Identification of novel growth factor-responsive genes in neuroendocrine gastrointestinal tumour cells

Targeting growth-regulatory pathways is a promising approach in cancer treatment. A prerequisite to the development of such therapies is characterisation of tumour growth regulation in the particular tumour cell type of interest. In order to gain insight into molecular mechanisms underlying proliferative responses in neuroendocrine (NE) gastrointestinal (GI) tumours, we investigated gene expression in human carcinoid BON cells after exposure to gastrin, hepatocyte growth factor (HGF), pituitary adenylate cyclase-activating polypeptide or epidermal growth factor. We particularly focused on gastrin- and HGF-induced gene expression, and identified 95 gastrin- and 101 HGF-responsive genes. The majority of these genes are known mediators of processes central in tumour biology, and a number of them have been associated with poor prognosis and metastasis in cancer patients. Furthermore, we identified 12 genes that were regulated by all four factors, indicating that they may be universally regulated during NE GI tumour cell proliferation. Our findings provide useful hypotheses for further studies aimed to search for new therapeutic targets as well as tumour markers in NE GI tumours.     

Signaling satellite-cell activation in skeletal muscle: markers, models, stretch, and potential alternate pathways

Activation of skeletal muscle satellite cells, defined as entry to the cell cycle from a quiescent state, is essential for normal growth and for regeneration of tissue damaged by injury or disease. This review focuses on early events of activation by signaling through nitric oxide and hepatocyte growth factor, and by mechanical stimuli. The impact of various model systems used to study activation and the regulation of satellite-cell quiescence are placed in the context of activation events in other tissues, concluding with a speculative model of alternate pathways signaling satellite-cell activation.     

抑癌基因PTEN与pAkt在肝细胞肝癌中表达及其意义

目的研究肝细胞癌（HCC）中抑癌基因第10号染色体上缺失与张力蛋白同源的磷酸酯酶基因（PTEN）与磷酸化丝氨酸／苏氨酸蛋白激酶B（pAkt）表达及其意义。方法采用免疫组化S—P法检测65例HCC及癌旁组织中FFEN与pAkt表达并分析两者与肝癌患者年龄、临床分期、病理类型及侵袭转移性之间关系。结果HCC中PTEN蛋白阳性率明显低于癌旁肝组织，且随HCC恶性程度、侵袭转移性升高而显著下降（P〈0．05）；pAkt在HCC中表达率明显高于癌旁肝组织，且其表达率随HCC恶性程度、侵袭转移性升高而增加（P〈0．05）；肝癌及癌旁组织中，FFEN与pAkt表达均呈负相关（P〈0．01）。结论PTEN与pAkt表达与肝癌组织恶性程度相关，联合检测PTEN与pAkt在癌组织中表达情况，可作为肿瘤预后评估指标之一。     

中药HD02抗脑缺血/再灌注损伤的作用及机制研究

目的:观察中药HD02制剂对小鼠反复缺血/再灌注损伤脑组织的保护作用.方法:随机分为假手术对照组、缺血再灌注模型组、HD02低、中、高剂量组,采用小鼠全脑反复缺血/再灌注模型,取脑组织进行脑含水量、SOD活性及MDA、Na /K -ATP酶、Ca2 -ATP含量酶的测定.结果:与假手术组比较,模型组脑含水量显著增加(P＜0.01)、SOD活性明显降低、MDA含量明显升高(P＜0.01)、ATP酶有明显下降(P＜0.01),HD02低、中、高剂量组均可明显减少脑组织含水量(P＜0.01)、提高SOD活性,降低MDA含量(P＜0.01),提高缺血/再灌注脑组织ATP酶活性(P＜0.01).结论:中药HD02可减少小鼠缺血/再灌注脑组织的损伤,其机制可能通过提高SOD活性,减轻自由基对组织的氧化损伤,同时保护细胞ATP酶活性从而使脑水肿程度降低,保护缺血再灌注导致的脑组织损伤.     

三价铬与六价铬化合物对L-02肝细胞毒性的比较

目的　评价三价铬 (Cr(III) )和六价铬 (Cr(VI) )对L -0 2肝细胞的细胞毒效应差异。　方法　以L -0 2肝细胞为研究对象 ,用MTT法检测L -0 2肝细胞死亡指数 ,比色法检测细胞内乳酸脱氢酶 (LDH)、天冬氨酸氨基转移酶(ALT)、丙氨酸氨基转移酶 (AST)的渗出程度。　结果　细胞处理 12h ,Cr(VI)处理组的细胞死亡指数明显高于Cr(III)细胞处理组 ,在 4～ 2 5 6μmol/L浓度范围具有明显的浓度 -效应关系 (相关系数r =0 .945 ,P <0 .0 5 )。细胞处理 5h后 ,Cr(VI)低剂量和高剂量组 (16μmol/L和 12 8μmol/L)LDH的漏出比均明显高于相应剂量的Cr(III) (P <0 .0 5 ) ;在Cr(VI)高剂量组 (12 8μmol/L)ALT与AST的漏出比显著高于相同剂量的Cr(III) (P <0 .0 5 )。　 结论　Cr(VI)对L -0 2肝细胞的细胞毒效应明显大于Cr(III)。     

促肝细胞生长素活性测定方法的研究

目的　研究促肝细胞生长素活性测定的新方法。方法　用SMMC -7721细胞株,MTT(溴化四唑蓝)染色法测定该药的活性。结果　该法结果与现行标准方法的结果无显著性差异。结论　该法可用于促肝细胞生长素活性的测定。     

