汉防己甲素逆转人肝癌耐药细胞株多药耐药性的研究

目的研究汉防己甲素对人肝癌多药耐药细胞株Hep-3B／ADM耐药性的逆转作用及其机制。方法通过阿霉素（ADM）浓度梯度递增诱导法，建立人肝癌多药耐药细胞株Hep-3B／ADM。MTT法检测细胞对化学疗法药物的敏感性；流式细胞仪检测细胞表面多药耐药基因表达产物P-170及分析细胞内若丹明123染剂相对荧光强度。结果汉防己甲素（0．10～1．00μmol／L）可逆转肝癌耐药细胞的耐药性；汉防己甲素明显降低细胞表面P-170的表达。结论汉防己甲素具有增强阿霉素对Hep-3B／ADM细胞的毒性作用，其作用机制与逆转多药耐药基因有关。     

细胞外基质金属蛋白酶诱导因子在肝癌细胞7721中对多药耐药的调节作用

目的采用2种方法构建人肝癌多药耐药细胞模型,封闭其细胞外基质金属蛋白酶诱导因子(EMMPRIN)(CD147)的表达,研究其生物学特性。探讨EMMPRIN在肝癌细胞中对多药耐药的作用。方法应用人肝癌细胞株7721,采用浓度梯度诱导法和高浓度阿霉素间接诱导法构建人肝癌多药耐药细胞模型(7721/Adm1和7721/Adm2细胞),应用RNAi技术封闭7721/Adm1和7721/Adm2细胞EMMPRIN的表达,构建封闭EMMPRIN的人肝癌多药耐药细胞7721/Adm1/RNAi和7721/Adm2/RNAi细胞。用反转录-聚合酶链反应(RT-PCR)、流式细胞技术检测EMMPRIN、细胞表面多药耐药基因(MDR-1)mRNA及其表达产物的表达水平。噻唑蓝(MTT)法检测上述各细胞的多药耐药性。结果 2种多药耐药模型可用于肝癌多药耐药研究。多药耐药细胞7721/Adm1和7721/Adm2中EMMPRIN,MDR-1的表达水平较7721细胞均升高,且增加了其对多种化疗药物的耐药性。而利用RNAi封闭EMMPRIN的7721/Adm1和7721/Adm2细胞可致MDR-1表达降低,增加了其对化疗药物的敏感性。结论 EMMPRIN是参与肝癌细胞7721多药耐药且为调节多药耐药的重要分子。     

乳腺癌细胞的HER2过表达降低其对紫杉醇的药物敏感性

目的紫杉醇的耐药性由多种因素引起,本文研究乳腺癌细胞中的HER2蛋白水平是否影响细胞对紫杉醇的药物敏感性。方法以HER2低表达的MCF-7/pcDNA3.1细胞和经稳定转染获得的HER2高表达的MCF-7/HER2细胞为研究对象,MTT方法测定紫杉醇对这两种细胞的生长抑制作用,流式细胞仪测定紫杉醇对细胞周期分布的影响,An-nexin V-FITC/PI实验测定紫杉醇诱导的细胞凋亡,两种细胞的裸鼠移植瘤实验测定紫杉醇的抑瘤率。结果紫杉醇对MCF-7/HER2细胞的IC50值是MCF-7/pcDNA3.1细胞的6.2倍;紫杉醇诱导细胞G2/M期阻滞,且是HER2非依赖性的;0.01、0.1和1.0μmol.L-1紫杉醇诱导MCF-7/pcDNA3.1细胞凋亡的百分比分别是15.1%±2.1%、21.0%±2.9%和35.7%±3.8%,诱导MCF-7/HER2细胞凋亡的百分比分别是7.5%±1.7%、14.1%±2.3%和24.2%±3.4%,同一浓度的紫杉醇诱导两细胞的凋亡百分比差异有显著性;5、10和20 mg.kg-1的紫杉醇对裸鼠移植MCF-7/pcDNA3.1肿瘤生长抑制率分别是36.9%、58.7%和75.4%,对裸鼠移植MCF-7/HER2肿瘤生长抑制率分别是20.1%、33.3%和67.3%。在相同剂量下紫杉醇对裸鼠移植的两种肿瘤的抑瘤率差异有显著性。结论HER2蛋白的高表达可降低乳腺癌细胞对紫杉醇的药物敏感性。     

