青龙衣多糖对结肠癌HCT-116细胞增殖、凋亡及PI3K/Akt信号通路的影响

目的:从磷脂酰肌醇3激酶/蛋白激酶B(PI3K/Akt)信号通路方面探讨青龙衣多糖对结肠癌HCT-116细胞增殖、凋亡的影响。方法:青龙衣多糖(10,20,50,100 mg·L-1)处理处于对数生长期的HCT-116细胞,另设空白组,MTS法检测24,48,72,96 h后的细胞增殖抑制率,PI单染法,Annexin-FITC/PI双染法分别检测48 h后细胞周期及细胞凋亡情况,蛋白质免疫印迹(Western blot)法检测48 h后Akt及p-Akt蛋白表达水平。结果:青龙衣多糖对HCT-116细胞的增殖具有明显的抑制作用,呈剂量依赖和时间依赖效应;与空白组比较,各处理组G0/G1期细胞比例增加,S期和G2/M期细胞比例下降,且各质量浓度间的差异具有统计学意义(P0.05);与空白组比较,除10 mg·L-1组外,其余组早期凋亡率均有显著性增加,而各剂量组的晚期凋亡率及总凋亡率均明显升高,且各质量浓度间的凋亡率均具有统计学意义(P0.05);与空白组比较,各给药组p-Akt/Akt明显降低,且各质量浓度间p-Akt/Akt差异具有统计学意义(P0.05)。结论:青龙衣多糖在体外可直接抑制或杀伤人结肠癌HCT-116细胞,具有较强的增殖抑制及诱导凋亡能力,其抗肿瘤机制可能与PI3K/Akt信号通路相关。     

Polymethoxyflavonoids Tangeretin and Nobiletin Increase Glucose Uptake in Murine Adipocytes

Tangeretin and nobiletin are polymethoxyflavonoids that are contained in citrus fruits. Polymethoxyflavonoids are reported to have several biological functions including anti‐inflammatory, anti‐atherogenic, or anti‐diabetic effects. However, whether polymethoxyflavonoids directly affect glucose uptake in tissues is not well understood. In the current study, we investigated whether tangeretin and nobiletin affect glucose uptake in insulin target cells such as adipocytes. We observed that treatment with tangeretin or nobiletin significantly increased the uptake of [³H]‐deoxyglucose in differentiated 3T3‐F442A adipocytes in a concentration‐dependent manner. Data showed that phosphatidyl inositol 3 kinase, Akt1/2, and the protein kinase A pathways were involved in the increase in glucose uptake induced by polymethoxyflavonoids. These data suggest that the anti‐diabetic action of polymethoxyflavonoids is partly exerted via these signaling pathways in insulin target tissues. Copyright © 2012 John Wiley & Sons, Ltd.     

Fructus ligustri lucidi extracts induce human glioma cell death through regulation of Akt/mTOR pathway In Vitro and reduce glioma tumor growth in U87MG xenograft mouse model

The present study was undertaken to examine the effect of Fructus ligustri lucidi (FLL) extracts on glioma cell growth and to determine the underlying mechanism by which FLL extracts exert anticancer properties in human U87MG glioma cells. The FLL extracts resulted in cell death in a dose‐ and time‐dependent manner. Western blot analysis showed that treatment with FLL extracts caused down‐regulation of the phosphatidylinositol‐3 kinase (PI3K)/Akt pathway. Overexpression of Akt prevented the cell death induced by the FLL extracts. The FLL extracts caused a decrease in the expression of mammalian target of rapamycin (mTOR) and the FLL extract‐induced cell death was increased by the mTOR inhibitor rapamycin. The FLL extracts decreased the expression of survivin. Oral administration of FLL extracts in subcutaneous U87MG xenograft models reduced the glioma tumor volume. These findings indicate that the FLL extracts resulted in glioma cell death through regulation of the Akt/mTOR/survivin pathway in vitro and inhibited glioma tumor growth in vivo. These data suggest that the FLL extracts may serve as a potential therapeutic agent for malignant human gliomas. Copyright © 2010 John Wiley & Sons, Ltd.     

