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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., Graphical Abstract, As an actin-bundling protein, FSCN1 plays an important role in cancer progression and metastasis. Its expression has been correlated with an aggressive clinical course and poor prognosis. This review summarizes not only the role of FSCN1 in cancers but also its clinical application in cancer therapy by targeting FSCN1.

Fascin-1 and actinin-4 are involved in key processes of tumor cell adhesion, migration and metastasis. Actinin-4 plays an important role in promotion of cell proliferation, whereas fascin-1 regulates cellular motility. Its over-expression leads to the loss of cell adhesion and metastasis. The aim of our study was to assess fascin-1 and actinin-4 expression in normal pancreatic ducts and in pancreatic intraepithelial neoplasia (PanIN) - precursor lesion of pancreatic ductal adenocarcinoma (PDAC).The study involved 70 patients treated surgically due to PDAC, cysts and pancreatitis, who had also been diagnosed with pancreatic intraepithelial neoplasia. Fascin-1 and actinin-4 expressions were evaluated using the immunohistochemistry method.A statistically significant relationship was observed between the expression of fascin-1 and actinin-4 (cytoplasmic) and patients' age (P = 0.01, P = 0.002, respectively). The expression of fascin-1 and actinin-4 was associated with the diagnosis (P 0.001, P = 0.04, respectively). Statistical analysis revealed correlations of fascin-1 and actinin-4 expressions with the presence and grade of PanIN (P0.001, P = 0.002, respectively). The expression of these proteins was observed in each degree of PanIN and increased with the pancreatic intraepithelial neoplasia progression.The expression of fascin-1 and actinin-4 is connected with the degree of PanIN advancement and depends on the type of the primary disease. Overexpression of these proteins may be linked to cytological and architectural abnormalities observed in advanced PanIN. Elevated expression of fascin-1 and actinin-4 indicates the role of these proteins in the progression from PanIN to PDAC.

The therapeutics having ability to target cancer cells specifically and exhibit nominal cytopathic effect on normal healthy cells are highly significant for cancer therapeutic applications. Recombinant porcine natural killer lysin (rpNK-lysin) has proven cationic anti-bacterial and anti-tumor peptide. Herein, we report its anti-invasion and anti-metastasis effects on hepatocellular carcinoma (HCC) cells in vitro. We first investigate the maximum non-toxic concentration (MNTC) of rpNK-lysin for the normal hepato cells (L-02). Using MNTC rpNK-lysin, we explore anti-proliferative, anti-adhesive, anti-invasive and anti-metastatic effect of rpNK-lysin on three different HCC cells lines (SMMC-7721, 97-H and HepG2) through MTT, wound-healing, adhesion and invasion assay along with mRNA and protein expression. The results reveal that rpNK-lysin has potential to specifically inhibit HCC cells growth in a dose and time-dependent manner with a little cytopathic effect on the L-02 cells, effectively reduce migration, adhesion and invasion ability of HCC cells. rpNK-lysin significantly reduce Fascin1 expression, which subsequently decrease β-catenin expression and metaloproteinases (MMP-2 and MMP9). This study suggest that MNTC rpNK-lysin has an anti-invasion and anti-metastasis effect on HCC cells in vitro through inhibition of Fascin 1 expression which regulates Wnt/β-catenin signaling pathway by inducing β-catenin degradation and subsequently results in suppression of MMP-2 and MMP9 expression.

Graft microvasculature is a major target of donor-specific antibodies (DSA) and endothelial damage is direct evidence of antibody-mediated rejection (ABMR). Using immunohistochemistry, we analyzed the expression of three microvascular endothelial activation markers (fascin, vimentin, and hsp47), suggestive of endothelial-to-mesenchymal transition (EndMT) in 351 graft biopsies from 248 kidney recipients, with concomitant screening of circulating antihuman leukocyte antigen (HLA) DSA at the time of the biopsy. The factors associated with EndMT marker expression were DSA and the presence of microvascular inflammation (MI). EndMT expressing grafts had significantly more allograft loss compared to EndMT negative grafts (P < .0001). The expression of EndMT markers positively correlated with anti-HLA DSA class II mean fluorescence intensity (MFI) levels and especially identified DQ and DR antibodies as being more closely associated with microvascular injury. Moreover, only DSA linked to positive EndMT score affected allograft survival, regardless of DSA MFI levels or presence of C4d deposition. Thus, EndMT markers could represent a clinically relevant tool for early identification of ongoing endothelial injury, harmful DSA, and patients at high risk for allograft failure.

The actin cortex is a thin network coupled to the plasma membrane of cells, responsible for e.g., cell shape, motility, growth and division. Several model systems for minimal actin cortices (MACs) have been discussed in literature trying to mimic the complex interplay of membrane and actin. We recapitulate on different types of MACs using either three dimensional droplet interfaces or lipid bilayers to which F-actin networks are attached to or planar lipid bilayers with bound actin networks. Binding of the network to the membrane interface significantly influences its properties as well as its dynamics. This in turn also influences, how cross-linkers as well as myosin motors act on the network. Here, we describe the coupling of a filamentous actin network to a model membrane via the protein ezrin, a member of the ezrin-radixin-moesin family, which forms a direct linkage between the plasma membrane and the cortical web. Ezrin binding to the membrane is achieved by the lipid PtdIns(4,5)P2, while attachment to F-actin is mediated via the C-terminal domain of the protein leading to a two dimensional arrangement of actin filaments on the membrane. Addition of cross-linkers such as fascin and α-actinin influences the architecture of the actin network, which we have investigated by means of fluorescence microscopy. The results are discussed in terms of the dynamics of the filaments on the membrane surface.

Objective Ovarian cancer (OvCa) metastasis requires the coordinated motility of both cancer and stromal cells. Cellular movement is a dynamic process that involves the synchronized assembly of f-actin bundles into cytoskeletal protrusions by fascin. Fascin directly binds f-actin and is an integral component of filopodia, lamellapodia and stress fibers. Here, we examine the expression pattern and function of fascin in the cancer and stromal cells of OvCa tumors. Methods Fascin expression was evaluated in human cells and tissues using immunohistochemistry and immunofluorescence. The functional role of fascin in cancer and stromal cells was assessed with in vitro functional assays, an ex vivo colonization assay and in vivo metastasis assays using siRNA/shRNA and an inhibitor. The effect of fascin inhibition on Cdc42 and Rac1 activity was evaluated using GTPase activity assays and immunofluorescence. Results Fascin expression was found to be higher in the stromal cell, when compared to the cancer cell, compartment of ovarian tumors. The low expression of fascin in the cancer cells of the primary tumor indicated a favorable prognosis for non-serous OvCa patients. In vitro, both knockdown and pharmacologic inhibition of fascin decreased the migration of cancer and stromal cells. The inhibition of fascin impaired Cdc42 and Rac1 activity in cancer cells, and cytoskeletal reorganization in the cancer and stromal cells. Inhibition of fascin ex vivo blocked OvCa cell colonization of human omental tissue and in vivo prevented and reduced OvCa metastases in mice. Likewise, knockdown of fascin specifically in the OvCa cells using a fascin-specific lentiviral-shRNA also blocked metastasis in vivo. Conclusion This study reveals the therapeutic potential of pharmacologically inhibiting fascin in both cancer and stromal cells of the OvCa tumor microenvironment.

