Ornitholimnology: Effects of grazing by the Andean flamingo (Phoenicoparrus andinus)

Experimental exclusion of the Andean flamingo (Phoenicoparrus andinus) from shallow water areas of a salt lake in the Bolivian Andes caused large increases in the biomass of microorganisms inhabiting the surface sediments, especially a large diatom (Surirella wetzeli), amebas, ciliates, and nematodes. This is a conservative demonstration of the influences that water birds in general exert on the structure of aquatic ecosystems.

The analysis of decomposition methods for support vector machines

The support vector machine (SVM) is a new and promising technique for pattern recognition. It requires the solution of a large dense quadratic programming problem. Traditional optimization methods cannot be directly applied due to memory restrictions. Up to now, very few methods can handle the memory problem and an important one is the "decomposition method." However, there is no convergence proof so far. In this paper, we connect this method to projected gradient methods and provide theoretical proofs for a version of decomposition methods. An extension to bound-constrained formulation of SVM is also provided.We then show that this convergence proof is valid for general decomposition methods if their working set selection meets a simple requirement.

Synergistic growth inhibition of anaplastic large cell lymphoma cells by combining cellular ALK gene silencing and a low dose of the kinase inhibitor U0126

Abnormal expression of anaplastic lymphoma kinase (ALK) gene is an important pathogenic factor for anaplastic large cell lymphoma (ALCL). To study the function of ALK, an inducible short hairpin RNA (shRNA) system was stably introduced into cultured human ALCL cells. Inducing shRNA expression in the generated cells resulted in cellular ALK gene silencing and led to inactivation of multiple signaling pathways and growth arrest. Interestingly, a combination of ALK gene silencing with U0126, a kinase inhibitor specific for the extracellular signal-regulated kinases 1/2 pathway, resulted in an augmented reduction in cellular JunB expression. Functional studies indicated that combining ALK gene silencing with U0126 treatment provided a synergistic growth inhibition, which occurred faster and was more profound than with either treatment alone. This synergistic effect was also observed when measuring cell proliferation, apoptosis, and in vitro cell colony formation. Importantly, the combination of ALK gene silencing and U0126 had a prolonged inhibitory effect, preventing recovery of ALCL cell growth even after treatments were removed. Moreover, this synergistic inhibitory effect was confirmed in vivo using a mouse model with xenografted ALCL tumors. Our findings indicate that combining cellular ALK gene silencing with a low dose of U0126 may prove to be an effective and more specific therapeutic approach to treating ALCL.

N-3 vs. saturated fatty acids: effects on the arterial wall

Cardiovascular disease is a leading cause of death worldwide. Atherosclerosis and unstable plaques are underlying causes for cardiovascular diseases. Cardiovascular disease is associated with consumption of diets high in saturated fats. In contrast there is increasing evidence that higher intakes of dietary n-3 fatty acids decrease risk for cardiovascular disease. Recent studies are beginning to clarify how n-3 compared with saturated fatty acids influence cardiovascular disease risk via pathways in the arterial wall. In this paper we will review studies that report on mechanisms whereby dietary fatty acids affect atherosclerosis through modulation of arterial wall lipid deposition, inflammation, cell proliferation, and plaque vulnerability.

Simvastatin inhibits cytokine-stimulated Cyr61 expression in osteoblastic cells: a therapeutic benefit for arthritis

OBJECTIVE

To examine the effects of proinflammatory cytokines on Cyr61 expression in osteoblastic cells and the modulatory action of simvastatin, to assess the role of CREB in Cyr61 induction, and to investigate the relationship of osteoblastic expression of Cyr61 to disease progression in experimental arthritis.

METHODS

Cyr61 expression and CREB phosphorylation at serine 133 were examined by Western blotting. Promoter activity of Cyr61 was assessed by luciferase assay with promoter deletion/mutagenesis and forced expression/gene silencing of CREB. Interaction between CREB and the Cyr61 promoter was evaluated by electrophoretic mobility shift assay and chromatin immunoprecipitation. CCL2 expression was examined by Northern blotting and enzyme-linked immunosorbent assay. In rats with collagen-induced arthritis (CIA), osteoblastic expression of Cyr61 was examined by immunohistochemistry, and disease progression was assessed by clinical, radiographic, and histologic examination.

