NDRG2 controls COX-2/PGE₂-mediated breast cancer cell migration and invasion

The Antioxidant Potential and Anticancer Activity of Halodule uninervis Ethanolic Extract against Triple-Negative Breast Cancer Cells

Natural remedies have been indispensable to traditional medicine practices for generations, offering therapeutic solutions for various ailments. In modern times, these natural products continue to play a pivotal role in the discovery of new drugs, especially for cancer treatment. The marine ecosystem offers a wide range of plants with potential anticancer activities due to their distinct biochemical diversity and adaptation to extreme situations. The seagrass Halodule uninervis is rich in diverse bioactive metabolites that bestow the plant with various pharmacological properties. However, its anticancer activity against invasive triple-negative breast cancer (TNBC) is still poorly investigated. In the present study, the phytochemical composition of an ethanolic extract of H. uninervis (HUE) was screened, and its antioxidant potential was evaluated. Moreover, the anticancer potential of HUE against MDA-MB-231 cells was investigated along with the possible underlying mechanisms of action. Our results showed that HUE is rich in diverse phytochemicals that are known for their antioxidant and anticancer effects. In MDA-MB-231 cells, HUE targeted the hallmarks of cancer, including cell proliferation, adhesion, migration, invasion, and angiogenesis. The HUE-mediated anti-proliferative and anti-metastatic effects were associated with the downregulation of the proto-oncogenic STAT3 signaling pathway. Taken together, H. uninervis could serve as a valuable source for developing novel drugs targeting TNBC.

NDRGs in Breast Cancer: A Review and In Silico Analysis

The N-myc downstream regulated gene family (NDRGs) includes four members: NDRG1, NDRG2, NDRG3, and NDRG4. These members exhibit 53-65% amino acid identity. The role of NDRGs in tumor growth and metastasis appears to be tumor- and context-dependent. While many studies have reported that these family members have tumor suppressive roles, recent studies have demonstrated that NDRGs, particularly NDRG1 and NDRG2, function as oncogenes, promoting tumor growth and metastasis. Additionally, NDRGs are involved in regulating different signaling pathways and exhibit diverse cellular functions in breast cancers. In this review, we comprehensively outline the oncogenic and tumor suppressor roles of the NDRG family members in breast cancer, examining evidence from in vitro and in vivo breast cancer models as well as tumor tissues from breast cancer patients. We also present analyses of publicly available genomic and transcriptomic data from multiple independent cohorts of breast cancer patients.

Anticancer Effect of E26 Transformation-Specific Homologous Factor through the Induction of Senescence and the Inhibition of Epithelial-Mesenchymal Transition in Triple-Negative Breast Cancer Cells

The aim of the present study was to evaluate the effect of ETS homologous factor (EHF) in malignant breast cancer cells. The overexpression and knockdown of the EHF gene in human and mouse breast cancer cells were performed, and the TCGA dataset and Q-omics were analyzed. We found that the tumor suppressor NDRG2 is correlated with EHF gene expression in triple-negative breast cancer cells, that EHF overexpression results in reduced cell proliferation and that apoptosis is promoted by the chemotherapeutic reagent treatment of EHF-overexpressing cells. By EHF overexpression, senescence-associated β-galactosidase activity and p21WAF1/CIP1 expression were increased, suggesting that EHF may induce cellular senescence. In addition, the overexpression of EHF reduced the migratory ability and inhibited epithelial-mesenchymal transition (EMT). Furthermore, EHF inhibited the phosphorylation of STAT3. The overexpression of EHF also reduced the tumor size, and lung metastasis in vivo. At the tumor site, β-galactosidase activity was increased by EHF. Finally, the Kaplan-Meier-plotter analysis showed that TNBC patients with a high expression of EHF had a longer relapse-free survival rate. Our findings demonstrated that EHF inhibits breast tumor progression by inducing senescence and regulating EMT in TNBC cells.

Targeting Store-Operated Calcium Entry Regulates the Inflammation-Induced Proliferation and Migration of Breast Cancer Cells

Persistent challenges complicating the treatment of breast cancer remain, despite some recent undeniable successes. Sufficient evidence currently exists demonstrating the crucial role of inflammation, characterized by the enhanced activation of Toll-like receptor 4 (TLR4) and the COX-2/PGE2 pathway, in the migration and proliferation of breast cancer cells. Interestingly, the store-operated calcium entry (SOCE) pathway was shown to be essential for the TLR4 activity and COX-2 expression in immune cells such as macrophages and microglia. However, whether SOCE influences inflammatory signaling and the inflammation-induced proliferation and migration of breast cancer cells is still unknown. Thus, the current study intended to delineate the role of SOCE in the TLR4-induced inflammation, migration, and proliferation of breast cancer cells. To this end, MDA-MB-231 breast cancer cells were treated with lipopolysaccharide (LPS) to activate TLR4, BTP2 to inhibit SOCE, and Thapsigargin to induce SOCE. Following these treatments, several experiments were conducted to evaluate the proliferation and migration rates of the MDA-MB-231 cells and the expression of several inflammatory and oncogenic genes, including COX-2, PGE2, IL-6, IL-8, and VEGF. Different techniques were used to achieve the aims of this study, including qRT-PCR, Western blotting, ELISA, MTT, and wound healing assays. This study shows that SOCE inhibition using BTP2 suppressed the LPS-induced migration and proliferation of breast cancer cells. Additionally, treatment with LPS caused approximately six- and three-fold increases in COX-2 mRNA and protein expression, respectively, compared to the controls. The LPS-induced elevations in the COX-2 mRNA and protein levels were suppressed by BTP2 to the control levels. In addition to its effect on COX-2, BTP2 also suppressed the LPS-induced productions of PGE2, IL-6, IL-8, and VEGF. Conversely, SOCE induction using Thapsigargin enhanced the LPS-induced inflammation, migration, and proliferation of breast cancer cells. Collectively, these results provide evidence for the potentially important role of SOCE in inflammation-induced breast cancer progression processes. Thus, we argue that the current study may provide novel targets for designing new therapeutic approaches for the treatment of breast cancer.

