美洲大蠊多肽提取物对SMMC-7721细胞凋亡及Bcl-2和Bax蛋白表达的影响

目的：研究美洲大蠊多肽提取物诱导人肝癌细胞SMMC-7721凋亡及其分子机制。方法：采用不同质量浓度的美洲大蠊多肽提取物作用于SMMC-7721,以Cell Counting Kit-8（CCK-8）法检测细胞抑制率;Hoechst33342/PI与Annexin V-FITC/PI双染法相结合检测SMMC-7721细胞的凋亡;蛋白免疫印迹（Western blotting）法检测细胞凋亡相关因子Bcl-2和Bax蛋白表达。结果：不同质量浓度的美洲大蠊多肽提取物可抑制SMMC-7721细胞的增殖,诱导其凋亡,呈一定的量效关系;Western Blot法显示Bax表达增多,Bcl-2蛋白表达减少,Bcl-2/Bax比值降低。结论：美洲大蠊多肽提取物可明显诱导SMMC-7721细胞凋亡,抑制其增殖,其机制可能与下调Bcl-2蛋白表达,上调Bax蛋白表达,降低Bcl-2/Bax比值有关。     

牡荆素对人肝细胞癌SMMC-7721细胞的增殖抑制作用及其机制的影响

目的: 研究牡荆素(vitexin)对人肝癌细胞SMMC-7721的增殖抑制作用, 并初步探讨其作用机制。方法: 体外培养人肝癌细胞SMMC-7721, 分别采用MTT法和Hoechst33258核染色法检测牡荆素对人肝癌细胞SMMC-7721活力的影响以及观察细胞形态学变化;流式细胞仪检测细胞凋亡率和线粒体膜电位(ΔΨm) 变化;蛋白免疫印迹法检测p53、Bcl-2、Bax等相关凋亡蛋白水平的表达情况。结果: 牡荆素培养人肝癌细胞SMMC-7721 48, 72, 96 h后能明显抑制细胞增殖, 呈时间-剂量依赖性(P<0.05), 其IC₅₀分别是150.37, 116.24, 90.19 μmol·L^-1。牡荆素作用于人肝癌细胞SMMC-7721 72 h后, 以浓度依赖性方式增加细胞凋亡率、降低线粒体膜电位(ΔΨm) 以及上调p53、Bax、Caspase-3等相关促凋亡蛋白的表达, 下调Bcl-2抗凋亡蛋白的表达。结论: 牡荆素能抑制人肝癌细胞SMMC-7721增殖诱导凋亡, 呈时间-剂量依赖性, 其作用机制可能通过依赖P53途径下调Bcl-2, 上调Casepase-3、Bax、P53、PARP等基因表达, 进而诱导凋亡有关。     

20(S)-原人参二醇对SMMC-7721细胞体内外作用的研究

目的观察不同剂量的20(S)-原人参二醇(Protopanaxadiol,PPD)在体内外对人肝癌细胞株SMMC-7721抗肿瘤作用。方法建立人肝癌裸鼠皮下移植瘤模型,观察20(S)-原人参二醇的肿瘤抑制作用。MTT比色法检测20(S)-原人参二醇对SMMC-7721细胞的增殖抑制作用,Ho-echst33342核染色观察细胞凋亡形态学改变,采用FITC-An-nexinⅤ/PI双染流式细胞术分析凋亡情况,同时检测Caspase-3活性。结果在体内,PPD可抑制SMMC-7721细胞裸鼠异种移植瘤生长;在体外,PPD对SMMC-7721细胞的增殖具有明显的抑制及诱导其凋亡作用,呈时间和剂量依赖性,Hoechst33342核染色可见凋亡小体,同时伴有Caspase-3活性的增加。结论20(S)-原人参二醇在体内外均可抑制SMMC-7721细胞增殖,并诱导其凋亡,其机制可能通过活化Caspase-3诱导细胞凋亡而发挥抗肿瘤作用。     