RESULTS

In primary human osteoblasts and U2OS cells, Cyr61 expression stimulated by tumor necrosis factor α, interleukin-1β (IL-1β), oncostatin M (OSM), and other IL-6-family cytokines was suppressed by simvastatin. In U2OS cells, simvastatin inhibited OSM-induced CREB phosphorylation and CREB-DNA binding. Knockdown of CREB by short hairpin RNA reduced Cyr61 synthesis. OSM-induced Cyr61 promoter activation was dependent on CRE-CREB interaction and inhibited by simvastatin. Cyr61 enhanced CCL2 expression by U2OS cells. Intraarticular injection of simvastatin inhibited CIA progression and diminished the number of Cyr61+ osteoblasts and infiltrating macrophages.

CONCLUSION

Simvastatin inhibited cytokine-stimulated Cyr61 expression in osteoblastic cells and suppressed disease progression and osteoblastic expression of Cyr61 in inflammatory arthritis. This finding indicates that simvastatin may have potential as a therapeutic agent for inflammatory arthritis.

Towards a combined prognostic index for survival in HIV infection: the role of 'non-HIV' biomarkers

BACKGROUND

As those with HIV infection live longer, 'non-AIDS' condition associated with immunodeficiency and chronic inflammation are more common. We ask whether 'non-HIV' biomarkers improve differentiation of mortality risk among individuals initiating combination antiretroviral therapy (cART).

METHODS

Using Poisson models, we analysed data from the Veterans Aging Cohort Study (VACS) on HIV-infected veterans initiating cART between 1 January 1997 and 1 August 2002. Measurements included: HIV biomarkers (CD4 cell count, HIV RNA and AIDS-defining conditions); 'non-HIV' biomarkers (haemoglobin, transaminases, platelets, creatinine, and hepatitis B and C serology); substance abuse or dependence (alcohol or drug); and age. Outcome was all cause mortality. We tested the discrimination (C statistics) of each biomarker group alone and in combination in development and validation data sets, over a range of survival intervals, and adjusting for missing data.

RESULTS

Of veterans initiating cART, 9784 (72%) had complete data. Of these, 2566 died. Subjects were middle-aged (median age 45 years), mainly male (98%) and predominantly black (51%). HIV and 'non-HIV' markers were associated with each other (P < 0.0001) and discriminated mortality (C statistics 0.68-0.73); when combined, discrimination improved (P < 0.0001). Discrimination for the VACS Index was greater for shorter survival intervals [30-day C statistic 0.86, 95% confidence interval (CI) 0.80-0.91], but good for intervals of up to 8 years (C statistic 0.73, 95% CI 0.72-0.74). Results were robust to adjustment for missing data.

CONCLUSIONS

When added to HIV biomarkers, 'non-HIV' biomarkers improve differentiation of mortality. When evaluated over similar intervals, the VACS Index discriminates as well as other established indices. After further validation, the VACS Index may provide a useful, integrated risk assessment for management and research.

Anti-tumor activity of histone deacetylase inhibitors and the effect on ATP-binding cassette in ovarian carcinoma cells

INTRODUCTION

Ovarian cancer is of worldwide importance, and has a significantly high mortality rate due to therapy failure. Drug resistance might be one of most importance factors. Histone deacetylase inhibitors (HDACi) have been reported to be a new class of promising anti-tumor agents, thus this study aimed to investigate the effect of HDAC on the chemo-resistance genes of human ovarian carcinoma cell lines.

METHODS

The expressions of ATP binding cassette (ABC) transporter genes, multidrug-resistant protein (MDR1) and multidrug resistance-associated proteins (MRP1 and 2) of ovarian cancer cell lines OC-109 and SK-OV-3 after HDACi treatment were determined.

RESULTS

HDACi, including sodium butyrate (NaB), suberoylanilide hydroxamic acid (SAHA) and trichostatin A (TSA) reduced ovarian cancer cell viability from 4.4% to 68.8%, in both dose- and time-dependent manners. The effect of HDACi on MDR1, MRP1, and MRP2 showed induced expression of MDR1 mRNA, but reduced mRNA expression of MRP1 and MRP2.

CONCLUSIONS

The effect of HDACi on the reduced viability of ovarian cancer cell lines, concomitant with the induced expression of MDR1 and reduced expression of MRP1 and 2, might provide additional benefits in the management of ovarian cancers in the future.

