Anti-metastatic therapy by urinary trypsin inhibitor in combination with an anti-cancer agent

Molecular and pathobiological insights of bikunin/UTI in cancer

Bikunin is a small chondroitin sulfate proteoglycan (PG) with Ser-protease inhibitory activity that plays pleiotropic roles in health and disease. It is involved in several physiological processes including stabilization of the extracellular matrix (ECM) of connective tissues and key reproductive events. Bikunin is also implicated in both acute and chronic inflammatory conditions and represents a non-invasive circulating and/or urinary (as Urinary Trypsin Inhibitor or UTI) biomarker. It exerts inhibitory effects on urokinase-type plasminogen activator (uPA) and its receptor (uPAR) mediating tumor invasiveness by a down-regulation of uPA mRNA expression, thus representing an anti-metastatic agent. However, only limited data on its potential as a diagnostic and/or prognostic marker of cancer have been reported so far. Recent technological advances in mass spectrometry-based proteomics have provided researchers with a huge amount of information allowing for large-scale surveys of the cancer proteome. To address such issues, we analyzed bikunin expression data across several types of tumors, by using UALCAN proteogenomic analysis portal. In this article we critically review the roles of bikunin in human pathobiology, with a special focus on its inhibitory effects and mechanisms in cancer aggressiveness as well as its significance as cancer circulating biomarker.

Role of the small proteoglycan bikunin in human reproduction

PURPOSE

Female reproductive events, including ovulation, menstruation, implantation, and delivery, are physiologically characterized by deep tissue remodeling and display hallmark signs of inflammation. This review discusses the pleiotropic roles played by bikunin in human reproduction.

METHODS

A comprehensive literature search of the Medline/PubMed database was performed on the following topics: bikunin structure, roles in pathophysiological conditions and involvement in human reproduction, and usefulness as a marker of gestational complications or as a drug to improve pregnancy outcomes.

RESULTS

Bikunin is a small chondroitin sulfate proteoglycan found in blood, urine, and amniotic and cerebrospinal fluids, known for its anti-inflammatory and anti-proteolytic activities. Its levels are usually low, but they can increase several-fold in both acute and chronic inflammatory diseases. Bikunin plays key roles in reproductive events, such as cumulus-oocyte complex formation, pregnancy, and delivery. Its levels have been associated with the most common pregnancy complications such as preterm delivery, pre-eclampsia, and gestational diabetes mellitus. Finally, its intravaginal administration has been reported to reduce the risk of preterm delivery and to improve neonatal outcomes.

CONCLUSIONS

Because of its pleiotropic roles in several reproductive events and its association with some life-threatening pathological conditions of pregnancy, bikunin may represent a non-invasive marker for improving follow-up and early diagnosis. Studies showing its usefulness as a drug for reducing the risk of preterm delivery and improving neonatal outcomes have yielded interesting results that deserve to be investigated through further research.

Potential of Protein-based Anti-metastatic Therapy with Serpins and Inter α-Trypsin Inhibitors

In this review we summarize the principles of anti-metastatic therapy with selected serpin family proteins, such as pigment epithelial-derived factor (PEDF) and maspin, as well as inter α-trypsin inhibitor (IαIs) light chains (bikunin) and heavy chains (ITIHs). Case-by-case, antimetastatic activity may be dependent or independent of the protease-inhibitory activity of the corresponding proteins. We discuss the incidence of target deregulation in different tumor entities, mechanisms of deregulation, context-dependent functional issues as well as in vitro and in vivo target validation studies with transfected tumor cells or recombinant protein as anti-metastatic agents. Finally, we comment on possible clinical evaluation of these proteins in adjuvant therapy.

The synergistic effect of propofol and ulinastatin suppressed the viability of the human lung adenocarcinoma epithelial A549 cell line

Ulinastatin and propofol (PPF) are recognized for their anticancer properties. The aim of the present study was to evaluate the synergistic antitumor effect of PPF followed by ulinastatin against A549 cells. In MTT assays, PPF (10, 20 and 30 µM) followed by 200 U/ml ulinastatin was more effective at inhibiting A549 cell viability compared with PPF (10, 20 and 30 µM) or 200 U/ml ulinastatin. PPF (10, 20 and 30 µM) followed by 200 U/ml ulinastatin treatments synergistically increased the number of S cells and synergistically reduced the number of G2/M cells associated with PPF stimulation in a dose-dependent manner. Western blot analysis demonstrated that the antitumor effect of PPF followed by 200 U/ml ulinastatin treatments were associated with the downregulated expression of extracellular signal-regulated kinase 1 and 2 phosphorylation (p-ERK1/2) and matrix metalloproteinases 2 (MMP-2). In conclusion, these data demonstrated that PPF (20 and 30 µM) followed by 200 U/ml ulinastatin treatments synergistically stimulated a significant proportion of A549 cells in S phase. Furthermore, the combination synergistically reduced a significant proportion of A549 cells in G2/M phase and synergistically suppressed the viability of A549 cells, which was possibly related regulation of the expression of p-ERK1/2 and MMP-2 in A549 cells.

Significance of urinary glycosaminoglycans/proteoglycans in the evaluation of type 1 and type 2 diabetes complications

Because of the high incidence of kidney disease in diabetic patients, the early diagnosis of renal impairment is a key point for intervention and management. Although urinary albumin excretion currently represents the accepted standard to assess both diabetic nephropathy and cardiovascular risk, it has some limitations as structural changes in the glomerular basement membrane may occur before the onset of microalbuminuria. It is therefore important to identify urinary markers that may provide greater sensitivity, earlier detection, and greater predictive power for diabetes complications. In this respect, urinary glycosaminoglycans/proteoglycans (GAGs/PGs) have been long associated with several kidney diseases as well as diabetic nephropathies as their levels increase more readily than albuminuria. In particular, heparan sulfate, a key component of the glomerular basement membrane responsible for its charge-dependent permeability, is excreted into urine at higher concentrations during the early kidney remodeling events caused by the altered glucose metabolism in diabetes. Over the past few years, also urinary trypsin inhibitor has been linked to a chronic inflammatory condition in both type 1 and 2 diabetes. The underlying mechanisms of such increase are not completely known since either a systemic inflammatory condition or a more localized early renal impairment could play a role. Nevertheless, the association with other inflammatory markers and a detailed urinary trypsin inhibitor structural characterization in diabetes remain to be elucidated. This review will discuss a great deal of information on the association between urinary GAGs/PGs and type 1 and 2 diabetes, with particular emphasis on renal involvement, and their potential as markers useful in screening, diagnosis and follow up to be associated with the current standard tests.

