索拉非尼联合三氧化二砷治疗肝癌的研究

目的探讨索拉非尼联合三氧化二砷(As2O3)对肝癌的治疗作用。方法采用MTT实验检测索拉非尼联合As2O3对肝癌细胞的毒性。流式细胞仪检测索拉非尼联合As2O3诱导肿瘤细胞凋亡。构建肝癌异位瘤模型,检测索拉非尼联合As2O3对肝癌荷瘤裸鼠生存期的影响。结果与生理盐水组和单独给药组相比,联合干预组对肝癌具有更强的细胞毒性,差异具有统计学意义(P0.05)。细胞凋亡实验结果表明,联合干预能够促进肿瘤干细胞凋亡,差异具有统计学意义(P0.01)。体内治疗实验结果显示,索拉非尼与As2O3联合干预能够显著延长荷瘤小鼠的中位生存期,诱导肿瘤细胞的凋亡。结论索拉非尼联合As2O3能够增强对肝癌HepG2细胞的增殖抑制作用,是一种潜在的肝癌有效治疗方法。     

5-氟尿嘧啶联合蒽贝素对结肠癌小鼠Caspase-3及NF-κB活性表达的影响

目的探讨5-氟尿嘧啶联合蒽贝素对结肠癌小鼠Caspase-3及NF-KB活性表达的影响。方法入选小鼠结肠癌细胞系SW480培养,并建立动物模型,对实验细胞及动物分为四组,每组10只,实验组分别予以5-氟尿嘧啶、蒽贝素、5-氟尿嘧啶联合蒽贝素,对照组予以生理盐水,对四组培养细胞分别进行细胞活性、肿瘤球体积大小、NF-k B活性及caspase-3活性、细胞凋亡的检测,对实验动物行肿瘤球变化率及小鼠生存时间检测,比较四组间差异。结果联合应用5-FU及蒽贝素组细胞caspase-3活性显著高于对照组及单纯使用5-FU、蒽贝素组(P0.05);而NF-κB活性低于其他各组(P0.05);5-FU、蒽贝素组caspase-3活性显著高于对照组(P0.05),NF-κB活性低于对照组(P0.05);联合应用5-FU及蒽贝素组细胞的肿瘤体积变化率及生存时间显著优于对照组及单纯使用5-FU、蒽贝素组(P0.05);联合应用5-FU及蒽贝素组细胞的细胞处理24 h后细胞凋亡率显著高于对照组及单纯使用5-FU、蒽贝素组(P0.05);单纯使用5-FU、蒽贝素组24h后细胞凋亡率显著高于对照组(P0.05)。结论蒽贝素同5-FU对C26结肠癌细胞抑制增殖促进凋亡有协同作用,经抑制NF-κB通路进而影响肿瘤生长,经与XIAP蛋白BIR-3功能域的结合,提高Caspase-3活性,进而导致细胞增殖,促进细胞凋亡,为临床治疗结肠癌开辟新的化疗途径提供更多的实验依据。     

氯喹增强LOVO细胞对5-氟尿嘧啶化疗敏感性的作用

目的研究结肠癌细胞LOVO在氯喹(CQ)作用下对化疗药物5-氟尿嘧啶(5-FU)的敏感性变化及机制。方法用MTT法分别检测CQ和5-FU作用24 h和48 h对LOVO细胞的增殖抑制作用。实验分为4组:空白对照组、CQ组、5-FU组和联合作用组。CQ、5-FU及两者联合作用于LOVO细胞后,通过细胞划痕实验和Transwell分别检测细胞迁移和侵袭的变化,采用流式细胞术和TUNEL方法检测细胞凋亡,采用Western blot检测细胞自噬及凋亡相关蛋白的表达情况。结果在不同浓度CQ、5-FU作用下LOVO细胞增殖受到抑制,且呈现剂量依赖性,48 h时CQ和5-FU的IC50分别为11.8μg/ml和2.5μmol/L。与空白对照组相比,CQ、5-FU作用后细胞迁移率和细胞侵袭能力显著降低,且两药联用组的抑制效应更显著。流式细胞术检测显示,CQ组、5-FU组细胞凋亡率分别为(17.85±1.04)%、(17.36±0.96)%,显著高于空白对照组(4.11±0.23)%,两药联用组凋亡率为(25.03±2.27)%,两药联用组与CQ、5-FU单用组相比,细胞凋亡率更高,差异均有统计学意义(P<0.01)。TUNEL检测显示,CQ组、5-FU组细胞凋亡指数显著高于空白对照组,两药联用组与CQ、5-FU单用组相比细胞核凋亡指数更高。Western blot检测显示CQ和5-FU处理后导致P53、Bax、caspase3、caspase9和P62蛋白表达水平显著升高,而Bcl-2、LC3和Beclin-1蛋白表达水平则显著降低,差异均有统计学意义(P<0.01)。结论 CQ能抑制结直肠癌细胞LOVO的增殖、迁移、侵袭和自噬,促进其凋亡,并能增强细胞对化疗药物5-FU的敏感性。     

