关键词： 肝细胞癌ATF3   MMP-2   maspin   组织芯片  

摘要： 目的:检测ATF3、MMP-2及maspin在肝细胞癌(hepatocellular carcinoma,HCC)组织芯片中的表达情况,探讨ATF3、MMP-2及maspin表达与HCC发生、发展的关系及其意义。方法:对手工制作组织芯片的方法进行改良,构建含HCC、癌旁肝组织、远癌肝组织、正常肝组织及肝内转移灶的组织芯片,应用免疫组织化学和图像分析技术检测ATF3、MMP-2及maspin的相对表达量,并分析其与各临床病理参数的关系及其意义。结果:ATF3及MMP-2在HCC中表达明显高于癌旁肝组织、远癌肝组织及正常肝组织(P<0.01),而maspin在HCC中的表达明显低于癌旁肝组织、远癌肝组织及正常肝组织(P<0.01)。ATF3蛋白在女性HCC患者中的表达量高于男性患者(P<0.01),在转移组中表达高于无转移组(P<0.01);MMP-2蛋白随HCC病理学分级的升高,相对表达量降低(P<0.05),MMP-2蛋白在直径大于3cm的HCC中的相对表迭量高于直径小于3cm的表达量(P<0.05),包膜侵犯组高于无包膜侵犯组(P<0.05),肝内转移灶表达量高于原发灶(P<0.05);ATF3和MMP-2均随着HCC的进展表达量逐渐增高,maspin却随着HCC病理学分级的升高,相对表达量降低(P<0.05)。ATF3蛋白表达与MMP-2表达呈正相关(r_s=0.13,P<0.05),与maspin表达呈负相关(r_s=-0.23,P<0.01);MMP-2蛋白表达与maspm表达呈负相关(r_s=-0.17,P<0.01)。结论:在HCC组织中,ATF3、MMP-2及maspin的表达存在相关关系,ATF3、MMP-2高表达及maspin缺失表达与HCC的发生密切相关,他们可能在HCC发生发展、侵袭转移过程中发挥重要作用。选择性抑制ATF3有可能成为治疗HCC新的靶点。

关键词： 膀胱尿路上皮癌   ATF3   免疫组织化学   RT—PCR  

摘要： 目的探讨膀胱尿路上皮癌中转录因子ATF3的表达及其临床意义。方法采用逆转录聚合酶链反应(RT-PCR)和免疫组织化学方法检测32例膀胱癌组织和14例正常膀胱粘膜中ATF3 mRNA和ATF3蛋白的表达,分析其表达与肿瘤病理分级、临床分期的关系。结果膀胱癌组织中ATF3 mRNA相对表达量稍高于正常膀胱粘膜组织,浸润膀胱癌组织中ATF3 mRNA相对表达量稍高于浅表膀胱癌组织,但差别均无显著性。ATF3蛋白在膀胱癌组织和正常膀胱粘膜中的阳性表达率分别为93.7%(30/32)、21.4%(3/14),差异有显著性。结论ATF3表达参与了膀胱尿路上皮癌的发病过程,进一步研究其功能有可能揭示膀胱癌的发病机制。

关键词： ATF3   shRNA   肾小球系膜细胞  

摘要： 目的:构建针对大鼠ATF3(activating transcription factor3,ATF3)基因的特异性短发卡RNA(small hairpinRNA,sh RNA)真核表达质粒。方法:用DNA重组技术将针对大鼠ATF3基因不同位点所设计的5个shRNA序列克隆到真核表达质粒pGenesil-1中。在酶切分析及序列测定后,用脂质体将5个shRNA分别转染至大鼠肾小球系膜细胞(glomerular mesangial cells,GMC),随后用Western blot检测蛋白的相对表达量来筛选最佳沉默效率的shRNA。结果:限制性酶切及核酸序列分析证明重组质粒构建正确。Western blot证实在重组质粒中,shATF3-1具有最佳的沉默效率。结论:成功构建了针对ATF3基因的shRNA的真核表达质粒,并且该shRNA可以特异性地降低大鼠肾小球系膜细胞ATF3的蛋白表达。

关键词： DNA repair   ATF3   p15(paf)   PCNA   UV  

摘要： After genotoxic stress, normal cells trigger DNA repair or, if unable to repair, undergo apoptosis to eradicate the cells that bear the risk of becoming tumorigenic. Here we show that repression of the transcription factor, activating transcription factor 3 (ATF3), after ultraviolet (UV)-mediated genotoxic stress impairs the DNA repair process. We provide evidence that ATF3 directly regulates the proliferating cell nuclear antigen (PCNA)-associated factor KIAA0101/p15(PAF). We further show that the expressions of ATF3 and p15(PAF) is sufficient to trigger the DNA repair machinery, and that attenuation of their expression alters DNA repair mechanisms. We show that the expression of p15(PAF) compensates for a lack of ATF3 expression, thereby constituting a major effector of ATF3 in the DNA repair process. In addition, we provide evidence that p15(PAF) expression is required for the correct function of PCNA during DNA repair, as prevention of their interaction significantly alters DNA repair mechanisms. Finally, defective DNA repair, because of the downregulation of p15(PAF) expression, rendered the cells more sensitive to UV-induced cell death. Therefore, our results suggest ATF3 and p15(PAF) as novel gatekeepers of genomic integrity after UV exposure.