Two legume defense proteins suppress the mobility of nasopharyngeal carcinoma cells

A 16-kDa trypsin inhibitor was isolated from an edible legume using various chromatographic procedures. The protein was unadsorbed on Affi-gel blue gel but adsorbed on DEAE-Sepharose and Mono Q following which media the protein was subsequently subjected to gel filtration on Superdex 75 and a final 21-fold purification was achieved. This trypsin inhibitor showed remarkable pH and thermal stability. Its inhibitory activity was impaired in the presence of 1 mM dithiothreitol. The anti-proliferative and anti-mobility activities of this trypsin inhibitor and a hemagglutinin isolated from the same legume were tested on nasopharyngeal carcinoma cells. These two defense proteins demonstrated discrepant anti-proliferative efficacies that the hemagglutinin could greatly suppress the proliferation of nasopharyngeal carcinoma cells, while the trypsin inhibitor revealed a minor effect. However, these two proteins could both attenuate the mobility of nasopharyngeal carcinoma cells. The present study revealed the potential of applying plant defense proteins in cancer treatment.

PDGF-D/PDGF-ββ receptor-regulated chemotaxis of malignant mesothelioma cells

BACKGROUND/AIMS

Our earlier study suggested that platelet-derived growth factor (PDGF)- ββ receptor regulates chemotaxis of human malignant mesothelioma cells such as MSTO-211H, NCIH-2052, NCIH-2452, and NCIH-28 cells, but not non-malignant Met5A cells. The present study was designed to gain further insight into the PDGF-ββ receptor signals underlying the chemotaxis.

METHODS

PDGF-D secreted from cells, activation of Akt and ERK, and cell migration were monitored for cells with and without knocking-down PDGF-ββ receptor.

RESULTS

FBS significantly stimulated PDGF-D secretion from malignant mesothelioma cells, but not Met5A cells. PDGF-D activated Akt and ERK in both the non-malignant and malignant cells. PDGF-D significantly facilitated migration of malignant mesothelioma cells, but not Met5A cells, with the extent varying among the cell types. The facilitatory action of PDGF-D was clearly prevented by knocking-down PDGF-ββ receptor or inhibitors of PI3 kinase, PDK1, Akt, Rac1, ROCK, and MEK.

CONCLUSION

The results of the present study indicate that PDGF-D promotes malignant mesothelioma cell chemotaxis through PDGF-ββ receptor signaling pathways along a PI3 kinase/PDK1/Akt/Rac1/ROCK axis and relevant to ERK activation.

Cysteine peptidases and their inhibitors in breast and genital cancer

Cysteine proteinases and their inhibitors probably play the main role in carcinogenesis and metastasis. The metastasis process need external proteolytic activities that pass several barriers which are membranous structures of the connective tissue which includes, the basement membrane of blood vessels. Activities of the proteinases are regulated by endogenous inhibitors and activators. The imbalance between cysteine proteinases and cystatins seems to be associated with an increase in metastatic potential in some tumors. It has also been reported that proteinase inhibitors, specific antibodies for these enzymes and inhibition of the urokinase receptor may prevent cancer cell invasion. Some proteinase inhibitor could serve as agents for cancer treatment.

Effects of ulinastatin and docataxel on breast tumor growth and expression of IL-6, IL-8, and TNF-α

Objective

This study investigated the effects of Ulinastatin (UTI) and docataxel (Taxotere, TAX) on tumor growth and expression of interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) in breast cancer.

Methods

MDA-MB-231 human breast carcinoma cells were cultured in vitro and injected into nude mice to establish breast tumor xenografts in vivo. Cultured cells and mice with tumors were randomly divided into four groups for treatment with TAX, UTI, and TAX+UTI. The effects of these drug treatments on cell proliferation and apoptosis was measured using the MTT assay and the Annexin V/propidium iodide (PI) double-staining method, respectively. IL-6, IL-8, and TNF-α expression levels were determined by measuring mRNA transcripts in cultured cells by RT-PCR and cytokine proteins in solid tumors using immunohistochemistry.

Results

UTI, TAX, and UTI+TAX inhibited the growth of MDA-MB-231 cells in vitro and tumors in vivo. These two drugs, particularly when used in combination, promote tumor cell apoptosis and down-regulate the expression IL-6, IL-8, and TNF-α cytokines.

Conclusion

Both UTI and TAX inhibited the growth of MDA-MB-231 breast carcinoma cells. UTI enhanced the inhibitory effect of TAX by a mechanism consistent with the down-regulated expression of IL-6, IL-8, and TNF-α.

Effects of ulinastatin and cyclophosphamide on the growth of xenograft breast cancer and expression of CXC chemokine receptor 4 and matrix metalloproteinase-9 in cancers

The aim of this study was to evaluate the effects of ulinastatin (UTI) and cyclophosphamide (CTX) as mono therapies and as combination therapy on the growth of mouse xenograft breast tumours. MCF-7 breast cancer cells were xenografted into 48 nu/nu nude mice in order to construct a breast cancer xenograft nude mouse model; mice were then untreated (control), or treated with CTX 0.1 g/kg every other day, UTI once a day at 25 000 U (low), 50 000 U (medium) or 100 000 U (high), or CTX + UTI (low), CTX + UTI (medium) or CTX + UTI (high) (n = 6 mice/group). Compared with controls, mice in each drug-treated group had a significantly reduced tumour weight, and protein and mRNA levels of CXC chemokine receptor 4 and matrix metalloproteinase-9 in both the UTI (low, medium and high doses) and CTX groups were significantly reduced, while levels in the UTI (low, medium and high doses) + CTX combination groups were significantly reduced compared with the CTX group and the UTI (low, medium, high) groups. Thus, both UTI and CTX can significantly inhibit xenograft tumours, and the UTI + CTX combination exhibited an additive effect that was superior to both CTX and UTI monotherapy.

Bikunin suppresses expression of pro-inflammatory cytokines induced by lipopolysaccharide in neutrophils

Activated neutrophils contribute to the development of preterm delivery. Because of its ability to suppress inflammation, bikunin, a Kunitz-type protease inhibitor, is currently in clinical trials. To investigate the molecular mechanism of this inhibition, we analyzed the effect of bikunin on pro-inflammatory cytokine production and nuclear factor-kappaB (NF-kappaB) activation in mouse neutrophils stimulated by lipopolysaccharide (LPS), an inflammatory inducer. Here, we show that bikunin: (i) blocks LPS-induced secretion of pro-inflammatory cytokines, including TNF-alpha and IL-1beta, in a dose-dependent manner; (ii) has an inhibitory effect on cytokine production at a concentration of 0.2 microM, reaching 65% inhibition at the highest doses of bikunin tested (5 microM); (iii) has the suppressive capacity of ERK1/2 and p38 signaling pathways; and (iv) inhibited sequentially the LPS-induced phosphorylation of IkappaB-alpha, degradation of IkappaB-alpha, and nuclear translocation of NF-kappaB. When the MAPK data are analyzed, a significant decrease in phosphorylation is not seen at 0.2 microM bikunin but is at 1.0 microM dosing. Bikunin can inhibit LPS-induced neutrophil activation and cytokine release, although it is unlikely that it works primarily through the inhibition of MAPK phosphorylation. These data suggest that such effects are important in vivo and play a major contributory role in abrogation of neutrophil-mediated inflammatory responses, such as preterm delivery.

