Direct evidence linking expression of matrix metalloproteinase 9 (92-kDa gelatinase/collagenase) to the metastatic phenotype in transformed rat embryo cells

New insights into RAS in head and neck cancer

RAS genes are known to be dysregulated in cancer for several decades, and substantial effort has been dedicated to develop agents that reduce RAS expression or block RAS activation. The recent introduction of RAS inhibitors for cancer patients highlights the importance of comprehending RAS alterations in head and neck cancer (HNC). In this regard, we examine the published findings on RAS alterations and pathway activations in HNC, and summarize their role in HNC initiation, progression, and metastasis. Specifically, we focus on the intrinsic role of mutated-RAS on tumor cell signaling and its extrinsic role in determining tumor-microenvironment (TME) heterogeneity, including promoting angiogenesis and enhancing immune escape. Lastly, we summarize the intrinsic and extrinsic role of RAS alterations on therapy resistance to outline the potential of targeting RAS using a single agent or in combination with other therapeutic agents for HNC patients with RAS-activated tumors.

Inhibition of nonsense-mediated mRNA decay reduces the tumorigenicity of human fibrosarcoma cells

Nonsense-mediated mRNA decay (NMD) is a eukaryotic RNA decay pathway with roles in cellular stress responses, differentiation, and viral defense. It functions in both quality control and post-transcriptional regulation of gene expression. NMD has also emerged as a modulator of cancer progression, although available evidence supports both a tumor suppressor and a pro-tumorigenic role, depending on the model. To further investigate the role of NMD in cancer, we knocked out the NMD factor SMG7 in the HT1080 human fibrosarcoma cell line, resulting in suppression of NMD function. We then compared the oncogenic properties of the parental cell line, the SMG7-knockout, and a rescue cell line in which we re-introduced both isoforms of SMG7. We also tested the effect of a drug inhibiting the NMD factor SMG1 to distinguish NMD-dependent effects from putative NMD-independent functions of SMG7. Using cell-based assays and a mouse xenograft tumor model, we showed that suppression of NMD function severely compromises the oncogenic phenotype. Molecular pathway analysis revealed that NMD suppression strongly reduces matrix metalloprotease 9 (MMP9) expression and that MMP9 re-expression partially rescues the oncogenic phenotype. Since MMP9 promotes cancer cell migration and invasion, metastasis and angiogenesis, its downregulation may contribute to the reduced tumorigenicity of NMD-suppressed cells. Collectively, our results highlight the potential value of NMD inhibition as a therapeutic approach.

Biochemical features and therapeutic potential of α-Mangostin: Mechanism of action, medicinal values, and health benefits

α-Mangostin (α-MG) is a natural xanthone obtained from the pericarps of mangosteen. It exhibits excellent potential, including anti-cancer, neuroprotective, antimicrobial, antioxidant, and anti-inflammatory properties, and induces apoptosis. α-MG controls cell proliferation by modulating signaling molecules, thus implicated in cancer therapy. It possesses incredible pharmacological features and modulates crucial cellular and molecular factors. Due to its lesser water solubility and pitiable target selectivity, α-MG has limited clinical application. As a known antioxidant, α-MG has gained significant attention from the scientific community, increasing interest in extensive technical and biomedical applications. Nanoparticle-based drug delivery systems were designed to improve the pharmacological features and efficiency of α-MG. This review is focused on recent developments on the therapeutic potential of α-MG in managing cancer and neurological diseases, with a special focus on its mechanism of action. In addition, we highlighted biochemical and pharmacological features, metabolism, functions, anti-inflammatory, antioxidant effects and pre-clinical applications of α-MG.

Molecular and clinical characterization of H3 K27M-mutant "non-midline" glioblastoma: A case report and literature review

The WHO classification of tumors of the CNS in 2016 defined "diffuse midline glioma, H3 K27M-mutant" as a new tumor entity locating in the CNS midline. However, the H3 K27M-mutation in "non-midline" glioblastoma are rare and their characteristics have been rarely reported. A 16-year-old girl presented a hyper-intense lesion at her left temporal stem on T2WI, FLAIR and DWI. Biopsy was performed and molecular pathological diagnosis was glioblastoma with H3 K27M-mutant. Accordingly, the possibility of H3 K27M-mutant should be examined not only for diffuse glioma without IDH mutation that develops at a midline location, but also in non-midline locations.

Phenotypic Changes in Mammary Adenocarcinoma (4T1) cells In Vitro after Treatment with Carcinosinum

OBJECTIVE

 The present study aimed to identify possible phenotypic changes in 4T1 (murine mammary adenocarcinoma) cells in vitro, including viability, HER-2 (human epidermal growth factor receptor-type 2) expression, and metastatic potential, after treatment with Carcinosinum in different homeopathic dilutions (12cH, 30cH, 200cH) shaken mechanically in pure, sterile, water from a commercial stock dilution.

METHOD

 Treated cells were cultured in R10 medium, using 24-well plates, 10⁵ cells per well, and treated with vehicle, Carcinosinum 12cH, 30cH or 200cH; untreated cells were used as the baseline control. After 24 hours of treatment, the percentage of apoptotic cells was analyzed by annexin V. Cell morphology was evaluated by microscopy after hematoxylin-eosin and Giemsa staining, whilst HER-2 expression was assessed using immunocytochemistry. The metastatic potential was determined by the expression and activity of the enzyme matrix metalloproteinase 9 (MMP-9) using zymography. The cytokine profile was established using the cytometric bead array method.

RESULT

 Treatment of 4T1 cells in vitro with Carcinosinum 30cH produced an increase in the number of annexin V-positive cells (apoptosis) and decreased expression of proactivated MMP-9. Cells treated with Carcinosinum 200cH presented hyper-expression of HER-2 on the plasma membrane, identified by immunocytochemistry. There were no differences in cytokine production among treatments.

CONCLUSION

 The data show promising results for Carcinosinum 30cH in vitro, but in vivo studies are also required to evaluate the role of tumor microenvironment in its effects.

Distinct Oncogenic Transcriptomes in Human Mammary Epithelial Cells Infected With Cytomegalovirus

Human cytomegalovirus is being recognized as a potential oncovirus beside its oncomodulation role. We previously isolated two clinical isolates, HCMV-DB (KT959235) and HCMV-BL (MW980585), which in primary human mammary epithelial cells promoted oncogenic molecular pathways, established anchorage-independent growth in vitro, and produced tumorigenicity in mice models, therefore named high-risk oncogenic strains. In contrast, other clinical HCMV strains such as HCMV-FS, KM, and SC did not trigger such traits, therefore named low-risk oncogenic strains. In this study, we compared high-risk oncogenic HCMV-DB and BL strains (high-risk) with low-risk oncogenic strains HCMV-FS, KM, and SC (low-risk) additionally to the prototypic HCMV-TB40/E, knowing that all strains infect HMECs in vitro. Numerous pro-oncogenic features including enhanced expression of oncogenes, cell survival, proliferation, and epithelial-mesenchymal transition genes were observed with HCMV-BL. In vitro, mammosphere formation was observed only in high-risk strains. HCMV-TB40/E showed an intermediate transcriptome landscape with limited mammosphere formation. Since we observed that Ki67 gene expression allows us to discriminate between high and low-risk HCMV strains in vitro, we further tested its expression in vivo. Among HCMV-positive breast cancer biopsies, we only detected high expression of the Ki67 gene in basal tumors which may correspond to the presence of high-risk HCMV strains within tumors. Altogether, the transcriptome of HMECs infected with HCMV clinical isolates displays an “oncogenic gradient” where high-risk strains specifically induce a prooncogenic environment which might participate in breast cancer development.

p62 functions as a signal hub in metal carcinogenesis

A number of metals are toxic and carcinogenic to humans. Reactive oxygen species (ROS) play an important role in metal carcinogenesis. Oxidative stress acts as the converging point among various stressors with ROS being the main intracellular signal transducer. In metal-transformed cells, persistent expression of p62 and erythroid 2-related factor 2 (Nrf2) result in apoptosis resistance, angiogenesis, inflammatory microenvironment, and metabolic reprogramming, contributing to overall mechanism of metal carcinogenesis. Autophagy, a conserved intracellular process, maintains cellular homeostasis by facilitating the turnover of protein aggregates, cellular debris, and damaged organelles. In addition to being a substrate of autophagy, p62 is also a crucial molecule in a myriad of cellular functions and in molecular events, which include oxidative stress, inflammation, apoptosis, cell proliferation, metabolic reprogramming, that modulate cell survival and tumor growth. The multiple functions of p62 are appreciated by its ability to interact with several key components involved in various oncogenic pathways. This review summarizes the current knowledge and progress in studies of p62 and metal carcinogenesis with emphasis on oncogenic pathways related to oxidative stress, inflammation, apoptosis, and metabolic reprogramming.

