AIM and METHODES: To evaluate the possible signal transduction mechanism of nontargeted mutagenesis in vero cells induced by DNA damaging agent N-methyl-N-nitro-N-nitrosoguanidine(MNNG),the activation of c-Jun NH 2-terminal kinase/stress activated protein kinase(SAPK/JNK) pathway in vero cells induced by MNNG was studied. Western Blot analysis and Solid-phase kinase assay were used to measure the phosphorylation of JNK1 and kinase activity of JNKs, respectively. RESULTS: After 0.2 ?mol/L, 2.5 h MNNG or 1 mg/L, 1 h cycloheximide (CHM) treatment, the proportion of phosphorylated JNK1 in cell extract increased significantly, simultaneously the kinase activity of JNKs increased dramatically(6.7 and 3.0 folds respectively), as measured by the phosphorylation of c-Jun, a substrate of JNKs. CONCLUSION: Both 0.2 ?mol/L 2.5 h MNNG and 1 mg/L 1 h CHM treatment can induce the activation of JNK/SAPK pathway, one of the stress signal transduction pathways, in vero cells.

100 d),and the histological grade of rejection was significantly lower than that in group Ⅱ(P

AIM: To investigate the effect of mycophenolate acid(MPA) on hepatitis B virus(HBV) replication in vitro.METHODS: In the presence or absence of guanosine,the HepG2.2.15 cells were treated with different concentrations of MPA(1-20 mg/L) for 4 days.Hepatitis B surface antigen(HBsAg) and hepatitis Be antigen(HBeAg) in supernatant were detected by ELISA.Intracellular HBV core mRNA and HBV DNA were analyzed by reverse transcription-polymerase chain reaction(RT-PCR) and slot blot hybridization,respectively.RESULTS: MPA suppressed the expression of HBsAg and HBeAg,and inhibited the replication of HBV DNA.The effect of MPA on HBV replication was reversed by addition of exogenous guanosine.CONCLUSION: MPA suppresses the expression of HBsAg,HBeAg and replication of HBV DNA in HepG2.2.15 cells.Reducing the synthesis of guanosine nucleotides may be involved in the mechanism of the inhibitory activity of MPA on HBV replication.

AIM: To evaluate the effects of NS-398, a cyclooxygenase-2(COX-2) inhibitor, on the proliferation and apoptosis in HepG2 cells. METHODS: The effects of NS-398 on the proliferation of HepG2 cells was evaluated by MTT. DNA fragmentation gel analysis was used to analyze the apoptotic cells; DNA ploidy and apoptotic cell percentage were examined by flow cytometry. Furthermore, the expression of COX-2 and Bcl-2 mRNA was identified by competitive RT-PCR. RESULTS: NS-398 inhibited cell proliferation and induced apoptosis in HepG2 in a concentration-dependent manner. DNA ploidy analysis showed that S phase cells were significantly decreased with NS-398 concentration increasing. The quiescent G_0/G_1 phase was accumulated with decreasing of Bcl-2 mRNA. Whereas NS-398 had no effect on the expression of COX-2 mRNA, no correlations were found between COX-2 mRNA and the HepG2 cell proliferation and apoptosis induced by NS-398 (r=0.056 and r=0.119, respectively). CONCLUSION: NS-398 significantly inhibits the proliferation and induces apoptosis in HepG2. Mechanisms may be involved in accumulation of quiescent G_0/G_1 phase and decrease in Bcl-2 mRNA expression, but independent to COX-2 mRNA expression. [

AIM: To investigate whether viable apoptotic cells and phagocytosis of them affect the activation of T lymphocytes. METHODS: Ultraviolet irradiation was used to induce apoptotic cells in vitro and the model of phagocytosis of these cells was established. Cytokine TGF ?1 was detected by ELISA. The rate of apoptotic cells and phagocytosis of them were assessed by flow cytometry. Furthermore, flow cytometry was also employed to examine the expression of activation signs, such as CD69, CD25, CD71, of T lymphocytes under the intervention of apoptotic cells and macrophage which ingested apoptotic cells, to reflect whether the apoptotic cells and the phagocytosis of these cells could influence the activation of lymphocytes stimulated by Con A. RESULTS: Ingestion of apoptotic cells increased TGF ?1 secretion. Only the macrophages that had ingested apoptotic cells could suppress the activation of lymphocytes. The expression of the markers of lymphocytes activation such as CD69, CD25, CD71 had been restrained. These inhibition effects were abolished by monoclonal anti-TGF ?1 antibody. CONCLUSION: The macrophages that have ingested apoptotic cells inhibit expression of CD69, CD25 and CD71 of T lymphocytes stimulated by ConA. This effect is dependent on the increase in TGF ?1 secretion in local site. [

