Involvement of CYR61 and CTGF in the fascin-mediated proliferation and invasiveness of esophageal squamous cell carcinomas cells

KAT8/SIRT7-mediated Fascin-K41 acetylation/deacetylation regulates tumor metastasis in esophageal squamous cell carcinoma

Fascin actin-bundling protein 1 (Fascin) is highly expressed in a variety of cancers, including esophageal squamous cell carcinoma (ESCC), working as an important oncogenic protein and promoting the migration and invasion of cancer cells by bundling F-actin to facilitate the formation of filopodia and invadopodia. However, it is not clear how exactly the function of Fascin is regulated by acetylation in cancer cells. Here, in ESCC cells, the histone acetyltransferase KAT8 catalyzed Fascin lysine 41 (K41) acetylation, to inhibit Fascin-mediated F-actin bundling and the formation of filopodia and invadopodia. Furthermore, NAD-dependent protein deacetylase sirtuin (SIRT) 7-mediated deacetylation of Fascin-K41 enhances the formation of filopodia and invadopodia, which promotes the migration and invasion of ESCC cells. Clinically, the analysis of cancer and adjacent tissue samples from patients with ESCC showed that Fascin-K41 acetylation was lower in the cancer tissue of patients with lymph node metastasis than in that of patients without lymph node metastasis, and low levels of Fascin-K41 acetylation were associated with a poorer prognosis in patients with ESCC. Importantly, K41 acetylation significantly blocked NP-G2-044, one of the Fascin inhibitors currently being clinically evaluated, suggesting that NP-G2-044 may be more suitable for patients with low levels of Fascin-K41 acetylation, but not suitable for patients with high levels of Fascin-K41 acetylation. © 2024 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Serine/threonine-protein kinase D2-mediated phosphorylation of DSG2 threonine 730 promotes esophageal squamous cell carcinoma progression

Desmoglein-2 (DSG2) is a transmembrane glycoprotein belonging to the desmosomal cadherin family, which mediates cell-cell junctions; regulates cell proliferation, migration, and invasion; and promotes tumor development and metastasis. We previously showed serum DSG2 to be a potential biomarker for the diagnosis of esophageal squamous cell carcinoma (ESCC), although the significance and underlying molecular mechanisms were not identified. Here, we found that DSG2 was increased in ESCC tissues compared with adjacent tissues. In addition, we demonstrated that DSG2 promoted ESCC cell migration and invasion. Furthermore, using interactome analysis, we identified serine/threonine-protein kinase D2 (PRKD2) as a novel DSG2 kinase that mediates the phosphorylation of DSG2 at threonine 730 (T730). Functionally, DSG2 promoted ESCC cell migration and invasion dependent on DSG2-T730 phosphorylation. Mechanistically, DSG2 T730 phosphorylation activated EGFR, Src, AKT, and ERK signaling pathways. In addition, DSG2 and PRKD2 were positively correlated with each other, and the overall survival time of ESCC patients with high DSG2 and PRKD2 was shorter than that of patients with low DSG2 and PRKD2 levels. In summary, PRKD2 is a novel DSG2 kinase, and PRKD2-mediated DSG2 T730 phosphorylation promotes ESCC progression. These findings may facilitate the development of future therapeutic agents that target DSG2 and DSG2 phosphorylation. © 2024 The Pathological Society of Great Britain and Ireland.

Prenylated PALM2 Promotes the Migration of Esophageal Squamous Cell Carcinoma Cells Through Activating Ezrin

Proteins containing a CAAX motif at the C-terminus undergo prenylation for localization and activity and include a series of key regulatory proteins, such as RAS superfamily members, heterotrimeric G proteins, nuclear lamina protein, and several protein kinases and phosphatases. However, studies of prenylated proteins in esophageal cancer are limited. Here, through research on large-scale proteomic data of esophageal cancer in our laboratory, we found that paralemmin-2 (PALM2), a potential prenylated protein, was upregulated and associated with poor prognosis in patients. Low-throughput verification showed that the expression of PALM2 in esophageal cancer tissues was higher than that in their paired normal esophageal epithelial tissues, and it was generally expressed in the membrane and cytoplasm of esophageal cancer cells. PALM2 interacted with the two subunits of farnesyl transferase (FTase), FNTA and FNTB. Either the addition of an FTase inhibitor or mutation in the CAAX motif of PALM2 (PALM2C408S) impaired its membranous localization and reduced the membrane location of PALM2, indicating PALM2 was prenylated by FTase. Overexpression of PALM2 enhanced the migration of esophageal squamous cell carcinoma cells, whereas PALM2C408S lost this ability. Mechanistically, PALM2 interacted with the N-terminal FERM domain of ezrin of the ezrin/radixin/moesin (ERM) family. Mutagenesis indicated that lysine residues K253/K254/K262/K263 in ezrin's FERM domain and C408 in PALM2's CAAX motif were important for PALM2/ezrin interaction and ezrin activation. Knockout of ezrin prevented enhanced cancer cell migration by PALM2 overexpression. PALM2, depending on its prenylation, increased both ezrin membrane localization and phosphorylation of ezrin at Y146. In summary, prenylated PALM2 enhances the migration of cancer cells by activating ezrin.

Do not overwork: cellular communication network factor 3 for life in cartilage

Cellular communication network factor (CCN) 3, which is one of the founding members of the CCN family, displays diverse functions. However, this protein generally represses the proliferation of a variety of cells. Along with skeletal development, CCN3 is produced in cartilaginous anlagen, growth plate cartilage and epiphysial cartilage. Interestingly, CCN3 is drastically induced in the growth plates of mice lacking CCN2, which promotes endochondral ossification. Notably, chondrocytes in these mutant mice with elevated CCN3 production also suffer from impaired glycolysis and energy metabolism, suggesting a critical role of CCN3 in cartilage metabolism. Recently, CCN3 was found to be strongly induced by impaired glycolysis, and in our study, we located an enhancer that mediated CCN3 regulation via starvation. Subsequent investigations specified regulatory factor binding to the X-box 1 (RFX1) as a transcription factor mediating this CCN3 regulation. Impaired glycolysis is a serious problem, resulting in an energy shortage in cartilage without vasculature. CCN3 produced under such starved conditions restricts energy consumption by repressing cell proliferation, leading chondrocytes to quiescence and survival. This CCN3 regulatory system is indicated to play an important role in articular cartilage maintenance, as well as in skeletal development. Furthermore, CCN3 continues to regulate cartilage metabolism even during the aging process, probably utilizing this regulatory system. Altogether, CCN3 seems to prevent "overwork" by chondrocytes to ensure their sustainable life in cartilage by sensing energy metabolism. Similar roles are suspected to exist in relation to systemic metabolism, since CCN3 is found in the bloodstream.

The Role of Fascin-1 in Human Urologic Cancers: A Promising Biomarker or Therapeutic Target?

Human cancer statistics show that an increased incidence of urologic cancers such as bladder cancer, prostate cancer, and renal cell carcinoma. Due to the lack of early markers and effective therapeutic targets, their prognosis is poor. Fascin-1 is an actin-binding protein, which functions in the formation of cell protrusions by cross-linking with actin filaments. Studies have found that fascin-1 expression is elevated in most human cancers and is related to outcomes such as neoplasm metastasis, reduced survival, and increased aggressiveness. Fascin-1 has been considered as a potential therapeutic target for urologic cancers, but there is no comprehensive review to evaluate these studies. This review aimed to provide an enhanced literature review, outline, and summarize the mechanism of fascin-1 in urologic cancers and discuss the therapeutic potential of fascin-1 and the possibility of its use as a potential marker. We also focused on the correlation between the overexpression of fascin-1 and clinicopathological parameters. Mechanistically, fascin-1 is regulated by several regulators and signaling pathways (such as long noncoding RNA, microRNA, c-Jun N-terminal kinase, and extracellular regulated protein kinases). The overexpression of fascin-1 is related to clinicopathologic parameters such as pathological stage, bone or lymph node metastasis, and reduced disease-free survival. Several fascin-1 inhibitors (G2, NP-G2-044) have been evaluated in vitro and in preclinical models. The study proved the promising potential of fascin-1 as a newly developing biomarker and a potential therapeutic target that needs further investigation. The data also highlight the inadequacy of fascin-1 to serve as a novel biomarker for prostate cancer.