Identification of Immune and Hypoxia Risk Classifier to Estimate Immune Microenvironment and Prognosis in Cervical Cancer

Purpose

Cervical cancer (CC) is one of the most common gynecologic neoplasms. Hypoxia is an essential trigger for activating immunosuppressive activity and initiating malignant tumors. However, the determination of the role of immunity and hypoxia on the clinical outcome of CC patients remains unclear.

Methods

The CC independent cohort were collected from TCGA database. Consensus cluster analysis was employed to determine a molecular subtype based on immune and hypoxia gene sets. Cox relevant analyses were utilized to set up a risk classifier for prognosis assessment. The underlying pathways of classifier genes were detected by GSEA. Moreover, we conducted CIBERSORT algorithm to mirror the immune status of CC samples.

Results

We observed two cluster related to immune and hypoxia status and found the significant difference in outcome of patients between the two clusters. A total of 251 candidate genes were extracted from the two clusters and enrolled into Cox relevant analyses. Then, seven hub genes (CCL20, CXCL2, ITGA5, PLOD2, PTGS2, TGFBI, and VEGFA) were selected to create an immune and hypoxia-based risk classifier (IHBRC). The IHBRC can precisely distinguish patient risk and estimate clinical outcomes. In addition, IHBRC was closely bound up with tumor associated pathways such as hypoxia, P53 signaling and TGF β signaling. IHBRC was also tightly associated with numerous types of immunocytes.

Conclusion

This academic research revealed that IHBRC can be served as predictor for prognosis assessment and cancer treatment estimation in CC.

The Function of N-Myc Downstream-Regulated Gene 2 (NDRG2) as a Negative Regulator in Tumor Cell Metastasis

N-myc downstream-regulated gene 2 (NDRG2) is a tumor-suppressor gene that suppresses tumorigenesis and metastasis of tumors and increases sensitivity to anti-cancer drugs. In this review, we summarize information on the clinicopathological characteristics of tumor patients according to NDRG2 expression in various tumor tissues and provide information on the metastasis inhibition-related cell signaling modulation by NDRG2. Loss of NDRG2 expression is a prognostic factor that correlates with TNM grade and tumor metastasis and has an inverse relationship with patient survival in various tumor patients. NDRG2 inhibits cell signaling, such as AKT-, NF-κB-, STAT3-, and TGF-β-mediated signaling, to induce tumor metastasis, and induces activation of GSK-3β which has anti-tumor effects. Although NDRG2 operates as an adaptor protein to mediate the interaction between kinases and phosphatases, which is essential in regulating cell signaling related to tumor metastasis, the molecular mechanism of NDRG2 as an adapter protein does not seem to be fully elucidated. This review aims to assist the research design regarding NDRG2 function as an adaptor protein and suggests NDRG2 as a molecular target to inhibit tumor metastasis and improve the prognosis in tumor patients.

Origanum syriacum L. Attenuates the Malignant Phenotype of MDA-MB231 Breast Cancer Cells

Breast cancer is the leading cause of cancer-related deaths among women. Among breast cancer types, triple negative breast cancer (TNBC) is the most aggressive, and is resistant to hormonal and chemotherapeutic treatments. As such, alternative approaches that may provide some benefit in fighting this debilitating pathology are critically needed; hence the utilization of herbal medicine. Origanum syriacum L., one of the most regularly consumed plants in the Mediterranean region, exhibits antiproliferative effect on several cancer cell lines. However, whether this herb modulates the malignant phenotype of TNBC remains poorly investigated. Here, we show that in MDA-MB-231, a TNBC cell line, Origanum syriacum L. aqueous extract (OSE) inhibited cellular viability, induced autophagy determined by the accumulation of lipidized LC3 II, and triggered apoptosis. We also show that OSE significantly promoted homotypic cell-cell adhesion while it decreased cellular migration, adhesion to fibronectin, and invasion of MDA-MB-231 cells. This was supported by decreased activity of focal adhesion kinase (FAK), reduced α2 integrin expression, and downregulation of secreted PgE₂, MMP2 and MMP-9, in OSE-treated cells. Finally, we also show that OSE significantly inhibited angiogenesis and downregulated the level of nitric oxide (NO) production. Our findings demonstrate the ability of OSE to attenuate the malignant phenotype of the MDA-MB-231 cells, thus presenting Origanum syriacum L. as a promising potential source for therapeutic compounds for TNBC.

NDRG2 Expression in Breast Cancer Cells Downregulates PD-L1 Expression and Restores T Cell Proliferation in Tumor-Coculture

Simple Summary

N-myc downstream-regulated gene 2 (NDRG2) is a candidate tumor suppressor in various cancers, including breast cancer. Increased expression of programmed death ligand 1 (PD-L1) is frequently observed in human cancers. Despite its role in cancer cells, the effects of NDRG2 on PD-L1 expression and PD-L1-PD-1 pathway disruption have not been investigated. We demonstrated that NDRG2 overexpression inhibits PD-L1 expression in human breast cancer cells. Blocking T cell proliferation by coculture with 4T1 mouse tumor cells that express high levels of PD-L1 could be significantly reversed by NDRG2 overexpression in the same tumor cells. NDRG2 knockdown in NDRG2-transfected cells elicited the upregulation of PD-L1 expression and accelerated the inhibition of T cell proliferation. These findings were confirmed from The Cancer Genome Atlas (TCGA) data that PD-L1 expression in basal and triple-negative breast cancer (TNBC) patients, but not in luminal A or B cancer patients, was negatively correlated with the NDRG2 expression.