Ovarian carcinomatosis presenting as bilateral inguinal hernia: a brief report

The differential diagnosis for what may seem an inguinal hernia may be complex, as lateral pain may be of many types of origin. We report the case of a 48-year-old female patient who presented with a history of painful, progressively protruding soft bulging masses over the bilateral inguinal area and a 20-year history of head cancer and hepatitis B virus. Pathological analysis, gynecological ultrasound and abdominal computed tomography scan were required to make final determination. Final diagnosis was Stage IV ovarian carcinomatosis, which responded to chemotherapy. Initial diagnosis of inguinal hernia should not rule out other potential diagnoses, particularly in complex cases with other risk factors.

High-resolution spectroscopy of Lambda16N by electroproduction

An experimental study of the (16)O(e,e'K(+))(Lambda)(16)N reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e,e'K(+))Lambda, Sigma(0) exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76+/-0.16 MeV was obtained for (Lambda)(16)N with better precision than previous measurements on the mirror hypernucleus (Lambda)(16)O. Precise energies have been determined for peaks arising from a Lambda in s and p orbits coupled to the p(1/2) and p(3/2) hole states of the (15)N core nucleus.

A study of particulates and metallic element concentrations in temple

Concentrations of ambient suspended particulates were measured at Tzu Yun Yen temple in Taiwan (120 degrees , 34', 46.2''E, 24 degrees , 16', 17.1''N), where semi-open incense burning is characteristic. Many pilgrims from different areas with various beliefs visit the temple and burn incense. Samples were collected with a universal sampler used for measuring suspended particulate concentrations. Sampling period was from August 8, 2006, to October 6, 2006. The average PM(10) concentrations measured at the temple were 16% higher than 125 microg/m(3) (this value is the outdoor air quality standard according to Taiwan Environmental Protection Administration (EPA)). In coarse particulates (PM(2.5-10)), the mean metallic elements concentrations are in the order of Ca>Mg>Zn>Fe>Mn>Cr>Cu>Pb during weekend and weekday sampling. In addition, the fine particulates (PM(2.5)) mean metallic elements concentrations are in the order of Ca>Mg>Fe>Zn>Cr>Mn>Pb>Cu during weekend sampling and Ca>Fe>Mg>Zn>Cr>Mn>Pb>Cu during weekday sampling.

Cognitive deficits in multiple system atrophy correlate with frontal atrophy and disease duration

BACKGROUND AND PURPOSE

Dementia remains an exclusion criterion in diagnosing multiple system atrophy (MSA). This study aimed to determine the cognitive changes and brain atrophy patterns in the Parkinsonian (MSA-P) and cerebellar (MSA-C) variants of MSA.

METHODS

Voxel-based morphometry (VBM) of magnetic resonance imaging (MRI) and neuro-psychological tests were applied to 10 MSA-C and 13 MSA-P patients, and compared to 37 age-matched controls. Correlation analyses were performed between cognitive test results and morphometric data extracted from the VBM data.

RESULTS

In neuro-psychological testing, the 23 MSA patients scored lower in the Stroop interference test and took longer in the trail-making test as compared with the controls, whereas MSA-C performed worse than MSA-P in the memory scores, Stroop test, and time to complete the trail-making test. MSA, as a group, showed atrophy in the cerebellum, insular cortex, fusiform gyrus, inferior orbito-frontal gyrus, superior temporal gyrus, and caudate nucleus. Memory scores correlated well with pre-frontal lobe atrophy but not in the insular area.

CONCLUSION

In conclusion, although dementia is not a typical presenting feature of MSA and is regarded as a sub-cortical movement disorder, frontal atrophy, cognitive changes, and dementia are identifiable as MSA progresses.

Assessment of dose rate scaling factors used in NCTPlan treatment planning code for the BNCT beam of THOR

Tsing Hua open-pool reactor (THOR) at Tsing Hua University in Taiwan has been used to investigate the feasibility and to enhance the technology of boron neutron capture therapy (BNCT) for years. A rebuilt epithermal beam port for BNCT at THOR was finished in the summer of 2004, and then researches and experiments were performed to hasten the first clinical treatment case of BNCT in Taiwan in the near future. NCTPlan, a Monte Carlo-based clinical treatment planning code, was used to calculate the dose-rate distributions of BNCT in this work. A self-made Snyder head phantom with a servo-motor control system was irradiated in front of the THOR BNCT beam exit. The phantom was made from a 3mm shell of quartz wool impregnated with acrylic casting resin mounted on an acrylic base, and was filled with water. Gold foils (bare and cadmium-covered) and paired ion chambers (one with graphite wall and filled with CO(2) gas, another with A-150 plastic tissue equivalent wall and filled with tissue equivalent gas) were placed inside the Snyder phantom to measure and estimate the depth-dose distributions in the central axis of the beam. Dose components include the contribution of thermal neutrons, fast neutrons, photons and emitted alpha particles from (10)B(n,alpha)(7)Li reaction. Comparison and analysis between computed and measured results of depth-dose distributions were made in this work. Dose rate scaling factors (DRSFs) were defined as normalization factors derived individually for each dose component in the BNCT in-phantom radiation field that provide the best agreement between measured and computed data. This paper reports the in-phantom calculated and experimental dosimetry and the determined DRSFs used in NCTPlan code for the BNCT beam of THOR.