SN50联合5-氟尿嘧啶通过调节NF-κB信号通路抑制人胃癌裸鼠移植瘤生长的研究

目的探讨NF-κB通路抑制剂SN50联合5-氟尿嘧啶(5-FU)对人胃癌裸鼠移植瘤生长的影响及机制。方法建立荧光素酶标记的人胃癌细胞株SGC7901,常规传代培养,采用对数生长期细胞建立人胃癌裸鼠皮下移植瘤模型。14 d后随机分为4组:对照组、5-FU干预组、SN50干预组、5-FU+SN50干预组。每组8只动物,共给药4周。观察并记录各组裸鼠皮下移植瘤的生长情况,游标卡尺测量瘤体长短径,于停药次日处死裸鼠,称取瘤重,计算肿瘤体积、肿瘤生长抑制率、绘制肿瘤生长曲线。通过体内可见光成像技术分别于第1、7、14、21、28天对裸鼠进行活体成像,记录移植瘤光子数,绘制皮下移植瘤光子数曲线图。免疫组化方法检测移植瘤中NF-κBp65表达情况。结果与其他三组相比,5-FU+SN50干预组肿瘤体积、抑瘤率及光子数差异均有统计学意义(P0.05);与对照组及SN50干预组比较,5-FU干预组肿瘤体积和光子数明显减少(P0.05),抑瘤率明显增加(P0.05);SN50干预组与对照组相比,肿瘤体积、抑瘤率及光子数差异无统计学意义(P0.05)。NF-κBp65阳性率依次为对照组47.4%、5-FU组57.1%、SN50组11.8%、5-FU+SN50组25.0%。结论 5-FU单药及5-FU+SN50均能抑制裸鼠胃癌皮下移植瘤的生长,而联合应用效果更明显;SN50可通过抑制NF-κB信号转导通路的活化,显著增强5-FU对裸鼠胃癌皮下移植瘤的抑制作用。     

三氧化二砷联合塞来昔布对上皮性卵巢癌细胞的增殖抑制和凋亡诱导作用

目的探讨三氧化二砷(As2O3)联合塞来昔布(celecoxib)对上皮性卵巢癌细胞的增殖抑制和凋亡诱导作用及其机制。方法以上皮性卵巢癌细胞株(OVCAR-3)为研究对象,As2O3、celecoxib及两药联合作用于细胞株48 h后,噻唑蓝(MTT)法体外检测药物对细胞增殖抑制作用,并采用金正均q值法计算联合用药的q值。采用凋亡染色和流式细胞仪(FCM)检测药物对细胞凋亡和细胞周期影响,蛋白质印迹法(Western印迹)检测Bcl-2和caspase-3凋亡相关蛋白的表达水平。结果 As2O3和celecoxib对OVCAR-3细胞呈剂量依赖性的生长抑制作用,As2O3的半数抑制浓度(IC50)为4.00μmol/L,celecoxib的IC50为40.00μmol/L;As2O3和celecoxib联合用药后,OVCAR-3细胞的增殖抑制率和凋亡率均大于单药作用组(P0.05),联合用药的q值1.15,有显著的协同抗肿瘤效应。As2O3和celecoxib联合用药后OVCAR-3细胞发生明显的G2/M期阻滞,Bc1-2表达明显下调,而caspase-3表达则明显上调(P0.05)。结论 As2O3和celecoxib单药对OVCAR-3细胞的生长均有抑制作用,联合用药具有显著的协同作用。As2O3和celecoxib联合用药对于上皮性卵巢癌的药物治疗有重要的应用前景。     

