奥沙利铂诱导人小细胞肺癌NCI-H446细胞凋亡的研究

目的:研究奥沙利铂对人肺癌细胞株NCI-H446生长抑制及诱导凋亡的作用并探讨其机制。方法:以不同浓度的奥沙利铂作用于NCI-H446细胞,应用采用噻唑蓝(MTT)法检测奥沙利铂对NCI-H446细胞生长的抑制作用。Hoechst33258荧光染色法观察细胞凋亡形态学变化;流式细胞术检测细胞周期和凋亡;分光光度法检测caspase-3、caspase-8、caspase-9的活性。结果:奥沙利铂可抑制NCI-H446细胞的生长并具有时间和剂量依赖性,Hoechst 33258荧光染色可见典型的细胞凋亡特征,流式细胞仪检测到细胞阻滞于S期和sub-G1峰。经过奥沙利铂诱导,caspase-3、caspase-9活性被上调,较对照组明显升高(P<0.05),caspase-8活性未见明显改变(P>0.05)。结论:奥沙利铂具有抑制肺癌细胞株NCI-H446增殖及诱导凋亡作用,此作用可能通过激活内源性凋亡途径实现。     

奥沙利铂诱导人小细胞肺癌NCI-H446细胞凋亡的研究

目的：研究奥沙利铂对人肺癌细胞株NCI-H446生长抑制及诱导凋亡的作用并探讨其机制。方法：以不同浓度的奥沙利铂作用于NCI-H446细胞,应用采用噻唑蓝（MTT）法检测奥沙利铂对NCI-H446细胞生长的抑制作用。Hoechst33258荧光染色法观察细胞凋亡形态学变化;流式细胞术检测细胞周期和凋亡;分光光度法检测caspase-3、caspase-8、caspase-9的活性。结果：奥沙利铂可抑制NCI-H446细胞的生长并具有时间和剂量依赖性,Hoechst 33258荧光染色可见典型的细胞凋亡特征,流式细胞仪检测到细胞阻滞于S期和sub-G1峰。经过奥沙利铂诱导,caspase-3、caspase-9活性被上调,较对照组明显升高（P〈0.05）,caspase-8活性未见明显改变（P〉0.05）。结论：奥沙利铂具有抑制肺癌细胞株NCI-H446增殖及诱导凋亡作用,此作用可能通过激活内源性凋亡途径实现。     

17-AAG通过抑制Erk信号通路增强奥沙利铂诱导结肠癌细胞凋亡

目的 研究17-AAG与奥沙利铂是否存在协同效应,并探讨PI3K/Akt、Erk信号通路在奥沙利铂联合17-AAG诱导人结肠癌细胞凋亡过程中的作用。方法 四甲基偶氮唑盐比色实验（MTT法）检测17-AAG、奥沙利铂对细胞增殖的抑制作用;流式细胞术分析细胞凋亡情况;Western blot法检测相关蛋白的表达水平。结果 17-AAG能抑制RKO细胞的增殖;17-AAG联合奥沙利铂作用于RKO细胞24 h后,G₂/M期细胞比例及凋亡率明显增加;奥沙利铂抑制p-Akt、p-Erk的活化,上调Bax,下调Bcl-2蛋白表达,活化裂解Caspase-3,联合使用17-AAG后可进一步增强上述作用,但对PI3K/Akt信号通路影响不大。结论 本实验表明17-AAG具有增强奥沙利铂诱导结肠癌RKO细胞凋亡的作用,同时也说明17-AAG与奥沙利铂存在协同效应;17-AAG上调Bax,下调Bcl-2蛋白表达及增强奥沙利铂对Erk信号通路的抑制作用可能是其促进凋亡的重要机制之一。     

