Expression of Fas and induction of apoptosis by anti-Fas monoclonal antibody in human bile duct carcinoma cells,and enhancement of induction of apoptosis by IFN-gamma

We investigated the expression of Fas, the induction of apoptosis by anti-Fas monoclonal antibody CH-11, and the effect of IFN-gamma on the induction of apoptosis in human bile duct carcinoma cells HuCCT1 and HuH28. Fas was expressed in 21.7% and 30.9% of HuCCT1 and HuH28 cells, respectively. Pretreatment with IFN-gamma increased the Fas expression by 17.6% in HuCCT1 cells. However, IFN-gamma did not affect the expression of Fas in HuH28 cells. In HuCCT1 and HuH28 cells treated with CH-11, the peak corresponding to that of positive control cells was detected with the TUNEL method by FCM. The condensation and fragmentation of the nucleus, and the apoptotic body were observed as morphological changes specific to apoptosis. CH-11 dose-dependently reduced HuCCT1 and HuH28 cell counts by up to 16.4% and 71.7%, respectively on day 3. Interferon-gamma attenuated the reduction of HuCCT1 cell counts by 12.8% on day 3. However, IFN-gamma had no effect on HuH28 cell counts. These results suggest that Fas was expressed, apoptosis was induced by CH-11 and the induction of apoptosis was enhanced by IFN-gamma in human bile duct carcinoma cells.     

Metformin Inhibits Migration and Invasion of Cholangiocarcinoma Cells

Background: Metformin is an oral anti-diabetic agent that has been widely prescribed for treatment of type II diabetes. Anti-cancer properties of metformin have been revealed for numerous human malignancies including cholangiocarcinoma (CCA) with anti-proliferative effects in vitro. However, effects on CCA cell migration and invasion have not been fully investigated. The present study aimed to explore the inhibitory effects of metformin on motility, migration and invasion of the CCA cell line HuCCT1, and examine molecular mechanisms underlying metformin effects. Methods: HuCCT1 cells were exposed to increasing doses of metformin. Viability and growth of HuCCT1 cells were assessed by MTS and colony formation assays, respectively. Motility, migration and invasion of metformin-treated HuCCT1 cells were determined in vitro using wound healing, transwell migration and matrigel invasion assays. Expression of signaling molecules and epithelial-mesenchymal transition (EMT) markers was assessed by Western blotting. Results: It was observed that metformin significantly decreased HuCCT1 cell viability and colony formation. The agent also markedly reduced wound closure, migration and invasion of HuCCT1 cells. Furthermore, metformin exposure resulted in decreased STAT3 activation and down-regulation of anti-apoptotic protein Bcl-2 and Mcl-1 expression. In addition, it upregulated the expression of E-cadherin, while downregulating that of N-cadherin, Snail, and MMP-2. Conclusion: These results demonstrated inhibitory effects of metformin on CCA cell migration and invasion, possibly involving the STAT3 pathway and reversal of EMT markers expression. They further suggest that metformin may be useful for CCA management.     

Atractylodin and β-eudesmol from Atractylodes lancea (Thunb.) DC. Inhibit Cholangiocarcinoma Cell Proliferation by Downregulating the Notch Signaling Pathway

Objective: Notch signaling pathway has been reported to be involved in the development and progression of various types of cancer, including cholangiocarcinoma (CCA).  Compounds that modulate this signaling pathway could be promising candidates for CCA treatment and control. The study investigated the antiproliferative activities and modulatory effects of atractylodin and β-eudesmol, the two bioactive compounds of Atractylodes lancea (Thunb.) DC. , on Notch signaling and upstream molecules (Notch1 and Notch2 receptors, JAG1, mTOR, PI3K, and YAP), and downstream molecules (Snail) in HuCCT-1 (CCA cell line) and OUMS-36T-1 (normal fibroblast cell line). Gemcitabine (standard drug for CCA), and Notch inhibitors (DAPT and zebularine) were included in the experiments as positive control compounds. Methods: The antiproliferative activity was evaluated using MTT assay.  mRNA and protein expression of Notch signaling molecules were evaluated using real-time PCR and Western blot analysis. Results: Atractylodin and β-eudesmol moderately inhibited HuCCT-1  cell growth with IC50 (concentration that inhibits cell growth by 50%) of 29.00 ± 6.44 and 16.80 ± 4.41 µg/ml (mean±SD), respectively. The direction and extent of the modulatory effects on mRNA and protein expression in the CCA cell line varied with the signaling molecules. Notch1 receptor was shown to be the most promising target of atractylodin and β-eudesmol in CCA. The level of gene expression was significantly downregulated (0.042 to 0.195 fold of control) after treating HuCC-T1 cells with both compounds at low and high concentrations. The extent and change in Notch1 gene expression correlated well with protein expression. Conclusion: The notch signaling pathway could be a promising target of atractylodin and β-eudesmol in CCA.     