Molecular and Genetic Interactions between CCN2 and CCN3 behind Their Yin-Yang Collaboration

Cellular communication network factor (CCN) 2 and 3 are the members of the CCN family that conduct the harmonized development of a variety of tissues and organs under interaction with multiple biomolecules in the microenvironment. Despite their striking structural similarities, these two members show contrastive molecular functions as well as temporospatial emergence in living tissues. Typically, CCN2 promotes cell growth, whereas CCN3 restrains it. Where CCN2 is produced, CCN3 disappears. Nevertheless, these two proteins collaborate together to execute their mission in a yin–yang fashion. The apparent functional counteractions of CCN2 and CCN3 can be ascribed to their direct molecular interaction and interference over the cofactors that are shared by the two. Recent studies have revealed the mutual negative regulation systems between CCN2 and CCN3. Moreover, the simultaneous and bidirectional regulatory system of CCN2 and CCN3 is also being clarified. It is of particular note that these regulations were found to be closely associated with glycolysis, a fundamental procedure of energy metabolism. Here, the molecular interplay and metabolic gene regulation that enable the yin–yang collaboration of CCN2 and CCN3 typically found in cartilage development/regeneration and fibrosis are described.

AKT serine/threonine kinase 2-mediated phosphorylation of fascin threonine 403 regulates esophageal cancer progression

Fascin is the main actin-bundling protein in filopodia and is highly expressed in metastatic tumor cells. The overexpression of Fascin has been associated with poor clinical prognosis and metastatic progression. Post-translational modifications of Fascin, such as phosphorylation, can affect the proliferation and invasion of tumor cells by regulating the actin-bundling activity of Fascin. However, the phosphorylation sites of Fascin and their corresponding kinases require further exploration. In the current study, we identified novel phosphorylation of Fascin Threonine 403 (Fascin-T403) mediated by AKT serine/threonine kinase 2 (AKT2), which was studied using mass spectrometry data from esophageal cancer tissues (iProX database: IPX0002501000). A molecular dynamics simulation revealed that Fascin-Threonine 403 phosphorylation (Fascin-T403D) had a distinct spatial structure and correlation of amino acid residues, which was different from that of the wild type (Fascin-WT). Low-speed centrifugation assay results showed that Fascin-T403D affected actin cross-linking. To investigate whether Fascin-T403D affected the function of esophageal cancer cells, either Fascin-WT or Fascin-T403D were rescued in Fascin-knockout or siRNA cell lines. We observed that Fascin-T403D could suppress the biological behavior of esophageal cancer cells, including filopodia formation, cell proliferation, and migration. Co-immunoprecipitation (Co-IP) and Duolink in situ proximity ligation assay (PLA) were performed to measure the interaction between Fascin and AKT2. Using in vitro and in vivo kinase assays, we confirmed that AKT2, but not AKT1 or AKT3, is an upstream kinase of Fascin Threonine 403. Taken together, the AKT2-catalyzed phosphorylation of Fascin Threonine 403 suppressed esophageal cancer cell behavior, actin-bundling activity, and filopodia formation.

Transcriptome analysis reveals the potential biological function of FSCN1 in HeLa cervical cancer cells

Fascin actin-bundling protein 1 (FSCN1), an actin-bundling protein associated with cell migration and invasion, is highly expressed in various tumor tissues. FSCN1 has also been reported to be a marker of increased invasive potential in cervical cancers. However, the functions of FSCN1 are still not fully understood in cervical cancers. Here, the gene expression profile of HeLa cells transfected with FSCN1 shRNA (shFSCN1) was compared with that of cells transfected with empty vector (shCtrl). The results showed that shFSCN1 extensively affected the transcription level of 5,043 genes in HeLa cells. In particular, Gene Ontology (GO) analysis showed that a large number of upregulated genes were annotated with terms including transcription regulation and DNA binding. The downregulated genes were enriched in some cancer pathways, including angiogenesis and cell adhesion. qPCR validation confirmed that FSCN1 knockdown significantly affected the expression of selected genes in HeLa cells either negatively or positively. Expression analysis in TCGA (The Cancer Genome Atlas) revealed that FSCN1 had negative correlations with several transcription factors and a positive correlation with an angiogenic factor (angiopoietin like 4, ANGPTL4) in cervical tumor tissue. In particular, validation by Western blotting showed that FSCN1 knockdown decreased the protein level of ANGPTL4. Our results demonstrated that FSCN1 is not only an actin-binding protein but also a transcriptional regulator and an angiogenic factor in cervical cancer. Thus, our study provides important insights for further study on the regulatory mechanism of FSCN1 in cervical cancer.

WISP3 suppresses ESCC progression by inhibiting the IGF-2-IGF1R-AKT signaling cascade

Esophageal squamous cell carcinoma (ESCC) is a major health problem worldwide, especially in the Chinese population. However, the intrinsic molecular mechanisms of ESCC progression are largely unclear, thus there is an unmet need to identify essential genes governing this disease. Here, we discovered WISP3, an important member of the CCN family, is markedly downregulated in ESCC tissues compared to the normal esophageal epithelium. Downregulation of WISP3 in cancer tissue correlates with worse overall survival of ESCC patients. Using ESCC cell lines as models, we found that forced expression of WISP3 not only suppressed proliferation and migration of cancer cells in vitro, but also inhibited ESCC tumor growth and metastasis in vivo. On the contrary, WISP3 depletion strongly promoted the tumorigenicity of ESCC cells. Mechanistically, we found that WISP3 negates the activity of AKT via inhibiting the IGF-2-IGF1R signaling cascade, which mediates the tumor-suppressive function of WISP3 in esophageal cancers. Together, we identified a novel factor driving the development of ESCC, and revealed a potential therapeutic target for ESCC treatment.

New insights into the function of Fascin in actin bundling: A combined theoretical and experimental study

Fascin, one of actin bundling proteins, plays an important role in the cross-linking of actin filaments (F-actin). Phosphorylation of Fascin is an important posttranslational modification to affect its structure and function. For example, a phosphomimetic mutation of Fascin-S39D decrease its bundling ability with F-actin significantly. In this paper, we studied the actin-bundling activity of Fascin by using molecular dynamics (MD) simulations and biochemical methods. All single-site mutations from serine/threonine to aspartic acid were mimicked by MD simulations. For five mutants (S146D, S156D, S218D, T239D and S259D), the mutated residues in domain 2 of Fascin were found to form salt-bridge interactions with an adjacent residue, indicating that mutations of these residues could potentially reduce actin-bundling activity. Further, F-actin-bundling assays and immunofluorescence technique showed S146D and T239D to have a strong effect on Fascin bundling with F-actin. Finally, we show that single-site mutations do not change the general shape of Fascin, but local structures near the mutated residues in Fascin-S146D and T239D become unstable, thereby affecting the ability of Fascin to bind with F-actin. These findings suggest that targeting domain 2 of Fascin would be very useful for the drug design. In addition, our study indicates that MD simulation is a useful method to screening which residues on Fascin are important.

Fascin as a useful marker for cancer-associated fibroblasts in invasive lung adenocarcinoma

Cancer-associated fibroblasts (CAFs) have been attracting attention in recent years, but their nature has not been fully elucidated. Although CAFs have been recognized as an important therapeutic target, therapeutic agents have not been developed to date. CAFs are characterized by their high migration rate and involvement in epithelial-to-mesenchymal transition with some displaying a dendritic morphology that is reminiscent of fascin expression.The present study was designed to immunohistochemically investigate fascin expression in lung adenocarcinoma including CAFs and compare the results with existing CAF markers.We immunohistochemically investigated fascin expression in not only cancer tissue but also CAFs from 26 autopsy cases of lung adenocarcinoma. Immunohistochemistry of α-smooth muscle actin and fibroblast activation protein was also performed.Fascin-positive staining in CAFs was observed in all cases, with a strong correlation observed with existing CAF markers α-smooth muscle actin and fibroblast activation protein (P < .001). In addition, the proportion of tumor cells showing fascin-positive staining was found to correlate with its expression in CAFs (P < .05).We propose that CAFs express fascin, and that fascin may mediate crosstalk between cancer tissue and CAFs. Fascin might be a novel therapeutic target for treatments that target the cancer stroma.

