise from subclones that can develop naturally or during therapy, resulting in molecular alterations with a heterogeneous distribution. Variant histologies in tumour tissues that have developed distinct morphological characteristics divergent from urothelial carcinoma are extreme examples of tumour heterogeneity. Ultimately, heterogeneity contributes to drug resistance and relapse after therapy, resulting in poor survival outcomes. Mutation profile differences between patients with muscle-invasive and metastatic urothelial cancer (interpatient heterogeneity) probably contribute to variability in response to chemotherapy and immunotherapy as first-line treatments. Heterogeneity can occur on multiple levels and averaging or normalizing these alterations is crucial for clinical trial and drug design to enable appropriate therapeutic targeting. Identification of the extent of heterogeneity might shape the choice of monotherapy or additional combination treatments to target different drivers and genetic events. Identification of the lethal tumour cell clones is required to improve survival of patients with urothelial carcinoma.

Genomic Subtyping in Bladder Cancer

PURPOSE OF REVIEW

Molecular characterization of cancer allows us to understand oncogenesis and clinical prognosis as well as facilitates development of biomarkers and treatment. Our aim was to review the current literature on genomic characterization of bladder cancer, and how far we are in implementing genomics into clinical practice.

RECENT FINDINGS

Bladder cancers are molecularly diverse tumors with a high mutational rate. On molecular level, bladder cancer can be categorized into at least six subtypes called luminal-papillary, luminal-unstable, luminal non-specified, basal-squamous, neuroendocrine-like, and stroma-rich. These subtypes have characteristic genomic and transcriptomic profiles and appear to have different prognoses. Several molecular subtypes have been identified in bladder cancer. Prospective trials are underway to validate the applicability of genomic subtypes for clinical decision making. Further integrative analyses of genomic alterations, gene expression, epigenetics, and proteomics need to be performed before genomic subtyping can be attained in clinical practice.

Genomic characterization for familial cases with urothelial carcinoma

In this report, we present familial cases of urothelial carcinoma. To investigate the possibility of hereditary urothelial cancer, we performed semiconductor-based next-generation DNA sequencing. A woman in her 80s who had bladder and left ureteral cancer was hospitalized in Sapporo Shirakaba-dai Hospital due to consciousness disturbance. Radiographic evaluation revealed multiple liver metastases and she died 38 days later. Needle necropsy was done for a left ureteral tumor that continued to her bladder tumor and for liver metastases. At the same time, her son in his 60s, who also had muscle-invasive bladder cancer, was admitted to Sapporo Medical University Hospital and underwent neoadjuvant chemotherapy followed by laparoscopic radical cystectomy. DNA was isolated from both cancers and normal controls in each case and analyzed by massive parallel sequencing of 409 cancer-related genes using a targeted, multiplex PCR approach followed by semiconductor sequencing. Somatic mutations of KMT2C and KMT2D were detected in the mother's tumor. Copy number gains of FGFR1, IkBKB, NFkB2, FGFR2, and FLT3 and copy number losses of IGF2R and TP53 were also found in her cancer. In her son's tumor, somatic mutations of FGFR3 and EP300 were identified. Copy number gains of IkBKE/MAPK1/PARP1, EGFR, BRAF, IRS2, MAPK2K1, IGF1R, and ERBB2 and copy number loss of TP53 were also found in his cancer. There were no germline gene mutations related to familial urothelial carcinoma. Although somatic mutation of TP53 was a common feature, these cases with urothelial carcinoma might not be the result of a heredity syndrome.

Tissue biomarkers in nonmuscle-invasive bladder cancer: any role in clinical practice?

PURPOSE OF REVIEW

To summarize recent findings on tissue biomarkers for nonmuscle-invasive bladder cancer (NMIBC) with an emphasis on their prognostic and predictive role.

RECENT FINDINGS

Accurate risk stratification is essential and the major driver in patient counseling regarding surveillance and decision making relative to therapeutic strategies. In NMIBC, there is an unmet need for improving the accuracy of current prognostic and predictive models, which rely only on clinicopathologic features and do not reflect the biological heterogeneity of the cancer in each individual. Studies continuously shed novel light on some processes involved in cancerogenesis, host response and interactions in the tumor's own microenvironment, which may be considered as potential biomarkers and targets for future directed therapies.