Laryngeal squamous cell carcinoma (LSCC) is a common form of head and neck cancer with poor prognosis. However, the mechanism underlying the pathogenesis of LSCC remains unclear. Here, we demonstrated increased expression of fascin actin-bundling protein 1 (FSCN1) and decreased expression of microRNA-145-5p (miR-145-5p) in a clinical cohort of LSCC. Luciferase assay revealed that miR-145-5p is a negative regulator of FSCN1. Importantly, low miR-145-5p expression was correlated with TNM (tumor, node, metastasis) status and metastasis. Moreover, cases with low miR-145-5p/high FSCN1 expression showed poor prognosis, and these characteristics together served as independent prognostic indicators of survival. Gain- and loss-of-function studies showed that miR-145-5p overexpression or FSCN1 knockdown inhibited LSCC migration, invasion, and growth by suppressing the epithelial-mesenchymal transition along with inducing cell-cycle arrest and apoptosis. Additionally, hypermethylation of the miR-145-5p promoter suggested that repression of miR-145-5p arises through epigenetic inactivation. LSCC tumor growth in vivo could be inhibited by using miR-145-5p agomir or FSCN1 small interfering RNA (siRNA), which highlights the potential for clinical translation. Collectively, our findings indicate that miR-145-5p plays critical roles in inhibiting the progression of LSCC by suppressing FSCN1. Both miR-145-5p and FSCN1 are important potential prognostic markers and therapeutic targets for LSCC., Graphical Abstract, Gao et al. demonstrate that miR-145-5p expression is prognostic for LSCC with low expression associated with poorer outcomes. Underlying this pathology, miR-145-5p suppresses FSCN1 expression, but its inactivation facilitates epithelial-to-mesenchymal transition (EMT), proliferation, and survival. LSCC growth in vivo is inhibited by miR-145-5p agomir, highlighting potential as a biomarker and therapeutic target.

Cancer-associated fibroblasts (CAFs) are an important constituent of the cancer stroma. In intrahepatic cholangiocarcinoma (ICC), the features of CAFs at the primary site and in the metastatic lymph nodes (Met-LNs) and their origin have been unclear. In the present study, we characterized CAFs at the primary site (n = 42) and in the Met-LNs (n = 10) of human ICC by immunohistochemistry using potential molecular markers of CAFs, portal fibroblasts (PFs), hepatic stellate cells (HSCs), and bone marrow-derived fibrocytes (BMDFs). At the primary site, the stroma was strongly positive for α-smooth muscle actin (α-SMA; marker for CAFs), platelet-derived growth factor receptor-β (PDGFR-β) (common marker for HSCs and PFs), fibulin-2, and thymus cell antigen-1 (Thy-1; PF marker), whereas immunoreactivity for fascin (HSC marker) was scarce. Most of the α-SMA-positive cells were found to express PDGFR-β, Thy-1, and fibulin-2 by double immunostaining. A small population of BMDF marker-positive (α-SMA+CD45+CD34+) cells was found by triple immunostaining. In the micro-Met-LNs, α-SMA-positive cells were absent in cancer aggregates of the LN sinus, whereas they were present in the invasion area of cancer cells from the LN sinus to the LN parenchyma. In the macro-Met-LNs, there were abundant α-SMA-positive cells that were also positive for PDGFR-β and Thy-1 but negative for fibulin-2 and fascin. Thus, regarding the expression of molecular markers, CAFs at the primary site of ICC are similar to PFs and different from those of HSCs or CAFs in the Met-LNs. CAFs at the primary sites and in the Met-LN are thought to be derived from PFs/BMDFs and resident cells of LNs, respectively.

Filopodia are dynamic, narrow, plasma membrane protrusions filled with bundled actin filaments. Fresh actin monomers are incorporated at the tips furthest away from the cell body, where barbed end polymerases such as formins and Ena/VASP proteins are present in a complex with other regulatory proteins, including Myosin-X. The tightly packed, parallel alignment of actin filaments in the shaft is mediated by bundling, notably by fascin but also fimbrin and some formins. Filopodia often, but need not necessarily, emerge from areas of Arp2/3 complex nucleated F-actin. The membrane surrounding filopodia is tightly curved, where inverse-Bin-Amphiphysin-Rvs proteins deform the membrane, together with Ezrin-Radixin-Moesin proteins. Recent studies have revealed that phosphoinositide lipid metabolism and endophilin-dependent endocytosis are associated with filopodia and that filopodia are a site for virus and exosome internalization. The composition of filopodia can share similarity with the integrin adhesome, and adhesion plays mechanical and tissue matching roles in filopodia function. This review considers how filopodia form and discusses putative mechanistic integration between filopodia, endocytosis and adhesion.

In human hematologic malignancies, some of the TNF receptor family members are up-regulated and have the ability to evoke reactions favoring tumor progression. Moreover, cell migration molecules, Fascin-1 and Versican are involved in proliferation, migration and invasion of cancer cells. They are linked to many human cancers. Therefore, we conducted this study to evaluate both the plasma and leukocytes concentrations of tumor necrosis factor receptor super family 2 (TNFRSF2), TNFRSF9, Fascin-1 and Versican in patients with acute leukemia, as well as to correlate these values with clinical features and treatment outcome. Therefore, forty-eight patients with acute myeloid leukemia (AML), thirty-two patients with acute lymphoblastic leukemia (ALL) and fifteen control subjects were included. TNFRSF2, TNFRSF9, Fascin-1 and Versican were measured in plasma and leukocytes of all subjects by enzyme-linked immunosorbent assay. We found that plasma TNFRSF9 was highly elevated in ALL and AML as compared with the control group. In addition, AML patients who failed to achieve complete remission showed a significant increase in leukocytes TNFRSF9 level. TNFRSF2 is significantly increased in plasma and leukocytes of ALL patients when compared with the control group and AML patients. Fascin-1 significantly increased in AML, but not in ALL cases. Plasma and leukocytes levels of Versican significantly increased in AML compared to both control and ALL subjects. Plasma Versican correlated with poor response to induction of chemotherapy in AML cases. In conclusion, TNFRSF2 and TNFRSF9 could act as a possible prognostic biomarkers for the outcomes of ALL patients and TNFRSF9 could be a potential target in AML. Versican may be used as a diagnostic biomarker and as a predictor of the response to chemotherapy in AML. In addition, plasma Fascin-1 is a potential biomarker for AML.

Chlamydia trachomatis entry into host cells is mediated by pathogen-directed remodeling of the actin cytoskeleton. The chlamydial type III secreted effector, translocated actin recruiting phosphoprotein (Tarp), has been implicated in the recruitment of actin to the site of internalization. Tarp harbors G-actin binding and proline rich domains required for Tarp-mediated actin nucleation as well as unique F-actin binding domains implicated in the formation of actin bundles. Little is known about the mechanical properties of actin bundles generated by Tarp or the mechanism by which Tarp mediates actin bundle formation. In order to characterize the actin bundles and elucidate the role of different Tarp domains in the bundling process, purified Tarp effectors and Tarp truncation mutants were analyzed using Total Internal Reflection Fluorescence (TIRF) microscopy. Our data indicate that Tarp mediated actin bundling is independent of actin nucleation and the F-actin binding domains are sufficient to bundle actin filaments. Additionally, Tarp-mediated actin bundles demonstrate distinct bending stiffness compared to those crosslinked by the well characterized actin bundling proteins fascin and alpha-actinin, suggesting Tarp may employ a novel actin bundling strategy. The capacity of the Tarp effector to generate novel actin bundles likely contributes to chlamydia's efficient mechanism of entry into human cells.

