GATA3 transcription factor abrogates Smad4 transcription factor-mediated fascin overexpression, invadopodium formation, and breast cancer cell invasion

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.

EGF/EGFR-YAP1/TEAD2 signaling upregulates STIM1 in vemurafenib resistant melanoma cells

Stromal interaction molecule 1 (STIM1) is the endoplasmic reticulum Ca2+ sensor for store-operated calcium entry and is closely associated with carcinogenesis and tumor progression. Previously, we found that STIM1 is upregulated in melanoma cells resistant to the serine/threonine-protein kinase B-raf inhibitor vemurafenib, although the mechanism underlying this upregulation is unknown. Here, we show that vemurafenib resistance upregulates STIM1 through an epidermal growth factor (EGF)/epidermal growth factor receptor (EGFR)-Yes-associated protein 1 (YAP1)/TEA domain transcription factor 2 (TEAD2) signaling axis. Vemurafenib resistance can lead to an increase in EGF and EGFR levels, causing activation of the EGFR signaling pathway, which promotes YAP1 nuclear localization to increase the expression of STIM1. Our findings not only reveal the mechanism by which vemurafenib resistance promotes STIM1 upregulation, but also provide a rationale for combined targeting of the EGF/EGFR-YAP1/TEAD2-STIM1 axis to improve the therapeutic efficacy of BRAF inhibitor in melanoma patients.

CDC20 Holds Novel Regulation Mechanism in RPA1 during Different Stages of DNA Damage to Induce Radio-Chemoresistance

Targeting CDC20 can enhance the radiosensitivity of tumor cells, but the function and mechanism of CDC20 on DNA damage repair response remains vague. To examine that issue, tumor cell lines, including KYSE200, KYSE450, and HCT116, were utilized to detect the expression, function, and underlying mechanism of CDC20 in radio-chemoresistance. Western blot and immunofluorescence staining were employed to confirm CDC20 expression and location, and radiation could upregulate the expression of CDC20 in the cell nucleus. The homologous recombination (HR) and non-homologous end joining (NHEJ) reporter gene systems were utilized to explore the impact of CDC20 on DNA damage repair, indicating that CDC20 could promote HR repair and radio/chemo-resistance. In the early stages of DNA damage, CDC20 stabilizes the RPA1 protein through protein-protein interactions, activating the ATR-mediated signaling cascade, thereby aiding in genomic repair. In the later stages, CDC20 assists in the subsequent steps of damage repair by the ubiquitin-mediated degradation of RPA1. CCK-8 and colony formation assay were used to detect the function of CDC20 in cell vitality and proliferation, and targeting CDC20 can exacerbate the increase in DNA damage levels caused by cisplatin or etoposide. A tumor xenograft model was conducted in BALB/c-nu/nu mice to confirm the function of CDC20 in vivo, confirming the in vitro results. In conclusion, this study provides further validation of the potential clinical significance of CDC20 as a strategy to overcome radio-chemoresistance via uncovering a novel role of CDC20 in regulating RPA1 during DNA damage repair.

The crucial role of fascin-1 in the pathogenesis, metastasis, and chemotherapeutic resistance of breast cancer

Breast cancer (BC) is the most common type of cancer in women to be diagnosed, and it is also the second leading cause of cancer death in women globally. It is the disease that causes the most life years adjusted for disability lost among women, making it a serious worldwide health issue. Understanding and interpreting carcinogenesis and metastatic pathways is critical for curing malignancy. Fascin-1 was recognized as an actin-bundling protein with parallel, rigid bundles as a result of the cross-linking of F-actin microfilaments. Increasing levels of fascin-1 have been associated with bad prognostic profiles, aggressiveness of clinical courses, and poor survival outcomes in a variety of human malignancies. Cancer cells that overexpress fascin-1 have higher capabilities for proliferation, invasion, migration, and metastasis. Fascin-1 is being considered as a potential target for therapy as well as a potential biomarker for diagnostics in a variety of cancer types. This review aims to provide an overview of the FSCN1 gene and its protein structure, elucidate its physiological and pathological roles, and throw light on its involvement in the initiation, development, and chemotherapeutic resistance of BC.

RBFOX2 deregulation promotes pancreatic cancer progression and metastasis through alternative splicing

RNA splicing is an important biological process associated with cancer initiation and progression. However, the contribution of alternative splicing to pancreatic cancer (PDAC) development is not well understood. Here, we identify an enrichment of RNA binding proteins (RBPs) involved in splicing regulation linked to PDAC progression from a forward genetic screen using Sleeping Beauty insertional mutagenesis in a mouse model of pancreatic cancer. We demonstrate downregulation of RBFOX2, an RBP of the FOX family, promotes pancreatic cancer progression and liver metastasis. Specifically, we show RBFOX2 regulates exon splicing events in transcripts encoding proteins involved in cytoskeletal remodeling programs. These exons are differentially spliced in PDAC patients, with enhanced exon skipping in the classical subtype for several RBFOX2 targets. RBFOX2 mediated splicing of ABI1, encoding the Abelson-interactor 1 adapter protein, controls the abundance and localization of ABI1 protein isoforms in pancreatic cancer cells and promotes the relocalization of ABI1 from the cytoplasm to the periphery of migrating cells. Using splice-switching antisense oligonucleotides (AONs) we demonstrate the ABI1 ∆Ex9 isoform enhances cell migration. Together, our data identify a role for RBFOX2 in promoting PDAC progression through alternative splicing regulation.

