Piroxicam and C-phycocyanin mediated apoptosis in 1,2-dimethylhydrazine dihydrochloride induced colon carcinogenesis: exploring the mitochondrial pathway

Apoptosis is a synchronized procedure of cell death that is regulated by caspases and proapoptotic proteins. During apoptosis, translocation of cytochrome c, an electron carrier, from mitochondria into the cytosol is regulated by Bcl-2 family members. Cytochrome c in association with an apoptotic protease activating factor (Apaf), a proapoptotic protein essential for cell differentiation and procaspase-9 form the apoptosome complex, which consecutively activates effector caspase, caspase-3, and coordinate the implementation of apoptosis. In the current study, an attempt has been made to gain insight into piroxicam, a traditional nonsteroidal antiinflammatory drug and c-phycocyanin, a biliprotein from Spirulina platensis (cyanobacterium) mediated apoptosis in DMH-induced colon cancer. Male Sprague-Dawley rats were segregated into 5 groups: control, DMH, DMH + piroxicam, DMH + c-phycocyanin, and DMH + piroxicam + c-phycocyanin. Results illustrated that piroxicam and c-phycocyanin treatments stimulate cytochrome c release by downregulating the Bcl-2 (an antiapoptotic protein) expression significantly, while promoting the level of Bax (a proapoptotic protein), thereby activating caspases (caspases-9 and -3) and Apaf-1. The outcomes of the present study clearly signify that piroxicam and c-phycocyanin may mediate mitochondrial-dependent apoptosis in DMH-induced colon cancer. Moreover, apoptosis induction was more apparent in the combination regimen of piroxicam and c-phycocyanin than the individual drugs alone.     

Piroxicam and C-Phycocyanin Mediated Apoptosis in 1,2-Dimethylhydrazine Dihydrochloride Induced Colon Carcinogenesis: Exploring the Mitochondrial Pathway

Apoptosis is a synchronized procedure of cell death that is regulated by caspases and proapoptotic proteins. During apoptosis, translocation of cytochrome c, an electron carrier, from mitochondria into the cytosol is regulated by Bcl-2 family members. Cytochrome c in association with an apoptotic protease activating factor (Apaf), a proapoptotic protein essential for cell differentiation and procaspase-9 form the apoptosome complex, which consecutively activates effector caspase, caspase-3, and coordinate the implementation of apoptosis. In the current study, an attempt has been made to gain insight into piroxicam, a traditional nonsteroidal antiinflammatory drug and c-phycocyanin, a biliprotein from Spirulina platensis (cyanobacterium) mediated apoptosis in DMH-induced colon cancer. Male Sprague-Dawley rats were segregated into 5 groups: control, DMH, DMH + piroxicam, DMH + c-phycocyanin, and DMH + piroxicam + c-phycocyanin. Results illustrated that piroxicam and c-phycocyanin treatments stimulate cytochrome c release by downregulating the Bcl-2 (an antiapoptotic protein) expression significantly, while promoting the level of Bax (a proapoptotic protein), thereby activating caspases (caspases-9 and -3) and Apaf-1. The outcomes of the present study clearly signify that piroxicam and c-phycocyanin may mediate mitochondrial-dependent apoptosis in DMH-induced colon cancer. Moreover, apoptosis induction was more apparent in the combination regimen of piroxicam and c-phycocyanin than the individual drugs alone.     

Synergistic Induction of Apoptosis by Quercetin and Curcumin in Chronic Myeloid Leukemia (K562) Cells

Chronic myeloid leukemia is a major hematopoietic malignancy characterized by expansion of myeloid cells. In this study, we have investigated whether quercetin, curcumin and their combination induce apoptosis and inhibit growth of K562 cells. We have observed that quercetin and curcumin combination induced apoptosis accompanied by increased ROS and decreased GSH levels as well as loss of mitochondrial membrane potential. Our mRNA and protein expression results suggested that cytochrome c was released from mitochondria causing PARP and caspase-9 cleavages, the hallmarks of mitochondrial apoptotic pathway. We believe that triggering of apoptosis is mostly via mitochondrial pathway and ROS generation may induce impairment of mitochondrial membrane potential. The use of quercetin and curcumin combination potentiates individual apoptotic effects of the polyphenols and reduces their effective dose thereby preventing potential toxic effects on normal cells. Additional preclinical studies and clinical trials are certainly required to further validate their usefulness as potent anticancer agents.     

