Regulation of invasive behavior by vascular endothelial growth factor is HEF1-dependent

Rethinking the chemokine cascade in brain metastasis: Preventive and therapeutic implications

Brain metastasis (BrM) is one of the major causes of death in cancer patients and is associated with an estimated 10-40 % of total cancer cases. The survival rate of brain metastatic patients has not improved due to intratumor heterogeneity, the survival adaptations of brain homing metastatic cells, and the lack of understanding of underlying molecular mechanisms that limit the availability of effective therapies. The heterogeneous population of immune cells and tumor-initiating cells or cancer stem cells in the tumor microenvironment (TME) release various factors, such as chemokines that upon binding to their cognate receptors enhance tumor growth at primary sites and help tumor cells metastasize to the brain. Furthermore, brain metastatic sites have unique heterogeneous microenvironment that fuels cancer cells in establishing BrM. This review explores the crosstalk of chemokines with the heterogeneous TME during the progression of BrM and recognizes potential therapeutic approaches. We also discuss and summarize different targeted, immunotherapeutic, chemotherapeutic, and combinatorial strategies (with chemo-/immune- or targeted-therapies) to attenuate chemokines mediated BrM.

Polygenic and Network-Based Studies in Risk Identification and Demystification of cancer

INTRODUCTION

Diseases were initially thought to be the consequence of a single gene mutation. Advances in DNA sequencing tools and our understanding of gene behavior have revealed that complex diseases, such as cancer, are the product of genes cooperating with each other and with their environment in orchestrated communication networks. Seeing that the function of individual genes is still used to analyze cancer, the shift to using functionally interacting groups of genes as a new unit of study holds promise for demystifying cancer.

AREAS COVERED

The literature search focused on three types of cancer, namely breast, lung, and prostate, but arguments from other cancers were also included. The aim was to prove that multigene analyses can accurately predict and prognosticate cancer risk, subtype cancer for more personalized and effective treatments, and discover anti-cancer therapies. Computational intelligence is being harnessed to analyze this type of data and is proving indispensable to scientific progress.

EXPERT OPINION

In the future, comprehensive profiling of all kinds of patient data (e.g., serum molecules, environmental exposures) can be used to build universal networks that should help us elucidate the molecular mechanisms underlying diseases and provide appropriate preventive measures, ensuring lifelong health and longevity.

Aurora Kinases as Therapeutic Targets in Head and Neck Cancer

ABSTRACT

The Aurora kinases (AURKA and AURKB) have attracted attention as therapeutic targets in head and neck squamous cell carcinomas. Aurora kinases were first defined as regulators of mitosis that localization to the centrosome (AURKA) and centromere (AURKB), governing formation of the mitotic spindle, chromatin condensation, activation of the core mitotic kinase CDK1, alignment of chromosomes at metaphase, and other processes. Subsequently, additional roles for Aurora kinases have been defined in other phases of cell cycle, including regulation of ciliary disassembly and DNA replication. In cancer, elevated expression and activity of Aurora kinases result in enhanced or neomorphic locations and functions that promote aggressive disease, including promotion of MYC expression, oncogenic signaling, stem cell identity, epithelial-mesenchymal transition, and drug resistance. Numerous Aurora-targeted inhibitors have been developed and are being assessed in preclinical and clinical trials, with the goal of improving head and neck squamous cell carcinoma treatment.

Genomic Landscapes of Noncoding RNAs Regulating VEGFA and VEGFC Expression in Endothelial Cells

Vascular endothelial growth factors (VEGFs) are best known as key regulators of angiogenesis and lymphangiogenesis. Although VEGFs have been promising therapeutic targets for various cardiovascular diseases, their regulatory landscape in endothelial cells remains elusive. Several studies have highlighted the involvement of noncoding RNAs (ncRNAs) in the modulation of VEGF expression. In this study, we investigated the role of two classes of ncRNAs, long ncRNAs (lncRNAs) and enhancer RNAs (eRNAs), in the transcriptional regulation of VEGFA and VEGFC. By integrating genome-wide global run-on sequencing (GRO-Seq) and chromosome conformation capture (Hi-C) data, we identified putative lncRNAs and eRNAs associated with VEGFA and VEGFC genes in endothelial cells. A subset of the identified putative enhancers demonstrated regulatory activity in a reporter assay. Importantly, we demonstrate that deletion of enhancers and lncRNAs by CRISPR/Cas9 promoted significant changes in VEGFA and VEGFC expression. Transcriptome sequencing (RNA-Seq) data from lncRNA deletions showed downstream factors implicated in VEGFA- and VEGFC-linked pathways, such as angiogenesis and lymphangiogenesis, suggesting functional roles for these lncRNAs. Our study uncovers novel lncRNAs and eRNAs regulating VEGFA and VEGFC that can be targeted to modulate the expression of these important molecules in endothelial cells.

Invadopodia: clearing the way for cancer cell invasion

The invasive nature of many cancer cells involves the formation of F-actin-based, lipid-raft-enriched membrane protrusions known as invadopodia or, more broadly, invadosomes. Invadopodia are specialized adhesive structures arising from ventral cell surface within cell-extracellular matrix (ECM) contacts and concentrate high proteolytic activities that allow cells to overcome the dense scaffold of local microenvironment, comprising a natural barrier to cell spreading. This degradative activity distinguishes invadopodia from other adhesive structures like focal adhesions, lamellipodia or filopodia, and is believed to drive cancer progression.

Anti-metastatic properties of a potent herbal combination in cell and mice models of triple negative breast cancer

AIM

To determine the anti-metastatic potential of combinations of two bioactive carotenoids of saffron, crocin and crocetin, on 4T1 breast cancer and on a mice model of TNBC, and assess the effect of the most potent combination on the Wnt/β-catenin pathway.

MAIN METHODS

The effects of the carotenoid combinations on the viability of 4T1 cells were determined by MTT assay. The effects of the nontoxic doses on migration, mobility, invasion and adhesion to ECM were examined by scratch assay, Transwell/Matrigel-coated Transwell chamber and adhesion assay respectively. Tumors were inoculated by injecting mice with 4T1 cells. The weights and survival rates of the mice and tumor sizes were monitored. Histological analysis of the tissues was conducted. The expression levels of Wnt/β-catenin pathway genes were measured by Real-time PCR and western blotting.

KEY FINDINGS

Treatment of 4T1 cells with combination doses inhibited viability in a dose-dependent manner. The nontoxic combinations significantly inhibited migration, cell mobility and invasion, also attenuating adhesion to ECM. The combination therapy mice possessed more weight, higher survival rates and smaller tumors. Histological examination detected remarkably fewer metastatic foci in their livers and lungs. It was also demonstrated that the combinations exerted anti-metastatic effects by disturbing the Wnt/β-catenin target genes in the liver and tumors.

SIGNIFICANCE

Our findings propose a carotenoid combination as an alternative potent herbal treatment for TNBC, which lacks the adverse effects associated with either chemotherapeutic agents or herb-chemotherapeutic drugs.

Tumor microenvironment differences between primary tumor and brain metastases

The present review aimed to discuss contemporary scientific literature involving differences between the tumor microenvironment (TME) in melanoma, lung cancer, and breast cancer in their primary site and TME in brain metastases (BM). TME plays a fundamental role in the behavior of cancer. In the process of carcinogenesis, cells such as fibroblasts, macrophages, endothelial cells, natural killer cells, and other cells can perpetuate and progress carcinogenesis via the secretion of molecules. Oxygen concentration, growth factors, and receptors in TME initiate angiogenesis and are examples of the importance of microenvironmental conditions in the performance of neoplastic cells. The most frequent malignant brain tumors are metastatic in origin and primarily originate from lung cancer, breast cancer, and melanoma. Metastatic cancer cells have to adhere to and penetrate the blood-brain barrier (BBB). After traversing BBB, these cells have to survive by producing various cytokines, chemokines, and mediators to modify their new TME. The microenvironment of these metastases is currently being studied owing to the discovery of new therapeutic targets. In these three types of tumors, treatment is more effective in the primary tumor than in BM due to several factors, including BBB. Understanding the differences in the characteristics of the microenvironment surrounding the primary tumor and their respective metastasis might help improve strategies to comprehend cancer.