Emerging Role of Fascin-1 in the Pathogenesis, Diagnosis, and Treatment of the Gastrointestinal Cancers

Simple Summary

Gastrointestinal (GI) cancers, including esophageal, gastric, colorectal, liver, and pancreatic cancers, remain as one of the leading causes of death worldwide, with a large proportion accounting for fatalities related to metastatic disease. The active involvement of fascin-1 in forming membrane protrusions crucial for cellular movement has been identified as an important molecular mechanism behind the phenotypic switch from the localized to the metastatic tumor. Thus, fascin-1 expression status in the malignant tissue has been utilized as an important component in determining the patient’s clinicopathological outcomes. In this review, we provide an up-to-date literature review of the role of fascin-1 in the initiation and metastatic progression of GI tract cancers, its involvement in patients’ clinical outcomes, and its potential as a therapeutic target.

Abstract

Gastrointestinal (GI) cancers, including esophageal, gastric, colorectal, liver, and pancreatic cancers, remain as one of the leading causes of death worldwide, with a large proportion accounting for fatalities related to metastatic disease. Invasion of primary cancer occurs by the actin cytoskeleton remodeling, including the formation of the filopodia, stereocilia, and other finger-like membrane protrusions. The crucial step of actin remodeling in the malignant cells is mediated by the fascin protein family, with fascin-1 being the most active. Fascin-1 is an actin-binding protein that cross-links filamentous actin into tightly packed parallel bundles, giving rise to finger-like cell protrusions, thus equipping the cell with the machinery necessary for adhesion, motility, and invasion. Thus, fascin-1 has been noted to be a key component for determining patient diagnosis and treatment plan. Indeed, the overexpression of fascin-1 in GI tract cancers has been associated with a poor clinical prognosis and metastatic progression. Moreover, fascin-1 has received attention as a potential therapeutic target for metastatic GI tract cancers. In this review, we provide an up-to-date literature review of the role of fascin-1 in the initiation of GI tract cancers, metastatic progression, and patients’ clinical outcomes.

Fascin actin-bundling protein 1 in human cancer: promising biomarker or therapeutic target?

Fascin actin-bundling protein 1 (FSCN1) is a highly conserved actin-bundling protein that cross links F-actin microfilaments into tight, parallel bundles. Elevated FSCN1 levels have been reported in many types of human cancers and have been correlated with aggressive clinical progression, poor prognosis, and survival outcomes. The overexpression of FSCN1 in cancer cells has been associated with tumor growth, migration, invasion, and metastasis. Currently, FSCN1 is recognized as a candidate biomarker for multiple cancer types and as a potential therapeutic target. The aim of this study was to provide a brief overview of the FSCN1 gene and protein structure and elucidate on its actin-bundling activity and physiological functions. The main focus was on the role of FSCN1 and its upregulatory mechanisms and significance in cancer cells. Up-to-date studies on FSCN1 as a novel biomarker and therapeutic target for human cancers are reviewed. It is shown that FSCN1 is an unusual biomarker and a potential therapeutic target for cancer.

Systematic Proteome and Lysine Succinylome Analysis Reveals Enhanced Cell Migration by Hyposuccinylation in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is an aggressive malignancy with poor therapeutic outcomes. However, the alterations in proteins and posttranslational modifications (PTMs) leading to the pathogenesis of ESCC remain unclear. Here, we provide the comprehensive characterization of the proteome, phosphorylome, lysine acetylome, and succinylome for ESCC and matched control cells using quantitative proteomic approach. We identify abnormal protein and PTM pathways, including significantly downregulated lysine succinylation sites in cancer cells. Focusing on hyposuccinylation, we reveal that this altered PTM was enriched on enzymes of metabolic pathways inextricably linked with cancer metabolism. Importantly, ESCC malignant behaviors such as cell migration are inhibited once the level of succinylation was restored in vitro or in vivo. This effect was further verified by mutations to disrupt succinylation sites in candidate proteins. Meanwhile, we found that succinylation has a negative regulatory effect on histone methylation to promote cancer migration. Finally, hyposuccinylation is confirmed in primary ESCC specimens. Our findings together demonstrate that lysine succinylation may alter ESCC metabolism and migration, providing new insights into the functional significance of PTM in cancer biology.

Prognostic significance of FSCN family in multiple myeloma

Multiple myeloma (MM) is a hematologic tumor with monoclonal proliferation of malignant plasma cells in the bone marrow. Fascin (FSCN) is an actin-binding protein that plays a crucial role in cell migration and invasion, contributing to tumor metastasis. There are three members (FSCN1-3) in FSCN family. However, the prognostic role of FSCN family in MM remains unclear. In this study, we used four independent Gene Expression Omnibus (GEO) datasets to explore the relationships between FSCN1-3 expression profiles and patient survival in MM. We found that FSCN1 was dramatically down-regulated in MM compared to normal donors (p < 0.001) and monoclonal gammopathy of undetermined significance (MGUS) (p = 0.032). Patients with high expression of FSCN1 and FSCN2 had significantly longer OS (p = 0.023 and 0.028, respectively). Univariate and multivariate analysis showed that FSCN1 (p = 0.003, 0.002) and FSCN2 (p = 0.018, 0.013) were independent favorable prognostic factors for OS in MM. Moreover, the combination of high expression of FSCN1 and FSCN2 could effectively predict both longer EFS (p = 0.046) and OS (p = 0.015). Our study suggested that FSCN1 and FSCN2 can be used as favorable biomarkers for predicting clinical outcomes in MM.

Lysyl oxidase-like 2 promotes esophageal squamous cell carcinoma cell migration independent of catalytic activity

Lysyl oxidase-like 2 (LOXL2) is a member of the lysyl oxidase (LOX) family that contributes to tumor cell metastasis. Our previous data identified two splice variants of LOXL2 (i.e., LOXL2 Δ72 and Δ13) in esophageal squamous cell carcinoma (ESCC) cells that increased cell invasiveness and migration but had lower LOX activities than wild-type LOXL2 (LOXL2 WT). We generated a series of LOXL2 deletion mutants with different deleted biochemical domains and examined the relationship between the cell migration abilities and catalytic activities, as well as subcellular locations, of these deletion mutants compared with LOXL2 WT in ESCC cells to explore the mechanism of LOXL2-driven ESCC cell migration. Our results indicated that the deletion mutants of LOXL2 had impaired deamination enzymatic activity; LOXL2 ΔSRCR4, which lacks the fourth scavenger receptor cysteine-rich (SRCR) domain, had lower enzymatic activity; and LOXL2 Y689F had no catalytic activity compared with LOXL2 WT. However these two mutants stimulated greater cellular migration than LOXL2 WT. Furthermore, the degree of cell migration promoted by LOXL2 ΔLO (in which the LOX-like domain was deleted) was higher than that of LOXL2 WT, and LOXL2 ΔSRCR3, which does not have the third SRCR domain, had lower LOX activity and cellular migration ability than LOXL2 WT. These results suggested that LOXL2 promotes ESCC cell migration independent of catalytic activity.

SREBP2 is upregulated in esophageal squamous cell carcinoma and co‑operates with c‑Myc to regulate HMGCR expression

Dysregulations of the mevalonate pathway (MVA) have been previously identified. Our previous study demonstrated that 3‑hydroxy‑3‑methylglutaryl‑coenzyme A reductase (HMGCR), the rate‑limiting enzyme of the MVA pathway, was upregulated in esophageal squamous cell carcinoma (ESCC) and statin‑inhibited ESCC tumorigenesis. However, the underlying mechanism of HMGCR regulation in ESCC remains unknown. In the present study, western blotting and immunohistochemistry analysis demonstrated that sterol regulatory element‑binding protein 2 (SREBP2), the master regulator for HMGCR, was upregulated in ESCC clinical samples. Overexpression of SREBP2 expression in ESCC cell lines promoted the growth, migration and colony formation of cancer cells in the MTT, Boyden chamber and soft agar assays, respectively, which was inhibited by lovastatin. Downregulation of SREBP2 expression in ESCC cell lines inhibited the viability, and migration and colony formation abilities of cancer cells. Assessment of the molecular mechanism demonstrated that SREBP2 interacted with c‑Myc and cooperated with c‑Myc to activate HMGCR expression. Collectively, the present study identified SREBP2 as an oncogene associated with the tumorigenesis of ESCC and further demonstrated the therapeutic effects of statins in ESCC.

