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Objectives The majority of patients with non-small cell lung cancer (NSCLC) present with advanced stage disease, at which time chemotherapy is usually the most common treatment option. While somewhat effective, patients treated with platinum-based regimens will eventually develop resistance, with others presenting with intrinsic resistance. Multiple pathways have been implicated in chemo-resistance, however the critical underlying mechanisms have yet to be elucidated. The aim of this project was to determine the role of inflammatory mediators in cisplatin-resistance in NSCLC. Materials and methods Inflammatory mediator, NF-κB, and its associated pathways were investigated in an isogenic model of cisplatin-resistant NSCLC using age-matched parental (PT) and corresponding cisplatin-resistant (CisR) sublines. Pathways were assessed using mass spectrometry, western blot analysis and qRT-PCR. The cisplatin sensitizing potential of an NF-κB small molecule inhibitor, DHMEQ, was also assessed by means of viability assays and western blot analysis. Results Proteomic analysis identified dysregulated NF-κB responsive targets in CisR cells when compared to PT cells, with increased NF-κB expression identified in four out of the five NSCLC sub-types examined (CisR versus PT). DHMEQ treatment resulted in reduced NF-κB expression in the presence of cisplatin, and re-sensitized CisR cells to the cytotoxic effects of the drug. Conclusion This study identified NF-ĸB as a potential therapeutic target in cisplatin-resistant NSCLC. Furthermore, inhibition of NF-ĸB using DHMEQ re-sensitized chemo-resistant cells to cisplatin treatment.

We have developed a new positron annihilation measurement system via electron-positron pair creation using by laser Compton scattering (LCS) gamma beam direct implantation into bulk materials at NewSUBARU synchrotron radiation facility, LASTI, University of Hyogo, Japan. LCS gamma beam is easy to control energy, and its energy is quasi-monochromatic and high directivity. These parameters are determined by laser wavelength and electron kinetic energy. In this study, maximum energy 16.9 MeV LCS gamma beam generation by Nd:YVO4 laser (wavelength 1064 nm) and circling electron (982 MeV) directly irradiated into samples for Doppler broadening measurement in an atmosphere. The gamma beam created high energetic positrons to MeV order. This measurement could be a simple setup consisting of a single HP-Ge detector, amplifier, and multi-channel analyzer. As a demonstration, we have tried to measure the Doppler broadening spectra of pure iron, electron irradiated iron and silicon by this system.We have developed a new positron annihilation measurement system via electron-positron pair creation using by laser Compton scattering (LCS) gamma beam direct implantation into bulk materials at NewSUBARU synchrotron radiation facility, LASTI, University of Hyogo, Japan. LCS gamma beam is easy to control energy, and its energy is quasi-monochromatic and high directivity. These parameters are determined by laser wavelength and electron kinetic energy. In this study, maximum energy 16.9 MeV LCS gamma beam generation by Nd:YVO4 laser (wavelength 1064 nm) and circling electron (982 MeV) directly irradiated into samples for Doppler broadening measurement in an atmosphere. The gamma beam created high energetic positrons to MeV order. This measurement could be a simple setup consisting of a single HP-Ge detector, amplifier, and multi-channel analyzer. As a demonstration, we have tried to measure the Doppler broadening spectra of pure iron, electron irradiated iron and silicon by this system.

The origin and the generation mechanism of ion implantation-induced dislocations is investigated with an Si/sub 3/N/sub 4/ band line/space pattern. The Si/sub 3/N/sub 4/ film-edge stress not only causes dislocation propagation but also causes the formation and deformation of extended dislocations at the initial stage of annealing. The behavior is clarified that the dislocation loops are deformed into pattern-edge dislocation half loops, which accumulate at the film edge and are punched out from the edge.

