Subtypes Of Muscle-invasive Bladder Cancer Research Articles

178 - The pathological and clinical response of the luminal and basal subtypes of muscle-invasive bladder cancer to neoadjuvant cisplatin-based chemotherapy and radical cystectomy depend on the immunohistochemical classification system

178 - The pathological and clinical response of the luminal and basal subtypes of muscle-invasive bladder cancer to neoadjuvant cisplatin-based chemotherapy and radical cystectomy depend on the immunohistochemical classification system

In stage pT1 non-muscle-invasive bladder cancer (NMIBC), high KRT20 and low KRT5 mRNA expression identify the luminal subtype and predict recurrence and survival.

Differential expression of cytokeratins (CK) is a characteristic feature of chemoresistant luminal (KRT20) and chemosensitive intrinsic aggressive basal (KRT5) subtypes in muscle-invasive bladder cancer (MIBC). We investigated mRNA expression of KRT5 and KRT20 and its predictive value in stage pT1 bladder cancer. In retrospective analysis of clinical data and formalin-fixed paraffin-embedded tissues (FFPE) of patients with stage pT1 NMIBC who underwent transurethral resection of the bladder, a single-step RT-qPCR was used to measure mRNA expression. Furthermore, immunohistochemical (IHC) staining of CK20, panCK, and MIB1 was performed. Valid measurements were obtained from 231 samples out of a series of 284 patients. Spearman correlation revealed significant associations between mRNA and protein expression of KRT20/CK20 (ρ 0.6096, p<0.0001) and MKI67/MIB1 (ρ 0.5467, p<0.0001). A positive correlation was found between MKI67 and KRT20 expression (ρ 0.3492, p<0.0001), while MKI67 and KRT5 were negatively correlated (ρ -0.1693, p=0.01). High KRT20 expression (≥40.26) was significantly associated with worse recurrence free survival (RFS) (p=0.001), progression-free survival (PFS) (p=0.0003), and cancer specific survival (CSS) (p=0.0414). The combination of high KRT20 expression and low KRT5 expression (<36.83) was associated with unfavorable RFS (p=0.0038) and PFS (p=0.0003) and proved to be the only independent predictor for RFS (p=0.0055) and PFS (p=0.0023) in multivariate analysis. KRT20 mRNA determination was superior to CK20 protein estimation with regard to RFS and PFS prediction. KRT20 and KRT5 mRNA quantification can predict recurrence and progression of stage pT1 NMIBC reflecting basal and luminal subtypes of MIBC and is superior to CK20 protein expression determined by IHC.

Impact of Molecular Subtypes in Muscle-invasive Bladder Cancer on Predicting Response and Survival after Neoadjuvant Chemotherapy

Impact of Molecular Subtypes in Muscle-invasive Bladder Cancer on Predicting Response and Survival after Neoadjuvant Chemotherapy

Age at diagnosis, obesity, smoking, and molecular subtypes in muscle-invasive bladder cancer

Age at diagnosis, obesity, smoking, and molecular subtypes in muscle-invasive bladder cancer

Specific micro-RNA expression patterns distinguish the basal and luminal subtypes of muscle-invasive bladder cancer.

The roles of non-coding RNAs in controlling clinical and biological heterogeneity in bladder cancer remain unclear. We used TCGA's published dataset (n = 405 tumors) as a discovery cohort and created a new validation cohort to define the miRNA expression patterns in the basal and luminal molecular subtypes of muscle-invasive bladder cancer (MIBC). We identified 63 miRNAs by PAM, which optimally identified basal and luminal tumors. The targets of the top luminal miRNAs were activators of EMT (ZEB1, ZEB2) and basal subtype transcription (IL-6, EGFR, STAT3), whereas the targets of the top basal miRNAs were involved in adipogenesis pathways and luminal breast cancer (ERBB2, ERBB3). We also identified a 15-miRNA signature that identified stromally infiltrated basal and luminal MIBCs corresponding to the “cluster IV/immune undifferentiated/claudin-low” and “cluster II/luminal immune” subtypes identified previously, which likely contain samples with higher infiltration rates. Using the 63-miRNA signature, we accurately assigned MIBCs to the basal and luminal subtypes and confirmed that patients with basal tumors had shorter overall survival. The results strongly suggest that miRNAs contribute to the control of the gene expression patterns observed in basal and luminal MIBCs and that they can be used as biomarkers and candidate therapeutic targets.