裸鼠人肝癌移植瘤耐药模型的建立

目的 建立裸鼠人肝癌(HCC)移植瘤多药耐药(MDR)模型.方法 体外培养肝癌细胞系HepG2,建立裸鼠的皮下肿瘤.诱导组(12只)用阿霉素(ADM)间歇腹腔注射,诱导建立裸鼠肝癌耐药模型;对照组(4只)腹腔注射等容积的生理盐水.MTT比色法检测耐药细胞的MDR,RT-PCR和流式细胞术检测肿瘤耐药基因MDR1-mRNA和P-糖蛋白(P-gp)的表达,罗丹明试验观察该蛋白功能.结果 移植瘤组织形态及生物学方面符合人肝癌特征.诱导组肝癌细胞MDR1-mRNA和P-gp蛋白的表达均明显高于对照组.诱导组HepGZ对ADM的耐药指数增加了15.6倍.耐药细胞有较强的药物外排功能.结论 成功地建立了与临床肝癌相似的裸鼠肝癌耐药模型.     

一种肝癌多药耐药细胞系的建立及鉴定

目的 建立肝癌细胞系HepG2的多药耐药细胞系HepG2／ADM，为研究肝癌细胞多药耐药创造前提奈件。方法 用0．01～2μg／mL的阿霉素（ADM）分级诱导HepG2细胞的多药耐药性，使其在含高浓度的ADM（2μg／mL）的DMEM培养基中保持90％的存活率，并能正常地传代、冻存和复苏；用MTT法分析ADM、5-氟尿嘧啶（5-Fu）、丝裂霉素（MMC）和氨甲蝶呤（MTX）四种药物在其1Cmax,10Cmax，20Cmax和30Cmax。时分别作用于HepG2和HepG2／ADM时的细胞生长抑制率；用免疫组化法观察细胞膜P-糖蛋白（P—gP）170的表达；用流式细胞仪（FCM）分析细胞膜P—gP170对进入细胞内药物罗丹明-123的泵出效果。结果 HepG2／ADM细胞系表现了较强抗药活性；免疫组化法观察到HepG2／ADM细胞膜有较强P—gP170表达；FCM检测到HepG2／ADM细胞能有效泵出罗丹明-123．而HepG2细胞则不能有效泵出罗丹明一-123。结论 用ADM梯度诱导耐受法成功诱导出了HepG2细胞的多药耐药细胞系HepG2／ADM。     

麻黄碱逆转K562/A02细胞多药耐药性的研究

目的：观察非细胞毒性质量浓度的麻黄碱对耐药的白血病细胞株（KS62／A02）多药耐药性的逆转作用，并探讨其逆转机制。方法：用MTT法检测麻黄碱的细胞毒作用；用流式细胞仪检测非细胞毒性浓度的麻黄碱处理后K562／A02细胞膜表面糖蛋白P170表达及功能的变化。结果：麻黄碱对K562／A02有一定的细胞毒作用，其非细胞质量浓度（IC10）为75mg·L^-1，非细胞毒性质量浓度的麻黄碱对K562／A02细胞对阿霉素的耐药性有部分逆转作用（5．67倍），作用于K562／A02细胞后，细胞膜糖蛋白P170的表达从（85．3±5．5）％下调至（34．8±1．2）％，DNR外渗试验显示，细胞内化疗药物的质量浓度明显增加。结论：麻黄碱通过下调K562／A02细胞膜糖蛋白P170的表达，抑制其将化疗药物“泵”出细胞外的功能，提高化疗药物在K562／A02细胞内的有效质量浓度，能部分逆转K562／A02细胞的多药耐药性。     

半夏水提取液逆转多药耐药细胞系K562/A02耐药性的研究

目的观察非细胞毒性浓度半夏水提取液对耐阿霉素的人白血病细胞系K562/A02多药耐药性的逆转作用,并探讨其逆转机制.方法采用MTT法测定半夏水提取液的细胞毒性及其对K562/A02细胞敏感性的影响,用流式细胞仪检测非细胞毒性浓度的半夏水提取液处理后K562/A02细胞膜表面糖蛋白P170表达的变化.结果半夏水提取液对K562/A02细胞有一定的细胞毒作用,非细胞毒性浓度半夏水提取液可显著降低阿霉素对K562/A02细胞的IC50,显著降低细胞膜糖蛋白P170的表达.结论半夏水提取液可部分逆转多药耐药细胞系K562/A02细胞对阿霉素的耐药性.     

