肝癌多药耐药细胞株的建立及其多药耐药机理的研究

 为建立人肝癌多药耐药细胞株并研究其多药耐药的机理，本文应用BEL－7402细胞株，通过不断提高培养液中阿霉素（Doxorubicin）的浓度，长期筛选培养，得到肝癌多药耐药株BEL7402/DoX。经MTT法检测BEL－7402对长春新碱（VCR）等8种抗癌药的抗性提高了27－1100倍不等。以流式细胞技术检测了此细胞株表面MDR1蛋白P－gp、多药耐药相关蛋白MRP及谷胱甘肽硫转移系统（GSH/GST）的表达；用RT－PCR方法检测了MDR及MRP基因表达水平。发现BEL7402/Dox细胞表面P－gp表达为93.5～97.4％；MRP的表达为84.7～90.2％；RT－PCR证实此细胞株中有MDR及MRPmRNA的高表达；未发现GSH/GST的表达升高。     

膀胱肿瘤T24／ADM多药耐药细胞株的建立及耐药机制的研究

目的建立人类膀胱肿瘤多药耐药（MDR）细胞株并研究其耐药机制。方法以人类膀胱肿瘤细胞株T24为研究对象，用多柔比星（ADM）浓度梯度递增诱导法，建立人类膀胱肿瘤细胞多药耐药模型（简称T24／ADM）。用MTT法检测肿瘤细胞的MDR特性；RT—PCR检测膀胱肿瘤耐药细胞株MDR基因的表达情况。流式细胞术检测耐药细胞P-糖蛋白（P—gP）的表达。结果T24／ADM对多种化疗药物产生耐药，对ADM的耐药性提高了16-3倍。RT—PCR检测发现T24／ADM中MDR基因和P—gp的表达明显增强。结论T24／ADM细胞具有MDR特性，其耐药性与MDR基因和P—gP的过表达有关。     

野生型p53基因对肝癌细胞多药耐药的逆转作用及其相关机制

背景与目的：细胞凋亡的发生机制在肿瘤多药耐药中起重要作用,野生型p53基因是细胞凋亡的激活剂,与肿瘤多药耐药密切相关。本研究旨在探讨野生型p53基因能否实现对肝癌细胞多药耐药的逆转以及逆转的相关机制。方法：构建野生型P53蛋白表达序列的真核表达载体pCR3．1-p53,用脂质体转染技术建立人肝癌细胞Bel-7402的p53转染细胞株,对转染细胞株进行MTT实验,观察p53基因对肿瘤细胞生长的抑制作用和对肝癌细胞对长春新碱（vincristine,VCR）药物敏感性的影响,姬姆萨染色法观察细胞形态,免疫组织化学SP法检测细胞P糖蛋白（P—glycoprotein,P—gp）的表达,逆转录PCR法检测细胞内mdr1、MRP、GSTπ、TopoⅡ mRNA的表达。结果：转染p53的Bel—p53细胞生长明显慢于未转染的Bel-7402细胞。转染野生型p53的Bel-p53细胞在VCR浓度为0．01μg／ml,0．1μg／ml,1．0μg／ml,10μg／ml,25μg／ml时,其药物敏感性增加;VCR作用最佳浓度为1．0μg／ml。形态学检查转染细胞,在VCR作用下细胞数明显减少,细胞散在不成片、细胞高度水肿、胞体不规则突起,可见核固缩、核裂解、核溶解。p53基因对Bel-7402细胞的mdr1／P—gP的表达有明显的抑制作用．对TopoⅡα基因的表达有上调作用,对GSTπ、MRP基因表达没有影响。结论：p53基因对肝癌细胞多药耐药有逆转作用．其逆转机制可能与降低mdr1／P—gp的表达、上调TopoⅡα的表达．从而增加细胞内VCR药物浓度和VCR药效有关。     