Resveratrol protects against oxidized LDL-induced breakage of the blood-brain barrier by lessening disruption of tight junctions and apoptotic insults to mouse cerebrovascular endothelial cells

Cerebrovascular endothelial cells (CEC) comprise the blood-brain barrier (BBB). In a previous study, we showed that oxidized LDL (oxLDL) can induce apoptosis of mouse CEC. Resveratrol possesses chemopreventive potential. This study aimed to evaluate the effects of resveratrol on oxLDL-induced insults to mouse CEC and its possible mechanisms. Exposure of mouse CEC to 200 μmol/L oxLDL for 1 h did not cause cell death but significantly altered the permeability and transendothelial electrical resistance of the cell monolayer. However, resveratrol completely normalized such injury. As for the mechanisms, resveratrol completely protected oxLDL-induced disruption of F-actin and microtubule cytoskeletons as well as occludin and zona occludens-1 (ZO-1) tight junctions. The oxLDL-induced decreases in the mitochondrial membrane potential and intracellular ATP levels were normalized by resveratrol. Exposure of mouse CEC to 200 μmol/L oxLDL for 24 h elevated oxidative stress and simultaneously induced cell apoptosis. However, resveratrol partially protected against oxLDL-induced CEC apoptosis. The oxLDL-induced alterations in levels of Bcl-2, Bax, and cytochrome c were completely normalized by resveratrol. Consequently, resveratrol partially decreased oxLDL-induced activation of caspases-9 and -3. Therefore, in this study, we show that resveratrol can protect against oxLDL-induced damage of the BBB through protecting disruption of the tight junction structure and apoptotic insults to CEC.     

Bromelain-induced apoptosis in GI-101A breast cancer cells

Bromelain is a proteolytic enzyme extracted from the stems and the immature fruits of pineapple that was found to be antitumorigenic in different in vitro models. Bromelain has been reported to promote apoptosis, particularly in breast cancer cells, with the up-regulation of c-Jun N-terminal kinase and p38 kinase. Our study was designed to determine if bromelain could induce apoptosis in GI-101A breast cancer cells. GI-101A cells were treated with increasing concentrations of bromelain for 24 hours. The effect of bromelain for inducing cell death via activation of the apoptosis mechanism in GI-101A cells was further determined by using caspase-9 and caspase-3 assays along with the M30-Apoptosense assay to measure cytokeratin 18 (CK18) levels in the cytoplasm of the cultured cancer cells. A dose-dependent increase in the activities of caspase-9 and caspase-3 coinciding with elevation of CK18 levels was found in bromelain-treated cells compared with control cells. Furthermore, the apoptosis induction by bromelain was confirmed by DNA fragmentation analysis and 4,6'-diamino-2-phenylindole dihydrochloride fluorescence staining of the nucleus. Our results indicate an increase in apoptosis-related cell death in breast cancer cells with increasing concentrations of bromelain.     

Deoxycholic acid can induce apoptosis in the human colon cancer cell line HCT116 in the absence of Bax

In the human colon cancer cells HCT116, deoxycholic acid (DCA) induces apoptosis via the mitochondrial pathway by triggering the release of mitochondrial factors such as cytochrome c. To elucidate if Bax, a proapoptotic member of the Bcl-2 family known to trigger cytochrome c release in response to various types of apoptotic stimuli, is involved in DCA-induced apoptosis in HCT116 cells, we analyzed DCA-induced apoptosis in Bax-knockout (Bax(-/-)) HCT116 cells. Cytochrome c release and caspase-9 activation were detectable after 5 min in both Bax(-/-) and Bax(+/-) HCT116 cells. Caspase-3 and caspase-8 activation was observed after 15 and 30 min, respectively. Bax(-/-) cells were protected from apoptosis by treating them with ursodeoxycholic acid for 12 h prior to DCA treatment. These results are consistent with our previous observations that were obtained by using wild-type HCT116 cells and suggest that Bax is not indispensable for DCA-induced apoptosis in HCT116 cells.     

