Gaseous nitrogen oxide promotes human lung cancer cell line A549 migration, invasion, and metastasis via iNOS-mediated MMP-2 production

The new perspective of gasotransmitters in cancer metastasis

Cancer metastasis is the leading cause of death in cancer patients, which renders heavy burdens to family and society. Cancer metastasis is a complicated process in which a large variety of biological molecules, cells and signaling pathways are involved. Nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) are common air pollutants which are harmful to human bodies and environments. However, recent studies show that these gases, which are collectively termed gasotransmitters, play significant roles in physiological homeostasis and pathogenesis including immunological responses, neuronal regulations, respiratory as well as cardiovascular diseases, metabolic disorders and cancers. These gases are abnormally expressed in cancer cells or tissues, along with the gas-producing enzymes. They have been demonstrated to participate in cancer metastasis intensively by modulating diverse signaling axes. This review introduces the nature of gasotransmitters, summaries novel research progression in gasotransmitters-induced cancer metastasis and elucidates multifaceted mechanisms how the process is modulated, with an effort to bring new therapeutic targets for cancer management in the future.

Efficient Nitric Oxide Scavenging by Urea-Functionalized Push-Pull Chromophore Modulates NO-Mediated Diseases

The excess nitric oxide (NO) produced in the body in response to bacterial/proinflammatory stimuli is responsible for several pathological conditions. The current approaches that target the production of excess NO, either through the inhibition of nitric oxide synthase enzyme or its downstream mediators have been clinically unsuccessful. With an aim to regulate the excess NO, urea-functionalized push-pull chromophores containing 1,1,4,4-tetracyanobuta-1,3-dienes (TCBD) or expanded TCBD (eTCBD) were developed as NO scavengers. The NMR mechanistic studies revealed that upon NO binding, these molecules are converted to uncommon stable NONOates. The unique emissive property of Urea-eTCBD enables its application in vitro, as a NO-sensor. Furthermore, the cytocompatible Urea-eTCBD, rapidly inactivated the NO released from LPS-activated cells. The therapeutic efficacy of the molecule in modulating NO-mediated pathological condition was confirmed using a carrageenan-induced inflammatory paw model and a corneal injury model. While the results confirm the advantages of scavenging the excess NO to address a multitude of NO-mediated diseases, the promising sensing and bioactivity of Urea-eTCBD can motivate further exploration of such molecules in allied areas of research.

The role of extracellular matrix in tumour angiogenesis: the throne has NOx servants

The extracellular matrix (ECM) dynamics in tumour tissue are deregulated compared to the ECM in healthy tissue along with disorganized architecture and irregular behaviour of the residing cells. Nitric oxide (NO) as a pleiotropic molecule exerts different effects on the components of the ECM driving or inhibiting augmented angiogenesis and tumour progression and tumour cell proliferation and metastasis. These effects rely on the concentration of NO within the tumour tissue, the nature of the surrounding microenvironment and the sensitivity of resident cells to NO. In this review article, we summarize the recent findings on the correlation between the levels of NO and the ECM components towards the modulation of tumour angiogenesis in different types of cancers. These are discussed principally in the context of how NO modulates the expression of ECM proteins resulting in either the promotion or inhibition of tumour growth via tumour angiogenesis. Furthermore, the regulatory effects of individual ECM components on the expression of the NO synthase enzymes and NO production were reviewed. These findings support the current efforts for developing effective therapeutics for cancers.