The relevance between the immune response-related gene module and clinical traits in head and neck squamous cell carcinoma

Purpose

Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent cancer in the world, accounting for more than 90% of head and neck malignant tumors. However, its molecular mechanism is largely unknown. To help elucidate the potential mechanism of HNSCC tumorigenesis, we investigated the gene interaction patterns associated with tumorigenesis.

Methods

Weighted gene co-expression network analysis (WGCNA) can help us to predict the intrinsic relationship or correlation between gene expression. Additionally, we further explored the combination of clinical information and module construction.

Results

Sixteen modules were constructed, among which the key module most closely associated with clinical information was identified. By analyzing the genes in this module, we found that the latter may be related to the immune response, inflammatory response and formation of the tumor microenvironment. Sixteen hub genes were identified-ARHGAP9, SASH3, CORO1A, ITGAL, PPP1R16B, TBC1D10C, IL10RA, ITK, AKNA, PRKCB, TRAF3IP3, GIMAP4, CCR7, P2RY8, GIMAP7, and SP140. We further validated these genes at the transcriptional and translation levels.

Conclusion

The innovative use of a weighted network to analyze HNSCC samples provides new insights into the molecular mechanism and prognosis of HNSCC. Additionally, the hub genes we identified can be used as biomarkers and therapeutic targets of HNSCC, laying the foundation for the accurate diagnosis and treatment of HNSCC in clinical and research in the future.

NEDD9 overexpression predicts poor prognosis in solid cancers: a meta-analysis

Background: The oncogenicity of neural precursor cell-expressed developmentally down-regulated 9 (NEDD9) has been demonstrated in multiple cancer types. However, the prognostic value of NEDD9 in some solid cancers remains controversial. Thus, this meta-analysis was conducted to evaluate the relationship between NEDD9 expression survival rates in solid tumors.

Method: Our meta-analysis included studies searched from various search engines with specific inclusion criteria and exclusion criteria. Combined HRs for overall survival (OS) and disease-free survival (DFS) or progression-free survival (PFS) or recurrence-free survival (RFS) or cancer-specific survival (CSS) were assessed using fixed-effects and random-effects models. The source of heterogeneity was identified by subgroup analysis. Additionally, publication bias was assessed using funnel plot and Egger’s regression asymmetry test.

Result: Eighteen studies with a total of 2,476 patients were retrieved for analysis. Pooled HRs and 95% CIs were calculated. Both OS (HR=1.82; 95% CI: 1.43–2.31) and DFS/PFS/RFS/CSS (HR=2.54; 95% CI: 1.93–3.33) indicated that NEDD9 overexpression is associated with poor OS in cancer patients with solid tumors.

Conclusion: NEDD9 overexpression might be a potential marker to predict prognosis in solid cancer patients.

Invadopodia formation: An important step in matrix stiffness-regulated tumor invasion and metastasis

Highly motile and invasive abilities are symbolic features of metastatic tumor cells. Being a critical molecular event for maintaining the highly migratory and invasive capabilities of tumor cells, invadopodia formation undoubtedly determines the progression of tumor invasion and metastasis. Growing numbers of studies suggest that increased matrix stiffness, as a notable property of physical mechanics in solid tumors, participates in the regulation of tumor invasion and metastasis via different molecular mechanisms. However, to date the relevant mechanisms of matrix stiffness-induced invadopodia formation and activity in tumor cells remain largely unclear. This paper is to make a review on the structure and function of invadopodia, the stages and inductive factors of invadopodia formation, the regulatory mechanisms of matrix stiffness-induced invadopodia formation and so on, with an aim to reveal the important roles of invadopodia in matrix stiffness-regulated tumor invasion and metastasis.

Stretch Induces Invasive Phenotypes in Breast Cells Due to Activation of Aerobic-Glycolysis-Related Pathways

It is increasingly being accepted that cells' physiological functions are substantially dependent on the mechanical characteristics of their surrounding tissue. This is mainly due to the key role of biomechanical forces on cells and their nucleus' shapes, which have the capacity to regulate chromatin conformation and thus gene regulations. Therefore, it is reasonable to postulate that altering the biomechanical properties of tissue may have the capacity to change cell functions. Here, the role of cell stretching (as a model of biomechanical variations) is probed in cell migration and invasion capacity using human normal and cancerous breast cells. By several analyses (i.e., scratch assay, invasion to endothelial barrier, real-time RNA sequencing, confocal imaging, patch clamp, etc.), it is revealed that the cell-stretching process could increase the migration and invasion capabilities of normal and cancerous cells, respectively. More specifically, it is found that poststretched breast cancer cells are found in low grades of invasion; they substantially upregulate the expression of manganese-dependent superoxide dismutase (MnSOD) through activation of H-Ras proteins, which subsequently induce aerobic glycolysis followed by an overproduction of matrix metalloproteinases (MMP)-reinforced filopodias. Presence of such invadopodias facilitates targeting of the endothelial layer, and increased invasive behaviors in breast cells are observed.

Effect of tumor microenvironment on pathogenesis of the head and neck squamous cell carcinoma: a systematic review

The tumor microenvironment (TME) is comprised of many different cell populations, such as cancer-associated fibroblasts and various infiltrating immune cells, and non-cell components of extracellular matrix. These crucial parts of the surrounding stroma can function as both positive and negative regulators of all hallmarks of cancer development, including evasion of apoptosis, induction of angiogenesis, deregulation of the energy metabolism, resistance to the immune detection and destruction, and activation of invasion and metastasis. This review represents a summary of recent studies focusing on describing these effects of microenvironment on initiation and progression of the head and neck squamous cell carcinoma, focusing on oral squamous cell carcinoma, since it is becoming clear that an investigation of differences in stromal composition of the head and neck squamous cell carcinoma microenvironment and their impact on cancer development and progression may help better understand the mechanisms behind different responses to therapy and help define possible targets for clinical intervention.

Vimentin and Non-Muscle Myosin IIA are Members of the Neural Precursor Cell Expressed Developmentally Down-Regulated 9 (NEDD9) Interactome in Head and Neck Squamous Cell Carcinoma Cells

Here we demonstrate an interaction between neural precursor cell expressed, developmentally-downregulated 9 (NEDD9) and the cytoskeletal proteins vimentin and non-muscle myosin IIA (NMIIA), based on co-immunoprecipitation and mass spectrometric sequence identification. Vimentin was constitutively phosphorylated at Ser56 but vimentin associated with NEDD9-was not phosphorylated at Ser56. In contrast, NMIIA bound to NEDD9 was phosphorylated on S1943 consistent with its function in invasion and secretion. Treatment of cells with the vimentin-targeting steroidal lactone withaferin A had no effect on vimentin turnover as previously reported, instead causing NEDD9 cleavage and cell death. The NMIIA-selective inhibitor blebbistatin induced cells to form long extensions and attenuated secretion of matrix metalloproteinases (MMPs) 2 and 9. While the site of vimentin interaction on NEDD9 was not defined, NMIIA was found to interact with NEDD9 at its substrate domain. NEDD9 interactions with vimentin and NMIIA are consistent with these proteins having roles in MMP secretion and cell invasion. These findings suggest that a better understanding of NEDD9 signaling is likely to reveal novel therapeutic targets for the prevention of invasion and metastasis.

