Ezrin immunoreactivity in relation to survival in serous ovarian carcinoma patients

Ezrin silencing by small hairpin RNA reverses metastatic behaviors of human breast cancer cells

Ezrin primarily acts as a linker between the plasma membrane and the cytoskeleton and is a key component in tumor metastasis. In the present study, RNA interference (RNAi) using ezrin small hairpin RNAs (ezrin shRNAs) was used to define the roles of ezrin in the regulation of malignant behaviors of human breast cancer. The highly metastatic human breast cancer cell MDA-MB-231, in which ezrin mRNA and protein levels are the highest, was selected as a cell model in vitro. In addition, we also found that ezrin expression was up-regulated and its immuno-staining trans-located from cell membrane to cytoplasm, whereas E-cadherin expression decreased and showed the same cell distribution as ezrin in lymphatic metastases of human breast carcinomas. After repression of ezrin by more than 85% of G3PDH and 75% of beta-actin in mRNA and protein levels was maintained in the stable expressing ezrin shRNAs MDA-MB-231 cell clones, the abilities of cell motility and invasiveness were obviously inhibited with a 4-fold and 2-fold, respectively, and the altered cell polarity was observed. Western blot analyses further revealed that the silencing of ezrin induced an increased E-cadherin expression and a decreased phosphorylation of beta-catenin by inhibiting phosphorylation levels of c-src. These data indicate that ezrin overexpression positively correlated with metastatic potentials of human breast cancer cells, especially lymphatic system metastasis. Decreased ezrin expression by shRNA reversed metastatic behaviors of human breast cancer cells by inducing c-src-mediated E-cadherin expression, suggesting that ezrin may have potential values in assessing lymphatic metastasis of human breast cancers.

Adhesion molecules as prognostic markers in pancreatic adenocarcinoma

BACKGROUND AND OBJECTIVES

Pancreatic adenocarcinoma is a highly aggressive cancer with high metastatic potential and therefore, a high mortality rate. Ezrin, radixin, moesin, and E-cadherin are transmembrane glycoproteins that regulate cell motility, migration, and metastasis. In this study, we investigated the relationship of ezrin, moesin, and E-cadherin expression with the clinicopathological features of pancreatic ductal adenocarcinoma.

METHODS

Data including demographic features, size and grade of tumor, presence of perineural and lymphovascular invasion, and survival were obtained retrospectively from 46 patient records.

RESULTS

No significant correlation was found among ezrin, moesin, and E-cadherin. Significant correlations were found between ezrin and the tomographic size of the tumor (P = 0.034) and resectability (P = 0.052). Moesin-stained tumors were found to have high lymphovascular (P = 0.030) and perineural (P = 0.036) invasion rates and a high histopathologic grade (P = 0.053). E-cadherin staining was correlated with perineural invasion (P = 0.003) but not with lymphovascular invasion (P = 0.334). Only moesin was correlated with survival in resected pancreatic adenocarcinomas and moesin-negative patients had longer survivals compared with moesin-positive patients (P = 0.021).

CONCLUSIONS

We could not demonstrate a relation between ezrin and E-cadherin staining with survival. However, we found ezrin to be related to local tumor behavior, and moesin to be a potential prognostic molecule.

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

AIM: To investigate the correlation between ezrin expression and types of gastric carcinoma and clinico-pathological variables.

METHODS: We examined ezrin protein expression in 75 gastric carcinoma (53 intestinal types of adenocarcinoma, 22 diffuse types of carcinoma) tissues by immunohistochemistry. The results were compared with clinicopathological parameters such as tumor type, grade of tumor, clinical stage, presence of metastatic lymph node, and depth of invasion.

RESULTS: Ezrin immunostaining was positive in 43 cases (81.1%) of intestinal type and in 9 (40.9%) cases of diffuse type adenocarcinomas (P < 0.001). In gastric carcinomas, the expression of ezrin protein correlated with the status of H pylori and survival. There was no correlation between expression of ezrin with TNM stage and histological grade of gastric carcinomas (P > 0.05).

