Effect of long-term dietary arginyl-fructose (AF) on hyperglycemia and HbA1c in diabetic db/db mice.

We have previously reported that Amadori compounds exert anti-diabetic effects by lowering sucrose-induced hyperglycemia in normal Sprague-Dawley rats. In the present study we extended our recent findings to evaluate whether α-glucosidase inhibitor arginyl-fructose (AF) lowers blood glucose level in diabetic db/db mice, a genetic model for type 2 diabetes. The db/db mice were randomly assigned to high-carbohydrate diets (66.1% corn starch) with and without AF (4% in the diet) for 6 weeks. Changes in body weight, blood glucose level, and food intake were measured daily for 42 days. Dietary supplementation of AF resulted in a significant decrease of blood glucose level (p < 0.001) and body weight (p < 0.001). The level of HbA1c, a better indicator of plasma glucose concentration over prolonged periods of time, was also significantly decreased for 6-week period (p < 0.001). Dietary treatment of acarbose® (0.04% in diet), a positive control, also significantly alleviated the level of blood glucose, HbA1c, and body weight. These results indicate that AF Maillard reaction product improves postprandial hyperglycemia by suppressing glucose absorption as well as decreasing HbA1c level.

Proteomic analysis of human small cell lung cancer tissues: up-regulation of coactosin-like protein-1.

Small cell lung cancer (SCLC) is the leading cause of cancer death, with a high propensity for aggressiveness and metastasis even in an early stage. Thus, identification of biomarkers as early diagnostics and treatment is needed. In this study, we investigated differentially regulated proteins between human SCLC tissues and normal bronchial epithelium by proteomic analysis using two-dimensional electrophoresis (2-DE) and MALDI-TOF mass spectrometry. Seven proteins and protein isoforms, including, γ-actin, tubulin α-1B, laminin B1, coactosin-like protein-1 (COTL-1), ubiquitin carboxyl-terminal esterase L1, ubiquitin-conjugating enzyme E2-25K, and carbonic anhydrase 1, were up-regulated more than 2 fold in SCLC tissues. In particular, up-regulated COTL-1 expression was validated by Western blot analysis, immunohistochemistry, and reverse transcription quantitative polymerase chain reaction (RT-qPCR). Moreover, most SCLC tissues (93%; 28/30) were COTL-1-positive in immunohistochemistry, whereas only 16% (10/64) of nonsmall cell lung cancer (NSLC) tissues were. Taken together, this SCLC proteomic data may help in establishing a human SCLC proteome database. COTL-1 may be a biomarker or a therapeutic target in SCLC patients.

Proteomic identification of paclitaxel-resistance associated hnRNP A2 and GDI 2 proteins in human ovarian cancer cells.

Ovarian cancer is a gynecological malignancy with the highest mortality. Chemoresistance is an important subject for the treatment of ovarian cancer, because obtaining significant drug resistance to the first line chemotherapy, paclitaxel, causes major therapeutic obstacles. It is essential to improve the survival rate of ovarian cancer patients by mining the biomarkers indicating the drug resistance and prognosis, and by further understanding underlying mechanisms of drug resistance. In the present study, we established paclitaxel-resistant subline (SKpac) from human epithelial ovarian cancer cell line, SKOV3, and performed comparative analysis of whole proteomes between paclitaxel-resistant SKpac sublines and paclitaxel-sensitive parental SKOV3 cells to identify differentially expressed proteins and useful biomarkers indicating chemoresistance. Proteins related to chemoresistant process were identified by two-dimensional gel electrophoresis (2DE) with mass spectrometry (MALDI-TOF and LC-MS/MS). Eighteen spots were differentially expressed and were identified in SKpac chemoresistant cells compared to SKOV3. The expressions of ALDH 1A1, annexin A1, hnRNP A2, and GDI 2 proteins were validated by Western blot, which was consistent with proteomic analysis. Among the selected proteins, downregulation of hnRNP A2 and GDI 2 was found to be the most significant finding in SKpac cells and chemoresistant ovarian cancer tissues. Our results suggest that hnRNP A2 and GDI 2 may represent potential biomarkers of the paclitaxel-resistant ovarian cancers for tailored cancer therapy.

Proteomic identification of overexpressed PRDX 1 and its clinical implications in ovarian carcinoma.