氧化砷对人结肠癌裸鼠腹腔种植的抑制作用

目的 :研究氧化砷 (As2 O3)对结肠癌裸鼠腹腔转移的影响及其作用机制。方法 :建立BALB/C nu/nu裸鼠SW 480结肠癌腹水型移植瘤模型 ,腹腔内注射As2 O3,观察As2 O3对荷瘤鼠的抗癌作用。结果 :5 氟脲嘧啶 (5 FU)、低剂量As2 O3和高剂量As2 O3均可明显延长腹水型荷瘤鼠的生存时间 ,其延命率分别为 40 .1± 7.83 %、47.2 2± 8.69%和 92 .1 0± 1 4 .2 % ,高剂量As2 O3延命率明显高于 5 FU ,两组比较差异有显著性 (P <0 .0 1 )。治疗组腹水CEA水平明显低于阴性对照组。在普通光学显微镜下观察腹水标本 ,部分结肠癌细胞发生了较典型的细胞凋亡形态学改变。腹水细胞流式细胞仪检测可见凋亡峰。低剂量As2 O3凋亡率为 8.36± 2 .1 4 % ,高剂量As2 O3凋亡率为 1 5 .3± 3 .82 % ,均明显高于生理盐水组的 2 .40± 1 .1 8% (P <0 .0 1 )。结论 :As2 O3对结肠癌荷瘤鼠具有延长生命的作用 ,其作用机制主要是诱导结肠癌细胞凋亡。     

三氧化二砷-泊洛沙姆407缓释剂治疗裸鼠肝癌移植瘤的作用与机制

目的:对比三氧化二砷(As2O3)-泊洛沙姆407缓释剂(As2O3-P407)与亚砷酸注射液(As2O3溶液)对裸鼠肝癌移植瘤的疗效并探讨可能机制。方法:以人肝癌HepG2细胞为来源建立裸鼠皮下移植瘤模型,实验共分3组,As2O3-P407缓释制剂治疗组(As2O3-P407组),As2O3治疗组(As2O3组)与生理盐水对照组(NS组),于造模后6～8天分别行瘤体注射每4天1次,4次为1个疗程。观察各组裸鼠治疗前后肿瘤体积变化及抑瘤率,各组裸鼠肿瘤组织分别行HE染色、TUNEL法检测、透射电镜观察,对比病理改变及肿瘤细胞的凋亡情况。结果:治疗后As2O3-P407组裸鼠肿瘤体积较As2O3组和NS组明显缩小(P0.05);两治疗组抑瘤率分别为72%和46%;光镜下各治疗组肿瘤组织病理改变有意义;As2O3-P407组肿瘤细胞凋亡率明显高于As2O3组;电镜超微结构同样提示As2O3-P407组肿瘤凋亡细胞增加。结论:As2O3-P407缓释剂瘤内注射,可维持局部有效药物浓度、延长作用时间,疗效优于普通AsO注射液瘤内注射,其作用机制可能与增加肿瘤细胞凋亡有关。     

三氧化二砷对胰腺癌细胞增殖及凋亡的影响

目的试用三氧化二砷(As2O3)以提高胰腺癌的疗效。方法分别比较对照组和As2O3组裸鼠原位胰腺癌模型肿瘤体积、细胞增殖指数和细胞凋亡率。结果As2O3组肿瘤体积较对照组缩小31.2%。胰腺癌细胞增殖指数对照组为(21.05±2.18)%,As2O3组为(10.03±2.86)%(P<0.05);胰腺癌细胞凋亡率对照组(4.7±1.4)%,As2O3组(13.4±1.8)%(P<0.05)。结论As2O3体内能显著抑制胰腺癌的生长,其机制与抑制细胞增殖和诱导细胞凋亡有关。     

