EFFECTS OF MONOCLONAL ANTIBODY ANTIEGF RECEPTOR ON HUMAN NASOPHARYNGEAL CARCINOMA CELL AND OTHER TUMOR CELLS

Three anti-EGF receptor MoAbs were used in these studies. Administration of MoAbs 3 and 176 inhibited tumor formation in nude mice by CNE-2, a poorly differentiated nasopharyngeal carcinoma cell line and A431, an epidermoid carcinoma cell line. When the same MoAbs were used in treatment against HeLa, a cervical carcinoma, tumor growth was not affected. The number of EGF receptors and apparent dissociation constants for ~(125)I-EGF on CNE-2 and A431 was 1.3×10~(?)/cell (Kd 7.7×10~(-8)mol/L) and 1.4×10~6/cell(Kd 2.4×10~(-9)mol/L), respectively. Both MoAbs 3 and 176, capable of competing with EGF for receptor binding, showed significant tumor growth inhibition. MoAb 101 was incapable of blocking the binding of EGF to its receptor, and not as effective as MoAbs 3 and 176 in tumor growth inhibition. Our observation is that the MoAb anti-EGF receptor is cytostatic rather than cytocidal, in vitro against CNE-2 and A431.     

Design,Synthesis and Anticancer Activity Evaluation of Novel Quinazoline Derivatives as EFGR Inhibitors

Malignant tumor is one of the major diseases that seriously threaten human health today. Compared with traditional chemotherapy, targeted drug therapy has become a new idea of tumor therapy. And EGFR(epidermal growth factor receptor) is highly expressed in many human tumor cell lines, which is a biomarker of tumor proliferation. In this paper, small molecule tyrosine kinase inhibitors with quinazoline structure aiming at EGFR were studied. A series of novel quinazoline derivatives(4 a～4 l) have been designed and synthesized from 4-hydroxyquinazoline as the parent core. Structures of target compounds were characterized by ~1H NMR and ~(13)C NMR spectra. The in vitro anticancer activity of compounds 4 a～4 l was evaluated by MTT assay against Hela,MCF-7 and A549 tumor cell lines, and apoptosis-inducing capacity was investigated by Annexin-V/PI staining assay.The results showed that all compounds had good antitumor activity against the test tumor cell lines. Especially,compound 4 a exhibited the best anticancer activity(IC_(50) = 10.23 μM) against Hela cell lines, remarkable ability to induce apoptosis, and low toxicity, which identified 4 a as a promising anticancer drug aiming at EFGR.     

The Properties of an HBV Surface Antigen Protein Carrying the Binding Site for the Receptor of Hepatocytes——Its Formation of Surface Antigen Particles and Secretion From Discrete Cell Lines

A human hepatitis B virus (HBV) gene, which encodes the major surface antigen protein(S protein) carrying the hepatocyte receptor-binding site, was constructed with site-directed mutagenesis and in vitro recombination. When expressed in monkey kidney cell line COS-M6, this gene product (S309 protein) formed surface antigen (HBsAg) particles and secreted from the cells. It was stable within the cells and in the culture medium and could be immunoprecipitated with antisera directed against plasma-derived HBsAg or synthetic preS1 polypeptide. Isopycnic CsCl gradient centrifugation showed that the density of S309 protein particles (1.25 g/ml) was slightly higher than that of S protein particles. The S309 protein was readily secretable from hepatoma cell lines, and the amount secreted was comparable to that of the S protein. By contrast, only about 10% of the S309 protein was secreted from COS-M6 cells, and its appearance in culture medium was delayed. The efficiency of the secretion of the S309 protein can b     

A new sesquiterpene from hairy root culture of Artemisia annua

<正>A new sesquiterpene(Z)-7-acetoxy-methyl-11-methyl-3-methylenedodeca-1,6,10-triene(AMDT) was isolnted and identified from the methanol extract of the hairy root culture of Artemisia annua.The structure of AMDT was determined based on the analysis of spectroscopic data,notably of the 2D NMR spectra.This new compound showed cytotoxicity against human tumor cell lines 95-D and HeLa with IC_(50) values of 27.08 and 20.12μmol/L,respectively.     

