circBMPR2通过靶向miRNA-20a/smac轴促进人卵巢癌耐药细胞SKOV-3/Taxol的凋亡

背景与目的 卵巢癌是育龄期女性常见的恶性肿瘤,多数患者就诊时已为中晚期,导致临床手术成功率和预后较差,化疗耐药是卵巢癌患者不良预后的主要原因.研究报道非编码基因circBMPR2与卵巢癌的化疗耐药密切相关,且对化疗药物介导的细胞凋发挥重要调控作用.本研究探讨circBMPR2是否通过靶向抑制miRNA-20a,进而上调...     

应用表达谱芯片筛选卵巢癌紫杉醇耐药差异表达基因

目的 应用表达谱芯片研究人卵巢癌紫杉醇耐药细胞株SKOV3/TAX300及SKOV3/TAX30与敏感细胞SKOV3之间的基因表达谱差异,筛选耐药相关基因.方法 分别提取细胞的总RNA并纯化mRNA,mRNA逆转录合成cDNA后,用Cy5和Cy3-dUTP标记,与基因芯片进行杂交反应,扫描芯片荧光信号图像,用基因图像分析软件对扫描图像进行数字化处理和分析.采用荧光定量PCR、RT-PCR验证差异表达基因TNC mRNA和MDR1 mRNA水平,Western blot法验证TNC和MDR1蛋白表达.结果 SKOV3/TAX300细胞与敏感细胞SKOV3筛选出202个差异基因,其中上调基因88个,下调基因114个;SKOV3/TAX30细胞与SKOV3敏感细胞筛选出358个差异基因,其中上调基因144个,下调基因214个.这些基因主要包括细胞外基质、细胞信号传递、细胞周期、细胞凋亡、药物代谢等方面.其中细胞外基质成分TNC在两种耐药细胞中均为明显上调.荧光定量PCR、RT-PCR检测TNC mRNA和MDR1 mRNA水平,Western blot验证TNC和MDR1的表达,结果均与芯片结果一致.结论 本研究筛选出的基因可能为进一步探讨卵巢癌肿瘤细胞耐药机制提供新的途径,细胞外基质成分TNC可能是紫杉醇耐药的相关基因.     

卵巢癌中紫杉醇耐药机制与克服耐药策略的研究进展

化疗耐药是卵巢癌复发的主要原因,严重影响患者的预后。紫杉醇是卵巢癌化疗的一线用药之一,因此,有关紫杉醇耐药的机制和克服耐药的策略得到了广泛而深入的研究。本文简要介绍了近年来有关紫杉醇耐药和克服耐药策略的研究进展。     

卵巢癌紫杉醇耐药机制的研究进展

紫杉醇是美国北卡罗莱纳州三角研究所的Wall博士和Wani博士于1967年发现的。他们从太平洋红豆杉中分离出了这种化合物并发现它具有广泛的抗恶性肿瘤作用。紫杉醇分子是一个极其复杂的四环二萜类化合物,它是继长春新碱之后又一类具有新作用机制、抗微管解聚的细胞毒类药物。1992年经FDA批准紫杉醇作为治疗卵巢癌的新药应用于临床,随后又批准用于治疗乳腺癌。     

卵巢癌紫杉醇耐药机制的研究进展

紫杉醇是美国北卡罗莱纳州三角研究所的Wall博士和Wani博士于1967年发现的。他们从太平洋红豆杉中分离出了这种化合物并发现它具有广泛的抗恶性肿瘤作用。紫杉醇分子是一个极其复杂的四环二萜类化合物,它是继长春新碱之后又一类具有新作用机制、抗微管解聚的细胞毒类药物。1992     