Mechanism of activation of caspase cascade during beta-carotene-induced apoptosis in human tumor cells

In this study, we examined possible mechanisms of caspase activation during carotenoid-induced apoptosis in tumor cells. We found that beta-Carotene induces apoptosis by the activation of caspase-3 in human leukemia (HL-60), colon adenocarcinoma (HT-29) as well as melanoma (SK-MEL-2) cell lines. This activation is dose dependent and follows that of caspase-8 and caspase-9. Although caspase-8 cleavage is an early event, reaching its maximum activation at 3 h, caspase-9 reaches its maximum activation only at 6 h. The addition of IETD-CHO, a caspase-8-specific inhibitor, completely prevents beta-Carotene-induced apoptosis, whereas only a partial prevention was observed in the presence of LEHD-CHO, a caspase-9-specific inhibitor. beta-Carotene activates caspase-9 via cytochrome c release from mitochondria and loss of mitochondrial membrane potential (Dym). Concomitantly, a dose-dependent decrease in the antiapoptotic protein Bcl-2 and a dose-dependent increase in the cleaved form of BID (t-BID) are observed. Moreover, NF-kB activation is involved in beta-Carotene-induced caspase cascade. These results support a pharmacological role for beta-Carotene as a candidate antitumor agent and show a possible sequence of molecular events by which this molecule may induce apoptosis in tumor cells.     

Apelin抑制小鼠成骨细胞MC3T3-E1凋亡

目的观察Apelin对小鼠成骨细胞MC3T3-E1凋亡的作用。方法 ELISA和吖啶橙/溴乙啶（AO/EB）染色法检测细胞凋亡,Western blot检测细胞Bcl-2和Bax表达以及cytochrome c的分泌,通过荧光素（AFC、AMC）标记的底物来检测活性。结果 Apelin抑制无血清饥饿诱导的MC3T3-E1细胞凋亡;Apelin抑制无血清饥饿诱导的cyto-chrome c的分泌和caspase-3、caspase-8c、aspase-9的活化;Apelin抑制地塞米松或肿瘤坏死因子-α（TNF-α）诱导的MC3T3-E1细胞凋亡。结论 Apelin可抑制成骨细胞凋亡。     

Myricetin Protects Against Cytokine-Induced Cell Death in RIN-m5f β Cells

Abstract Cytokine-induced cell death is recognized as a major cause of progressive β-cell loss. Tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and interferon γ (IFN-γ) in combination trigger a series of events that lead to β-cell death. In the past few decades, the use of myricetin as an anti-inflammatory and cytoprotective agent has gained much attention. The present study focused on the protective roles of myricetin against cytokine-induced cell death in insulin-secreting RIN-m5f β cells. The results showed that myricetin (especially at concentrations of 10?μM and 20?μM) increased cell viability and decreased cell apoptosis induced by the cytokine mixture of TNF-α (10?ng/mL), IL-1β (5?ng/mL), and IFN-γ (1000?IU/mL) for 3 days. Moreover, the cytokines increased the total and p65 subunit levels of nuclear factor κB, decreased inhibitor κB α levels, stimulated the accumulation of nitric oxide, increased cytochrome c release from mitochondria, and induced reactive oxygen species generation; myricetin (especially at the concentration of 20?μM) abolished all of these parameters. These results suggest that myricetin might have therapeutic value for preventing β-cell death.     

Induction of apoptosis by epigallocatechin-3-gallate via mitochondrial signal transduction pathway

PURPOSE: To elucidate the apoptosis induction of Epigallocatechin-3-gallate (EGCG) on nasopharyngeal carcinoma (NPC) cells via mitochondrial signal transduction pathway regulated by EB-virus-encoded latent membrane protein 1 (LMP1). METHODS: The survival rates of pTet-on-LMP1 HNE2 cells after the EGCG treatment were determined by MTT assay. Induction of apoptosis in pTet-on-LMP1 HNE2 cells after the EGCG treatment was analyzed by agarose gel electrophoresis. The activity of caspase-9 was determined by ApoAlert Caspase-9 Fluorescent Assay kit after the EGCG treatment. The protein expressions of cytochrome c and Bcl-2 were analyzed by Western blotting after the EGCG treatment. RESULTS: EGCG inhibited the survival rates of pTet-on-LMP1 HNE2 cells and induced apoptosis of pTet-on-LMP1 HNE2 cells. EGCG raised the activities of caspase-9, enhanced the releasing of cytochrome c from the mitochondria, and suppressed the protein expression of Bcl-2. These are the key targets on the mitochondrial signal transduction pathway in apoptosis. CONCLUSIONS: EGCG inhibited the survival rate of NPC cells and induced apoptosis of NPC cells via the mitochondrial signal transduction pathway. This study suggests that the interference effect of EGCG on targets of the mitochondrial signal transduction pathway plays an important role in the anticancer function.     

