Hsa-miR-4282对肝癌细胞系SMMC-7721生长的影响

目的  探讨Hsa-miR-4282在肝癌细胞系SMMC-7721中的表达及其对细胞生长的影响。方法 采用实时荧光定量PCR法检测Hsa-miR-4282在人正常肝上皮细胞系HL-7702和人肝癌细胞系MHCC97-H、SMMC-7721，以及 20例肝癌组织及其相应癌旁组织中的表达。采用瞬时转染法将Hsa-miR-4282 mimics（上调组）和Hsa-miR-4282 inhibitor（下调组）分别转染肝癌SMMC-7721细胞，上调组和下调组分别设置相应阴性对照组。转染后采用MTT法检测细胞增殖能力，平板克隆形成实验检测细胞克隆形成能力，流式细胞仪检测细胞凋亡能力。结果 Hsa-miR-4282在肝癌组织、肝癌细胞MHCC97-H及肝癌细胞SMMC-7721中的表达均低于癌旁组织及正常肝细胞HL-7702（P＜0.05）。MTT实验结果显示，Hsa-miR-4282上调后肝癌SMMC-7721细胞的OD值低于其阴性对照组，而下调后OD值高于其阴性对照组 （P＜0.05）。平板克隆形成实验显示，下调组的细胞克隆数高于其阴性对照组［（240±7） 个 vs （191±10） 个，P=0.005）］，而上调组细胞克隆数低于基阴性对照组［（146±10） 个 vs （193±12） 个，P=0.013）］。流式细胞仪检测结果显示，Hsa-miR-4282上调组细胞凋亡率较其阴性对照组升高［（23.89±1.89）% vs（16.6±1.14）%，P=0.009）］，下调组细胞凋亡率较期阴性对照组降低［（14.98±0.46）% vs （17.79±0.73）%，P=0.010］。结论 Hsa-miR-4282上调可抑制肝癌SMMC-7721细胞增殖，促进细胞凋亡，可能与肝癌的发病机制有关。     

蛇床子素诱导内质网应激抑制SMMC7721人肝癌细胞增殖的机制研究＊

目的 研究蛇床子素抑制肝癌细胞增殖的机制。方法 采用20 - 100 μM蛇床子素干预SMMC7721人肝癌细胞24 h、48 h和72 h，运用MTT方法检测细胞增殖；采用20 - 80 μM蛇床子素干预SMMC7721肝癌细胞24 h，运用流式细胞术检测细胞凋亡及Western blot检测Bax和Bcl-2蛋白表达；采用 60 μM蛇床子素干预SMMC7721肝癌细胞48 h，运用流式细胞术检测细胞周期，以实时荧光定量PCR技术检测GRP78、DDIT3、GADD34、ATF4、EIF2A、GDF15、CDKN1B、FOXO3、RICTOR、SGK1基因表达，Western blot方法检测CyclinD1、CyclinE1、p27^Kip1和CDK4细胞周期蛋白及GRP78、GRP94、PERK、XBP-1s、CHOP、p-eIF2α(Ser51)内质网应激蛋白表达。各实验均以0.1% DMSO为对照组，并以0.1 μM毒胡萝卜素为内质网应激诱导剂组。结果 与对照组比较，100 μM蛇床子素干预24 h显著抑制SMMC7721肝癌细胞增殖，其抑制率为36.76%（P < 0.05）；60 - 100 μM蛇床子素干预48 h后显著抑制SMMC7721肝癌细胞增殖，抑制率为30.84%-52.49%（P < 0.05）；40 - 100 μM蛇床子素干预72 h后显著抑制SMMC7721肝癌细胞增殖，抑制率为32.7%-73.15%（P < 0.05）。大于60 μM蛇床子素可诱导SMMC7721肝癌细胞晚期凋亡且显著抑制促凋亡蛋白Bax表达（P < 0.05）。60 μM蛇床子素干预SMMC7721肝癌细胞48 h后，G1期细胞数增加、G2期和S期减少，且CyclinD1、CyclinE1和p27^Kip1蛋白表达显著被抑制（P < 0.05）。20 - 80 μM蛇床子素处理SMMC7721肝癌细胞24 h后，均显著促进GRP78、DDIT3（CHOP）、ATF4、FOXO3、RICTOR和SGK1基因表达（P < 0.05）； 20 μM蛇床子素显著促进GADD34和EIF2A基因表达（P < 0.05）；80 μM蛇床子素显著促进GDF15基因表达（P < 0.05），且CHOP、XBP-1s蛋白表达显著增强。结论 蛇床子素通过诱导内质网应激反应以抑制SMMC7721肝癌细胞增殖，从而发挥抗肝癌活性。     