SUMMARY

Biomarkers are necessary to transform bladder cancer management and usher in the age of personalized medicine. The clinical use is, however, still limited because of heterogeneity in study design, staining methods and an overall lacking adherence to a structured biomarker testing process.

Multiregion human bladder cancer sequencing reveals tumour evolution, bladder cancer phenotypes and implications for targeted therapy

We present an evolutionary analysis of the relative time of genetic events underlying tumorigenesis in human bladder cancers from 10 whole cystectomy specimens using multiregional whole-exome sequencing. We timed bladder cancer drivers, mutational signatures, ploidy and copy number alterations, provided evidence for kataegis and correlated alterations with tumour areas and histological phenotypes. We found that: (1) heterogeneous tumour areas/phenotypes had distinct driver mutations, (2) papillary-invasive tumours divided early into two parallel evolving branches and (3) parallel evolution of subclonal driver mutations occurred. APOBEC mutational signatures were found to be very early events, active in carcinoma in situ, and often remained a dominant source of mutations throughout tumour evolution. Genetic progression from carcinoma in situ followed driver mutations in NA13/FAT1, ZBTB7B or EP300/USP28/KMT2D. Our results point towards a more diverse mutational trajectory of bladder tumorigenesis and underpin the importance of timing of mutational processes and clonal architecture in bladder cancer as important aspects for successful prognostication and therapy. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Circular RNA hsa_circ_0068871 regulates FGFR3 expression and activates STAT3 by targeting miR-181a-5p to promote bladder cancer progression

BACKGROUND

FGFR3 plays an important role in the development of bladder cancer (BCa). Hsa_circ_0068871 is a circRNA generated from several exons of FGFR3. However, the potential functional role of hsa_circ_0068871 in BCa remains largely unknown. Here we aim to evaluate the role of hsa_circ_0068871 in BCa.

METHODS

We selected miR-181a-5p as the potential target miRNA of hsa_circ_0068871. The expression levels of hsa_circ_0068871 and miR-181a-5p were examined in BCa tissues and paired adjacent normal tissues by quantitative real-time PCR. To characterize the function of hsa_circ_0068871, BCa cell lines were stably infected with lentivirus targeting hsa_circ_0068871, followed by examinations of cell proliferation, migration and apoptosis. In addition, xenografts experiment in nude mice were performed to evaluate the effect of hsa_circ_0068871 in BCa. Biotinylated RNA probe pull-down assay, fluorescence in situ hybridization and luciferase reporter assay were conducted to confirm the relationship between hsa_circ_0068871, miR-181a-5p and FGFR3.

RESULTS

Hsa_circ_0068871 is over-expressed in BCa tissues and cell lines, whereas miR-181a-5p expression is repressed. Depletion of has_circ_0068871 or upregulation of miR-181a-5p inhibited the proliferation and migration of BCa cells in vitro and in vivo. Mechanistically, hsa_circ_0068871 upregulated FGFR3 expression and activated STAT3 by targeting miR-181a-5p to promote BCa progression.

CONCLUSIONS

Hsa_circ_0068871 regulates the miR-181a-5p/FGFR3 axis and activates STAT3 to promote BCa progression, and it may serve as a potential biomarker.

Targeting Cellular Trafficking of Fibroblast Growth Factor Receptors as a Strategy for Selective Cancer Treatment

Fibroblast growth factor receptors (FGFRs) in response to fibroblast growth factors (FGFs) transmit signals across the cell membrane, regulating important cellular processes, like differentiation, division, motility, and death. The aberrant activity of FGFRs is often observed in various diseases, especially in cancer. The uncontrolled FGFRs' function may result from their overproduction, activating mutations, or generation of FGFRs' fusion proteins. Besides their typical subcellular localization on the cell surface, FGFRs are often found inside the cells, in the nucleus and mitochondria. The intracellular pool of FGFRs utilizes different mechanisms to facilitate cancer cell survival and expansion. In this review, we summarize the current stage of knowledge about the role of FGFRs in oncogenic processes. We focused on the mechanisms of FGFRs' cellular trafficking-internalization, nuclear translocation, and mitochondrial targeting, as well as their role in carcinogenesis. The subcellular sorting of FGFRs constitutes an attractive target for anti-cancer therapies. The blocking of FGFRs' nuclear and mitochondrial translocation can lead to the inhibition of cancer invasion. Moreover, the endocytosis of FGFRs can serve as a tool for the efficient and highly selective delivery of drugs into cancer cells overproducing these receptors. Here, we provide up to date examples how the cellular sorting of FGFRs can be hijacked for selective cancer treatment.

