雷帕霉素诱导人肝癌细胞BEL-7402凋亡中Bcl-2作用研究

目的探讨雷帕霉素(rapamycin,RAPA)体外对肝癌BEL-7402细胞生长抑制及诱导细胞凋亡中的作用及Bcl-2变化在凋亡机制中的意义。方法以5、10、20、30、40和50nmol/L不同浓度的RAPA作用于体外培养的BEL-7402细胞,MTT法检测细胞生长抑制率,应用流式细胞仪检测细胞凋亡,Hoechst33258荧光染色法观察细胞凋亡时的形态学变化,Westernblot观察Bcl-2、Bcl-xl和bax等凋亡相关表达变化。结果RAPA可显著抑制BEL-7402细胞的生长,诱导细胞发生凋亡,并呈现出明显的量-效与时-效关系。RAPA作用肝癌细胞BEL-740248h后,在Hoechst33258荧光染色图片上可见核浓缩及核碎裂等典型的细胞凋亡特征,凋亡过程中伴有抗凋亡蛋白Bcl-2、Bcl-xl表达的降低和促凋亡蛋白bax上调。结论RAPA可能通过诱导抗凋亡蛋白Bcl-2、Bcl-xl表达的降低和促凋亡蛋白bax表达上调而诱导凋亡发生,抑制BEL-7402细胞的生长。     

miR-125a表达对肝癌HepG2细胞增殖、凋亡及细胞周期的影响分析

目的 探讨microRNA-125a（miR-125a）对肝癌HepG2细胞增殖、凋亡及细胞周期的影响。方法 采用实时荧光定量PCR（qPCR）法检测人肝癌HepG2细胞及人正常肝细胞7702中的miR-125a水平,同时采用真核表达载体pGenesil-1质粒制备过表达miR-125a的重组质粒pGenesil-miR-125a及表达随机序列的阴性对照pGenesil-NC,根据实验设计将HepG2细胞分为3组：空白对照组、阴性对照组和过表达组,其中空白对照组未进行转染,阴性对照组和过表达组分别成功转染pGenesil-NC和pGenesil-miR-125a,待3组转染24、48、72及96 h后采用qPCR法检测各组的miR-125a水平,噻唑盐比色法检测各组转染24、48、72及96 h的细胞增殖率,分别采用Hoechst染色和流式细胞术检测转染24、48 h后的凋亡指数和caspase-3活化率来评价凋亡情况,流式细胞仪Annexin V-FITC/PI双染流式细胞术检测各组转染48 h后的细胞周期,同时采用免疫印迹法检测转染48 h后对凋亡相关基因（Bcl-2、Bax和Cleaved caspase-3）表达的影响。结果 HepG2细胞中miR-125a水平为（0.24±0.06）,低于正常肝细胞7702细胞（P<0.05）;与阴性表达组相比,过表达组转染24、48、72及96 h的miR-125a水平升高,增殖率降低,差异有统计学意义（P<0.05）;与其余两组相比,过表达组转染后的凋亡指数、caspase-3活化率、G0/G1期细胞比例及Bax和Cleaved caspase-3水平均升高,S和G2/M期细胞比例及Bcl-2水平均降低,以上差异有统计学意义（P<0.05）。     

Dryocrassin ABBA Induces Apoptosis in Human Hepatocellular Carcinoma HepG2 Cells Through a Caspase-Dependent Mitochondrial Pathway

Background: Biological and pharmacological activities of dryocrassin ABBA, a phloroglucinol derivative extracted from Dryopteris crassirhizoma, have attracted attention. In this study, the apoptotic effect of dryocrassin ABBA on human hepatocellular carcinoma HepG2 cells was investigated. Materials and Methods: We tested the effects of dryocrassin ABBA on HepG2 in vitro by MTT, flow cytometry, real-time PCR, and Western blotting. KM male mice were used to detect the effect of dryocrassin ABBA on H22 cells in vivo. Results: Dryocrassin ABBA inhibited the growth of HepG2 cells in a concentration-dependent manner. After treatment with 25, 50, and 75 g/mL dryocrassin ABBA, the cell viability was 68%, 60% and 49%, respectively. Dryocrassin ABBA was able to induce apoptosis, measured by propidium iodide (PI)/annexin V-FITC double staining. The results of real-time PCR and Western ting showed that dryocrassin ABBA up-regulated p53 and Bax expression and inhibited Bcl-2 expression which led to an activation of caspase-3 and caspase-7 in the cytosol, and then induction of cell apoptosis. In vivo experiments also showed that dryocrassin ABBA treatment significantly suppressed tumor growth, without major side effects. Conclusions: Overall, these findings provide evidence that dryocrassin ABBA may induce apoptosis in human hepatocellular carcinoma cells through a caspase-mediated mitochondrial pathway.     