Effects of Artemetin on Nitric Oxide Release and Protection against Peroxidative Injuries in Porcine Coronary Artery Endothelial Cells

Artemetin is one of the main components of Achillea millefolium L. and Artemisia absinthium, which have long been used for the treatment of various diseases. To date, however, available information about protective effects of their extracts on the cardiovascular system is scarce. Therefore, we planned to analyze the effects of artemetin on nitric oxide (NO) release and the protection exerted against oxidation in porcine aortic endothelial (PAE) cells. In PAE, we examined the modulation of NO release caused by artemetin and the involvement of muscarinic receptors, β2‐adrenoreceptors, estrogenic receptors (ER), protein‐kinase A, phospholipase‐C, endothelial‐NO‐synthase (eNOS), Akt, extracellular‐signal‐regulated kinases 1/2 (ERK1/2) and p38 mitogen activated protein kinase (p38 MAPK). Moreover, in cells treated with hydrogen peroxide, the effects of artemetin were examined on cell survival, glutathione (GSH) levels, apoptosis, mitochondrial membrane potential and transition pore opening. Artemetin increased eNOS‐dependent NO production by the involvement of muscarinic receptors, β2‐adrenoreceptors, ER and all the aforementioned kinases. Furthermore, artemetin improved cell viability in PAE that were subjected to peroxidation by counteracting GSH depletion and apoptosis and through the modulation of mitochondrial function. In conclusion, artemetin protected endothelial function by acting as antioxidant and antiapoptotic agent and through the activation of ERK1/2 and Akt. Copyright © 2015 John Wiley & Sons, Ltd.     

白皮杉醇对三阴性乳腺癌细胞系MDA-MB-468抗肿瘤作用及机制

目的:考察白皮杉醇(PIC)对三阴性乳腺癌细胞MDA-MB-468增殖、凋亡及细胞周期的作用,并对其作用机制进行探讨。方法:采用噻唑蓝(MTT)比色法考察PIC(0,2.5,5.0,10.0,20.0,40.0,80.0,160.0μmol·L-1)对三阴性乳腺癌MDA-MB-468细胞成活率的影响,并计算半抑制率(IC50);采用碘化丙啶(PI)染色观察PIC(5.0,10.0,20.0μmol·L^-1)对MDA-MB-468细胞周期的影响;采用细胞凋亡检测(Annexin V-FITC/PI)双染法观察PIC(5.0,10.0,20.0μmol·L^-1)对三阴性乳腺癌MDA-MB-468细胞的诱导凋亡作用;采用蛋白免疫印迹法(Western blot)观察不同浓度PIC(5.0,10.0,20.0μmol·L^-1)对MDA-MB-468细胞增殖、凋亡蛋白的影响,并用Western blot对分泌型糖蛋白Wnt/β-连环蛋白(Wnt/β-catenin)信号通路相关蛋白进行检测。结果:MTT比色法结果显示,与空白组比较,PIC(5.0,10.0,20.0,40.0,80.0,160.0μmol·L^-1)可呈浓度依赖性地抑制MDA-MB-468细胞的增殖(P<0.05,P<0.01),IC50为(39.4±4.6)μmol·L^-1;作用48 h,PIC(5.0,10.0,20.0μmol·L^-1)呈浓度依赖性地升高MDA-MB-468细胞处于细胞周期G0/G1期细胞(P<0.01);呈浓度依赖性地诱导MDA-MB-468细胞凋亡(P<0.01),其中,PIC(20.0μmol·L^-1)诱导细胞凋亡率为49.87%;PIC(10.0,20.0μmol·L^-1)可明显降低MDA-MB-468细胞中β-catenin及原癌基因(C-myc),黏附因子(CD44)蛋白的表达水平(P<0.05,P<0.01);PIC(5.0,10.0,20.0μmol·L^-1)可显著抑制蛋白激酶B(Akt)磷酸化,p38丝裂原活化蛋白激酶(p38 MAPK)蛋白的磷酸化,B淋巴细胞瘤-2(Bcl-2)的蛋白表达水平(P<0.01);增强半胱氨酸天冬氨酸蛋白酶-3(Caspase-3),Bcl-2相关X蛋白(Bax)和磷酸化β-catenin的蛋白表达(P<0.01)。结论:PIC可能通过抑制Wnt/β-catenin信号通路抑制MDA-MB-468细胞增殖,并将细胞周期阻滞在G0/G1期,从而诱导其凋亡。     

