Association of ezrin expression in intestinal and diffuse gastric carcinoma with clinicopathological parameters and tumor type

Transcriptomics analysis identified ezrin as a potential druggable target in cervical and gastric cancer cells

OBJECTIVE

Cancer genomics and transcriptomics studies have provided a large volume of data that enables to test of hypotheses based on real data from cancer patients. Ezrin (encoded by the EZR gene) is a highly expressed protein in cancer that contributes to linking the actin cytoskeleton to the cell membrane and signal transduction pathways involved in oncogenesis and disease progression. NSC305787 is a pharmacological ezrin inhibitor with potential antineoplastic effects. In the present study, the authors prospected EZR mRNA levels in a pan-cancer analysis and identified potential cancers that could benefit from anti-EZR therapies.

METHODS

This study analyzed TCGA data for 32 cancer types, emphasizing cervical squamous cell carcinoma and stomach adenocarcinoma. It investigated the impact of EZR transcript levels on clinical outcomes and identified differentially expressed genes. Cell lines were treated with NSC305787, and its effects were assessed through various cellular and molecular assays.

RESULTS

EZR mRNA levels are highly expressed, and their expression is associated with biologically relevant molecular processes in cervical squamous carcinoma and stomach adenocarcinoma. In cellular models of cervical and gastric cancer, NSC305787 reduces cell viability and clonal growth (p < 0.05). Molecular analyses indicate that the pharmacological inhibition of EZR induces molecular markers of cell death and DNA damage, in addition, to promoting the expression of genes associated with apoptosis and inhibiting the expression of genes related to survival and proliferation.

CONCLUSION

The present findings provide promising evidence that ezrin may be a molecular target in the treatment of cervical and gastric carcinoma.

Pathophysiological Roles of Actin-Binding Scaffold Protein, Ezrin

Ezrin is one of the members of the ezrin/radixin/moesin (ERM) family of proteins. It was originally discovered as an actin-binding protein in the microvilli structure about forty years ago. Since then, it has been revealed as a key protein with functions in a variety of fields including cell migration, survival, and signal transduction, as well as functioning as a structural component. Ezrin acts as a cross-linker of membrane proteins or phospholipids in the plasma membrane and the actin cytoskeleton. It also functions as a platform for signaling molecules at the cell surface. Moreover, ezrin is regarded as an important target protein in cancer diagnosis and therapy because it is a key protein involved in cancer progression and metastasis, and its high expression is linked to poor survival in many cancers. Small molecule inhibitors of ezrin have been developed and investigated as candidate molecules that suppress cancer metastasis. Here, we wish to comprehensively review the roles of ezrin from the pathophysiological points of view.

Association of Ezrin expression with the progression and prognosis of gastrointestinal cancer: a meta-analysis

Background

Ezrin, a cytoskeletal protein, is involved in cell adhesion. Several studies have been performed to explore the association between Ezrin and gastrointestinal cancers, but the results are inconclusive. This meta-analysis aims to assess the prognostic value of Ezrin.

Materials and Methods/Findings

PubMed and EMBASE were searched. Pooled hazard ratio (HR), odds ratio (OR) and 95% confidence intervals (CI) were utilized to evaluate the association between Ezrin expression and various clinical parameters. 2701 patients from 19 studies were included in the meta-analysis. For gastric cancer, Ezrin expression was associated with tumor grade (OR 2.32, 95% CI 1.53-3.52), TNM stage (OR 4.69, 95% CI 1.38-15.89), lymph node involvement (OR 3.96, 95% CI 1.47-10.70) and overall survival (HR 1.88, 95% CI 1.33-2.66). In colorectal cancer, Ezrin expression was associated with tumor grade (OR 3.94, 95% CI 2.10-3.78), TNM stage (OR 5.66, 95% CI 1.41-22.67), lymph node metastasis (OR 9.52, 95% CI 3.93-23.02), distant metastasis (OR 3.06, 95% CI 1.77-5.31), disease free survival (HR 2.48, 95% CI 1.44-4.28). For esophageal cancer, Ezrin expression was associated with lymph node metastasis (OR 2.07, 95% CI 1.00-4.28) and overall survival (HR 1.49, 95% CI 1.17-1.89).

Conclusions

Ezrin expression is significantly associated with tumor grade, TNM stage, and lymph node metastasis in gastric and colorectal cancers. For gastric cancers, Ezrin is useful in predicting distant metastasis. Survival data showed that high Ezrin expression is associated with poor prognosis in gastric, colorectal and esophageal cancers. Our findings suggest that Ezrin might be a potential biomarker in several gastrointestinal cancers.

