5,812 research outputs found

    TFPI-2 is a putative tumor suppressor gene frequently inactivated by promoter hypermethylation in nasopharyngeal carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Epigenetic silencing of tumor suppressor genes play important roles in NPC tumorgenesis. Tissue factor pathway inhibitor-2 (TFPI-2), is a protease inhibitor. Recently, <it>TFPI-2 </it>was suggested to be a tumor suppressor gene involved in tumorigenesis and metastasis in some cancers. In this study, we investigated whether <it>TFPI-2 </it>was inactivated epigenetically in nasopharyngeal carcinoma (NPC).</p> <p>Methods</p> <p>Transcriptional expression levels of <it>TFPI-2 </it>was evaluated by RT-PCR. Methylation status were investigated by methylation specific PCR and bisulfate genomic sequencing. The role of <it>TFPI-2 </it>as a tumor suppressor gene in NPC was addressed by re-introducing <it>TFPI-2 </it>expression into the NPC cell line CNE2.</p> <p>Results</p> <p><it>TFPI-2 </it>mRNA transcription was inactivated in NPC cell lines. <it>TFPI-2 </it>was aberrantly methylated in 66.7% (4/6) NPC cell lines and 88.6% (62/70) of NPC primary tumors, but not in normal nasopharyngeal epithelia. <it>TFPI-2 </it>expression could be restored in NPC cells after demethylation treatment. Ectopic expression of TFPI-2 in NPC cells induced apoptosis and inhibited cell proliferation, colony formation and cell migration.</p> <p>Conclusions</p> <p>Epigenetic inactivation of <it>TFPI-2 </it>by promoter hypermethylation is a frequent and tumor specific event in NPC. <it>TFPI-2 </it>might be considering as a putative tumor suppressor gene in NPC.</p

    Expression and methylation status of tissue factor pathway inhibitor-2 gene in non-small-cell lung cancer

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    Tissue factor pathway inhibitor-2 (TFPI-2) is a Kunitz-type serine proteinase inhibitor that inhibits plasmin-dependent activation of several metalloproteinases. Downregulation of TFPI-2 could thus enhance the invasive potential of neoplastic cells in several cancers, including lung cancer. In this study, TFPI-2 mRNA was measured using a real-time PCR method in tumours of 59 patients with non-small-cell lung cancer (NSCLC). Tumour TFPI-2 mRNA levels appeared well correlated with protein expression evaluated by immunohistochemistry and were 4ā€“120 times lower compared to those of nonaffected lung tissue in 22 cases (37%). Hypermethylation of the TFPI-2 gene promoter was demonstrated by restriction enzyme-polymerase chain reaction in 12 of 40 cases of NSCLC (30%), including nine of 17 for whom tumour TFPI-2 gene expression was lower than in noncancerous tissue. In contrast, this epigenetic modification was shown in only three of 23 tumours in which no decrease in TFPI-2 synthesis was found (P=0.016). Decreased TFPI-2 gene expression and hypermethylation were more frequently associated with stages III or IV NSCLC (eight out of 10, P=0.02) and the TFPI-2 gene promoter was more frequently hypermethylated in patients with lymph node metastases (eight out of 16, P=0.02). These results suggest that silencing of the TFPI-2 gene by hypermethylation might contribute to tumour progression in NSCLC

    Tissue factor pathway inhibitor (TFPI) in patients with occlusive arterial diseases in consideration with risk factors and conservative treatment of the disease

