Fascin1 in carcinomas: Its regulation and prognostic value

The FSCN1 gene rs2966447 variant is associated with increased serum fascin-1 levels and breast cancer susceptibility

Fascin-1 (FSCN1) is recognized as an actin-binding protein, commonly exhibits up-regulation in breast cancer (BC) and is crucial for tumor invasion and metastasis. The existence of FSCN1 gene polymorphisms may raise the potential for developing BC, and there are still no studies focusing on the relationship between the FSCN1 rs2966447 variant and BC risk in Egyptian females. Thus, we investigated the serum fascin-1 levels in BC patients and the association between the FSCN1 rs2966447 variant with its serum levels and BC susceptibility. Genotyping was conducted in 153 treatment-naïve BC females with different stages and 144 apparent healthy females by TaqMan® allelic discrimination assay, whereas serum fascin-1 level quantification was employed by ELISA. The FSCN1 rs2966447 variant demonstrated a significant association with BC susceptibility under all utilized genetic models, cancer stages and estrogen receptor negativity. Also, BC females with AT and TT genotypes had higher serum fascin-1 levels and tumor size than those with the AA genotype. Moreover, serum fascin-1 levels were significantly elevated in the BC females, notably in those with advanced-stages. Furthermore, serum fascin-1 levels were markedly positively correlated with number of positive lymph nodes as well as tumor size. Collectively, these findings revealed that the FSCN1 rs2966447 variant may be regarded as a strong candidate for BC susceptibility. Also, this intronic variant is associated with increased serum fascin-1 levels and tumor size.

Fascin-1 Promotes Cell Metastasis through Epithelial-Mesenchymal Transition in Canine Mammary Tumor Cell Lines

Canine mammary tumors (CMTs) are the most common type of tumor in female dogs. In this study, we obtained a metastatic key protein, Fascin-1, by comparing the proteomics data of in situ tumor and metastatic cell lines from the same individual. However, the role of Fascin-1 in the CMT cell line is still unclear. Firstly, proteomics was used to analyze the differential expression of Fascin-1 between the CMT cell lines CHMm and CHMp. Then, the overexpression (CHMm-OE and CHMp-OE) and knockdown (CHMm-KD and CHMp-KD) cell lines were established by lentivirus transduction. Finally, the differentially expressed proteins (DEPs) in CHMm and CHMm-OE cells were identified through proteomics. The results showed that the CHMm cells isolated from CMT abdominal metastases exhibited minimal expression of Fascin-1. The migration, adhesion, and invasion ability of CHMm-OE and CHMp-OE cells increased, while the migration, adhesion, and invasion ability of CHMm-KD and CHMp-KD cells decreased. The overexpression of Fascin-1 can upregulate the Tetraspanin 4 (TSPAN4) protein in CHMm cells and increase the number of migrations. In conclusion, re-expressed Fascin-1 could promote cell EMT and increase lamellipodia formation, resulting in the enhancement of CHMm cell migration, adhesion, and invasion in vitro. This may be beneficial to improve female dogs' prognosis of CMT.

A nanobody inhibitor of Fascin-1 actin-bundling activity and filopodia formation

Fascin-1-mediated actin-bundling activity is central to the generation of plasma membrane protrusions required for cell migration. Dysregulated formation of cellular protrusions is observed in metastatic cancers, where they are required for increased invasiveness, and is often correlated with increased Fascin-1 abundance. Therefore, there is interest in generating therapeutic Fascin-1 inhibitors. We present the identification of Nb 3E11, a nanobody inhibitor of Fascin-1 actin-bundling activity and filopodia formation. The crystal structure of the Fascin-1/Nb 3E11 complex reveals the structural mechanism of inhibition. Nb 3E11 occludes an actin-binding site on the third β-trefoil domain of Fascin-1 that is currently not targeted by chemical inhibitors. Binding of Nb 3E11 to Fascin-1 induces a conformational change in the adjacent domains to stabilize Fascin-1 in an inhibitory state similar to that adopted in the presence of small-molecule inhibitors. Nb 3E11 could be used as a tool inhibitor molecule to aid in the development of Fascin-1 targeted therapeutics.

FSCN1 and epithelial mesenchymal transformation transcription factor expression in human pancreatic intraepithelial neoplasia and ductal adenocarcinoma

BACKGROUND

The actin regulatory protein fascin (FSCN1) and epithelial mesenchymal transition (EMT) transcription factor (TF) SLUG/SNAI2 have been shown to be expressed in PDAC and its precursor lesions (pancreatic intraepithelial neoplasia (PanIN), graded 1-3) in in vitro and murine in vivo studies. Our aim was to investigate the expression of FSCN1 and EMT-TFs and their association with survival in human PanIN and PDAC.