Tumor metastasis is responsible for ~90% of all cancer deaths. One of the key steps of tumor metastasis is tumor cell migration and invasion. Filopodia are cell surface extensions that are critical for tumor cell migration. Fascin protein is the main actin-bundling protein in filopodia. Small-molecule fascin inhibitors block tumor cell migration, invasion, and metastasis. Here we present the structural basis for the mechanism of action of these small-molecule fascin inhibitors. X-ray crystal structural analysis of a complex of fascin and a fascin inhibitor shows that binding of the fascin inhibitor to the hydrophobic cleft between the domains 1 and 2 of fascin induces a ~35o rotation of domain 1, leading to the distortion of both the actin-binding sites 1 and 2 on fascin. Furthermore, the crystal structures of an inhibitor alone indicate that the conformations of the small-molecule inhibitors are dynamic. Mutations of the inhibitor-interacting residues decrease the sensitivity of fascin to the inhibitors. Our studies provide structural insights into the molecular mechanism of fascin protein function as well as the action of small-molecule fascin inhibitors.

Gastric cancer is a heterogeneous disorder for which predicting clinical outcomes is challenging, although various biomarkers have been suggested. The Smad4 and Fascin proteins are known prognostic indicators of different types of malignancy. Smad4 primarily functions as a key regulator of tumor suppression, whereas Fascin exhibits oncogenic function by enhancing tumor infiltration. A combined marker based on these opposing roles may improve prognostic accuracy in gastric cancer. Smad4 and Fascin expression was assessed in tissue microarrays obtained from 285 primary gastric adenocarcinoma, 201 normal tissue, and 51 metastatic adenocarcinoma samples. A Smad4/Fascin index based on the relative expression of each protein was divided into low- and high-expression groups using receiver operating characteristic curves. We compared normal tissue, primary adenocarcinoma, and metastatic adenocarcinoma in Smad4 and Fascin expression and the differences in clinicopathological findings between low Smad4/Fascin and high Smad4/Fascin expression in gastric adenocarcinoma. High Smad4/Fascin expression was significantly associated with worse outcomes, such as old age, advanced T and N category, large tumor size, high histological grade, lymphatic and vascular invasion, and presence of Epstein-Barr virus (EBV) (all p 0.05). Univariate and multivariate analyses revealed a significant relationship between disease-free or overall survival and Smad4/Fascin index in diffuse-type or EBV-associated gastric cancer (all p 0.05). A dual marker system using Smad4 and Fascin may be a reliable indicator for predicting clinical outcomes in patients with diffuse-type or EBV-associated gastric cancer.

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.

Autoantibodies against tumor-associated antigens (TAAs) have been found in many kinds of cancers, and might serve as biomarkers for early cancer diagnosis. The present study was carried out to test if there is any relation between autoantibodies against Fascin and esophageal squamous cell carcinoma (ESCC).One hundred and forty-nine patients with ESCC and 98 control subjects were recruited in the study. The levels of circulating autoantibodies against Fascin were measured by enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) was used to calculate diagnostic accuracy.The levels of autoantibodies against Fascin in patients with ESCC were significantly higher than in control subjects (P0.001). Measurement of autoantibodies against Fascin provided an area under the curve (AUC) of 0.636, [95% confidence interval (CI): 0.568-0.704] 24.8% sensitivity (95% CI: 18.3%-37.2%) and 99.0% specificity (95% CI: 93.6%-99.9%). Moreover, serum level of autoantibodies against Fascin in early-stage ESCC was significantly higher than that of normal controls (P0.05). The positive rates of autoantibodies against Fascin were correlated with age (P0.05), but not with gender, tumor size, tumor site, histological grade, T stage, N stage or TNM stage (P0.05).Our results suggest that Fascin autoantibody may be a potential biomarker for the early detection of ESCC.

Fascin is an actin bundling protein that cross-links individual actin filaments into straight, compact, and stiff bundles, which are crucial for the formation of filopodia, stereocillia, and other finger-like membrane protrusions. The dysregulation of fascin has been implicated in cancer metastasis, hearing loss, and blindness. Here we identified monoubiquitination as a novel mechanism that regulates fascin bundling activity and dynamics. The monoubiquitination sites were identified to be Lys247 and Lys250, two residues located in a positive charge patch at the actin binding site 2 of fascin. Using a chemical ubiquitination method, we synthesized chemically monoubiquitinated fascin and determined the effects of monoubiquitination on fascin bundling activity and dynamics. Our data demonstrated that monoubiquitination decreased the fascin bundling EC50, delayed the initiation of bundle assembly, and accelerated the disassembly of existing bundles. By analyzing the electrostatic properties on the solvent-accessible surface of fascin, we proposed that monoubiquitination introduced steric hindrance to interfere with the interaction between actin filaments and the positively charged patch at actin binding site 2. We also identified Smurf1 as a E3 ligase regulating the monoubiquitination of fascin. Our findings revealed a previously unidentified regulatory mechanism for fascin, which will have important implications for the understanding of actin bundle regulation under physiological and pathological conditions.

SUMMARY Fascin protein is the main actin-bundling protein in filopodia and invadopodia, which are critical for tumor cell migration, invasion, and metastasis. Small-molecule fascin inhibitors block tumor invasion and metastasis and increase the overall survival of tumor-bearing mice. Here, we report a finding that fascin blockade additionally reinvigorates anti-tumor immune response in syngeneic mouse models of various cancers. Fascin protein levels are increased in conventional dendritic cells (cDCs) in the tumor microenvironment. Mechanistically, fascin inhibitor NP-G2–044 increases the number of intratumoral-activated cDCs and enhances the antigen uptake by cDCs. Furthermore, together with PD-1 blocking antibody, NP-G2–044 markedly increases the number of activated CD8+ T cells in the otherwise anti-PD-1 refractory tumors. Reduction of fascin levels in cDCs, but not fascin gene knockout in tumor cells, mimics the anti-tumor immune effect of NP-G2–044. These data demonstrate that fascin inhibitor NP-G2–044 simultaneously limits tumor metastasis and reinvigorates anti-tumor immune responses., Graphical Abstract, In brief Wang et al. report that fascin inhibitors act on intratumoral dendritic cells to block the migration and increase the antigen uptake. Together with anti-PD-1 antibody, fascin inhibitors increase the number of intratumoral proliferating and activated CD8+ T cells and the overall survival of mice bearing the otherwise anti-PD-1 refractory tumors.

Follicular dendritic cell sarcoma (FDCS) can be divided into the conventional type, and the inflammatory pseudotumor (IPT)-like variant type. Epstein-Barr virus (EBV) infection is considered to be closely associated with the pathogenesis of IPT-like variant of FDCS. Hepatic FDCS has an exceedingly low incidence of only 29 cases reported, with most of these tumors being classified as the IPT-like type. We report a case of an IPT-like variant of FDCS of the liver in a 61-year old man who presented with no marked symptoms. The patient underwent laparoscopic surgery for the mass and was well during a 13-month follow-up periods. The postoperative pathological examination found a proliferation of spindle cells and a diffuse infiltration of inflammatory cells within the tumor. Immunohistochemistry revealed that neoplastic cells were positive for CD23, clusterin, fascin, and PD-L1, and weakly positive for CD35, SMA, and D2-40. The infiltrating lymphocytes were strongly positive for PD1, and IgG4-positive plasma cells were less than 10 cells/high-power field. In situ hybridization for Epstein-Barr virus encoded RNA (EBER) was negative. To our knowledge, the present case is the second case of hepatic IPT-like variant of FDCS without EBV involvement, indicating that EBV infection is not an absolute prerequisite for a diagnosis of the IPT-like variant of FDCS.

