Product inhibition slow down the moving velocity of processive chitinase and sliding-intermediate state blocks re-binding of product.

Processive movement is the key reaction for crystalline polymer degradation by enzyme. Product release is an important phenomenon in resetting the moving cycle, but how it affects chitinase kinetics was unknown. Therefore, we investigated the effect of diacetyl chitobiose (C2) on the biochemical activity and movement of chitinase A from Serratia marcescens (SmChiA). The apparent inhibition constant of C2 on crystalline chitin degradation of SmChiA was 159 µM. The binding position of C2 obtained by X-ray crystallography was at subsite +1, +2 and Trp275 interact with C2 at subsite +1. This binding state is consistent with the competitive inhibition obtained by biochemical analysis. The apparent inhibition constant of C2 on the moving velocity of high-speed (HS) AFM observations was 330 µM, which is close to the biochemical results, indicating that the main factor in crystalline chitin degradation is also the decrease in degradation activity due to inhibition of processive movement. The Trp275 is a key residue for making a sliding intermediate complex. SmChiA W275A showed weaker activity and affinity than WT against crystalline chitin because it is less processive than WT. In addition, biochemical apparent inhibition constant for C2 of SmChiA W275A was 45.6 µM. W275A mutant showed stronger C2 inhibition than WT even though the C2 binding affinity is weaker than WT. This result indicated that Trp275 is important for the interaction at subsite +1, but also important for making sliding intermediate complex and physically block the rebinding of C2 on the catalytic site for crystalline chitin degradation.

The effect of small dose of topiroxostat on serum uric acid in patients receiving hemodialysis.

INTRODUCTION: Topiroxostat, a recently developed xanthine oxidase inhibitor, is expected to have fewer adverse effects than allopurinol because it has different mechanism of action from alloprinol. However, its dosage, usage and safety have not been established in patients with impaired renal function or those undergoing dialysis at the development since no studies was conducted in these patients. METHODS: Cross over clinical trial using 3 months of allopurinol and topiroxostat on 27 maintain Japanese HD patients were carried out. The effects on oxidative stress status of both drugs were also evaluated by measuring oxidation reduction potential. FINDINGS: Twenty-five of twenty-seven patients completed study. The mean serum uric acid levels in the topiroxostat-treated arm was significantly lower than it in the allopurinol-treated arm time-dependently (P < 0.0001). Corrected oxidative stress ratio defined as biological antioxidant potential/diacron reactive oxygen metabolites was significantly increased in topiroxostat-arm (*P = 0.0035), but not in allopurinol-arm (P = 0.1429). No significant difference was seen in diacron reactive oxygen metabolites, biological antioxidant potential, static oxidation-reduction potential, and capacity oxidation-reduction potential between pre and post treatment of both drugs. DISCUSSION: It is suggested that a low dose of topiroxostat decreased serum uric acid sufficiently to maintain it below 7.0 mg/dL in patients receiving hemodialysis.

Acne conglobata in a long-term survivor with trisomy 13, accompanied by selective IgM deficiency.

Trisomy 13 (T13) is a congenital chromosomal disorder that is usually fatal within 2 years of birth, and only a few patients have been reported to reach adolescence. Here, we report a male long-term survivor of T13, currently 15 years of age, with a several-year history of extensive acne conglobata (AC) with abscesses on the face and neck. Methicillin-resistant Staphylococcus aureus was consistently isolated from the pustular lesions. Serum IgM levels were extremely low at 10 mg/dl. There were no abnormalities in neutrophil and total B cell number, or in serum IgA and IgG levels. Increased CD8+ T cell counts and inversion of the CD4/CD8 ratio were observed repeatedly. The patient's clinical features and laboratory data support a diagnosis of selective IgM deficiency (SIgMD) with concurrent AC. Immunoglobulin replacement therapy elevated serum IgM levels to the normal range and reduced the severity of AC. We suggest that T13 may represent a syndromic disorder associated with multiple organ malformation and a risk of developing immunodeficiency involving SIgMD. Because pediatric SIgMD is rare and an immunological abnormality in T13 patients has not previously been reported, we describe the patient's clinical course.

Improvement of MBD parameters in dialysis patients by a switch to, and combined use of lanthanum carbonate: Josai Dialysis Forum collaborative study.