METHODS

Expression was investigated in silico using TCGA PanCancer Atlas data (177 PDAC samples with mRNA data) and immunohistochemical staining of a tissue microarray (TMA) (59 PDAC patients).

RESULTS

High FSCN1 expression was associated with poorer overall survival (p = 0.02) in the TCGA data. EMT-TF expression was not associated with survival, however FSCN1 expression correlated with that of the EMT-TFs SLUG/SNAI2 (rho = 0.49, p < 0.001) and TWIST1 (rho = 0.52, p < 0.001). TMA IHC showed low expression of SNAI2 and TWIST1 in normal ductal epithelium, while FSCN1 was not expressed. SNAI2 increased slightly in PanIN1-2, then decreased in higher grade lesions. TWIST1 increased in PanIN2-3 and was retained in PDAC. FSCN1 was increasingly expressed from PanIN2 onwards. SNAI2 and TWIST1 expression positively correlated in all grades of PanIN and PDAC (rho = 0.52, p < 0.001). FSCN1 correlated positively with SNAI2 in PanIN1 (rho = 0.56, p < 0.01).

CONCLUSIONS

Increased expression of EMT-TFs in low-grade PanIN followed by FSCN1 in PanIN3 and PDAC suggests EMT-TFs may trigger FSCN1 expression and are potential early diagnostic markers. FSCN1 expression correlated with overall survival in PDAC and may have value as a prognostic marker.

Disassembly of bundled F-actin and cellular remodeling via an interplay of Mical, cofilin, and F-actin crosslinkers

Cellular form and function are controlled by the assembly and stability of actin cytoskeletal structures-but disassembling/pruning these structures is equally essential for the plasticity and remodeling that underlie behavioral adaptations. Importantly, the mechanisms of actin assembly have been well-defined-including that it is driven by actin's polymerization into filaments (F-actin) and then often bundling by crosslinking proteins into stable higher-order structures. In contrast, it remains less clear how these stable bundled F-actin structures are rapidly disassembled. We now uncover mechanisms that rapidly and extensively disassemble bundled F-actin. Using biochemical, structural, and imaging assays with purified proteins, we show that F-actin bundled with one of the most prominent crosslinkers, fascin, is extensively disassembled by Mical, the F-actin disassembly enzyme. Furthermore, the product of this Mical effect, Mical-oxidized actin, is poorly bundled by fascin, thereby further amplifying Mical's disassembly effects on bundled F-actin. Moreover, another critical F-actin regulator, cofilin, also affects fascin-bundled filaments, but we find herein that it synergizes with Mical to dramatically amplify its disassembly of bundled F-actin compared to the sum of their individual effects. Genetic and high-resolution cellular assays reveal that Mical also counteracts crosslinking proteins/bundled F-actin in vivo to control cellular extension, axon guidance, and Semaphorin/Plexin cell-cell repulsion. Yet, our results also support the idea that fascin-bundling serves to dampen Mical's F-actin disassembly in vitro and in vivo-and that physiologically relevant cellular remodeling requires a fine-tuned interplay between the factors that build bundled F-actin networks and those that disassemble them.

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.

Identifying a lactic acid metabolism-related gene signature contributes to predicting prognosis, immunotherapy efficacy, and tumor microenvironment of lung adenocarcinoma

Lactic acid, once considered as an endpoint or a waste metabolite of glycolysis, has emerged as a major regulator of cancer development, maintenance, and progression. However, studies about lactic acid metabolism-related genes (LRGs) in lung adenocarcinoma (LUAD) remain unclear. Two distinct molecular subtypes were identified on basis of 24 LRGs and found the significant enrichment of subtype A in metabolism-related pathways and had better overall survival (OS). Subsequently, a prognostic signature based on 5 OS-related LRGs was generated using Lasso Cox hazards regression analysis in TCGA dataset and was validated in two external cohorts. Then, a highly accurate nomogram was cosntructed to improve the clinical application of the LRG_score. By further analyzing the LRG_score, higher immune score and lower stromal score were found in the low LRG_score group, which presented a better prognosis. Patients with low LRG_score also exhibited lower somatic mutation rate, tumor mutation burden (TMB), and cancer stem cell (CSC) index. Three more independent cohorts (GSE126044: anti-PD-1, GSE135222: anti-PD-1, and IMvigor210: anti-PD-L1) were analyzed, and the results showed that patients in the low LRG_score category were more responsive to anti-PD-1/PD-L1 medication and had longer survival times. It was also determined that gefitinib, etoposide, erlotinib, and gemcitabine were more sensitive to the low LRG_score group. Finally, we validated the stability and reliability of LRG_score in cell lines, clinical tissue samples and HPA databases. Overall, the LRG_score may improve prognostic information and provide directions for current research on drug treatment strategies for LUAD patients.

