PI3K/Akt抑制剂LY294002对胃癌细胞化疗增敏作用的探讨

目的 探讨PI3K/Akt特异性抑制剂LY294002与化疗药物5-Fu及奥沙利铂联合使用对3种胃癌细胞系(MGC803、BGC823和SGC7901)化疗效果的影响.方法 将PI3K/Akt特异性抑制剂LY294002联合化疗药物5-Fu及奥沙利铂作用于3种胃癌细胞系,MTT法检测单独使用5-Fu、奥沙利铂及联合LY294002对体外培养的3种胃癌细胞系的增殖抑制作用,流式细胞术检测细胞凋亡.结果 联合LY294002作用后,5-Fu、奥沙利铂对3种胃癌细胞系的增殖抑制作用明显增强(P<0.05),且凋亡率显著提高(P<0.05).结论结果 LY294002能有效提高化疗药物5-Fu、奥沙利铂体外对胃癌细胞的增殖抑制作用,抑制PI3K/Akt信号转导通路可显著提高胃癌的化疗疗效.     

化疗药物对胆管癌细胞的敏感性及PTEN蛋白表达的影响

目的 探讨化疗药物体外对胆管癌细胞系QBC939作用的敏感性及对PTEN蛋白表达的影响。方法 采用MTT法和流式细胞术检测常用的六种化疗药物体外对胆管癌细胞株QBC939的敏感性。并运用Western Blot法检测药物体外作用于胆管癌细胞系QBC939后PTEN蛋白的表达。结果 六种化疗药物对于胆管癌细胞的敏感性依次为5-氟脲嘧啶、丝裂霉紊、长春新碱、阿霉素、顺铂、氨甲蝶呤。与对照组比较，六种化疗药物体外作用于胆管癌细胞系QBC93948h后，PTEN的表达量有不同程度的增高。结论 化疗药物体外作用于QBC939细胞系，可通过上调PTEN的表达最终达到抗癌的作用。     

腺病毒介导的p16和顺铂的联合应用对胆管癌细胞系QBC939的生长抑制作用

目的研究p16基因和顺铂联合应用对胆管癌细胞的作用.方法将重组体腺病毒p16(Ad-p16)和顺铂联合作用于人胆管癌细胞QBC939,对p16基因的表达、细胞的生长抑制及机制进行分析.结果用Ad-LacZ进行重组体腺病毒转导效率的检测,发现当MOI为100以上时,重组体腺病毒可使90%以上的培养的人胆管癌QBC939细胞被转导.用RT-PCR方法检测,在胆管癌QBC939细胞系中p16呈低表达.重组体腺病毒能介导外源基因p16在胆管癌QBC939细胞系中高效表达.重组体腺病毒介导的p16在QBC939细胞中表达,能抑制QBC939细胞的生长和集落形成.其与顺铂联合应用对QBC939细胞的生长抑制具有明显作用.并显著地抑制该肿瘤细胞的克隆形成能力.流式细胞计数证实p16能诱导QBC939细胞发生凋亡并导致其发生G1期阻滞,顺铂能诱导QBC939细胞发生凋亡并导致细胞发生明显的G2期阻滞.结论p16基因能够增加QBC939细胞对顺铂的敏感性.     

PI3K／Akt信号转导通路阻断剂对卵巢癌细胞顺铂敏感性的影响

目的 探讨磷脂酰肌醇3-激酶／丝氨酸-苏氨酸蛋白激酶（P13K／Akt）信号转导通路阻断剂LY294002对卵巢癌细胞顺铂（DDP）敏感性的影响。方法DDP和LY294002单独或联合作用人卵巢癌细胞,MTT法检测细胞生长抑制率,倒置显微镜观察凋亡细胞形态,流式细胞术检测凋亡细胞。结果加用LY294002后,DDP对卵巢癌细胞的抑制作用增强,细胞凋亡率上升。结论PI3K／AKt信号转导通路阻断剂可有效提高卵巢癌细胞对DDP的敏感性,在卵巢癌治疗中与DDP有一定协同作用。     

Cox-2抑制剂NS-398对人胆管癌QBC939细胞增殖侵袭的影响

目的观察选择性Cox-2抑制剂NS-398对人胆管癌细胞株QBC939增殖、侵袭的影响。方法体外培养人胆管癌QBC939细胞,加入不同浓度的NS-398培养后,采用MTT比色法观察不同浓度NS-398作用不同时间对QBC939细胞的增殖抑制情况;采用Transwell小室法检测不同浓度NS-398作用后QBC939细胞的侵袭能力。结果 NS-398对QBC939细胞的增殖有抑制作用,并呈时间及浓度依赖性(P均<0.01),最大抑制浓度为100μmol/L。加入NS-398培养36 h后,随着药物浓度的增加,QBC939细胞体外侵袭能力明显减弱(P<0.01)。结论NS-398可抑制人胆管癌QBC939细胞的增殖,并减弱其体外侵袭能力。     