Ovarian carcinoma is the most lethal gynecological malignancy in worldwide. The discovery of reliable marker for early detection of ovarian carcinoma is critical for increasing patient's survival because high mortality rate is associated with late diagnosis of this tumor. In the present study, we performed comparative analysis of whole proteomes between serous borderline tumor and serous carcinoma to identify a useful biomarker for the early diagnosis and progression of ovarian carcinoma. Nine proteins were significantly overexpressed in ovarian serous carcinomas compared to borderline tumors. After validation with Western blotting and immunohistochemical analysis, prdx 1 was found to be the strongest overexpressed protein in malignant ovarian tumors among the selected proteins. In addition, the high level of prdx 1 expression (>50% positive cancer cells) was significantly correlated with poor overall survival in ovarian serous carcinomas. On a multivariate cox analysis, the relative risk of death was 8.74 in patients with serous carcinomas showing >50% of prdx 1-positive cancer cells. Our results suggest that prdx 1 may be a useful diagnostic and prognostic biomarker in ovarian carcinoma, especially serous carcinoma.

Acute and repeated dose toxicity studies of recombinant saxatilin, a disintegrin from the Korean snake (Gloydius saxatilis).

To examine the toxicological effect of saxatilin, a disintegrin isolated from the venom of a Korean snake (Gloydius saxatilis), recombinant saxatilin was highly expressed as a biologically active form in Pichia pastoris, and was successfully purified to homogeneity from the culture broth supernatant. The molecular and biological properties of the recombinant protein were the same as those of its natural form. Plasma half-life of the protein in rat was determined to 13.8 min. The maximum tolerated dose of the recombinant saxatilin was examined in ICR mice. The determined LD(50) values were 400 and 600 mg/kg of the body weight of a male and female mouse, respectively. To investigate the repeated dose toxicity of saxatilin in mice, the test item was intravenously administered to groups of ICR mice every day for 4 weeks. We observed a decrease in locomotor activity, piloerection, and crouching in clinical findings, a decrease of red blood cells (RBCs) in hematology, and hyperplasia of the spleen in histology related to administration of the test item. These results suggest that the target organ of intravenous administration of the test item is the spleen. The no adverse effect level (NOAEL) in this test for both males and females is considered to be 3mg/kg. Our results also indicate that recombinant saxatilin is non-toxic at an administration dose with an anti-platelet effect, and might be a potential anti-adhesion therapeutic agent for thrombosis, cancer, restenosis, cataract, and osteoporosis.

Suppressive effect and mechanism of saxatilin, a disintegrin from Korean snake (Gloydius saxatilis), in vascular smooth muscle cells.

RGD-peptides can inhibit the binding of ligands to certain beta3 integrins, alphaIIbbeta3 and alphavbeta3, both of which are involved in neointimal hyperplasia that contributes to atherosclerosis and restenosis of arterial walls. Saxatilin, a disintegrin from a Korean snake (Gloydius saxatilis), interacts with integrins alphaIIbbeta3 and alphavbeta3. It suppressed the adhesion of human coronary artery smooth muscle cells (HCASMCs) to vitronectin with an IC(50) of 2.5 microM, and growth factor (PDGF-BB or bFGF)-induced proliferation was inhibited at an IC(50) of 25 microM. Saxatilin disassembled the actin cytoskeleton of focal adhesion and induced cell detachment. This disassembly of focal adhesion in saxatilin-treated HCASMCs involved caspase-induced paxillin degradation. Saxatilin temporally phosphorylated FAK and ERKs and affected the cell cycle of HCASMCs by increasing CDK inhibitors (p21 and p27) and reducing cyclins (D1/2 and E). These results may have significant implications for integrin antagonistic therapy used for the treatment of atherosclerosis and restenosis.

Design, synthesis and evaluation of 2-phenyl-1H-benzo[d]imidazole-4,7-diones as vascular smooth muscle cell proliferation inhibitors.

A series of 2-phenyl-1H-benzo[d]imidazole-4,7-diones were synthesized and tested for their inhibitory activity on the PDGF-stimulated proliferation of rat aortic vascular smooth muscle cells. Among the tested compounds, 6-arylthio-5-chloro-2-phenyl-1H-benzo[d]imidazole-4,7-diones exhibited an potent antiproliferative activity.

Antiproliferative effects of 6-anilino-5-chloro-1H-benzo[d]imidazole-4,7-dione in vascular smooth muscle cells.