Blockade of the pro-fibrotic reaction mediated by the miR-143/-145 cluster enhances the responses to targeted therapy in melanoma

Lineage dedifferentiation toward a mesenchymal‐like state displaying myofibroblast and fibrotic features is a common mechanism of adaptive and acquired resistance to targeted therapy in melanoma. Here, we show that the anti‐fibrotic drug nintedanib is active to normalize the fibrous ECM network, enhance the efficacy of MAPK‐targeted therapy, and delay tumor relapse in a preclinical model of melanoma. Acquisition of this resistant phenotype and its reversion by nintedanib pointed to miR‐143/‐145 pro‐fibrotic cluster as a driver of this mesenchymal‐like phenotype. Upregulation of the miR‐143/‐145 cluster under BRAFi/MAPKi therapy was observed in melanoma cells in vitro and in vivo and was associated with an invasive/undifferentiated profile. The 2 mature miRNAs generated from this cluster, miR‐143‐3p and miR‐145‐5p, collaborated to mediate transition toward a drug‐resistant undifferentiated mesenchymal‐like state by targeting Fascin actin‐bundling protein 1 (FSCN1), modulating the dynamic crosstalk between the actin cytoskeleton and the ECM through the regulation of focal adhesion dynamics and mechanotransduction pathways. Our study brings insights into a novel miRNA‐mediated regulatory network that contributes to non‐genetic adaptive drug resistance and provides proof of principle that preventing MAPKi‐induced pro‐fibrotic stromal response is a viable therapeutic opportunity for patients on targeted therapy.

Functional analysis of the miR-145/Fascin1 cascade in canine oral squamous cell carcinoma

OBJECTIVES

Canine oral squamous cell carcinoma (SCC) often develops in the gingiva and tonsils. The biological behaviour of canine oral SCC is similar to that of human head and neck SCC (HNSCC). Inhibiting invasion and metastasis is major importance for the treatment of canine and human HNSCC. In this study, the significance of microRNA (miR)-145 and Fascin1 (FSCN1) in the invasion of canine oral SCC was explored.

MATERIALS AND METHODS

Canine oral SCC tissues and cell lines were used for miR-145 and FSCN1 expression analysis via real-time PCR and immunohistochemistry. Canine oral SCC cell lines were used for in vitro assays.

RESULTS

miR-145 was downregulated while FSCN1 mRNA was upregulated in canine oral SCC. Immunohistochemistry revealed that FSCN1 was upregulated in SCC when compared to normal mucosa. Transfection of canine SCC cells with miR-145 or FSCN1 siRNA suppressed cell growth and attenuated cell migration as well as invasion by inhibiting the epithelial-to-mesenchymal transition. Furthermore, the promoter region of miR-145 was highly methylated in SCC cell lines and tissues.

CONCLUSION

The expression profile and functions of miR-145 in canine oral SCC are similar to those in human HNSCC. Thus, canine oral SCC may represent a valuable preclinical model for human HNSCC.

Alternative NF-κB Signaling Discriminates Induction of the Tumor Marker Fascin by the Viral Oncoproteins Tax-1 and Tax-2 of Human T-Cell Leukemia Viruses

Transcriptional regulation of the actin-bundling protein and tumor marker Fascin is highly diverse depending on cell and tumor type. Previously, we discovered that the viral oncoprotein Tax-1 of human T-cell leukemia virus type 1 (HTLV-1) considerably enhances Fascin expression in T-cells, depending on classical NF-κB signaling. In this study, we asked if the non-oncogenic Tax-2 of the related HTLV-2 is still able to induce Fascin by using luciferase assays, immunoblot, and qPCR. We found that Tax-2 only slightly induces Fascin expression compared to Tax-1; however, both Tax-1 and Tax-2 comparably activated a 1.6 kb fragment in the human Fascin promoter including Tax-responsive elements. Furthermore, we identified a link between Tax-induced activity of the alternative NF-κB pathway and Fascin induction. While treatment with the second mitochondria-derived activator of caspases (SMAC)-mimetic AZD5582, a compound known to robustly activate alternative NF-κB signaling, did not induce Fascin, combination of AZD5582 with activation of classical NF-κB signaling by Tax-2 significantly induced Fascin expression. In conclusion, our data demonstrate that both classical and alternative NF-κB activity are necessary for strong Fascin induction by the viral Tax oncoproteins, thus, shedding new light on the regulation of Fascin in T-cells and during viral transformation.