普乐可复和环孢素A对肝细胞分泌白蛋白作用的影响

目的：研究细胞因子及普乐可复（FK506）和环孢素A（CSA）对肝细胞分泌白蛋白的影响。比较FK506和CSA对IL-6抑制肝细胞分泌白蛋白的作用。方法：分别用IL-6，IL-2和IL-10（0-10μg／L）以及FK506和CSA（1-100μg／L）体外刺激人肝癌细胞株（HepG2）48h；另外用IL-6（5μg／L）刺激HepG2细胞，同时分别加入FK506和CSA（0.1-10μg／L）刺激细胞48h，采用全自动生化仪检测FK506和CSA组细胞上清中乳酸脱氢酶（LDH）的量，采用放射免疫法检测各组细胞上清白蛋白的量。结果：IL-6能明显降低HepG2细胞上清中白蛋白的水平，且在一定范围内呈剂量依赖性，IL-6为5μg／L时白蛋白的分泌量达最低（P〈0.05）。IL-2，IL-10和FK506对HepG2细胞白蛋白的分泌无明显影响，CSA能轻度降低HepG2细胞白蛋白的分泌，且当CSA为10和100μg／L时差异有统计学意义（P〈0.05）。FK506明显减少HepG2细胞释放LDH（P〈0.05），CSA则轻度增加HepG2细胞分泌LDH（但P〉0.05）。另外，FK506能减轻IL-6抑制HepG2细胞分泌白蛋白的作用（P〈0.01），但CSA对此无作用。结论：IL-6而非IL-2和IL-10能明显抑制HepG2细胞分泌白蛋白，FK506而非CSA能减轻肝细胞的损伤，并能减轻IL-6抑制肝细胞分泌白蛋白的作用，这为FK506用于治疗免疫性肾脏病低白蛋白血症提供了的理论依据。     

Improvement of cardiac function by hepatocyte growth factor via intracoronary transfection in the swine myocardial infarction model

Objective： To study the amelioration effect of AdenovirusS-mediated human hepatocyte growth factor （AdsHGF） on postinfarction heart failure in the swine myocardial infarction model. Methods： Twelve SuZhong young swine were randomly divided into 2 groups with 6 swine in each group： Ad5-HGF-treated group and null-Ad5 group. Four weeks after ligation at left anterior descending coronary artery in swine hearts, Ad5-HGF was transferred to the swine myocardium. Simultaneously, Gated myocardial perfusion imaging was performed to evaluate cardiac perfusion and heart function. After three weeks, Gated myocardial perfusion imaging was performed again, then the hearts were harvested and sectioned to examine the expression of HGF through ELISA. Results： High expression of human HGF was observed in the myocardium of Ad5-HGF-treated group. From 4 weeks to 7 weeks after operation, Left ventricular ejection fraction was increased in Ad5-HGF-treated group. The improvement in LVEF was greater in Ad5-HGF-treated group than that in null-Ad5 group at 7 weeks after operation. Cardiac perfusion was significantly improved in the Ad5-HGF-treated group. Conclusion： High expression of human HGF was observed in the myocardium through intracoronary transfection, which suggests that HGF can ameliorate heart function in swine with postinfarction heart failure.     

人端粒酶逆转录酶诱导的猪肝细胞初步鉴定

目的观察应用四步灌流法分离后原代猪肝细胞的数量和活力,初步鉴定人端粒酶逆转录酶(hTERT)诱导的猪肝细胞的生物学特性。方法四步灌流法分离12只猪肝脏组织中的猪肝细胞,采用锥虫蓝拒染法测定其肝实质细胞数量和活力;将含hTERT真核表达的载体转染到原代猪肝细胞,经G418硫酸盐筛选,获得耐药性的猪肝细胞克隆并传代3代。观察原代猪肝细胞和hTERT诱导后的猪肝细胞的形态,检测两种猪肝细胞不同时期培养上清液中白蛋白、尿素氮的浓度。结果每只肝脏的肝细胞产量约为2.0×1010个,具有活力的肝细胞所占百分比为(95.5±3.2)%。原代猪肝细胞和hTERT诱导的猪肝细胞培养上清中分泌白蛋白和尿素氮在前3天无统计学差异(P>0.05),第4、5天差异有统计学意义(P<0.05)。结论四步灌流法分离获取的猪肝细胞产量高、功能活性好。hTERT诱导的猪肝细胞具有正常肝细胞的基本功能,可作为生物人工肝及细胞移植等的理想的细胞源。     

Effect of polo-like kinase 1 gene silence on cell cycle and drug resistance in K562/A02 cell

Polo-like kinase 1（PLK1） plays an important role in many cell-cycle-related events. At G2/Mtransition, PLK1 contributes to the activation of cyclinB/Cdc by phosphorylation of Cdc25C, centrosome functional maturation, bipolar spindle formation. In later stage of mitosis, PLK1 is involved in regulating components of the anaphase-promoting complex （APC） for mitotic exit and in the execution of cytokinesis. Moreover, recent reports have shown that PLK1 is involved in both G2 and mitotic DNA damage checkpoints. When G2/M DNA damage occurs, PLK1 activity is suppressed and cell cycle arrests to repair the damaged DNA. So far, the deregulated expression of PLK1 has been detected in many types of human tumors and PLK1 is considered as a novel prognostic marker for several tumors.