ESTABLISHMENT AND BIOLOGICAL PROPERTIES OF MOUSE GRANULOCYTIC LEUKEMIC CELL LINE-L_(833)

A granulocytic Leukemic cell line, called L_(833), has been established through culturing in vitro frommouse bone marrow of transplantable granulocytic leukemia. More than 280 passages have been performedin 3 years. Cell growth has been rapid and stable. Incidence of tumour formation was 100% with variousroutes of inoculation. The nature of granulocytic leukemia was confirmed by examination of cytology,cytochemistry, pathology and ultrastructural changes. Analysis proved chromosomes to be hypodiploid with model number of 39, loss of chromosomes, andpresence of a marker. Besides the chromosomal change as mentioned above, both L_(883-A) and L_(833-B)derived from colonies formed from the L_(833) cells cultuerd in semi-solid agar medium, have their ownmarker. The cell line was sensitive to various types of antitumour agents in varying degrees. It was alsosensitive to ionizing radiation. D_0 values of L_(833) and L_(833-A) cells were 98.8 and 104.9 rad, respec-tively. The results were similar to that of L_(8     

Synthesis and cytotoxic activity of novel curcumin analogues

Five novel curcumin analogues bearing different substituents at 4-position of phenyl group were synthesized. Their structures were confirmed by NMR and HRMS spectrum. Their cytotoxic activities against six tumor cell lines were tested by the standard MTT assay in vitro. The results indicated that four analogues （1A-1C, 1E） with solubilizing moieties showed selective potent cytotoxicity against HepG2, HeLa and CT26 cell lines, and analogue 1A and 1C exhibited more potent cytotoxicity than curcumin against CT26 cell line. It was suggested that introduction of appropriate substituents to 4-position of phenyl group might be a potential option for structural modification of curcumin.     

FORCING INTERCELLULAR CHROMATIN MI GRATION BETWEEN THE EMBRYOGENIC CELLS OF N. tabacum AND S.oleracea BY ARTIFICIAL MOTIVE FORCE AND THE SUBSEQUENT REGENERA TION OF HYBRID PLANTS——A NEW CELL ENGINEERING TECHNIQUE (L. B. TECHNIQUE)

A new cell engineering technique is established. The technique procedures included inducement andisolation and purification of the embryogenic calluses of two parents, dispersion and combination andcentrifugation multiplication culture of the embryogenic cells of different parents to make them contactand bind with each other, treating the two parents' embryogenic calluses by active potassium solutionand strengthened centrifugation culture to force chromatin and cytoplasm to pass through cell walls andthe establishment of the selective culture system and regeneration of the hybrid plants. By the techniqueintercellular chromatin and cytoplasm migration are manipulated successfully among the embryogenic cellsof tobacco and spinage and the subsequent regeneration of hybrid plants. Studies of genetics and cytologyshowed that regenerated plants retained the genetic traits and the chromosomes found in the original par-ents. It is strongly suggested that the establishment of the technique may give rise to a new     

周期性负载变化提高乙醇燃料电池效率(英文)

We present a simple method to increase the efficiency of a direct ethanol fuel cell by a periodic modulation of the load(pulsed mode). The fuel cell was periodically short circuited with a resistor(1 Ω) for a few seconds(high load period) followed by a low load period of up to 100 s when the resistor was disconnected. The open circuit voltage(OCV) values before and after the short circuit of the cell showed an increase of up to 70 mV. The higher OCV was due to the oxidation and removal of strongly adsorbed CO during the electric short circuit when the electric potential of the anode was increased to be close to the cathode potential. The depoisoned anode surface was much more active directly after the short circuit. The slow decrease of the OCV observed after the short circuit was caused by the subsequent poisoning of the anode surface, which can be neutralized by another short circuit. In general, a stable increase in cell performance was obtained by repetition of the electric short circuit. The data showed that the pulse mode gave an increase in the power generated by the direct ethanol fuel cell by up to 51% and was 6% on average. It is anticipated that this mode of operation can be used also in different types of polymer electrolyte membrane fuel cells where CO poisoning is a problem, and after optimization of the parameters, a much higher gain in efficien-cy can be obtained.     

