塞来昔布对结肠癌HT-29细胞生长及骨桥蛋白表达的影响

目的 观察塞来昔布对结肠癌HT-29细胞的生长、凋亡和骨桥蛋白(OPN)表达的影响.方法 体外培养结肠癌HT-29细胞分为对照组和不同浓度塞来昔布干预组.MTT法检测细胞增殖抑制情况,流式细胞术分析细胞的凋亡,RT-PCR和免疫组化分析细胞中的OPN mRNA与OPN蛋白表达变化.结果 塞来昔布对HT-29细胞增殖有明显的时间与浓度依赖性抑制作用(P＜0.01).塞来昔布能诱导HT-29细胞凋亡,塞来昔布15、30和50μmol/L的细胞凋亡率分别为28.2％、32.8％和33.1％,均明显高于对照组的26.0％ (P＜0.05).药物干预组OPN mRNA及OPN蛋白表达明显低于对照组(P＜0.01).结论 塞来昔布可能通过抑制OPN表达而抑制结肠癌HT-29细胞的增殖,诱导其凋亡.     

表没食子儿茶素没食子酸酯对结肠癌HT-29细胞MMP-9表达的影响

目的:探讨表没食子儿茶素没食子酸酯(EGCG)对人结肠癌细胞株HT-29基质金属蛋白酶-9(MMP-9)表达的影响.方法:应用RT-PCR法和Western blot法检测EGCG干预前后HT-29结肠癌细胞中MMP-9 mRNA及MMP-9蛋白表达.结果:EGCG 25、50、100 mg/L作用于结肠癌细胞株HT-29 48 h后,与对照组比较,MMP-9 mRNA及MMP-9蛋白的表达量随着EGCG浓度的增加而下降,且各浓度组间差异也有统计学意义(P<0.05).结论:EGCG可显著抑制HT-29细胞中MMP-9 mRNA及MMP-9蛋白的表达,呈剂量依赖性,可能是其抗癌机制之一.     

青蒿琥酯通过介导铁死亡逆转结肠癌细胞5-氟尿嘧啶耐药的作用研究

目的 探讨青蒿琥酯(ART)通过介导铁死亡逆转结肠癌细胞对5-氟尿嘧啶(5-FU)耐药的作用。方法 以人结肠癌HT-29/5-FU耐药细胞株为研究对象,采用MTS法检测5-FU、ART以及5-FU+ART对HT-29/5-FU细胞的抑制作用,并计算其逆转耐药倍数;克隆形成实验检测HT-29/5-FU细胞克隆形成能力;流式细胞术检测细胞内活性氧(ROS)水平;试剂盒检测细胞内丙二醛(MDA)水平;Western blotting检测细胞内Nrf2和GPX4蛋白表达水平。结果 40μmol·L^-1ART可逆转HT-29/5-FU细胞对5-FU的耐药,逆转倍数为2.9倍;5-FU联合ART可抑制HT-29/5-FU细胞的克隆形成能力,升高细胞内ROS和MDA水平,并降低Nrf2及GPX4蛋白表达水平,且这些效应能够被铁死亡抑制剂Ferrostatin-1所逆转。结论 ART能够通过抑制Nrf2、GPX4表达诱导铁死亡,从而逆转HT-29/5-FU细胞对5-FU的耐药。     

p-JNK在结肠癌组织中的表达及抑制JNK通路后HT-29细胞增殖和凋亡变化

目的研究p-JNK在结肠癌组织中的表达以及抑制JNK信号通路后人结肠癌HT-29细胞增殖和凋亡的变化。方法使用免疫组织化学方法检测50例结肠癌组织标本和50例正常结肠组织标本中p-JNK的表达情况并和临床资料进行比较分析;在人结肠癌细胞株HT-29中使用SP600125抑制JNK信号通路后,MTT法检测细胞增殖,TUNEL法检测凋亡。结果 p-JNK在结肠癌组织中的表达水平明显高于正常对照组织(P<0.05);并和淋巴结转移、肿瘤分化程度、肿瘤的侵犯深度相关(P<0.05);而与肿瘤部位无关。抑制JNK信号通路后,HT-29细胞中的p-JNK表达降低(P<0.05);增殖减少,凋亡增加(P<0.05)。结论在结肠癌组织中存在p-JNK的高表达,抑制JNK信号通路能降低人结肠癌细胞株HT-29细胞的增殖,并促进凋亡;JNK信号通路和结肠癌的发生发展有关。     