Network-Based Predictors of Progression in Head and Neck Squamous Cell Carcinoma

The heterogeneity in head and neck squamous cell carcinoma (HNSCC) has made reliable stratification extremely challenging. Behavioral risk factors such as smoking and alcohol consumption contribute to this heterogeneity. To help elucidate potential mechanisms of progression in HNSCC, we focused on elucidating patterns of gene interactions associated with tumor progression. We performed de-novo gene co-expression network inference utilizing 229 patient samples from The Cancer Genome Atlas (TCGA) previously annotated by Bornstein et al. (2016). Differential network analysis allowed us to contrast progressor and non-progressor cohorts. Beyond standard differential expression (DE) analysis, this approach evaluates changes in gene expression variance (differential variability DV) and changes in covariance, which we denote as differential wiring (DW). The set of affected genes was overlaid onto the co-expression network, identifying 12 modules significantly enriched in DE, DV, and/or DW genes. Additionally, we identified modules correlated with behavioral measures such as alcohol consumption and smoking status. In the module enriched for differentially wired genes, we identified network hubs including IL10RA, DOK2, APBB1IP, UBASH3A, SASH3, CELF2, TRAF3IP3, GIMAP6, MYO1F, NCKAP1L, WAS, FERMT3, SLA, SELPLG, TNFRSF1B, WIPF1, AMICA1, PTPN22; the network centrality and progression specificity of these genes suggest a potential role in tumor evolution mechanisms related to inflammation and microenvironment. The identification of this network-based gene signature could be further developed to guide progression stratification, highlighting how network approaches may help improve clinical research end points and ultimately aid in clinical utility.

NEDD9 stimulated MMP9 secretion is required for invadopodia formation in oral squamous cell carcinoma

Neural precursor cell expressed developmentally downregulated 9 (NEDD9) is a component of the metastatic signatures of melanoma, breast cancer, glioblastoma, lung cancer and head and neck squamous cell carcinoma (HNSCC). Here we tested the efficacy of NEDD9's domains in stimulating matrix metalloproteinase (MMP) secretion and invadopodia formation in cells stably expressing various NEDD9 mutants. Replacement of the 13 YxxP motif substrate domain (SD) tyrosines and the C-terminal Y629 with phenylalanines (F14NEDD9) eliminated tyrosine phosphorylation, MMP9 secretion and loss of invadopodia formation. Mutation of the N-terminal SH3 domain Y12 to glutamic acid (Y12ENEDD9) or phenylalanine (Y12FNEDD9) reduced MMP9 secretion and inhibited invadopodia formation. SH3 domain deletion (∆SH3NEDD9) resulted in the loss of MMP9 secretion and a lack of invadopodia formation. The SH3–SD domain (SSNEDD9) construct exhibited tyrosine phosphorylation and stimulated MMP9 secretion, as did ∆CTNEDD9 which lacked the C-terminus (∆C-terminal; ∆CT). E13NEDD9 expression blocked MMP9 secretion and invadopodia formation. MICAL1 (molecule interacting with Cas-L1) silencing with a short hairpin RNA reduced MMP9 secretion, vimentin and E-cadherin levels while increasing N-cadherin and Rab6 levels, consistent with reduced invasive behavior. These findings indicate that NEDD9 SD phosphorylation and SH3 domain interactions are necessary for increasing MMP9 secretion and invadopodia formation.

NEDD9 may regulate hepatocellular carcinoma cell metastasis by promoting epithelial-mesenchymal-transition and stemness via repressing Smad7

Overexpression of neural precursor cell expressed, developmentally downregulated 9 (NEDD9) is a prognostic marker of many cancers, including hepatocellular carcinoma (HCC). However, the functions and mechanisms of NEDD9 are unclear. We found that upregulation of NEDD9 promoted migration, invasion and cell-to-extracellular matrix adhesion of HCC cells. NEDD9 also induced the epithelial-mesenchymal transition (EMT) and expression of matrix metalloprotein 2 (MMP2). Increased aldehyde dehydrogenase (ALDH) activity and CD133-positive cells were observed in HCC cells with high expression of NEDD9, corresponding to greater sphere formation in cancer stem cells (CSCs). NEDD9 deregulated Smad7 expression to inhibit Smad signaling and binding to the FAK-Src-Crk complex. We propose that this is the mechanism by which NEDD9 induced CSC properties.

Phosphorylation of human enhancer filamentation 1 (HEF1) stimulates interaction with Polo-like kinase 1 leading to HEF1 localization to focal adhesions

Elevated expression of human enhancer filamentation 1 (HEF1; also known as NEDD9 or Cas-L) is an essential stimulus for the metastatic process of various solid tumors. This process requires HEF1 localization to focal adhesions (FAs). Although the association of HEF1 with FAs is considered to play a role in cancer cell migration, the mechanism targeting HEF1 to FAs remains unclear. Moreover, up-regulation of Polo-like kinase 1 (Plk1) positively correlates with human cancer metastasis, yet how Plk1 deregulation promotes metastasis remains elusive. Here, we report that casein kinase 1δ (CK1δ) phosphorylates HEF1 at Ser-780 and Thr-804 and that these phosphorylation events promote a physical interaction between Plk1 and HEF1. We found that this interaction is critical for HEF1 translocation to FAs and for inducing migration of HeLa cells. Plk1-docking phosphoepitopes were mapped/confirmed in HEF1 by various methods, including X-ray crystallography, and mutated for functional analysis in HeLa cells. In summary, our results reveal the role of a phosphorylation-dependent HEF1-Plk1 complex in HEF1 translocation to FAs to induce cell migration. Our findings provide critical mechanistic insights into the HEF1-Plk1 complex-dependent localization of HEF1 to FAs underlying the metastatic process and may therefore contribute to the development of new cancer therapies.

A pyrrole-based natural small molecule mitigates HSP90 expression in MDA-MB-231 cells and inhibits tumor angiogenesis in mice by inactivating HSF-1

Heat shock proteins (HSPs), molecular chaperones, are crucial for the cancer cells to facilitate proper functioning of various oncoproteins involved in cell survival, proliferation, migration, and tumor angiogenesis. Tumor cells are said to be "addicted" to HSPs. HSPs are overexpressed in many cancers due to upregulation of transcription factor Heat-shock factor 1 (HSF-1), the multifaceted master regulator of heat shock response. Therefore, pharmacological targeting of HSPs via HSF-1 is an effective strategy to treat malignant cancers like triple negative breast cancer. In the current study, we evaluated the efficacy of a pyrrole derivative [bis(2-ethylhexyl)1H-pyrrole-3,4-dicarboxylate], TCCP, purified from leaves of Tinospora cordifolia for its ability to suppress heat shock response and angiogenesis using MDA-MB-231 cells and the murine mammary carcinoma: Ehrlich ascites tumor model. HSP90 was downregulated by TCCP by inactivation of HSF-1 resulting in inhibition of tumor cell proliferation, VEGF-induced cell migration, and concomitant decrease in tumor burden and neo-angiogenesis in vivo. The mechanism of suppression of HSPs involves inactivation of PI3K/Akt and phosphorylation on serine 307 of HSF-1 by the activation of ERK1. HSF-1 and HSP90 and 70 localization and expression were ascertained by immunolocalization, immunoblotting, and qPCR experiments. The anti-angiogenic effect of TCCP was studied in vivo in tumor-bearing mice and ex vivo using rat corneal micro-pocket assay. All the results thus corroborate the logic behind inactivating HSF-1 using TCCP as an alternative approach for cancer therapy.

NEDD9 expression is correlated with epithelial-to-mesenchymal transition markers in colorectal cancer

The epithelial-to-mesenchymal transition (EMT) is a critical step in tumor metastasis. NEDD9 has been shown to be an oncogene in colorectal cancer. However, little is known about the relationship between NEDD9 and EMT in colorectal cancer metastasis. A total of 63 pairs of freshly frozen colorectal cancer tissues and adjacent noncancerous tissues were evaluated for NEDD9 gene expression using quantitative real-time PCR. The expression of NEDD9 and three epithelial-mesenchymal transition (EMT)-related proteins (E-cadherin, β-catenin and vimentin) was examined in 122 colorectal cancers by immunohistochemistry. The expression of NEDD9 was markedly increased in colorectal cancer tissues compared with adjacent noncancerous tissues. The expression level of NEDD9 was positively correlated and TNM stage but not with other clinicopathological features of colorectal tumors. Furthermore, the expression of NEDD9 was strongly associated with the loss of epithelial marker E-cadherin and acquired expression of the mesenchymal markers nuclear β-catenin and vimentin. These findings suggested that NEDD9 might promote EMT and the progression of colorectal cancer, and thus may be a potential therapeutic target of colorectal cancers.

