Reduced expression of ezrin in urothelial bladder cancer signifies more advanced tumours and an impaired survival: validatory study of two independent patient cohorts

Telocytes and ezrin expression in normal-appearing tissues adjacent to urothelial bladder carcinoma as predictors of invasiveness and recurrence

Recurrence and progression rates vary widely among different histological subtypes of bladder cancer (BC). Normal-appearing mucosa in non-muscle invasive bladder cancer and muscle-invasive bladder cancer in cystoscopy and histopathology is a factor in staging and treatment. Telocytes (TCs) are spindle-shaped cells that connect with other cell types allowing communication though cytoskeletal signaling. They are involved in tissue regeneration and pathogenesis of diseases and cancer. In this study, 12 normal-appearing tissues from urinary bladder with BC, both invasive and non-invasive were evaluated in patients who had either trans-urethral resection of bladder tumor or cystectomy. In each case, cystoscopy, intraoperative inspection, and histopathology all confirmed the absence of cancerous elements. Five patients with neurogenic bladder were used as a control group. Immunohistochemistry revealed that c-Kit + cells were intensively distributed in bladder layers from BC samples, while they were seldom detected in the control group. Ultrastructural examination of reprocessed tissue showed an intense distribution of TCs and telopodes in the submucosa and between smooth muscle cells in BC. Telopodes were numerous, arborizing, and intercommunicating. Whereas TCs and telopodes were scarce in the neurogenic bladder. Also, cancerous tissue had the highest expression level of ezrin protein, and this level gradually decreased as we moved away from the tumor. Our finding of TCs number in normal-appearing tissues in conjunction with ezrin expression may compete invasiveness and possibly a trail to reduce recurrence rates.

Ezrin gone rogue in cancer progression and metastasis: An enticing therapeutic target

Cancer metastasis is the primary cause of morbidity and mortality in cancer as it remains the most complicated, devastating, and enigmatic aspect of cancer. Several decades of extensive research have identified several key players closely associated with metastasis. Among these players, cytoskeletal linker Ezrin (the founding member of the ERM (Ezrin-Radixin-Moesin) family) was identified as a critical promoter of metastasis in pediatric cancers in the early 21st century. Ezrin was discovered 40 years ago as a aminor component of intestinal epithelial microvillus core protein, which is enriched in actin-containing cell surface structures. It controls gastric acid secretion and plays diverse physiological roles including maintaining cell polarity, regulating cell adhesion, cell motility and morphogenesis. Extensive research for more than two decades evinces that Ezrin is frequently dysregulated in several human cancers. Overexpression, altered subcellular localization and/or aberrant activation of Ezrin are closely associated with higher metastatic incidence and patient mortality, thereby justifying Ezrin as a valuable prognostic biomarker in cancer. Ezrin plays multifaceted role in multiple aspects of cancer, with its significant contribution in the complex metastatic cascade, through reorganizing the cytoskeleton and deregulating various cellular signaling pathways. Current preclinical studies using genetic and/or pharmacological approaches reveal that inactivation of Ezrin results in significant inhibition of Ezrin-mediated tumor growth and metastasis as well as increase in the sensitivity of cancer cells to various chemotherapeutic drugs. In this review, we discuss the recent advances illuminating the molecular mechanisms responsible for Ezrin dysregulation in cancer and its pleiotropic role in cancer progression and metastasis. We also highlight its potential as a prognostic biomarker and therapeutic target in various cancers. More importantly, we put forward some potential questions, which we strongly believe, will stimulate both basic and translational research to better understand Ezrin-mediated malignancy, ultimately leading to the development of Ezrin-targeted cancer therapy for the betterment of human life.

