Salinomycin Potentiates the Cytotoxic Effects of TRAIL on Glioblastoma Cell Lines

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been reported to exhibit therapeutic activity in cancer. However, many tumors remain resistant to treatment with TRAIL. Therefore, small molecules that potentiate the cytotoxic effects of TRAIL could be used for combinatorial therapy. Here we found that the ionophore antibiotic salinomycin acts in synergism with TRAIL, enhancing TRAIL-induced apoptosis in glioma cells. Treatment with low doses of salinomycin in combination with TRAIL augmented the activation of caspase-3 and increased TRAIL-R2 cell surface expression. TRAIL-R2 upmodulation was required for mediating the stimulatory effect of salinomycin on TRAIL-mediated apoptosis, since it was abrogated by siRNA-mediated TRAIL-R2 knockdown. Salinomycin in synergism with TRAIL exerts a marked anti-tumor effect in nude mice xenografted with human glioblastoma cells. Our results suggest that the combination of TRAIL and salinomycin may be a useful tool to overcome TRAIL resistance in glioma cells and may represent a potential drug for treatment of these tumors. Importantly, salinomycin+TRAIL were able to induce cell death of well-defined glioblastoma stem-like lines.     

雄激素非依赖性前列腺癌细胞中差异甲基化基因的初步筛选

应用全基因组DNA甲基化芯片(Illumina Infinium HumanMethylation27 BeadChip)杂交技术以及转录组RNA测序技术,检测了雄激素依赖性前列腺癌(androgen-dependent prostate cancer,ADPC)细胞株LNCaP和雄激素非依赖性前列腺癌(androgen-independent prostate cancer,AIPC)细胞株LNCaP-AI(androgen independent)中的差异甲基化基因。发现与LNCaP细胞株相比,LNCaP-AI细胞株有990个CpG位点表现为高甲基化,涉及855个基因;2 305个CpG位点表现为低甲基化,涉及1 970个基因。结合转录组mRNA表达结果,筛选出6个超甲基化基因:FAM111B、RAB36、PCDH7、COL6A2、IGF1R、GULP1;8个低甲基化基因:EPHA3、TM4SF1、IGFBP5、FAM105A、RASD1、ITPR2、CYP27B1、UBE2E3。这些差异甲基化基因涉及钙离子信号通路、Wnt信号通路等多个信号通路,参与了细胞的基因表达、信号传导、细胞通讯、细胞运动、细胞黏附以及血管生成等功能,为探讨这些差异甲基化基因在前列腺癌雄激素非依赖性转化过程中发挥的作用奠定了基础。     

PSCA与前列腺癌研究进展

前列腺干细胞抗原(prostate stem cell antigen,PSCA)是一种前列腺癌相关肿瘤抗原,也是一种GPI(gly-cosyl phosphatidylinositol)锚定蛋白,通过其C端的GPI锚定结构锚定到细胞膜表面.PSCA在正常前列腺组织中的表达较低,提高的PSCA表达伴随着增加的肿瘤分期、分级以及雄激素非依赖性和转移癌的形成,且不随癌症进展而降低,是前列腺癌诊断和治疗的理想靶抗原.动物实验显示,PSCA抗体和疫苗可能在前列腺癌免疫靶向治疗中具有重要价值.     

The Effect of Quercetin Nanosuspension on Prostate Cancer Cell Line LNCaP via Hedgehog Signaling Pathway

Background:Prostate cancer (PCa) is the second leading cause of cancer death in American population. In this manner, novel therapeutic approaches for identification of therapeutic targets for PCa has significant clinical implications. Quercetin is a potent cancer therapeutic agent and dietary antioxidant present in fruit and vegetables.Methods:To investigate the underlying mechanism by which the PCa was regulated, nanoparticles of quercetin were administrated to cells. For in vitro experiments, human PCa cell line LNCaP were involved. Cell viability assay and quantitative RT-PCR (qRT-PCR) for hedgehog signaling pathway genes were used to determine the key signaling pathway regulated for PCa progression.Results:The cell viability gradually decreased with increased concentration of quercetin nanoparticles. At 48 h, 40 mM concentration of quercetin treatment showed near 50% of viable cells. Quercetin nanoparticles upregulates Su(Fu) mRNA expressions and downregulates gli mRNA expressions in the LNCaP cells.Conclusion:The results showed that the hedgehog signaling targeted inhibition may have important implications of PCa therapeutics. Additionally, the outcomes provided new mechanistic basis for further examination of quercetin nanoparticles to discover potential treatment strategies and new targets for PCa inhibition.Key Words: Hedgehog, Prostate cancer, Proliferation, Quercetin nanoparticles, Signaling pathway     