塞来昔布抑制肝癌细胞株增殖及其机制的实验研究

目的:研究特异性环氧化酶-2(COX-2)抑制剂塞来昔布对人肝癌细胞株SMMC-7721是否有抑制增殖、诱导凋亡作用并初步探讨其作用机制。方法:采用四氮唑盐比色法(MTT法)观察不同浓度的塞来昔布作用后细胞增殖活力改变;流式细胞仪检测细胞凋亡百分率及细胞周期变化;免疫组化观察Bcl-2蛋白和Bax蛋白表达情况。结果:MTT法显示随着塞来昔布浓度和作用时间增加,细胞增殖抑制率上升;流式细胞仪测定空白对照组未见明显凋亡峰,塞来昔布组出现凋亡峰,凋亡率随着时间及药物浓度变化而变化,二者呈正相关;免疫组化显示经塞来昔布干预后,凋亡蛋白Bax表达增加,而Bcl-2表达减少,并随时间和药物浓度变化而明显。结论:塞来昔布抑制SMMC-7721细胞增殖,促进SMMC-7721细胞凋亡,并呈剂量和时间依赖性。其作用机制之一可能是通过减少Bcl-2的表达,增加Bax的表达,从而启动细胞凋亡途径。     

δ-生育三烯酚诱导人肝癌HepG2细胞凋亡的机制研究

目的:探讨δ-生育三烯酚诱导人肝癌HepG2细胞凋亡的作用机制.方法:应用MTT法检测δ-生育三烯酚对人肝癌HepG2细胞增殖的影响,应用高内涵活细胞成像系统检测δ-生育三烯酚对人肝癌HepG2细胞凋亡率、细胞周期以及线粒体膜电位的影响,Western印迹法检测δ-生育三烯酚对人肝癌HepG2细胞凋亡相关蛋白(如caspase-3、caspase-8、caspase-9、Bcl-2、Bax、tBid和cytochrome C)表达的影响.结果:δ-生育三烯酚呈浓度依赖性地抑制肝癌HepG2细胞生长并诱导其凋亡,其机制为δ-生育三烯酚降低线粒体膜电位,并诱导cytochrome C从线粒体释放到细胞质中,调控Bcl-2家族蛋白表达(如上调Bax及tBid蛋白的表达,下调Bcl-2蛋白的表达),继而引起caspase-3、caspase-8和caspase-9的活化,最终导致肝癌 HepG2细胞凋亡.结论:δ-生育三烯酚可能通过线粒体途径及膜死亡受体途径共同诱导人肝癌细胞 HepG2凋亡.     

苦参素改变端粒酶活性对人肝癌细胞株HepG2、QGY体外增殖影响的研究

[目的]观察苦参素对人肝癌细胞株HepG2、QGY体外增殖和端粒酶活性的影响.[方法]应用MTT法检测HepG2与QGY增殖抑制的程度;流式细胞仪分析细胞周期的分布及凋亡;PCR-ELISA法检测端粒酶活性的变化.[结果]苦参素对HepG2和QGY细胞增殖的抑制随着时间的延长而增加,具有时间依赖性,各浓度时间之间均有显著性差异(P＜0.001);从细胞周期分析,苦参素能阻滞HepG2和QGY细胞周期进程,同时诱导细胞凋亡,各细胞之间均有显著性差异(P＜0.001);苦参素对细胞端粒酶均有时间和剂量依赖性,各组间均有显著性差异(P＜0.001).[结论]对端粒酶活性的抑制可能是苦参素发挥抗肿瘤作用的机制之一.     

Zerumbone causes Bax- and Bak-mediated apoptosis in human breast cancer cells and inhibits orthotopic xenograft growth in vivo