超声微泡造影剂增强TRAIL基因转染肝癌细胞的实验研究

目的 探讨采用超声辐照联合微泡造影剂增强重组表达质粒plRES-EGFP-sTRAIL转染肝癌细胞的有效性.方法 构建携带肿瘤坏死因子相关细胞凋亡诱导配体(TRAIL)基因及绿色荧光蛋白(GFP)的真核表达质粒pIBES-EGEP-sTRAIL,转染肝癌细胞HepG2,分为超声辐照联合微泡造影剂转染组、脂质体转染组、单纯微泡造影剂转染组及对照组.荧光显微镜检测GFP以评价转染效率,四甲基偶氮唑盐微量酶反应比色法(MTT)检测细胞生长抑制率,Hoechst33258荧光染色观察细胞形态变化,流式细胞术检测细胞凋亡率,Western blot检测TRAIL凋亡途径中关键凋亡分子caspase-8和caspase-3的蛋白变化.结果 超声辐照联合微泡造影剂可增强pIREs-EGFP-sTRAIL有效转染HepG2细胞,其转染效率与脂质体转染组、单纯微泡造影剂组及对照组比较差异均有统计学意义(P<0.05);携带sTRAIL基因的表达质粒能够激活caspase通路,促进肝癌细胞凋亡,有效抑制肝癌细胞生长.结论 构建的真核表达载体pIRES-EGFP-sTRAIL在肝癌细胞中能有效表达,联合超声微泡造影剂及低强度超声,可显著增强sTRAIL对肝癌细胞的增殖抑制及诱导凋亡作用.     

文殊兰叶氯仿提取物诱导NCI-H460细胞凋亡的研究

目的研究文殊兰叶氯仿提取物（CE）对非小细胞肺癌NCI-H460细胞增殖和凋亡的影响。方法通过MTT法检测CE对NCI-H460细胞的生长抑制作用;采用Hoechst 33258荧光染色法检测CE作用后凋亡细胞形态的变化;通过免疫细胞化学检测细胞凋亡相关蛋白Bcl-2和Bax的表达;采用流式细胞术（FCM）检测CE作用后对细胞周期的影响。结果CE抑制NCI-H460细胞增殖,其24、48、72 h的IC50分别为：（36.22 ±3.04）、（41.21±2.50）、（62.55±3.47） mg/L;荧光染色显示,经CE作用后的细胞出现细胞核裂解,染色质浓缩,产生凋亡小体;免疫细胞化学法显示CE能增强促进凋亡蛋白Bax和降低抑制凋亡蛋白Bcl-2的表达;FCM检测表明CE作用后的细胞被阻滞在G1/S期。结论CE在体外能有效地抑制NCI-H460细胞生长,其机制可能与改变细胞周期并诱导细胞凋亡有关。     

Cucurbitacin B induces apoptosis and S phase cell cycle arrest in BEL-7402 human hepatocellular carcinoma cells and is effective via oral administration

Cucurbitacin B is an anti-cancer drug candidate and its efficacy has been demonstrated in hepatocellular carcinoma (HCC). To explore its mechanism against HCC, BEL-7402 cells were treated with cucurbitacin B in vitro. Treatment with cucurbitacin B induced S phase arrest and apoptosis. The growth inhibition effect was associated with cyclin D1 and cdc-2 down regulations. Western blotting analysis of cell signaling molecules indicated that cucurbitacin B inhibited c-Raf activation without affecting STAT3 phosphorylation. Moreover, in vivo study demonstrated that cucurbitacin B is effective against BEL-7402 xenograft when administrated orally.     

