Etoposide (VP-16) sensitizes p53-deficient human non-small cell lung cancer cells to caspase-7-mediated apoptosis

Human non-small-cell-lung-cancer (NSCLC) cells of (p)53-null genotype were exposed to low-dosage topoisomearse II inhibitor etoposide (VP-16). The cellular proliferation rate could be effectively inhibited by VP-16 in dose-dependent manner. The effective drug concentration for growth inhibition could be as low as 0.5 microM and the apoptotic phenotype became evident 48 h later. In H1299 cells, VP-16-induced cytotoxic effect was demonstrated associated with apoptosis that disappeared when restored with wild-type p53. Cell cycle analysis revealed that, upon VP-16 induction, cell death began with growth arrest by accumulating cells at the G(2)-M phase. The cells at sub-G(1) phase increased at the expense of those at G(2)-M transition state. To assess the regulation of cell cycle modulators, western blot analysis of H1299 cell lysates showed the release of apoptosis initiator, cytochrome c and apaf-1 hours following drug induction. The cleavage of downstream effectors, procaspase-9 and procaspase-7, but not procaspase-3, was accompanied with proteolysis of poly-(ADP-ribose) polymerase (PARP). VP-16-activated procaspase-7 cleavage was abrogated in cells with ectopically expressed p53. On the other hand, the inhibited procaspase-7 fragmentation by caspase-specific inhibitor reversed apoptotic phenotype caused by drug induction. Thus, VP-16-induced apoptotic cell death was contributed by caspase-7 activation in(p)53-deficient human NSCLC cells.

Multicentric reticulohistiocytosis with generalized systemic involvement

We describe a 33-year-old woman with a 2-year history of rheumatoid arthritis-like joint changes and a 1-year history of papulonodules on the fingers, ears, oral mucosa, forearm, elbows and thighs, and erythematous plaques on the buttocks. Six months after the onset of the cutaneous lesions she had dyspnoea, 3 months later she developed a husky sound. Biopsies from the nodules on the ear and left forearm revealed multinucleated giant cells with eosinophilic 'ground-glass' cytoplasm. Bronchoscopy revealed that there were nodules in the bronchus. A biopsy taken from a nodule from the bronchus was consistent with multicentric reticulohistiocytosis. Fibrostic laryngoscopy showed a mass 1.5 x 2.0 cm(2) in size on the left aryepiglottic fold and posterior commissure. Magnetic resonance imaging revealed a large pleural effusion and pericardiac effusion. Ultrasound revealed splenomegaly and peritoneal fluid. Combination therapy with prednisone, cyclophosphamide and methotrexate significantly improved cutaneous and joint symptoms. The huge cutaneous erythematous plaques and the generalized systemic involvement make this case interesting.

Genetic testing in spinocerebellar ataxia in Taiwan: expansions of trinucleotide repeats in SCA8 and SCA17 are associated with typical Parkinson's disease

DNA tests in normal subjects and patients with ataxia and Parkinson's disease (PD) were carried out to assess the frequency of spinocerebellar ataxia (SCA) and to document the distribution of SCA mutations underlying ethnic Chinese in Taiwan. MJD/SCA3 (46%) was the most common autosomal dominant SCA in the Taiwanese cohort, followed by SCA6 (18%) and SCA1 (3%). No expansions of SCA types 2, 10, 12, or dentatorubropallidoluysian atrophy (DRPLA) were detected. The clinical phenotypes of these affected SCA patients were very heterogeneous. All of them showed clinical symptoms of cerebellar ataxia, with or without other associated features. The frequencies of large normal alleles are closely associated with the prevalence of SCA1, SCA2, MJD/SCA3, SCA6, and DRPLA among Taiwanese, Japanese, and Caucasians. Interestingly, abnormal expansions of SCA8 and SCA17 genes were detected in patients with PD. The clinical presentation for these patients is typical of idiopathic PD with the following characteristics: late onset of disease, resting tremor in the limbs, rigidity, bradykinesia, and a good response to levodopa. This study appears to be the first report describing the PD phenotype in association with an expanded allele in the TATA-binding protein gene and suggests that SCA8 may also be a cause of typical PD.