High-pressure needle interface for thermoplastic microfluidics

A robust and low dead volume world-to-chip interface for thermoplastic microfluidics has been developed. The high pressure fluidic port employs a stainless steel needle inserted into a mating hole aligned to an embedded microchannel, with an interference fit used to increase pressure resistance. Alternately, a self-tapping threaded needle screwed into a mating hole is also demonstrated. In both cases, the flat bottom needle ports seat directly against the microchannel substrate, ensuring low interfacial dead volumes. Low dispersion is observed for dye bands passing the interfaces. The needle ports offer sufficient pull-out forces for applications such as liquid chromatography that require high internal fluid pressures, with the epoxy-free interfaces compatible with internal microchannel pressures above 40 MPa.

Is planned surgery important in sinonasal inverted papilloma?

OBJECTIVE

To evaluate which clinical characteristics of inverted papilloma (IP) can result easily in misdiagnosis by clinicians and to determine the recurrence rate of inverted papilloma depending on diagnosis confirmation pre-operatively, intra-operatively or post-operatively.

PATIENTS AND METHODS

Fifty-one patients were treated for IP and 47 patients attended regular post-operative follow-up appointments for at least one year (mean: 54 months).

RESULTS

The patients were assigned to 3 groups: group Ia, in which IP was not confirmed until the post-operative pathology findings; group Ib, in which IP was confirmed during the operation; and group II, in which IP was confirmed before the operation. There were nineteen (37%) patients in group Ia, nine patients (18%) in group Ib and twenty-three patients (45%) in group II. The recurrence rates for groups Ia, Ib and II were 33%, 11% and 5% respectively.

CONCLUSIONS

The initial presentation of bilateral sinonasal disease can easily lead the doctor into the misdiagnosis of IP. Bony erosion, remodelling, and a widening of the natural orifice of the sinuses on a CT scan are useful signs indicating IP. The correct diagnosis prior to surgery is a determinant of outcome. The use of frozen sections should, however, improve outcome as well. In this study we highlight the high prevalence and relatively low control rate of misdiagnosed IP (pathology undetermined pre-operatively) and hope to remind clinicians that early recognition of the tumour is most beneficial to patients.

Identification of calreticulin as a prognosis marker and angiogenic regulator in human gastric cancer

The purpose of this study was to identify genes of interest for a subsequent functional and clinical cohort study using complementary (c)DNA microarrays. cDNA microarray hybridization was performed to identify differentially expressed genes between tumor and nontumor specimens in 30 gastric cancer patients. Subsequent functional studies of the selected gene were carried out, including cell cycle analysis, cell migration analysis, analyses of vascular endothelial growth factor (VEGF) and placenta growth factor (PlGF), and oligo-microarray studies using two pairs of stable cell lines of the selected gene. Another independent cohort study of 79 gastric cancer patients was conducted to evaluate the clinical significance of the selected gene in human gastric cancer. Calreticulin (CRT) was selected for further investigation. Two pairs of stable cell lines of CRT overexpression and CRT knockdown were constructed to perform functional studies. CRT enhanced gastric cancer cell proliferation and migration. Overexpressed CRT upregulated the expression and secretion of PlGF and VEGF. CRT had a reciprocal effect on connective tissue growth factor (CTGF) expression. Positive immunohistochemical staining of calreticulin was significantly correlated with high microvessel density (MVD) (p = 0.014), positive serosal invasion (p = 0.013), lymph node metastasis (p = 0.002), perineural invasion (p = 0.008), and poor patient survival (p = 0.0014). Multivariate survival analysis showed that CRT, MVD, and serosal invasion were independent prognosticators. We conclude that CRT overexpression enhances angiogenesis, and facilitates proliferation and migration of gastric cancer cells, which is in line with the association of CRT with MVD, tumor invasion, lymph node metastasis, and survival in gastric cancer patients.