The present study was undertaken to determine the anticancer efficacy of zerumbone (ZER), a sesquiterpene from subtropical ginger, against human breast cancer cells in vitro and in vivo. ZER treatment caused a dose-dependent decrease in viability of MCF-7 and MDA-MB-231 human breast cancer cells in association with G₂/M phase cell cycle arrest and apoptosis induction. ZER-mediated cell cycle arrest was associated with downregulation of cyclin B1, cyclin-dependent kinase 1, Cdc25C, and Cdc25B. Even though ZER treatment caused stabilization of p53 and induction of PUMA, these proteins were dispensable for ZER-induced cell cycle arrest and/or apoptosis. Exposure of MDA-MB-231 and MCF-7 cells to ZER resulted in downregulation of Bcl-2 but its ectopic expression failed to confer protection against ZER-induced apoptosis. On the other hand, the SV40 immortalized mouse embryonic fibroblasts derived from Bax and Bak double knockout mice were significantly more resistant to ZER-induced apoptosis. ZER-treated MDA-MB-231 and MCF-7 cells exhibited a robust activation of both Bax and Bak. In vivo growth of orthotopic MDA-MB-231 xenografts was significantly retarded by ZER administration in association with apoptosis induction and suppression of cell proliferation (Ki-67 expression). These results indicate that ZER causes G₂/M phase cell cycle arrest and Bax/Bak-mediated apoptosis in human breast cancer cells, and retards growth of MDA-MB-231 xenografts in vivo.     

塞来昔布对NB4细胞增殖、凋亡及VEGF表达的影响

目的 探讨塞来昔布对急性早幼粒细胞白血病细胞的抑制作用及可能机制.方法 不同浓度塞来昔布处理急性早幼粒细胞白血病细胞株NB4,MTT法检测塞来昔布作用后细胞的增殖情况.采用流式细胞术测定NB4细胞周期分布及凋亡;Western blot检测细胞凋亡相关蛋白Bcl-2表达以及RTPCR检测塞来昔布作用对VEGF、HIF-1α在mRNA水平的表达.结果 MTT显示塞来昔布对NB4细胞生长有明显抑制作用.20～80 μmol/L塞来昔布作用24 h,NB4细胞G0/G1期比例明显升高,而S期细胞比例下降(P＜0.05);塞来昔布处理组细胞凋亡率明显高于对照组,Western blot显示Bcl-2蛋白表达下调(P＜0.05);RT-PCR显示塞来昔布可抑制VEGF及HIF 1α的mRNA表达.结论 塞来昔布在体外可抑制急性早幼粒细胞白血病细胞增殖并诱导凋亡.     

Sulforaphane induces G2–M arrest and apoptosis in high metastasis cell line of salivary gland adenoid cystic carcinoma

New chemotherapeutic strategy should be investigated to enhance clinical management in salivary gland adenoid cystic carcinoma (ACC). Recently, sulforaphane (SFN), as a natural compound from cruciferous vegetables exhibits a potent anti-cancer activity in various tumor cells, but remains uncertain in ACC cells. The present study examined whether SFN suppresses proliferation and in ACC cells, if so, the possible molecular targets would be further investigated. Cell survives, apoptosis, cell cycle progression and molecular targets were identified by multiple detecting techniques, including trypan blue dye exclusion assay, electron microscopy, AO/EB staining, flow cytometry and immunoblotting in human lung high metastasis cell line of salivary gland adenoid cystic carcinoma (ACC-M). The results showed that 5–20 μM SFN suppressed proliferation and induced apoptosis of ACC-M cells in dose- and time-dependent manners. Cell cycle analysis demonstrated treatment of ACC-M cells with 20 μM SFN resulted in G₂/M cell cycle arrest, which was associated with a marked decline in protein levels of G₂/M regulatory proteins including cyclin B1 and cyclin-dependent kinase 1 (Cdk1). In terms of apoptosis, SFN increased the expression of Bax and decreased the level of Bcl-2 and subsequently triggered release of cytochrome c from mitochondria and activation of caspase-3, but Fas level and caspase-8 activity remained unchanged at all time points. Furthermore, levels of nuclear factor-κB (NF-κB) p65 in both of the cytoplasm and the nucleus have also been markedly suppressed by SFN in a time-dependent manner. Taken together, these results suggest SFN inhibits cell growth via inducing G₂/M cell arrest and apoptosis in ACC-M cells. These events have been associated with SFN-regulated multiple targets involved in ACC-M cell proliferation. The present study provides an evidence for testing SFN efficacy in vivo and warranting future investigations to exam the clinical potential of SFN in ACC chemotherapy.     