As2O3与Aspirin联合应用对人胃癌SGC-7901细胞凋亡的影响

目的:观察As2O3与Aspirin联合应用对人胃癌SGC-7901细胞凋亡的影响并探讨其可能机制.方法:As2O3和Aspirin处理SGC-7901细胞,实验分为:阴性对照组、2 mmol/L Aspirin组、1 mmol/L Aspirin组、4 pmoI/L As2O3组、2μmol/L As2O3组和2 Bmol/L As2O3组 1 mmol/LAspirin组,流式细胞术检测As2O3和Aspirin单独及联合应用对SGC-7901细胞凋亡的作用,免疫细胞化学法检测Bcl-2和Bax蛋白的表达.结果:2 μmol/L As2O3 1 mmol/L Aspirin联合应用组与4 μmol/L As2O3组、2 mmol/L Aspirin 组SGC-7901细胞在细胞周期G1期前均出现明显的亚二倍体凋亡峰,差异无明显统计学意义,与阴性对照组细胞、2 μmol/L As2O3及1 mmol/L Aspirin单药组相比,差异均有统计学意义(均P＜0.05).As2O3与Aspirin联合应用组使Bcl-2表达下降,Bax表达增高,与阴性对照组、2 μmol/L As2O3及1 mmol/L Aspirin单药组相比,差异均具统计学意义(50.21%±5.94% VS 91.65%±11.51%,88.66%±10.53%,89.27%±9.84%;40.72%±9.54% VS 21.03%±4.32%,23.07%±6.23%,22.67%±3.1 6%,均P＜0.05).结论:As2O3和Aspirin可能通过改变Bcl-2和Bax表达诱导SGC-7901细胞凋亡,两者联合应用具有协同作用.     

TPA增强As2O3诱导HL-60细胞凋亡的实验研究

目的 观察12-氧-十四烷酰醇-13-乙酸酯(TPA)和三氧化二砷(As2O3)联合应用对白血病细胞凋亡有无协同作用,并初步探讨其诱导凋亡的机制,为As2O3和TPA联合用于白血病的治疗提供理论依据.方法 采用不同浓度的As2O3联合TPA作用于人白血病细胞系HL-60,用MTT法检测细胞增殖,用TUNEL法检测细胞凋亡,分析不同浓度的As2O3联合TPA对HL-60细胞增殖和凋亡的影响.c-jun氨基末端激酶(JNK)检测法检测JNK活性.结果 TPA联合2.0×10-6 mol/L的As2O3对HL-60细胞增殖抑制作用明显增强,抑制程度大于单用As2O3组(P<0.05).2.0×10-6 mol/L As2O3组诱导HL-60细胞发生凋亡的比率高于对照组,而TPA联合2.0×10-6 mol/L As2O3组引起的细胞凋亡率高于单用As2O3组(P均<0.05).TPA和As2O3均能激活JNK,且二者有协同作用.结论 TPA增强As2O3抑制HL-60细胞增殖和促进凋亡的作用,以上体外实验结果为TPA和As2O3联合用药治疗难治/复发性白血病提供了理论依据.     

尼美舒利和5-氟尿嘧啶联用对胃癌细胞的协同抑制作用及机制

目的 体外研究选择性环氧合酶-2（COX-2）抑制剂尼美舒利和5-氯尿嘧啶（5-FU）对胃癌细胞的抑制作用及机制。方法 以胃癌细胞株MKN45、MKN28为研究对象．观察尼美舒利和5-FU单独或联合应用对细胞增殖、凋亡和细胞周期的影响。应用MTT法检测细胞增殖，流式细胞仪检测细胞凋亡（FITC-Annexin-V/PI双标记）和细胞剧期，RT-PCR观察朋药前后COX-2 mRNA在两株细胞中的表达，Western免疫印迹法观察经两种药物单独和联合作用48h后细胞内凋亡相关蛋白Bax和Bcl-2的表达。结果 在MKN45和MKN28细胞中均可观察到不同水平的COX-2 mRNA表达，尼美舒利和5FU联合应用可明显抑制COX-2 mRNA表达。尼美舒利可抑制两株细胞的增殖并诱导凋亡。尼美舒利和5-FU具有协同抑制细胞增殖及诱导凋亡的作用，该作用与两种药物作用顺序无关，但在联用时作用最强。两药协同抑制增殖的作用主要通过协同杀伤和诱导凋亡而实现。5-FU增强了凋亡诱导蛋白Bax的表达，而尼美舒利则减少凋亡抑制蛋白Bcl-2的表达。两药联用可明显抑制胃癌细胞株生长。结论 选择性环氧合酶-2抑制剂尼美舒利和5-FU通过抑制COX-2 mRNA的表达硬增强Bax／Bcl-2的表达比率诱导胃癌细胞凋亡．从而对胃癌细胞起到协同抑制增殖的作用。     