沙利度胺调控PD-L1抑制HT-29结肠癌细胞的作用及机制研究

目的：探讨沙利度胺对HT-29结肠癌细胞的抑制作用及其机制。方法：CCK-8检测沙利度胺对HT-29结肠癌细胞增殖的作用;流式细胞术检测沙利度胺对HT-29结肠癌细胞凋亡的作用和对HT-29结肠癌细胞PD-L1表达的作用;Western Blot检测沙利度胺对HT-29结肠癌细胞c-Myc、STAT3、HIF-1蛋白表达的影响。结果：沙利度胺各浓度（40、80、160、320 μmol·L-1）明显抑制HT-29结肠癌细胞的增殖;沙利度胺各浓度（20、40、80 μmol·L-1）明显促进HT-29结肠癌细胞的凋亡,明显减少HT-29结肠癌细胞表面PD-L1的表达,明显减少HT-29结肠癌细胞c-Myc、STAT3、HIF-1蛋白的表达。结论：沙利度胺对HT-29结肠癌细胞具有抑制作用,其机制可能与减少PD-L1表达及抑制癌细胞上游c-Myc、STAT3、HIF-1信号分子表达有关。     

沙利度胺调控PD-L1抑制HT-29结肠癌细胞的作用及机制研究

目的：探讨沙利度胺对HT-29结肠癌细胞的抑制作用及其机制。方法：CCK-8检测沙利度胺对HT-29结肠癌细胞增殖的作用;流式细胞术检测沙利度胺对HT-29结肠癌细胞凋亡的作用和对HT-29结肠癌细胞PD-L1表达的作用;Western Blot检测沙利度胺对HT-29结肠癌细胞c-Myc、STAT3、HIF-1蛋白表达的影响。结果：沙利度胺各浓度（40、80、160、320 μmol·L-1）明显抑制HT-29结肠癌细胞的增殖;沙利度胺各浓度（20、40、80 μmol·L-1）明显促进HT-29结肠癌细胞的凋亡,明显减少HT-29结肠癌细胞表面PD-L1的表达,明显减少HT-29结肠癌细胞c-Myc、STAT3、HIF-1蛋白的表达。结论：沙利度胺对HT-29结肠癌细胞具有抑制作用,其机制可能与减少PD-L1表达及抑制癌细胞上游c-Myc、STAT3、HIF-1信号分子表达有关。     

白藜芦醇抑制结肠癌细胞系HT-29体外增殖作用的研究

目的通过观察白藜芦醇对结肠癌细胞系HT-29增殖的影响并检测程序性细胞死亡4蛋白表达水平,探讨白藜芦醇的抗结肠癌增殖作用及部分相关机制。方法 HT-29细胞经不同浓度白藜芦醇作用后,流式细胞术检测细胞周期分布及凋亡情况,Western blot法检测程序性细胞死亡4蛋白表达水平变化。结果不同浓度的白藜芦醇对HT-29细胞的增殖有抑制作用,并且呈现出一定的剂量依赖性(P<0.01),白藜芦醇改变细胞周期分布,细胞周期阻滞在S期,同时诱导HT-29细胞凋亡,试验组与空白对照组相比,S期细胞比例及凋亡率明显增高(P<0.05),细胞周期被阻滞,增殖抑制。白藜芦醇处理后HT-29细胞程序性细胞死亡4蛋白表达水平上调,与对照组比较,差异有统计学意义(P<0.01)。结论白藜芦醇能够显著抑制HT-29细胞株的增殖,细胞周期阻滞于S期,诱导肿瘤细胞凋亡,其肿瘤抑制作用可能与程序性细胞死亡4蛋白表达上调有关。     

