Objective:To study the anti-proliferation effects of thiazolidinedione compounds-troglitazone, which is a high affinity ligand of PPAR-? , on rat pituitary adenoma GH3 cell line and explore the related mechanisms.Methods: GH3 cells were separately treated with troglitazone (10-7,10-6 and 10-5 mol/L), dimethyl sulfoxide (DMSO) (DMSO control group) and phenol red- and serum-free F-12 medium (blank group). MTT was used to examine the cell growth in each group and FACS was used to detect the distribution of cell cycle. Semi-quantitative RT-PCR method was utilized to determine the expression of CyclinD1 mRNA. ANOVA was used for statistical analysis.Results:The 72 h treatment with troglitazone inhibited GH3 cell proliferation in a dose-Dependent manner. The treatment also induced cell cycle arrest in G1/S phase and significantly decreased the expression of CyclinD1 mRNA as compared to the other 2 groups (P

AIM: To investigate the effect of ethanol and chemical carcinogen N,N'-dinitrosopiperazine(DNP) on the exogenous expression of CYP2E1.METHODS: Exogenous hCYP2E1 was introduced into NIH3T3 mediated by lipofectamine. Then the integration of exogenous gene was showed by Southemrn blot. After treated with different concentration of ethanol and DNP,RT-PCR and Western blotting were used to analyze the expression change of hCYP2E1 in NIH 3T3. RESULTS: Two cell clones with integration and stable expression of exogenous hCYP2E1 were obtained. The RT-PCR and Western blotting showed that human CYP2E1 mRNA and protein expression was enhanced with increase in ethanol and DNP concentration. CONCLUSION: Exogenous expression of hCYP2E1 was steadily induced by ethanol and DNP. The mechanism may be due to the activation of its transcription. The DNP carcinogenesis might be related to its in situ activation by CYP2E1.

OBJECTIVETo establish an in vitro heterogeneous expression model of human CYP2E1 (hCYP2E1) cDNA and investigate the effect of the chemical carcinogenic N, N'-dinitrosopiperazine (DNP) on the expression of CYP2E1.

METHODSExogenous hCYP2E1 was introduced into the mouse derived NIH3T3 cells using the lipofectamine transfection technique. Integration of exogenous hCYP2E1 gene was identified by PCR and Southern blot. After treatment with various concentration of ethanol and DNP on the transfected NIH3T3 cell cultures, RT-PCR and Western blot was applied to detect the expression level of CYP2E1.

RESULTSTwo cell clones with integration and stable expression of exogenous hCYP2E1 were obtained and designated as NIH3T3-2E1-A4 and NIH3T3-2E1-A8 respectively. The expression of both hCYP2E1 mRNA and protein products was promoted after either ethanol or DNP treatment.

CONCLUSIONThe results suggested that the promoted expression of hCYP2E1 induced by DNP and /or ethanol is due to enhanced transcription. The mechanism of DNP carcinogenes is might be related to this in situ activated metabolism by CYP2E1.

3T3 Cells ; Animals ; Carcinogens ; toxicity ; Cytochrome P-450 CYP2E1 ; genetics ; Ethanol ; pharmacology ; Gene Expression Regulation, Enzymologic ; drug effects ; Humans ; Mice ; Nitrosamines ; toxicity ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection

OBJECTIVETo establish a cell line with human NADH-cytochrome b5 reductase (b5R) deficiency via RNA interference (RNAi).

METHODSTwo siRNA expressing vectors targeting the b5R mRNA were designed and constructed. Hepatocellular carcinoma BEL-7402 cells were transiently transfected with the two recombinants by lipofectamine (TM) 2000, and semi-quantitative RT-PCR was carried out to analyze the suppression of b5R mRNA; BEL-7402 cells stably transfected with the two siRNA expressing vectors were selected in the media with G418. By analyses of the mRNA, enzymatic activity and protein level of b5R, several cell clones with deficiency of b5R were established. The cell growth curve of BEL-7402 cells with b5R deficiency was detected by MTT assay.

RESULTSTwo siRNA expressing vectors targeting b5R mRNA were obtained, namely pSib5R-1 and pSib5R-2. When BEL-7402 cells were transfected transiently with pSib5R-2, the expression of b5R mRNA was significantly suppressed with a suppression ratio of 68.3%, indicating that pSib5R-2 could trigger the degradation of b5R mRNA effectively. Eighteen clones stably integrated exogenous plasmids were obtained. In two clones from pSib5R-2 transfection, the expression of b5R mRNA was suppressed by up to 48.2% and 56.2%, and the enzymatic activity was inhibited by up to 54.6% and 63.5%, respectively. The protein levels also decreased significantly. The defect of b5R did not change the cell growth rate.

CONCLUSIONThe expression of b5R in BEL-7402 could be suppressed by vector-based RNA interference effectively. We established a cellular model with defect of b5R successfully, which can be used as a tool in investigation of the biological function of b5R and molecular mechanism of type II recessive congenital methemoglobinemia.

Cell Culture Techniques ; Cell Line, Tumor ; enzymology ; Cells ; enzymology ; Cytochrome-B(5) Reductase ; deficiency ; genetics ; Gene Expression ; drug effects ; Genetic Vectors ; Humans ; RNA Interference ; physiology ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; pharmacology ; Transfection

To screen the differentially-expressed microRNAs (miRNAs) in mouse models with renal ischemia-reperfusion injury (IRI),aiming to offer foundation for unraveling the molecular mechanism of the incidence and progression of IRI.Methods The mouse models with acute IRI were established by renal artery clamping.Fifteen mice were divided into the IRI group and sham surgery group (E group).The animals in the IRI group were subdivided into the A group (45 min ischemia followed by 24 h reperfusion),B group (25 min ischemia followed by 24 h reperfusion),C group (45 min ischemia followed by 4 h reperfusion) and D group (25 min ischemia followed by 4 h reperfusion) (n=3 for each group).The severity ofIRI was evaluated by histological changes and renal function.The differentially-expressed miRNAs in the IRI mouse models at different ischemia time (25 and 45 min) and reperfusion time (4 and 24 h) were screened by using cluster analysis of miRNAs microarray data.The differential expression of miR-695 and miR-145 was validated by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR).Results Both histological changes and renal function confirmed that the IRI mouse models were successfully established.Compared with the sham surgery group,71 differentially-expressed miRNAs were detected in the IRI group including 30 down-regulated miRNAs and 40 up-regulated miRNAs.The results of qRT-PCR demonstrated that if the standardized expression level of miRNAs in the E group was 1,the relative expression levels of miR-695 and miR-145 were 11.82 and 0.31 in the IRI group (both P＜0.05),which were consistent with the chip results.Conclusions After renal IRI,different changes occur in the gene expression profile of miRNAs.These differentially-expressed miRNAs act as molecular biomarkers for renal IRI with potential clinical and scientific research values.