白藜芦醇通过降低galectin-3的表达抑制宫颈癌SiHa细胞的增殖并促进其凋亡

目的：探讨白藜芦醇对人宫颈癌SiHa细胞增殖和凋亡的影响及galectin-3在其中的作用。方法：以体外培养的人宫颈癌SiHa细胞为研究对象,实验分为对照组、白藜芦醇处理组及[白藜芦醇＋galectin-3（5、10、20μg/mL）]共5组,分别给予生理盐水、300μmol/L白藜芦醇及[300μmol/L白藜芦醇＋Galectin-3（5、10、20μg/mL）]处理。48小时后,分别收集各组细胞,采用MTT法检测细胞的增殖情况,Caspase-3活性试剂盒测定细胞的凋亡情况,Western Blot技术测定细胞内galectin-3的蛋白表达水平。结果：300μmol/L的白藜芦醇明显抑制SiHa细胞的增殖,并显著增加其凋亡水平,同时减少了细胞内galectin-3的蛋白表达。在白藜芦醇处理的同时,给予5、10及20μg/mL的Galectin-3,随着Galectin-3蛋白浓度的增加,SiHa细胞的增殖抑制率逐渐降低,凋亡水平也逐渐下降,但是VEGF-R3受体的磷酸化水平却逐渐升高。结论：白藜芦醇通过降低galectin-3的表达抑制宫颈癌SiHa细胞的增殖并促进其凋亡。     

白藜芦醇通过降低galectin-3 的表达抑制宫颈癌SiHa细胞的增殖并促进其凋亡

目的：探讨白藜芦醇对人宫颈癌SiHa 细胞增殖和凋亡的影响及galectin-3 在其中的作用。方法：以体外培养的人宫颈癌 SiHa 细胞为研究对象,实验分为对照组、白藜芦醇处理组及[白藜芦醇+galectin-3(5、10、20 ug/mL)]共5 组,分别给予生理盐水、 300 umol/L白藜芦醇及[300 umol/L白藜芦醇+Galectin-3 (5、10、20 ug/mL)]处理。48 小时后,分别收集各组细胞,采用MTT法检 测细胞的增殖情况,Caspase-3 活性试剂盒测定细胞的凋亡情况,Western Blot技术测定细胞内galectin-3 的蛋白表达水平。结果： 300 umol/L的白藜芦醇明显抑制SiHa 细胞的增殖,并显著增加其凋亡水平,同时减少了细胞内galectin-3 的蛋白表达。在白藜芦 醇处理的同时,给予5、10 及20 ug/mL 的Galectin-3,随着Galectin-3 蛋白浓度的增加,SiHa 细胞的增殖抑制率逐渐降低,凋亡水 平也逐渐下降,但是VEGF-R3 受体的磷酸化水平却逐渐升高。结论：白藜芦醇通过降低galectin-3 的表达抑制宫颈癌SiHa 细胞 的增殖并促进其凋亡。     

Silencing of FABP3 Inhibits Proliferation and Promotes Apoptosis in Embryonic Carcinoma Cells

Fatty acid–binding protein 3 (FABP3) facilitates the movement of fatty acids in cardiac muscle. Previously, we reported that FABP3 is highly upregulated in the myocardium of ventricular septal defect patients and overexpression of FABP3 inhibited proliferation and promoted apoptosis in embryonic carcinoma cells (P19 cells). In this study, we aimed to investigate the effect of FABP3 gene silencing on P19 cell differentiation, proliferation and apoptosis. We used RNA interference and a lentiviral-based vector system to create a stable FABP3-silenced P19 cell line; knockdown of FABP3 was confirmed by quantitative real-time PCR. Expression analysis of specific differentiation marker genes using quantitative real-time PCR and observation of morphological changes using an inverted microscope revealed that knockdown of FABP3 did not significantly affect the differentiation of P19 cells into cardiomyocytes. CCK-8 proliferation assays and cell cycle analysis demonstrated that FABP3 gene silencing significantly inhibited P19 cell proliferation. Furthermore, Annexin V-FITC/propidium iodide staining and the caspase-3 activity assay revealed that FABP3 gene silencing significantly promoted serum starvation–induced apoptosis in P19 cells. In agreement with our previous research, these results demonstrate that FABP3 may play an important role during embryonic heart development, and that either overexpression or silencing of FABP3 will lead to an imbalance between proliferation and apoptosis, which may result in embryonic cardiac malformations.     

