Inhibition of topoisomerase II by a novel antitumor cyclic depsipeptide, BE-22179

BE-22179, a novel cyclic depsipeptide antibiotic having two 3-hydroxyquinoline moieties, inhibited the DNA-relaxing activity of L1210 topoisomerase II completely at 0.08 microM. This effect was far stronger than that of VP-16. However, it did not show any marked effect on topoisomerase II-mediated DNA cleavage. BE-22179 was ineffective in inhibiting the DNA relaxation by topoisomerase I at concentrations up to 10 microM, but showed DNA-intercalating ability (DNA unwinding) at 30 microM. The structure of BE-22179 is quite novel for a topoisomerase II inhibitor. Echinomycin, a quinoxaline antibiotic structurally related to BE-22179, interfered with DNA relaxation by topoisomerase II, though the effect was not due to inhibition of the catalytic activity of topoisomerase II but to conformational change of DNA based on its intercalation into DNA. Therefore, the potent inhibitory activity on topoisomerase II might not be a common activity of quinoxaline antibiotics, but might rather be specific to BE-22179. BE-22179 prevented DNA synthesis as well as RNA synthesis in L1210 cells and inhibited the growth of the cells. However, it remains unclear to what extent the topoisomerase II inhibition was responsible for the cytotoxicity of BE-22179.

Determination of mirosamicin in animal tissues by high-performance liquid chromatography

A simple and rapid method using high-performance liquid chromatography (HPLC) for the determination of mirosamicin in animal tissues has been developed. The drug was extracted with 0.3% metaphosphoric acid-methanol (7:3, v/v), and the extracts were cleaned on a Bond Elut SCX (500 mg) cartridge. The HPLC separation was performed on a Puresil 5C18 column (150 x 4.6 mm I.D.) with 0.05 M phosphate buffer (pH 2.5)-acetonitrile (70:30) as the mobile phase at a flow-rate of 0.5 ml/min; the drug was detected at 230 nm with 0.04 AUFS. The calibration graph was linear from 5 to 100 ng. The recoveries of microsamicin from various animal tissues fortified at 1.0 microgram/g were 83.7-88.6% with a relative standard deviation (R.S.D.) of 2.0-5.7%. The detection limit was 0.05 microgram/g.

Immunohistochemical detection of alpha-catenin expression in human cancers

The function of E-cadherin is thought to be regulated by its associated cytoplasmic proteins including alpha-catenin. To determine whether possible downregulation of alpha-catenin expression may play a role in tumor invasion and metastasis through the dysfunction of E-cadherin, we investigated the expression of alpha-catenin in human carcinoma samples (esophagus, stomach, and colon) by immunohistochemistry using our monoclonal antibody against alpha-catenin (alpha-18). Normal epithelium expressed alpha-catenin strongly without exception. However, alpha-catenin expression was frequently reduced in primary tumors of esophagus (12 of 15:80%), stomach (14 of 20: 70%), and colon (8 of 10: 80%). Of the tumors with reduced alpha-catenin expression, alpha-catenin expression was completely negative in 70.6% of them (9 of 12 in esophagus, 9 of 14 in stomach, and 6 of 8 in colon). These results also suggested that some human cancer cells may have impaired E-cadherin-mediated cell adhesiveness through the downregulation of alpha-catenin expression.

A study of endotoxaemia in patients with primary biliary cirrhosis

Hepatic reticuloendothelial function may be diminished in patients with primary biliary cirrhosis. Endotoxin concentrations in peripheral blood and in the superior mesenteric vein were measured, by the beta-glucan sensitive, factor-free, endotoxin-specific limulus assay, in patients with primary biliary cirrhosis and liver cirrhosis (non-PBC cirrhosis). Endotoxaemia was detected in the peripheral blood of seven out of nine patients (78%) with asymptomatic primary biliary cirrhosis, but in only two out of thirteen patients (15%) with non-PBC cirrhosis. The endotoxin level was significantly higher in the earlier stages of primary biliary cirrhosis than in the later stages (P < 0.05). The endotoxin level in superior mesenteric vein blood was significantly lower in patients with primary biliary cirrhosis than in patients with non-PBC cirrhosis. Peripheral endotoxaemia in patients with primary biliary cirrhosis may be due to the diminished capacity of the hepatic reticuloendothelial system, for phagocytosis of endotoxin.