关键词： Diarylheptanoid   Cell cycle arrest   Apoptosis   p53   ATF3  

摘要： Purpose The aim of the study is to dissect the cytotoxic mechanisms of 1-(4-hydroxy-3-methoxyphenyl)-7-(3,4dihydroxyphenyl)-4E-en-3-heptanone (compound 1) in SH-SY5Y cells and therefore to provide new insight into neuroblastoma chemotherapy. Methods Nine diarylheptanoids were isolated from Alpinia officinarum by chromatography and their cytotoxicity was evaluated by an MTS assay. Flow cytometry, BrdU incorporation assay and fluorescence staining were employed to investigate cytostatic and apoptotic effects induced by the compound 1. In addition, Western blot, qPCR and siRNA techniques were used to elucidate the molecular mechanisms of the cytotoxicity. Results The study to elucidate the cytotoxic mechanisms of compound 1, the most potent diarylheptanoid showed that cell cycle-related proteins, cyclins, CDKs and CDKIs, as well as two main apoptotic related families, caspase and Bcl 2 were involved in S phase arrest and apoptosis in neuroblastoma cell line SH-SY5Y. Furthermore, following the drug treatment, the protein expression of p53, phospho-p53 (Ser20) as well as the p53 transcriptional activated genes ATF3, puma and Apaf-1 were increased dramatically;MDM2 and Aurora A, the two p53 negative regulators were decreased;the p53 protein stability was enhanced, whereas the p53 mRNA expression level slightly decreased and ATF3 mRNA expression apparently increased. In addition, the knockdown of ATF3 gene by siRNA partially suppressed p53, caspase 3, S phase arrest and apoptosis triggered by compound 1. Conclusion These results suggest that compound 1 induces S phase arrest and apoptosis via up regulation of ATF3 and stabilization of p53 in SH-SY5Y cell line. Therefore, compound 1 might be a promising lead structure for neuroblastoma therapy.

关键词： Ribotoxic stress   Activating transcription factor 3 (ATF3)   Epithelial cell survival   p38 MAP kinase   Double-stranded RNA (dSRNA)-activated protein kinase (PKR)  

摘要： Ribotoxic stress responses lead to the expression of genes important for cellular homeostasis by modulating cell survival, proliferation and differentiation. ATF3 was investigated for its modulation of the epithelial cellular integrity in response to mucosal ribotoxic stress. ATF3 expression was up-regulated by chemical agents causing ribotoxic stress such as deoxynivalenol. and anisomycin in different types of intestinal epithelial cells. Moreover, reduction of ATF3 gene expression promoted ribotoxic stress-triggered programmed cell death, implicating a protective role of ATF3 in epithelial cell survival. Mechanistically, stabilization of ATF3 messenger RNA and protein played a critical role in maintaining enhanced levels of ATF3 production in response to the ribotoxic chemical agent. For ATF3 mRNA stability, p38 specific inhibitor SB203580 was the most efficient agent for suppression, suggesting the involvement of the p38 MAP kinase in ATF3 mRNA stabilization. in addition, the p38 MAP kinase as well as its downstream mediator glycogen synthase kinase 30 (GSK3 beta) was involved in ATF3 protein stabilization caused by chemical ribotoxic stress in human epithelial cells. As another separate signaling cascade, double-stranded RNA (dsRNA)-activated protein kinase (PKR) was demonstrated to translationally modulate ATF3 expression and contribute to the epithelial cell survival. PKR interference caused cells to be more susceptible to cell death caused by the chemical ribotoxic stress. The results of this study showed that enhanced ATF3 production was associated with cellular defenses by maintaining the epithelial survival after ribotoxic mucosal insults. (C) 2009 Published by Elsevier Inc.

关键词： EUKARYOTIC cells   DNA damage   DNA replication   PROTEIN kinase C   PROTEIN kinases   PHOSPHORYLATION  

摘要： Eukaryotic cells respond to DNA damage and stalled replication forks by activating signaling pathways that promote cell cycle arrest and DNA repair. A systematic screening of the protein kinase small interfering RNA library reveals that Chk1 and ataxia telangiectasia-mutated (ATM) and Rad3-related (ATR) are the main kinases responsible for intra-S-phase checkpoint upon topoisomerase I inhibitor camptothecin-induced DNA damage. It is well known that ATR-Chk1-mediated protein degradation of Cdc25A protein phosphatase is a crucial mechanism conferring this checkpoint activation. Here we describe another mechanism underlying Cdc25A down-regulation in response to DNA damage that occurs at the transcriptional level. We show that activation of tumor suppressor p53 by DNA damage results in inhibition of Cdc25A transcription as a result of activation of transcriptional repressor ATF3 that directly binds to the Cdc25A promoter. In cells deficient in both Chk1 and p53, Cdc25A down-regulation upon camptothecin-induced DNA damage is completely abolished, leading to severe defects in cell cycle checkpoints and remarkable cell death in mitosis. Our findings reveal two independent mechanisms acting in concert in regulation of Cdc25A in DNA damage response. Although Chk1 affects Cdc25A via rapid phosphorylation and protein turnover, inhibition of Cdc25A transcription by p53-ATF3 is required for the maintenance of cell cycle arrest.