Abstract A1-68: The long noncoding RNA SNHG18 promotes PPARγ function and luminal gene expression in muscle-invasive bladder cancer

Abstract Long noncoding RNAs (lncRNAs) are emerging as important drivers of disease progression and have been shown to modulate gene expression at several levels. While many lncRNAs have been discovered, the molecular functions of a majority of identified lncRNAs are still poorly understood. Recent studies in muscle-invasive bladder cancer (MIBC) identified intrinsic molecular subtypes at the mRNA level, however the role of non-coding RNAs in the context of subtypes has not been explored. Therefore, the overall goal of this study was to obtain a deeper understanding of the lncRNAs that contribute to the molecular mechanisms that underlie the intrinsic subtypes of MIBC. In this study, we utilized TCGA's RNA-sequencing data to extract whole genome lncRNA expression from 211 MIBCs. Using an unsupervised approach, consensus clustering of lncRNA expression identified two intrinsic subtypes of MIBCs, which were synonymous with the intrinsic basal and luminal subtypes discovered through mRNA expression profiling. Previous data has shown PPARγ to be amplified in approximately 15% of luminal MIBCs, and luminal MIBCs are enriched with an active PPARγ mRNA expression signature. To further study the lncRNAs associated with the luminal subtype, cell lines were exposed to rosiglitazone, a PPARγ agonist, and RNA-sequencing was performed. Gene set enrichment analysis (GSEA) confirmed lncRNAs up-regulated after exposure to rosiglitazone were highly expressed in luminal MIBCs. Differential expression analysis revealed SNHG18 to be up-regulated after PPARγ activation, and to be highly expressed in luminal MIBCs. RNA immunoprecipitation studies confirmed that SNHG18 is directly bound by PPARγ, and subsequent knockdown of SNHG18 resulted in decreased expression of several luminal PPARγ target genes including uroplakins and fibroblast growth factor receptor-3 (FGFR3). Currently, FGFR3 is an important therapeutic target in MIBCs with activating mutations occurring in approximately 17% of cases. Overall, we have identified a novel lncRNA, SNHG18, to be a co-activator of PPARγ that controls downstream expression of several luminal target genes. The results suggest that SNHG18 could potentially serve as a predictive biomarker, as a possible drug target to increase the efficiency of FGFR3 targeted therapies, or as a therapeutic target in luminal MIBC. Citation Format: Andrea E. Ochoa, Jianping Zhang, Woonyoung Choi, Gabriel G. Malouf, Erika J. Thompson, John N. Weinstein, Nizar M. Tannir, Colin Dinney, David J. McConkey, Xiaoping Su. The long noncoding RNA SNHG18 promotes PPARγ function and luminal gene expression in muscle-invasive bladder cancer. [abstract]. In: Proceedings of the AACR Special Conference on Translation of the Cancer Genome; Feb 7-9, 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 1):Abstract nr A1-68.

MP72-06 THE LONG NON-CODING RNA SNHG18 PROMOTES PPARγ FUNCTION AND “LUMINAL” GENE EXPRESSION IN MUSCLE-INVASIVE BLADDER CANCER