PML-RARα表达对细胞凋亡诱导剂敏感性差异的分子机制研究

目的 研究PML-RARα表达阴性的HL-60细胞和表达阳性的NB4细胞对三氧化二砷(As2O3)诱导细胞凋亡敏感性差异的分子机制.方法 经As2O3作用人急性早幼粒细胞白血病HL-60和NB4细胞后,MTT法检测细胞增殖变化,流式细胞术测定细胞凋亡水平的变化,RT-PCR检测Bcl-2、Bax、Fas等基因在mRNA水平的表达变化.结果 As2O3可诱导NIM细胞出现明显的凋亡现象,细胞增殖受到明显抑制(P<0.05),Bcl-2基因表达明显下调(P<0.05),但Bax、Fas基因表达没有明显变化(P>0.05),Bcl-2/Bax比值明显降低(P<0.05).而对于PML-RARa表达阴性的HL-60细胞,经小剂量As2O3作用后,对细胞的增殖抑制作用不明显(P>0.05),未出现明显凋亡现象,Bcl-2、Bax、Fas或Bcl-2/Bax表达水平及比值变化不明显(P>0.05).结论 Bcl-2/Bax表达比值变化与否,可能是小剂量As2O3诱导PML-RARα表达阴性的HL-60细胞和表达阳性的NB4细胞发生凋亡差异的分子机制.     

叶黄素对人前列腺癌PC3细胞增殖和凋亡影响的机制

目的 探究叶黄素对人前列腺癌PC3细胞增殖和凋亡影响的作用机制,为前列腺癌预防及治疗提供新的理论依据。方法 不同浓度叶黄素作用于PC3细胞,CCK8法检测细胞增殖情况;流式细胞仪检测细胞周期分布和凋亡变化;细胞划痕和Transwell实验观察细胞迁移和侵袭能力;RT-PCR和Western blot技术检测细胞中Bax、Bcl-2的mRNA水平和蛋白表达。结果 叶黄素显著抑制PC3细胞的增殖,并呈时间和浓度依赖性。叶黄素可以将细胞生长阻滞在G0/G1期,抑制细胞迁移和侵袭;还可促进细胞凋亡,使Bcl-2表达下降,Bax表达上升。叶黄素可在转录水平上下调Bcl-2 mRNA和上调BaxmRNA。结论 叶黄素抑制PC3细胞增殖并促进其凋亡,其机制可能与阻滞细胞周期、抑制细胞迁移、侵袭以及调节凋亡相关基因和蛋白表达有关。     

Diosgenin induces cell cycle arrest and apoptosis in human leukemia K562 cells with the disruption of Ca2+ homeostasis

Purpose Diosgenin is a steroidal sapogenin with estrogenic and antitumor properties. In order to elucidate the mechanism of its antiproliferative activity, we investigated its effects on the cell cycle and apoptosis in human chronic myelogenous leukemia K562 cells.Methods Cell viability was assessed via an MTT assay. Apoptosis was investigated in terms of nuclear morphology, DNA fragmentation, and phosphatidylserine externalization. Cell cycle analysis was performed via PI staining and flow cytometry (FCM). Western blotting and immunofluorescence methods were used to determine the levels of p53, cell cycle-related proteins and Bcl-2 family members. FCM was also used to estimate the changes in mitochondrial membrane potential (MMP), intracellular Ca²⁺ concentration and reactive oxygen species (ROS) generation.Results Cell cycle analysis showed that diosgenin caused G₂/M arrest independently of p53. The levels of cyclin B1 and p21^Cip1/Waf1 were decreased, whereas cdc2 levels were increased. Subsequent apoptosis was demonstrated with the dramatic activation of caspase-3. A dramatic decline in intracellular Ca²⁺ concentration was observed as an initiating event in the process of cell cycle arrest and apoptosis, which was followed by the hyperpolarization and depolarization of MMP. Generation of ROS was observed in the progression of apoptosis. The antiapoptotic Bcl-2 and Bcl-x_L proteins were downregulated, whereas the proapoptotic Bax was upregulated.Conclusions Diosgenin inhibits K562 cell proliferation via cell cycle G₂/M arrest and apoptosis, with disruption of Ca²⁺ homeostasis and mitochondrial dysfunction playing vital roles.     