It has been known that benzimidazol-4,7-diones have antiproliferative activity against various cancer cell lines. Recently, we have also reported that these compounds strongly inhibited the proliferation of vascular smooth muscle cell (SMC) and human umbilical vein endothelial cells (HUVECs). Although benzimidazol-4,7-diones have important biological activities, the molecular mechanism of the compounds in these cells remains to be elucidated. In order to investigate the anti-proliferation mechanism of the compounds in smooth muscle cell, we selected 6-anilino-6-chloro-5-chloro-1H-benzo{d}midazole-4,7-dione (BUD-0203) among 12 benzimidazol-4,7-dione derivatives and examined its antiproliferative effects. Phosphorylation of the extracellular-signal regulated kinase (ERK) reached a maximal level at 1h after treatment with BUD-0203 and was sustained during the examined period. We also observed that phosphorylation of p38 reached a maximal level at 4h and decreased to control levels after 8h. These results showed that BUD-0203 sustainedly activated MAP kinase pathways in SMC. However, this compound did not induce cell cycle arrest in G1 or G2 phase in these cells. We also demonstrated that BUD-0203 not only induced apoptosis of SMC, but it also strongly inhibited SMC migration induced by platelet-derived growth factor (PDGF) or serum. Taken together, our experiments indicate that benzimidazol-4,7-diones induce apoptosis of smooth muscle cell via simultaneously prolonged activation of MAP kinase pathways including ERK, p38, and JNK/SAPK, similar with the apoptosis mechanism reported previously.

Dendritic Cell-Based Immunotherapy for Solid Tumors.

As a treatment for solid tumors, dendritic cell (DC)-based immunotherapy has not been as effective as expected. Here, we review the reasons underlying the limitations of DC-based immunotherapy for solid tumors and ask what can be done to improve immune cell-based cancer therapies. Several reports show that, rather than a lack of immune induction, the limited efficacy of DC-based immunotherapy in cases of renal cell carcinoma (RCC) likely results from inhibition of immune responses by tumor-secreted TGF-ß and an increase in the number of regulatory T (Treg) cells in and around the solid tumor. Indeed, unlike DC therapy for solid tumors, cytotoxic T lymphocyte (CTL) responses induced by DC therapy inhibit tumor recurrence after surgery; CTL responses also limit tumor metastasis induced by additional tumor-challenge in RCC tumor-bearing mice. Here, we discuss the mechanisms underlying the poor efficacy of DC-based therapy for solid tumors and stress the need for new and improved DC immunotherapies and/or combination therapies with killer cells to treat resistant solid tumors.

Acute and repeated dose (28 days) toxicity studies in rats and dogs of recombinant batroxobin, a snake venom thrombin-like enzyme expressed from Pichia pastoris.

Recombinant batroxobin is a thrombin-like enzyme of Bothrops atrox moojeni venom. To evaluate its toxicological effect, it was highly expressed in Pichia pastorisand successfully purified to homogeneity from culture broth supernatant following Good Manufacturing Practice (GMP). The maximum tolerated dose of the recombinant batroxobin was examined in Sprague-Dawley (SD) rat and Beagle dogs following Good Laboratory Practice (GLP) regulations. The approximate lethal dose of recombinant batroxobin was 10 National Institute of Health (NIH) u/kg in male and female rats. Slight test substance-related effects were clearly in male and female dogs at more than 10 NIH u/kg. The maximum tolerated dose (MTD) was considered to be greater than 30 NIH u/kg in dogs. To investigate the repeated dose toxicity of batroxobin, the test item was intravenously administered to groups of SD rat and Beagle dog every day for 4 weeks. We observed that all animals survived the duration of the study without any effects on their mortality. There were no effects in both rats and dogs regarding their clinical signs, body weight, food consumption, ophthalmological examination, urinalysis, hematology, clinical chemistry, organ weightand gross post mortem examinations. The no adverse effect level (NOAEL) of recombinant batroxobin for both males and females is considered to be greater than 2.5 NIH u/kgin rats and 1 NIH u/kg in dogs, respectively. No toxic effects were noted in target organs. In conclusion, these results show a favorable preclinical profile and may contribute clinical development of recombinant batroxobin.

Correlation of ALDH1 and Notch3 Expression: Clinical implication in Ovarian Carcinomas.