Establishment of cell lines from a tropical grouper, Epinephelus awoara (Temminck & Schlegel), and their susceptibility to grouper irido- and nodaviruses

Four tropical marine fish cell lines have been established from the eye, fin, heart and swim bladder of grouper, Epinephelus awoara (Temminck & Schlegel). Optimum media and temperature conditions for maximum growth were standardized. The eye and swim bladder cells were mostly epithelial, but the fin and heart cells were mostly fibroblastic. The viability of cells was 95% after 1 year of storage in liquid nitrogen (-196 degrees C). Besides these four cell lines, previously established grouper brain, kidney and liver cell lines were also used for a viral susceptibility study which showed that all the cell lines were sensitive to grouper iridovirus, whereas only brain, fin and liver cell lines were susceptible to the yellow grouper nervous necrosis virus (a nodavirus). Electron microscopy studies of the grouper irido- and nodaviruses in ultrathin sections of infected cells showed an abundance of viral particles in the cytoplasm of the virus-infected cells indicating the effective replication of these two viruses. It is suggested that these cell lines can be used for the isolation of putative fish specific viruses and provide a valuable tool to study the mechanisms of host-pathogen interactions. Furthermore, these cell lines upon transfection, using pEGFP-C1 and pEGFP-aMT2.5 (ayu metallothionein promoter), produced significant fluorescent signals indicating their utility for exogenous studies.

New biotransformation products of nemadectins

Selected nemadectins (formerly LL-F28249 series) have been fed to a panel of microorganisms with the aim of generating new derivatives. In addition to products resulting from the oxidation of the terminal methyl group (C-29), a unique phosphorylated nemadectin was isolated. The phosphate group was determined to be at C-23 by HMBC between phosphorus and H-23. Milbemycin or nemadectin derivatives with natural substituents involving the 23-hydroxyl group were hitherto unknown.

S-Nitrosylation of mitochondrial caspases

Caspase-3 is a cysteine protease located in both the cytoplasm and mitochondrial intermembrane space that is a central effector of many apoptotic pathways. In resting cells, a subset of caspase-3 zymogens is S-nitrosylated at the active site cysteine, inhibiting enzyme activity. During Fas-induced apoptosis, caspases are denitrosylated, allowing the catalytic site to function. In the current studies, we sought to identify the subpopulation of caspases that is regulated by S-nitrosylation. We report that the majority of mitochondrial, but not cytoplasmic, caspase-3 zymogens contain this inhibitory modification. In addition, the majority of mitochondrial caspase-9 is S-nitrosylated. These studies suggest that S-nitrosylation plays an important role in regulating mitochondrial caspase function and that the S-nitrosylation state of a given protein depends on its subcellular localization.

High-performance liquid chromatographic analysis for a non-chromophore-containing phosphatidyl inositol analog, 1-[(1-O-octadecyl-2-O-methyl-sn-glycero)-phospho]-1D-3-deoxy-myo-inositol, using indirect UV detection

Phosphatidylinositide-3-kinase (PI3 kinase) is an important constituent of growth factor regulation. It is also involved in oncogene signaling pathways. An ether-containing phosphatidyl inositol(PI) analog, OMDPI, 1-[(1-O-octadecyl-2-O-methyl-sn-glycero)-phospho]-1D-3-deoxy-myo-inositol, is a potent inhibitor of this pathway and may be clinically useful in the treatment of a variety of neoplasms. OMDPI is currently being investigated as an anti-tumor agent by the National Cancer Institute, NIH. OMDPI, a non-chromophore-containing PI analog, is not directly adaptable to the commonly used UV detection of HPLC. This paper reports the development and validation of an HPLC assay for OMDPI based on indirect UV detection, in which a UV-absorbing ion-pair reagent (the probe), protriptyline, is added to the mobile phase to induce a signal for the compound. The method is sensitive (limit of detection <5 microl of 1 microg/ml or 5 ng), precise (R.S.D.<2.5%), linear (r2=0.9995) and accurate (error<0.7%). It is superior to refractive index detection and evaporative light scattering detection in either sensitivity or linearity and does not require special equipment.