Resveratrol Inhibits the Proliferation of Neural Progenitor Cells and Hippocampal Neurogenesis

Resveratrol is a phytoalexin and natural phenol that is present at relatively high concentrations in peanuts and red grapes and wine. Based upon studies of yeast and invertebrate models, it has been proposed that ingestion of resveratrol may also have anti-aging actions in mammals including humans. It has been suggested that resveratrol exerts its beneficial effects on health by activating the same cellular signaling pathways that are activated by dietary energy restriction (DR). Some studies have reported therapeutic actions of resveratrol in animal models of metabolic and neurodegenerative disorders. However, the effects of resveratrol on cell, tissue and organ function in healthy subjects are largely unknown. In the present study, we evaluated the potential effects of resveratrol on the proliferation and survival of neural progenitor cells (NPCs) in culture, and in the hippocampus of healthy young adult mice. Resveratrol reduced the proliferation of cultured mouse multi-potent NPCs, and activated AMP-activated protein kinase (AMPK), in a concentration-dependent manner. Administration of resveratrol to mice (1–10 mg/kg) resulted in activation of AMPK, and reduced the proliferation and survival of NPCs in the dentate gyrus of the hippocampus. Resveratrol down-regulated the levels of the phosphorylated form of cyclic AMP response element-binding protein (pCREB) and brain-derived neurotrophic factor (BDNF) in the hippocampus. Finally, resveratrol-treated mice exhibited deficits in hippocampus-dependent spatial learning and memory. Our findings suggest that resveratrol, unlike DR, adversely affects hippocampal neurogenesis and cognitive function by a mechanism involving activation of AMPK and suppression of CREB and BDNF signaling.     

Maduramicin Inhibits Proliferation and Induces Apoptosis in Myoblast Cells

Maduramicin, a polyether ionophore antibiotic derived from the bacterium Actinomadura yumaensis, is currently used as a feed additive against coccidiosis in poultry worldwide. It has been clinically observed that maduramicin can cause skeletal muscle and heart cell damage, resulting in skeletal muscle degeneration, heart failure, and even death in animals and humans, if improperly used. However, the mechanism of its toxic action in myoblasts is not well understood. Using mouse myoblasts (C2C12) and human rhabdomyosarcoma (RD and Rh30) cells as an experimental model for myoblasts, here we found that maduramicin inhibited cell proliferation and induced cell death in a concentration-dependent manner. Further studies revealed that maduramicin induced accumulation of the cells at G₀/G₁ phase of the cell cycle, and induced apoptosis in the cells. Concurrently, maduramicin downregulated protein expression of cyclin D1, cyclin-dependent kinases (CDK4 and CDK6), and CDC25A, and upregulated expression of the CDK inhibitors (p21^Cip1 and p27^Kip1), resulting in decreased phosphorylation of Rb. Maduramicin also induced expression of BAK, BAD, DR4, TRADD and TRAIL, leading to activation of caspases 8, 9 and 3 as well as cleavage of poly ADP ribose polymerase (PARP). Taken together, our results suggest that maduramicin executes its toxicity in myoblasts at least by inhibiting cell proliferation and inducing apoptotic cell death.     