Breast tumor kinase phosphorylates p190RhoGAP to regulate rho and ras and promote breast carcinoma growth, migration, and invasion

Breast tumor kinase (Brk), an Src-like nonreceptor tyrosine kinase, is overexpressed in breast cancer and several other cancer types. Our previous study indicates that Brk promotes cell migration and tumor invasion by phosphorylating the focal adhesion protein paxillin. Here, we report the identification of p190RhoGAP-A (p190) as a Brk substrate. Brk phosphorylates p190 at the Y(1105) residue both in vitro and in vivo, thereby promoting the association of p190 with p120RasGAP (p120). As a consequence, Brk stimulates p190 and attenuates p120 functions, leading to RhoA inactivation and Ras activation, respectively. In carcinoma cells expressing high levels of Brk, endogenous Brk functions as a key contributor to epidermal growth factor-induced p190 tyrosine phosphorylation. We present evidence showing that p190 phosphorylation plays essential roles in both migratory and proliferative effects of Brk. Furthermore, disruption of p190 phosphorylation-induced p190/p120 complex in breast cancer cells abolishes not only the abilities of Brk to regulate RhoA and Ras but also the stimulatory effects of Brk on proliferation, migration, invasion, transformation, and tumorigenicity. Together, our findings reveal a previously unknown function of Brk in regulating both RhoA and Ras by phosphorylating p190 and provide evidence for the crucial roles of this Brk-elicited signaling pathway in promoting breast malignancy.

Quark-hadron duality in neutron (3He) spin structure

We present experimental results of the first high-precision test of quark-hadron duality in the spin-structure function g_{1} of the neutron and 3He using a polarized 3He target in the four-momentum-transfer-squared range from 0.7 to 4.0 (GeV/c);{2}. Global duality is observed for the spin-structure function g_{1} down to at least Q;{2}=1.8 (GeV/c);{2} in both targets. We have also formed the photon-nucleon asymmetry A1 in the resonance region for 3He and found no strong Q2 dependence above 2.2 (GeV/c);{2}.

RNA-binding protein insulin-like growth factor II mRNA-binding protein 3 expression promotes tumor invasion and predicts early recurrence and poor prognosis in hepatocellular carcinoma

Insulin-like growth factor II mRNA-binding protein 3 (IMP3) is an RNA-binding protein expressed in embryonic tissues and multiple cancers. To investigate the role of IMP3 in hepatocellular carcinoma (HCC), its protein expression in the surgically resected unifocal tumors of 377 HCC patients (296 men and 81 women) with ages ranging from 7 to 88 years (mean, 55.49 years) was analyzed by immunohistochemistry. IMP3 was expressed in 255 (67.6%) of 377 resected unifocal primary HCCs. IMP3 protein was predominantly expressed in tumor border and invasive front, and it was more abundant in the satellite nodules and tumor thrombi than in the main tumors. The expression correlated with high alpha-fetoprotein (>200 ng/mL, P < 1 x 10(-7)), larger tumor size (>5 cm, P = 0.006), high tumor grade (P < 1 x 10(-7)), and high tumor stage with vascular invasion and various degrees of intrahepatic metastasis (P < 1 x 10(-7)). IMP3 expression predicted early tumor recurrence (P < 1 x 10(-7)) and was a strong indicator of poor prognosis (P < 0.0001). Depletion of IMP3 with RNA interference in HCC cell line HA22T caused a decrease in cell motility, invasion, and transendothelial migration. Microarray analysis revealed that IMP3 depletion was associated with downregulation of multiple genes involved in tumor invasion.

CONCLUSION

Our results indicate that IMP3 plays an important role in tumor invasion and metastasis and is a strong prognostic factor for patients with HCC.

Malaysian Psoriasis Registry--preliminary report of a pilot study using a newly revised registry form

The Malaysian Psoriasis Registry, established in 1998, is the first skin disease clinical registry in Malaysia. It aims to provide useful data on various aspects of psoriasis. Following an extensive revision of the registry form in 2007, a total of 509 psoriasis patients from 10 government dermatologic centres were reviewed in a three month pilot study. The onset of psoriasis was during the second to fourth decade of life in the majority of patients. There was no sexual and ethnic predilection. A positive family history was present in 21.2%, and more common in patients with younger disease onset. The main aggravating factors of psoriasis were stress, sunlight and infection. Plaque psoriasis was the commonest clinical type (80.9%). Joint disease was present in 17.3% of patients, among which mono-/oligoarticular type being the commonest. Nail changes occurred in 68%. More psoriasis patients were overweight and obese compared to the normal population. The mean Dermatologic Life Quality Index (DLQI) score was 8.08 +/- 6.29, and changes during subsequent follow-up may reflect therapeutic effectiveness. This study enabled evaluation of the revised registry form and helped in identifying shortcomings in the implementation of the registry.