Tumor microenvironment-activated cancer cell membrane-liposome hybrid nanoparticle-mediated synergistic metabolic therapy and chemotherapy for non-small cell lung cancer

BACKGROUND

Biomimetic nanotechnology-based RNA interference (RNAi) has been successful in improving theranostic efficacy in malignant tumors. Its integration with hybrid biomimetic membranes made of natural cell membranes fused with liposomal membranes is mutually beneficial and extends their biofunctions. However, limited research has focused on engineering such biomimetics to endow them with unique properties and functions, in particular, those essential for a "smart" drug delivery system, such as a tumor microenvironment (TME)-activated multifunctional biomimetic nanoplatform.

RESULTS

Herein, we utilized an integrated hybrid nanovesicle composed of cancer cell membranes (Cm) and matrix metallopeptidase 9 (MMP-9)-switchable peptide-based charge-reversal liposome membranes (Lipm) to coat lipoic acid-modified polypeptides (LC) co-loaded with phosphoglycerate mutase 1 (PGAM1) siRNA (siPGAM1) and DTX. The nanovesicle presented a negatively charged coating (citraconic anhydride-grafted poly-L-lysine, PC) in the middle layer for pH-triggered charge conversion functionalization. The established chemotherapeutic drug (DTX) co-delivery system CLip-PC@CO-LC nanoparticles (NPs) have a particle size of ~ 193 nm and present the same surface proteins as the Cm. Confocal microscopy and flow cytometry results indicated a greater uptake of MMP-9-treated CLip-PC@CO-LC NPs compared with that of the CLip-PC@CO-LC NPs without MMP-9 pretreatment. The exposure to MMP-9 activated positively charged cell-penetrating peptides on the surface of the hybrid nanovesicles. Moreover, pH triggered membrane disruption, and redox triggered DTX and siRNA release, leading to highly potent target-gene silencing in glycolysis and chemotherapy with enhanced antiproliferation ability. The biodistribution results demonstrated that the CLip-PC@LC-DiR NPs accumulated in the tumor owing to a combination of long blood retention time, homologous targeting ability, and TME-activated characteristics. The CLip-PC@CO-LC NPs led to more effective tumor growth inhibition than the DTX and free siPGAM1 formulations.

CONCLUSIONS

TME-activated cancer cell membrane-liposome integrated hybrid NPs provide an encouraging nanoplatform that combines RNAi with chemotherapy for precise treatment of non-small cell lung cancer.

Sinomenine Inhibits Migration and Invasion of Human Lung Cancer Cell through Downregulating Expression of miR-21 and MMPs

Sinomenine is an alkaloid derived from Sinomenium acutum. Recent studies have found that sinomenine can inhibit various cancers by inhibiting the proliferation, migration and invasion of tumors and inducing apoptosis. This study aims to investigate the effect and mechanism of sinomenine on inhibiting the migration and invasion of human lung adenocarcinoma cells in vitro. The results demonstrate that viabilities of A549 and H1299 cells were inhibited by sinomenine in a dose-dependent manner. When treated with sub-toxic doses of sinomenine, cell migration and invasion are markedly suppressed. Sinomenine decreases the mRNA level of matrix metalloproteinase-2 (MMP-2), MMP-9, and the extracellular inducer of matrix metalloproteinase (EMMPRIN/CD147), but elevates the expression of reversion-inducing cysteine-rich proteins with kazal motifs (RECK) and the tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2. In addition, sinomenine significantly increases the expression of the epithelial marker E-cadherin but concomitantly decreases the expression of the mesenchymal marker vimentin, suggesting that it suppresses epithelial–mesenchymal transition (EMT). Moreover, sinomenine downregulates oncogenic microRNA-21 (miR-21), which has been known to target RECK. The downregulation of miR-21 decreases cell invasion, while the upregulation of miR-21 increases cell invasion. Furthermore, the downregulation of miR-21 stimulates the expression of RECK, TIMP-1/-2, and E-cadherin, but reduces the expression of MMP-2/-9, EMMPRIN/CD147, and vimentin. Taken together, the results reveal that the inhibition of A549 cell invasion by sinomenine may, at least in part, be through the downregulating expression of MMPs and miR-21. These findings demonstrate an attractive therapeutic potential for sinomenine in lung cancer anti-metastatic therapy.

A combination of bovine serum albumin with insulin-transferrin-sodium selenite and/or epidermal growth factor as alternatives to fetal bovine serum in culture medium improves bovine embryo quality and trophoblast invasion by induction of matrix metalloproteinases

This study investigated the use of bovine serum albumin (BSA) plus insulin-transferrin-sodium selenite (ITS) and/or epidermal growth factor (EGF) as alternatives to fetal bovine serum (FBS) in embryo culture medium. The developmental ability and quality of bovine embryos were determined by assessing their cell number, lipid content, gene expression and cryotolerance, as well as the invasion ability of trophoblasts. The percentage of embryos that underwent cleavage and formed a blastocyst was higher (P<0.01) in medium containing ITS plus EGF and BSA than in medium containing FBS. Culture with ITS plus EGF and BSA also increased the hatching ability of blastocysts and the total cell number per blastocyst. Furthermore, the beneficial effects of BAS plus ITS and EGF on embryos were associated with a significantly reduced intracellular lipid content, which increased their cryotolerance. An invasion assay confirmed that culture with ITS plus EGF and BSA significantly improved the invasion ability of trophoblasts. Real-time quantitative polymerase chain reaction analysis showed that the mRNA levels of matrix metalloproteinase-2 (MMP2) and MMP9, acyl-CoA synthetase long-chain family member 3, acyl-coenzyme A dehydrogenase long-chain and hydroxymethylglutaryl-CoA reductase significantly increased upon culture with ITS plus EGF and BSA. Moreover, protein expression levels of matrix metalloproteinase-2 and -9 increased (P<0.01) in medium supplemented with ITS plus EGF and BSA compared with medium supplemented with FBS. Taken together, these data suggest that supplementation of medium with ITS plus EGF and BSA improves invitro bovine embryo production, cryotolerance and invasion ability of trophoblasts.

TIMP-3 as a therapeutic target for cancer

Tissue inhibitor of metalloproteinase-3 (TIMP-3), a secreted glycoprotein, plays an important role in carcinogenesis. It can bind to many proteinases to suppress their activity and thus protect the extracellular matrix from degradation. TIMP-3 may have many anticancer properties, including apoptosis induction and antiproliferative, antiangiogenic, and antimetastatic activities. This review summarizes the structure, proteinase inhibition ability, genetic and epigenetic regulation, cancer therapy potential, and contribution to cancer development of TIMP-3. Furthermore, in this review we discuss its potential as a biomarker for predicting cancer progression and the current state of drugs that target TIMP-3, either alone or in combination with clinical treatment. In conclusion, TIMP-3 can be a biomarker of cancer and a potential target for cancer therapy. This review article can serve as a basis to understand how to modulate TIMP-3 levels as a drug target of cancers.