The focal adhesion targeting (FAT) domain of p130 Crk associated substrate (p130Cas) confers mechanosensing function

The Cas family of focal adhesion proteins contain a highly conserved C-terminal focal adhesion targeting (FAT) domain. To determine the role of the FAT domain we compared wildtype exogenous NEDD9 with a hybrid construct in which the NEDD9 FAT domain is exchanged for the p130Cas FAT domain. Fluorescence recovery after photobleaching (FRAP) revealed significantly slowed exchange of the fusion protein at focal adhesions and significantly slower 2D migration. No differences were detected in cell stiffness measured with Atomic Force Microscopy (AFM) and cell adhesion forces measured with a magnetic tweezer device. Thus the slowed migration was not due to changes in cell stiffness or adhesion strength. Analysis of cell migration on surfaces of increasing rigidity revealed a striking reduction of cell motility in cells expressing the p130Cas FAT domain. The p130Cas FAT domain induced rigidity-dependent tyrosine phosphorylation of the NEDD9 substrate domain. This in turn reduced post-translational cleavage of NEDD9 which we show inhibits NEDD9-induced migration. Collectively, our data therefore suggest that the p130Cas FAT domain uniquely confers mechanosensing function.

Force-dependent breaching of the basement membrane

Clinically, non-invasive carcinomas are confined to the epithelial side of the basement membrane and are classified as benign, whereas invasive cancers invade through the basement membrane and thereby acquire the potential to metastasize. Recent findings suggest that, in addition to protease-mediated degradation and chemotaxis-stimulated migration, basement membrane invasion by malignant cells is significantly influenced by the stiffness of the associated interstitial extracellular matrix and the contractility of the tumor cells that is dictated in part by their oncogenic genotype. In this review, we highlight recent findings that illustrate unifying molecular mechanisms whereby these physical cues contribute to tissue fibrosis and malignancy in three epithelial organs: breast, pancreas, and liver. We also discuss the clinical implications of these findings and the biological properties and clinical challenges linked to the unique biology of each of these organs.

Brain metastasis: Unique challenges and open opportunities

The metastasis of cancer to the central nervous system (CNS) remains a devastating clinical reality, carrying an estimated survival time of less than one year in spite of recent therapeutic breakthroughs for other disease contexts. Advances in brain metastasis research are hindered by a number of factors, including its complicated nature and the difficulty of modeling metastatic cancer growth in the unique brain microenvironment. In this review, we will discuss the clinical challenge, and compare the merits and limitations of the available models for brain metastasis research. Additionally, we will specifically address current knowledge on how brain metastases take advantage of the unique brain environment to benefit their own growth. Finally, we will explore the distinctive metabolic and chemical characteristics of the brain and how these paradoxically represent barriers to establishment of brain metastasis, but also provide ample supplies for metastatic cells' growth in the brain. We envision that multi-disciplinary innovative approaches will open opportunities for the field to make breakthroughs in tackling unique challenges of brain metastasis.

Downregulation of NEDD9 by apigenin suppresses migration, invasion, and metastasis of colorectal cancer cells

Apigenin is a natural flavonoid which possesses multiple anti-cancer properties such as anti-proliferation, anti-inflammation, and anti-metastasis in many types of cancers including colorectal cancer. Neural precursor cell expressed developmentally downregulated 9 (NEDD9) is a multi-domain scaffolding protein of the Cas family which has been shown to correlate with cancer metastasis and progression. The present study investigates the role of NEDD9 in apigenin-inhibited cell migration, invasion, and metastasis of colorectal adenocarcinoma DLD1 and SW480 cells. The results show that knockdown of NEDD9 inhibited cell migration, invasion, and metastasis and that overexpression of NEDD9 promoted cell migration and invasion of DLD1 cells and SW4890 cells. Apigenin treatment attenuated NEDD9 expression at protein level, resulting in reduced phosphorylations of FAK, Src, and Akt, leading to inhibition on cell migration, invasion, and metastasis of both DLD1 and SW480 cells. The present study has demonstrated that apigenin inhibits cell migration, invasion, and metastasis through NEDD9/Src/Akt cascade in colorectal cancer cells. NEDD9 may function as a biomarker for evaluation of cancer aggressiveness and for selection of therapeutic drugs against cancer progression.

A Golgi-based KDELR-dependent signalling pathway controls extracellular matrix degradation

We recently identified an endomembrane-based signalling cascade that is activated by the KDEL receptor (KDELR) on the Golgi complex. At the Golgi, the KDELR acts as a traffic sensor (presumably via binding to chaperones that leave the ER) and triggers signalling pathways that balance membrane fluxes between ER and Golgi. One such pathway relies on Gq and Src. Here, we examine if KDELR might control other cellular modules through this pathway. Given the central role of Src in extracellular matrix (ECM) degradation, we investigated the impact of the KDELR-Src pathway on the ability of cancer cells to degrade the ECM. We find that activation of the KDELR controls ECM degradation by increasing the number of the degradative structures known as invadopodia. The KDELR induces Src activation at the invadopodia and leads to phosphorylation of the Src substrates cortactin and ASAP1, which are required for basal and KDELR-stimulated ECM degradation. This study furthers our understanding of the regulatory circuitry underlying invadopodia-dependent ECM degradation, a key phase in metastases formation and invasive growth.

Prognostic significance of the tumour-adjacent tissue in head and neck cancers

Even with significant advances in operative skills and adjuvant therapies, the overall survival of patients suffering with head and neck squamous cancers (HNSCC) is unsatisfactory. Accordingly, no clinically useful prognostic biomarkers have been found yet for HNSCC. Many studies analysed the expression of potential markers in tumour tissues compared to adjacent tissues. Nevertheless, due to the sharing of the same microenvironment, adjacent tissues show molecular similarity to tumour tissues. Thus, gene expression patterns of 94 HNSCC tumorous tissues were compared with 31 adjacent tissues and with 10 tonsillectomy specimens of non-cancer individuals. The genes analysed at RNA level using quantitative RT-PCR and correlated with clinico-pathological conditions were as follows: EGF, EGFR, MKI67, BCL2, BAX, FOS, JUN, TP53, VEGF, FLT1, MMP2, MMP9, MT1A and MT2A. The elevated MT2A, BAX, EGF and JUN expression was associated with the influence of tumour cells on the rearrangement of healthy tissues, as well as a significant shift in the BAX/BCL2 ratio. Our investigation also indicated that adjacent tissues play an important role in cancerogenesis by releasing several tumour-supporting factors such as EGF. A gradual increase in the metallothionein expression, from the lowest one in tonsillectomy samples to the highest ones in tumour samples, suggests that MT expression might be tissue reaction to the presence of tumour cells. The results of this study confirmed the significance of metallothionein in tumori-genesis and gave evidences for its use as a potential HNSCC biomarker. Furthermore, this study highlighted the importance of histologically normal tumour-adjacent tissue in prediction of HNSCC progress.