丹参多酚酸盐体外抗肿瘤作用研究

目的:研究丹参多酚酸盐体外抗肿瘤的作用,探讨其可能机制。方法:采用MTT比色法测定注射用丹参多酚酸盐体外对人肝癌细胞株SMMC-7721细胞、人肺腺癌细胞株SPC-A-1细胞、B淋巴瘤细胞株Raji细胞和急性粒细胞白血病细胞株HL-60细胞4种肿瘤细胞株增殖的影响;采用流式细胞仪检测细胞周期的改变及细胞凋亡情况;采用吉姆萨染色及吖啶橙荧光染色观察细胞形态变化。结果:注射用丹参多酚酸盐对SMMC-7721、SPC-A-1、Raji、HL-60细胞增殖均有显著的抑制作用,且呈时间和剂量依赖关系;可诱导SMMC-7721细胞阻滞于S期继而发生细胞凋亡;可观察到细胞逐渐凋亡形态。结论:注射用丹参多酚酸盐有较强的体外抗肿瘤作用,可能是通过作用于细胞周期、诱导肿瘤细胞凋亡来发挥的。     

Cardioprotective effects of fucoidan against hypoxia-induced apoptosis in H9c2 cardiomyoblast cells

Abstract

Context: Cardiomyocyte apoptosis plays a critical role in the progress of heart diseases. Fucoidan, a complex-sulfated polysaccharide, has been reported to possess potential cardioprotective efficacy in vivo.

Objective: The present study determines whether fucoidan could provide cardioprotection on hypoxia-induced cardiomyocyte apoptosis.

Materials and methods: H9c2 cardiomyoblast cells were incubated with various concentrations (15, 30, and 60?μg/ml) of fucoidan in a humidified incubator at 37?°C with 95% O₂ and 5% CO₂. After 6?h, hypoxia was processed and the cardioprotective effects of fucoidan were evaluated by applying MTT, ELISA, Hoechst 33258 nucleus staining, and western blot.

Results: Following a 6?h exposure of H9c2 to hypoxic condition, significant reduction was found in cell survival (0.57-fold) and superoxide dismutase (SOD) activity (0.56-fold), which were associated with the increase of malondialdehyde (MDA) level (2.58-fold), creatine phosphokinase (CK, 3.57-fold), and lactate dehydrogenase (LDH) activities (2.39-fold). Moreover, hypoxia-induced apoptosis was confirmed by Hoechst 33258 nuclear staining, and these changes were accompanied by the increase of Bcl-2 (1.27-fold) and Bax expression (2.6-fold). However, preincubation of the cells with fucoidan prior to hypoxia exposure elevated the cell viability (30?μg/ml, 1.18-fold; 60?μg/ml, 1.32-fold) and SOD activity (30?μg/ml, 1.12-fold; 60?μg/ml, 1.25-fold), but decreased the MDA level (30?μg/ml, 0.70-fold; 60?μg/ml, 0.80-fold), CK (30?μg/ml, 0.69-fold; 60?μg/ml, 0.76-fold), and LDH (30?μg/ml, 0.67-fold; 60?μg/ml, 0.86-fold) leakages. Hoechst 33258 nuclear staining observations demonstrated the same protective effect of fucoidan on hypoxia-induced myocardial injury. Also, cardioprotective effects of fucoidan were reflected by increasing Bcl-2 (60?μg/ml, 1.84-fold), as well as decreasing Bax (60?μg/ml, 0.6-fold).

Conclusion: Fucoidan had protective effect against hypoxia-induced cardiomyocytes apoptosis, and the mechanism might involve protections of the cell from oxidative injury.     

Cytotoxic effects and pro-apoptotic mechanism of TBIDOM, a novel dehydroabietylamine derivative, on human hepatocellular carcinoma SMMC-7721 cells

