Multiple signaling pathways involved in activation of matrix metalloproteinase-9 (MMP-9) by heregulin-beta1 in human breast cancer cells

Dual-Sensitive Fluorescent Nanoprobes for Simultaneously Monitoring In Situ Changes in pH and Matrix Metalloproteinase Expression in Stiffness-Tunable Three-Dimensional In Vitro Scaffolds

A tumor microenvironment often presents altered physicochemical characteristics of the extracellular matrix (ECM) including changes in matrix composition, stiffness, protein expression, pH, temperature, or the presence of certain stromal and immune cells. Of these, overexpression of matrix metalloproteinases (MMPs) and extracellular acidosis are the two major hallmarks of cancer that can be exploited for tumor detection. The change in matrix stiffness and the release of certain cytokines (TNF-α) in the tumor microenvironment play major roles in inducing MMP-9 expression in cancerous cells. This study highlights the role of mechanical cues in upregulating MMP-9 expression in cancerous cells using stiffness-tunable matrix compositions and dual-sensitive fluorescent nanoprobes. Ionically cross-linked 3D alginate/gelatin (AG) scaffolds with three stiffnesses were chosen to reflect the ECM stiffnesses corresponding to healthy and pathological tissues. Moreover, a dual-sensitive nanoprobe, an MMP-sensitive peptide conjugated to carbon nanoparticles with intrinsic pH fluorescence properties, was utilized for in situ monitoring of the two cancer hallmarks in the 3D scaffolds. This platform was further utilized for designing a 3D core-shell platform for spatially mapping tumor margins and for visualizing TNF-α-induced MMP-9 expression in cancerous cells.

Role of human epidermal growth factor receptor 3 in treatment resistance of anaplastic lymphoma kinase translocated non-small cell lung cancer

BACKGROUND

ALK tyrosine kinase inhibitors (TKI) have revolutionized the treatment of ALK+ non-small cell lung cancer (NSCLC), and therapy resistance occurs in virtually all patients. Multiple TKI resistance mechanisms have been characterized, including ERBB receptor coactivation. In this study, we investigated the role of HER3 in ALK TKI resistance.

METHODS

In vitro studies were carried out using ALK+ NSCLC cell lines H3122, H2228, and DFCI032. Pharmacological co-targeting of ALK and HER3 was investigated with ALK and ERBB TKIs, and HER3 knockdown was achieved using the CRISPR-Cas9 system. Co-localization of ALK and HER3 was investigated by immunoprecipitation (IP) and proximity ligation assay (PLA) in vitro and in vivo using six ALK+ NSCLC tumor samples.

RESULTS

In all tested cell lines, combined targeting with ALK and pan-ERBB TKI resulted in marked inhibition of colony formation and long-term (72 h) downregulation of pAKT levels. HER3 knockdown resulted in multiple effects on ALK+ cell lines, including the downregulation of ALK expression and visible morphological changes (H2228). Co-immunoprecipitation (IP) and proximation ligation assay (PLA) experiments provided evidence that both ALK and HER3 could interact in vitro, and this finding was verified by PLA using ALK+ NSCLC tumors.

CONCLUSIONS

This study provides evidence that HER3 may mediate TKI resistance in ALK+ NSCLC. Interestingly, we were able to show that both translocated ALK and HER3 could interact. Joint targeting of ALK and HER3 could be further investigate in ALK+ NSCLC.

NRG1 promotes tumorigenesis and metastasis and afatinib treatment efficiency is enhanced by NRG1 inhibition in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a highly aggressive tumor with significant heterogeneity in incidence and outcomes. The role of Neuregulin 1 (NRG1) in ESCC and its contribution to aggressiveness remain unknown. This study aims to investigate the functions and molecular mechanisms of NRG1 in ESCC as well as the treatment strategy for ESCC with overexpression of NRG1. We firstly demonstrated the upregulation of NRG1 and a negative correlation trend between patients' overall survival (OS) and the expression level of NRG1 in esophageal cancer. And then we found NRG1 promoted cell proliferation, migration, inhibited apoptosis, and accelerated tumorigenesis and metastasis in ESCC using cell lines and xenograft models. Furthermore, we discovered that NRG1 activated the NF-κB/MMP9 signaling pathway, contributing to the metastatic phenotype in ESCC. Finally, we show that afatinib (FDA approved cancer growth blocker) could inhibit ESCC with overexpressed NRG1 and down-regulation of NRG1 along with afatinib treatment provides higher efficient strategy. This study uncovers the critical role and molecular mechanism of NRG1 in ESCC tumorigenesis and metastasis, suggesting its potential as a novel biomarker for ESCC treatment.

Inhibition of cell invasion and migration by targeting matrix metalloproteinase-9 expression via sirtuin 6 silencing in human breast cancer cells

Sirtuin 6 (SIRT6) regulation is involved in carcinogenesis. However, its role in breast cancer (BC) metastasis remains unclear. We investigated the effects of SIRT6 on protein kinase C activator- and cytokine-mediated cancer cell invasion and migration in MCF-7 and MDA-MB-231 cells and the association between SIRT6 and matrix metalloproteinase-9 (MMP-9) expression. To assess MMP-9 and SIRT6 expression in patients, protein levels in BC tissues were analyzed. MCF-7 and MDA-MB-231 cell viability was analyzed using MTT assays. SIRT6 was silenced in both cell lines and protein secretion, expression, and mRNA levels were analyzed. Transcription factor DNA activity was investigated using luciferase assays. Matrigel invasion assays were used to assess the effects of SIRT6 in both cell lines. SIRT6 and MMP-9 expression in cancer tissues was significantly higher than in paired normal breast tissues. 12-O-tetradecanoylphorbol-13-acetate (TPA) or tumor necrosis factor-α (TNF-α) increased MMP-9 expression and cell invasion and migration, but SIRT6 knockdown abolished these effects. SIRT6 overexpression additively increased TPA- and TNF-α-induced MMP-9 expression. SIRT6 knockdown suppressed the mitogen-activated protein kinase (MAPK) signaling pathway and thus TPA- and TNF-α-induced MMP-9 expression. SIRT6 silencing suppressed TPA- and TNF-α-induced nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) expressions in both cell lines, and treatment with MAPK, NF-κB, and AP-1 inhibitors reduced MMP-9 expression. The anti-invasive effects of SIRT6 in BC cells might be mediated by suppression of MAPK phosphorylation and reduction in NF-κB and AP-1 DNA activities, leading to MMP-9 downregulation, suggesting that SIRT6 modulation has the potential to target BC metastasis.

Tumor suppressor p53 restrains cancer cell dissemination by modulating mitochondrial dynamics

Tumor suppressor p53 plays a central role in preventing tumorigenesis. Here, we unravel how p53 modulates mitochondrial dynamics to restrain the metastatic properties of cancer cells. p53 inhibits the mammalian target of rapamycin complex 1 (mTORC1) signaling to attenuate the protein level of mitochondrial fission process 1 (MTFP1), which fosters the pro-fission dynamin-related protein 1 (Drp1) phosphorylation. This regulatory mechanism allows p53 to restrict cell migration and invasion governed by Drp1-mediated mitochondrial fission. Downregulating p53 expression or elevating the molecular signature of mitochondrial fission correlates with aggressive tumor phenotypes and poor prognosis in cancer patients. Upon p53 loss, exaggerated mitochondrial fragmentation stimulates the activation of the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling resulting in epithelial-to-mesenchymal transition (EMT)-like changes in cell morphology, accompanied by accelerated matrix metalloproteinase 9 (MMP9) expression and invasive cell migration. Notably, blocking the activation of mTORC1/MTFP1/Drp1/ERK1/2 axis completely abolishes the p53 deficiency-driven cellular morphological switch, MMP9 expression, and cancer cell dissemination. Our findings unveil a hitherto unrecognized mitochondria-dependent molecular mechanism underlying the metastatic phenotypes of p53-compromised cancers.