The role of the mitochondria in apoptosis induced by 7beta-hydroxycholesterol and cholesterol-5beta,6beta-epoxide

Oxysterols are oxygenated derivatives of cholesterol that may be formed endogenously or absorbed from the diet. Significant amounts of oxysterols have frequently been identified in foods of animal origin, in particular highly processed foods. To date, oxysterols have been shown to possess diverse biological activities; however, recent attention has focused on their potential role in the development of atherosclerosis. Oxysterols have been reported to induce apoptosis in cells of the arterial wall, a primary process in the development of atheroma. The aim of the present study was to identify the role of the mitochondria in the apoptotic pathways induced by the oxysterols 7beta-hydroxycholesterol (7beta-OH) and cholesterol-5beta,6beta-epoxide (beta-epoxide) in U937 cells. To this end, we investigated the effects of these oxysterols on mitochondrial membrane potential, caspase-8 activity, the mitochondrial permeability transition pore and cytochrome c release. 7beta-OH-induced apoptosis was associated with a loss in mitochondrial membrane potential after 2 h, accompanied by cytochrome c release from the mitochondria into the cytosol after 16 h. Pre-treatment with a range of inhibitors of the mitochondrial permeability transition pore protected against 7beta-OH-induced cell death. In contrast, beta-epoxide induced a slight increase in caspase-8 activity but had no effect on mitochondrial membrane potential or cytochrome c release. The present results confirm that 7beta-OH-induced apoptosis occurs via the mitochondrial pathway and highlights differences in the apoptotic pathways induced by 7beta-OH and beta-epoxide in U937 cells.     

Genistein-induced apoptosis of p815 mastocytoma cells is mediated by Bax and augmented by a proteasome inhibitor,lactacystin

Although genistein has been demonstrated to induce apoptosis of various cells, there is no report of its effect on mast cell proliferation. Here we show that genistein reduced the viability of mast cell tumor cell lines, p815 and RBL-2H, but not of a human mast cell line, HMC-1. Further investigation on its growth-inhibitory mechanism was undertaken on p815 mastocytoma cells. Genistein induced G2/M arrest and subsequent apoptotic death. p815 cells undergoing apoptosis showed many apoptotic manifestations, such as reduction of mitochondrial membrane potential, release of cytochrome c to cytosol, translocation of apoptosis-inducing factor to nucleus, activation of caspase-3, nuclear condensation, and generation of DNA fragmentation. Genistein treatment resulted in the increase of Bax expression and its translocation into mitochondria, whereas expression levels of Bcl-2 remained unchanged. Proteasome activity decreased at the early time points after genistein treatment, but thereafter it fluctuated at increased levels. A proteasome inhibitor, lactacystin, potentiated the induction of apoptosis. Taken together, genistein-induced apoptosis of p815 mastocytoma cells is at least in part mediated by proteasome, Bax, apoptosis-inducing factor, and caspase and augmented by cotreatment with a proteasome inhibitor, lactacystin.     

Biphasic Regulation of Cell Death and Survival by Hydrophobic Bile Acids in HCT116 Cells

A secondary bile acid, namely, deoxycholic acid (DCA), has been known to promote colon tumors; on the other hand, it also induces apoptosis in several human colon cancer cell lines. A hydrophobic primary bile acid, namely, chenodeoxycholic acid (CDCA), exhibits a similar property of apoptosis induction; DCA and CDCA also trigger some specific intracellular signal pathways in the human colon cancer cell line HCT116. In this article, we report that hydrophobic bile acids induce different cellular responses depending on their concentration, that is, a sublethal concentration of hydrophobic bile acids can suppress the apoptosis induced by a higher concentration of DCA. Pretreatment with DCA or CDCA at a concentration of ≤ 200 μ M for 8 h suppressed the apoptosis induced by 500 μ M DCA in HCT116 cells. Under this condition, the association of caspase-9 and Apaf-1 and subsequent activation of caspase-9 were inhibited, but the release of cytochrome c from the mitochondria was not. At 200 μ M, DCA and CDCA induced the phosphorylation of Akt and ERK1/2, although these phosphorylations do not appear to be indispensable for the cytoprotection. It is interpreted that prolonged exposure to sublethal concentrations of hydrophobic bile acids induces resistance to apoptosis, leading to promotion of colorectal tumorigenesis.     