A narrative review of the migration and invasion features of non-small cell lung cancer cells upon xenobiotic exposure: insights from in vitro studies

Lung cancer (LC) is the leading cause of cancer deaths worldwide, being non-small lung cancer (NSCLC) sub-types the most prevalent. Since most LC cases are only detected during the last stage of the disease the high mortality rate is strongly associated with metastases. For this reason, the migratory and invasive capacity of these cancer cells as well as the mechanisms involved have long been studied to uncover novel strategies to prevent metastases and improve the patients’ prognosis. This narrative review provides an overview of the main in vitro migration and invasion assays employed in NSCLC research. While several methods have been developed, experiments using conventional cell culture models prevailed, specifically the wound-healing and the transwell migration and invasion assays. Moreover, it is provided herewith a summary of the available information concerning chemical contaminants that may promote the migratory/invasive properties of NSCLC cells in vitro, shedding some light on possible LC risk factors. Most of the reported agents with pro-migration/invasion effects derive from cigarette smoking [e.g., Benzo(a)pyrene and cadmium] and air pollution. This review further presents several studies in which different dietary/plant-derived compounds demonstrated to impair migration/invasion processes in NSCLC cells in vitro. These chemicals that have been proposed as anti-migratory consisted mainly of natural bioactive substances, including polyphenols non-flavonoids, flavonoids, bibenzyls, terpenes, alkaloids, and steroids. Some of these compounds may eventually represent novel therapeutic strategies to be considered in the future to prevent metastasis formation in LC, which highlights the need for additional in vitro methodologies that more closely resemble the in vivo tumor microenvironment and cancer cell interactions. These studies along with adequate in vivo models should be further explored as proof of concept for the most promising compounds.

Rose (Rosa gallica) Petal Extract Suppress Proliferation, Migration, and Invasion of Human Lung Adenocarcinoma A549 Cells through via the EGFR Signaling Pathway

We sought to investigate the effect of rose petal extract (RPE) on the proliferation, migration, and invasion of cancer cells. RPE significantly inhibited the growth of lung and colorectal cancer cell lines, with rapid suppression of A549 lung cancer cells at low concentrations. These effects occurred concomitantly with downregulation of the cell proliferation mediators PCNA, cyclin D1, and c-myc. In addition, RPE suppressed the migration and invasion of A549 cells by inhibiting the expression and activity of matrix metalloproteinase-2 and matrix metalloproteinase-9 (MMP-2 and -9). We hypothesize that the suppressive activity of RPE against lung cancer cell proliferation and early metastasis occurs via the EGFR-MAPK and mTOR-Akt signaling pathways. These early results highlight the significant potency of RPE, particularly for lung cancer cells, and warrant further investigation.

Anti-cancer effects of 3,5-dimethylaminophenol in A549 lung cancer cells

Exposure to 3,5-dimethylaminophenol (3,5-DMAP), the metabolite of the 3-5-dimethylaniline, was shown to cause high levels of oxidative stress in different cells. The aim of the present work was to observe whether this metabolite can lead to cytotoxicity, oxidative stress, DNA damage and cell cycle changes in non-small cell lung cancer A549 cells. 3,5-DMAP caused a dose-dependent increase in cytotoxicity, generation of superoxide (O₂^-.), inductions in the enzyme activities orchestrating cellular antioxidant balance, increases in lipid peroxidation as well as DNA damage. However, 3,5-DMAP showed significantly lower cytotoxicity towards human lung fibroblast (HLF) cells. 3,5-DMAP also led to molecular events, like inducing apoptotic markers (ie. p53, Bad, Bax and cytochrome c); decreasing anti-apoptotic proteins (Bcl-2) and alterations in cell cycle. Our findings indicate that the cytotoxicity caused by this particular alkylaniline metabolite led to initiation of caspase 3-mediated apoptosis. Furthermore, 3,5-DMAP attenuated carcinogenic properties like migration capacity of A549 cells and eventually inhibited growth of A549 cells in an in vivo mouse model. Tumor sections showed that 3,5-DMAP down-regulated c-Myc expression but up-regulated p53 and cytochrome c, all of which might result in tumor growth arrest. Co-treatment with N-acetylcysteine provided reductions in cytotoxicity and positively modulated genetic events induced by 3,5-DMAP in A549 cells. In conclusion, our findings demonstrate 3,5-DMAP may be a potential anti-cancer drug in cancer, due to its self redox cycling properties.