Enhanced spontaneous metastasis in bikunin-deficient mice

Previously, we showed that bikunin, a Kunitz-type protease inhibitor, inhibits invasion and metastasis in several types of cancer cells possibly through suppression of upregulation of urokinase-type plasminogen activator (uPA) expression. Bikunin corresponds to a light chain of the inter-alpha inhibitor. To explore critical role of endogenous bikunin, we used bikunin knockout (Bik-/-) mice. Here, we show that 1) higher frequency of spontaneous 3LL lung metastasis was observed in Bik-/- mice compared to Bik+/+ mice, suggesting that bikunin deficiency increases the sensitivity of mice to lung metastasis; 2) administration of exogenous bikunin caused a significant reduction of lung metastasis in Bik-/- and Bik+/+ mice; 3) primary and metastatic tumors significantly upregulated uPA and PAI-1 expression in Bik-/- mice relative to Bik+/+ mice at least through phosphorylation of ERK1/2 and 4) exogenous bikunin suppressed phosphorylation of ERK1/2 and upregulation of uPA and PAI-1 expression in 3LL cells in response to G-CSF. These data allow us to conclude that the increased sensitivity of Bik-/- mice to lung metastasis in vivo is due to a lack of circulating proteins of the inter-alpha inhibitor family, especially bikunin.

Bikunin down-regulates heterodimerization between CD44 and growth factor receptors and subsequently suppresses agonist-mediated signaling

We provided evidence previously that bikunin, a Kunitz-type protease inhibitor, can disrupt dimerization of CD44 proteins, which may result in suppression of receptor-mediated MAP kinase signaling. However, to what extent dimerization may alter ligand-induced signaling has not been documented. Given the recent recognition that some growth factor receptors can form heterodimers with CD44, the present study was undertaken to determine whether the CD44 and growth factor receptors (e.g., EGFR, FGFR, HGFR, VEGFR, TGF-betaRI, or TGF-betaRII) can form heterodimers in cancer cells and, if so, to investigate the potential functional consequences of such heterodimerization. We also examined whether bikunin can abrogate these heterodimerizations and inhibit CD44/growth factor-dependent signaling. Here, we show direct evidence for heterodimerization of CD44-FGFR and CD44-TGF-betaRI in human chondrosarcoma HCS-2/8 cells, CD44-EGFR complex in human glioma U87MG cells, and CD44-TGF-betaRI heterodimer in human ovarian cancer HRA cells. Coupling of CD44 and growth factor receptor may be selective, depending on a cell type. Bikunin does not alter the ligand binding, whereas functionally reduces heterodimerization between CD44 and growth factor receptors. The disruption of heterodimerization substantially reduces receptor-induced tyrosine phosphorylation and ERK1/2 activation. Taken together, our data suggest that bikunin-mediated suppression of heterodimerization between CD44 and growth factors may inhibit the agonist-promoted activation of the signaling pathway.

Suppression of urokinase expression and invasion by a soybean Kunitz trypsin inhibitor are mediated through inhibition of Src-dependent signaling pathways

A soybean Kunitz trypsin inhibitor (KTI) interacts with cells as a negative modulator of the invasive cells. Using complementary pharmacological and genetic approaches, we provide novel findings regarding mechanisms by which KTI inhibits signaling pathways in ovarian cancer cells leading to invasion. Transforming growth factor-beta1 (TGF-beta1) directly activates Src kinase, which in turn activates ERK-phosphatidylinositol 3-kinase/Akt, the downstream targets of Src, for urokinase-type plasminogen activator (uPA) up-regulation in human ovarian cancer HRA cells. Preincubation of the HRA cells with KTI reduced the ability of TGF-beta1 to trigger the uPA expression at the gene level and at the protein level. To further elucidate the mechanism of the KTI-dependent suppressive effect of TGF-beta1-induced uPA expression and invasion, we investigated which signaling pathway transduced by KTI is responsible for this inhibitory effect. Here, we show that 1) KTI suppressed TGF-beta1-induced phosphorylation of Src, ERK1/2, and Akt by 40-60%; 2) KTI was insensitive to suppress the phosphorylation of ERK1/2 and Akt in the constitutively active (CA)-c-Src (Y529F) cells; 3) uPA expression was up-regulated in TGF-beta1-stimulated HRA cells and in unstimulated Y529F cells; 4) the addition of KTI reduced the TGF-beta1-induced increase of uPA gene and protein expression in the wild-type c-Src-transfected cells (in contrast, KTI could not inhibit uPA expression in the Y529F cells); and 5) CA-c-Src transfection resulted in a 2-fold increase in invasiveness, whereas KTI did not reduce invasion of the Y529F cells. Using additional complementary genetic approaches (CA-MEK1, CA-Akt, or kinase-dead-Akt), we conclude that KTI may suppress uPA expression and promotion of invasion possibly through one or more upstream targets of Src.

Bikunin inhibits lipopolysaccharide-induced tumor necrosis factor alpha induction in macrophages

Bikunin, a Kunitz-type protease inhibitor, exhibits anti-inflammatory activity in protection against cancer and inflammation. To investigate the molecular mechanism of this inhibition, we analyzed the effect of bikunin on tumor necrosis factor alpha (TNF-alpha) production in human peripheral mononuclear cells stimulated by lipopolysaccharide (LPS), an inflammatory inducer. Here, we show the following results. (i) LPS induced TNF-alpha expression in time- and dose-dependent manners through phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase pathways. (ii) Bikunin inhibits LPS-induced up-regulation of TNF-alpha protein expression in a dose-dependent manner, reaching 60% inhibition at the highest doses of bikunin tested (5.0 microM). (iii) Inhibition by bikunin of TNF-alpha induction correlates with the suppressive capacity of ERK1/2, JNK, and p38 signaling pathways, implicating repressions of at least three different signals in the inhibition. (iv) Bikunin blocks the induction of TNF-alpha target molecules interleukin-1beta (IL-1beta) and IL-6 proteins. (v) Bikunin is functional in vivo, and this glycoprotein blocks systemic TNF-alpha release in mice challenged with LPS. (vi) Finally, bikunin can prevent LPS-induced lethality. In conclusion, bikunin significantly inhibits LPS-induced TNF-alpha production, suggesting a mechanism of anti-inflammation by bikunin through control of cytokine induction during inflammation. Bikunin might be a candidate for the treatment of inflammation, including septic shock.

Upregulation of bikunin in tumor-infiltrating macrophages as a factor of favorable prognosis in ovarian cancer

OBJECTIVE

This study was carried out to clarify the localization of bikunin, a Kunitz-type protease inhibitor, and relation between expression of individual bikunin protein and ovarian cancer progression.