胆管癌组织、细胞中CXCR3 mRNA及其蛋白的表达变化

目的检测趋化因子受体3（CXCR3）在胆管癌中的表达，并探讨其意义。方法采用逆转录聚合酶链反应（RT-PCR）、免疫细胞化学和Western-Blot方法检测胆管癌细胞系QBC939和ICC-9810中的CXCR3 mRNA及其蛋白；采用免疫组化SP法检测人胆管癌组织和癌旁组织中的CXCR3蛋白，并分析探讨其与胆管癌分化程度及淋巴结转移的关系。结果QBC939和ICC-9810中CXCR3 mRNA和蛋白表达均呈阳性；胆管癌组织中CXCR3蛋白阳性表达率为80％，癌旁组织中没有检测到CXCR3蛋白，CXCR3蛋白与胆管肿瘤分化程度和淋巴转移有关（P〈0.05）。结论CXCR3在胆管肿瘤细胞系中呈阳性表达，CXCR3和胆管肿瘤的分化及侵袭转移有一定关系。     

索拉非尼联合塞来昔布对胆管癌细胞株SK—ChA-1增殖的影响

目的研究索拉非尼联合塞来昔布在体外对胆管癌细胞株SK—ChA-1增殖的影响。方法体外培养人胆管癌细胞株SK—ChA-1,通过MTF法检测索拉非尼单用或与塞来昔布联用时对胆管癌细胞株增殖的抑制作用,WesternBlot分析索拉非尼单用或与塞来昔布联用时对胆管癌细胞株内多聚ADP核糖聚合酶（PARP）蛋白表达的影响。结果索拉非尼抑制胆管癌细胞株SK-ChA-1的增殖并诱导细胞凋亡。索拉非尼联合塞来昔布协同抑制胆管癌细胞株SK—ChA-1的增殖。塞来昔布使索拉非尼诱导的胆管癌细胞株SK—ChA-1的凋亡增加。结论索拉非尼联合塞来昔布能协同抑制胆管癌细胞株SK—ChA-1的增殖,这与塞来昔布使索拉非尼诱导的细胞凋亡增加有关。     

Survivin对人胆管癌细胞凋亡相关信号通路的作用机制

目的:探讨Survivin基因对人胆管癌细胞凋亡信号通路的调节机制.方法:构建针对Survivin基因的siRNA和对照siRNA,分别转染QBC939人胆管癌细胞,Western blot检测siRNA对细胞Survivin的干扰效果.继而分别用流式细胞仪,激酶活性测定和Westernblot检测不同Survivin表达状态下,QBC939细胞的凋亡状态,caspase-3的活性和caspase-3,caspase-9及procaspase-9凋亡信号分子的表达.结果:siRNA-Survivin显著抑制Survivin在QBC939细胞的表达(P<0.05).Survivin表达抑制后,QBC939细胞凋亡明显增加(18.9%±2.3%,P<0.05),caspase-3活性显著升高(0.83±0.15,P<0.01),caspase-3和caspase-9表达明显上调(P<0.05),而procaspase-9表达降低(P<0.05).未转染和转染对照siRNA的QBC939细胞上述变化无显著性差异(P>0.05).结论:Survivin基因通过促进procaspase-9的活化以阻止caspase-3和caspase-9的激活从而抑制胆管癌细胞的凋亡.     

PI3K/AKT抑制剂对肺腺癌细胞株生长的影响

目的检测磷脂酰肌醇3-激酶（PI3K/AKT）特异性抑制剂Ly294002对肺腺癌细胞系XWLC-05增殖和凋亡的作用。方法 MTT法检测Ly294002对肺腺癌细胞XWLC-05体外细胞培养株诱导凋亡作用,流式细胞术测定不同条件下细胞的周期分布比例和细胞凋亡情况。结果 Ly294002对XWLC-05细胞株生长有抑制作用,但Ly294002需达到50μmol.L-1才能产生明显差异。Ly294002处理XWLC-05细胞24 h、48 h后G2/M期细胞相对增加,有统计学意义（P〈0.05）,凋亡细胞增加,但无统计学意义（P〉0.05）。结论 LY294002对肺腺癌细胞有抑制生长的作用,且抑制细胞增殖与导致细胞凋亡并无直接关系。     

WWOX基因转染对胆管癌细胞增殖、凋亡及侵袭的影响

目的:探讨WWOX基因转染胆管癌细胞株QBC939后对其增殖、凋亡与侵袭性的影响.方法:用脂质体转染法将WWOX重组真核表达质粒转染QBC939细胞,建立稳定表达WWOX基因的细胞株.将其分为以下3组:QBC939组,QBC939/con组和QBC939/WWOX组.荧光定量RT-PCR和Western blot法检测...     