Ezrin interacts with the tumor suppressor CHL1 and promotes neuronal differentiation of human neuroblastoma

In a previous study, we demonstrated that CHL1, the neuronal cell adhesion molecule close homolog of L1, acts as a tumor suppressor in human neuroblastoma (NB), a still highly lethal childhood malignancy, influencing its differentiation and proliferation degree. Here we found that ezrin, one of the ERM (ezrin, radixin, moesin) proteins involved in cytoskeleton organization, strongly interacts with CHL1. The low expression of EZRIN, as well as the low expression of CHL1 and of the neuronal differentiation marker MAP2, correlates with poor outcome in NB patients. Knock-down of ezrin in HTLA-230 cell line induces neurite retraction, enhances cell proliferation and migration, and triggers anchorage-independent growth, with effects very similar to those already obtained by CHL1 silencing. Furthermore, lack of ezrin inhibits the expression of MAP2 and of the oncosuppressor molecule p53, whereas it enhances MAPK activation, all typical features of tumor aggressiveness. As already described, CHL1 overexpression in IMR-32 cell line provokes an opposite trend, but the co-silencing of ezrin reduces these effects, confirming the hypothesis that CHL1 acts in close connection with ezrin. Overall, our data show that ezrin reinforces the differentiating and oncosuppressive functions of CHL1, identifying this ERM protein as a new targetable molecule for NB therapy.

Ezrin Mediates Invasion and Metastasis in Tumorigenesis: A Review

Ezrin, as encoded by the EZR gene, is a member of the Ezrin/Radixin/Moesin (ERM) family. The ERM family includes three highly related actin filament binding proteins, Ezrin, Radixin, and Moesin. These three members share similar structural properties containing an N-terminal domain named FERM, a central helical linker region, and a C-terminal domain that mediates the interaction with F-actin. Ezrin protein is highly regulated through the conformational change between a closed, inactivate form and an open, active form. As a membrane-cytoskeleton linker protein, Ezrin facilitates numerous signal transductions in tumorigenesis and mediates diverse essential functions through interactions with a variety of growth factor receptors and adhesion molecules. Emerging evidence has demonstrated that Ezrin is an oncogene protein, as high levels of Ezrin are associated with metastatic behavior in various types of cancer. The diverse functions attributed to Ezrin and the understanding of how Ezrin drives the deadly process of metastasis are complex and often controversial. Here by reviewing recent findings across a wide spectrum of cancer types we will highlight the structures, protein interactions and oncogenic roles of Ezrin as well as the emerging therapeutic agents targeting Ezrin. This review provides a comprehensive framework to guide future studies of Ezrin and other ERM proteins in basic and clinical studies.

Lymphocyte antigen 6 superfamily member D is a marker of urothelial and squamous differentiation: implications for risk stratification of bladder cancer

Background

Screening across a multitude of normal and malignant tissues revealed an enhanced expression of lymphocyte antigen 6 superfamily member D (LY6D) in squamous epithelium and urothelium, as well as in malignancies derived therefrom. The aim of this study was to further delineate the protein expression of LY6D in urothelial bladder cancer, with particular attention to its relationship with clinicopathological characteristics and patient outcome.

Methods

Immunohistochemical expression of LY6D was assessed in tissue microarrays with urothelial bladder cancer tumours from three independent patient cohorts; one with transurethral resection of the bladder (TURB) specimens of mixed tumour stages from 110 consecutive cases, one with tumours of mixed stages from 260 incident cases in a population-based cohort, and one with paired TURB specimens, resected tumours and a subset of lymph node metastases from 145 patients with muscle-invasive bladder cancer (MIBC). Chi-square and non-parametric tests were applied to examine associations of LY6D expression with clinicopathological characteristics. Kaplan-Meier and Cox regression analyses were applied to examine 5-year overall survival (OS) and recurrence free survival (RFS) in relation to LY6D expression.

Results

In the two cohorts with mixed stages, positive LY6D expression was denoted in 63 and 64% of the cases, respectively, and found to be significantly higher in low-grade and less invasive tumours. Negative LY6D expression was significantly associated with a reduced 5-year OS, although not independently of established prognostic factors. In the population-based cohort, LY6D expression was higher in tumours with squamous differentiation and lower in other variant histologies compared to pure urothelial tumours, and the association of LY6D expression with survival was somewhat enhanced after exclusion of the former. LY6D expression was generally lower in the MIBC cohort, and even more reduced in resected tumours compared to TURB specimens in patients who had not received neoadjuvant chemotherapy. There were no significant associations between LY6D expression and RFS, neither allover nor in relation to neoadjuvant chemotherapy.

Conclusion

LY6D is a marker of urothelial and squamous differentiation that may add useful diagnostic and prognostic information to better guide the clinical management of bladder cancer, given that the presence of variant histology is taken into account.

