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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the effect of cell surface glycosaminoglycans (GAGs) on the inactivation of factor VIIa-tissue factor activity by antithrombin III (ATIII) on a human bladder carcinoma (J82) cell line and an ovarian carcinoma (OC-2008) cell line, two tumor cell lines which constitutively synthesize and express high levels of cell surface tissue factor. We observed that ATIII inactivated factor VIIa-tissue factor more readily on OC-2008 cells than on J82 cells in the absence of added heparin. Likewise, factor Xa was more effectively inactivated on OC-2008 cells than on J82 cells. The ability of ATIII to inactivate factor VIIa-tissue factor activity on the OC-2008 cell was reduced following treatment of the cells with heparinase. This indicated that heparin-like GAGs were expressed on the OC-2008 cell surface, and that these GAGs were important for the inhibition of factor VIIa-tissue factor activity by ATIII. In addition, we demonstrated that the ability of ATIII to inactivate factor VIIa-tissue factor activity was markedly reduced following treatment of cells with calcium ionophore (A23187). However, the effect of cell surface GAGs on the inhibition of factor Xa by ATIII remained even after treatment of OC-2008 cells with A23187. In contrast to the manner of inhibition by ATIII/heparin, TFPI effectively inactivated factor VIIa-tissue factor activity on the cell surfaces even after induced physical damage or disruption of the cell by treatment with A23187. Our collective findings suggest that GAGs on cell surfaces play an important role in regulating factor VIIa-tissue factor activity by ATIII under normal conditions, or in the early phases of physical damage or destruction of the cell. However, TFPI may play a more important role than ATIII in regulating the activity of factor VIIa-tissue factor in a vascular trauma site following extensive cell injury.
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PMID:The effect of cell surface glycosaminoglycans (GAGs) on the inactivation of factor VIIa--tissue factor activity by antithrombin III. 971 70

Engineering of recombinant coagulation factor X variants, which can be activated by tumor-associated proteinases may lead to the development of new therapeutic molecules. However, the evaluation of such variants requires an appropriate animal model. Therefore, we isolated the complete coding sequence of mouse coagulation factor X from mouse liver cDNA by polymerase chain reaction. The deduced amino acid sequence codes for a prepro protein of 481 amino acids homologous to factor X sequences from various species. Recombinant mouse factor X was expressed in human embryonic kidney cells and secreted into cell culture supernatant as zymogen, which could be converted to catalytically active factor Xa by Russell's viper venom. Purified recombinant mouse factor X restored coagulation in human factor X deficient plasma, demonstrating that mouse factor X is able to functionally interact with the human blood coagulation system. Recombinant mouse factor X opens the possibility to analyze therapeutically useful variants in the mouse system.
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PMID:Cloning and recombinant expression of mouse coagulation factor X. 978 72

Eight cats with visceral or cutaneous hemangiosarcoma were evaluated, and unusual metastatic and clinicopathologic behavior was evident in each. Cutaneous hemangiosarcoma is generally believed to be locally aggressive and slow to metastasize. These 8 cats with cutaneous hemangiosarcoma, however, developed metastatic disease after initial surgical resection; only 1 had local regrowth of the tumor. All cats with visceral hemangiosarcoma had metastasis at the time of diagnosis, which is consistent with cats of other reports. Three of 8 cats had evidence of disseminated intravascular coagulation, including increased prothrombin time and partial thromboplastin time, decreased number of platelets, and anemia. These potential complications need to be considered when planning diagnostic and treatment protocols.
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PMID:Unusual metastatic behavior and clinicopathologic findings in eight cats with cutaneous or visceral hemangiosarcoma. 1008 16

Sixty female dogs with untreated mammary carcinoma, comprising equal numbers of dogs in tumour stages I to IV, were evaluated for haemostatic abnormalities using the following tests: platelet count, prothrombin time, activated partial thromboplastin time, thrombin time, plasma activity of factor V, VIII and X, plasma concentration of fibrinogen, fibrin monomers and fibrinogen degradation products, and plasma antithrombin III activity. Two-thirds of all dogs had one or more haemostatic test abnormality of which the likelihood and frequency was increased in those with stage III and IV neoplasia. Haemostatic abnormalities were more frequently observed in dogs which had mammary tumours with distant metastases, extended tumour necrosis, inflammatory carcinomas, tumours fixed to underlying structures, or tumours in which there was penetration of the tumour capsule by tumour cells. As in humans with mammary carcinoma, these haemostatic abnormalities might be used as prognostic indicators, but their clinical importance remains unknown.
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PMID:Correlation of haemostatic abnormalities with tumour stage and characteristics in dogs with mammary carcinoma. 1044 52