Fascin in migration and metastasis of breast cancer cells - A review

Cancer cell migration and metastasis are the biggest problems in the treatment of cancer patients. The most aggressive breast cancer (BC) is the triple-negative type. Therefore, effective therapeutic targets that limit cell migration are sought. One such target may be fascin, as its overexpression is characteristic to triple-negative breast cancer. The high level of fascin enables the formation of protrusion and thus promotes the invasion of cancer cells. Fascin also shows co-localization or functional relationships with other proteins. These are proteins involved in the epithelial-mesenchymal transition process, vimentin, cadherins, β-catenin, and matrix metalloproteinases 2/9 (MMP-2/9). Fascin is also involved in many signaling pathways protein kinase C-δ (PKCδ), Wnt/β-catenin, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and phosphatidylinositol 3-kinase (PI3K)-Akt. Therefore, in this article, we review currently available in vitro studies and compare them with The Cancer Genome Atlas (TCGA) data analysis of BC patients to demonstrate the role of fascin in the migration and invasion of cancer cells.

Fascin-1 in Cancer Cell Metastasis: Old Target-New Insights

As metastasis is responsible for most cancer-related deaths, understanding the cellular and molecular events that lead to cancer cell migration and invasion will certainly provide insights into novel anti-metastatic therapeutic targets. Fascin-1 is an actin-bundling protein fundamental to all physiological or pathological processes that require cell migration. It is responsible for cross-linking actin microfilaments during the formation of actin-rich cellular structures at the leading edge of migrating cells such as filopodia, lamellipodia and invadopodia. While most epithelial tissues express low levels of Fascin-1, it is dramatically elevated in the majority of cancers and its expression has been associated with more aggressive disease and decreased overall survival. Hence, it has been proposed as a potential anti-cancer target. In the present review, we studied recent literature with regard to Fascin-1 expression in different cancers, its role in altering the mechanical properties of cancer cells, promoting cancer cell migration, invasion and metastasis and the effect of its inhibition, via various pharmacological inhibitors, in eliminating metastasis in vitro and/or in vivo. Recent studies corroborate the notion that Fascin-1 is critically involved in metastasis and prove that it is a valuable anti-metastatic target that is worth investigating further.

Lactate-mediated Fascin protrusions promote cell adhesion and migration in cervical cancer

Background: Lactate is associated with the poor prognosis of many human malignancies. Cervical cancer, one of main causes of women mortality worldwide, is aggressive and absent of effective pharmacological treatment, and its underlying mechanisms of progression remain elusive. Methods: The regulation of β-catenin to fascin protrusion formation upon acidic lactate (Lactic acid [LA]) stimulation was evaluated through in β-catenin or fascin deficiency cell line models by immunofluorescence assays, and subcellular fractionation. The effect of β-catenin and fascin relocation by LA and its antagonist were evaluated by immunohistochemistry assay in patient tissues and mouse tumor xenograft model. Trypsin digestion, Transwell assay, cell proliferation in vitro was performed to explore the role of LA in the cell growth, adhesion and migration. Results: Low concentration of LA significantly promotes cytoskeleton remodeling via `protrusion formation to increase cell adhesion and migration. Mechanistically, upon LA stimulation, β-catenin diffuses from the cytoplasmic membrane into the nucleus, which in turn induces fascin nuclear-cytoplasm redistribution to the protrusion compartment. Moreover, the antagonist of LA sufficiently blocks the LA-mediated β-catenin nuclear import, fascin nuclear export, and the growth and invasion of cervical cancer cells in vitro and in vivo using a murine xenograft model. Conclusions: This study uncovers β-catenin-fascin axis as a key signal in response to extracellular lactate and indicates that antagonist of LA may serve as a potential clinical intervention for cancer development.

The post-translational modification of Fascin: impact on cell biology and its associations with inhibiting tumor metastasis

The post-translational modifications (PTMs), which are crucial in the regulation of protein functions, have great potential as biomarkers of cancer status. Fascin (Fascin actin-bundling protein 1, FSCN1), a key protein in the formation of filopodia that is structurally based on actin filaments (F-actin), is significantly associated with tumor invasion and metastasis. Studies have revealed various regulatory mechanisms of human Fascin, including PTMs. Although a number of Fascin PTM sites have been identified, their exact functions and clinical significance are much less explored. This review explores studies on the functions of Fascin and briefly discusses the regulatory mechanisms of Fascin. Next, to review the role of Fascin PTMs in cell biology and their associations with metastatic disease, we discuss the advances in the characterization of Fascin PTMs, including phosphorylation, ubiquitination, sumoylation, and acetylation, and the main regulatory mechanisms are discussed. Fascin PTMs may be potential targets for therapy for metastatic disease.

Realization of the T Lineage Program Involves GATA-3 Induction of Bcl11b and Repression of Cdkn2b Expression

The zinc-finger transcription factor GATA-3 plays a crucial role during early T cell development and also dictates later T cell differentiation outcomes. However, its role and collaboration with the Notch signaling pathway in the induction of T lineage specification and commitment have not been fully elucidated. We show that GATA-3 deficiency in mouse hematopoietic progenitors results in an early block in T cell development despite the presence of Notch signals, with a failure to upregulate Bcl11b expression, leading to a diversion along a myeloid, but not a B cell, lineage fate. GATA-3 deficiency in the presence of Notch signaling results in the apoptosis of early T lineage cells, as seen with inhibition of CDK4/6 (cyclin-dependent kinases 4 and 6) function, and dysregulated cyclin-dependent kinase inhibitor 2b (Cdkn2b) expression. We also show that GATA-3 induces Bcl11b, and together with Bcl11b represses Cdkn2b expression; however, loss of Cdkn2b failed to rescue the developmental block of GATA-3-deficient T cell progenitor. Our findings provide a signaling and transcriptional network by which the T lineage program in response to Notch signals is realized.

Fascin-1: Updated biological functions and therapeutic implications in cancer biology

Filopodia are cellular protrusions that respond to a variety of stimuli. Filopodia are formed when actin is bound to the protein Fascin, which may play a crucial role in cellular interactions and motility during cancer metastasis. Significantly, the noncanonical features of Fascin-1 are gradually being clarified, including the related molecular network contributing to metabolic reprogramming, chemotherapy resistance, stemness ac-tivity, and tumor microenvironment events. However, the relationship between biological characteristics and pathological features to identify effective therapeutic strategies needs to be studied further. The pur-pose of this review article is to provide a broad overview of the latest molecular networks and multiomics research regarding fascins and cancer. It also highlights their direct and indirect effects on available cancer treatments. With this multidisciplinary approach, researchers and clinicians can gain the most relevant in-formation on the function of fascins in cancer progression, which may facilitate clinical applications in the future.