Objective. Identifying markers that influence oral squamous cell carcinoma (OSCC) prognosis is a fundamental strategy to improve the overall survival of patients. Markers such as eukaryotic translation elongation factor 1 delta (EEF1D), fascin, N-terminal propeptide of type I collagen (PINP), and cancer-associated fibroblasts (CAFs) have been noticed in OSCCs and their levels are closely related to the prognosis of tumors. Our aim was to confirm the role of those markers in OSCC prognosis. Study Design. Immunohistochemistry was performed in 90 OSCC specimens. The associations between clinicopathologic features and expression of markers were assessed by chi(2) test. Kaplan-Meier curves and univariate and multivariate Cox regression models were used for survival analysis. Markers were analyzed individually and in combination. Results. High expression of EEF1D (P =.017) and PINP (P =.02) and abundant density of CAFs in tumor stroma (P =.005) predicted significantly poor survival in OSCC patients. Multivariate analysis revealed that all 3 parameters are individually independent prognostic factors of OSCC patients, and their combination improved the discrimination of patients at high risk for poor survival. Conclusions. Our results suggested that the expression of EEF1D and PINP and the density of CAFs might influence the survival of patients with OSCC.

Follicular dendritic cell sarcoma (FDCS) is a rare low-grade neoplasm with the phenotype of FDC cells. This rare sarcoma has been well known for being mistaken for a variety of neoplasms (mainly meningioma), particularly at extranodal sites. Diagnosis of FDCS mainly relies on characteristic histologic appearance supplemented by immunohistochemistry and electron microscopy. In this study, we reviewed 15 FDCSs retrieved from our consultation files and stained them for newly reported or novel markers (PD-L1, Rb1, MDM2, and somatostatin receptor 2A [SSTR2A]) in addition to conventional FDC markers. Patients were 7 men and 7 women (1 unspecified) with a mean age of 47 years (20-75 years). The tumor site was lymph nodes (6) or spleen (2), both (1) and extranodal sites of head and neck (4) or abdominal cavity (2). Treatment was variable combinations of surgery and aggressive chemotherapy/radiotherapy. Four of 8 patients with follow-up died of disease within 1 to 10 years. All tumors expressed at least 1 FDC marker: CD21 (8/13), CD23 (2/13), CD35 (8/12), CNA.42 (13/14), Clusterin (8/13), Fascin (15/15) and D2-40/podoplanin (7/14). Epstein-Barr virus (EBER-1/2 in situ hybridization) was performed successfully in 10 conventional variants; all were negative. Five of 14 cases (36%) stained strongly for SSTR2A with a distinctive membranous pattern. Residual lymphoid follicles surrounding some of the tumors stained similarly for SSTR2A. Seven (54%) of 13 assessable cases showed moderate to strong membranous staining for PD-L1 in greater than 5% of the neoplastic cells. The Rb1 antigen was lost in 4 (28%) of 14 cases. MDM2 stained less than 5% to 20% of the tumor cells in 5 (36%) of 14 cases; 2 of them showed amplification by fluorescence in situ hybridization (FISH). CDK4 was negative except for weak staining in 1 of 14 cases. This study adds to the existing few clinicopathologic series on FDCS and represents the first study to show MDM2 amplification in this entity. Our results regarding frequent SSTR2A expression in FDCS are novel and might be of potential diagnostic and therapeutic relevance. SSTR2A expression in FDCS represents a further confusing factor when thinking of meningioma which uniformly expresses this receptor. FDCS occurring within the retroperitoneum and/or the abdominal cavity may closely mimic dedifferentiated liposarcoma, particularly if MDM2 positive and/or amplified and should thus be carefully assessed for expression of FDC markers.

Inositol displays multi-targeted effects on many biochemical pathways involved in epithelial-mesenchymal transition (EMT). As Akt activation is inhibited by inositol, we investigated if such effect could hamper EMT in MDA-MB-231 breast cancer cells. In cancer cells treated with pharmacological doses of inositol E-cadherin was increased, β-catenin was redistributed behind cell membrane, and metalloproteinase-9 was significantly reduced, while motility and invading capacity were severely inhibited. Those changes were associated with a significant down-regulation of PI3K/Akt activity, leading to a decrease in downstream signaling effectors: NF-kB, COX-2, and SNAI1. Inositol-mediated inhibition of PS1 leads to lowered Notch 1 release, thus contributing in decreasing SNAI1 levels. Overall, these data indicated that inositol inhibits the principal molecular pathway supporting EMT. Similar results were obtained in ZR-75, a highly metastatic breast cancer line. These findings are coupled with significant changes on cytoskeleton. Inositol slowed-down vimentin expression in cells placed behind the wound-healing edge and stabilized cortical F-actin. Moreover, lamellipodia and filopodia, two specific membrane extensions enabling cell migration and invasiveness, were no longer detectable after inositol addiction. Additionally, fascin and cofilin, two mandatory required components for F-actin assembling within cell protrusions, were highly reduced. These data suggest that inositol may induce an EMT reversion in breast cancer cells, suppressing motility and invasiveness through cytoskeleton modifications.

Invadopodia and filopodia are dynamic, actin-based protrusions contributing to cancer cell migration, invasion, and metastasis. The force of actin bundles is essential for their protrusive activity. The bundling protein fascin is known to play a role in both invadopodia and filopodia. As it is more and more acknowledged that functionally related proteins cooperate, it is unlikely that only fascin bundles actin in these protrusions. Another interesting candidate is L-plastin, normally expressed in hematopoietic cells, but considered a common marker of many cancer types. We identified L-plastin as a new component of invadopodia, where it contributes to degradation and invasiveness. By means of specific, high-affinity nanobodies inhibiting bundling of fascin or L-plastin, we further unraveled their cooperative mode of action. We show that the bundlers cannot compensate for each other due to strikingly different bundling characteristics: L-plastin bundles are much thinner and less tightly packed. Composite bundles adopt an intermediate phenotype, with fascin delivering the rigidity and strength for protrusive force and structural stability, whereas L-plastin accounts for the flexibility needed for elongation. Consistent with this, elevated L-plastin expression promotes elongation and reduces protrusion density in cells with relatively lower L-plastin than fascin levels.

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplastic proliferation with variable clinical behavior; the male:female ratio is 1.6:1.0. The pathogenesis of LCH is imperfectly understood. A newborn boy, 1 month old, had a small focal lesion with a papillomatous surface, was cured, and the tissue removed was granulomatous, friable, and bleeding. The microscopic examination revealed histiocytes with abundant eosinophilic cytoplasm and lobulated or coffee bean-like nucleus admixed with a variable number of eosinophils, lymphocytes, and neutrophils. In a immunohistochemical study, cells were positive for CD1A, S100, CD68, and fascin. The patient was referred to the onco-hematology service of a pediatric hospital and had his body fully examined, without other lesions being identified. After a 2-year follow-up, there was no recurrence. At the site where the lesion was cured, an ulcer remained, through which the early eruption of the tooth 84 occurred. This tooth is currently present.