miR-346靶向调控SFRP4介导5-FU诱导的结肠癌细胞毒性

目的观察miR-346及SFRP4对5-FU诱导的结肠癌细胞毒性的影响,为结肠癌化疗增效提供新的靶基因。方法构建pcDNA3.1-SFRP4上调SFRP4表达,以pcDNA3.1-SFRP4、NC、Con-miR、miR-346、miR-346+Vector、miR-346+SFRP4等转染SW480和HT-29细胞,Western blot法观察miR-346上调或下调后对SFRP4蛋白水平的影响,MTT观察不同转染条件下5-FU细胞存活率变化,流式细胞术观察细胞凋亡变化。结果 SFRP4可增加5-FU诱导的SW480、HT-29细胞毒性及细胞凋亡,miR-346能够降低5-FU诱导的SW480、HT-29细胞毒性及细胞凋亡。miR-346对SFRP4表达具有负向调控作用。结论 miR-346通过负向调控SFRP4表达降低5-FU诱导的结肠癌细胞毒性。     

丁酸钠诱导结肠癌HT-29细胞凋亡的信号通路及对AQP3基因表达影响的研究

目的：探讨丁酸钠诱导结肠癌HT-29细胞凋亡过程的分子机理及其对水通道蛋白AQP3基因表达的影响。方法：MTT法检测不同浓度的丁酸钠对结肠癌HT-29细胞生长的影响;RT-PCR检测不同浓度的丁酸钠对细胞周期蛋白Cyclin D1、CDK4、p16和AQP3的基因表达水平,同时使用流式细胞仪检测细胞周期。结果：加入浓度超过2.5mmol/L的丁酸钠后,结肠癌HT-29细胞生长受到抑制,Cyclin D1、CDK4和AQP3的表达水平下降,p16的表达水平上调,细胞阻滞于G1/S期。结论：浓度超过2.5mmol/L的丁酸钠可以诱导结肠癌HT-29细胞凋亡,使其细胞周期阻滞于G1/S期,且这种诱导作用是剂量依赖型的,其分子通路可能是通过p16-Cyclin D1/CDK4这条信号途径,在此过程中,伴随着AQP3的基因表达水平降低。     

半枝莲提取物对人大肠癌细胞系凋亡的影响

目的 探讨半枝莲提取物(SBE)诱导人大肠癌细胞系(SW480、LoVo、HT-29)的凋亡作用及其可能机制.方法 体外培养SW480、LoVo、HT-29细胞,以药物康复新、露蜂房作对照,应用MTT法和流式细胞术检测不同浓度SBE处理三种细胞48 h后的抑制率、细胞凋亡率及周期变化;RT-PCR检测SBE处理后凋亡相关基因Bcl-2和Caspase-3 mRNA表达.结果 与康复新、露蜂房比较,SBE对三种细胞的抑制率和细胞凋亡率均呈剂量依赖性显著升高(P＜0.01);S期细胞含量增多,出现S期阻滞;Caspase-3 mRNA表达亦显著上升,Bcl-2表达明显下降(P＜0.01).结论 SBE具有诱导大肠癌细胞系凋亡和抑制增殖作用,作用强于康复新和露蜂房提取物.其机制可能与Caspase-3基因表达的上调及Bcl-2基因表达下降有关.     

Ciprofloxacin decreases survival in HT-29 cells via the induction of TGF-��1 secretion and enhances the anti-proliferative effect of 5-fluorouracil

Background and purpose:

Fluoroquinolones are potent anti-microbial agents with multiple effects on host cells and tissues. Previous studies have highlighted their pro-apoptotic effect on human cancer cells and an immunoregulatory role in animal models of inflammatory bowel disease. We examined the effect of ciprofloxacin on proliferation, cell cycle and apoptosis of HT-29 cells, a human colonic epithelial cell line sensitive to transforming growth factor (TGF)-β1-mediated growth inhibition and its role in TGF-β1 production. We also examined the effect of ciprofloxacin on proliferation of HT-29 cells in combination with 5-fluorouracil (5-FU), a well-established pro-apoptotic agent.

Experimental approach:

Using subconfluent cultures of HT-29 and Caco-2 cells, we studied the effect of ciprofloxacin, TGF-β1 and 5-FU on proliferation, apoptosis, necrosis and cell cycle. The effect of ciprofloxacin on TGF-β1 mRNA expression and production was studied in RNA extracts and cell culture supernatants respectively, using confluent cultures.