We have investigated the antiproliferative effects of TBIDOM (N-(4-(2,2,2-trifluoroethyl) benzylidene) (7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydrophenanthren-1-yl) meth-anamine) and have explored its possible mechanisms on human hepatocellular carcinoma SMMC-7721 cells. The proliferative status of cells treated with TBIDOM was measured by the colorimetric MTT assay. Cellular apoptosis was analysed using Hoechst 33342 staining and flow cytometry. Reduction of mitochondrial membrane potential (Delta psi(m)) was also detected by flow cytometry. Western blotting assay was used to evaluate the release of cytochrome c and expression of p53, Bcl-2 and Bax proteins. It was shown that TBIDOM displayed a significant inhibitory effect on growth of SMMC-7721 cells in a dose- and time-dependent manner. Hoechst 33342 staining and flow cytometry analysis showed an increase of apoptosis rate and decrease of mitochondrial membrane potential after SMMC-7721 cells were exposed to TBIDOM for 24 h. Pretreatment of SMMC-7721 cells with TBIDOM significantly induced a decrease of Bcl-2 protein expression and an increase of caspase-3 activity and Bax protein expression. The results indicated that TBIDOM could effectively inhibit proliferation by induction of apoptosis and could be a promising candidate in the development of a novel class of antitumour agent.     

Piperonal ciprofloxacin hydrazone induces growth arrest and apoptosis of human hepatocarcinoma SMMC-7721 cells

Aim:

To investigate the cytotoxic effects of piperonal ciprofloxacin hydrazone (QNT4), a novel antibacterial fluoroquinolone derivative, against human hepatocarcinoma SMMC-7721 cells.

Methods:

Human hepatocarcinoma cells (SMMC-7721), human breast adenocarcinoma cells (MCF-7) and human colon adenocarcinoma cells (HCT-8) were tested. The effects of QNT4 on cell proliferation were examined using MTT assay. Cell apoptosis was determined using Hoechst 33258 fluorescence staining, TUNEL assay and agarose gel electrophoresis. The topoisomerase II activity was measured using agarose gel electrophoresis with the DNA plasmid pBR322 as the substrate. Mitochondrial membrane potential (Δψm) was measured using a high content screening imaging system. Protein expression of caspase-9, caspase-8, caspase-3, p53, Bcl-2, Bax, and cytochrome c was detected with Western blot analysis.

Results:

Treatment with QNT4 (0.625–10 μmol/L) potently inhibited the proliferation of the cancer cells in time- and dose-dependent manners (the IC₅₀ value at 24 h in SMMC-7721 cells, MCF-7 cells and HCT-8 cells was 2.956±0.024, 3.710±0.027, and 3.694±0.030 μmol/L, respectively). Treatment of SMMC-7721 cells with QNT4 (0.2146, 2.964, and 4.600 μmol/L) for 24 h dose-dependently increased the percentage of apoptotic cells, elicited characteristic DNA “ladder” bands, and decreased the mitochondrial membrane potential. QNT4 dose-dependently increased topoisomerase II-mediated DNA breaks while inhibiting DNA relegation, thus keeping the DNA in fragments. Treatment of SMMC-7721 cells with QNT4 significantly increased cytochrome c in the cytosol, and decreased cytochrome c in the mitochondrial compartment. QNT4 (3–7.39 μmol/L) significantly increased the protein expression of p53, Bax, caspase-9, caspase-3, and the cleaved activated forms of caspase-9 and caspase-3 in SMMC-7721 cells. In contrast, the expression of Bcl-2 was decreased, while caspase-8 had no significant change.

Conclusion:

QNT4 induced the apoptosis of SMMC-7721 cells via inhibiting topoisomerase II activity and modulating mitochondrial-dependent pathways.     

Reactive oxygen species production and Bax/Bcl-2 regulation in honokiol-induced apoptosis in human hepatocellular carcinoma SMMC-7721 cells

We investigated possible mechanism(s) where honokiol induces apoptosis in human hepatocellular carcinoma SMMC-7721 cells. MTT assay showed that honokiol has strong inhibition on SMMC-7721 cells in a dose-dependent manner. SMMC-7721 cells after honokiol treatment display morphological characteristics such as cell shrinkage, detachment from the culture plate, formation of apoptotic bodies, change to a round shape, and marked nuclear condensation and fragmentation after 32258 staining. Cell apoptosis was measured by Annexin-V/PI staining and alternatively, by the subG0/G1 percentage of the cell cycle analysis followed by FACS. An obvious loss of ΔΨ(m) and a quick burst of ROS was detected when honokiol reached 4μg/ml, which was coincident with the high apoptosis percentage in our previous research. Up-regulation of Bax and down-regulation of Bcl-2 were observed, suggesting that honokiol-induced apoptosis was associated with reactive oxygen species (ROS) production and an increase of Bax/Bcl-2 ratios.     

