YY1 regulates the proliferation and invasion of triple-negative breast cancer via activating PLAUR.

It is well-established that breast cancer is a highly prevalent malignancy among women, emphasizing the need to investigate mechanisms underlying its pathogenesis and metastasis. In this study, the Gene Expression Omnibus (GEO) database was utilized to conduct differential expression analysis in breast cancer and adjacent tissues. Upregulated genes were selected for prognostic analysis of breast cancer. The expression of urokinase plasminogen activator receptor (uPAR), also known as PLAUR, was assessed using RT-qPCR and western blot. Immunofluorescence staining was employed to determine PLAUR localization. Various cellular processes were analyzed, including proliferation, migration, invasion, apoptosis, and cell cycle. Bioinformatics analysis was used to predict transcription factors of PLAUR, which were subsequently validated in a double luciferase reporter gene experiment. Rescue experiments confirmed the impact of PLAUR on the proliferation, apoptosis, and migration of MDA-MB-231 cells. Furthermore, the effects of PLAUR were evaluated in an orthotopic tumor transplantation and lung metastasis nude mouse model. Our findings substantiated the critical involvement of PLAUR in the progression of triple-negative breast cancer (TNBC) in vitro and among TNBC patients with a poor prognosis. Additionally, we demonstrated Yin Yang-1 (YY1) as a notable transcriptional regulator of PLAUR, whose activation could transcriptionally enhance the proliferation and invasion capabilities of TNBC cells. We also identified the downstream mechanism of PLAUR associated with PLAU, focal adhesion kinase (FAK), and AKT. Overall, these findings offer a novel perspective on PLAUR as a potential therapeutic target for TNBC.

Carotenoids in Cancer Metastasis-Status Quo and Outlook.

Metastasis represents a major obstacle in cancer treatment and the leading cause of cancer-related deaths. Therefore, the identification of compounds targeting the multi-step and complex process of metastasis could improve outcomes in the management of cancer patients. Carotenoids are naturally occurring pigments with a plethora of biological activities. Carotenoids exert a potent anti-cancer capacity in various cancer models in vitro and in vivo, mediated by the modulation of signaling pathways involved in the migration and invasion of cancer cells and metastatic progression, including key regulators of the epithelial-mesenchymal transition and regulatory molecules, such as matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), urokinase plasminogen activator (uPA) and its receptor (uPAR), hypoxia-inducible factor-1α (HIF-1α), and others. Moreover, carotenoids modulate the expression of genes associated with cancer progression and inflammatory processes as key mediators of the complex process involved in metastasis. Nevertheless, due to the predominantly preclinical nature of the known anti-tumor effects of carotenoids, and unclear results from certain carotenoids in specific cancer types and/or specific parts of the population, a precise analysis of the anti-cancer effects of carotenoids is essential. The identification of carotenoids as effective compounds targeting the complex process of cancer progression could improve the outcomes of advanced cancer patients.

A uPAR targeted nanoplatform with an NIR laser-responsive drug release property for tri-modal imaging and synergistic photothermal-chemotherapy of triple-negative breast cancer.

In the present work, an iridium (Ir) complex loaded theranostic nanoplatform was designed for high-efficiency triple-negative breast cancer (TNBC) therapy. For this purpose, the Ir complex was firstly loaded on a photothermal agent of gold nanostars (GNS) by simply mixing followed by functionalization using a urokinase-type plasminogen activator receptor (uPAR) targeted polyetherimide-AE105 peptide conjugate (P-AE105) with the formation of GNS@Ir@P-AE105. It was demonstrated that the resultant GNS@Ir@P-AE105 was a multifunctional nanoplatform with advantages of (1) NIR laser controlled release of the Ir complex; (2) precise delivery of the Ir complex to TNBC cells; (3) excellent photothermal (PT)/photoacoustic (PA)/X-ray computed tomography (CT) tri-modal imaging ability; and (4) a synergistic photothermal-chemotherapeutic effect. An in-depth investigation of the mechanism revealed that binding forces of the Ir complex-GNS and P-AE105-GNS were significantly diminished upon NIR laser irradiation, which conferred an NIR laser-responsive Ir complex release property to the nanoplatform. Moreover, the nanoplatform exerted high efficiency anti-TNBC effects via a ROS-induced p53 apoptotic pathway. Specifically, combinational photothermal-chemotherapeutic treatments stimulated intracellular ROS generation, which significantly up-regulated apoptotic-relative p53 gene expression either by causing severe DNA damage or inducing an arrest effect on the sub-G1 phase of the cell cycle. Taken together, our work provides a novel theranostic nanoplatform for efficient and simultaneous diagnosis and therapy of TNBC.