Elevated nitric oxide metabolite levels in chronic sinusitis

Decreased exhaled nitric oxide (NO) is found in chronic sinusitis. NO metabolites (nitrates, nitrites, and S-nitrosothiols) were measured in sinus lavages with a rabbit model of chronic sinusitis. NO metabolite levels (mean +/- SD) were 3.0+/-1.6 micromol/L in uninfected rabbits, 10.7+/-11.4 micromol/L in infected animals, and 7.6+/-5.4 micromol/L in postantrostomy recovering animals. Infected sinuses had elevated levels of NO metabolites that were statistically significant (P<0.01) when compared with uninfected sinuses. Mucociliary transport velocity was measured in uninfected (16.0+/-5.7 mm/minute), infected (5.2+/-1.3 mm/minute), and recovery phases (3.0 mm/minute). Endoscopic appearance, light and electron microscopy, and bacterial cultures improved during recovery. Elevated levels of NO metabolites were found during chronic sinusitis and began to return to normal levels during recovery. The possible link between NO in epithelial autotoxicity and host defense mechanisms warrants further investigation.

S-nitrosoglutathione breakdown prevents airway smooth muscle relaxation in the guinea pig

Airway levels of the endogenous bronchodilator S-nitrosoglutathione (GSNO) are low in children with near-fatal asthma. We hypothesized that GSNO could be broken down in the lung and that this catabolism could inhibit airway smooth muscle relaxation. In our experiments, GSNO was broken down by guinea pig lung homogenates, particularly after ovalbumin sensitization (OS). Two lung protein fractions had catabolic activity. One was NADPH dependent and was more active after OS. The other was NADPH independent and was partially inhibited by aurothioglucose. Guinea pig lung tissue protein fractions with GSNO catabolic activity inhibited GSNO-mediated guinea pig tracheal ring relaxation. The relaxant effect of GSNO was partially restored by aurothioglucose. These observations suggest that catabolism of GSNO in the guinea pig 1) is mediated by lung proteins, 2) is partially upregulated after OS, and 3) may contribute to increased airway smooth muscle tone. We speculate that enzymatic breakdown of GSNO in the lung could contribute to asthma pathophysiology by inhibiting the beneficial effects of GSNO, including its effect on airway smooth muscle tone.

[Quantitative analysis of 4(3)-quinazolinedione in 4 "daqingye", leave of Isatis indigotica, Baphicacanthus cusia, Polygonum tinctorium and Clerodendron cyrtophyllum]

Using 4(3)-quinazolinedione, the active constituent of "Daqingye", as the quality control criteria, 4 samples of the herbal drug collected from Isatis indigotica, Baphicacanthus cusia, Polygonum tinctorium and Clerodendron cyrtophyllum were comparetively analyzed by RP-HPLC. The results showed that the average 4(3)-quinazolinedione contents (microgram/g) were 30.7, 7.2, 4.4 and 27.5 respectively. This method was proved to be quick, simple and reproducible, and provided a reliable basis for the quality control and evaluation of Chinese Traditional Drug "Daqingye".

Stability-indicating LC assay of and impurity identification in homoharringtonine samples

Homoharringtonine (HHT) is a potent myelosuppressive agent and has antitumor activity. Recent studies suggest that it inhibits tumor growth by inducing apoptosis. HHT is an ester of the alkaloid cephalotaxine. It is isolated from genus Cephalotaxus. At least ten HHT analogs have been identified from cephalotaxus extracts. High performance liquid chromatography (HPLC) separations of the cephalotaxine alkaloids in plant extracts have been reported, they have not been validated as specific and stability-indicating for HHT. Due to the complexity of the alkaloid extracts, it is conceivable that additional analogs may still be unresolved from HHT. This paper presents an improved and validated HPLC assay for HHT. The assay is stability-indicating, precise (R.S.D. < 1%), linear (r2 = 0.9999), and accurate (error < 1%). The assay reveals three congeners present as impurities in HHT samples. Two are new and have not been previously reported. Identities of the impurities and forced decomposition products, elucidated with their HPLC retention and spectral data, are also presented.