对甲氧基肉桂醛左氧氟沙星酰腙诱导人肝癌SMMC-7721细胞凋亡的作用

目的探讨喹诺酮酰腙类化合物诱导人肝癌SMMC-7721细胞凋亡的作用。方法用不同浓度的对甲氧基肉桂醛左氧氟酰腙(FQ-10)与SMMC-7721细胞体外培养。MTT法检测FQ-10对SMMC-7721细胞的增殖抑制作用;Hoechst33258/PI双染荧光染色法、TUNEL法及琼脂糖凝胶电泳检测细胞凋亡变化;高内涵活细胞成像系统测定细胞线粒体膜电位(△ψm)变化;Western blot方法测定caspase-9、caspase-8、caspase-3、p53、Bcl-2、Bax蛋白表达。结果 FQ-10在0.625～10.00μmol.L-1的浓度范围能抑制细胞增殖,呈时间、浓度依赖性;作用于细胞24 h的IC50值是4.40μmol.L-1;各组FQ-10作用24 h后,细胞凋亡率高于对照组(P<0.05);琼脂糖凝胶电泳可见凋亡细胞典型的梯状DNA条带,并伴有线粒体膜电位降低。荧光染色观察细胞形态学变化,显示凋亡细胞染色质凝集,细胞核碎裂成碎片等典型细胞凋亡特征性变化,晚期凋亡细胞可见特异性PI染色。与对照组比较,FQ-10作用后p53、Bax、caspase-9、caspase-3蛋白表达量增加,其中caspase-9、caspase-3活性裂解片段明显增加,caspase-8无变化,而Bcl-2蛋白表达水平下降。结论对甲氧基肉桂醛左氧氟酰腙能够激活线粒体凋亡通路,诱导人肝癌细胞凋亡。     

新型金属铜络合物对SMMC-7721细胞增殖与凋亡的影响

目的研究新型金属铜络合物(N-Cu)在体外对人肝癌SMMC-7721细胞增殖与凋亡的影响及其作用机制。方法将不同浓度的N-Cu(0.3～24μmol.L-1)作用于体外培养的SMMC-7721细胞,应用MTT法检测细胞生长抑制率,FCM法检测细胞周期及凋亡率,RT-PCR和Western blot法检测细胞中Bcl-2、Bax、Caspase-3 mRNA和蛋白表达的变化。结果 N-Cu可明显抑制SMMC-7721细胞的增殖,呈明显的量效与时效关系。随着药物浓度的增加,G0/G1期的细胞比率上升,G2/M和S期细胞比率下降,并促进凋亡率增加。N-Cu可上调细胞中Bax、Caspase-3基因及蛋白的表达,抑制Bcl-2基因及蛋白的表达,且均呈剂量依赖性。结论一定浓度的N-Cu可抑制SMMC-7721细胞的增殖并诱导其凋亡,阻滞细胞周期于G0/G1期。上调Bax、Caspase-3基因及蛋白的表达,降低Bcl-2/Bax比值,可能是其诱导细胞凋亡的重要机制。     

Corosolic acid analogue,a natural triterpenoid saponin,induces apoptosis on human hepatocarcinoma cells through mitochondrial pathway in vitro

Context 2a,-3a,-24-Trihydroxyurs-12-en-28-oic acid (TEO, a corosolic acid analogue) is a triterpenoid saponin isolated from Actinidia valvata Dunn (Actinidiaceae), a well-known traditional Chinese medicine.

Objective This study investigated the anti-proliferation and inducing apoptosis effects of TEO in three human hepatocellular carcinoma (HCC) cell lines.

Materials and methods Cytotoxic activity of TEO was determined by the MTT assay at various concentrations from 2.5 to 40?μg/mL in BEL-7402, BEL-7404 and SMMC-7721 cell lines. Cell morphology was assessed by acridine orange/ethidium bromide and 4′-6-diamidino-2-phenylindole dihydrochloride staining and fluorescence microscopy. Cell-cycle distribution and DNA damage were determined by flow cytometry and comet assay. Mitochondrial dysfunction was assessed by JC-1 staining and transmission electron microscopy. Apoptosis changes were explored by Western blot, TNF-α and caspase-3, -8, -9 assays.

