Objective To study the association of methylation status of C5 of the cytosine in the CpG di-nucleotide of caspase-8 promoter and expression of caspase-8 mRNA with the resistance to tumor necrosis factor-related apoptosis-inducing ligand(TRAIL) in human hepatocellular carcinoma cell lines,and to evaluate the effect of demethylation agent 5-Aza-2′-deoxycytidine(5-Aza-CdR) on the resistance to TRAIL of human hepatocellular carcinoma cell lines.Methods Methylation status of caspase-8 promoter was measured with methylation-specific PCR method(MSP).Expression of caspase-8 mRNA was detected with RT-PCR.Apoptosis induced by TRAIL was observed by Acridine Orange/Ethidium Bromide(AO/EB) staining.Results Unmethylated status of caspase-8 promoter was found in both HepG2 and SMMC 7721 hepatocellular carcinoma cells.5-Aza-CdR neither up-regulated caspase-8 mRNA expression nor increased the sensitivity of hepatocellular carcinoma cells to TRAIL.Conclusion caspase-8 promoter methylation status and caspase-8 mRNA expression are not related to the resistance to TRAIL.5-Aza-CdR can not increase the sensitivity of hepatocellular carcinoma cells to TRAIL.

Objective To probe the mechanism of hepatocarcinoma cell apoptosis promoted by human telomerase reverse transcriptase (hTERT) RNA interference (RNAi) by mitochondrial pathway in vitro. Methods Westernblot was employed to detect the intracellular expressions of caspase-9, hTERT, Bcl-2 and Bax, and mitochondrial and cytoplastic cytochrome C (cyt C) in HepG2 cells transfected by pSliencer 3.1-H1 neo-shTERT (small hairpin RNA hTERT). Result In the HepG2 cells transfected by pSliencer 3.1-H1 neo-shTERT, expressions of hTERT, Bcl-2 and mitochondrial cyt C were significantly down-regulated, while Bax and cytoplastic cyt C were obviously up-regulated, and active caspase-9 was found in addition to procaspase-9 compared with that in negative control cells and untransfected cells. Conculsion hTERT RNAi may suppress hTERT expression to result in reduction of Bcl-2 and increase of Bax, and then induce hepatocarcinoma HepG2 cell apoptosis by mitochondrial pathway subsequent to cyt C release from mitochondria to cytoplast.

Objective To investigate the association adiponectin gene polymorphism with primary macroangiopathy in diabetes mellitus. Methods Type 2 diabetes mellitus (T2DM) patients were included, 56 patients complicated with atherosclerosis (AS) and 120 non-AS group. We evaluated their Gly15Gly polymorphism of adiponectin gene by PCR restriction fragment length polymorphism (PCR-RFLP). Results The AS patients were more likely to have GG genotype than the non-AS patients (25.0% vs 6.2%, P

Objective To investigate the polymorphism of peroxisome proliferator-activated receptors-?2(PPAR-?2) and its association with obesity in Chinese population.Methods According to BMI,89 subjects who are in normal body weight range and 116 overweighted and obese subjects were included in this study.Their Pro12Ala mutation in the PPAR-?2 gene was detected by PCR restriction fragment length polymorphism.Results Allele frequency of Ala mutation of PPAR-?2 in overweighted and obese subjects(qA=11.64%) was significantly higher than that of normal body weight group(qA=5.06%,P

Objective Using a model of H.pylori infected Mongolian gerbil , we observed the effect of H.pylori and N methyl N’ nitro N nitrosoguanidine (MNNG) on gastric mucosa, in an attempt to clarify the potential role of vitamin C in the prevention of gastric carcinoma. Methods A total of 160 Mongolian gerbils , eight week old, were randomly divided into five groups(each 32 animals): Group A, infected with H.pylori ; Group B, infected with H.pylori followed by MNNG administration; Group C, received MNNG without H.pylori infection; Group D, infected with H pylori followed by administration of MNNG and vitamin C; Group E as control. Eight animals from each group were killed at 12, 24, 36, 48 weeks, and histopathological changes in their stomachs were examined for chronic gastritis, intestinal metaplasia, atypical hyperplasia and adenoma. Results The incidences of intestinal metaplasia and dysplasia in groups A and B were significantly higher than those in the other groups( P