Several studies highlight the role of inflammatory markers in thrombosis as well as in cancer. However, their combined role in cancer-associated deep vein thrombosis (DVT) and the molecular mechanisms, involved in its pathophysiology, needs further investigations. In the present study, C-reactive protein, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1β), matrix metalloproteases-9 (MMP-9), vascular endothelial growth factor (VEGF), tissue factor (TF), fibrinogen and soluble P-selectin, were analyzed in plasma and in monocyte samples from 385 cancer patients, of whom 64 were concomitantly affected by DVT (+). All these markers were higher in cancer patients DVT+ than in those DVT-. Accordingly, significantly higher NF-kB activity was observed in cancer patients DVT+ than DVT-. Significant correlation between data obtained in plasma and monocyte samples was observed. NF-kB inhibition was associated with decreased levels of all molecules in both cancer DVT+ and DVT-. To further demonstrate the involvement of NF-kB activation by the above mentioned molecules, we treated monocyte derived from healthy donors with a pool of sera from cancer patients with and without DVT. These set of experiments further suggest the significant role played by some molecules, regulated by NF-kB, and detected in cancer patients with DVT. Our data support the notion that NF-kB may be considered as a therapeutic target for cancer patients, especially those complicated by DVT. Treatment with NF-kB inhibitors may represent a possible strategy to prevent or reduce the risk of DVT in cancer patients.

In order to investigate the effect of Pr-substitution for Y element in Y123 high-Tc superconductors, Fe57-Mossbauer effect is measured for the samples of Y1-xPrxBa2(Cu1-yFey)3O7-z. The Mossbauer spectrum can be decomposed into 4 sets of doublet spectrum, D1,D2,D3 and D4, and isomer shift (δ) and quadruple splitting (Eq) for each component are obtained. We find that δ on CuO2plane increases with x inY1-xPrxBa2(Cu0.96Fe0.04)3O7-z as well as increase with oxygen reduction in YBa2(Cu0.96Fe0.04)3O7-z while δ in the samples containing Pr decreases by oxygen reduction above z=0.25. These variation of δ can be interpreted by the change of 4p electrons in virtual Fe4p orbital which is induced by hybridization with O2p of the nearest oxygen ions.

We used angle-resolved photoemission spectroscopy to reveal directly the momentum distribution of the superconducting gap in FeTe1-xSex, which has the simplest structure of all Fe-based superconductors. We found isotropic superconducting gaps on all Fermi surfaces whose sizes can be fitted by a single gap function derived from a strong coupling approach, promoting local antiferromagnetic exchange interactions as a serious candidate for the pairing origin.

We have performed high-resolution angle-resolved photoemission spectroscopy on Fe-based superconductor LiFeAs (Tc = 18 K). We reveal multiple nodeless superconducting (SC) gaps with 2D/kBTc ratios varying from 2.8 to 6.4, depending on the Fermi surface (FS). We also succeeded in directly observing a gap anisotropy along the FS with magnitude up to ~30 %. The anisotropy is four-fold symmetric with an antiphase between the hole and electron FSs, suggesting complex anisotropic interactions for the SC pairing. The observed momentum dependence of the SC gap offers an excellent opportunity to investigate the underlying pairing mechanism., Comment: 5 pages, 4 figures

We have performed high-resolution angle-resolved photoemission measurements on superconducting electron-doped NaFe0.95Co0.05As (T-c similar to 18 K). We observed a holelike Fermi surface around the zone center and two electronlike Fermi surfaces around the M point, which can be connected by the Q = (pi, pi) wave vector, suggesting that scattering over the near-nested Fermi surfaces is important in this 111 pnictide. Nearly isotropic superconducting gaps with sharp coherent peaks are observed below T-c on all three Fermi surfaces. Upon increasing temperature through T-c, the gap size shows little change while the coherence vanishes. Large ratios of 2 Lambda/k(B)T(c) similar to 8 are observed for all the bands, indicating a strong coupling in this system. These results are not expected from a classical phonon-mediated pairing mechanism.