Discordant molecular subtype classification in the basal-squamous subtype of bladder tumors and matched lymph-node metastases

Molecular subtypes of muscle-invasive bladder tumors have emerged as a promising research tool with potential to stratify patients for neoadjuvant treatment. Prior to radical cystectomy, the utility of molecular classification and biomarkers depend on concordance between tissue from transurethrally resected specimens and disseminated disease. We assess the concordance of molecular subtypes and a large number of potential biomarkers in 67 pairs of muscle-invasive bladder tumors and synchronous lymph-node metastases. Tissue cores were stained for 29 immunohistochemistry markers and immunohistochemistry-based molecular subtype classification was performed. Molecular subtype was determined by mRNA profiling for 57 bladder tumors and 28 matched lymph-node metastases. Full section immunohistochemistry was performed to assess intra-tumor subtype heterogeneity in discordant cases, and exome sequencing was performed for 20 sample pairs. Discordant subtype classification between the bladder tumor and lymph-node metastasis was generally rare (12/67, 18%), but most (7/12, 58%) involved the Basal/Squamous-like subtype. Discordant Basal/Squamous-like tumors showed either Urothelial-like or Genomically Unstable, luminal-like phenotype in the lymph-node metastasis. Full section immunohistochemistry revealed intra-tumor subtype heterogeneity for six discordant cases including four involving the Basal/Squamous-like subtype. Subtype concordance for non- Basal/Squamous-like tumors was 91%. RNA-based classification agreed with immunohistochemistry classification but quantitative assessment is necessary to avoid false detection of subtype shifts. Most high confidence cancer mutations were shared between samples (n = 93, 78%), and bladder tumor private mutations (n = 20, 17%) were more frequent than those private to the lymph-node metastasis (n = 7, 6%). We conclude that bladder tumors and lymph-node metastases have overall similar molecular subtype, biomarker expression, and cancer mutations. The main exception was tumors of the Basal/Squamous-like subtype where most cases showed discordant classification, some with evidence of intra-tumor heterogeneity. The data are of relevance for neoadjuvant treatment stratification and raises questions on the dynamics of molecular subtypes during bladder cancer progression.

FGFR3 mutation increases bladder tumourigenesis by suppressing acute inflammation

Recent studies of muscle-invasive bladder cancer show that FGFR3 mutations are generally found in a luminal papillary tumour subtype that is characterised by better survival than other molecular subtypes. To better understand the role of FGFR3 in invasive bladder cancer, we examined the process of tumour development induced by the tobacco carcinogen OH-BBN in genetically engineered models that express mutationally activated FGFR3 S249C or FGFR3 K644E in the urothelium. Both occurrence and progression of OH-BBN-driven tumours were increased in the presence of an S249C mutation compared to wild-type control mice. Interestingly, at an early tumour initiation stage, the acute inflammatory response in OH-BBN-treated bladders was suppressed in the presence of an S249C mutation. However, at later stages of tumour progression, increased inflammation was observed in S249C tumours, long after the carcinogen administration had ceased. Early-phase neutrophil depletion using an anti-Ly6G monoclonal antibody resulted in an increased neutrophil-to-lymphocyte ratio at later stages of pathogenesis, indicative of enhanced tumour pathogenesis, which supports the hypothesis that suppression of acute inflammation could play a causative role. Statistical analyses of correlation showed that while initial bladder phenotypes in morphology and inflammation were FGFR3-dependent, increased levels of inflammation were associated with tumour progression at the later stage. This study provides a novel insight into the tumour-promoting effect of FGFR3 mutations via regulation of inflammation at the pre-tumour stage in the bladder. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Structural Alterations in Human Fibroblast Growth Factor Receptors in Carcinogenesis