鼻咽癌干细胞的生物学行为特征及CD44对Ras信号通路的调控作用

目的探讨鼻咽癌干细胞的生物学行为和Ras信号通路特征,以及CD44与Ras信号通路活化之间的调控关系。方法采用无血清悬浮培养法获得鼻咽癌CNE2和5-8F细胞的干细胞CNE2-SC和5-8F-SC。采用细胞计数试剂盒8(CCK-8)法检测细胞增殖,细胞平板克隆形成实验观察细胞克隆形成情况,Transwell细胞迁移实验检测细胞的迁移能力,细胞黏附实验观察细胞贴壁情况,Western blot法检测细胞中Ras信号通路相关蛋白的表达水平,采用RNA干扰技术明确CD44对Ras信号通路的调控作用。结果接种后24、48和72 h,鼻咽癌干细胞CNE2-SC和5-8F-SC的增殖能力分别低于其来源鼻咽癌细胞(均P<0.05)。细胞种植14 d后,CNE2-SC细胞的克隆形成率为(44.5±1.9)%,高于其来源细胞CNE2[(34.9±1.5)%,P<0.01];5-8F-SC细胞的克隆形成率为(47.4±1.8)%,亦高于其来源细胞5-8F[(37.2±1.7)%,P<0.01]。CNE2-SC细胞的迁移细胞数为(87.6±7.8)个/视野,是CNE2细胞的3.97倍(P<0.01)。5-8F-SC细胞的迁移细胞数为(67.2±5.7)个/视野,是5-8F细胞的3.07倍(P<0.01)。接种后3 h,CNE2-SC和CNE2细胞的黏附贴壁率分别为(42.1±7.6)%和(8.9±2.0)%;接种后6 h,分别为(82.4±5.0)%和(12.1±2.2)%。CNE2-SC细胞的黏附贴壁率均高于CNE2细胞(均P<0.01)。接种后3 h,5-8F-SC和5-8F细胞的黏附贴壁率分别为(53.6±6.1)%和(7.3±1.5)%;接种后6 h,分别为(90.7±3.6)%和(11.0±1.2)%。5-8F-SC细胞的黏附贴壁率均高于5-8F细胞(均P<0.01)。与普通鼻咽癌细胞相比,鼻咽癌干细胞中CD44、Ras和N-钙黏蛋白(N-cadherin)的表达水平升高(均P<0.01),E-钙黏蛋白(E-cadherin)、10号染色体缺失的磷酸酶和张力蛋白同源物(PTEN)表达水平降低(均P<0.01),磷酸化丝裂原细胞外激酶1/2(p-MEK1/2)、磷酸化细胞外信号调节蛋白激酶1/2(p-ERK1/2)磷酸化水平升高(均P<0.01)。相关分析显示,CNE2细胞与CNE2-SC细胞中,5-8F细胞与5-8F-SC细胞中,CD44与Ras蛋白表达水平均呈高度正相关(r=0.985,P=0.002;r=0.962,P=0.038)。沉默CNE2-SC细胞中CD44的表达后,人表皮生长因子受体2(HER-2)和Ras的蛋白表达水平显著降低,p-ERK1/2、p-Akt和p-PKCδ磷酸化水平下降(均P<0.01)。结论相对于来源鼻咽癌细胞,鼻咽癌干细胞增殖能力降低,但其克隆形成能力、迁移能力、黏附能力增强,可能与其CD44调控的Ras信号通路异常激活有关。     

The Potential of Atractylodin-Loaded PLGA Nanoparticles as Chemotherapeutic for Cholangiocarcinoma