Objective To study the effects of demethylation agent 5-Aza-2′-deoxycytidine (5-Aza-CdR) on the antitumor activity of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) against gastric carcinoma. Methods Expression of caspase-8 mRNA was examined by RT-PCR. Antitumor activity of TRAIL protein was measured by MTT method. Results The inhibition rates of treatment with 200 ng/ml TRAIL for 72 h on gastric cell lines SGc 7901, Kato 3, and AGS were 9.83%, 11.94%, and 4.04%. After treatment with 5-Aza-CdR, the inhibition rates of 200 ng/ml TRAIL on gastric cell lines increased to 38.98%, 52.42%, and 30.72%. Before exposure to 5-Aza-CdR, expression of caspase-8 mRNA was low and an increased expression of the caspase-8 was found in the three gastric cancer cells after treatment with 5-Aza-CdR. Conclusion Treatment with 5-Aza-CdR can increase TRAIL antitumor activity on human gastric cancer and its mechanisms might be involved in the up-regulation of caspase-8 gene.

Objective To evaluate the role of mitochondrial pathway in apoptosis of gastric cancer cell line SGC-7901 induced by Helicobacter pylori(H.pylori).MethodsApoptosis was evaluated in SGC-7901 cells by flow cytometry.RT-PCR and Western blotting were used to measure the expressions of genes and proteins associated with mitochondrial pathway.Effect of caspase inhibitors on apoptosis induced by H.pylori strain NCTC11637 was investigated.ResultsNCTC11637 directly induced apoptosis in SGC-7901 cells.Apoptotic rate was 6.30%,11.57%,8.63% and 7.22% respectively at 6,12,24 and 48 h after coculture with H.pylori.H.pylori upregulated the expression of Bax,and induced a time-dependent activation of caspase-9 and-3.Apoptosis was inhibited significantly by pre-incubation with the inhibitors of caspase-9 and-3.Caspase-8 inhibitor reduced H.pylori-induced apoptosis by 20%.ConclusionH.pylori infection upregulates the expressions of Bax mRNA and protein in gastric cancer cell line SGC-7901,and induces activation of caspase-9 and-3.Mitochondrial pathway may be the major one in H.pylori-induced apoptosis in SGC-7901.

0 05), but correlated positively with that of Bcl 2 in adjacent gastric tissue (Bid vs Bcl 2, r =0 331, P

Objective To study the effect of methylation state of C5 of the cytosine in the CpG di nucleotide of caspase 8 promoter on tumor necrosis factor related apoptosis inducing ligand (TRAIL) antitumor activity in gastric carcinomas. Methods The methylation states of the caspase 8 promoter region of 5 kinds of gastric carcinoma strains were measured by methylation specific PCR method. The antitumor activity of TRAIL protein was measured by MTT method. Results No methylation of caspase 8 promoter was found in gastric carcinoma cells. Treatment with demethylation agent 5 Aza 2′ deoxycytidine (5 Aza CdR) increased sensitivity of gastric cancer cells to TRAIL, but did not change methylation status of caspase 8 promoter in gastric carcinoma cells. Conclusion Caspase 8 promoter methylation status is not associated with TRAIL antitumor activity.

Objective To observe the impacts of the transfection of antisense DNA methyltransferase Ⅰ(DNMT1) gene fragment into SMMC 7721 cell on the changes of cell sensitivities to tumor necrosis factor related apoptosis inducing ligand(TRAIL). Methods The eukaryon expression vector pCl neo was transfected into SMMC 7721 cells by liposomes and the transfection was identified by PCR. Survival cell rate was measured by trypan blue exclusion, apoptotic rate was determined by in situ TdT dUTP terminal nick end labeling(TUNEL) method. Results PCR detection indicated that the eukaryon expression vector pCl neo was successfully transfected into SMMC 7721 cells. Survival cell rate of SMMC 7721 cells transfected with antisense DNMT1 gene fragment was remarkably lower than that of transfected with sense DNMT1 gene fragment and empty vector ( P