Antitumor and anti-metastatic mechanisms of Rhizoma paridis saponins in Lewis mice

Lung cancer is one of the most common causes of death in the world. Rhizoma paridis saponins (RPS) have been found to show inhibition of pulmonary adenoma in previous research. However, the detailed mechanisms of RPS from a holistic view have not been established. In this study, Lewis pulmonary adenoma mice were successfully established to analyze the pathways involved in RPS intervening tumor formation and progression. As a result, RPS inhibited levels of cytokines or receptors such as VEGFD, VEGFR3, RAGE, IL6R, IL17BR, and CXCL16 which were regarded as the initiators induced tumor cell proliferation, adhesion, angiogenesis, and invasion. Meanwhile, RPS raised the content of SOD and CAT enzymes and thereby inhibited the aberrantly active NF-κB, and phosphorylation of PI3K/Akt and MAPK (including p38, Erk1/2, and JNK) signaling pathways. Soon after, RPS changed mRNA expression of nuclear factors containing NF-κB, HIF-1A, STAT3, and Jun, and consequentially suppressed the expression of angiogenesis, lymphangiogenesis, adhesion, inflammation, and invasion enzymes. In conclusion, this research provided a holistic view to understand the multi-target antitumor mechanisms of RPS which promoted the application of RPS in the future.

Winter Polycyclic Aromatic Hydrocarbon-Bound Particulate Matter from Peri-urban North China Promotes Lung Cancer Cell Metastasis

On the basis of the close relationship between human exposure to high concentrations of small particulate matter (PM) and increased lung cancer mortality, PM was recently designated as a Group I carcinogen. Considering that PM is highly heterogeneous, the potential health risks of PM promoting tumor metastasis in lung cancer, as well as its chemical characteristics, remain elusive. In the present study, we collected PM2.5 and PM10 in a peri-urban residential site of Taiyuan and determined the concentration and source of polycyclic aromatic hydrocarbons (PAHs). The results indicated that 18 PAHs, ranging from 38.21 to 269.69 ng/m(3) (for PM2.5) and from 44.34 to 340.78 ng/m(3) (for PM10), exhibited seasonal variations, and the PAHs in winter PM mainly originated from coal combustion. We calculated the benzo(a)pyrene-equivalent (BaPeq) and found that the PAH-bound PM in winter exhibited higher carcinogenic risks for humans. Following this result, in vitro bioassays demonstrated that PM2.5 and PM10 induced A549 cell migration and invasion, and the mechanism involved reactive oxygen species (ROS)-mediated epithelial-to-mesenchymal transition (EMT) activation and extracellular matrix (ECM) degradation. Our data indicate the potential risk for winter PAH-bound PM from peri-urban North China promoting lung cancer cell metastasis and reveal a mechanistic basis for treating, ameliorating, or preventing outcomes in polluted environments.

Hexane extract from Sargassum serratifolium inhibits the cell proliferation and metastatic ability of human glioblastoma U87MG cells

The present study is the first to demonstrate the anticancer effects of a hexane extract from the brown algae Sargassum serratifolium (HES) on human cancer cell lines, including glioblastoma U87MG, cervical cancer HeLa and gastric cancer MKN-28 cells, as well as liver cancer SK-HEP 1 cells. Among these cancer cell lines, U87MG cells were most sensitive to the cell death induced by HES. HES exhibited a cytotoxic effect on U87MG cells at concentrations of 14-16 µg/ml, yet an effect was not observed in human embryonic kidney HEK293 cells. The antiproliferative effects of HES were regulated by inhibition of the MAPK/ERK signaling pathway which plays a pivotal role in the proliferation of glioblastoma U87MG cells. In addition, treatment with HES led to cell morphological changes and cell cytoskeleton degradation through regulation of actin dynamic signaling. Furthermore, migration and invasion of the U87MG cells were inhibited by HES via suppression of matrix metalloproteinase (MMP)-2 and -9 expression. Thus, our results suggest that HES is a potential therapeutic agent which has anticancer effects on glioblastoma.