TOTAL SYNTHESIS OF Trichosanthes TRYPSIN INHIBITOR AND ITS ANALOGUE

Trichosanthes trypsin inhibitor (TTI) is a peptide consisting of 27 amino acid residues with three pairs of disulfide bonds. This paper reports the total synthesis and disulfide bond refolding of this inhibitor and its analogue. After purification, the amino acid sequence and stoichiometrical inhibitory activity against trypsin of the synthetic inhibitor were compatible with those of the natural inhibitor. The analogue of this inhibitor in which residue Met in position 6 was replaced by Ala was also synthesized. The antitrypsin activity of this synthetic analogue was also approximate to that of the natural inhibitor.     

A New Spirostanol Saponin from Dioscorea futshauensis

A new screening bioassay detecting deformation of mycelia germinated from conidia of Pyricularia oryzae P-2b was first developed for quantitative application to screen antifungal and antineoplastic agents by H. Kobayashi1,2. We have introduced and applied this bioassay in the search of bioactive agents from Traditional Chinese Medicine3,4. The ethanol extract of Dioscorea futshauensis R. Kunth (Dioscoreaceae) showed a strong activity against the growth of Pyricularia oryzae P-2b. Its buta…     

ESTABLISHMENT AND CHARACTERIZATION OF HUMAN MALIGNANT PLEURAL MESOTHELIOMA CELL LINE SMC-1

A cell line (SMC-1) has been established from the resected tissue of a patient with malignant pleural mesothelioma which has been pathologically confirmed to be the mixed type. The cell line is characterized by the pleomorphy and multilaycred growth of the cells with the population-doubling time of approximately 32h, the highest mitotic index of 46—50‰ and the modal chromosome number of 69—70. Transplantation of the cells into the anireals can produce tumors bearing histological resemblance to the original material. The cultured cells, xenografted tumor cells and the cells from the host specimen show similar histochemical expressions. These data meet the requirements of a human malignant pleural mesothelioma cell line. The establishment of this cell line will serve as a useful tool in clinical research of diagnosis and treatment of this devastating disease.     

Expression and Characterization of Catalytic Domain of T Cell Protein Tyrosine Phosphatase(ΔTC-PTP)——Immunohistochemical Study of ΔTC-PTP Expression in Non-small Cell Lung Carcinomas

This study objective was to express and characterize the catalytic domain of the human T cell protein tyrosine phosphatase(ΔTC-PTP) and to study immunohistochemically the expression of ΔTC-PTP in human non-small cell lung cancers. ΔTC-PTP gene was PCR amplified with the cDNA of human TC-PTP as template, and cloned into the pT7 expression vector. The recombinant pT7-ΔTC-PTP was expressed in E.coli Rosetta(DE3) host cells and purified. The enzymatic characteristics of ΔTC-PTP including enzyme activity and kinetics assay were measured. The antiserum was prepared by immunizing rabbit with the purified recombinant ΔTC-PTP. Rabbit polyclonal antibody against ΔTC-PTP was purified by PVDF immobilized antigen affinity chromatography. Immunohistochemical staining of lung cancer tissues was performed with antibody against ΔTC-PTP protein. ΔTC-PTP gene was correctly cloned, expressed, and purified. The recombinant ΔTC-PTP had a highly catalytic activity of PTPase. Squamous cell lung carcinoma showed a significantly higher expression rate of ΔTC-PTP(76.92%, 10/13) than adenocarcinoma(57.14%, 4/7) and normal lung tissue(20%, 1/5). This study represents the first demonstration that ΔTC-PTP is highly expressed in human squamous cell lung carcinomas. In addition, this study provides an important basis for further studying the biological function of TC-PTP and its relationship with lung carcinomas and other diseases.     