Key results:

Ciprofloxacin decreased proliferation of HT-29 cells in a concentration- and time-dependent manner. This was mediated by accumulation of HT-29 cells into the S-phase but without any effect on apoptosis or necrosis. Additionally, ciprofloxacin enhanced the antiproliferative effect of 5-FU. Interestingly, ciprofloxacin was found to up-regulate TGF-β1 production by HT-29 cells and its anti-proliferative effect was abolished when TGF-β1 was blocked. Confirming this mechanism further, ciprofloxacin had no effect on Caco-2, a human colonic epithelial cell line that lacks functional TGF-β1 receptors.

Conclusions and implications:

We demonstrate a novel anti-proliferative and immunoregulatory effect of ciprofloxacin on human intestinal epithelial cells mediated via TGF-β1.     

Induction of apoptosis in HT-29 colon cancer cells by crude saponin from Platycodi Radix

This study examined the apoptotic effects of crude saponins acquired from the roots of Platycodon grandiflorum (SPR) in HT-29 human colon cancer cells.SPR decreased HT-29 cell proliferation in dose- and time-dependent manners by inducing apoptosis via DNA fragmentation and poly (ADP-ribose) polymerase (PARP) cleavage. The apoptosis induced by SPR was associated with the activation of initiator caspases-8 and -9, as well as the effector caspase-3. SPR stimulated Bid cleavage, indicating that the apoptotic action of caspase-8-mediated Bid cleavage leads to the activation of caspase-9. SPR increased the expression of the pro-apoptotic protein, Bax, and decreased the expression of the anti-apoptotic protein, Bcl-2. SPR also increased the expression of the caspase-independent mitochondrial apoptosis factor, AIF, in HT-29 cells. These results indicate that SPR inhibits HT-29 cell proliferation by inducing apoptosis, which may be mediated via both caspase-dependent and -independent pathways.     

异叶败酱总苷片对人大肠癌HT-29细胞凋亡的影响

目的：研究异叶败酱总苷片对人大肠癌细胞凋亡的影响及作用机制。方法：建立人大肠癌HT-29裸鼠移植瘤模型，设立异叶败酱总苷片低、中、高剂量组和空白组、5-氟脲嘧啶（5-FU）＋甲酰四氢叶酸钙（CF）对照组，给药8周后处死裸鼠，瘤体称重,末端原位标记染色法（TUEL）检测凋亡指数，分别行半胱天冬氨酸蛋白酶-3（caspase-3），Bax和Bcl-2免疫组化染色，图象分析系统定量检测并比较该3种物质表达情况。结果：异叶败酱总苷片各组瘤重小于空白对照组，而凋亡指数均高于空白对照组和5-FU＋CF组，其中高剂量组与空白对照组和5-FU＋CF组比较差异有极显著性（P＜0．01）。异叶败酱总苷片各组移植瘤caspase-3表达及Bax、Bcl-2表达的相对比率（Bax／Bcl-2）均高于空白对照组。结论：异叶败酱总苷片具有诱导人大肠癌HT-29裸鼠移植瘤细胞凋亡的作用，其机制可能与促进移植瘤caspase-3表达及增大Bax／Bcl-2表达比率有关。     

Molecular mechanism of gossypol-induced cell growth inhibition and cell death of HT-29 human colon carcinoma cells

Gossypol, a male contraceptive drug, has been demonstrated to have antiproliferative and antimetastatic effects on many kinds of cancer cells in vitro. HT-29 human carcinoma cell line is one of the most susceptible cell lines to gossypol-induced cell death. Here, it is shown that treatment of HT-29 cells with gossypol not only induces cell cycle arrest on the G0/G1 phase, but also induces apoptosis. With a serial of Western blot analysis, it is revealed that gossypol-induced cell cycle arrest is involved in P21 up-regulation and cyclin D1 down-regulation; gossypol-induced apoptosis triggers down-regulation of anti-apoptosis Bcl-2 members: Bcl-X(L), Bag-1 and Mcl-1, up-regulation of pro-apoptosis Bcl-2 member Bak, activation of caspase-3, -6, -7, -8, and -9, up-regulation of Apaf-1, release of cytochrome c (cyto-c) from mitochondria, and activation of both DFF45 and PARP. Taken together, gossypol-induced cell death initiates extensive alterations of cell cycle and apoptosis proteins. Gossypol-induced apoptosis of HT-29 cells is through first the mitochondrial pathway, then the death receptor pathway, and the mitochondria pathway is, at least in part, involved in cyto-c release.     