Fibroblast growth factor (FGF) plays an important role in human embryogenesis, angiogenesis, cell proliferation, and differentiation. Carcinogenesis is accompanied by aberrant constitutive activation of FGF receptors (FGFRs) resulting from missense mutation in the FGFR1-4 genes, generation of chimeric oncogenes, FGFR1-4 gene amplification, alternative splicing shift toward formation of mesenchymal FGFR isoforms, and FGFR overexpression. Altogether, these alterations contribute to auto- and paracrine stimulation of cancer cells and neoangiogenesis. Certain missense mutations are found at a high rate in urinary bladder cancer and can be used for non-invasive cancer recurrence diagnostics by analyzing urine cell pellet DNA. Chimeric FGFR1/3 and amplified FGFR1/2 genes can predict cell response to the targeted therapy in various oncological diseases. In recent years, high-throughput sequencing has been used to analyze exomes of virtually all human tumors, which allowed to construct phylogenetic trees of clonal cancer evolution with special emphasis on driver mutations in FGFR1-4 genes. At present, FGFR blockers, such as multi-kinase inhibitors, specific FGFR inhibitors, and FGF ligand traps are being tested in clinical trials. In this review, we discuss current data on the functioning of the FGFR family proteins in both normal and cancer cells, mutations in the FGFR1-4 genes, and mechanisms underlying their oncogenic potential, which might be interesting to a broad range of scientists searching for specific tumor markers and targeted anti-cancer drugs.

Fibroblast growth factor receptor 3 (FGFR3) aberrations in muscle-invasive urothelial carcinoma

BACKGROUND

Recent studies suggest that FGFR3 is a potential therapeutic target in urothelial carcinoma (UC). The purpose of this study was to evaluate the rates and types of FGFR3 aberrations in patients with muscle-invasive UC who received radical resection.

METHODS

We analyzed surgical tumor samples from 74 UC patients who had received radical cystectomy (n = 40) or ureteronephrectomy (n = 34). Ion AmpliSeq Cancer Hotspot Panel v2 and nCounter Copy Number Variation Assay were used to detect FGFR3 aberrations.

RESULTS

Fifty-four patients (73%) had high-grade tumors, and 62% had lymph node involvement. Sixteen patients (22%) harbored FGFR3 alterations, the most common of which was FGFR3 mutations (n = 13): Y373C (n = 3), N532D (n = 3), R248C (n = 2), S249C (n = 1), G370C (n = 1), S657S (n = 1), A797P (n = 1), and 746_747insG (n = 1). Three additional patients had a FGFR3-TACC3 rearrangement. The frequency of FGFR3 aberrations was higher in bladder UC (25%) than in UC of the renal pelvis and ureter (18%) but the difference was not statistically significant (P = 0.444). Genes that were co-aberrant with FGFR3 included APC (88%), PDGFRA (81%), RET (69%), and TP53 (69%).

CONCLUSIONS

We report the frequency and types of FGFR3 aberrations in Korean patients with UC. Patients with FGFR3 mutations or FGFR3-TACC3 fusion may constitute potential candidates for a novel FGFR-targeted therapy in the perioperative setting.

Progressive tissue biomarker profiling in non-muscle-invasive bladder cancer

INTRODUCTION

The recurrence rate of non-muscle-invasive bladder cancer (NMIBC) is up to 60% within the first year of therapy. Accurate risk stratification is necessary for patient counselling, follow-up scheduling and individualized therapeutic decision making. Current prognostic models rely on clinicopathologic features, but their discrimination remains limited when in external cohorts. Despite intense efforts regarding the value of biomarkers in prognosticating outcomes in NMIBC, clinical utility remains suboptimal. It is clear that a single biomarker is not enough for the prediction of disease recurrence. Therefore, panels of non-redundant biomarkers have been created and integrated in clinical prognostic model further research relying on high throughput technologies is required. Areas covered: We performed a systematic research of the English-language literature on tissue biomarkers for prediction of NMIBC outcomes up to December 2017. Expert commentary: Despite the essential milestones achieved in our knowledge and understanding of the molecular biology underlying NMIBC, no biomarker has been implemented together with clinical feature in clinical practice. Integration of such biomarkers into predictive and prognostic model could, however, improve our accuracy, thereby paving the way for personalized medicine in the management of NMIBC.