槲皮素对结肠癌细胞生长的影响

通过MTT试验观察槲皮素对结肠癌细胞系RKO生长的影响;通过流式细胞仪技术观察槲皮素对细胞周期和细胞凋亡的影响;采用RT-PCR和western印迹技术,确定槲皮素对p21、p27和p53表达的影响.MTT法显示槲皮素加药组生长抑制作用明显,且具有剂量依赖性;流式细胞仪分析结果显示,经5μmol/L槲皮素作用后细胞周期明显阻滞在G0/G1期;5、10、20μmol/L3个剂量组的细胞凋亡率分别为23.4%、24.2%、47.9%,而对照组为13.2%;p21和p27的mRNA及蛋白质表达水平上调,促凋亡蛋白p53表达水平上调.因此,槲皮素对RKO生长有明显的抑制作用,槲皮素可能通过上调p21和p27表达使RKO细胞周期阻滞于G0/G1期,可能通过上调促凋亡蛋白p53表达诱导RKO细胞发生凋亡.     

Garlic Compound, Diallyl Disulfide Induces Cell Cycle Arrest in Prostate Cancer Cell Line PC-3

Prostate cancer is the most predominant cancer in men and related death rate increases every year. Till date, there is no effective therapy for androgen independent prostate cancer. Previous studies reported that aged garlic extract suppresses cancer growth. In the present study, diallyl disulfide [DADS], oil soluble organosulfur compound of garlic, was studied for its antiproliferative and induction of cell cycle arrest on prostate cancer cells in vitro. The suppression of cell growth was assessed by MTT assay. Induction of cell cycle arrest was assessed and confirmed by propidium iodide staining in flowcytometric analysis and western blotting analysis of major cell cycle regulator proteins. The results showed that DADS inhibited the growth of prostate cancer cells in a dose dependent manner, compared to the control. At 25 μM and 40 μM concentrations, DADS induced cell cycle arrest at G2/M transition in PC-3 cells. Western blotting analysis of cyclin A, B₁ and cyclin dependent kinase 1 [CDK1] revealed that DADS inhibited the cell cycle by downregulating CDK1 expression. It is concluded that DADS, inhibits proliferation of prostate cancer cells through cell cycle arrest. Dose dependent effect of DADS on PC-3 cell line was observed in the present study.     

miR-125b在前列腺癌1E8细胞运动转移中的作用及其分子机制的初步探讨

目的 研究 miR-125b在前列腺癌高低转移潜能细胞中的表达差异及其对高转移细胞株1E8细胞的运动转移中的作用和可能的分子机制.方法 realtime PCR法检测前列腺癌高低转移潜能配对细胞系中 miR-125b的表达差异.通过划痕实验及transwell实验观察1E8细胞及转染 miR-125b 抑制剂及其阴性对照后该细胞运动转移能力的变化.结果 realtime PCR结果显示高转移潜能1E8细胞中miR-125b表达水明显高于低转移潜能2B4细胞;下调miR-125b会减弱1E8细胞的运动转移能力.结论 miR-125b可促进前列腺癌细胞的运动转移能力.     