Palbinone from Paeonia suffruticosa Protects Hepatic Cells via Up‐regulation of Heme Oxygenase‐1

Paeonia suffruticosa has been traditionally employed for vitalizing blood circulation and alleviating liver and inflammatory diseases. The pathways by which palbinone (PB) isolated from P. suffruticosa mediates heme oxygenase‐1 (HO‐1) induction were investigated using the specific inhibitors for PI3K and mitogen activated protein kinases pathways. The effect of PB‐treatment on Nrf2 translocalization and HO‐1‐antioxidant response element (ARE) regulation was examined employing Western blot and luciferase assays. PB induced HO‐1 expression via the activation of Nrf2 in the hepatic cells, and ARE‐dependent genes were stimulated via the PB‐mediated Nrf2 activation. PB‐mediated HO‐1 expression could be involved with PI3K/Akt and ERK1/2 pathways. Our study suggests the mechanism by which PB induces HO‐1 expression in the hepatic cells. This might substantiate the traditional applications of P. suffruticosa for the treatment of oxidative stress‐related diseases including oxidant and inflammatory‐mediated vascular and liver diseases. Copyright © 2013 John Wiley & Sons, Ltd.     

筋骨草总环烯醚萜对乳腺癌干细胞特性的干预作用及其机制分析

目的:研究筋骨草总环烯醚萜(iridoids in Ajuga decumbens,ADI)对乳腺癌干细胞特性的干预作用及分子机制。方法:采用无血清悬浮微球体形成实验,transwell迁移和侵袭实验检测乳腺癌干细胞自我更新能力、运动和侵袭能力。流式细胞法分析CD44+CD24-/low细胞亚群比例。蛋白免疫印迹法(Western blot)检测肿瘤干细胞干性相关蛋白,细胞外信号调节激酶(ERK)和磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(PKB或Akt)信号通路相关蛋白的表达。结果:5~80 mg·L-1ADI能浓度依赖性降低乳腺癌MCF-7细胞微球体形成的数量和体积,减少CD44+CD24-/low细胞亚群比例(P0.05,P0.01)。10~40 mg·L-1ADI对乳腺癌MCF-7干细胞的迁移和侵袭能力有明显抑制作用(P0.05,P0.01)。进一步研究发现,ADI能明显降低p-ERK,p-Akt,干性标志物八聚体结合转录因子-3/4(Oct-3/4),SRY相关的HMG盒转录因子-2(Sox-2)和胚胎干细胞转录因子(Ecat4或Nanog)蛋白表达(P0.05,P0.01)。结论:筋骨草总环烯醚萜能有效地抑制乳腺癌干细胞的自我更新和转移潜能等"干性"特性,作用机制可能与其调控ERK1/2丝裂原活化蛋白激酶(MAPK)和PI3K/Akt信号通路,下调相关干性标志物表达有关。     

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??OBJECTIVE To study the changes of VEGF signaling pathway in colon cancer patients and the effect of schisandrin B on SW620 cells and to analyze its possible mechanism. METHODS The protein expression of VEGFA, VEGF-R2, PI3K, Akt and p-Akt in human cancerous colon samples and adjacent normal samples were detected by Western blotting. The proliferation of SW620 cells was detected by CCK-8 method. The mRNA expression of VEGFA, VEGF-R2, PI3K and Akt in SW620 cells were detected by real-time PCR. The protein expression of VEGFA, VEGF-R2, PI3K, Akt and p-Akt in SW620 cells were detected by Western blotting. RESULTS The protein expression of VEGF-R2, PI3K, Akt and p-Akt in human cancerous colon samples was significantly higher than that in the adjacent normal samples(P<0.05). Compared with the control group, schisandrin B could significantly inhibit the proliferation and migration of SW620 cells, the mRNA expression of VEGFA, VEGF-R2, PI3K and Akt(P<0.01) and the protein expression of VEGFA, VEGF-R2, PI3K, Akt and p-Akt(P<0.05) in SW620 cells also were significantly decreased by schisandrin B. CONCLUSION The VEGF/PI3K/Akt signaling pathway is activated in colon cancer patients. Schisandrin B could inhibit the activity and migration of SW620 cells and inhibit the VEGF/PI3K/Akt signaling pathway.     