[Intracranial extracerebral glioma]

A case of solitary leptomeningeal extracerebral glioma is reported. A 75-year-old man was admitted to our hospital because of headache and right hemiparesis. CT scan and carotid angiography revealed a tumor in the left convexity. At operation, the tumor was located between the dura mater and the arachnoid membrane and adhered to the brain surface only in a limited area. Histological study including immunostain and electron microscopy showed the tumor as anaplastic oligo-astrocytoma. We speculate that our case may originate from a heterotopic glial nest in the dural border cell layer of dura mater. This explanation seems likely because the tumor was located mostly in the subdural space.

Prospective study of alpha-fetoprotein in cirrhotic patients monitored for development of hepatocellular carcinoma

The usefulness of measurements of serum alpha-fetoprotein elevation for diagnosis of the development of hepatocellular carcinoma was evaluated by a prospective study of 260 patients with cirrhosis. Hepatocellular carcinoma was found in 55 patients during the 5-yr follow-up, excluding 7 found to have hepatocellular carcinoma in the first 6 mo. The cumulative incidence of hepatocellular carcinoma was 26% in the 185 patients who had alpha-fetoprotein levels below 20 ng/ml at the time of entry and 46% in the 68 patients who had alpha-fetoprotein levels of 20 ng/ml or more but below 200 ng/ml. In 169 of the patients, serum levels of alpha-fetoprotein were assayed regularly for at least 2 yr. The incidence of hepatocellular carcinoma development in the 36 patients who had repeated transient increases in alpha-fetoprotein to above 100 ng/ml was 36%. This was significantly higher than the incidence in the 99 patients who had alpha-fetoprotein levels consistently below 20 ng/ml. Thus patients who had alpha-fetoprotein levels of 20 ng/ml or more, who had transient increases in alpha-fetoprotein or who had both should be treated as being in a super-high-risk group for hepatocellular carcinoma. Frequent and careful examination by ultrasonography of such patients is recommended.

Correlation of altered Q-T interval and sympathetic nervous system dysfunction in diabetic autonomic neuropathy

We examined the relationship between the Q-T interval and autonomic dysfunction in 74 diabetic patients and age-matched controls. The expected Q-T interval was standardized as a function of the R-R interval in 646 healthy controls, and the delta Q-T defined as the difference from the expected value. Propranolol increased delta Q-T, confirming this as a parameter of autonomic function. No relationship between delta Q-T and duration of disease, glucose control, retinopathy or proteinuria was observed. However, significant correlations were found between the delta Q-T and delay of nerve conduction velocity, orthostatic hypotension, altered Valsalva ratio, abnormal Valsalva overshoot, cold pressor response, decreased norepinephrine concentration and sympathetic function score in diabetic patients.

Relationship between e-cadherin expression and lymph-node metastasis in human esophageal cancer

Expression of E-cadherin in esophageal carcinoma was studied immunohistochemically in 65 patients using an anti-human E-cadherin monoclonal antibody (HECD-1). In normal esophageal epithelium, E-cadherin was strongly expressed on cell-cell boundaries. On the contrary, a reduced E-cadherin expression (Rd-type) was frequently observed in cancer tissues (56/65, 88%). The frequency of Rd-type was much higher in cases with deeper invasion (48/52, 92%) than that in cases with superficial invasion (8/13, 62%) (p<0.05). Concerning lymph node metastasis, the frequency of Rd-type in the metastatic tumor group (47/49, 96%) was significantly higher than that in the non-metastatic tumor group (9/16, 56%) (p<0.01). These results suggest that E-cadherin might play a key role in the progression of carcinogenesis and that the reduction of E-cadherin expression is associated with malignant potential such as invasion and metastasis in human esophageal cancer.

[The managements of nutrition for hepatic cirrhosis]

Hepatic cirrhosis is the end stage in chronic liver diseases and this condition cause the patient's death because of hepatic failure. A prognosis of patients with hepatic cirrhosis depend on the liver function, especially the function of mass of residual hepatocytes and this function expressed by level of serum albumin, cholinesterase (Ch E) or ICGR-15. This function is improved a management of nutrition because hepatocytes are regenerate by intake of protein. In compensated hepatic cirrhosis, hepatocytes are regenerate by dietary intake of 100-120 g/day of protein and the function of mass of residual hepatocytes is increased. The prognosis of these patients with compensated hepatic cirrhosis are improved by this management of nutrition.

