帕博西尼逆转人食管鳞癌奥沙利铂耐药细胞株耐药性的研究

  目的  建立人食管鳞癌(esophageal squamous cell carcinoma,ESCC)奥沙利铂(oxaliplatin,L-OHP)耐药细胞株KYSE150-OXA,研究细胞周期蛋白依赖性激酶4/6(cyclin-dependent kinase 4/6,CDK4/6)抑制剂帕博西尼(palbociclib)对耐药细胞株耐药性的逆转及其机制。  方法  CCK-8检测耐药细胞对奥沙利铂、紫杉醇(paclitaxel,PTX)、5-氟尿嘧啶(5-fluorouracil,5-FU)以及CDK4/6抑制剂palbociclib的耐药性;流式细胞术检测化疗药物对耐药细胞凋亡和周期的影响;Western blot检测细胞中多药耐药基因1(multidrug resistance gene 1,MDR1)及细胞周期相关蛋白的表达量;CalcuSyn软件计算palbociclib与L-OHP联合用药对细胞增殖的作用。  结果  成功建立人体外ESCC L-OHP耐药细胞株KYSE150-OXA,耐药指数(resistance index,RI)为11.23±0.59,耐药细胞KYSE150-OXA对PTX和5-FU也表现出耐药性,Western blot结果显示耐药细胞中MDR1蛋白表达升高(4.46±0.22)倍;与亲本细胞KYSE150相比,耐药细胞株G1期细胞显著增多,且CDK4、CDK6及Cyclin D1表达显著升高;palbociclib增加KYSE150-OXA对L-OHP的敏感性;低浓度palbociclib与L-OHP表现出拮抗作用,高浓度时表现为协同作用;palbociclib处理组细胞中磷酸化视网膜母细胞瘤蛋白(phospho-retinoblastoma,pRb)降低(91±2)%及细胞周期蛋白A(Cyclin A)降低(89±6)%。  结论  成功建立人体外ESCC L-OHP耐药细胞株KYSE15 0-OXA;palbociclib可能通过抑制异常激活的Cyclin D-CDK4/6-pRb信号通路逆转耐药细胞对L-OHP的耐药性。      

上海中医药大学附属普陀医院实验中心，上海中医药大学中西医结合肿瘤介入研究所，上海200062

背景与目的：细胞凋亡受阻是肿瘤细胞产生耐药的重要因素,从细胞凋亡的研究入手,将为肿瘤的治疗和耐药性的逆转开辟新的途径。本研究观察一种新型萘酰亚胺类衍生物8c对结肠癌HCT116/L-OHP耐药细胞的作用,探讨诱导HCT116/L-OHP耐药细胞凋亡的分子机制。方法：采用CCK-8法检测8c对HCT116/L-OHP细胞的增殖抑制作用;采用流式细胞术观察8c对HCT116/L-OHP细胞凋亡的影响;采用实时定量PCR(realtime PCR)检测p53 mRNA、Bax mRNA及Bcl-2 mRNA水平变化;蛋白［质］印迹法(Western blot)检测p-p53、Bax、Bcl-2及细胞色素c(Cyt-c)的蛋白表达水平。结果：8c抑制HCT116/L-OHP细胞增殖的半数抑制浓度(IC₅₀=8.16 μmol/L)低于阳性对照氨奈菲特(IC₅₀=28.37 μmol/L);药物作用后,8c诱导耐药细胞产生凋亡,凋亡通路中p53(Ser15)磷酸化水平上升,但p53 mRNA水平不受影响;Bax蛋白水平及mRNA水平明显上升,Bcl-2蛋白及mRNA水平下降,使得Bax/Bcl-2比例增加,同时8c又引起细胞色素c的释放。结论：8c通过磷酸化p53 Ser-15位点激活p53,随即激活细胞凋亡通路相关蛋白的表达,这可能是8c抑制结肠癌HCT116/L-OHP耐药细胞增殖的重要机制之一。8c具有良好的抗肿瘤及抗耐药潜力和开发应用前景。     