Lysophosphatidic acid upregulates vascular endothelial growth factor-C and tube formation in human endothelial cells through LPA(1/3), COX-2, and NF-kappaB activation- and EGFR transactivation-dependent mechanisms

Lysophosphatidic acid (LPA) is a lipid bioactive mediator which binds to G-protein-coupled receptors and activates a variety of cellular functions. LPA modulates multiple behaviors in endothelial cells, including cell proliferation and migration, capillary-like tube formation in vitro, activation of proteases, interactions with leukocytes, and expressions of inflammation-related genes, thereby regulating vessel formation. LPA has been reported to modulate the angiogenesis process. However, the role of LPA in the lymphangiogenesis process has not been studied. In this study, we showed that LPA upregulated vascular endothelial growth factor-C (VEGF-C) mRNA expression in human umbilical vein endothelial cells (HUVECs) and subsequent endothelial cell tube formation in vitro and in vivo. These enhancement effects were LPA(1)- and LPA(3)-dependent and required cyclooxygenase-2 (COX-2), endothelial growth factor receptor (EGFR) transactivation and activation of nuclear factor kappaB (NF-kappaB). Moreover, LPA induced the protein expressions of the lymphatic markers, Prox-1, LYVE-1, and podoplanin, in HUVECs, and these enhancement effects were dependent on LPA(1) and LPA(3) activation and EGFR transactivation. Our results demonstrated that LPA might regulate VEGF-C and lymphatic marker expression in endothelial cells, which contributes to endothelial cell tube formation in vitro and in vivo, thus facilitating endothelial cell participation in the lymphangiogenesis process. This study clarifies the signaling mechanism of LPA-regulated VEGF-C expression and lymphatic marker expressions in endothelial cells, which suggest that LPA may be a suitable target for generating therapeutics against lymphangiogenesis and tumor metastasis.

Involvement of hypoxia-inducing factor-1alpha-dependent plasminogen activator inhibitor-1 up-regulation in Cyr61/CCN1-induced gastric cancer cell invasion

Cysteine-rich 61 (Cyr61/CCN1), one of the members of CCN family, has been implicated in the progression of human malignancies. Previously, our studies have demonstrated that Cyr61/CCN1 has a role in promoting gastric cancer cell invasion, but the mechanism is not clear yet. Here, we found that hypoxia-inducing factor-1alpha (HIF-1alpha) protein, but not mRNA, expression was significantly elevated in gastric cancer cells overexpressing Cyr61. Supportively, a profound reduction of endogenous HIF-1alpha protein was noted in one highly invasive cell line, TSGH, when transfected with antisense Cyr61. By comparison, the induction kinetics of HIF-1alpha protein by recombinant Cyr61 (rCyr61) was distinct from that of insulin-like growth factor-1 and CoCl(2) treatment, both well known for induction of HIF-1alpha. Using cycloheximide and MG132, we demonstrated that the Cyr61-mediated HIF-1alpha up-regulation was through de novo protein synthesis, rather than increased protein stability. rCyr61 could also activate the PI3K/AKT/mTOR and ERK1/2 signaling pathways, both of which were essential for HIF-1alpha protein accumulation. Blockage of HIF-1alpha activity in Cyr61-expressing cells by transfecting with a dominant negative (DN)-HIF-1alpha strongly inhibited their invasion ability, suggesting that elevation in HIF-1alpha protein is vital for Cyr61-mediated gastric cancer cell invasion. In addition, several HIF-1alpha-regulated invasiveness genes were examined, and we found that only plasminogen activator inhibitor-1 (PAI-1) showed a significant increase in mRNA and protein levels in cells overexpressing Cyr61. Treatment with PAI-1-specific antisense oligonucleotides or function-neutralizing antibodies abolished the invasion ability of the Cyr61-overexpressing cells. Transfection with dominant negative-HIF-1alpha to block HIF-1alpha activity also effectively reduced the elevated PAI-1 level. In conclusion, our data provide a detailed mechanism by which Cyr61 promoted gastric cancer cell invasive ability via an HIF-1alpha-dependent up-regulation of PAI-1.