Construction of Urokinase-Type Plasminogen Activator Receptor-Targeted Heterostructures for Efficient Photothermal Chemotherapy against Cervical Cancer To Achieve Simultaneous Anticancer and Antiangiogenesis.

Rational design and construction of theranostic nanomedicines based on clinical characteristics of cervical cancer is an important strategy to achieve precise cancer therapy. Herein, we fabricate a cervical cancer-targeting gold nanorod-mesoporous silica heterostructure for codelivery of synergistic cisplatin and antiangiogenic drug Avastin (cisplatin-AuNRs@SiO2-Avastin@PEI/AE105) to achieve synergistic chemophotothermal therapy. Based on database analysis and clinical sample staining, conjugation of the AE105-targeting peptide obviously improves the intracellular uptake of the nanosystem and enhances the cancer-killing ability and selectivity between cervical cancer and normal cells. It could also be used to specifically monitor the urokinase-type plasminogen activator receptor (uPAR) expression level in clinical cervical specimens, which would be an early indicator of prognosis in cancer treatment. Under 808 nm laser irradiation, the nanosystem demonstrates smart NIR-light-triggered drug release and prominent photodynamic activity via induction of reactive oxygen species overproduction-mediated cell apoptosis. The nanosystem also simultaneously suppresses HeLa tumor growth and angiogenesis in vivo, with no evident histological damage observed in the major organs. In short, this study not only provides a clinical data-based rational design strategy of smart nanomedicine for precise treatment and rapid clinical diagnosis of cervical cancer but also contributes to the development of the clinical translation of nanomedicines.

Statin treatment reduces matrix degradation capacity of proinflammatory polarized macrophages.

BACKGROUND AND AIMS: Macrophages are versatile immune cells involved in tissue degradation and remodeling. Proinflammatory macrophages have the highest capacity of matrix degradation and proteolysis. Within atherosclerotic lesions, proinflammatory macrophages are associated with unstable plaques. Statins have been demonstrated to increase plaque stability. Possible changes of polarized macrophage tissue degradation behavior under statin treatment are currently unknown. METHODS: Polarized macrophages were tested in vitro for matrix degradation capacity with or without statin treatment. RESULTS: Proinflammatory macrophages show high matrix degradation capacity, which is lost after statin treatment. Statin concentrations were within a physiological range and did not influence overall macrophage polarization. Proinflammatory macrophages showed however a loss of filopodia where activators of MMPs are located. Loss of matrix degradation in proinflammatory macrophages was associated with changes of MMP14 activation and loss of uPAR localization at filopodia. Supplementation of mevalonate restored localization of uPAR to cellular protrusions and matrix degradation capacity. CONCLUSION: Statins reduce the matrix degradation potential of proinflammatory macrophages by reducing uPAR localization to cellular filopodia and reducing intracellular MMP14 activation.

Quercetin Has Antimetastatic Effects on Gastric Cancer Cells via the Interruption of uPA/uPAR Function by Modulating NF-κb, PKC-δ, ERK1/2, and AMPKα.