UGCG通过调控MDR1/P-gp参与人结肠癌奥沙利铂耐药的初步研究

目的 建立人结肠癌耐奥沙利铂（L-OHP）细胞株,检测该细胞株的多药耐药性并初步探讨其可能的耐药机制。方法 以人结肠癌细胞HCT116为对象,采用药物浓度梯度递增诱导法建立人结肠癌耐奥沙利铂细胞株HCT-116/L-OHP。CCK-8法检测L-OHP、顺铂（DDP）、5-氟尿嘧啶（5-Fu）对亲本细胞和耐药细胞株的半数抑制浓度（IC50）。使用UDP-葡萄糖神经酰胺糖基转移酶（UGCG）siRNA转染HCT-116/L-OHP细胞,实时荧光定量 PCR和Western blot检测干扰前后UGCG基因和多药耐药基因1（MDR1）mRNA及其编码的蛋白表达水平。结果 HCT-116/L-OHP对L-OHP的耐药指数为10.5,与DDP有一定程度的交叉耐药,耐药指数为4.61,但对5-Fu无交叉耐药。耐药细胞HCT-116/L-OHP中UGCG、MDR1 mRNA和UGCG、P-糖蛋白（P-gp, MDR1编码的蛋白）表达均增加,相比HCT-116细胞,差异具有统计学意义（P<0.05）。UGCG siRNA成功抑制HCT-116/L-OHP细胞中UGCG的表达,各干扰组MDR1 mRNA、P-gp表达减少,与对照组相比差异具有统计学意义（P<0.05）。结论 成功构建了人结肠癌耐药细胞株;UGCG基因通过调控MDR1/P-gp的表达参与人结肠癌奥沙利铂的耐药机制的形成。     

结肠癌耐药细胞株LoVo/L-OHP的建立及其耐药机制

目的:建立获得性奥沙利铂(L-OHP)耐药的结肠癌细胞模型LoVo/L-OHP,并初步研究其耐药机制。方法:采用L-OHP浓度递增法建立人结肠癌细胞耐药模型LoVo/L-OHP,观察其生长规律并绘制细胞生长曲线;用MTT法鉴定耐药细胞株耐药性并计算耐药指数(RI);用半定量RT-PCR方法对部分耐药相关基因在耐药细胞及其亲本细胞中的表达情况进行分析。结果:成功建立了耐药的结肠癌细胞模型LoVo/L-OHP,LoVo/L-OHP细胞与LoVo细胞相比,生长缓慢,触角增多。通过RT-PCR半定量分析,P-gp、bcl-2、ERCC-1在LoVo/L-OHP中的表达上调,而p53基因表达下调。结论:LoVo/L-OHP细胞株耐药性稳定,耐药机制可能与P-gp、bcl-2、ERCC-1基因上调、p53基因下调多因素有关。     

miR-126-5p靶向抑制ERCC1增加结肠癌细胞对奥沙利铂化疗的敏感性

目的 探讨miR-126-5p通过靶向抑制切除修复交叉互补基因1(excision repair cross complement 1,ERCC1)促进结肠癌细胞对奥沙利铂(oxaliplatin,L-OHP)的敏感性及其分子机制。方法 利用L-OHP浓度梯度递增法处理结肠癌细胞HCT116,建立耐L-OHP的人结肠癌细胞株HCT116/L-OHP。CCK-8法检测并计算L-OHP作用后的半数抑制浓度(half maximal inhibitory concentration,IC₅₀)值。qRT-PCR法检测miR-126-5p和ERCC1在HCT116和HCT116/L-OHP细胞株中的表达。利用Lipofectamine^? 2000转染miR-126-5p mimics(miR-126-5p mimics组)和miR-NC质粒(miR-NC组)后,CCK-8法检测HCT116/L-OHP细胞对L-OHP的敏感性的变化,流式细胞术检测细胞凋亡率。利用双荧光素酶报告实验验证miR-126-5p和ERCC1的相互作用机制。Western bl...     