Epigenetic regulation of miR-129-2 and its effects on the proliferation and invasion in lung cancer cells

MicroRNAs (miRNAs) play a pivotal role in carcinogenesis. Dysregulation of miRNAs, both oncogenic miRNAs and tumour-suppressive miRNAs, is closely associated with cancer development and progression. The levels of miRNAs could be changed epigenetically by DNA methylation in the 5′ untranslated region (UTR) of pre-mature miRNAs. To investigate whether DNA methylation alters the expression of miR-129 in lung cancer, we did DNA methylation assays and found that 5′ UTR region of miR-129-2 gene was absolutely methylated in both A549 and SPCA-1 lung cancer cells, but totally un-methylated in 95-D cells. The expression of miR-129 was restored by 5-Aza-2’-deoxycytidine (DAC), a de-methylation agent, in both A549 and SPCA-1 cells, resulting in attenuated cell migration and invasion ability, and decreased protein level of NF-κB, which indicates the involvement of NF-κB pathway. To further illustrate the roles of miR-129 in lung tumourigenesis, we overexpressed miR-129 in lung cancer cells by transfection of miR-129 mimics, and found arrested cell proliferation at G2/M phase of cell cycle and inhibited cell invasion. These findings strongly suggest that miR-129 is a tumour suppressive miRNA, playing important roles in the development and progression of human lung cancer.

Actin-binding protein alpha-actinin 4 (ACTN4) is a transcriptional co-activator of RelA/p65 sub-unit of NF-kB

ACTN4 is an actin-binding protein that participates in cytoskeleton organisation. It resides both in the cytoplasm and nucleus and physically associates with various transcription factors. Here, we describe an effect of ACTN4 expression on transcriptional activity of the RelA/p65 subunit of NF-kB. We demonstrate that ACTN4 enhances RelA/p65-dependant expression of c-fos, MMP-3 and MMP-1 genes, but it does not affect TNC, ICAM1 and FN1 expression. Importantly, actin-binding domains of ACTN4 are not critical for the nuclear translocation and co-activation of RelA/p65-dependent transcription. Collectively, our data suggest that in the nucleus, ACTN4 functions as a selective transcriptional co-activator of RelA/p65.

Nitrosyl-cobinamide (NO-Cbi), a new nitric oxide donor, improves wound healing through cGMP/cGMP-dependent protein kinase

Nitric oxide (NO) donors have been shown to improve wound healing, but the mechanism is not well defined. Here we show that the novel NO donor nitrosyl-cobinamide (NO-Cbi) improved in vitro wound healing in several cell types, including an established line of lung epithelial cells and primary human lung fibroblasts. On a molar basis, NO-Cbi was more effective than two other NO donors, with the effective NO-Cbi concentration ranging from 3 to 10μM, depending on the cell type. Improved wound healing was secondary to increased cell migration and not cell proliferation. The wound healing effect of NO-Cbi was mediated by cGMP, mainly through cGMP-dependent protein kinase type I (PKGI), as determined using pharmacological inhibitors and activators, and siRNAs targeting PKG type I and II. Moreover, we found that Src and ERK were two downstream mediators of NO-Cbi's effect. We conclude that NO-Cbi is a potent inducer of cell migration and wound closure, acting via cGMP, PKG, Src, and extracellular signal regulated kinase (ERK).

