工频均匀强磁场促进体外培养SNU细胞凋亡及其相关机理的研究

观察50Hz工频均匀强磁场(0.097T)对人低分化胃腺癌细胞株-SNU细胞凋亡的影响,并通过检测Bax、Bcl-2和Caspase-3三种蛋白表达的变化探讨其可能机制。体外培养SNU细胞,给予50Hz工频均匀强磁场(0.097T)处理后应用流式细胞定量检测和透射电镜超微结构观察,研究该磁场对SNU细胞凋亡的影响,并应用流式细胞定量检测、免疫细胞化学染色和蛋白免疫印迹相结合的方法,检测三种凋亡相关蛋白的表达。给予工频均匀强磁场处理后SNU细胞的凋亡率明显升高,此外,SNU细胞内Bax和Caspase-3蛋白的表达量随处理时间延长逐渐增加,而给予磁场处理后Bcl-2蛋白的表达量随处理时间延长逐渐下降。工频均匀强磁场处理可以促进体外培养SNU细胞凋亡,其可能机理为上调Bax和Caspase-3蛋白的表达,下调Bcl-2蛋白的表达。

工频磁场对离体细胞胞浆钙离子浓度的影响

研究了50 Hz工频均匀强磁场(0.097 T)对人低分化胃腺癌细胞株—SNU细胞和人淋巴细胞胞浆钙离子浓度的影响.将体外培养的SNU细胞和人淋巴细胞,施加50 Hz工频均匀强磁场(0.097 T),处理不同时间后,应用共聚焦显微镜检测胞浆内钙离子浓度.实验表明,给予工频均匀强磁场处理后,SNU细胞和人淋巴细胞胞浆内钙离子浓度均升高.

Berberine induces cell cycle arrest and apoptosis in human gastric carcinoma SNU-5 cell line

AIM： To investigate the relationship between the inhibited growth （cytotoxic activity） of berberine and apoptotic pathway with its molecular mechanism of action. METHODS： The in vitro cytotoxic techniques were complemented by cell cycle analysis and determination of sub-G1 for apoptosis in human gastric carcinoma SNU-5 cells. Percentage of viable cells, cell cycle, and sub431 group （apoptosis） were examined and determined by the flow cytometric methods. The associated proteins for cell cycle arrest and apoptosis were examined by Western blotting. RESULTS： For SNU-5 cell line, the IC （50） was found to be 48 μmol/L of berberine. In SNU-5 cells treated with 25-200 μmol/L berberine, G2/M cell cycle arrest was observed which was associated with a marked increment of the expression of p53, Wee1 and CDk1 proteins and decreased cyclin B. A concentration-dependent decrease of cells in G0/G1 phase and an increase in G2/M phase were detected. In addition, apoptosis detected as sub-Go cell population in cell cycle measurement was proved in 25-200 μmol/L berberine-treated cells by monitoring the apoptotic pathway. Apoptosis was identified by sub-Go cell population, and upregulation of Bax, downregulation of Bcl-2, release of Ca^2＋, decreased the mitochondrial membrane potential and then led to the release of mitochondrial cytochrome C into the cytoplasm and caused the activation of caspase-3, and finally led to the occurrence of apoptosis. CONCLUSION： Berberine induces p53 expression and leads to the decrease of the mitochondrial membrane potential, Cytochrome C release and activation of caspase-3 for the induction of apoptosis.

Amygdalin inhibits genes related to cell cycle in SNU-C4 human colon cancer cells

AIM： The genes were divided into seven categories according to biological function; apoptosis-related, immune response-related, signal transduction-related, cell cyclerelated, cell growth-related, stress response-related and transcription-related genes. METHODS： We compared the gene expression profiles of SNU-C4 cells between amygdalin-treated （5 mg/mL, 24 h） and non-treated groups using cDNA microarray analysis. We selected genes downregulated in cDNA microarray and investigated mRNA levels of the genes by RT- PC R. RESULTS： Microarray showed that amygdalin downregulated especially genes belonging to cell cycle category： exonuclease 1 （EXO1）, ATP-binding cassette, sub-family F, member 2 （ABCF2）, MRE11 meiotic recombination 11 homolog A （MRE11A）, topoisomerase （DNA） Ⅰ （TOP1）, and FK506 binding protein 12-rapamycin-associated protein 1 （FRAP1）. RT-PCR analysis revealed that mRNA levels of these genes were also decreased by amygdalin treatment in SNU-C4 human colon cancer cells. CONCLUSION： These results suggest that amygdalin have an anticancer effect via downregulation of cell cycle-related genes in SNU-C4 human colon cancer cells, and might be used for therapeutic anticancer drug.