结肠癌耐药细胞株LoVo/L-OHP的建立及其耐药机制

目的：建立获得性奥沙利铂（L-OHP）耐药的结肠癌细胞模型LoVo/L-OHP,并初步研究其耐药机制。方法：采用L-OHP浓度递增法建立人结肠癌细胞耐药模型LoVo/L-OHP,观察其生长规律并绘制细胞生长曲线;用MTT法鉴定耐药细胞株耐药性并计算耐药指数（RI）;用半定量RT-PCR方法对部分耐药相关基因在耐药细胞及其亲本细胞中的表达情况进行分析。结果：成功建立了耐药的结肠癌细胞模型LoVo/L-OHP,LoVo/L-OHP细胞与LoVo细胞相比,生长缓慢,触角增多。通过RT-PCR半定量分析,P-gp、bcl-2、ERCC-1在LoVo/L-OHP中的表达上调,而p53基因表达下调。结论：LoVo/L-OHP细胞株耐药性稳定,耐药机制可能与P-gp、bcl-2、ERCC-1基因上调、p53基因下调多因素有关。     

羟基喜树碱联合奥沙利铂诱导人大肠癌耐药细胞株LoVo/5-FU的凋亡机制

目的:体外观察羟基喜树碱(HCPT)联合奥沙利铂(L-OHP)对人大肠癌耐药细胞株LoVo/5-FU增殖抑制及诱导凋亡作用,并初步探讨其诱导凋亡方面机制.方法:MTT法测定HCPT联合L-OHP对LoVo/5-FU细胞增殖抑制作用,并根据中效原理判断两药合用时的效应.流式细胞仪观察两药对LoVo/5-FU细胞的凋亡诱导作用.半定量RT-PCR方法检测单药及联合作用后X染色体连锁的凋亡抑制蛋白(XIAP) mRNA表达变化.结果:HCPT联合L-OHP对LoVo/5-FU细胞有明显的抑制增殖作用,细胞增殖的抑制率与药物浓度呈正相关.在抑制率(fa)>0.18时合用指数(CI)<1,两药表现为协同作用.HCPT浓度分别为0.02、0.04和0.08 mg/L.作用48 h后,LoVo/5-FU细胞凋亡率分别为5.92±0.58、9.93±0.62和3.76±0.45.当0.04 mg/L HCPT联合L-OHP作用48 h后,其凋亡率为18.44±0.57,联合组与单药组比较差异有统计学意义,P<0.05.耐药细胞LoVo/5-FU较亲本细胞LoVo高表达XIAP mRNA(0.88±0.03 vs 0.11±0.02,P<0.01),两药联合作用后XIAP mRNA降低明显为0.21±0.03,P<0.01.结论:HCPT联合L-OHP能够协同抑制LoVo/5-FU细胞增殖,其机制可能与诱导细胞凋亡有关,抑制XIAP表达发挥作用.     

基于生物信息学和转录组测序分析结直肠癌5-FU耐药关键靶点北大核心

目的:筛选结直肠癌5-氟尿嘧啶(5-FU)耐药靶基因,并探究该基因对结直肠癌耐药细胞的作用及其作用机制。方法:通过GEO数据库分析GSE28702芯片筛选结直肠癌患者5-FU耐药与5-FU敏感的差异表达基因(differentially expressed genes,DEGs);利用GO与KEGG数据库对DEGs进行通路富集分析;通过STRING数据库构建蛋白质相互作用(protein-protein interaction,PPI)网络,利用Cytoscpae的cytohubba工具筛选枢纽基因。构建5-FU耐药细胞株HCT8/5-FU,利用高通量转录组测序鉴定;采用受试者工作特征曲线(receiver operating characteristic curve,ROC)对诊断价值进行评价并基于TCGA数据库COAD数据集分析关键基因表达及预后;构建TF基因过表达载体转染到HCT8/5-FU细胞系,MTT法检测细胞活力;流式细胞术测定细胞凋亡与细胞周期;qRT-PCR与Western Blot检测基因mRNA和蛋白水平。结果:共筛选出239个DEGs;DEGs主要富集在细胞外囊泡、内吞囊泡腔、药物代谢等通路;PPI得到20个枢纽基因;转录组学显示转铁蛋白(transferrin,TF)在耐药株中显著下调(P<0.05)与生物信息学分析得到的DEGs中TF基因改变趋势相同;与正常结直肠组织相比,癌组织中TF低表达(P<0.05);TF高表达患者总体生存期更长(P<0.05);上调TF表达增强了耐药细胞的5-FU敏感性(P<0.05);上调TF表达增加了5-FU诱导的细胞凋亡与G_(0)/G_(1)期的阻滞(P<0.05);上调TF表达抑制了耐药细胞ABCC1的表达(P<0.05)。结论:基于生物信息学和转录组测序筛选出结直肠癌5-FU耐药靶基因TF,TF基因可能通过调控ABCC1表达降低结直肠癌5-FU的耐药性。     