Heat shock protein family B member 1 facilitates ezrin activation to control cell migration in esophageal squamous cell carcinoma

Ezrin plays an important role in the development and progression of human esophageal squamous cell carcinoma (ESCC), providing a link between the cortical actin cytoskeleton and the plasma membrane to govern membrane structure and protrusions. However, the mechanism by which ezrin is activated still remains unknown in ESCC. Here, we identify a novel interaction between ezrin and heat shock protein family B (small) member 1 (HSPB1) in ESCC cells by mass spectroscopy and co-immunoprecipitation. HSPB1 only interacts with inactive ezrin and binds to the α-helical coiled coil region of ezrin. Knockdown of HSPB1 resulted to the decline of phosphorylation at ezrin Thr567, markedly suppressing the ability of ezrin to bind to the actin cytoskeleton and migration of ESCC cells. Furthermore, neither the constitutively active phosphomimetic ezrin T567D, nor inactivated ezrin T567A could restore cell migration following HSPB1 knockdown. Low HSPB1 expression was associated with favorable overall survival of ESCC patients. Taken together, HSPB1, as an important partner, participates in the activation of ezrin and merits further evaluation as a novel therapeutic target against human ESCC.

The Role of TGF-β and Its Receptors in Gastrointestinal Cancers

Early detection of gastrointestinal tumors improves patient survival. However, patients with these tumors are typically diagnosed at an advanced stage and have poor prognosis. The incidence and mortality of gastrointestinal cancers, including esophageal, gastric, liver, colorectal, and pancreatic cancers, are increasing worldwide. Novel diagnostic and therapeutic agents are required to improve patient survival and quality of life. The tumor microenvironment, which contains nontumor cells, signaling molecules such as growth factors and cytokines, and extracellular matrix proteins, plays a critical role in cancer cell proliferation, invasion, and metastasis. Transforming growth factor beta (TGF-β) signaling has dual roles in gastrointestinal tumor development and progression as both a tumor suppressor and tumor promoter. Here, we review the dynamic roles of TGF-β and its receptors in gastrointestinal tumors and provide evidence that targeting TGF-β signaling may be an effective therapeutic strategy.

F806 Suppresses the Invasion and Metastasis of Esophageal Squamous Cell Carcinoma via Downregulating F-Actin Assembly-Related Rho Family Proteins

Invasion and metastasis are critical pathological and mortal processes in esophageal squamous cell carcinoma (ESCC). Novel drugs, targeting the two cancer migration stages, will augment the treatment options for ESCC therapy and improve overall survival. A novel natural macrolide F806 specifically promotes apoptosis of various ESCC cells. However, whether F806 can inhibit metastasis of ESCC cells needs further evaluation. Here, our data showed that F806 inhibits dynamic F-actin assembly and then suppresses the migration of ESCC cells in vitro and their invasion and metastasis in vivo. The correlation between cancer migration and actin cytoskeleton assembly was consistent with the ability of F806 to prevent the aggregation of Paxillin, an essential protein for focal adhesion formation through binding to the ends of actin filaments. Furthermore, F806 downregulated the expression and activity of the Rho family proteins cell division cycle 42 (CDC42), RAC family small GTPase 1 (RAC1), and RAS homolog family member A (RHOA). Taken together, these results suggest that F806 can suppress cancer invasion and metastasis via interrupting the assembly of migration components involving F-actin.

Ezrin Ser66 phosphorylation regulates invasion and metastasis of esophageal squamous cell carcinoma cells by mediating filopodia formation

BACKGROUND

Ezrin, links the plasma membrane to the actin cytoskeleton, and plays an important role in the development and progression of human esophageal squamous cell carcinoma (ESCC). However, the roles of ezrin S66 phosphorylation in tumorigenesis of ESCC remain unclear.

METHODS

Distribution of ezrin in membrane and cytosol fractions was examined by analysis of detergent-soluble/-insoluble fractions and cytosol/membrane fractionation. Both immunofluorescence and live imaging were used to explore the role of ezrin S66 phosphorylation in the behavior of ezrin and actin in cell filopodia. Cell proliferation, migration and invasion of ESCC cells were investigated by proliferation and migration assays, respectively. Tumorigenesis, local invasion and metastasis were assessed in a nude mouse model of regional lymph node metastasis.

RESULTS

Ezrin S66 phosphorylation enhanced the recruitment of ezrin to the membrane in ESCC cells. Additionally, non-phosphorylatable ezrin (S66A) significantly prevented filopodia formation, as well as caused a reduction in the number, length and lifetime of filopodia. Moreover, functional experiments revealed that expression of non-phosphorylatable ezrin (S66A) markedly suppressed migration and invasion but not proliferation of ESCC cells in vitro, and attenuated local invasion and regional lymph node metastasis, but not primary tumor growth of ESCC cells in vivo.

CONCLUSION

Ezrin S66 phosphorylation enhances filopodia formation, contributing to the regulation of invasion and metastasis of esophageal squamous cell carcinoma cells.

Effects of TAZ on human dental pulp stem cell proliferation and migration

Transcriptional coactivator with PDZ‑binding motif (TAZ) acts as the key downstream regulatory target in the Hippo signaling pathway. TAZ overexpression has been reported to promote cellular proliferation and induce epithelial‑mesenchymal transition in human mammary epithelial cells. However, the effects of TAZ in the regulation of human dental pulp stem cell (hDPSC) proliferation and migration, as well as the molecular mechanisms underlying its actions, remain to be elucidated. The present study demonstrated that TAZ was expressed in hDPSCs. TAZ silencing, following hDPSC transfection with TAZ‑specific small interfering (si)RNA (siTAZ), inhibited cellular proliferation and migration in vitro. These effects appeared to be associated with the downregulation of connecting tissue growth factor (CTGF) and cysteine‑rich angiogenic inducer (Cyr) 61 expression. Further investigation of the mechanisms underlying the actions of TAZ in hDPSCs revealed that TAZ silencing suppressed CTGF and Cyr61 expression by interfering with transforming growth factor (TGF)‑β signaling pathways. The present results suggested that TAZ may be implicated in the proliferation and migration of hDPSCs, through the modulation of CTGF and Cyr61 expression via a TGF‑β‑dependent signaling pathway.

Fascin phosphorylation sites combine to regulate esophageal squamous cancer cell behavior

Filopodia are dynamic membrane extensions generated by F-actin bundling and are involved in cancer cell migration, invasion and metastasis. Fascin is the crucial actin-bundling protein in filopodia, with phosphorylation at fascin serine 39 being well characterized to regulate fascin-mediated actin bundling in filopodia. However, increasing evidence indicates that fascin is phosphorylated at a number of sites. Whether phosphorylation at other sites also regulates fascin function is unknown. In this study, we show that four potential phosphorylation sites in fascin, specifically tyrosine 23, serine 38, serine 39 and serine 274, regulate cell behavior and filopodia formation in esophageal squamous cancer cells. Expression of non-phosphorylatable mutations at each of the four sites promoted anchorage-independent growth, cell motility and filopodia formation, whereas phosphomimetic mutations at each of these sites inhibited these cell behaviors, implying that fascin function in esophageal squamous cancer is regulated by fascin phosphorylation at multiple sites. Furthermore, phosphorylation at S38 and S39 cooperatively regulated cell behavior and filopodia formation, with dual dephosphorylation at both S38 and S39 residues maximally enhancing cell proliferation, migration and filopodia formation, and phosphorylation at any of the two phosphorylatable sites resulting in reduced enhancement. Taken together, our results reveal that phosphorylation at fascin amino acids Y23, S38, S39 and S274, in combination, downregulates the extent of anchorage-independent growth, cell migration and filopodia formation in esophageal squamous cancer cells.

MicroRNA-145 Inhibits Cell Migration and Invasion and Regulates Epithelial-Mesenchymal Transition (EMT) by Targeting Connective Tissue Growth Factor (CTGF) in Esophageal Squamous Cell Carcinoma

Background

This study investigated the mechanism of miR-145 in targeting connective tissue growth factor (CTGF), which affects the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of ESCC cells.