Knockdown of miR-214 Promotes Apoptosis and Inhibits Cell Proliferation in Nasopharyngeal Carcinoma

MicroRNA-214 (MiR-214) is aberrantly expressed in several human tumors such as ovarian cancer and breast cancer. However, the role of miR-214 in nasopharyngeal carcinoma (NPC) is still unknown. In this study, we report that miR-214 was overexpressed in NPC cell lines and tissues. Silencing of miR-214 by LNA-antimiR-214 in NPC cells resulted in promoting apoptosis and suppressing cell proliferation in vitro, and suppressed tumor growth in nude mice in vivo. Luciferase reporter assay was performed to identify Bim as a direct target of miR-214. Furthermore, this study showed that low Bim expression in NPC tissues correlated with poor survival of NPC patients. Taken together, our findings suggest that miR-214 plays an important role in NPC carcinogenesis.     

沉默ABCE1对神经胶质瘤细胞U251增殖、迁移和凋亡的影响

ABCE1是ATP结合盒蛋白亚家族成员之一,在病毒感染,细胞增殖,抗凋亡,翻译起始和核糖体生物发生等过程中有重要的作用。为了探讨ABCE1对神经胶质瘤细胞U251增殖、迁移和凋亡的作用,本研究通过实时荧光定量PCR和免疫印迹实验检测ABCE1在神经胶质瘤细胞和正常胶质细胞中的mRNA和蛋白质表达水平,结果发现ABCE1在神经胶质瘤细胞U251中的表达高于在正常胶质细胞中的表达。利用siRNA靶向沉默ABCE1后,神经胶质瘤细胞U251中ABCE1 mRNA和蛋白的表达水平均显著减少,细胞的凋亡率显著提高,细胞增殖和迁移明显受到抑制,而且细胞对化疗药物替莫唑胺的敏感性增强。此外,沉默ABCE1后,Bcl-2的mRNA和蛋白质表达水平显著下调,而Bax的mRNA和蛋白质表达水平显著上调。以上研究结果表明,ABCE1与神经胶质瘤细胞的增殖和迁移密切相关,通过siRNA靶向沉默ABCE1基因可显著降低U251细胞的增殖和迁移能力。     

miR-455 Inhibits HepG2 Cell Proliferation and Promotes Apoptosis by Targeting RhoC

Molecular Biology - Hepatocellular carcinoma (HCC) is a common malignancy worldwide with poor prognosis and high mortality. The aberrant expression or alteration of microRNAs (miRNAs) contributes...     

MiR-133b Is Down-Regulated in Human Osteosarcoma and Inhibits Osteosarcoma Cells Proliferation,Migration and Invasion,and Promotes Apoptosis

MicroRNAs (miRNAs) decrease the expression of specific target oncogenes or tumor suppressor genes and thereby play crucial roles in tumorigenesis and tumor growth. To date, the potential miRNAs regulating osteosarcoma growth and progression are not fully identified yet. In this study, the miRNA microarray assay and hierarchical clustering analysis were performed in human osteosarcoma samples. In comparison with normal human skeletal muscle, 43 miRNAs were significantly differentially expressed in human osteosarcomas (fold change ≥2 and p≤0.05). Among these miRNAs, miR-133a and miR-133b expression was decreased by 135 folds and 47 folds respectively and the decreased expression was confirmed in both frozen and paraffin-embedded osteosarcoma samples. The miR-133b precursor expression vector was then transfected into osteosarcoma cell lines U2-OS and MG-63, and the stable transfectants were selected by puromycin. We found that stable over-expression of miR-133b in osteosarcoma cell lines U2-OS and MG-63 inhibited cell proliferation, invasion and migration, and induced apoptosis. Further, over-expression of miR-133b decreased the expression of predicted target genes BCL2L2, MCL-1, IGF1R and MET, as well as the expression of phospho-Akt and FAK. This study provides a new insight into miRNAs dysregulation in osteosarcoma, and indicates that miR-133b may play as a tumor suppressor gene in osteosarcoma.     