Establishment of a Tumor-bearing Mouse Model Stably Expressing EGFP Labeled Human MUC1 VNTRs

Two eukaryotic vectors expressing 9 tandem repeats of human MUCI（VNTR）, VR1012-VNTR, and pEGFP-VNTR, were constructed by cloning VNTR gene into VR1012 and pEGFP, respectively. VNTR stably expressing murine Lewis lung carcinoma（LLC） cell line（VNTR^＋ LLC） was established by Lipofectamine-mediated transfection of pEGFP-VNTR into LLC cells. The EGFP expression was observed under a fluorescent microscope and VNTR expression in VNTR^＋ LLC cells was confirmed by means of Western blotting. A syngenic graft tumor model was generated by subcutaneous injection of VNTR^＋ LLC cells into C57/BL6 mice and tumor size increased rapidly with time and in a cell qumber dependent manner. VNTR mRNA expression in the tumor formed was confirmed by RT-PCR. After the third immunization mice were challenged subcutaneously with 5×10^5 VNTR^＋ LLC cells, a significant reduction of subcutaneous tumor growth was observed in the groups immunized with VNTR plasmid DNA compared with that in the groups immunized with the vector DNA alone. Thus, the suppression of subcutaneous tumor was antigen-specific. This model is useful for the development of tumor vaccines targeting MUCI VNTRs.     

Expression and Characterization of Catalytic Domain of T Cell Protein Tyrosine Phosphatase(ΔTC-PTP)——Immunohistochemical Study of ΔTC-PTP Expression in Non-small Cell Lung Carcinomas

This study objective was to express and characterize the catalytic domain of the human T cell protein tyrosine phosphatase(ΔTC-PTP) and to study immunohistochemically the expression of ΔTC-PTP in human non-small cell lung cancers. ΔTC-PTP gene was PCR amplified with the cDNA of human TC-PTP as template, and cloned into the pT7 expression vector. The recombinant pT7-ΔTC-PTP was expressed in E.coli Rosetta(DE3) host cells and purified. The enzymatic characteristics of ΔTC-PTP including enzyme activity and kinetics assay were measured. The antiserum was prepared by immunizing rabbit with the purified recombinant ΔTC-PTP. Rabbit polyclonal antibody against ΔTC-PTP was purified by PVDF immobilized antigen affinity chromatography. Immunohistochemical staining of lung cancer tissues was performed with antibody against ΔTC-PTP protein. ΔTC-PTP gene was correctly cloned, expressed, and purified. The recombinant ΔTC-PTP had a highly catalytic activity of PTPase. Squamous cell lung carcinoma showed a significantly higher expression rate of ΔTC-PTP(76.92%, 10/13) than adenocarcinoma(57.14%, 4/7) and normal lung tissue(20%, 1/5). This study represents the first demonstration that ΔTC-PTP is highly expressed in human squamous cell lung carcinomas. In addition, this study provides an important basis for further studying the biological function of TC-PTP and its relationship with lung carcinomas and other diseases.     

Transalkylation of N-methyl tertiary amines with 3, 4-dibromobutenolides

The selective transalkylation of N-methyl tertiary amines with 3,4-dibromobutenolides is described.The N-methyl group of the parent tertiary amines was replaced by alkenyl units of the butenolides;and a series of butenolide-containing tertiary enamines were obtained in moderate to good yields.Interestingly,the product 2b has shown a promising anticancer activity against HeLa cell lines(IC50=0.19 mmol/L).     

Synthesis and biological evaluation of new pyrrolopyrazinone compounds as potential antitumor agents

A series of pyrrolo[1,2-a]pyrazinone compounds(5a-9f) were synthesized,and their cytotoxic activity against SKOV-3,A549.HeLa cells in vitro were evaluated by the MTT method.Some of the compounds showed potential antitumor activity against three tumor cell lines.Among them,compounds 9c and 9d showed the most potent cytotoxic activity.The preliminary mechanism of action was discussed.     