Contribution of Stemness-linked Transcription Regulators to the Progression of Breast Cancer

Although there are currently several factors that allow measuring the risk of having breast cancer or predicting its progression, the underlying causes of this malignancy have remained unknown. Several molecular studies have described some mechanisms involved in the progress of breast cancer. These have helped in identifying new targets with therapeutic potential. However, despite the therapeutic strategies implemented from the advances achieved in breast cancer research, a large percentage of patients with breast cancer die due to the spread of malignant cells to other tissues or organs, such as bones and lungs. Therefore, determining the processes that promote the migration of malignant cells remains one of the greatest challenges for oncological research. Several research groups have reported evidence on how the dedifferentiation of tumor cells leads to the acquisition of stemness characteristics, such as invasion, metastasis, the capability to evade the immunological response, and resistance to several cytotoxic drugs. These phenotypic changes have been associated with a complex reprogramming of gene expression in tumor cells during the Epithelial-Mesenchymal Transition (EMT). Considering the determining role that the transcriptional regulation plays in the expression of the specific characteristics and attributes of breast cancer during ETM, in the present work, we reviewed and analyzed several transcriptional mechanisms that support the mesenchymal phenotype. In the same way, we established the importance of transcription factors with a therapeutic perspective in the progress of breast cancer.

PYK2 mediates the BRAF inhibitor (vermurafenib)-induced invadopodia formation and metastasis in melanomas

Objective:

The BRAF inhibitor, vemurafenib, has been widely used in the treatment of patients with melanoma-bearing BRAF^V600E mutations. While the initial response to vemurafenib is usually excellent, the majority of patients eventually develop resistance and metastatic disease. However, the underlying molecular mechanism remains elusive. The objective of this study was therefore to identify additional molecular targets responsible for vemurafenib resistance.

Methods:

Western blots and immunohistochemistry analyses were used to evaluate expressions of PYK2 and p-PYK2 in cultured cells and melanoma tissue microarrays. The relationships of p-PYK2 with clinicopathological parameters were statistically analyzed. Invadopodia cell invasion, and a Ca²⁺ assay were used to determine the effect of vemurafenib resistance-induced p-PYK2 on melanoma progression. A mouse model was used to assess the effects of PYK2 on melanoma metastasis.

Results:

Elevated p-PYK2 levels were detected in vemurafenib-resistant melanoma cells, and PYK2 was shown to regulate invadopodia formation in melanoma cells. Vemurafenib triggered invadopodia formation by activation of PYK2. Inhibition of PYK2 with either shRNA or the small molecule inhibitor, PF562711, dramatically reduced vemurafenib-induced invadopodia formation. Furthermore, knockdown of PYK2 significantly reduced melanoma lung metastasis in vivo. Increased expressions of p-PYK2 in melanoma patients were positively correlated with advanced stage (P = 0.002), metastasis (P < 0.001), and Clark grade (P < 0.001), and were also associated with short overall survival [hazard ratio (HR) = 3.304, P = 0.007] and progression-free survival (HR = 2.930, P = 0.001).

Conclusions:

PYK2 mediated vemurafenib-induced melanoma cell migration and invasion. Inhibition of PYK2 resensitized melanoma cells to vemurafenib. Phospho-PYK2 was a prognostic biomarker in melanoma patients.

Prominent Prognostic Factors in Aggressive Breast Cancer: A Review

Context: Breast cancer (BC) is the most common cancer in women worldwide. Hereditary susceptibility created by mutations in autosomal dominant genes is responsible for 5 to 10% of all BC cases in women. Recent studies have identified genes associated with increased risk for aggressive BC, providing the basis for better risk management. Evidence Acquisition: The latest information in National Center for Biotechnology Information (NCBI), Google Scholar, ScienceDirect, and Scopus were the main databases for finding articles. A combination of keywords of ‘metastasis’, ‘invasion’, ‘aggressive breast cancer’, ‘prognostic factor’, ‘mutation’, and ‘cancer treatment’ was searched in the databases to identify related articles. Titles and abstracts of the articles were studied to choose the right articles. Results: Mutations in breast cancer type 1 susceptibility protein (BRCA1) and breast cancer type 2 susceptibility protein (BRCA2) genes are two central players related to the high risk of BC. Mutation in tumor protein p53 (TP53) is another important mutation that leads to triple-negative BC. Although the majority of BC types are not associated with high-throughput mutant genes such as BRCA1, BRCA2, and TP53, they are associated with low-throughput genes, including DNA repair protein Rad50 (RAD50), Nijmegen breakage syndrome gene (NBS1), checkpoint kinase 2 (CHEK2), BRCA1-interacting protein 1 (BRIP1), E-cadherin gene (CDH1) and PALB2, UCHL1, aldehydedehydrogenase1A3 (ALDH1A3), androgen receptor (AR), 5-bisphosphate 3-kinase (PIK3CA), phosphatidylinositol-4, and luminal gene expression that are generally mutated in the global population. High tumor mutational burden (TMB) was associated with improved progression-free survival. Conclusions: The lymph node status, early tumor size, ER, PR, human epidermal growth factor receptor-2 (HER2), and Ki-67 are conventional prognostic factors for BC. However, these factors cannot exactly predict the aggressive behavior of BC. Hence, in this review, we discussed new prognostic factors of aggressive BCs that are useful for the treatment of patients with BC.