α-干扰素和COX-2抑制剂对人肝癌细胞SMMC-7721细胞增殖的抑制作用研究

目的研究α-干扰素和环氧合酶(COX-2)抑制剂塞来昔布(Celecoxib)对人肝癌SMMC-7721细胞的生长抑制作用。方法采用MTT比色法观察不同浓度的塞来昔布和α-干扰素处理对肝癌细胞增殖的影响;通过荧光显微镜检测细胞凋亡。结果实验组与对照组相比,能抑制人肝癌SMMC-7721细胞的增殖,两种药物高浓度联合作用48 h后,对肝癌细胞的生长抑制率可达92.44%±0.98%。α-干扰素和塞来昔布对肝癌细胞的增殖抑制具有协同作用。荧光显微镜观察到细胞皱缩、核质浓缩、核碎裂以及凋亡小体形成等凋亡形态学改变。结论 COX-2抑制剂塞来昔布和α-干扰素对人肝细胞癌SMMC-7721细胞的增殖有协同抑制作用,同时能诱导其凋亡,并且呈剂量和时间依赖性,这提示α-干扰素和COX-2抑制剂塞来昔布对HCC的预防和治疗可能有积极意义。     

抗癌扶正方对人肝癌细胞SMMC-7721的Bcl-2基因表达的调控作用

目的:研究与分析抗癌扶正方对人肝癌细胞SMMC-7721的Bcl-2基因表达的调控作用。方法:首先培养人肝癌细胞SMMC-7721,然后使用噻唑蓝比色法(MTT比色法)检测抗癌扶正方对人肝癌细胞SMMC-7721增殖能力,使用流式细胞仪检测人肝癌细胞SMMC-7721抑制能力和Bcl-2基因表达水平。结果:通过检测发现,抗癌扶正方可以有效抑制人肝癌细胞SMMC-7721增殖。通过流式细胞仪检测发现,抗癌扶正方作用于人肝癌细胞SMMC-7721后,Bcl-2基因表达水平明显降低。结论:抗癌扶正方可以通过调控Bcl-2基因表达从而抑制人肝癌细胞SMMC-7721的活性。     

Nutlin-3-induced redistribution of chromatin-bound IFI16 in human hepatocellular carcinoma cells in vitro is associated with p53 activation

Aim:

Interferon-γ inducible protein 16 (IFI16), a DNA sensor for DNA double-strand break (DSB), is expressed in most human hepatocellular carcinoma cell (HCC) lines. In this study we investigated the re-localization of chromatin-bound IFI16 by Nutlin-3, a DNA damage agent, in HCC cells in vitro, and the potential mechanisms.

Methods:

Human HCC SMMC-7721 (wild-type TP53), Huh-7 (mutant TP53), Hep3B (null TP53) and normal fetal liver L02 cell lines were examined. DSB damage in HCC cells was detected via γH2AX expression and foci formation assay. The expression of IFI16 and IFNB mRNA was measured using RT-PCR, and subcellular localization and expression of the IFI16 protein were detected using chromatin fractionation, Western blot analysis, and fluorescence microscopy.

Results:

Treatment of SMMC-7721 cells with Nutlin-3 (10 μmol/L) or etoposide (40 μmol/L) induced significant DSB damage. In SMMC-7721 cells, Nutlin-3 significantly increased the expression levels of IFI16 and IFNB mRNA, and partially redistributed chromatin-bound IFI16 protein to the cytoplasm. These effects were blocked by pretreatment with pifithrin-α, a p53 inhibitor. Furthermore, Nutlin-3 did not induce ectopic expression of IFI16 protein in Huh-7 and Hep3B cells. Moreover, the association of IFI16 with chromatin and Nutlin-3-induced changes in localization were not detected in L02 cells.

Conclusion:

Nutlin-3 regulates the subcellular localization of IFI16 in HCC cells in vitro in a p53-dependent manner.     

Holotransferrin enhances selective anticancer activity of artemisinin against human hepatocellular carcinoma cells

Artemisinin, also termed qinghaosu, is extracted from the traditional Chinese medicine ar- temesia annua L. （the blue-green herb） in the early 1970s, which has been confirmed for effectively treating malaria, Additionally, emerging data prove that artemisinin exhibits anti-cancer effects against many types of cancers such as leukemia, melanoma, etc. Artemisinin becomes cytotoxic in the presence of ferrous iron. Since iron influx is high in cancer cells, artemisinin and its analogs selectively kill can- cer cells with increased intracellular iron concentrations. This study is aimed to investigate the selective inhibitory effects of artemisinin on SMMC-7721 cells in vitro and determine the effect of holotransfer- fin, which increases the concentration of ferrous iron in cancer cells, combined with artemisinin on the anticancer activity. MTT assay was used for assessing the proliferation of SMMC-7721 cells treated with artemisinin. The induction of apoptosis and inhibition of colony formation in SMMC-7721 cells treated with artemisinin were determined by TdT-mediated dUTP nick end labeling （TUNEL） and col- ony formation assay, respectively. The results showed that artemisinin at various concentrations signifi- cantly inhibited growth, colony formation and cell viability of SMMC-7721 cells （P〈0.05）, likely due to induction of apoptosis of SMMC-7721 cells. Of interest, it was found that incubation of artemisinin combined with holotransferrin sensitized the growth inhibitory effect of artemisinin on SMMC-7721 cells （P〈0.01）. Our data suggest that treatment with artemisinin leads to inhibition of viability and pro- liferation, and apoptosis of SMMC-7721 ceils. Furthermore, we observed that holotransferrin signifi- cantly enhanced the anti-cancer activity of artemisinin. This study may provide a potential therapeutic choice for liver cancer.     