Membrane-constituting phospholipids include glycerol phospholipids such as phos- phatidylcholine and phosphatidylinositol (PI) and sphingolipids. Recently, signal transduction starting from hydrolysis of these phospholipids have attracted attention as regulatory mechanisms for cell growth, differentiation, and apoptosis. During this process, phosphatidylcholine is hydrolyzed by phospholipase-D into phosphatidic acid and choline, and the former is dephosphosphorylated into diacylglycerol (DAG). DAG stimulates protein kinase C and often promotes cell growth or differentiation. In case of PI, it is first phosphorylated by PI 3-kinase or PI 4-kinase. PI 3-kinase is often activated by phosphotyrosine of the activated growth factor receptors. Metabolic pathways including PI 4-kinase are now known as classical PI turnover pathways. PI-4-P formed with PI 4-kinase is then phosphorylated by PI-4-P kinase into PI-4,5-P(2). Phosphatidylinositol-specific phospholipase C(PI-PLC) is the rate-limiting enzyme of PI turnover (1), and catalyzes the hydrolysis of PI-4,5-P(2) to produce two second messengers, inositol 1,4,5-trisphosphate (IP(3)) and DAG. The former mobilizes Ca(2+)from internal stores by binding to the receptor on endoplasmic reticulum. PI-PLC is activated in response to a wide variety of physiological stimuli such as growth factors and hormones and often shows enhanced activity in transformed cells.

We have performed angle-resolved photoemission spectroscopy on the overdoped Ba${}_{0.3}$K${}_{0.7}$Fe${}_{2}$As${}_{2}$ superconductor (${T}_{c}=22$ K). We demonstrate that the superconducting (SC) gap on each Fermi surface (FS) is nearly isotropic whereas the gap value varies from 4.4 to 7.9 meV on different FSs. By comparing with under- and optimally doped Ba${}_{1\ensuremath{-}x}$K${}_{x}$Fe${}_{2}$As${}_{2}$, we find that the gap value on each FS nearly scales with ${T}_{c}$ over a wide doping range ($0.25\ensuremath{\leqslant}x\ensuremath{\leqslant}0.7$). Although the FS volume and the SC gap magnitude are strongly doping dependent, the multiple nodeless gaps can be commonly fitted by a single gap function assuming pairing up to the second nearest neighbor, suggesting the universality of the short-range pairing states with the ${s}_{\ifmmode\pm\else\textpm\fi{}}$-wave symmetry.

Spirobenzopyran units were bound to the side chains of poly (L-glutamic acid) and partially methylated poly(L-glutamate)s. The modified polymers were found to exhibit “reverse photochromism” in hexafluoro-2-propanol (HFP), so the samples kept in the dark were characterized by an intense absorption band in the visible range of the spectrum, which was completely erased upon exposure to sunlight or irradiation at 500–550 nm. The CD spectra showed that the macromolecules adopted a random coil conformation in the dark, whereas the bleached solutions after exposure to light displayed the typical CD pattern of the α-helix. The back reaction in the dark was accompanied by the progressive decrease of the helix content and recovery of the original disordered conformation. The photoinduced conformational changes resulted in large and reversible viscosity variations. When spiropyran side chains were converted to “spiropyran salts” of trifluoroacetic acid, the system was still photochromic, but the macromolecules were disordered both in the dark and light conditions. However, when appropriate amounts of methanol were added as a cosolvent to the HFP solutions, the system responded to light, giving reversible variations of the α-helix content. Irradiation at appropriate solvent compositions allowed modulation of the extent of the photoresponse. © 1993 John Wiley & Sons, Inc.

Using impact collision ion scattering spectroscopy, we have studied the initial stage of the deposition of Au and Ag onto the Cu(001) surface. Our analysis provides evidence for surface alloying by the substitution of Cu with Au atoms in the surface, even at very low coverages at room temperature. However, the diffusion of Au atoms into the Cu substrate was not observed at coverages below 0.25 ML. The growth of an hexagonal c(2 × 14)-Au layer on top of the first c(2 × 2) structure was found to promote the diffusion of Au atoms into the Cu substrate, destroying the ordered arrangement of the c(2 × 2) structure. Ag was confirmed to form a simple overlayer up to 1 ML without any diffusion of Ag atoms into the substrate. The growth mode of the Ag deposition was identified to be of the Stranski-Krastanov type.