Immunohistochemical negative expression of ezrin predicts poor prognosis in clear cell renal cell carcinoma

PURPOSE

To analyze the immunohistochemical expression of ezrin and moesin in clear cell renal cell carcinoma (ccRCC). These proteins, as part of the ezrin-radixin-moesin complex link the cell membrane to the actin cytoskeleton, affecting such processes as cell adhesion, cell survival, cell motility, and signal transduction. Our aim was to examine the impact of their expression on clinical outcomes and survival rates.

PATIENTS AND METHODS

Five hundred seventy-five consecutive patients who had been treated surgically for ccRCC in a single center between 1985 and 2016 were selected. A single pathologist reviewed all cases to perform a uniform reclassification and determined the most representative tumor areas for construction of a tissue microarray.

RESULTS

Of all ccRCC specimens, 106 (18.3%) were negative for ezrin, and 469 (81.7%) had positive ezrin expression; 16 (2.8%) were negative and 559 (97.2%) were positive for moesin, respectively. Ezrin expression was associated with pT stage (P < 0.001), clinical stage (P = 0.012), synchronic metastasis (P < 0.001), incidental tumors (P = 0.007), and International Society of Urological Pathology histological grade (P = 0.025). There was a correlation between moesin expression and clinical stage (P = 0.027), pT stage (P = 0.025), and pN stage (P = 0.007). Ezrin expression significantly influenced tumor-related deaths. By multivariate analysis, negative ezrin expression was an independent risk factor for disease-specific survival (HR 1.89; 95% CI 1.11-3.20).

CONCLUSIONS

Negativity for ezrin in ccRCC patients significantly impacts survival rates. We encourage further prospective studies to analyze ezrin analysis to evaluate its significance in the prognosis of ccRCC.

The clinical prognostic significance of ezrin in patients with bone and soft tissue sarcomas: a meta-analysis

Ezrin is a member of the ezrin–radixin–moesin (ERM) protein family and has been shown to be associated with poor prognosis in patients with a variety of solid tumors. However, the clinical prognostic significance of ezrin in patients with bone and soft tissue sarcomas remains unclear. Here, we performed a systematic meta‐analysis by searching PubMed, the Cochrane Library Database, EMBASE, the Web of Science, and the CBM, WanFang Med Online and CNKI databases. In total, 19 studies with a total of 1316 bone and soft tissue sarcoma patients were included. Pooled analyses showed that ezrin overexpression was correlated with a higher rate of tumor metastasis (OR 6.59, 95% CI: 2.84–15.33, P < 0.01, P_FDR < 0.01) and recurrence (OR 3.18, 95% CI: 1.88–5.37, P < 0.01, P_FDR < 0.01) and a more advanced tumor grade (OR 3.252, 95% CI: 1.371–7.715, P = 0.01, P_FDR = 0.03). Moreover, elevated ezrin expression could predict poor OS (HR 3.02, 95% CI: 2.35–3.89, P < 0.01, P_FDR < 0.01), MFS (HR 5.22, 95% CI: 2.08–13.08, P < 0.01, P_FDR < 0.01), and EFS (HR 1.07, 95% CI: 1.03–1.11, P < 0.01, P_FDR < 0.01). Subgroup analyses revealed the underlying sources of heterogeneity. Publication bias was observed in the analysis of metastasis. Sensitivity analysis revealed that the results were robust. Our findings indicated that ezrin overexpression was significantly correlated with poor survival and more advanced tumor progression in bone and soft tissue sarcomas, which suggests that ezrin might be a valuable prognostic biomarker and a potential therapeutic target.