Gastric cancer (GC) is a malignancy with few effective treatment options after metastasis occurs. Quercetin (Qu) intake has been associated with reduced incidence and slow development of GC, probably due to its anti-proliferative and apoptotic effects, but it is unclear whether Qu can inhibit the metastatic activity. The urokinase plasminogen activator (uPA)/uPA receptor (uPAR) system plays an important role in cancer metastasis. In this study, we measured both uPA activity and uPAR expression in GC and pericarcinous tissues, and we investigated the correlation between uPAR expression and the migratory and invasive activities of various GC cell lines. GC BGC823 and AGS cells were subjected to treatment with 10 µM Qu for 72 hours and uPAR knockdown, alone or in combination, before evaluating cell metastasis. The results showed that uPA activity and uPAR expression were higher in GC tissues than in pericarcinous tissues. Migratory and invasive activities of GC cell lines positively correlated with uPAR expression. Qu treatment decreased BGC823 and AGS cell migration and invasion, accompanied by reduced uPA and uPAR protein expression. Both Qu treatment and uPAR knockdown decreased matrix metalloproteinase-2 and -9 activity and blocked Pak1-Limk1-cofilin signaling. Qu treatment was associated with inhibition of NF-κb, PKC-δ, and ERK1/2, and with AMPKα activation. Specific inhibitors of NF-κb, PKC, and ERK1/2, and an AMPKα activator suppressed uPA and uPAR expression in GC cells. Collectively, Qu showed an antimetastatic effect on GC cells via the interruption of uPA/uPAR function and modulation of NF-κb, PKC-δ, ERK1/2, and AMPKα. This suggests that Qu is a promising agent against GC metastasis.

Imaging of Prostate Cancer Using Urokinase-Type Plasminogen Activator Receptor PET.

Urokinase-type plasminogen activator receptor (uPAR) overexpression is an important biomarker for aggressiveness in cancer including prostate cancer (PC) and provides independent clinical information in addition to prostate-specific antigen and Gleason score. This article focuses on uPAR PET as a new diagnostic and prognostic imaging biomarker in PC. Many preclinical uPAR-targeted PET imaging studies using AE105 in cancer models have been undertaken with promising results. A major breakthrough was obtained with the recent human translation of uPAR PET in using 64Cu- and 68Ga-labelled versions of AE105, respectively. Clinical results from patients with PC included in these studies are encouraging and support continuation with large-scale clinical trials.

Modified Panax ginseng Extract Inhibits uPAR-Mediated α[Formula: see text]ß1-Integrin Signaling by Modulating Caveolin-1 to Induce Early Apoptosis in Lung Cancer Cells.

Urokinase receptor (uPAR) is enhanced in many human cancer cells and is frequently an indicator of poor prognosis. Activation of [Formula: see text]1-integrin requires caveolin-1 and is regulated by uPAR. However, the underlying molecular mechanism responsible for the interaction between uPAR and [Formula: see text]1-integrin remains obscure. We found that modified regular Panax ginseng extract (MRGX) had a negative modulating effect on the uPAR/[Formula: see text]1-integrin interaction, disrupted the uPAR/integrin interaction by modulating caveoline-1, and caused early apoptosis in cancer cells. Additionally, we found that siRNA-mediated caveoline-1 downregulation inhibited uPAR-mediated [Formula: see text]1-integrin signaling, whereas caveoline-1 up-regulation stimulated the signaling, which suppressed p53 expression, thereby indicating negative crosstalk exists between the integrin [Formula: see text]1 and the p53 pathways. Thus, these findings identify a novel mechanism whereby the inhibition of [Formula: see text]1 integrin and the activation of p53 modulate the expression of the anti-apoptotic proteins that are crucially involved in inducing apoptosis in A549 lung cancer cells. Furthermore, MRGX causes changes in the expressions of members of the Bcl-2 family (Bax and Bcl-2) in a pro-apoptotic manner. In addition, MGRX-mediated inhibition of [Formula: see text]1 integrin attenuates ERK phosphorylation (p-ERK), which up-regulates caspase-8 and Bax. Therefore, ERK may affect mitochondria through a negative regulation of caspase-8 and Bax. Taken together, these findings reveal that MRGX is involved in uPAR-[Formula: see text]1-integrin signaling by modulating caveolin-1 signaling to induce early apoptosis in A549 lung-cancer cells and strongly indicate that MRGX might be useful as a herbal medicine and may lead to the development of new herbal medicine that would suppress the growth of lung-cancer cells.

[Effect of jianpi-jiedu formula on tumor angiogenesis-relevant genes expression in colorectal cancer].