亚砷酸钠对人肺癌Spc-A1细胞Bcl-2、Fas表达的影响

目的:探讨亚砷酸钠对人肺癌细胞株Spc-A1的抗癌机制。方法:用MTT法检测亚砷酸钠对Spc-A1细胞的增殖抑制作用;用Hoechst33258荧光染色法观察凋亡细胞的形态学改变;细胞凋亡率及相关蛋白Bcl-2和Fas的表达采用流式细胞仪测定。结果:亚砷酸钠对人肺癌细胞株Spc-A1的增殖具有一定程度的抑制作用。2μg/ml亚砷酸钠干预Spc-A1细胞12h、24h和48h后,在Hoechst荧光染色图片上可见细胞染色质浓缩及细胞核碎裂等典型的凋亡改变。给与1μg/ml、2μg/m l和4μg/ml亚砷酸钠作用Spc-A1细胞24h后,可以见到亚G1期凋亡峰,凋亡率随着药物浓度的增加明显增加。同时,流式细胞仪显示Bcl-2蛋白表达减少,而Fas蛋白表达增加。结论:亚砷酸钠对Spc-A1细胞的生长有明显的抑制作用,并可诱导细胞周期阻滞及细胞凋亡和坏死。Bcl-2的下调和Fas的上调可能是其中一种作用机制。     

Suppressive Effect of Sinomenine Combined with 5-Fluorouracil on Colon Carcinoma Cell Growth

It is reported that sinomenine (SIN) and 5-fluorouracil (5-FU) both are effective for colon cancer, but their cooperative suppressive effects and toxicity remain to be clarified in detail. This study aimed to determine suppressive effects and toxicity of sinomenine (SIN) plus 5-fluorouracil (5-FU) on LoVo colon carcinoma cellsin vitro and in vivo. CCK-8, Hoechst 33258 staining and an annexin V-FITC/PI apoptosis kit were used to detect suppressive effects. Western blotting was applied to investigate the essential mechanism underlying SIN and 5-FU-induced apoptosis. SIN or 5-FU or both were injected into nude mice, and then suppressive effects and side effects were observed. SIN plus 5-FU apparently inhibited the proliferation of LoVo cells and induced apoptosis. Moreover the united effects were stronger than individually (p<0.05). The results of annexin V-FITC /PI staining and Hoechst 33258 staining showed that the percentage of apoptotic cells induced by SIN and 5-FU combined or alone was significantly higher than the control group (p<0.05). Expression of Bax and Bcl-2 wasup-regulated and down-regulated respectively. SIN or 5-FU significantly inhibited effects on the volume of tumour xenografts and their combined suppressive effects were stronger (p<0.05). No obvious side effects were observed. It was apparent that the united effects of SIN and 5-FU on the growth of colorectal carcinoma LoVo cells in vitro and in vivo were superior to those using them individually, and it did not markedly increase the side effects of chemotherapy.     

The growth inhibition of hepatocellular and cholangiocellular carcinoma cells by gemcitabine and the roles of extracellular signal-regulated and checkpoint kinases

We examined the effects of gemcitabine, a pyrimidine analogue, on hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC) cells. After HCC cells (HepG2, Hep3B, HLF and PLC/PRF/5) and CCC cells (HuCCT-1) were treated with gemcitabine, cellular growth, cell cycle, nuclear morphology and activity of signaling molecules were evaluated by WST-8 assays, flow cytometry analysis, Hoechst 33258 staining and Western blotting, respectively. We found that gemcitabine significantly inhibited the growth of HCC and CCC cells in a dose- and time-dependent manner. Gemcitabine induced cell cycle arrest at the G1 phase, however, the sub-G1 fraction was not observed and nuclear morphology did not indicate the induction of apoptosis. Gemcitabine induced differential activation of checkpoint kinases, Chk2 and Chk1, in HCC and CCC cells, respectively and gemcitabine activated extracellular signal-regulated kinase (ERK)1/2 in both cell types. After the cells were pretreated with a MEK inhibitor U0126, activations of these checkpoint kinases were abrogated and the cell death was enhanced. These results demonstrate that gemcitabine inhibited the growth of HCC and CCC cells by cell cycle arrest without apoptosis and that the ERK/Chk1/2 signaling pathway was in part responsible for the resistance to gemcitabine. Our findings shed light on treating patients with HCC and CCC by gemcitabine, especially when combined with a MEK inhibitor and Chk1/2 inhibitors.     