Results TEO exhibited inhibition effects on BEL-7402, BEL-7404 and SMMC-7721 cells treated for 24?h, the IC₅₀ values were 34.6, 30.8 and 30.5?μg/mL, respectively. TEO (40?μg/mL)-treated three cell lines increased by more than 21% in the G1 phase and presented the morphological change and DNA damage. TEO also declined the mitochondrial membrane potential and altered mitochondrial ultra-structure. Furthermore, caspase-3, caspase-8, caspase-9 and TNF-α were also activated. Mechanism investigation showed that TEO could decrease anti-apoptotic Bcl-2 protein expression, increase proapoptotic Bax and Bid proteins expressions and increase Bax/Bcl-2 ratio.

Conclusion Our results demonstrate for the first time that TEO inhibited growth of HCC cell lines and induced G1 phase arrest. Moreover, proapoptotic effects of TEO were mediated through the activation of TNF-α, caspases and mitochondrial pathway.     

表没食子儿茶素-3-没食子酸酯通过ERK1/2通路对肝癌HepG2细胞凋亡、增殖、迁移和侵袭的影响

目的 探讨表没食子儿茶素-3-没食子酸酯（EGCG）通过ERK1/2通路对肝癌HepG2细胞凋亡、增殖、迁移和侵袭的影响。方法 将体外培养的肝癌HepG2细胞分为空白组、EGCG组、EGCG+ERK抑制剂组。收集细胞裂解液,CCK-8检测细胞增殖,相差显微镜和Hoechst 33258染色观察细胞形态变化,流式细胞术检测细胞凋亡,RT-qPCR检测ERK mRNA水平,Western blotting分析ERK、磷酸化ERK、Bax和Bcl-2表达水平,并计算Bax/Bcl-2比值。结果 EGCG可以显著抑制肝癌HepG2细胞的增殖、迁移和侵袭（P<0.01）,并促进HepG2细胞的凋亡（P<0.01）;加入ERK通路抑制剂可显著逆转EGCG对HepG2的作用。结论 EGCG可通过ERK1/2信号通路发挥对肝癌HepG2细胞的抑制作用。     

莪术油对直肠癌SW1463细胞株增殖、凋亡及Caspase-3、Bax、Bcl-2蛋白表达的影响

目的 探讨莪术油对直肠癌SW1463细胞株增殖、凋亡及相关蛋白Caspase-3、Bax、Bcl-2表达的影响。方法 水蒸气蒸馏法提取黔产莪术挥发油,配制成40、80、120、160、200、240、280 mg/L浓度梯度,干预SW1463细胞24、48、72 h,MTT法检测莪术油对SW1463细胞的增殖抑制率;Giemsa染色法观察莪术油对SW1463细胞凋亡形态的影响;蛋白免疫印迹法（Western blotting）检测Capase-3、Bax与Bcl-2蛋白表达。结果 莪术油对SW1463细胞的增殖有明显抑制作用,并呈现时间-剂量相关性,24、48、72 h的半数抑制浓度（IC₅₀）分别为144.33、134.11、120.04 mg/L;Giemsa染色可见细胞明显的凋亡形态学特征;莪术油干预SW1463细胞24 h后,与对照组比较,Caspase-3、Bax蛋白表达显著上调、Bcl-2蛋白表达显著下调（P<0.05）。结论 莪术油能明显抑制SW1463细胞增殖,诱导细胞凋亡,其机制可能与上调Caspase-3和Bax蛋白表达、下调Bcl-2蛋白表达相关。     