Nicotine upregulates FGFR3 and RB1 expression and promotes non-small cell lung cancer cell proliferation and epithelial-to-mesenchymal transition via downregulation of miR-99b and miR-192

BACKGROUND

Tobacco smoke is by far the greatest risk factor for non-small-cell lung cancer (NSCLC). Nicotine, an active alkaloid in tobacco, is unable to initiate tumorigenesis in humans and rodents, but can promote the growth and metastasis of various tumors, including NSCLC, initiated by tobacco carcinogens. Recently, cigarette smoke is reported to downregulate 24 miRNAs more than 3-fold in the lungs of rats, and most of these downregulated miRNAs are associated with NSCLC initiation and development. Nicotine as the major tobacco component might be associated with the expression changes of some miRNAs.

METHODS

qRT-PCR was performed to determine the miRNA and mRNA expression, and western blot was conducted to measure protein expression. MTT assay was used to detect cell proliferation.

RESULTS

The effects of nicotine on the expression of 24 miRNAs in NSCLC cell lines were determined, and the results showed that nicotine treatment decreased miR-99b and miR-192 expression. Cell proliferation and epithelial-to-mesenchymal transition (EMT) detection showed that nicotine promoted NSCLC cell proliferation and EMT, and restoration of miR-99b or miR-192 expression relieved the effects of nicotine on NSCLC cell proliferation and EMT. Subsequently, fibroblast growth factor receptor 3 (FGFR3) and retinoblastoma 1 (RB1) were confirmed to be the targets of miR-99b and miR-192, respectively, and were upregulated by nicotine in NSCLC cells. In addition, FGFR3 or RB1 knockdown inhibited NSCLC cell proliferation and EMT.

CONCLUSION

This study, for the first time, elucidates nicotine-miR-99b/miR-192-FGFR3/RB1 regulatory network that nicotine promotes NSCLC cell proliferation and EMT by downregulating miR-99b and miR-192, and upregulating their targets FGFR3 and RB1. These findings offer novel insights into the understanding of underlying molecular mechanisms of NSCLC related with the nicotine effects.

Precision medicine for urothelial bladder cancer: update on tumour genomics and immunotherapy

Effective management of advanced urothelial bladder cancer is challenging. New discoveries that improve our understanding of molecular bladder cancer subtypes have revealed numerous potentially targetable genomic alterations and demonstrated the efficacy of treatments that harness the immune system. These findings have begun to change paradigms of bladder cancer therapy. For example, DNA repair pathway mutations in genes such as ERCC2, FANCC, ATM, RB1, and others can predict responses to neoadjuvant platinum-based chemotherapies and to targeted therapies on the basis of mutation status. Furthermore, an increasing number of pan-cancer clinical trials (commonly referred to as basket or umbrella trials) are enrolling patients on the basis of molecular and genetic predictors of response. These studies promise to provide improved insight into the true utility of personalized medicine in the treatment of bladder cancer and many other cancer types. Finally, therapies that modulate immune responses have shown great benefit in many cancer types. Several immune checkpoint inhibitors that target programmed cell death protein 1 (PD1), its ligand PDL1, and cytotoxic T lymphocyte-associated protein 4 (CTLA4) have already been approved for use in bladder cancer, representing the most important change to the urological oncologist's tool-kit in over a decade. These advances also provide opportunities for personalization of bladder cancer therapy.