The effects of lanthanum carbonate on MBD parameters were investigated in 59 hemodialysis patients who were taking calcium carbonate. Lanthanum carbonate (initial dosage: 750 mg/day), as a replacement for or in combination with calcium carbonate and/or sevelamer hydrochloride, was administered for 12 months with increase/decrease of dosages. Lanthanum carbonate replaced calcium carbonate for 21 cases and was co-administered in 38 cases. It replaced sevelamer hydrochloride in 20 cases and was co-administered in 10 cases. Both the number of cases to which calcium carbonate was administered and their dosages decreased to about 70-80% 12 months after the initiation, and cases administered sevelamer decreased to about 30%. In the cases for which lanthanum carbonate was co-administered, the dosages of calcium carbonate and sevelamer slightly decreased. A significant decrease in serum calcium level was observed. In the serum phosphorus levels (P levels), significant decrease compared with the initial level was observed only at six and nine months. Intact parathyroid hormone (iPTH) level remained stable at around 230 pg/mL without significant change. The dosage of vitamin D and cinacalcet remained without significant change. The results of this trial suggest that, if dosages of vitamin D and cinacalcet are adequately controlled, a switch to lanthanum carbonate and its concomitant use are effective to control the Ca and P levels without changing iPTH levels.

Associations between vascular calcification, arterial stiffness and bone mineral density in chronic hemodialysis patients.

AIM: The aim of our study was to examine the associations between vascular calcification, arterial stiffness and bone mineral density (BMD) in chronic hemodialysis (HD) patients. METHODS: The study subjects were 83 (70 men and 13 women) HD patients. All patients had computed tomography (CT) to determine aortic calcification index (ACI), pulse wave velocity (PWV) using a volume-plethysmographic apparatus, and BMD estimated by digital image processing (DIP). RESULTS: Patients, 84.3% male, 38.6% diabetic, had a mean age of 59.3 +/- 11.2 years. In univariate linear regression analysis, ACI correlated positively with age (r = 0.586, P < 0.0001), dialysis vintage (r = 0.47, P = 0.002), pulse pressure (r = 0.311, P = 0.004), C-reactive protein (CRP) (r = 0.226, P = 0.0397) and PWV (r = 0.422, P < 0.0001). There was no significant association between ACI and serum markers of mineral metabolism. There was also a positive association between PWV and systolic blood pressure (P = 0.0004) or pulse pressure (P < 0.0001), and a trend towards greater PWV with increasing age (r = 0.494). In multivariate regression analysis only increasing age, pulse pressure, serum levels of albumin and CRP were significantly associated with ACI and PWV. Mean BMD on DIP was 2.7 +/- 0.4 mmAL. ACI was inversely correlated with BMD (r = -0.234, P = 0.0331). CONCLUSIONS: Vascular calcification is closely associated with arterial stiffness in HD patients. BMD is inversely correlated with ACI, suggesting that measurement of hand BMD by DIP is a useful tool for assessment of renal bone disease in these patients.

Plasma levels of fibroblast growth factor-23 and mineral metabolism in diabetic and non-diabetic patients on chronic hemodialysis.

OBJECTIVE: Fibroblast growth factor (FGF) 23 is a circulating factor that regulates phosphate (P) metabolism. Since higher P levels are associated with vascular calcification, we examined the role of serum FGF-23 levels in P metabolism and vascular calcification in hemodialysis (HD) patients with and without diabetes mellitus (DM). MATERIALS AND METHODS: Chronic HD patients with DM (n = 39) and without DM (n = 50) were enrolled. Serum samples were obtained before the start of dialysis sessions, and the FGF-23 levels were determined by enzyme-linked immunosorbent assay. Abdominal computed tomography (CT) scan was performed, and the aortic calcification index (ACI) was determined by one examiner, blinded to the patient characteristics. Measurements of bone mineral density (BMD) were performed at the time of ACI estimation. RESULTS: Log plasma FGF-23 levels were higher in non-DM (3.74 +/- 0.71 pg/ml) than in DM (3.35 +/- 0.74 pg/ml) patients. The log FGF-23 correlated positively with serum creatinine (r = 0.424, P < 0.0001), albumin (r = 0.225, P = 0.0337), Ca (r = 0.392, P = 0.0001), P (r = 0.735, P < 0.0001), and Ca x P product (r = 0.780, P < 0.0001). There were negative correlations between log FGF-23 and age (r = -0.208, P = 0.0497), glucose (r = -0.231, P = 0.0294), and CRP (r = -0.222, P = 0.0359). Multiple regression analyses were performed to explore the correlations between plasma FGF-23 and other factors associated with vascular calcification in all HD patients. Independent variables were selected based on the results of univariate analyses. The significant factors associated with FGF-23 in HD patients were age, serum levels of creatinine, albumin, glucose, Ca, P, and Ca x P product. Plasma FGF levels did not correlate significantly with either ACI or BMD in these patients. CONCLUSION: Our findings indicate that the plasma FGF-23 level is associated with calcium-phosphate metabolism disorders, but not with aortic calcification, in both non-DM and DM patients on chronic HD. In addition, plasma FGF-23 is associated with serum levels of creatinine and albumin. Therefore, the plasma FGF-23 level may provide a reliable marker for Ca and P imbalance and nutritional status in HD patients.