A 70-year-old patient with a history of hypertension and hypercholesterolemia was referred for evaluation of necrotic toes. The patient had a history of several cerebrovascular accidents during the previous month. Initially, she developed sudden-onset left upper extremity weakness which, over the ensuing 4 days, progressed to complete left-sided weakness. This was followed by the development of acute dysarthria. A transesophageal echocardiogram revealed moderate left ventricular hypertrophy, several vegetations on her tri-leaflet aortic valve associated with moderate aortic regurgitation, and a large right atrial thrombus with a mobile component. Bubble studies failed to reveal any septal defects. The patient's electrocardiogram was nonspecific. As serial blood cultures were negative despite fevers of up to 39.8 degrees C, the patient was treated with a 6-week course of intravenous ceftriaxone, ampicillin, gentamicin, and ciprofloxacin for a presumed diagnosis of culture-negative endocarditis. Fungal cultures of the blood were negative. The patient, however, progressed and developed several necrotic toes. Physical examination was significant for ischemic changes of the left first, second, third, and fifth toes, as well as the right first and second toes. Diffuse subungual splinter hemorrhages in the toenails, numerous 2-4-mm palpable purpuric papules on the lower extremities, and nontender hemorrhagic lesions of the soles were also noted. Peripheral and carotid pulses were intact and no carotid bruits were heard. Cardiopulmonary and abdominal examinations were unremarkable. Neurologic examination revealed a disoriented, dysarthric patient with left central facial nerve paralysis, as well as spasticity, hyperactive reflexes, and diminished strength and sensation in the left upper and lower extremities. A left visual field defect and left hemineglect were also present. The patient's last brain computerized tomogram revealed areas of low attenuation consistent with cerebral infarctions in three distinct areas of the brain. These included the left occipitotemporal area, the right parieto-occipital area, and the right posterior frontal region. The regions affected were in the distribution of both the anterior and posterior circulation. No evidence of hemorrhage was noted. The patient subsequently complained of abdominal discomfort. A computerized tomogram of the abdomen with oral and intravenous contrast revealed a 4-cm x 3-cm irregular mass in the tail of the pancreas with several low-attenuation lesions throughout the liver which were consistent with infarctions or metastases. Several splenic infarctions were also present. A biopsy of the tumor revealed pancreatic adenocarcinoma. The patient's carcinoembryonic antigen level was 18. 4 ng/mL (0-3) and the CA 19-9 antigen level was 207,000 U/mL (0-36). The alpha-fetoprotein level was normal. Other significant laboratory findings included a prothrombin time of 16.7 (international normalized ratio, 1.4), an activated partial thromboplastin time of 32 (ratio, 1.3), and a platelet count of 85,000/mm3. The Russell viper venom time, sedimentation rate, and C3 levels were normal, and the patient was negative for antinuclear antibodies, anticardiolipin antibodies, and antibodies to extractable nuclear antigens. Of note, the patient was not receiving any anticoagulation. Blood cultures for mycobacteria and fungi, human immunodeficiency virus serology, and urinalysis and culture were negative. The patient subsequently developed an inferior wall myocardial infarction and was transferred to the coronary care unit. In line with the family's request, aggressive care was ceased and the patient expired. The patient's family refused an autopsy.
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PMID:Cutaneous manifestations of marantic endocarditis. 1080 80