OBJECTIVE: To investigate the effect of the jianpi-jiedu formula (JPJD) on the expression of angiogenesis-relevant genes in colon cancer.
 Methods: Crude extract was obtained from JPJD by water extract method. The effect of JPJD crude extract on colon cancer cell proliferation capacity was determined by MTT assays. The IC50 value was calculated by GraphPad Prism5 software. Affymetrix gene expression profiling chip was used to detect significant differences in expressions of genes after JPJD intervention, and pathway enrichment analysis was performed to analyze the differentially expressed genes. Ingenuity Pathway Analysis software was applied to analyze differentially expressed genes relevant to tumor angiogenesis based on mammalian target of rapamycin (mTOR) signaling pathway and then the network diagram was built. Western blot was used to verify the protein levels of key genes related to tumor angiogenesis.
 Results: JPJD crud extract inhibited the proliferation capacity in colon cancer cells. The IC50 values in 24, 48, and 72 hours after treatment were 13.060, 9.646 and 8.448 mg/mL, respectively. The results of chip showed that 218 genes significantly upgraded, and 252 genes significantly downgraded after JPJD treatment. Most of the genes were related to the function of biosynthesis, metabolism, cell apoptosis, antigen extraction, angiogenesis and so on. There were 12 differentially expressed angiogenesis genes. IPA software analysis showed that the JPJD downregulated expression of sphingomyelin phosphodiesterase 3 (SMPD3), VEGF, vascular endothelial growth factor A (VEGFA), integrin subunit alpha 1 (ITGA1), cathepsin B (CTSB), and cathepsin S (CTSS) genes, while upregulated expressions of GAB2 and plasminogen activator, urokinase receptor (PLAUR) genes in the colorectal cancer cell. Western blot results demonstrated that JPJD obviously downregulated expressions of phospho-mTOR (P-mTOR), signal transducer and activator of transcription 3 (STAT3), hypoxia inducible factor-1α (HIF-1α), and VEGF proteins, while obviously upregulated the level of phospho-P53 (P-P53) protein.
 Conclusion: JPJD may inhibit colorectal tumor angiogenesis through regulation of the mTOR-HIF-1α-VEGF signal pathway.

Inhibition of tumor growth by ß-elemene through downregulation of the expression of uPA, uPAR, MMP-2, and MMP-9 in a murine intraocular melanoma model.

This paper explores the underlying mechanism through which ß-elemene inhibits the growth of intraocular melanoma in a mouse model. C57BL/6J mice were administered a subretinal injection of B16F10 melanoma cells and divided into two groups: treatment and control. The treatment group was administered ß-elemene through an intravitreal injection and the control group was injected with a blank emulsion. After 21 days of continuous treatment, tumor masses were removed and weighed. The mRNA expression levels of the urokinase-type plasminogen activator (uPA), uPA receptor (uPAR), matrix metalloproteinase (MMP)-2, and MMP-9 were assayed by real-time PCR, and the protein expression levels of uPA, uPAR, MMP-2, and MMP-9 were assayed by immunocytochemistry and western blotting. Tumor size was inhibited by ß-elemene in the treatment group, and the expressions of uPA, uPAR, MMP-2, and MMP-9 were all downregulated at both the mRNA and the protein level compared with the control group. In a mouse model of intraocular melanoma, ß-elemene inhibits tumor growth by downregulating the expression of uPA, uPAR, MMP-2, and MMP-9.

Mammary cancer chemoprevention by withaferin A is accompanied by in vivo suppression of self-renewal of cancer stem cells.

Current dogma favors elimination of therapy-resistant cancer stem cells for chemoprevention of breast cancer. We showed recently that mammary cancer development in a transgenic mouse model (mouse mammary tumor virus-neu; MMTV-neu) was inhibited significantly upon treatment with withaferin A (WA), a steroidal lactone derived from a medicinal plant. Herein, we demonstrate that the mammary cancer prevention by WA is accompanied by in vivo suppression of breast cancer stem cells (bCSC). In vitro mammosphere formation was dose-dependently inhibited by WA treatment in MCF-7 and SUM159 human breast cancer cells. Other markers of bCSC, including aldehyde dehydrogenase 1 (ALDH1) activity and CD44(high)/CD24(low)/epithelial-specific antigen-positive (ESA+) fraction, were also decreased significantly in the presence of plasma achievable doses of WA. However, WA exposure resulted in cell line-specific changes in Oct4, SOX-2, and Nanog mRNA expression. WA administration to MMTV-neu mice (0.1 mg/mouse, 3 times/week for 28 weeks) resulted in inhibition of mammosphere number and ALDH1 activity in vivo. Mechanistic studies revealed that although urokinase-type plasminogen activator receptor overexpression conferred partial protection against bCSC inhibition by WA, Notch4 was largely dispensable for this response. WA treatment also resulted in sustained (MCF-7) or transient (SUM159) downregulation of Bmi-1 (B-cell-specific Moloney murine leukemia virus insertion region-1) protein. Ectopic expression of Bmi-1 conferred partial but significant protection against ALDH1 activity inhibition by WA. Interestingly, WA treatment caused induction of Kruppel-like factor 4 (KLF4) and its knockdown augmented bCSC inhibition by WA. In conclusion, this study shows in vivo effectiveness of WA against bCSC.