The role of tyrosine kinases in the responses of human neutrophils to chemotactic factors was examined using the recently described inhibitor erbstatin. Pre-incubation with erbstatin decreased the amount of tyrosine phosphorylation induced by the formylated oligopeptide formyl- methionyl-leucyl-phenylalanine (fMet-Leu-Phe) without effecting the binding of [3H]-fMet-Leu-Phe. Erbstatin also dose-dependently inhibited the production of superoxide anion induced by fMet-Leu-Phe and platelet- activating factor, but did not affect the oxidative burst induced by either the calcium ionophore A23187 or the phorbol ester phorbol 12- myristate 13-acetate. Furthermore, erbstatin diminished the cytosolic acidification elicited by fMet-Leu-Phe, platelet-activating factor, and leukotriene B4. In contrast, erbstatin was without effect on the increase in the levels of cytoplasmic free calcium and polymerized actin elicited by fMet-Leu-Phe, C5a, leukotriene B4 and platelet- activating factor, whereas the increase in cytoplasmic free calcium elicited by platelet-derived growth factor was inhibited by erbstatin. In addition, erbstatin affected neither the release of elastase stimulated by these agonists nor the release of beta-glucosaminidase, lysozyme or vitamin B12-binding protein induced by fMet-Leu-Phe. These results indicate that tyrosine protein kinases are involved in the signaling pathways employed by chemotactic factors in the stimulation of selective functional responses (and superoxide production in particular) in human neutrophils.

Optical microscopy is used for the in situ observation of the nucleation and growth of crystallites in the amorphous antimony layer prepared on an as-deposited ultrathin sublayer of copper, silver, gold, tin or lead. A whole specimen is deposited on a cover glass in a vacuum of 1 × 10−4 Pa. With the use of sublayers of copper, gold and silver it is possible to measure the growth rate v of antimony crystallites as a function of thickness dSb of the antimony layer. An analysis of the relation of v to dSb on the basis of the model previously presented gives such parameters as the thicknesses ds0 and dv0 of surface regions near the substrate and the vacuum respectively and the growth rates us and uv at surfaces adjacent to the substrate and the vacuum respectively: ds0 = 2.0 nm, dv0 = 5.5nm, us = 11 μm s−1 and uv = 0.21 μm s−1 when dCu is 4.3 × 10−2 nm while ds0 = 0.7 nm, dv0 = 4.4 nm, us = 7.7 μm s−1 and uv = 0.13 μm s−1 when dAu is 4.0 × 10−2 nm. The effective activation energy for the growth of crystallites is determined from an Arrhenius plot of v from 30 to 60°C to be, for example, 1.2 eV at dSb = 3.0 nm and 0.7 eV at dSb = 5.2 nm when dCu is 4.3 × 10−2 nm while it is 1.0 eV at dSb = 2.2 nm and 0.9 eV at dSb = 3.7 nm when dAu is 4.0 × 10−2nm. Sublayers of tin and lead play an extremely progressive role on nucleation of antimony crystallites, resulting in such a high nucleation density that v could not be measured. This originates mainly from the larger area of interface between coupled layers of Sb/Sn or Sb/Pb according to electron microscopy.

A wavelength‐dispersive x‐ray fluorescence detector system has been developed that can be used to discriminate fluorescent photon energies for practically any incident flux. The system uses a Kumakhov polycapillary lens to collimate fluorescent photons from a sample. The collimated photons are transmitted to a crystal‐counter combination on a stepping motor driven θ–2θ stage. The stage diffracts the photon wavelength of interest and a photon‐counting or current‐mode counter is used to measure the photons. The system had a resolution of less than 150 eV at 8 keV using the (200) reflection from an abraded and etched LiF crystal, and was easily able to discriminate between Zn Kα (8.620 keV) and Cu Kβ (8.905 keV) x rays emitted from a brass sample. The LiF (400) reflection had a resolution of approximately 50 eV, but with ten times less intensity.

Dehydroxymethylepoxyquinomicin (DHMEQ), a synthetic derivative of epoxyquinomicin C, is a potent and specific inhibitor of NF-kappa B in cultured cells. Tritium-labeled DHMEQ was synthesized with sodium borotritium. Specific radioactivity of the synthesized tritium-labeled DHMEQ was 15.45 mCi/mmol. This compound would be for the study of the mechanism of action and the stability of DHMEQ.