The first infant case with hepatosplenic gammadelta T-cell lymphoma after acute disseminated encephalomyelitis (ADEM)-like exacerbation.

We report the first infant case with hepatosplenic gammadelta T-cell lymphoma after recurrent acute disseminated encephalomyelitis-like, which were rapidly resolved with steroid pulse therapy. The patient had a history of recurrent bronchitis, intractable diarrhea, and failure to thrive since 4 months of age. Immunologic analysis revealed higher percentage of circulating gammadelta T-cells with markedly reduced numbers of CD3TCRalphabetaCD8 T-cells. The patient developed gammadelta T-cell lymphoma at the age of 15 months. Clinical course of the patient suggests the importance of immunological background for the development of hepatosplenic gammadelta T-cell lymphoma.

[Setting up of a day group service system for severely disabled children, the "Koala Club"].

This is a report of the setting up of a day group service system for severely disabled children, the "Koala Club". The "Koala Club" was started in 1993, and has been running outside of the hospital since 1997. A support group for the "Koala Club" was established in 1999. Currently 13 children attend the "Koala Club". The staff of the "Koala Club" consists of one coordinater, four nurses and eight care workers. The medical care is fulfilled by nurses. The "Koala Club" open two days a week. It has been supervised by a doctor and a case worker. There is an important role for physicians in the regional care of disabled children.

Thyme (Thymus vulgaris L.) leaves and its constituents increase the activities of xenobiotic-metabolizing enzymes in mouse liver.

The effects of thyme (Thymus vulgaris L.) leaves and its phenolic compounds, thymol and carvacrol, on the activities of xenobiotic-metabolizing enzymes, i.e., phase I enzymes such as 7-ethoxycoumarin O-deethylase (ECOD) and phase II enzymes such as glutathione S-transferase (GST) and quinone reductase (QR), were investigated. Mice were fed with a diet containing thyme (0.5% or 2.0%) or treated orally with thymol (50-200 mg/kg) or carvacrol (50-200 mg/kg) once a day for 7 successive days, and then the enzyme activities in the livers were analyzed. Dietary administration of 2% thyme caused slightly but significantly higher ECOD, GST, and QR activities by 1.1-1.4-fold. Thymol (200 mg/kg) treatment resulted in significantly higher ECOD, GST, and QR activities by 1.3-1.9-fold, and carvacrol (200 mg/kg) treatment caused significantly higher ECOD, GST, and QR activities by 1.3-1.7-fold. Thymol-treated animals had significantly higher protein levels of GST alpha and GST micro, and carvacrol-treated animals had significantly higher levels of GST micro. These results imply that thyme contains bifunctional inducers (i.e., substances capable of inducing both phase I and phase II enzymes) and that thymol and carvacrol may account for the effects of thyme.

Sex- and menstrual cycle-related differences in sweating and cutaneous blood flow in response to passive heat exposure.

To examine sex- and menstrual cycle-related differences in thermoregulatory responses to heat exposure, ten young women and six young men were heated passively by immersing their legs in water heated to 42 degrees C for 60 min (in ambient conditions of 30 degrees C and 45% relative humidity). The women underwent heat exposure during the mid-follicular (F) and mid-luteal (L) phases of the menstrual cycle, which were confirmed by assaying plasma female reproductive hormones. The rectal and mean body (T(b)) temperatures of women in the L phase were significantly greater than those of women in the F phase and of men during a pre-heating equilibration period (28 degrees C) and during heat exposure. During heat exposure, the local sweat rates (m(sw)) on the forehead, chest, back, and forearm of women in either phase were significantly lower than those of men, but the thigh (m(sw)) was similar to that of men. The m(sw) did not change at any site during the different phases of the menstrual cycle. The cutaneous blood flow (%LDF) was significantly greater on the thigh for women in either phase compared with men, but no difference was found at any other site (forehead, chest, back, and forearm). The %LDF on the back was significantly greater for women in the L phase than in the F phase, but those at other sites were similar in both phases. We conclude that, compared with men, heat loss from women depends more on cutaneous vasodilation (especially on the thigh) than on sweating, irrespective of the phase of the menstrual cycle. This phenomenon was due to peripheral mechanisms, as reflected in the greater slope of the relationship between %LDF and T(b) lower slope of the relationship between m(sw)) and frequency of sweat expulsion, and lower sweat output per gland. The menstrual cycle modified the T(b) threshold for vasodilation and sweat onset in women. Therefore, the sex difference in the T(b) threshold was more marked for women during the L phase than during the F phase. Moreover, the menstrual cycle modified the slope of the relationship between %LDF on the back and T(b).