华蟾素诱导人肝癌细胞株HepG2凋亡及其作用机制

为了观察华蟾素体外抑制肝癌细胞株HepG₂增殖、诱导细胞凋亡作用及其机制, 将不同浓度华蟾素作用于HepG₂细胞。采用MTT法观察华蟾素对HepG₂细胞的增殖抑制作用; 用Hoechst 33258染色法观察细胞凋亡的形态学改变; 以流式细胞术观察细胞的凋亡率和细胞周期的变化; 以实时荧光定量PCR技术 (real time-PCR) 和蛋白免疫印迹 (Western blotting) 法检测细胞凋亡相关因子Bcl-2、Bax及p53 mRNA水平和蛋白水平的表达情况。结果表明, 华蟾素对体外培养的肝癌HepG₂细胞有抑制增殖作用, 且具有剂量、时间相关性; 华蟾素可致HepG₂细胞阻滞于G₂/M期, 细胞凋亡率随药物浓度增加亦呈增长趋势; 细胞凋亡相关因子Bax及p53 mRNA和蛋白表达上调, Bcl-2的mRNA和蛋白表达下调。因此, 华蟾素可抑制肝癌细胞株HepG₂的增殖, 诱导肝癌HepG₂细胞凋亡, 其机制可能与调节凋亡相关因子Bcl-2、Bax及p53的表达有关。     

A novel homospermidine conjugate inhibits growth and induces apoptosis in human hepatoma cells

Aim： To elucidate the mechanism responsible for the antiproliferative effects of a novel homospermidine conjugate, anthracenylmethyl homospermidine （ANTMHspd）, in the human hepatoma BEL-7402 cell line. Methods： The viability of the cells was assessed by MTT assay and the trypan blue dye exclusion method. Morphological changes were observed by fluorescence microscopy with Hoechst 33258 staining. Cell cycle distribution, apoptosis, and mitochondrial membrane potential were measured by flow cytometry. Protein expression was detected by Western blot analysis. Results： ANTMHspd strongly decreased BEL-7402 cell proliferation in a dose- and time-dependent manner. Hoechst 33258 staining and the flow cytometry assay showed that ANTMHspd induced cell apoptosis and cell cycle perturbation. Furthermore, ANTMHspd could induce mitochondrial membrane potential loss and cytochrome c release and enhance cleaved caspase-3, cleaved caspase-9, and Bax protein expression without caspase-8 activation. ANTMHspd could also decrease the expression of Bcl-2 and cytochrome c in mitochondria. In addition, the specific inhibitors of caspase-9 and caspase-3 almost abolished the ANTMHspd-induced caspase-9 and caspase-3 activation, respectively. Conclusion： ANTMHspd could induce BEL-7402 cell apoptosis via the mitochondrial/caspase-dependent pathway and the Bcl-2 family was involved in the control of apoptosis.     

Ardisiphenol D,a resorcinol derivative identified from Ardisia brevicaulis,exerts antitumor effect through inducing apoptosis in human non-small-cell lung cancer A549 cells

Context: The in vitro and in vivo antitumor activities of ardisiphenol D, a natural product isolated from the roots of Ardisa brevicaulis Diels (Myrsinaceae), have been studied.

Objective: Previously, we have isolated and identified some chemical constituents from this plant. Furthermore, these compounds showed significant inhibition of the proliferation of human pancreatic PANC-1, human lung A549, human gastrointestinal carcinoma SGC 7901, human breast MCF-7, and human prostate PC-3 cancer cells. In the present paper, a major resorcinol derivative called ardisiphenol D was further studied for its antitumor mechanism.

Materials and methods: MTT assay was used to detect the proliferation of A549 cancer cells. Apoptosis induced by ardisiphenol D was observed by Hoechst 33258 fluorescence staining. Caspase-3 enzyme activity was measured by a commercial caspase-3 enzyme activity detection kit. Protein expression of bax, bcl-2, and caspase-3 was tested by Western blots. In vivo antitumor activity of ardisiphenol D was evaluated by determination of A549 tumor growth in nude mice.

Results: Ardisiphenol D significantly inhibited the proliferation of A549 cells with an IC₅₀ of 0.997?μM with a 48?h treatment. Hoechst 33258 fluorescence staining results indicated the apoptosis of A549 cells induced by 3.125?μM of ardisiphenol D. About 0.39 and 0.78?μM of ardisiphenol D also potently increased the caspase-3 enzyme activity in 24?h. Furthermore, 0.39–3.125?μM of ardisiphenol D induced the activation of caspase-3 protein and the up-regulation of the ratio of bax/bcl-2 protein expression in A549 cells. After i.p. injection, ardisiphenol D (5?mg/kg) also strongly suppressed the A549 tumor growth in nude mice.