Abstract

(1) Background: The aim of the present study was to evaluate the effect of NDRG2 expression in regulating PD-L1 or PD-L2 on malignant breast cancer cells. (2) Methods: Overexpression and knockdown of the NDRG2 gene in human and mouse cancer cells were applied and quantitative real-time PCR and Western blot analysis were performed. T cell proliferation and TCGA analysis were conducted to validate negative correlation of the PD-L1 expression with the NDRG2 expression. (3) Results: We found that NDRG2 overexpression inhibits PD-L1 expression in human breast cancer cells through NF-κB signaling. NDRG2 overexpression in 4T1 mouse breast cancer cells followed by PD-L1 downregulation could block the suppressive activity of cancer cells on T cell proliferation and knockdown of NDRG2 expression enhanced the expression of PD-L1, leading to the inhibition of T cell proliferation by tumor cell coculture. Finally, we confirmed from TCGA data that PD-L1 expression in basal and triple-negative breast cancer patients was negatively correlated with the expression of NDRG2. Intriguingly, linear regression analysis using TNBC cell lines showed that the PD-L1 level was negatively associated with the NDRG2 expression level. (4) Conclusions: Our findings demonstrate that NDRG2 expression is instrumental in suppressing PD-L1 expression and restoring PD-L1-inhibited T cell proliferation activity in TNBC cells.

CD147 receptor is essential for TFF3-mediated signaling regulating colorectal cancer progression

Major gaps in understanding the molecular mechanisms of colorectal cancer (CRC) progression and intestinal mucosal repair have hampered therapeutic development for gastrointestinal disorders. Trefoil factor 3 (TFF3) has been reported to be involved in CRC progression and intestinal mucosal repair; however, how TFF3 drives tumors to become more aggressive or metastatic and how TFF3 promotes intestinal mucosal repair are still poorly understood. Here, we found that the upregulated TFF3 in CRC predicted a worse overall survival rate. TFF3 deficiency impaired mucosal restitution and adenocarcinogenesis. CD147, a membrane protein, was identified as a binding partner for TFF3. Via binding to CD147, TFF3 enhanced CD147-CD44s interaction, resulting in signal transducer and activator of transcription 3 (STAT3) activation and prostaglandin G/H synthase 2 (PTGS2) expression, which were indispensable for TFF3-induced migration, proliferation, and invasion. PTGS2-derived PGE2 bound to prostaglandin E2 receptor EP4 subtype (PTGER4) and contributed to TFF3-stimulated CRC progression. Solution NMR studies of the TFF3-CD147 interaction revealed the key residues critical for TFF3 binding and the induction of PTGS2 expression. The ability of TFF3 to enhance mucosal restitution was weakened by a PTGS2 inhibitor. Blockade of TFF3-CD147 signaling using competitive inhibitory antibodies or a PTGS2 inhibitor reduced CRC lung metastasis in mice. Our findings bring strong evidence that CD147 is a novel receptor for TFF3 and PTGS2 signaling is critical for TFF3-induced mucosal restitution and CRC progression, which widens and deepens the understanding of the molecular function of trefoil factors.

Extracellular ATP Mediates Cancer Cell Migration and Invasion Through Increased Expression of Cyclooxygenase 2

The tumor microenvironment plays a major role in the ability of the tumor cells to undergo metastasis. A major player of tumors gaining metastatic property is the inflammatory protein, cyclooxygenase 2 (COX-2). Several tumors show upregulation of this protein, which has been implicated in mediating metastasis in various cancer types such as of colon, breast and lung. In this report, we show that the concentration of extracellular ATP (eATP) is increased in response to cell death mediated by chemotherapeutic agents such as doxorubicin. By using three different cell-lines-HeLa (cervical), IMR-32 (neuronal) and MCF-7 (breast)-we show that this eATP goes on to act on purinergic (P2) receptors. Among the various P2 receptors expressed in these cells we identified P2X7, in IMR-32 and MCF-7 cells, and P2Y12, in HeLa cells, as important in modulating cell migration and invasion. Downstream of the P2 receptor activation, both p42/44 mitogen-activated protein kinase (MAPK) and the p38 MAPK are activated in these cells. These result in an increase in the expression of COX-2 mRNA and protein. We also observe an increase in the activity of matrix metalloproteinase 2 (MMP-2) enzyme in these cells. Blocking the P2 receptors not only blocks migration and invasion, but also COX-2 synthesis and MMP-2 activity. Our results show the link between purinergic receptors and COX-2 expression. Increased levels of ATP in the tumor microenvironment, therefore, leads to increased COX-2 expression, which, in turn, affords migratory and invasive properties to the tumor. This provides P2 receptor-based anti-inflammatory drugs (PBAIDs) a potential opportunity to be explored as cancer therapeutics.

The Role of Noncoding RNAs in the Regulation of Anoikis and Anchorage-Independent Growth in Cancer

Cancer is a global health concern, and the prognosis of patients with cancer is associated with metastasis. Multistep processes are involved in cancer metastasis. Accumulating evidence has shown that cancer cells acquire the capacity of anoikis resistance and anchorage-independent cell growth, which are critical prerequisite features of metastatic cancer cells. Multiple cellular factors and events, such as apoptosis, survival factors, cell cycle, EMT, stemness, autophagy, and integrins influence the anoikis resistance and anchorage-independent cell growth in cancer. Noncoding RNAs (ncRNAs), such as microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), are dysregulated in cancer. They regulate cellular signaling pathways and events, eventually contributing to cancer aggressiveness. This review presents the role of miRNAs and lncRNAs in modulating anoikis resistance and anchorage-independent cell growth. We also discuss the feasibility of ncRNA-based therapy and the natural features of ncRNAs that need to be contemplated for more beneficial therapeutic strategies against cancer.