Backgrounds: The anti-cholangiocarcinoma (CCA) activity of atractylodin isolated from Atractylodes lacea (Thunb.) DC. has previously been demonstrated both in vitro and in vivo. However, the compound is insoluble in water and must be dissolved in organic solvent which might be harmful to human body. The aim of the study was to develop atractylodin-loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) (ALNPs) and to investigate its cytotoxic activity against CCA. Methods: The ALNPs were prepared using PLGA MW 12,000 and 48,000 by solvent displacement methods. Particle size, polydispersity index (PDI), zeta potential, encapsulation efficiency (%EE) and loading efficiency (%LE) as well as drug releasing profile of ALNPs were characterized. The selected ALNPs formulation was then investigated cytotoxic activity against CCA cell lines, CL-6 and HuCC-T1. Results: The ALNPs preparation was achieved using PLGA MW 12,000 (ALNPs-1) with mean (±SD) values of particle diameter, PDI and zeta potential of 158.13±0.21 nm, 0.076±0.003, and (-) 23.80± (-) 0.75 mV, respectively. The transmission electron microscopy (TEM) showed spherical morphology of NPs. The %EE and %LE were 50.16±1.77% and 2.22±0.08%, respectively. The release of atractylodin from ALNPs-1 in PBS was up to 88% in 72 h. The potency of ALNPs-1 cytotoxic activity including selectivity against CCA cell line, CL-6, were about twice of the unformulated atractylodin after 24 h of exposure (IC50: 29.28 vs 56.36 µg/mL, selectivity index 2.99 vs 1.50). Conclusion: ALNPs were successfully prepared by solvent displacement method using PLGA MW 12,000 (ALNPs-1) with suitable pharmaceutical properties and cytotoxic activity against CCA. However, nano-formulation with improved pharmaceutical properties (higher %EE and %LE) and cytotoxic activity (improved selectivity to CCA) should be further developed for potential used as drug delivery systems for the treatment of CCA.     

哈萨克族食管癌患者组织中细胞外信号调节激酶/丝裂原活化蛋白激酶信号通路的表达

目的 探讨细胞外信号调节激酶(ERK)/丝裂原活化蛋白激酶(MAPK)信号通路在哈萨克族食管鳞癌患者组织中的表达变化及意义.方法 采用Western blot技术检测在血清饥饿条件下、U0126梯度浓度处理下,食管癌细胞系EC9706中磷酸化ERK1(p-ERK1)和磷酸化ERK2(p-ERK2)的表达变化.采用实时荧光定量PCR法检测25例哈萨克族食管癌患者肿瘤组织和癌旁正常组织中总ERK1(t-ERK1)和总ERK2(t-ERK2)mRNA的表达变化.采用Western blot技术检测25例哈萨克族食管癌患者肿瘤组织、癌旁正常组织以及5例哈萨克族非食管癌者正常食管组织中t-ERK1、t-ERK2、p-ERK1和p-ERK2蛋白的表达变化.采用免疫组化染色法,在126例石蜡包埋标本(正常食管黏膜19例,食管原位癌55例,食管浸润癌52例)中验证p-ERK1和p-ERK2蛋白的表达变化.结果 在食管癌EC9706细胞中,ERK/MAPK信号通路呈高度活化状态.血清瞬时刺激10 min后,p-ERK1和p-ERK2的表达达到峰值.EC9706细胞在50 μmol/L的U0126处理下,p-ERK1和p-ERK2的表达几乎完全被抑制.t-ERK1 mRNA在25例哈萨克族食管癌患者肿瘤组织中的表达量为1.92±3.49,明显低于癌旁组织(3.67±7.47,P<0.05);t-ERK2 mRNA在食管癌组织和癌旁组织中的表达量差异无统计学意义(P>0.05).t-ERK1和t-ERK2蛋白在食管癌组织、相应癌旁组织和正常食管黏膜组织中的表达差异无统计学意义(P>0.05);但p-ERK1和p-ERK2蛋白在食管癌组织中的表达量(分别为0.87±0.14和0.79±0.10)均明显低于癌旁组织(分别为1.10±0.13和1.32±0.12,P<0.05)和正常食管黏膜组织(分别为1.50±0.22和1.64±0.18,P<0.05).免疫组化染色验证的结果 显示,p-ERK1和p-ERK2蛋白在浸润性食管癌组织中的阳性表达率均为7.7%(4/52),在癌旁正常食管黏膜组织中的阳性表达率均为31.6%(6/19),在食管原位癌组织中的阳性表达率均为85.5%(47/55),不同组织间的表达差异有统计学意义(P<0.05).结论 在食管癌细胞中,ERK/MAPK信号通路呈活化状态.ERK/MAPK信号通路活化水平的改变可能参与了哈萨克族食管癌患者肿瘤的早期发生.