Showed the feasibility of 4.7-GB DVD-RAM media for 5/spl times/ recording. In order to maintain compatibility with current 2/spl times/ drives, we reduced jitter in both 2/spl times/ and 5/spl times/ recording. The most important design concept is to control the crystal growth velocity and crystal nucleation frequency: the former should be reduced and the latter increased. To control these values, we prepared a medium having a Ge-Sb-Te recording film and a nucleation promoting film. It showed jitter lower than 10% in both 2/spl times/ and 5/spl times/ recording.

The ion beam synthesized /spl beta/-FeSi/sub 2//n-Si heterojunction is examined as a candidate of IR sensitive materials. The large grain (/spl sim/10 /spl mu/m) polycrystalline /spl beta/-FeSi/sub 2//n-Si heterojunction can be formed by triple energy implantation and subsequent annealing at 800/spl deg/C. The /spl beta/-FeSi/sub 2/ grains show good crystallinity with an optical direct band-gap of 0.84 eV and a large hole mobility of 440 cm/sup 2//Vs at 293 K. The heterojunction shows a diode characteristic with high concentration of acceptors. The photovoltaic properties for visible and IR light are very sensitive to surface recombination processes.

Nuclear factor (NF)-kappaB is a transcription factor that induces the immunoglobulin kappa chain, cytokines such as interleukin (IL)-1, IL-2, IL-6, IL-8, tumor necrosis factor (TNF)-alpha and interferon gamma, and cell adhesion proteins. It also induces anti-apoptotic proteins, and inhibits TNF-alpha and anticancer drug-induced apoptosis. Therefore, NF-kappaB function inhibitors may be useful as anti-inflammatory and anticancer agents. Microbial products such as panepoxydone, cycloepoxydon and gliotoxin are known to inhibit activation of NF-kappaB. We have designed and synthesized new NF-kappaB inhibitors from the structure of an antibiotic, epoxyquinomicin C. The designed compound, DHM2EQ, inhibited TNF-alpha-induced activation of NF-kappaB and showed a therapeutic effect in mouse rheumatoid arthritis model.

Angiogenesis consists of endothelial cell proliferation, migration and tube formation. It is useful to investigate endothelial cell behavior using immortalized endothelial cell lines. We characterized cell growth property, growth factor dependency and response to angioinhibitory drugs; TNP-470, staurosporine, radicicol and genistein, using human umbilical vein endothelial cells (HUVECs) immortalized by human papilloma virus (HPV)-16 E6-E7, named HUVECs/E6-E7, and HUVECs/E6-E7 transformed by v-Ki-ras gene, named HUVECs/E6-E7/ras. The dependency to vascular endothelial cell growth factor (VEGF) and basic fibroblast growth factor (bFGF) for cell proliferation decreased in HUVECs/E6-E7, but were restored in HUVECs/E6-E7/ras. Flow cytometric analysis demonstrated that a VEGF receptor KDR/flk-1 was down-regulated in HUVECs/E6-E7 but not in HUVECs/E6-E7/ras. Expression of another VEGF receptor flt-1 was consistent in all cells including HUVECs, HUVECs/E6-E7 and HUVECs/E6-E7/ras. According to the analysis of the angioinhibitory drugs, HUVECs/E6-E7 was obviously resistant to TNP-470, but HUVECs/E6-E7/ras showed similar response compared to HUVECs which suggests that v-Ki-ras signaling pathway is associated with VEGF receptor expression and make HUVECs/E6-E7 sensitive to TNP-470 by modulating the signal transduction cascade. In conclusion, HPV-16 E6-E7 and v-Ki-ras genes have unique growth properties and these immortalized cells are useful for investigating signal transduction pathways of endothelial cells, and for screening of angioinhibitory drugs.

The effect of conophylline, a new vinca alkaloid that inhibits ras expression, on tumour cell adhesion and infiltration was evaluated using a human endometrial cancer cell line. When SNG-II, a highly differentiated human endometrial cancer cell line, was exposed to conophylline, the cells developed filamentous processes at concentrations which did not affect cell proliferation (0.03-0.3 microgram/ml). After exposure to conophylline (0.3 microgram/ml), cells adherent to matrigel- and type IV collagen-coated wells respectively decreased to 26.9% and 33.3% of the number in the untreated control culture (p0.01). In an in vitro invasion assay using a Boyden chamber, infiltration of cells exposed to conophylline decreased to 19.4% (0.3 microgram/ml) (p0.01) of the control. In a wound assay, conophylline inhibited the movement of cells at 24 hr after wounding. Flow cytometric analysis revealed that expression of integrin beta 1 was not altered by conophylline, but E-cadherin and CD44 were decreased. The expression of E-cadherin and CD44 could be changed by conophlline.