Background Renal fibrosis is the characteristic of all kinds of chronic kidney diseases (CKDs). Fascin-1 plays an important role in tumor development, but the roles of fascin-1 in renal fibrosis have not been studied. Here, we explored the role of fascin-1 in renal fibrosis and the potential mechanisms. Methods Kidney unilateral ureteral obstruction (UUO) mouse model was used as an in vivo model, and proximal tubule epithelial cell lines treated with TGF-β1 were used as in vitro model of renal fibrosis. Cell transfection was performed to manipulate the expression of miR-200b/c, fascin-1 and CD44. Western blotting, qRT-PCR, immunohistochemistry or immunofluorescence assays were used to measure levels of miR-200b/c, fascin-1, CD44, and fibrosis and EMT-related markers. H&E and Masson stainings were used to examine the degree of injury and fibrosis in kidneys. Dual luciferase assay was used to examine the interaction between miR-200b/c family and fascin-1. Results Fascin-1 and CD44 levels were both significantly up-regulated while miR-200b/c family was reduced in models of renal fibrosis. Furthermore, overexpression of miR-200b/c family and inhibition of fascin-1 or CD44 ameliorated renal fibrosis through suppressing EMT process. Mechanistically, miR-200b/c family directly and negatively regulated the expression of fascin-1. Overexpression of fascin-1 could reverse the effects of miR-200b/c family on renal fibrosis, and fascin-1 regulated renal fibrosis by activating CD44. Conclusion Our study is the first to show that fascin-1 plays a critical role in renal fibrosis. MiR-200b/c family could inhibit renal fibrosis through modulating EMT process by directly targeting fascin-1/CD44 axis.

Oral cancer is a relevant public health problem, with a reduced survival rate and absence of specific markers capable of predicting the prognosis. This study aimed to analyze the association of tumor budding and depth of invasion (BD) model and specific markers (stc2: stanniocalcin 2; pinp: type I collagen N-terminal propeptide; effd1: eukaryotic translation elongation factor 1 delta; plectin; and fascin) with clinicopathologic parameters and outcome of 124 tongue and floor of mouth squamous cell carcinomas (SCCs) to identify their roles in prognosis. Significant associations with survival were observed for BD model and tumor budding in the univariate analysis, and these parameters resisted the Cox multivariate analysis. Surgical margins, recurrence, and metastasis were also independent markers of reduced survival. The immunoexpression of pinp and stc2 were significantly associated with shortened survival of patients with tongue and floor of mouth SCC. Our findings indicate that the intensity of tumor budding and the BD model may be novel prognostic markers for patients with tongue and floor of mouth SCC and also identified potential new therapeutic targets such as pinp and stc2. Financial support: FAPEMIG (Brasil); FONDECYT (Chile).

Objectives The purpose of this study was to assess and compare fascin expression in 4 lesions which differ in aggressiveness: odontogenic keratocyst (OKC), dentigerous cyst (DC) and two types of solid and unicystic ameloblastoma, and to find out whether fascin expression is associated with aggressiveness of these lesions or not. Methods 9 solid ameloblastomas (SA), 12 unicystic ameloblastomas (UA), 13 OKC and 12 DC were assessed in this study. The slides were examined at x400 magnification. Finally the lesions were divided into two groups based on microscopic examination, “low expression” and “high expression”. Findings There were no significant differences between the lesions, except that fascin expression was slightly higher in UA in comparison to other groups in intensity and count of the immunostaining cells. Conclusions The results of this study suggest that fascin might be more involved in cell invasion and migration (as in carcinomas) than local aggressiveness. We suggest more studies with more samples, assessing expression of different proteins be done in the future.

Article, Previous studies have shown that overexpression of enzymatically active GFP-HAS induces the growth of long, slender protrusions that share many features of both filopodia and microvilli. These protrusions are dependent on continuing hyaluronan synthesis, and disrupt upon digestion of hyaluronan by hyaluronidase. However, complete understanding of their nature is still missing. This work shows that the protrusions on rat peritoneal surface are ultrastructurally indistinguishable from those induced by GFP-HAS3 in MCF-7 cells. Analysis of the actin-associated proteins villin, ezrin, espin, fascin, and Myo10 indicated that the HAS3-induced protrusions share most cytoskeletal features with filopodia, but they do not require adherence to the substratum like traditional filopodia. GFP-HAS3 overexpression was found to markedly enhance filamentous actin in the protrusions and their cortical basis. Analysis of the protrusion dynamics after enzymatic digestion of hyaluronan revealed that while GFP-HAS3 escape from the protrusions and the protrusion collapse takes place immediately, the complete retraction of the protrusions occurs more slowly. This finding also suggests that hyaluronan chain maintains HAS3 in the plasma membrane. The results of this work suggest that protrusions similar to those of HAS3 overexpressing cells in vitro exist also in cells with active hyaluronan synthesis in vivo. These protrusions are similar to common filopodia but are independent of substratum attachment due to the extracellular scaffolding by the hyaluronan coat that accounts for the growth and maintenance of these structures, previously associated to invasion, adhesion and multidrug resistance., final draft, http://purl.org/eprint/status/PeerReviewed

Background Actin filament bundling proteins mediate numerous processes in cells such as the formation of cell membrane protrusions or cell adhesions and stress fiber based locomotion. Among them alpha-actinin and fascin are the most abundant ones. This work characterizes differences in molecular motions in actin filaments due to the binding of these two actin bundling proteins. Methods We investigated how alpha-actinin and fascin binding modify the conformation of actin filaments by using conventional and saturation transfer EPR methods. Results The result characteristic for motions on the microsecond time scale showed that both actin bundling proteins made the bending and torsional twisting of the actin filaments slower. When nanosecond time scale molecular motions were described the two proteins were found to induce opposite changes in the actin filaments. The binding of one molecule of alpha-actinin or fascin modified the conformation of numerous actin protomers. Conclusion As fascin and alpha-actinin participates in different cellular processes their binding can serve the proper tuning of the structure of actin by establishing the right conformation for the interactions with other actin binding proteins. Our observations are in correlation with the model where actin filaments fulfill their biological functions under the regulation by actin-binding proteins. General significance Supporting the general model for the cellular regulation of the actin cytoskeleton we showed that two abundant actin bundling proteins, fascin and alpha-actinin, alter the conformation of actin filaments through long range allosteric interactions in two different ways providing the structural framework for the adaptation to specific biological functions.

While absent from normal epithelia, an actin bundling protein, fascin, becomes expressed in invasive carcinoma of different origins. It is highly enriched at the tumors’ invasive front suggesting that it could play a role in cancer invasion. Multiple studies have shown that fascin, through its role in formation of cellular protrusions such as filopodia and invadopodia, enhances cancer cell migration and invasion in vitro. However, the role of fascin in vivo remains unknown. We have generated a compound transgenic mouse model that allows expression of fascin in the intestinal epithelium in the Apc-mutated background. Conditional expression of fascin led to decrease in mice survival and increase in tumor burden compared to control animals. Induction of fascin expression in adult tumor-bearing animals accelerated tumor progression and led to formation of invasive adenocarcinoma. Altogether, our study shows that fascin can promote tumor progression in vivo, but also unravels an unexpected role of fascin in tumor initiation.

Invadopodia are actin-rich protrusions that degrade the extracellular matrix and are required for penetration through the basement membrane, stromal invasion and intravasation. Invadopodia are enriched in actin regulators, such as cortactin, cofilin, N-WASp, Arp2/3 and fascin. Much of the work to date has centered around identifying the proteins involved in regulating actin polymerization and matrix degradation. Recently, there have been significant advances in characterization of the very early stages of invadopodium precursor assembly and the role of adhesion proteins, such as β1 integrin, talin, FAK and Hic-5, in promoting invadopodium maturation. This review summarizes these findings in the context of our current model of invadopodial function and highlights some of the important unanswered questions in the field.