Abstract：

Objective To investigate the expression variation and significance of ERK1/2 MAPK signaling transduction pathway in the pathogenesis of esophageal squamous cell carcinoma (ESCC) in Kazakh patients. Methods The expression level of p-ERK1/2 after serum starvation and treatment with U0126 inhibitor was detected in esophageal cancer cell line EC9706 by Western blot assay. The mRNA level of total ERK1/2 (t-ERK1/2) and expression level of t-ERK1/2 and p-ERK1/2 proteins of 25 pairs of ESCC and adjacent normal esophageal mucosal tissues of Kazakh patients were examined and identified by real-time quantitative PCR (qRT-PCR) and Western blotting, respectively. The expression of p-ERK1/2 protein was verified by immunohistochemistry in 126 paraffin-embeded specimens, including 19 normal esophageal mucosa, 55 esophageal carcinomas in situ and 52 invasive carcinomas. Results ERK1/2 MAPK signaling transduction pathway was in an active status in the EC9706 cells. The expression level of p-ERK1/2 in Ec9706 cells reached a peak at 10 min after transient serum stimulation, and p-ERK1/2 expression was totally restrained after the treatment with 50 μmol/L U0126. In the 25 pairs of ESCC and adjacent normal mucosa, the t-ERK1 mRNA level was 1.92±3.49 in the ESCC tissues and 3.67±7.47 in the adjacent normal mucosa. The t-ERK1 mRNA level in ESCC tissues was significantly lower than that in adjacent normal mucosa (P<0.05), whereas there was no significant difference of t-ERK2 mRNA level between them(P>0.05). The expression levels of p-ERK1 and p-ERK2 proteins were 0.87±0.14 and 0.79±0.10 in the ESCC tissues, and 1.10±0.13 and 1.32±0.12 in the adjacent normal mucosae. p-ERK1/2 protein in the ESCC tissues was significantly lower than that in the adjacent normal tissue (P<0.01). However, there was no significant difference between their t-ERK1/2 protein levels (P>0.05). In the 126 cases of paraffin-embeded specimens, positive expressions of both p-ERK1 and p-ERK2 in esophageal cancer tissues were 7.7% (4/52), significantly lower than those in adjacent normal mucosa (31.6%, 6/19) and carcinoma in situ (85.5%, 47/55, P<0.05). Conclusions ERK1/2 MAPK signaling pathway is in an active status in esophageal cancer and adjacent normal mucosa. Our results imply that the activation of p-ERK1/2 MAPK signaling transduction pathway plays a role in the early pathogenesis of ESCC in Kazakh patients.     

葫芦素E对非小细胞肺癌细胞的生长抑制作用

目的:体外观察葫芦素E（cucurbitacin E,CuE）对非小细胞肺癌细胞系A549增殖的影响及分子作用机制。方法:采用MTT法检测不同浓度 CuE（0、1、10、100以及1000nmol/L）处理A549细胞24、48和72小时后的细胞增殖情况。流式细胞仪检测CuE对A549细胞凋亡的影响。 Western blot法检测被处理细胞中p-STAT3、p-Raf-1、p-MEK1/2、p-ERK1/2、Bcl-2、Fas蛋白表达水平的变化。结果:CuE可显著抑制A549细胞的增殖（P＜0.05）,且呈时间和浓度依赖性。流式细胞仪检测显示随着CuE作用浓度的逐渐升高（0、100、200、400nmol/L）,A549细胞凋亡率由（4.63±0.70）%分别提高到（6.80±0.10）%、（20.53±0.49）%、（24.57±0.55）%,差异有统计学意义（P均<0.05）。Western blot结果显示CuE处理A549细胞,可降低p-STAT3、p-Raf-1、p-MEK1/2、p-ERK1/2、Bcl-2蛋白表达水平,增强Fas蛋白表达水平,且上述作用随CuE浓度升高而增强。结论:CuE可显著抑制A549细胞的增殖并诱导凋亡,其作用机制与阻断STAT3和Raf/MEK/ERK信号通路,同时激活Fas信号通路有关。     