阿霉素诱导人肝癌细胞多药耐药株的建立及其生物学特性评价

背景与目的:多药耐药(multidrugresistance,MDR)是肿瘤治疗的主要障碍,为探讨体外逆转肿瘤MDR的新方法,本研究建立人肝癌细胞多药耐药模型HepG2/Adm,并研究其生物学特性。方法:以人肝癌细胞株HepG2为研究对象,用阿霉素(adriamycin,ADM)浓度梯度递增诱导法,建立HepG2/Adm。观察细胞的生长规律;用MTT法检测多药耐药性;流式细胞术检测细胞周期分布、细胞表面多药耐药基因(mdr1)的表达产物P-糖蛋白(P-glycoprotein,P-gp)、多药耐药相关蛋白(multidrugresistance-associatedprotein,MRP)、肺耐药蛋白(lung-relatedprotein,LRP)及谷胱甘肽S-转移酶(glutathioneS-transferase,GST)的表达;逆转录PCR半定量检测4种MDR基因mRNA表达量。结果:与HepG2细胞比较,HepG2/Adm细胞倍增时间延长30.01h,S期细胞减少(5.6±0.03)%,G1、G2期细胞增多犤(4.2±0.09)%,(1.5±0.08)%犦。该细胞对多种抗肿瘤药物耐药,HepG2/Adm对阿霉素的耐药指数是亲本细胞的26倍,细胞表面多药耐药蛋白P-gp、MRP及GST的表达显著增加,LRP表达有一定的增加;上述四种耐药蛋白基因的表达均明显增加。结论:HepG2/Adm细胞具有多药耐药特性,其耐药性与P-gp、MRP及GST的过表达有关。     

载体介导的RNA干扰技术抑制肝癌耐药细胞MDR1表达的研究

目的 :构建含多药耐药基因MDR1的短发夹状RNA(shorthairpinRNA ,shRNA)表达质粒 ,观察对肝癌耐药细胞Bel 740 2 /R的MDR1mRNA的抑制作用。方法 :利用分子克隆技术 ,将含MDR1的双链DNA ,与经双酶切后的载体PGE 1连接 ,构建pshRNA MDR1重组质粒 ,在脂质体的介导下转染肝癌耐药细胞株Bel 740 2 /R ;RT PCR分析MDR1mRNA的表达 ,MTT法检测细胞对药物的敏感性 ,流式细胞仪检测细胞内罗丹明 12 3 (Rh12 3 )的潴留和P gp的表达。结果 :PCR和DNA测序证实了表达质粒构建成功 ,并能明显地抑制MDR1mRNA的表达 ;对盐酸表柔比星和顺铂的半数抑制浓度IC50明显降低 ,P <0 0 5 ;P gp的表达阳性率降低了 5 7 3 % ;细胞内Rh12 3的浓度显著增高 ,P <0 0 5。结论 :构建的pshRNA MDR1表达质粒能有效地降低肝癌耐药细胞MDR1mRNA和P gp的表达。     

切割MDR1 RNA的核酶(Ribozyme)对肝癌多药耐药细胞株BEL-7402/DOX化疗耐药性的逆转作用

为逆转肿瘤多药耐药基因(MDR1)产物P-gp蛋白所介导的肿瘤细胞对多种化疗药物的耐受性,设计合成了一种能切割MDR1 mRNA第196密码子GUC序列的锤头状核酶(Ribozlyme)并定向克隆于转录病毒载体pDOR-neo的BamH Ⅰ位点.经病毒包装细胞PA317包装后感染人肝癌多药耐药细胞株BEL-7402/DOX细胞,经G418筛选得到稳定的转化细胞株.Northem Blot杂交证实包装细胞PA317及转化的BEL-7402/DOX细胞中均有病毒的高表达,RT-PCR证实转化细胞中MDR1 mRNA与未转化细胞相比明显减少甚至不能扩增出来,流式细胞技术检测转化细胞P-gp的表达与非转化细胞的93.4～97.5%相比下降至8.2～14.6%.MTT法检测证实转化细胞对多种化疗药物重新产生较高的敏感性.结果表明,表达Ribozyme的逆转录病毒载体转化肝癌多药耐药细胞BEL-7402/DOX后能有效抑制MDR1的表达和翻译,使已产生耐药的肿瘤细胞的多药耐药表型发生逆转.     

shRNA逆转耐阿霉素人乳腺癌细胞株（MCF-7/AdrR）的多药耐药性

目的〖HT5"SS〗： 利用短发夹RNA（short hairpin RNA,shRNA）表达载体逆转耐阿霉素人乳腺癌细胞株(MCF7/AdrR)的多药耐药性（multidrug resistance,MDR）。〖HT5W〗方法〖HT5"SS〗： 构建2个MDR1基因shRNA表达质粒,稳定转染MCF7/AdrR细胞。RTPCR分析MDR1基因mRNA的表达,Western blotting检测P糖蛋白(Pgp)的表达,流式细胞术和MTT法分别检测乳腺癌细胞的凋亡和对阿霉素的敏感     