Reproductive failure in mice lacking inter-alpha-trypsin inhibitor (ITI)--ITI target genes in mouse ovary identified by microarray analysis.

Bikunin, a Kunitz-type protease inhibitor, is found in blood and urine. It has been established by two laboratories independently that the bikunin knockout female mice display a severe reduction in fertility: the cumulus oophorus has a defect in forming the extracellular hyaluronan-rich matrix during expansion. Proteins of the inter-alpha-trypsin inhibitor (ITI) family are eliminated in mice in which the bikunin gene has been inactivated, since bikunin is essential for their biosynthesis. Proteins of the ITI family may contribute to the microenvironment in which ovulation takes place. It is not clear, however, whether a single mechanism affects the reproductive function including ovulation. For identifying the full repertoire of the ITI deficiency-related genes, a cDNA microarray hybridization screening was conducted using mRNA from ovaries of wild-type or bik(-/-) female mice. A number of genes were identified and their regulation was confirmed by real-time RT-PCR analysis. Our screen identified that 29 (0.7%) and 5 genes (0.1%) of the genes assayed were, respectively, up- and down-regulated twofold or more. The identified genes can be classified into distinct subsets. These include stress-related, apoptosis-related, proteases, signaling molecules, aging-related, cytokines, hyaluronan metabolism and signaling, reactive oxygen species-related, and retinoid metabolism, which have previously been implicated in enhancing follicle development and/or ovulation. Real-time RT-PCR analysis confirmed that these genes were up- and down-regulated two- to tenfold by bikunin knockout. These studies demonstrate that proteins of the ITI family may exert potent regulatory effects on a major physiological reproductive process, ovulation.

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.

Genetic downregulation of pregnancy-associated plasma protein-A (PAPP-A) by bikunin reduces IGF-I-dependent Akt and ERK1/2 activation and subsequently reduces ovarian cancer cell growth, invasion and metastasis.

A Kunitz-type protease inhibitor, bikunin, downregulates expression of uPA and its receptor uPAR at the mRNA and protein levels in several types of tumor cells. Our recent work showed that, using a cDNA microarray analysis, pregnancy-associated plasma protein-A (PAPP-A) is a candidate bikunin target gene. To clarify how reduced levels of PAPP-A may confer repressed invasiveness, we transfected human ovarian cancer cell line HRA with antisense (AS)-PAPP-A cDNA and compared the properties of the transfected cells to those of parental HRA cells. Here, we show that regulation of uPA mRNA and protein by IGF-I depends on the PI3K and MAPK signaling pathways and phosphorylation of Akt and ERK1/2 is required for IGF-I-mediated cell invasion; that IGFBP-4 protease in HRA cells is identified as PAPP-A; that reduced PAPP-A expression is associated with the upregulation of IGFBP-4 expression; that higher intact IGFBP-4 levels were associated with low invasive potential and growth rate in AS-PAPP-A cells in response to IGF-I; that IGF-I stimulates Akt and ERK1/2 activation of both the control and antisense cells, but the relative potency and efficacy of IGF-I were lower in the antisense cells compared to the control; and that genetic downregulation of PAPP-A reduces the proliferation, invasion and metastasis of HRA cells. In conclusion, our data identify a novel role for PAPP-A as a bikunin target gene. IGF-I-induced IGFBP-4 proteolysis by PAPP-A may enhance cell growth and invasion through IGF-I-dependent Akt and ERK1/2 activation and subsequently upregulation of uPA.

Transforming growth factor-beta1-dependent urokinase up-regulation and promotion of invasion are involved in Src-MAPK-dependent signaling in human ovarian cancer cells.