沙利度胺通过诱导G1阻滞和凋亡抑制血管内皮细胞增殖

沙利度胺是一种抗血管生成药物,临床上用于治疗多种肿瘤,但其抗肿瘤血管生成机制尚不十分清楚. 本文采用MTT法观察沙利度胺对体外培养的血管内皮细胞增殖的影响. 结果发现,沙利度胺能够抑制血管内皮细胞的增殖,其IC50为16.47 μg/mL;然后采用Hoechst染色和流式细胞仪检测细胞凋亡和细胞周期,发现沙利度胺能够诱导内皮细胞凋亡,并干扰细胞的周期,出现G0/G1期阻滞. 最后,通过Western印迹方法分析沙利度胺对血管内皮细胞Bcl-2蛋白表达的影响,发现抗凋亡的Bcl-2蛋白表达水平随沙利度胺浓度增大而降低. 初步结果提示,沙利度胺可能通过阻遏抗凋亡分子Bcl-2表达,激活诱导G1期阻滞的信号通路而抑制内皮细胞新生,从而抑制肿瘤生长. 诱导内皮细胞凋亡及G1期阻滞的具体分子机制正在研究中.     

EB病毒潜伏膜蛋白1通过Survivin介导细胞增殖和抑制细胞凋亡

利用间接免疫荧光、基因转染、抗体剔除 (Ab knock out)、细胞平板集落形成、流式细胞术以及半胱氨酸天冬酰胺酶 (caspase3)活性检测等方法 ,从survivin核移位、Rb磷酸化、细胞周期演进、细胞克隆形成和细胞凋亡等方面 ,探讨EB病毒潜伏膜蛋白 1(LMP1)调控细胞增殖和细胞凋亡双重效应的分子机制 .结果发现 ,LMP1表达介导survivin核移位 ,促进细胞Rb磷酸化增加 ,S期细胞数显著增加 ;LMP1通过survivin促进细胞克隆形成 .用Ab knock out阻断survivin核移位和survivin反义核酸抑制survivin表达时 ,Rb磷酸化水平降低 ,S期细胞减少 ,抑制LMP1介导的细胞增殖 ,活化细胞caspase 3,诱导细胞凋亡 .结果提示 ,EB病毒LMP1通过survivin促进细胞增殖和抑制细胞凋亡     

Knockdown of VEGFR2 Inhibits Proliferation and Induces Apoptosis in Hemangioma-Derived Endothelial Cells

Angiogenesis is a process of development and growth of new capillary blood vessels from pre-existing vessels. Angiogenic growth factors play important roles in the development and maintenance of some malignancies, of which vascular endothelial growth factor (VEGF)/VEGFR2 interactions are involved in proliferation, migration, and survival of many cancer cells. The aim of this study was to investigate the function of VEGFR2 in human hemangiomas (HAs). Using immunohistochemistry assay, we examined the expression levels of VEGF, VEGFR2, Ki-67, glucose transporter-1 (Glut-1), phosphorylated protein kinase B (p-AKT) and p-ERK in different phases of human HAs. Positive expression of VEGF, VEGFR2, Ki-67, Glut-1, p-AKT and p-ERK was significantly increased in proliferating phase HAs, while decreased in involuting phase HAs (P=0.001; P=0.003). In contrast, cell apoptotic indexes were decreased in proliferating phase HAs, but increased in involuting phase HAs (P<0.01). Furthermore, we used small hairpin RNA (shRNA)-mediated VEGFR2 knockdown in primary HA-derived endothelial cells (HemECs) to understand the role of VEGF/VEGFR2 signaling. Knockdown of VEGFR2 by Lv-shVEGFR2 inhibited cell viability and induced apoptosis in primary HemECs companied with decreased expression of p-AKT, p-ERK, p-p38MAPK and Ki-67 and increased expression of caspase-3 (CAS-3); Overexpression of VEGFR2 promoted cell viability and blocked apoptosis in Lv-VEGFR2-transfected HemECs. Taken together, our findings demonstrate that, increased expression of VEGFR2 is involved in the development of primary HemECs possibly through regulation of the AKT and ERK pathways, suggesting that VEGFR2 may be a potential therapeutic target for HAs.Key words: vascular endothelial growth factor receptor 2, hemangioma, proliferation, apoptosis     