Fascin promotes lung cancer growth and metastasis by enhancing glycolysis and PFKFB3 expression

Fascin is a pro-metastatic actin-bundling protein that is upregulated in all metastatic carcinomas. Fascin promotes cancer cell migration and invasion by facilitating membrane protrusions, such as filopodia and invadopodia. Aerobic glycolysis is a key feature of cancer metabolism and provides critical intermediate metabolites for tumor growth. Here, we report that fascin increases glycolysis in lung cancer to promote tumor growth and metastasis. Fascin promotes glycolytic flux by increasing the expression and activities of phosphofructose-kinases 1 and 2 (PFK1 and 2). Fascin mediates glycolytic functions via activation of yes-associated protein 1 (YAP1) through its canonical actin-bundling activity by promoting the binding of YAP1 to a TEAD1/4 binding motif located 30 bp upstream of the PFKFB3 transcription start site to activate its transcription. Examination of the TCGA database suggests that the fascin-YAP1-PFKFB3 axis is likely conserved across different types of cancers. Importantly, pharmacological inhibitors of fascin suppressed YAP1-PFKFB3 signaling and glycolysis in cancer cell lines, organoid cultures, and xenograft metastasis models. Taken together, our data reveal that the glycolytic function of fascin is essential for the promotion of lung cancer growth and metabolism, and suggest that pharmacological inhibitors of fascin may be used to reprogram cancer metabolism in lung and potentially other cancers with fascin upregulation.

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.

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.

Fascin Controls Metastatic Colonization and Mitochondrial Oxidative Phosphorylation by Remodeling Mitochondrial Actin Filaments

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.

How does fascin promote cancer metastasis?

Fascin is an F-actin-bundling protein that cross-links individual actin filaments into straight and stiff bundles. Fascin overexpression in cancer is strongly associated with poor prognosis and metastatic progression across different cancer types. It is well established that fascin plays a causative role in promoting metastatic progression. We will review the recent progress in our understanding of mechanisms underlying fascin-mediated cancer metastasis. This review will cover the biochemical basis for fascin-bundling activity, the mechanisms by which cancer cells upregulate fascin expression and the mechanism underlying fascin-mediated cancer cell migration, invasion, and metastatic colonization. We propose that fascin has broad roles in both metastatic dissemination and metastatic colonization. Understanding these mechanisms will be crucial to the development of anti-metastasis therapeutics targeting fascin.

SOX11 and SOX4 drive the reactivation of an embryonic gene program during murine wound repair

Tissue injury induces changes in cellular identity, but the underlying molecular mechanisms remain obscure. Here, we show that upon damage in a mouse model, epidermal cells at the wound edge convert to an embryonic-like state, altering particularly the cytoskeletal/extracellular matrix (ECM) components and differentiation program. We show that SOX11 and its closest relative SOX4 dictate embryonic epidermal state, regulating genes involved in epidermal development as well as cytoskeletal/ECM organization. Correspondingly, postnatal induction of SOX11 represses epidermal terminal differentiation while deficiency of Sox11 and Sox4 accelerates differentiation and dramatically impairs cell motility and re-epithelialization. Amongst the embryonic genes reactivated at the wound edge, we identify fascin actin-bundling protein 1 (FSCN1) as a critical direct target of SOX11 and SOX4 regulating cell migration. Our study identifies the reactivated embryonic gene program during wound repair and demonstrates that SOX11 and SOX4 play a central role in this process.

Regeneration Enhances Metastasis: A Novel Role for Neurovascular Signaling in Promoting Melanoma Brain Metastasis

Neural repair after stroke involves initiation of a cellular proliferative program in the form of angiogenesis, neurogenesis, and molecular growth signals in the surrounding tissue elements. This cellular environment constitutes a niche in which regeneration of new blood vessels and new neurons leads to partial tissue repair after stroke. Cancer metastasis has similar proliferative cellular events in the brain and other organs. Do cancer and CNS tissue repair share similar cellular processes? In this study, we identify a novel role of the regenerative neurovascular niche induced by stroke in promoting brain melanoma metastasis through enhancing cellular interactions with surrounding niche components. Repair-mediated neurovascular signaling induces metastatic cells to express genes crucial to metastasis. Mimicking stroke-like conditions in vitro displays an enhancement of metastatic migration potential and allows for the determination of cell-specific signals produced by the regenerative neurovascular niche. Comparative analysis of both in vitro and in vivo expression profiles reveals a major contribution of endothelial cells in mediating melanoma metastasis. These results point to a previously undiscovered role of the regenerative neurovascular niche in shaping the tumor microenvironment and brain metastatic landscape.

The fucose salvage pathway inhibits invadopodia formation and extracellular matrix degradation in melanoma cells

The fucose salvage pathway is a two-step process in which mammalian cells transform L-fucose into GDP-L-fucose, a universal fucose donor used by fucosyltransferases to modify glycans. Emerging evidence indicates the fucose salvage pathway and the fucosylation of proteins are altered during melanoma progression and metastasis. However the underlying mechanisms are not completely understood. Here, we report that the fucose salvage pathway inhibits invadopodia formation and extracellular matrix degradation by promoting α-1,2 fucosylation. Chemically or genetically increasing the fucose salvage pathway decreases invadopodium numbers and inhibits the proteolytic activity of invadopodia in WM793 melanoma cells. Inhibiting fucosylation by depleting fucokinase abrogates L-fucose-mediated inhibition of invadopodia, suggesting dependence on the fucose salvage pathway. The inhibition of invadopodium formation by L-fucose or ectopically expressed FUK could be rescued by treatment with α-1,2, but not α-1,3/α-1,4 fucosidase, implicating an α-1,2 fucose linkage-dependent anti-metastatic effect. The expression of FUT1, an α-1,2 fucosyltransferase, is remarkably down-regulated during melanoma progression, and the ectopic expression of FUT1 is sufficient to inhibit invadopodium formation and ECM degradation. Our findings indicate that the fucose salvage pathway can inhibit invadopodium formation, and consequently, invasiveness in melanoma via α-1,2 fucosylation. Re-activation of this pathway in melanoma could be useful for preventing melanoma invasion and metastasis.