The anti-tumoral effect of PI3K inhibitor and MEK inhibitor combined with STI571 on chronic myeloid leukemia cells in a bone marrow stromal cell co-culture system

The goal of this study was to elucidate the functional roles of PI3K/AKT and MEK/ERK signaling on the proliferation and apoptosis of STI571-sensitive and -resistant CML cell lines in a co-culture system with human marrow stromal cells (MSCs), mimicking the bone marrow microenvironment. The phosphorylation of AKT and ERK was enhanced by co-culture with MSCs in both STI571-sensitive KBM-5 and STI571-resistant KBM-5/STI cells. In KBM-5 cells, the STI571 and PI3K inhibitor LY294002 combination was effective on apoptosis induction in the MSC co-culture system. In KBM-5/STI cells, treatment with LY294002 or PD98059 alone resulted in massive apoptosis, which was enhanced by co-culture with MSCs. These results provide a rationale for multi-molecular target therapy approaches based on a combination of signal transduction inhibitors with STI571 in CML.     

Phosphatidylinositol 3-kinase is involved in the protection of primary cultured human erythroid precursor cells from apoptosis.

Little is known about the physiologic role of phosphatidylinositol 3-kinase (PI-3K) in the development of erythrocytes. Previous studies have shown that the effects of the PI-3K inhibitor wortmannin on erythropoietin (EPO)-dependent cell lines differed depending on the cell type used. Wortmannin inhibited EPO-induced differentiation of some cell lines without affecting their proliferation; however, the EPO-induced proliferation of other cell lines was inhibited by wortmannin. In neither case were signs of apoptosis observed. We have previously reported that signaling in highly purified human colony forming units-erythroid (CFU-E), generated in vitro from CD34(+) cells, differed from that in EPO-dependent cell lines. In the current study, we examined the effects of a more specific PI-3K inhibitor (LY294002) on human CFU-E. We found that LY294002 dose-dependently inhibits the proliferation of erythroid progenitor cells with a half-maximal effect at 10 micromol/L LY294002. LY294002 at similar concentrations also induces apoptosis of these cells, as evidenced by the appearance of annexin V-binding cells and DNA fragmentation. The steady-state phosphorylation of AKT at Ser-473 that occurs as a result of PI-3K activation was also inhibited by LY294002 at similar concentrations, suggesting that the effects of LY294002 are specific. Interestingly, the acceleration of apoptosis by LY294002 was observed in the presence or absence of EPO. Further, deprivation of EPO resulted in accelerated apoptosis irrespective of the presence of LY294002. Our study confirms and extends the finding that signaling in human primary cultured erythroid cells is significantly different from that in EPO-dependent cell lines. These data suggest that PI-3K has an antiapoptotic role in erythroid progenitor cells. In addition, 2 different pathways for the protection of primary erythroid cells from apoptosis likely exist: 1 independent of EPO that is LY294002-sensitive and one that is EPO-dependent and at least partly insensitive to LY294002.     

细胞色素P450表氧化酶通过PI3K/AKT及ERK/MAPK途径抗内皮细胞凋亡的机制

目的:研究细胞色素P450表氧化酶对肿瘤坏死因子(TNF)-α诱导内皮细胞抗凋亡的机制。方法:在原代培养的牛主动脉内皮细胞(BAECs)中,分别转染细胞色素P450表氧化酶基因rAAV-F87V2周,证实其在内皮细胞中高效表达。用TNF-α(10ng/ml)和放线菌素D(ActD)(5ng/ml)诱导凋亡,流式细胞计数观察其凋亡变化,用Western blot法检测蛋白激酶B(AKT)及细胞外信号调节蛋白激酶(ERK)的磷酸化水平,用流式细胞计数的方法观察空白组及转染F87V组加入AKT抑制剂、LY294002、芹菜素及PD98059后的细胞凋亡比例。结果:与对照组比较,转染细胞色素P450表氧化酶基因后BAECs能高效表达P450表氧化酶基因F87V(P<0.05);流式计数凋亡细胞数,转染表氧化酶较对照组明显减少(P<0.05);转染CYP P450表氧化酶后,AKT及ERK的磷酸化增加;磷脂酰肌醇3激酶(PI3K)、丝裂原活化蛋白激酶(MAPK)和MKK的抑制剂后转染F87V组较对照组凋亡细胞比例明显减少(P<0.05)。结论:细胞色素P450表氧化酶基因rAAV-F87V能通过MAPK(ERK1/2)与PI3K/AKT途径发挥抗凋亡作用。     