Endogenous airway acidification. Implications for asthma pathophysiology

Airway concentrations of many reactive nitrogen and oxygen species are high in asthma. The stability and bioactivities of these species are pH-dependent; however, the pH of the airway during acute asthma has not previously been studied. As with gastric and urinary acidification, asthmatic airway acidification could be expected dramatically to alter the concentrations and bioactivities/cytotoxicities of endogenous nitrogen oxides. Here, we demonstrate that the pH of deaerated exhaled airway vapor condensate is over two log orders lower in patients with acute asthma (5.23 +/- 0.21, n = 22) than in control subjects (7.65 +/- 0.20, n = 19, p < 0. 001) and normalizes with corticosteroid therapy. Values are highly reproducible, unaffected by salivary or therapeutic artifact, and identical to samples taken directly from the lower airway. Further, at these low pH values, the endogenous airway compound, nitrite, is converted to nitric oxide (NO) in quantities sufficient largely to account for the concentrations of NO in asthmatic expired air, and eosinophils undergo accelerated necrosis. We speculate that airway pH may be an important determinant of expired NO concentration and airway inflammation, and suggest that regulation of airway pH has a previously unsuspected role in asthma pathophysiology.

[Improvements on radical neck dissection]

OBJECTIVE

To improve the surgery of radical neck dissection for a better curative effect.

METHOD

Some improvements on incision, path to exploration and manipulation of operation were made in 65 patients with head and neck tumors while radical neck dissection were done.

RESULT

The average surgical time was 110 minutes and the average amount of bleeding was 120 ml in the patients when radical neck dissection had been completed. The complications decreased to 1.54%. The surviual rates of 2 and 3 years are 86.2% (56/65) and 81.6 (31/38) respectively.

CONCLUSION

With these improvements on radical neck dissection, the curative effect in the near future is improved.

Decreased levels of nitrosothiols in the lower airways of patients with cystic fibrosis and normal pulmonary function

Airway S-nitrosothiols (SNOs) are naturally occurring bronchodilators. SNOs, nitrate, and nitrite were measured in bronchoalveolar lavage fluid of 23 patients with cystic fibrosis (CF) and mild pulmonary disease (aged 6-16 years) and 13 healthy children (aged 8-15 years). Concentrations of SNOs were decreased in the lower airways of patients with CF and mild pulmonary disease (median, range: 0, 0-320 nmol/L vs 80, 0-970 nmol/L) despite normal levels of the inert nitric oxide metabolites nitrate and nitrite (mean +/- SEM: 3.7 +/- 0.5 micromol/L vs 4.8 +/- 0.9 micromol/L). S-nitrosolation- mediated bioreactivities may be impaired by depletion of the CF airway SNO reservoir.

Preparation and biological properties of biotinylated PhTX derivatives

We report the synthesis of several highly functionalized biotinylated philanthotoxin (PhTX) analogues (7, 8, 10, 13-16) designed on the basis of earlier structure-activity relationship studies. Despite the extensive modifications, the binding to nicotinic acetylcholine receptor (nAChR) is in the low micromolar range according to an inhibition assay using 3H-thienylcyclohexyl-piperidine (TCP). A patch clamp functional assay gave comparable results. Compounds exemplified by 16, which consists of a biotinylated ligand linked to a bifunctional photoaffinity probe (BPP), represent a new type of probe which should find use in photo-crosslinking studies of ligand receptor interactions.

Transfection of anti-sense complementary DNA of human epidermal-growth-factor receptor attenuates the proliferation of human non-small-cell-lung-cancer cells