Discussion and conclusion: Ardisiphenol D induced apoptosis of A549 cells via activation of caspase-3 and up-regulation of the ratio of bax/bcl-2 protein expression. Ardisiphenol D also strongly suppressed the A549 tumor growth in nude mice and exerted antitumor activity in vivo.     

维生素D对过氧化氢诱导MIN6细胞凋亡的保护作用

目的探讨维生素D(vitamin D,VitD)对过氧化氢(hydrogen peroxide,H 2O 2)诱导小鼠胰岛β细胞株MIN6细胞凋亡的保护作用及机制。方法VitD预处理后,用H 2O 2处理MIN6细胞,分别运用CCK-8法、Hoechst 33258荧光染色法、流式细胞术检测MIN6细胞增殖、形态及凋亡百分率。Western blot检测增殖与凋亡相关基因Bax、Bcl-2、Caspase-3以及Cleaved caspase-3的表达。结果H 2O 2呈时间和剂量依赖性抑制MIN6细胞增殖,诱导细胞凋亡,降低Bcl-2表达、增加Bax及Cleaved caspase-3表达,Bcl-2/Bax比值降低,Cleaved caspase-3/caspase-3比值增加;当用VitD预处理后,Bcl-2表达增加,Bax、Cleaved caspase-3表达降低,Bcl-2/Bax比值增加,Cleaved caspase-3/caspase-3比值降低,MIN6细胞活力增加。结论VitD预处理后,通过增加抗凋亡Bcl-2表达,降低促凋亡Bax和Cleaved caspase-3表达,减少由H 2O 2诱导的小鼠胰岛β细胞株MIN6细胞凋亡。     

Formononetin induces the mitochondrial apoptosis pathway in prostate cancer cells via downregulation of the IGF-1/IGF-1R signaling pathway

Context: Formononetin, an isoflavone, can inhibit the proliferation of cancer cells, including those of the prostate. However, its antitumor mechanism remains unclear.

Aim: To investigate whether the insulin-like growth factor 1 (IGF-1)/insulin-like growth factor 1 receptor (IGF-1?R) signaling pathway mediates the formononetin antitumor effect on prostate cancer cells.

Materials and methods: The viability of PC-3 cells was measured by MTT assay 48?h after formononetin treatment (25, 50 and 100?μM). Formononetin-induced cell apoptosis was measured by Hoechst 33258 staining and flow cytometry. Expression of Bax mRNA was detected by real-time PCR, and the expression levels of Bax and IGF-1?R proteins were detected by western blots.

Results: At concentrations >12.5?μM, formononetin significantly inhibited the proliferation of human prostate cancer cells. Formononetin increased Bax mRNA and protein expression levels and decreased the expression levels of pIGF-1?R protein in a dose-dependent manner.

Conclusion: High concentrations of formononetin-induced apoptosis in androgen-independent prostate cancer cells through inhibition of the IGF-1/IGF-1?R pathway.     

In vitro anti-tumor activity of 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone against six established human cancer cell lines.

2',4'-Dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC), isolated from the buds of Cleistocalyx operculatus, was investigated in its cytotoxicity and its influence on six human cancer cell lines. Among SMMC-7721, 8898, HeLa, SPC-A-1, 95-D and GBC-SD cell lines, SMMC-7721 cells was the most sensitive one in these tested cell lines, with IC50 equal to 32.3 +/- 1.13 microM, EC50 equal to 9.00 +/- 0.36 microM and the therapeutic index equal to 3.59. Staining with Hoechst 33258 showed fragmentation and condensation of chromatin in the cells treated with 9 microM DMC for 48 h. Flow cytometric analysis was performed to determine hypodiploid cells. The results of flow cytometry assay indicated that the percentage of hypodiploid SMMC-7721 cells were 49.44 +/- 1.06% after 48 h treatment with 18.0 microM DMC. The treatment resulted in the appearance of a hypodiploid peak (A0 region), probably due to the presence of apoptosing cells and/or apoptotic bodies with DNA content less than 2n. To our knowledge, this is the first report on anti-tumor activity by DMC.