瘦素对人肺腺癌A549细胞增殖及p-ERK1/2、VEGF表达的影响

 目的观察瘦素对人肺腺癌 A549 细胞增殖及p-ERK1/2、VEGF 表达的影响。初步探讨瘦素在促进肿瘤血管生成中的机制。方法 对人肺腺癌 A549 细胞采用细胞培养,MTT 法检测不同浓度瘦素对人肺腺癌A549细胞增殖影响,免疫组织化学法检测VEGF表达、Western blot 方法检测瘦素对p-ERK1/2、VEGF表达的影响。结果 在一定范围内,瘦素呈时间、剂量依赖性促进A549细胞的生长(P<0.05);与阴性对照组相比,不同浓度瘦素作用48h 后p-ERK1/2、VEGF 蛋白表达明显增加并具有剂量依赖性(P<0.05);p-ERK1/2和VEGF 之间呈正相关性(r=0.694,P<0.05)。结论 在体外瘦素对人肺腺癌A549 细胞有明显增殖作用,通过促进p ERK1/2和VEGF的表达,瘦素在促进肺癌血管的生长机制中可能具有一定作用。     

木鳖子醇提物诱导小鼠黑素瘤B16细胞分化的作用机制

目的:探讨木鳖子醇提物(ethanol extract of cochinchina momordica seed,CMSEE)诱导黑素瘤B16细胞分化的作用机制。方法:CMSEE处理B16细胞后,瑞氏染色法观察B16细胞的形态变化;比色法检测B16细胞的黑素含量。Westernblotting检测经CMSEE和p38、ERK通路抑制剂SB203580、SD98059分别处理后B16细胞中p-p38、p-ERK表达的变化。结果:CMSEE可诱导B16细胞分化,使细胞的黑素量含量明显升高(P<0.01),10、20、40μg/ml CMSEE处理组B16细胞的黑素量D值分别为(0.057±0.007)、(0.173±0.005)和(0.249±0.002),而对照组为(0.037±0.002)。20μg/ml CMSEE处理B16细胞后,p-p38蛋白表达水平明显升高,处理60 min时的相对表达量最高,为对照组的5.6倍;而p-ERK表达水平明显降低(P<0.01),处理60 min时的相对表达量为对照组的25%倍。p38通路抑制剂SB203580可阻断CMSEE对B16细胞的分化诱导作用,而ERK通路抑制剂SD98059可增强CMSEE对B16细胞的分化诱导作用。结论:p38通路和ERK通路的活化参与了CMSEE对B16细胞的分化诱导作用。     

右旋柠烯对人结肠癌LS174T细胞p-ERK和p-Akts表达的影响

目的研究右旋柠烯(D-limonene)对人结肠癌细胞(LS174T)中信号传导分子ERK1/2、Akt及其磷酸化蛋白(p-ERK和p-Akts蛋白)表达的影响。方法 采用四甲基偶氮唑盐(MTT)方法检测右旋柠烯对LS174T细胞增殖的抑制作用;采用Western blot方法检测不同浓度右旋柠烯对LS174T细胞中ERK1/2、Akt及其磷酸化蛋白表达情况的影响。结果 右旋柠烯作用LS174T细胞48h后,呈剂量依赖性抑制细胞增殖;Western blot结果显示右旋柠烯对细胞中ERK1/2、Akt蛋白的表达没有明显影响,但显著下调p-ERK1/2蛋白和p-Akts的表达。结论 右旋柠烯抑制LS174T细胞增殖可能与其抑制p-ERK1/2和p-Akts表达有关。     

Statin attenuates cell proliferative ability via TAZ (WWTR1) in hepatocellular carcinoma

Diabetes and obesity are associated with non-alcoholic steatohepatitis and an increased incidence of hepatocellular carcinoma (HCC). TAZ and YAP are equivalently placed downstream effectors of the Hippo pathway with oncogenic roles in human cancers. Statins are commonly used to patients with metabolic problems as hypercholesterolemia. Statins also have anti-cancer properties, and the cross-talk between mevalonate pathway and Hippo pathway was known. The aim of this study is to confirm the statin’s anti-cancer effects on HCC cells and its survival benefits in HCC patients with curative surgery. TAZ expression level in HCC cell lines was analyzed by western blot. Two cell lines (HLF and HuH1) were used in this study. Then the mechanism of statin’s anti-proliferative effect was examined in HLF and HuH1 cells. In clinical setting, overall survival and recurrence-free survival (RFS) rate were examined in comparison between statin intake and statin non-intake group. The proliferation assay using four different statins (atorvastatin, pravastatin, fluvastatin, simvastatin). Simvastatin and fluvastatin showed very strong growth suppressive effects, and induced apoptosis in HLF cells, but not HuH1 cells. TAZ expression was suppressed in HLF cells by fluvastatin and simvastatin treatment. The similar change pattern was confirmed in p-ERK1/2 and ERK. In HuH1 cells, such expression change was not confirmed. In clinical setting, statin intake was significantly associated with longer RFS in the HCC patients with hepatectomy (P = 0.038). The statin had the anti-proliferative effects and induced apoptosis in HCC cells and improved the prognosis of HCC patients.     