The Combination of RAD001 and MK-2206 Exerts Synergistic Cytotoxic Effects against PTEN Mutant Gastric Cancer Cells: Involvement of MAPK-Dependent Autophagic,but Not Apoptotic Cell Death Pathway

In the current study, we showed that the combination of mammalian target of rapamycin (mTOR) inhibitor RAD001 (everolimus) and Akt inhibitor MK-2206 exerted synergistic cytotoxic effects against low-phosphatase and tensin homolog (PTEN) gastric cancer cells (HGC-27 and SNU-601 lines). In HGC-27 cells, RAD001 and MK-2206 synergistically induced G1/S cell cycle arrest, growth inhibition, cell death but not apoptosis. RAD001 and MK-2206 synergistically induced light chain 3B (LC3B) and beclin-1 expression, two important autophagy indicators. Meanwhile, the autophagy inhibitor 3-methyladenine (3-MA) and chloroquine inhibited the cytotoxic effects by RAD001 and MK-2206, suggesting that autophagic, but not apoptotic cell death was important for the cytotoxic effects by the co-administration. We observed that the combination of RAD001 and MK-2206 exerted enhanced effects on Akt/mTOR inhibition, cyclin D1 down-regulation and ERK/MAPK(extracellular signal-regulated kinase/mitogen-activated protein kinases) activation. Intriguingly, MEK/ERK inhibitors PD98059 and U0126 suppressed RAD001 plus MK-2206-induced beclin-1 expression, autophagy induction and cytotoxicity in HGC-27 cells. In conclusion, these results suggested that the synergistic anti-gastric cancer cells ability by RAD001 and MK-2206 involves ERK-dependent autophagic cell death pathway.     

以前列腺干细胞抗原为靶点的前列腺癌免疫治疗研究进展

前列腺干细胞抗原(PSCA)为细胞膜表面抗原,在正常前列腺组织中低表达,在雄激素依赖性和非依赖性前列腺癌组织中高表达,有较高的组织特异性,是前列腺癌治疗的理想靶标,近年来以PSCA为靶点的前列腺癌治疗性疫苗的研究已成为热点。我们简要综述以PSCA为靶点治疗前列腺癌的研究进展。     

Concentration-Dependent Effects of Zinc Sulfate on DU-145 Human Prostate Cancer Cell Line: Oxidative,Apoptotic, Inflammatory,and Morphological Analyzes

Biological Trace Element Research - Zinc takes part in several of cellular signaling pathways, containing defense against free radicals, apoptosis, and inflammation. However, interaction between...     

NGX6基因对人结肠癌细胞HT-29细胞周期的影响

NGX6基因是新克隆的候选抑瘤基因,研究表明NGX6重表达可抑制结肠癌细胞的增殖.为进一步研究NGX6对细胞周期的影响,采用流式细胞仪检测NGX6重表达对结肠癌细胞HT-29细胞周期的影响,发现NGX6重表达可增加HT-29细胞在G0/G1期的分布比例,减少了S,G2,M期细胞数.利用蛋白质印迹和流式细胞术分析NGX6转染前后HT-29细胞周期素(cyclins)和细胞周期素依赖性蛋白激酶抑制物(cyclin-dependentkinaseinhibitor,CKI)的表达变化,发现NGX6可下调HT-29细胞中cyclinE、cyclinD1的表达及上调p27的表达,对cyclinA和cyclinB的表达无明显影响,p16在三组结肠癌细胞中均无表达.研究结果表明,NGX6在HT-29细胞中通过下调cyclinE、cyclinD1和上调p27的表达,阻滞细胞周期于G0/G1期,从而发挥其在结肠癌中的抑瘤作用.     

一个新的前列腺癌细胞系分泌蛋白磷酸甘油酸酯激酶的鉴定与分析

目的：建立前列腺癌细胞系C4-2B分泌蛋白双向电泳图谱,并对感兴趣的蛋白进行质谱鉴定,对其表达调控进行初步分析。方法：收集前列腺癌细胞系C4-2B的分泌蛋白,利用双向电泳结合质谱的方法对感兴趣的蛋白进行鉴定,而后利用Western blot等方法对结果进行验证和分析。结果：得到较为稳定的前列腺癌细胞系分泌蛋白C4-2B双向电泳图谱,鉴定了一个新的前列腺癌细胞系分泌蛋白磷酸甘油酸酯激酶,并发现1nmol/L人工合成雄激素R1881可上调其表达。结论：建立了简便的前列腺癌细胞系分泌蛋白双向电泳及质谱分析的研究方法,初步证明磷酸甘油酸酯激酶是前列腺癌细胞系C4-2B新的分泌蛋白,且人工合成雄激素R1881可诱导其表达上调。     