AIM: To evaluate the effects of lactacystin (LAC) and ?-lactacystin (?-LAC), proteasome inhibitor, on the proliferation and activation of T lymphocytes. METHODS: Flow cytometry was used to analyse the proliferation and the expression of CD69, CD25 and CD3 in PHA activated T-lymphocytes. Furthermore, the expression of PA28 and IL-2 mRNA were assayed by competitive RT-PCR. RESULTS: (1) LAC and ?-LAC significantly decreased the incorporation in PHA activated T-lymphocytes. (2) Although LAC and ?-LAC did not affect the expression of CD69 at any time, they significantly inhibited the expression of CD25 (48 h, 72 h, P

Objective To investigate the effects of insulin-like growth factor-1（IGF-1）on the cell proliferation of human non-small-cell lung cancer（NSCLC） and the possible molecular mechanism.Methods MTT assay was used to examine the effects of IGF-1 （0.1,1,10,100 ng/mL）on the cell proliferation of NSCLC cell lines（A549,LK2,H460）,Flow cytometry（FCM）and Western blot to ana-lyze the cell cycles and the protein expression of S-Phase Kinase-Associated Proteins 2（Skp2）and CDC20 homolog 1（CDH1）,respectively.Results The cell proliferation of NSCLC cell lines（A549,LK2,H460）could be promoted by the IGF-1 at different concentrations and the proliferation rate peaked when the cells were treated with 1 ng/mL IGF-1.Compared with control,the percentage of the S-phase cell population was significantly increased after the treatment of IGF-I（P 〈 0.01）and the protein expression of SKP2 also increased obviously（P 〈0.05）.However,there was no change in the CDH1 protein expression（P 〉 0.05）.Conclusion IGF-1 may accelerate the cell-cycle pro-gression of NSCLC cells by negatively modulating p27 protein via the up-regulation of SKP2 protein expression.

AIM:To clon human cytochrome P450 2A6 cDNA. METHODS:Using reverse transcription polymerase chain reaction(RT-PCR) and DNA recombinant technique, a full-length cDNA encoding cytochrome P450 2A6( CYP2A6 ) from human liver was cloned into pBluescript vector. The cDNA segment was identified by DNA sequencing.RESULTS: Comparing with the CYP2A6 sequence, the cloned CYP2A6 cDNA had two different bases, codon 8 CTG(Leu)→TTG(Leu), codon 479 GGC(Gly)→GTC(Val) and was quite different in their 3′end noncoding region. Comparing with CYP2A7 seqence reported by Fernandez-Salguero,the cloned CYP2A6 cDNA had some different in 5′ end coding sequence and several differencey in the 3′ end coding and noncoding sequence, but both codon 479 were GTC(Val).Comparing with the CYP2A7 seqence reported by Yamano,the cloned CYP2A6 cDNA had some difference in the coding sequence but the 3′ end no-coding area was the same. CONCLUSION: The cloned cDNA was a new cDNA of CYP2A6 which may be transcripted from a new allele of CYP2A6.

AIM:To explore the effect of the pretreatment of hypertonic saline(HTS) in hepatic ischemia reperfusion(I/R) injury.METHODS:The rats were divided into sham group(sham group),ischemia reperfusion group(IR group) and pretreatment of hypertonic saline group(HTS group).Partial hepatic ischemia reperfusion model was used.The rats were sacrificed at the time of 1 h,3 h,6 h,12 h and 24 h after reperfusion in each group,respectively.Blood samples were obtained to examine ALT.The expression of the CD11b/CD18(Mac-1) on the neutrophils was analyzed by flow cytometry.RT-PCR and Western blotting were used to examine the expression of intercellular adhesion molecule-1(ICAM-1) in livers and chromatometry was performed to detect the activity of myeloperoxidase(MPO) in livers.The morphology of hepatocytes and the structure of sinusoid were observed by histological examinations.RESULTS:① HTS pretreatment decreased the level of ALT at the time points of 3 h,6 h and 12 h after reperfusion(P

AIM: To investigate the possible role of nuclear transcription factor kappa B (NF-?B), Bcl-2, Bax and caspase-3 in etodolac-induced apoptosis of liver tumor SMMC7721 cell line. METHODS: Cell apoptosis was determined by flow cytometry analysis with PI staining and DNA laddering. Expression of Bcl-2 and Bax protein was measured by Western blotting. Caspase-3 activity was evaluated by active caspase-3 apoptosis kit with flow cytometry. NF-?B activation was detected by ELISA-based TransAM~(TM) NF-?B p65/p50 kit. RESULTS: Etodolac, a selective COX-2 inhibitor, stimulated apoptosis in liver tumor SMMC7721 cell line significantly. Flow cytometry showed that the apoptotic rate was 16.3%?3.1%, 19.9%?3.6%, 22.9%?3.2%, 31.2%?3.3% with different concentrations of etodolac (0.25, 0.50, 1.0 or 2.0 mmol/L), while the apoptotic peak did not appear in the control group (0 mmol/L) (P