Glypican-6在胃肠道间质瘤组织中的表达及其通过ERK1/2通路促进细胞的增殖、迁移及侵袭

目的:探究Glypican-6对胃肠道间质瘤的作用及其可能的作用机制.方法:收集胃肠道间质瘤组织及其癌旁组织27例,RT-PCR和Western blot检测组织中Glypican-6的表达.选取胃肠道间质瘤细胞系GIST-T1进行体外研究.RT-PCR实验检测细胞中Glypican-6 mRNA的表达;Western...     

Ras和磷酸化ERK信号通路参与三氧化二砷逆转耐药作用机制的研究

  目的   体外实验研究三氧化二砷(As₂O₃)对人胃癌阿霉素耐药细胞株(SGC7901/ADM)的逆转耐药机制。   方法   MTT法检测磷酸化ERK(p-ERK)激动剂G-CSF作用前后As₂O₃的逆转耐药倍数; 免疫细胞化学法测定As₂O₃及G-CSF作用前后SGC7901/ADM细胞内Ras和p-ERK的变化; 流式细胞仪测定G-CSF和As₂O₃干预后SGC7901/ADM的细胞周期和凋亡率。   结果   SGC7901/ADM对ADM耐药, As₂O₃可逆转耐药, 其中0.5μmol/L As₂O₃作用48 h后逆转耐药倍数约为6.29。G-CSF干预后, 逆转耐药倍数降至4.72;SGC7901/ADM中Ras表达高于亲本细胞株SGC7901/S, 而p-ERK无明显差异, As₂O₃可下调Ras及p-ERK的表达。G-CSF干预后, As₂O₃下调Ras及p-ERK表达的能力较干预前显著降低。0.1μmol/L和0.5μmol/L As₂O₃组的G₀~G₁期细胞比例和凋亡率均显著高于各个对照组; G-CSF干预后同一剂量的As₂O₃组G₀~G₁期细胞及凋亡率较干预前均显著降低。   结论   As₂O₃可逆转人胃癌耐药细胞株SGC7901/ADM对ADM的耐药作用, 其机制与下调Ras/p-ERK信号传导通路中Ras、磷酸化ERK的表达有关。      

三氧化二砷对人胃癌耐药细胞系SGC7901/ADM耐药逆转及凋亡诱导作用的探讨

  目的   体外实验研究三氧化二砷(As₂O₃)对人胃癌阿霉素耐药细胞株(SGC7901/ADM)的逆转耐药机制。   方法   MTT法检测磷酸化ERK(p-ERK)激动剂G-CSF作用前后As₂O₃的逆转耐药倍数; 免疫细胞化学法测定As₂O₃及G-CSF作用前后SGC7901/ADM细胞内Ras和p-ERK的变化; 流式细胞仪测定G-CSF和As₂O₃干预后SGC7901/ADM的细胞周期和凋亡率。   结果   SGC7901/ADM对ADM耐药, As₂O₃可逆转耐药, 其中0.5μmol/L As₂O₃作用48 h后逆转耐药倍数约为6.29。G-CSF干预后, 逆转耐药倍数降至4.72;SGC7901/ADM中Ras表达高于亲本细胞株SGC7901/S, 而p-ERK无明显差异, As₂O₃可下调Ras及p-ERK的表达。G-CSF干预后, As₂O₃下调Ras及p-ERK表达的能力较干预前显著降低。0.1μmol/L和0.5μmol/L As₂O₃组的G₀~G₁期细胞比例和凋亡率均显著高于各个对照组; G-CSF干预后同一剂量的As₂O₃组G₀~G₁期细胞及凋亡率较干预前均显著降低。   结论   As₂O₃可逆转人胃癌耐药细胞株SGC7901/ADM对ADM的耐药作用, 其机制与下调Ras/p-ERK信号传导通路中Ras、磷酸化ERK的表达有关。     