Effect of Chinese traditional herb Epimedium grandiflorum C. Morren and its extract Icariin on osteoarthritis via suppressing NF-kappaB pathway.

Osteoarthritis (OA), which is also called degenerative arthritis, is the leading cause of disabilities in the old people. The Chinese traditional herb Epimedium grandiflorum had long been found to attenuate osteoarthritis process, but the detailed mechanism was not clear. To study the mechanisms of E. grandiflorum in the treatment of osteoarthritis, rabbit osteoarthritis model combined with D-galactose was used. After different treatments for 10 weeks, cartilage sections were analyzed by immunohistochemistry for uPA, uPAR and PAI expression level. E. grandiflorum could significantly attenuate OA condition and decrease uPA, uPAR and PAI expression. The extract of E. grandiflorum, icariin also had a similar effect when compared with E. grandiflorum treatment alone. Rabbit chondrocytes were further isolated to be stimulated by TNFalpha combined with different reagents treatment. Here, icariin treatment significantly reduced nuclear factor kappa B NF-kappaB (P65) activity, decreased uPA expression level and increased Ikappabetaalpha protein level. The results indicated that E. grandiflorum and its extract icariin could attenuate OA condition, reduce the expression of uPA and uPAR and increase PAI in experimental rabbit model and this effect may be conducted by suppressing NF-kappaB activity by increasing IkappaBalpha level.

Targeting of peptide conjugated magnetic nanoparticles to urokinase plasminogen activator receptor (uPAR) expressing cells.

Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles are currently being used as a magnetic resonance imaging (MRI) contrast agent in vivo, mainly by their passive accumulation in tissues of interest. However, a higher specificity can ideally be achieved when the nanoparticles are targeted towards cell specific receptors and this may also facilitate specific drug delivery by an enhanced target-mediated endocytosis. We report efficient peptide-mediated targeting of magnetic nanoparticles to cells expressing the urokinase plasminogen activator receptor (uPAR), a surface biomarker for poor patient prognosis shared by several cancers including breast, colorectal, and gastric cancers. Conjugation of a uPAR specific targeting peptide onto polyethylene glycol (PEG) coated USPIO nanoparticles by click chemistry resulted in a five times higher uptake in vitro in a uPAR positive cell line compared to nanoparticles carrying a non-binding control peptide. In accordance with specific receptor-mediated recognition, a low uptake was observed in the presence of an excess of ATF, a natural ligand for uPAR. The uPAR specific magnetic nanoparticles can potentially provide a useful supplement for tumor patient management when combined with MRI and drug delivery.

Evodiamine induces apoptosis and inhibits metastasis in MDA­MB-231 human breast cancer cells in vitro and in vivo.

Breast cancer remains the leading cause of cancer-related deaths among women. Owing to high efficiency and low toxic effects, further exploration of natural compounds from Chinese herbal medicine may be an efficient approach for breast cancer drug discovery. In this study, we investigated the effects of evodiamine on the growth and metastasis of MDA-MB-231 human breast cancer cells in vitro and in vivo. In vitro, evodiamine inhibited cell migration and invasion abilities through downregulation of MMP-9, urokinase-type plasminogen activator (uPA) and uPAR expression. Evodiamine-induced G0/G1 arrest and apoptosis were associated with a decrease in Bcl-2, cyclin D1 and cyclin-dependent kinase 6 (CDK6) expression and an increase in Bax and p27Kip1 expression. Moreover, evodiamine regulated p-ERK and p-p38 MAPK expression. Evodiamine-induced apoptosis was enhanced by its combination with the extracellular signal-regulated kinase (ERK) inhibitor PD98059 or the p38 mitogen-activated protein kinase (p38 MAPK) inhibitor SB203580. Evodiamine-inhibited metastasis was partly blocked by combination with PD98059 or SB203580. In vivo, the administration of evodiamine (10 mg/kg) significantly reduced tumor growth and pulmonary metastasis. These results demonstrate that evodiamine possesses antitumor activities via inhibition of cell migration and invasion, arrest of the cell cycle and induction of cell apoptosis in MDA-MB-231 cells.