Downregulation of matriptase suppresses the PAR‑2/PLCγ2/PKC‑mediated invasion and migration abilities of MCF‑7 breast cancer cells

Matriptases, members of the type II transmembrane serine protease family, are cell surface proteolytic enzymes that mediate tumor invasion and metastasis. Matriptase is highly expressed in breast cancer and is associated with poor patient outcome. However, the cellular mechanism by which matriptase mediates breast cancer invasion remains unknown. The present study aimed to determine the role of matriptase in the protein kinase C (PKC)‑mediated metastasis of MCF‑7 human breast cancer cells. Matriptase small interfering RNA‑mediated knockdown significantly attenuated the 12‑O‑tetradecanoylphorbol‑13‑acetate (TPA)‑induced invasiveness and migration of MCF‑7 cells, and inhibited the activation of phospholipase C γ2 (PLCγ2)/PKC/MAPK signaling pathways. Matriptase‑knockdown also suppressed the expression of MMP‑9 and inhibited the activation of NF‑κB/activator protein‑1 in MCF‑7 cells. Additionally, GB83 [an inhibitor of protease‑activated receptor‑2 (PAR‑2)] inhibited PKC‑mediated MMP‑9 expression and metastatic ability in MCF‑7 cells. Furthermore, downregulation of matriptase suppressed TPA‑induced MMP‑9 expression and invasiveness via PAR‑2/PLCγ2/PKC/MAPK activation. These findings shed light on the mechanism underlying the role of matriptase in MCF‑7 cell invasion and migration ability, and suggest that matriptase modulation could be a promising therapeutic strategy for preventing breast cancer metastasis.

Protease-Activation of Fc-Masked Therapeutic Antibodies to Alleviate Off-Tumor Cytotoxicity

The interaction of the Fc region of therapeutic antibodies and antibody-drug conjugates with Fcγ receptors (FcγRs) can lead to unpredictable and severe side effects. Over the last decades several strategies have been developed to overcome this drawback, including extensive Fc- and glycoengineering and antibody isotype switching. However, these approaches result in permanently Fc-silenced antibody derivates which partially or completely lack antibody-mediated effector functions. Nevertheless, for a majority of antibody-based drugs, Fc-mediated effector functions, like antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cell-mediated phagocytosis (ADCP) as well as complement-dependent cytotoxicity (CDC), represent the most substantial modes of action. We argued that a new strategy combining the beneficial properties of Fc-silencing and controlled activation of effector functions can pave the way to potent antibody therapeutics, reducing the FcγRs-mediated off-target toxicity. We present a novel Fc-tamed antibody format, where the FcγR-binding sites of antibodies are blocked by anti-isotypic masking units, hindering the association of FcγR and complement component 1 (c1q) to the Fc domain. The masking units were genetically fused to trastuzumab, including a protease-addressable peptide-liker. Our Fc-tamed antibodies demonstrated completely abolished interaction to soluble high-affinity Fcγ-Receptor I and c1q. In reporter cell-based ADCC assays, our Fc-tamed antibodies exhibited a 2,700 to 7,100-fold reduction in activation, compared to trastuzumab. Upon demasking by a tumor-associated protease, the Fc-activated antibodies demonstrated restored FcγR-binding, c1q-binding and the ability to induce potent ADCC activation. Furthermore, cell killing assays using donor-derived NK cells were performed to validate the functionality of the Fc-tamed antibody variants. To our knowledge, this approach represents the first non-permanently Fc-silenced antibody, which can be re-activated by a tumor-associated protease, eventually extending the field of novel antibody formats.

Extracellular Matrix Components Regulate Bone Sialoprotein Expression in MDA-MB-231 Breast Cancer Cells

Bone sialoprotein (BSP) has become a target in breast cancer research as it is associated with tumor progression and metastasis. The mechanisms underlying the regulation of BSP expression have been largely elusive. Given that BSP is involved in the homing of cancer cells in bone metastatic niches, we addressed regulatory effects of proteolytic cleavage and extracellular matrix components on BSP expression and distribution in cell culture models. Therefore, MDA-MB-231 human breast cancer cells were kept in 2D and 3D spheroid cultures and exposed to basement membrane extract in the presence or absence of matrix metalloproteinase 9 or the non-polar protease, dispase. Confocal imaging of immunofluorescence samples stained with different antibodies against human BSP demonstrated a strong inducing effect of basement membrane extract on anti-BSP immunofluorescence. Similarly, protease incubation led to acute upregulation of anti-BSP immunofluorescence signals, which was blocked by cycloheximide, suggesting de novo formation of BSP. In summary, our data show that extracellular matrix components play an important function in regulating BSP expression and hint at mechanisms for the formation of bone-associated metastasis in breast cancer that might involve local control of BSP levels by extracellular matrix degradation and release of growth factors.

Resveratrol inhibited the metastatic behaviors of cisplatin-resistant human oral cancer cells via phosphorylation of ERK/p-38 and suppression of MMP-2/9

Cisplatin resistance is a major clinical problem in the clinical management of oral squamous cell carcinoma (OSCC) patients. Resveratrol is a natural phytoestrogen with antitumor activities. Whether resveratrol can overcome cisplatin resistance and prevent metastasis in OSCC cells is not known. In this study, we first examined the anti-metastatic capacity of resveratrol and then explored the underlying mechanisms using a cisplatin-resistant human OSCC cell line (CAR). The results demonstrated that at a non-toxic dose range (25 to 75 µM), 24-hr treatment of resveratrol was able to suppress the migration and invasion capacities of CAR cells dose dependently. Interestingly, 50 µM resveratrol treatment could significantly down-regulate the expression of the phosphorylated forms of ERK and p-38, in addition to those of MMP-2 and MMP-9. At the same time, the expression levels of phosphorylated ERK together with those unphosphorylated forms of ERK, p38, and JNK were all insignificantly altered. In conclusion, the signaling cascade for resveratrol's suppression of cisplatin-resistant human oral cancer CAR cells was revealed and summarized. Also the rapid effectiveness in suppressing metastatic behaviors of drug-resistant oral cancer cells of non-toxic resveratrol might extend its application to the drug-resistant oral cancer treatment in the near future. PRACTICAL APPLICATIONS: Based on the evidence we provided in the study, we have proposed a model recording the possible pathway for resveratrol inhibiting the metastasis of cisplatin-resistant oral cancer cells. We suppose this signaling pathway may work in other cancer cell lines, and can be helpful in full understanding of the drug-resistance.

Heregulin-β1 Activates NF-E2-related Factor 2 and Induces Manganese Superoxide Dismutase Expression in Human Breast Cancer Cells via Protein Kinase B and Extracellular Signal-regulated Protein Kinase Signaling Pathways

Heregulin-β1, a ligand of ErbB-2 and ErbB-3/4 receptors, has been reported to potentiate oncogenicity and metastatic potential of breast cancer cells. In the present work, treatment of human mammary cancer (MCF-7) cells with heregulin-β1 resulted in enhanced cell migration and expression of manganese superoxide dismutase (MnSOD) and its mRNA transcript. Silencing of MnSOD abrogated clonogenicity and migrative ability of MCF-7 cells. Heregulin-β1 treatment also increased nuclear translocation, antioxidant response element binding and transcriptional activity of NF-E2-related factor 2 (Nrf2). A dominant-negative mutant of Nrf2 abrogated heregulin-β1-induced MnSOD expression. Treatment with heregulin-β1 caused activation of protein kinase B (Akt) and extracellular signal-regulated protein kinase (ERK). The pharmacological inhibitors of phosphatidylinositol 3-kinase and mitogen-activated protein kinase kinase 1/2, which are upstream of Akt and ERK, respectively, attenuated heregulin-β1-induced MnSOD expression and nuclear localization of Nrf2. In conclusion, heregulin-1 induces upregulation of MnSOD and activation of Nrf2 via the Akt and ERK signaling in MCF-7 cells, which may confer metastatic potential and invasiveness of these cells.