Synergetic Inhibition of Human Colorectal Cancer Cells by Combining Polyyne-Enriched Fraction from Oplopanax elatus and Irinotecan

Although irinotecan is an important anticancer drug for treating colorectal cancer, its dose-dependent side effects limited its clinical application. Thus, it’s important to develop low-toxic candidates to enhance the efficacy of irinotecan. Polyynes from genus Oplopanax were reported to possess potential anticancer effects on colorectal cancer. Hereby, we evaluated the synergetic inhibition of human colorectal cancer cells by combining polyyne-enriched fraction from Oplopanax elatus (the dichloromethane fraction of Oplopanax elatus, OED) and irinotecan. The results showed that 5 μg/ml of OED combined with 40 μM of irinotecan possessed significant synergetic inhibition on SW-480 cells with a combination index (CI) of 0.56. Besides, the percentage of apoptotic cells was significantly increased from 69.57% (40 μM of irinotecan) or 72.7% (5 μg/ml of OED) to 95.6% after treatment of OED combined with irinotecan (OCI), suggesting OED and irinotecan possess the synergistic apoptotic effect (P?P?相似文献   

全氟辛烷磺酸盐通过线粒体途径诱导N9细胞凋亡

目的 以小胶质细胞株(N9)作为靶细胞,观察全氟辛烷磺酸盐(PFOS)通过线粒体途径诱发N9细胞凋亡效应。方法 设定5、10、50、100、200 μmol/L PFOS染毒组及对照组。PFOS染毒24 h后流式细胞术分析凋亡细胞率,罗丹明123检测线粒体膜电位,荧光定量PCR检测染毒24 h后凋亡相关基因p53、Bax、Bcl-2、caspase-3和caspase-9表达。结果 与对照组(2.24%)比较,50、100、200 μmol/L PFOS组细胞凋亡率(分别为20.81%、33.26%、48.72%)均增加(P<0.05);PFOS染毒降低了线粒体膜电位,200 μmol/L组细胞出现明显核周小斑点状荧光;此外,随剂量增加,PFOS染毒组p53、Bax、caspase-3和caspase-9基因表达水平呈上升趋势,Bcl-2表达水平呈下降趋势,但未见浓度依赖性。结论 PFOS暴露可破坏神经小胶质细胞自稳态,破坏线粒体,影响凋亡相关基因表达,诱导神经细胞凋亡。     

二甲基甲酰胺通过活性氧介导线粒体通路诱导H9c2心肌细胞凋亡研究

目的 初步探讨二甲基甲酰胺（dimethylformamide,DMF）是否通过线粒体通路致H9c2心肌细胞凋亡及可能机制。方法 H9c2心肌细胞体外培养,分组给予不同处理：正常对照组,N-乙酰半胱氨酸（N-acetyl-L-cysteine,NAC）（4 mmol/L）组,DMF（200 mmol/L）组,NAC（4 mmol/L）+DMF（200 mmol/L）组,24 h后使用免疫荧光细胞化学法（immune-fluorescence cytochemistry,IFC）检测细胞内细胞色素C（cytochrome C,Cyt-c）定位,蛋白免疫印迹法检测胞浆Cyt-c、Bcl-2、Cleaved caspse-3水平。结果 IFC观察发现,正常对照及NAC组Cyt-c呈点状或斑块状分布于胞浆,DMF作用24 h导致Cyt-c弥散分布于胞浆,而NAC可抑制DMF的这种作用;蛋白免疫印迹结果表明,Cyt-c蛋白水平组间差异具有统计学意义（F=26.14,P<0.001）,与对照组相比,DMF组Cyt-c水平升高,NAC+DMF组较DMF组Cyt-c水平降低,差异均有统计学意义（均有P<0.001）;Bcl-2蛋白水平组间差异具有统计学意义（F=28.92,P<0.001）,与对照组相比,DMF组Bcl-2蛋白水平降低,与DMF组相比,NAC+DMF组Bcl-2蛋白水平升高,差异均有统计学意义（均有P<0.001）;Cleaved caspase-3蛋白水平组间差异具有统计学意义（F=28.98,P<0.001））,与对照组相比,DMF组Cleaved caspase-3水平上升,NAC+DMF组较DMF组Cleaved caspase-3水平降低,差异均具有统计学意义（均有P<0.001）。结论 DMF可以通过线粒体通路诱导H9c2心肌细胞凋亡,氧化应激可能参与该通路的发生。     