You have accessJournal of UrologyBladder Cancer: Invasive V1 Apr 2015MP72-06 THE LONG NON-CODING RNA SNHG18 PROMOTES PPARγ FUNCTION AND “LUMINAL” GENE EXPRESSION IN MUSCLE-INVASIVE BLADDER CANCER Andrea Ochoa, Jianping Zhang, Woonyoung Choi, Gabriel Malouf, Erika Thompson, John Weinstein, Nizar Tannir, Colin Dinney, David McConkey, and Xiaoping Su Andrea OchoaAndrea Ochoa More articles by this author , Jianping ZhangJianping Zhang More articles by this author , Woonyoung ChoiWoonyoung Choi More articles by this author , Gabriel MaloufGabriel Malouf More articles by this author , Erika ThompsonErika Thompson More articles by this author , John WeinsteinJohn Weinstein More articles by this author , Nizar TannirNizar Tannir More articles by this author , Colin DinneyColin Dinney More articles by this author , David McConkeyDavid McConkey More articles by this author , and Xiaoping SuXiaoping Su More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.2640AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Long non-coding RNAs (lncRNAs) are emerging as important drivers of disease progression, and have been shown to modulate gene expression at several levels. Unfortunately, the molecular functions of a majority of lncRNAs identified are still poorly understood. While recent studies have identified subtypes of muscle-invasive bladder cancer (MIBC) at the mRNA level, the overall goal of this study is to obtain a deeper understanding of the lncRNAs that contribute to the molecular mechanisms that underlie the intrinsic subtypes of MIBC. METHODS In this study, we utilized TCGA's RNA-sequencing data to extract whole genome lncRNA expression from 211 MIBCs. Unsupervised consensus clustering was utilized to identify subtypes based on lncRNA expression profiles, and differential expression analysis was performed in the R statistical programming environment. To further study the lncRNAs associated with the luminal subtype, cell lines were exposed to rosiglitazone, a PPARγ agonist, and RNA-sequencing was performed. PPARγ associated lncRNA candidates were validated in an independent cohort using quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS Consensus clustering of lncRNA expression identified two intrinsic subtypes of MIBCs, which were synonymous with the intrinsic basal and luminal subtypes recently discovered through mRNA expression profiling. Previous work has shown that PPARγ is amplified in approximately 15% of luminal MIBCs, and luminal MIBCs are enriched with an active PPARγ mRNA expression signature. In this study, lncRNAs up-regulated after exposure to rosiglitazone were highly expressed in luminal MIBCs, as confirmed by gene set enrichment analysis (GSEA). Differential expression analysis revealed SNHG18 to be up-regulated after PPARγ activation, and to be highly expressed in luminal MIBCs. RNA immunoprecipitation studies confirmed that SNHG18 is directly bound by PPARγ, and subsequent knockdown of SNHG18 resulted in decreased expression of several luminal PPARγ target genes including uroplakins and fibroblast growth factor receptor-3 (FGFR3). CONCLUSIONS Currently, FGFR3 is an important therapeutic target in MIBCs with activating mutations occurring in approximately 17% of cases. Overall, we have identified a novel lncRNA, SNHG18, to be a co-activator of PPARγ that controls downstream expression of FGFR3. The results suggest that SNHG18 could potentially serve as a predictive biomarker, or as a possible drug target to increase the efficiency of FGFR3 targeted therapies. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e923 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Andrea Ochoa More articles by this author Jianping Zhang More articles by this author Woonyoung Choi More articles by this author Gabriel Malouf More articles by this author Erika Thompson More articles by this author John Weinstein More articles by this author Nizar Tannir More articles by this author Colin Dinney More articles by this author David McConkey More articles by this author Xiaoping Su More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...

Intrinsic basal and luminal subtypes of muscle-invasive bladder cancer.

Whole-genome analyses have revealed that muscle-invasive bladder cancers (MIBCs) are heterogeneous and can be grouped into basal and luminal subtypes that are highly reminiscent of those found in breast cancer. Basal MIBCs are enriched with squamous and sarcomatoid features and are associated with advanced stage and metastatic disease at presentation. Like basal breast cancers, basal bladder tumours contain a claudin-low subtype that is enriched with biomarkers characteristic of epithelial-to-mesenchymal transition. The stem cell transcription factor ΔNp63α controls basal MIBC gene expression, just as it does in basal breast cancers. Luminal MIBCs are enriched with activating FGFR3 and ERBB3 mutations and ERBB2 amplifications, and their gene expression profiles are controlled by peroxisome proliferator activator receptor γ (PPARγ) and possibly also by oestrogen receptor activation. Luminal bladder cancers can be further subdivided into two subtypes, p53-like and luminal, which can be distinguished from one another by different levels of biomarkers that are characteristic of stromal infiltration, cell cycle progression, and proliferation. Importantly, basal bladder cancers are intrinsically aggressive, but are highly sensitive to cisplatin-based combination chemotherapy. Although the luminal subtypes are not as intrinsically aggressive as basal cancers, p53-like tumours are resistant to chemotherapy and might, therefore, represent a problem for treated patients.