CONCLUSION: The low expression of ezrin implicates the loss of adhesion in diffuse carcinomas. Furthermore, overexpression of ezrin in carcinomas with H pylori infection may be a genuine specific pathway in which H pylori may cause/initiate gastric carcinoma.

High level of ezrin mRNA expression in an osteosarcoma biopsy sample with lung metastasis

Osteosarcoma (OS) remains a life-threatening malignancy and its molecular character is not fully understood. Ezrin is a cytoskeleton linker protein involved in regulating the growth and metastatic capacity of cancer cells. However, the correlation between ezrin mRNA expression and clinical severity has not yet been examined in OS biopsy samples. Furthermore, recent evidence has demonstrated that the level of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) expression is increased in human cancers of various origins, but this has not yet been examined in OS cells. To clarify the correlation between the clinical severity and the levels of ezrin and GAPDH mRNA expression, we quantified these mRNA levels in 4 pediatric OS biopsy samples using real-time quantitative polymerase chain reaction. Among these 4 samples, ezrin mRNA expression was approximately 5-fold higher in a case with lung metastasis compared with the other cases without metastasis, suggesting an association between the ezrin mRNA expression level and metastasis. On the other hand, the GAPDH mRNA expression level was not related to the clinical severity. This is the first report to demonstrate a high level of ezrin mRNA expression in an OS biopsy sample with lung metastasis.

Ezrin expression predicts survival in stage IIB osteosarcomas

Ezrin, a cytoskeleton linker protein, has been reported to be involved in the metastasis of solid tumors in animal models and patients in small clinical studies. We analyzed the relationship between immunohistochemical expression of ezrin and the prognosis of osteosarcoma. We retrospectively identified 64 patients with Stage IIB osteosarcomas between 1995 and 2000. Tissue microarrays were constructed from incisional biopsy specimens and immunohistochemical staining was performed. Ezrin expression and other clinicopathologic variables such as age, gender, pathologic subtype, tumor size and location, and histologic response were compared with outcomes. The minimum followup was 12 months (mean, 78.2 months; range, 12-137 months). Twenty-three of 64 patients (35.9%) showed late distant metastasis; 33 of 64 patients (51.6%) showed expression of ezrin, and of these 33 patients, 22 (66.7%) had distant metastasis develop. Multivariate analysis revealed histologic response to preoperative chemotherapy and expression of ezrin predicted disease-free survival. Expression of ezrin in osteosarcoma biopsy specimens is promising as a marker to predict outcome in patients with osteosarcoma.

[The up-regulation of vimentin and ezrin in the Epstein-Barr virus LMP1 gene transfected cells]

Epstein-Barr virus (EBV) is associated with the development of a variety of highly metastatic carcinomas, including nasopharyngeal carcinoma (NPC). EBV-encoded latent membrane protein 1 (LMP1) is essential for B-cell transformation. In this study, we used two-dimensional differential gel electrophoresis (2D-DIGE) and liquid chromatography-tandem mass spectrometry (LC/MS/MS) to study the mechanism behind tumor invasion and metastasis. Eight proteins, including Vimentin and Ezrin, were identified from the alteration of expressed proteins in HEK-293 cells responding to LMP1 gene transfection. Vimentin is a major protein of the mesenchymal intermediate filament, which maintains the cytoskeleton conformation. Ezrin is also an essential protein that links the cell membrane to the actin cytoskeleton. The up-regulation of Vimentin and Ezrin in the LMP1 gene-transfected cells suggests that EBV LMP1 is involved in the progression and metastasis of NPC.

Ezrin promotes ovarian carcinoma cell invasion and its retained expression predicts poor prognosis in ovarian carcinoma