Bruton's agammaglobulinemia tyrosine kinase (Btk) regulates TPA‑induced breast cancer cell invasion via PLCγ2/PKCβ/NF‑κB/AP‑1‑dependent matrix metalloproteinase‑9 activation

Bruton's agammaglobulinemia tyrosine kinase (BTK) is an important cytoplasmic tyrosine kinase involved in B-lymphocyte development, differentiation, and signaling. Activated protein kinase C (PKC), in turn, induces the activation of mitogen-activated protein kinase (MAPK) signaling, which promotes cell proliferation, viability, apoptosis, and metastasis. This effect is associated with nuclear factor-κB (NF-κB) activation, suggesting an anti-metastatic effect of BTK inhibitors on MCF-7 cells that leads to the downregulation of matrix metalloproteinase (MMP)-9 expression. However, the effect of BTK on breast cancer metastasis is unknown. In this study, the anti-metastatic activity of BTK inhibitors was examined in MCF-7 cells focusing on MMP-9 expression in 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated MCF-7 cells. The expression and activity of MMP-9 in MCF-7 cells were investigated using quantitative polymerase chain reaction analysis, western blotting, and zymography. Cell invasion and migration were investigated using the Matrigel invasion and cell migration assays. BTK inhibitors [ibrutinib (10 µM), CNX-774 (10 µM)] significantly attenuated TPA-induced cell invasion and migration in MCF-7 cells and inhibited the activation of the phospholipase Cγ2/PKCβ signaling pathways. In addition, small interfering RNA specific for BTK suppressed MMP-9 expression and cell metastasis. Collectively, results of the present study indicated that BTK suppressed TPA-induced MMP-9 expression and cell invasion/migration by activating the MAPK or IκB kinase/NF-κB/activator protein-1 pathway. The results clarify the mechanism of action of BTK in cancer cell metastasis by regulating MMP-9 expression in MCF-7 cells.

A conceptualized model linking matrix metalloproteinase-9 to schizophrenia pathogenesis

Matrix metalloproteinase 9 (MMP-9) is an extracellularly operating zinc-dependent endopeptidase that is commonly expressed in the brain, other tissues. It is synthesized in a latent zymogen form known as pro-MMP-9 that is subsequently converted to the active MMP-9 enzyme following cleavage of the pro-domain. Within the central nervous system, MMP-9 is localized and released from neurons, astrocytes and microglia where its expression levels are modulated by cytokines and growth factors during both normal and pathological conditions as well as by reactive oxygen species generated during oxidative stress. MMP-9 is involved in a number of key neurodevelopmental processes that are thought to be affected in schizophrenia, including maturation of the inhibitory neurons that contain the calcium-binding protein parvalbumin, developmental formation of the specialized extracellular matrix structure perineuronal net, synaptic pruning, and myelination. In this context, the present article provides a narrative synthesis of the existing evidence linking MMP-9 dysregulation to schizophrenia pathogenesis. We start by providing an overview of MMP-9 involvement in brain development and physiology. We then discuss the potential mechanisms through which MMP-9 dysregulation may affect neural circuitry maturation as well as how these anomalies may contribute to the disease process of schizophrenia. We conclude by articulating a comprehensive, cogent, and experimentally testable hypothesis linking MMP-9 to the developmental pathophysiologic cascade that triggers the onset and sustains the chronicity of the illness.

FOXK1, Regulated by miR-365-3p, Promotes Cell Growth and EMT Indicates Unfavorable Prognosis in Breast Cancer

Background

Forkhead box K1 (FOXK1) is members of the FOX transcription factor family. Previous work has found out that FOXK1 promotes cell proliferation, migration and invasion in several cancers, such as gastric cancer, glioma cancer and lung cancer; however, the exact role of FOXK1 in breast cancer is still poorly known.

Methods

Here, the association between FOXK1 expression and the clinicopathological characteristics of patients with breast cancer was identified. To further decipher the functional roles of FOXK1, it was overexpressed or knocked down in MCF-7, MDA-MB-231 and MCF-10A cells. Cell Counting Kit-8, colony formation and cell cycle assays were performed to examine the proliferation of breast cancer cells. Moreover, wound-healing and Transwell invasion analyses were carried out to explore the effect of FOXK1 on breast cancer cell migration and invasion.

Results

Our findings discovered that FOXK1 promotes cell proliferation, migration and invasion in breast cancer. In addition, consistent with the previous report, FOXK1 also facilitates EMT in breast cancer. TargetScan was used to predict up-stream of FOXK1, indicating that miR-365-3p could regulate FOXK1 expression in breast cancer.

Conclusion

The findings of the present study demonstrated that miR-365-3p-FOXK1 axis plays a key role in breast cancer.

Solanine Attenuates Hepatocarcinoma Migration and Invasion Induced by Acetylcholine

AIM

Evidence has provided an explanation of the correlation between the nervous system and the tumor microenvironment. Neurotransmitters may be involved in different aspects of cancer progression. The glycoalkaloid solanine has been reported to suppress neural signaling pathways and exists in numerous plants, including Solanum nigrum, which have been demonstrated to inhibit cancer cell proliferation.

METHODS

We evaluated the potentials of solanine on inhibiting acetylcholine-induced cell proliferation and migration in hepatocellular carcinoma cells.

RESULTS

The results indicated that solanine markedly attenuated cell proliferation and migration via inhibiting epithelial-mesenchymal transition and matrix metalloproteinases in acetylcholine-treated Hep G2 cells. In addition, exosomes derived from acetylcholine-treated Hep G2 cells were isolated, and solanine showed inhibiting effects of extrahepatic metastasis on blocking cell proliferation in exosome-treated A549 lung carcinoma cells through regulating microRNA-21 expression.

CONCLUSION

Solanine has strong potential for application in integrative cancer therapy.

DHEAS prevents pro-metastatic and proliferative effects of 17ß-estradiol on MCF-7 breast cancer cells

It is generally assumed that circulating dehydroepiandrosterone sulfate (DHEAS) can be desulfated and further metabolized to estrogen, which is of concern for all patients with estrogen-responsive breast cancer. We addressed this issue by comparing the effects of DHEAS, its desulfated form DHEA, and 17ß-estradiol on human metastatic, estrogen-responsive MCF-7 breast cancer cells. Physiological concentrations of DHEAS promoted phosphorylation of Erk1/2, whereas DHEA and 17ß-estradiol failed to stimulate Erk1/2 phosphorylation, indicating that the sulfated steroid acts as an autonomous hormone. Exposure of MCF-7 cells to 17ß-estradiol stimulated cell proliferation and the expression of pro-metastatic and pro-invasive elements such as claudin-1, matrix metalloproteinase 9 (MMP9), and the CC chemokine ligand 2 (CCL2). In contrast, treatment with DHEAS did not stimulate these responses but prevented all of the actions of 17ß-estradiol, and as a consequence cell migration and invasion were completely inhibited. The results of this study not only challenge the assumption that DHEAS poses a danger as an endogenous source of estrogen, they rather favor the idea that keeping DHEAS levels within a physiological range might be supportive in treating estrogen-responsive breast cancer.

Hic-5 in pancreatic stellate cells affects proliferation, apoptosis, migration, invasion of pancreatic cancer cells and postoperative survival time of pancreatic cancer

Pancreatic cancer is one of the most severe types of tumors, with a 5-year survival rate of less than 7%. The prognosis and treatment of pancreatic cancer are largely limited by the extent of tumor invasion and the presence of lymph node and distant metastases. Therefore, exploring the biological behavior of pancreatic cancer cells (PCCs) is extremely important for the understanding, diagnosis, and treatment of pancreatic cancer. Current studies have shown that pancreatic stellate cells (PSCs) regulate the biological behavior of PCCs, such as their proliferation, apoptosis, invasion, and migration, by remodeling the extracellular matrix. Though Hic-5 is an important gene in PSCs, no study has investigated the regulation of PCCs by Hic-5. Here, we demonstrate that Hic-5 expression is upregulated in pancreatic cancer and that siRNA transfection can effectively inhibit Hic-5 expression. Compared to the control group, Hic-5 inhibition significantly reduced proliferation, increased apoptosis, and reduced invasion and migration of PCCs. Moreover, the inhibition of Hic-5 expression simultaneously reduced matrix metalloproteinase-9 (MMP-9) expression. Statistical analysis revealed that Hic-5 expression was higher among the pancreatic cancer group than among the normal group and was negatively correlated with postoperative survival time among patients with pancreatic cancer. These results have important clinical significance for further exploring the molecular mechanism involved in Hic-5-mediated invasion and metastasis of pancreatic cancer and ameliorating the prognosis of patients with pancreatic cancer.