Identification of Distinct Basal and Luminal Subtypes of Muscle-Invasive Bladder Cancer with Different Sensitivities to Frontline Chemotherapy

Muscle-invasive bladder cancers (MIBCs) are biologically heterogeneous and have widely variable clinical outcomes and responses to conventional chemotherapy. We discovered three molecular subtypes of MIBC that resembled established molecular subtypes of breast cancer. Basal MIBCs shared biomarkers with basal breast cancers and were characterized by p63 activation, squamous differentiation, and more aggressive disease at presentation. Luminal MIBCs contained features of active PPARγ and estrogen receptor transcription and were enriched with activating FGFR3 mutations and potential FGFR inhibitor sensitivity. p53-like MIBCs were consistently resistant to neoadjuvant methotrexate, vinblastine, doxorubicin and cisplatin chemotherapy, and all chemoresistant tumors adopted a p53-like phenotype after therapy. Our observations have important implications for prognostication, the future clinical development of targeted agents, and disease management with conventional chemotherapy.

Molecular Subtyping of Invasive Bladder Cancer: Time to Divide and Rule?

Therapeutic decisions for muscle-invasive bladder cancer (MIBC) are largely based on histopathologic characteristics. In this issue of Cancer Cell, Choi and colleagues report three molecular subtypes of MIBC with the potential to guide prognosis, patient stratification, and treatment.

Loss of the Urothelial Differentiation Marker FOXA1 Is Associated with High Grade, Late Stage Bladder Cancer and Increased Tumor Proliferation

Approximately 50% of patients with muscle-invasive bladder cancer (MIBC) develop metastatic disease, which is almost invariably lethal. However, our understanding of pathways that drive aggressive behavior of MIBC is incomplete. Members of the FOXA subfamily of transcription factors are implicated in normal urogenital development and urologic malignancies. FOXA proteins are implicated in normal urothelial differentiation, but their role in bladder cancer is unknown. We examined FOXA expression in commonly used in vitro models of bladder cancer and in human bladder cancer specimens, and used a novel in vivo tissue recombination system to determine the functional significance of FOXA1 expression in bladder cancer. Logistic regression analysis showed decreased FOXA1 expression is associated with increasing tumor stage (p<0.001), and loss of FOXA1 is associated with high histologic grade (p<0.001). Also, we found that bladder urothelium that has undergone keratinizing squamous metaplasia, a precursor to the development of squamous cell carcinoma (SCC) exhibited loss of FOXA1 expression. Furthermore, 81% of cases of SCC of the bladder were negative for FOXA1 staining compared to only 40% of urothelial cell carcinomas. In addition, we showed that a subpopulation of FOXA1 negative urothelial tumor cells are highly proliferative. Knockdown of FOXA1 in RT4 bladder cancer cells resulted in increased expression of UPK1B, UPK2, UPK3A, and UPK3B, decreased E-cadherin expression and significantly increased cell proliferation, while overexpression of FOXA1 in T24 cells increased E-cadherin expression and significantly decreased cell growth and invasion. In vivo recombination of bladder cancer cells engineered to exhibit reduced FOXA1 expression with embryonic rat bladder mesenchyme and subsequent renal capsule engraftment resulted in enhanced tumor proliferation. These findings provide the first evidence linking loss of FOXA1 expression with histological subtypes of MIBC and urothelial cell proliferation, and suggest an important role for FOXA1 in the malignant phenotype of MIBC.