Functional Mechanism of Resveratrol in Inhabiting Growth of Cells Is174t and Its Mechanism in Subcutaneously Transplanted Tumor of Nude Mice

To explore the functional mechanism of Resveratrol against colon cancer cells ls174t and the growth of colon cancer tissue of tumor-bearing mice, MTT method was used to observe the functions of resveratrol for inhibition against cells ls174t in vitro. Transmission electron microscope was used to observe the cell apoptosis. FCM assay was performed to measure the change of the cell apoptosis rate and of cell cycle. RT-PCR method was used to detect the expressions of bcl-2 and bax mRNA. Western blot method was used to detect the expressions of bcl-2 and bax protein. Ceils ls174t were transplanted subcutaneously to nude mice to observe the effect of resveratrol on the growth of subcutaneously transplanted tumor, RT-PCR method was used to detect the expressions of bcl-2 and bax mRNA in the tumor tissue. Western blot method was used to detect the expressions of bcl-2 and bax protein in the tumor tissue. Resveratrol has an effect of inhibiting proliferation of cells ls174t in vitro（P〈0.01）. It is able to induce the apoptosis of cells ls174t, causing the decrease in the expression of bcl-2 and the increase in the expression of bax. Resveratrol could inhibit the growth of subcutaneously transplanted tumor of nude mice（P〈0.05）, causing the decrease in the expression of bcl-2 and the increase in the expression of bax. Resveratrol can inhibit the growth of cells 174t and the growth of subcutaneously transplanted tumor. The mechanism is possibly related to the induction of the cell apoptosis and the regulation of bcl-2/bax expression.     

Synthesis and in vitro cytotoxic activities of sorafenib derivatives

A series of novel sorafenib derivatives have been designed and synthesized.The cytotoxic activities of these compounds were tested in three tumor cell lines.Most of the compounds showed potent antiproliferative activity against the tested cell lines with IC50= 0–20 mmol/L.Some compounds demonstrated competitive antiproliferative activities to sorafenib against all three cancer cell lines.Among them,compound 5g demonstrated significant inhibitory activity against A549,ACHN and MDAMB-231 cell lines with IC50values of 1.29,1.99,3.11 mmol/L,respectively.     

THE STUDY OF PHOTOELECTROCHEHICAL CELLS BASED ON CHLOROPHYLL AND ORGANIC DYES

Tetraiodofluorescein(TIF)and safranine T(ST)had great effects on the photovoltaicparameters of the cells.The Voc of the cells was about 3-5 times higher than that of thecells without TIK and ST,Isc increased 1 to 2 orders of magnitude.The Voc and Isc couldbe increased greatly only when Voc and Isc of the cell with Pt as WE properly combinedwith the Voc and Isc produced by chla in the original cell.According to absorption spectraand output characters,the results were elucidated.     

RETROVIRUS MEDIATED TRANSFER OF ANTISENSE HUMAN c-myc GENE INTO HUMAN ESOPHAGEAL CANCER CELLS SUPPRESSED CELL PROLIFERATION AND MALIGNANCY

A retroviral vector, called pDAM3, containing the neomycin resistant gene and the antisense human c-myc gene fragment (the third exon and 3'flanking sequence) was constructed. pDAM3 was introduced into amphotropic packaging cells PA317 by the calcium phosphate precipitation method. Several G418-resistant PA317 clones were isolated. The virus titer of these cell lines was determined by infectivity of their cuhure fluid to NIH/3T3 cells. The highest titer obtained was 8×10~5 G418-resistant colony forming units/ml. Clonal and pooled G418-resistant PA317 colonies with high titers were expanded and analyzed by Southern blot for the presence of intact viral sequences. All cell lines were found to harbor the internal sequences of the pDAM3 vector without any rearrangement. Recombinant virus DAM3 infected human esophageal cancer cell line EC8712 efficiently. The DAM3-infected EC8712 (called EC-DAM3) was found to contain the full DAM3 sequence (4.8kb) by Southern blot analysis. Antisense myc RNA expressed in th