METHODS

We performed a retrospective study on the immunohistochemical expression of bikunin, urokinase-type plasminogen activator (uPA) and macrophages (CD68) in surgical specimens derived from 89 ovarian cancer patients to investigate correlations between the expression of bikunin and the clinicopathologic features and the prognosis. Furthermore, bikunin and uPA levels were measured by immunoblot analysis.

RESULTS

Immunohistochemical staining revealed that the localization of bikunin was similar to that of CD68 for macrophages. We identified high expression of bikunin in 40 (45%) of 89 ovarian cancers. The results of Western blot analysis showed a significant correlation with immunohistochemical data. There was a significant inverse correlation between bikunin levels and uPA levels in ovarian cancer tissues. High bikunin expression was an independent predictor for disease-free survival (P = 0.040) and overall survival (P = 0.042). The 5-year survival rate of the 49 patients with low bikunin expression in ovarian cancers was 39%, whereas that of the other 40 patients with high bikunin expression was 63%. In addition, macrophage-derived bikunin protein was induced by exogenous IL-6.

CONCLUSION

Bikunin derived from tumor-infiltrating macrophages might be a prognostic indicator as an antiinvasive factor supplied from macrophages within and around the tumor possibly through down-regulation of tumor-associated uPA expression.

A soybean Kunitz trypsin inhibitor suppresses ovarian cancer cell invasion by blocking urokinase upregulation

We have previously reported in a series of papers that a Kunitz-type protease inhibitor, bikunin, suppresses up-regulation of urokinase-type plasminogen activator (uPA) and its specific receptor (uPAR) expression, phosphorylation of ERK1/2 and cancer cell invasion in vitro and peritoneal disseminated metastasis in vivo. In the present study, we investigated the effects of soy bean trypsin inhibitor (SBTI) on the net enzymatic activity of secreted, extracellular uPA, signal transduction involved in the expression of uPA and invasion in HRA human ovarian cancer cells. SBTI contains a Kunitz trypsin inhibitor (KTI) and a Bowman-Birk inhibitor (BBI). Here, we show 1) that KTI and BBI were purified separately from soybeans; 2) that neither KTI nor BBI effectively inhibits enzymatic activity of uPA; 3) that uPA upregulation observed in HRA cells was inhibited by preincubation of the cells with KTI with an IC50 of approximately 2 microM, whereas BBI failed to repress uPA upregulation, as measured by enzyme-linked immunosorbent assay; 4) that cell invasiveness was inhibited by treatment of the cells with KTI with an IC50 of approximately 3 microM, whereas BBI failed to suppress cell invasion, as measured by an in vitro invasion assay; 5) KTI suppresses HRA cell invasion by blocking uPA up-regulation which may be mediated by a binding protein(s) other than a bikunin binding protein and/or its receptor; and 6) that transforming growth factor-beta 1 (TGF-beta1)-mediated activation of ERK1/2 was significantly reduced by preincubation of the cells with KTI. In conclusion, KTI, but not BBI, could inhibit cell invasiveness at least through suppression of uPA signaling cascade, although the mechanisms of KTI may be different from those of bikunin.

A soybean Kunitz trypsin inhibitor suppresses ovarian cancer cell invasion by blocking urokinase upregulation

We have previously reported in a series of papers that a Kunitz-type protease inhibitor, bikunin, suppresses up-regulation of urokinase-type plasminogen activator (uPA) and its specific receptor (uPAR) expression, phosphorylation of ERK1/2 and cancer cell invasion in vitro and peritoneal disseminated metastasis in vivo. In the present study, we investigated the effects of soy bean trypsin inhibitor (SBTI) on the net enzymatic activity of secreted, extracellular uPA, signal transduction involved in the expression of uPA and invasion in HRA human ovarian cancer cells. SBTI contains a Kunitz trypsin inhibitor (KTI) and a Bowman-Birk inhibitor (BBI). Here, we show 1) that KTI and BBI were purified separately from soybeans; 2) that neither KTI nor BBI effectively inhibits enzymatic activity of uPA; 3) that uPA upregulation observed in HRA cells was inhibited by preincubation of the cells with KTI with an IC50 of approximately 2 microM, whereas BBI failed to repress uPA upregulation, as measured by enzyme-linked immunosorbent assay; 4) that cell invasiveness was inhibited by treatment of the cells with KTI with an IC50 of approximately 3 microM, whereas BBI failed to suppress cell invasion, as measured by an in vitro invasion assay; 5) KTI suppresses HRA cell invasion by blocking uPA up-regulation which may be mediated by a binding protein(s) other than a bikunin binding protein and/or its receptor; and 6) that transforming growth factor-beta 1 (TGF-beta1)-mediated activation of ERK1/2 was significantly reduced by preincubation of the cells with KTI. In conclusion, KTI, but not BBI, could inhibit cell invasiveness at least through suppression of uPA signaling cascade, although the mechanisms of KTI may be different from those of bikunin.

Bikunin plus paclitaxel markedly reduces tumor burden and ascites in mouse model of ovarian cancer

Our previous studies of intraperitoneal ovarian carcinoma in a mouse model demonstrated that bikunin gene transfection could prevent ascites formation and intraperitoneal disseminated metastasis. Although ascites was almost completely inhibited, tumor burden was variably reduced. Several reports have indicated that bikunin may be involved in tumor survival. In the present study, the effectiveness of exogenous bikunin and the biodistribution characteristics of (125)I-bikunin were initially examined in a mouse model of human ovarian cancer HRA cells. The once-daily i.p. administration of bikunin significantly decreased progressive growth of HRA tumors and ascites formation in a dose-dependent manner. Maximal radioisotope tumor uptake peaked at 7.4% injected dose/g at 3 hr. Bikunin binding specificity was demonstrated by reduced tumor uptake after coinjection of excess nonradioactive bikunin. Bikunin was rapidly excreted renally. The bikunin therapy produced the significant inhibition in expression of the proteolysis (uPA and uPAR) and angiogenesis-related molecules (VEGF and bFGF). The second purpose of our study was to optimize the antimetastatic activity of bikunin in combination with paclitaxel against HRA cells growing orthotopically in mice. The once-daily i.p. administration of bikunin (25 microg/g body weight/day) in combination with paclitaxel (i.p., 100 microg/20 g at days 2 and 5) significantly decreased progressive growth of HRA cells in a synergistic fashion. In conclusion, combination therapy with bikunin plus paclitaxel may be an effective way to markedly reduce i.p. tumor growth and ascites in ovarian carcinoma possibly through suppression of uPA, uPAR, VEGF and bFGF expression.

Therapeutic efficacy of once-daily oral administration of a Kunitz-type protease inhibitor, bikunin, in a mouse model and in human cancer

BACKGROUND

Bikunin, a Kunitz-type protease inhibitor, specifically inhibits tumor invasion and metastasis.