培美曲塞联合舒尼替尼对肝癌细胞生物学行为的影响

目的:探讨培美曲塞联合舒尼替尼对肝癌细胞增殖、细胞周期和细胞凋亡的影响。方法:以培美曲塞和舒尼替尼单药或联合处理肝癌SK-Hep1细胞后,MTT法检测细胞的增殖抑制率,FCM检测细胞的周期变化和凋亡率,Western blot检测蛋白激酶B（AKT）、磷酸化蛋白激酶B（p-AKT）、增殖细胞核抗原（PCNA）、B淋巴细胞瘤-2基因（Bcl-2）和切割型半胱天冬酶3（Cleaved caspase-3）蛋白的表达。结果:培美曲塞和舒尼替尼均能够呈时间-浓度依赖性抑制SK-Hep1细胞增殖,72 h IC50分别为（2.89±0.20）μmol/L和（2.12±0.12）μmol/L（P＜0.05）;培美曲塞和舒尼替尼均能够诱导SK-Hep1细胞凋亡（P＜0.05）;培美曲塞使SK-Hep1细胞周期阻滞于S期,舒尼替尼使细胞周期阻滞于G0/G1期（P＜0.05）;培美曲塞和舒尼替尼均可使p-AKT、PCNA、Bcl-2的表达下降,Cleaved caspase-3表达升高。两药联用使SK-Hep1细胞阻滞在G2/M期,细胞增殖抑制率和细胞凋亡率较单药更加明显,且p-AKT、PCNA、Bcl-2表达下降及Cleaved caspase-3表达升高更为显著（P＜0.05）。结论:培美曲塞联合舒尼替尼可抑制SK-Hep1细胞增殖,并诱导SK-Hep1细胞周期阻滞和凋亡,其作用机制可能与下调p-AKT、PCNA、Bcl-2表达和上调Cleaved caspase-3表达有关。     

Molecular mechanisms of action and prediction of response to oxaliplatin in colorectal cancer cells

The platinum compound oxaliplatin has been shown to be an effective chemotherapeutic agent for the treatment of colorectal cancer. In this study, we investigate the molecular mechanisms of action of oxaliplatin to identify means of predicting response to this agent. Exposure of colon cancer cells to oxaliplatin resulted in G2/M arrest and apoptosis. Immunofluorescent staining demonstrated that the apoptotic cascade initiated by oxaliplatin is characterised by translocation of Bax to the mitochondria and cytochrome c release into the cytosol. Oxaliplatin treatment resulted in caspase 3 activation and oxaliplatin-induced apoptosis was abrogated by inhibition of caspase activity with z-VAD-fmk, but was independent of Fas/FasL association. Targeted inactivation of Bax or p53 in HCT116 cells resulted in significantly increased resistance to oxaliplatin. However, the mutational status of p53 was unable to predict response to oxaliplatin in a panel of 30 different colorectal cancer cell lines. In contrast, the expression profile of these 30 cell lines, assessed using a 9216-sequence cDNA microarray, successfully predicted the apoptotic response to oxaliplatin. A leave-one-out cross-validation approach was used to demonstrate a significant correlation between experimentally observed and expression profile predicted apoptosis in response to clinically achievable doses of oxaliplatin (R=0.53; P=0.002). In addition, these microarray experiments identified several genes involved in control of apoptosis and DNA damage repair that were significantly correlated with response to oxaliplatin.     