The molecular mechanisms of celecoxib in tumor development

BACKGROUND

Clinical studies have shown that celecoxib can significantly inhibit the development of tumors, and basic experiments and in vitro experiments also provide a certain basis, but it is not clear how celecoxib inhibits tumor development in detail.

METHODS

A literature search of all major academic databases was conducted (PubMed, China National Knowledge Internet (CNKI), Wan-fang, China Science and Technology Journal Database (VIP), including the main research on the mechanisms of celecoxib on tumors.

RESULTS

Celecoxib can intervene in tumor development and reduce the formation of drug resistance through multiple molecular mechanisms.

CONCLUSION

Celecoxib mainly regulates the proliferation, migration, and invasion of tumor cells by inhibiting the cyclooxygenases-2/prostaglandin E2 signal axis and thereby inhibiting the phosphorylation of nuclear factor-κ-gene binding, Akt, signal transducer and activator of transcription and the expression of matrix metalloproteinase 2 and matrix metalloproteinase 9. Meanwhile, it was found that celecoxib could promote the apoptosis of tumor cells by enhancing mitochondrial oxidation, activating mitochondrial apoptosis process, promoting endoplasmic reticulum stress process, and autophagy. Celecoxib can also reduce the occurrence of drug resistance by increasing the sensitivity of cancer cells to chemotherapy drugs.

Enhancing Anti-Tumor Activity of Sorafenib Mesoporous Silica Nanomatrix in Metastatic Breast Tumor and Hepatocellular Carcinoma via the Co-Administration with Flufenamic Acid

INTRODUCTION

Because tumor-associated inflammation is a hallmark of cancer treatment, in the present study, sorafenib mesoporous silica nanomatrix (MSNM@SFN) co-administrated with flufenamic acid (FFA, a non-steroidal anti-inflammatory drug (NSAID)) was investigated to enhance the anti-tumor activity of MSNM@SFN.

METHODS

Metastatic breast tumor 4T1/luc cells and hepatocellular carcinoma HepG2 cells were selected as cell models. The effects of FFA in vitro on cell migration, PGE2 secretion, and AKR1C1 and AKR1C3 levels in 4T1/luc and HepG2 cells were investigated. The in vivo anti-tumor activity of MSNM@SFN co-administrating with FFA (MSNM@SFN+FFA) was evaluated in a 4T1/luc metastatic tumor model, HepG2 tumor-bearing nude mice model, and HepG2 orthotopic tumor-bearing nude mice model, respectively.

RESULTS

The results indicated that FFA could markedly decrease cell migration, PGE2 secretion, and AKR1C1 and AKR1C3 levels in both 4T1/luc and HepG2 cells. The enhanced anti-tumor activity of MSNM@SFN+FFA compared with that of MSNM@SFN was confirmed in the 4T1/luc metastatic tumor model, HepG2 tumor-bearing nude mice model, and HepG2 orthotopic tumor-bearing nude mice model in vivo, respectively.

DISCUSSION

MSNM@SFN co-administrating with FFA (MSNM@SFN+FFA) developed in this study is an alternative strategy for improving the therapeutic efficacy of MSNM@SFN via co-administration with NSAIDs.

Inhibitory effects of ceramide kinase on Rac1 activation, lamellipodium formation, cell migration, and metastasis of A549 lung cancer cells

Ceramide kinase (CerK) phosphorylates ceramide to ceramide-1-phosphate (C1P), a bioactive sphingolipid. Since the mechanisms responsible for regulating the proliferation and migration/metastasis of cancer cells by the CerK/C1P pathway remain unclear, we conducted the present study. The knockdown of CerK in A549 lung and MCF-7 breast cancer cells (shCerK cells) increased the formation of lamellipodia, which are membrane protrusions coupled with cell migration. Mouse embryonic fibroblasts prepared from CerK-null mice also showed an enhanced formation of lamellipodia. The overexpression of CerK inhibited lamellipodium formation in A549 cells. The knockdown of CerK increased the number of cells having lamellipodia with Rac1 and the levels of active Rac1-GTP form, whereas the overexpression of CerK decreased them. CerK was located in lamellipodia after the epidermal growth factor treatment, indicating that CerK functioned there to inhibit Rac1. The migration of A549 cells was negatively regulated by CerK. An intravenous injection of A549-shCerK cells into nude mice resulted in markedly stronger metastatic responses in the lungs than an injection of control cells. The in vitro growth of A549 cells and in vivo expansion after the injection into mouse flanks were not affected by the CerK knockdown. These results suggest that the activation of CerK/C1P pathway has inhibitory roles on lamellipodium formation, migration, and metastasis of A549 lung cancer cells.

Bioactive Lipids in Age-Related Disorders

Our own studies and those of others have shown that defects in essential fatty acid (EFA) metabolism occurs in age-related disorders such as obesity, type 2 diabetes mellitus, hypertension, atherosclerosis, coronary heart disease, immune dysfunction and cancer. It has been noted that in all these disorders there could occur a defect in the activities of desaturases, cyclo-oxygenase (COX), and lipoxygenase (LOX) enzymes leading to a decrease in the formation of their long-chain products gamma-linolenic acid (GLA), arachidonic acid, eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA). This leads to an increase in the production of pro-inflammatory prostaglandin E2 (PGE2), thromboxanes (TXs), and leukotrienes (LTs) and a decrease in anti-inflammatory lipoxin A4, resolvins, protectins and maresins. All these bioactive molecules are termed as bioactive lipids (BALs). This imbalance in the metabolites of EFAs leads to low-grade systemic inflammation and at times acute inflammatory events at specific local sites that trigger the development of various age-related disorders such as obesity, type 2 diabetes mellitus, hypertension, coronary heart disease, atherosclerosis, and immune dysfunction as seen in rheumatoid arthritis, lupus, nephritis and other localized inflammatory conditions. This evidence implies that methods designed to restore BALs to normal can prevent age-related disorders and enhance longevity and health.