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    Celem badań była ocena stężenia TFPI u chorych na zarostowe choroby tętnic kończyn dolnych oraz zbadanie korelacji stężenia TFPI z wybranymi czynnikami ryzyka rozwoju tych chorĆ³b: paleniem tytoniu, hiperlipidemią, a także z wiekiem. Dodatkowo oceniano wpływ leczenia zachowawczego u chorych na zarostową miażdżycę tętnic kończyn dolnych na stężenie TFPI. Stężenie czynnika tkankowego i jego inhibitora nie rĆ³Å¼niło się wśrĆ³d osĆ³b zdrowych z poszczegĆ³lnych grup wiekowych, bez klinicznych objawĆ³w chorĆ³b naczyń. U chorych na zarostową miażdżycę tętnic kończyn dolnych oraz u chorych na chorobę Buergera wykazano istotnie wyższe stężenie TFPI niż u osĆ³b zdrowych - odpowiednio 333,3 &plusmn; 100,2 ng/ml, 177,9 &plusmn; 67,1 ng/ml, 95,7 &plusmn; 25,3 ng/ml. Nie stwierdzono istotnych rĆ³Å¼nic średniego stężenia TFPI w grupach zdrowych osĆ³b: niepalących tytoniu, aktualnie palących tytoń czy palących tytoń w przeszłości. Leczenie zachowawcze alprostadylem i pentoksyfiliną nie wpłynęło istotnie na stężenie TFPI u chorych na zarostową miażdżycę tętnic kończyn dolnych. Wyniki badań sugerują, że podwyższone stężenie TFPI u chorych na zarostowe choroby tętnic zależy gÅ‚Ć³wnie od stanu śrĆ³dbłonka naczyniowego.The aim of the study was to determine the level of tissue factor pathway inhibitor (TFPI) in patients with arterial occlusive diseases of the lower limbs and to consider correlation of TFPI with some risk factors of the development of these diseases: cigarette smoking, hyperlipidaemia and age. The effect of conservative treatment with pentoxifylline and alprostadil of the peripheral arterial occlusive disease (PAOD) on plasma concentration of TFPI was also investigated. TFPI concentration was not dependent on the age of healthy per sons. Patients with PAOD or Buerger`s disease showed elevated concentrations of TFPI compared to healthy adults without any symptoms of the arterial disease, 333.3 &plusmn; 100.2 ng/mL, 177.9 &plusmn; 67.1 ng/mL, 95.7 &plusmn; &plusmn; 25.3 ng/mL respectively. There are no significant differences of TFPI concentration in smokers, former smokers and non-smokers in the group of healthy persons. Conservative treatment of PAOD with pentoxifylline or alprostadil had no effect on TFPI concentration in patients with PAOD. The results of the study suggest, that the elevated TFPI concentration in patients with arterial occlusive diseases mainly depends on state of the vascular endothelium

    Reduced expression of tissue factor pathway inhibitor-2 contributes to apoptosis and angiogenesis in cervical cancer

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    <p>Abstract</p> <p>Background</p> <p>Tissue factor pathway inhibitor-2 (TFPI-2) is an extracellular matrix associated broad-spectrum Kunitz-type serine proteinase inhibitor. Recently, down regulation of TFPI-2 was suggested to be involved in tumor invasion and metastasis in some cancers.</p> <p>Methods</p> <p>This study involved 12 normal cervical squamous epithelia, 48 cervical intraepithelial neoplasia (CIN), and 68 cervical cancer. The expression of TFPI-2, Ki-67 and vascular endothelial growth factor (VEGF) were investigated by immunohistochemistry staining. The apoptolic index(AI) was determined with an in situ end-labeling assay(TUNEL). And the marker of CD34 staining was used as an indicator of microvessel density (MVD).</p> <p>Results</p> <p>TFPI-2 expression has a decreasing trend with the progression of cervical cancer and was significantly correlated with FIGO stage, lymph node metastasis and HPV infection. In addition, there were significant positive correlations between the grading of TFPI-2 expression and AI(P = 0.004). In contrast, the expression of TFPI-2 and VEGF or MVD was negatively correlated (both p < 0.001). However, we did not establish any signiļ¬cant correlation between Ki-67 and TFPI-2 expression in cervical cancer.</p> <p>Conclusions</p> <p>The results suggested that the expression of TFPI-2 had a decreasing trend with tumor progression of cervical cancer. There was a close association between the expression of TFPI-2 and tumor cell apoptosis and angiogenesis in patients with cervical cancer. TFPI-2 may play an inhibitive role during the development of cervical cancer.</p

    Role of tissue factor pathway inhibitor-2 in the expressions of matrix metallopro- teinases in keratocytes in vitro