The majority of patients diagnosed with ovarian carcinoma are classified as being in advanced stage of disease. In a situation of cancer spread throughout the abdominal cavity, a successful curative treatment is difficult to achieve. Therefore, preventing binding of tumor cells to the mesothelium is crucial for patients' outcome. One important mechanism is the interaction between hyaluronic acid and the CD44 receptor with its submembrane linking complex. This consists of ezrin, radixin, and moesin and connects the CD44 receptor with the cytoskeleton. To assess the role of ezrin and moesinfor ovarian carcinoma progression, we analyzed ovarian carcinoma samples from 105 patients for expression of ezrin and moesin by immunohistochemistry and correlated these data with several clinicopathological parameters. To elucidate the functional importance of ezrin and moesin, their expression was inhibited in SKOV-3 cells by RNA interference. Ezrin and moesin were strongly expressed in 49 and 48% of ovarian carcinoma samples, respectively, and their presence correlated with reduced overall survival in univariate analysis (ezrin, p=0.0189; moesin, p=0.0351). In multivariate analysis (including FIGO stage, residual tumor, histological type, and Silverberg grading), ezrin still remained significant as an independent risk factor (relative risk, 2.39; p=0.012). In SKOV-3 cells, siRNA against ezrin but not moesin inhibited in vitro invasion. These data imply that ezrin is necessary for tumor cell invasion, and the better prognosis of ovarian carcinomas lacking ezrin is probably related to their impaired invasion.

Value of ezrin, maspin and nm23-H1 protein expressions in predicting outcome of patients with head and neck squamous-cell carcinoma treated with radical radiotherapy

BACKGROUND

Prognostic factors in predicting outcomes in patients with head and neck squamous-cell carcinoma (HNSCC) are limited to the clinical-pathological parameters, including lymph node metastasis, location, grade and stage of the disease.

AIM

To determine whether the expression of these proteins has a value in predicting patient outcome.

METHODS

Ezrin, maspin and nm23-H1 immunohistochemistry in tissue samples of 120 patients with HNSCC were evaluated using the microarray technique.

RESULTS

In determining the association among each of the three proteins and the clinical-pathological parameters, low maspin expression was the only one found to be significantly associated with high tumour grade (p = 0.007); all others showed no significant associations. In univariate analysis, patients with tumours expressing high ezrin had a shorter disease-free survival (DFS) of 51% than those with low ezrin expression (DFS 84%; p = 0.08). In multivariate analysis, tumours with the combination of loss of maspin and low histological grade had longer DFS (83%) compared with those with high maspin and high histological grade (DFS 42%; p = 0.08).

CONCLUSION

Our study is the first to determine the value of ezrin and maspin in HNSCC in a large series of patients with long follow-up. Ezrin and maspin seem to have a potential prognostic value in patients with HNSCC but results should be confirmed with further studies.

Altered Expression of Ezrin in Esophageal Squamous Cell Carcinoma

Ezrin is a membrane-cytoskeletal linker belonging to the ezrin-radixin-moesin (ERM) family and has been suggested to be involved in tumorigenesis. In this study we investigated ezrin expression pattern in normal esophageal mucosa and esophageal squamous cell carcinoma (ESCC) and the correlation with clinical characteristics. Immunohistochemical staining showed a tendency for ezrin to translocate from membrane to cytoplasm in the progression from normal epithelium to invasive carcinoma of the esophagus. By Western blot, we found that ezrin expression was downregulated in 13 ESCC specimens and upregulated in 36 others. Moreover, quantitative real-time RT-PCR demonstrated that ezrin mRNA level in normal esophageal mucosa was 3.60 ± 3.60 times that in ESCC ( p<0.001). Proliferating cell nuclear antigen (PCNA) expression level was higher in ezrin downregulated group compared with that in ezrin upregulated group ( p<0.05). However, there was no significant association between ezrin expression and clinical characteristics. The results suggested that the localization of ezrin by immunohistochemistry may be useful in the diagnosis of ESCC, and ezrin may play a suppressive role in the tumorgenesis of ESCC.

Abnormal ezrin localization is associated with clinicopathological features in invasive breast carcinomas