E-cadherin and alpha-catenin expression in human esophageal cancer

Intercellular adhesion of the epithelial tissue is mainly regulated by the E-cadherin (E-cad) molecule. alpha-Catenin (alpha-cat) is one of the E-cad-associated cytoplasmic proteins that forms a linkage to the cytoskeleton and regulates E-cad function. To investigate the mechanism of dysfunction in cell-cell adhesion in cancerous tissues, we examined E-cad and alpha-cat expression by immunohistochemical staining on 46 human esophageal cancers using our specific monoclonal antibodies. By grading of E-cad and alpha-cat expression as uniformly positive (+), heterogeneous (+/-), or uniformly negative (-), the 46 tumors could be classified into 9 (20%) E-cad(+)/alpha-cat(+), 15 (33%) E-cad(+/-)/alpha-cat(+/-), 21 (46%) E-cad(+/-)/alpha-cat(-), and 1 (2%) E-cad(-)/alpha-cat(-). Twenty-five (54%) of the 46 tumors showed a similar expression of both molecules, while the other 21 tumors (46%) showed E-cad(+/-)/alpha-cat(-). Thus, although the expression of alpha-cat was significantly correlated with that of E-cad, in some tumors the reduction of alpha-cat was greater. Regarding the clinicopathological features, the reduction of alpha-cat expression, as well as that of E-cad, was significantly associated with tumor dedifferentiation, infiltrative growth, and lymph node metastasis (P < 0.01). Furthermore, the frequency of lymph node metastasis in E-cad(+/-)/alpha-cat(-) tumors was significantly higher (90%) than in E-cad(+)/alpha-cat(+) tumors (22%) (P < 0.01) or in E-cad(+/-)/alpha-cat(+/-) tumors (47%) (P < 0.05). These results suggest that not only E-cad but also alpha-cat are important regulators of intercellular adhesion and that alpha-cat is also involved in invasion and metastasis. In particular, reduction of alpha-cat expression is more correlated with invasive phenotype and lymph node metastasis than E-cad expression in human esophageal cancer.

Stable in vivo expression of the cystic fibrosis transmembrane conductance regulator with an adeno-associated virus vector

Adeno-associated virus (AAV) vectors expressing the normal cystic fibrosis transmembrane conductance regulator (CFTR) cDNA complement the cystic fibrosis (CF) defect in vitro. Unlike other DNA virus vectors, AAV is a stably integrating virus, which could make possible long-term in vivo complementation of the CF defect in the airway epithelium. We report AAV-CFTR gene transfer and expression after infection of primary CF nasal polyp cells and after in vivo delivery of AAV-CFTR vector to one lobe of the rabbit lung through a fiberoptic bronchoscope. In the rabbit, vector DNA could be detected in the infected lobe up to 6 months after administration. A 26-amino acid polypeptide sequence unique to the recombinant AAV-CFTR protein was used to generate both oligonucleotide probes and a polyclonal antibody which allowed the unambiguous identification of vector RNA and CFTR protein expression. With these reagents, CFTR RNA and protein were detected in the airway epithelium of the infected lobe for up to 6 months after vector administration. AAV vectors do, therefore, efficiently promote in vivo gene transfer to the airway epithelium which is stable over several months. These findings indicate that AAV-CFTR vectors could potentially be very useful for gene therapy.

The mode of cerebellar activation of pyramidal neurons in the cat parietal cortex (areas 5 and 7): an intracellular HRP study