关键词： Atf3   妊娠   胰岛β细胞   细胞增殖   催乳素  

摘要： 目的:探讨Atf3在大鼠妊娠期胰岛β细胞中的表达及其对体外催乳素作用下INS-1细胞增殖的影响。方法:运用RT-PCR,Real-timePCR和Westernblotting检测大鼠妊娠期Atf3mRNA及蛋白的表达;MTT法测定不同浓度催乳素作用下INS-1细胞的增殖情况;RT-PCR检测催乳素作用不同时间后INS-1细胞Atf3 mRNA的表达;Western blotting检测相应蛋白表达。结果:与正常未孕组相比,孕10.5天组Atf3 mRNA表达明显增强,孕14.5天时降至正常未孕组水平。Atf3蛋白在孕期表达亦呈一过性增强,于孕10.5天达高峰。体外不同浓度催乳素(50～1000ng/ml)作用24h后,INS-1细胞增殖显著增加,且呈浓度依赖性。200ng/ml催乳素作用3h,Atf3 mRNA表达开始增加,6h达高峰,其后又复降低;蛋白表达则从6h开始上调,12h显著增加,一直持续至24h。结论:转录因子Atf3在大鼠妊娠期表达一过性增强,且时相上早于胰岛增殖的高峰(孕14.5天),提示它可能与胰岛再生相关。另外,催乳素可促进INS-1细胞增殖,并伴随Atf3表达的相应增加,提示Atf3在催乳素介导的细胞增殖效应中发挥重要作用,且于早期即启动。

关键词： NF-kappa B p50   melanoma   angiogenesis   IL-6   ATF3  

摘要： Nuclear factor kappa B (NF-kappa B) signaling is deregulated in many tumor types, resulting in aberrant expression and/or activation of NF-kappa B transcriptional complexes. We have previously reported that nuclear expression of the NF-kappa B subunit p50 is strongly correlated with melanoma progression and poor 5-year patient survival. In this study, we used cDNA microarray to analyze the gene expression profiles of melanoma cells overexpressing NF-kappa B p50. We found that NF-kappa B p50 expression strongly induced interleukin-6 (IL-6) upregulation in melanoma cells at both the transcriptional and translational levels and that IL-6 production by melanoma cells enhanced the growth of endothelial cells in vitro. Expression of activating transcription factor 3 (ATF3), a negative regulator of IL-6 gene transcription, inhibited p50-mediated IL-6 upregulation. Knockdown of p50 expression using lentiviral-based shRNA abrogated IL-6 induction in melanoma cells and inhibited its effects on endothelial cell growth. Finally, we used an in vivo matrigel plug assay to show that NF-kappa B p50 overexpression promotes angiogenesis, while silencing NF-kappa B p50 inhibits blood vessel formation. Our results demonstrate for the first time that the NF-kappa B p50 subunit mediates melanoma angiogenesis by specifically upregulating IL-6, highlighting a novel and important role for the NF-kappa B p50/IL-6 signaling axis in melanoma progression. (c) 2008 Wiley-Liss, Inc.

关键词： Di-(2-ethylhexyl) phthalate   Hypospadias   Activating transcription factor 3   Apoptosis   Mouse  

摘要： Di-(2-ethylhexyl) Phthalate Upregulates ATF3 Expression and Suppresses Apoptosis in Mouse Genital Tubercle: Xing Liu, et al. Department of Pediatric Urology, Chongqing Children's Hospital, Chongqing Medical University, China-Objectives: To investigate the effect of di-(2-ethylhexyl) phthalate (DEHP) on the expression of activating transcription factor 3 (ATF3) and apoptosis of fetal mouse genital tubercle (GT). Methods: In this developmental toxicity study, pregnant C57BL/6 mice were exposed to corn oil or DEHP (100 or 500 mg/kg/day) from embryonic day 12 (ED12) to ED16. Apoptosis was characterized by Terminal transferase dUTP nick end labeling (TUNEL) assay. Using RT-PCR and western blot, the expressions of ATF3 and apoptosis-related genes (P53, Bcl-2 and Bax) were investigated. Results: Apoptosis of fetal mouse GT cells notably decreased after DEHP treatment. DEHP activated ATF3 both at the mRNA and protein levels in GT. Furthermore, pro-apoptotic P53 was downregulated and the ratio of anti-apoptotic (Bcl-2)/pro-apoptotic (Bax) was not significantly changed. Conclusions: These results suggest that DEHP may induce external genital defects via a mechanism involving apoptosis, which might correlate with the regulation of ATF3 and P53 expressions.