OBJECTIVETo identify the role of reactive oxygen species (ROS) formation on cell death induced by Ent-11alpha-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F) in HepG2 cells.

METHODMTT assay was used to determine the effect of 5F on proliferation of HepG2 cells, and apoptotic morphological changes were assessed using Hoechst/PI assay. To evaluate intracellular ROS levels, a GENMED kit was used. HepG2 cells were treated with 5F for 24 h or with 1 mmol x L(-1) GSH for 1 h prior to treatment with 5F for 24 h, then cytoplasmic mono- and oligonucleosomes were assessed with Cell Death Detection ELISA kit.

RESULTThe cytotoxicity of 5F on HepG2 cells was elevated with increasing 5F concentrations, as evidenced by the cell viability assay, and the apoptotic changes such as chromatin condensation were confirmed by Hoechst/PI staining. The decrease in ROS generation was observed in HepG2 cells following treatment with 5F. Cytoplasmic mono- and oligonucleosomes induced by 5F were not changed by decreasing basal level of ROS-mediated signaling with GSH. Further more, induction of ROS production by cisplatinum (CDDP) was canceled by treatment with 5F and 5F revealed a additive effect to cell killing by CDDP.

CONCLUSION5F can not only induce apoptosis through non-ROS-depandent pathway, and can abate oxidant stress.

Apoptosis ; drug effects ; Cell Death ; drug effects ; Diterpenes ; toxicity ; Drugs, Chinese Herbal ; toxicity ; Hep G2 Cells ; Humans ; Pteris ; chemistry ; Reactive Oxygen Species ; metabolism

OBJECTIVETo investigate the effects of PsL5F (ent-11alpha-hydroxy-15-oxo-kaur-16-en-19-oic-acid, an extract from Pteris semipinnata L) on the expression of nuclear receptor subfamily 1, group D, member 1 (Nr1d1) in highly metastatic ovarian carcinoma HO-8910PM cells, and its mechanisms.

METHODMicroarray Chip was used to examine the level of Nr1d1 mRNA expression on HO-8910PM cells treated with PsL5F. Fluorescent quantitative real-time PCR assay and Western blot were performed to verify the effects of PsL5F on Nr1d1 mRNA and protein expression.

RESULTAfter 24 h treatment of 100 micromol x L(-1) PsL5F, the mRNA and protein levels of Nr1d1 in HO-8910PM cells were 35.34 +/- 1.07 and 7.71 +/- 0.43 times compared to those of control group (P < 0.01, P < 0.01), respectively.

CONCLUSIONPsL5F can up-regulate significantly the expression of Nr1d1 in HO-8910PM cells. Antitumor effects and its mechanisms of PsL5F in HO-8910PM cells may be involved in the up-regulation of Nr1d1 expression.

Antineoplastic Agents, Phytogenic ; pharmacology ; Cell Line, Tumor ; Drug Screening Assays, Antitumor ; Female ; Gene Expression ; drug effects ; Humans ; Neoplasm Invasiveness ; Ovarian Neoplasms ; pathology ; Piperidones ; pharmacology ; Pteris ; chemistry ; RNA, Messenger ; drug effects ; metabolism

This paper describes the construction and practical experience of the key laboratory for teaching of biochemistry and molecular biology,and indicates that the laboratory promotes the development of teaching and scientific research.It is proved to be a suitable measure for sharing teaching resource,improving teaching quality and raising teacher' academic level.

A paper published in Proc Natl Acad Sci USA On March 14,2006,by Ligang Wu et al, New York University School of Medicine, indicating that rapid readenylation is a new mechanism of miRNA inhibiting gene expression.

Objective To construct shRNA expression vector of SURVIVIN for RNAi-mediated therapy of lung cancer.Methods DNA templates of SURVIVIN shRNA were designed,synthesized and cloned into the shuttle vector to get recombinant plasmids.After plasmids were transfected into A549 cells,the one with the most repression was screened by means of RT-PCR.Then MTT and Western blot were done to ascertain whether the proliferation of A549 cells were inhibited and SURVIVIN was down-regulated.Results The recombinants were constructed and screened successfully.The proliferation of A549 cells and SURVIVIN expression were repressed.Conclusion Mediated by RNAi,SURVIVIN expression was down-regulated,which suggested a potential gene therapy of huaman lung cancer.

