目的:观察香加皮杠柳苷(periplocin from cortex periplocae,CPP)对人结肠癌细胞株SW480在体内外增殖的抑制作用,研究其对SW480细胞内Wnt/β-catenin信号转导通路的调控作用和对β-catenin/TCF下游靶基因的影响,以探讨CPP的抗肿瘤作用机...
详细信息
目的:乙型肝炎病毒(hepatitis B virus,HBV)的持续感染与肝癌的发生具有十分密切的关系,乙肝病毒X基因在肝癌的发生中起重要作用。然而,HBx的致癌作用机理目前仍不十分清楚。为了进一步阐明HBx与肝癌发病的关系,本研究应用人肝细胞系和...
详细信息
目的:乙型肝炎病毒(hepatitis B virus,HBV)的持续感染与肝癌的发生具有十分密切的关系,乙肝病毒X基因在肝癌的发生中起重要作用。然而,HBx的致癌作用机理目前仍不十分清楚。为了进一步阐明HBx与肝癌发病的关系,本研究应用人肝细胞系和鼠纤维母细胞系,探讨了HBx致癌作用。结果和讨论:为了探讨乙肝病毒X基因在肝癌发生中的作用,建立稳定转染所研究基因的细胞模型具有十分重要的意义。本研究通过基因转染技术将克隆有乙肝病毒X基因的质粒导入培养的人肝细胞系L-O2和鼠纤维母细胞系NIH3T3中,经G-418筛选,获得了稳定细胞系,分别将其命名为L-O2-P/3T3-P(转染空载体)和L-O2-X/3T3-X(转染X基因)。利用上述细胞进行基因组PCR和Western blot及免疫荧光检测,显示L-O2-X/3T3-X细胞中存在X基因的整合及X蛋白的表达。为了阐明上述各个细胞系的恶性表型,进行了免疫印迹实验。结果显示,在L-O2-X细胞中有甲胎蛋白(AFP)的表达,初步显示这些细胞发生了转化。进一步克隆形成实验的结果显示,L-O2-X细胞克隆形成能力相比对照细胞系显著增强。将L-O2、L-O2-P和L-O2-X细胞接种裸鼠后,L-O2和L-O2-P细胞系不能使裸鼠成瘤;L-O2-X细胞接种的裸鼠中8只中有3只成瘤。在上述研究基础上,流式细胞仪检测发现L-O2-X细胞增殖明显加快。在L-O2和NIH3T3系统中的报告基因实验显示,HBx存在的时候NF-κB,AP-1 andsurvivin报告基因的活性显著增强,表明HBx发挥转化功能。对癌蛋白的检测发现,L-O2-X/3T3-X具有转化细胞的特征,癌蛋白呈高水平表达;而对HBx进行RNA干扰以后,癌蛋白的表达下降。应用免疫荧光染色检测中心体标志物蛋白γ-tubulin,结果显示与对照组L-O2细胞相比,L-O2-X细胞的中心体数目明显增多。进一步在L-O2和NIH3T3系统中检测人端粒酶反转录酶(hTERT)报告基因的活性,结果显示HBx能显著增强hTERT的转录活性,并能刺激hTERT的活性大大增加。结论:HBx基因的整合导致了细胞的恶性转化、增殖加速、癌蛋白高表达以及基因组不稳定性,这些因素进一步促进了肝癌的发生;另一方面,HBx蛋白的反式激活功能在肝癌的发生和发展过程中也扮演了重要的功能。我们的研究表明,用人肝细胞L-O2建立的研究HBx的细胞模型明显优于肝癌细胞和鼠细胞模型,以这种模型为基础研究HBx的转化功能及相关机制更贴近体内HBx发挥功能的自然状态。在此模型基础上进行的进一步研究,将为深入揭示HBx的致癌机理提供新的实验依据,可进一步丰富HBx致癌的分子机理,对于肝癌的预防及治疗具有重要的理论价值。
PURPOSE:Vascular endothelial growth factor(VEGF) plays an important role in tumor angiogenesis and cancer progression The VEGF genetic polymorphisms were shown to be independently associated with an adverse outcome in...
详细信息
PURPOSE:Vascular endothelial growth factor(VEGF) plays an important role in tumor angiogenesis and cancer progression The VEGF genetic polymorphisms were shown to be independently associated with an adverse outcome in various *** investigated the possible associations of two polymorphisms (-2578C/A and +936C/T) in the VEGF gene with the clinicopathologic parameters for patients with non-Hodgkin's lymphoma(NHL).METHODS:We studied the genotype and allele frequencies of the -2578C/A and +936C/T polymorphism in DNA samples of 431 patients with NHL using restriction fragment length polymorphism typing ***:The-2578A allele was significantly associated with less frequent clinical staging III,IV and bone marrow involvement(The odds ratio(OR) 0.59;95%confidence interval(CI) 0.43-0.82;and OR,0.66;95%CI,0.48-0.91;respectively).The CA and CA + AA genotype of the-2578C/A were significantly associated with less frequent bone marrow involvement than CC genotypes (OR,0.57;95%CI,0.38-0.86;and OR,0.57;95%CI,0.39-0.85;respectively).The TT genotype of the +936C/T polymorphism was significantly associated with less frequent T cell histological type,clinical staging III,IV and bone marrow involvement(OR,0.25;95%CI,0.07-0.89;OR,0.37;95%CI,0.15-0.89;and OR, 0.31;95%CI,0.10-0.96;respectively).The +936 T allele was marginally associated with less frequent bone marrow involvement and with Clinical stagingⅢ,Ⅳ(OR,0.71;95%CI,0.49-1.01;and OR,0.70;95%CI, 0.49-1.00;respectively).None of the evaluated genotypes of-2578C/A was significantly associated with the gender,age,tumor size,B symptoms and immunohistological *** significant associations between the genotype of +936C/T and the clinicopathologic variables,gender,age,tumor size and B symptoms were *** of the-2578C/A and +936C/T polymorphisms were not related to the patients' overall ***:We present the first data on VEGF gene polymorphisms in *** findings support the hypothesis that
暂无评论