Multifunctional polymeric micelle-based chemo-immunotherapy with immune checkpoint blockade for efficient treatment of orthotopic and metastatic breast cancer

Immunotherapy has become a highly promising paradigm for cancer treatment. Herein, a chemo-immunotherapy was developed by encapsulating chemotherapeutic drug doxorubicin (DOX) and Toll-like receptor 7 agonist imiquimod (IMQ) in low molecular weight heparin (LMWH)-d-α-tocopheryl succinate (TOS) micelles (LT). In this process, LMWH and TOS were conjugated by ester bond and they were not only served as the hydrophilic and hydrophobic segments of the carrier, but also exhibited strong anti-metastasis effect. The direct killing of tumor cells mediated by DOX-loaded micelles (LT-DOX) generated tumor-associated antigens, initiating tumor-specific immune responses in combination with IMQ-loaded micelles (LT-IMQ). Furthermore, the blockade of immune checkpoint with programmed cell death ligand 1 (PD-L1) antibody further elevated the immune responses by up-regulating the maturation of DCs as well as the ratios of CD8+ CTLs/Treg and CD4+ Teff/Treg. Therefore, such a multifunctional strategy exhibited great potential for inhibiting the growth of orthotopic and metastatic breast cancer.

Enhanced Melanoma-Targeted Therapy by "Fru-Blocked" Phenyboronic Acid-Modified Multiphase Antimetastatic Micellar Nanoparticles

Metastasis remains the main driver of mortality in patients suffering from cancer because of the refractoriness resulting from the multi-phase metastatic cascade. Herein, a multifunctional self-delivering PBA-LMWH-TOS nanoparticle (PLT NP) is established that acts as both nanocarrier and anti-metastatic agent with effects on most hematogenous metastases of cancers. The hydrophilic segment (low molecular weight heparin, LMWH) inhibits the interactions between tumor cells and platelets. The hydrophobic segment (d-α-tocopheryl succinate, TOS) could inhibit the expression of matrix metalloproteinase-9 (MMP-9) in B16F10 cells which is first reported in this article. Surprisingly, even the blank NPs showed excellent anti-metastatic capacity in three mouse models by acting on different phases of the metastatic cascade. Moreover, the overexpression of sialic acid (SA) residues on tumor cells is implicated in the malignant and metastatic phenotypes of cancers. Thus, these 3-aminophenylboronic acid (PBA)-modified doxorubicin (DOX)-loaded NPs offer an efficient approach for the treatment of both solid melanomas and metastases. Furthermore, a simple pH-sensitive "Fructose (Fru)-blocking" coping strategy is established to reduce the NP distribution in normal tissues and distinctly increases the accumulation in melanoma tumors. These micellar NPs consisting of biocompatible materials offer a promising approach for the clinical therapy of highly invasive solid tumors and metastases.

STEAP1 Inhibits Breast Cancer Metastasis and Is Associated With Epithelial-Mesenchymal Transition Procession

PURPOSE

Six-transmembrane epithelial antigen of prostate 1 (STEAP1) is a cell surface antigen overexpressed in multiple cancers and is associated with malignancy and disease prognosis. The aims of this study were to evaluate STEAP1 expression in breast cancer and to determine the mechanisms involved.

METHODS

STEAP1 expression was compared in normal breast tissue (n = 40), benign fibroadenoma (n = 52), and primary breast cancer (n = 211) using immunohistochemistry. Quantitative real-time polymerase chain reaction, Western blot analysis, and immunocytochemistry were used to evaluate STEAP1 expression in 3 breast cancer cell lines and in a normal mammary epithelial cell line. STEAP1 expression and its prognostic value in breast cancer were verified using the Oncomine and Kaplan-Meier Plotter databases. Transfection of cells to up-regulate or knock down STEAP1 expression was used to determine the effect of STEAP1 on cell invasion and proliferation, and to evaluate its relationship to epithelial-mesenchymal transition (EMT) progression.

RESULTS

STEAP1 expression was lower in breast cancers cells, and low expression was associated with a malignant phenotype and poor prognosis. Analysis of public databases supported our conclusions. Knockdown of STEAP1 expression enhanced cellular invasion and migration abilities, increased expression of EMT-related genes MMP2, MMP9, MMP13, VIM, and CDH2, and decreased CDH1 expression. Enhanced STEAP1 expression significantly inhibited cellular invasion and migration abilities, decreased expression of the EMT-related genes, and increased CDH1 expression. Up-regulation or knockdown of STEAP1 had little effect on cellular proliferation.

CONCLUSION

STEAP1 was down-regulated in breast cancer, inhibited metastasis of breast cancer, and hampered the levels of EMT markers, which thus implicated STEAP1 in the suppression of EMT.

Exocellular extract of Fusarium oxysporum, fungus free, is able to permeate and act selectively in skin

The skin is an important gateway for Fusarium infection in humans. Our hypothesis is that metabolites produced by Fusarium oxysporum should change the barrier structure to permeate the skin. Male Wistar rats received a topical application of a solution (0.05 mg/mL) of Fusarium metabolites. The animals were euthanized 3, 6, 12, 24 h after and the skin was processed for immunostaining by laminin and E-cadherin to investigate whether the Fusarium metabolites can break the barrier of healthy skin. Other techniques were employed: H&E to study the morphology; metalloproteinase-9 (MMP-9), TUNEL, and PCNA immunostaining to evaluate the inflammation, cell death, and proliferation, respectively. There was an inflammatory response mainly centered in the dermis. Qualitatively, the skin of the experimental group showed reduced E-cadherin and laminin immunostaining at 3, 12, and 24 h. Higher intensity staining by TUNEL at 3 h, and PCNA at 6, 12, and 24 h. There was intense MMP-9 activity at 6, 12, and 24 h. None of analyses revealed any changes in the epidermis. It was concluded that the fraction was able to permeate the skin and act selectively in dermis, inducing inflammatory response, increasing MMP-9 immunostaining, inducing apoptosis, and reducing E-cadherin and laminin immunostaining.

Hinokitiol Inhibits Migration of A549 Lung Cancer Cells via Suppression of MMPs and Induction of Antioxidant Enzymes and Apoptosis

Hinokitiol, a natural monoterpenoid from the heartwood of Calocedrus formosana, has been reported to have anticancer effects against various cancer cell lines. However, the detailed molecular mechanisms and the inhibiting roles of hinokitiol on adenocarcinoma A549 cells remain to be fully elucidated. Thus, the current study was designed to evaluate the effect of hinokitiol on the migration of human lung adenocarcinoma A549 cells in vitro. The data demonstrates that hinokitiol does not effectively inhibit the viability of A549 cells at up to a 10 µM concentration. When treated with non-toxic doses (1–5 µM) of hinokitiol, the cell migration is markedly suppressed at 5 µM. Hinokitiol significantly reduced p53 expression, followed by attenuation of Bax in A549 cells. A dose-dependent inhibition of activated caspase-9 and -3 was observed in the presence of hinokitiol. An observed increase in protein expression of matrix metalloproteinases (MMPs) -2/-9 in A549 cells was significantly inhibited by hinokitiol. Remarkably, when A549 cells were subjected to hinokitiol (1–5 µM), there was an increase in the activities of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) from the reduction in cells. In addition, the incubation of A549 cells with hinokitiol significantly activated the cytochrome c expression, which may be triggered by activation of caspase-9 followed by caspase-3. These observations indicate that hinokitiol inhibited the migration of lung cancer A549 cells through several mechanisms, including the activation of caspases-9 and -3, induction of p53/Bax and antioxidant CAT and SOD, and reduction of MMP-2 and -9 activities. It also induces cytochrome c expression. These findings demonstrate a new therapeutic potential for hinokitiol in lung cancer chemoprevention.

Prognostic Significance of the Combined Expression of Matrix Metalloproteinase-9, Urokinase Type Plasminogen Activator and its Receptor in Breast Cancer as Measured by Northern Blot Analysis

Using Northern blot analysis we have measured the co-expression of the matrix metalloprotease MMP-9, plasminogen activator urokinase type (uPA) and its receptor (uPAR) mRNAs in 81 biopsies of breast carcinomas with the objective of analyzing the impact of these factors on the overall survival probability of the patients (median follow-up time: 4 years). Individual mRNA levels of either uPA or uPAR showed parallel variations with MMP-9 mRNA, suggesting a coordinate transcription of these markers. When median values were used as cutoff points to discriminate between high and low factor expression, no association was found with patient outcome and MMP-9 or uPA mRNA distribution. However, increased uPAR mRNA levels were associated with poor prognosis (p = 0.01). The combination of MMP-9 and uPAR mRNA measurements has not enhanced prognostic information compared to information supplied by the receptor alone (p = 0.01). The combination of MMP-9 and high levels of uPA mRNA led to a significant association with poor outcome (p = 0.03). Multivariate analysis supported the notion that increased uPAR mRNA production in primary breast cancer may be a predictor of overall survival.