The impact of immunohistochemical staining with ezrin-carbonic anhydrase IX and neuropilin-2 on prognosis in patients with metastatic renal cell cancer receiving tyrosine kinase inhibitors

The identification of prognostic factors in patients with renal cell carcinoma (RCC) represents an area of increasing interest. In this retrospective study, we evaluated the prognostic role of carbonic anhydrase-IX, ezrin, and neuropilin in metastatic RCC patients. The expression of several biomarkers were measured by immunohistochemistry (IHC) in 45 patients with advanced stage RCC treated with second-line tyrosine kinase inhibitors (TKIs) targeting vascular endothelial growth factor (VEGF) after failure of interferon-alpha between January 2007 and June 2012. Kaplan-Meier curves and log-rank tests were used for analysis of progression-free survival (PFS) and overall survival (OS), and a multivariate Cox proportional hazard model was employed to identify factors with an independent effect on the survival. Age, ezrin and neuropilin-2 overexpression were found to be statistically significant factors (P < 0.05) for PFS in the univariate analysis. Ezrin and neuropilin-2 overexpression, hemoglobin and albumin level were statistically significant factors (P < 0.05) for OS in the univariate analysis. Multivariate analysis revealed that low expression of ezrin and neuropilin-2 was an independent prognostic factor for PFS and OS. The median PFS was 4 months for patients overexpressing neuropilin-2 versus 11 months for those with lower expression of neuropilin-2 (p = 0.033). The median OS was longer in patients with low levels of neuropilin-2 expression (26 months) compared to patients overexpressing neuropilin-2 (13 months) (p = 0.023). Increased expression of ezrin was associated with poor prognosis in patients treated with TKIs targeting VEGF (PFS, 3 vs 7 months; p = 0.012). High ezrin expression was associated with shorter OS (p = 0.009). This is the first study in the literature showing that neuropilin-2 and ezrin are related with prognosis in patients with advanced RCC.

Ezrin expression and its phosphorylation in gastric carcinoma with lymphoid stroma and Epstein-Barr virus infection

Gastric carcinoma with lymphoid stroma (GCLS) is a unique variant of gastric carcinoma that represents prominent lymphocytic infiltration and is correlated with Epstein-Barr virus (EBV) infection. Ezrin expression and activation are crucial in tumor metastasis and induce cell migration of EBV-related nasopharyngeal carcinomas. Using immunohistochemical methods, the expression of total and phosphorylated ezrin (p-ezrin), Thr567, was examined in 104 GCLS cases, including 78 EBV-positive and 26 EBV-negative cases, as well as 29 non-GCLS cases. Positive ezrin expression was detected to be at markedly higher levels in GCLS compared to non-GCLS (P<0.0001). Furthermore, ezrin expression was detected to be at higher levels in EBV-positive compared to EBV-negative GCLS (P=0.0294). High expression of p-ezrin in GCLS was associated with positive lymph node metastasis (P=0.0187). In summary, these results demonstrated that ezrin overexpression is correlated with the histologic characteristics of GCLS and EBV infection. Phosphorylation of ezrin may, therefore, contribute to lymph node metastasis in GCLS.

Ezrin overexpression predicts the poor prognosis of gastric adenocarcinoma

Background

Ezrin is a cytoskeletal protein that is involved in tumor growth and invasion. It has been suggested that Ezrin expression plays an important role in tumor metastasis. This study is aimed to investigate the clinicopathological significance of Ezrin overexpression in gastric adenocarcinomas.

Methods

Ezrin protein expression was examined by immunohistochemistry in 26 normal gastric mucosa, 32 dysplasia, and 277 gastric adenocarcinomas. The relationship between Ezrin expression and the clinicopathological features of gastric cancers was analyzed. In addition, a gastric cancer cell line, MKN-1, was also used for immunofluorescence staining to evaluate the distribution of Ezrin protein.

Results

Ezrin protein located in the cytoplasm and/or membrane in the migrating gastric cancer cells, and it mainly concentrated at the protrusion site; however, only cytoplasmic distribution was observed in the non-migrating cancer cells by immunofluorescence staining. The positive rate of Ezrin protein expression was significantly higher in gastric adenocarcinoma and dysplasia compared with that in the normal gastric mucosa. Moreover, expression frequency of Ezrin protein increased significantly in lymph node metastasis and late clinical stages. Consistently, strong expression of Ezrin was significantly correlated with poor prognosis of gastric cancer.

Conclusion

The detection of Ezrin expression can be used as the marker for early diagnosis and prognosis of gastric adenocarcinoma.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2303598677653946

Decreased ezrin and paxillin expression in human urothelial bladder tumors correlate with tumor progression

OBJECTIVES

F-actin binding proteins ezrin and paxillin are involved in cell adhesion and cell migration/invasion. The aim of the study was to investigate their role in urothelial bladder carcinogenesis.