Ad—PTEN对乳腺癌细胞系MCF-7生长抑制作用的影响及机制

目的探讨携带野生型PTEN基因的重组腺病毒（Ad—PTEN）和LY294002对乳腺癌细胞系MCF-7生长抑制作用的影响及机制。方法在MCF-7中导人Ad—PTEN和P13K抑制剂LY294002。Westem blotting法检测P11EN／P13K／AKT及其下游相关蛋白表达,M1Tr法检测MCF-7细胞存活率,流式细胞仪检测细胞周期,AnnexinV法检测细胞凋亡率。结果与DMSO组、空载病毒和LY294002组相比,联合组（LY294002＋Ad—PTEN）PTEN蛋白明显上调,而P13K／AKT及下游蛋白水平显著下降;联合组细胞阻滞于G0／C1期;细胞凋亡率增加明显;自培养第2天起,联合组细胞生存率呈下降趋势。结论Ad—PTEN联合LY294002通过阻滞细胞周期、促进细胞凋亡抑制MCF-7的增殖能力,两者具有正向协同作用;其机制可能与下调P13K／AKT信号通路下游蛋白有关。     

活性维生素D3联合LY294002体外抑制大鼠肝星状细胞增殖作用研究*

目的探究维生素D的活性形式—1,25-(OH）2D3联合磷脂酰肌醇-3激酶/蛋白激酶B(PI3K/Akt）信号通路的特异抑制剂LY294002对体外培养大鼠肝星状细胞的抑制作用。方法将HSC-T6细胞分为正常对照、 DMSO组、1,25-(OH）2D3、LY294002组和1,25-(OH）2D3+ LY294002 联合组,采用MTT法检测细胞增殖;在倒置显微镜下观察细胞形态变化;使用流式细胞术检测HSC-T6细胞凋亡;采用Western blotting法检测Phospho-Akt（Ser473）、AKT（PAN）、半胱氨酸天冬氨酸蛋白酶（caspase）-3蛋白表达。结果体外干预肝星状细胞48 h后,两药联合干预组细胞抑制率为87.5%,显著高于1,25-（OH）2D3组的50.3%或LY294002组的40.3%（P<0.05）;联合组细胞凋亡率为92.12%,显著高于1,25-(OH）2D3组的71.0%或LY294002组的34.0%（P<0.05）;在显微镜下观察,两药处理组细胞形状由星形变为不规则形,凋亡数量增多,表现为正常活细胞数目明显减少,胞间隙增宽,细胞体积缩小,胞浆浓缩,胞核固缩,可见空泡及细胞碎片,有的细胞出现数量不等的凋亡小体;与单药干预组比,联合组细胞Bax/Bcl-2比值上升明显（P<0.05）,活化的凋亡蛋白caspase-3表达显著增加（P<0.05）。结论1,25-（OH）2D3可协同LY294002 共同诱导 HSC-T6 细胞凋亡,增强其抗肝纤维化的效果。     

Inhibition of the PI3K-Akt signaling pathway enhances the sensitivity of Fas-mediated apoptosis in human gastric carcinoma cell line,MKN-45

It is well known that Fas ligand and anti-Fas antibodies can induce apoptosis, although some cancer cells are resistant to their stimuli. On the other hand, phosphatidylinositol 3-kinase (PI3 K) and Akt mediate the survival signal and allow the cells to escape from apoptosis in various human cancers. Thus, we postulated that LY294002, a PI3 K inhibitor, should inactivate Akt, consequently inhibiting cell proliferation and increase apoptosis in the human gastric carcinoma cell line, MKN-45. Previously, we reported that MKN-45 was resistant against the anti-Fas antibody, CH-11, without interferon-gamma pretreatment in vitro. LY294002 caused a decrease of phosphorylated-Akt and an inhibition of cell proliferation via cell cycle arrest in the G0/G1 phase by P27/Kip1 accumulation, but there was no obvious induction of apoptosis. The simultaneous treatment of LY294002 and CH-11 significantly induced apoptosis confirmed by morphology and DNA ladder formation. Decreased phosphorylated-Akt by LY294002 treatment led to a down-regulation of Mcl-2 and phosphorylated Bad proteins, which are anti-apoptotic factors and belong to the Bcl-2 family. On the other hand, expression levels of the other anti-apoptotic factors, such as FLICE-inhibitory protein (FLIP), Bcl-2 and Bcl-XL, which are associated with the Fas-mediated apoptotic signal pathway, did not change after LY294002 treatment. We concluded that: 1) the PI3K-Akt pathway plays an important role in preventing Fas-mediated apoptosis; and 2) a PI3 K inhibitor, such as LY294002, might be a useful anti-tumoral agent for gastric carcinoma.