Material/Methods

A total of 50 ESCC tissues and their corresponding normal adjacent esophageal tissue samples were collected. Then, miR-145 expression in both ESCC clinical specimens and cell lines was detected using quantitative real-time PCR. CTGF protein was detected using immunohistochemistry. Dual luciferase reporter gene assay was employed to assess the effect of miR-145 on the 3′UTR luciferase activity of CTGF. Eca109 cells were transfected with miR-145 mimics and CTGF siRNA, respectively, and changes in cellular proliferation, migration, and invasion were detected via MTT assay, wound-healing assay, and Transwell assay, respectively. Western blotting assay was used to detect the expression of marker genes related to EMT.

Results

MiR-145 was significantly down-regulated in ESCC tissues and cell lines compared with normal tissues and cell lines (P<0.05). We found significantly more positively expressed CTGF protein in ESCC tissues was than in normal adjacent esophageal tissues (P<0.01). Dual luciferase reporter gene assay showed that miR-145 can specifically bind with the 3′UTR of CTGF and significantly inhibit the luciferase activity by 55% (P<0.01). Up-regulation of miR-145 or down-regulation of CTGF can suppress the proliferation, migration, invasion, and EMT process of ESCC cells.

Conclusions

MiR-145 was significantly down-regulated in ESCC tissues and cell lines, while the protein expression of CTGF exhibited the opposite trend. MiR-145 inhibited the proliferation, migration, invasiveness, and the EMT process of ESCC cells through targeted regulation of CTGF expression.

Lipocalin 2 promotes the migration and invasion of esophageal squamous cell carcinoma cells through a novel positive feedback loop

Lipocalin 2 (LCN2) is a poor prognostic factor in esophageal squamous cell carcinoma (ESCC), however its functional roles and molecular mechanisms of action remain to be clarified. Here, we described the functions and signaling pathways for LCN2 in ESCC. Overexpression of LCN2 in ESCC cells accelerated cell migration and invasion in vitro, and promoted lung metastasis in vivo. Blocking LCN2 expression inhibited its pro-oncogenic effect. Either overexpression of LCN2 or treatment with recombinant human LCN2 protein enhanced the activation of MEK/ERK pathway, which in turn increases endogenous LCN2 to increase MMP-9 activity. The decreased p-cofilin and increased p-ERM induced by pERK1/2 cause the cytoskeleton F-actin rearrangement and alter the behavior of ESCC cells mediated by LCN2. As a consequence, activation of MMP-9 and the rearrangement of F-actin throw light on the mechanisms for LCN2 in ESCC. These results imply that LCN2 promotes the migration and invasion of ESCC cells through a novel positive feedback loop.

Evaluation of tumor metastasis-associated markers for molecular classification in patients with esophageal squamous cell carcinoma

This study aims to ascertain the relationship of tumor metastasis-associated markers cyclin D1, connective tissue growth factor (CTGF) and vascular endothelial growth factor (VEGF) with the clinicopathologic features and prognosis of patients with esophageal squamous cell carcinoma (ESCC), and to investigate their value in ESCC molecular classification. The expression of cyclin D1, CTGF and VEGF in 100 specimens from patients and 20 from normal esophageal mucosa were detected by immunohistochemistry. The relationship of their expression with prognosis of the patients with ESCC was evaluated by Cox regression model and Kaplan-Meier survival curve analysis. High levels of expression of cyclin D1, CTGF, and VEGF were observed in 61 (61%), 53 (53%), 49 (49%) cases, respectively. Univariate survival analysis indicated that the levels of expression of cyclin D1, CTGF and VEGF were associated with survival (all P-value < 0.05). Multivariate analysis indicated that cyclin D1 and VEGF were independent prognostic factors affecting the three-year survival rate of patients (P = 0.001, 0.017, respectively). Furthermore, high level expression of cyclin D1, CTGF and VEGF in stage I patients was found associated with poor three-year survival rate (all P-value < 0.05). The prognosis probably was favorable for patients with low expression of cyclin D1 even in stage III, or VEGF even in stage IV. Tumor metastasis-associated markers such as cyclin D1 and VEGF may be independent prognostic factors affecting survival rate of postoperative ESCC patients. It is possible to judge prognosis better and tailor treatments to each individual patient when these markers were applied to ESCC molecular classification.

Fascin expression predicts an aggressive clinical course in patients with advanced breast cancer

Fascin is an actin cross-linking protein, which regulates actin dynamics and filopodia or spike formation, as well as the epithelial-mesenchymal transition, and has been implicated in cell motility. Although, fascin is pivotal in mediating the aggressive behaviour of various types of cancer, its prognostic significance according to tumour stage has yet to be evaluated. Therefore, the present study investigated fascin expression in 194 patients diagnosed with invasive ductal carcinoma of the breast between 2000 and 2005. Fascin protein expression levels were evaluated by immunostaining on a tissue microarray, and the association between fascin expression and various clinicopathological parameters was analysed. Fascin expression was significantly correlated with various clinicopathological parameters, including high histological grade, tumour necrosis, resistance to adjuvant therapy, high expression of p53 and Ki-67 and specific therapeutic markers (oestrogen and progesterone receptor negativity; all P<0.05). Furthermore, univariate and multivariate analyses identified a significant association between fascin expression, and poor disease-free and overall survival, in late-stage breast cancer (all P<0.05). Therefore, fascin may be crucial in predicting aggressive tumour behaviour, particularly in patients with advanced-stage disease that has acquired the properties of migration and invasion.

Macrolide analog F806 suppresses esophageal squamous cell carcinoma (ESCC) by blocking β1 integrin activation

The paucity of new drugs for the treatment of esophageal squamous cell carcinoma (ESCC) limits the treatment options. This study characterized the therapeutic efficacy and action mechanism of a novel natural macrolide compound F806 in human ESCC xenograft models and cell lines. F806 inhibited growth of ESCC, most importantly, it displayed fewer undesirable side effects on normal tissues in two human ESCC xenograft models. F806 inhibited proliferation of six ESCC cells lines, with the half maximal inhibitory concentration (IC50) ranging from 9.31 to 16.43 μM. Furthermore, F806 induced apoptosis of ESCC cells, contributing to its growth-inhibitory effect. Also, F806 inhibited cell adhesion resulting in anoikis. Mechanistic studies revealed that F806 inhibited the activation of β1 integrin in part by binding to a novel site Arg610 of β1 integrin, suppressed focal adhesion formation, decreased cell adhesion to extracellular matrix and eventually triggered apoptosis. We concluded that F806 would potentially be a well-tolerated anticancer drug by targeting β1 integrin, resulting in anoikis in ESCC cells.

ATF3 functions as a novel tumor suppressor with prognostic significance in esophageal squamous cell carcinoma

ATF3 was a transcription factor involved in the progression of certain cancers. Here, we sought to explore the expression and biological function of ATF3 in esophageal squamous cell carcinomas (ESCC). The prognostic significance of ATF3 expression was evaluated in 150 ESCC samples and 21 normal squamous cell epithelium tissues. Results showed that ATF3 was down-regulated in ESCC lesions compared with paired non-cancerous tissues and low tumorous ATF3 expression significantly correlated with shorter overall survival (OS) and disease-free survival (DFS). Cox regression analysis confirmed that ATF3 expression was an independent prognostic factor. Experimentally, forced expression of ATF3 led to decreased growth and invasion properties of ESCC cells in vitro and in vivo, whereas knockdown of ATF3 did the opposite. Furthermore, ATF3 upregulated the expression of MDM2 by increasing the nuclear translocation of P53 and formed an ATF3/MDM2/MMP-2 complex that facilitated MMP-2 degradation, which subsequently led to inhibition of cell invasion. Finally, we showed that Cisplatin could restrain the invasion of ESCC cells by inducing the expression of ATF3 via P53 signaling. Combined, our findings highlight a suppressed role for ATF3 in ESCC and targeting ATF3 might be a potential therapeutic strategy.