Hibiscus sabdariffa leaf polyphenolic extract inhibits LDL oxidation and foam cell formation involving up-regulation of LXRα/ABCA1 pathway

The oxidative modification of low-density lipoprotein (LDL) is involved in the pathogenesis of atherosclerotic lesions through the formation of macrophage-derived foam cells. In the present study, we aimed to investigate the anti-atherosclerotic effect of Hibiscus sabdariffa leaf polyphenolic extract (HLP), which is rich in flavonoid. The inhibitory effect of HLP on oxidation and lipid peroxidation of LDL was defined in vitro. HLP showed potential in reducing foam cell formation and intracellular lipid accumulation in oxidised-LDL (ox-LDL)-induced macrophage J774A.1 cells under non-cytotoxic concentrations. Molecular data showed these influences of HLP might be mediated via liver-X receptor α (LXRα)/ATP-binding cassette transporter A1 (ABCA1) pathway, as demonstrated by the transfection of LXRα siRNA. Our data implied that HLP up-regulated the LXRα/ABCA1 pathway, which in turn led to stimulation of cholesterol removal from macrophages and delay atherosclerosis. These results suggested that HLP potentially could be developed as an anti-atherosclerotic agent.

Key molecular mechanisms in lung cancer invasion and metastasis: a comprehensive review

Lung cancer remains one of the most common and malignant cancers worldwide. It is most often diagnosed at late stages, when it has already presented local invasion and distal metastases. The basic stages of invasion and metastasis involve the detachment of tumor cells from the extracellular matrix, invasion of surrounding tissues and basal lamina, intravasation into the blood stream, survival and transport through the blood stream, migration, arrest and extravasation at a distal site and formation of a metastatic lesion. These steps require fundamental mechanisms such as angiogenesis, degradation of matrix barriers, disruption of cell-cell and cell-matrix adhesion and inducement of cellular motility. Genes that regulate functions like unlimited growth potential, survival, genomic instability, angiogenesis, epithelial to mesenchymal transition and apoptosis evasion, are involved in giving lung cancer tumors invasive and metastatic competence. Improving of understanding of the underlying molecular and cellular mechanisms remains an urgent and essential issue, in order to develop new more effective strategies in preventing and treating lung cancer.

Insidious role of nitric oxide in migration/invasion of colon cancer cells by upregulating MMP-2/9 via activation of cGMP-PKG-ERK signaling pathways

Nitric oxide (NO), an uncharged free radical is implicated in various physiological and pathological processes. The present study is an investigation on the effect of NO on proliferation, apoptosis and migration of colon cancer cells. Colon adenocarcinoma cells, WiDr, were used for the in vitro experiments. Tissues from colon adenocarcinoma, adjacent normal and inflammatory tissue and lymph node with metastasis were evaluated for iNOS, MMP-2/9 and Fra-1/Fra-2. NO increases the proliferation of cancer cells and simultaneously prevents apoptosis. Expression of MMP-2/9, RhoB and Rac-1 was enhanced by NO in a time dependent manner. Further, NO increased phosphorylation of ERK1/2 and induced nuclear translocation of Fra-1 and Fra-2. Electrophoretic mobility shift analysis and use of deletion mutant promoter constructs identified role of AP-1 in NO-mediated regulation of MMP-2/9. iNOS, MMP-2/9, Fra-1 and Fra-2 in normal and colon adenocarcinoma tissues were analyzed and it was found that increased expression of these proteins in cancer when compared to normal provides support to our in vitro findings. The study showed that the NO-cGMP-PKG promotes MMP-2/9 expression by activating ERK-1/2 and AP-1. This study reveals the insidious role of NO in imparting tumor aggressiveness.

Nitrosothiol Signaling in Anoikis Resistance and Cancer Metastasis

Nitric oxide (NO) has been widely recognized as an important cell-signaling molecule that regulates various physiological and pathological processes. S-nitrosylation, or covalent attachment of NO to protein sulfhydryl groups, is a key mechanism by which NO regulates protein functions and cellular processes. In this article we discuss the various roles of NO and protein nitrosylation in cancer development, with a focus on cell invasion and anoikis resistance, both of which are key determinants of cancer metastasis. We specially address some of the mechanisms by which NO-mediated S-nitrosylation modulates substrates that have putative effects on key steps of metastasis. We propose that nitrosothiol signaling is a key regulatory mechanism common to several pathways involved in cancer progression and metastasis, and identifying such a mechanism will improve our understanding of the disease process and aid in the development of novel anticancer therapeutics.