A multi-orbit synchrotron (MOS) with fixed field alternating gradient (FFAG) focusing is attractive for acceleration of high intensity hadron beams because acceleration cycle could be increased. The magnetic field of MOS is static, therefore, the repetition rate of acceleration could be increased more than 10 times larger than that of ordinary rapid cycling synchrotron (RCS) if an efficient high voltage RF accelerating system becomes available. Recently, a new type of high gradient RF cavity (HGC) using high permeability magnetic alloy (MA) has been developed and MOS with FFAG focusing becomes very promising. In order to clarify the feasibility of rapid cycling MOS (RCMOS) experimentally, proof-of-principle (POP) machine, which accelerates protons up to 1 MeV with 1 kHz repetition, is under development. We have also made several designs on high intensity proton accelerators with RCMOS for various applications such as an accelerator driven system (ADS) as an energy breeder, a spallation neutron source and a proton driver for a muon collider.

Phosphatidylinositol (PI) turnover is considered to be involved in the regulation of cell growth. The enzymes for PI turnover include phospholipase C (PLC), PI4-kinase and PI synthase. We have isolated pholipeptin and fluvirucin B2 from microorganisms and akaterpin from a marine sponge as PLC gamma inhibitors. We also isolated echiguanines from Streptomyces as PI4-kinase inhibitors. Since echiguanines did not inhibit the enzyme in situ, we synthesized their ribosylated derivatives that were effective in cultured cells. We previously isolated inostamycin from Streptomyces as an inhibitor of PI synthase. We found that inostamycin induced G1 block in cycling NRK cells. Inostamycin inhibited the serum-induced S-phase induction in quiescent NRK cells. Inostamycin was found to decrease serum-induced expression of cyclin D and cyclin E, without inhibiting the activation of MAP kinase. It also inhibited serum-induced activation of CDK2 and phosphorylation of pRB. Thus, PI synthesis was suggested to be involved in regulation of serum-induced S-phase induction by modulating G1 cyclin expression.

4 wk after intraperitoneal inoculation of 0.2 LD50 (50% lethal dose) of murine cytomegalovirus (MCMV) in adult BALB/c mice, MCMV remained detectable in the salivary glands, but not in the lungs or other organs. When the T cells of these mice were activated in vivo by a single injection of anti-CD3 monoclonal antibody, interstitial pneumonitis was induced in the lungs that were free of the virus with an excessive production of the cytokines. In the lungs of such mice persistently infected with MCMV, the mRNA of the cytokines such as IL-2, IL-6, TNF-alpha, and IFN-gamma were abundantly expressed 3 h after the anti-CD3 injection, and the elevated levels continued thereafter. A marked expression of inducible nitric oxide synthetase (iNOS) was then noted in the lungs, suggesting that such cytokines as TNF-alpha and IFN-gamma may have induced iNOS. Although the increase in NO formation was demonstrated by the significant elevation of the serum levels of nitrite and nitrate, the interstitial pneumonitis was not associated with either increased superoxide formation or peroxynitrite-induced tyrosine nitration. Nevertheless, the administration of an NO antagonist also alleviated the interstitial pneumonitis provoked by anti-CD3 mAb. Based on these findings, it was concluded that MCMV-associated pneumonitis is mediated by a molecule of cytokine-induced NO other than peroxynitrite.

Reactive oxygen species (ROS) are often involved in the mechanism of apoptosis. Bleomycin consists of an oxygen activating domain and a DNA binding domain, and is an antitumour agent that induces double-strand scission in DNA by oxygen activation. However, bleomycin only weakly induces apoptosis in limited conditions. Previously we have reported efficient oxygen activation by iron complexes of synthetic models of bleomycin namely PYML designed by the direct analogy to the BLM metal core. Recently, novel ligands having symmetrized coordination environment consisting of two histidine units and a pyridine (HPH) were prepared. Oxygen activating efficiency of the iron complexes of the synthetic ligands increased by introducing electron donating substituent into the pyridine ring. HPH compounds have no DNA binding region which is present in bleomycin. HPH compounds but not bleomycin induced apoptosis in mouse leukemia L1210 cells.