CXC chemokine‑7 inhibits growth and migration of oral tongue squamous cell carcinoma cells, mediated by the epithelial‑mesenchymal transition signaling pathway

Oral tongue squamous cell carcinoma (OTSCC) is the most common oral malignancy with different histopathological symptoms and etiology of tumorigenesis. Migration and invasion is the most important characteristics of OTSCC, and limits tumor therapy in clinics. The epithelial‑to‑mesenchymal transition (EMT) signaling pathway is an important process in the progress of tumor cell migration and invasion. Previous studies have indicated that C‑X‑C chemokine receptor‑7 (CXCR‑7) promotes the progression and metastasis of tumor cells, presenting a potential target molecule for cancer therapy. The present study investigated the inhibitory effects of C‑X‑C chemokine‑7 (CXC‑7) on human OTSCC cells both in vitro and in vivo. The results demonstrated that the Tca8113 human OTSCC cell line expressed higher levels of CXC‑7 mRNA compared with the hNOE human normal oral epithelial cell line. MTT assays indicated that CXC‑7 suppressed Tca8113 cell growth, and the cytotoxicity of CXC‑7 was indicated as the cell survival of the negative control group was significantly decreased compared with the blank control and hNOE cells. Migration and invasion assays revealed that CXC‑7 inhibited Tca8113 cell local expansion and distant metastasis. In addition, the results demonstrated that the extracellular signal‑regulated kinase (ERK)/protein kinase B (AKT) signaling pathway was inhibited after CXC‑7 treatment in Tca8113 cells. N‑cadherin, E‑Cadherin, Snail and Slug expression levels in the ERK/AKT signaling pathway were inhibited in Tca8113 cells after treatment with CXC‑7. It was demonstrated that important extracellular matrix proteins involved in cell migration, including Slug, collagen type I and Vimentin, were significantly downregulated by CXC‑7 treatment. In conclusion, CXC‑7 inhibited growth and migration in OTSCC cells, mediated by the EMT signaling pathway. This suggests that CXC‑7 serves an inhibitory role in OTSCC migration, implicating CXCR‑7 as a promising biomarker for chemokine receptor‑based drug development.

The prognostic significance of DAPK1 in bladder cancer

Bladder cancer is one of the leading causes of cancer-related death in men, however, there was only limited effective treatment for invasive bladder cancer. DAPK1 has been shown to play important role in apoptosis and autophagy to suppress cancer progression. Previous results have shown that DAPK1 promoter was hypermethylated in the majority of bladder cancer specimens, however, the prognostic significance of DAPK1 in bladder cancer has yet to be demonstrated. In the present study, we found that DAPK1 expression was negatively associated with tumor stage and a low level expression of DAPK1 in bladder cancer specimens were associated with shorter survival in bladder cancer patients in 3 independent bladder cancer datasets (n = 462). Further investigation showed that FGFR3 knockdown resulted in downregulation of DAPK1 in bladder cancer cell line, suggesting that FGFR3 may be an upstream factor of DAPK1. Further analysis of the 3 independent bladder cancer datasets have identified ACOX1, UPK2, TRAK1, PLEKHG6 and MT1X genes had their expression significantly correlated with that of DAPK1. Knockdown of DAPK1 in bladder cancer T24 cells resulted in downregulation of ACOX1, UPK2 and TRAK1. Interestingly, TRAK1, by itself, was a favorable prognostic marker in the 3 independent bladder cancer datasets. Importantly, by using connectivity mapping with DAPK1-associated gene signature, we found that vemurafenib and trametinib could possibly reverse DAPK1-associated gene signature, suggesting that inhibition of Raf/MEK pathway may be a potential therapeutic approach for bladder cancer. Indeed, treatment of vemurafenib in T24 bladder cancer cells resulted in upregulation of DAPK1 confirming our connectivity mapping, while knockdown of DAPK1 resulted in reduced sensitivity towards inhibition of Braf signaling by vemurafenib. Together, our results suggest that DAPK1 is an important prognostic marker and therapeutic target for bladder cancer and have identified possible therapeutic agents for future testing in bladder cancer models with low DAPK1 expression.