Inflammation and matrix remodeling during repair of ventilator-induced lung injury

High-pressure ventilation triggers different inflammatory and matrix remodeling responses within the lung. Although some of them may cause injury, the involvement of these mediators in repair is largely unknown. To identify mechanisms of repair after ventilator-induced lung injury (VILI), mice were randomly assigned to baseline conditions (no ventilation), injury [90 min of high-pressure ventilation without positive end-expiratory pressure (PEEP)], repair (injury followed by 4 h of low-pressure ventilation with PEEP), and ventilated controls (low-pressure ventilation with PEEP for 90 and 330 min). Histological injury and lung permeability increased during injury, but were partially reverted in the repair group. This was accompanied by a proinflammatory response, together with increases in TNF-α and IFN-γ, which returned to baseline during repair, and a decrease in IL-10. However, macrophage inflammatory protein-2 (MIP-2) and matrix metalloproteinases (MMP)-2 and -9 increased after injury and persisted in being elevated during repair. Mortality in the repair phase was 50%. Survivors showed increased cell proliferation, lower levels of collagen, and higher levels of MIP-2 and MMP-2. Pan-MMP or specific MMP-2 inhibition (but not MIP-2, TNF-α, or IL-4 inhibition) delayed epithelial repair in an in vitro wound model using murine or human alveolar cells cultured in the presence of bronchoalveolar lavage fluid from mice during the repair phase or from patients with acute respiratory distress syndrome, respectively. Similarly, MMP inhibition with doxycycline impaired lung repair after VILI in vivo. In conclusion, VILI can be reverted by normalizing ventilation pressures. An adequate inflammatory response and extracellular matrix remodeling are essential for recovery. MMP-2 could play a key role in epithelial repair after VILI and acute respiratory distress syndrome.

Nimbolide retards tumor cell migration, invasion, and angiogenesis by downregulating MMP-2/9 expression via inhibiting ERK1/2 and reducing DNA-binding activity of NF-κB in colon cancer cells

Nimbolide, a plant-derived limonoid has been shown to exert its antiproliferative effects in various cell lines. We demonstrate that nimbolide effectively inhibited proliferation of WiDr colon cancer cells through inhibition of cyclin A leading to S phase arrest. It also caused activation of caspase-mediated apoptosis through the inhibition of ERK1/2 and activation of p38 and JNK1/2. Further nimbolide effectively retarded tumor cell migration and invasion through inhibition of metalloproteinase-2/9 (MMP-2/9) expression, both at the mRNA and protein level. It was also a strong inhibitor of VEGF expression, promoter activity, and in vitro angiogenesis. Finally, nimbolide suppressed the nuclear translocation of p65/p50 and DNA binding of NF-κB, which is an important transcription factor for controlling MMP-2/9 and VEGF gene expression.

Extracellular heat shock protein (Hsp)70 and Hsp90α assist in matrix metalloproteinase-2 activation and breast cancer cell migration and invasion

Breast cancer is second only to lung cancer in cancer-related deaths in women, and the majority of these deaths are caused by metastases. Obtaining a better understanding of migration and invasion, two early steps in metastasis, is critical for the development of treatments that inhibit breast cancer metastasis. In a functional proteomic screen for proteins required for invasion, extracellular heat shock protein 90 alpha (Hsp90α) was identified and shown to activate matrix metalloproteinase 2 (MMP-2). The mechanism of MMP-2 activation by Hsp90α is unknown. Intracellular Hsp90α commonly functions with a complex of co-chaperones, leading to our hypothesis that Hsp90α functions similarly outside of the cell. In this study, we show that a complex of co-chaperones outside of breast cancer cells assists Hsp90α mediated activation of MMP-2. We demonstrate that the co-chaperones Hsp70, Hop, Hsp40, and p23 are present outside of breast cancer cells and co-immunoprecipitate with Hsp90α in vitro and in breast cancer conditioned media. These co-chaperones also increase the association of Hsp90α and MMP-2 in vitro. This co-chaperone complex enhances Hsp90α-mediated activation of MMP-2 in vitro, while inhibition of Hsp70 in conditioned media reduces this activation and decreases cancer cell migration and invasion. Together, these findings support a model in which MMP-2 activation by an extracellular co-chaperone complex mediated by Hsp90α increases breast cancer cell migration and invasion. Our studies provide insight into a novel pathway for MMP-2 activation and suggest Hsp70 as an additional extracellular target for anti-metastatic drug development.