卵巢癌多细胞球体对紫杉醇耐药及其机制的探讨

背景和目的:多细胞球体(multicellularspheroids,MCS)对传统细胞毒化疗药物的敏感性明显低于单层细胞。本实验旨在探讨卵巢癌MCS耐药的分子机制。方法:以单层细胞为对照,以三维培养方法获得的人卵巢癌A2780MSC和CAOV3MCS为模型,采用台盼蓝拒染法比较紫杉醇对单层细胞和MCS生长的抑制作用,流式细胞仪比较单层细胞和MCS细胞周期的分布和细胞凋亡率;采用流式细胞仪、蛋白质免疫印迹法、激光共聚焦显微镜检测单层细胞及MCS的P-糖蛋白(P-glycoprotein,P-gp)表达及亚细胞分布;采用RT-PCR法检测mdr1mRNA表达水平。结果:(1)不同浓度的紫杉醇(0.2、2.0、10.0、20.0μmol/L)作用后,MCS细胞生长抑制率明显低于单层细胞(PA2780=0.003,PCAOV3=0.015);经20.0μmol/L的紫杉醇作用后,单层细胞的细胞凋亡率明显高于MCS,差异有统计学意义(PA2780=0.034,PCAOV3=0.032)。(2)流式细胞仪、蛋白质免疫印迹法、激光共聚焦显微镜检测提示P-gp在单层细胞中不表达,在MCS中表达明显升高(P均<0.05);RT-PCR证实MCS中有mdr1mRNA表达,而单层细胞中未检出其表达。(3)流式细胞仪检测提示将单层细胞培养成MCS时,G0/G1期细胞比率增加,S期和G2/M期细胞比率降低(P均<0.05)。结论:卵巢癌MCS对紫杉醇化疗耐药性增加,其高表达P-gp,并且与G0/G1期细     

乳腺癌耐阿霉素细胞MCF-7/ADR外泌体传递tTG参与MCF-7细胞耐药的研究

目的:研究乳腺癌耐阿霉素细胞MCF-7/ADR通过外泌体传递tTG参与敏感细胞MCF-7耐药的过程。方法:本实验首先培养MCF-7、MCF-7/ADR细胞,然后检测MCF-7、MCF-7/ADR细胞中外泌体的含量,并将外泌体提取后备用。MCF-7/ADR细胞外泌体(EXO/ADR)与MCF-7细胞共培养建立MCF-7的外泌体耐药细胞(MCF-7+EXO/ADR)。使用Western blot法检测MCF-7、MCF-7/ADR、MCF-7+EXO/ADR细胞中的tTG蛋白的表达水平,使用流式细胞术分别检测敏感细胞株外泌体(EXO/S)、耐药细胞株外泌体(EXO/ADR)中tTG的表达水平。使用CCK-8法分别检测MCF-7、MCF-7/ADR、MCF-7+EXO/ADR细胞对阿霉素的敏感性情况。结果:实验结果显示,在EXO/S、EXO/ADR中均可以表达CD63、TSG101,但是较低表达Calnexin。经过流式细胞术检测发现,EXO/S、EXO/ADR中的tTG表达水平分别为(18.3±3.63)%、(46.07±8.31)%,二者tTG的表达有明显差异。经过Western blo...     

紫杉醇耐药卵巢癌细胞系的建立及耐药机制研究

目的建立人卵巢癌紫杉醇耐药细胞株,探讨其耐药机制。方法采用梯度浓度递增法诱导建立对紫杉醇（Paclitaxel,TAX）耐药的人卵巢癌细胞耐药株SKOV3／TAX,MTF法检测SKOV3／TAX对SKOV3的耐药指数（resistanceindex,RI）,WesternBlot法检测耐药细胞中凋亡及耐药相关蛋白多聚ADP核糖聚合酶（polyADP．ribosepolymerase,PARP）的表达情况,探讨其耐药机制。结果成功建立人卵巢癌耐紫杉醇细胞株SKOV3/TAX,耐药指数高达88．46;与SKOV3相比,紫杉醇耐药细胞株形态较不规则,细胞扁平,且贴壁较牢;WesternBlot及免疫荧光实验均证实SKOVMTAX中PARP水平明显下调,且加用TAX后PARP的剪切带较亲本细胞明显减少甚至缺失。结论紫杉醇耐药卵巢癌细胞中PARP蛋白表达明显下调,该下调很可能参与了卵巢癌对紫杉醇的耐药调控。     

蛋白激酶C激活剂及抑制剂对紫杉醇耐药的卵巢癌细胞中P-糖蛋白表达及功能的影响

目的:探讨PKC(protein kinase C)激活剂及抑制剂对紫杉醇诱导的卵巢癌耐药细胞系A2780/Taxol中P-gp(P-glyco-protein)的表达及功能的影响。方法:免疫细胞化学SP法检测P-gp和PKC-α在耐药细胞A2780/Taxol及其亲本细胞中的表达;Western Blot检测PKC激动剂佛波脂(PMA)和抑制剂十字孢碱(SP)作用后P-gp在2种细胞上的表达水平;以罗丹明123(Rohdamin123,R123)作为荧光探针用流式细胞仪检测PMA及SP对细胞膜P-gp功能的影响。结果:P-gp在耐药细胞A2780/Taxol中呈阳性表达,在亲本细胞中不表达;PMA处理细胞,细胞内R123的平均荧光强度明显减低,Pgp的功能增强而表达量无明显变化;SP处理细胞,细胞内R123的平均荧光强度明显增加,Pgp的功能减弱而表达也无明显减少。结论:PKC通过对P-gp功能的调节而参与卵巢癌紫杉醇耐药的形成。     