加味四君子汤含药血清对肝癌Hep-G2细胞的影响

目的:探讨加味四君子汤含药血清对肝癌Hep-G2细胞增殖、凋亡、周期的影响及其作用机制。方法:不同浓度加味四君子汤含药血清处理Hep-G2细胞后,采用细胞活性检测试剂盒(CCK-8)检测细胞增殖;Annexin V/碘化丙啶(PI)流式细胞术检测细胞凋亡率和周期;hoechst33342荧光染色观察细胞凋亡形态;免疫印迹法(Western blot)检测细胞中磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(Akt)/雷帕霉素靶蛋白(m TOR)信号通路相关蛋白表达水平。结果:加味四君子汤含药血清呈浓度依赖性抑制肝癌Hep-G2细胞的增殖,诱导Hep-G2细胞凋亡,阻滞细胞于G0/G1期。hoechst33342染色后,随着含药血清浓度的增加,Hep-G2细胞核显著呈碎块状致密浓染。同时,加味四君子汤含药血清能够抑制Hep-G2细胞Akt,m TOR,核糖体S6蛋白激酶(S6),真核翻译起始因子4E结合蛋白1(4EBP1)的磷酸化,从而上调Bcl-2相关X蛋白(Bax)和下调细胞周期蛋白(Cyclin D1),B淋巴细胞瘤-2(Bcl-2)的表达。加味四君子汤含药血清与300 nmol·L-1的PI3K/m TOR双重抑制剂VS-5584联合使用具有协同作用,含药血清能增强PI3K/m TOR双重抑制剂VS-5584对Hep-G2细胞中PI3K/Akt/m TOR信号通路靶点Akt和m TOR磷酸化的抑制作用。结论:加味四君子汤含药血清能抑制Hep-G2细胞的增殖,诱导其凋亡,阻滞其于G0/G1期,其机制可能通过阻断PI3K/Akt/m TOR信号通路而实现。     

Brassinin Induces Apoptosis in PC‐3 Human Prostate Cancer Cells through the Suppression of PI3K/Akt/mTOR/S6K1 Signaling Cascades

The oncogenic PI3K/Akt/mammalian target of rapamycin (mTOR) signaling axis and its downstream effector, the ribosomal protein S6 kinase 1 (S6K1) play a key role in mediating cell survival in various tumor cells. Here, we investigated the effects of brassinin (BSN), a phytoalexin first identified as a constituent of cabbage, on the PI3K/Akt/mTOR/S6K1 activation, cellular proliferation, and apoptosis in PC‐3 human prostate cancer. BSN exerted a significant dose‐dependent cytotoxicity and reduced constitutive phosphorylation of Akt against androgen‐independent PC‐3 cells as compared to androgen‐dependent LNCaP cells. Moreover, knockdown of androgen receptor (AR) by small interfering RNA enhanced the potential effect of BSN on induction of apoptosis in LNCaP cells. BSN clearly suppressed the constitutive activation of PI3K/Akt/mTOR/S6K1 signaling cascade, which correlated with the induction of apoptosis as characterized by accumulation of cells in subG1 phase, positive Annexin V binding, TUNEL staining, loss of mitochondrial membrane potential, down‐regulation of antiapoptotic and proliferative proteins, activation of caspase‐3, and cleavage of PARP. Additionally, BSN could block broad‐spectrum inhibition of PI3K/Akt/mTOR/S6K1 axes, and aberrant Akt activation by pcDNA3‐myr‐HA‐Akt1 plasmid could not prevent the observed suppressive effect of BSN on constitutive mTOR activation. Finally, overexpression of Bcl‐2 also attenuated BSN‐mediated apoptosis in PC‐3 cells. Taken together, our findings suggest that BSN can interfere with multiple signaling cascades involved in tumorigenesis and might be provided as a potential therapeutic candidate for both the prevention and treatment of prostate cancer. Copyright © 2013 John Wiley & Sons, Ltd.     