Fascin Overexpression Promotes Cholangiocarcinoma RBE Cell Proliferation, Migration, and Invasion

Fascin is overexpressed in various tumor tissues and is closely related to tumor metastasis and invasion. However, the role of fascin in cholangiocarcinoma RBE cells has not been clearly reported. This study aimed to establish a cholangiocarcinoma cell line with stable and high expression of fascin to observe the effect of fascin on cell proliferation, migration, and invasion. A fascin overexpression vector, pcDNA3.1-Fascin, was constructed and transfected into the human cholangiocarcinoma RBE cell line. The results of real-time polymerase chain reaction, Western blot, and immunofluorescence indicated that fascin was steadily and highly expressed in RBE cells. The results of 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide and colony formation assay indicated that upregulated fascin expression could enhance cholangiocarcinoma cell proliferation. The results of wound healing assay and transwell assay indicated that fascin could promote cholangiocarcinoma cell migration and invasion, and a further study found that the nuclear factor-κB signaling pathway was activated after upregulation of fascin, whereas E-cadherin expression in these cells was significantly decreased. Additionally, E-cadherin expression was significantly increased after inhibiting nuclear factor-κB activity using inhibitor or small interfering RNA, and E-cadherin expression was decreased by fascin overexpression after nuclear factor-κB inhibition, suggesting that nuclear factor-κB signaling pathway was not involved in the regulation of E-cadherin by fascin. In summary, the results of this study demonstrated that fascin effectively promoted cholangiocarcinoma RBE cell proliferation, migration, and invasion. This study provides evidence for fascin as a potential target in the treatment of cholangiocarcinoma.

Quantitative proteomics reveals the downregulation of GRB2 as a prominent node of F806-targeted cell proliferation network

High-throughput proteomics has successfully identified thousands of proteins as potential therapeutic targets during investigations into mechanisms of drug action. A novel macrolide analog, denoted F806, is a potential antitumor drug. Here, using the quantitative proteomic approach of stable isotope labeling with amino acids in cell culture (SILAC) coupled to high-resolution mass spectrometry (MS), we characterize the F806-regulating protein profiles and identify the potential target molecules or pathways of F806 in esophageal squamous cell carcinoma (ESCC) cells. From a total of 1931 quantified proteins, 181 proteins were found to be down-regulated (FDR p-value<0.1, H/L ratio<0.738), and 119 proteins were up-regulated (FDR p-value<0.1, H/L ratio>1.156). Among the down-regulated proteins, we uncovered the over- and under-represented protein clusters in biological process and molecular function respectively by Gene Ontology analysis. Furthermore, down-regulated and up-regulated proteins were significantly enriched in 37 pathways and 60 sub-pathways by bioinformatic analysis (FDR p-value<0.1), while a down-regulated molecule growth factor receptor-bound protein 2 (GRB2) was a prominent node in fourteen cell proliferation-related sub-pathways. We concluded that GRB2 downregulation would be a potential target of F806 in ESCC cells.

BIOLOGICAL SIGNIFICANCE

This study used SILAC-based quantitative proteomics screen to systematically characterize molecular changes induced by a novel macrolide analog F806 in esophageal squamous cell carcinoma (ESCC) cells. Followed by bioinformatic analyses, signal pathway networks generated from the quantified proteins, would facilitate future investigation into the further mechanisms of F806 in ESCC cells. Notably, it provided information that growth factor receptor-bound protein 2 (GRB2) would be a prominent node in the F806-targeted cell proliferation network.

Downregulation of VGLL4 in the progression of esophageal squamous cell carcinoma

VGLL4, a member of the Vestigial-like (VGLL) proteins, has been reported to be dysregulated in several cancer types. However, its function in esophageal squamous cell carcinoma (ESCC) remains poorly understood. Here, it was found that the expression level of VGLL4 was decreased in ESCC tissues. Moreover, forced expression of VGLL4 in ESCC cells inhibited cell growth and migration, while knockdown of VGLL4 expression promoted the tumorigenecity of ESCC cells. Mechanistically, VGLL4 regulated the growth and motility of ESCC cells through downregulating the expression of connective tissue growth factor (CTGF), a known oncogene in the progression of ESCC. Taken together, our study suggested that downregulation of VGLL4 was very important in the progression of ESCC, and restoring the function of VGLL4 might be a promising therapeutic strategy for ESCC.

Identification of a novel lysyl oxidase-like 2 alternative splicing isoform, LOXL2 Δe13, in esophageal squamous cell carcinoma

Lysyl oxidase-like 2 (LOXL2) participates in every stage of cancer progression and promotes invasion and metastasis. In this study, we identified a novel alternative splicing isoform of LOXL2, namely LOXL2 Δe13, which lacked exon 13. Deletion of exon 13 caused an open reading frame shift and produced a truncated protein. LOXL2 Δe13 was expressed ubiquitously in cell lines and tissues and was mainly localized to the cytoplasm. Although it showed impaired deamination enzymatic activity compared with full-length LOXL2, LOXL2 Δe13 promoted the cell mobility and invasion of esophageal squamous cell carcinoma (ESCC) cells to greater degrees. In further research on the mechanisms, gene expression profiling and signaling pathway analysis revealed that LOXL2 Δe13 induced the expression of MAPK8 without affecting the FAK, AKT, and ERK signaling pathways. RNAi-mediated knockdown of MAPK8 could block the cell migration promoted by LOXL2De13, but it had little effect on that of full-length LOXL2. Our data suggest that LOXL2 Δe13 modulates the effects of cancer cell migration and invasion through a different mechanism from that of full-length LOXL2 and that it may play a very important role in tumor carcinogenesis and progression.

A novel staging model to classify oesophageal squamous cell carcinoma patients in China

BACKGROUND

Oesophageal squamous cell carcinoma (ESCC) is the predominant subtype of oesophageal carcinoma in China, with the overall 5-year survival rate of <10%. The current tumour-node-metastasis (TNM) staging system has become so complex that it is not easy to use in the life expectancy assessment. We aim to combine clinical variables and biomarkers to develop and validate a relative simple and reliable model, named the FENSAM, for ESCC prognosis.

METHODS

To build the FENSAM, we analysed 22 potential prognostic factors from 461 patients, including 9 biomarkers (Ezrin, Fascin, desmocollin 2 (DSC2), pFascin, activating transcription factor 3 (ATF3), connective-tissue growth factor (CTGF), neutrophil gelatinase-associated lipocalin (NGAL), NGAL receptor (NGALR), and cysteine-rich angiogenic protein 61 (CYR61)) and other 13 clinical variables. We selected significant factors associated with survival of ESCC patients, and used them to build our FENSAM model. We then obtained the hazard risk score of the model to classify ESCC patients. In addition, we validated the model in an independent cohort of 290 patients from the same hospital. The predictive performance of the model was assessed by the Area under the Receiver Operating Characteristic Curve (AUC) and Kaplan-Meier survival analysis.

RESULTS

We found six markers significantly associated with survival of ESCC patients (Ezrin, Fascin, ATF3, surgery extent, N-stage, and M-stage). They were combined to create a novel four-stage FENSAM model for patients' classification. FENSAM possessed a high classification precision similar to the TNM staging system, but with a much simpler model. The efficiency of FENSAM was evaluated by different quantiles of AUC and the results of survival analysis. The validation result demonstrated the potential of the FENSAM model to improve classification accuracy for ESCC patients.

CONCLUSIONS

FENSAM provides an alternative classifier for ESCC patients with a high classification precision using a simple model.

Stratifying fascin and cortactin function in invadopodium formation using inhibitory nanobodies and targeted subcellular delocalization

Invadopodia are actin-rich protrusions arising through the orchestrated regulation of precursor assembly, stabilization, and maturation, endowing cancer cells with invasive properties. Using nanobodies (antigen-binding domains of Camelid heavy-chain antibodies) as perturbators of intracellular functions and/or protein domains at the level of the endogenous protein, we examined the specific contribution of fascin and cortactin during invadopodium formation in MDA-MB-231 breast and PC-3 prostate cancer cells. A nanobody (K(d)~35 nM, 1:1 stoichiometry) that disrupts fascin F-actin bundling emphasizes the importance of stable actin bundles in invadopodium array organization and turnover, matrix degradation, and cancer cell invasion. Cortactin-SH3 dependent WIP recruitment toward the plasma membrane was specifically inhibited by a cortactin nanobody (K(d)~75 nM, 1:1 stoichiometry). This functional domain is shown to be important for formation of properly organized invadopodia, MMP-9 secretion, matrix degradation, and cancer cell invasion. Notably, using a subcellular delocalization strategy to trigger protein loss of function, we uncovered a fascin-bundling-independent role in MMP-9 secretion. Hence, we demonstrate that nanobodies enable high resolution protein function mapping in cells.