Redox-Responsive Dual Drug Delivery Nanosystem Suppresses Cancer Repopulation by Abrogating Doxorubicin-Promoted Cancer Stemness, Metastasis, and Drug Resistance

Chemotherapy is a major therapeutic option for cancer patients. However, its effectiveness is challenged by chemodrugs' intrinsic pathological interactions with residual cancer cells. While inducing cancer cell death, chemodrugs enhance cancer stemness, invasiveness, and drug resistance of remaining cancer cells through upregulating cyclooxygenase-2/prostaglandin-E2 (COX-2/PGE2) signaling, therefore facilitating cancer repopulation and relapse. Toward tumor eradication, it is necessary to improve chemotherapy by abrogating these chemotherapy-induced effects. Herein, redox-responsive, celecoxib-modified mesoporous silica nanoparticles with poly(β-cyclodextrin) wrapping (MSCPs) for sealing doxorubicin (DOX) are synthesized. Celecoxib, an FDA-approved COX-2 inhibitor, is employed as a structural and functional element to confer MSCPs with redox-responsiveness and COX-2/PGE2 inhibitory activity. MSCPs efficiently codeliver DOX and celecoxib into the tumor location, minimizing systemic toxicity. Importantly, through blocking chemotherapy-activated COX-2/PGE2 signaling, MSCPs drastically enhance DOX's antitumor activity by suppressing enhancement of cancer stemness and invasiveness as well as drug resistance induced by DOX-based chemotherapy in vitro. This is also remarkably achieved in three preclinical tumor models in vivo. DOX-loaded MSCPs effectively inhibit tumor repopulation by blocking COX-2/PGE2 signaling, which eliminates DOX-induced expansion of cancer stem-like cells, distant metastasis, and acquired drug resistance. Thus, this drug delivery nanosystem is capable of effectively suppressing tumor repopulation and has potential clinical translational value.

Association of HIF-1α and NDRG2 Expression with EMT in Gastric Cancer Tissues

OBJECTIVE

This study aims to investigate the differences in the expression of hypoxia-inducible factor-1α (HIF-1α), N-myc downstream-regulated gene 2 (NDRG2) and epithelial mesenchymal transition (EMT)-related proteins in normal gastric tissues, gastric cancer tissues and lymph node metastasis.

METHODS

Immunohistochemistry was used to detect the expression of HIF-1α, NDRG2, E-cadherin, Snail and Twist in normal gastric tissues, gastric cancer tissues and lymph node metastasis.

RESULTS

In normal gastric tissues, HIF-1α was not expressed, NDRG2 was highly expressed. There was a significant between the expression of NDRG2 and Snail, as well as of NDRG2 and Twist. In gastric cancer tissues, there was no statistically difference between the expression of HIF-1α and E-cadherin, NDRG2 and E-cadherin. However, there was a significant difference in expression between the expression of HIF-1α and Snail, HIF-1α and Twist, NDRG2 and Snail, and NDRG2 and Twist. In lymph node metastasis tissues, we show that HIF-1α was highly expressed, while NDRG2 was not, and the difference between the expression of HIF-1α and E-cadherin, HIF-1α and Snail, HIF-1α and Twist was not significant.

CONCLUSION

HIF-1α may promote EMT, possibly by inhibiting the expression of NDRG2.

Cordycepin inhibits lipopolysaccharide-induced cell migration and invasion in human colorectal carcinoma HCT-116 cells through down-regulation of prostaglandin E2 receptor EP4

Prostaglandin E₂ (PGE₂), a major product of cyclooxygenase-2 (COX-2), plays an important role in the carcinogenesis of many solid tumors, including colorectal cancer. Because PGE₂ functions by signaling through PGE₂ receptors (EPs), which regulate tumor cell growth, invasion, and migration, there has been a growing amount of interest in the therapeutic potential of targeting EPs. In the present study, we investigated the role of EP4 on the effectiveness of cordycepin in inhibiting the migration and invasion of HCT116 human colorectal carcinoma cells. Our data indicate that cordycepin suppressed lipopolysaccharide (LPS)-enhanced cell migration and invasion through the inactivation of matrix metalloproteinase (MMP)-9 as well as the down-regulation of COX-2 expression and PGE₂ production. These events were shown to be associated with the inactivation of EP4 and activation of AMP-activated protein kinase (AMPK). Moreover, the EP4 antagonist AH23848 prevented LPS-induced MMP-9 expression and cell invasion in HCT116 cells. However, the AMPK inhibitor, compound C, as well as AMPK knockdown via siRNA, attenuated the cordycepin-induced inhibition of EP4 expression. Cordycepin treatment also reduced the activation of CREB. These findings indicate that cordycepin suppresses the migration and invasion of HCT116 cells through modulating EP4 expression and the AMPK-CREB signaling pathway. Therefore, cordycepin has the potential to serve as a potent anti-cancer agent in therapeutic strategies against colorectal cancer metastasis.

Clinicopathological and prognostic significance of COX-2 immunohistochemical expression in breast cancer: a meta-analysis

The prognostic significance of COX-2 in patients with breast cancer remains controversial. The aims of our meta-analysis are to evaluate its association with clinicopathological characteristics and prognostic value in patients with breast cancer. PubMed, EMBASE, Web of Science, the Ovid Database and Grey literature were systematically searched up to May 2016. Twenty-one studies including 6739 patients with breast cancer were analyzed. The meta-analysis indicated that the incidence difference of COX-2 expression was significant when comparing the lymph node positive group to negative group (OR = 1.76, 95% CI [1.30, 2.39]) and the tumor size ≥ 2cm group to the tumor size < 2cm group (OR = 1.71, 95% CI [1.22, 2.39]). None of other clinicopathological parameters such as the ER status, PR status, HER2 status and the vascular invasion status were associated with COX-2 overexpression. The detection of COX-2 was significantly correlated with the disease-free survival (DFS) of patients (HR = 1.58, 95% CI [1.23, 2.03]) and the overall survival (OS) of patients (HR = 1.51, 95% CI [1.31, 1.72]). Our meta-analysis demonstrates that the presence of high levels of COX-2 is associated with poor prognosis for breast cancer patients and predicts bigger tumor size and lymph node metastasis.