METHODS

The authors initially evaluated the therapeutic efficacy of once-daily oral administration of different doses of bikunin against human ovarian carcinoma HRA cells growing in the peritonea of nude mice. For the in vivo studies, female 7-week-old nude mice were randomized to 1 of 4 groups: bikunin-treated groups (n = 9 in each group) received 3, 10, or 30 microg/g body weight per day bikunin for 7 days via gastrointestinal gavage, and a control group (n = 9) received the vehicle solution (phosphate-buffered saline) via gastrointestinal gavage. On Day 9, the abdominal cavity was examined by two observers who were blinded to treatment.

RESULTS

After oral administration, intact bikunin was detectable in mouse serum specimens at 3 and 6 hours. This was followed by a decline at 12 hours. The mice given bikunin at the highest dose level had a 40% decrease in tumor load. The highest uptake in the tumor was obtained with [125I]bikunin 12 hours postadministration. No effect on either food intake or body weight was observed in the treated versus sham groups. The current study was the first to report the potent activity of once-daily oral administration of bikunin against ovarian carcinoma. Next, the authors performed a Phase I trial to determine the maximum-tolerated dose (MTD) and safety of a once-daily oral administration schedule. The indication was locally advanced uterine cervical carcinoma after definitive treatment. An escalating dose (3, 10, and 30 mg/kg per day) of bikunin was administered orally to nine patients for 7 days. There were no dose-limiting toxicities and the MTD of the bikunin schedule was not defined. The authors also obtained preliminary data on its effect on urokinase-type plasminogen activator expression at the highest dose level.

CONCLUSIONS

Once-daily oral administration of bikunin was found to be safe in humans and exhibited signs of biologic activity.

Plasma and urine levels of urinary trypsin inhibitor in patients with chronic liver diseases and hepatocellular carcinoma

BACKGROUND AND AIM

Because urinary trypsin inhibitor (UTI) is synthesized by hepatocytes and excreted into the urine, plasma and urine levels of UTI may alter in liver diseases. However, there are few reports on the changes in these levels in chronic liver diseases and hepatocellular carcinoma (HCC). The aim of the present study was to evaluate the relationships between plasma and urine UTI levels and the severity of liver damage or progression of HCC in patients with chronic liver diseases and HCC.

METHODS

Plasma and urine UTI levels were measured by a newly developed enzyme-linked immunosorbent assay in 16 patients with chronic hepatitis (CH), 19 patients with liver cirrhosis (LC) and 39 patients with HCC.

RESULTS

Plasma UTI level exhibited a significant positive correlation with the urine UTI level. Plasma and urine UTI levels significantly decreased in LC patients compared with those of normal controls. In contrast, the plasma UTI level in HCC patients was higher than that in LC patients, but there was no difference between the groups in the urine UTI level. Plasma and urine UTI levels in LC and HCC patients were significantly correlated with the degree of liver damage according to the Child-Pugh classification. Although neither the plasma nor urine level of UTI in HCC patients were related to the clinical stage of HCC, both levels were closely associated with the level of protein induced by vitamin K absence or antagonist-II.

CONCLUSIONS

The present findings indicate that the levels of plasma and urine UTI in patients with LC reflect the severity of liver damage. In HCC patients, these levels may also reflect progression of HCC, although further study is required.

Transforming growth factor-beta1 produced by ovarian cancer cell line HRA stimulates attachment and invasion through an up-regulation of plasminogen activator inhibitor type-1 in human peritoneal mesothelial cells

The processes of ovarian cancer dissemination are characterized by altered local proteolysis, cellular proliferation, cell attachment, and invasion, suggesting that the urokinase-type plasminogen activator (uPA) and its specific inhibitor (plasminogen activator inhibitor type-1 (PAI-1)) could be involved in the pathogenesis of peritoneal dissemination. We showed previously that expression of uPA and PAI-1 in the human ovarian cancer cell line HRA can be down-regulated by exogenous bikunin (bik), a Kunitz-type protease inhibitor, via suppression of transforming growth factor-beta1 (TGF-beta1) up-regulation and that overexpression of the bik gene can specifically suppress the in vivo growth and peritoneal dissemination of HRA cells in an animal model. We hypothesize that the plasminogen activator system in mesothelial cells can be modulated by HRA cells. To test this hypothesis, we used complementary techniques in mesothelial cells to determine whether uPA and PAI-1 expression are altered by exposure to culture media conditioned by HRA cells. Here we show the following: 1) that expression of PAI-1, but not uPA, was markedly induced by culture media conditioned by wild-type HRA cells but not by bik transfected clones; 2) that by antibody neutralization the effect appeared to be mediated by HRA cell-derived TGF-beta1; 3) that exogenous TGF-beta1 specifically enhanced PAI-1 up-regulation at the mRNA and protein level in mesothelial cells in a time- and concentration-dependent manner, mainly through MAPK-dependent activation mechanism; and 4) that mesothelial cell-derived PAI-1 may promote tumor invasion possibly by enhancing cell-cell interaction. This represents a novel pathway by which tumor cells can regulate the plasminogen activator system-dependent cellular responses in mesothelial cells that may contribute to formation of peritoneal dissemination of ovarian cancer.

Reduced bikunin gene expression as a factor of poor prognosis in ovarian carcinoma

BACKGROUND

In previous studies, the authors showed that various types of cultured tumor cells treated with exogenous bikunin protein or ovarian carcinoma cells transfected with bikunin cDNA have low invasiveness and diminished metastatic potential. This study was carried out to clarify the relation between the expression of individual bikunin mRNA and tumor progression.

METHODS

Forty-one newly diagnosed ovarian carcinomas were investigated using a semiquantitative reverse transcriptase-polymerase chain reaction.

RESULTS

The authors found that 24 patients had tumors that overexpressed bikunin and that gene expression was reduced in the tumors of the remaining 17 individuals. Bikunin mRNA expression was independent of age, surgical stage, tumor size, degree of differentiation, histologic subtype, and serum CA 125 levels. There was a significant correlation between low expression of bikunin mRNA and lymph node status (P=0.035) or peritoneal status (P=0.042). Multivariate analysis indicated that bikunin was an independent prognostic marker (P=0.013; hazard ratio, 2.30; 95 % confidence interval, 1.13-4.19), even after controlling for lymph node metastasis and the degree of peritoneal dissemination. In addition, low expression was a significant predictor for poor prognosis compared with high expression (2-year survival rate; 75.0 % vs. 47.1 %, respectively; P<0.05).

CONCLUSIONS

The data suggest that low bikunin mRNA expression by ovarian carcinoma cells may be associated with poor prognosis. It is conceivable that testing for bikunin mRNA may identify patients with ovarian carcinoma who are at high risk for early disease recurrence and a poor prognosis.

The protease inhibitor bikunin, a novel anti-metastatic agent

Bikunin is a Kunitz-type protease inhibitor predominantly found in human amniotic fluid. In cancers, administration of bikunin may block tumor cell invasion by a direct inhibition of tumor cell-associated plasmin activity as well as by inhibiting urokinase-type plasminogen activator (uPA) expression at the gene and protein levels, possibly through suppression of CD44 dimerization and/or the MAP kinase signaling cascade. Treatment of cancer patients with bikunin may be beneficial in the adjuvant setting to delay the onset of metastasis development and/or in combination with cytotoxic agents to improve treatment efficacy in patients with advanced ovarian cancer.