1-磷酸鞘氨醇通过PI3K/Akt信号通路对冠心病大鼠心肌细胞凋亡的调控作用研究

目的:观察1-磷酸鞘氨醇通过磷脂酰肌醇3-激酶(Phosphatidylinositol-3-OH kinase,PI3K)/蛋白激酶B (Protein kinase B,Akt)信号通路对冠心病(Coronary heart disease,CHD)大鼠心肌细胞凋亡的调控作用。方法:将45只清洁级Wistar雄性大鼠,随机分为假手术组、模型组和1-磷酸鞘氨醇(Sphingosine-1-phosphate,S1P)组,每组各15只。模型组和S1P组诱导CHD模型。模型诱导成功1周后,进行尾静脉注射给药。S1P组按1.0 mg/kg剂量给予S1P,假手术组和模型组分别给予等体积的生理盐水,每周1次,连续给药4周。采用TTC染色法测定各组大鼠的心肌梗死面积,使用TUNEL染色方法观察计算各组大鼠心肌细胞的凋亡指数,通过Western blot检测PI3K/Akt信号通路中相关蛋白PI3K、Akt及凋亡因子含半胱氨酸的天冬氨酸蛋白水解酶3 (Cysteinyl aspartate specific proteinase 3,Caspase-3)的表达情况。结果:TTC染色检测结果显示,与假手术组比较,模型组大鼠均出现大面积的心肌梗死(P<0.01);与模型组比较,S1P组大鼠心肌梗死面积显著减小(P<0.01)。TUNEL染色结果显示,与假手术组比较,模型组大鼠心肌细胞凋亡数量明显增加,其凋亡率显著升高(P<0.01);与模型组比较,S1P组大鼠心肌细胞的凋亡指数显著降低(P<0.05)。Western blot检测结果显示,各组间PI3K、Akt蛋白表达量无显著性差异(P>0.05);与假手术组比较,模型组心肌细胞内p-PI3K、p-Akt的表达量显著下降(P<0.01),Caspase-3的表达水升高(P<0.05);与模型组比较,S1P组p-PI3K、p-Akt的表达水平显著增加(P<0.01)。Caspase-3的表达水平降低(P<0.05)。结论:S1P可能是通过调节PI3K/Akt信号通路中相关蛋白的表达来有效抑制CHD大鼠心肌细胞凋亡的。     

Inhibitory Effects of Nobiletin on Hepatocellular Carcinoma In Vitro and In Vivo

Nobiletin (5, 6, 7, 8, 3′ 4′‐hexamethoxyflavone) is a major anticancer component in juice from zhishi (Rutaceae). This study aimed to investigate the inhibitory effect of Nobiletin on hepatic cancer cells both in vitro and in vivo. The 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide (MTT), growth curve, and clonogenic assay showed that nobiletin inhibited the proliferation of SMMC‐7721 cells in vitro. Hoechst staining observed the characteristics of cell apoptosis in nobiletin‐treated cells, and the apoptotic rates of treated groups were increased in a dose‐dependent manner. Flow cytometric analysis demonstrated that nobiletin could block the cell cycle arrested at G2 phase. Cell cycle analysis was performed using flow cytometry. Results showed that cell cycle phase distribution analysis showed G2 arrest. It was found that nobiletin downregulated the expressions of Bcl‐2 and COX‐2 and up‐regulated the expressions of Bax and caspase‐3 in SMMC‐7721 cells by western blotting. The experiment in vivo demonstrated that nobiletin significantly inhibited the growth of H22 transplantable tumor, downregulated the expressions of COX‐2, up‐regulated the expressions of Bax and caspase‐3 detected by immunohistochemistry and western blotting, and the ratios of Bcl‐2/Bax were decreased. Our results suggest that nobiletin has significant inhibitory effects on hepatocellular carcinoma both in vitro and in vivo. Copyright © 2013 John Wiley & Sons, Ltd.     