Secreted glyceraldehye-3-phosphate dehydrogenase is a multifunctional autocrine transferrin receptor for cellular iron acquisition.

BACKGROUND: The long held view is that mammalian cells obtain transferrin (Tf) bound iron utilizing specialized membrane anchored receptors. Here we report that, during increased iron demand, cells secrete the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) which enhances cellular uptake of Tf and iron. METHODS: These observations could be mimicked by utilizing purified GAPDH injected into mice as well as when supplemented in culture medium of model cell lines and primary cell types that play a key role in iron metabolism. Transferrin and iron delivery was evaluated by biochemical, biophysical and imaging based assays. RESULTS: This mode of iron uptake is a saturable, energy dependent pathway, utilizing raft as well as non-raft domains of the cell membrane and also involves the membrane protein CD87 (uPAR). Tf internalized by this mode is also catabolized. CONCLUSIONS: Our research demonstrates that, even in cell types that express the known surface receptor based mechanism for transferrin uptake, more transferrin is delivered by this route which represents a hidden dimension of iron homeostasis. GENERAL SIGNIFICANCE: Iron is an essential trace metal for practically all living organisms however its acquisition presents major challenges. The current paradigm is that living organisms have developed well orchestrated and evolved mechanisms involving iron carrier molecules and their specific receptors to regulate its absorption, transport, storage and mobilization. Our research uncovers a hidden and primitive pathway of bulk iron trafficking involving a secreted receptor that is a multifunctional glycolytic enzyme that has implications in pathological conditions such as infectious diseases and cancer.

Androgen deprivation by flutamide modulates uPAR, MMP-9 expressions, lipid profile, and oxidative stress: amelioration by daidzein.

The growth and development of prostate gland is governed by testosterone. Testosterone helps in maintaining the adipose tissue stores of the body. It is well documented that with advancing age there has been a gradual decline in testosterone levels. Our aim was to study the protective role of daidzein on flutamide-induced androgen deprivation on matrix degrading genes, lipid profile and oxidative stress in Wistar rats. Sub-chronic (60 days) flutamide (30 mg/kg b.wt) administration resulted in marked increase in expressions of matrix degrading genes [matrix metalloproteases 9 and urokinase plasminogen activation receptor]. Additionally, it increased the levels of low density lipoproteins, total cholesterol, triglycerides, and lowered the levels of high density lipoproteins and endogenous antioxidant levels. Oral administration of daidzein (20 and 60 mg/kg b.wt) restituted the levels to normal. Daidzein administration resulted in amelioration of the prostate atrophy, degeneracy and invasiveness induced by flutamide. Our findings suggest that the daidzein may be given as dietary supplement to patients who are on androgen deprivation therapy, to minimize the adverse effects related to it and also retarding susceptibility of patients to cardiovascular diseases.

Synaptic protein expression is regulated by a pro-oxidant diet in APPxPS1 mice.

Dietary factors may play a role in Alzheimer's disease (AD) pathogenesis. In an effort to recapitulate some of the synaptic protein changes observed in the disease, AD transgenic and wild-type mice were fed either a normal or pro-oxidant diet for 3 months from three months of age. Pro-oxidant diet treatment resulted in altered expression of vesicular glutamate transporter-1 and glutamine synthetase, suggesting changes in glutamatergic synaptic function, and increased expression of urokinase plasminogen activator receptor, possibly reflecting oxidative stress.

SorLA modulates atheroprotective properties of CLA by regulating monocyte migration.