Antiproliferative effect of resveratrol in human prostate carcinoma cells

Resveratrol, a polyphenolic phytoalexin found in grapes, may have potential for the prevention and treatment of human cancer. We report here that resveratrol inhibits the growth of human prostate carcinoma DU145 cells and provide a molecular explanation of the effect. Resveratrol treatment in DU145 cells resulted in a dose-dependent inhibition of cell growth and induced apoptotic cell death. The antiproliferative effect of resveratrol was associated with the inhibition of D-type cyclins and cyclin-dependent kinase (Cdk) 4 expression, and the induction of tumor suppressor p53 and Cdk inhibitor p21. Moreover, the kinase activities of cyclin E and Cdk2 were inhibited by resveratrol without alteration of their protein levels. Resveratrol treatment also up-regulated the Bax protein and mRNA expression in a dose-dependent manner; however, Bcl-2 and Bcl-xL levels were not significantly affected. These effects were found to correlate with an activation of caspase-3 and caspase-9. Taken together, our study suggests that resveratrol has a strong potential for development as an agent for the prevention of human prostate cancer.     

North American cranberry (Vaccinium macrocarpon) stimulates apoptotic pathways in DU145 human prostate cancer cells in vitro

Diets rich in fruits and vegetables have been shown to improve patient prognosis in a variety of cancers, a benefit partly derived from phytochemicals, many of which target cell death pathways in tumor cells. Cranberries (Vaccinium macrocarpon) are a phytochemical-rich fruit containing a variety of polyphenolic compounds. As flavonoids have been shown to induce apoptosis in human tumor cells, this study investigated the hypothesis that cranberry-mediated cytotoxicity in DU145 human prostate adenocarcinoma cells involves apoptosis. The results showed that induction of apoptosis in these cells occurred in response to treatment with whole cranberry extract and occurred through caspase-8 mediated cleavage of Bid protein to truncated Bid resulting in cytochrome-C release from the mitochondria. Subsequent activation of caspase-9 ultimately resulted in cell death as characterized by DNA fragmentation. Increased Par-4 protein expression was observed, and this is suggested to be at least partly responsible for caspase-8 activation. Proanthocyanidin-enriched and flavonol-enriched fractions of cranberry also increased caspase-8 and caspase-9 activity, suggesting that these compounds play a possible role in apoptosis induction. These findings indicate that cranberry phytochemicals can induce apoptosis in prostate cancer cells in vitro, and these findings further establish the potential value of cranberry phytochemicals as possible agents against prostate cancer.     

Smac联合顺铂对人肝癌细胞凋亡调控因子影响

目的研究第二线粒体源的半胱天冬酶激活物(Smac)基因联合顺铂对人肝癌细胞SMMC-7721中半胱氨酸天冬氨酸蛋白酶(caspase)-3、caspase-9和细胞色素c(Cyt c)蛋白表达的影响。方法利用脂质体介导的方法将Smac转染入SMMC-7721,G418筛选后采用逆转录-聚合酶链式反应(RT-PCR)和蛋白印迹(western blot)法检测筛选所得SMMC-7721/Smac细胞中Smac mRNA和蛋白的表达,四甲基偶氮噻唑蓝(MTT)法绘制细胞生长曲线;顺铂处理后采用免疫细胞化学法检测细胞中caspase-3、caspase-9和Cyt c蛋白的表达。结果SMMC-7721/Smac细胞中Smac mRNA和蛋白表达均明显增加,12～120 h A₄₉₀值为0.28～0.70,均明显低于同一时间点的SMMC-7721(0.31～1.10)(P<0.05);与SMMC-7721比较,SMMC-7721/Smac细胞中caspase-3和Cyt c蛋白表达均增高,累积光密度值(IOD)分别从19 939/14 924增至28 347/21 017(P<0.05);顺铂作用下,SMMC-7721和SMMC-7721/Smac细胞中caspase-3、caspase-9和Cyt c蛋白表达均增加,且后者更明显;剂量为25μg/mL时,SMMC-7721/Smac的caspase-3、caspase-9的IOD分别从对照的28 347/22 412增至46 696/39 728(P<0.001)。结论Smac稳定过表达联合顺铂可明显增强细胞中凋亡相关蛋白caspase-3、caspase-9和Cyt c表达,从而促进细胞凋亡。