泛素偶联酶2C促进肺癌细胞增殖和迁移与抑制细胞衰老

泛素偶联酶2C与多种肿瘤细胞的增殖密切相关,但其与肺癌发生和发展的关系尚不明确。 本研究以肺癌A549细胞为材料,通过RT-PCR、Western印迹、免疫荧光、SA-β-Gal细胞衰老染色、细胞划痕和Trans-well实验,阐明UBE2C与肺癌细胞的增殖、衰老和迁移能力的关系。结果显示,UBE2C在肺癌细胞中的表达明显高于正常细胞。利用基因修饰技术瞬时过表达或靶向沉默UBE2C后,在肺癌A549细胞中,UBE2C的mRNA和蛋白质水平显著增加3.5倍或减少0.5倍,显著促进或抑制细胞增殖,进而减少或增加细胞的凋亡率。过表达UBE2C后,显著抑制细胞衰老;但沉默UBE2C后,则增加细胞衰老。此外,过表达UBE2C后,下调转移相关基因E-钙黏着蛋白的mRNA和蛋白质表达水平,且上调波形蛋白基因的表达水平,进而促进肺癌细胞的迁移。但靶向敲除UBE2C后,上调E-钙黏着蛋白,同时下调波形蛋白表达水平,进而抑制肺癌细胞的迁移。本研究的开展将明确UBE2C在肺癌中的作用及其机制,为以UBE2C为靶点,提高病人生存期提供了理论基础。     

白藜芦醇对胰腺癌细胞增殖和凋亡影响的研究

为了研究白藜芦醇对人胰腺癌细胞增殖和存活的影响,利用不同浓度白藜芦醇处理PANC-1和Bx PC-3细胞,通过MTS和软琼脂集落实验检测白藜芦醇对胰腺癌细胞的停泊依赖和停泊非依赖增殖的抑制。同时,采用免疫印迹的方法,检测不同浓度白藜芦醇对胰腺癌细胞增殖相关信号通路的调控,及不同时间点凋亡激活相关蛋白分子的表达。结果发现白藜芦醇能剂量依赖性抑制PANC-1和Bx PC-3细胞增殖,并且这种增殖抑制作用与表皮生长因子受体(epithelial growth factor receptor,EGFR)及下游信号通路的抑制有关。一定浓度的白藜芦醇能诱导胰腺癌细胞发生凋亡,caspase3和caspase7被剪切活化。通过检测Bcl-2(B-cell lymphoma-2,Bcl-2)促存活家族蛋白,证实白藜芦醇能有效抑制Mcl-1(myeloid cell leukemia-1,Mcl-1)的表达,并不改变Bcl-2和Bcl-XL的表达。实验结果初步表明,白藜芦醇抑制胰腺癌的增殖与存活与EGFR信号通路及促存活蛋白Mcl-1的表达下调有关。     

DNA Methyltransferase Inhibitor Zebularine Inhibits Human Hepatic Carcinoma Cells Proliferation and Induces Apoptosis

Hepatocellular carcinoma is one of the most common cancers worldwide. During tumorigenesis, tumor suppressor and cancer-related genes are commonly silenced by aberrant DNA methylation in their promoter regions. Zebularine (1-(β-_D-ribofuranosyl)-1,2-dihydropyrimidin-2-one) acts as an inhibitor of DNA methylation and exhibits chemical stability and minimal cytotoxicity both in vitro and in vivo. In this study, we explore the effect and possible mechanism of action of zebularine on hepatocellular carcinoma cell line HepG2. We demonstrate that zebularine exhibits antitumor activity on HepG2 cells by inhibiting cell proliferation and inducing apoptosis, however, it has little effect on DNA methylation in HepG2 cells. On the other hand, zebularine treatment downregulated CDK2 and the phosphorylation of retinoblastoma protein (Rb), and upregulated p21^WAF/CIP1 and p53. We also found that zebularine treatment upregulated the phosphorylation of p44/42 mitogen-activated protein kinase (MAPK). These results suggest that the p44/42 MAPK pathway plays a role in zebularine-induced cell-cycle arrest by regulating the activity of p21^WAF/CIP1 and Rb. Furthermore, although the proapoptotic protein Bax levels were not affected, the antiapoptotic protein Bcl-2 level was downregulated with zebularine treatment. In addition, the data in the present study indicate that inhibition of the double-stranded RNA-dependent protein kinase (PKR) is involved in inducing apoptosis with zebularine. These results suggest a novel mechanism of zebularine-induced cell growth arrest and apoptosis via a DNA methylation-independent pathway in hepatocellular carcinoma.     