敲低前列腺癌相关基因PC-1的表达抑制前列腺癌细胞C4-2雄激素非依赖性生长

目的:研究敲低癌基因D52家族成员PC-1的表达对前列腺癌细胞雄激素非依赖性生长的影响。方法:利用RNA干扰技术构建PC-1稳定低表达的C4-2细胞株;利用四唑盐(MTT)比色实验检测敲低PC-1基因表达对C4-2细胞雄激素非依赖生长的影响。结果:敲低PC-1表达抑制前列腺癌C4-2细胞的生长,并降低了C4-2细胞雄激素非依赖性生长的能力。结论:PC-1基因参与了前列腺癌向雄激素非依赖阶段发展和维持的过程,为进一步研究PC-1在促进前列腺癌细胞发生发展过程中的作用奠定了基础。     

Effect of Acute Exercise on Prostate Cancer Cell Growth

Physical activity is associated with reduced risk of several cancers, including aggressive prostate cancer. The mechanisms mediating the effects are not yet understood; among the candidates are modifications of endogenous hormone levels. Long-term exercise is known to reduce serum levels of growth stimulating hormones. In contrast, the endocrine effects of acute endurance exercise include increased levels of mitogenic factors such as GH and IGF-1. It can be speculated that the elevation of serum growth factors may be detrimental to prostate cancer progression into malignancy. The incentive of the current study is to evaluate the effect of acute exercise serum on prostate cancer cell growth. We designed an exercise intervention where 10 male individuals performed 60 minutes of bicycle exercise at increasing intensity. Serum samples were obtained before (rest serum) and after completed exercise (exercise serum). The established prostate cancer cell line LNCaP was exposed to exercise or rest serum. Exercise serum from 9 out of 10 individuals had a growth inhibitory effect on LNCaP cells. Incubation with pooled exercise serum resulted in a 31% inhibition of LNCaP growth and pre-incubation before subcutaneous injection into SCID mice caused a delay in tumor formation. Serum analyses indicated two possible candidates for the effect; increased levels of IGFBP-1 and reduced levels of EGF. In conclusion, despite the fear of possible detrimental effects of acute exercise serum on tumor cell growth, we show that even the short-term effects seem to add to the overall beneficial influence of exercise on neoplasia.     

Inhibition of AKT with the Orally Active Allosteric AKT Inhibitor, MK-2206, Sensitizes Endometrial Cancer Cells to Progestin

Progestin resistance is a major obstacle to treating early stage, well-differentiated endometrial cancer as well as recurrent endometrial cancer. The mechanism behind the suboptimal response to progestin is not well understood. The PTEN tumor suppressor gene is frequently mutated in type I endometrial cancers and this mutation results in hyperactivation of the PI3K/AKT pathway. We hypothesized that increased activation of AKT promotes an inadequate response to progestins in endometrial cancer cells. Ishikawa cells stably transfected with progesterone receptor B (PRB23 cells) were treated with the AKT inhibitor, MK-2206, which effectively decreased levels of p(Ser473)-AKT in a dose-dependent (10 nM to 1 uM) and time-dependent manner (0.5 h to 24 h). MK-2206 inhibited levels of p(Thr308)-AKT and a downstream target, p(Thr246)-PRAS40, but did not change levels of p(Thr202/Tyr204)ERK or p(Thr13/Tyr185)SAPK/JNK, demonstrating specificity of MK-2206 for AKT. Additionally, MK-2206 treatment of PRB23 cells resulted in a significant increase in levels of progesterone receptor B (PRB) protein. Microarray analysis of PRB23 cells identified PDK4 as the most highly upregulated gene among 70 upregulated genes in response to R5020. Inhibition of AKT further upregulated progestin-mediated expression of PDK4 but did not affect another progestin-responsive gene, SGK1. Treatment of PRB23 cells with R5020 and MK-2206 independently decreased viability of cells while the combination of R5020 and MK-2206 caused the greatest decrease in cell viability. Furthermore, mice with xenografted tumors treated with MK-2206 alone or with progesterone alone exhibited modest reductions in their tumor volume. The largest decrease in tumor size was observed in the mice treated with both MK-2206 and progesterone; these tumors exhibited the least proliferation (Ki67) and the most apoptosis (cleaved caspase-3) of all the treatment groups. In summary, inhibition of AKT stabilizes the Progesterone Receptor B and augments progesterone response in endometrial cancer cells that have hyperactivated AKT.     