The proliferation of human non-small-cell-lung-cancer (NSCLC) cells is regulated by the epidermal-growth-factor-receptor (EGFR)-mediated autocrine loop that interacts with transforming growth factor-alpha (TGF-alpha) of autocrine or paracrine origin. We have shown that EGFR expression is elevated in the brain metastatic variant of human NSCLC cells H226Br, which thereby acquire their increased sensitivity toward exogenous TGF-alpha. To determine detailed cell-phenotype changes as a result of EGFR down-regulation, H226Br cells were transfected with a human EGFR-cDNA construct encompassing an N-terminal fragment (1.8 kb) in anti-sense orientation downstream of the cytomegalovirus (CMV) promoter. The EGFR transcript expressed in the 3'-5' direction is expected to neutralize EGFR mRNA and to reduce protein expression correspondingly. The established cell lines resistant to G418 were shown integrated with the transfected construct and their proliferation rates reduced as compared with the parental cells and with those transfected with vector alone. Down-regulated EGFR expression in cells with the anti-sense construct can be confirmed by Scatchard analysis and suppressed EGFR kinase activity. The restrained-growth phenotype is also demonstrated in the prolonged G2-M phase during the cell cycle, and correlated with impairment of cell proliferation. This finding suggests that EGFR over-expression is critical in maintaining the malignant phenotype of NSCLC cells, thereby providing a valuable biomarker and potential target prevention for lung-cancer-cell proliferation.

Reductive assays for S-nitrosothiols: implications for measurements in biological systems

Bioactive SNOs are found in many tissues. We speculated SNOs might be misidentified in conventional assays which reduce NO-3 to NO. S-Nitrosothiols were exposed to saturated VCl3 in HCl, 1% KI in acetic acid, photolysis, or CuCl and CSH in He; NO was measured by chemiluminescence. S-Nitrosothiols were readily detected in VCl3 but not in KI. Reduction in CuCl/cysteine was linear (r2 = 1.0, n = 6), sensitive to 10 pmol, and eliminated by HgCl2; it did not detect NO-2, NO-3, or 3-nitrotyrosine. S-Nitrosothiols represented approximately 2.9% of NOx assayed by VCl3 in human serum, of which <5% were low-mass species. In summary, (i) conventional assays may misidentify NO-3, but not NO-2, as SNOs; and (ii) chemiluminescence/reduction systems may be sensitive and specific as SNO assays. We suggest that assay of the SNO fraction in biological NOx may be more relevant and feasible than is now appreciated.

[Spectroscopic ellipsometry characteristics and the optical properties of liquid crystalline copolyesters]

The optical properties of two thermotropic liquid crystalline copolyesters were characterized by spectroscopic ellipsometry and UV-visible spectroscopy. The differences in the refractive index variation and chromatic dispersion have been revealed and discussed in terms of differences in the vibrating transition of excited electrons and the molecular structures of the polymers.

A toxin conjugate containing transforming growth factor-alpha and ricin A specifically inhibits growth of A431 human epidermoid cancer cells

The inhibitory effect of human epidermoid cancer cells A431 caused by conjugate toxin containing transforming growth factor (TGF-alpha) and ricin A was studied. TGF-alpha is a protein with 50 amino acids that specifically binds and stimulates phosphorylation of cell surface epidermal growth factor receptor (EGFR) and, subsequently, triggers cell proliferation. TGF-alpha as a ligand for EGFR is internalized upon binding and decomposed within lysosome. Lectin ricin is contained in the castor bean plant. The lectin consists of two subunits, ricin A and B. Toxic ricin A binds to ribosome and inhibits protein synthesis of target cells. In view of the abundance of EGFR in human cancer cells, the receptor-mediated endocytosis with the conjugate toxin composed of TGF-alpha and ricin A was synthesized, purified and tested for growth inhibition in both normal and tumor cells. The cytotoxicity of the conjugate was studied within the range of 10(-12) and 10(-8) M and IC50 was found to be 10(-10) M for human A431 epidermoid cells that over-express EGFR. Compared to A431 cells, the brain metastatic variant of human Non-Small Cell Lung Cancer (NSCLC) H226Br squamous cells showed a reduced inhibitory effect. On the other hand, no inhibitory effect was found with other NSCLC cells studied and normal human lung cells because of the fewer available EGF binding sites on the surface of the cells. These results indicated that the amount of the available EGFR contributes to the cytotoxic effect on human cancer cells, thereby demonstrating involvement of the receptor-mediated endocytosis of the conjugate. The result from 12labeled EGF-mediated competition assay further demonstrated the specific inhibition activity conferred by TGF-alpha and ricin A conjugation. Due to poor recovery of the chemical conjugation, modification in the form of a recombinant toxin is needed for further in-depth studies.