Upregulation of miR-183-5p is responsible for the promotion of apoptosis and inhibition of the epithelial-mesenchymal transition, proliferation, invasion and migration of human endometrial cancer cells by downregulating Ezrin

Endometrial cancer is a life‑threatening malignancy that affects women all over the world, and it has an increasing incidence. MicroRNAs (miRNAs/miRs) have been reported to be involved in cellular activities in endometrial cancer. The present study aimed to examine the effects of miR‑183‑5p on the epithelial‑mesenchymal transition (EMT), proliferation, invasion, migration and apoptosis of human endometrial cancer cells by targeting Ezrin. Primary endometrial cancer tissues and adjacent normal tissues were obtained for the investigation. The protein expression of Ezrin in tissues was detected by immunohistochemistry. The expression level of miR‑183‑5p and the mRNA and protein expression levels of Ezrin and EMT‑associated genes were determined by reverse transcription‑quantitative polymerase chain reaction and western blot analyses. Endometrial cancer cells were treated with miR‑183‑5p inhibitors, small interfering RNA targeting Ezrin or miR‑183‑5p inhibitors. Cell proliferation, cell cycle, apoptosis, migration and invasion were then evaluated using an MTT assay, flow cytometry, scratch test and Transwell assay, respectively. Compared with normal adjacent tissues, the expression of miR‑183‑5p was decreased in endometrial cancer tissues, and the expression of Ezrin was significantly increased in endometrial cancer tissues. The protein expression of Ezrin was correlated with the severity and poor prognosis of endometrial cancer. Notably, the target prediction program and the luciferase reporter gene assay confirmed that miR‑183‑5p targeted and negatively regulated the expression of Ezrin. In vivo experiments revealed that the increased expression of miR‑183‑5p and decreased expression of Ezrin inhibited EMT, cell proliferation, migration and invasion, but promoted cell apoptosis in Ishikawa cells. These results suggested that the upregulated expression of miR‑183‑5p promoted apoptosis and suppressed the EMT, proliferation, invasion and migration of human endometrial cancer cells by downregulating Ezrin.

Ezrin as a possible diagnostic and/or prognostic biomarker in mice lymphatic metastatic hepatocellular carcinoma in vivo

Hepatocellular carcinoma (HCC) ranks in the top of cancers leading to death. Early diagnosis is the big challenge in the case of HCC. Our in vitro study showed that Ezrin expression in lymphatic metastasis hepatocellular carcinoma (LNM-HCC) was associated with the metastatic rate. Here we aim to evaluate Ezrin expression as diagnostic and/or prognostic biomarker of LNM-HCC in mice. Chinese inbred 615 mice, Hca-F and Hca-P cell lines were used in the study. Histological changes were determined by Hematoxylin and Eosin, while Ezrin expression was assessed by qRT-PCR, western blot, immunohistochemistry, and enzyme-linked immunosorbent assay. Ezrin expression in this study gives credit to our in vitro study which Ezrin expression was positively correlated with LNM-HCC and negatively with Annexin7 (A7) expression. The highest histological changes were observed in high metastatic primary/secondary tumors combined with high Ezrin expression. Ezrin and A7 are higher in total primary tumors than in total secondary tumors (P = 0.0001, P = 0.021), respectively. Ezrin expression was enhanced in Hca-P A7 down-regulated primary/secondary tumors (P = 0.004), whereas, Ezrin expression was suppressed in Hca-F A7 upregulated primary/secondary tumors. Serum ELISA indicated differential expression of Ezrin among the study groups (P ≤ 0.0001). Ezrin expression was higher in NC-Hca-F than NC-Hca-P (P ≤ 0.0001), suppressed in Hca-F A7 upregulation (P ≤ 0.0001) and in enhanced in Hca-P A7 down-regulation (P = 0.0001). In conclusion, Ezrin level may serve as a differential diagnostic and/or prognostic biomarker for high and low LNM-HCC and may be beneficial in the diagnosis of HCC disease. © 2017 BioFactors, 43(5):662-672, 2017.

Ezrin is Significantly Overexpressed in Luminal A, Luminal B, and HER2 Subtype Breast Cancer

Ezrin, a membrane-linking protein, has been shown to play an important role in the carcinogenesis of infiltrating breast ductal carcinoma and its strong expression has been used to predict poor prognosis in patients with breast carcinoma. In this study, we compared ezrin protein distribution pattern in benign breast disease and breast cancer molecular subtypes and evaluated their association with clinicopathologic variables. A total of 376 breast cases (142 benign and 234 malignant cases) were studied. Immunohistochemical analysis for ezrin was performed and its expression was observed in terms of its distribution, intensity, and proportion of cells reactive for ezrin. Ezrin was expressed in all benign cases and 91.7% of malignant cases. Apical staining was positively associated with benign breast disease, whereas membranous and cytoplasmic staining were more frequently observed in malignant cases, specifically of hormone receptor-positive subtypes (luminal A and luminal B). Ezrin was significantly overexpressed in luminal A, luminal B, and HER2 subtypes. Reduced ezrin expression was significantly associated with triple-negative breast cancer molecular subtype. No significant association was demonstrated between ezrin expression and Her2 gene amplification, tumor grading, or staging.