P300/CBP-associated factor (PCAF)-mediated acetylation of Fascin at lysine 471 inhibits its actin-bundling activity and tumor metastasis in esophageal cancer

BACKGROUND

Fascin is crucial for cancer cell filopodium formation and tumor metastasis, and is functionally regulated by post-translational modifications. However, whether and how Fascin is regulated by acetylation remains unclear. This study explored the regulation of Fascin acetylation and its corresponding roles in filopodium formation and tumor metastasis.

METHODS

Immunoprecipitation and glutathione-S-transferase pull-down assays were performed to examine the interaction between Fascin and acetyltransferase P300/CBP-associated factor (PCAF), and immunofluorescence was used to investigate their colocalization. An in vitro acetylation assay was performed to identify Fascin acetylation sites by using mass spectrometry. A specific antibody against acetylated Fascin was generated and used to detect the PCAF-mediated Fascin acetylation in esophageal squamous cell carcinoma (ESCC) cells using Western blotting by overexpressing and knocking down PCAF expression. An in vitro cell migration assay was performed, and a xenograft model was established to study in vivo tumor metastasis. Live-cell imaging and fluorescence recovery after photobleaching were used to evaluate the function and dynamics of acetylated Fascin in filopodium formation. The clinical significance of acetylated Fascin and PCAF in ESCC was evaluated using immunohistochemistry.

RESULTS

Fascin directly interacted and colocalized with PCAF in the cytoplasm and was acetylated at lysine 471 (K471) by PCAF. Using the specific anti-AcK471-Fascin antibody, Fascin was found to be acetylated in ESCC cells, and the acetylation level was consequently increased after PCAF overexpression and decreased after PCAF knockdown. Functionally, Fascin-K471 acetylation markedly suppressed in vitro ESCC cell migration and in vivo tumor metastasis, whereas Fascin-K471 deacetylation exhibited a potent oncogenic function. Moreover, Fascin-K471 acetylation reduced filopodial length and density, and lifespan of ESCC cells, while its deacetylation produced the opposite effect. In the filipodium shaft, K471-acetylated Fascin displayed rapid dynamic exchange, suggesting that it remained in its monomeric form owing to its weakened actin-bundling activity. Clinically, high levels of AcK471-Fascin in ESCC tissues were strongly associated with prolonged overall survival and disease-free survival of ESCC patients.

CONCLUSIONS

Fascin interacts directly with PCAF and is acetylated at lysine 471 in ESCC cells. Fascin-K471 acetylation suppressed ESCC cell migration and tumor metastasis by reducing filopodium formation through the impairment of its actin-bundling activity.

Fascin in Gynecological Cancers: An Update of the Literature

Simple Summary

Fascin, an actin-binding protein, is upregulated in different types of human cancers. It is reportedly responsible for increasing the invasive and metastatic ability of cancer cells by reducing cell–cell adhesions. This review provides a brief overview of fascin and its interactions with other genes and oncoviruses to induce the onset and progression of cancer.

Abstract

Fascin is an actin-binding protein that is encoded by the FSCN1 gene (located on chromosome 7). It triggers membrane projections and stimulates cell motility in cancer cells. Fascin overexpression has been described in different types of human cancers in which its expression correlated with tumor growth, migration, invasion, and metastasis. Moreover, overexpression of fascin was found in oncovirus-infected cells, such as human papillomaviruses (HPVs) and Epstein-Barr virus (EBV), disrupting the cell–cell adhesion and enhancing cancer progression. Based on these findings, several studies reported fascin as a potential biomarker and a therapeutic target in various cancers. This review provides a brief overview of the FSCN1 role in various cancers with emphasis on gynecological malignancies. We also discuss fascin interactions with other genes and oncoviruses through which it might induce cancer development and progression.