硒化卡拉胶联合阿霉素对HepG-2/ADR细胞的协同抗肿瘤效应及其逆转机制研究

目的 探究硒化卡拉胶(KSC)联合阿霉素(ADR)对肝癌耐药细胞HepG-2/ADR的协同抗肿瘤效应及其逆转作用机制。方法 MTT法分别检测HepG-2/ADR耐药细胞对阿霉素、顺铂(DDP)、紫杉醇(TAX)3种化疗药物的多药耐药性,并判断KSC对HepG-2/ADR耐药细胞的逆转作用;流式细胞术检测KSC和ADR对HepG-2/ADR耐药细胞周期和细胞凋亡的影响;Western blot检测KSC和ADR对HepG-2/ADR细胞中耐药相关蛋白、细胞周期和细胞凋亡蛋白的影响。RT-qPCR进一步验证HepG-2/ADR细胞中耐药相关基因的表达。结果 MTT结果显示,HepG-2/ADR耐药细胞对ADR、TAX、DDP均具有耐药性,且KSC具有逆转肝癌HepG-2/ADR细胞多药耐药性的作用,两药联合表现为相加作用。流式细胞术表明KSC和ADR均可诱导HepG-2/ADR细胞发生凋亡和S期周期阻滞。Western blot结果显示,KSC和ADR显著下调耐药蛋白P-gp、MRP1、ABCG2以及细胞周期蛋白Cyclin A、Cyclin E、CDK2、Survivin和抑凋亡因子Bcl-2的表达(P<0.05或P<0.01),显著上调促凋亡蛋白Bax、Caspase-3、Caspase-9、Cleaved-Caspase-3和Cleaved-Caspase-9的表达(P<0.05或P<0.01);联合组可协同促进或抑制细胞凋亡和细胞周期相关蛋白的表达。RT-qPCR表明KSC和ADR单独及联合均能显著下调P-gp1、MRP1和ABCG2耐药基因的表达。结论 KSC可有效逆转肝癌多药耐药性,协同提高HepG-2/ADR细胞对阿霉素的化疗敏感性,其机制可能与诱导细胞凋亡与细胞周期阻滞有关,通过下调多药耐药相关蛋白P-gp、MDR1和ABCG2的表达,进而逆转肝癌多药耐药性。     

红霉素逆转人肝癌细胞BEL-7402多药耐药性的研究

目的　研究红霉素 (ERY)对BEL 740 2细胞 (人肝癌细胞 )多药耐药性的逆转作用。方法　将BEL 740 2细胞连续培养在含阿霉素 (ADM )的培养液中诱导耐药细胞株BEL 740 2 /ADM ,用cell ELASA法检测细胞膜表面P gp的表达 ,细胞毒试验采用MTT法 ,用荧光分光光度法测定细胞内ADM浓度。结果　BEL 740 2 /ADM细胞表面P gp高度表达 ,除对ADM耐药外 ,对长春新碱 (VCR)和丝裂霉素(MMC)也有不同程度的交叉耐药 ;ERY可增强ADM、VCR、MMC对BEL 740 2 /ADM细胞的增殖抑制作用 ,可增加BEL 740 2 /ADM细胞内ADM的浓度而对细胞膜表面P gp的表达没有影响。结论　ERY通过竞争性地饱和BEL 740 2 /ADM细胞表面P gp通道 ,使细胞内药物外排减少、浓度增加 ,从而发挥对BEL 740 2 /ADM细胞多药耐药性的逆转作用     

地塞米松对肝癌微循环及能量代谢影响机制的研究

探讨地塞米松对肝癌微循环血管生成及能量代谢的影响。通过绿色荧光蛋白GFP标记肝癌HepG2细胞,原位移植法建立原位肝模型,荧光成像系统观察地塞米松对裸鼠肿瘤负荷情况;建立金黄地鼠颊囊肝癌模型,微循环活体观测显微镜记录给药周期内模型鼠微循环生长状态及肿瘤生长情况;免疫印迹试验检测小鼠肝癌H22细胞不同给药浓度下糖异生关链酶PEPCK、G6Pase蛋白的表达情况;建立小鼠肝癌移植瘤模型,WB法检测PEPCK、G6Pase表达情况,双抗酶联免疫吸附法(ELISA)检测血管内皮生长因子(VEGF)表达情况。结果显示：1.裸鼠原位肝癌模型对照组小鼠体重增长了27.3%,肝癌面积增长了6.7倍;而地塞米松给药组小鼠体重只增长了0.3%,肝癌面积仅增长了4.7倍。2.金黄地鼠颊囊肝癌模型新生瘤体明显,血管明显比正常组多;地塞米松治疗组血管增长缓慢,7 d仅增长4.2%,其肿瘤体积也明显变小。3.不同浓度地塞米松处理肝癌H22细胞后,PEPCK、G6Pase的表达量随给药浓度增加逐渐升高。4.地塞米松小鼠肝癌移植瘤,PEPCK、G6Pase随给药浓度的增加表达量逐渐升高,蛋白表达量超过正常组的50%;...     