Overview of the Anticancer Profile of Avenanthramides from Oat

Cancer represents one of the leading causes of death worldwide. Progresses in treatment of cancer have continued at a rapid pace. However, undesirable side effects and drug resistance remain major challenges for therapeutic success. Natural products represent a valuable starting point to develop new anticancer strategies. Polyphenols, well-known as antioxidant, exert anticancer effects through the modulation of multiple pathways and mechanisms. Oat (Avena sativa L., Poaceae) is a unique source of avenanthramides (AVAs), a group of polyphenolic alkaloids, considered as its signature compounds. The present review aims to offer a comprehensive and critical perspective on the chemopreventive and chemotherapeutic potential of AVAs. AVAs prevent cancer mainly by blocking reactive species. Moreover, they exhibit potential therapeutic activity through the modulation of different pathways including the activation of apoptosis and senescence, the block of cell proliferation, and the inhibition of epithelial mesenchymal transition and metastatization. AVAs are promising chemopreventive and anticancer phytochemicals, which need further clinical trials and toxicological studies to define their efficacy in preventing and reducing the burden of cancer diseases.

MoS2 Field-Effect Transistor-Amyloid-β1-42 Hybrid Device for Signal Amplified Detection of MMP-9

The detection of circulating protein (CP) is very important for the diagnosis and therapeutics of cancer. Conventional techniques based on a specific antibody-antigen interaction are still lacking because of a shortage of cost effectiveness, complicated sandwich structure and tagging process, and inconsistent detection of CP due to the inherent instability of antibodies. Herein, we demonstrate a hybrid device consisting of two-dimensional (2D) nanoscale molybdenum disulfide (MoS₂) field-effect transistor (FET) with an amyloid-β_1-42 (Aβ_1-42) functionalized surface, which amplifies electric signals of the FET in order to detect matrix metalloproteinase-9 (MMP-9), which is a certain type of CP that degrades Aβ_1-42. With the hybrid device, we detected the concentrations of MMP-9 in the range from 1 pM to 10 nM. Moreover, using tapping-mode atomic force microscopy and Kelvin probe force microscopy, we verified that the signal amplification corresponding to the MMP-9 concentrations was caused by the reduced length and the decreased surface potential of degraded Aβ_1-42 due to MMP-9. The hybrid device studied in this paper can be very useful for monitoring MMP-9 activity, as well as serving as a sensing platform for the electrical signal amplification of 2D MoS₂ FET-biosensors.

5p and 3p Strands of miR-34 Family Members Have Differential Effects in Cell Proliferation, Migration, and Invasion in Cervical Cancer Cells

The micro RNA (miR)-34 family is composed of 5p and 3p strands of miR-34a, miR-34b, and miR-34c. The 5p strand's expression and function is studied in cervical cancer. The 3p strand's function and regulation remain to be elucidated. To study the function of the passenger strands of miR-34 family members, we overexpressed 5p and 3p strands using a synthetic miRNA in cervical cell lines. Cell proliferation was evaluated using crystal violet. Migration and invasion were tested using transwell assays, Western blot, and zymography. Possible specific targets and cell signaling were investigated for each strand. We found that miR-34a-5p inhibited proliferation, migration, and cell invasion accompanied by matrix metalloproteinase 9 (MMP9) activity and microtubule-associated protein 2 (MAP2) protein reduction. We also found that miR-34b-5p and miR-34c-5p inhibit proliferation and migration, but not invasion. In contrast, miR-34c-5p inhibits MMP9 activity and MAP2 protein, while miR-34b-5p has no effect on these genes. Furthermore, miR-34a-3p and miR-34b-3p inhibit proliferation and migration, but not invasion, despite the later reducing MMP2 activity, while miR-34c-3p inhibit proliferation, migration, and cell invasion accompanied by MMP9 activity and MAP2 protein inhibition. The difference in cellular processes, MMP2 and MMP9 activity, and MAP2 protein inhibition by miR-34 family members suggests the participation of other regulated genes. This study provides insights into the roles of passenger strands (strand*) of the miR-34 family in cervical cancer.

Breast Cancer Metastasis: Are Cytokines Important Players During Its Development and Progression?

In breast cancer, an uncontrolled cell proliferation leads to tumor formation and development of a multifactorial disease. Metastasis is a complex process that involves tumor spread to distant parts of the body from its original site. Metastatic dissemination represents the main physiopathology of cancer. Inter- and intracellular communication in all systems in vertebrates is mediated by cytokines, which are highly inducible, secretory proteins, produced not only by immune system cells, but also by endocrine and nervous system cells. It has become clear in recent years that cytokines, as well as their receptors are produced in the organisms under physiological and pathological conditions; recently, they have been closely related to breast cancer metastasis. The exact initiation process of breast cancer metastasis is unknown, although several hypotheses have emerged. In this study, we thoroughly reviewed the role of several cytokines in breast cancer metastasis. Data reviewed suggest that cytokines and growth factors are key players in the breast cancer metastasis induction. This knowledge must be considered with the aim to development of new therapeutic approaches to counter breast cancer metastasis.

Impairment of the Gnα11-controlled expression of claudin-1 and MMP-9 and collective migration of human breast cancer MCF-7 cells by DHEAS

Although dehydroepiandrosterone sulfate (DHEAS) constitutes the most abundant steroid in humans, in-depth investigations of its effects are rather scarce. We address here DHEAS effects on the estrogen receptor-positive metastatic human breast cancer cell line MCF-7. We focus on DHEAS-mediated signaling that might influence expression of claudin-1 and matrix metalloproteinase-9 (MMP-9), both known to be critical factors for migration and invasiveness of various cancers, including breast cancer cells. Physiological concentrations of DHEAS trigger persistent phosphorylation of Erk1/2 in MCF-7 cells. Exposure of these cells for 24 h to 1 μM DHEAS also leads to a significant reduction of claudin-1 expression that cannot be prevented by high concentrations of the steroid sulfatase inhibitor STX64, indicating that desulfation and further conversion of DHEAS to some other steroid hormone is not required for this action. In addition, exposure of MCF-7 cells to the same concentration of DHEAS completely abolishes MMP-9 expression and considerably impairs cell migratory behavior. Abrogation of Gnα11 expression by siRNA prevents the stimulatory effect of DHEAS on Erk1/2 phosphorylation, consistent with a G-protein-coupled receptor being involved in the DHEAS-induced signaling. Nevertheless, Gnα11 also has direct effects that do not depend on DHEAS; thus, when Gnα11 expression is suppressed, expression of claudin-1 and MMP-9 as well as cell migration are significantly reduced. This is the first report demonstrating direct involvement of DHEAS and Gnα11 in the regulation of claudin-1 and MMP-9 expression and migration of MCF-7 cells.

Silencing of casein kinase 2 inhibits PKC‑induced cell invasion by targeting MMP‑9 in MCF‑7 cells

Casein kinase 2 (CK2) is a serine/threonine protein kinase that has been considered to represent an important factor in mammary tumorigenesis. Increased expression of matrix metalloproteinase‑9 (MMP‑9) via nuclear factor‑κB (NF‑κB) activation has been demonstrated to promote breast cancer cell invasion. In the present study, the involvement of CK2 in protein kinase C (PKC) induced cell invasion in MCF‑7 breast cancer cells was investigated as well as the underlying molecular mechanisms. The mRNA and protein levels of MMP‑9 in MCF‑7 cells were investigated using reverse transcription‑quantitative polymerase chain reaction, western blot analyses and a zymography assay. Cell invasiveness was investigated using a Matrigel invasion assay, and it was revealed that small interfering RNA specific for CK2 suppressed PKC induced cell invasion by regulating MMP‑9 expression via activation of the p38 kinase/c‑Jun N‑terminal kinase/NF‑κB pathway. In addition, it was demonstrated that CK2 inhibitors [apigenin (20 µM), emodin (20 µM) or 2‑dimethylamino‑4,5,6,7‑tetrabromo‑1H‑benzimidazole (2 µM)] suppressed PKC induced cell invasion and MMP‑9 expression. The results of the present study suggested that CK2 is an important factor involved in the induction of MCF‑7 breast cancer cell invasion by PKC. Therefore, CK2 may represent novel candidates for therapy intended to inhibit invasion in breast cancer.