BackgroundBundles of unipolar actin filaments (F-actin), cross-linked via the actin-binding protein fascin, are important in filopodia of motile cells and stereocilia of inner ear sensory cells. However, such bundles are also useful as shuttles in myosin-driven nanotechnological applications. Therefore, and for elucidating aspects of biological function, we investigate if the bundle tendency to follow straight paths (quantified by path persistence length) when propelled by myosin motors is directly determined by material properties quantified by persistence length of thermally fluctuating bundles.MethodsFluorescent bundles, labeled with rhodamine-phalloidin, were studied at fascin:actin molar ratios: 0:1 (F-actin), 1:7, 1:4 and 1:2. Persistence lengths (Lp) were obtained by fitting the cosine correlation function (CCF) to a single exponential function: =exp(−s/(2Lp)) where θ(s) is tangent angle; s: path or contour lengths. < > denotes averaging over filaments.ResultsBundle-Lp (bundles

Prognostication and therapeutic evaluation of urothelial carcinomas significantly depends on the depth of invasion. The assessment of invasion on routine histopathological sections may be difficult in some cases. Fascin is an actin-bundling protein involved in tumor cell migration with enhanced expression associated with invasive tumors. The data available on fascin-1 expression in urothelial carcinoma however is limited. To characterize fascin-1 expression in urothelial neoplasms and its correlation with invasiveness in urothelial carcinomas.A descriptive study design wherein fascin-1 immunoreactivity was studied in 126 urothelial neoplasms using monoclonal antibody against fascin by immunohistochemistry. 52/126 (41.26%) were low grade carcinomas (48/52 stage pTa and 4/52 stage pT1), 46/126 (36.5%) high grade carcinomas (13/46 stage pTa, 8/46 stage pT1 and 25/46 stage pT2), 02/126 carcinoma-in-situ, 03/126 papilloma, 12/126 papillary urothelial neoplasm of uncertain malignant potential and 11/126 were other variants of urothelial carcinomas. Fascin-1 cytoplasmic immunoreactivity was assessed semiquantitatively in terms of extent, intensity and a combined immunoreactivity score. Correlation between immunoreactivity scores and invasiveness was evaluated using Pearson's chi-square (χ2) and Nonparametric Spearman rho (ρ) correlation coefficient two tailed.The scores for intensity, extent and combined immunoreactivity were significantly higher in invasive carcinomas. In addition, strong staining was observed exclusively in invasive carcinomas. None of the pTa tumors demonstrated intense staining, including those categorized as high grade carcinomas.Fascin-1 overexpression may be used as a marker in urothelial carcinomas where it is morphologically difficult to determine the status of invasion.

Background The actin cytoskeleton is critically involved in the regulation of neurite outgrowth. Results The actin cytoskeleton-associated protein tropomyosin induces neurite outgrowth in B35 neuroblastoma cells and regulates neurite branching in an isoform-dependent manner. Conclusions Our data indicate that tropomyosins are key regulators of the actin cytoskeleton during neurite outgrowth. Significance Revealing the molecular machinery that regulates the actin cytoskeleton during neurite outgrowth may provide new therapeutic strategies to promote neurite regeneration after nerve injury. Summary The formation of a branched network of neurites between communicating neurons is required for all higher functions in the nervous system. The dynamics of the actin cytoskeleton is fundamental to morphological changes in cell shape and the establishment of these branched networks. The actin-associated proteins tropomyosins have previously been shown to impact on different aspects of neurite formation. Here we demonstrate that an increased expression of tropomyosins is sufficient to induce the formation of neurites in B35 neuroblastoma cells. Furthermore, our data highlight the functional diversity of different tropomyosin isoforms during neuritogenesis. Tropomyosins differentially impact on the expression levels of the actin filament bundling protein fascin and increase the formation of filopodia along the length of neurites. Our data suggest that tropomyosins are central regulators of actin filament populations which drive distinct aspects of neuronal morphogenesis.

Introduction Serrated adenocarcinoma (SAC) is a histological subtype of colorrectal carcinoma characterised by its poor prognosis, prominent invasive front and over-expression of fascin, the key protein involved in actine bundling needed for cell migration and invasion. Given that the frequency of KRAS or BRAF mutations in SAC are higher than in conventional colorectal carcinoma, this tumour type is usually resistant to anti-EGFR therapy. For these reason, anti-fascin treatment could be an interesting aproach to treat SAC and other tumours over-expressing fascin. In this work we have charaterized the anti-migratory and anti-invasive properties of compound G2 (N-(1-(4-(trifluoromethyl)benzyl)−1H-indazol-3-yl)furan-2-carboxamide), a patented anti-fascin molecule and compared its effect with migrastatine, a typical fascin inhibitor. Material and methods We have used molecular modelling to predict the fascin aminoacids involved in G2 binding. A qPCR assay was carried to find out which from eigth different colorectal cancer cell lines expressed the highest amount of fascin. After cell viability assay, scratch and IBIDI assays were performed to evaluate the anti-migratory effect of the compounds. Immunofluoresce for fascin was used for assessing lamelipodia formation. Anti-invasive effect was evaluated using cell invasion assay Transwell with matrigel and a myoma organotypic invasion model. Results and discussions Molecular modelling using blind docking calculations identified a region in fascin possibly involved in G2 binding. HCT116 cells expressed the highest fascin levels and its migration capacity was clearly reduced by migrastatin and G2, the latter even at lower concentrations. Still, G2 inhibited the migration of all the cell lines demonstrating that G2 affected fascin functional capacity. Invasion and confocal studies were performed with HCT116 cells and both inhibitors strongly abolished the protrusion of lamellipodium (p=0.003). The Transwell Matrigel invasion assay also evidenced the anti-invasive effects of migrastatin and G2. Myoma discs showed that both compounds were similarly able to significantly decrease both the invasion depth and invasion area of HCT116 cells at 50% (p Conclusion This study demonstrates an interesting anti-migratory and anit-invasive effect of G2 in a similar extent to migrastatin and provides significant evidence that G2 is an interesting candidate for further investigation/chemical modifications to develop new fascin-specific therapies for colorectal cancer.

SUMMARY The deregulation of the actin cytoskeleton has been extensively studied in metastatic dissemination. However, the post-dissemination role of the actin cytoskeleton dysregulation is poorly understood. Here, we report that fascin, an actin-bundling protein, promotes lung cancer metastatic colonization by augmenting metabolic stress resistance and mitochondrial oxidative phosphorylation (OXPHOS). Fascin is directly recruited to mitochondria under metabolic stress to stabilize mitochondrial actin filaments (mtF-actin). Using unbiased metabolomics and proteomics approaches, we discovered that fascin-mediated mtF-actin remodeling promotes mitochondrial OXPHOS by increasing the biogenesis of respiratory Complex I. Mechanistically, fascin and mtF-actin control the homeostasis of mtDNA to promote mitochondrial OXPHOS. The disruption of mtF-actin abrogates fascin-mediated lung cancer metastasis. Conversely, restoration of mitochondrial respiration by using yeast NDI1 in fascin-depleted cancer cells is able to rescue lung metastasis. Our findings indicate that the dysregulated actin cytoskeleton in metastatic lung cancer could be targeted to rewire mitochondrial metabolism and to prevent metastatic recurrence., Graphical Abstract, In Brief Lin et. al. show that fascin, a prometastasis actin-bundling protein, promotes mitochondrial oxidative phosphorylation and metabolic stress resistance in lung adenocarcinoma by remodeling mitochondrial actin filaments and regulating the homeostasis of mitochondrial DNA.