Suppression of invasion and peritoneal carcinomatosis of ovarian cancer cell line by overexpression of bikunin

Bikunin (bik), a Kunitz-type protease inhibitor, also known as urinary trypsin inhibitor, is proposed as a main participant in the inhibition of tumor cell invasion and metastasis, possibly through the direct inhibition of cell-associated plasmin activity and suppression of urokinase-type plasminogen activator (uPA) mRNA expression. In the present study, we transfected the human ovarian carcinoma cell line HRA, highly invasive cells, with an expression vector harboring a cDNA encoding for human bik. Our study was designed to investigate the effect of bik overexpression and changes in tumor cell phenotype and invasiveness in the stably transfected clones. Bik gene transfection of HRA gave the following results: 1) transfection of HRA with the bik cDNA resulted in 5 variants stably expressing functional bik; 2) bik(+) clones exhibited a significantly reduced uPA mRNA expression as compared to the parental cells; 3) bikunin negatively regulates the ERK1/2 activity; 4) secretion-blocking treatments of bik(+) clones abrogated bik-mediated suppression of ERK1/2 activation and uPA expression; 5) the regulation of invasion seen in the HRA cells is mainly mediated by the uPA-plasmin-MMP-2 system; 6) transfection of HRA with the bik gene significantly reduced invasion, but not proliferation, adhesion, or migration relative to the parental cells; and 7) animals with bik(+) clones induced reduced peritoneal dissemination and long term survival. We conclude that transfection of HRA cells with the bik cDNA constitutively suppresses ERK1/2 activation, which results in inhibition of uPA expression and subsequently reduces dissemination of bik(+) clones.

A Kunitz-type protease inhibitor, bikunin, inhibits ovarian cancer cell invasion by blocking the calcium-dependent transforming growth factor-beta 1 signaling cascade

Bikunin is a Kunitz-type protease inhibitor, acting at the level of tumor invasion and metastasis. The goal of this study was to investigate the effect of bikunin-dependent signal transduction involved in the expression of a plasminogen activator (PA) system and invasion. We report here the following. 1) The human ovarian cancer cell line HRA produced secreted and cell-associated urokinase-type PA (uPA) and PA inhibitor type 1 (PAI-1). The plasma membrane of the cells showed enzymatically active uPA even in the presence of high level of PAI-1, as measured by zymography, Western blot, chromogenic assay, enzyme-linked immunosorbent assay, and Northern blot. 2) HRA cells leading to invasion are induced through up-regulation of uPA expression. 3) HRA cells specifically released transforming growth factor-beta type 1 (TGF-beta1) participating in an autocrine/paracrine regulation of cell invasion. 4) Elimination of endogenous TGF-beta1 could induce change in uPA/PAI-1 expression, which could in turn modify the invasive behavior of the cells. 5) The constitutive expression of TGF-beta1 as well as up-regulation of the PA system observed in HRA cells was inhibited by preinoculation of the cells with bikunin or calcium channel blocker SK&F 96365 but not with nifedipine or verapamil, with an IC(50) of approximately 100 nm for bikunin or approximately 30 microm for SK&F 96365, respectively, as measured by enzyme-linked immunosorbent assay. Bikunin showed no additive effect on SK&F 96365-mediated suppression of TGF-beta1 expression. 6) The ability of TGF-beta1 to elevate free intracellular Ca(2+), followed by activation of Src and ERK, was reduced by preincubation of the cells with bikunin. In conclusion, bikunin could inhibit the constitutive expression of TGF-beta1 and TGF-beta1-mediated, Src- and ERK-dependent, PA system signaling cascade, at least in part, through inhibition of a non-voltage-sensitive calcium channel.

Effects of combined in vivo treatment of transplantable solid mammary carcinoma in wistar rats using vitamin E and cysteine peptidase inhibitors from human placenta

Cysteine cathepsin B and its endogenous inhibitor play an important role in tumor progression. Increase in cathepsin B expression and reduced levels of its inhibitors were associated with tumor malignancy in breast cancer. The objective of this study was to investigate the effects of a new therapy combining vitamin E and placental inhibitor on the level of endogenous protease inhibitor in sera and tumor tissues with mammary cancer. The inhibitor was used in doses of 100 and 200 micrograms per animal for 8 days. Vitamin E was added after the last treatment with inhibitor and was injected daily in doses of 10 and 20 mg per animal for one mouth. The size and survival time of treated animals as well as cathepsin B and the inhibitor activity in tumor and sera before and after treatment in comparison with the control groups were determined. The activity of cathepsin B significantly decreased both in tumor tissues and in sera (P < or = 0.0001). Cathepsin B activity in tumor tissue homogenates and in sera decreased two-fold and three-fold, respectively, after the animals were treated with vitamin E at a dose of 20 mg, and decreased five-fold and 15-fold, respectively, when treated with vitamin E plus inhibitor in comparison with untreated animals. Endogenous inhibitor activity increased six-fold and 12-fold in the sera and tissue homogenates, respectively, after the animals were treated with 200 micrograms of cysteine protease inhibitor plus 20 mg of vitamin E, in comparison with untreated animals. The total cure responses were higher in eight of 10 rats, as compared with untreated animals. The combination of placental inhibitor and vitamin E resulted in a significant reduction in breast metastasis and might provide a therapeutic basis for anti-metastasis therapy.

Kunitz-type protease inhibitor bikunin disrupts phorbol ester-induced oligomerization of CD44 variant isoforms containing epitope v9 and subsequently suppresses expression of urokinase-type plasminogen activator in human chondrosarcoma cells

We previously found that bikunin (bik), a Kunitz-type protease inhibitor, suppresses phorbol ester (PMA)-stimulated expression of urokinase-type plasminogen activator (uPA). In the present study, we tried to answer this mechanism using human chondrosarcoma HCS-2/8 cells. Our results showed the following novel findings: (a) the standard form of CD44 (CD44s; 85 kDa) is expressed in both unstimulated and PMA-stimulated cells, while CD44v isoforms containing epitope v9 (110 kDa) are strongly up-regulated in response to treatment with PMA; (b) CD44v isoforms containing epitope v9 present on the same cell exclusively form aggregates in stimulated cells; (c) induction of uPA mRNA expression could be achieved by using a second cross-linker antibody to cross-link Fab monomers of anti-CD44; (d) co-treatment of stimulated cells with anti-CD44 mAb alone or anti-CD44v9 mAb alone suppresses PMA-induced clustering of CD44, which results in inhibition of uPA overexpression; (e) bikunin efficiently disrupts PMA-induced clustering of CD44, but does not prevent PMA-induced up-regulation of CD44v isoforms containing epitope v9; and (f) after exposure to bik, approximately 150-kDa band is mainly detected with immunoprecipitation and this band is shown to be a heterodimer composed of the 110-kDa v9-containing CD44v isoforms and a 45-kDa bik receptor (bik-R). In conclusion, we provide, for the first time, evidence that the bik-R can physically interact with the CD44v isoforms containing epitope v9 and function as a repressor to down-regulate PMA-stimulated uPA expression, at least in part, by preventing clustering of CD44v isoforms containing epitope v9.