MDR1短发夹RNA表达质粒的构建及其功能的初步研究

目的构建在哺乳动物细胞中表达MDR1短发夹RNA(short hairpin RNA,shRNA)的表达质粒,并初步探讨其对耐药肝癌细胞MDR1 mRNA的抑制作用及抗肿瘤药物耐药性的影响.方法根据Genbank中MDR1 mRNA设计的两条多聚核苷酸序列,退火形成双链DNA,再与经双酶切后的载体PGE-1连接,构建pshRNA-MDR1重组质粒,在脂质体的介导下转染肝癌细胞株BEL-7402/ADM,RT-PCR分析MDR1 mRNA的表达,MTT法检测阿霉素对细胞的半数抑制浓度(IC50).结果PCR和DNA测序证实了表达质粒构建成功,并能明显地抑制BEL-7402/ADM MDR1 mRNA的表达,对阿霉素的耐药指数降低了17.5倍(299.2/17.1).结论构建的pshRNA-MDR1表达质粒能有效地抑制转染细胞MDR1 mRNA,从而提高肿瘤细胞的药物敏感性.     

23,24-二氢葫芦素B抑制Nrf2-ARE通路逆转肝癌耐药的实验研究

目的探讨23,24-二氢葫芦素B(DHCB)抑制核因子E2相关因子2(Nrf2)/抗氧化反应元件(ARE)通路逆转肝癌细胞耐药的作用机制。方法采用阿霉素(ADM)浓度梯度递增法建立肝癌耐药细胞株Bel-7402/ADM,分为空白对照组、ADM组、DHCB组、ADM+DHCB组、DHCB+TBHQ组和DHCB+N-乙酰基-L-半胱氨酸(NAC)组。MTT法和平板克隆实验检测DHCB对Bel-7402/ADM细胞增殖活性的抑制作用;流式细胞术检测DHCB对Bel-7402/ADM细胞活性氧(ROS)含量和细胞凋亡。Western blotting法检测DHCB对Bel-7402/ADM细胞中Nrf2、醌氧化还原酶1(NQO1)、谷胱甘肽S转移酶-π(GST-π)、多药耐药相关蛋白1(MRP1)、cleaved caspase-3蛋白表达的影响。结果Bel-7402/ADM细胞对ADM的耐药指数RI为6.56;而经DHCB(4μmol/L)协同作用后,Bel-7402/ADM细胞对ADM的耐药指数RI为2.21。与空白对照组比较,ADM+DHCB组细胞克隆形成率明显降低(P<0.05);MRP1、Nrf2、NQO1和GST-π蛋白表达量下调,cleaved caspase-3蛋白表达量升高(P<0.05)。与Nrf2激活剂TBHQ合用后,DHCB抑制Nrf2/ARE通路的作用被逆转。与空白对照组比较,DHCB可上调Bel-7402/ADM细胞ROS表达水平;与DHCB组比较,DHCB+NAC组细胞ROS表达水平降低。DHCB可明显促进Bel-7402/ADM细胞凋亡。结论DHCB可增强Bel-7402/ADM细胞对ADM的敏感性,其作用机制可能为抑制Nrf2/ARE信号通路,进而促进肿瘤细胞发生氧化应激损伤,诱导细胞凋亡。     

mdr-1特异性核酶逆转卵巢癌的多药耐药

目的：探讨卵巢癌多药耐药的机制及应用核酶对阿霉素(ADM)引起的多药耐药(MDR)的逆转。方法应用共聚焦激光显微镜(confocal)、逆转录聚合酶链反应(RT-PCR)、蛋白免疫印迹法(Western blot)等检测卵巢癌细胞株A2780及阿霉素耐药株A2780／ADM多药耐药基因(mdr-1)及其编码的p-糖蛋白(p-gp)的表达,并比较导入mdr-1特异性核酶后A2780／ADM细胞MDR表型的改变。结果：A2780／ADM细胞对ADM的耐药性是A2780细胞的8．43倍。A2780／ADM细胞中mdr-1基因和p-gp表达较A2780细胞增高,转染mdr-1核酶基因后,A2780／ADM细胞的mdr-1 mRNA和p-gp表达明显下降。结论:ADM所致的卵巢癌细胞MDR与mdr-1基因过度表达有关,应用mdr-1核酶能在一定程度上逆转A2780／ADM细胞的MDR。     

Comparison of the multi-drug resistant human hepatocellular carcinoma cell line Bel-7402/ADM model established by three methods

Background

To compare the biological characteristics of three types of human hepatocellular carcinoma multi-drug resistant cell sub-lines Bel-7402/ADM models established by three methods.

Methods

Established human hepatocellular carcinoma adriamycin (ADM) multi-drug resistant cell sub-lines models Bel-7402/ADM_V, Bel-7402/ADM_L and Bel-7402/ADM_S by three methods of in vitro concentration gradient increased induction, nude mice liver-implanted induction and subcutaneous-implanted induction respectively. Phase contrast microscopy was used to observe the cells and the MTT (methyl thiazolyl tetrazolium) method was used to detect drug resistance of the three different sub-lines of cells.