The evolving genomic landscape of urothelial carcinoma

Survival of patients with urothelial carcinoma (including bladder cancer and upper tract urothelial carcinoma) is limited by our current approaches to staging, surgery, and chemotherapy. Large-scale, next-generation sequencing collaborations, such as The Cancer Genome Atlas, have already identified drivers and vulnerabilities of urothelial carcinoma. This disease has a high degree of mutational heterogeneity and a high frequency of somatic mutations compared with other solid tumours, potentially resulting in an increased neoantigen burden. Mutational heterogeneity is mediated by multiple factors including the apolipoprotein B mRNA editing enzyme catalytic polypeptide family of enzymes, smoking exposure, viral integrations, and intragene and intergene fusion proteins. The mutational landscape of urothelial carcinoma, including specific mutations in pathways and driver genes, such as FGFR3, ERBB2, PIK3CA, TP53, and STAG2, affects tumour aggressiveness and response to therapy. The next generation of therapies for urothelial carcinoma will be based on patient-specific targetable mutations found in individual tumours. This personalized-medicine approach to urothelial carcinoma has already resulted in unique clinical trial design and has the potential to improve patient outcomes and survival.

Epigenome-Wide DNA Methylation Profiling Identifies Differential Methylation Biomarkers in High-Grade Bladder Cancer

Epigenetic changes, including CpG island hypermethylation, occur frequently in bladder cancer (BC) and may be exploited for BC detection and distinction between high-grade (HG) and low-grade (LG) disease. Genome-wide methylation analysis was performed using Agilent Human CpG Island Microarrays to determine epigenetic differences between LG and HG cases. Pathway enrichment analysis and functional annotation determined that the most frequently methylated pathways in HG BC were enriched for anterior/posterior pattern specification, embryonic skeletal system development, neuron fate commitment, DNA binding, and transcription factor activity. We identified 990 probes comprising a 32-gene panel that completely distinguished LG from HG based on methylation. Selected genes from this panel, EOMES, GP5, PAX6, TCF4, and ZSCAN12, were selected for quantitative polymerase chain reaction–based validation by MethyLight in an independent series (n = 84) of normal bladder samples and LG and HG cases. GP5 and ZSCAN12, two novel methylated genes in BC, were significantly hypermethylated in HG versus LG BC (P ≤ .03). We validated our data in a second independent cohort of LG and HG BC cases (n = 42) from The Cancer Genome Atlas (TCGA). Probes representing our 32-gene panel were significantly differentially methylated in LG versus HG tumors (P ≤ .04). These results indicate the ability to distinguish normal tissue from cancer, as well as LG from HG, based on methylation and reveal important pathways dysregulated in HG BC. Our findings were corroborated using publicly available data sets from TCGA. Ultimately, the creation of a methylation panel, including GP5 and ZSCAN12, able to distinguish between disease phenotypes will improve disease management and patient outcomes.

Targeting and Regulating of an Oncogene via Nanovector Delivery of MicroRNA using Patient-Derived Xenografts

In precision cancer nanomedicine, the key is to identify the oncogenes that are responsible for tumorigenesis, based on which these genetic drivers can be each specifically regulated by a nanovector-directed, oncogene-targeted microRNA (miRNA) for tumor suppression. Fibroblast Growth Factor Receptor 3 (FGFR3) is such an oncogene. The molecular tumor-subtype harboring FGFR3 genomic alteration has been identified via genomic sequencing and referred to as the FGFR3-driven tumors. This genomics-based tumor classification provides further rationale for the development of the FGFR3-targeted miRNA replacement therapy in treating patients with FGFR3 gene abnormity. However, successful miRNA therapy has been hampered by lacking of an efficient delivery vehicle. In this study, a nanovector is developed for microRNA-100 (miR-100) -mediated FGFR3 regulation. The nanovector is composed of the mesoporous magnetic clusters that are conjugated with ternary polymers for efficient miRNA in-vivo delivery. The miRNA-loading capacity of the nanovector is found to be high due to the polycation polymer functionalized mesoporous structure, showing excellent tumor cell transfection and pH-sensitive miRNA release. Delivery of miR-100 to cancer cells effectively down-regulates the expression of FGFR3, inhibits cell proliferation, and induces cell apoptosis in vitro. Patient-derived xenografts (PDXs) are used to evaluate the efficacy of miRNA delivery in the FGFR3-driven tumors. Notably, sharp contrasts are observed between the FGFR3-driven tumors and those without FGFR3 genomic alteration. Only the FGFR3-driven PDXs are significantly inhibited via miR-100 delivery while the non-FGFR3-driven PDXs are not affected, showing promise of precision cancer nanomedicine.