Crosstalk between VEGF and MTA1 signaling pathways contribute to aggressiveness of breast carcinoma

The expression of metastasis associated protein (MTA1) correlates well with tumor metastasis; however its role as a proangiogenic protein and the molecular mechanisms underlying the same are not fully understood. In this study the MTA1 protein was expressed and purified to evaluate its angiogenic potential. In both MCF-7 and MDA-MB-231 cells, endogenous MTA1 protein was localized in the nucleus; while added recombinant MTA1 protein was bound to cell membrane as per immunofluorescence data. MTA1 was detected both in conditioned media and in human serum samples. Recombinant MTA1 regulated cellular functions of HUVEC's such as, proliferation, tube formation, and migration. MTA1 was more potent than VEGF in inducing invasion of breast cancer cells. Analogous to VEGF, MTA1 could induce angiogenesis in both non-tumor and tumor context, as verified by rat cornea, shell less CAM and xenograft models respectively. However MTA-1 was more potent an inducer of angiogenesis. VEGF or Flt-1 gene promoter, luciferase gene reporter analysis revealed that MTA1 up regulates the expression of VEGF and its receptor Flt-1 genes. Kinetics of VEGF-induced expression of MTA1 and qPCR studies showed that there is an increased expression of MTA1 in tumor cells. VEGF induced phosphorylation of endogenous MTA1 on tyrosine residues; phosphorylation was mediated through VEGFR2 and p38-MAP kinase. Recombinant MTA1 activated signaling, in MCF-7 and MDA-MB-231 cells, involved ERK and JNK pathways. In conclusion, MTA1 is a potent angiogenic molecule and cross talk between VEGF and MTA1 protein regulates tumor angiogenesis and metastasis.

Expression of NEDD9 in hepatocellular carcinoma and its clinical significance

Neural precursor cell expressed, developmentally downregulated 9 (NEDD9) plays an integral role in natural and pathological cell biology. Overexpression of NEDD9 protein has been correlated with poor prognosis in various types of cancer. However, few available data address the precise function of the NEDD9 gene in hepatocellular carcinoma (HCC). In the present study, we investigated NEDD9 expression in 40 primary human HCC tissues compared with matched adjacent non-tumor hepatic tissues using RT-qPCR and western blot analysis. Immunohistochemistry was performed to analyze the correlations between NEDD9 expression and clinicopathological factors. Statistical analyses were applied to derive prognostic values of NEDD9 in HCC. The results showed that the NEDD9 mRNA and protein expression levels in HCC tissues were significantly higher than those in matched adjacent non-tumor hepatic tissues. High NEDD9 expression was correlated with larger tumor size, advanced tumor grade, metastasis, intrahepatic venous invasion and high UICC TNM stages in HCC patients. Patients with high NEDD9 expression levels exhibited poorer recurrence-free and overall survival than those with a low NEDD9 expression. Additionally, NEDD9 expression status was an independent prognostic factor for survival. This correlation remained significant in patients with early-stage HCC or with normal serum AFP levels. The results of this study suggest that NEDD9 may be a valuable prognostic biomarker for HCC, including early-stage and AFP-normal patients.

Elevated expression of NEDD9 is associated with metastatic activity in gastric cancer

Objective

To investigate the protein and mRNA expression of NEDD9 in gastric cancer (GC) tissues, adjacent atypical hyperplasia tissues, and normal gastric mucosa tissues, and analyze its relationship with the pathological features and prognosis of GC.

Methods

Forty cases of GC tissues, 20 cases of adjacent atypical hyperplasia tissues, and 40 cases of normal gastric mucous tissues were collected. Immunohistochemistry and Western blot were used to examine the expression of NEDD9 protein in various tissues. Situ hybridization and reverse transcription polymerase chain reaction were applied to detect the expression of NEDD9 mRNA in various tissues. The correlation of NEDD9 expression with invasion and metastasis of GC was analyzed.

Results

The protein expression level of NEDD9 was significantly higher in GC tissues than in adjacent atypical hyperplasia tissues and normal gastric mucous tissues (P<0.05). The protein expression level of NEDD9 was positively related to the invasion depth of carcinoma and tumor lymph node metastasis (P<0.05), but unrelated to age, sex, tumor size, and clinical classification of cancer (P<0.05). The mRNA expression level of NEDD9 was also significantly higher in GC tissues than in adjacent atypical hyperplasia tissues and normal gastric mucous tissues (P<0.05), and positively related with the tumor lymph node metastasis and invasion depth of carcinoma (P<0.05).

Conclusion

NEDD9 is involved in the occurrence and development of GC, and it may be an important biological marker of GC metastasis and infiltration.

Effects of Hypoxia, Surrounding Fibroblasts, and p16 Expression on Breast Cancer Cell Migration and Invasion

Cancer cell migration and invasion play essential roles in the metastatic cascade that transforms the local, noninvasive confined tumor cells to the motile, metastatic cancer cells moving through the extracellular matrix and basement into the circulation. Accumulated evidences suggest that intratumoral hypoxia, a characteristic of fast-growing solid tumors, promotes cancer cell motile and invasive abilities. In this study, we investigated the effects of hypoxia, surrounding fibroblasts, and p16 expression on the migration and invasion of breast cancer cells. We found that hypoxia promoted breast cancer cell migration and invasion, and cocultured fibroblasts stimulated invasiveness of breast cancer cells. Moreover, by using a Tet-on inducible system, we found that p16 is capable of inhibiting hypoxia-induced cell migration and invasion of breast cancer cells, and suppressing cocultured fibroblast-stimulated invasiveness of breast cancer cells. These results suggest that p16, in addition to its well-known anti-tumor proliferation function, has novel anti-cancer properties capable of suppressing hypoxia-mediated cancer cell migration and invasion. This study may provide important validation for p16-mediated cancer therapy either by gene therapy or pharmacological activation of internal p16 gene that is usually inactive due to hypermethylation in the tumor cells.

NEDD9/Arf6-dependent endocytic trafficking of matrix metalloproteinase 14: a novel mechanism for blocking mesenchymal cell invasion and metastasis of breast cancer

NEDD9 is an established marker of invasive and metastatic cancers. NEDD9 downregulation has been shown to dramatically reduce cell invasion and metastasis in multiple tumors. The mechanisms by which NEDD9 regulates invasion are largely unknown. In the current study, we have found that NEDD9 is required for MMP14 enzymatic recovery/recycling through the late endosomes to enable disengagement of tissue inhibitor of matrix metalloproteinase 2 (TIMP2) and tumor invasion. Depletion of NEDD9 decreases targeting of the MMP14/TIMP2 complex to late endosomes and increases trafficking of MMP14 from early/sorting endosomes back to the surface in a small GTPase Arf6-dependent manner. NEDD9 directly binds to Arf6-GAP, ARAP3, and Arf6 effector GGA3 thereby facilitating the Arf6 inactivation required for MMP14/TIMP2 targeting to late endosomes. Re-expression of NEDD9 or a decrease in Arf6 activity is sufficient to restore MMP14 activity and the invasive properties of tumor cells. Importantly, NEDD9 inhibition by Vivo-Morpholinos, an antisense therapy, decreases primary tumor growth and metastasis in xenograft models of breast cancer. Collectively, our findings uncover a novel mechanism to control tumor cells dissemination through NEDD9/Arf6-dependent regulation of MMP14/TIMP2 trafficking, and validates NEDD9 as a clinically relevant therapeutic target to treat metastatic cancer.

Arene ruthenium(ii) complex, a potent inhibitor against proliferation, migration and invasion of breast cancer cells, reduces stress fibers, focal adhesions and invadopodia

Effective chemotherapy drugs for cancer that would inhibit tumor growth and suppress metastasis are currently lacking. In this study, a series of arene ruthenium complexes, [(η6-arene)Ru(H2iip)Cl]Cl (arene = p-cymene, RAWQ03; CH3C6H5, RAWQ04; and C6H6, RAWQ11), were synthesized and their inhibitory activity against tumor cells were evaluated. The results showed that the complex RAWQ11 inhibited the growth of MDA-MB-231 breast cancer cells by inducing S-phase arrest, which is closely related to the inhibition of cell mitosis-mediated cell nucleus damage. Further studies showed that RAWQ11 can inhibit the invasion and metastasis of MDA-MB-231 cells. The morphology of MDA-MB-231 cells changed, the number of focal adhesions decreased, and the stress fibers de-polymerized upon dealing with the complex RAWQ11. The FITC-gelatin assay confirmed that the formation of invadopodia in MDA-MB-231 cells was significantly blocked by RAWQ11. Furthermore, RAWQ11 can block the AKT signal pathway by upregulating the PTEN expression through binding and downregulating miR-21. These results demonstrated that this type of arene ruthenium(ii) complex can block the invadopodia formation by regulating the PTEN/AKT signal pathway mediated by miR-21 to inhibit the invasion and metastasis of breast cancer cells. Therefore, this complex can be used as a potential dual functional agent to inhibit the growth and metastasis of tumor cells.