Results

The three groups of drug resistant cells, Bel-7402/ADM_V, Bel-7402/ADM_L and Bel-7402/ADM_S generated cross-resistance to ADM and CDDP (cis-Diaminedichloroplatinum), but showed a significant difference in resistance to Bel-7402 IC₅₀ value (P < 0.01). The doubling times were significantly extended compared to the parent cell line (39 h) and were 65 h (Bel-7402/ADM_V), 46 h (Bel-7402/ADM_L), and 45 h (Bel-7402/ADM_S). The excretion rates of ADM were significantly increased compared with the parent cell (34.14%) line and were 81.06% (Bel-7402/ADM_V), 66.56% (Bel-7402/ADM_L) and 61.56% (Bel-7402/ADM_S). Expression of P-gp and MRP in the three groups of resistant cells was significantly enhanced (P < 0.01). There was no significant variation in the expression of GSH/GST (P > 0.05).

Conclusions

Stable resistance was involved in the resistant cell line model established by the above three methods. Liver implantation was a good simulation of human hepatocellular and proved to be an ideal model with characteristics similar to human hepatocellular biology and the pharmacokinetics of anticancer drugs.     

Motesanib inhibits Kit mutations associated with gastrointestinal stromal tumors

Background

To compare the biological characteristics of three types of human hepatocellular carcinoma multi-drug resistant cell sub-lines Bel-7402/ADM models established by three methods.

Methods

Established human hepatocellular carcinoma adriamycin (ADM) multi-drug resistant cell sub-lines models Bel-7402/ADM_V, Bel-7402/ADM_L and Bel-7402/ADM_S by three methods of in vitro concentration gradient increased induction, nude mice liver-implanted induction and subcutaneous-implanted induction respectively. Phase contrast microscopy was used to observe the cells and the MTT (methyl thiazolyl tetrazolium) method was used to detect drug resistance of the three different sub-lines of cells.

Results

The three groups of drug resistant cells, Bel-7402/ADM_V, Bel-7402/ADM_L and Bel-7402/ADM_S generated cross-resistance to ADM and CDDP (cis-Diaminedichloroplatinum), but showed a significant difference in resistance to Bel-7402 IC₅₀ value (P < 0.01). The doubling times were significantly extended compared to the parent cell line (39 h) and were 65 h (Bel-7402/ADM_V), 46 h (Bel-7402/ADM_L), and 45 h (Bel-7402/ADM_S). The excretion rates of ADM were significantly increased compared with the parent cell (34.14%) line and were 81.06% (Bel-7402/ADM_V), 66.56% (Bel-7402/ADM_L) and 61.56% (Bel-7402/ADM_S). Expression of P-gp and MRP in the three groups of resistant cells was significantly enhanced (P < 0.01). There was no significant variation in the expression of GSH/GST (P > 0.05).

Conclusions

Stable resistance was involved in the resistant cell line model established by the above three methods. Liver implantation was a good simulation of human hepatocellular and proved to be an ideal model with characteristics similar to human hepatocellular biology and the pharmacokinetics of anticancer drugs.     

丙戊酸钠对人肝癌细胞株Bel-7402增殖及VEGF、bFGF表达的影响

目的 探讨丙戊酸钠(sodium valproate,VPA)对人肝癌Bel-7402细胞的增殖抑制作用及其机制.方法 采用MTr比色法检测VPA对Bel-7402细胞增殖的抑制作用;应用流式细胞术(FCM)检测药物作用细胞后细胞凋亡率的变化;通过RT-PCR技术和Western Blot方法检测药物作用细胞后血管内皮生长因子(vascular endothelial growth factor,VEGF)和碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)在mRNA和蛋白水平表达量的改变.结果 VPA对Bel-7402细胞的生长抑制作用呈现时间和剂量依赖性;经0、1、2和4 mmol/L VPA作用细胞72小时后,细胞的凋亡率由处理前的(2.78±0.32)％,上升为(8.79±0.53)％、(18.65±1.02)％和(36.41±1.93)％,RT-PCR和Weatem Blot技术发现VPA作用细胞72小时后,可明显降低VEGF和bFGF的表达,并呈浓度依赖性(P＜0.05).结论 VPA通过下调Bci-7402细胞VEGF和bFGF的表达,对Bel-7402细胞的增殖起抑制作用.     