靶向STAT5的RNAi重组质粒的构建与鉴定

摘要:目的：构建靶向信号转导及转录激活因子5（STAT5）的RNAi重组质粒并进行鉴定。 方法：设计针对STAT5编码区的有短发夹结构的3对DNA序列,克隆到质粒载体Pgenesil-1中构建重组质粒,再对其进行酶切鉴定、DNA 测序分析。脂质体法转染重组质粒至SMMC7721细胞株中,westernblot、RT-PCR检测STAT5基因表达。 结果：酶切鉴定和测序分析提示,靶向STAT5的RNAi重组质粒构建成功,3条靶向STAT5的序列特异性小发夹状RNA（shRNA）可有效抑制SMMC7721细胞STAT5表达,mRNA表达抑制率分别为70.43%、43.02%、45.07%,蛋白质表达抑制率分别为67.45%、37.36%、41.86%(P<0.05)。其中以Pgenesil-1-STAT5A1抑制效应最强。 结论：成功构建靶向STAT5的RNAi重组质粒,为进一步用该重组干扰载体进行体内肿瘤基因治疗的研究奠定了基础。     

SMMC-7721肝癌细胞膜上β_2糖蛋白I可能的受体

研究β2糖蛋白I(β2GPI)与肝细胞相互作用的过程,以进一步探讨β2GPI在乙型肝炎病毒感染肝细胞过程中所发挥的作用。采用L igand b lot技术,从SMMC-7721、HL-60及SGC-7901三个细胞株中,筛选出具有与人β2GPI特异结合蛋白成分的细胞。SMMC-7721细胞在40kD处出现一特异染色带,而HL-60及SGC-7901二种细胞则无此反应。在SMMC-7721细胞中存在有与人β2GPI特异结合的蛋白,这种蛋白可能参与了HBV感染肝细胞的过程。     

NF-κB在肝癌细胞株SMMC-7721中的表达及意义

目的　了解NF -kB和ⅠkB在肝癌细胞中的表达情况及意义。方法　通过RT -PCR和Westernblot方法研究NF -kB和ⅠkB在肝癌细胞和正常肝细胞中的mRNA和蛋白表达的变化情况。结果　在肝癌细胞株SMMC -772 1中P65、P5 0mRNA表达增强而ⅠkBmRNA表达下降 (P <0 0 1) ;Westernblot结果显示肝癌细胞株SMMC -772 1细胞的胞核中P5 0、P65蛋白高水平表达 ,而正常肝细胞仅检测出极低水平的P5 0、P65蛋白 ,但是在SMMC -772 1细胞的胞质中ⅠkB蛋白低水平表达 ,正常肝细胞高水平表达。结论　肝癌细胞株SMMC -772 1中NF -kB的P5 0、P65亚基表达升高、ⅠkB表达下降与肿瘤细胞的生长密切相关。     

双萘酰亚胺类化合物诱导SMMC-7721细胞凋亡的研究

目的 观察双萘酰亚胺类化合物(C8)对人肝癌细胞株SMMC-7721细胞的作用. 方法 四甲基偶氮唑盐法检测C8对SMMC 7721细胞的抑制情况;流式细胞术检测细胞周期和凋亡率;Western blot检测Bcl 2蛋白表达量;流式细胞术分析细胞内Bcl 2蛋白量;酶联免疫法检测Caspase9和Caspase 3表达量. 结果 C8抑制SMMC 7721细胞增殖,半数抑制浓度为15 umol/L.C8作用浓度在10,15、20 umol/L时,SMMC 7721细胞的凋亡比例分别为16.8%、29.4%和35.8%,对照组为2.1%,SMMC 7721细胞的凋亡率明显高于对照组,P<0.01.细胞内Bcl-2蛋白表达水平下降.酶联免疫检测结果表明Caspase 9和Caspase 3被活化.结论 C8可诱导人肝癌SMMC 7721细胞的凋亡,为抗肿瘤药物的研究提供新的化合物.