AIM In order to search inhibitors of protein kinase CK2, we observed the inhibitory effects of kaempferol on recombinant human protein kinase CK2 holoenzyme and its kinetics in vitro. METHODSCloning, prokaryotic expression and purification of human protein kinase CK2 α' and β subunits by gene engineering, the two subunits were mixed at equal molar ratio to reconstitute CK2 holoenzyme and identify its biological properties. The CK2 activity was assayed by detecting incorporation of 32P of [γ-32P]ATP into the substrate. The inhibitory effect of kaempferol on CK2 was assayed in the presence of different concentrations of kaempferol. Kinetic analysis of kaempferol-induced inhibition was carried out in the condition that casein concentration was fixed at 2 g·L-1 and ATP was changed at various concentrations(10, 20, 40, 80 μmol·L-1), or ATP was fixed at 10 μmol·L-1 and casein was changed at different concentrations (1, 2, 4, 8 g·L-1). RESULTS Kaempferol was shown to strongly inhibit the holoenzyme activity of recombinant human protein kinase CK2 with IC50 of 1.9 μmol·L-1, which was more effective than chrysin, morin and genistein which are both known as CK2 special inhibitors. Kinetic studies of kaempferol on recombinant human CK2 showed that kaempferol acted as a noncompetitive inhibitor with substrate ATP(Ki=1.1 μmol·L-1) and casein (Ki=3.1 μmol·L-1). CONCLUSIONKaempferol is a novel potent inhibitor of protein kinase CK2 in vitro. Discussions indicate that flavonoid inhibitors of CK2 may adopt different orientations in theactive site of CK2 and that these are determined by the number and position of their hydroxyl groups.

Research of cell cycle is the bas is of investigating the organism growth,development,heredity and other medical associated events. The molecular basis of cell cycle control is the regulator control system with CDK-Cyclin-CKI as the core.Protein kinase CK2 is one of the most conservative protein kinase during evolution and more and more researches have proved that protein kinase CK2 plays an important role in cell cycle control.

AIM To investigate the anti-inflammatory eff ec t of total flavonoids isolated from Platychadus orientalis and its mechanism . METHODS The inflammatory models in mice and swelling of rats hind paws were induced by dimethylbenzene and carrageenan respectivel y. The biosynthesis of leukotriene and ?-glucuronidase release in the cells we re measured by HPLC and fluorescence spectrophotometer respectively. RES ULTS Total flavonoids isolated from Platychadus orientalis remarkably inhibited the ear edema induced by dimethylbenzene in mice at the dose of 12.5 ～50.0 mg?kg -1 and the swelling of rats hind paws induced by carrageenan at the dose of 25.0～50.0 mg?kg -1 . Total flavonoids at final concentrati on of 5.0～125.0 mg?L -1 inhibited 5-HETE and LTB 4 synthesis by 30.5%～ 87.3% and 27.8%～84.3% respectively. In comparision with controls, Total flavono ids at final concentration of 5.0～45.0 mg?L -1 inhibited ?-glucuronidas e release by 13.4%～32.2%. CONCLUSION Total flavonoids isolated f rom Platychadus orientalis has an anti-inflammatory effect which may be rel ated to inhibiting 5-HETE and LTB 4 production and ?-glucuronidase release.

AIM To find a new method for purifying the active compound 5F isolated from Pteris semipinnata L.(PsL ) and observe its enhanced cytotoxicity when combined with other antitumor agents. METHODS Silica gel combined with AgNO 3 was made to purify 5F. Cytotoxicity was detected with trypan blue dye exclusion assay. RESULTS After purification, the concentration of compound 5F in purified products was higher than 99%. The inhibitory rates of 5F combined with 5 Fu or CDDP or VCR were higher than that of these drugs used alone. CONCLUSIONS Compound 5F could be purified effectively using silica gel combined with AgNO 3. 5F could enhance the cytotoxicity on HL 60 and K562 cells of the drugs mentioned above. The different effect of these agents on the various phases of cell cycle kinetics may explain the enhanced effect of 5F.

AIM To study the expression, purification and activity assay of recombinant mouse protein kinase CK2? subunit from Escherichia coli. METHEDS The recombinant plasmid containing mouse protein kinase CK2? subunit cDNA constructed successfully was transformed into Escherichia coli BL21 (DE3) and specifically induced by IPTG. The recombinant mouse CK2? subunit was sequentially purified by DE 52, P11 phosphocellulose and Heparin Sepharose chromatography. The purified recombinant protein was analysed by SDS PAGE. RESULTS One protein with molecular mass of 42 ku was overexpressed by inducing ITPG. The recombinant protein was composed of approximately 30 6% of the total bacterial proteins. From 278 mg soluble proteins, the yield of the CK2? protein was 4 7 mg. SDS PAGE analysis of the purified recombinant protein showed only one band in agreement with native mouse CK2? subunit. The recombinant mouse CK2? and ? subunits were mixed at the same molar ratio. The produced CK2 holoenzyme displayed full activity. The characteristics and functions of reconstituted CK2 holoenzyme were consistent with those of the given native CK2. CONCLUSION The recombinant protein is mouse protein kinase CK2? subunit.