三氧化二砷对裸鼠结肠癌腹腔转移的抑制作用

目的　研究Ａｓ２Ｏ３ 对裸鼠结肠癌腹腔转移的影响及其作用机制。方法　ＢＡＬＢ／Ｃｎｕ／ｎｕ裸鼠腹腔内接种结肠癌Ｌｏｖｏ 细胞后,随机分为５ 组,分别腹腔内注射生理盐水、表阿霉素及不同剂量的Ａｓ２Ｏ３ ,观察各组的致瘤率、腹水生成及生存时间。结果　表阿霉素、低剂量Ａｓ２Ｏ３ 与对照组相比可明显抑制裸鼠腹水的生长,延长生存期（ Ｐ＜ ０．０１） ;中高剂量Ａｓ２Ｏ３ 除上述作用外还可通过诱导肿瘤细胞凋亡消除腹腔内肿瘤细胞,抑制腹水生成,并使裸鼠寿命明显延长。结论　Ａｓ２Ｏ３ 可诱导结肠癌细胞凋亡,抑制或消除裸鼠肿瘤性腹水的生成,不同程度地延长生存期。     

Effect of resveratrol and in combination with 5-FU on murine liver cancer

AIM: To study the anti-tumor effect of resveratrol and in combination with 5-FU on murine liver cancer. METHODS: Transplantable murine hepatoma22 model was used to evaluate the anti-tumor activity of resveratrol (RES) alone or in combination with 5-FU in vivo. H22 cell cycles were analyzed with flow cytometry. RESULTS: Resveratrol could inhibit the growth of murine hepatoma22, after the mice bearing H22 tumor were treated with 10 mg/kg or 15 mg/kg resveratrol for ten days, and the inhibition rates were 36.3% (n = 10) and 49.3% (n = 9), respectively, which increased obviously compared with that in control group (85+/-22 vs 68+/-17, P<0.01). RES could induce the S phase arrest of H22 cells, and increase the percentage of cells in S phase from 59.1% (n = 9) to 73.5% (n = 9) in a dose-dependent manner (P<0.05). The enhanced inhibition of tumor growth by 5-FU was also observed in hepatoma22 bearing mice when 5-FU was administered in combination with 10 mg/kg resveratrol. The inhibition rates for 20 mg/kg or 10 mg/kg 5-FU in combination with 10 mg/kg resveratrol were 77.4% and 72.4%, respectively, compared with the group of 20 mg/kg or 10 mg/kg 5-FU alone, in which the inhibition rates were 53.4% and 43.8%, respectively (n = 8). There was a statistical significance between the combination group and 5-FU group. CONCLUSION: RES could induce the S phase arrest of H22 cells and enhance the anti-tumor effect of 5-FU on murine hepatoma22 and antagonize its toxicity markedly. These results suggest that resveratrol, as a biochemical modulator to enhance the therapeutic effects of 5-FU, may be potentially useful in cancer chemotherapy.     

As2O3对TRAIL抑制人肺癌A549细胞增殖及调节DR4 mRNA、DR5 mRNA表达作用的影响

目的观察三氧化二砷（As2O3）对人肿瘤坏死因子相关凋亡诱导配体（TRAIL）抑制人肺癌A549细胞增殖作用的影响及机制。方法体外培养A549细胞至对数生长期后随机分为As2O3组、TRAIL组、联合组及对照组,As2O3组分别加入1、10μmol／LAs2O3,TRAIL组加入100μg／LTRAIL,联合组分别加入1μmol／LAs2O3＋100μg/LTRAIL、10μmol／LAs2O3＋100μg／LTRAIL,对照组加入DMEM培养液。四组均继续培养24、48、72h,采用四甲基偶氮唑蓝（MTT）比色法检测细胞生长情况,计算细胞增殖抑制率（IR）;用RT-PCR法检测死亡受体4（DR4）mRNA、死亡受体5（DR5）mRNA表达变化。结果 联合组IR显著高于As2O3,组及TRAIL组,尤以作用48h和72h为著（P均〈0．05）;联合组DR4 mRNA和DR5 mRNA表达均明显强于As2O3组及TRAIL组（P均〈0.05）。结论 As2O3,可增强TRAIL对A549细胞增殖的抑制作用,机制可能为上调DR4m RNA和DR5 mRNA表达;此为肺癌的临床靶向治疗根供了依据．     

Effects of endogenous nitric oxide induced by 5-fluorouracil and L-Arg on liver carcinoma in nude mice