AKT2通过调控p27表达逆转卵巢癌顺铂耐药

目的：探讨上皮性卵巢癌中蛋白激酶B beta（v-akt murine thymoma viral oncogene homolog2，AKT2）与p27在卵巢癌多细胞球体顺铂耐药中的作用。方法：三维培养获得人卵巢癌多细胞球体（multi—cellular spheroids，MCS）；Western印迹法分析p27及AKT2表达；构建AKT2干扰载体，脂质体法转染A2780细胞后三维培养形成多细胞球体，不同浓度顺铂处理后通过FCM法检测细胞凋亡，MTT法比较细胞对顺铂的敏感性。结果：Western印迹法结果提示，MCS中AKT2及p27的表达高于单层细胞；转染AKT2干扰载体（shRNA—AKT2）的MCS中AKT2、p27表达量较未转染MCS及转染空载体的MCS明显降低。流式细胞仪分解结果表示，不同浓度顺铂作用后，MCS凋亡率明显低于单层细胞；转染shRNA—AKT2的细胞球凋亡率较未转染MCS及转染空载体的MCS升高。MTT法示瞬时转染shRNA—AKT2的细胞球顺铂对细胞抑制率较未转染MCS及转染空载体的MCS升高。结论：干扰AKT2可降低p27的表达，从而逆转卵巢癌对顺铂的化疗耐药。     

Induction of p53 and drug resistance following treatment with cisplatin or paclitaxel in ovarian cancer cell lines

Treatment failures result from resistance to chemotherapy in ovarian cancer. The effect of cisplatin and paclitaxel treatments on chemosensitivity was studied in ovarian cancer cells developed from a patient with stage IIIC disease. Cells (UL-3A, UL-3B) that recovered from cisplatin (Cis) and paclitaxel (Tax) treatments showed higher levels of p53, mdr-1 and chemoresistance than untreated controls. EC50 values of Cis and Tax for UL-3A clones were 7.2-34.6, average 20.9 microg/ml, while UL-3B clones ranged from 11.8-252.0 microg/ml, with a mean value of 73.2 microg/ml for Cis, and 260.0-4400.0 nM (mean 2555.0 nM) for Tax. Selection pressures during treatment may contribute to drug resistance.     

microRNA在乳腺癌耐药中的作用

乳腺癌是危害全球女性健康的主要疾病,而乳腺癌患者对现有治疗方法产生获得性耐药成为目前乳腺癌临床治疗所面临的难题.微小RNA (miRNA)是一种内源性的非编码RNA,它参与调控多种生物学过程,包括细胞增殖、侵袭、转移、上皮间质转化和耐药等.获得性耐药包含多种复杂机制,可通过特定miRNA的异常表达影响细胞相关蛋白的表达、抗肿瘤药物与相应靶点的结合以及凋亡相关途径引起乳腺癌耐药.本文将重点关注在乳腺癌内分泌治疗、化疗、分子靶向治疗发生获得性耐药中表达异常的miRNA.相信miRNA能够成为乳腺癌临床诊断与治疗以及对抗获得性耐药的生物标志物和新的治疗靶点.     

乳腺癌耐药机制研究进展和应对策略

乳腺癌是女性最常见的恶性肿瘤之一,其分型的多样性与临床治疗密切相关。近年来随着分子生物学的快速发展,乳腺癌的治疗进展迅速,效果显著,但治疗方案产生的耐药仍是临床一线治疗最常遇到的问题。本文就不同类型的乳腺癌及其临床特征进行了分类分析,针对不同分型的治疗方案和耐药机制进行了总结和探讨,旨在通过研究治疗的分子机制和可能存在的耐药机制,对临床治疗起到引导作用。     