Summary Filopodia are adhesive cellular protrusions specialized in the detection of extracellular matrix (ECM)-derived cues. Although ECM engagement at focal adhesions is known to trigger the recruitment of hundreds of proteins (“adhesome”) to fine-tune cellular behavior, the components of the filopodia adhesions remain undefined. Here, we performed a structured-illumination-microscopy-based screen to map the localization of 80 target proteins, linked to cell adhesion and migration, within myosin-X-induced filopodia. We demonstrate preferential enrichment of several adhesion proteins to either filopodia tips, filopodia shafts, or shaft subdomains, suggesting divergent, spatially restricted functions for these proteins. Moreover, proteins with phosphoinositide (PI) binding sites are particularly enriched in filopodia. This, together with the strong localization of PI(3,4)P2 in filopodia tips, predicts critical roles for PIs in regulating filopodia ultra-structure and function. Our mapping further reveals that filopodia adhesions consist of a unique set of proteins, the filopodome, that are distinct from classical nascent adhesions, focal adhesions, and fibrillar adhesions. Using live imaging, we observe that filopodia adhesions can give rise to nascent adhesions, which, in turn, form focal adhesions. We demonstrate that p130Cas (BCAR1) is recruited to filopodia tips via its C-terminal Cas family homology domain (CCHD) and acts as a mechanosensitive regulator of filopodia stability. Finally, we demonstrate that our map based on myosin-X-induced filopodia can be translated to endogenous filopodia and fascin- and IRSp53-mediated filopodia., Highlights • A super-resolution microscopy screen reveals filopodia core and accessory proteins • FAK and paxillin are accessory, and not core, components of filopodia tip adhesions • PI(3,4)P2 is the prominent phosphatidylinositol species enriched at filopodia tips • p130Cas is a mechanosensitive regulator of filopodia stability, Jacquemet et al. perform super-resolution imaging of filopodia and define a map of core and accessory components based on a pool of target proteins linked to cell adhesion. They show that filopodia adhesions are distinct from classical adhesions and nucleate nascent adhesions and are mechanosensitive, requiring phospho-p130Cas for stabilization.

a b s t r a c t Objectives: Fascin, a conserved actin bundling protein family member, is frequently up-regulated in vari- ous cancer types, including non-small-cell lung cancer (NSCLC), and it plays increasingly important roles in the progression of tumor invasion and metastasis. However, variations in the serum fascin level in tumor patients are usually neglected. Materials and Methods: In the present study, serum samples from 501 stage I-IV NSCLC patients and 109 healthy volunteers were investigated by an enzyme-linked immunosorbent assay. Results: The serum fascin level was markedly increased in the NSCLC patients (P < 0.05), particularly in advanced cases (P < 0.01), compared with that in the healthy controls. We also found that the serum fascin level was significantly correlated with female sex (P = 0.02), non-smoking status (P = 0.044), and adenocarcinoma histology (P < 0.001), with a higher positive rate relative to each counterpart. Further- more, our results suggested that the serum fascin level reflects the aggressive progress of both lymphatic (P < 0.001) and distant (P < 0.001) metastases in NSCLC. A survival analysis of 283 eligible patients who underwent a follow-up examination after 3 years revealed that the patients in the serum fascin-positive group had a significantly lower overall survival rate compared with those in the negative group for 134 non-distant metastatic (stage M0) cases (P = 0.044). A subsequent Cox regression analysis revealed that the serum fascin level was an independent prognostic factor for M0-stage NSCLC (univariate, P = 0.001; multivariate, P = 0.038). Conclusion: Our study suggests that the serum fascin level is an effective indicator of tumor aggressiveness, and that it plays an important role in the prognosis of NSCLC, particularly for non-distant metastatic

This study investigated the differential expression of fascin, E-cadherin and vimentin in human carcinogenesis.This study detected their expressions in 142 cholangiocarcinoma and 20 benign bile duct tissue specimens using immunohistochemistry. Clinicopathologic characteristics and survival data were also collected and analyzed for their association with expression of these 3 proteins.The data showed that both fascin and vimentin proteins were significantly overexpressed in cholangiocarcinoma, whereas E-cadherin expression was reduced in cholangiocarcinoma compared with normal tissues. Fascin protein expression was associated with tumor dedifferentiation, venous invasion and lymph node or distant metastasis. Similarly, vimentin expression was associated with tumor dedifferentiation and venous invasion, as well as hepatitis virus infection. In contrast, loss of E-cadherin expression was associated with tumor dedifferentiation (P0.05). Because the functions of these 3 proteins were closely related, the data showed that fascin and E-cadherin protein expression was reversely associated. However, fascin and vimentin protein expression was positively associated with cholangiocarcinoma. Cox multiple regression analysis showed that distant tumor metastasis, tumor differentiation and overexpression of fascin and vimentin proteins were all independent risk factors for prognosis (P0.05).The data from the current study demonstrated that overexpression of fascin and vimentin proteins could be further evaluated as biomarkers for the prediction of cholangiocarcinoma patient survival.

SummaryFilopodia are slender cellular protrusions that dynamically extend and retract to facilitate directional cell migration, pathogen sensing, and cell-cell adhesion [1–4]. Each filopodium contains a rigid and organized bundle of parallel actin filaments, which are elongated at filopodial tips by formins and Ena/VASP proteins [5–10]. However, relatively little is known about how the actin filaments in the filopodial shaft are spatially organized to form a bundle with appropriate dimensions and mechanical properties. Here, we report that the mammalian formin Daam1 (Disheveled-associated activator of morphogenesis 1) is a potent actin-bundling protein and localizes all along the filopodial shaft, which differs from other formins that localize specifically to the tips. Silencing of Daam1 led to severe defects in filopodial number, integrity, and architecture, similar to silencing of the bundling protein fascin. This led us to investigate the potential relationship between Daam1 and fascin. Fascin and Daam1 coimmunoprecipitated from cell extracts, and silencing of fascin led to a striking loss of Daam1 localization to filopodial shafts, but not tips. Furthermore, purified fascin bound directly to Daam1, and multicolor single-molecule TIRF imaging revealed that fascin recruited Daam1 to and stabilized Daam1 on actin bundles in vitro. Our results reveal an unanticipated and direct collaboration between Daam1 and fascin in bundling actin, which is required for proper filopodial formation.

Histiocytic sarcoma (HS) is a rare neoplasm that occurs most commonly in the intestinal tract, skin, soft tissue, and lymph node. The incidence of primary central nervous system (CNS) HS is even rarer, with a total of 6 cases reported in the literature. An etiologic link has not been identified for CNS HS, and the current case of primary CNS HS is unique in that an etiologic link to prior radiation therapy is identified, associated with complex cytogenetic abnormalities in the tumor. Although radiation-associated sarcomas can present as any number of different pathologic entities, this is the first reported case of a radiation-associated CNS HS. The pathologic and immunophenotypic characteristics of this case, with a nearly obscuring heavy inflammatory infiltrate and expression of monocytic/histiocytic markers (CD163, CD68, CD4, fascin), are characteristic of CNS HS. A discussion of the differential diagnosis and review of relevant literature are presented.