Imbalance between matrix metalloproteinases and their tissue inhibitors in preeclampsia and gestational trophoblastic diseases

The invasion cascade exhibited by placental trophoblasts and cancerous cells bears many similarities, and it is attributed to extracellular matrix degradation mediated by matrix metalloproteinases (MMPs). Although proper and controlled invasion by trophoblasts into the maternal uterus is an essential requirement for maintenance of normal pregnancy, any abnormality in this phenomenon results in the development of invasion-related disorders such as gestational trophoblastic diseases (GTDs) and preeclampsia. We studied the epigenetic basis of differential expression of two placental MMPs (MMP2 and MMP9) and tissue inhibitors of metalloproteinases (TIMP2 and TIMP1) during normal gestation and invasion-related disorders, i.e., preeclampsia and GTDs. Our study suggests the association of H3K9/27me3 with differential expression of these MMPs and their inhibitors, which regulate the placental invasion during normal pregnancy, whereas no role of CpG methylation was observed in the differential expression of MMPs/TIMPs. Further, development of GTDs was associated with abnormally higher expression of these MMPs and lower levels of their inhibitors, whereas the reverse trends were observed for MMPs and their TIMPs in case of preeclampsia, in association with abnormal changes in H3K9/27me3. These results suggest the involvement of higher levels of MMPs in an aggressive invasive behavior depicted by GTDs, whereas lower levels of these MMPs in shallow and poor invasive phenotype associated with preeclampsia. Thus, our study shows the significance of a proper balance regulated by histone trimethylation between differential expression of MMPs and their TIMPs for maintaining normal pregnancy and its deregulation as a contributing factor for pathogenesis of invasive disorders during pregnancy.

Re-evaluating the role of epithelial-mesenchymal-transition in cancer progression

Epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) are essential for embryonic development and also important in cancer progression. In a conventional model, epithelial-like cancer cells transit to mesenchymal-like tumor cells with great motility via EMT transcription factors; these mesenchymal-like cells migrate through the circulation system, relocate to a suitable site and then convert back to an epithelial-like phenotype to regenerate the tumor. However, recent findings challenge this conventional model and support the existence of a stable hybrid epithelial/mesenchymal (E/M) tumor population. Hybrid E/M tumor cells exhibit both epithelial and mesenchymal properties, possess great metastatic and tumorigenic capacity and are associated with poorer patient prognosis. The hybrid E/M model and associated regulatory networks represent a conceptual change regarding tumor metastasis and organ colonization. It may lead to the development of novel treatment strategies to ultimately stop cancer progression and improve disease-free survival.

Evidence for participation of neutrophil gelatinase-associated lipocalin/matrix metalloproteinase-9 (NGAL•MMP-9) complex in the inflammatory response to infection in pregnancies complicated by preterm birth

PROBLEM

Neutrophil gelatinase-associated lipocalin (NGAL) is expressed in neutrophils and involved in innate immunity by sequestering iron. NGAL's ability to complex with matrix metalloproteinase-9 (MMP-9) and extend its gelatinolytic activity led us to investigate its role in pregnancies complicated by preterm birth (PTB) and intra-amniotic infection/inflammation (IAI).

METHOD OF STUDY

We assayed the amniotic fluid (AF) levels of NGAL and MMP-9 in 308 women that had a clinically indicated amniocentesis and a normal pregnancy outcome or PTB. qRT-PCR was employed to determine NGAL mRNA expression of placental villous trophoblast and amniochorion. Immunohistochemistry was used for cellular localization.

RESULTS

AF NGAL levels were gestational age-regulated. Women with IAI and PTB had significantly higher levels of NGAL, MMP-9 and NGAL•MMP-9 complex.

CONCLUSION

The amniochorion is a source of NGAL and similarly to other inflammatory conditions, this protein may augment the collagenolytic effect of MMP-9 and modulate host-microbe interactions in pregnancies complicated by IAI.

Chloride intracellular channel 1 regulates migration and invasion in gastric cancer by triggering the ROS-mediated p38 MAPK signaling pathway

Chloride intracellular channel 1 (CLIC1) has been demonstrated to be overexpressed in gastric cancer, and elevated CLIC1 expression levels are markedly associated with the processes of tumor cell migration and invasion. However, the regulatory mechanism and signaling pathway underlying these processes have remained to be elucidated. The present study examined the impact of N-acetyl cysteine (NAC), indanyloxyacetic acid (IAA)-94 and SB203580, inhibitors of reactive oxygen species (ROS), as well as CLIC1 and p38 mitogen-activated protein kinase (MAPK) on the migration and invasion of SGC-7901 gastric cancer cells in a hypoxia-reoxygenation (H-R) microenvironment. The results demonstrated that intracellular ROS and CLIC1 levels were increased under H-R conditions, and that functional inhibition of CLIC1 significantly decreased the H-R-elevated ROS generation and p-p38 MAPK levels in SGC-7901 cells, as well as inhibited the migration and invasion of SGC-7901 cells. In addition, the expression levels of MMP-2 and MMP-9 were inhibited by NAC, IAA-94 and SB203580. These results indicated that CLIC1 regulates gastric cancer-cell migration and invasion via the ROS-mediated p38 MAPK signaling pathway.

Continuous activation of Nrf2 and its target antioxidant enzymes leads to arsenite-induced malignant transformation of human bronchial epithelial cells

Long-term exposure to arsenite leads to human lung cancer, but the underlying mechanisms of carcinogenesis remain obscure. The transcription factor of nuclear factor-erythroid-2 p45-related factor (Nrf2)-mediated antioxidant response represents a critical cellular defense mechanism and protection against various diseases. Paradoxically, emerging data suggest that the constitutive activation of Nrf2 is associated with cancer development, progression and chemotherapy resistance. However, the role of Nrf2 in the occurrence of cancer induced by long-term arsenite exposure remains to be fully understood. By establishing transformed human bronchial epithelial (HBE) cells via chronic low-dose arsenite treatment, we showed that, in acquiring this malignant phenotype, continuous low level of ROS and sustained enhancement of Nrf2 and its target antioxidant enzyme levels were observed in the later-stage of arsenite-induced cell transformation. The downregulation of Keap1 level may be responsible for the over-activation of Nrf2 and its target enzymes. To validate these observations, Nrf2 was knocked down in arsenite-transformed HBE cells by SiRNA transfection, and the levels of Nrf2 and its target antioxidant enzymes, ROS, cell proliferation, migration, and colony formation were determined following these treatments. Results showed that blocked Nrf2 expression significantly reduced Nrf2 and its target antioxidant enzyme levels, restored ROS levels, and eventually suppressed cell proliferation, migration, and colony formation of the transformed cells. In summary, the results of the study strongly suggested that the continuous activation of Nrf2 and its target antioxidant enzymes led to the over-depletion of intracellular ROS levels, which contributed to arsenite-induced HBE cell transformation.