Epidermal growth factor receptor (EGFR) gene overexpression and mutations play an important role in the pathogenesis of a variety of malignant human cancers. In this study, we tested the effects of a novel EGFR tyrosine kinase inhibitor, ethyl-2,5-dihydroxycinnamate (EtDHC), against related human glioblastoma cell lines expressing specific forms of EGFR gene mutations. EtDHC more potently inhibited cell growth and DNA synthesis in glioblastoma cells with endogenous or overexpressed wild-type EGFR compared with those with truncated EGFR, by preferentially inhibiting the tyrosine kinase activity and autophosphorylation of the wild-type EGFR. Higher concentrations of EtDHC were required to inhibit cells expressing the truncated EGFR. These findings are the reverse of another highly specific tyrosine kinase inhibitor, tyrphostin AG 1478, which preferentially inhibited glioblastoma cells with truncated EGFR compared with those with wild-type EGFR. The differential susceptibility of various glioblastoma cells to highly specific tyrosine kinase inhibitors is significant because human gliomas are composed of heterogeneous cells with subsets of cells expressing specific gene mutations. This cellular heterogeneity could be one of the reasons why tumor cells are resistant to chemotherapy. Thus, EtDHC, especially when in combination with drugs targeting other specific gene mutations (such as tyrphostin AG 1478), holds a significant potential for chemotherapy for human glioblastomas.

In the course of screening for Ras function inhibitors from plant extracts, we isolated lycorine from a chloroform extract of Eucharis grandiflora leaves. Lycorine induced flat morphology in K-ras-NRK cells after treatment for 2-3 days, whereas its morphological effect on NRK cells was weaker. Lycorine was found to inhibit protein synthesis specifically in cultured K-ras-NRK cells. It also lowered the cellular amount of Ras in 2-3 days.

Tyrosine kinase inhibitor, erbstatin, induced morphological apoptosis and DNA fragmentation in human small cell lung carcinoma (SCLC) cells. Erbstatin-induced apoptosis was inhibited by antioxidants, whereas erbstatin-inhibited tyrosine phosphorylation was not affected by them. Erbstatin was shown by means of flow cytometry to induce hydrogen peroxide generation. Furthermore, hydrogen peroxide induced morphological apoptosis and DNA fragmentation in the SCLC cells. We also demonstrated that erbstatin-induced hydrogen peroxide production and DNA fragmentation were partially suppressed by inhibition of protein synthesis. Thus, erbstatin-induced apoptosis would be due to hydrogen peroxide generation via newly synthesized protein.

Conophylline, a new vinca alkaloid isolated from the plant Ervatamia microphylla induced normal flat morphology in K-ras-NRK and K-ras-NIH cell lines, and lowered the increased uptake of 2-deoxyglucose in K-ras-NRK cells. Conophylline inhibited the growth of K-ras-NRK cells, but this inhibition was reversible. The alkaloid also inhibited the growth of K-ras-NRK and K-ras-NIH3T3 tumours transplanted into nude mice. On the other hand, it showed no effect on survival of the mice loaded with L1210 leukaemia. Thus, conophylline is a new antitumour vinca alkaloid that induced normal phenotypes in ras-expressing cells.

The trapping of nitric oxide (NO) and nitrite (NO 2 ) reduction were examined using cytochrome c , which had been denatured under pressure (0.1– 500MPa), in 10% isopropanol at 60°C. A reducing agent and electron donor were used in the NO 2 - reduction system. ESR and UV-vis. studies have shown that denatured cytochrome c rapidly forms an iron-nitrosyl (Fe II -NO) complex. Cytochrome c was shown to have a high NO 2 - reducing activity and the rate of NO 2 - reduction to NH 4 + was faster at low pH. The reduction mechanism is proposed to be NO 2 - → NO → NH 4 + . This reaction is a net 6-electron, 8-proton process. These results suggest that high pressure denatured cytochrome c can be used as an NO-trapper.