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

Podoplanin promotes the carcinogenicity of gastric cancer by activating ezrin and mediating the crosstalk between tumour cells and cancer-associated fibroblasts

NEW FINDINGS

What is the central question of this study? To reveal the role and biological mechanism of PDPN in the progression of gastric cancer. What is the main finding and its importance? This study focused on a prognostic predictor, PDPN, which acted as a promoter in the progression of gastric cancer through the activation of Ezrin expression and CAFs. This finding may expand a new route for the gene-targeted therapy in gastric cancer.

ABSTRACT

Gastric cancer (GC) is a frequent malignant disease and the main cause of cancer-related death in the world. Podoplanin (PDPN) has been proved to be involved in the progression of various cancers. However, the role and biological mechanism of PDPN in GC are still vague. In our study, we detected the expression of PDPN in GC tissues and cell lines using RT-qPCR, western blot and datasets. The overall survival of GC patients was analysed with a Kaplan-Meier plot. The effects of PDPN overexpression and silencing on GC cell progression were assessed by Cell Counting Kit-8, flow cytometry and a wound healing assay. Besides, the modulation of PDPN on ezrin activation was investigated. We further explored the role of PDPN in the crosstalk between GC cells and cancer associated fibroblasts (CAFs). Results showed that PDPN was upregulated in GC tissues and cell lines. High expression of PDPN was correlated with poor prognosis of GC patients. PDPN positively regulated the viability, migration and invasion, but inhibited apoptosis, of GC cells by mediating the activation of ezrin. Meanwhile, the change in PDPN in GC cells activated CAFs and promoted the production of cytokines secreted by CAFs, which induced the progression of GC cells. These findings may provide a novel target for GC 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.

Cytoskeletal Remodeling in Cancer

Simple Summary

Cell migration is an essential process from embryogenesis to cell death. This is tightly regulated by numerous proteins that help in proper functioning of the cell. In diseases like cancer, this process is deregulated and helps in the dissemination of tumor cells from the primary site to secondary sites initiating the process of metastasis. For metastasis to be efficient, cytoskeletal components like actin, myosin, and intermediate filaments and their associated proteins should co-ordinate in an orderly fashion leading to the formation of many cellular protrusions-like lamellipodia and filopodia and invadopodia. Knowledge of this process is the key to control metastasis of cancer cells that leads to death in 90% of the patients. The focus of this review is giving an overall understanding of these process, concentrating on the changes in protein association and regulation and how the tumor cells use it to their advantage. Since the expression of cytoskeletal proteins can be directly related to the degree of malignancy, knowledge about these proteins will provide powerful tools to improve both cancer prognosis and treatment.

Abstract

Successful metastasis depends on cell invasion, migration, host immune escape, extravasation, and angiogenesis. The process of cell invasion and migration relies on the dynamic changes taking place in the cytoskeletal components; actin, tubulin and intermediate filaments. This is possible due to the plasticity of the cytoskeleton and coordinated action of all the three, is crucial for the process of metastasis from the primary site. Changes in cellular architecture by internal clues will affect the cell functions leading to the formation of different protrusions like lamellipodia, filopodia, and invadopodia that help in cell migration eventually leading to metastasis, which is life threatening than the formation of neoplasms. Understanding the signaling mechanisms involved, will give a better insight of the changes during metastasis, which will eventually help targeting proteins for treatment resulting in reduced mortality and longer survival.

Tumor-associated antigens and their antibodies in the screening, diagnosis, and monitoring of esophageal cancers

Despite the advances in the treatment and management, esophageal cancers continue to carry a dismal prognosis with an overall 5-year survival rate ranging from 15 to 25%. Delayed onset of symptoms and lack of effective screening methods and guidelines for diagnosis of the early disease contribute to the high mortality rate of esophageal cancers. Detection of esophageal cancer at their early stage is really a challenge for physicians including primary care physicians, gastroenterologists and oncologists. Although imaging, endoscopy and biopsy have been proved to be useful diagnostic tools for esophageal cancers, their diagnostic accuracy is unsatisfactory. In addition, expensive costs, invasiveness and special training operator have limited the clinical application of these tools. Recently, tumor-associated antigens (TAAs) and their antibodies have been reported to be potential markers in esophageal cancer screening, diagnosis, monitoring and prognostication. Because TAAs and their antibodies have the advantages of inexpensive cost, noninvasiveness and easy access, they have attracted much attention as an affordable option for early esophageal cancer diagnosis. In this review, we summarized the advances in TAAs and their antibodies in esophageal cancer screening, diagnosis, monitoring and prognostication.