Targeting invadopodia for blocking breast cancer metastasis

Dissemination of cancer cells from the primary tumor and their spread to distant sites of the body is the leading cause of mortality in metastatic cancer patients. Metastatic cancer cells invade surrounding tissues and blood vessels by forming F-actin-rich protrusions known as invadopodia, which degrade the extracellular matrix and enable invasion of tumor cells through it. Invadopodia have now been observed in vivo, and recent evidence demonstrates direct molecular links between assembly of invadopodia and cancer metastasis in both mouse models and in human patients. While significant progress has been achieved in the last decade in understanding the molecular mechanisms and signaling pathways regulating invadopodia formation and function, the application of this knowledge to development of prognostic and therapeutic approaches for cancer metastasis has not been discussed before. Here, we provide a detailed overview of current prognostic markers and tests for cancer metastasis and discuss their advantages, disadvantages, and their predicted efficiency. Using bioinformatic patient database analysis, we demonstrate, for the first time, a significant correlation between invadopodia-associated genes to breast cancer metastasis, suggesting that invadopodia could be used as both a prognostic marker and as a therapeutic target for blocking cancer metastasis. We include here a novel network interaction map of invadopodia-associated proteins with currently available inhibitors, demonstrating a central role for the recently identified EGFR-Pyk2-Src-Arg-cortactin invadopodial pathway, to which re-purposing of existent inhibitors could be used to block breast cancer metastasis. We then present an updated overview of current cancer-related clinical trials, demonstrating the negligible number of trials focusing on cancer metastasis. We also discuss the difficulties and complexity of performing cancer metastasis clinical trials, and the possible development of anti-metastasis drug resistance when using a prolonged preventive treatment with invadopodia inhibitors. This review presents a new perspective on invadopodia-mediated tumor invasiveness and may lead to the development of novel prognostic and therapeutic approaches for cancer metastasis.

Smad4/Fascin index is highly prognostic in patients with diffuse type EBV-associated gastric cancer

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.

Docosahexaenoic acid inhibits 12-O-tetradecanoylphorbol-13- acetate-induced fascin-1-dependent breast cancer cell migration by suppressing the PKCδ- and Wnt-1/β-catenin-mediated pathways

Fascin-1, an actin-bundling protein, plays an important role in cancer cell migration and invasion; however, the underlying mechanism remains unclear. On the basis of a 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced cell migration model, it was shown that TPA increased fascin-1 mRNA and protein expression and fascin-1-dependent cell migration. TPA dose- and time-dependently increased PKCδ and STAT3α activation and GSK3β phosphorylation; up-regulated Wnt-1, β-catenin, and STAT3α expression; and increased the nuclear translocation of β-catenin and STAT3α. Rottlerin, a PKCδ inhibitor, abrogated the increases in STAT3α activation and β-catenin and fascin-1 expression. WP1066, a STAT3 inhibitor, suppressed TPA-induced STAT3α DNA binding activity and β-catenin expression. Knockdown of β-catenin attenuated TPA-induced fascin-1 and STAT3α expression as well as cell migration. In addition to MCF-7, migration of Hs578T breast cancer cells was inhibited by silencing fascin-1, β-catenin, and STAT3α expression as well. TPA also induced Wnt-1 expression and secretion, and blocking Wnt-1 signaling abrogated β-catenin induction. DHA pretreatment attenuated TPA-induced cell migration, PKCδ and STAT3α activation, GSK3β phosphorylation, and Wnt-1, β-catenin, STAT3α, and fascin-1 expression. Our results demonstrated that TPA-induced migration is likely associated with the PKCδ and Wnt-1 pathways, which lead to STAT3α activation, GSK3β inactivation, and β-catenin increase and up-regulation of fascin-1 expression. Moreover, the anti-metastatic potential of DHA is partly attributed to its suppression of TPA-activated PKCδ and Wnt-1 signaling.

FSCN1 gene polymorphisms: biomarkers for the development and progression of breast cancer

Breast cancer is a major cause of cancer mortality worldwide. Fascin-1 (FSCN1) is an actin-binding protein found in mammalian cells, including endothelial, neuronal and mesenchymal cells. FSCN1 overexpression has been indicated in breast cancer patients. However, scant information is available regarding the association between FSCN1 single nucleotide polymorphisms (SNPs) and the risk or prognosis of breast cancer. We report on the association between 6 SNPs of the FSCN1 gene (rs56156320, rs8772, rs3801004, rs2966447, rs852479 and rs1640233) and breast cancer susceptibility as well as clinical outcomes in 316 patients with breast cancer and in 222 healthy controls. Carriers of the AC or AC + CC allele of the variant rs56156320 were at greater risk of breast cancer compared with wild-type (AA) carriers. Moreover, carriers of at least one G allele in rs3801004 were likely to progress to stage III/IV disease and lymph node metastasis. Individuals with at least one T allele at FSCN1 SNP rs2966447 were at higher risk of developing pathologic grade G3 disease. Furthermore, individuals bearing the C/C haplotype at SNPs rs56156320 and rs3801004 had nearly twice the risk of breast cancer. Our results indicate that genetic variations in the FSCN1 gene may serve as an important predictor of early-stage breast cancer.

The meta and bioinformatics analysis of fascin expression in gastric cancer: a potential marker for aggressiveness and worse prognosis

Fascin is a FSCN1-encoded actin bundling protein, and positively associated with proliferation, migration and metastasis of malignancies. Here, we performed a systematic meta and bioinformatics analysis through multiple online databases up to March 14, 2017. We found up-regulated fascin expression in gastric cancer, compared with normal mucosa (p<0.05). Fascin expression was positively with lymph node metastasis, TNM staging and worse prognosis of gastric cancer (p<0.05). According to bioinformatics database, FSCN1 mRNA expression was higher in gastric cancer than normal tissues (p<0.05). According to Kaplan-Meier plotter, we found that a higher FSCN1 expression was negatively correlated with overall and progression-free survival rates of all cancer patients, even stratified by aggressive parameters (p<0.05). These findings indicated that fascin expression might be employed as a potential marker to indicate gastric carcinogenesis and subsequent progression, even prognosis.