AIM： To study the effects of endogeous nitric oxide induced by 5-fluorouracil （5-FU） and L-arginine （L-Arg） on the human liver carcinoma model in nude mice. METHODS： The human liver carcinoma model in nude mice was established with BEL-7402 cells and normal saline （NS）, 5-FU and 5-FU ＋ L-Arg injected intraperitoneally. The tumor size was measured. The necrotic degree and range were observed under microscope. The apoptosis of cancer cell was detected by turmina deoxynucleotidyl transferanse mediated dUTP nick end labeling （TUNEL） method. Immunohistochemical method was performed to determine the expression of iNOS, P16, BAX. The chemical colorimetry was used to test the activity and nitrate reductase method was adopted to test the concentration of nitric oxide （NO） in the tumor tissue. The BI2000 pathological image analyzer was used to analyze the result of immunohistochemistry. RESULTS： 5-FU combined with L-Arg could inhibit the tumor growth apparently. In NS, 5-FU and 5-FU＋L- Arg groups, the changes of tumor volumes were 257.978 ± 59.0, 172.232 ± 66.0 and 91.523 ± 26.7 mm3, respectively （P 〈 0.05 5-FU vs 5-FU ± L-Arg group;P 〈 0.05 NS ys 5-FU ± L-Arg group; P 〈 0.05, NS ys 5-FU group）. The necrotic range and apoptosis index were significantly increased after the drug injection. The necrotic range was biggest in 5-FU ＋ L-Arg group （X^2= 15.963, P 〈 0.05）. The apoptosis indexes were as follows： NS, 17.4% ± 6.19%; 5-FU, 31.3% ± 12.3%; and 5-FU ± L-Arg, 46% ± 15.24% （P 〈 0.05, 5-FU ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU）. The expression and activity of iNOS were increased in the tumor tissue. The concentration of NO was also increased. F of opticaldensity of iNOS, iNOS activity and NO concentration are 31.693, 21.949, and 33.909, respectively, P 〈 0.05. The concentration of NO was related to the expression of PI6 and BAX. The correlation coefficient was 0.764 and 0.554. CONCLUSION： 5-FU combined with L-Arg can inhi     

Synergistic efficacy of 3n-butyrate and 5-fluorouracil in human colorectal cancer xenografts via modulation of DNA synthesis

BACKGROUND & AIMS: Butyrate, produced in the colon lumen, maintains mucosal cell homeostasis. Poorly diffusible, its access is compromised in growing colon cancers and absent in distant metastases. Butyrate regulates DNA synthesis. We postulated that systemic administration of butyrate should reduce colon cancer growth and enhance 5-fluorouracil (5-FU) efficacy. METHODS: A stable derivative of butyrate (3n-But) was used. The antitumoral efficacy of 5-FU and 3n-But, alone or combined, was evaluated in human colorectal cancers (hCRCs) subcutaneously, orthotopically, or intrasplenically grafted into nude mice. Thymidylate synthase (TS) and thymidine kinase (TK) mRNA expression, proliferation, apoptosis, and cell cycle alterations were studied. RESULTS: In vivo, 5-FU alone inhibited growth of only 3 of the 12 hCRCs tested and 3n-But alone had no effect; the 5-FU/3n-But combination inhibited growth of all 16 hCRCs tested. The hCRCs differed in their p53 and microsatellite instability status. 5-FU/3n-But decreased TK and TS mRNA expression by 20- and 40-fold, respectively, and TS activity by 75%, stopped cell proliferation without affecting cell differentiation, and significantly enhanced apoptosis. 3n-But potentiated the efficacy of Tomudex and methotrexate, 2 TS inhibitors, but not that of oxaliplatin. In vitro, 5-FU/3n-But inhibited [3H]thymidine but not bromodeoxyuridine incorporation and induced apoptosis in hCRC cell lines. Cells treated with 5-FU/3n-But did not accumulate in G1 nor in S phase of the cell cycle, while 5-FU and 3n-But arrested the cycle in S and in G1 phase, respectively. 3n-But prevented the cell rescue from 5-FU-induced cytotoxicity by uridine or thymidine. CONCLUSIONS: 3n-But and TS inhibitors acted synergistically against colorectal cancers, independently of the genetic alterations of the hCRCs. The mechanism of action of 5-FU/3n-But could be enhanced reduction of TS and prevention of thymidine salvage in DNA synthesis.     