胃癌耐药细胞株SGC-7901/5-FU的建立及其耐药机制的初步探讨

目的构建耐5-FU的胃癌耐药细胞株,初步探讨细胞发生5-FU耐药的可能机制.方法 通过药物耐药间歇冲击并浓度梯度递增法诱导建立胃癌耐药细胞株SGC-7901/5-FU.应用MTT法检测亲代细胞对4种化疗药物的IC50并计算耐药指数(RI).通过MTT法绘制细胞的生长曲线计算细胞倍增时间.流式细胞仪分析细胞周期分布.RT-PCR检测抑癌基因P53、癌基因Bcl-2、促凋亡基因半胱氨酰天冬氨酸特异性蛋白酶-3(caspase-3)、死亡相关蛋白激酶(death associated protein kinase,DAPK)家族成员(DAPK-1、DAPK-2、DAPK-3)、多药耐药蛋白(multidrug resistance proteins,MRP)亚家族中的MRP-6、多药耐药基因1(multidrug resistance 1,MDR1)、切除交叉互补修复基因(excision repair cross-complementing 1,ERCC-1)的表达.Western Blot检测MDR1 编码的P糖蛋白(P-gp)的表达水平.结果SGC-7901/5-FU对5-FU、顺铂、环磷酰胺的耐药指数分别为6.26、3.71、5.25.SGC-7901与SGC-7901/5-FU细胞倍增时间分别为(30.82±1.46)h和(46.01±4.15)h,SGC-7901/5-FU细胞增殖速率显著变缓(P＜0.05).与亲代细胞比较,耐药子株S期细胞显著减少,G0/G1期细胞则显著增高(P＜0.01),而G2/M期细胞无显著差异(P＞0.05).耐药子株SGC-7901/5-FU细胞MDR-1、MRP-6、DAPK-3和P-gp表达显著上调(P＜0.01),而ERCC-1、caspase-3、P53、DAPK-1、DAPK-2、Bcl-2的表达均无显著变化(P＞0.05). 结论成功构建胃癌耐5-FU细胞株SGC-7901/5-FU,其对顺铂、环磷酰胺具有交叉耐药,耐药机制与细胞周期S期细胞比例减少、G0/G1期细胞比例升高有关,可能与MDR-1、MRP-6、DAPK-3基因及P-gp蛋白表达上调有关.     

Circ_0001946靶向miR-671-5p调控Wnt/β-catenin通路对结直肠癌细胞恶性进展的影响

摘 要：［目的］ 探讨circ_0001946对结直肠癌细胞恶性进展的影响。［方法］培养结直肠癌HCT116、SW480、Colo320、HT29细胞和正常结直肠CCC-HIE-2细胞,实时定量PCR检测circ_0001946、miR-671-5p表达量。miRcode和双荧光素酶报告实验分析circ_0001946和miR-671-5p的关系。circ_0001946、miR-671-5p在HCT116细胞中的表达量被上调或下调后,分别检测HCT116细胞生长活性、细胞凋亡率及细胞迁移能力。免疫蛋白印迹法检测Bcl-2、Bax、Caspase-3和Caspase-9蛋白表达及Wnt/β-catenin信号通路蛋白表达。［结果］ HCT116（4.76±0.47）、HT29（2.85±0.57）、SW480（2.75±0.62）、Colo320（3.12±0.68）细胞中circ_0001946表达水平高于CCC-HIE-2细胞（1.24±0.09）（t=7.238、8.129、6.893、6.875,P均<0.05）。下调circ_0001946表达显著降低了HCT116细胞增殖（P<0.05）和迁移能力（P<0.05）,促进了细胞凋亡（P<0.01）; circ_0001946靶向miR-671-5p; circ_0001946表达被上调或miR-671-5p表达被下调后,HCT116细胞增殖和迁移能力显著上升,细胞凋亡率明显降低,Wnt/β-catenin信号通路被激活。［结论］ circ_0001946靶向miR-671-5p激活了Wnt/β-catenin信号通路,促进了结直肠癌细胞恶性进展。     