Fascin limits Myosin activity within Drosophila border cells to control substrate stiffness and promote migration

A key regulator of collective cell migrations, which drive development and cancer metastasis, is substrate stiffness. Increased substrate stiffness promotes migration and is controlled by Myosin. Using Drosophila border cell migration as a model of collective cell migration, we identify, for the first time, that the actin bundling protein Fascin limits Myosin activity in vivo. Loss of Fascin results in: increased activated Myosin on the border cells and their substrate, the nurse cells; decreased border cell Myosin dynamics; and increased nurse cell stiffness as measured by atomic force microscopy. Reducing Myosin restores on-time border cell migration in fascin mutant follicles. Further, Fascin’s actin bundling activity is required to limit Myosin activation. Surprisingly, we find that Fascin regulates Myosin activity in the border cells to control nurse cell stiffness to promote migration. Thus, these data shift the paradigm from a substrate stiffness-centric model of regulating migration, to uncover that collectively migrating cells play a critical role in controlling the mechanical properties of their substrate in order to promote their own migration. This understudied means of mechanical regulation of migration is likely conserved across contexts and organisms, as Fascin and Myosin are common regulators of cell migration.

Iodothyronine deiodinase 2 (DiO2) regulates trophoblast cell line cycle, invasion and apoptosis; and its downregulation is associated with early recurrent miscarriage

INTRODUCTION

Trophoblast development is a crucial event in placentation and pregnancy complications but its underlying mechanisms remain unclear. Thus, we aimed at investigating the role of DiO2 in trophoblast cell line decisions and assessing its placental villous expression in early recurrent miscarriage (ERM) patients.

METHODS

The placental villous expression of DiO2 was determined with immunofluorescence. Cell proliferation was measured with the CCK8 kit while cell-cycle and apoptosis were studied with flow-cytometry. Cell migration and invasion were measured with wound-healing and transwell assays, respectively. Gene expression was then assessed with RT-qPCR and western blotting.

RESULTS

DiO2 is expressed in the CTB, PCT, DCT and STB of the placenta. Its overexpression arrested trophoblast cell line proliferation at the G1 phase of the cell-cycle by downregulating cyclin-D1 and PCNA, while promoting apoptosis via increased caspase-3 activity and inhibition of the AKT and ERK1/2 signaling pathways. Also, it augmented trophoblast cell line migration and invasion via the upregulation of N-cadherin, vimentin, fascin-1, twist-1 and other epithelial-mesenchymal transition genes. DiO2 knockdown elicited the opposite effects. Surprisingly, each of these effects of DiO2 manipulation was not mediated by thyroid hormone metabolism. Assessment of the ERM placental villi revealed a downregulation of DiO2, N-cadherin, vimentin, fascin-1 and twist-1. The expression of E-cadherin remained unchanged in these placentae.

DISCUSSION

During placentation, DiO2 may inhibit trophoblast proliferation while facilitating their differentiation into an invasive phenotype; and that its downregulation may contribute to the shallow trophoblast invasion that precedes ERM. Hence, DiO2 is a potential therapeutic target against ERM.

Downregulation of Stemness Genes and Induction of Necrosis in Rat LA7 Cancer Stem Cells Induced Tumors Treated with Starved Fibroblasts Culture Supernatant

BACKGROUND

Stem cell differentiation therapy is a promising strategy in cancer treatment. we show that protein cocktail prepared from serum starved fibroblasts has therapeutic potential based on this strategy.

METHODS

The condition medium was prepared from foreskin isolated fibroblasts and analyzed by Liquid chromatography electrospray ionization mass spectrometry-mass spectrometry (LC-ESI-MS/MS). LA7 mammary gland cancer stem cells originated tumors were induced in Sprague Dawley rats. The rats treated subcutaneously with DMEM (group A), condition medium (group B), or normal saline (group C) once daily for 7 days. Then the tumors were removed and divided into the two parts, one part was used to quantify gene expression by stem-loop RT-qPCR assay and the other part was used for Hematoxylin & Eosin (H & E), Giemsa, and immunohistochemistry (IHC) staining.

RESULTS

All induced tumors appeared as sarcomatoid carcinoma (SC). Immunohistochemistry staining confirmed this conclusion by recognizing the tumor as Ki67+, cytokeratin+, vimentine+, and estrogen receptor negative SC. RT-qPCR analysis revealed that Oct4-, Sox-2, Nanog- gene expression was much reduced in the condition medium treated tumors versus proper controls (p< 0.05). Tissue necrosis was more prevalent in this group while tumors volume was diminished almost by 40%. The LC-ESI-MS/MS analysis unrevealed the stemness reducing and the cell death inducing proteins such as, pigment epithelium-derived factor (PEDF), insulin like growth factor binding protein-5 (IGFBP-5) and -7 (IGFBP-7) in the condition medium.