反义寡脱氧核苷酸抑制多药耐药基因mdr1表达并逆转耐药肝癌细胞的体外试验研究

目的:探讨反义寡脱氧核苷酸(ASODN)抑制多药耐药基因(mdr1)对耐阿霉素(ADM)肝癌细胞HepG2/ADM化疗敏感性的影响。方法:以多药耐药基因mdr1人工合成寡脱氧核苷酸(ODN),其中ODN分为ASODN和正义寡脱氧核苷酸(SODN),并采用脂质体转染技术将ODN与HepG2/ADM共培养,试验分为反义寡脱氧核苷酸(mdr1-ASODN)处理组、正义寡脱氧核苷酸(mdr1-SODN)对照组和空白对照组,通过逆转录聚合酶链式反应和蛋白免疫印迹法观察HepG2/ADM细胞中mdr1mRNA及其蛋白表达情况;MTT法观察HepG2/ADM细胞转染mdr1-ASODN前、后对化疗药物(ADM、顺铂、5-氟尿嘧啶)的敏感性。结果:与mdr1-SODN对照组和空白对照组比较,mdr1-ASODN处理组HepG2/AMD细胞中mdr1mRNA及其蛋白表达均明显降低(P<0.05);与转染前比较,HepG2/ADM细胞的增殖抑制率明显增加(P<0.05)。结论:ASODN能有效抑制mdr1基因表达,并恢复肝癌HepG2/ADM细胞对化疗药物的敏感性。     

抗多药耐药基因肽核酸与反义寡脱氧核苷酸增强K562／ADM细胞的敏感性和促进凋亡

AIM: To investigate the reversal effect and apoptosis enhancement of peptide nucleic acid (PNA) and antisenseoligodeoxyribonucleotide (ASODN) targeted to multidrug resistance gene (mdrl) on human multidrug resistantleukemia K562/ADM cells. METHODS: A 15-mer PNA and the same sequence of ASODN, complementary to the5' end of the AUG initiator codon-containing region of mdrl messenger RNA (MDR1-PNA, MDR1-ASODN), weredesigned and synthesized. Proliferation and sensitivity to adriamycin of K562/ADM cells treated with MDRI-PNAand MDR1-ASODN were analyzed with a MTT colorimetric assay. Apoptotic morphologies, P-glycoprotein (P-gp)expression, intracellular adriamycin accumulation, and cell cycle were measured. RESULTS: MDRI-PNA 1 to 10μmol/L and MDR1-ASODN 2 to 20 μmol/L alone had no inhibitory effects on the proliferation of K562/ADM cells,but significantly inhibited the growth of K562/ADM cells cultured in adriamycin-containing medium. After treatment with MDRI-PNA and MDRI-ASODN, intracellular adriamycin accumulation in K562/ADM cells increasedgreatly and P-gp synthesis was strikingly reduced. The resistance to adriamycin of the drug-resistant cells waspartly reversed and the cells were induced to apoptosis by adriamycin. The reversal efficacy of MDR1-PNA was3.1-fold higher than that of the same sequence of MDR-ASODN, but neither MDRI-PNA nor MDRI-ASODNcould completely block the mdrllP-gp expression. CONCLUSION: Sequence-special PNA targeted to mdr1 genemore effectively than the same sequence of MDR1-ASODN inhibited the expression of P-glycoprotein to overcomethe drug-resistance.     

雷公藤内酯醇对DU145/ADM细胞阿霉素化疗敏感性及逆转耐药的影响

目的探讨雷公藤内酯醇（TP）对DU145/ADM细胞阿霉素敏感性及逆转耐药的影响。方法采用MTT法检测TP预处理DU145/ADM细胞对阿霉素敏感性的影响,采用RT-PCR和Western blot分别检测相关基因转录水平与蛋白水平的变化。结果不同浓度TP（20、40、80 ng mL^-1）预处理DU145/ADM细胞72 h后,均可使细胞对不同浓度阿霉素（10、20、30、40、50 ng mL-1）敏感性较TP预处理前明显增加,mdr1表达较TP预处理前明显下降,并呈剂量相关性。结论 TP通过下调mdr1表达增强DU145/ADM细胞对阿霉素的敏感性,其有可能成为一种耐药逆转剂。     