circRNAs in drug resistance of breast cancer

Breast cancer (BC) is the most common heterogeneous disease in women and one of the leading causes ofcancer-related death. Surgery, chemotherapy, radiotherapy, hormone, and targeted therapy are the gold standards forBC treatment. One of the significant challenges during the treatment of BC represents resistance tochemotherapeutics, resistance that severely limits the use and effectiveness of the drugs used for BC treatment.Therefore, it is essential to develop new strategies to improve therapeutic efficacy. Circular RNAs (circRNAs) are alarge group of non-coding RNAs that covalently form closed circular loops by joining their 5′, and 3′; ends.Accumulating evidence suggests that circRNAs have a vital role in cancer development, progression, and BCresistance to chemotherapy. The purpose of this review is to discuss the biological properties of circRNAs, and howcircRNAs induce resistance to conventional therapeutic anti-cancer drugs used in BC treatment, by emphasizing andsummarizing the potential roles of circRNAs in mechanisms of drug resistance, such as drug efflux, apoptosisdysfunction, autophagy, and DNA damage repair. CircRNAs are associated with drug resistance via ATP-bindingcassette (ABC) efflux transporters, while some others by inhibition of cell apoptosis, thus leading to resistance totamoxifen in BC cells. In contrast, others are involved in the promotion of BC cells chemoresistance by doxorubicininduced autophagy. CircRNAs may have clinical significance in regulating or overcoming BC drug resistance and maygive directions towards a novel approach to personalized BC treatment. CircRNAs may significantly contribute to theidentification of new therapeutic targets for the prevention of BC chemoresistance.     

Cyclin A1 expression and paclitaxel resistance in human ovarian cancer cells

BackgroundThe development of intrinsic and acquired resistance to antineoplastic agents is a major obstacle to successful chemotherapy in ovarian cancers. Identification and characterisation of chemoresponse-associated biomarkers are of paramount importance for novel therapeutic development.MethodsGlobal RNA expression profiles were obtained by high-throughput microarray analysis. Cell cycle, proliferation rate, and paclitaxel sensitivity of ovarian cancer cells harbouring cyclin A1-inducible expression construct were compared with and without tetracycline induction, as well as when the cyclin A1 expression was suppressed by short inhibiting RNA (siRNA). Cellular senescence was evaluated by β-galactosidase activity staining.ResultsGlobal RNA expression profiling and subsequent correlation studies of gene expression level and drug response has identified that elevated expression of cyclin A1 (CCNA1) was significantly associated with cellular resistance to paclitaxel, doxorubicin and 5-fluorouracil. The role of cyclin A1 in paclitaxel resistance was confirmed in ovarian cancer cells that harbour an inducible cyclin A1 expression construct, which showed reduced paclitaxel-mediated growth inhibition and apoptosis when cyclin A1 expression was induced, whereas downregulation of cyclin A1 expression in the same cell lines using cyclin A1-specific siRNAs sensitised the cells to paclitaxel toxicity. However, ovarian cancer cells with ectopic expression of cyclin A1 demonstrated slowdown of proliferation and senescence-associated β-galactosidase activity.ConclusionsOur profiling and correlation studies have identified cyclin A1 as one chemoresistance-associated biomarker in ovarian cancer. The results of the characterisation studies suggest that cyclin A1 functions as an oncogene that controls proliferative and survival activities in tumourigenesis and chemoresistance of ovarian cancer.     

微小RNA-451在乳腺癌细胞中的表达及其与耐药的关系

目的:研究人类微小RNA-451(Homo sapiens micro RNA-451,hsa-miR-451)在乳腺癌细胞中的表达及其与多柔比星(adriamycin,ADM)耐药的关系。方法:用实时荧光定量PCR一步法检测乳腺癌亲本细胞MCF-7和耐ADM细胞MCF-7/ADM中hsa-miR-451的表达;利用脂质体分别将成熟miR-451的模拟物(mimics)及阴性对照转染MCF-7/ADM细胞,然后采用实时荧光定量PCR法检测细胞中多药耐药基因1(multi-drug resistance gene 1,MDR1)mRNA的表达,蛋白质印迹法检测细胞中P-糖蛋白(P-glycoprotein,P-gp)的表达,MTT法检测不同浓度ADM作用下的细胞增殖情况。结果:miR-451在MCF-7/ADM耐药细胞中低表达,与亲本细胞MCF-7相比明显降低(P<0.05)。MCF-7/ADM细胞转染miR-451mimics后,MDR1 mRNA和P-gp蛋白的相对表达量比阴性对照转染组均明显下降(P<0.05);而miR-451 mimics转染组细胞对ADM的敏感性增加,其半数抑制浓度(half inhibition concentration,IC50)值与阴性对照转染组细胞相比差异有统计学意义(P<0.05)。结论:在乳腺癌耐药细胞MCF-7/ADM中miR-451异常低表达,可能通过作用于MDR1/P-gp参与乳腺癌细胞耐药的发生和发展。     