Down-regulated desmocollin-2 promotes cell aggressiveness through redistributing adherens junctions and activating beta-catenin signalling in oesophageal squamous cell carcinoma

In contrast to the well-recognized loss of adherens junctions in cancer progression, the role of desmosomal components in cancer development has not been well explored. We previously demonstrated that desmocollin-2 (DSC2), a desmosomal cadherin protein, is reduced in oesophageal squamous cell carcinoma (ESCC), and is associated with enhanced tumour metastasis and poor prognosis. Here, we report that restoration of DSC2 in ESCC cells impeded cell migration and invasion both in vitro and in vivo, whereas siRNA-mediated suppression of DSC2 expression increased cell motility. In E-cadherin-expressing ESCC cells, DSC2 restoration strengthened E-cadherin-mediated adherens junctions and promoted the localization of β-catenin at these junctions, which indirectly inhibited β-catenin-dependent transcription. These effects of DSC2 were not present in EC109 cells that lacked E-cadherin expression. ESCC patients with tumours that had reduced E-cadherin and negative DSC2 had poorer clinical outcomes than patients with tumours that lacked either E-cadherin or DSC2, implying that the invasive potential of ESCC cells was restricted by both DSC2 and E-cadherin-dependent junctions. Further studies revealed that DSC2 was a downstream target of miR-25. Enhanced miR-25 promoted ESCC cell invasiveness, whereas restoration of DSC2 abolished these effects. Collectively, our work suggests that miR-25-mediated down-regulation of DSC2 promotes ESCC cell aggressiveness through redistributing adherens junctions and activating beta-catenin signalling.

The up-regulation of cysteine-rich protein 61 induced by transforming growth factor beta enhances osteosarcoma cell migration

Overexpressed cysteine-rich protein 61 (Cyr61) is believed to enhance osteosarcoma (OS) cell metastasis, but the mechanism of Cyr61 overexpression in OS is not clear so far. In this study 33 OS samples were analyzed by immunostaining and focused on two parts: the correlation between overexpression of Cyr61 and OS metastasis; the mechanism of regulating Cyr61 expression in OS. Twenty-five out of 33 cases (75.76 %) with metastasis showed high expression of Cyr61. Furthermore, Cyr61 expression in Saos-2 cells was reduced by siRNA, and lower expression of Cyr61 in Saos-2 cell resulted in a cell migration deficiency and had no effect on cell proliferation. Particularly, Cyr61 expression was significantly increased in Saos-2 cells in response to different dosages of transforming growth factor beta (TGF-β), indicating that the expression of Cyr61 is TGF-β dependent. A transwell assay showed that Saos-2 cells stimulated with TGF-β had a greater capacity for migration than the control cells. The p38 MAPK-specific inhibitor SB203580 was able to reduce Cyr61 expression and inhibit the migration of Saos-2 cells stimulated with TGF-β. These results obtained provide new evidence that overexpressed Cyr61 plays a key role in the metastasis of OS cells and Cyr61 is a potential target downstream of TGF-β/p38 MAPK to regulate cell migration.

DACT2 is a candidate tumor suppressor and prognostic marker in esophageal squamous cell carcinoma

In animals ranging from fish to mice, the function of DACT2 as a negative regulator of the TGF-β/Nodal signal pathway is conserved in evolution, indicating that it might play an important role in human cancer. In this study, we showed that tumors with higher DACT2 protein level were correlated with better differentiation and better survival rate in patients with esophageal squamous cell carcinoma. Restored expression of DACT2 significantly inhibited growth, migration, and invasion of ESCC cells in vitro, and reduced tumorigenicity in vivo. Furthermore, when DACT2 expression was restored, the activity of TGF-β/SMAD2/3 was suppressed via both proteasome and lysosomal degradation pathways, leading to F-actin rearrangement that might depend on the involvement of cofilin and ezrin-redixin-moesin (ERM) proteins. Taken together, we propose here that DACT2 serves as a prognostic marker that reduces tumor cell malignancy by suppressing TGF-β signaling and promotes actin rearrangement in ESCC.

Reduced CTGF expression promotes cell growth, migration, and invasion in nasopharyngeal carcinoma

Background

The role of CTGF varies in different types of cancer. The purpose of this study is to investigate the involvement of CTGF in tumor progression and prognosis of human nasopharyngeal carcinoma (NPC).

Experimental design

CTGF expression levels were examined in NPC tissues and cells, nasopharynx (NP) tissues, and NP69 cells. The effects and molecular mechanisms of CTGF expression on cell proliferation, migration, invasion, and cell cycle were also explored.

Results

NPC cells exhibited decreased mRNA expression of CTGF compared to immortalized human nasopharyngeal epithelial cell line NP69. Similarly, CTGF was observed to be downregulated in NPC compared to normal tissues at mRNA and protein levels. Furthermore, reduced CTGF was negatively associated with the progression of NPC. Knocking down CTGF expression enhanced the colony formation, cell migration, invasion, and G1/S cell cycle transition. Mechanistic analysis revealed that CTGF suppression activated FAK/PI3K/AKT and its downstream signals regulating the cell cycle, epithelial-mesenchymal transition (EMT) and MMPs. Finally, DNA methylation microarray revealed a lack of hypermethylation at the CTGF promoter, suggesting other mechanisms are associated with suppression of CTGF in NPC.

Conclusion

Our study demonstrates that reduced expression of CTGF promoted cell proliferation, migration, invasion and cell cycle progression through FAK/PI3K/AKT, EMT and MMP pathways in NPC.

Loss of connective tissue growth factor as an unfavorable prognosis factor activates miR-18b by PI3K/AKT/C-Jun and C-Myc and promotes cell growth in nasopharyngeal carcinoma

Connective tissue growth factor (CTGF) has different roles in different types of cancer. However, the involvement and molecular basis of CTGF in tumor progression and prognosis of human nasopharyngeal carcinoma (NPC) have almost never been reported. In this study, we observed that downregulated CTGF expression was significantly associated with NPC progression and poor prognosis. Knockdown of CTGF markedly elevated the ability of cell proliferation in vivo and in vitro. Subsequently, we discovered that the reduction of CTGF increased the expression of miR-18b, an oncomir-promoting cell proliferation. Further, we discovered that attenuated CTGF-mediated upregulation of miR-18b was dependent on the increased binding of transcription factors Jun proto-oncogene (C-Jun) and v-Myc myelocytomatosis viral oncogene homolog (C-Myc) to miR-18b promoter region via phosphoinositide 3-kinase (PI3K)/AKT pathway. Finally, we further found that miR-18b directly suppressed the expression of CTGF in NPC. In clinical fresh specimens, miR-18b was widely overexpressed and inversely correlated with CTGF expression in NPC. Our studies are the first to demonstrate that reduced CTGF as an unfavorable prognosis factor mediates the activation of miR-18b, an oncomir directly suppresses CTGF expression, by PI3K/AKT/C-Jun and C-Myc and promotes cell growth of NPC.

Fascin 1 is transiently expressed in mouse melanoblasts during development and promotes migration and proliferation

Fascins, a family of actin-bundling proteins, are expressed in a spatially and temporally restricted manner during development and often in cancer. Fascin 1 has a clear role in cell migration in vitro, but its role in vivo in mammals is not well understood. Here, we investigate the role of fascin 1 in the melanocyte lineage and in melanoma cells. Fascin 1 knockout causes hypopigmentation in adult mice owing to migration and cell cycle progression defects in melanoblasts, the melanocyte precursor cell. Study of live embryo skin explants reveals that E14.5 fascin 1-null melanoblasts migrate slower, and generate fewer and thinner pseudopods. By contrast, fascin 1 expression drives faster migration and lamellipodia protrusion in melanocytes in vitro. In addition, fascin 1 depletion retards melanoblast proliferation in vivo and melanoma cell growth in vitro. These data indicate that fascin 1 not only promotes cell migration in mouse melanocytes but it also has a role in growth and cell cycle progression.