Physiological, pathological, and structural implications of non-enzymatic protein-protein interactions of the multifunctional human transglutaminase 2

Transglutaminase 2 (TG2) is a ubiquitously expressed member of an enzyme family catalyzing Ca(2+)-dependent transamidation of proteins. It is a multifunctional protein having several well-defined enzymatic (GTP binding and hydrolysis, protein disulfide isomerase, and protein kinase activities) and non-enzymatic (multiple interactions in protein scaffolds) functions. Unlike its enzymatic interactions, the significance of TG2's non-enzymatic regulation of its activities has recently gained importance. In this review, we summarize all the partners that directly interact with TG2 in a non-enzymatic manner and analyze how these interactions could modulate the crosslinking activity and cellular functions of TG2 in different cell compartments. We have found that TG2 mostly acts as a scaffold to bridge various proteins, leading to different functional outcomes. We have also studied how specific structural features, such as intrinsically disordered regions and embedded short linear motifs contribute to multifunctionality of TG2. Conformational diversity of intrinsically disordered regions enables them to interact with multiple partners, which can result in different biological outcomes. Indeed, ID regions in TG2 were identified in functionally relevant locations, indicating that they could facilitate conformational transitions towards the catalytically competent form. We reason that these structural features contribute to modulating the physiological and pathological functions of TG2 and could provide a new direction for detecting unique regulatory partners. Additionally, we have assembled all known anti-TG2 antibodies and have discussed their significance as a toolbox for identifying and confirming novel TG2 regulatory functions.

Phyllanthus spp. Exerts Anti-Angiogenic and Anti-Metastatic Effects Through Inhibition on Matrix Metalloproteinase Enzymes

Tumor angiogenesis and metastasis are the major causes for high morbidity and mortality rates in cancer patient. Modulation on tumor angiogenesis and metastasis provides opportunities to halt progression of cancer. From our previous findings, Phyllanthus plant possesses antiproliferative effects on melanoma and prostate cancer cell lines and induction of apoptosis. The main aims of the present work were further investigated on the antimetastatic and antiangiogenic effects on cancer cells (MeWo and PC-3) and human umbilical vein endothelial cells (HUVECs) of 4 Phyllanthus species (P.amarus, P.niruri, P.urinaria and P.watsonii). Phyllanthus extracts significantly inhibited cell adhesion, migration, invasion, and transendothelial migration activities of cancer (MeWo and PC-3) cells in a dose-dependent manner (P < 0.05) by cell-matrix adhesion, Transwell migration, invasion, and transendothelial migration assays. Phyllanthus extracts were exhibited low cytotoxicity on HUVECs up to a concentration of 500.0 μg/ml by MTS reduction assay. Phyllanthus extracts also exhibited antiangiogenic effects through inhibition of migration, invasion, and microcapillary like-tube structure formation in HUVECs. These observations were due to alteration in activities of matrix metalloproteinase (MMP) -2, -7, -9, and -26 in treated-endothelial and cancer cells by zymographies. These findings suggest that Phyllanthus plant has the potential to inhibit tumour metastasis and angiogenesis through the suppression of MMP enzymes.

Bone morphogenetic protein 4 (BMP-4) and epidermal growth factor (EGF) inhibit metalloproteinase-9 (MMP-9) expression in cancer cells

Matrix metalloproteinase-9 (MMP-9) plays a central role in the progression of the cancer. While a large number of studies have contributed to our understanding of the molecular mechanisms responsible for upregulating MMP-9 gene expression in normal and cancer cells, our knowledge on the signals that suppress MMP-9 expression is much more limited. Here, we report that EGF and BMP-4 cooperate to inhibit MMP-9 expression in cancer cells. Treatment with EGF reduces the expression of MMP-9 at both mRNA while augmenting BMP-4 expression. Interestingly, recombinant BMP-4 suppressed constitutive and PMA-induced MMP-9 expression in both fibrosarcoma and breast cancer cells. Addition of gremlin a natural inhibitor of BMP-4, inhibited the suppression of MMP-9 by EGF. The suppression of MMP-9 by BMP-4 likely occurs at the transcriptional level since BMP-4 suppressed MMP-9 mRNA expression and activation of a reporter vector encoding the human MMP-9 promoter. The suppressive effect of BMP-4 occurs via Smad1/5/8 and is specific since BMP-4 did not inhibit MMP-2 while BMP-2 was ineffective in suppressing MMP-9. Taken together, these results are consistent with a new paradigm for the role of EGF and BMPs in controlling MMP gene expression in cancer cells.

miR-663 attenuates tumor growth and invasiveness by targeting eEF1A2 in pancreatic cancer

Background

miR-663 is associated with many important biologic processes, such as the evolution, development, viral infection, inflammatory response, and carcinogenesis among vertebrates. However, the molecular function and mechanism of miR-663 in pancreatic cancer growth and invasion is still unclear.

Methods

Western blot and real-time PCR were used to study the expression level of eEF1A2 protein and miR-663 in pancreatic cancer tissues and cell lines. The Pearson χ² test was used to determine the correlation between miR-663 expression and clinicopathologic features of patients. Patients’ survival was analyzed using the Kaplan–Meier method, using the log-rank test for comparison. The biological function of miR-663 was examined by measuring cell growth, cell invasion and apoptosis analysis in vitro and in vivo. miR-663 target gene and signaling pathway was identified by luciferase activity assay and western blot.

Results

We found that, in pancreatic cancer, eEF1A2 was significantly upregulated but miR-663 was significantly downregulated. Further results showed that the expression level of eEF1A2 and miR-663 was strongly associated with TNM stage and node metastasis status of the patients. miR-663 and eEF1A2 were inversely correlated with each other, and the changes in the expression levels of each can also predict the survival of patients with pancreatic cancer. We identified miR-663 as a tumor attenuate molecular that attenuated the proliferation and invasion of pancreatic cancer cells both in vitro and in vivo. Finally, we confirmed that the expression of eEF1A2 can partially restore the pro-apoptotic and anti-invasion functions of miR-663.

Conclusions

miR-663 attenuated the proliferation and invasion of pancreatic cells both in vitro and in vivo by directly targeting eEF1A2. miR-663 and eEF1A2 might be potential targets for the treatment of pancreatic cancer in the future.

Functional and molecular characterisation of EO771.LMB tumours, a new C57BL/6-mouse-derived model of spontaneously metastatic mammary cancer

The translation of basic research into improved therapies for breast cancer patients requires relevant preclinical models that incorporate spontaneous metastasis. We have completed a functional and molecular characterisation of a new isogenic C57BL/6 mouse model of breast cancer metastasis, comparing and contrasting it with the established BALB/c 4T1 model. Metastatic EO771.LMB tumours were derived from poorly metastatic parental EO771 mammary tumours. Functional differences were evaluated using both in vitro assays and spontaneous metastasis assays in mice. Results were compared to non-metastatic 67NR and metastatic 4T1.2 tumours of the 4T1 model. Protein and transcript levels of markers of human breast cancer molecular subtypes were measured in the four tumour lines, as well as p53 (Tp53) tumour-suppressor gene status and responses to tamoxifen in vivo and in vitro. Array-based expression profiling of whole tumours identified genes and pathways that were deregulated in metastatic tumours. EO771.LMB cells metastasised spontaneously to lung in C57BL/6 mice and displayed increased invasive capacity compared with parental EO771. By immunohistochemical assessment, EO771 and EO771.LMB were basal-like, as was the 4T1.2 tumour, whereas 67NR had a luminal phenotype. Primary tumours from all lines were negative for progesterone receptor, Erb-b2/Neu and cytokeratin 5/6, but positive for epidermal growth factor receptor (EGFR). Only 67NR displayed nuclear estrogen receptor alpha (ERα) positivity. EO771 and EO771.LMB expressed mutant p53, whereas 67NR and 4T1.2 were p53-null. Integrated molecular analysis of both the EO771/EO771.LMB and 67NR/4T1.2 pairs indicated that upregulation of matrix metalloproteinase-3 (MMP-3), parathyroid hormone-like hormone (Pthlh) and S100 calcium binding protein A8 (S100a8) and downregulation of the thrombospondin receptor (Cd36) might be causally involved in metastatic dissemination of breast cancer.

Effects of ubiquitin-conjugating enzyme 2C on invasion, proliferation and cell cycling of lung cancer cells

The aims of this study were to investigate the influence of ubiquitin- conjugating enzyme E2C (UBE2C) on biological behavior of lung cancer cells. Using MTT, flow cytometry and invasion assays, we detected UBE2C expression and evaluated its biological properties in these cells, including effects on proliferation, the cell cycle profile and invasive capability. Compared with control cells, the UBE2C transfected cells demonstrated increased cellular proliferation (p<0.05). UBE2C transfected cells also had a lower percentage in G1 phase and a higher percentage in S phase (p<0.05). Importantly, the UBE2C transfected cells had a notable enhancement of cell numbers penetrating the basement membrane compared with the control group (p<0.05). Ectopic up- regulation UBE2C promoted the growth of lung cancer cells in vivo. Furthermore, we found UBE2C increased the expression of cyclin D1 and MMP-2. These results show UBE2C may represent a potential therapeutic target for lung cancer.