Response properties of 180 pyramidal neurons (11 layer II, 66 layer III, 7 layer IV, 76 layer V and 20 layer VI neurons) in the cat parietal cortex (areas 5 and 7) were examined intracellularly with stimulations of the cerebellar nucleus (CN), the thalamic ventroanterior nucleus (VA) and the lateral posterior nucleus (LP) under pentobarbital anesthesia. Pyramidal neurons were identified morphologically or electrophysiologically with antidromic responses by pontine nuclei (PN) stimulation. CN and VA stimulations evoked EPSPs in layer II, III, V and VI pyramidal neurons, but scarcely induced EPSPs in layer IV pyramidal ones. The mean latencies of CN-EPSPs were nearly the same through layers II to V, giving values of around 4.5 ms, but that of layer VI pyramidal neurons was much longer (5.5 +/- 0.8 ms: mean +/- SD). Those of VA-EPSPs were also nearly the same through all layers (around 2.2-2.8 ms). In case of LP stimulation, EPSPs were scarcely recorded in layer II and IV pyramidal neurons. The mean latency of LP-EPSPs was much shorter in layer III (2.6 +/- 1.0 ms) than those in layers V and VI (3.8-3.9 ms). It was noted that pyramidal neurons in layers II and III responded more frequently to CN and VA stimulations than those in deeper layers, and that the amplitudes of CN- and VA-EPSPs were large and conspicuous in layer III. In layer V, a statistical difference in the latency distributions of CN-, VA-, and LP-EPSPs between fast- and slow-type pyramidal neurons was not detected. The present results suggest that there exist the different modes of thalamocortical (T-C) innervations in the cat parietal cortex; the superficial T-C innervation of CN-VA inputs and the deep T-C innervation of LP inputs.

Modulation of T cell production of interferon-gamma by human monocytes: effect of engagement of CD14 on monocytes

It has been suggested that CD14 might have influences on a variety of immunoregulatory functions of monocytes. The current studies therefore examined in detail the immunoregulatory roles of CD14 by studying the effects of anti-CD14 mAb. Anti-CD14 mAb suppressed the monocyte-dependent interferon-gamma (IFN-gamma) production by CD4+ T cells induced by soluble anti-CD3. Although anti-CD14 mAb also suppressed the IL-6 production by monocytes, the inhibition of the IFN-gamma production induced by soluble anti-CD3 was not restored by addition of exogenous IL-6 or factors generated from cultured monocytes. Of note, anti-CD14 mAb decreased the expression of CD54, but not that of CD11a or CD18, on monocytes, suggesting that inhibition of the soluble anti-CD3-induced IFN-gamma production by anti-CD14 mAb might be a result from decrease in CD11a/CD18-CD54-mediated interactions between CD4+ T cells and monocytes. By contrast, anti-CD14 mAb enhanced the IFN-gamma production by immobilized anti-CD3-activated CD4+ T cells in the presence of monocytes. This enhancement of the IFN-gamma production required physical contact between monocytes and T cells, which does not involve MHC class II antigen-CD4 interactions. These results indicate that CD14 on monocytes plays a variety of immunomodulatory functions depending upon the nature of stimulation. The data thus demonstrated the presence of several different interactions between monocytes and T cells that regulate the T cell cytokine production.

Prognostic value of DNA ploidy in squamous cell carcinoma of esophagus. Analyzed with improved flow cytometric measurement

BACKGROUND

The prognostic value of flow cytometric DNA analysis on paraffin-embedded tumor samples has been controversial in esophageal cancer. To clarify its true significance, the authors developed an improved method that excludes the possibility of contamination by lymphocytes in tumor sample.

METHODS

Single nuclear suspension was prepared from paraffin-embedded samples on 103 patients with squamous cell carcinoma of the esophagus. Both DNA content and nuclear size were simultaneously measured by flow cytometry on 30,000 nuclei, and contaminated lymphocyte nuclei were eliminated from the data by optimal gating. Correlation between DNA ploidy and postoperative survival was examined.

RESULTS

Analysis using a flow cytometric cell sorter showed that the frequency of tumor cells in the lymphocyte-reducing gating fraction (LGF) was significantly higher than that in the conventional nongating fraction (NGF). LGF analysis showed aneuploid peaks in 58 patients (56.3%), but NGF analysis showed aneuploid peaks in only 38 patients. LGF analysis revealed that the aneuploid tumors had higher histologic grading (P < 0.05) and worse survival rate (P < 0.01) compared with diploid tumors. However, conventional methods could not detect this difference.

CONCLUSIONS

Flow cytometric analysis gating by nuclear size may be helpful to detect aneuploid peaks, and for predicting prognosis of patients with squamous cell carcinoma of esophagus.

