miR-142-3p靶向HMGB1逆转乳腺癌细胞MCF-7对阿霉素的耐药性

目的化疗耐药是乳腺癌复发转移、治疗效果不理想的主要因素。本文探讨miR-142-3p通过靶向高迁移率族蛋白1(high-mobility group box 1,HMGB1)提高乳腺癌化疗敏感性的分子机制。方法实时荧光定量PCR检测人乳腺癌MCF-7细胞及阿霉素耐药株MCF-7/DOX细胞中的miR-142-3p水平;MTT法检测阿霉素(doxorubicin,DOX)处理后各组的增殖情况、流式细胞术检测凋亡率、Western blot检测HMGB1和自噬有关蛋白的表达水平;双荧光素酶报告实验评价miR-142-3p对HMGB1的靶向调控作用。结果阿霉素耐药株MCF-7/DOX细胞中的miR-142-3p水平明显下调。miR142-3p的过度表达增强了乳腺癌细胞对阿霉素的敏感性和提高阿霉素诱导的凋亡比率。HMGB1是乳腺癌细胞中miR-142-3p的直接功能靶点,HMGB1的过表达可以明显解除由miR-142-3p上调所产生的细胞凋亡和自噬抑制。结论miR-142-3p的过表达可能通过抑制自噬靶向HMGB1,增强乳腺癌细胞对阿霉素的化学敏感性。miR-142-3p/HMGB1为提高乳腺癌对药物的敏感性提供了新的靶点,具有一定价值。     

miR-1307-3p通过靶向ISM1促进乳腺癌细胞的增殖和迁移

目的 探讨miR-1307-3p通过靶向ISM1促进乳腺癌细胞增殖和迁移的分子机制。方法 （1）利用TCGA 数据库分析miR-1307-3p在乳腺癌患者中的表达水平及其与临床指标的关系。（2）利用qPCR、CCK-8实验、细胞划 痕实验和流式细胞术检测过表达或沉默miR-1307-3p后乳腺癌MCF-7细胞miR-1307-3p表达、细胞增殖、迁移和凋 亡水平变化。（3）生物信息学分析软件预测 miR-1307-3p 的靶基因,同时采用双荧光素酶实验进行验证。结果 miR-1307-3p在乳腺癌细胞及乳腺癌组织中均显著上调。miR-1307-3p过表达可促进MCF-7细胞增殖和迁移;而 miR-1307-3p inhibitor则抑制细胞迁移,并诱导凋亡。ISM1可能是miR-1307-3p的靶基因。乳腺癌组织中ISM1表 达水平明显低于正常乳腺组织,且与临床病理分期有关。 结论miR-1307-3p可促进乳腺癌细胞增殖和迁移,可能 通过调控ISM1基因而影响乳腺癌的发生发展。     

miR-539对乳腺癌细胞增殖与凋亡的调控作用研究

目的：研究miR-539对乳腺癌细胞增殖和凋亡的调控作用。方法采用荧光定量PCR检测乳腺癌细胞(MCF-7、MDA-MB-453、ZR-75-30)和正常乳腺上皮细胞(MCF-10A)中miR-539表达的差异;通过转染miR-539-mim-ics在MCF-7细胞中上调miR-539的表达,并通过MTT和TUNEL实验检测miR-539对乳腺癌细胞增殖和凋亡的影响。结果与正常乳腺上皮细胞相比,乳腺癌细胞中miR-539的表达显著降低( P<0．01)。与空白对照组和阴性对照组相比,过表达miR-539能显著降低过表达组乳腺癌MCF-7细胞的增殖能力并增加其对地塞米松诱导凋亡的敏感性(P<0．01)。结论 miR-539能够抑制乳腺癌细胞增殖并促进其凋亡,有望作为乳腺癌基因治疗的靶点。     