CONCLUSION

This study showed that the substances released from starved human fibroblasts were able to down-regulate the stemness-related genes and induce necrosis in LA7 derived tumors.

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.

Targeting the cytoskeleton against metastatic dissemination

Cancer is a pathology characterized by a loss or a perturbation of a number of typical features of normal cell behaviour. Indeed, the acquisition of an inappropriate migratory and invasive phenotype has been reported to be one of the hallmarks of cancer. The cytoskeleton is a complex dynamic network of highly ordered interlinking filaments playing a key role in the control of fundamental cellular processes, like cell shape maintenance, motility, division and intracellular transport. Moreover, deregulation of this complex machinery contributes to cancer progression and malignancy, enabling cells to acquire an invasive and metastatic phenotype. Metastasis accounts for 90% of death from patients affected by solid tumours, while an efficient prevention and suppression of metastatic disease still remains elusive. This results in the lack of effective therapeutic options currently available for patients with advanced disease. In this context, the cytoskeleton with its regulatory and structural proteins emerges as a novel and highly effective target to be exploited for a substantial therapeutic effort toward the development of specific anti-metastatic drugs. Here we provide an overview of the role of cytoskeleton components and interacting proteins in cancer metastasis with a special focus on small molecule compounds interfering with the actin cytoskeleton organization and function. The emerging involvement of microtubules and intermediate filaments in cancer metastasis is also reviewed.

Fascin in Cell Migration: More Than an Actin Bundling Protein

Simple Summary

Cell migration is an essential biological process that regulates both development and diseases, such as cancer metastasis. Therefore, understanding the factors that promote cell migration is crucial. One of the factors known to regulate cell migration is the actin-binding protein, Fascin. Fascin is typically thought to promote cell migration through bundling actin to form migratory structures such as filopodia and invadapodia. However, Fascin has many other functions in the cell that may contribute to cell migration. How these novel functions promote cell migration and are regulated is still not well understood. Here, we review the structure of Fascin, the many functions of Fascin and how they may promote cell migration, how Fascin is regulated, and Fascin’s role in diseases such as cancer metastasis.

Abstract

Fascin, an actin-binding protein, regulates many developmental migrations and contributes to cancer metastasis. Specifically, Fascin promotes cell motility, invasion, and adhesion by forming filopodia and invadopodia through its canonical actin bundling function. In addition to bundling actin, Fascin has non-canonical roles in the cell that are thought to promote cell migration. These non-canonical functions include regulating the activity of other actin-binding proteins, binding to and regulating microtubules, mediating mechanotransduction to the nucleus via interaction with the Linker of the Nucleoskeleton and Cytoskeleton (LINC) Complex, and localizing to the nucleus to regulate nuclear actin, the nucleolus, and chromatin modifications. The many functions of Fascin must be coordinately regulated to control cell migration. While much remains to be learned about such mechanisms, Fascin is regulated by post-translational modifications, prostaglandin signaling, protein–protein interactions, and transcriptional means. Here, we review the structure of Fascin, the various functions of Fascin and how they contribute to cell migration, the mechanisms regulating Fascin, and how Fascin contributes to diseases, specifically cancer metastasis.

The miR-143/145 Cluster, a Novel Diagnostic Biomarker in Chondrosarcoma, Acts as a Tumor Suppressor and Directly Inhibits Fascin-1

Chondrosarcoma is the second most frequent bone sarcoma. Due to the inherent chemotherapy and radiotherapy resistance and absence of known therapeutic targets, clinical management is limited to surgical resection. Consequently, patients with advanced disease face a poor prognosis. Hence, elucidating regulatory networks governing chondrosarcoma pathogenesis is vital for development of effective therapeutic strategies. Here, miRNA and mRNA next generation sequencing of different subtypes of human chondrogenic tumors in combination with in silico bioinformatics tools were performed with the aim to identify key molecular factors. We identified miR-143/145 cluster levels to inversely correlate with tumor grade. This deregulation was echoed in the miRNA plasma levels of patients and we provided the first evidence that circulating miR-145 is a potential noninvasive diagnostic biomarker and can be valuable as an indicator to improve the currently challenging diagnosis of cartilaginous bone tumors. Additionally, artificial upregulation of both miRNAs impelled a potent tumor suppressor effect in vitro and in vivo in an orthotopic xenograft mouse model. A combined in silico/sequencing approach revealed FSCN1 as a direct target of miR-143/145, and its depletion phenotypically resembled miR-143/145 upregulation in vitro. Last, FSCN1 is a malignancy-promoting factor associated with aggressive chondrosarcoma progression. Our findings underscore miR-143/145/FSCN1 as important players in chondrosarcoma and may potentially open new avenues for specific therapeutic intervention options. © 2020 American Society for Bone and Mineral Research.

