Plasminogen activator inhibitor type 1 promotes fibrosarcoma cell migration by modifying cellular attachment to vitronectin via alpha(v)beta(5) integrin

Both urokinase plasminogen activator (u-PA) and plasminogen activator inhibitor type 1 (PAI-1) are associated with a poor prognosis in cancer patients. We demonstrate that PAI-1 inhibits human fibrosarcoma cell (HT-1080) adhesion to vitronectin (Vn) via alpha (v)beta (5) integrin, and stimulates cell migration from Vn toward collagen type IV (Col). The cells attached more strongly to Vn and Col than to fibronectin (Fn), whereas PAI-1 interfered with cell attachment to Vn only. An integrin antagonist, RGD peptide, and anti-alpha (v)beta (5) integrin antibodies, which similarly inhibited cell attachment to Vn, also stimulated cell migration from Vn toward Col. u-PA did not modify cell attachment directly, but reversed the PAI-1-mediated inhibitory effect on cell adhesion to Vn, and its stimulatory effect on cell migration from Vn toward Col. Thus HT-1080 cell migration appears to be modified by u-PA and PAI-1, altering cell adhesion to Vn via alpha (v)beta (5) integrin. This may be related to their tumor-promoting effect.     

A case report of complication liked jejunal conduit syndrome induced by reconstruction of ileal conduit

The patient was a 77-year-old man who underwent radical cystectomy and ileal conduit urinary diversion due to bladder cancer in 1989. A stenosis of the right uretero-ileal anastomosis occurred in 1992, and of the left uretero-ileal anastomosis in 1999. These were treated with indwelling of a ureteral stent and percutaneous nephrostomy, respectively. He was admitted to our hospital for progressive renal dysfunction due to frequent pyelonephritis. We performed a reconstruction of the ileal conduit urinary diversion and after the removal of the bilateral ureteral stent he complained of nausea and general malaise. The laboratory data showed hyponatremia, hyperkalemia and azotemia, which were diagnosed as complication liked jejunal conduit syndrome. He was treated with hydration and salt supplementation. With regard to this case, we considered that a long ileal conduit close to the jejunum and renal dysfunction caused the complication liked jejunal conduit syndrome. Careful observation and follow-up laboratory examination should be performed if the patient has renal dysfunction and a long conduit near the jejunum is used for the ileal conduit.     

Self-organization model of cytochrome oxidase blobs and ocular dominance columns in the primary visual cortex

There are regularly arranged blobs that contain neurons labeled by cytochrome oxidase (CO) in the supragranular layer of the primary visual cortex (V1) of monkeys and cats. This theoretical study demonstrates that CO-blob-like patterns can be reproduced based on the thermodynamic model for the activity-dependent self-organization of afferent inputs from two different groups of neurons to the supragranular layer of the visual cortex. Computer simulation based on the model shows that within a particular parameter range each blob is centered in the ocular dominance (OD) band, as observed in macaque monkeys and galagos. Furthermore, by increasing the strength of correlation in activity between inputs from the two eyes, nearby blobs merge across OD borders, as seen in the cat visual cortex. Finally, for monocular deprivation, blobs in the deprived eyes shrink as observed in monkeys and cats. For binocular deprivation, less intensely labeled blobs were reproduced, while the blob density did not change as observed in monkeys.     

Relationships between brachial-ankle pulse wave velocity and conventional atherosclerotic risk factors in community-dwelling people

BACKGROUND: A simple instrument has been developed to measure brachial-ankle pulse wave velocity (baPWV). The aim of the present study was to use this instrument to study the relationship between baPWV and conventional atherosclerotic risk factors. METHODS: Community-dwelling Japanese (632) living in a rural area (234 men and 398 women) participated in a municipal medical health survey that included baPWV measurement and a traditional clinical examination, conducted in June, 2002. RESULTS: Men had a significantly higher baPWV than women. No interaction between gender and age on baPWV was identified. Multiple linear regression analysis indicated that age, hemodynamic factors (diastolic blood pressure, pulse pressure, and heart rate), hemoglobinA1c, current drinking and smoking status, and mild retinal changes had significant independent influences on higher baPWV. CONCLUSIONS: In this rural population, age, gender, and hemodynamic factors were independently associated with baPWV, along with traditional atherosclerotic risk factors, although no significant associations between baPWV and histories of atherosclerotic diseases or subclinical atherosclerosis except for mild retinal changes were demonstrated.     

A case of 9p-deletion syndrome with congenital median nasal fistula

We report a case of 9p-syndrome with congenital median nasal fistula in a boy born to a 28-year-old mother as the second child by normal delivery. The fistula opened at the base of the bridge of the nose and ran between the nasal septum cartilage to the anterior cranial fossa. A frontal craniotomy and transcolumellar skin incision were conducted to extirpate the fistula. In the 10 months since, no fistula has recurred.     

Reversal of drug resistance mediated by hammerhead ribozyme against multidrug resistance-associated protein 1 in a human glioma cell line

We examined the effects of suppressing multidrug resistance-associated protein 1 (MRP1) gene expression in a human glioma cell line U87MG. Hammerhead ribozymes, designed to cleave MRP1 mRNA (alphaMRP1-Rz), were transfected into the U87MG cells. The U87MG/alphaMRP1-Rz cells were significantly sensitive to nitrosourea (ACNU) and doxorubicin (DOX) compared with the U87MG cells (p<0.01 and p<0.05, respectively, unpaired t-test). There was no significant difference in the expression of other human genes between the U87MG/alphaMRP1-Rz and controls by cDNA array. The hammerhead ribozyme-mediated specific suppression of MRP1 was sufficient to reverse the resistance of ACNU and DOX in the human glioma cell line.     