ERRγ对子宫内膜癌细胞移植瘤组织中Akt、ERK表达的影响

目的:以ERα（+）子宫内膜癌细胞株Ishikawa为研究对象,建立子宫内膜癌细胞的裸鼠皮下移植瘤模型,进一步研究在子宫内膜癌细胞移植瘤中ERK、p-ERK、Akt、p-Akt蛋白的表达及其意义。方法:利用转染前后的Ishikawa细胞建立子宫内膜癌细胞裸鼠皮下移植瘤模型,采用免疫组织化学链霉亲和素-生物素过氧化物酶复合物(SABC法)检测裸鼠移植瘤中ERRγ蛋白的表达情况。Western blot方法检测移植瘤组织中Akt、p-Akt、ERK、p-ERK蛋白的表达情况。结果:免疫组化检测Ishikawa 细胞移植瘤组与no-silence Ishikawa细胞移植瘤组（空载体组）ERRγ蛋白表达阳性率无显著性差异（P＞0.05）,Ishikawa 细胞移植瘤组与ERRγ-shRNA Ishikawa细胞移植瘤组阳性率具有显著性差异（P＜0.05）。Western blot方法检测3组组织的活化情况:ERRγ-shRNA Ishikawa细胞移殖瘤组中Akt、p-Akt、ERK、p-ERK表达量均低于Ishikawa 细胞移殖瘤及no-silence Ishikawa细胞移殖瘤组（P＜0.05）。结论:沉默ERRγ基因的瘤组织的ERK及Akt的表达呈现低表达,从而可以推测:通过ERRγ的表达来调节ERK及Akt信号通路的表达,进一步抑制子宫内膜癌Ishikawa细胞增殖,促进其凋亡。     

Ras transformation of RIE-1 cells activates cap-independent translation of ornithine decarboxylase: regulation by the Raf/MEK/ERK and phosphatidylinositol 3-kinase pathways

Ornithine decarboxylase (ODC) is the first and generally rate-limiting enzyme in polyamine biosynthesis. Deregulation of ODC is critical for oncogenic growth, and ODC is a target of Ras. These experiments examine translational regulation of ODC in RIE-1 cells, comparing untransformed cells with those transformed by an activated Ras12V mutant. Analysis of the ODC 5' untranslated region (5'UTR) revealed four splice variants with the presence or absence of two intronic sequences. All four 5'UTR species were found in both cell lines; however, variants containing intronic sequences were more abundant in Ras-transformed cells. All splice variants support internal ribosome entry site (IRES)-mediated translation, and IRES activity is markedly elevated in cells transformed by Ras. Inhibition of Ras effector targets indicated that the ODC IRES element is regulated by the phosphorylation status of the translation factor eIF4E. Dephosphorylation of eIF4E by inhibition of mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase (MEK) or the eIF4E kinase Mnk1/2 increases ODC IRES activity in both cell lines. When both the Raf/MEK/ERK and phosphatidylinositol 3-kinase/mammalian target of rapamycin pathways are inhibited in normal cells, ODC IRES activity is very low and cells arrest in G(1). When these pathways are inhibited in Ras-transformed cells, cell cycle arrest does not occur and ODC IRES activity increases, helping to maintain high ODC activity.     

ghrelin调控ERK信号通路对乳腺癌细胞多药耐药的影响及机制

目的:探讨ghrelin调控ERK信号传导通路对乳腺癌细胞多药耐药的影响及机制.方法:人乳腺癌细胞MDA-MB-231细胞培养,设立对照组、多柔比星组、gbrelin组、ghrelin联合多柔比星组、ghrelin联合多柔比星加PD098059抑制剂组,采用流式细胞法检测细胞凋亡,Western-blot方法检测细胞ERK、p-ERK、P-gp蛋白的表达.结果:在ghrelin干预下人乳腺癌MDA-MB-231细胞凋亡率最低(P＜0.01),在多柔比星的干预下人乳腺癌MDA-MB-231细胞凋亡率最高(P＜0.01),ghrelin联合多柔比星能够抑制多柔比星对人乳腺癌MDA-MB-231细胞的促凋亡作用(P＜0.01),ghrelin联合多柔比星加ERK信号通路特异性阻滞剂PD98059能够减弱ghrelin联合多柔比星对人乳腺癌MDA-MB-231细胞凋亡的抑制作用(P＜0.01).多柔比星组与ghrelin组相比ERK表达及p-ERK水平明显下降(P＜0.05)、且ghrelin组与多柔比星组相比P-gp蛋白表达明显上升(P＜0.05),ghrelin联合多柔比星组与多柔比星组相比ERK表达及p-ERK水平明显增加(P＜0.05)、且P-gp蛋白表达明显增加(P＜0.05),ghrelin联合多柔比星加抑制剂组与ghrelin联合多柔比星组相比ERK表达及p-ERK水平明显下降(P＜0.01),P-gp蛋白表达无显著性差异(P=0.07).结论:一定浓度的ghrelin激活乳腺癌细胞ERK信号通路增加P-gp蛋白表达,从而抑制多柔比星诱导乳腺癌细胞凋亡而诱发耐药的产生,阻断ghrelin-ERK信号通路可能逆转乳腺癌细胞多药耐药的发生.     