Growth-regulatory mechanism of two human esophageal-cancer cell lines in protein-free conditions

We investigated the growth-regulatory mechanism of 2 esophageal squamous-cancer cell lines, TE2-NS and TE3-OS cells, both of which can grow stably in protein-free conditions in vitro. Protein-free conditioned media from TE2-NS and TE3-OS cells stimulated the growth of these cells. Exogenous epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), insulin-like growth factor (IGF)-I and -II enhanced cell proliferation by 2.2- to 3.8-fold in protein-free conditions, as compared with an untreated control. Receptor-binding assays showed that both TE2-NS and TE3-OS cells possessed a single class of high-affinity binding sites for IGF-I and 2 classes of binding sites for TGF-alpha, as confirmed on the cell membrane by immunochemistry. These results suggest that EGF, TGF-alpha and IGFs are candidates for the autocrine growth factor in cancer cells. The addition of inhibitory monoclonal antibodies against TGF-alpha and EGFR, but not those against either EGF or IGF-IR, significantly inhibited growth of the cells. Immunocytochemical staining and ELISA of the conditioned media both confirmed the production of TGF-alpha protein, but not EGF protein, in these cell lines. The data for a protein-free culture system strongly suggested that TGF-alpha, but not EGF or IGF, is biologically important as an autocrine growth factor in the growth of these cell lines in vitro.

Prognostic value of DNA ploidy in squamous cell carcinoma of esophagus. Analyzed with improved flow cytometric measurement

BACKGROUND

The prognostic value of flow cytometric DNA analysis on paraffin-embedded tumor samples has been controversial in esophageal cancer. To clarify its true significance, the authors developed an improved method that excludes the possibility of contamination by lymphocytes in tumor sample.

METHODS

Single nuclear suspension was prepared from paraffin-embedded samples on 103 patients with squamous cell carcinoma of the esophagus. Both DNA content and nuclear size were simultaneously measured by flow cytometry on 30,000 nuclei, and contaminated lymphocyte nuclei were eliminated from the data by optimal gating. Correlation between DNA ploidy and postoperative survival was examined.

RESULTS

Analysis using a flow cytometric cell sorter showed that the frequency of tumor cells in the lymphocyte-reducing gating fraction (LGF) was significantly higher than that in the conventional nongating fraction (NGF). LGF analysis showed aneuploid peaks in 58 patients (56.3%), but NGF analysis showed aneuploid peaks in only 38 patients. LGF analysis revealed that the aneuploid tumors had higher histologic grading (P < 0.05) and worse survival rate (P < 0.01) compared with diploid tumors. However, conventional methods could not detect this difference.

CONCLUSIONS

Flow cytometric analysis gating by nuclear size may be helpful to detect aneuploid peaks, and for predicting prognosis of patients with squamous cell carcinoma of esophagus.

Congenital histidine-rich glycoprotein deficiency

The proband, a 43-year-old woman, suffered from right transverse sinus thrombosis during oral contraceptive treatment. A month after stopping the drug, her plasma activities of antithrombin III, protein C, protein S, heparin cofactor II, plasminogen and plasminogen activator inhibitor were normal, but her plasma histidine-rich glycoprotein (HRG) level was only 21% of the normal level of 109.5 +/- 51.5% (mean +/- 2 SD). The HRG concentrations in her plasma determined on four different occasions over 6 months were similar. She showed no clinical signs of liver insufficiency or sepsis. Low levels of plasma HRG (20% to 35% of normal) were also found in her aunt, uncle and two daughters. These results suggest that congenital HRG deficiency is inheritary in this family.

Enflurane increases the adrenaline threshold for the development of slow responses in isolated canine trabeculae