The membrane-cytoskeleton crosslinker ezrin is associated with malignant progression and metastasis in human neoplasias. To study the role of ezrin in breast cancer, we first assessed ezrin expression in a panel of breast cancer cell lines by western blot and confocal microscopy. Western blot revealed no differences in total ezrin levels among these breast cell lines. However, immunofluorescence staining revealed that Estrogen receptor (ER)-positive, noninvasive and nontumorigenic cell lines concentrated ezrin at the apical surface, whereas invasive cell lines localized ezrin in motile structures (membrane ruffles and filopodia) but also had more diffuse cytoplasmic staining. We next studied ezrin expression in 509 breast carcinomas using tissue microarrays. Immunohistochemical staining for ezrin, p53, Ki-67, phospho-Akt, HER2, and hormonal receptors was performed. Ezrin staining in normal breast epithelium localized at the apical, but not lateral, cell surface, whereas, in most breast tumor cases (331, 70.3%), it localized in the cytoplasm. Complete membranous staining occurred in 89 (18.9%) samples, and apical staining was seen in 51 (10.8%) cases. There were significant positive associations between cytoplasmic ezrin localization and adverse tumor characteristics such as high grade, high level of Ki-67 expression, hormonal-receptor negativity, and lymph-node metastases. Apical ezrin staining was associated with favorable clinicopathological features and node-negative tumors. Membranous ezrin staining was associated with high grade, strong HER2 and p-Akt expression. In conclusion, the switch of ezrin localization from the apical membrane to either the complete membrane or to the cytoplasm is correlated with dedifferentiation and adverse features in invasive breast tumors and cancer cell lines.

Prognostic impact of immunohistochemical expression of ezrin in highly malignant soft tissue sarcomas

PURPOSE

Ezrin is a cytoskeleton linker protein that is actively involved in regulating the growth and metastatic capacity of cancer cells. It has recently been reported to be involved in dissemination of pediatric soft tissue sarcoma (STS).

EXPERIMENTAL DESIGN

To further evaluate the prognostic value of ezrin in STS progression, we screened 50 primary STSs of high malignancy grade using immunohistochemistry. At the initial surgery, all patients were without local or distant metastasis. The expression was then compared with the outcome during follow-up for at least 4 years or until the patients' death.

RESULTS

Twenty-five of the 50 STSs analyzed (50%) showed ezrin immunoreactivity in the membrane and cytoplasm of the tumor cells. A significant association was shown between positive expressions of ezrin and death in disease as well as overall survival (P = 0.014 and 0.007, respectively). Similarly, ezrin expression was significantly associated with development of distant metastasis during follow-up (P = 0.031), also excluding locally recurrent disease (P = 0.049). The relative abundance of metastasis in ezrin-positive cases was observed both over time and irrespective of time. In comparison with clinical, histopathologic, and genetic characteristics of the STSs, ezrin expression was found to correlate significantly with an infiltrative growth pattern outside the tumor capsule as well as with copy number gain of chromosomal region 9cen-q22.

CONCLUSION

Our findings suggest that ezrin immunoreactivity could be valuable as an additional prognostic marker in highly malignant STSs and support a causative role of ezrin in STS tumor dissemination.

Ezrin in primary cutaneous melanoma

Ezrin is a member of the ezrin-radixin-moesin family of proteins that link the actin-containing cytoskeleton to the plasma membrane. Ezrin is also connected to signaling molecules involved in the regulation of cell survival, proliferation and migration. Here, we examined the expression of ezrin in 95 primary cutaneous melanomas and correlated ezrin expression with conventional prognostic factors and biomarkers. From 12 patients metastatic tissue samples were also examined. In addition to ezrin staining, Mib-1 proliferation antigen, p53 and Bcl-2 were evaluated. Ezrin immunoreactivity was seen in most tumors; only 19 (20%) melanomas were negative. A total of 48 (51%) tumors had weak immunoreactivity and 28 (29%) strong immunoreactivity. The intensity of ezrin immunoreactivity was associated with tumor thickness (Breslow, P=0.0008) and with tumor invasion level (Clark, P=0.004), thicker tumors having stronger immunoreactivity. Also, there was a correlation between higher Mib-1 index in tumors and strong ezrin expression. All metastatic samples (n=12) showed positive ezrin immunoreactivity. In univariate analysis of survival, patients (n=76) with positive ezrin immunoreactivity had worse clinical disease behavior than those (n=19) without ezrin immunoreactivity, but the difference was not significant (P=0.19). In multivariate analysis of survival, the ezrin immunoreactivity was not a significant marker. The results indicate that ezrin is expressed in most primary melanomas of the skin and in all metastatic tumors. Ezrin expression correlates with tumor thickness and level of invasion suggesting an association between ezrin expression and tumor progression.