Structure and function analysis of urinary trypsin inhibitor (UTI): identification of binding domains and signaling property of UTI by analysis of truncated proteins

The binding of urinary trypsin inhibitor (UTI) to its binding sites/receptors on tumor cells inhibits cell invasion in a number of experimental systems and that UTI downregulates constitutive and phorbol ester-induced urokinase production by certain tumor cells. To determine whether the carbohydrate moieties and core protein are required for urokinase suppression, we obtained UTI derivatives that contained O-glycoside-linked N-terminal glycopeptide (UTIm1), N-glycoside-linked C-terminal tandem Kunitz domains (UTIm2), UTI lacking O-glycoside (UTIc), asialo UTI (UTIa), UTI lacking N-glycoside (UTIn), purified Kunitz domain II of UTI (HI-8), and recombinant Kunitz domain II of UTI (R-020). The IC(50) of inhibiting binding of (125)I-labeled UTI to cells was indistinguishable for UTIa, UTIn and intact UTI, whereas the IC(50) for inhibiting binding of (125)I-labeled UTI to cells was 2.5-, 25- and 29-fold greater for UTIm1, UTIm2 and UTIc than for native UTI. We next looked at the suppression of the urokinase expression by UTI derivatives. An enzyme-linked immunosorbent assay was carried out to measure secreted and cell-associated urokinase. Intact UTI, UTIa, or UTIn effectively suppressed urokinase expression, but UTIm1, UTIm2, UTIc, HI-8 and R-020 had no significant effect. These data show that UTI requires either the N-terminal extension with the O-linked carbohydrate moiety (chondroitin 4-sulfate sugar side chain; Ala1 to Lys21 residues) or the Kunitz domain I (Lys22 to Arg77 residues) of UTI to bind to cells, but the urokinase expression was inhibited only by the O-glycoside-linked core protein without the N-glycoside side chain.

Characterization of binding properties of urinary trypsin inhibitor to cell-associated binding sites on human chondrosarcoma cell line HCS-2/8

Urinary trypsin inhibitor (UTI) forms membrane complexes with UTI-binding proteins (UTI-BPs) and initiates modulation of urokinase-type plasminogen activator (uPA) expression, which results in UTI-mediated suppression of cell invasiveness. It has been established that suppression of uPA expression and invasiveness by UTI is mediated through inhibition of protein kinase C-dependent signaling pathways and that human chondrosarcoma cell line HCS-2/8 expresses two types of UTI-BPs; a 40-kDa UTI-BP (UTI-BP(40)), which is identical to link protein (LP), and a 45-kDa UTI-BP (UTI-BP(45)). Here we characterize binding properties of UTI-BPs.UTI complexes in the cells. In vitro ligand blot, cell binding and competition assays, and Scatchard analyses demonstrate that both UTI-BP(40) and UTI-BP(45) bind (125)I-UTI. A deglycosylated form of UTI (NG-UTI), from which the chondroitin-sulfate side chain has been removed, binds only to UTI-BP(40). Additional experiments, using various reagents to block binding of (125)I-UTI and NG-UTI to the UTI-BP(40) and UTI-BP(45) confirm that the chondroitin sulfate side chain of UTI is required for its binding to UTI-BP(45). Analysis of binding of (125)I-UTI and NG-UTI to the cells suggests that low affinity binding sites are the UTI-BP(40) (which can bind NG-UTI), and the high affinity sites are the UTI-BP(45). In addition, UTI-induced suppression of phorbol ester stimulated up-regulation of uPA is inhibited by reagents that were shown to prevent binding of UTI to the 40- and 45-kDa proteins. We conclude that UTI must bind to both of the UTI-BPs to suppress uPA up-regulation.

Suppression of urokinase expression and invasiveness by urinary trypsin inhibitor is mediated through inhibition of protein kinase C- and MEK/ERK/c-Jun-dependent signaling pathways

Urinary trypsin inhibitor (UTI), a Kunitz-type protease inhibitor, interacts with cells as a negative modulator of the invasive cells. Human ovarian cancer cell line, HRA, was treated with phorbol ester (PMA) to evaluate the effect on expression of urokinase-type plasminogen activator (uPA), since the action of uPA has been implicated in matrix degradation and cell motility. Preincubation of the cells with UTI reduced the ability of PMA to trigger the uPA expression at the gene level and at the protein level. UTI-induced down-regulation of PMA-stimulated uPA expression is irreversible and is independent of a cytotoxic effect. Down-regulation of uPA by UTI is mediated by its binding to the cells. We next asked whether the mechanism of inhibition of uPA expression by UTI was due to interference with the protein kinase C second messenger system. An assay for PKC activity demonstrated that UTI does not directly inhibit the catalytic activity of PKC and that PMA translocation of PKC from cytosol to membrane was inhibited by UTI, indicating that UTI inhibits the activation cascade of PKC. PMA could also activate a signaling pathway involving MEK1/ERK2/c-Jun-dependent uPA expression. When cells were preincubated with UTI, we could detect suppression of phosphorylation of these proteins. Like several types of PKC inhibitor, UTI inhibited PMA-stimulated invasiveness. We conclude that UTI markedly suppresses the cell motility possibly through negative regulation of PKC- and MEK/ERK/c-Jun-dependent mechanisms, and that these changes in behavior are correlated with a coordinated down-regulation of uPA which is likely to contribute to the cell invasion processes.

Suppression of urokinase-type plasminogen activator expression from human ovarian cancer cells by urinary trypsin inhibitor

Urinary trypsin inhibitor (UTI), a Kunitz-type protease inhibitor, efficiently inhibits tumor cell invasion and metastasis. We examined the effect of UTI on urokinase-type plasminogen activator (uPA) expression in ovarian cancer cell lines, HOC-I and HRA. By Northern blot, Western blot, ELISA, and zymographic analyses, we demonstrated that UTI inhibited the expression of uPA mRNA and protein in these cells in a time- and dose-dependent manner, independent of whether induction was triggered by phorbol ester. Monoclonal antibody 4G12, which inhibits UTI binding to the cells, produced a dose-dependent abrogation in UTI-mediated down-regulation of uPA expression. These data suggest that UTI significantly down-regulates tumor cell uPA mRNA expression and protein secretion, and that UTI binding to the cells is necessary to exert the UTI's action.