ALCAM shedding at the invasive front of the tumor is a marker of myometrial infiltration and promotes invasion in endometrioid endometrial cancer

Endometrial cancer (EC) is the sixth deadliest cancer in women. The depth of myometrial invasion is one of the most important prognostic factors, being directly associated with tumor recurrence and mortality. In this study, ALCAM, a previously described marker of EC recurrence, was studied by immunohistochemistry at the superficial and the invasive tumor areas from 116 EC patients with different degree of myometrial invasion and related to a set of relevant epithelial and mesenchymal markers. ALCAM expression presented a heterogeneous functionality depending on its localization, it correlated with epithelial markers (E-cadherin/β-catenin) at the superficial area, and with mesenchymal markers at the invasive front (COX-2, SNAIL, ETV5, and MMP-9). At the invasive front, ALCAM-negativity was an independent marker of myometrial invasion. This negativity, together with an increase of soluble ALCAM in uterine aspirates from patients with an invasive EC, and its positive correlation with MMP-9 levels, suggested that ALCAM shedding by MMP-9 occurs at the invasive front. In vivo and in vitro models of invasive EC were generated by ETV5-overexpression. In those, we demonstrated that ALCAM shedding was related to a more invasive pattern and that full-ALCAM recovery reverted most of the ETV5-cells mesenchymal abilities, partially through a p-ERK dependent-manner.

Troglitazone Inhibits Matrix Metalloproteinase-9 Expression and Invasion of Breast Cancer Cell through a Peroxisome Proliferator-Activated Receptor γ-Dependent Mechanism

Purpose

Peroxisome proliferator-activated receptor γ (PPARγ) is involved in the pathology of numerous diseases including atherosclerosis, diabetes, obesity, and cancer. Matrix metalloproteinases (MMPs) play a significant role in tissue remodeling related to various processes such as morphogenesis, angiogenesis, tissue repair, invasion, and metastasis. We investigated the effects of PPARγ on MMP expression and invasion in breast cancer cells.

Methods

MCF-7 cells were cultured and then cell viability was monitored in an MTT assay. Western blotting, gelatin zymography, real-time polymerase chain reaction, and luciferase assays were performed to investigate the effect of the synthetic PPARγ ligand troglitazone on MMP expression. Transcription factor DNA binding was analyzed by electrophoretic mobility shift assay. A Matrigel invasion assay was used to assess the effects of troglitazone on MCF-7 cells.

Results

Troglitazone did not affect MCF-7 cell viability. 12-O-tetradecanoylphorbol-13-acetate (TPA) induced MMP-9 expression and invasion in MCF-7 cell. However, these effects were decreased by troglitazone. TPA increased nuclear factor κB and activator protein-1 DNA binding, while troglitazone inhibited these effects. The selective PPARγ antagonist GW9662 reversed MMP-9 inhibition by troglitazone in TPA-treated MCF-7 cells.

Conclusion

Troglitazone inhibited nuclear factor κB and activator protein-1-mediated MMP-9 expression and invasion of MCF-7 cells through a PPARγ-dependent mechanism.

A comprehensive review of heregulins, HER3, and HER4 as potential therapeutic targets in cancer

Heregulins (HRGs) bind to the receptors HER3 or HER4, induce receptor dimerization, and trigger downstream signaling that leads to tumor progression and resistance to targeted therapies. Increased expression of HRGs has been associated with worse clinical prognosis; therefore, attempts to block HRG-dependent tumor growth have been pursued. This manuscript summarizes the function and signaling of HRGs and review the preclinical evidence of its involvement in carcinogenesis, prognosis, and treatment resistance in several malignancies such as colorectal cancer, non-small cell lung cancer, ovarian cancer, and breast cancer. Agents in preclinical development and clinical trials of novel therapeutics targeting HRG-dependent signaling are also discussed, including anti-HER3 and -HER4 antibodies, anti-metalloproteinase agents, and HRG fusion proteins. Although several trials have indicated an acceptable safety profile, translating preclinical findings into clinical practice remains a challenge in this field, possibly due to the complexity of downstream signaling and patterns of HRG, HER3 and HER4 expression in different cancer subtypes. Improving patient selection through biomarkers and understanding the resistance mechanisms may translate into significant clinical benefits in the near future.

Salvia miltiorrhiza extract inhibits TPA-induced MMP-9 expression and invasion through the MAPK/AP-1 signaling pathway in human breast cancer MCF-7 cells

Cancer cell invasion is crucial for metastasis. A major factor in the capacity of cancer cell invasion is the activation of matrix metalloproteinase-9 (MMP-9), which degrades the extracellular matrix. Salvia miltiorrhiza has been used as a promotion for blood circulation to remove blood stasis. Numerous previous studies have demonstrated that S. miltiorrhiza extracts (SME) decrease lipid levels and inhibit inflammation. However, the mechanism behind the effect of SME on breast cancer invasion has not been identified. The inhibitory effects of SME on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced MMP-9 expression were assessed using western blotting, reverse transcription-quantitative polymerase chain reaction and zymography assays. MMP-9 upstream signal proteins, including mitogen-activated protein kinases and activator protein 1 (AP-1) were also investigated. Cell invasion was assessed using a matrigel invasion assay. The present study demonstrated the inhibitory effects of the SME ethanol solution on MMP-9 expression and cell invasion in TPA-treated MCF-7 breast cancer cells. SME suppressed TPA-induced MMP-9 expression and MCF-7 cell invasion by blocking the transcriptional activation of AP-1. SME may possess therapeutic potential for inhibiting breast cancer cell invasiveness.

Rab5a is overexpressed in oral cancer and promotes invasion through ERK/MMP signaling

Ras-related protein Rab-5A (Rab5a) has been identified to be overexpressed in several types of human cancer. However, its clinical significance and biological roles in oral cancer remain unclear. In the present study, the protein expression of Rab5a was examined in 79 cases of oral squamous cell carcinoma samples using immunohistochemistry. It was demonstrated that Rab5a protein was upregulated in 49.3% (39/79) of cancer samples. Small interfering RNA knockdown was performed on Detroit 562 cells with high endogenous expression. Rab5a transfection was performed in FaDu cells with low endogenous levels. Rab5a depletion was revealed to inhibit cell growth, invasion and colony formation while its overexpression facilitated cell growth, invasion, and colony formation. In addition, Rab5a facilitated cell cycle progression and cell migration. It was also demonstrated that Rab5a depletion downregulated and its overexpression upregulated the expression levels of various cell cycle-associated proteins, and matrix metalloproteinase-2 (MMP-2). Furthermore, Rab5a positively regulated the extracellular signal-regulated kinase (ERK) signaling pathway and promoted epithelial-mesenchymal transition (EMT). ERK inhibitor PD98059 partially inhibited the role of Rab5a on MMP-2, cyclin D1, cell proliferation and invasion. The results of the present study suggest that Rab5a is overexpressed in oral cancer tissue samples and promotes the malignant phenotype through EMT and the ERK/MMP-2 signaling pathway.

Derlin-1 overexpression confers poor prognosis in muscle invasive bladder cancer and contributes to chemoresistance and invasion through PI3K/AKT and ERK/MMP signaling

Derlin-1 has been found to be overexpressed in several human cancers. However, its clinical significance and biological roles in bladder cancer remain unexplored. Here, we found that Derlin-1 was upregulated in 38.6% (58/150) cases of cancer samples. The rate of Derlin-1 overexpression was higher in muscle invasive bladder cancer (MIBC) than non-muscle invasive bladder cancer (NMIBC) (p=0.0079). Derlin-1 was a predicting factor for poor patient prognosis. Derlin-1 depletion inhibited while its overexpression facilitated cell invasion and colony formation. In addition, Derlin-1 overexpression induced cisplatin resistance while its depletion sensitized cancer cells to cisplatin. Further analysis demonstrated that Derlin-1 activated AKT phosphorylation and upregulated Bcl-2 expression. Blockage of AKT signaling by LY294005 abolished the effects of Derlin-1 on Bcl-2 and cisplatin resistance. Immunoprecipitation indicated Derlin-1 interacted with p110α subunit of PI3K. In addition, we showed that Derlin-1 depletion downregulated and its overexpression upregulated cell MMP-2/9 expression and ERK phosphorylation. Derlin-1 mediated upregulation of MMP-2/9 could be blocked by ERK inhibitor. In conclusion, our study demonstrated that Derlin-1 is overexpressed in bladder cancer and promotes malignant phenotype through ERK/MMP and PI3K/AKT/Bcl-2 signaling pathway.

