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The expression of N-cadherin/catenins/actin complex in human lung normal and carcinoma cells

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Chinese Science Bulletin 1998年第9期43卷 774-779页

作者： Wenjun Zhang Zhongxiang Lin Zhiqian Zhang Ying Hu Beijing Inst Canc Res Dept Cell Biol Beijing 100034 Peoples R China Beijing Med Univ Sch Oncol Beijing 100034 Peoples R China

The difference between human normal and carcinoma lung cells.was studied with regard to the protein expression level and localization of the cadherin/catenin/actin complex. Results demonstrated that normal lung cell RF expressed high levels of N-cadherin, β-catenin, α-catenin. These 3 proteins were colocalized at AJs and their submembrane adhesion plaques where they link the Rho-phalloidin-positive actin stress fibers, indicating the existence of N-cadherin/catenin/actin complexes at the AJs. Aberrant expression of AJ proteins and the actin cytoskelecton in carcinoma PG cells.was observed: (1) inhibition of N-cadherin and to a degree of inhibition of α-catenin protein expression; (2) varied protein modification of β-catenin in cytoplasm soluble fraction and altered distribution of immunofluorescence: majorly in the cytoplasm and minorly on the membrane; (3) disassembly of actin stress fibers and formation of actin bodies in the cytoplasm. The data suggest that inhibited expression of AJ proteins is correlated with the disruption of the AJ complexes and the actin cytoskeleton in carcinoma PG cells. and responsible for its metastasis behaviors.

关键词： N-cadherin/catenin/actin complex protein expression human lung normal and carcinoma cells.

Effects of overexpressing p14^(ARF) on the apoptosis in human melanoma cells.irradiated with γ-ray

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Chinese Science Bulletin 2003年第18期48卷 1971-1975页

作者： PENG Lixia, ZHANG Wei, LIU Huitu, HE Dacheng & GAO Ping Key Laboratry of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Science, Beijing Normal University, Bei-jing 100875, China Correspondence should be addressed to Liu Huitu (e-mail: liuhuitu@ ***) Key Laboratry of Cell Proliferation and Regulation Biology of Ministry of Education College of Life Science Beijing Normal University Beijing 100875 China

Tumor suppressor ARF can induce cell cycle arrest or apoptosis by activating p53. In order to explore the molecular mechanism of the induction of apoptosis by p14ARF, a human melanoma cell model overexpressing p14ARF was constructed. Present study indicated that in the cells.overex-pressing p14ARF, p53 was accumulated in nucleus while it dispersed in cytosol in the control cells. Irradiated with g-ray, overexpressing p14ARF promoted the apoptosis of A375 cells. triggered Smac release from mitochondria to cytosol, and increased the expression of p53, Bax, Caspase-3, Caspase-9, p21cip1 and p27kip1. However, the protein level of Bcl-2 and phospho-ERK was down-regulated. These results suggested a possible mechanism of p14ARF in promotion of apoptosis.

关键词： p14ARF p53 g-ray apoptosis A375 cells.

Expression of bcl-2 gene increases in apoptosis of vascular endothelial cells.induced by rattlesnake venom

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Chinese Science Bulletin 2000年第13期45卷 1195-1198页

作者： Araki Satohiko Hayashi Hiroshi Sugashima Marine Biological Laboratory School of ScienceNagoya UniversityTobaMie517JapanSugashima Marine Biological LaboratorySchool of ScienceNagoya UniversityTobaMie517Japan

Apoptosis of vascular endothelial cells.(VEC) has been induced by deprivation of survival factors (aFGF and serum) and by rattlesnake venom. The expression of bcl-2 gene has been examined by Northern blotting in the two apoptosis inducing systems. Our results show that the expression of bcl-2 has not been detected in normal culture cells.and in apoptotic cells.induced by deprivation of survival factors. But in apoptotic cells.induced by rattlesnake venom (10 μg/mL), the expression of bcl-2 increases, and its mRNA exhibits two bands. The data first suggest that increasing expression and splitting of bcl-2 mRNA may play an important role in apoptosis of VEC induced by rattlesnake venom, and this finding is helpful to understanding the role of bcl-2 in regulation of apoptosis.

关键词： bcl-2 gene rattlesnake venom apoptosis vascular endothelial cells.

Recombinant sTRAIL induces cell death of tumor cell lines as well as primary cancer cells

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Chinese Science Bulletin 1999年第14期44卷 1306-1309页

作者： Yanxin Liu Xun Zhu Zhengyu Ma Dexian Zheng Peking Union Med Coll Chinese Acad Med Sci Inst Basic Med Sci Natl Lab Med Mol Biol Beijing 100005 Peoples R China Peking Union Med Coll Chinese Acad Med Sci Inst Hematol Natl Lab Expt Hematol Tianjin 300020 Peoples R China

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a new member of TNF family. It was reported that TRAIL could induce apoptosis of tumor cells.but not normal cells.in tissue culture system. To further study the biological activity and potential clinical significance, a recombinant soluble TRAIL (rsTRAIL) has been expressed stably in E. coli after transformation of pET28b vector containing the extracellular domain of TRAIL. The yield of rsTRAIL is approximately as high as 60% of whole bacterial proteins. The rsTRAIL, purified by Ni^+ -agarose affinity chromatography, could remarkably trigger apoptosis at the concentrations of 0.1—1 μg/mL in all 7 tumor cell lines tested in vitro. However, this killing activity has not been observed in mouse fibroblast cell line (NIH3T3) as normal control. Further investigation shows that the rsTRAIL could also kill primary tumor cells.isolated freshly from patients with cardiac cancer, breast cancer and malignant thymoma, while the normal human

关键词： rsTRAIL apoptosis primary cancer cells.