靶向下调FOXM1基因表达对乳腺癌MDA-MB-231细胞增殖的影响

目的：探讨靶向抑制FOXM1对乳腺癌细胞增殖能力的影响,为乳腺癌的个性化靶向治疗提供理论依据。方法：利用重组真核转录载体pSilencer1．0-U6-FOXMI—shRNA,脂质体法转染乳腺癌细胞株MDA-MB-231,下调其FOXM1基因表达。采用四甲基偶氮唑盐（MTT）比色法、平板克隆形成实验观察细胞增值曲线以及克隆形成能力;采用实时定量·聚合酶链反应（Real—timeqPCR）、蛋白免疫印迹法（Westemblot）分别检测FOXMl基因在mRNA、蛋白水平的表达变化。结果：重组载体pSileneerl．0-U6-FOXMl-shRNA转染MDA-MB-231细胞后,与对照组相比,增殖速率明显下降（P〈0．05）,平板克隆形成显著减少（P〈0．05）,重组载体转染后显著抑制MDA—MB-231细胞中FOXM1基因在mRNA、蛋白水平的表达。结论：沉默FOXMI基因对乳腺癌细胞株MDA—MB-231生长具有抑制作用,为阐明乳腺癌发病机制提供了新的切入点,也为临床抑制肿瘤生长提供了新的作用靶点。     

PPARγ激动剂罗格列酮诱导人前列腺癌细胞系LNCAP凋亡的作用

目的:探讨罗格列酮(ROZ)对体外培养细胞系LNCAP增殖及凋亡的作用.方法:20、50、100 μmol/LROZ作用LNCAP细胞24 h、48 h、72 h后,MTT法检测ROZ对LNCAP细胞生长的影响.采用末端脱氧核苷酸转移酶原位标记(TUNEL法)和流式细胞术检测细胞凋亡情况.Western Blot检测LNCAP细胞中Casepase-3表达水平的变化.结果:ROZ(20μmol/L至100μmol/L)对前列腺癌细胞有显著的增殖抑制作用,以100μmol/L浓度最为明显.ROZ(100μmol/L)作用72h后最高增殖抑制率达78.58%.流式细胞仪检测结果显示,LNCAP细胞凋亡数目随药物浓度的增加呈递增趋势;100μmol/LROZ作用72h后凋亡细胞数达48.11%.与此一致,TUNEL染色阳性细胞数目在ROZ处理组显著增多,Western Blot检测显示,ROZ显著增加LNCAP细胞中Caspase-3蛋白表达水平.结论:ROZ在体外对前列腺癌细胞系LNCAP有明显的增殖抑制及促进凋亡作用,有望成为前列腺癌患者新的治疗方法.     

色胺酮对乳腺癌MCF-7细胞凋亡的诱导作用

目的:探讨色胺酮(Tryptanthrin,Try)对人乳腺癌MCF-7细胞增殖和凋亡的影响。方法:利用MTT方法检测Try(1.56-100μmol/L)对细胞增殖的影响;透射电镜观察细胞的形态学改变;流式细胞术检测细胞周期、凋亡情况及线粒体跨膜电位等指标。结果:MTT结果显示,Try在12.5-100μmol/L浓度范围内能明显抑制MCF-7细胞的增殖,并具有时间和浓度依赖性;透射电镜下可见Try作用48h后,MCF-7细胞有典型的凋亡样改变。Annexin V-FITC与PI双染,流式细胞仪检测结果显示:50、100μmol/LTry作用后,细胞的凋亡情况明显,与对照组相比差异显著;且影响了MCF-7的细胞周期分布,将细胞阻滞于G1期,抑制其DNA的合成;并导致细胞线粒体跨膜电位下降。结论:色胺酮能明显抑制MCF-7细胞增殖并具有诱导细胞发生凋亡的作用。