Purpose : ALDH1 is a putative cancer stem cell marker, while the Notch signaling pathway is involved in regulation of cancer stem cell (CSC)s. This study aims to determine the expression of Notch signaling genes in ovarian CSCs, and to assess the clinical impact of expression of ALDH1 and Notch signaling genes in ovarian cancers. Methods : We examined expression of Notch signaling genes in FACS-sorted ALDH1(+) putative ovarian CSCs and expression of ALDH1 and Notch signaling genes in 86 ovarian epithelial tumors and various ovarian cancer cell lines by real-time RT-PCR, including Notch receptors (Notch1-4), Notch ligands (Jagged1 and Jagged2), and the downstream molecule, Hes1. Furthermore, we correlated their expression with clinicopathological parameters and patient's survival in ovarian serous carcinoma (OSC)s, the most prevalent type of ovarian cancer. Results : The higher expression levels of ALDH1 and Notch related genes, especially Notch3 were associated with CSCs and with chemoresistant OSCs and paclitaxel-resistant SKpac ovarian cancer cells. Among the Notch signaling genes, high Notch3 expression was significantly associated with all the parameters of poor prognosis, i.e., advanced stage, lymph node and distant metastases, and chemoresistance, whereas other genes were less correlated with these parameters. A combined upregulation of ALDH1 and Notch3 was an independent poor prognostic factor in OSCs. Conclusions : ALDH1 correlates with Notch3 expression in ovarian carcinomas. ALDH1 and Notch3 overexpression is an independent poor prognostic indicator for worse patient's survival in this subset of OSCs.

Novel monoclonal antibody that recognizes new neoantigenic determinant of D-dimer.

Our novel monoclonal antibody (mAb) B4 reacted with only D-dimer but not intact fibrinogen, or fibrinogen degradation products (FgDP) such as D-monomer, E fragment on ELISA. B4 didn't react with denatured D-dimer, while it reacted well with denatured D-monomer rather than the native form, indicating that B4 recognizes some neoconformational epitope in D-dimer. In our epitope study, B4 recognized the N-terminal (Bbeta134-142) of D-dimer, which corresponds to the most flexible segment of coiled coil backbone. It was confirmed by inhibition assay of B4 binding to D-dimer using the synthesized peptides with this sequence. As the other evidence, B4 didn't bind to some D-dimer species produced from a particular fibrinogen variant. This fibrinogen variant is mutated BbetaLys133 residue to Gln133 thus it doesn't produce the particular N-terminal epitope of D134 approximately by plasmin. Finally, our mAb was useful for clinical application. ELISA using our mAbs was well correlated with other commercial D-dimer ELISAs and in some clinical samples it was preferable to them. These results suggest that the epitope for B4 is another neoantigenic determinant in native D-dimer as distinct from native D-monomer.

Expression, purification and transduction of PEP-1-botulinum neurotoxin type A (PEP-1-BoNT/A) into skin.

Botulinum neurotoxin A (BoNT/A) has been used therapeutically to treat muscular hypercontractions and sudomotor hyperactivity and it has been reported that BoNT/A might have analgesic properties in headache. PEP-1 peptide is a known carrier peptide that delivers full-length native proteins in vitro and in vivo. In this study, a BoNT/A gene were fused with PEP-1 peptide in a bacterial expression vector to produce a genetic in-frame PEP-1-BoNT/A fusion protein. The expressed and purified PEP-1-BoNT/A fusion proteins were efficiently transduced into cells in a time- and dose-dependent manner when added exogenously in a culture medium. In addition, immunohistochemical analysis revealed that PEP-1-BoNT/A fusion protein efficiently penetrated into the epidermis as well as the dermis of the subcutaneous layer, when sprayed on mice skin. These results suggest that PEP-1-BoNT/A fusion protein provide an efficient strategy for therapeutic delivery in various human diseases related to this protein.

Functional characterization of recombinant batroxobin, a snake venom thrombin-like enzyme, expressed from Pichia pastoris.

A thrombin-like enzyme of Bothrops atrox moojeni venom, batroxobin, specifically cleaves fibrinogen alpha chain, resulting in the formation of non-crosslinked fibrin clots. The cDNA encoding batroxobin was cloned, expressed in Pichia pastoris and the molecular function of purified recombinant protein was also characterized. The recombinant batroxobin had an apparent molecular weight of 33 kDa by SDS-PAGE analysis and biochemical activities similar to those of native batroxobin. The purified recombinant protein strongly converted fibrinogen into fibrin clot in vitro, and shortened bleeding time and whole blood coagulation time in vivo. However, it did not make any considerable alterations on other blood coagulation factors. Several lines of experimental evidence in this study suggest that the recombinant batroxobin is a potent pro-coagulant agent.