Monoubiquitination Inhibits the Actin Bundling Activity of Fascin

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.

Fscn1 is required for the trafficking of TGF-β family type I receptors during endoderm formation

Microtubules function in TGF-β signalling by facilitating the cytoplasmic trafficking of internalized receptors and the nucleocytoplasmic shuttling of Smads. However, nothing is known about whether actin filaments are required for these processes. Here we report that zebrafish actin-bundling protein fscn1a is highly expressed in mesendodermal precursors and its expression is directly regulated by the TGF-β superfamily member Nodal. Knockdown or knockout of fscn1a leads to a reduction of Nodal signal transduction and endoderm formation in zebrafish embryos. Fscn1 specifically interacts with TGF-β family type I receptors, and its depletion disrupts the association between receptors and actin filaments and sequesters the internalized receptors into clathrin-coated vesicles. Therefore, Fscn1 acts as a molecular linker between TGF-β family type I receptors and the actin filaments to promote the trafficking of internalized receptors from clathrin-coated vesicles to early endosomes during zebrafish endoderm formation.

It is unclear how the cytoskeleton acts to assist in TGF-β signalling downstream of the receptor. Here, in zebrafish, the authors show that the actin-bundling protein FSCN1 interacts with TGF-β type I receptors ALK 4 and 5, enabling actin filament mediated vesicle trafficking and endoderm formation.

Negative association between GATA3 and fascin could predict relapse-free and overall survival in patients with breast cancer

GATA3 and fascin proteins are known prognostic markers in several cancers. GATA3 is a key regulator of mammary gland morphogenesis and luminal cell differentiation, whereas fascin is a pro-metastatic actin-bundling protein. In this study, we analyzed and compared the predictive abilities of GATA3 and fascin for clinical outcomes of patients with breast cancer. The combined expression pattern based on GATA3-/+ and fascin-/+ was evaluated by immunostaining using a tissue microarray, and relationships between protein expression and several clinicopathological parameters were analyzed. GATA3 expression was associated with good prognostic parameters, but fascin was correlated with poor prognostic parameters. On comparing GATA3 and fascin, we found an inverse relationship between fascin and GATA3 expressions. On analysis of combined markers, GATA3+/fascin- was correlated with improved clinical outcomes compared to GATA3-/fascin+. Univariate and multivariate analyses revealed significant differences in relapse-free and overall survival between GATA3+/fascin- and GATA3-/fascin+. Combined marker analysis of GATA3/fascin showed an inverse association and improved prognostic information for patients with breast cancer.

Inhibition of leucine aminopeptidase 3 suppresses invasion of ovarian cancer cells through down-regulation of fascin and MMP-2/9

Leucine aminopeptidase 3 (LAP3) is a cell surface aminopeptidase that catalyzes the hydrolysis of leucine residues from the amino termini of protein or peptide substrates. The over-expression of LAP3 correlates with prognosis and malignant development of several human cell carcinomas. However, the molecular mechanism remains unknown. In this study, we used ES-2 ovarian cancer cell line as a model system to explore the role of LAP3 in regulation of cancer cell invasion by employing a natural LAP3 inhibitor bestatin and LAP3 siRNA. Bestatin inhibited tumor cell migration and invasion in a dose-dependent manner. More interestingly, bestatin down-regulated expression of fascin protein and inhibited activity of fascin promoter luciferase reporter. Both proteome profiler array and Western blot assay showed that bestatin up-regulated the phosphorylation of Hsp27. Furthermore, LAP3 siRNA could up-regulate the phosphorylation of Hsp27 and down-regulate the expression of fascin. Meanwhile, LAP3 siRNA could also down-regulate the phosphorylation of Akt and the expression of MMP-2/9. Taken together, LAP3 could affect the expression of fascin and MMP-2/9 and may act as a potential anti-metastasis therapeutic target.

STIM1 overexpression promotes colorectal cancer progression, cell motility and COX-2 expression

Tumor metastasis is the major cause of death among cancer patients, with >90% of cancer-related death attributable to the spreading of metastatic cells to secondary organs. Store-operated Ca(2+) entry (SOCE) is the predominant Ca(2+) entry mechanism in most cancer cells, and stromal interaction molecule 1 (STIM1) is the endoplasmic reticulum (ER) Ca(2+) sensor for store-operated channels. Here we reported that the STIM1 was overexpressed in colorectal cancer (CRC) patients. STIM1 overexpression in CRC was significantly associated with tumor size, depth of invasion, lymph node metastasis status and serum levels of carcinoembryonic antigen. Furthermore, ectopic expression of STIM1 promoted CRC cell motility, while depletion of STIM1 with short hairpin RNA inhibited CRC cell migration. Our data further suggested that STIM1 promoted CRC cell migration through increasing the expression of cyclooxygenase-2 (COX-2) and production of prostaglandin E2 (PGE2). Importantly, ectopically expressed COX-2 or exogenous PGE2 were able to rescue migration defect in STIM1 knockdown CRC cells, and inhibition of COX-2 with ibuprofen and indomethacin abrogated STIM1-mediated CRC cell motility. In short, our data provided clinicopathological significance for STIM1 and SOCE in CRC progression, and implicated a role for COX-2 in STIM1-mediated CRC metastasis. Our studies also suggested a new approach to inhibit STIM1-mediated metastasis with COX-2 inhibitors.