姜黄素对胆管癌 MZ-Cha-1细胞凋亡的诱导作用

目的： 研究姜黄素对胆管癌MZ-Cha-1细胞凋亡的诱导作用。方法：用0、10、20、40 μg/mL姜黄素处理MZ-Cha-1 细胞12、24、36 h后，应用噻唑蓝 (MTT)检测姜黄素对MZ-Cha-1细胞的抑制情况，再选择10 μg/mL姜黄素处理MZ-Cha-1细胞24 h后应用Giemsa和Hoechst33258染色检测MZ-Cha-1细胞的凋亡情况，应用流式细胞术检测细胞周期分布。结果：与对照组相比较，各姜黄素处理组对胆管癌MZ-Cha-1细胞有明显的抑制作用，并显示出对剂量和时间的依赖效应 (P<0.05)。10 μg/mL姜黄素诱导处理24 h后，经Giemsa染色显示细胞体积缩小、核固缩、染色质凝聚等显著的凋亡特征；细胞核经Hoechst33258 染色出现浓染致密的固缩形态和颗粒状荧光；细胞周期检测出现细胞被阻滞在G0/G1期，G2/M期细胞较对照组显著减少 (P<0.05)。结论：姜黄素能够有效诱导人胆管癌MZ-Cha-1细胞的凋亡。     

AG490 在膀胱癌中的抗癌效应及其机制

 目的 观察JAK2激酶抑制剂AG490对膀胱癌细胞增殖和凋亡的影响，并探讨其抗癌机制。方法 应用不同剂量AG490处理膀胱癌细胞系BIU-87，台盼蓝排斥试验检测细胞活力，噻唑蓝比色试验检测细胞增殖，克隆形成试验进一步检测膀胱癌细胞系干细胞对药物的敏感性，Hoechst33258／PI荧光双染检测细胞凋亡特征，流式细胞仪检测细胞周期和凋亡，Western blot检测州AK2、STAT3、p-STAT3、Cyclin D1、bcl—xL蛋白表达水平；并建立膀胱癌荷瘤模型，观察AG490体内抗肿瘤作用。结果 AG490明显抑制膀胱癌细胞增殖和干细胞克隆形成，使细胞周期阻滞，促进膀胱癌细胞凋亡；并可使p-JAK2、STAT3、p-STAT3、Cyclin D1、bcl-xL蛋白表达水平明显下降。裸鼠移植瘤在AG490的作用下明显缩小。结论 AG490通过阻断STAT3信号通路，抑制膀胱癌细胞的增殖，促进其调亡。     

慢病毒载体介导端粒酶逆转录酶小干扰RNA治疗肝癌的实验研究

目的 探讨慢病毒介导的端粒酶逆转录酶(hTERT)小干扰RNA(siRNA)对肝癌细胞生长的影响.方法 构建携带hTERT siRNA的慢病毒表达载体,在体外转染人肝癌HepG2细胞系,以MTT法测定细胞生长变化,半定量逆转录聚合酶链反应(RT-PCR)检测hTERT mRNA的表达.将转染hTERT siRNA的HepG2细胞,接种于裸鼠腋窝皮下,观察移植瘤生长情况.取移植瘤组织,常规HE染色,行组织学观察,应用原位末端标记(TUNEL)技术检测细胞凋亡情况.结果 hTERT siRNA转染HepG2细胞后,随着时间的延长,对细胞增殖的抑制作用逐渐增强,到第8天,干扰组细胞抑制率为57.5%,与对照组比较,差异有统计学意义(P<0.01).RT-PCR产物凝胶电泳图显示,hTERT siRNA转染后,肿瘤细胞的端粒酶活性明显下降.转染后72 h,干扰组hTERT mRNA的表达水平为0.035±0.007,明显低于空载体对照组(0.151±0.016)和空白对照组(0.155±0.014,均P<0.01).转染细胞皮下接种后,干扰组的肿瘤生长速度明显慢于两个对照组,随着时间的延长,差异越来越明显.移植瘤组织常规HE染色显示,组织坏死增多,周围炎性细胞浸润.TUNEL检测结果显示,细胞凋亡增多,增殖减慢.结论 慢病毒介导的hTERT siRNA转染能明显抑制肝癌细胞的生长.     