To determine if enflurane has different effects on myocardial sensitivity to adrenaline than those previously reported for halothane, we have studied the enflurane-adrenaline interaction in isolated canine trabeculae using doses of adrenaline necessary to produce slow responses (adrenaline threshold for the development of slow responses, ATSR) as an indicator. The preparations were depolarized in Tyrode's solution containing potassium chloride 26 mmol litre-1, then adrenaline concentrations in the solution were increased stepwise. Enflurane 1% had no significant effect, but 2% and 4% significantly increased the ATSR two-fold and seven-fold, respectively. To investigate the influence of enflurane on the adrenaline-adrenoceptor interaction, we studied the effects on the ATSR of 2% enflurane alone or in combination with either prazosin 8 ng ml-1 or metoprolol 17 ng ml-1. Compared with the ATSR obtained with 2% enflurane alone, alpha 1-block with prazosin did not alter, but beta 1-block with metoprolol significantly increased the ATSR (three-fold). These effects on enflurane are qualitatively as well as quantitatively similar to those reported previously for halothane. Thus, assuming that the MAC value for enflurane is about 2-2.5 times greater than that for halothane, the effects of enflurane on slow channel conductance (antiarrhythmic effects of enflurane) might be about two to three times greater than those of halothane at equivalent depth of anaesthesia. Such differences may explain in part the clinical observation that ventricular arrhythmias are less likely with enflurane than with halothane.

Correlation between E-cadherin expression and invasiveness in vitro in a human esophageal cancer cell line

E-cadherin, a member of the cadherin family, plays a major role in cell-cell adhesion of normal epithelium. Recent studies have shown that reduction or loss of E-cadherin expression in carcinomas have some relationship with their clinicopathological manifestation including invasion and metastasis. In the present study, we have established cell clones with different E-cadherin expression from human esophageal cancer, TE-2, and examined their adhesive capacity and invasiveness in vitro. Cell clones with positive E-cadherin expression [ECD(+) cells] were round and formed cobblestone colonies, while cell clones negative for E-cadherin [ECD(-) cells] had spindle shapes and formed dispersed colonies. ECD(+) cells showed higher adhesive capacity than ECD(-) cells, in both an aggregation assay with gyratory shaking culture and a dissociation assay of cells passing through the micropore membrane. Monoclonal antibody against human E-cadherin (HECD1) effectively diminished the mutual adhesion of ECD(+) cells but did not affect that of ECD(-) cells. Tumor invasiveness was evaluated with organotypic raft culture which is a coculture system consisting of two layers, a collagen gel layer containing fibroblasts and overlying reconstituted stratified squamous epithelium. ECD(+) cells formed complete stratified epithelium, but ECD(-) cells did not. ECD(+) cells did not invade the collagen/fibroblast gel, but ECD(-) cells did. Furthermore, ECD(+) cells showed invasion when an antibody against E-cadherin was used. Thus, loss or dysfunction of E-cadherin diminishes intercellular adhesion and results in the acquisition of invasive capacity in the cell line we examined.

[The effects of nicotine on a patient with spinocerebellar degeneration whose symptoms temporarily exacerbated by cigarette smoking]

The purpose of the present study was to elucidate the influences of nicotine on a patient with spinocerebellar degeneration whose symptoms temporarily exacerbated by cigarette smoking. We have examined the influences of nicotine gum on cerebellar ataxia. Limb ataxia, dysarthria and truncal titubation were maximally aggravated 15 min after nicotine gum chewing, which paralleled blood nicotine level. Specific increased accumulation of 123I-IMP was observed in the cerebellum 15 min after nicotine gum load by 123I-IMP-SPECT. On the other hand, in a control with spinocerebellar degeneration whose symptoms not changed by nicotine gum load, the specific finding on 123I-IMP-SPECT was not detected. These findings suggested a direct effect of nicotine on the cerebellum.

[E-cadherin expression and cancer invasion and metastasis]

E-cadherin (ECD) is a transmembrane glycoprotein that mediates the calcium dependent adhesion of cells and plays a major role in cell-cell adhesion of normal epithelium. In present study, we have established the positive ECD expressed clone (ECD(+)) and the negative ECD expressed clone (ECD(-)). Anti human ECD monoclonal antibody (HECD-1) disturbed the mutual adhesion of ECD(+) effectively but didn't disturb that of ECD(-). ECD(+) did not invade the collagen/fibroblast gel, but ECD(-) did. Furthermore, ECD(+) acquired invasiveness in the collagen gel when HECD-1 was used. Clinicopathologically, we have investigated the correlation between expression of ECD and metastasis in human esophageal and gastric cancers by immunohistochemical staining using HECD-1. ECD expression of these lymph node metastatic tumor in the primary sites was more reduced than that of non metastatic tumor significantly. These results indicated that reduction or dysfunction of ECD diminishes intercellular adhesion and acquires invasive and metastatic capacity in human cancer cells.