Identification and characterization of a Kunitz-type protease inhibitor in ascites fluid from patients with ovarian carcinoma

Urinary trypsin inhibitor (UTI; Mr 40 kDa) is a Kunitz-type protease inhibitor that efficiently inhibits cell-associated trypsin and plasmin activities. The aim of this study is to examine the expression pattern of UTI in the human ovarian carcinoma ascites fluid by Western blotting, zymography, immunoprecipitation, immunohistochemistry, biochemical and gene analyses and animal experiments. We have identified and characterized the 40 kDa immunoreactive UTI (UTI(40)) and 8 kDa degradation fragment (UTI(8)) in ascites fluid. The levels of UTI(40) and UTI(8) are elevated in ascites fluid taken from patients with ovarian carcinoma relative to paired plasma samples. The UTI(40) and UTI(8) were identified immunologically by the reactivity with 2 different anti-UTI antibodies recognizing different epitopes of the UTI molecule, functionally by its ability to bind trypsin and structurally by its apparent molecular mass with and without deglycosylation treatment. The purified polypeptides have been sequenced and were identical with sequences obtained from UTI and the carboxyl-terminal domain of UTI, respectively. However, UTI mRNA was not detected in the ovarian carcinoma tissue and ovarian carcinoma cell lines examined. Based on extravasation experiments using intravenously injected biotinylated inter-alpha-trypsin inhibitor (IalphaI; a precursor of UTI), we conclude that UTI(40) and UTI(8) found in the ascites fluid may result from (i) the extravasation of plasma proteins such as IalphaI into the peritoneal cavity via hyperpermeable vessels and (ii) the subsequent degradation of IalphaI and UTI(40) by tumor cell-associated trypsin-like enzymes.

Immunohistochemical distribution of inter-alpha-trypsin inhibitor chains in normal and malignant human lung tissue

The inter-alpha-trypsin inhibitor (ITI) family is a group of plasma proteins built up from heavy (HC1, HC2, HC3) and light (bikunin) chains synthesized in the liver. In this study we determined the distribution of ITI constitutive chains in normal and cancerous lung tissues using polyclonal antibodies. In normal lung tissue, H2, H3, and bikunin chains were found in polymorphonuclear cells, whereas H1 and bikunin proteins were found in mast cells. Bikunin was further observed in bronchoepithelial mucous cells. In lung carcinoma, similar findings were obtained on infiltrating polymorphonuclear and mast cells surrounding the tumor islets. Highly differentiated cancerous cells displayed strong intracytoplasmic staining with H1 and bikunin antiserum in both adenocarcinoma and squamous cell carcinoma. Moreover, weak but frequent H2 expression was observed in adenocarcinoma cells, whereas no H3-related protein could be detected in cancer cells. Local lung ITI expression was confirmed by RT-PCR. Although the respective role of inflammatory and tumor cells in ITI chain synthesis cannot be presently clarified, these results show that heavy chains as well as bikunin are involved in malignant transformation of lung tissue.(J Histochem Cytochem 47:1625-1632, 1999)

Identification and characterization of the cell-associated binding protein for urinary trypsin inhibitor

Urinary trypsin inhibitor (UTI) inhibits not only tumor cell invasion but also production of experimental and spontaneous metastasis. Cell-binding experiments indicated that human choriocarcinoma SMT-cc1 cells have specific binding sites for UTI on their cell surface. [Kobayashi et al., J. Biol. Chem. 269, 1994, 20,642-20,647]. UTI binding protein (UTIBP) was purified to homogeneity by a combination of UTI-coupled affinity beads, preparative polyacrylamide gel electrophoresis and reverse phase HPLC. This protein is very similar to a truncated form of human cartilage link protein (LP). LP was identified structurally by its apparent molecular mass with and without deglycosylation treatment: Immunologically by the reactivity with anti-UTIBP antibody, and functionally by its ability to bind the NH2-terminal domain of UTI. UTI and UTIBP are distributed uniformly in the cytoplasm and/or over the cell surface of tumor cells and fibroblasts. The level of staining for hyaluronic acid, UTIBP and UTI is much lower in sections digested with hyaluronidase. These results suggest that the cell membrane-derived UTI-associated binding protein is the LP of proteoglycan-hyaluronic acid aggregates, which interacts with hyaluronic acid. Cell-associated LP may play a role in modulating protease activity to the environment close to tumor and fibroblast cell surface.

Urinary trypsin inhibitor reduces the release of histamine from rat peritoneal mast cells

We determined the ability of urinary trypsin inhibitor (UTI), which is a Kunitz-type protease inhibitor present in serum and in urine, to inhibit rat peritoneal mast cell (RPMC) mediator release induced by several stimuli. UTI attenuated the immunoglobulin E-mediated release of both preformed (histamine) and newly formed (leukotriene C4) mediators from RPMCs. Inhibition (21%+/-5%) of the anti-IgE-triggered release of histamine was observed after a 30-minute incubation of RPMCs with UTI (5 micromol/L). To investigate the specificity of the UTI effect, we studied the stimulatory activity of phorbol ester (phorbol 12-myristate 13-acetate (PMA)) or calcium ionophore A23187 in control and UTI-treated mast cells. The efficacy of UTI as an inhibitor was dependent on the nature of the stimulus, because histamine release induced by PMA-mediated or calcium ionophore A23187-mediated processes was not inhibited by UTI. A series of structurally distinct protease inhibitors did not inhibit IgE-induced release of mediators from RPMCs. The Kunitz-type protease inhibitors are important in the regulation of RPMC function. In parallel with the UTI-related decrease in anti-IgE stimulatory activity on mediator release, increased microviscosity of membrane lipids could be observed by two independent experiments on fluorescence polarization with diphenylhexatriene (DPH) and on the fluorescence probe fluorescein isothiocyanate-concanavalin A. UTI reduces mediator release by a mechanism-possibly an interruption of the coupling of receptor and effector systems-because UTI acts as an agent to decrease biologic lipid membrane fluidity.

Hyaluronidase activity in gynaecological cancer tissues with different metastatic forms

We investigated hyaluronidase activity in gynaecological normal and malignant tissues. Hyaluronidase activity in culture medium of tissue specimens was detected by hyaluronic acid zymography and quantified by densitometry. Hyaluronidase activity was shown as one dominant band (molecular weight 65 kDa) at pH 3.5. Hyaluronidase activity was significantly higher in normal ovary (P < 0.05) and normal endometrium (P< 0.05) than in normal cervix. One dominant 65-kDa hyaluronidase was expressed in 100% (14 out of 14) of ovarian cancer tissues and in 91% (10 out of 11) of endometrial cancer tissues. However, hyaluronidase activity was not observed in cervical cancer tissues. Hyaluronidase activity was significantly higher in ovarian (P < 0.001) and endometrial (P < 0.01) cancer tissues than in cervical cancer tissue and was significantly higher in ovarian cancer tissue than in endometrial cancer tissue (P < 0.05). These facts suggest that the cancer cells make use of the original characteristic of the organ to invade and metastasize. Moreover, these results reflect the difference in metastatic forms and are suggestive of a strong relationship between hyaluronidase activity and invasion and metastasis of ovarian and endometrial cancers compared with cervical cancer.