Protocatechuic acid inhibits cancer cell metastasis involving the down-regulation of Ras/Akt/NF-κB pathway and MMP-2 production by targeting RhoB activation

BACKGROUND AND PURPOSE

Protocatechuic acid (PCA) is plentiful in edible fruits and vegetables and is thus one anti-oxidative component of normal human diets. However, the molecular mechanisms involved in the chemopreventive activity of PCA are poorly understood. Here, we investigated the mechanism(s) underlying the anti-metastatic potential of PCA.

EXPERIMENTAL APPROACH

We used AGS cells in a wound healing model and Boyden chamber assays in vitro and injection of B16/F10 melanoma cells in mice (metastasis model in vivo) to analyse the effect of PCA on cancer cell invasion and metastasis. The activities and expression of molecular proteins were measured by zymographic assay, real-time RT-PCR and Western blotting.

KEY RESULTS

PCA inhibited cell migration and invasion at non-cytotoxic concentrations. Decreased expression of matrix metalloproteinase (MMP)-2 and a coincident increase in tissue inhibitor of MMP followed treatment with PCA. The PCA-inhibited MMP-2 activity and expression was accompanied by inactivation of NF-κB. All these effects of PCA could be mediated via the RhoB/ protein kinase Cε (PKCε) and Ras/Akt cascade pathways, as demonstrated by inhibition of PKCε and transfection of PKCε siRNA and ras overexpression vector. Finally, PCA inhibited metastasis of B16/F10 melanoma cells to the liver in mice.

CONCLUSION AND IMPLICATIONS

Our data imply that PCA down-regulated the Ras/Akt/NF-κB pathway by targeting RhoB activation, which in turn led to a reduction of MMP-mediated cellular events in cancer cells and provides a new mechanism for the anti-cancer activity of PCA.

Expression of periostin in the serum of NSCLC and its function on proliferation and migration of human lung adenocarcinoma cell line (A549) in vitro

Periostin is over expressed in many epithelial malignant cancers, including lung cancer, breast cancer, ovarian cancer and colon cancer. It is related with the progression and migration of breast and ovarian cancer cells in vitro. The aim of this study was to investigate the serum level of periostin in non-small cell lung cancer (NSCLC) and its relationship with established biological and prognostic factors by enzyme-linked-immunosorbent serologic assay. We also observe the function of periostin on the proliferation and migration of human lung adenocarcinoma cell line (A549) and discuss the mechanism. The mean value for serum periostin (POSTN) was elevated in NSCLC patients (242.84 + or - 5.33 pg/ml) compared to the normal healthy volunteers (215.66 + or - 11.67 pg/ml) (p = 0.030). The serum level of periostin of NSCLC patients had no connection with gender, age, pathological type, TNM stage, lymph node status, tumor size and invasiveness. We constructed a plasmid named pEGFP-N1/POSTN expressing full-length human periostin. Transfecting the plasmid to A549 cells and periostin was efficiently expressed in transfected A549 cells. Our data showed that periostin could promote the proliferation and migration of A549 cells by inducing vimentin and N-cadherin expression and downregulating E-cadherin expression. These results strongly suggest that periostin is a novel molecular which play an important role during the progression and development of NSCLC.