Intra-tumour IgA1 is common in cancer and is correlated with poor prognosis in bladder cancer

A high frequency of IgA1-positive tumour cells was found in tissue micro-arrays of oesophagus, colon, testis, lung, breast, bladder and ovarian cancer. IgA1 was observed in the cytoplasm and the plasma membrane. A correlation was found between intra-tumour IgA1 and poor overall survival in a large cohort of bladder cancer patients (n = 99, p = 0.011, log-rank test). The number of IgA1-positive tumour cells was also found to be higher in female than male bladder cancer patients. The presence of IgA1 was confirmed in formalin-fixed paraffin-embedded ovarian carcinoma samples using LC-MS/MS analysis. Uptake of IgA1 was also observed in breast cancer and melanoma cell lines when cultivated in the presence of serum from healthy individuals, indicating a possible origin of the IgA1 antibodies in cancer cells.

Proteomic characterization of peroxisome proliferator-activated receptor-γ (PPARγ) overexpressing or silenced colorectal cancer cells unveils a novel protein network associated with an aggressive phenotype

Peroxisome proliferator-activated receptor-γ (PPARγ) is a transcription factor of the nuclear hormone receptor superfamily implicated in a wide range of processes, including tumorigenesis. Its role in colorectal cancer (CRC) is still debated; most reports support that PPARγ reduced expression is associated with poor prognosis. We employed 2-Dimensional Differential InGel Electrophoresis (2-D DIGE) followed by Liquid Chromatography (LC)-tandem Mass Spectrometry (MS/MS) to identify differentially expressed proteins and the molecular pathways underlying PPARγ expression in CRC progression. We identified several differentially expressed proteins in HT29 and HCT116 CRC cells and derived clones either silenced or overexpressing PPARγ, respectively. In Ingenuity Pathway Analysis (IPA) they showed reciprocal relation with PPARγ and a strong relationship with networks linked to cell death, growth and survival. Interestingly, five of the identified proteins, ezrin (EZR), isoform C of prelamin-A/C (LMNA), alpha-enolase (ENOA), prohibitin (PHB) and RuvB-like 2 (RUVBL2) were shared by the two cell models with opposite expression levels, suggesting a possible regulation by PPARγ. mRNA and western blot analysis were undertaken to obtain a technical validation and confirm the expression trend observed by 2-D DIGE data. We associated EZR upregulation with increased cell surface localization in PPARγ-overexpressing cells by flow cytometry and immunofluorescence staining. We also correlated EZR and PPARγ expression in our series of CRC specimens and the expression profiling of all five proteins levels in the publicly available colon cancer genomic data from Oncomine and Cancer Genome Atlas (TCGA) colon adenocarcinoma (COAD) datasets. In summary, we identified a panel of proteins correlated with PPARγ expression that could be associated with CRC unveiling new pathways to be investigated for the selection of novel potential prognostic/predictive biomarkers and/or therapeutic targets.

Loss of ezrin in human intrahepatic cholangiocarcinoma is associated with ectopic expression of E-cadherin

AIMS

Ezrin connects proteins from the plasma membrane to the subcortical cytoskeleton, and contributes to epithelial integrity by interacting with the cell-cell adhesion molecule E-cadherin. In the liver, ezrin is restricted to cholangiocytes, where it regulates biliary secretory functions. During carcinogenesis, ezrin expression is impaired and associated with enhancement of cell migratory activity in cancer cells; therefore, we aimed to analyse ezrin in cholangiocarcinogenesis.