斑蝥酸钠维生素B6诱导人肝癌HepG2细胞凋亡及周期阻滞

目的: 研究斑蝥酸钠维生素B6（艾易舒）注射液对人肝癌HepG2细胞增殖、细胞周期与凋亡的影响,探讨其分子机制。 方法: 将不同浓度的斑蝥酸钠维生素B6注射液（0,1,5,10 mg·L^-1）作用于人肝癌HepG2细胞12,24,48 h,MTT法检测细胞增殖抑制率,流式细胞学技术检测细胞凋亡率及细胞周期的变化,Western blot检测蛋白激酶B（Akt）,磷酸化蛋白激酶B（pAkt）,B细胞淋巴瘤-2基因相关X蛋白（Bax）,B细胞淋巴瘤-2基因（Bcl-2）及细胞周期依赖性激酶抑制因子p21蛋白表达变化,RT-PCR检测Bax,Bcl-2及p21 mRNA表达变化。 结果: 斑蝥酸钠维生素B6可显著抑制HepG2细胞的增殖,诱导细胞凋亡,具有显著的时间和浓度效应（P<0.05）;同时G₀/G₁期细胞比例显著升高,S期细胞比例显著降低（P<0.05）。Western blot结果显示斑蝥酸钠维生素B6可下调HepG2细胞中pAkt和Bcl-2蛋白的表达,上调Bax和p21蛋白的表达（P<0.05）。RT-PCR结果显示Bax,p21 mRNA的表达水平明显升高,而Bcl-2 mRNA的表达水平下降（P<0.05）。 结论: 斑蝥酸钠维生素B6可抑制人肝癌HepG2细胞的增殖,诱导其凋亡并引发G₀/G₁期阻滞,其机制可能与斑蝥酸钠维生素B6参与调控磷脂酰肌醇-3-激酶/蛋白激酶B（PI3K/Akt）通路有关。     

Poncirin downregulates ATP‐binding cassette transporters to enhance cisplatin sensitivity in cisplatin‐resistant osteosarcoma cells

Poncirin, a flavanone glycoside with bitter taste extracted from dried immature fruit of Poncirus trifoliate, exhibits multiple biological activities including anti‐tumor activity. Our study aimed to determine the effect and potential mechanism of poncirin on cisplatin resistance in osteosarcoma (OS) cells. CCK‐8, flow cytometry analysis, and caspase‐3/7 activity assays were used to evaluate cisplatin sensitivity. The expression changes of multidrug resistance 1 (MDR1), multidrug resistance‐associated protein (MRP1), breast cancer resistance protein (BCRP), and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) pathway‐related proteins were detected by RT‐qPCR or western blot analyses. Results showed that poncirin exposure enhanced cisplatin sensitivity, promoted apoptosis, and increased caspase‐3/7 activity in cisplatin‐resistant OS cells. Poncirin decreased the expression levels of MDR1, MRP1, and BCRP, and inhibited the PI3K/Akt signaling in OS cells. Rescue experiments suggested that activation of the PI3K/Akt signaling by 740Y‐P abolished poncirin‐induced expression reduction of MDR1, MRP1, and BCRP, and attenuated the facilitative effects of poncirin on cisplatin sensitivity and apoptosis in cisplatin‐resistant OS cells. In summary, poncirin suppressed cisplatin resistance in cisplatin‐resistant OS cells by downregulating the expression of MDR1, MRP1, and BCRP through inhibiting the PI3K/Akt pathway.     