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    AIM:To elucidate the relation between tissue factor pathway inhibitor-2(TFPI-2)expression and the expression of matrix metalloproteinases(MMPs)in keratocytes. METHODS: Primary culture and subculture of rabbit keratocytes were established in vitro. Plasmid vector pBos-Cite-neo/TFPI-2 was transfected into keratocytes with Lipofectamine 2000. After being selected by G418, three groups of cells including TFPI-2 gene transfected cells K-TFPI-2, empty vector transfected cells K-V and non-transfected cells K-P were screened for TFPI-2 mRNA and protein by reverse transcription-polymerase chain reaction and Western blot analysis, respectively. The activity of MMPs in the three groups of cells was detected by substrate zymography and compared by ANOVA. RESULTS: Expression of mRNA and protein of TFPI-2 was more in the cells of K-TFPI-2 than in the other cells of K-P and K-V with a significant difference(mRNA:0.79Ā±0.02 vs 0.51Ā±0.03 and 0.48Ā±0.02, P=0.000 and P=0.000; Protein:24.5Ā±0.8 vs 15.5Ā±0.5 and 14.9Ā±0.9,P=0.000 and P=0.000). Compared with the two groups of K-P and K-V, the cells of K-TFPI-2 had a significant decreased activity of MMP1(12.3Ā±0.7 vs 16.7Ā±1.2 and 15.9Ā±0.7, P=0.001 and P=0.003)and MMP2(15.4Ā±1.3 vs 18.2Ā±1.1 and 17.8Ā±1.1, P=0.027 and P=0.046). CONCLUSION: It is suggested that the expression of TFPI-2 may strongly inhibit the activity of MMPs in keratocytes in vitro, which provides an experimental basis for curing CNV with gene therapy

    The Release of Tissue Factor Pathway Inhibitor and Platelet Factor 4 After Heparin Injection in Patients with Thrombocytosis.

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    Platelet factor 4 (PF4) and tissue factor pathway inhibitor (TFPI) are two proteins with high affinity for heparin. They are each stored in platelets, as well as on endothelial cell surfaces, from where both are displaced or released following an injection of heparin with a rapid and marked increase in serum levels. Prior work has demonstrated that the platelet count is one of the factors affecting the levels of heparin-releasable PF4. We therefore characterized the response to a dose of intravenous heparin previously demonstrated to completely displace PF4 from the non-platelet pool in subjects with normal or increased platelet counts. Seventeen patients with essential thrombocytosis (ET), 10 patients with polycythemia vera and high platelet counts (PV-H), 7 patients with polycythemia vera and normal platelet counts (PV-N) and 10 controls received an initial bolus of 40 I.U./kg of unfractionated heparin, followed 2 hours later by a 2nd bolus of a fixed dose of 1000 I.U. TFPI activity did not show any variation among the different groups, either before (TFPI) or after (HR-TFPI) the first bolus of heparin: ET, TFPI 92.6 Ā± 21.5%, HR-TFPI 298.3 Ā± 165.8; PV-H, TFPI 91.5 Ā± 32.0, HR-TFPI 210 Ā± 1.0; PV-N, TFPI 69.4 Ā± 24.0, HR-TFPI 203.0 Ā± 79.0; C, TFPI 109.5 Ā± 33.5, HR-TFPI 234.0 Ā± 60.4. TFPI activity returned to basal values prior to the 2nd injection of heparin, which again elicited a rise in TFPI, albeit smaller due to the lower level of heparin injected. In contrast to the lack of any difference between groups with respect to TFPI, the level of heparin-releasable PF4 (HR-PF4) was significantly higher in ET and PV-H patients compared to PV-N patients or controls. However when normalized for platelet count, both PV-H and PV-N had HR-PF4 levels after the 1st heparin injection that were significantly higher than observed in ET patients (PV-H 1.163 + 0.108, PV-N 1.411 + 0.019, ET 0.737 + 0.086 ng/10/3 platelets) supporting an increased platelet activation in PV. Thus, although platelets contain approximately 5-10% of the total amount of TFPI in plasma, they do not affect the major intravascular pool of TFPI mobilizable by heparin. However, since the concentration at the site of vessel wall injury is enhanced several-fold, TFPI could play a role in competing with PF4 to limit thrombus formation in patients with high platelet count

    Impact of the tissue factor pathway inhibitor gene on apoptosis in human vascular smooth muscle cells