MicroRNAs (miRNAs) are small, non-coding RNAs that are up- or downregulated in several types of cancer, and have an important role in the tumorigenesis and progression. To better understand the role of aberrantly expressed miRNAs and their target genes affecting the biology of gastrointestinal stromal tumor (GIST), we performed miRNA array in 19 cases of GIST, and found that several miRNAs, including miR-133b, were downregulated in high-grade GISTs. Subsequently, quantitative real-time reverse transcription-PCR revealed that fascin-1 mRNA was upregulated in accordance with miR-133b downregulation in high-grade GIST; this result was consistent with a previous report showing that fascin-1 might be a direct target of miR-133b. We then examined the fascin-1 protein expression by immunohistochemical staining in 147 cases of GIST, and found that fascin-1 overexpression was significantly correlated with shorter disease-free survival time and several aggressive pathological factors, including tumor size, mitotic counts, risk grade, blood vessel invasion and mucosal ulceration. Our results suggest that downregulation of miR-133b and overexpression of fascin-1 may have an important role in the progression of GIST, and that fascin-1 may be a useful biomarker to predict the aggressive behavior.

Today's living systems are organized in highly dynamic and structured functional units providing a platform for life. Despite the origin of life took place under extreme environmental conditions, few higher organisms can still be found in regions with extreme conditions of pressure and temperature. In vivo experiments revealed that, compared to other cellular components, the temperature and pressure stability of the cytoskeleton is rather limited. Actin, a key protein for cell shape and movement, is highly conserved and the most abundant protein in eukaryotes. Its polymerization reaction is essential to provide driving force for cellular motility and mechanical resistance for cell shape. Upon polymerization, actin filaments (F-actin) can be further organized into different architectures including crosslinked and bundled networks. In this study, using the examples of actin polymerization and bundling we illustrate the importance of actin-binding proteins for maintaining the stability and dynamics of the cytoskeleton in a pressurized world. Using preformed gelsolin-actin nuclei and applying stopped-flow methodology, we quantitatively studied the polymerization process of actin as a function of temperature and pressure and found that the temperature-pressure sensitivity of its kinetics is essentially due to the initial de novo nucleation event rather than the elongation reaction of F-actin, highlighting the need of actin nucleation factors to bypass the energetically costly and pressure-sensitive de novo nucleation in vivo ensuring formation of the microfilament (1). Furthermore, using small-angle X-ray scattering and transmission electron microscopy we compare the temperature-pressure stability of actin bundles formed by the protein fascin and Mg2+ and show that the naturally occurring bundles are more adapted to apply mechanical forces, also under high pressure conditions (2).(1) M. Gao, R. Winter (2015) ChemPhysChem, http://dx.doi.org/10.1002/cphc.201500633.(2) M. Gao, M. Berghaus, ⋯, R. Winter (2015) Angew. Chemie Int. Ed. 54:11088.

Objectives To evaluate the expression of fascin in bladder urothelial carcinoma, and to analyze its association with clinicopathologic features and prognosis of urinary bladder urothelial carcinoma. Materials and methods Immunohistochemistry was used to detect the expression of fascin, Ki-67, p53, CK20, and multidrug resistance gene (MDR) in 111 bladder urothelial carcinoma and 42 normal epithelial tissues. The association between fascin expression and clinicopathologic parameters and prognostic factors on tumor recurrence was analyzed by Kaplan-Meier method, log-rank test, and Cox proportional hazards model. Results Ninety-four of 111 cases of bladder urothelial carcinoma showed positive fascin expression, while no fascin expression was detected in normal transitional epithelium. There was a significant difference in the expression of fascin in normal epithelium and bladder urothelial carcinoma ( P = 0.000). Fascin expression was positively correlated with p T stage ( P = 0.001) and tumor size ( P = 0.011), while it had no association with age, gender, and tumor grade ( P > 0.05). p T stage and the expression of fascin, Ki-67, p53, and CK20 were significantly correlated with urothelial carcinoma recurrence, and fascin expression was an independent factor predicting tumor recurrence. Conclusions Fascin expression was up-regulated in bladder urothelial carcinoma. Over-expression of fascin might play an important role in invasiveness and recurrence of bladder urothelial carcinoma. Fascin may be used as a prognostic marker and a new target for the treatment of bladder urothelial carcinoma.

Our previous study demonstrated that fascin homolog 1 (FSCN1) might have an oncogenic function in bladder cancer (BC) and that its expression was regulated by specific microRNAs (miRNAs). Recently, LIM and SH3 protein 1 (LASP1) as well as FSCN1 have been reported as actin filament bundling proteins in the same complexes attached to the inner surfaces of cell membranes. We hypothesize that LASP1 as well as FSCN1 have an oncogenic function and that is regulated by miRNAs targeting LASP1 mRNA.The expression levels of LASP1 mRNA in 86 clinical samples were evaluated by real-time RT-PCR. LASP1-knockdown BC cell lines were transfected by siRNA in order to examine cellular viability by XTT assay, wound healing assay, and matrigel invasion assay. We employed web-based software in order to search for candidate miRNAs targeting LASP1 mRNA, and we focused on miR-1, miR-133a, miR-145, and miR-218. The luciferase reporter assay was used to confirm the actual binding sites between the miRNAs and LASP1 mRNA.Real-time RT-PCR showed that LASP1 mRNA expression was higher in 76 clinical BC specimens than in 10 normal bladder epitheliums (P0.05). Loss-of-function studies using si-LASP1-transfected BC cell lines demonstrated significant cell viability inhibition (P0.0005), cell migration inhibition (P0.0001), and a decrease in the number of invading cells (P0.005) in the transfectants compared with the controls. Transient transfection of three miRNAs (miR-1, miR-133a, and miR-218), which were predicted as the miRNAs targeting LASP1 mRNA, repressed the expression levels of mRNA and protein levels of LASP1. The luciferase reporter assay demonstrated that the luminescence intensity was significantly decreased in miR-1, miR-133a, and miR-218 transfectants (P0.05), suggesting that these miRNAs have actual target sites in the 3' untranslated region of LASP1 mRNA. Furthermore, significant cell viability inhibitions occurred in miR-218, miR-1, and miR-133a transfectants (P0.001).Our data indicate that LASP1 may have an oncogenic function and that it might be regulated by miR-1, miR-133a, and miR-218, which may function as tumor suppressive miRNAs in BC.

Cell motility is locally achieved by the interplay between lamellipodia and filopodia at the protrusion sites. The actin cytoskeleton rearranges from a highly branched short filamentous network to well aligned elongated bundles from lamellipodia to filopodia, respectively. This process is governed predominantly by actin binding proteins, VASP and fascin, at the leading edge of migratory cells. Here we use an Arp2/3-complex dependent bead motility assay to study the effect of fascin both on its own and in the presence of VASP. The Young's modulus of phalloidin stabilized comets grown in the presence of fascin increased linearly with concentration above a 0.5 μM threshold. Inversely, the initial velocity of the comets decreased linearly with fascin concentration above the same threshold. Interestingly, VASP and fascin together increased the Young's modulus of the comets compared to those grown in the presence of only one of the two proteins. This effect was most remarkable at low concentration, below 0.5 and 0.15 μM for fascin and VASP, respectively. Our results showed that fascin and VASP work cooperatively to enhance the Young's modulus of the actin network within the comets.

Intracellular vesicular transport through the cell's physically challenging, three dimensional (3D), actin cytoskeleton requires teams of Myosin Va (MyoVa) motors to navigate vastly different structures, such as the dense cortical actin network and bundled actin filaments in filopodia. To understand how MyoVa cargo transport is achieved through and along these cytoskeletal structures, we created 3 µm thick biomimetic actin networks in vitro, using actin organizing/binding proteins (fascin, Arp2/3, WASP, gelsolin) and imaged the networks using 3D STORM microscopy.