OBJECTIVE: We have previously shown that CLA induces regression of pre-established atherosclerotic lesions in apoE(-/-) mice. CLA is a known ligand of peroxisome proliferator activated receptors (PPARs) and it is postulated that CLA mediates its atheroprotective effects through activation of PPARs. Earlier work in our group identified the monocyte/macrophage cell as the primary cellular target of CLA. In this study we identified novel genes regulated by CLA during the regression of atherosclerosis and characterised a role for one of these, SorLA. SorLA is a member of the vacuolar protein sorting 10 protein (Vps10p) domain receptor family, which has structural homology with the LDLR family. METHODS AND RESULTS: Expression of SorLA was identified with its Vps10p family member Sort1 by transcriptomic analysis of murine aorta following CLA-induced regression of atherosclerosis. Decreased expression of both receptors was confirmed by real-time PCR in the aorta of CLA-supplemented mice. SorLA protein expression was predominantly localised to monocyte/macrophage cells in the vasculature by immunohistochemistry. CLA and the PPAR-γ agonists, troglitazone, and 15-deoxy-prostaglandin (PG) J(2), decreased protein and RNA expression of SorLA in THP-1 monocytes; while pre-treatment with a PPAR-γ antagonist established a PPAR-γ dependent role for CLA regulation of SorLA. CLA inhibits monocyte migration. Consistent with a role for SorLA in mediating this response, overexpression of SorLA increased migration of THP-1 monocytes to monocyte chemoattractant protein-1 with a coincident increase in UPAR expression. CONCLUSION: CLA may mediate its atheroprotective effects in part through reduced expression of SorLA and a resulting inhibition of monocyte migration in vitro.

Radiation-inducible silencing of uPA and uPAR in vitro and in vivo in meningioma.

Stereospecific radiation treatment offers a distinct opportunity for temporal and spatial regulation of gene expression at tumor sites by means of inducible promoters. To this end, a plasmid, pCArG-U2, was constructed by incorporating nine CArG elements (in tandem) of EGR1 gene upstream to uPA and uPAR siRNA oligonucleotides in a pCi-neo vector. Radiation-induced siRNA expression was detected in a meningioma cell line (IOMM-Lee). Immunoblotting and RT-PCR analyses confirmed downregulation of uPA and uPAR. A similar effect was observed in transfected cells followed by H2O2 treatment. Moreover, pre-treatment of transfected cells with N-acetyl L-cysteine blocked the silencing of uPA and uPAR, which further confirmed the oxidative damage-mediated downregulation. Cell proliferation assays and Western blot analysis for apoptotic molecules confirmed cell death in a radiation-inducible fashion. Migration and matrigel invasion assays also revealed a marked decrease in migration and invasion. Immunocytochemistry showed a marked decrease in uPA and uPAR levels in transfected and irradiated cells. H&E staining revealed a decrease in the pre-established tumor volume among the animals treated with pCArG-U2 and radiation. Immunohistochemistry of the brain sections established with intracranial tumors also revealed a marked decrease in uPA and uPAR in a radiation-inducible fashion. Taken together, our data suggest pCArG-U2 as a suitable candidate for radiation-inducible gene therapy.

Survivin is an essential mediator of arthritis interacting with urokinase signalling.

Proto-oncogene survivin has recently been identified as a prognostic marker distinguishing patients with destructive rheumatoid arthritis (RA). In the present material of 132 RA patients and 82 controls, the levels of survivin correlated to urokinase (uPA) (r= 0.46), a plasminogen activator over-expressed in inflamed joints and known to exhibit potent arthritogenic properties. Here we evaluate the functional relationship between these proteins using primary synovial fibroblasts and leucocytes of RA patients, human monocytic (THP-1) and fibroblast (MRC-5) cell lines. Using inhibitors of intracellular signalling, we show that uPA and survivin share common transduction pathways in synovial fibroblasts being dependent on the activity of tyrosine kinases, phosphatidylinositide 3 kinase and mitogen effector kinase. Moreover, uPA production is significantly reduced in fibroblasts if survivin synthesis has been silenced by siRNA. Importantly, silencing of survivin in fibroblasts prevented their invasive growth in knee joints of severe combined immune deficient mice. Interaction of uPA with receptor up-regulates survivin expression in leucocytes. In turn, survivin is required for the up-regulation of uPA receptor on the cell surface. These findings indicate that survivin is an essential mediator of arthritogenic properties of uPA regulating its synthesis in synovial fibroblasts and uPAR expression in leucocytes. Close correlation between survivin and uPA levels in patients with RA supports the importance of this connection for the pathogenesis of arthritis.