Antimetastatic and anti-inflammatory potentials of essential oil from edible Ocimum sanctum leaves

Antimetastatic and anti-inflammatory activities of Ocimum sanctum essential oil (OSEO) have been assessed in this study. OSEO at the concentration of 250 μg/mL and above showed a significant (^*P < 0.05) decrease in the number of migrated cancer cells. In addition, OSEO at concentration of 250 μg/mL and above suppressed MMP-9 activity in lipopolysaccharide (LPS) induced inflammatory cells. A dose-dependent downregulation of MMP-9 expression was observed with the treatment of OSEO compared to the control. Our findings indicate that OSEO has both antimetastatic and anti-inflammatory potentials, advocating further investigation for clinical applications in the treatment of inflammation associated cancer.

HDAC-inhibitor (S)-8 disrupts HDAC6-PP1 complex prompting A375 melanoma cell growth arrest and apoptosis

Histone deacetylase inhibitors (HDACi) are agents capable of inducing growth arrest and apoptosis in different tumour cell types. Previously, we reported a series of novel HDACi obtained by hybridizing SAHA or oxamflatin with 1,4-benzodiazepines. Some of these hybrids proved effective against haematological and solid cancer cells and, above all, compound (S)-8 has emerged for its activities in various biological systems. Here, we describe the effectiveness of (S)-8 against highly metastatic human A375 melanoma cells by using normal PIG1 melanocytes as control. (S)-8 prompted: acetylation of histones H3/H4 and α-tubulin; G₀/G₁ and G₂/M cell cycle arrest by rising p21 and hypophos-phorylated RB levels; apoptosis involving the cleavage of PARP and caspase 9, BAD protein augmentation and cytochrome c release; decrease in cell motility, invasiveness and pro-angiogenic potential as shown by results of wound-healing assay, down-regulation of MMP-2 and VEGF-A/VEGF-R2, besides TIMP-1/TIMP-2 up-regulation; and also intracellular accumulation of melanin and neutral lipids. The pan-caspase inhibitor Z-VAD-fmk, but not the antioxidant N-acetyl-cysteine, contrasted these events. Mechanistically, (S)-8 allows the disruption of cytoplasmic HDAC6-protein phosphatase 1 (PP1) complex in A375 cells thus releasing the active PP1 that dephosphorylates AKT and blocks its downstream pro-survival signalling. This view is consistent with results obtained by: inhibiting PP1 with Calyculin A; using PPP1R2-transfected cells with impaired PP1 activity; monitoring drug-induced HDAC6-PP1 complex re-shuffling; and, abrogating HDAC6 expression with specific siRNA. Altogether, (S)-8 proved very effective against melanoma A375 cells, but not normal melanocytes, and safe to normal mice thus offering attractive clinical prospects for treating this aggressive malignancy.

Phosphatidylinositol 3-kinase mediates the ability of retinol to decrease colorectal cancer cell invasion

Previously, we showed that retinol (vitamin A) decreased both colorectal cancer cell invasion and phosphatidylinositol 3-kinase (PI3K) activity through a retinoic acid receptor-independent mechanism. Here, we determined if these phenomena were related by using parental HCT-116 cells that harbor 1 allele of wild-type PI3K and 1 allele of constitutively active (ca) PI3K and 2 mutant HCT-116 cell lines homozygous for caPI3K. In vitro, treatment of parental HCT-116 cells with 10 μM retinol reduced cell invasion whereas treatment of mutant HCT-116 cell lines with retinol did not. Treatment with 10 μM retinol also decreased the activity of matrixmetalloproteinase-9 and increased tissue inhibitor of matrixmetalloproteinase-I levels in parental, but not mutant, HCT-116 cells. Finally, parental or mutant cells were intrasplenically injected into athymic mice consuming diets with or without supplemental vitamin A. As expected, vitamin A supplementation tended (P = 0.18) to reduce the incidence of metastases in mice injected with the parental cell line and consuming the supplemented diet. In contrast, metastatic incidence was not affected (P = 1.00) by vitamin A supplementation in mice injected with mutant cells. These data indicate that the capacity of retinol to inhibit PI3K activity confers its ability to decrease colorectal cancer metastasis.

α-Solanine inhibits invasion of human prostate cancer cell by suppressing epithelial-mesenchymal transition and MMPs expression

α-Solanine, a naturally occurring steroidal glycoalkaloid found in nightshade (Solanum nigrum Linn.), was found to inhibit proliferation and induce apoptosis of tumor cells. However, the mechanism involved in suppression of cancer cell metastasis by α-solanine remains unclear. This study investigates the suppression mechanism of α-solanine on motility of the human prostate cancer cell PC-3. Results show that α-solanine reduces the viability of PC-3 cells. When treated with non-toxic doses of α-solanine, cell invasion is markedly suppressed by α-solanine. α-Solanine also significantly elevates epithelial marker E-cadherin expression, while it concomitantly decreases mesenchymal marker vimentin expression, suggesting it suppresses epithelial-mesenchymal transition (EMT). α-Solanine reduces the mRNA level of matrix metalloproteinase-2 (MMP-2), MMP-9 and extracellular inducer of matrix metalloproteinase (EMMPRIN), but increases the expression of reversion-inducing cysteine-rich protein with kazal motifs (RECK), and tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2. Immunoblotting assays indicate α-solanine is effective in suppressing the phosphorylation of phosphatidylinositide-3 kinase (PI3K), Akt and ERK. Moreover, α-solanine downregulates oncogenic microRNA-21 (miR-21) and upregulates tumor suppressor miR-138 expression. Taken together, the results suggest that inhibition of PC-3 cell invasion by α-solanine may be, at least in part, through blocking EMT and MMPs expression. α-Solanine also reduces ERK and PI3K/Akt signaling pathways and regulates expression of miR-21 and miR-138. These findings suggest an attractive therapeutic potential of α-solanine for suppressing invasion of prostate cancer cell.

Upregulation of adenylate cyclase 3 (ADCY3) increases the tumorigenic potential of cells by activating the CREB pathway

Adenylate cyclase 3 (ADCY3) is a widely expressed membrane-associated protein in human tissues, which catalyzes the formation of cyclic adenosine-3′,5′-monophosphate (cAMP). However, our transcriptome analysis of gastric cancer tissue samples (NCBI GEO GSE30727) revealed that ADCY3 expression was specifically altered in cancer samples. Here we investigated the tumor-promoting effects of ADCY3 overexpression and confirmed a significant correlation between the upregulation of ADCY3 and Lauren's intestinal-type gastric cancers. ADCY3 overexpression increased cell migration, invasion, proliferation, and clonogenicity in HEK293 cells; conversely, silencing ADCY3 expression in SNU-216 cells reduced these phenotypes. Interestingly, ADCY3 overexpression increased both the mRNA level and activity of matrix metalloproteinase 2 (MMP2) and MMP9 by increasing the levels of cAMP and phosphorylated cAMP-responsive element-binding protein (CREB). Consistent with these findings, treatment with a protein kinase A (PKA) inhibitor decreased MMP2 and MMP9 expression levels in ADCY3-overexpressing cells. Knockdown of ADCY3 expression by stable shRNA in human gastric cancer cells suppressed tumor growth in a tumor xenograft model. Thus, ADCY3 overexpression may exert its tumor-promoting effects via the cAMP/PKA/CREB pathway. Additionally, bisulfite sequencing of the ADCY3 promoter region revealed that gene expression was reduced by hypermethylation of CpG sites, and increased by 5-Aza-2′-deoxycytidine (5-Aza-dC)-induced demethylation. Our study is the first to report an association of ADCY3 with gastric cancer as well as its tumorigenic potentials. In addition, we demonstrate that the expression of ADCY3 is regulated through an epigenetic mechanism. Further study on the mechanism of ADCY3 in tumorigenesis will provide the basis as a new molecular target of gastric cancer.