Adaptors for disorders of the brain? The cancer signaling proteins NEDD9, CASS4, and PTK2B in Alzheimer's disease

No treatment strategies effectively limit the progression of Alzheimer's disease (AD), a common and debilitating neurodegenerative disorder. The absence of viable treatment options reflects the fact that the pathophysiology and genotypic causes of the disease are not well understood. The advent of genome-wide association studies (GWAS) has made it possible to broadly investigate genotypic alterations driving phenotypic occurrences. Recent studies have associated single nucleotide polymorphisms (SNPs) in two paralogous scaffolding proteins, NEDD9 and CASS4, and the kinase PTK2B, with susceptibility to late-onset AD (LOAD). Intriguingly, NEDD9, CASS4, and PTK2B have been much studied as interacting partners regulating oncogenesis and metastasis, and all three are known to be active in the brain during development and in cancer. However, to date, the majority of studies of these proteins have emphasized their roles in the directly cancer relevant processes of migration and survival signaling. We here discuss evidence for roles of NEDD9, CASS4 and PTK2B in additional processes, including hypoxia, vascular changes, inflammation, microtubule stabilization and calcium signaling, as potentially relevant to the pathogenesis of LOAD. Reciprocally, these functions can better inform our understanding of the action of NEDD9, CASS4 and PTK2B in cancer.

High expression of NEDD9 predicts adverse outcomes of colorectal cancer patients

NEDD9, a member of Crk-associated substrate (CAS) family, is highly expressed in multiple cancer types and involved cancer cell adhesion, migration, invasion. The prognostic value of NEDD9 has not been evaluated before. The aim of this study was to evaluate the association between NEDD9 expression and survival in colorectal cancer (CRC) patients. NEDD9 expression was analyzed by immunohistochemistry in 92 patients with CRC. Patients were followed-up annually by telephone or at outpatient clinic. The results revealed that high expression of NEDD9 in 68/92 CRC samples, compared with 12/92 normal tissues (P<0.01). Correlation analysis showed high level of expression of NEDD9 was significantly correlated with advanced TNM stage (P=0.014), pT grade (P=0.009), pN (P=0.013) and pM status (P=0.047). Patients with a higher NEDD9 expression had a significantly shorter overall survival (OS) (P<0.01). The multivariate analysis revealed that NEDD9 expression could serve as an independent predictive factor of OS. Our finding demonstrated the potential value of NEDD9 expression level as a prognostic molecular marker and a target for new therapies for CRC patients.

Focal adhesion protein expression in human diffuse large B-cell lymphoma

AIMS

Focal adhesions have been associated with poor prognosis in multiple cancer types, but their prognostic value in diffuse large B-cell lymphoma (DLBCL) has not been evaluated. The aim of this study was to investigate the expression patterns and the prognostic value of the focal adhesion proteins FAK, Pyk2, p130Cas and HEF1 in DLBCL.

METHODS AND RESULTS

Focal adhesion protein expression was examined using immunohistochemistry in normal lymphoid tissues and in 60 DLBCL patient samples. Kaplan-Meier survival and Cox regression analysis were performed to evaluate the correlation of focal adhesion protein expression with patient prognosis. FAK, Pyk2, p130Cas and HEF1 expression was mostly found in the germinal centres of normal human lymphoid tissues. When assessed in DLBCL samples, FAK, Pyk2, p130Cas and HEF1 were highly expressed in 45%, 34%, 42% and 45% of the samples, respectively. Multivariate Cox analysis revealed that decreased FAK expression was a significant independent predictor of poorer disease outcome.

CONCLUSIONS

FAK expression is an independent prognostic factor in DLBCL. Our results suggest that the addition of FAK immunostaining to the current immunohistochemical algorithms may facilitate risk stratification of DLBCL patients.

NEDD9 regulates actin dynamics through cortactin deacetylation in an AURKA/HDAC6-dependent manner

The prometastatic protein NEDD9 (neural precursor cell expressed, developmentally downregulated 9) is highly expressed in many cancers and is required for mesenchymal individual cell migration and progression to the invasive stage. Nevertheless, the molecular mechanisms of NEDD9-driven migration and the downstream targets effecting metastasis are not well defined. In the current study, knockdown of NEDD9 in highly metastatic tumor cells drastically reduces their migratory capacity due to disruption of actin dynamics at the leading edge. Specifically, NEDD9 deficiency leads to a decrease in the persistence and stability of lamellipodial protrusions similar to knockdown of cortactin (CTTN). Mechanistically, it was shown that NEDD9 binds to and regulates acetylation of CTTN in an Aurora A kinase (AURKA)/HDAC6-dependent manner. The knockdown of NEDD9 or AURKA results in an increase in the amount of acetylated CTTN and a decrease in the binding of CTTN to F-actin. Overexpression of the deacetylation mimicking (9KR) mutant of CTTN is sufficient to restore actin dynamics at the leading edge and migration proficiency of the tumor cells. Inhibition of AURKA and HDAC6 activity by alisertib and Tubastatin A in xenograft models of breast cancer leads to a decrease in the number of pulmonary metastases. Collectively, these findings identify CTTN as the key downstream component of NEDD9-driven migration and metastatic phenotypes.

IMPLICATIONS

This study provides a mechanistic platform for therapeutic interventions based on AURKA and HDAC6 inhibition for patients with metastatic breast cancer to prevent and/or eradicate metastases.

NEDD9 depletion leads to MMP14 inactivation by TIMP2 and prevents invasion and metastasis

The scaffolding protein NEDD9 is an established prometastatic marker in several cancers. Nevertheless, the molecular mechanisms of NEDD9-driven metastasis in cancers remain ill-defined. Here, using a comprehensive breast cancer tissue microarray, it was shown that increased levels of NEDD9 protein significantly correlated with the transition from carcinoma in situ to invasive carcinoma. Similarly, it was shown that NEDD9 overexpression is a hallmark of highly invasive breast cancer cells. Moreover, NEDD9 expression is crucial for the protease-dependent mesenchymal invasion of cancer cells at the primary site but not at the metastatic site. Depletion of NEDD9 is sufficient to suppress invasion of tumor cells in vitro and in vivo, leading to decreased circulating tumor cells and lung metastases in xenograft models. Mechanistically, NEDD9 localized to invasive pseudopods and was required for local matrix degradation. Depletion of NEDD9 impaired invasion of cancer cells through inactivation of membrane-bound matrix metalloproteinase MMP14 by excess TIMP2 on the cell surface. Inactivation of MMP14 is accompanied by reduced collagenolytic activity of soluble metalloproteinases MMP2 and MMP9. Reexpression of NEDD9 is sufficient to restore the activity of MMP14 and the invasive properties of breast cancer cells in vitro and in vivo. Collectively, these findings uncover critical steps in NEDD9-dependent invasion of breast cancer cells.

IMPLICATIONS

This study provides a mechanistic basis for potential therapeutic interventions to prevent metastasis.