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    Tissue factor pathway inhibitor (TFPI) plays a vitally important role in the blood coagulation pathway. Recent studies indicated that TFPI induces apoptosis in vascular smooth-muscle cells (VSMCs) in animals. The present study investigated whether the TFPI gene could also induce apoptosis in human vascular smooth-muscle cells (hVSMCs). Such cells were isolated from human umbilical arteries and subsequently transfected with pIRES-TFPI plasmid (2 Ī¼g/mL). MTT assaying and cell counting were applied to measure cell viability and proliferation, RT-PCR was utilized to analyze TFPI gene expression in the cells. Apoptosis was analyzed by fluorescence activated cell sorting (FACS). Several key proteins involved in apoptosis were examined through Western blotting. It was shown that TFPI gene transfer led to its increased cellular expression, with a subsequent reduction in hVSMC proliferation. Further investigation demonstrated that TFPI gene expression resulted in lesser amounts of procaspase-3, procaspase-8 and procascase-9, and an increased release of mitochondrial cytochrome c (cyt-c) into cytoplasm, thereby implying the involvement of both extrinsic and intrinsic pathways in TFPI gene-induced apoptosis in hVSMCs

    Concizumab restores thrombin generation potential in patients with haemophilia: Pharmacokinetic/pharmacodynamic modelling results of concizumab phase 1/1b data

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    Introduction: Concizumab enhances thrombin generation (TG) potential in haemophilia patients by inhibiting tissue factor pathway inhibitor (TFPI). In EXPLORER3 (phase 1b), a doseā€dependent pharmacokinetic/pharmacodynamic (PK/PD) relationship was confirmed between concizumab dose, free TFPI and TG potential. Aim: Determine the association between concizumab exposure, PD markers (free TFPI; peak TG) and bleeding episodes to establish the minimum concizumab concentration for achieving sufficient efficacy. Methods: Free TFPI predictions were generated using an estimated concizumabā€free TFPI exposureā€response (Emax) model based on concizumab phase 1/1b data for which simultaneously collected concizumab and free TFPI samples were available. Concizumab concentration at the time of a bleed was predicted using a PK model, based on available data for concizumab doses >50 Ī¼g/kg to ā‰¤9 mg/kg. Peak TG vs concizumab concentration analyses and an Emax model were constructed based on EXPLORER3 observations. Results: The Emax model showed a tight PK/PD relationship between concizumab exposure and free TFPI; free TFPI decreased with increasing concizumab concentration. A strong correlation between concizumab concentration and peak TG was observed; concizumab >100 ng/mL reā€established TG potential to within the normal reference range. Estimated EC50 values for the identified concizumabā€free TFPI and concizumabā€TG potential models were very similar, supporting free TFPI as an important biomarker. A correlation between bleeding episode frequency and concizumab concentration was indicated; patients with a concizumab concentration >100 ng/mL experienced less frequent bleeding. The PK model predicted that onceā€daily dosing would minimize withinā€patient concizumab PK variability.Novo Nordis

    Tissue factor pathway inhibitor-2 was repressed by CpG hypermethylation through inhibition of KLF6 binding in highly invasive breast cancer cells

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    <p>Abstract</p> <p>Background</p> <p>Tissue factor pathway inhibitor-2 (TFPI-2) is a matrix-associated Kunitz inhibitor that inhibits plasmin and trypsin-mediated activation of zymogen matrix metalloproteinases involved in tumor progression, invasion and metastasis. Here, we have investigated the mechanism of DNA methylation on the repression of TFPI-2 in breast cancer cell lines.</p> <p>Results</p> <p>We found that both protein and mRNA of TFPI-2 could not be detected in highly invasive breast cancer cell line MDA-MB-435. To further investigate the mechanism of TFPI-2 repression in breast cancer cells, 1.5 Kb TFPI-2 promoter was cloned, and several genetic variations were detected, but the promoter luciferase activities were not affected by the point mutation in the promoter region and the phenomena was further supported by deleted mutation. Scan mutation and informatics analysis identified a potential KLF6 binding site in TFPI-2 promoter. It was revealed, by bisulfite modified sequence, that the CpG island in TFPI-2 promoter region was hypermethylated in MDA-MB-435. Finally, using EMSA and ChIP assay, we demonstrated that the CpG methylation in the binding site of KLF-6 diminished the binding of KLF6 to TFPI-2 promoter.</p> <p>Conclusion</p> <p>In this study, we found that the CpG islands in TFPI-2 promoter was hypermethylated in highly invasive breast cancer cell line, and DNA methylation in the entire promoter region caused TFPI-2 repression by inducing inactive chromatin structure and decreasing KLF6 binding to its DNA binding sequence.</p
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