37-kDa laminin receptor precursor promotes lung adenocarcinoma cell invasion and metastasis by epithelial-to-mesenchymal transition

37-kDa laminin receptor precursor (37LRP) has a crucial role in migration of some human cancers. Epithelial-to-mesenchymal transition (EMT) has received much attention in invasion and metastasis of lung cancer. Nevertheless, the role of 37LRP is not entirely clear in EMT promotion of lung cancer at present. In this study, we firstly examined the possible role of 37LRP in the invasiveness and metastasis process of lung cancer using immunohistochemistry of 80 lung adenocarcinoma cases, western blot and real-time PCR of 12 fresh lung adenocarcinoma tissues. The results showed that 37LRP significantly correlated with clinical stage and were highly expressed in metastatic lung adenocarcinomas compared with nonmetastatic ones. In vitro, we observed that 37LRP significantly increased the adhesive, invasive and metastatic abilities of human lung adenocarcinoma cell lines A549 by 37LRP-lentivirus interference. Furthermore, inoculation of A549 cells transduced with 37LRP-lentivirus in nude mice resulted in multi-metastases including the lung. In addition, western blotting and immunofluorescence were used to detect the significant difference in expression of E-cadherin and fibronectin in A549 by 37LRP-lentivirus interference compared with 37LRP-small interference RNA-lentivirus interference in vitro and vivo. The data indicated that A549 cells of epithelial cell characteristics might be induced to undergo EMT by 37LRP. A549 cells transduced with 37LRP-lentivirus showed marked morphological changes, accompanied by the decrease of epithelial marker E-cadherin and the increase of mesenchymal marker fibronectin. These results indicated that 37LRP may promote lung adenocarcinoma invasion and metastasis via the mechanism of EMT.

Gelatinase B/MMP-9 in Tumour Pathogenesis and Progression

Since its original identification as a leukocyte gelatinase/type V collagenase and tumour type IV collagenase, gelatinase B/matrix metalloproteinase (MMP)-9 is now recognised as playing a central role in many aspects of tumour progression. In this review, we relate current concepts concerning the many ways in which gelatinase B/MMP-9 influences tumour biology. Following a brief outline of the gelatinase B/MMP-9 gene and protein, we analyse the role(s) of gelatinase B/MMP-9 in different phases of the tumorigenic process, and compare the importance of gelatinase B/MMP-9 source in the carcinogenic process. What becomes apparent is the importance of inflammatory cell-derived gelatinase B/MMP-9 in tumour promotion, early progression and triggering of the "angiogenic switch", the integral relationship between inflammatory, stromal and tumour components with respect to gelatinase B/MMP-9 production and activation, and the fundamental role for gelatinase B/MMP-9 in the formation and maintenance of tumour stem cell and metastatic niches. It is also apparent that gelatinase B/MMP-9 plays important tumour suppressing functions, producing endogenous angiogenesis inhibitors, promoting inflammatory anti-tumour activity, and inducing apoptosis. The fundamental roles of gelatinase B/MMP-9 in cancer biology underpins the need for specific therapeutic inhibitors of gelatinase B/MMP-9 function, the use of which must take into account and substitute for tumour-suppressing gelatinase B/MMP-9 activity and also limit inhibition of physiological gelatinase B/MMP-9 function.

Romidepsin induces cell cycle arrest, apoptosis, histone hyperacetylation and reduces matrix metalloproteinases 2 and 9 expression in bortezomib sensitized non-small cell lung cancer cells

Histone deacetylase (HDAC) inhibitors have been proven to be effective therapeutic agents to kill cancer cells through inhibiting HDAC activity or altering the structure of chromatin. We recently reported that chemotherapy by the HDAC inhibitor, romidepsin activates the anti- apoptotic transcription factor NF-κB in A549 non-small cell lung cancer (NSCLC) cells and fails to induce significant levels of apoptosis. We also demonstrated that NF-κB inhibition with proteasome inhibitor bortezomib enhanced HDAC inhibitor induced mitochondrial injury and sensitize A549 NSCLC cells to apoptosis through the generation of reactive oxygen species. In this study, we investigate whether combined treatment with romidepsin and bortezomib would induce apoptosis in A549 NSCLC cells by activating cell cycle arrest, enhanced generation of p21 and p53, down-regulation of matrix metalloproteinases (MMPs) 2,9 also altering the acetylation status of histone proteins. Our data show that combination of romidepsin and bortezomib caused cell cycle arrest at Sub G0-G1 transition, up-regulation of cell cycle protein p21 and tumour suppressor protein p53. In addition, romidepsin down-regulated the expression of MMP-2,9 and hyperacetylation of histone H3 and H4 in bortezomib sensitised A549 NSCLC cells. From this study we concluded that romidepsin and bortezomib cooperatively inhibit A549 NSCLC cell proliferation by altering the histone acetylation status, expression of cell cycle regulators and MMPs. Romidepsin along with bortezomib might be an effective treatment approach for A549 NSCLC cells.

Levels of vascular endothelial growth factor and matrix metalloproteinase-9 proteins in patients with glioma

OBJECTIVE

To investigate the levels of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) proteins in patients with glioma, in order to determine if either protein has prognostic value.

METHOD

The presence of VEGF and MMP-9 proteins in paraffin-embedded tumour specimens from patients with glioma was detected using immunohistochemistry. The correlation between the levels of VEGF and MMP-9 proteins and tumour grade was analysed.

RESULTS

A total of 32 patients with low-grade gliomas (World Health Organization [WHO] grade II) and 48 patients with high-grade gliomas (WHO grades III-IV) participated in the study. Positive immunohistochemical staining of VEGF and MMP-9 proteins was detected in 58/80 (72.5%) and 60/80 (75.0%) of patients, respectively. The level of VEGF immunostaining was significantly positively correlated with the level of MMP-9 immunostaining (r = 0.78). Significantly more high-grade gliomas (grades III-IV) demonstrated positive VEGF and MMP-9 immunostaining compared with the low grade gliomas (grades I-II).

CONCLUSIONS

These data suggest that VEGF and MMP-9 play an important role in the malignant behaviour of gliomas.

Discovery of potent inhibitor for matrix metalloproteinase-9 by pharmacophore based modeling and dynamics simulation studies

Matrix metalloproteinase-9 (MMP-9) is an attractive target for anticancer therapy. In the present study ligand based pharmacophore modeling was performed to elucidate the structural elements for a diverse class of MMP-9 inhibitors. The pharmacophore model was validated through Güner-Henry (GH) scoring method. The final pharmacophore model consisted of three hydrogen bond acceptors (HBA), and two ring aromatic regions (RA). This model was utilized to screen the natural compound database to seek novel compounds as MMP-9 inhibitors. The identified hits were validated using molecular docking and molecular dynamics simulation studies. Finally, one compound named Hinokiflavone from Juniperus communis had high binding free energy of -26.54kJ/mol compared with the known inhibitors of MMP-9. Cytotoxicity for hinokiflavone was evaluated by MTT assay. Inhibition of MMP-9 in the presence of hinokiflavone was detected by gelatin zymography and gelatinolytic inhibition assay. Results revealed that the natural compounds derived based on the developed pharmacophore model would be useful for further design and development of MMP-9 inhibitors.