Effect of selective small molecule inhibitors on MMP-9 and VEGFR-1 expression in p16-positive and -negative squamous cell carcinoma

The identification of molecular targets in the therapy of human papilloma virus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) is a primary aim of cancer research. Matrix metalloproteinase 9 (MMP-9) and vascular endothelial growth factor receptor (VEGFR) have important roles in the development of HNSCC. The tyrosine kinase inhibitors, nilotinib, dasatinib, erlotinib and gefitinib are well established in the targeted therapy of tumors other than HNSCC. The present study aimed to investigate the alteration of MMP-9 and VEGFR-1 expression patterns following treatment with these tyrosine kinase inhibitors in p16-positive and -negative squamous carcinoma cells. MMP-9 and VEGFR-1 expression was evaluated using an ELISA in HNSCC 11A, HNSCC 14C and p16-positive CERV196 tumor cell lines, following treatment with nilotinib, dasatinib, erlotinib and gefitinib. A statistically significant reduction in MMP-9 and VEGFR-1 expression was observed in the p16-negative HNSCC 11A cells following treatment with all inhibitors (P<0.05). VEGFR-1 expression was significantly increased in p16-positive SCC cells following treatment with nilotinib, dasatinib, erlotinib and gefitinib (P<0.05). The expression of MMP-9 and VEGFR-1 was significantly altered by treatment with nilotinib, dasatinib, erlotinib and gefitinib in vitro. The results of the present study are attributed to the efficacy of the tested drugs and present potential compensatory strategies of cancer cells to avoid the antiangiogenic properties of the tested tyrosine kinase inhibitors in vitro.

Inhibitors of PI3K/ERK1/2/p38 MAPK Show Preferential Activity Against Endocrine-Resistant Breast Cancer Cells

Current mainstream pharmacological options for the treatment of endocrine-resistant breast cancer have limitations in terms of their side effect profile and lack of discrimination between normal and cancer cells. In the current study, we assessed the responses of normal breast epithelial cells MCF10A, estrogen receptor-positive (ER⁺) MCF-7, and ER-silenced pII breast cancer cells to inhibitors (either individually or in combination) of downstream signaling molecules. The expression/activity of ERK1/2, p38 MAPK, and Akt was determined by Western blotting. Cell proliferation, motility, and invasion were determined using MTT, wound healing, and Matrigel assays, respectively. Morphological changes in response to variation in external pH were assessed by light microscopy. Our results demonstrated that the inhibitors of ERK1/2 (PD0325901), p38 MAPK (SB203580), and PI3K (LY294002) preferentially reduce breast cancer cell proliferation. In pII cells, they also reduced motility, invasion, and bleb formation induced by alkaline conditions. Combination treatment with lower concentrations of inhibitors was significantly more effective than single agents and was more effective against the cancer cell lines than the normal MCF10A. In contrast, the commonly used cytotoxic agent paclitaxel did not sufficiently discriminate between the MCF10A and the cancer cells. We concluded that combination therapy using ERK1/2 inhibitor and either p38 MAPK or PI3K inhibitor may provide a greater therapeutic benefit in treating breast cancer by specifically targeting cancer cells with lower doses of each drug than needed individually, potentially reducing unwanted side effects.

DHA blocks TPA-induced cell invasion by inhibiting MMP-9 expression via suppression of the PPAR-γ/NF-κB pathway in MCF-7 cells

Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is considered to have applications in cancer prevention and treatment. The beneficial effects of DHA against cancer metastasis are well established; however, the mechanisms underlying these effects in breast cancer are not clear. Cell invasion is critical for neoplastic metastasis, and involves the degradation of the extracellular matrix by matrix metalloproteinase (MMP)-9. The present study investigated the inhibitory effect of DHA on MMP-9 expression and cell invasion induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in the MCF-7 breast cancer cell line. DHA inhibited the TPA-induced activation of mitogen-activated protein kinase (MAPK) and the transcription of nuclear factor (NF)-κB, but did not inhibit the transcription of activator protein-1. DHA increased the activity of peroxisome proliferator-activated receptor (PPAR)-γ, an effect that was reversed by the application of the PPAR-γ antagonist GW9662. In addition, combined treatment with GW9662 and DHA increased NF-κB-related protein expression. These results indicate that DHA regulates MMP-9 expression and cell invasion via modulation of the MAPK signaling pathway and PPAR-γ/NF-κB activity. This suggests that DHA could be a potential therapeutic agent for the prevention of breast cancer metastasis.

PYK2 integrates growth factor and cytokine receptors signaling and potentiates breast cancer invasion via a positive feedback loop

The involvement of ErbB family members in breast cancer progression and metastasis has been demonstrated by many studies. However, the downstream effectors that mediate their migratory and invasive responses have not been fully explored. In this study, we show that the non-receptor tyrosine kinase PYK2 is a key effector of EGFR and HER2 signaling in human breast carcinoma. We found that PYK2 is activated by both EGF and heregulin (HRG) in breast cancer cells, and positively regulates EGF/HRG-induced cell spreading, migration and invasion. PYK2 depletion markedly affects ERK1/2 and STAT3 phosphorylation in response to EGF/HRG as well as to IL8 treatment. Importantly, PYK2 depletion also reduced EGF/HRG-induced MMP9 and IL8 transcription, while IL8 inhibition abrogated EGF-induced MMP9 transcription and attenuated cell invasion. IL8, which is transcriptionally regulated by STAT3 and induces PYK2 activation, prolonged EGF-induced PYK2, STAT3 and ERK1/2 phosphorylation suggesting that IL8 acts through an autocrine loop to reinforce EGF-induced signals. Collectively our studies suggest that PYK2 is a common downstream effector of ErbB and IL8 receptors, and that PYK2 integrates their signaling pathways through a positive feedback loop to potentiate breast cancer invasion. Hence, PYK2 could be a potential therapeutic target for a subset of breast cancer patients.

Mangiferin inhibits tumor necrosis factor-α-induced matrix metalloproteinase-9 expression and cellular invasion by suppressing nuclear factor-κB activity

We investigated the effects of mangiferin on the expression and activity of metalloproteinase (MMP)-9 and the invasion of tumor necrosis factor (TNF)-α-stimulated human LNCaP prostate carcinoma cells. Reverse-transcription polymerase chain reaction (RT-PCR) and western blot analysis showed that mangiferin significantly reversed TNF-α-induced mRNA and protein expression of MMP-9 expression. Zymography data confirmed that stimulation of cells with TNF-α significantly increased MMP-9 activity. However, mangiferin substantially reduced the TNF-α-induced activity of MMP-9. Additionally, a matrigel invasion assay showed that mangiferin significantly reduced TNF-α-induced invasion of LNCaP cells. Compared to untreated controls, TNF-α-stimulated LNCaP cells showed a significant increase in nuclear factor-κB (NF-κB) luciferase activity. However, mangiferin treatment markedly decreased TNF-α-induced NF-κB luciferase activity. Furthermore, mangiferin suppressed nuclear translocation of the NF-κB subunits p65 and p50. Collectively, our results indicate that mangiferin is a potential anti-invasive agent that acts by suppressing NF-κB-mediated MMP-9 expression. [BMB Reports 2015; 48(10): 559-564]

Heregulin-HER3-HER2 signaling promotes matrix metalloproteinase-dependent blood-brain-barrier transendothelial migration of human breast cancer cell lines

HER2-positive breast tumors are associated with a high risk of brain relapse. HER3 is thought to be an indispensible signaling substrate for HER2 (encoded by ERBB2) and is induced in breast cancer-brain metastases, though the molecular mechanisms by which this oncogenic dimer promotes the development of brain metastases are still elusive. We studied the effects of the HER3-HER2 ligand, heregulin (neuregulin-1, broadly expressed in the brain), on luminal breast cancer cell lines in vitro. Treatment of SKBr3 (ERBB2-amplified), MDA-MB-361 (ERBB2-amplified, metastatic brain tumor-derived) and MCF7 (HER2-positive, not ERBB2-amplified) cells with exogenous heregulin increased proliferation and adhesive potential, concomitant with induction of cyclin D1 and ICAM-1, and suppression of p27. All three cell lines invaded through matrigel toward a heregulin chemotactic signal in transwell experiments, associated with activation of extracellular cathepsin B and matrix metalloproteinase-9 (MMP-9). Moreover, heregulin induced breast cancer cell transmigration across a tight barrier of primary human brain microvascular endothelia. This was dependent on the activity of HER2, HER3 and MMPs, and was completely abrogated by combination HER2-HER3 blockade using Herceptin^® and the humanized HER3 monoclonal antibody, EV20. Collectively these data suggest mechanisms by which the HER3-HER2 dimer promotes development of metastatic tumors in the heregulin-rich brain microenvironment.