MATERIALS AND METHODS

Expression of ezrin and paxillin was studied by immunohistochemistry in 104 and 96 cases of urothelial bladder tumors, respectively. Correlations with clinicopathologic data and expression of p53, E-cadherin, and β-catenin were examined.

RESULTS

Positive ezrin and paxillin protein expression was found in 99% and 93.7% of cases, respectively. Membranous expression of ezrin was significantly lower in high grade tumors and correlated with invasion. Multivariate analysis showed that ezrin is an independent predictor of muscularis propria invasion. Paxillin expression was significantly decreased in urothelial carcinomas compared with tumors of low malignant potential and low paxillin levels also correlated with advancing tumor stage and invasion. A statistically significant correlation was found between membranous ezrin and E-cadherin as well as between ezrin and paxillin expression in urothelial tumors.

CONCLUSIONS

Down-regulation of ezrin and paxillin in urothelial bladder tumors is associated with aggressive tumor features and invasiveness.

Expression of ezrin in human embryonic, fetal, and normal adult tissues

Ezrin, which cross-links the cytoskeleton and plasma membrane, was involved in a wide variety of cellular processes. Here, to investigate the distribution of ezrin, tissue microarray technology was employed to perform immunohistochemical experiments on human embryos, fetuses at 4 to 22 weeks' gestation, and adult tissue specimens. Results showed that ezrin was widely expressed in the gastrointestinal tract throughout the human developmental stages studied. At 6 to 8 weeks' gestation, ezrin was found in epithelial cells, and this staining pattern was particularly pronounced in the brush border of mature absorptive cells lining the villus in later developmental stages and adult tissues. Throughout neural development, ezrin was only expressed in the neural tube at 4 weeks' gestation. Ezrin was also detected in the cortex and medulla of the adrenal gland at 8 to 12 weeks' gestation, whereas its immunoreactivity was increased from the zona glomerulosa through the zona reticularis and was essentially undetectable in the adrenal medulla of adult tissues. Significant expression of ezrin was seen throughout development in the kidney, spleen, lymph nodes, and cells of stratified squamous epithelia. However, ezrin was undetectable in lung, liver, heart, and blood vessels. These results demonstrated that the expression pattern of ezrin was highly time specific and tissue specific.

Ezrin is associated with gastric cancer progression and prognosis

To investigat the clinical significance of Ezrin in the development and progression of gastric cancer. Immunohistochemistry was employed to analyze Ezrin expression in 436 clinicopathologically characterized gastric cancer cases. Ezrin protein levels were up-regulated in gastric cancer lesions compared with adjacent noncancerous tissues. Positive expression of Ezrin correlated with age, size of tumor, location of tumor, depth of invasion, vessel invasion, lymph node and distant metastasis and TNM stage. In stages I, II and III, the 5 year survival rate of patients with a high expression of Ezrin was significantly lower than those in patients with low expression. In stage IV, Ezrin expression did not correlate with the 5 year survival rate. Further multivariate analysis suggested that the depth of invasion, lymph node and distant metastasis, TNM stage, and up-regulation of Ezrin were independent prognostic indicators for the disease. Expression of Ezrin in gastric cancer is significantly associated with lymph node and distant metastasis, and poor prognosis. Ezrin protein could be useful markers to predict tumor progression and prognosis.

Ezrin expression as a prognostic marker in colorectal adenocarcinoma

Ezrin protein acts in the regulation of cytoskeletal and directly influences survival and tumor progression; there is an increase in its expression in metastatic cells and tissues in several types of cancer including colorectal cancer. 250 Patients with colorectal cancer submitted to surgery from 1995 to 2002. Protein expression was carried through by Tissue Micro Array immunohistochemical tests of paraffined neoplasic tissues and associated with clinical variables. Differentiation degree, lymph node invasion, metastasis at diagnosis, and palliative surgery were associated to a higher expression of the protein and survival. Higher expression of the Ezrin correlates with tumor aggressiveness and worse prognosis for colorectal cancer.