Kuwanon V Inhibits Proliferation,Promotes Cell Survival and Increases Neurogenesis of Neural Stem Cells

Neural stem cells (NSCs) have the ability to proliferate and differentiate into neurons and glia. Regulation of NSC fate by small molecules is important for the generation of a certain type of cell. The identification of small molecules that can induce new neurons from NSCs could facilitate regenerative medicine and drug development for neurodegenerative diseases. In this study, we screened natural compounds to identify molecules that are effective on NSC cell fate determination. We found that Kuwanon V (KWV), which was isolated from the mulberry tree (Morus bombycis) root, increased neurogenesis in rat NSCs. In addition, during NSC differentiation, KWV increased cell survival and inhibited cell proliferation as shown by 5-bromo-2-deoxyuridine pulse experiments, Ki67 immunostaining and neurosphere forming assays. Interestingly, KWV enhanced neuronal differentiation and decreased NSC proliferation even in the presence of mitogens such as epidermal growth factor and fibroblast growth factor 2. KWV treatment of NSCs reduced the phosphorylation of extracellular signal-regulated kinase 1/2, increased mRNA expression levels of the cyclin-dependent kinase inhibitor p21, down-regulated Notch/Hairy expression levels and up-regulated microRNA miR-9, miR-29a and miR-181a. Taken together, our data suggest that KWV modulates NSC fate to induce neurogenesis, and it may be considered as a new drug candidate that can regenerate or protect neurons in neurodegenerative diseases.     

Doxycycline Induces Apoptosis and Inhibits Proliferation and Invasion of Human Cervical Carcinoma Stem Cells

BackgroundCancer stem cells (CSCs) are proposed to be responsible for high recurrence rate in cervical carcinoma. Reagents that can suppress the proliferation and differentiation of CSCs would provide new opportunities to fight against tumor recurrence. Doxycycline has been reported as a potential anti-cancer compound. However, few studies investigated its inhibitory effect against cervical cancer stem cells.MethodsHeLa cells were cultured in cancer stem cell conditional media in a poly-hema-treated dish. In this non-adhesive culture system, HeLa cells were treated with cisplatin until some cells survived and formed spheroids, which were then collected and injected into the immunodeficient mice. Cisplatin was administered every three days for five times. The tumor xenografts with CSC enrichment were cultured in cancer stem cell specific medium again to form tumorsphere, which we called HeLa-CSCs. Expression of cancer stem cell markers in HeLa-CSCs was measured by flow cytometry and qPCR. HeLa-CSCs were then treated with doxycycline. Proliferation and differentiation rates were determined by the size of spheres formed in vitro and tumor formed in vivo.ResultsWe developed a new strategy to selectively enrich CSCs from human cervical carcinoma cell line HeLa, and these HeLa-CSCs are CD133+/CD49f+ cell populations with significantly enhanced expression of stem cell markers. When these HeLa-CSCs were treated with doxycycline, the colony formation, proliferation, migration and invasion, and differentiation were all suppressed. Meanwhile, stem cell markers SOX-2, OCT-4, NANOG, NOTCH and BMI-1 decreased in doxycycline treated cells, so as the surface markers CD133 and CD49f. Furthermore, proliferation markers Ki67 and PCNA were also decreased by doxycycline treatment in the in vivo xenograft mouse model.ConclusionsCancer stem cells are enriched from sphere-forming and chemoresistant HeLa-derived tumor xenografts in immunodeficient mice. Doxycycline inhibits proliferation, invasion, and differentiation, and also induces apoptosis of these HeLa-CSCs in vitro and in vivo.