Purification and molecular cloning of a novel serine protease from the centipede, Scolopendra subspinipes mutilans.

A novel serine protease, named as scolonase, was purified and characterized from the tissue of the Korean centipede, Scolopendra subspinipes mutilans. Purified scolonase showed an apparent molecular weight of 25 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and an isoelectric point of 4.8 on isoelectric focusing gel. Scolonase was able to preferentially hydrolyze arginine over lysine at the cleavage site among the several synthetic peptide substrates. Scolonase has also a potent fibrinolytic activity by converting human Glu-plasminogen to activated plasmin due to the specific cleavage of the molecule at the peptide bond Arg(561)-Val(562). The enzyme activity of scolonase was completely inhibited by phenylmethanesulfonyl fluoride and difluorophosphate. The cDNA encoding scolonase was cloned from the cDNA library of the centipede constructed with oligonucleotide probe, which was designed on the basis of the N-terminal amino acid sequence of scolonase. The deduced complete amino acid sequence of scolonase demonstrated that the protein is composed of 277 amino acids including 33 amino acids as a leader sequence, and that it has significant sequence homology with other serine proteases.

A novel metalloprotease from Gloydius halys venom induces endothelial cell apoptosis through its protease and disintegrin-like domains.

A novel hemorrhagic metalloprotease, halysase, isolated from the snake venom of Gloydius halys induces apoptosis in endothelial cells. The purified metalloprotease is a monomeric glycoprotein with an isoelectric point of 4.8. Analysis of the cDNA sequence encoding halysase revealed that the enzyme consists of multifunctional domains including a proprotein domain, a protease domain, a disintegrin-like domain and a cysteine-rich domain. The metalloprotease has a DECD sequence in the disintegrin-like domain instead of the typical RGD sequence. Halysase strongly inhibits proliferation of human umbilical vein endothelial cells in a dose-dependent manner as well as adhesion of the cells to extracellular matrix proteins. The enzyme specifically hydrolyzes not only extracellular matrix proteins such as fibronectin, vitronectin, and type IV collagen, but also integrins alpha1beta1 and alpha5beta1. The apoptosis of endothelial cells induced by halysase is closely associated with activation of caspase-3 and decreased level of Bcl-X(L)/Bax. Apohalysase, which lacks metalloprotease activity, is also able to induce the apoptosis. Several lines of experimental evidence suggest that the protease domain and the disintegrin-like domain of halysase cooperatively contribute to the induction of endothelial cell apoptosis.

Phospholipase C-delta1 rescues intracellular Ca2+ overload in ischemic heart and hypoxic neonatal cardiomyocytes.

Ischemia and simulated ischemic conditions cause intracellular Ca2+ overload in the myocardium. The relationship between ischemia injury and Ca2+ overload has not been fully characterized. The aim of the present study was to investigate the expression and characteristics of PLC isozymes in myocardial infarction-induced cardiac remodeling and heart failure. In normal rat heart tissue, PLC-delta1 (about 44 ng/mg of heart tissue) was most abundant isozymes compared to PLC-gamma1 (6.8 ng/mg) and PLC-beta1 (0.4 ng/mg). In ischemic heart and hypoxic neonatal cardiomyocytes, PLC-delta1, but not PLC-beta1 and PLC-gamma1, was selectively degraded, a response that could be inhibited by the calpain inhibitor, calpastatin, and by the caspase inhibitor, zVAD-fmk. Overexpression of the PLC-delta1 in hypoxic neonatal cardiomyocytes rescued intracellular Ca2+ overload by ischemic conditions. In the border zone and scar region of infarcted myocardium, and in hypoxic neonatal cardiomyocytes, the selective degradation of PLC-delta1 by the calcium sensitive proteases may play important roles in intracellular Ca2+ regulations under the ischemic conditions. It is suggested that PLC isozyme-changes may contribute to the alterations in calcium homeostasis in myocardial ischemia.

Antiproliferative mechanisms of raxofelast (IRFI-016) in H2O2-stimulated rat aortic smooth muscle cells.