An endothelium-derived factor modulates purinergic neurotransmission to mesenteric arterial smooth muscle of hamster

The interaction between the endothelium and purinergic perivascular nerves was investigated by measuring the changes in amplitude of excitatory junction potential (EJP) of smooth muscle cells in hamster mesenteric arteries (100-350 microm). Uridin-5'-triphosphate (UTP) (100 microM) applied to endothelium-intact preparations evoked a hyperpolarization of 17.0 +/- 0.7 mV (n=46). During this hyperpolarization, the amplitude of electrically evoked EJPs was inhibited to about 50% of that of the control. In endothelium-denuded preparations, UTP (100 microM) neither hyperpolarized the smooth muscle nor inhibited the amplitude of the EJP. Neither a nitric oxide (NO) synthase inhibitor, Nomega-nitro-L-arginine methyl ester (L-NAME) (100 microM), nor a cyclooxygenase inhibitor, indomethacin (1 microM), had an effect on the UTP-evoked hyperpolarization and inhibition of the electrically evoked EJP. The UTP-evoked membrane hyperpolarization and inhibition of the EJP amplitude was antagonized by the P2Y receptor antagonist, cibacron blue (100 microM). Endothelium-derived hyperpolarizing factor (EDHF)-mediated hyperpolarization was inhibited by either adventitial or intimal application of apamin (0.1 micro and charybdotoxin (0.1 microM). However, the EJP inhibition was still present. In apamin- and charybdotoxin-treated preparations, focal application of adenosine 5'-triphosphate (ATP) (10 mM) evoked a depolarization of 15.5 +/- 1.3 mV (n=15). This postjunctional response was not modified by UTP (15.3 +/- 1.7 mV, n=4, P>0.05). These results suggest that exogenously applied UTP activates P2Y receptors of endothelium to release endothelium-derived factors, which in turn inhibit ATP release from purinergic nerves.     

Does the antitumor cyclopropylpyrroloindole antibiotic CC-1065 cross-link DNA in tumor cells?

We have found that a cyclopropylpyrroloindole antibiotic, compound CC-1065 (benzo[1,2-b:4,3-b']dipyrrole-3(2H)-carboxamide, 7-[[1, 6-dihydro-4-hydroxy-5-methoxy-7-[(4,5,8, 8a-tetrahydro-7-methyl-4-oxocyclopropan[c]pyrrolo[3, 2-e]indol-2(1H)-yl)carbonyl]benzo[1,2-b:4, 3-b']dipyrrol-3(2H)-yl]-carbonyl]-1,6-dihydro-4-hydroxy-5-methoxy, (7bR,8aS)), forms interstrand DNA cross-links of an apparently covalent nature in HeLa S(3) cells. This compound induced interstrand cross-links at concentrations ranging from 0.1 to 1 nM/3 hr in whole cells, but these cross-links were absent or marginally low when the drug was added to cell lysates with inactivated cellular enzymes or isolated nuclei, which suggests that metabolic activation of the drug is a necessary step for DNA cross-linking to occur. In contrast, an analog of CC-1065, Bizelesin, which forms DNA-DNA cross-links by direct alkylation, induced interstrand DNA cross-links in both whole cells and in cell lysates. Interestingly, a demethoxy analog of CC-1065, Adozelesin, did not induce DNA cross-links under the same conditions. CC-1065 was found to be extremely potent in terms of concentrations required to cross-link DNA of tumor cells, and this may be related to its remarkable cytotoxic activity.     

The influence of tumor cell density on cellular accumulation of doxorubicin or cisplatin in vitro

Summary The effect of tumor cell density on the cellular pharmacokinetics of doxorubicin (DXR) and cisplatin (CDDP) was studied using MOLT-3 human acute lymphoblastic leukemia cells. As determined by the MTT assay, the growth-inhibitory effect of DXR was approx. 40 times lower when cell density was increased from 10⁶ to 10⁸ cells/ml (positive inoculum effect), whereas little or no influence of cell density was observed in CDDP-induced cell-growth inhibition. As measured by high-performance liquid chromatography using a fluorescence detector, the cellular accumulation of DXR showed 6- and 18-fold decreases after 1 h incubation when the cells were concentrated from 10⁶ to 10⁷ and 10⁸ cells/ml, respectively. Only at low cell density (10⁶ cells/ml) did the amount of DXR in the cells increase with increasing exposure times of up to 6 h. The DXR concentration in the supernatant that was separated from a cell suspension showing a density of 10⁸ cells/ml fell to 20% of that obtained at 10⁶ cells/ml. The metabolites of DXR, including Adriamycinol and Adriamycinone, were not detectable in the cell extracts or supernatants at any cell density examined. In contrast, the cellular accumulation of CDDP calculated from the platinum concentration, which was measured with a flameless atomic absorption spectrophotometer, was essentially identical at all cell densities examined; moreover, extension of the exposure period resulted in a linear increase in the amount of CDDP in the cells. CDDP concentrations in the supernatants were equally retained, inrrespective of cell densities. These observations indicate that the positive inoculum effect shown in DXR-induced cell-growth inhibition results from the decreased cellular accumulation of the drug at high cell densities. We found no influence for cell density on the cellular accumulation of CDDP that might be relevant to the therapeutic potentiation of this drug at high tumor-cell density.Abbreviations DXR doxorubicin - CDDP cisplatin,cis-diamminedichloroplatinum(II) - HPLC high-performance liquid chromatography - D-PBS Dulbecco's phosphate-buffered saline - FBS fetal bovine serum - MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium - ID₅₀ drug concentration that produces inhibition of cell growth to 50% of control values This work was supported by Grants-in-Aid from the Ministry of Education, Science and Culture of Japan (61 304 038) and by the Clinical Pathology Research Foundation of Japan