Targeted Inhibition of Snail Activity in Breast Cancer Cells by Using a Co(III) -Ebox Conjugate

The transition from a non-invasive to an invasive phenotype is an essential step in tumor metastasis. The Snail family of transcription factors (TFs) is known to play a significant role in this transition. These TFs are zinc fingers that bind to the CAGGTG Ebox consensus sequence. Co(III) -Ebox is a cobalt(III) complex attached to an Ebox oligonucleotide that confers specificity towards Snail TFs. Co(III) -Ebox has been shown to inhibit Snail-mediated embryonic neural crest development in Xenopus laevis, but its efficacy in inhibiting Snail-induced cancer cell invasiveness has not been explored. Here, we describe the efficacy of Co(III) -Ebox in inhibiting the invasive aspects of heregulin-β1(HRG)-treated breast cancer cells. Co(III) -Ebox was found to inhibit the capacity of Snail to repress target genes after HRG induction. Snail inhibition by Co(III) -Ebox reduced the invasive propensity of cells in 2D and 3D, thereby demonstrating promise in inhibiting metastasis.

Aurora kinases are essential for PKC-induced invasion and matrix metalloproteinase-9 expression in MCF-7 breast cancer cells

The Aurora kinase family of serine/threonine kinases are known to be crucial for cell cycle control. Aurora kinases are considered a target of anticancer drugs. However, few studies have assessed the effect of Aurora kinases in breast cancer. In the present study, to determine whether Aurora kinases play a role in oncogenic actions of protein kinase C (PKC), we investigated the effect of Aurora kinases on PKC-induced invasion and MMP-9 expression using breast cancer cells. Treatment of MCF-7 cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) induced the upregulation and phosphorylation of Aurora kinases via the MAPK signaling pathway. Moreover, the inhibition of Aurora kinases by their siRNAs and inhibitors suppressed TPA-induced cell invasion and expression of MMP-9 by inhibiting the activation of NF-κB/AP-1, major transcription factors for MMP-9 expression in MCF-7 cells. These results suggested that Aurora kinases mediate PKC-MAPK signal to NF-κB/AP-1 with increasing MMP-9 expression and invasion of MCF-7 cells. To the best of our knowledge, this is the first study to show that Aurora kinases are key molecules in PKC-induced invasion in breast cancer cells.

Serum Levels of IL-1 β , IL-6, TGF- β , and MMP-9 in Patients Undergoing Carotid Artery Stenting and Regulation of MMP-9 in a New In Vitro Model of THP-1 Cells Activated by Stenting

Inflammation plays an important role in the pathophysiological process after carotid artery stenting (CAS). Monocyte is a significant source of inflammatory cytokines in vascular remodeling. Telmisartan could reduce inflammation. In our study, we first found that, after CAS, the serum IL-1β, IL-6, TGF-β, and MMP-9 levels were significantly increased, but only MMP-9 level was elevated no less than 3 months. Second, we established a new in vitro model, where THP-1 monocytes were treated with the supernatants of human umbilical vein endothelial cells (HUVECs) that were scratched by pipette tips, which mimics monocytes activated by mechanical injury of stenting. The treatment enhanced THP-1 cell adhesion, migration and invasion ability, and the phosphorylation of ERK1/2 and Elk-1 and MMP-9 expression were significantly increased. THP-1 cells pretreated with PD98095 (ERK1/2 inhibitor) attenuated the phosphorylation of ERK1/2 and Elk-1 and upregulation of MMP-9, while pretreatment with telmisartan merely decreased the phosphorylation of Elk-1 and MMP-9 expression. These results suggested that IL-1β, IL-6, TGF-β, and MMP-9 participate in the pathophysiological process after CAS. Our new in vitro model mimics monocytes activated by stenting. MMP-9 expression could be regulated through ERK1/2/Elk-1 pathway, and the protective effects of telmisartan after stenting are partly attributed to its MMP-9 inhibition effects via suppression of Elk-1.

Aberrantly hypermethylated Homeobox A2 derepresses metalloproteinase-9 through TBP and promotes invasion in Nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is notorious for its high invasiveness and metastatic ability. In this study, we identified a differential hypermethylated transcription repressor, Homeobox A2 (HOXA2), which may render NPC cells invasive and metastatic. Aberrant hypermethylation of HOXA2 led to low RNA expression in NPC tumors and cells. Addition of methylation inhibitor 5'Aza restored HOXA2 RNA expression in NPC cells. Methylated HOXA2 promoter reduces the binding affinity of the transcriptional co-activator p300, causing transcriptional repression of HOXA2. In NPC cells, re-expression of ectopic HOXA2 was correlated with decreased invasive ability and reduced metalloproteinase MMP-9 RNA and protein expression. Promoter, ChIP and DNA-pull down assays indicated that HOXA2 competes with the transcription activator, TATA-box binding protein (TBP) for a recognition sequence near the MMP-9 transcription start site, and suppresses MMP-9 transcription. Thus, HOXA2 acts as a suppressor or TBP-antagonist to inhibit MMP-9 expression; while methylation-mediated inactivation of HOXA2 in NPC derepresses MMP-9 production and increases invasion of NPC cells. In NPC plasma samples, increased plasma EBV copy number was correlated with increased in cell-free HOXA2 hypermethylation and elevated MMP-9 levels. Plasma EBV DNA and methylated cell-free HOXA2 can be used as biomarkers for monitoring NPC treatment.

Rho GDP dissociation inhibitor beta promotes cell proliferation and invasion by modulating the AKT pathway in hepatocellular carcinoma

Rho GDP dissociation inhibitor (GDI) beta, (RhoGDI2), has been identified as a proto-oncogene that is upregulated in human cancers, but the role of RhoGDI2 in hepatocellular carcinoma (HCC) remains unclear. In the present study, we investigated the RhoGDI2 expression level in HCC tissues and the function of RhoGDI2 in HCC cell growth and metastasis. We examined the RhoGDI2 mRNA expression level in 64 sets of HCC tissue and their adjacent nontumor tissue counterparts using quantitative real-time polymerase chain reaction. In vitro proliferation and invasion assays were conducted to determine the effect of RhoGDI2 on the ability of HCC cells to proliferate and invade, respectively. Western blot analysis was conducted to examine expression levels of RhoGDI2p-AKT, MMP-2, and MMP-9 in HCC cells. RhoGDI2 mRNA was significantly overexpressed in the HCC specimens compared with the nonneoplastic liver specimens, and the RhoGDI2 mRNA and protein levels were higher in the HCC cell lines, especially the highly metastatic cell lines 97L and 97H. To further investigate the role that RhoGDI2 plays in HCC, we overexpressed RhoGDI2 using a lentivirus-mediated overexpression technique in two HCC cell lines (Huh7 and 7721) that endogenously express a low level of RhoGDI2. Stable cells overexpressing RhoGDI2 demonstrated a significant increase in cell proliferation and invasion. Furthermore, our additional findings indicated that RhoGDI2-mediated cellular invasion requires the PI3K/Akt signaling-dependent expression of matrix metalloproteinases (MMPs). Our findings suggest that RhoGDI2 plays an important role in HCC growth and invasion and should be considered a novel HCC therapeutic target candidate.

MMP-9 expression varies according to molecular subtypes of breast cancer

Background

In 2014, breast cancer remains a major cause of mortality worldwide mostly due to tumor relapse and metastasis. There is currently a great interest in identifying cancer biomarkers and signalling pathways mechanistically related to breast cancer progression. Matrix metalloproteinase-9 (MMP-9) is a member of matrix degrading enzymes involved in cancer development, invasion and metastasis. Our objective was to investigate MMP-9 expression in normal human breast tissue and to compare it to that of breast cancer of various histological grades and molecular subtypes. We also sought to correlate MMP-9 expression with the incidence of metastasis, survival rates and relapse in breast cancer patients.