微小 RNA-525-5p通过靶向 RECQ样蛋白 5调控乳腺癌放射敏感性

目的探讨微小 RNA-525-5p(miR-525-5p)对乳腺癌细胞辐射照射敏感性的影响及机制。方法该研究起止时间为 2019年 6月至 2020年 6月,人乳腺癌细胞 MDA-MB-231、MCF-7、BT474、非恶性乳腺上皮细胞 MCF-10A均购自美国菌种保藏中心。运用 qRT-PCR法检测人乳腺癌细胞 MDA-MB-231、MCF-7、BT474、非恶性乳腺上皮细胞 MCF-10A中 miR-525-5p的 mRNA的表达;将 miR-525-5p模拟物( miR-525-5p mimics)阴性对照( miR-NC)组(转染 miR-NC)、 miR-525-5p组(转染 miR-525-5p mim. ics)、 RECQL5小干扰 RNA阴性对照( si-NC)组(转染 si-NC)、 RECQL5小干扰 RNA(si-RECQL5)组(转染 si-RECQL5)、 miR-525-5p+RECQL5过表达空载体( pcDNA)组(共转染 miR-525-5p mimics和 pcDNA)、 miR-525-5p+RECQL5过表达载体( pcDNA-REC. QL5)组(共转染 miR-525-5p mimics和 pcDNA-RECQL5),均用脂质体法转染至 MDA-MB-231细胞; Western blotting检测细胞中 RECQ样蛋白 5(RECQL5)的蛋白表达;流式细胞术检测细胞凋亡;双荧光素酶报告基因检测实验检测细胞的荧光活性;克隆形成实验检测细胞的存活分数。结果与非恶性乳腺上皮细胞 MCF-10A相比,人乳腺癌细胞 MDA-MB-231、MCF-7、BT474中 miR-525-5p表达［ 0.28±0.02,0.33±0.02,0.42±0.03比 1.01±0.08］显著降低, RECQL5 mRNA和蛋白表达［ 1.68±0.15,1.58±0.12,     

miR-34a靶向调控Akt/Bcl-2对乳腺癌细胞多柔比星耐药性的影响

目的：探讨miR-34a通过下调AKT/BCL2信号通路对乳腺癌细胞多柔比星耐药性的影响及其分子机制?方法：通过实时定量PCR法检测miR-34a-3p在乳腺癌细胞（MCF-7）和乳腺耐药细胞株（MCF-7/ADR）中的表达,并成功构建miR-34a mimics/inhibitor调控其表达水平;通过CCK8法分别筛选多柔比星处理MCF-7及MCF-7/ADR细胞的IC50值并处理细胞;使用CCK8,流式细胞技术以及免疫印迹实验验证在miR-34a过表达及干扰组中,乳腺癌细胞存活率,凋亡细胞百分比以及AKT/BCL2信号通路的改变。结果：miR-34a在MCF-7/ADR中的表达显著低MCF-7细胞,同时成功构建miR-34a过表达及敲减模型;多柔比星处理MCF-7及MCF-7/ADR细胞的IC50分别为0.89 μg/mL、13.61 μg/mL。当MCF-7及MCF-7/ADR细胞中miR-34a表达水平降低时,经多柔比星处理后,细胞存活率显著升高（P<0.05）,凋亡细胞比例显著减少（P<0.01）,同时下游AKT/BCL2信号表达上调（P<0.01）。而当MCF-7/ADR细胞中miR-34a表达升高时相应的观察到相反的细胞表型。结论：miR-34a在乳腺癌细胞中的表达下调,可能通过减少对AKT/BCL2信号的负向调控,减少细胞凋亡,进而增强细胞对多柔比星的耐药性。     

MiR-182对乳腺癌细胞顺铂耐药的相关性研究

目的 探讨miR-182与乳腺癌细胞顺铂耐药性的关系。方法 MTT法检测miR-182对顺铂杀伤乳腺癌细胞能力的影响。利用生物信息学、定量PCR及western blot法验证miR-182是否能调节乳腺癌细胞BNIP3的表达。运用JC-1染色、Annexin V染色及western blot法研究miR-182影响顺铂疗效的信号通路。结果 miR-182模拟物可减弱顺铂对MCF-7细胞的杀伤活性,而miR-182抑制剂则增强顺铂对MCF-7细胞的杀伤活性。定量PCR及western blot实验表明miR-182的靶基因可能为BNIP3。miR-182抑制剂联合顺铂可引起MCF-7细胞线粒体膜电位显著下降并诱导caspase-3的活化和凋亡的发生,转染BNIP3 siRNA后miR-182抑制剂联合顺铂对MCF-7细胞的凋亡诱导效应显著降低。结论 MiR-182在乳腺癌中通过下调BNIP3的表达影响顺铂对乳腺癌细胞的杀伤活性。     