A glycoprotein from Laminaria japonica induces apoptosis in HT-29 colon cancer cells

We isolated a novel glycoprotein from the brown alga Laminaria japonica that has antiproliferative effects on HT-29 colon cancer cells. We also identified the mechanism by which this glycoprotein, named LJGP, induces apoptosis. MTS assays showed that LJGP inhibited the proliferation of several cancer cell lines (AGS, HepG2, HT-29) in a dose-dependent manner. Especially in HT-29 cells, proliferation was significantly decreased. LJGP treatment on HT-29 displayed several apoptotic features, such as DNA fragmentation, sub-G1 arrest, caspase-3 activation, and PARP degradation. Consistent with sub-G1 arrest, LJGP decreased the expression of Cdk2, cyclin E, cyclin D1, PCNA, E2F-1, and phosphorylated pRb. Furthermore, the increase of p27 expression was observed. We also determined that LJGP-induced apoptosis leads to the formation of a death-induced signaling complex of Fas, FADD, and procaspase-8. LJGP induced the reduction of mitochondrial membrane potential with activation of the Bcl-2 family of proteins and caspase-9. These findings suggest that LJGP inhibits HT-29 cell proliferation by inducing apoptosis, which may be mediated via multiple pathways, including the Fas signaling pathway, the mitochondrial pathway, and cell cycle arrest. Therefore, LJGP can be a useful treatment option for colon cancer in humans.     

Anti-proliferative effects of Lethariella zahlbruckneri extracts in human HT-29 human colon cancer cells

This study was performed to elucidate the anti-proliferative effects and the apoptotic mechanisms of extracts from Lethariella zahlbruckneri in HT-29 human colon cancer cells. Both the acetone extract (AEL) and methanolic extract (MEL) of L. zahlbruckneri decreased viable cell numbers in a dose- and time-dependent manner in HT-29 cells. The AEL showed stronger cytotoxicity than MEL. Cell death induced by AEL increased cell populations in the sub-G1 phase, as well as the formation of apoptotic bodies and nuclear condensation, whereas MEL did not. Therefore, the potential of AEL to induce apoptosis was examined. Apoptosis induced by AEL was associated with the activation of initiator caspases-8 and -9, as well as the effector caspase-3. AEL stimulated Bid cleavage. This indicated that the apoptotic action of caspase-8-mediated Bid cleavage leads to the activation of caspase-9. AEL increased the expression of the pro-apoptotic protein, Bax, and decreased the expression of the anti-apoptotic protein, Bcl-2. AEL also increased the expression of the caspase-independent mitochondrial apoptosis factor, AIF, in HT-29 cells. These results indicate that AEL inhibited HT-29 cell proliferation by inducing apoptosis, which might be mediated via both caspase-dependent and -independent pathways.     

姜黄素与5-氟尿嘧啶联用对人结肠癌HT-29细胞增殖的影响

目的　体外观察 5 氟尿嘧啶与姜黄素联用对人结肠癌HT 2 9细胞增殖的相互作用。方法　采用MTT法观察不同浓度姜黄素、5 氟尿嘧啶单独或联合应用对HT 2 9细胞生长的抑制作用 ,并利用中效原理判定两药合用的效果。结果　两种药物单独应用时 ,对HT 2 9细胞的抑制作用呈明显的剂量效应关系 ;对于HT 2 9细胞 ,姜黄素的中位抑制浓度为(32± 11) μmol·L- 1,5 氟尿嘧啶的中位抑制浓度为(10 4 0± 4 5 6 ) μmol·L- 1。应用中效原理分析显示 ,两药在联合应用时为协同效应 ,并且在不同的药物浓度配比下呈相同的趋势。增大姜黄素的用量可在更宽的效应范围内获得两种药物的协同效应。结论姜黄素与 5 氟尿嘧啶在联合应用时的相互作用为协同效应 ,本结果对于结肠癌的治疗具有一定的临床意义。     