Urokinase-type plasminogen activator (uPA) has been implicated in tumor cell invasion and metastasis. We reported previously that transforming growth factor (TGF)-beta1 induces a dose- and time-dependent up-regulation of uPA mRNA and protein in highly invasive human ovarian cancer cell line HRA, leading to invasion. To further elucidate the mechanism of the invasive effect of TGF-beta1, we investigated which signaling pathway transduced by TGF-beta1 is responsible for this effect. Here, we show that 1) nontoxic concentrations of TGF-beta1 activated Src kinase; 2) TGF-beta1 rapidly phosphorylates ERK1/2 and Akt, but not p38; 3) pharmacological Src inhibitor PP2 or antisense (AS) c-Src oligodeoxynucleotide (ODN) treatment reduced TGF-beta1-induced phosphorylation of ERK1/2 and Akt by 85-90% compared with controls; 4) pharmacological inhibition of MAPK by PD98059 abrogated TGF-beta1-mediated Akt stimulation, whereas TGF-beta1-induced ERK1/2 stimulation was not inhibited by PI3K inhibitor LY294002 or AS-PI3K ODN transfection; 5) up-regulation of uPA mRNA in response to TGF-beta1 was almost totally blocked by PP2 and PD98059 and partially ( approximately 55%) by LY294002; 6) TGF-beta1-induced uPA mRNA up-regulation was inhibited by treatment with AS ODNs to c-Src or PI3K by 90 or 60%, respectively, compared with control ODN treatment; and 7) blockade of the release of the transcription factor NF-kappaB by pyrrolidinedithiocarbamate reduced the TGF-beta1-induced activation of the uPA gene by approximately 65%. In addition, curcumin, a blocker of the transcriptional factor AP-1, partially (35%) canceled this effect. Taken together, these data support a role for TGF-beta1 activation of two distinct pathways (Src-MAPK-PI3K-NF-kappaB-dependent and Src-MAPK-AP-1-dependent) for TGF-beta1-dependent uPA up-regulation and promotion of invasion.

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.

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.

Immunological detection of D-beta-aspartate-containing protein in lens-derived cell lines.

PURPOSE: Although the presence of biologically uncommon D-beta-aspartate (D-beta-Asp) in lens protein is thought to be related to aging, we recently found this isomer in lens alphaA-crystallin from human newborns. The objective of this study was to examine whether D-beta-Asp occurs in protein from lens-derived cell lines. METHODS: We examined the expression of D-beta-Asp-containing protein in the lens-derived cell lines alphaTN4-1 and N/N1003A, by western blot and immunoprecipitation analysis using a polyclonal antibody against Gly-Leu-D-beta-Asp-Ala-Thr-Gly-Leu-D-beta-Asp-Ala-Thr-Gly-Leu-D-beta-Asp-Ala-Thr (peptide 3R), which corresponds to three repeats of positions 149-153 in human alphaA-crystallin. The anti-peptide 3R antibody, prepared in a previous study, is a useful tool for investigating D-beta-Asp-containing peptides. RESULTS: Western immunoblot and immunoprecipitation analysis showed that a 50 kDa protein in N/N1003A cells was strongly immunoreactive with the anti-peptide 3R antibody. Antibodies against alphaA- and alphaB-crystallin also stained this protein. On the other hand, the alphaTN4-1 cell line only expressed proteins of about 20 kDa, which also reacted to antibodies against alphaA-crystallin and alphaB-crystallin. CONCLUSIONS: The results indicate that the N/N1003A cell line expressed a 50 kDa D-beta-Asp-containing protein, which may share a common amino acid sequence with alphaA- and alphaB-crystallin.

Bikunin target genes in ovarian cancer cells identified by microarray analysis.

Bikunin, a Kunitz-type protease inhibitor, could potentially suppress tumor cell invasion and metastasis. Our previous study revealed that overexpression of bikunin in a human ovarian cancer cell line, HRA, resulted in a down-regulation in uPA and uPAR gene expression. For identifying the full repertoire of bikunin-regulated genes, a cDNA microarray hybridization screening was conducted using mRNA from bikunin-treated or bikunin-transfected HRA cells. A number of bikunin-regulated genes were identified, and their regulation was confirmed by Northern blot analysis. Our screen identified 11 bikunin-stimulated genes and 29 bikunin-repressed genes. The identified genes can indeed be classified into distinct subsets. These include transcriptional regulators, oncogenes/tumor suppressor genes, signaling molecules, growth/cell cycle, invasion/metastasis, cytokines, apoptosis, ion channels, extracellular matrix proteins, as well as some proteases. This screen identified suppression of several genes such as CDC-like kinase, LIM domain binding, Ets domain transcription factor, Rho GTPase-activating protein, tyrosine phosphorylation-regulated kinase, hyaluronan-binding protein, matriptase, and pregnancy-associated plasma protein-A (PAPP-A), which have previously been implicated in enhancing tumor promotion. Northern blot analysis confirmed that several genes including matriptase and PAPP-A were down-regulated by bikunin by approximately 9-fold. Further, genetic inhibition of matriptase or PAPP-A could lead to diminished invasion. These results show that bikunin alters the pattern of gene expression in HRA cells leading to a block in cell invasion.

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.