Rapamycin synergizes with low-dose oxaliplatin in the HCT116 colon cancer cell line by inducing enhanced apoptosis

The present study aimed to examine the combined effects of oxaliplatin (L-OHP) and rapamycin (RAPA) in the HCT116 colon cancer cell line. The growth inhibitory effect was evaluated by MTT assay as a monotherapy or combination therapy. IC(50) values were determined using CalcuSyn 2.0 software. To determine the interaction of the drugs, the combination index (CI) was calculated using the Chou-Talalay method. Apoptosis was investigated using flow cytometry and Western blotting. Acridine orange staining was employed to observe morphological changes. The results showed the IC(50) values of L-OHP and RAPA to be 8.35±0.78 μM (r=0.99) and 223.44±38.10 nM (r=0.94), respectively. CI was ≤1 when L-OHP was used at doses ranging from 1 to 5 μM plus RAPA at a dose of 10 nM, suggesting synergistic or additive effects. CI was ≥1 when 100 nM RAPA was used in combination with low-dose L-OHP, showing additive to antagonistic effects. The combination of L-OHP (1 μM) and RAPA (10 nM) induced 19.76% Annexin V-positive cells, which was found to be higher than L-OHP (11.45%, p<0.01) or RAPA (6.89%, p<0.01) alone. The cleaved PARP protein expression levels were highest after 48 h of combination treatment. Acridine orange staining showed typical bright red Acidic vesicular organelles in the RAPA group, whereas the green condensed chromatin in the apoptotic bodies was found in both the L-OHP and combination groups. In conclusion, at a cytostatic concentration, RAPA was found to potentiate the anti-tumor effects of low-dose L-OHP in the HCT116 colon cancer cell by inducing enhanced apoptosis.     

青藤碱对肠癌细胞的抑制作用

目的:观察青藤碱对肠癌细胞的抑制作用。方法:选取HCT116细胞分3组,分别用DMSO（对照组）、20 μmol/L和40 μmol/L的青藤碱以及6 μmol/L的5氟尿嘧啶（5-FU）处理细胞。MTT检测不同浓度药物对HCT116细胞增殖的影响。PI染色技术和JC-1染色分别检测药物对细胞周期和凋亡的作用。通过Western blot检测青藤碱对HCT116细胞中Cyclin D1和bcl-2的影响。Transwell实验检测青藤碱对HCT116细胞迁移的影响。通过Western blot检测青藤碱对HCT116细胞中MMP2的影响。结果:与DMSO相比,20 μmol/L和40 μmol/L的青藤碱以及6 μmol/L的5-FU作用于HCT116细胞24 h后对细胞的抑制率分别为:(33.16±6.01)%、(47.48±2.32)%和(62.31±3.26)%。青藤碱抑制G1-S期转化,促进细胞凋亡。Western blot结果显示,青藤碱抑制Cyclin D1、bcl-2和MMP2在HCT116细胞中的表达。结论:青藤碱抑制HCT116细胞的生长和迁移。     

茯苓酸通过调控AKT/MDM2/p53通路影响结直肠癌HCT116细胞的恶性生物学行为

目的：探究茯苓酸（PA）是否通过AKT/MDM2/p53通路影响结直肠癌HCT116细胞的恶性生物学行为。方法：常规培养HCT116细胞,并将其分为对照组、MK-2206(AKT抑制剂)组、PA低浓度（PA-L）组、PA高浓度（PA-H）组、PA-H+SC79(AKT激活剂)组。CCK-8法、细胞克隆形成实验、流式细胞术、Transwell、qPCR法和WB法实验分别检测各组HCT116细胞的增殖活力,克隆形成能力,细胞凋亡,迁移、侵袭能力,E-cadherin、N-cadherin和vimentin mRNA表达以及AKT/MDM2/p53通路相关蛋白的表达。结果：PA可明显抑制HCT116细胞的增殖活力（P<0.05）、克隆形成能力（P<0.05）、迁移和侵袭能力（P<0.05）,诱导其凋亡（P<0.05）,抑制N-cadherin、vimentin mRNA的表达（P<0.05）,促进E-cadherin mRNA的表达（P<0.05）,抑制AKT、MDM2的磷酸化水平（P<0.05）,促进p53蛋白的表达（P<0.05）;AKT抑...     