Overexpression of COX2 indicates poor survival in urothelial bladder cancer

BACKGROUND

COX2 is a cyclo-oxygenase enzyme expressed in the tumor cells, inflammatory cells, stromal and non-epithelial cells. The study was conducted to evaluate the expression of COX2 in Urothelial carcinoma and find the association with progression and recurrence.

METHODS

The expression of COX2 was evaluated by real-time PCR and immunohistochemistry.

RESULTS

Gene expression of COX2 was found to be upregulated >28-fold in urothelial cancer compared to adjacent normal bladder mucosa. Inflammatory cell expression of COX2 was found in 92% cases whereas only 37% cases showed COX2 overexpression in tumor cells. Tumor cell COX2 overexpression was significantly associated with invasion and recurrence.

CONCLUSION

COX2 expression is a marker of invasion, recurrence and poor survival and may have a role in predicting the cases which will benefit from additional treatment with COX2 inhibitors in urothelial carcinoma.

Effects of NDRG2 Overexpression on Metastatic Behaviors of HCT116 Colorectal Cancer Cell Line

Purpose: N-myc downstream-regulated gene 2 (NDRG2) is frequently down-regulated in cancer, and plays an important role in the control of tumor growth and metastasis. Its manipulation has been suggested as a therapy in cancer. Here, we examined the outcome of NDRG2 overexpression on proliferation, invasion, migration and MMP activity of HCT116 colorectal cancer cell line.

Methods: The HCT116 cell line (human colorectal cancer) was transfected with pCMV6-AC-GFP-NDRG2. 2,5diphenyltetrazolium bromide (MTT) assay was used to detect cell proliferation. The invasion and migration of the transfected cells were examined through transwell chambers while the MMP-9 activity was detected by the ability of the cells to digest gelatin.

Results: Overexpression of NDRG2 by stable NDRG2 transfection decreased cell proliferation, migration and invasion ability, along with decreasing MMP-9 activity.

Conclusion: Our data indicate that NDRG2 overexpression can suppress several aspect of tumorigenesis. Further investigations are necessitated to verify if NDRG2 molecule can be a therapeutic target in colorectal cancer.

Macrophages induce EMT to promote invasion of lung cancer cells through the IL-6-mediated COX-2/PGE2/β-catenin signalling pathway

Infiltration of macrophages plays a critical role in the connection between inflammation and cancer invasion; however, the molecular mechanism that enables this crosstalk remains unclear. This paper investigates a molecular link between infiltration of macrophages and metastasis of lung cancer cells. In this study, the macrophage density and cyclooxygenase-2 (COX-2) protein were examined in surgical specimens by immunohistochemistry (IHC), and the prostaglandin E₂ (PGE₂) levels were determined in the blood of 30 non-small cell lung cancer (NSCLC) patients using enzyme-linked immunosorbent assay (ELISA). We demonstrated that macrophage infiltration was significantly associated with elevated tumour COX-2 expression and serum PGE₂ levels in NSCLC patients. Interestingly, the COX-2 and PGE₂ levels as well as macrophages were poor predictors of NSCLC patient survival. THP-1-derived macrophages were co-cultured in vitro with A549 and H1299 lung cancer cells. In the co-culture process, interleukin-6 (IL-6) induced the COX-2/PGE₂ pathway in lung cancer cells, which subsequently promoted β-catenin translocation from the cytoplasm to the nucleus, resulting in epithelial-mesenchymal transition (EMT) and lung cancer cell invasion. Our findings show that the IL-6-dependent COX-2/PGE₂ pathway induces EMT to promote invasion of tumour cells through β-catenin activation during the interaction between macrophages and lung cancer cells, which suggests that inhibition of COX-2/PGE₂ or macrophages has the potential to suppress metastasis of lung cancer cells.

Loss of NDRG2 Expression Confers Oral Squamous Cell Carcinoma with Enhanced Metastatic Potential

Loss of the tumor suppressor NDRG2 has been implicated in the development of oral squamous cell carcinoma (OSCC), acting by modulating PI3K/AKT-mediated dephosphorylation of PTEN at S380/S382/T383 (STT). Here, we show that the majority of OSCC tumors with lymph node metastasis, a major prognostic factor, exhibit high levels of phosphorylated AKT-S473 and PTEN-STT and low levels of NDRG2 expression. In Ndrg2-deficient mice, which develop a wide range of tumors, we developed a model of OSCC by treatment with the tobacco surrogate 4-nitroquinoline-1-oxide (4-NQO). In this model, both the number and size of OSCC tumors were increased significantly by Ndrg2 deficiency, which also increased invasion of cervical lymph nodes. 4-NQO treatment of human OSCC cell lines exhibiting low NDRG2 expression induced epithelial-mesenchymal transition via activation of NF-κB signaling. Conversely, ectopic expression of NDRG2 reversed the EMT phenotype and inhibited NF-κB signaling via suppression of PTEN-STT and AKT-S473 phosphorylation. Our results show how NDRG2 expression serves as a critical determinant of the invasive and metastatic capacity of OSCC. Cancer Res; 77(9); 2363-74. ©2017 AACR.