PI3K p85α蛋白表达缺失联合5-FU对大肠癌细胞的促凋亡作用

探讨RNA干扰靶向抑制PI3K p85α蛋白表达联合5-FU对大肠癌LoVo细胞的促凋亡作用。方法复苏培养PI3K p85α干扰组LoVo细胞（PI3Kp85ɑ/RNAi-LoVo）和LoVo对照组细胞,Western blot鉴定干扰效果,MTT法检测5-FU对两组细胞的半数抑制浓度（IC50）,Annexin-FITC标记法检测细胞凋亡。结果 Western blot结果显示LoVo干扰组细胞PI3K p85α蛋白抑制率为59%,MTT结果显示干扰组细胞5-FU的IC50值（4.57±0.16）μmol/L明显低于对照组细胞5-FU的IC50值（8.07±0.30）μmol/L（P=0.000）,细胞凋亡实验显示,干扰组细胞对5-FU诱导凋亡的敏感性增加（P=0.000）。结论 PI3K p85α蛋白表达缺失联合5-FU可促进大肠癌LoVo细胞凋亡,为基因治疗和化学药物联合治疗大肠癌提供新的策略。     

TNF-α联合阿霉素对人胃癌细胞株SGC-7901的作用及其机制研究

背景:肿瘤坏死因子-α(TNF-α)是抗肿瘤活性很强的细胞因子,但较多的全身毒副作用限制了其应用。目前发现小剂量TNF-α联合化疗药物可提高化疗效果。目的:探讨TNF-α联合阿霉素(ADM)对人胃癌细胞株SGC-7901的治疗作用及其机制。方法:体外常规培养人胃癌细胞株SGC-7901,并分为ADM组(64、16、4、1、0.25μg/mL)、TNF-α组(16 000、4000、1000、250、62.5 IU/mL)、联合组(ADM 5μg/mL+TNF-α4000 IU/mL)、阴性对照组和空白对照组。以MTT法观察细胞生长,流式细胞术检测细胞周期和凋亡,蛋白质印迹法检测caspase-8蛋白表达。构建裸鼠胃癌移植瘤模型,分为阴性对照组、ADM组(2 mg/kg)和联合组(ADM 2 mg/kg+TNF-α5×104IU/kg),观察肿瘤生长情况。结果:与ADM组相比,联合组SGC-7901细胞存活率明显降低,S期和G2期细胞比例、细胞凋亡率、caspase-8蛋白表达均明显升高;体内实验亦显示联合组对裸鼠移植瘤的抑瘤率明显高于ADM组。结论:TNF-α与ADM联合应用可增加化疗药物对胃癌细胞的杀伤作用,其机制部分与促进细胞凋亡和改变细胞周期有关。     

Combination of ZD55-MnSOD therapy with 5-FU enhances antitumor efficacy in colorectal cancer

Purpose ZD55-MnSOD is an E1B 55 kDa-deleted replication-competent adenovirus and armed with the therapeutic gene MnSOD. The expression of the therapeutic gene MnSOD increases with the selective replication of the oncolytic adenovirus (ZD55) so that ZD55-MnSOD has more significant activity than the replicate defective adenovirus Ad-MnSOD in vitro and in vivo. The tumor cannot be completely eradicated only with ZD55-MnSOD, although ZD55-MnSOD has obvious antitumor activity. 5-fluorouracil (5-FU) is still the most effective adjuvant therapy for patients with colorectal cancer. Methods We reasoned that combined treatment of cancer cells with ZD55-MnSOD and 5-FU might have a synergistic effect. In vitro experiments with SW620 colorectal carcinoma cell line demonstrated that it was sensitive to ZD55-MnSOD, especially most sensitive to ZD55-MnSOD plus 5-FU treatment. Treatment with both ZD55-MnSOD and 5-FU could induce more significant apoptosis in cancer cells compared with ZD55-MnSOD or 5-FU alone, respectively. A better antitumor activity was observed by ZD55-MnSOD plus 5-fluorouracil (5-FU) treatment. Tumor growth was greatly inhibited by this combined treatment, and animal survival time increased. Conclusion These results show that, by using the combination therapies, a significant decrease in tumor mass can be achieved, which suggest that ZD55-MnSOD in combination with 5-FU may have potential clinical implications.