Epigenetic silencing of HOPX promotes cancer progression in colorectal cancer

Homeodomain-only protein X (HOPX)-β promoter methylation was recently shown to be frequent in human cancers and was suggested as tumor suppressor gene in esophageal and gastric cancer. The aim of this study was to investigate the mechanistic roles of HOPX-β promoter methylation and its clinical relevance in colorectal cancer (CRC). HOPX-β promoter methylation was assessed in human CRC cell lines and 294 CRC tissues. HOPX mRNA and protein levels were measured in relation to HOPX-β promoter methylation. The effects of forced HOPX expression on tumorigenesis were studied using in vitro and in vivo assays. The association between HOPX-β promoter methylation and clinical relevance of CRC patients was determined. HOPX-β promoter methylation is cancer-specific and frequently found in CRC cell lines and tissues, resulting in the down-regulation of HOPX mRNA and protein levels. In CRC cell lines, forced expression of HOPX suppressed proliferation, invasion, and anchorage-independent growth. DNA microarray analyses suggested critical downstream genes that are associated with cancer cell proliferation, invasion or angiogenesis. In a mouse xenograft model, HOPX inhibited tumorigenesis and angiogenesis. Finally, HOPX-β promoter methylation was associated with worse prognosis of stage III CRC patients (hazard ratio= 1.40, P = .035) and also with poor differentiation (P = .014). In conclusion, HOPX-β promoter methylation is a frequent and cancer-specific event in CRC progression. This epigenetic alteration may have clinical ramifications in the diagnosis and treatment of CRC patients.

Association of fascin-1 with mortality, disease progression and metastasis in carcinomas: a systematic review and meta-analysis

BACKGROUND

Fascin-1 is an actin-bundling protein expressed in many human carcinomas, although absent from most normal epithelia. Fascin-1 promotes filopodia formation, migration and invasion in carcinoma cells; in mouse xenograft tumor models it contributes to metastasis. Fascin-1 is an interesting candidate biomarker for aggressive, metastatic carcinomas but data from individual studies of human tumors have not yet been pooled systematically.

METHODS

This systematic review was conducted in accordance with PRISMA guidelines, using fixed and random effects models, as appropriate, to undertake meta-analysis.

RESULTS

A total of 26 immunohistochemical studies of 5 prevalent human carcinomas were identified for meta-analysis. Fascin-1 was associated with increased risk of mortality for breast (pooled hazard ratio, (HR) = 2.58; 95% confidence interval (CI) 1.48 to 4.52; P = 0.001), colorectal (HR = 1.60 (1.37 to 1.86; P <0.001) and esophageal carcinomas (HR = 1.35; CI 1.13 to 1.60; P = 0.001). There was no evidence of association of fascin-1 with mortality in gastric and lung carcinomas. Fascin-1 was associated with increased risk of disease progression in breast (HR = 2.48; CI 1.38 to 4.46; P = 0.002) and colorectal carcinomas (HR = 2.12; CI 1.00 to 4.47; P = 0.05), but not with progression of lung carcinomas (HR = 0.95; CI 0.49 to 1.85; P = 0.9). Fascin-1 was associated with increased risk of lymph node metastasis in colorectal (pooled risk ratio (RR) = 1.47; CI 1.26 to 1.71; P <0.001) and gastric carcinomas (RR = 1.43; CI 1.21 to 1.70; P <0.001). There was no evidence of association of fascin-1 with lymph node metastasis in lung or esophageal carcinomas. Fascin-1 was associated with increased risk of distant metastasis in colorectal (RR = 1.70; CI 1.18 to 2.45; P = 0.004) and gastric carcinomas (RR = 1.93; CI 1.21 to 3.33; P = 0.02). No association with distant metastasis in esophageal carcinomas was observed. Pooling across all the carcinomas provided strong evidence for association of fascin-1 with increased risk of mortality (HR = 1.44; CI 1.24 to 1.68; P <0.001; n = 3,645), lymph node metastasis (RR = 1.36; CI 1.18 to 1.55; P <0.001; n = 2,906) and distant metastasis (1.76; 1.34 to 2.32; P <0.001; n = 1,514).

CONCLUSIONS

Fascin-1 is associated consistently with increased risk of mortality in breast, colorectal and esophageal carcinomas and with metastasis in colorectal and gastric carcinomas. The results were stable to various sensitivity analyses and did not vary by predefined subgroups. These data will assist rational decision making for focusing investigations of fascin-1 as a biomarker or therapeutic target onto the most relevant carcinomas.

Comprehensive bioinformation analysis of the mRNA profile of fascin knockdown in esophageal squamous cell carcinoma

BACKGROUND

Fascin, an actin-bundling protein forming actin bundles including filopodia and stress fibers, is overexpressed in multiple human epithelial cancers including esophageal squamous cell carcinoma (ESCC). Previously we conducted a microarray experiment to analyze fascin knockdown by RNAi in ESCC.

METHOD

In this study, the differentially expressed genes from mRNA expression profilomg of fascin knockdown were analyzed by multiple bioinformatics methods for a comprehensive understanding of the role of fascin.

RESULTS

Gene Ontology enrichment found terms associated with cytoskeleton organization, including cell adhesion, actin filament binding and actin cytoskeleton, which might be related to fascin function. Except GO categories, the differentially expressed genes were annotated by 45 functional categories from the Functional Annotation Chart of DAVID. Subpathway analysis showed thirty-nine pathways were disturbed by the differentially expressed genes, providing more detailed information than traditional pathway enrichment analysis. Two subpathways derivated from regulation of the actin cytoskeleton were shown. Promoter analysis results indicated distinguishing sequence patterns and transcription factors in response to the co-expression of downregulated or upregulated differentially expressed genes. MNB1A, c-ETS, GATA2 and Prrx2 potentially regulate the transcription of the downregulated gene set, while Arnt-Ahr, ZNF42, Ubx and TCF11-MafG might co-regulate the upregulated genes.

CONCLUSIONS

This multiple bioinformatic analysis helps provide a comprehensive understanding of the roles of fascin after its knockdown in ESCC.

microRNA and inflammatory gene expression as prognostic marker for overall survival in esophageal squamous cell carcinoma

MicroRNAs (miRNAs) and inflammatory genes have a role in the initiation and development of esophageal squamous cell carcinoma (ESCC). In our study, we examined the potential of using miRNA and inflammatory gene expression patterns as prognostic classifiers for ESCC. Five miRNAs and 25 inflammatory-related genes were measured by quantitative reverse transcriptase PCR in tumor tissues and adjacent noncancerous tissues from 178 Chinese patients with ESCC. The expression levels of miR-21 (p = 0.027), miR-181b (p = 0.002) and miR-146b (p = 0.021) in tumor tissue and miR-21 (p = 0.003) in noncancerous tissue were associated with overall survival of patients. These data were combined to generate a miRNA risk score that was significantly associated with worse prognosis (p = 0.0001), suggesting that these miRNAs may be useful prognostic classifiers for ESCC. To construct an inflammatory gene prognostic classifier, we divided the population into training (n = 124) and test cohorts (n = 54). The expression levels of CRY61, CTGF and IL-18 in tumor tissue and VEGF in adjacent noncancerous tissue were modestly associated with prognosis in the training cohort |Z-score| > 1.5 and were subsequently used to construct a Cox regression-based inflammatory risk score (IRS). IRS was significantly associated with survival in both the training cohort (p = 0.002) and the test cohort (p = 0.005). Furthermore, Cox regression models combining both miRNA risk score and IRS performed significantly better than models with either alone (p < 0.001 likelihood ratio test). Therefore, miRNA and inflammatory gene expression patterns, alone or in combination, have potential as prognostic classifiers for ESCC and may help to guide therapeutic decisions.

Fascin-1 and digestive system carcinomas

Invasion and metastasis are major reasons for poor prognosis of digestive system carcinomas. Motility and migratory capacity are important in contributing to tumor cell invasion and metastasis. Fascin-1 is a globular actin crosslinking protein that can form parallel actin bundles in cell protrusions and is involved in cell adhesion, movement, and signal transduction. In vitro up-regulation of Fascin-1 can increase migration and invasion capacity of cells, while down-regulation of Fascin-1 can decrease migration and invasion capacity of cells. Many studies show that up-regulation of Fascin-1 expression is significantly associated with worse prognosis, poorer differentiation, advanced TNM stage, lymph node metastasis, and distant metastasis in patients with digestive system carcinomas. Therefore, Fascin-1 may have prognostic value as an early biomarker for more aggressive digestive system carcinomas and may be a potential therapeutic target for tumor invasion and metastasis.