多种耐药基因蛋白在初治乳腺癌中的表达

目的:观察乳腺癌多种常见耐药相关基因蛋白的表达情况,探讨乳腺癌原发性耐药的状态及可能机制。方法:选取术前未行化疗及内分泌治疗的369例乳腺癌标本,采用免疫组化法检测LRP、GST、P190及P170的表达情况,观察上述指标之间以及与肿瘤大小、淋巴结转移的相关性。结果:这些基因蛋白表达的阳性率分别为:LRP57.99%,GST32.79%、P1905.96%和P17038.12%;多基因共表达率为40.10%;LRP与P170之间呈正相关(r=0.1702,P<0.001);4种耐药相关基因蛋白表达与肿瘤大小及淋巴结转移之间均无相关性(P>0.05)。结论:初治乳腺癌中存在多个耐药相关基因蛋白表达及共表达,可能反映了乳腺癌的原发性耐药状态及其复杂的机制。     

Down-regulation of P-glycoprotein expression in MDR breast cancer cell MCF-7/ADR by honokiol

P-glycoprotein accounts for the most intrinsic and acquired cancer multidrug resistance. To inhibit the expression of P-glycoprotein is one of the effective ways to reverse cancer drug resistance. Honokiol, a naturally occurring compound, has been demonstrated to combat cancer through mechanisms including inhibition of angiogenesis and induction of apoptosis. Here, we show that honokiol down-regulated the expression of P-glycoprotein at mRNA and protein levels in MCF-7/ADR, a human breast MDR cancer cell line. The down-regulation of P-glycoprotein was accompanied with a partial recovery of the intracellular drug accumulation, and of the sensitivities toward adriamycin. This study reveals a novel function of honokiol as an anti-cancer agent.     

Short hairpin RNA-mediated MDR1 gene silencing increases apoptosis of human ovarian cancer cell line A2780/taxol

Objective: Recurrent ovarian cancer is often resistant to drugs such as paclitaxel. Short hairpin RNA (shRNA) targeting MDR1, a gene involved in the process of drug resistance, may be a promising strategy to overcome drug resistance. Methods: Construction and identification of eukaryotic expression plasmid of shRNA targeting on MDR1 gene. The plasmid was transiently transfected into human ovarian cancer cell line A2780/Taxol. Apoptosis was determined by flow cytometry using annexin V-FITC/PI double labeling. Expression of MDR1 mRNA was detected by quantitative polymerase chain reaction (qPCR) and P-glycoprotein expression was detected using Western blot. Results: The IC50 of paclitaxel in MDR1 shRNA-transfected group was significantly reduced (1.986±0.153) μmol/ml as compared with that in negative control (5.246±0.107) μmol/ml and empty vector-transfected group (5.212±0.075) μmol/ml (P<0.05). The percent of the relative reverse sensitivity to paclitaxel on A2780/Taxol cells was 67.1%, and the apoptotic rate was significantly increased [(6.977±0.333)%] compared with control [(1.637±0.111)%] and empty vector-transfected group [(1.663±0.114)%] (P<0.05). Expressions of MDR1 mRNA and P-glycoprotein were significantly reduced compared with control (P<0.05). Conclusion: The present study demonstrated that the eukaryotic expression plasmid of shRNA targeting on MDR1 inhibited the expression of MDR1 effectively, thus enhance the sensitivity of A2780/Taxol cells to paclitaxel.     

乳腺癌组织中COX-2与MDR1/P-gp表达的相关性研究

目的:探讨环氧化酶-2(COX-2)蛋白与P糖蛋白(P-gp)在乳腺癌组织中表达的相关性。方法:应用免疫组织化学染色法,检测32例乳腺癌组织中COX-2蛋白与P-gp蛋白的表达情况。结果:32例乳腺癌组织中COX-2表达阳性率为62·5%(20/32),P-gp表达阳性率为46·9%(15/32),两者表达呈正相关性(r=0·598,P<0·05)。结论:乳腺癌组织中COX-2与P-gp表达呈正相关,COX-2可干预P-gp的表达并参与乳腺癌多药耐药(MDR)的调节。