A novel compound RY10-4 induces apoptosis and inhibits invasion via inhibiting STAT3 through ERK-, p38-dependent pathways in human lung adenocarcinoma A549 cells

Previous reports suggested that protoapigenone showed remarkable antitumor activities against a broad spectrum of human cancer cell lines, but had no effect on human lung adenocarcinoma A549 cell. The lack of effective remedies had necessitated the application of new therapeutic scheme. A novel compound RY10-4 which has the similar structure close to protoapigenone showed better antitumor activity. Treatment with RY10-4 inhibited the expression of pro-caspase-3, pro-caspase-9, Bcl-2 as well as phosphorylation of signal transducer and activator of transcription-3 (p-STAT3). It also reduced the expressions of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) and increases the expressions of reversion-inducing cysteine-rich protein with kazal motifs (RECK), as well as tissue inhibitor of metalloproteinase (TIMP) via inhibiting STAT3 by activating the mitogen-activated protein (MAP) kinases (the c-Jun N-terminal kinase (JNK), the p38 and extracellular signal-regulated kinase (ERK)) in A549 cells treated with RY10-4. Moreover, the cytotoxic effect of RY10-4 was induction of apoptosis in A549 cells by enhancing production of reactive oxygen species (ROS). Taken together, the observations suggested that RY10-4 had affected Bcl-2 family members, caspases, MMPs, TIMPs expressions and ROS production via inhibiting STAT3 activities through ERK and p38 pathways in A549 cells.

Ikappa B kinase alpha involvement in the development of nasopharyngeal carcinoma through a NF-κB-independent and ERK-dependent pathway

OBJECTIVES

Ikappa B kinase alpha (IKKα) plays an inhibitory role in the development of epithelial-derived tumors. However, its specific function in the development of nasopharyngeal carcinoma (NPC) remains unknown. In this study we identify the role and mechanism of IKKα in IKKα-mediated NPC development.

MATERIAL AND METHODS

The effect of IKKα on migration, invasion and tumorigenesis of NPC cell lines was determined using in vitro and in vivo studies. SUNE-1-5-8F cells transfected to overexpress IKKα, SUNE-1-6-10B cells with shRNA-mediated knockdown of IKKα, and three NPC cell lines were studied using Western blotting techniques to compare the major molecules in NF-κB pathways. Additionally, the extracellular signal-regulated kinase (ERK) pathway and matrix metalloproteinases (MMPs) in IKKα-regulated NPC and the effect of Epstein-Barr Nuclear Antigen 1 (EBNA1) on IKKα were examined.

RESULTS

IKKα was underexpressed in highly invasive SUNE-1-5-8F cells compared with non-invasive cells (SUNE-1 and SUNE-6-10B). Overexpression of IKKα in SUNE-1-5-8F cells was achieved through transfection and resulted in inhibited migration and invasion in vitro. Furthermore, IKKα inhibited tumorigenesis in mice inoculated with IKKα-transfected NPC cells in vivo. These processes were independent of the conventional effect of IKKα on Nuclear factor κB (NF-κB) pathways. The ERK pathway was involved in IKKα-related NPC inhibition. Phosphorylation of ERK1/2 and subsequent secretion of MMP-9 were inhibited by the ERK inhibitor U0126 and not regulated by overexpressed IKKα. EBNA1 knockdown using small interfering RNA (siRNA) did not alter the expression of IKKα.

CONCLUSION

Increase in IKKα expression suppresses the progression of NPC through a NF-κB-independent and ERK-dependent pathway.

Clusterin plays an important role in clear renal cell cancer metastasis

OBJECTIVE

Clusterin (CLU) is implicated in regulating clear renal cell carcinoma (CRCC) progression and metastasis, yet the mechanisms are not elucidated. In the present study, we explored the potential role of CLU in CRCC metastasis.

METHODS

Levels of CLU mRNA and CLU protein were measured by RT-PCR and immunohistochemistry analysis in 22 CRCC with metastasis and 22 without metastasis and 22 samples of normal kidney tissue. After CLU silencing and re-expression, the migration and invasion in vitro and in vivo of Caki-2 cells were determined by wound healing assay, transwell migration assay and pulmonary nodule assay, respectively. The expression of pERK1/2 and MMP-9 were detected by RT-PCR and Western blot assay.

RESULTS

We found a significant increase of CLU and CLU mRNA expression in CRCC, and the expression of CLU is strongly correlated in patients with metastatic disease. We discovered that CLU-rich Caki-2 cells displayed higher invasive ability which prompted us to investigate if CLU silencing could reduce the migration and invasion in Caki-2 cells. Compared with the vector-transfected cells, CLU knocked-down (CLUi) cells showed reduced migration and invasion in vitro, as well as decreased metastatic potential in experimental metastasis. Re-expression of CLU in CLUi cells restored the invasive phenotypes. We found that MMP-9 was downregulated in CLUi cells. We also discovered that levels of activated ERK1/2 correlated with the rich expression of CLU and MMP-9.

CONCLUSION

Our data suggest that CLU may regulate aggressive behavior of human CRCC cells through modulating ERK1/2 signaling and MMP-9 expression.

Adenosine dialdehyde suppresses MMP-9-mediated invasion of cancer cells by blocking the Ras/Raf-1/ERK/AP-1 signaling pathway

Adenosine dialdehyde (AdOx) inhibits transmethylation by the accumulation of S-adenosylhomocysteine (SAH), a negative feedback inhibitor of methylation, through the suppression of SAH hydrolase (SAHH). In this study, we aimed to determine the regulatory effect of AdOx on cancer invasion by using three different cell lines: MDA-MB-231, MCF-7, and U87. The invasive capacity of these cells in the presence (MCF-7) or absence (MDA-MB-231 and U87) of phorbal 12-myristate 13-acetate (PMA) was strongly decreased by AdOx treatment. Furthermore, the expression, secretion, and activation of matrix metalloproteinase (MMP)-9, a critical enzyme regulating cell invasion, in these cells were diminished by AdOx treatment. AdOx strongly suppressed AP-1-mediated luciferase activity and, in parallel, reduced the translocation of c-Fos and c-Jun into the nucleus. AdOx was shown to block a series of upstream AP-1 activation signaling complexes composed of extracellular signal-related kinase (ERK), mitogen-activated protein ERK kinase (MEK)1/2, Raf-1, and Ras, as assessed by measuring the levels of the phosphorylated and membrane-translocated forms. Furthermore, we found that suppression of SAHH by siRNA and 3-deazaadenosine, knock down of isoprenylcysteine carboxyl methyltransferase (ICMT), and treatment with SAH showed inhibitory patterns similar to those of AdOx. Therefore, our data suggest that AdOx is capable of targeting the methylation reaction regulated by SAHH and ICMT and subsequently downregulating MMP-9 expression and decreasing invasion of cancer cells through inhibition of the Ras/Raf-1/ERK/AP-1 pathway.

eEF1A2 promotes cell migration, invasion and metastasis in pancreatic cancer by upregulating MMP-9 expression through Akt activation

eEF1A2 is a protein translation factor involved in protein synthesis that is overexpressed in various cancers, with important functions in tumor genesis and progression. We have previously showed that the ectopic expression of eEF1A2 is correlated with lymph node metastasis and perineural invasion in pancreatic cancer. In this study, we investigated the functional role of eEF1A2 in the regulation of cell migration, invasion, and metastasis in pancreatic cancer. Furthermore, we investigated the potential molecular mechanisms involved. By evaluating the invasive ability of a panel of pancreatic cancer cell lines with different metastatic potentials, eEF1A2 expression in cells was positively associated with their invasive ability. The knockdown of eEF1A2 by siRNA decreased the migration and invasion of PANC-1 cells. By contrast, the ectopic expression of exogenous eEF1A2 significantly promoted the migration and invasion of SW1990 cells. Stable eEF1A2 overexpression in a nude mouse model of peritoneal metastasis likewise dramatically enhanced the intraperitoneal metastatic ability of SW1990 cells. In addition, eEF1A2 overexpression could upregulate MMP-9 expression and activity. A significant positive correlation between the overexpression of both eEF1A2 and MMP-9 was observed in pancreatic cancer tissues. The inhibition of MMP-9 activity reduced the promoting effect of eEF1A2 on cell migration and invasion. Furthermore, eEF1A2-mediated cell migration and invasion, as well as MMP-9 expression and upregulation, were largely dependent on the eEF1A2-induced Akt activation. The findings suggested the potentially important role of eEF1A2 in pancreatic cancer migration, invasion, and metastasis. Thus, the results provide evidence of eEF1A2 as a potential therapeutic target in the treatment of aggressive pancreatic cancer.