贝母素乙通过调控PI3K/Akt信号通路诱导乳腺癌MCF-7细胞凋亡

目的：探究贝母素乙（Peiminine）对乳腺癌细胞MCF-7细胞凋亡的影响及其可能作用机制。方法：采用不同浓度贝母素乙或联合PI3K抑制剂LY294002干预MCF-7细胞,MTT法检测细胞增殖能力;Hoechst33258染色和Annexin V-FITC/PI流式细胞术检测细胞凋亡情况;JC-1染色法检测细胞线粒体膜电位变化;Western blotting检测细胞中PI3K(p110α)、Akt、p-Akt(ser473)、Bad、Bax、Bcl-2、cleaved-Caspase-3以及线粒体和胞浆中细胞色素C(Cyt C)等蛋白表达水平。结果：贝母素乙可呈时间-浓度依赖性抑制MCF-7细胞增殖,诱导细胞出现凋亡形态改变,促进细胞凋亡,并降低线粒体膜电位,上调细胞中Bad、Bax、cleaved-Caspase-3及胞浆中Cyt C蛋白表达水平,下调PI3K(p110α)、p-Akt、Bcl-2和线粒体中Cyt C蛋白表达水平,而Akt蛋白表达水平无显著变化。然而,联合LY294002干预可增强贝母素乙对MCF-7细胞凋亡的促进作用。结论：贝母素乙可诱导乳腺癌MCF-7细胞凋...     

Parthenolide-Induced Apoptosis,Autophagy and Suppression of Proliferation in HepG2 Cells

Purpose: To investigate the anticancer effects and underlying mechanisms of parthenolide on HepG2 human hepatocellular carcinoma cells. Materials and Methods: Cell viability was assessed by MTT assay and cell apoptosis through DAPI, TUNEL staining and Western blotting. Monodansylcadaverin(MDC) and AO staining were used to detect cell autophagy. Cell proliferation was assessed by Ki67 immunofluorescence staining. Results: Parthenolide induced growth inhibition in HepG2 cells. DAPI and TUNEL staining showed that parthenolidecould increase the number of apoptotic nuclei, while reducing the expression of the anti-apoptotic protein Bcl-2 and elevating the expression of related proteins, like p53, Bax, cleaved caspase9 and cleaved caspase3. Parthenolide could induce autophagy in HepG2 cells and inhibited the expression of proliferation-related gene, Ki-67. Conclusions: Parthenolide can exert anti-cancer effects by inducing cell apoptosis, activating autophagy and inhibiting cell proliferation.     