Structure-binding relation of philanthotoxins from nicotinic acetylcholine receptor binding assay

Philanthotoxins are noncompetitive inhibitors of the nicotinic acetylcholine receptor and the various glutamate receptors. Analogues carrying photoaffinity labels, fluorine atoms for solid-state NMR studies of ligand/receptor interaction, and large head groups such as porphyrins and planar bulky aromatic rings (BIG analogues) for clarifying mode of entry and orientation of analogues in receptors have been synthesized, assayed against the nicotinic acetylcholine receptor, and brief comments are given for the assay results.

[Detecting HPV DNA in tissue of epidermal neoplasms]

Fifty-eight cases (mean age 56.1 +/- 17.1 years) of cutaneous squamous cell carcinoma were studied, including 17 cases of Bowen's disease, 5 cases of Queyrat erythroplasia, 16 cases of Bowenoid papulosis and 20 cases of invasive cutaneous squamous cell carcinoma. All cases were confirmed by pathological findings. HPV6, 11, 16, 18 DNA were detected by multiple pair primers polymerase chain reaction in paraffin-embedded tissues. The results showed that 2(2/17) cases of Bowen's disease, 1 case of Queyrat erythroplasia and 9(9/16) cases of Bowenoid papulosis were positive for HPV16 DNA and that 20 cases of invasive cutaneous sqamous cell carcinoma were negative for HPV16 DNA. HPV16 is closely associated with Bowenoid papulosis and HPV16 might be a factor of multistep carcinogenesis in rare cases of Bowen's disease and Queyrat erythroplasia.

An enhanced and sensitive autocrine stimulation by transforming growth factor-alpha is acquired in the brain metastatic variant of a human non-small-cell lung cancer cell line

Transforming growth factor-alpha (TGF-alpha)-mediated autocrine regulation in human non-small-cell lung cancer (NSCLC) cells NCI-H226 and its brain metastatic variant H226Br were compared. An enhanced TGF-alpha-induced dose-dependent mitogenic responsiveness in H226Br cells was observed. Neutralising antibody that binds TGF-alpha inhibits H226Br cell growth more effectively than NCI-H226 cell growth. Binding assay with 125I-labelled epidermal growth factor (EGF) revealed that H226Br has two types of EGF receptors (EGFRs), whereas the parental cell line, NCI-H226, has only one. H226Br cells contain twice as many EGFRs as H226 cells, as proved by Scatchard analysis and immune kinase assay. Northern analysis indicated that there is more EGFR transcript in H226Br than in NCI-H226, indicating a transcriptional EGFR gene elevation during metastasis progression. The level of accumulated immunoactive TGF-alpha is lower in the conditioned medium of H226Br than in that of NCI-H226. demonstrating down-regulation of TGF-alpha transcript. The accumulated data suggest an elevated and sensitive autocrine modulation by TGF-alpha and EGFR in immortalising the brain metastatic variant cells that were derived from a human NSCLC squamous cell line.

Kinesin movement on glutaraldehyde-fixed microtubules

Glutaraldehyde-cross-linked microtubules were investigated as substrates for kinesin motility. Microtubules, formed in vitro from chicken brain tubulin, were stabilized with Taxol and chemically fixed with glutaraldehyde. The degree of tubulin monomer cross-linking as a function of time and glutaraldehyde concentration was characterized using polyacrylamide gel electrophoresis. Atomic force microscopy of fixed microtubules indicated that the cross-linking is sufficient to stabilize the gross structure of the microtubules against air drying or a distilled water challenge. Kinesin movement on immobilized, fixed microtubules was determined using a kinesin-coated bead motility assay observed with differential interference contrast microscopy. Within measurement error, kinesin bead movement velocities were independent of the degree of microtubule cross-linking. Binding affinity, however, decreased with increased cross-linking. Although air- and water-challenged microtubules did not support kinesin motility, a dilute suspension of glutaraldehyde-fixed microtubules in buffer supported kinesin motility for at least 2 days without any substantial degradation of activity. Fixed microtubules may be useful for several applications, including affinity purification of microtubule-associated proteins and motility measurements under extreme conditions of temperature and other variables.