Effects of mitomycin on human colon carcinoma cells

Subpopulations of malignant cells from primary cultures of human colon carcinoma were characterized with respect to their response to mitomycin (MMC). Growth inhibition assays indicated values of 2.06, 0.93, and 0.33 microM for the concentration of drug giving 50% inhibition of growth for sublines HCT 116b, HCT 116, and HCT 116a, respectively. Alkaline elution of filter-bound DNA from cells exposed to MMC in vitro showed a positive correlation between the amount of DNA cross-linking and growth inhibition as a function of drug concentration. Comparable DNA cross-linking was obtained at MMC concentrations of 10 microM for HCT 116b and 5 microM and HCT 116. The cross-linking of DNA from HCT 116a cells at 5 microM MMC was approximately equal to that from HCT 116 cells at doses between 10 and 20 microM MMC. Cross-link removal as a function of time after drug removal of MMC-treated cells was also measured. There was little difference in the rates of alkaline DNA elution after drug removal between HCT 116b and HCT 116a, suggesting that the ability to repair cross-links was not responsible for the differential sensitivities of the cells to MMC. The relative sensitivities of the subpopulations to MMC were reflected in vivo by MMC treatment of nude BALB/c mice bearing xenografts of the cultured sublines.     

地塞米松影响结肠癌细胞对奥沙利铂与氟脲嘧啶化疗敏感性的实验研究*

目的:检测糖皮质激素受体在结肠癌组织及细胞株中的表达,探讨地塞米松共处理或预处理24h,结肠癌细胞株对奥沙利铂和氟脲嘧啶化疗敏感性的变化。方法:采用免疫组化检测糖皮质激素受体在61例结肠癌组织标本及4 种结肠癌细胞株中的表达;Hoechst33342 染色、流式细胞仪检测体外地塞米松对结肠癌细胞株的凋亡诱导作用;以MTT 法检测地塞米松共处理或预处理24h 后,结肠癌Lovo 细胞株对奥沙利铂和氟脲嘧啶化疗敏感性的变化。结果:在57.3% 的结肠癌组织标本中糖皮质激素受体呈阳性表达,在四种结肠癌细胞株中仅Lovo 和HCT-116表达糖皮质激素受体,HT- 29和SW- 480 细胞不表达。单独应用地塞米松后,对糖皮质激素受体阳性的Lovo 和HCT-116 细胞有较强的促凋亡作用,对不表达糖皮质激素受体的HT- 29和SW- 480 细胞作用则不明显。以1 ×10-4 mol/L的地塞米松处理Lovo 细胞24h,或与奥沙利铂共处理可使奥沙利铂的 IC 50从（13.7 ± 1.3）μ g/mL 降低至（5.9 ± 0.6）μ g/mL 和（4.8 ± 0.7）μ g/mL;同样处理可使氟脲嘧啶的IC 50从（72.2 ± 8.1）μ g/mL 降低至（21.1 ± 4.1）μ g/mL 和（18.6 ± 4.0）μ g/mL。结论:部分结肠癌组织及细胞株表达糖皮质激素受体。地塞米松体外作用能够促进糖皮质激素受体阳性的结肠癌细胞发生凋亡,与奥沙利铂和氟脲嘧啶预处理或共处理后可以增加结肠癌细胞的化疗敏感性。      

hRFI overexpressed in HCT116 cells modulates Bcl-2 family proteins when treated with 5-fluorouracil

Exogenous overexpression of hRFI, originally isolated in our laboratory, inhibits not only death receptor-mediated apoptosis but also the mitochondrial apoptosis induced by several chemotherapeutic agents including 5-fluorouracil (5-FU). Recently, it has become clear that hRFI targets and degradates caspase-8 and -10 in death receptor-mediated apoptosis by E3 ubiquitin activity in a ring finger domain homologous to that of X-chromosome-linked inhibitor of apoptosis protein (XIAP). However, the cellular mechanism of the inhibition of mitochondrial apoptosis by hRFI has not been fully elucidated. We prepared HCT116 overexpressing hRFI (HCT116/hRFI) cells and comprehensively analyzed the expression changes of 51 apoptosis-related genes with or without 5-FU treatment between HCT116/hRFI and mock cells using microfluidic low-density arrays. As a result, we identified four genes (Bcl-2, Bcl-XL, cIAP2, and CFLAR) whose expression was four or more times higher in HCT116/ hRFI cells than in HCT116/LacZ cells, and found that Bcl-2 and the ratio of Bcl-2/Bax or Bcl-2/Bak were upregulated when HCT116/hRFI cells were treated with 5-FU. Furthermore, we also validated the up-regulation of Bcl-2 and Bcl-XL in HCT116/hRFI cells treated with 5-FU by Western blot analysis. Such evidence suggests that the modulation of Bcl-2 family proteins seen in 5-FU treatment plays an important role in the anti-apoptotic function of HCT116/hRFI cells.     