Dynamic aberrant NF-κB spurs tumorigenesis: a new model encompassing the microenvironment

Recently it was discovered that a transient activation of transcription factor NF-κB can give cells properties essential for invasiveness and cancer initiating potential. In contrast, most oncogenes to date were characterized on the basis of mutations or by their constitutive overexpression. Study of NF-κB actually leads to a far more dynamic perspective on cancer: tumors caused by diverse oncogenes apparently evolve into cancer after loss of feedback regulation for NF-κB. This event alters the cellular phenotype and the expression of hormonal mediators, modifying signals between diverse cell types in a tissue. The result is a disruption of stem cell hierarchy in the tissue, and pervasive changes in the microenvironment and immune response to the malignant cells.

Atlas of Cancer Signalling Network: a systems biology resource for integrative analysis of cancer data with Google Maps

Cancerogenesis is driven by mutations leading to aberrant functioning of a complex network of molecular interactions and simultaneously affecting multiple cellular functions. Therefore, the successful application of bioinformatics and systems biology methods for analysis of high-throughput data in cancer research heavily depends on availability of global and detailed reconstructions of signalling networks amenable for computational analysis. We present here the Atlas of Cancer Signalling Network (ACSN), an interactive and comprehensive map of molecular mechanisms implicated in cancer. The resource includes tools for map navigation, visualization and analysis of molecular data in the context of signalling network maps. Constructing and updating ACSN involves careful manual curation of molecular biology literature and participation of experts in the corresponding fields. The cancer-oriented content of ACSN is completely original and covers major mechanisms involved in cancer progression, including DNA repair, cell survival, apoptosis, cell cycle, EMT and cell motility. Cell signalling mechanisms are depicted in detail, together creating a seamless ‘geographic-like' map of molecular interactions frequently deregulated in cancer. The map is browsable using NaviCell web interface using the Google Maps engine and semantic zooming principle. The associated web-blog provides a forum for commenting and curating the ACSN content. ACSN allows uploading heterogeneous omics data from users on top of the maps for visualization and performing functional analyses. We suggest several scenarios for ACSN application in cancer research, particularly for visualizing high-throughput data, starting from small interfering RNA-based screening results or mutation frequencies to innovative ways of exploring transcriptomes and phosphoproteomes. Integration and analysis of these data in the context of ACSN may help interpret their biological significance and formulate mechanistic hypotheses. ACSN may also support patient stratification, prediction of treatment response and resistance to cancer drugs, as well as design of novel treatment strategies.

Fe65 Suppresses Breast Cancer Cell Migration and Invasion through Tip60 Mediated Cortactin Acetylation

Fe65 is a brain-enriched adaptor protein known for its role in the action of the Aβ amyloid precursor protein in neuronal cells and Alzheimer’s disease, but little is known about its functions in cancer cells. The present study documents for the first time a role of Fe65 in suppressing breast cancer cell migration and invasion. Mechanistic studies suggest that the suppression is mediated through its phosphotyrosine binding domain 1 that mediates the recruitment of Tip60 to cortactin to stimulate its acetylation. The studies identify the Tip60 acetyltransferase as a cytoplasmic drug target for the therapeutic intervention of metastatic breast cancers.

Linking patient outcome to high throughput protein expression data identifies novel regulators of colorectal adenocarcinoma aggressiveness

A key question in cancer systems biology is how to use molecular data to predict the biological behavior of tumors from individual patients. While genomics data have been heavily used, protein signaling data are more directly connected to biological phenotype and might predict cancer phenotypes such as invasion, metastasis, and patient survival. In this study, we mined publicly available data for colorectal adenocarcinoma from the Cancer Genome Atlas and identified protein expression and signaling changes that are statistically associated with patient outcome. Our analysis identified a number of known and potentially new regulators of colorectal cancer. High levels of insulin growth factor binding protein 2 (IGFBP2) were associated with both recurrence and death, and this was validated by immunohistochemical staining of a tissue microarray for a secondary patient dataset. Interestingly, GATA binding protein 3 (GATA3) was the protein most frequently associated with death in our analysis, and GATA3 expression was significantly decreased in tumor samples from stage I-II deceased patients. Experimental studies using engineered colon cancer cell lines show that exogenous expression of GATA3 decreases three-dimensional colony growth and invasiveness of colon cancer cells but does not affect two-dimensional proliferation. These findings suggest that protein data are useful for biomarker discovery and identify GATA3 as a regulator of colorectal cancer  aggressiveness.

LASP1 is a HIF1α target gene critical for metastasis of pancreatic cancer

LASP1 is an actin-binding protein associated with actin assembly dynamics in cancer cells. Here, we report that LASP1 is overexpressed in pancreatic ductal adenocarcinoma (PDAC) where it promotes invasion and metastasis. We found that LASP1 overexpression in PDAC cells was mediated by HIF1α through direct binding to a hypoxia response element in the LASP1 promoter. HIF1α stimulated LASP1 expression in PDAC cells in vitro and mouse tumor xenografts in vivo. Clinically, LASP1 overexpression in PDAC patient specimens was associated significantly with lymph node metastasis and overall survival. Overall, our results defined LASP1 as a direct target gene for HIF1α upregulation that is critical for metastatic progression of PDAC.

STIM1- and Orai1-mediated Ca(2+) oscillation orchestrates invadopodium formation and melanoma invasion

Calcium signaling mediated by STIM1 and Orai1 activates Src to promote invadopodium assembly while simultaneously promoting MT1-MMP recycling to the plasma membrane to promote ECM degradation.

Ca²⁺ signaling has been increasingly implicated in cancer invasion and metastasis, and yet, the underlying mechanisms remained largely unknown. In this paper, we report that STIM1- and Orai1-mediated Ca²⁺ oscillations promote melanoma invasion by orchestrating invadopodium assembly and extracellular matrix (ECM) degradation. Ca²⁺ oscillation signals facilitate invadopodial precursor assembly by activating Src. Disruption of Ca²⁺ oscillations inhibited invadopodium assembly. Furthermore, STIM1 and Orai1 regulate the proteolysis activity of individual invadopodia. Mechanistically, Orai1 blockade inhibited the recycling of MT1–matrix metalloproteinase (MMP) to the plasma membrane and entrapped MT1-MMP in the endocytic compartment to inhibit ECM degradation. STIM1 knockdown significantly inhibited melanoma lung metastasis in a xenograft mouse model, implicating the importance of this pathway in metastatic dissemination. Our findings provide a novel mechanism for Ca²⁺-mediated cancer cell invasion and shed new light on the spatiotemporal organization of store-operated Ca²⁺ signals during melanoma invasion and metastasis.