The E6 Zn(2+)-binding protein of high-risk human papillomaviruses (HPVs) is one of the major transforming proteins encoded by these tumor viruses. A bacterial system was used to express wild type and truncated forms of HPV-16 E6 linked to GST. The recombinant proteins were released from GST through cleavage of a factor Xa site. Functional analysis of these proteins demonstrated that amino acids 2--142 comprise the minimal domain of E6 required to promote the degradation of p53 in vitro in a rabbit reticulocyte lysate. This purified protein, E6(Delta 143--151), required a high salt concentration for maximum solubility, eluted as a monomer on gel filtration, and was shown to bind two Zn(2+) ions by atomic absorption analysis. An N-terminal subdomain of E6 (amino acids 2--77, E6-N) was similarly purified. Unlike E6(Delta 143--151), E6--N was very soluble in low-salt buffers and hence was highly amenable to biophysical characterization. E6-N was shown to bind one Zn(2+) ion by electrospray mass spectrometry and by atomic absorption analysis. UV--visible spectroscopic analysis of Co(2+)-substituted E6--N revealed that four cysteine residues coordinate the metal ion. Mutational studies of all the cysteine residues in E6--N substantiated a critical role for Cys 30, 33, 63, and 66 in Zn(2+) binding and in proper folding of the subdomain. Equilibrium sedimentation of E6-N demonstrated that it is a monomer, like E6(Delta 143--151), at low concentrations, but dimerization occurs at high concentrations (K(d) = 0.1 mM). Finally, circular dichroism studies revealed significant secondary structure for both E6(Delta 143--151) and E6--N. The results support a model of monomeric E6 possessing two functionally critical Zn(2+)-binding motifs.
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PMID:Purification and biophysical characterization of a minimal functional domain and of an N-terminal Zn2+-binding fragment from the human papillomavirus type 16 E6 protein. 1117 Apr 44

The blood coagulation mechanism regulates the growth and dissemination of malignancy by multiple mechanisms, and anticoagulant drugs have been shown to inhibit the progression of certain cancers. Although progress has been slow, there is ample information on the effects of anticoagulants in various tumors that suggests that the use of anticoagulants has considerable potential in the treatment of some cancers. For example, melanoma is one of a small number of human tumor types in which the tumor is associated with an intact coagulation pathway leading to thrombin generation and conversion of fibrinogen to fibrin in situ immediately adjacent to viable tumor cells. Observations in experimental models combined with the limited clinical trial data on this subject suggest that inhibition of tumor cell thrombin generation may improve outcomes in melanoma cases. Thus, we postulate that pharmacological interruption of the tumor cell-associated coagulation pathway at any one step or even at multiple levels might constitute effective therapy for this disease. Drugs that block the activity of tissue factor, factor Xa, or thrombin are available for clinical testing and, if effective, offer the prospect of a relatively nontoxic, novel treatment for this aggressive tumor.
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PMID:Treatment of cancer with anticoagulants: rationale in the treatment of melanoma. 1137 26

The present study was designed to determine the maximum tolerated dose (MTD), toxicity profile, pharmacokinetics (PKs), and antitumor activity of the protein kinase C-alpha antisense oligonucleotide ISIS 3521 (ISIS Pharmaceuticals, Inc., Carlsbad, CA) when administered in combination with 5-fluorouracil (5-FU) and leucovorin (LV). Patients with refractory solid tumors received ISIS 3521 as a 21-day continuous infusion administered simultaneously with 5-FU and LV given daily for 5 days repeated every 4-5 weeks (one cycle). 5-FU and ISIS 3521 PK analysis were performed on samples taken during the first cycle in all patients. Fifteen patients received ISIS 3521 at one of three dose levels: (a) 1.0 (n = 3 patients); (b) 1.5 (n = 3 patients); and (c) 2.0 (n = 9 patients) mg/kg/day. All patients simultaneously received 5-FU (425 mg/m(2)/day) and LV (20 mg/m(2)/day) for 5 consecutive days. Grade 1-2 toxicities included alopecia, fatigue, mucositis, diarrhea, anorexia, nausea/vomiting, and tumor pain. One patient had grade 3 chest pain considered to be related to 5-FU therapy, another patient had dose-limiting grade 3 mucositis resolving in <7 days, and one patient with a history of gastritis had an acute upper gastrointestinal bleed thought to be 5-FU-induced toxicity. Five patients developed cycle 1 grade 4 neutropenia, which resolved without colony-stimulating factors before the next treatment cycle. There were no effects on prothrombin time and activated partial thromboplastin time. A clinically defined MTD was not reached. The character and severity of these toxicities do not seem to be dose related, and, as such, there was no classical dose-limiting toxicity defining the MTD. ISIS 3521 PKs in the presence of 5-FU was consistent with those reported previously. 5-FU PK parameters were also similar in the presence or absence of ISIS 3521. Six of 14 patients ( approximately 43%) across all dose cohorts had an improvement in measurable tumor response ranging from minor reduction in tumor size (4 patients) to objective partial response (>50% reduction in tumor size, 2 patients). ISIS 3521 is tolerable at its recommended single-agent dose when given with 5-FU and LV. There is no apparent PK interaction between ISIS 3521 and 5-FU and LV. Antitumor activity was observed with the combination; however, it is uncertain whether clinical activity is a result of enhanced drug interaction. Our study warrants further exploration of efficacy in a Phase II and/or Phase III clinical trial setting.
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PMID:Phase I clinical and pharmacokinetic study of protein kinase C-alpha antisense oligonucleotide ISIS 3521 administered in combination with 5-fluorouracil and leucovorin in patients with advanced cancer. 1194 11