水通道蛋白-5对结直肠癌细胞迁移、凋亡的影响及机制研究

目的:探讨短发夹RNA（short hairpin RNA,shRNA）沉默水通道蛋白-5（aquaporin-5,AQP5）对人结直肠癌HT-29细胞和HCT116细胞迁移、凋亡的影响及相关机制。方法:构建pRNA-H1.1-AQP5的干扰质粒和pRNA-H1.1-NC的对照质粒转染HT-29和HCT116细胞,利用Real-time PCR（RT-PCR）、Western blot方法验证AQP5基因敲降效率,划痕试验检测AQP5-shRNA对结直肠癌细胞迁移率的影响,流式细胞术检测各组细胞的细胞凋亡率,Western blot检测凋亡相关蛋白Bax和Bcl-2基因在蛋白水平的表达。选用NF-κB抑制剂BAY 11-7082（BAY）处理转染AQP5-shRNA的HT-29和HCT116细胞,划痕试验检测各组细胞的迁移率,Western blot检测凋亡基因Bax和Bcl-2的表达情况。结果:AQP-shRNA转染HT-29和HCT116细胞中,AQP5表达量明显低于NC-shRNA转染的HT-29和HCT116细胞（P＜0.05）。划痕试验结果表明,对比NC组,AQP5-shRNA明显抑制HT-29和HCT116细胞的迁移（P＜0.05）。流式细胞术结果表明AQP5-shRNA显著提高HT-29和HCT116细胞的凋亡率（P＜0.05）。对比NC-shRNA组,AQP5-shRNA组细胞中Bax蛋白表达明显提高,而Bcl-2蛋白表达显著下降。BAY处理后,AQP5-shRNA所抑制的结直肠癌细胞迁移率显著下降,AQP5-shRNA所促进的细胞凋亡率显著升高,且对比AQP5-shRNA组,AQP5-shRNA与BAY共同处理的细胞中Bax蛋白表达明显升高,Bcl-2蛋白表达明显降低。结论:AQP5-shRNA抑制结直肠癌细胞迁移,促进结直肠癌细胞凋亡受NF-κB信号调控。     

Survival of colorectal cancer cell lines treated with paclitaxel, radiation, and 5-FU: effect of TP53 or hMLH1 deficiency

Clonogenic survival and early cell death during treatment of human colon carcinoma cells were investigated following X-irradiation (IR) alone, IR followed by 5-FU for 24 h, and Taxol administered 24 h before IR and 5F-U. The investigated cell lines were: HCT116, 40-16 clonally derived from HCT116, and two HCT116 variants: N6CHR3 expressing hMLH1, and TP53 null cells denoted HCT116 p53-/-. The objective was to determine efficacy of the combined treatment and to correlate response with constitutive levels of TP53, WAF1, and hMLH1 proteins, as well as with mRNA levels of the apoptosis-related genes survivin, BNIP3, and MYC. At the end of treatment with 5-FU, the proportion of viable cells was between 0.65 and 0.70 for all cell lines. Additional cell loss occurred in 40-16 and HCT116 p53-/- cells following administration of Taxol before IR and 5-FU. Radiation sensitivity was unaffected by combined treatments, except for Taxol, irradiation, and 5-FU sequence in the HCT116 p53-/- and 40-16 cell lines, where radiation sensitivity determined by clonogenic survival curve slopes was doubled or quadrupled, respectively. Under our present experimental conditions, treatment response did not correlate with TP53 or hMLH1 status, but was associated with apoptosis-related genes, most notably BNIP3. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 175-185 (2000).