MiR-200b/c family inhibits renal fibrosis through modulating epithelial-to-mesenchymal transition via targeting fascin-1/CD44 axis

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.

Structure-based design, synthesis and biological evaluation of a novel series of isoquinolone and pyrazolo[4,3-c]pyridine inhibitors of fascin 1 as potential anti-metastatic agents

Fascin is an actin binding and bundling protein that is not expressed in normal epithelial tissues but overexpressed in a variety of invasive epithelial tumors. It has a critical role in cancer cell metastasis by promoting cell migration and invasion. Here we report the crystal structures of fascin in complex with a series of novel and potent inhibitors. Structure-based elaboration of these compounds enabled the development of a series with nanomolar affinities for fascin, good physicochemical properties and the ability to inhibit fascin-mediated bundling of filamentous actin. These compounds provide promising starting points for fascin-targeted anti-metastatic therapies.

Fascin-1 enhances experimental osteosarcoma tumor formation and metastasis and is related to poor patient outcome

Background

Fascin-1, a prominent actin-bundling protein, is found to be upregulated in several human carcinomas. While it is accepted that Fascin-1 expression correlates with poor clinical outcome and decreased survival in various carcinomas, its role in sarcoma such as osteosarcoma (OS) remains unknown. In the present study, we evaluated the prognostic value and biological relevance of Fascin-1 in OS.

Methods

The correlation between Fascin-1 expression and the outcome of OS patients was determined by immunohistochemistry analysis of Fascin-1 expression in a tissue microarray of OS tissue specimens collected during primary tumor resection. To examine the effect of Fascin-1, shRNA and overexpression technology to alter Fascin-1 levels in OS cells were used in cellular assays as well as in intratibial xenograft OS models in SCID mice.

Results

Kaplan-Meier survival analysis of Fascin-1 expression in OS tumor specimens revealed a direct relationship between Fascin-1 expression and poor patient survival. Furthermore, overexpression of Fascin-1 in OS cells significantly increased their migratory capacity as well as the activity of the matrix metalloprotease MMP-9, known to be critical for the execution of metastasis. Finally, using relevant xenograft mouse models, orthotopic intratibial transplantation of two different OS cell lines overexpressing Fascin-1 promoted tumor growth and lung metastasis.

Conclusions

Collectively, our findings demonstrate for the first time that Fascin-1 has considerable potential as a novel prognostic biomarker in OS, and suggest that targeting of Fascin-1 might be a new anti-metastatic strategy in OS patient treatment.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5303-3) contains supplementary material, which is available to authorized users.

Promoter Methylation-Regulated miR-145-5p Inhibits Laryngeal Squamous Cell Carcinoma Progression by Targeting FSCN1

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.

Fascin is secreted in male's serum: results of a pilot study

Aim:

Fascin is a 55 kDa globular protein with an important role in cell migration. Aim of study was to investigate serum fascin in healthy males.

Materials & methods:

From 1 July 2016 to 31 December 2016, we collected serum from 46 males. Serum fascin level was performed using ELISA kit from USBiological (Salem, MA, USA).

Results:

Median age was 64 years. Mean fascin serum level was 9.84 ng/ml, mean prostate-specific antigen (PSA) was 2.74 ng/ml and mean prostate volume was 37.64 cc. The 51–60 years group had a mean of 10.53 ng/ml, the 61–70 group a mean of 9.7 ng/ml and the 71–80 group had a mean of 9.41 ng/ml fascin serum level.

Conclusion:

Fascin serum level did not differ according to age in males.

Fascin protein was previously associated with high-grade malignancies. This study presents the determination of fascin serum levels in 46 healthy males, providing a reference number in further determinations. The patients were divided into three subgroups according to age. The study presents the mean levels of each group, in association with PSA level and the mean prostate volumes. In conclusion, the study states that fascin is secreted in healthy male controls and the levels did not differ according to age.