蛇床子素诱导HL-60细胞凋亡及其分子机制研究

目的 研究蛇床子素对急性髓系白血病HL-60细胞增殖、凋亡的影响,并探讨其作用的分子机制.方法 CCK8实验检测蛇床子素对HL-60细胞的增殖抑制作用,Hoechst染色观察药物8h作用后细胞的形态学变化,流式细胞术检测细胞凋亡情况,反转录-聚合酶链式反应（RT-PCR）检测HL-60细胞的Bcl-2、Bax mRNA表达变化,Western bolt检测HL-60细胞的活性caspase-3、caspase-8、caspase-9、Fas、FasL蛋白表达变化.结果 蛇床子素可明显抑制HL-60细胞增殖并诱导其发生凋亡,抑制率最高达（90.7±4.5）％,F=138.46,P=0.000;总凋亡率为33.6％,F=27.75,P=0.006.诱导后Bcl-2 mRNA表达下调,Bax mRNA表达上调,Bax/Bcl-2比值升高（F=210.12,P=0.000）,活性caspase-3、caspase-8、caspase-9、Fas、FasL蛋白表达水平随药物作用时间延长而升高.结论 蛇床子素可抑制HL-60细胞增殖并诱导凋亡,其诱导凋亡机制与同时激活线粒体途径和死亡受体途径相关.     

Baicalein Exerts Anticancer Effect in Nasopharyngeal Carcinoma In Vitro and In Vivo

Baicalein, an active ingredient separated from Astragalus membranaceus, has shown its anticancer ability in various cancers. However, its effect on nasopharyngeal carcinoma has not been explored yet. The present study aimed to investigate the effect of baicalein on the growth, proliferation, apoptosis, and cell cycle of human nasopharyngeal carcinoma cells, as well as transplanted nude mouse xenograft. The results showed that baicalein inhibited the growth and proliferation of CNE1 and CNE2 cells in a time- and concentration-dependent manner. It also caused a significant increase in the number of cells in the G₀/G₁ phase and a decrease in the G₂/M phase, thereby reducing the number of cells entering mitosis and inhibiting the proliferation of tumor cells. Baicalein also significantly induced apoptosis of CNE1 and CNE2 cells. Western blots showed that baicalein decreased the expression of Bcl-xl and Mcl-1 and increased the expression of Bax, Bad, and caspase 3, 8, and 9. In CNE1- and CNE2-transplanted tumors of mice, baicalein significantly inhibited tumor growth. In conclusion, baicalein could inhibit the growth and proliferation of human nasopharyngeal carcinoma cells, change their cell cycle, and induce apoptosis. Baicalein also effectively limits both CNE1- and CNE2-transplanted tumors in nude mice. Downregulation of Bcl-xl and Mcl-1 proteins and upregulation of Bax and Bad may be involved in the mechanism.     

β-elemene Induces Caspase-dependent Apoptosis in Human Glioma Cells in vitro through the Upregulation of Bax and Fas/ FasL and Downregulation of Bcl-2

Background: β-elemene, extracted from herb medicine Curcuma wenyujin has potent anti-tumor effects invarious cancer cell lines. However, the activity of β-elemene against glioma cells remains unclear. In the presentstudy, we assessed effects of β-elemene on human glioma cells and explored the underlying mechanism. Materialsand Methods: Human glioma U87 cells were used. Cell proliferation was determined with MTT assay andcolony formation assay to detect the effect of β-elemene at different doses and times. Fluorescence microscopywas used to observe cell apoptosis with Hoechst 33258 staining and change of glioma apoptosis and cell cyclingwere analyzed by flow cytometry. Real-time quantitative PCR and Western-blotting assay were performed toinvestigated the influence of β-elemene on expression levels of Fas/FasL, caspase-3, Bcl-2 and Bax. The experimentwas divided into two groups: the blank control group and β-elemne treatment group. Results: With increase inthe concentration of β-elemene, cytotoxic effects were enhanced in the glioma cell line and the concentrationof inhibited cell viability (IC50) was 48.5 μg/mL for 24h. β-elemene could induce cell cycle arrest in the G0/G1phase. With Hoechst 33258 staining, apoptotic nuclear morphological changes were observed. Activation ofcaspase-3,-8 and -9 was increased and the pro-apoptotic factors Fas/FasL and Bax were upregulated, whilethe anti-apoptotic Bcl-2 was downregulated after treatment with β-elemene at both mRNA and protein levels.Furthermore, proliferation and colony formation by U87 cells were inhibited by β-elemene in a time and doesdependentmanner. Conclusions: Our results indicate that β-elemene inhibits growth and induces apoptosis ofhuman glioma cells in vitro. The induction of apoptosis appears to be related with the upregulation of Fas/FasLand Bax, activation of caspase-3,-8 and -9 and downregulation of Bcl-2, which then trigger major apoptoticcascades.     