MAP kinase specifically mediates the ABA-induced H_2O_2 generation in guard cells.of Vicia faba L.

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Chinese Science Bulletin 2003年第18期48卷 1919-1926页

作者： JIANG Jing1,2, AN Guoyong1, WANG Pengcheng1, WANG Pengtao1, HAN Jinfeng2, JIA Yanbin1 & SONG Chunpeng1 1. College of Life Sciences, Henan University, Kaifeng 475001, China 2. College of Agriculture Science, Henan Agriculture University, Zheng-zhou 450001, China Correspondence should be addressed to Song Chunpeng (e-mail: songcp @henu. ***) College of Life Sciences Henan University Kaifeng 475001 China College of Agriculture Science Henan Agriculture University Zhengzhou 450001 China

Mitogen-activated protein (MAP) kinase is involved in ABA- or H2O2-signaling, and H2O2 acts as inter-mediate in the downstream of ABA signal transduction pathway, which has recently emerged as a secondary mes-senger of ABA signaling. Using an epidermal strip bioassay and laser scanning confocal microscope, we provided the first evidence that MAP kinase plays an important role in H2O2 signal initial, amplification and specific targeting in response to stimuli in guard cells. ABA- or H2O2-induced Vicia faba stomatal closure was inhibited or reversed by the specific inhibitor PD98059 of MEK1/2; the guard cells.were pre-incubated or -microinjected by 10 mmol·L-1 PD98059, ABA could not enhance the fluorescence intensity of H2O2 probe dichlorofluorescein (DCF). Meanwhile, after ABA induced the H2O2 accumulation in guard cells. the exogenous or intracellular PD98059 could reduce the DCF fluorescence intensity. Most interestingly, on the contrary to ABA, the DCF fluorescence intensity of guard cells.treated by 100 mmol·L-1 salicylic acid (SA) was not down-regulated by PD98059, yet PD98059 did not regulate the stomatal move-ment being induced by light, dark or salicylic acid. These results suggest that MEK1/2 could mediate stomatal closure by abolishing the ABA-induced H2O2 generation/accumula- tion in the specific manner.

关键词： MAP kinase PD98059 ABA H2O2 guard cells.

Construction and expression of retroviruses encoding dual drug resistance genes in human umbilical cord blood CD34^+ cells

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Chinese Science Bulletin 2000年第15期45卷 1390-1394页

作者： SusanE.Kane Department of Cell and Tumor Biology City of Hope National Medical CenterCA91010USA

A series of retroviral vectors encoding human mdrl gene alone as well as in combination with either human mgmt gene or human mutant Ser31-dftfrgene are engineered. The resultant retroviruses are used to transduce human umbilical cord blood CD34+ cells. It has been shown that expression of dual drug resistance genes in transduced cells.confers a broad range of resistance to both kinds of corresponding drugs. These data suggest a rationale for the use of such double chemoresistance gene constructs in an in vivo model in which transduced hematopoietic cells.will acquire multiple protection against the cytotoxic side effects of combination chemotherapy and may have future application in chemoprotection of normal tissues, thus killing tumor cells.more effectively.

关键词： tumor chemotherapy retrovirus drug resistance gene cord blood CD34+ cells.

A Genetically Encoded Toolkit for Probing the Post Translational Modifications of Lysine in Mammalian cells

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生物物理学报 2009年第S1期25卷 166-167页

作者： Dan Groff Peter G.Schultz The Scripps Research Institute 10550 N.Torrey Pines RdLa JollaCA92037USA

Post translational modifications (PTMs) of lysine play a crucial role on modulating the activity and stability of essential proteins in eukaryotic cells.including the tumor

关键词： Post translational modifications photocaged Lysine Unnatural amino acid Mammalian cells.

Mutual relationships between contents of chromogranin A, cholecys-tokinin octapeptide and serotonin in individual EC cells

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Chinese Science Bulletin 1995年第5期40卷 417-421页

作者：王瑞安蔡文琴张成岗 M.Stridsberg 苏慧慈 Department of Histology and Embryology The 4th Military Medical University Xi'an 710032 China Department of Histology and Embryology The 3rd Military Medical UninersityChongqing 630038 China Department of Clinical Chemistry Uppsala UniversitySweden

Chromogranin A (CgA) is a kind of acidic protein originally isolated from the chromaffin cells.of the ox adrenal gland medulla. It was found that the CgA was also widely distributed in the neuroendocrine cells.besides the adrenal medulla. The physiological function of the CgA is not yet elucidated, but it was presumed to be involved in organizing the granule matrix and regulating the processing of the prohormones. Besides, CgA is also the precursor of some peptide hormones such

关键词： chromogranin A cholecystokinin 5-hydroxytryptamine EC cells.

Studies of Dielectrophoretic Spectra of Levitated Tobacco Leaf Protoplast

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Science China Chemistry 1993年第9期36卷 1093-1100页

作者：汪和睦杭军 Physics Department Nankai University Tianjin 300071 PRC

In this paper, we have utilized the principle of dielectrophoresis to determine the dielectrophoretic spectra of single levitated tobacco leaf protoplast at various suspending media conductivities (12.5 μS/cm-520 μS/cm) over wide frequencies (10 Hz—15 MHz). From the experimental data, the membrane capacitance of the single protoplast which was 0.40±0.03μF/cm^2 has been obtained and the dipole interaction of two protoplasts in electrofusion has also been analysed. When the external electric field E_c=1.5kV/cm was applied and the frequency was higher than 20 kHz, the dipole interaction pressure ~πd would be much larger than the membrane potential pressure ~πm, and the pressure ~πd could be the main reason for membraue pores. This conclusion will provide a new basis to improve the protocol of cell electrofusion.

关键词： plant protoplast levitated dielectrophoresis(DEP) membrane capacitance dipole interactions of cells.