反义STAT3对肿瘤细胞增殖抑制和诱导凋亡的作用

背景与目的：研究表明STAT3蛋白在多种肿瘤组织或细胞中高表达。STAT3蛋白可能参与了肿瘤的形成和发生。本文拟研究STAT3蛋白在鼠黑色素瘤细胞B16、人肝癌细胞SMMC-7721、人肝癌细胞HepG-2、人肺癌细胞A549、人宫颈癌HeLa细胞株中表达和活化情况,研究反义STAT3寡核苷酸对B16细胞的增殖抑制和促凋亡作用,为进一步反义药物设计及应用于辐射领域作前期研究。方法：利用Western blot检测所选几种肿瘤细胞的STAT3蛋白表达和磷酸化情况、反义干涉前后B16细胞中STAT3蛋白表达和磷酸化活化的变化情况,MTT法检测细胞增殖变化,利用Hoechst33258染色对细胞凋亡作形态学上的观察．用Annexin V／PI复染结合流式细胞仪检测细胞早期凋亡。结果：所研究的几种肿瘤细胞中均可检测到STAT3蛋白的高表达和磷酸化;反义STAT3转染后,B16细胞中STAT3蛋白的表达量及磷酸化水平均有下降;转染后48h,在0到200nmol／L范围内,反义核酸浓度越高。对B16细胞的增殖抑制效应越强,但是并不能够完全抑制肿瘤细胞的增殖（P〈0．01）。寡核苷酸浓度超过250nmol／L时．正义对照也表现出一定的增殖抑制作用（P〈0．05）;转染后不同时间内检测,结果表明转染后24h反义核酸即开始表现出一定的增殖抑制效应,48h起表现出明显的抑制效应;反义转染后,检测各组细胞早期凋亡率：对照组早期凋亡率为5．52％．反义400、800、2000nmol／L组早期凋亡率分别为8．22％、9．99％．16．97％,正义对照400、800、2000nmol／L组早期凋亡率分别为5．87％、5．36％、13．31％。统计分析表明反义寡核苷酸与B16细胞作用后能够促进细胞的早期凋亡（P〈0．01）,正义低浓度转染组（400、800nmol／L组）与对照组无明显差别（P〉0．05）,而对照组与正义2000nmol／L组相比,细胞的早期凋亡率也有统计学差异（P〈0．01）。结论：B16、SMMC-7721、HepG-2、A549、HeLa等恶性肿瘤细胞株中STAT3蛋白高表达并且可检测到磷酸化水平的增高;反义转染后B16细胞中STAT3蛋白的表达和磷酸化水平降低．细胞增殖受到明显抑制。细胞的凋亡增加．表明STAT3可能成为肿瘤治疗新的分子靶位。     

STAT3-mediated activation of mitochondrial pathway contributes to antitumor effect of dihydrotanshinone I in esophageal squamous cell carcinoma cells

BACKGROUNDEsophageal squamous cell carcinoma (ESCC) is one of the most common malignancies with a poor prognosis, and its treatment remains a great challenge. Dihydrotanshinone I (DHTS) has been reported to exert antitumor effect in many cancers. However, the role of DHTS in ESCC remains unclear. AIMTo investigate the antitumor effect of DHTS in ESCC and the underlying mechanisms.METHODSCCK-8 assay and cell cycle analysis were used to detect proliferation and cell cycle in ESCC cells. Annexin V-PE/7-AAD double staining assay and Hoechst 33258 staining were used to detect apoptosis in ESCC cells. Western blot was used to detect the expression of proteins associated with the mitochondrial pathway. Immunofluorescence was used to detect the expression of phosphorylated STAT3 (pSTAT3) in DHTS-treated ESCC cells. ESCC cells with STAT3 knockdown and overexpression were constructed to verify the role of STAT3 in DHTS induced apoptosis. A xenograft tumor model in nude mice was used to evaluate the antitumor effect of DHTS in vivo.RESULTSAfter treatment with DHTS, the proliferation of ESCC cells was inhibited in a dose- and time-dependent manner. Moreover, DHTS induced cell cycle arrest in the G0/1 phase. Annexin V-PE/7-AAD double staining assay and Hoechst 33258 staining revealed that DHTS induced obvious apoptosis in KYSE30 and Eca109 cells. At the molecular level, DHTS treatment reduced the expression of pSTAT3 and anti-apoptotic proteins, while increasing the expression of pro-apoptotic proteins in ESCC cells. STAT3 knockdown in ESCC cells markedly promoted the activation of the mitochondrial pathway while STAT3 overexpression blocked the activation of the mitochondrial pathway. Additionally, DHTS inhibited tumor cell proliferation and induced apoptosis in a xenograft tumor mouse model.CONCLUSIONDHTS exerts antitumor effect in ESCC via STAT3-mediated activation of the mitochondrial pathway. DHTS may be a novel therapeutic agent for ESCC.     