Bcl-2 inhibits early apoptotic events and reveals post-mitotic multinucleation without affecting cell cycle arrest in human epithelial tumor cells exposed to etoposide

Defective apoptotic mechanisms are considered to play a role in both the development of malignancy and resistance to chemotherapeutic drugs. The Bcl-2 family of proteins regulate the cellular commitment to survive or die when challenged with various apoptotic stimuli. Purpose: The purpose of this study was to identify the point at which Bcl-2 interrupts the apoptotic cascade initiated following exposure of human tumor cells to etoposide. Methods: A stable Bcl-2-expressing HeLa-transfected clonal cell line, along with its control-vector-transfected counterpart, were utilized in this study. Following etoposide exposure, cells were examined for cell cycle arrest, formation of hyperdiploid cells, apoptotic DNA degradation, loss of plasma membrane integrity, levels of expression of members of the Bcl-2 protein family, caspase activation, degradation of poly(ADP-ribose) polymerase and movement of Bax from cytosol to cellular membrane fractions. Results: Caspase activation, poly(ADP-ribose) polymerase degradation and Bax membrane insertion were initiated rapidly following etoposide removal, concomitantly with cell cycle arrest. Whereas Bcl-2 had no effect on etoposide-induced cell arrest, it interrupted all aspects of apoptosis, including activation of caspases, poly(ADP-ribose) polymerase degradation, DNA fragmentation and loss of plasma membrane integrity. Surprisingly, Bcl-2 also blocked Bax membrane insertion. In addition, Bcl-2 also prevented the increase in cellular levels of Bak, Bax and Bcl-x_L, along with degradation of actin and Bax. However, inhibition of etoposide-induced apoptosis by Bcl-2 resulted in the accumulation of giant, multinucleated cells that eventually lost the ability to exclude trypan blue without apoptotic morphology or DNA degradation. Conclusions: These results indicate that biochemical apoptotic processes are initiated concomitant with etoposide-induced cell cycle arrest and are interrupted by Bcl-2 overexpression. However, the aberrant mitotic events induced by etoposide are sufficient to kill these cells even in the absence of apoptosis. Received: 1 September 1998 / Accepted: 3 November 1998     

奥沙利铂通过调控miRNA-7-5p/RAF-1促进胃癌SGC-7901细胞凋亡的研究

目的探讨奥沙利铂如何调控MAPK通路,抑制胃癌细胞的增殖。方法NCBI检索文献,利用TargetScan、StarBase和miRBase数据库,进行GO分析与KEGG通路富集,找到相关miRNAs,预测靶基因。应用Real-time PCR、MTT、Hoechst33258、流式细胞术、细胞划痕实验、Western blot等方法分析人胃癌SGC-7901细胞的增殖、细胞周期、侵袭及蛋白表达情况。结果胃癌细胞中miR-7-5p显著低表达,RAF1与miR-7-5p存在互靶关系。miR-7-5p mimics与奥沙利铂均可促进SGC-7901细胞的凋亡,提高G1期细胞百分率(P<0.05),降低侵袭、迁移速度。caspase3、caspase9蛋白表达升高,Bcl-2/Bax比值降低(P<0.05)。结论过表达miR-7-5p与奥沙利铂均可促进胃癌SGC-7901细胞的凋亡,提示奥沙利铂可能通过上调miRNA-7-5p促进SGC-7901细胞的凋亡,降低侵袭、迁移速度。