小檗碱对体外HepG2细胞IR模型抗IR的效应及机制

目的:探讨小檗碱对HepG2细胞胰岛素抵抗(IR)模型的改善作用及机制。方法:HepG2细胞采用高糖(25 mmol·L~(-1))和高胰岛素(1×10~(-6)mol·L~(-1))联合诱导24 h,建立体外IR模型。模型培养液中分别加入1×10~(-5),1×10~(-6)mol·L~(-1)小檗碱,设1×10-3mol·L~(-1)二甲双胍作为阳性药,孵育24 h。葡萄糖氧化酶法检测培养液葡萄糖含量,计算细胞葡萄糖消耗量,细胞增殖活性检测(CCK-8)测定细胞增殖活性;生化法检测细胞丙酮酸激酶(PK)活性,酶联免疫吸附试验(ELISA)检测细胞葡萄糖激酶(GCK)和葡萄糖转运蛋白2(GLUT2)的活性;实时荧光定量聚合酶链式反应(Real-time PCR)检测细胞胰岛素受体(InsR),磷脂酰肌醇-3激酶(PI3K),丝氨酸/苏氨酸蛋白激酶B(Akt)和GLUT2 mRNA表达水平,蛋白免疫印迹法(Western blot)检测各组细胞胰岛素受体底物-1(IRS-1),磷酸化的磷脂酰肌醇-3激酶(p-PI3K)和磷酸化的丝氨酸/苏氨酸蛋白激酶B(p-Akt)的表达水平。结果:与正常组比较,模型组细胞葡萄糖消耗量显著降低(P0.01),PK,GCK,GLUT2蛋白活性显著降低(P0.01),InsR,PI3K,Akt,GLUT2 mRNA表达水平显著降低(P0.01),IRS-1,p-PI3K,p-Akt蛋白表达水平显著降低(P0.01)。与模型组比较,小檗碱组和二甲双胍组的细胞葡萄糖消耗量明显增加(P0.01),PK,GCK,GLUT2蛋白活性显著升高(P0.01),InsR,PI3K,Akt,GLUT2 mRNA和IRS-1,p-PI3K,p-Akt1蛋白表达水平均明显升高(P0.05,P0.01)。结论:小檗碱体外对HepG2细胞IR模型有显著的改善作用,其机制可能通过调节IRS-1/PI3K/Akt信号通路促进肝脏葡萄糖转运和改善葡萄糖代谢。     

阳和化岩汤对HER-2高表达型乳腺癌细胞PI3K/Akt通路HER-2,PI3K,p-Akt表达的机制

目的:观察阳和化岩汤与磷脂酰肌醇-3羟基激酶(PI3K)抑制剂LY294002对乳腺癌细胞株SK-BR-3[人表皮生长因子受体-2(HER-2)高表达型]PI3K/蛋白激酶B(Akt)信号通路中HER-2,PI3K,磷酸化蛋白激酶B(p-Akt)表达的影响,研究阳和化岩汤的干预机制。方法:制备阳和化岩汤肠吸收液,将乳腺癌细胞株SK-BR-3分为空白组,阳和化岩汤组,LY294002组,LY294002+阳和化岩汤组,阳和化岩汤(125 g·L-1),LY294002 (0. 05 g·L-1),阳和化岩汤+LY294002 (阳和化岩汤125 g·L-1,LY294002 0. 05 g·L-1),用药干预24 h后通过免疫组化、蛋白免疫印迹法(Western blot)检测HER-2,PI3K,p-Akt蛋白表达,通过逆转录聚合酶链式反应(RT-PCR)检测HER-2,PI3K,p-Akt mRNA表达。结果:与空白组比较,LY294002组,LY294002+阳和化岩汤组均能抑制乳腺癌细胞株HER-2,PI3K,p-Akt蛋白及mRNA表达(P 0. 05);阳和化岩汤组能抑制乳腺癌细胞株HER-2,p-Akt蛋白及mRNA表达(P 0. 05),但对PI3K的抑制作用不明显;联用LY294002较单用LY294002具有进一步抑制PI3K表达的作用(P 0. 05)。与阳和化岩汤组,LY294002组比较,LY294002+阳和化岩汤组能够明显抑制HER-2,PI3K,p-Akt蛋白及mRNA表达(P 0. 05)。结论:阳和化岩汤能够抑制乳腺癌脉管生成和侵袭,主要作用机制为通过干预PI3K/Akt通路,降低通路中HER-2,PI3K,p-Akt表达。     