mdr1反义寡核苷酸增强多药耐药肝癌细胞HepG2/ADM化疗敏感性的实验研究

目的：探讨在体外实验条件下mdr1反义寡核苷酸对多药耐药肝癌细胞株化疗敏感性的影响。方法以肝癌细胞HepG2/ADM为研究对象,设立mdr1反义寡核苷酸组和空白试剂组作对照,利用脂质体包载肿瘤耐药基因mdr1的反义寡核苷酸进行细胞转染,通过反转录聚合酶链反应（RT-PCR）、免疫印迹实验（Western blotting）分别检测mdr1基因mRNA和P-gp蛋白表达,通过MTT实验检测细胞转染前后对阿霉素（ADM）、顺铂（DDP）和5-氟尿嘧啶（5-FU）的化疗敏感性。结果 HepG2/AMD肝癌细胞经反义寡核苷酸处理后,mdr1 mRNA、P-gp蛋白表达水平均明显降低,对ADM、DDP 和5-FU的化疗敏感性明显增强。结论反义寡核苷酸能在体外有效增加肝癌细胞HepG2/ADM对化疗药物的敏感性。     

Profound differences in the transport of steroids by two mouse P-glycoproteins.

There are two mouse P-glycoproteins that convey multidrug resistance, mdr1 (mdr1b) and mdr3 (mdr1a), by serving as drug efflux transporters. These proteins each exhibit tissue-specific expression. There is relatively high expression of the mdr1 gene in the adrenals, the site of glucocorticoid and mineralocorticoid hormone synthesis. We previously demonstrated that mdr1 gene expression in murine thymoma cells correlated well with a decrease in their ability to accumulate the glucocorticoid dexamethasone and their increased resistance to glucocorticoid-induced apoptosis. Additional evidence is presented that supports the proposition that the mdr1 P-glycoprotein can transport glucocorticoids. Specifically, introduction and expression of the mouse mdr1 gene in the human HEK 293T cell line conveys a multidrug resistance phenotype that includes a reduced capacity to accumulate dexamethasone. Moreover, isolation of additional mdr1-expressing mouse lymphoid cells, without using steroids in the selection, confirms the linkage between multidrug resistance conveyed by the mdr1 P-glycoprotein and resistance to dexamethasone. In contrast, two newly isolated lymphoid lines, selectively expressing the mdr3 gene, were not found to have increased dexamethasone resistance or the capacity to accumulate significantly lower levels of hormone. The results support the concept that the mdr1 and mdr3 P-glycoproteins may serve alternative roles in the transport of endogenous substances such as steroids.     

槲皮素逆转人肝癌MDR相关基因的研究

摘 要 目的: 通过定量PCR芯片技术在基因转录水平上探讨槲皮素逆转人肝癌多药耐药( multi drug resistance, MDR)的作用机制。方法:采用体外培养人肝癌细胞Bel-7402及其耐5-氟尿嘧啶细胞Bel-FU, MTT法测定槲皮素的体外细胞毒性及浓度依赖的逆转耐药作用。定量PCR芯片检测BEL-7402细胞及Bel-FU细胞之间的差异基因,以及槲皮素作用于Bel-FU细胞前后的基因表达差异,实时定量PCR和western-blot法检测细胞中mdr1、H-ras基因以及P-gp蛋白的表达变化以验证基因芯片分析的结果。结果: 槲皮素对Bel-7402、Bel-FU细胞的IC10分别为59.2、58.2μM, IC50分别为226.7、193.9μM。16.5、33.0、49.5 μM 的槲皮素对Bel-FU 的耐药逆转倍数分别为1.14、1.68、2.38倍;与Bel-7402比较, Bel-FU细胞中的基因H-ras、Bcl-2、PDGFA、MDR1、BCRP表达上调（P＜0.05）表达上调。经槲皮素作用后,耐药细胞中基因H-ras、EGFR、FGF、VEGFA、PDGFA、MDR1、Erk1表达下调。实时定量PCR和western-blot证实了槲皮素可下调MDR1、H-ras基因以及P-gp蛋白在耐药细胞中高表达,与芯片检测到的基因水平变化一致。结论：槲皮素可逆转耐药细胞中耐药差异基因的高表达量,从而逆转人肝癌细胞的多药耐药性。     