Aurora kinases in head and neck cancer

In healthy cells, controlled activation of aurora kinases regulates mitosis. Overexpression and hyperactivation of aurora kinases A and B have major roles in tumorigenesis, and can induce aneuploidy and genomic instability. In squamous-cell carcinomas of the head and neck, overexpression of aurora kinase A is associated with decreased survival, and a reduction in aurora kinase A and aurora kinase B expression inhibits cell growth and increases apoptosis. In this Review, we provide an overview of the biological functions of aurora kinases in healthy cells and in cancer cells, and we review small studies and high-throughput datasets that particularly implicate aurora kinase A in the pathogenesis of squamous-cell carcinomas of the head and neck. Early phase trials are beginning to assess the activity of small-molecule inhibitors of aurora kinases. We summarise trials of aurora kinase inhibitors in squamous-cell carcinomas of the head and neck, and discuss directions for future drug combination trials and biomarkers to use with drugs that inhibit aurora kinases.

NEDD9 overexpression is associated with the progression of and an unfavorable prognosis in epithelial ovarian cancer

Neural precursor cell-expressed, developmentally down-regulated 9 (NEDD9), a scaffolding protein, has been identified as a prometastatic and poor prognostic gene in multiple malignant tumors. However, the potential role of the NEDD9 protein in epithelial ovarian cancer (EOC) remains unclear. In the present study, we investigated the expression of NEDD9 and the correlation between NEDD9 expression and prognosis in EOC. NEDD9 expression was detected in 129 archived EOC specimens by immunohistochemical staining and in 28 freshly frozen EOC specimens by Western blotting. The expression of NEDD9 was evaluated in ovarian cancer cell lines by Western blotting and immunofluorescence. The association between the expression of NEDD9 and prognosis was determined by survival analysis. Results suggested that NEDD9 was overexpressed in EOC specimens compared with noninvasive epithelial ovarian tumors and normal ovarian specimens. A high level of NEDD9 expression significantly correlated with advanced-stage tumors (International Federation of Gynecology and Obstetrics classes III-IV, P < .001), high-grade carcinoma (grades 2-3, P < .001), and suboptimal primary cytoreductive surgery (residual disease <1cm, P = .021). The expression level of NEDD9 varied in ovarian cancer cell lines. Multivariate analysis indicated that NEDD9 overexpression (P = .033), advanced stage (P < .001), and high-grade carcinoma (P = .01) were independent predictors of poor survival. In conclusion, NEDD9 is overexpressed and associated with an unfavorable prognosis in EOC. NEDD9 overexpression is an independent factor of poor prognosis and may serve as a potential biomarker in EOC.

The overexpression of scaffolding protein NEDD9 promotes migration and invasion in cervical cancer via tyrosine phosphorylated FAK and SRC

NEDD9, a focal adhesion scaffolding protein, has been recently proposed to regulate invasion and metastasis in some cancer types, but unknown in cervical cancer. The aim of this study was to determine if NEDD9 was involved in the progression and metastasis of cervical cancer. The experimental results showed NEDD9 protein was overexpressed in cervical cancer compared with normal cervical epithelium tissues. Overexpression of NEDD9 was correlated with histological grading, lymph node metastasis, and FIGO stage of cervical cancer. Silencing NEDD9 resulted in tyrosine dephosphorylation of FAK and SRC oncoproteins, and decreased cell migration and invasion in the cervical carcinoma SiHa and HeLa cells. Overexpression of NEDD9 led to tyrosine phosphorylation of FAK and SRC oncoproteins, and increased cell migration and invasion. Moreover, tyrosine phosphorylation of NEDD9 was significantly decreased via suppressing tyrosine phosphorylation of FAK or SRC, suggesting a positive feedback loop of tyrosine phosphorylation between NEDD9 and FAK or SRC. In addition, our data showed that silencing NEDD9 decreased Vimentin expression and increased E-cadherin expression in cervical cancer cells, and vice versa. E-cadherin was subject to regulation of NEDD9, FAK and SRC, but altered neither tyrosine-phosphorylated nor total NEDD9. Our findings suggest that NEDD9 is overexpressed in cervical cancer tissues and cells, and overexpressed NEDD9 promotes migration and invasion in cervical carcinoma cells, probably via a positive feedback loop of tyrosine phosphorylation between NEDD9 and FAK or SRC.

Signaling inputs to invadopodia and podosomes

Remodeling of extracellular matrix (ECM) is a fundamental cell property that allows cells to alter their microenvironment and move through tissues. Invadopodia and podosomes are subcellular actin-rich structures that are specialized for matrix degradation and are formed by cancer and normal cells, respectively. Although initial studies focused on defining the core machinery of these two structures, recent studies have identified inputs from both growth factor and adhesion signaling as crucial for invasive activity. This Commentary will outline the current knowledge on the upstream signaling inputs to invadopodia and podosomes and their role in governing distinct stages of these invasive structures. We discuss invadopodia and podosomes as adhesion structures and highlight new data showing that invadopodia-associated adhesion rings promote the maturation of already-formed invadopodia. We present a model in which growth factor stimulation leads to phosphoinositide 3-kinase (PI3K) activity and formation of invadopodia, whereas adhesion signaling promotes exocytosis of proteinases at invadopodia.

αB-crystallin stimulates VEGF secretion and tumor cell migration and correlates with enhanced distant metastasis in head and neck squamous cell carcinoma

Background

αB-crystallin is able to modulate vascular endothelial growth factor (VEGF) secretion. In many solid tumors VEGF is associated with angiogenesis, metastasis formation and poor prognosis. We set out to assess whether αB-crystallin expression is correlated with worse prognosis and whether this is related to VEGF secretion and cell motility in head and neck squamous cell carcinoma (HNSCC).

Methods

αB-crystallin expression was determined immunohistochemically in tumor biopsies of 38 HNSCC patients. Locoregional control (LRC) and metastasis-free survival (MFS) of the patients were analyzed in relation to αB-crystallin expression. Additionally, the effects of αB-crystallin knockdown on VEGF secretion and cell motility were studied in vitro.

Results

Patients with higher staining fractions of αB-crystallin exhibited a significantly shorter MFS (Log-Rank test, p < 0.005). Under normoxic conditions αB-crystallin knockdown with two different siRNAs in a HNSCC cell line reduced VEGF secretion 1.9-fold and 2.1-fold, respectively. Under hypoxic conditions, a similar reduction of VEGF secretion was observed, 1.9-fold and 2.2-fold, respectively. The effect on cell motility was assessed by a gap closure assay, which showed that αB-crystallin knockdown decreased the rate by which HNSCC cells were able to close a gap by 1.5- to 2.0-fold.

Conclusions

Our data suggest that αB-crystallin expression is associated with distant metastases formation in HNSCC patients. This association might relate to the chaperone function of αB-crystallin in mediating folding and secretion of VEGF and stimulating cell migration.

Decreased expression of ADAMTS-1 in human breast tumors stimulates migration and invasion

Background

ADAMTS-1 (a disintegrin and metalloprotease with thrombospondin motifs) is a member of the ADAMTS family of metalloproteases. Here, we investigated mRNA and protein levels of ADAMTS-1 in normal and neoplastic tissues using qPCR, immunohistochemistry and immunoblot analyses, and we addressed the role of ADAMTS-1 in regulating migration, invasion and invadopodia formation in breast tumor cell lines.

Results

In a series of primary breast tumors, we observed variable levels of ADAMTS-1 mRNA expression but lower levels of ADAMTS-1 protein expression in human breast cancers as compared to normal tissue, with a striking decrease observed in high-malignancy cases (triple-negative for estrogen, progesterone and Her-2). This result prompted us to analyze the effect of ADAMTS-1 knockdown in breast cancer cells in vitro. MDA-MB-231 cells with depleted ADAMTS-1 expression demonstrated increased migration, invasion and invadopodia formation. The regulatory mechanisms underlying the effects of ADAMTS-1 may be related to VEGF, a growth factor involved in migration and invasion. MDA-MB-231 cells with depleted ADAMTS-1 showed increased VEGF concentrations in conditioned medium capable of inducing human endothelial cells (HUVEC) tubulogenesis. Furthermore, expression of the VEGF receptor (VEGFR2) was increased in MDA-MB-231 cells as compared to MCF7 cells. To further determine the relationship between ADAMTS-1 and VEGF regulating breast cancer cells, MDA-MB-231 cells with reduced expression of ADAMTS-1 were pretreated with a function-blocking antibody against VEGF and then tested in migration and invasion assays; both were partially rescued to control levels.