A 22q11.2 amplification in the region encoding microRNA-650 correlates with the epithelial to mesenchymal transition in breast cancer primary cultures of Mexican patients

Breast cancer ranks first in incidence and mortality in working age women. Cancer initiation and progression relies on accumulation of genetic and epigenetic aberrations that alter cellular processes, among them, epithelial to mesenchymal transition (EMT) denotes particularly aggressive neoplasias given its capacity to invade and metastasize. Several microRNAs (miRNA) have been found able to regulate gene expression at the core of EMT. In this study, the Affymetrix CytoScan HD array was used to analyze three different primary tumor cell isolates from Mexican breast cancer patients. We found an amplification in band 22q11.2 shared by the three samples, in the region that encodes miRNA-650. Overexpression of this miRNA has been associated with downregulation of tumor suppressors ING4 and NDRG2, which have been implicated in cancer progression. Using the Pathway Linker platform the ING4 and NDRG2 interaction networks showed a significant association with signaling pathways commonly deregulated in cancer. Also, several studies support their participation in the EMT. Supporting the latter, we found that the three primary isolates were E-cadherin negative, vimentin positive, presented a cancer stem cell-like phenotype CD44⁺CD24^−/low and were invasive in Transwell invasion assays. This evidence suggests that the gain of region 22q11.2 contributes to trigger EMT. This is the first evidence linking miR-650 and breast cancer.

Cyclooxygenase-2 in tumor-associated macrophages promotes metastatic potential of breast cancer cells through Akt pathway

Tumor-associated macrophages (TAMs) promote cancer development and progression by releasing various cytokines and chemokines. Previously, we have found that the number of COX-2+ TAMs was associated with lymph node metastasis in breast cancer. However, the mechanism remains enigmatic. In this study, we show that COX-2 in breast TAMs enhances the metastatic potential of breast cancer cells. COX-2 in TAMs induces MMP-9 expression and promotes epithelial-mesenchymal transition (EMT) in breast cancer cells. In addition, COX-2/PGE2 induces IL-6 release in macrophages. Furthermore, we find that the activation of Akt pathway in cancer cells is crucial for the pro-metastatic effect of COX-2+ TAMs by regulating MMP-9 and EMT. These findings indicate that TAMs facilitate breast cancer cell metastasis through COX-2-mediated intercellular communication.

Doxycycline inhibits the cancer stem cell phenotype and epithelial-to-mesenchymal transition in breast cancer

Experimental evidence suggest that breast tumors originate from breast cancer stem cells (BCSCs), and that mitochondrial biogenesis is essential for the anchorage-independent clonal expansion and survival of CSCs, thus rendering mitochondria a significant target for novel treatment approaches. One of the recognized side effects of the FDA-approved drug, doxycycline is the inhibition of mitochondrial biogenesis. Here we investigate the mechanism by which doxycycline exerts its inhibitory effects on the properties of breast cancer cells and BCSCs, such as mammosphere forming efficiency, invasion, migration, apoptosis, the expression of stem cell markers and epithelial-to-mesenchymal transition (EMT) related markers of breast cancer cells. In addition, we explored whether autophagy plays a role in the inhibitory effect of doxycycline on breast cancer cells. We find that doxycyline can inhibit the viability and proliferation of breast cancer cells and BCSCs, decrease mammosphere forming efficiency, migration and invasion, and EMT of breast cancer cells. Expression of stem cell factors Oct4, Sox2, Nanog and CD44 were also significantly downregulated after doxycycline treatment. Moreover, doxycycline could down-regulate the expression of the autophagy marker LC-3BI and LC-3BII, suggesting that inhibiting autophagy may be responsible in part for the observed effects on proliferation, EMT and stem cell markers. The potent inhibition of EMT and cancer stem-like characteristics in breast cancer cells by doxycycline treatment suggests that this drug can be repurposed as an anti-cancer drug in the treatment of breast cancer patients in the clinic.

Abundant NDRG2 Expression Is Associated with Aggressiveness and Unfavorable Patients' Outcome in Basal-Like Breast Cancer

NDRG2, a member of the N-myc downstream-regulated gene family, is thought to be a putative tumor suppressor gene with promising clinical impact in breast cancer. Since breast cancer comprises heterogeneous intrinsic subtypes with distinct clinical outcomes we investigated the pivotal role of NDRG2 in basal-type breast cancers. Based on subtype classified tumor (n = 45) and adjacent normal tissues (n = 17) we examined NDRG2 mRNA expression and CpG-hypermethylation, whose significance was further validated by independent data sets from The Cancer Genome Atlas (TCGA). In addition, NDRG2 protein expression was evaluated immunohistochemically using a tissue micro array (TMA, n = 211). In vitro, we investigated phenotypic effects caused by NDRG2 silencing in the basal A-like HCC1806 as well as NDRG2 over-expression in basal A-like BT20 compared to luminal-type MCF7 breast cancer cells. Our tissue collections demonstrated an overall low NDRG2 mRNA expression in breast cancer subtypes compared to normal breast tissue in line with an increased CpG-hypermethylation in breast cancer tissue. Independent TCGA data sets verified a significant (P<0.001) expression loss of NDRG2 in breast tumors. Of interest, basal-like tumors more frequently retained abundant NDRG2 expression concordant with a lower CpG-hypermethylation. Unexpectedly, basal-like breast cancer revealed an association of NDRG2 expression with unfavorable patients’ outcome. In line with this observation, in vitro experiments demonstrated reduced proliferation and migration rates (~20%) in HCC1806 cells following NDRG2 silencing. In contrast, NDRG2 over-expressing luminal-type MCF7 cells demonstrated a 26% decreased proliferation rate. Until now, this is the first study investigating the putative role of NDRG2 in depth in basal-type breast cancer. Our data indicate that the described putative tumor suppressive function of NDRG2 may be confined to luminal- and basal B-type breast cancers.

