Roles of ezrin in the growth and invasiveness of esophageal squamous carcinoma cells

Abstract

Ezrin, which crosslinks the cytoskeleton and plasma membrane, is involved in the growth and metastatic potential of cancer cells. Ezrin expression in esophageal squamous cell carcinoma (ESCC) was described recently, but its roles and the underlying mechanism(s) remain unclear. In our study, we first showed that ezrin in ESCC cell is expressed in the nucleus as well as in the cytoplasm and plasma membrane. Then, by using RNAi, we revealed that interference of ezrin expression suppressed the growth, adhesion and invasiveness of ESCC cells. Tumorigenesis experiments revealed that ezrin may directly regulate tumor formation in vivo.To explore the molecular mechanisms through which ezrin contributes to the proliferation and invasiveness of ESCC cells, we used cDNA microarrays to analyze ezrin knockdown cells and the control cells; of 39,000 genes examined, 297 were differentially expressed upon ezrin knockdown, including some proliferationand invasiveness-related genes such as ATF3, CTGF and CYR61. Furthermore, pathway analysis showed that ezrin knockdown led to decreased activation of the TGF-b and MAPK pathways, and ezrin-mediated cell invasiveness alteration was dependent on the activation of these pathways. Finally, immunohistochemical staining on 80 ESCC specimens and 50 normal esophageal mucosae revealed that the expression levels of 3 altered genes involved in the regulation of cell proliferation and tumor metastasis, including CTGF, CYR61 and ATF3, were altered in ESCCs, and their expression pattern correlated with ezrin expression. Taken together, we propose that ezrin might function in the growth and invasiveness of ESCC cells through the MAPK and TGF-b pathways. ' 2008 Wiley-Liss, Inc.Key words: ezrin; esophageal squamous carcinoma; growth and invasiveness; RNAi and cDNA microarrays; TGF-b; and MAPK pathways Esophageal squamous cell carcinoma (ESCC) is one of the most fatal malignancies worldwide. One of the reasons for its poor prognosis is that ESCC exhibits extensive local invasion or regional lymph node metastasis even at initial diagnosis.1,2 Metastatic tumors are often refractory or only partially sensitive to current therapeutic strategies and are the primary cause of cancerrelated mortality.3 Therefore, a better understanding of tumor dissemination and growth is paramount, and identification of the genes that are crucial for metastatic dissemination is of great interest not only for a basic understanding of the molecular and cellular processes involved but also to provide potential new therapeutic targets.Certain genes, MTA1 and Fascin, 4-6 have been proven to be involved in ESCC invasion. Our study focuses on ezrin, which was initially isolated as a cytoskeletal component of intestinal microvilli and a substrate for tyrosine kinase.7 As a member of the ezrin-radixin-moesin (ERM) protein family, ezrin acts both as a linker between the actin cytoskeleton and plasma membrane proteins and as a signal transducer in responses involving cytoskeletal remodeling.7 Furthermore, ezrin is present in the nucl...

Expression of ezrin and moesin related to invasion, metastasis and prognosis of laryngeal squamous cell carcinoma

“…Ezrin is associated with malignant progression and metastasis in a variety of human malignancies (Chen et al, 2001;Weng et al, 2005;Sarrió et al, 2006;Deng et al, 2007;Mhawech-Fauceglia et al, 2007;Elzagheid et al, 2008;Xie et al, 2009;Morales et al, 2010;Wang et al, 2011). Ezrin shows high expression in epithelial cell resource tumors, such as esophageal squamous cell carcinoma (ESCC) (Xie et al, 2009), nasopharyngeal carcinoma (Wang et al, 2011), colorectal cancer (Elzagheid et al, 2008), and ovarian epithelial carcinoma (Mhawech-Fauceglia et al, 2007), which predicts poor prognosis in these tumors. Our results indicated that 75.0% (45/60) of LSCC and 84.8% (28/33) of metastatic lymph nodes showed increased expression of ezrin.…”

“…Ezrin is involved in L1 (cell-neural adhesion molecule-mediated activation of nuclear factor kappa B signaling, which is a major route of progression in colorectal cancer (Gavert et al, 2010). Ezrin may influence the growth and invasiveness of ESCC cells through the mitogen-activated protein kinase and transforming growth factor-b pathways or by affecting the expression of certain cell proliferation-or invasiveness-related genes, such as ATF3, CTGF, or CYR61 (Xie et al, 2009). In human gastric carcinoma SGC-7901 cells, ezrin, radixin, or moesin were knocked down by small interfering RNA, which reduced cell migration and invasion by upregulating expression of E-cadherin (Ou-Yang et al, 2011).…”

“…Moreover, they have important regulatory roles in maintaining cell morphology, differentiation, motility, and cell-cell and cell-matrix adhesion (Vaheri et al, 1997), which contribute to overcoming challenges for the metastasis of tumor cells. Several studies have suggested that ezrin and moesin are associated with tumor invasion and metastasis in several types of cancer, such as nasopharyngeal carcinoma (Wang et al, 2011), oral cancer (Kobayashi et al, 2004), esophageal squamous carcinoma (Xie et al, 2009), colon cancer (Elzagheid et al, 2008), soft tissue sarcoma (Weng et al, 2005), and glioblastoma (Morales et al, 2010).…”

Bioinformatics Analyses of m-RNA Profiling Following Ezrin Knockdown in Esophageal Squamous Cell Carcinoma

“…The knockdown of Ezrin expression by RNA interference leads to suppression of growth, adhesion and invasiveness of ESCC cells in vitro, and tumorigenicity in nude mice also reveals that Ezrin regulates tumor formation in vivo [10]. Furthermore, mRNA expression profiling was obtained using Affymetrix GeneChip Human genome U133 plus 2.0 and indicated that certain proliferation-and invasiveness-related genes are involved in Ezrin function [10].…”

“…Furthermore, mRNA expression profiling was obtained using Affymetrix GeneChip Human genome U133 plus 2.0 and indicated that certain proliferation-and invasiveness-related genes are involved in Ezrin function [10]. However, the biological meaning of this mRNA profile is not fully understood.…”