A mechanistic study on the cardiotoxicity of 5-fluorouracil in vitro and clinical and occupational perspectives

Fluoropyrimidines are key agents for the treatment of gastrointestinal tract adenocarcinomas. The possible cardiotoxic effects in patients and occupationally exposed workers are multifactorial and remain a puzzle to solve for investigators. In the present study, we study what cell death pathways and what doses can determine direct cardiotoxic effects of 5-fluorouracil (5-FU) and doxorubicin (DOXO) on rat cardiocytes (H9c2) and a human colon adenocarcinoma (HT-29) cell line, already reported to be sensitive to 5-FU. We have found that 5-FU induced 50% growth inhibition (IC:50) at 72 h with concentrations of 400 μM and 4 μM on H9c2 and HT-29, respectively. Moreover, we have found that the addition of Levofolinic Acid (LF) to 5-FU potentiated the growth inhibition induced by 5-FU. The growth inhibition induced by 5-FU alone or in combination with LF in cardiocytes was paralleled by an increase of thiobarbituric acid-reactive species (Tbars) and end products of nitric oxide (NO) suggesting the increase of the oxidative stress status in cardiocytes. Interestingly, these effects were strongly potentiated by the addition of LF, a biochemical modulator of 5-FU activity.     

Mechanisms of thiosulfinates from Allium tuberosum L.-induced apoptosis in HT-29 human colon cancer cells

This study was performed to elucidate the apoptotic pathways by thiosulfinates, major biologically active components of Allium tuberosum L., in HT-29 human colon cancer cells. Thiosulfinates significantly induced cell death in dose- and time-dependent manners in HT-29 cells, which is associated with apoptosis. Thiosulfinates activated the initiator caspase-8, and -9, and the effector caspase-3. In the present study, thiosulfinates were found to stimulate Bid cleavage, indicating that the apoptotic action of caspase-8-mediated Bid cleavage leads to the activation of caspase-9. Thiosulfinates down-regulated the expression of the anti-apoptotic protein Bcl-2, and up-regulated the expression of the pro-apoptotic protein Bax. We also found that thiosulfinates increased the expression of AIF, a caspase-independent mitochondrial apoptosis factor, and induced DNA fragmentation and chromatin condensation in HT-29 cells. These results indicate that thiosulfinates from A. tuberosum L. inhibited cell proliferation and activated both the caspase-dependent and caspase-independent apoptotic pathways in HT-29 cells.     

Alpha-chaconine, a potato glycoalkaloid, induces apoptosis of HT-29 human colon cancer cells through caspase-3 activation and inhibition of ERK 1/2 phosphorylation.

Although alpha-chaconine, one of the two major potato trisaccharide glycoalkaloids, have shown cytotoxic effects on human cancer cells, the exact mechanism of this action of alpha-chaconine is not completely understood. In this study, we found that alpha-chaconine induced apoptosis of HT-29 cells in a time- and concentration-dependent manner by using flow cytometric analysis. We also found that caspase-3 activity and the active form of caspase-3 were increased 12 h after alpha-chaconine treatment. Caspase inhibitors, N-Ac-DEVD-CHO and Z-VAD-fmk, prevented alpha-chaconine-induced apoptosis, whereas alpha-chaconine-induced apoptosis was potentiated by PD98059, an extracellular signal-regulated kinase (ERK) inhibitor. However, pretreatment of the cells with LY294002 and SB203580, inhibitors of PI3K and p38, respectively, BAPTA-AM, an intracellular Ca(2+) chelator, and antioxidants such as N-acetylcysteine (NAC) and Trolox had no effect on the alpha-chaconine-induced cell death. In addition, phosphorylation of ERK was reduced by the treatment with alpha-chaconine. Moreover, alpha-chaconine-induced caspase-3 activity was further increased by the pretreatment with PD98059. Thus, the results indicate that alpha-chaconine induces apoptosis of HT-29 cells through inhibition of ERK and, in turn, activation of caspase-3.