Prognostic implications of ezrin expression in human hepatocellular carcinoma

Ezrin is known to regulate cellular survival, adhesion, migration, and invasion and has been identified as one of the key components of tumor progression and metastasis. The authors investigated ezrin expression in human hepatocellular carcinoma (HCC) and sought to determine its relation with clinicopathologic parameters, patients' outcome, and interacting molecular markers. Ezrin expression was assessed by immunohistochemical staining in 100 surgically resected HCCs using the tissue microarray method. A total of 28 HCCs showed high ezrin immunoreactivity, mainly in cytoplasm. Ezrin expression exhibited a positive correlation with c-Met expression (P = 0.001), but showed no correlation with the expression of CD44s or E-cadherin. HCCs expressing high level of ezrin were significantly associated with advanced TNM stage, poor Edmondson's histological grade, macroscopic portal vein invasion, tumor recurrence, and extrahepatic recurrence (P < 0.05). Univariate analysis showed that HCCs with high ezrin immunoreactivity were strongly associated with unfavorable overall and disease-free survivals than HCCs with low or negative for ezrin immunoreactivity (P = 0.0001 and 0.0011, respectively). Furthermore, multivariate analysis demonstrated that a high level of ezrin expression was independently associated with poor overall survival (hazard ratio, 1.905; P = 0.011). The results suggest that ezrin expression could be a potential predictive marker of progression, metastasis, and prognosis in HCC.

Establishment and characterization of 4 new human pancreatic cancer cell lines: evidences of different tumor phenotypes

OBJECTIVES

Pancreatic cancer still remains a challenge for its biological complexity and lack of effective therapeutic strategies. Establishing new pancreatic cancer cell lines is therefore of paramount importance to clarify its biology.

METHODS

We established and characterized 4 new pancreatic cancer cell lines (PP78, PP109, PP117, and PP161) according to their genetic (K-Ras, TP53, CDKN2A, and MADH4; DNA fingerprinting; karyotype), cytostructural (cytokeratins 7, 8, 18, and 19 vimentin, and ezrin), and functional profiles (doubling time; migration assay).

RESULTS

K-Ras, TP53, and CDKN2A gene alterations were detected in all 4 of them. Each cell line had a unique DNA profile revealed by DNA fingerprinting. A complex karyotype with numerous structural and numeric chromosomal abnormalities was present in each cell line. All 4 cell lines showed positivity for cytokeratins 7, 8, and 18. All but PP78 expressed cytokeratin 19, whereas vimentin was expressed only in PP117 and PP78 cells. A different ezrin cellular distribution was noticed in PP78 and PP117, being mostly located at membrane ruffles. This peculiar distribution was associated with the strongest migratory capability.

CONCLUSIONS

Our results seem to confirm the pancreatic ductal adenocarcinoma heterogeneity; in fact, the same genetic abnormalities (K-Ras, TP53, and CDKN2A) may have different effects on tumor biology depending on cellular differentiation.

Ezrin expression is associated with hepatocellular carcinoma possibly derived from progenitor cells and early recurrence after surgical resection

Heterogeneous biological characteristics of hepatocellular carcinoma may be attributed to the cellular origin of the tumor. Patients with hepatocellular carcinoma probably derived from hepatic progenitor cells had early tumor recurrence after surgical resection or liver transplantation, suggesting that these tumors have aggressive characteristics. Ezrin, a member of the ERM (ezrin-radixin-moesin) cytoskeleton-associated protein family, is highly expressed in several types of human cancers and correlations between its immunoreactivity and patient outcome have been shown. In this study, ezrin expression, as well as cytokeratin19 and cytokeratin 7 expression, which are regarded as progenitor cell/ductular markers were immunohistochemically assessed in cases of hepatocellular carcinoma. In normal livers, ezrin expression was not found in any cell types, whereas cytokeratin 7 and cytokeratin 19 were exclusively stained in bile duct cells. In contrast, in livers with chronic hepatitis or cirrhosis, positive ezrin expression was observed in ductular reactions with strong intensity and intermediate hepatobiliary cells with various intensity. Of 77 cases of hepatocellular carcinoma, 28 (36%) had positive ezrin expression, 32 (42%) had cytokeratin 7 expression, and 11 (14%) had cytokeratin 19 expression. Ezrin expression in hepatocellular carcinoma was significantly associated with cytokeratin 19 expression, but not with cytokeratin 7 expression. Patients with ezrin-positive hepatocellular carcinoma had a significantly higher prevalence of elevated serum alpha-fetoprotein. Patients with immunohistochemical ezrin-positive hepatocellular carcinoma demonstrated significantly shorter recurrence-free and overall survival compared to patients with ezrin-negative hepatocellular carcinoma. Multivariate analysis revealed positive ezrin expression and multiple tumors to be independently associated with early recurrence in patients with hepatocellular carcinoma after curative surgical resection. These results suggested that hepatocellular carcinoma with ezrin expression might be at least partly derived from hepatic progenitor cells. Measurement of ezrin expression might be used to identify patients with an increased risk of early recurrence.