Reactive oxygen species-mediated cellular injury is involved in the pathogenesis of many diseases, including those affecting the cardiovascular system, such as myocardial ischemia-reperfusion injury, inflammation, and atheroscleosis. Raxofelast (IRFI-016; (+/-)-5-acetoxy-2, 3-dihydro-4, 6, 7-trimethyl-2-benzofuran-acetic acid) was designed with the aim of maximizing the antioxidant potency of phenols chemically related to vitamin E. The antioxidant activity of raxofelast has been convincingly demonstrated in several in vitro studies and in various models of ischemia-reperfusion injury. In this study, the antiproliferative effects of raxofelast were investigated to determine whether transduction signals and protooncogenes are affected in H(2)O(2)-stimulated rat aortic smooth muscle cells. In a tetrazolium-based colorimetric assay, the proliferation of rat aortic smooth muscle cells was increased by 3-fold in 0.1% fetal bovine serum/Dulbecco's modified Eagle's medium (DMEM) containing 500 microM H(2)O(2), indicating that exogenous 500 microM H(2)O(2) was a growth stimulator of rat aortic smooth muscle cells. Exogenous H(2)O(2) significantly activated extracellular signal-regulated kinases (ERKs) activity within 30 min and raxofelast inhibited the ERKs activation dose dependently in 500 microM H(2)O(2)-stimulated rat aortic smooth muscle cells (IC(50): 200 microM). Raxofelast reduced the intracellular reactive oxygen species generated by exogenous H(2)O(2) in a dose-dependent manner. In 500 microM H(2)O(2)-stimulated rat aortic smooth muscle cells, raxofelast dramatically attenuated the activation of mitogen-activating protein kinase (MAPK)/ERK kinase 1, 2 (MEK1,2) and protein kinase C (PKC) without affecting Ras expression. Induction of c-myc mRNA was significantly reduced dose dependently up to 100 microM by raxofelast in concentrations. These data indicate that the antiproliferative effects of raxofelast in H(2)O(2)-stimulated rat aortic smooth muscle cells may involve the suppression of intracellular reactive oxygen species formation and the inhibition of ERKs by inactivation through PKC and MEK1,2 and down-regulation of c-myc expression, regardless of Ras activation.

Snake venom disintegrin, saxatilin, inhibits platelet aggregation, human umbilical vein endothelial cell proliferation, and smooth muscle cell migration.

A novel disintegrin, saxatilin, was purified from Korean snake (Gloydius saxatilis) venom by means of chromatographic fractionations. We have also isolated the cDNA encoding the disintegrin using cDNA library of the snake venom gland and analyzed its complete nucleotide sequence. Saxatilin is a single-chain polypeptide composed of 73 amino acids including 12 cysteines as well as the tripeptide sequence Arg-Gly-Asp (RGD), a proposed recognition site of adhesive proteins. Molecular mass of saxatilin was determined to be 7712 Da by matrix-assisted laser desorption ionization mass spectrometry. Saxatilin inhibits glycoprotein (GP) IIb-IIIa binding to immobilized fibrinogen with IC(50) of 2.0 nM and ADP-induced platelet aggregation with IC(50) of 127 nM, respectively. The snake venom disintegrin also significantly suppresses basic fibroblast growth factor-induced human umbilical vein endothelial cell (HUVEC) proliferation, but has little effect on normal growth of the cell. Interaction of human umbilical vein cell to immobilized vitronectin is also inhibited by binding of saxatilin to alpha(v)beta(3) integrin. Adhesion of smooth muscle cells (SMCs) to vitronectin as well as vitronectin-induced migration of the cells was strongly inhibited by saxatilin. Several lines of experimental evidence suggest potential use of saxatilin for development of therapeutic agents.

Deficiency of von Willebrand factor-cleaving protease activity in the plasma of malignant patients.

von Willebrand factor (vWF) multimeric pattern and von Willebrand factor-cleaving protease activity (vWF-cp) were studied using plasmas from patients with advanced stage- and limited stage-malignant tumors. Deficiency of highly polymeric forms of vWF was observed in plasmas from 7 of 11 patients tested. vWF-cp activity was deficient in plasma samples of six patients with advanced stage-malignant tumors (ranging from 6% to 30% activity of normal plasma), whereas an essentially normal vWF-cp activity was observed in samples taken from patients with limited stage-malignant tumors. Inhibitor of vWF-cp was not detected in any plasma samples tested. To further analyze the relevance of this enzymatic activity in metastatic diagnosis, a study of vWF-cp activity was conducted in 17 patients with colon cancer, and it was shown that deficiency of vWF-cp was associated with the progression of the disease.