Anticancer effects of oligomeric proanthocyanidins on human colorectal cancer cell line, SNU-C4

AIM: Oligomeric proanthocyanidins (OPC), natural polyphenolic compounds found in plants, are known to have antioxidant and anti-cancer effects. We investigated whether the anti-cancer effects of the OPC are induced by apoptosis on human colorectal cancer cell line, SNU-C4.METHODS: Colorectal cancer cell line, SNU-C4 was cultured in RPMI 1640 medium supplemented with 10% fetal bovine serum. The cytotoxic effect of OPC was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenylt-etrazolium bromide (MTT) assay. To find out the apoptotic cell death, 4, 6-diamidino-2-phenylindole (DAPI) staining,terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, reverse transcriptionpolymerase chain reaction (RT-PCR), and caspase-3 enzyme assay were performed.RESULTS: In this study, cytotoxic effect of OPC on SNUC4 cells appeared in a dose-dependent manner. OPC treatment (100 μg/mL) revealed typical morphological apoptotic features. Additionally OPC treatment (100 μg/mL)increased level of BAX and CASPASE-3, and decreased level of BCL-2 mRNA expression. Caspase-3 enzyme activity was also significantly increased by treatment of OPC (100 μg/mL) compared with control.CONCLUSION: These data indicate that OPC caused cell death by apoptosis through caspase pathways on human colorectal cancer cell line, SNU-C4.

脱氧雪腐镰刀菌烯醇对体外培养胃癌细胞SNU凋亡的影响

目的探讨脱氧雪腐镰刀菌烯醇（DON）对胃癌细胞SNU凋亡的影响。方法体外培养的胃癌细胞株SNU经不同浓度（50、100、1000、2000μg／L）DON处理12h，以流式细胞术（FCM）和免疫蛋白印记（Western blotting）法检测细胞凋亡和凋亡相关蛋白bax、bcl-2、Caspase-3的表达情况。结果FCM榆测结果表明，DON处理12h后，各处理组SNU细胞凋亡率均高于对照组。在50～2000μg／L浓度范同内随着DON浓度升高凋亡率亦相应升高，两者呈明显剂量依赖关系（r=0．940，P〈0．01）。FCM和Westrn blotting法检测结果显示，DON作用12h后，SNU细胞bax和Caspase-3表达升高，bcl-2表达降低．结论DON可剂量依赖地诱导体外培养的胃癌细胞SNU凋亡，上调bax蛋白的表达，下调bcl-2蛋白的表达，进而激活Caspase-3，可能在SUN细胞凋亡过程中发挥作用。

姜黄素对人肝癌细胞SNU475增殖及凋亡的影响

目的：探讨姜黄素对人肝癌细胞SNU475增殖及凋亡的影响机制。方法：MTT法测定姜黄素对肝癌肿瘤细胞SNU475的增殖抑制率,进一步的利用Western blot法检测相关蛋白的表达,并利用荧光染色法检测姜黄素存在下,肝癌细胞SNU475形态的变化,最后对肝癌细胞凋亡蛋白Caspase 3活性进行了探讨。结果：姜黄素（0.5-1.5μmol/L）能够诱导了肝癌细胞SNU475的凋亡,且存在时间和剂量依赖性;Western blot法检测相关蛋白的表达结果表明,姜黄素（0.5、1.0μmol/L）能够诱导肝癌细胞SNU475中Akt、Bcl-2、组蛋白H3、H4和Cyclin D1的表达下降,有显著性差别,p21WAF1/CIP1蛋白表达水平显著上调;荧光染色法检测结果显示,在姜黄素（1.0μmol/L）药物作用后24h、48h、72h,肝癌细胞SNU475的形态均可见明显改变;Caspase 3活性检测结果表明,姜黄素（0.5、1.0μmol/L）能显著提高肝癌细胞SNU475中凋亡蛋白Caspase 3活性。结论：姜黄素作为组蛋白去乙酰化酶抑制剂能够诱导肝癌细胞SNU475的凋亡,并对相关蛋白的表达和Caspase 3活性造成影响,最终对肝癌细胞SNU475的凋亡起到重要作用。