Rhus coriaria suppresses angiogenesis, metastasis and tumor growth of breast cancer through inhibition of STAT3, NFκB and nitric oxide pathways

Recently, we reported that Rhus coriaria exhibits anticancer activities by promoting cell cycle arrest and autophagic cell death of the metastatic triple negative MDA-MB-231 breast cancer cells. Here, we investigated the effect of Rhus coriaria on the migration, invasion, metastasis and tumor growth of TNBC cells. Our current study revealed that non-cytotoxic concentrations of Rhus coriaria significantly inhibited migration and invasion, blocked adhesion to fibronectin and downregulated MMP-9 and prostaglandin E₂ (PgE2). Not only did Rhus coriaria decrease their adhesion to HUVECs and to lung microvascular endothelial (HMVEC-L) cells, but it also inhibited the transendothelial migration of MDA-MB-231 cells through TNF-α-activated HUVECs. Furthermore, we found that Rhus coriaria inhibited angiogenesis, reduced VEGF production in both MDA-MB-231 and HUVECs and downregulated the inflammatory cytokines TNF-α, IL-6 and IL-8. The underlying mechanism for Rhus coriaria effects appears to be through inhibiting NFκB, STAT3 and nitric oxide (NO) pathways. Most importantly, by using chick embryo tumor growth assay, we showed that Rhus coriaria suppressed tumor growth and metastasis in vivo. The results described in the present study identify Rhus coriaria as a promising chemopreventive and therapeutic candidate that modulate triple negative breast cancer growth and metastasis.

NDRG2 Expression Decreases Tumor-Induced Osteoclast Differentiation by Down-regulating ICAM1 in Breast Cancer Cells

Bone matrix is properly maintained by osteoclasts and osteoblasts. In the tumor microenvironment, osteoclasts are increasingly differentiated by the various ligands and cytokines secreted from the metastasized cancer cells at the bone metastasis niche. The activated osteoclasts generate osteolytic lesions. For this reason, studies focusing on the differentiation of osteoclasts are important to reduce bone destruction by tumor metastasis. The N-myc downstream-regulated gene 2 (NDRG2) has been known to contribute to the suppression of tumor growth and metastasis, but the precise role of NDRG2 in osteoclast differentiation induced by cancer cells has not been elucidated. In this study, we demonstrate that NDRG2 expression in breast cancer cells has an inhibitory effect on osteoclast differentiation. RAW 264.7 cells, which are monocytic preosteoclast cells, treated with the conditioned media (CM) of murine breast cancer cells (4T1) expressing NDRG2 are less differentiated into the multinucleated osteoclast-like cells than those treated with the CM of 4T1-WT or 4T1-mock cells. Interestingly, 4T1 cells stably expressing NDRG2 showed a decreased mRNA and protein level of intercellular adhesion molecule 1 (ICAM1), which is known to enhance osteoclast maturation. Osteoclast differentiation was also reduced by ICAM1 knockdown in 4T1 cells. In addition, blocking the interaction between soluble ICAM1 and ICAM1 receptors significantly decreased osteoclastogenesis of RAW 264.7 cells in the tumor environment. Collectively, these results suggest that the reduction of ICAM1 expression by NDRG2 in breast cancer cells decreases osteoclast differentiation, and demonstrate that excessive bone resorption could be inhibited via ICAM1 down-regulation by NDRG2 expression.

Loss of NDRG2 enhanced activation of the NF-κB pathway by PTEN and NIK phosphorylation for ATL and other cancer development

The activation of nuclear factor kappa B (NF-κB) signaling has a central role in the development of adult T-cell leukemia/lymphoma (ATL) and many other cancers. However, the activation mechanism of the NF-κB pathways remains poorly understood. Recently, we reported that N-myc downstream-regulated gene 2 (NDRG2) is a negative regulator of the phosphoinositide 3-kinase (PI3K)/AKT pathway by promoting the active dephosphorylated form of PTEN at its C-terminus via the recruitment of PP2A. Additionally, the down-regulation of NDRG2 expression promotes the inactive phosphorylated form of PTEN, which results in constitutively active PI3K/AKT signaling in various cancer cell types. Here, we investigated the involvement of NDRG2 in modulating NF-κB signaling. The forced expression of NDRG2 in ATL cells down-regulates not only the canonical pathway by inhibiting AKT signaling but also the non-canonical pathway by inducing NF-κB-inducing kinase (NIK) dephosphorylation via the recruitment of PP2A. Therefore, NDRG2 works as a PP2A recruiter to suppress not only PI3K/AKT signaling but also NF-κB signaling, which is particularly important in host defenses or immune responses to Human T-cell leukemia virus type 1 (HTLV-1) infection. Furthermore, the loss of NDRG2 expression might play an important role in the progression of tumor development after HTLV-1 infection.

Role of cyclooxygenase-2 in Trypanosoma cruzi survival in the early stages of parasite host-cell interaction

Chagas disease, caused by the intracellular protozoan Trypanosoma cruzi, is a serious health problem in Latin America. During this parasitic infection, the heart is one of the major organs affected. The pathogenesis of tissue remodelling, particularly regarding cardiomyocyte behaviour after parasite infection and the molecular mechanisms that occur immediately following parasite entry into host cells are not yet completely understood. When cells are infected with T. cruzi, they develop an inflammatory response, in which cyclooxygenase-2 (COX-2) catalyses rate-limiting steps in the arachidonic acid pathway. However, how the parasite interaction modulates COX-2 activity is poorly understood. In this study, the H9c2 cell line was used as our model and we investigated cellular and biochemical aspects during the initial 48 h of parasitic infection. Oscillatory activity of COX-2 was observed, which correlated with the control of the pro-inflammatory environment in infected cells. Interestingly, subcellular trafficking was also verified, correlated with the control of Cox-2 mRNA or the activated COX-2 protein in cells, which is directly connected with the assemble of stress granules structures. Our collective findings suggest that in the very early stage of the T. cruzi-host cell interaction, the parasite is able to modulate the cellular metabolism in order to survives.