Methods

MMP-9 was first studied using in silico analysis on available DNA microarray and RNA sequencing data of human breast cancer tissues and human breast cancer cell lines. We next ascertained MMP-9 expression in both normal breast tissue and in human breast carcinoma tissue microarrays.

Results

Significant increase in MMP-9 expression was found in breast cancer cells where compared to normal breast tissue. A positive correlation could also be established between elevated levels of MMP-9 and breast cancer of high histological grade. Furthermore, our results indicate that not only MMP-9 is differentially expressed between each molecular subset but also, more importantly MMP-9 overexpression revealed itself as a startling feature of triple-negative and HER2-positive breast cancers. Lastly, the clinical relevance of MMP-9 overexpression is strongly supported by its significant association with a higher incidence of metastasis and relapse.

Conclusions

Differential expression of MMP-9 reflects the extent of cellular differentiation in breast cancer cells and is closely related to the most aggressive subtypes of breast cancer. Hence, MMP-9 is a promising prognostic biomarker of high-grade breast cancer. In our opinion, MMP-9 expression could help segregate subsets of aggressive breast cancer into clinically meaningful subtypes.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-609) contains supplementary material, which is available to authorized users.

Role of p38 MAP Kinase Signal Transduction in Solid Tumors

Mitogen-activated protein kinases (MAPKs) mediate a wide variety of cellular behaviors in response to extracellular stimuli. One of the main subgroups, the p38 MAP kinases, has been implicated in a wide range of complex biologic processes, such as cell proliferation, cell differentiation, cell death, cell migration, and invasion. Dysregulation of p38 MAPK levels in patients are associated with advanced stages and short survival in cancer patients (e.g., prostate, breast, bladder, liver, and lung cancer). p38 MAPK plays a dual role as a regulator of cell death, and it can either mediate cell survival or cell death depending not only on the type of stimulus but also in a cell type specific manner. In addition to modulating cell survival, an essential role of p38 MAPK in modulation of cell migration and invasion offers a distinct opportunity to target this pathway with respect to tumor metastasis. The specific function of p38 MAPK appears to depend not only on the cell type but also on the stimuli and/or the isoform that is activated. p38 MAPK signaling pathway is activated in response to diverse stimuli and mediates its function by components downstream of p38. Extrapolation of the knowledge gained from laboratory findings is essential to address the clinical significance of p38 MAPK signaling pathways. The goal of this review is to provide an overview on recent progress made in defining the functions of p38 MAPK pathways with respect to solid tumor biology and generate testable hypothesis with respect to the role of p38 MAPK as an attractive target for intervention of solid tumors.

Saussurea lappa extract suppresses TPA-induced cell invasion via inhibition of NF-κB-dependent MMP-9 expression in MCF-7 breast cancer cells

Background

Saussurea lappa (SL) has been used as a traditional herbal medicine to treat abdominal pain and tenesmus, and has been suggested to possess various biological activities, including anti-tumor, anti-ulcer, anti-inflammatory, anti-viral, and cardiotonic activities. The effect of SL on breast cancer metastasis, however, is unknown. Cell migration and invasion are crucial in neoplastic metastasis. Matrix metalloproteinase-9 (MMP-9), which degrades the extracellular matrix, is a major component in cancer cell invasion.

Methods

Cell viability was examined by MTT assay, whereas cell motility was measured by invasion assay. Western blot, Real-time PCR, and Zymography assays were used to investigate the inhibitory effects of ESL on matrix metalloproteinase-9 (MMP-9) expression level in MCF-7 cells. EMSA confirmed the inhibitory effects of ESL on DNA binding of NF- κB in MCF-7 cells.

Results

Cells threated with various concentrations of Saussurea lappa (ESL) for 24 h. Concentrations of 2 or 4 μM did not lead to a significant change in cell viability or morphology. Therefore, subsequent experiments utilized the optimal non-toxic concentration (2 or 4 μM) of ESL. In this study, we investigated the inhibitory effect of ethanol extract of ESL on MMP-9 expression and cell invasion in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced MCF-7 cells. ESL inhibited the TPA-induced transcriptional activation of nuclear factor-kappa B (NF-κB). However, this result obtained that ESL did not block the TPA-induced phosphorylation of the kinases: p38, ERK, and JNK. Therefore, ELS-mediated inhibition of TPA-induced MMP-9 expression and cell invasion involves the suppression of NF-kB pathway in MCF-7 cells.

Conclusions

These results indicate that ELS-mediated inhibition of TPA-induced MMP-9 expression and cell invasion involves the suppression of NF-kB pathway in MCF-7 cells. Thus, ESL has potential for controlling breast cancer invasiveness in vitro.

Proteases in cardiometabolic diseases: Pathophysiology, molecular mechanisms and clinical applications

Cardiovascular disease is the leading cause of death in the U.S. and other developed countries. Metabolic syndrome, including obesity, diabetes/insulin resistance, hypertension and dyslipidemia is a major threat for public health in the modern society. It is well established that metabolic syndrome contributes to the development of cardiovascular disease collective called as cardiometabolic disease. Despite documented studies in the research field of cardiometabolic disease, the underlying mechanisms are far from clear. Proteases are enzymes that break down proteins, many of which have been implicated in various diseases including cardiac disease. Matrix metalloproteinase (MMP), calpain, cathepsin and caspase are among the major proteases involved in cardiac remodeling. Recent studies have also implicated proteases in the pathogenesis of cardiometabolic disease. Elevated expression and activities of proteases in atherosclerosis, coronary heart disease, obesity/insulin-associated heart disease as well as hypertensive heart disease have been documented. Furthermore, transgenic animals that are deficient in or over-express proteases allow scientists to understand the causal relationship between proteases and cardiometabolic disease. Mechanistically, MMPs and cathepsins exert their effect on cardiometabolic diseases mainly through modifying the extracellular matrix. However, MMP and cathepsin are also reported to affect intracellular proteins, by which they contribute to the development of cardiometabolic diseases. On the other hand, activation of calpain and caspases has been shown to influence intracellular signaling cascade including the NF-κB and apoptosis pathways. Clinically, proteases are reported to function as biomarkers of cardiometabolic diseases. More importantly, the inhibitors of proteases are credited with beneficial cardiometabolic profile, although the exact molecular mechanisms underlying these salutary effects are still under investigation. A better understanding of the role of MMPs, cathepsins, calpains and caspases in cardiometabolic diseases process may yield novel therapeutic targets for treating or controlling these diseases. This article is part of a Special Issue entitled: Autophagy and protein quality control in cardiometabolic diseases.

p27KIP1 is involved in ERK1/2-mediated MMP-9 expression via the activation of NF-κB binding in the IL-7-induced migration and invasion of 5637 cells

Interleukin-7 (IL-7) plays a pivotal role in the development and survival of lymphocytes, but its role in cancer cell responses remains unexplained. In this study, IL-7 treatment resulted in a significant induction in the wound-healing migration and Matrigel invasion of the 5637 bladder cancer cells, but it did not result in cell proliferation. In addition, IL-7 treatment strongly induced MMP-9 expression, and increased the binding activation of NF-κB and AP-1 motifs, the important transcription factors that regulate MMP-9 expression. Moreover, the treatment of 5637 cells with IL-7 stimulated the phosphorylation of ERK1/2. U0126, an ERK1/2-specific inhibitor, blocked IL-7-induced cell migration and invasion, and also suppressed the expression of MMP-9 in the presence of IL-7. Inhibition of the ERK1/2 function consistently reversed the binding activity of NF-κB without altering AP-1 activation in IL-7-stimulated cells. Among the cell cycle regulators examined, only the expression of the cell cycle inhibitor p27KIP1 was induced by IL-7. Moreover, the inhibition of p27KIP1 by small interfering RNA (siRNA) abolished the migration, invasion and phosphorylation of ERK1/2, the expression of MMP-9, and the binding activity of the NF-κB motif in IL-7-stimulated 5637 cells. These results demonstrated that the cell cycle inhibitor p27KIP1 is involved in ERK1/2-mediated MMP-9 expression via activation of the NF-κB binding motif, which leads to the migration and invasion of bladder cancer cells induced by IL-7. These novel results could help explain the migration and invasion of bladder tumor cells.