洛美利嗪逆转K562/ADM细胞多药耐药性

目的研究洛美利嗪(lomerizine,Lom)逆转K562/ADM细胞多药耐药性的作用及机制。方法MTT法检测细胞毒作用,流式细胞仪研究Lom对ADM和长春新碱(vincristine,VCR)的K562/ADM细胞凋亡诱导作用的影响及对罗丹明123(rhodamine 123,Rh123)外排和P-糖蛋白(P-glycoprotein,P-gp)表达的作用。结果Lom明显提高ADM对K562/ADM多药耐药细胞的细胞毒作用及ADM和VCR的凋亡诱导作用,3,10和30 μmol·L^-1 Lom使K562/ADM对ADM的IC₅₀值由79.03 μmol·L^-1分别降至28.14,8.16和3.16 μmol·L^-1。Lom增加胞内ADM的蓄积浓度并抑制Rh123外排;但作用72 h后对K562/ADM细胞P-gp表达无影响。结论Lom通过抑制P-gp的活性逆转K562/ADM细胞的多药耐药性。     

Altered expression of hepatic cytochromes P-450 in mice deficient in one or more mdr1 genes

We hypothesized that the drug efflux protein P-glycoprotein (Pgp), the product of the multidrug resistance gene MDR1, might influence hepatic expression of CYP3A or other cytochromes P-450 (P-450s) because Pgp can transport endogenous regulators of these cytochromes. We began with variants of a CF-1 mouse strain containing a defective mdr1a gene that is inherited in a Mendelian fashion. The amount of CYP3A protein in liver was inversely related to the gene dose of the normal mdr1a allele in these mice. mdr1a knockout mice of either mixed (FVB x 129/Ola) or pure FVB genetic background and housed in Amsterdam display an increased expression of CYP2B and CYP3A proteins. However, because mdr1a ablation causes a compensatory increase in hepatic mdr1b (which can efflux intracellular glucocorticoids), we reasoned that mdr1b might mask the overall effect of mdr1a absence on P-450 gene expression. Targeted inactivation of the mdr1b gene increased P-450 expression, but the effect was modest compared with mdr1a ablation. Mice nullizygous for both mdr1a and mdr1b-type Pgps and kept in Amsterdam had dramatically increased levels of CYP3A protein as well as other P-450s examined and of the electron donor P-450 reductase. Consistent with the protein results, CYP3A catalytic activity measured as midazolam 1'- and 4-hydroxylation in liver microsomes from these knockout mice revealed a rank order of activities with mdr1a/1b > mdr1a > mdr1b > (+/+) mice. In contrast to results in mice housed in Amsterdam, in the genetically identical mdr1a or mdr1a/1b (-/-) male mice housed in the United States, hepatic P-450 expression was unaffected by mdr1 genotype or actually showed a slight decrease in mdr1a (-/-) mice. These results provide a revealing picture of mdr1-type Pgp as an upstream regulator of hepatic P-450 expression, and demonstrate that these pharmacologically relevant phenotypes in knockout mice depend not only on the genetic make-up of the mice but also on the environment.     

Involvement of miR-133a and miR-326 in ADM resistance of HepG2 through modulating expression of ABCC1

Recent studies have shown that a class of small, functional RNAs, named microRNAs, may regulate multidrug resistance-associated protein 1 (ABCC1). Since ABCC1 is an important efflux transporter responsible for cellular drug disposition, the discovery of microRNAs (miRNA) brings an idea that there may be some other unknown multidrug resistance (MDR) mechanisms exist. Using computational programs, we predicted that the 3′untranslated region (3′UTR) of ABCC1 contains a potential miRNA binding site for miR-133a and also two other for miR-326. These binding sites were confirmed by luciferase reporter assay. ABCC1 mRNA degradation was accelerated dramatically in cells transfected with miR-133a or miR-326 mimics using qRT-PCR, Furthermore, western blot analysis indicated that ABCC1 protein expression was significantly down-regulated in hepatocellular carcinoma cells line HepG2 after transfection with miR-133a or miR-326 mimics, suggesting the involvement of mRNA degradation and protein expression mechanism. The effects of the two miRNAs on adriamycin (ADM) sensitivity to HepG2 cells were determined by MTT assay. Compared with mock transfection, miR-133a or miR-326 mimics transfection sensitized these cells to ADM. These findings for the first time demonstrated that the involvement of miR-133a and miR-326 in MDR is mediated by ABCC1 in hepatocellular carcinoma cell line HepG2 and suggested that miR-133a and miR-326 may be efficient agents for preventing and reversing ADM resistance in cancer cells.