Conclusions

ADAMTS-1 expression was decreased in human breast tumors, and ADAMTS-1 knockdown stimulated migration, invasion and invadopodia formation in breast cancer cells in vitro. Therefore, this series of experiments suggests that VEGF is involved in the effects mediated by ADAMTS-1 in breast cancer cells.

NSP-CAS Protein Complexes: Emerging Signaling Modules in Cancer

The CAS (CRK-associated substrate) family of adaptor proteins comprises 4 members, which share a conserved modular domain structure that enables multiple protein-protein interactions, leading to the assembly of intracellular signaling platforms. Besides their physiological role in signal transduction downstream of a variety of cell surface receptors, CAS proteins are also critical for oncogenic transformation and cancer cell malignancy through associations with a variety of regulatory proteins and downstream effectors. Among the regulatory partners, the 3 recently identified adaptor proteins constituting the NSP (novel SH2-containing protein) family avidly bind to the conserved carboxy-terminal focal adhesion-targeting (FAT) domain of CAS proteins. NSP proteins use an anomalous nucleotide exchange factor domain that lacks catalytic activity to form NSP-CAS signaling modules. Additionally, the NSP SH2 domain can link NSP-CAS signaling assemblies to tyrosine-phosphorylated cell surface receptors. NSP proteins can potentiate CAS function by affecting key CAS attributes such as expression levels, phosphorylation state, and subcellular localization, leading to effects on cell adhesion, migration, and invasion as well as cell growth. The consequences of these activities are well exemplified by the role that members of both families play in promoting breast cancer cell invasiveness and resistance to antiestrogens. In this review, we discuss the intriguing interplay between the NSP and CAS families, with a particular focus on cancer signaling networks.

Impact of the integrin signaling adaptor protein NEDD9 on prognosis and metastatic behavior of human lung cancer

PURPOSE

In a substantial population of non-small cell lung cancer (NSCLC), expression and activation of EGF receptor (EGFR) have been reported and is regarded as a novel molecular target. A growing body of evidence has shown the signaling crosstalk between EGFR and integrins in cellular migration and invasion. NEDD9 is an integrin signaling adaptor protein composed of multiple domains serving as substrate for a variety of tyrosine kinases. In the present study, we aimed at elucidating a role of NEDD9 in the signaling crosstalk between EGFR and integrins.

EXPERIMENTAL DESIGN

Using NSCLC cell lines, we conducted immunoblotting and cellular migration/invasion assay in vitro. Next, we analyzed metastasis assays in vivo by the use of xenograft transplantation model. Finally, we retrospectively evaluated clinical samples and records of patients with NSCLCs.

RESULTS

We showed that tyrosine phosphorylation of NEDD9 was reduced by the inhibition of EGFR in NSCLC cell lines. Overexpression of constitutively active EGFR caused tyrosine phosphorylation of NEDD9 in the absence of integrin stimulation. By gene transfer and gene knockdown, we showed that NEDD9 plays a pivotal role in cell migration and invasion of those cells in vitro. Furthermore, overexpression of NEDD9 promoted lung metastasis of an NSCLC cell line in NOD/Shi-scid, IL-2Rγ(null) mice (NOG) mice. Finally, univariate and multivariate Cox model analysis of NSCLC clinical specimens revealed a strong correlation between NEDD9 expression and recurrence-free survival as well as overall survival.

CONCLUSION

Our data thus suggest that NEDD9 is a promising biomarker for the prognosis of NSCLCs and its expression can promote NSCLC metastasis.

NEDD9, a novel target of miR-145, increases the invasiveness of glioblastoma

miR-145 is an important repressor of pluripotency in embryonic stem cells and a tumor suppressor in different cancers. Here, we found that miR-145 is strongly down-regulated in glioblastoma (GB) specimens and corresponding glioblastomaneurospheres (GB-NS, containing GB stem-like cells) compared to normal brain (NB) and to low-grade gliomas (LGG). We observed a direct correlation between miR-145 expression and the progression-free survival (PFS) in LGG patients and overall survival (OS) in GB patients. Using microarray analysis, we identified relevant differences in gene expression profiles between GB-NS over-expressing miR-145 (miRover-NS) and GB-NS Empty (Empty-NS). We focused our attention on HEF1/Cas-L/NEDD9, a scaffold protein involved in invasion in several types of cancer. We confirmed a significant down-regulation of NEDD9 in miRover-NS and we found a higher expression in GB and GB-NS compared to NB. Approximately 50% of LGG patients expressed higher levels of NEDD9 than NB, and the PFS of such patients was shorter than in patients expressing lower levels of NEDD9. We observed that intracranial injection of GB-NS over-expressing miR-145 delays significantly tumor development :deriving tumors showed a significant down-regulation of NEDD9. In addition, we demonstrated a significant inhibition of invasion in silencing experiments with GB-NS shNEDD9 (shNEDD9), and an up-regulation of miR-145 in shNEDD9, suggesting a doublenegative feedback loop between miR-145 and NEDD9. Our results demonstrate the critical role of miR-145 and NEDD9 in regulating glioblastoma invasion and suggest a potential role of NEDD9 as a biomarker for glioma progression.

Adhesion rings surround invadopodia and promote maturation

Invasion and metastasis are aggressive cancer phenotypes that are highly related to the ability of cancer cells to degrade extracellular matrix (ECM). At the cellular level, specialized actin-rich structures called invadopodia mediate focal matrix degradation by serving as exocytic sites for ECM-degrading proteinases. Adhesion signaling is likely to be a critical regulatory input to invadopodia, but the mechanism and location of such adhesion signaling events are poorly understood. Here, we report that adhesion rings surround invadopodia shortly after formation and correlate strongly with invadopodium activity on a cell-by-cell basis. By contrast, there was little correlation of focal adhesion number or size with cellular invadopodium activity. Prevention of adhesion ring formation by inhibition of RGD-binding integrins or knockdown (KD) of integrin-linked kinase (ILK) reduced the number of ECM-degrading invadopodia and reduced recruitment of IQGAP to invadopodium actin puncta. Furthermore, live cell imaging revealed that the rate of extracellular MT1-MMP accumulation at invadopodia was greatly reduced in both integrin-inhibited and ILK-KD cells. Conversely, KD of MT1-MMP reduced invadopodium activity and dynamics but not the number of adhesion-ringed invadopodia. These results suggest a model in which adhesion rings are recruited to invadopodia shortly after formation and promote invadopodium maturation by enhancing proteinase secretion. Since adhesion rings are a defining characteristic of podosomes, similar structures formed by normal cells, our data also suggest further similarities between invadopodia and podosomes.

Cas and NEDD9 Contribute to Tumor Progression through Dynamic Regulation of the Cytoskeleton

The Cas family proteins, p130(Cas) (Cas) and NEDD9, are adaptor molecules that regulate cytoskeletal dynamics to promote multiple cellular processes, including migration, invasion, proliferation, and survival. Because these functions are also critical for tumor initiation, growth, and metastasis, Cas and NEDD9 are well positioned to contribute to these oncogenic processes. Indeed, mouse models of cancer show that these proteins function during multiple stages of disease progression. Furthermore, in many human cancers, high expression of Cas and NEDD9 is associated with advanced stage disease and is predictive of poor outcome. This review explores the contribution of Cas and NEDD9 during cellular transformation and neoplastic growth, tumor progression, metastasis, and the development of therapeutic resistance. Given these roles, Cas and NEDD9 may prove to be viable candidates for use as biomarkers and therapeutic targets.