Migration and invasion induced by linoleic acid are mediated through fascin in MDA-MB-231 breast cancer cells

Epidemiological studies strongly suggest an association between high levels of dietary fat intake and an increased risk of developing breast cancer. Linoleic acid (LA) is an essential omega-6 PUFA and the major fatty acid in occidental diets. In breast cancer cells, LA induces expression of plasminogen activator inhibitor-1, proliferation, migration, and invasion. Fascin is an actin crosslinker globular protein that generates actin bundles made of parallel actin filaments, which mediate formation and stability of microspikes, stress fibers, membrane ruffles, and filopodia. However, the role of fascin in migration and invasion induced by LA in MDA-MB-231 breast cancer cells remains to be studied. We demonstrate here that LA induces an increase of fascin expression in MDA-MB-231 and MCF12A mammary epithelial cells. Particularly, LA induces the formation of filopodia and lamellipodia and the localization of fascin in these actin structures in MDA-MB-231 breast cancer cells. However, LA only induces formation of microspikes and the localization of fascin in these actin structures in mammary non-tumorigenic epithelial cells MCF12A. In addition, LA induces migration, invasion, and matrix metalloproteinase-9 secretion through a fascin-dependent pathway in MDA-MB-231 cells. In summary, our findings demonstrate that fascin is required for migration and invasion induced by LA in MDA-MB-231 breast cancer cells.

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.

Gene Signature in Sessile Serrated Polyps Identifies Colon Cancer Subtype

Sessile serrated colon adenoma/polyps (SSA/P) are found during routine screening colonoscopy and may account for 20% to 30% of colon cancers. However, differentiating SSA/Ps from hyperplastic polyps (HP) with little risk of cancer is challenging and complementary molecular markers are needed. In addition, the molecular mechanisms of colon cancer development from SSA/Ps are poorly understood. RNA sequencing (RNA-Seq) was performed on 21 SSA/Ps, 10 HPs, 10 adenomas, 21 uninvolved colon, and 20 control colon specimens. Differential expression and leave-one-out cross-validation methods were used to define a unique gene signature of SSA/Ps. Our SSA/P gene signature was evaluated in colon cancer RNA-Seq data from The Cancer Genome Atlas (TCGA) to identify a subtype of colon cancers that may develop from SSA/Ps. A total of 1,422 differentially expressed genes were found in SSA/Ps relative to controls. Serrated polyposis syndrome (n = 12) and sporadic SSA/Ps (n = 9) exhibited almost complete (96%) gene overlap. A 51-gene panel in SSA/P showed similar expression in a subset of TCGA colon cancers with high microsatellite instability. A smaller 7-gene panel showed high sensitivity and specificity in identifying BRAF-mutant, CpG island methylator phenotype high, and MLH1-silenced colon cancers. We describe a unique gene signature in SSA/Ps that identifies a subset of colon cancers likely to develop through the serrated pathway. These gene panels may be utilized for improved differentiation of SSA/Ps from HPs and provide insights into novel molecular pathways altered in colon cancer arising from the serrated pathway. Cancer Prev Res; 9(6); 456-65. ©2016 AACR.

Fascin Rigidity and L-plastin Flexibility Cooperate in Cancer Cell Invadopodia and Filopodia

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.

The preclinical evaluation of the dual mTORC1/2 inhibitor INK-128 as a potential anti-colorectal cancer agent

The colorectal cancer is the leading contributor of cancer-related mortality. Mammalian target of rapamycin (mTOR), existing in 2 complexes (mTORC1/2), is frequently dysregulated and constitutively activated in colorectal cancers. It represents an important drug target. Here we found that INK-128, the novel ATP-competitive kinase inhibitor of mTOR, blocked both mTORC1 and mTORC2 activation in colorectal cancer cells (both primary and transformed cells). The immunoprecipitation results showed that the assembly of mTORC1 (mTOR-Raptor association) and mTORC2 (mTOR-Rictor-Sin1 association) was also disrupted by INK-128. INK-128 inhibited colorectal cancer cell growth and survival, and induced both apoptotic and non-apoptotic cancer cell death. Further, INK-128 showed no effect on Erk/MAPK activation, while MEK/Erk inhibition by MEK-162 enhanced INK-128-induced cytotoxicity in colorectal cancer cells. Meanwhile, INK-128 downregulated Fascin1 (FSCN1)/E-Cadherin expressions and inhibited HT-29 cell in vitro migration. In vivo, daily INK-128 oral administration inhibited HT-29 xenograft growth in mice, which was further enhanced by MEK-162 administration. Finally, we found that INK-128 sensitized 5-fluorouracil-(5-FU)-mediated anti-HT-29 activity in vivo and in vitro. Thus, our preclinical studies strongly suggest that INK-128 might be investigated for colorectal cancer treatment in clinical trials.