An increased concentration of fibrin(ogen) degradation products (FDPs) commonly is used in conjunction with other hemostatic test abnormalities to identify patients with disseminated intravascular coagulation (DIC). Positive FDP results, however, have been observed in dogs without clinical evidence of DIC. The purpose of this study was to evaluate FDP concentrations in a group of clinically ill dogs with a variety of disorders. Dogs included in the study had the following hemostatic parameters evaluated: prothrombin time, activated partial thromboplastin time, fibrinogen concentration, platelet count, and FDP concentration. Two rapid latex agglutination methods were compared for detecting FDP in serum samples (Thrombo-Wellcotest, International Murex Technologies Corp) and plasma samples (FDP Plasma, American Bioproducts Inc). Results of the serum FDP method were positive in 8% (4/50) of the dogs tested: 3 with DIC and 1 with immune-mediated hemolytic anemia and liver disease. Results of the plasma FDP test were positive in 60% (30/50) of the animals tested: 6 with DIC, 3 with confirmed thrombosis, and 21 with a variety of conditions, including neoplasia, immune-mediated hemolytic anemia, pancreatitis, gastric dilatation-volvulus, heat stroke, severe trauma, sepsis, protein-losing nephropathy, liver disease, hyperadrenocorticism, and chronic heart failure. Because the plasma FDP test was positive more frequently than the serum FDP test in ill dogs, it may be more sensitive for the detection of canine FDP.
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PMID:Serum and plasma latex agglutination tests for detection of fibrin(ogen) degradation products in clinically ill dogs. 1202 12

Heparin (H), heparan sulfate (HS), and related glycosaminoglycans can inhibit cancer cell invasion, possibly due to their ability to interact with vascular growth factors, adhesion molecules, endoglycosidases, and signaling proteins, in addition to the well-known effects on the clotting system. We evaluated the antitumor activity of a series of semisynthetic sulfaminoheparosan sulfates (SAHSs) with different degree and distribution of sulfates, obtained by chemical modifications of the E. coli K5 polysaccharide, namely type A, B, and C compounds. B16-BL6 melanoma cells (10 5 cells/mouse) were injected intravenously (i.v.) in a lateral tail vein of C57BL6 mice at a dose of 0.5 mg/ mouse together with test compounds. Tumor lung nodules were significantly reduced as compared with controls only by H (95.5 +/- 1.0% inhibition), SAHS-2 (84.2 +/- 5.0% inhibition), and SAHS-4 (91.1 +/- 4.2% inhibition), among compounds tested. SAHS-2 and SAHS-4 are type B compounds, with a sulfate/carboxylate ratio similar to that of H. A typical mammalian HS showed only 54.8% inhibition. Supersulfated low-molecular-weight heparin and heparan sulfate (ssLMWH and ssLMWHS) showed an activity similar to that of unfractionated compounds. H and SAHS-4 inhibited dose dependently B16-BL6 lung colonies, with IC-50 values of 0.05 and 0.1 mg/mouse, respectively. The relationship with ex vivo anticoagulant potency was evaluated by activated partial thromboplastin time (aPTT) on mouse plasma at different time intervals after i.v. injection (0.1 to 0.5 mg/mouse) of the compound. H showed a dose-dependent anticoagulant activity lasting up to 2 hours, whereas SAHS-4 showed a potent anticoagulant effect only at a dose of 0.5 mg/mouse. Accordingly, H but not SAHS-4 consistently inhibited B16-BL6 lung colonies when given 1 hour before tumor cells. SAHS-4 derivatives, with different size and/or affinity depleted of AT binding sites, showed an inhibitory effect on B16-BL6 melanoma similar to that of SAHS-4, suggesting that the greater antitumor effect of H was not due to AT-mediated inhibition of blood clotting. Interactions with other blood inhibitors, such as heparin cofactor II or tissue factor pathway inhibitory protein cannot be ruled out. The better effect of H may be due to persistence in the circulation and/or ability to inhibit tumor neoangiogenesis.
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PMID:Inhibition of B16-BL6 melanoma lung colonies by semisynthetic sulfaminoheparosan sulfates from E. coli K5 polysaccharide. 1224 86


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