Targeting Mnks for cancer therapy

Deregulation of protein synthesis is a common event in human cancer and a key player in translational control is eIF4E. Elevated expression levels of eIF4E promote cancer development and progression. Recent findings suggest that eIF4E activity is a key determinant of the PI3K/Akt/mTOR and Ras/Raf/MEK/ERK mediated tumorigenic activity and targeting eIF4E should have a major impact on these pathways in human cancer. The function of eIF4E is modulated through phosphorylation of a conserved serine (Ser209) by Mnk1 and Mnk2 downstream of ERK. While the phosphorylation event is necessary for oncogenic transformation, it seems to be dispensable for normal development. Hence, pharmacologic Mnk inhibitors may provide non-toxic and effective anti-cancer strategy. Strong circumstantial evidence indicates that Mnk inhibition presents attractive therapeutic potential, but the lack of selective Mnk inhibitors has so far confounded pharmacological target validation and clinical development.     

Annexin A1 Is a Potential Prognostic Marker for,and Enhances the Metastasis of,Cholangiocarcinoma

Objective: Annexin A1 (ANXA1) is a calcium-dependent phospholipid-binding protein which contributes to proliferation, cancer progression and metastasis. Overexpression of ANXA1 is closely associated with metastasis in numerous types of cancer. Cholangiocarcinoma (CCA) is a bile-duct cancer which has high rates of metastasis. Previously, we demonstrated up-regulation of ANXA1 in a highly metastatic CCA cell line (KKU-213AL5). Here, we investigated the functions of ANXA1 in the progression of CCA cell lines and evaluated its clinical impacts in human CCA tissues.  Methods: Effects of ANXA1 on metastatic potential of CCA cell lines were evaluated using cell-proliferation, clonogenic, migration and invasion assays. The expression of ANXA1 in 44 intrahepatic human CCA tissues was investigated using immunohistochemistry (IHC). The association of ANXA1 with clinicopathological features of CCA patients was analyzed. Results: Silencing of ANXA1 expression using siRNA significantly decreased cell proliferation, colony formation, cell migration and invasion in the KKU-213AL5 cell line. IHC results showed low expression of ANXA1 in normal bile ducts in the non-tumor area. In contrast, high expression of ANXA1 in human CCA tissues was associated with advanced tumor stage, tumor size and presence of lymph-node metastasis. Conclusion: These findings strongly imply that ANXA1 contributes to the progression of CCA. ANXA1 can serve as a potential prognostic marker for CCA. Ablation of ANXA1 action may be an alternative strategy to prevent metastasis of CCA.     

Statins induce apoptosis and inhibit proliferation in cholangiocarcinoma cells

Given the poor prognosis for cholangiocarcinoma, new and effective treatments are urgently needed. HMG-CoA reductase inhibitors (statins) reportedly exert anticancer effects in a variety of diseases, but there have been no reports of these effects in cholangiocarcinoma. In this study, we investigated the utility of statins for cholangiocarcinoma treatment. Proliferation suppression by pitavastatin and atorvastatin was investigated in the human cholangiocarcinoma cell lines HuCCT1 and YSCCC while changes in the cell cycle and intracellular signals were examined by FACS and Western blotting, respectively. Additive proliferation suppression by statins and pre-existing anticancer drugs was also investigated. HuCCT1 and YSCCC cell proliferation was dramatically suppressed by incubation with statins for 72 h or longer. Cell cycle analysis revealed a reduction in the G2M fraction and an increase in the sub-G1 fraction in statin-treated cells, while Western blotting showed increased levels of cleaved caspase-3 and a reduction in p-ERK. Furthermore, statins in combination with gemcitabine, cisplatin and 5-FU showed additive proliferation suppression. In this study, treatment of human cholangiocarcinoma cells with statins induced apoptosis via suppression of the classical MAPK pathway. Together, these results suggest that statins may be a new cholangiocarcinoma treatment option that could potentially enhance the anticancer effect of pre-existing anticancer drugs.