Induction of apoptosis and inhibition of PI3K/Akt pathway in PC-3 and LNCaP prostate cancer cells by ethanolic neem leaf extract

Aim of the study

The present study is aimed to delineate the effect of ethanolic neem leaf extract on PI3K/Akt and apoptotic pathway in prostate cancer cell lines (PC-3 and LNCaP).

Materials and methods

To test the hypothesis, two different prostate cancer cell lines LNCaP (androgen dependent) and PC-3 (androgen independent) were taken. Cells were exposed to various concentrations of ethanolic neem leaf extract (ENLE) (25-125 μg/ml). The doses were fixed by cell viability (MTT) assay. For apoptotic detection in situ apoptosis assay, caspase-3 activity and protein expression of cytochrome c and Poly-ADP Ribose Polymerase (PARP) were analysed as well as mRNA expression of Bcl-2 family proteins was studied by RT-PCR. The phosphoinositide 3-kinase (PI3K) and p-Akt were analysed by western blotting and mRNA expression of Akt 1 and 2, PTEN was performed by RT-PCR. Immunoblotting of cyclin D1 and p21 was done to access the inhibition of cell proliferation.

Results

ENLE gives 50% inhibition at a dose of 100 μg/ml in both PC-3 and LNCaP cells and considered as effective dose. ENLE decreased the protein expression of PI3K as well as p-Akt and the mRNA expression of Akt 1and 2 in both the cells. There was a significant decrease in mRNA expression of PTEN in LNCaP cells. ENLE induced apoptosis and inhibited cell proliferation by inhibiting PI3K/Akt pathway. Decrease in p-Akt leads to increase in the protein level of Bad, p21 and decrease in the cyclin D1, respectively. ENLE treatment increased the cytochrome c expression and caspase-3 activity as well as regulated the mRNA expression of Bcl-2 family proteins thereby inducing apoptosis to both the cell lines. In situ apoptosis assay showed increased red fluorescence in 100 μg/ml of ENLE in both PC-3 and LNCaP cell lines.

Conclusions

The results suggested that ENLE induces apoptosis and inhibits cell proliferation through inhibiting PI3K/Akt pathway in both PC-3 and LNCaP cells.     

[6]‐Gingerol enhances the cisplatin sensitivity of gastric cancer cells through inhibition of proliferation and invasion via PI3K/AKT signaling pathway

Cisplatin‐based chemotherapy is a widely used chemotherapeutic regimen for gastric cancer; however, drug resistance limits its efficacy. [6]‐Gingerol has been found to exhibit anticancer effects. Here, we aim to explore the potential of [6]‐gingerol in combination with cisplatin as a new regimen for gastric cancer. CCK‐8 assay and colony formation assay were used to determine the effect of [6]‐gingerol in combination with cisplatin on cell viability of gastric cancer cells. Flow cytometry was performed to assess cell cycle distribution. Wound‐healing assay and transwell invasion assay were conducted to examine the migration and invasion abilities. Cell cycle and invasion‐related proteins and mRNAs, as well as PI3K/AKT signaling proteins, were assessed by western blotting and quantitative real‐time polymerase chain reaction. Combination of [6]‐gingerol with cisplatin inhibited cell viability and enhanced cell cycle arrest at G1 phase compared with cisplatin alone. The combination treatment inhibited cell migration and invasion ability and decreased cyclin D1, cyclin A2, matrix metalloproteinase‐9, p‐PI3K, AKT, and p‐AKT protein expressions and increased P21 and P27 mRNA levels. Our study demonstrates that [6]‐gingerol enhances the cisplatin sensitivity of gastric cancer cells and that the mechanisms involve G1 phase arrest, migration and invasion suppression via PI3K/AKT signaling pathway.