Regulation of serine protease inhibitor Kazal type-5 (SPINK5) gene expression in the keratinocytes

Objectives

Serine protease inhibitor Kazal type-5 (SPINK5) plays a crucial role in deciding the timing of desquamation of the skin. Its gene expression is limited at the very surface of the stratum granulosum (SG), whereas expression of kallikreins (KLKs) encoding proteases is usually found throughout the stratum spinosum and SG.

Methods

To explore the difference in expression regulation of these proteases/inhibitors, the function of SPINK5 promoter was examined using luciferase assay.

Results

Luciferase assay targeting the SPINK5 promoters (nucleotide −676/−532 and −318/−146 from the major transcription start site) showed high intensity in NHEK human keratinocyte. These two sites had neither common cis-elements nor GATA3 element but electrophoretic mobility shift assay showed similar retardation bands. Moreover, DNA footprinting did not display specific protected bands. Thus, we could not identify cis-element(s) that controlled these elements. Differentiation induced by high Ca²⁺ medium failed to alter their luciferase activities. Transfection of GATA3 expressing vector significantly but slightly increased them and that of vector expressing its dominant negative form decreased.

Conclusions

Although GATA3 is reportedly important for inhibition of proliferation and induction of differentiation of keratinocytes, its effect on SPINK5 expression was indirect and GATA3 alone was insufficient for final differentiation of keratinocytes where full SPINK5 expression was observed.

Longissimus dorsi transcriptome analysis of purebred and crossbred Iberian pigs differing in muscle characteristics

BACKGROUND

The two main genetic types in Iberian pig production show important phenotypic differences in growth, fattening and tissue composition since early developmental stages. The objective of this work was the evaluation of muscle transcriptome profile in piglets of both genetic types, in order to identify genes, pathways and regulatory factors responsible for their phenotypic differences. Contemporary families coming from pure Iberian pigs (IB) or from crossing with Duroc boars (DU×IB) were generated. Piglets (14 from each genetic type) were slaughtered at weaning (28 days) and longissimus dorsi was sampled for composition and gene expression studies. RNA was obtained and hybridized to Affymetrix Porcine Genechip expression arrays.

RESULTS

Loin muscle chemical composition showed significant differences between genetic types in intramuscular fat content (6.1% vs. 4.3% in IB and DUxIB animals, respectively, P = 0.009) and in saturated (P = 0.019) and monounsaturated fatty acid proportions (P = 0.044). The statistical analysis of gene expression data allowed the identification of 256 differentially expressed (DE) genes between genetic types (FDR < 0.10), 102 upregulated in IB and 154 upregulated in DU×IB. Transcript differences were validated for a subset of DE genes by qPCR. We observed alteration in biological functions related to extracellular matrix function and organization, cellular adhesion, muscle growth, lipid metabolism and proteolysis. Candidate genes with known effects on muscle growth were found among the DE genes upregulated in DU×IB. Genes related to lipid metabolism and proteolysis were found among those upregulated in IB. Regulatory factors (RF) potentially involved in the expression differences were identified by calculating the regulatory impact factors. Twenty-nine RF were found, some of them with known relationship with tissue development (MSTN, SIX4, IRX3), adipogenesis (CEBPD, PPARGC1B), or extracellular matrix processes (MAX, MXI1). Correlation among the expression of these RF and DE genes show relevant differences between genetic types.

CONCLUSION

These results provide valuable information about genetic mechanisms determining the phenotypic differences on growth and meat quality between the genetic types studied, mainly related to the development and function of the extracellular matrix and also to some metabolic processes as proteolysis and lipid metabolism. Transcription factors and regulatory mechanisms are proposed for these altered biological functions.

Hypoxia-inducible factor-1 promotes pancreatic ductal adenocarcinoma invasion and metastasis by activating transcription of the actin-bundling protein fascin

Because of the early onset of local invasion and distant metastasis, pancreatic ductal adenocarcinoma (PDAC) is the most lethal human malignant tumor, with a 5-year survival rate of less than 5%. In this study, we investigated the role of fascin, a prometastasis actin-bundling protein, in PDAC progression, invasion, and the molecular mechanisms underlying fascin overexpression in PDAC. Our data showed that the expression levels of fascin were higher in cancer tissues than in normal tissues, and fascin overexpression correlated with the PDAC differentiation and prognosis. Fascin overexpression promoted PDAC cell migration and invasion by elevating matrix metalloproteinase-2 (MMP-2) expression. Fascin regulated MMP-2 expression through protein kinase C and extracellular signal-regulated kinase. Importantly, our data showed that hypoxia induced fascin overexpression in PDAC cells by promoting the binding of hypoxia-inducible factor-1 (HIF-1) to a hypoxia response element on the fascin promoter and transactivating fascin mRNA transcription. Intriguingly, HIF-1α expression levels in PDAC patient specimens significantly correlated with fascin expression. Moreover, immunohistochemistry staining of consecutive sections demonstrated colocalization between HIF-1α and fascin in PDAC specimens, suggesting that hypoxia and HIF-1α were responsible for fascin overexpression in PDAC. When ectopically expressed, fascin was able to rescue PDAC cell invasion after HIF-1α knockdown. Our results demonstrated that fascin is a direct target gene of HIF-1. Our data suggested that the hypoxic tumor microenvironment in PDAC might promote invasion and metastasis by inducing fascin overexpression, and fascin might be targeted to block PDAC progression.