Reversing Multidrug-Resistant by RNA Interference Through Silencing MDR1 Gene in Human Hepatocellular Carcinoma Cells Subline Bel-7402/ADM

Multidrug resistance (MDR) in hepatocellular carcinoma (HC) significantly impedes the effect of chemotherapy and is considered as a primary reason leading to its recurrences and metastasis. The aim of present study was to explore new molecular targets for the reversal of MDR in HC by screening the adriamycin (ADM)-induced, human MDR-resistant HC cell subline Bel-7402/ADM. Small interfering RNAs (siRNAs) of four (MDR1si326, MDR1si1513, MDR1si2631 and MDR1si3071) targeting MDR1 were designed and transfected into Bel-7402/ADM cell strains. The experiments involved the following: mRNA expression of MDR1 gene by RT-PCR, P-glycoprotein (P-gp) expression by Western blot, intracellular ADM accumulation flow cytometry, and IC₅₀ of ADM by a cytotoxic MTT assay. Four siRNAs reversed MDR in HC mediated by MDR1 to varying degrees. The expression level of MDR1 mRNA in cells of MDR1si326 or MDR1si2631 group (0.190?±?0.038 or 0.171?±?0.011) was more decreased. The expression level of P-gp in cells of MDR1si326 group was the lowest. The accumulation of ADM in cells of MDR1si326 or MDR1si2631 group (77.0?±?3.5 or 75.4?±?2.9) was more increased. The IC₅₀ of cells to ADM was lowest in MDR1si326 group (11.32?±?0.69 mg/L). Compared with other three siRNAs, MDR1si326 performed the optimal reversal effect of drug resistance in human HC Bel-7402/ADM.     

The study of innate drug resistance of human hepatocellular carcinoma Bel7402 cell line

The innate drug resistance of human hepatocellular carcinoma (HCC) Bel7402 cell line was studied in vitro. MTT assay showed that Bel7402 cells were innately resistant to doxorubicin (Dox), and even more resistant to vincristine (VCR). This resistance could be effectively reversed by verapamil (Ver), one of the classical multidrug resistance (MDR) modulating agents. However, the differences in 5-fluorouracil (5-FU) toxicity between these two cell lines is much less and the resistance of Bel7402 cells could only be slightly reversed by Ver, which may be experimental noise. Immunocytochemical staining using anti-p-glycoprotein monoclonal antibody JSB-1 indicated that the expression of the P-glycoprotein (P-gp) in the innate Bel7402 cells was elevated compared with the sensitive KB cells. The accumulation of Dox in innate resistant Bel7402 cells was 50.7% lower than that in sensitive KB cells by using spectrofluometric analyses, and the accumulation of Dox increased 1.6 fold in Bel7402 cells in the presence of Ver. The susceptibility of Dox-induced apoptosis was also increased in the presence of Ver by using flow cytometric assay and DNA fragmentation quantitative assay as well as by Hoechst 33258 staining. It appears that the innate Bel7402 cells might be useful in screening new antitumour drugs or new chemosensitisers which could overcome the innate or acquired resistant mechanism, and the toxicity and reversal effects with 5-FU are different from those known to be P-gp substrates such as VCR, Dox, and taxol.     

MDR 逆转因子筛选技术P-gp 细胞系的建立及其生物学特性评价

 目的 通过基因转导和药物诱导，建立稳定表达P—gp的细胞系，用于筛选特异性逆转P-gp的药物。方法 经RT-PCR反应得到小鼠肿瘤细胞P-gp DNA，转化大肠杆茵，构建并将质粒DNA转导逆转录病毒载体中，进而感染B-MD-C1细胞。采用Northern印迹法和流式细胞技术检测细胞P-gp mRNA和P-gp分子的表达；以MTT法分析细胞的增殖活性；应用药物聚集和排放实验检测其生物学活性。结果 成功构建了稳定表达特异性P-gp基因和P-gP分子的B-MD-C1(ADR+／+)细胞系。经阿霉素诱导，B-MD-C1(ADR+／+)细胞P-gp的表达明显增高，在阿霉素增加至12000ng／mL时，仍有80％的细胞保持良好增殖状态，而B-MD-C1(wt)细胞在1000ng／mL时100％细胞死亡。B-MD-C1(ADR+／+)较(wt)细胞对MI>123有较低的聚集量和较高的排放量，加入P—gP逆转剂Verapamil后，B-MD-C1(ADR+／+)细胞MD-123聚集量增加，药物外排作用消失。结论 B-MD-C1(ADR+／+)细胞系具有较强的药物耐受性，可用于筛选特异性逆转P-gp的药物，Verapamil可逆转P—gP耐药性，具有Verapamil特性者可视为具有逆转P—gp耐药性。