Biomarkers in Colorectal Cancer: The Role of Translational Proteomics Research

Colorectal cancer is one of the most common cancers in the world, and it is one of the leading causes of cancer-related death. Despite recent progress in the development of screening programs and in the management of patients with colorectal cancer, there are still many gaps to fill, ranging from the prevention and early diagnosis to the determination of prognosis factors and treatment of metastatic disease, to establish a personalized approach. The genetic profile approach has been increasingly used in the decision-making process, especially in the choice of targeted therapies and in the prediction of drug response, but there are still few validated biomarkers of colorectal cancer for clinical practice. The discovery of non-invasive, sensitive, and specific biomarkers is an urgent need, and translational proteomics play a key role in this process, as they enable better comprehension of colorectal carcinogenesis, identification of potential markers, and subsequent validation. This review provides an overview of recent advances in the search for colorectal cancer biomarkers through proteomics studies according to biomarker function and clinical application.

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.

Clinicopathological significance of heterogeneic ezrin expression in poorly differentiated clusters of colorectal cancers

Multicellular structures, such as tumor buddings and poorly differentiated clusters (PDC), exist at the invasive front of colorectal cancers (CRC). Although it has been reported that CRC with PDC showed frequent lymph node metastases with a worse prognosis, the molecular markers of PDC that are responsible for prognosis have not been identified. We here noticed for the first time that Ezrin, a regulator of the actin cytoskeleton, is expressed in the corner cells of PDC. We then aimed to verify whether heterogeneous Ezrin expression in PDC predicts the prognosis of CRC patients. We immunohistochemically analyzed Ezrin expression in PDC of 184 patients with completely resected stages I-III CRC. We established the Ezrin corner score (ECS), which quantifies the tendency of Ezrin-positive cells to accumulate at the corners of PDC. On the basis of ECS values, 2 indices, the mean ECS and the number of PDC with high ECS, were obtained. Both indices were significantly higher in CRC with lymphatic invasion, higher PDC grade, and presence of micropapillary (MP) PDC. The mean ECS-high group showed shorter recurrence-free survival than the mean ECS-low group but without significance. The other index, the number of ECS-high PDC, was significantly associated with recurrence-free survival. These results suggest that Ezrin is involved in PDC progression and lymphatic invasion, and that ECS may be a marker for aggressive PDC.

Proteomic profiling reveals key cancer progression modulators in shed microvesicles released from isogenic human primary and metastatic colorectal cancer cell lines

Extracellular vesicles comprise two main classes - exosomes and shed microvesicles (sMVs). Whilst much is known about exosome cargo content and functionality, sMVs are poorly understood. Here, we describe the large-scale purification of sMVs released from primary (SW480) and metastatic (SW620) human isogenic colorectal cancer (CRC) cell lines using a combination of differential ultracentrifugation and isopycnic iodixanol density centrifugation. The yield of SW480-sMVs and SW620-sMVs was 0.75 mg and 0.80 mg, respectively. Both SW480-/SW620-sMVs are heterogeneous in size (100-600 nm diameter) and exhibit identical buoyant densities (1.10 g/mL). In contrast to exosomes, sMVs are ALIX^-, TSG101^-, CD63^- and CD9^-. Quantitative mass spectrometry identified 1295 and 1300 proteins in SW480-sMVs and SW620-sMVs, respectively. Gene Ontology enrichment analysis identified 'cell adhesion' (CDH1, OCLN, CTN families), 'signalling pathway' (KRAS, NRAS, MAPK1, MAP2K1), and 'translation/RNA related' processes (EIF, RPL, HNRNP families) in both sMV types. Strikingly, SW480- and SW620-sMVs exhibit distinct protein signatures - SW480-sMVs being enriched in ITGA/B, ANXA1, CLDN7, CD44 and EGFR/NOTCH signalling networks, while SW620-sMVs are enriched in PRKCA, MACC1, FGFR4 and MTOR/MARCKS signalling networks. Both SW480- and SW620-sMVs are taken up by NIH3T3 fibroblasts resulting in similar cell invasion capability. This study provides, for the first time, molecular insights into sMVs and CRC biology.