METHODS AND RESULTS

Ezrin expression was evaluated by immunohistochemistry on tissue microarrays from 94 surgical specimens of intrahepatic cholangiocarcinoma (CCA), and correlated with clinicopathological factors and E-cadherin expression. Ezrin function was also analysed in human CCA cell lines. In CCA, ezrin was negative/weakly expressed in 49 cases (52%) and moderately/strongly expressed in 45 cases (48%), mostly in cell cytoplasm. The negative/weak expression of ezrin was more frequent in peripheral than in perihilar CCA (P = 0.002), and was associated with high tumour size (P = 0.001), low mucus secretion (P = 0.042), the presence of satellite nodules (P = 0.024), and ectopic cytoplasmic expression of E-cadherin (P = 0.005). In vitro, silencing of ezrin in CCA cells caused internalization of E-cadherin and favoured cell migration.

CONCLUSIONS

Ezrin is down-regulated during cholangiocarcinogenesis, and its loss results in a more aggressive phenotype.

Prognostic Value of Ezrin in Various Cancers: A Systematic Review and Updated Meta-analysis

More and more studies have investigated the effects of Ezrin expression level on the prognostic role in various tumors. However, the results remain controversial rather than conclusive. Here, we performed a systematic review and meta-analysis to evaluate the correlation of Ezrin expression with the prognosis in various tumors. the pooled hazard ratios (HR) with the corresponding 95% confidence intervals (95% CI) were calculated to evaluate the degree of the association. The overall results of fifty-five studies with 6675 patients showed that elevated Ezrin expression was associated with a worse prognosis in patients with cancers, with the pooled HRs of 1.86 (95% CI: 1.51–2.31, P < 0.001) for over survival (OS), 2.55 (95% CI: 2.14–3.05, P < 0.001) for disease-specific survival (DFS) and 2.02 (95% CI: 1.13–3.63, P = 0.018) for disease-specific survival (DSS)/metastasis-free survival (MFS) by the random, fixed and random effect model respectively. Similar results were also observed in the stratified analyses by tumor types, ethnicity background and sample source. This meta-analysis suggests that Ezrin may be a potential prognostic marker in cancer patients. High Ezrin is associated with a poor prognosis in a variety of solid tumors.

Incident urothelial cancer in the Malmö Diet and Cancer Study: cohort characteristics and further validation of ezrin as a prognostic biomarker

BACKGROUND

Reduced membranous expression of the cytoskeleton-associated protein ezrin has previously been demonstrated to correlate with poor prognosis in urothelial bladder cancer in several independent studies. The present study provides a first description of clinicopathological characteristics of incident urothelial cancers, not only located to the bladder, in the prospective, population-based cohort study Malmö Diet and Cancer. In addition, the prognostic value of ezrin expression is validated in primary tumours, and the longitudinal expression of ezrin examined in a subset of primary and recurrent tumours (n=28).

METHODS

Among a total number of 355 incident tumours registered up until Dec 31 2010, 335 were located to the bladder. Immunohistochemical expression of cytoplasmic and membranous ezrin was evaluated in tissue microarrays with primary tumours from 272 cases and recurrent tumours from 28 cases. A combined score of the minimum, mean and maximum fraction and percentage of staining was calculated. Classification regression tree analysis was applied for selection of prognostic cutoff. Kaplan-Meier analysis, log rank test, univariable and multivariable Cox regression proportional hazards' modeling were used to evaluate the impact of ezrin expression on 5-year overall survival (OS).

RESULTS

Ezrin expression could be evaluated in 263/272 primary and all 28 recurrent tumours. Membranous but not cytoplasmic ezrin was significantly reduced in recurrent compared to primary tumours (p < 0.001). Low cytoplasmic and membranous ezrin expression were associated with more advanced T-stage (p = 0.004, p < 0.001) and high-grade tumours (p = 0.025, p < 0.001), but not with age, sex, tumour location or smoking status. Both low cytoplasmic and membranous ezrin staining were associated with a significantly reduced 5-year OS (HR = 1.65; 95% CI 1.06-2.57 and HR = 2.51, 95% CI 1.52-4.17), but only low membranous ezrin remained prognostic after adjustment for age, sex, stage, grade and smoking status (HR = 1.69, 95% CI 1.00-2.85).

CONCLUSIONS

This study provides a first description of the clinicopathological characteristics of 355 incident urothelial cancers in the Malmö Diet and Cancer Study up until 2010. In addition, the value of ezrin expression as a prognostic biomarker is further consolidated in this type of cancer.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_189.