携带mda-7基因的复制缺陷型腺病毒通过促进线粒体释放促凋亡蛋白杀伤肝癌细胞

目的 探讨黑色素瘤分化相关基因7/白介素24(mda-7/IL-24)基因选择性杀伤肝癌细胞的机制.方法 应用携带mda-7基因的复制缺陷型腺病毒Ad.mda-7感染正常肝细胞L02和肝癌细胞HepG2.通过逆转录聚合酶链反应(RT-PCR)、酶联免疫吸附实验(ELISA)及Western blot方法,观察mda-7/IL-24基因的表达;应用Hoeehst染色和流式细胞仪观察mda-7/IL-24对肝癌细胞的杀伤作用;采用RT-PCR和Western blot方法,观察Bcl-2家族和caspase-9基因表达的变化,分离不同感染时点细胞内线粒体和胞浆蛋白,并检测线粒体释放促凋亡蛋白细胞色素C(Cyt-C)和Smac/DIABLO的变化过程.结果 Ad.mda-7能介导mda-7/IL-24在两种细胞株中的高效表达.能选择性杀伤肝癌细胞,感染24 h后,HepG2细胞凋亡率为24.0%±4.6%,而对正常的肝细胞没有影响.RT-PCR和亚细胞蛋白的分析结果显示,胞浆内Bel-2和Bcl-xL的表达在HepG2细胞中明显下降,而在L02细胞中的表达无变化,Bax在肝癌细胞中的表达明显增强,Bak的表达无变化;Ad.mda-7能促进细胞线粒体释放cyt-C和Smac/DIABLO蛋白,并促进caspase-9的表达.结论 Ad.mda-7能选择性杀伤肝癌细胞HepG2,通过促进线粒体促凋亡蛋白的释放而诱导肝癌细胞凋亡.     

原花青素诱导人肺癌细胞A549凋亡作用研究

目的研究原花青素对人肺癌细胞株A549凋亡的影响并探讨其抗癌机制。方法以不同浓度的原花青素与人肺癌细胞株A549细胞共同培养,MTT法测定细胞增殖;Hoechst 33258/PI染色荧光显微镜下观察凋亡细胞形态学变化;DNA琼脂糖凝胶电泳检测凋亡特异性梯状DNA条带;Western blot检测细胞凋亡相关蛋白Caspase-9、Caspase-3和Bcl-2表达的变化。结果原花青素可体外抑制肺癌A549细胞生长,抑制率呈浓度、时间依赖性,药物浓度达25 mg/L时作用48小时,A549细胞皱缩、细胞核碎裂成碎片,呈现典型凋亡改变;琼脂糖凝胶电泳可见凋亡细胞典型的梯状DNA条带;Western blot检测结果显示,Caspase-9、Caspase-3蛋白表达量与药物浓度的增加呈增加趋势,Bcl-2与药物浓度呈负相关。结论原花青素能通过诱导细胞凋亡进而抑制人肺癌细胞增殖,其凋亡机制可能与线粒体通路有关。     

Downregulation of survivin expression and elevation of caspase-3 activity involved in pitavastatin-induced HepG 2 cell apoptosis

The aim of the present study was to research the apoptosis of human hepatocellular carcinoma cell line HepG 2 induced by pitavastatin. HepG 2 cells were treated with increasing doses of pitavastatin or with mevalonic acid for 48 h. The proliferation of cells was detected with WST-8. The morphology of the nucleus was observed under a microscope by Hoechst 33258 staining. The apoptosis peaks were examined by flow cytometry. The expression of survivin mRNA was examined with RT-PCR. The caspase-3 activity was detected with caspase-3 colorimetric protease assay. We found that growth inhibitory effects were observed for treatment with pitavastatin at 10-50 microM. Pitavastatin at 10 microM induced granular apoptotic bodies of HepG 2 cells. Furthermore, pitavastatin at 10 microM increased the appearance of sub-G1 population of HepG 2 cells. Finally, pitavastatin at 10 microM downregulated the expression of survivin mRNA and upregulated the caspase-3 activity, which was clearly related to the HMG-CoA reductase activity. These results suggest that pitavastatin at 10 microM induces apoptosis of HepG 2 cells, which is associated with the decreased expression of survivin mRNA and increased caspase-3 activity of HepG 2 cells.