miR-30a-5p在人乳腺癌MCF-7细胞对他莫昔芬耐药性中的作用研究

目的 探究miR-30a-5p在人乳腺癌MCF-7细胞对他莫昔芬(tamoxifen,TAM)耐药性中的作用,并阐明相关作用机制。方法 通过短时间高浓度TAM刺激MCF-7细胞诱导耐药株,MTT法检测细胞耐药性的改变;qRT-PCR法检测MCF-7细胞及其耐药细胞株MCF-7/TAM中miR-30a-5p的表达情况;吖啶橙染色及Western blotting检测MCF-7/TAM细胞相对于MCF-7细胞自噬的变化;转染miR-30a-5p模拟物后,采用MTT法检测MCF-7/TAM细胞对TAM敏感性的变化,并通过吖啶橙染色和Western blotting观察miR-30a-5p对MCF-7/TAM细胞自噬的影响;采用生物信息学方法对miR-30a-5p进行靶基因预测,荧光素酶报告基因试验验证miR-30a-5p对ATG5的靶向调控作用;Western blotting检测miR-30a-5p对ATG5表达的影响。结果 TAM对MCF-7/TAM细胞的抑制作用明显弱于对MCF-7细胞;miR-30a-5p在MCF-7/TAM细胞中的表达水平明显低于在MCF-7细胞中;相对于MCF-7细胞,MCF-7/TAM细胞的自噬水平明显升高;过表达miR-30a-5p后,MCF-7/TAM细胞对TAM敏感性显著增加,自噬水平显著降低;Targetscan软件分析表明ATG5是miR-30a-5p的下游靶基因,通过荧光素酶报告基因试验进一步证明miR-30a-5p靶向调控ATG5;MCF-7/TAM细胞中上调miR-30a-5p能够抑制ATG5的表达。结论 miR-30a-5p靶向调控ATG5,并能够抑制细胞的自噬,进而增强乳腺癌细胞对TAM的敏感性。     

Curcumin sensitizes prostate cancer cells to radiation partly via epigenetic activation of miR-143 and miR-143 mediated autophagy inhibition

Curcumin has been reported as a radiosensitizer in prostate cancer. But the underlying mechanism is not well understood. In this study, we firstly assessed how curcumin affects the expression of miR-143/miR-145 cluster. Then, we investigated whether miR-143 is involved in regulation of radiosensitivity and its association with autophagy in prostate cancer cells. Our data showed that PC3, DU145 and LNCaP cells treated with curcumin had significantly restored miR-143 and miR-145 expression. Curcumin showed similar effect as 5-AZA-dC on reducing methylation of CpG dinucleotides in miR-143 promoter. In addition, curcumin treatment reduced the expression of DNMT1 and DNMT3B, which contribute to promoter hypermethylation of the miR-143/miR-145 cluster. Therefore, we infer that curcumin can restore miR-143 and miR-145 expression via hypomethylation. MiR-143 overexpression and curcumin pretreatment enhanced radiation induced cancer cell growth inhibition and apoptosis. MiR-143 and curcumin remarkably reduced radiation-induced autophagy in PC3 and DU145 cells. MiR-143 overexpression alone also reduced the basal level of autophagy in DU145 cells. Mechanistically, miR-143 can suppress autophagy in prostate cancer cells at least via downregulating ATG2B. Based on these findings, we infer that curcumin sensitizes prostate cancer cells to radiation partly via epigenetic activation of miR-143 and miR-143 mediated autophagy inhibition.     

微小 RNA-338-3p靶向调控高迁移率族蛋白 B1增强子宫内膜癌对紫杉醇敏感性的研究

目的 探讨miR-338-3p靶向调控高迁移率族蛋白B1(HMGB1)影响子宫内膜癌对紫杉醇(Paclitaxel,PTX)敏感性的分子机制.方法 实时荧光定量聚合酶链反应(qRT-PCR)和蛋白印迹法(Western blottingting)检测miR-338-3p和HMGB1在子宫内膜癌细胞Ishikawa和HEC-1B中的表达;双荧光素酶报告基因实验验证miR-338-3p和HMGB1之间的靶向关系;将Ishikawa和HEC-1B细胞分为如下5组:miR-338-3p组(转染miR-338-3p mimics组)、miR-NC组(转染miRNA阴性对照组)、si-HMGB1组(转染干扰RNA)、si-NC组(转染siRNA阴性对照)、miR-338-3p+HMGB1组(共转染miR-338-3pmimics和pcDNA3.0 HMGB1组).将各组用转染试剂转染至细胞,用不同浓度的PTX处理上述转染组细胞,CCK-8法检测Ishikawa和HEC-1B细胞增殖,Annexin V-FITC/PI检测细胞凋亡,Western blotting检测HMGBI蛋白表达.结果 与人正常子宫内膜上皮细胞ESC相比,miR-338-3p在子宫内膜癌细胞Ishikawa和HEC-1B中表达下调[(1.00±0.10)比(0.51±0.04)、(0.46±0.04)],而HMGB1则相反;miR-338-3p靶向并负性调节HMGB1表达;过表达miR-338-3p抑制子宫内膜癌细胞Ishikawa和HEC-1B增殖,促进凋亡,增加其对PTX敏感,与敲低HMGB1结果一致;HMGB1可部分逆转miR-338-3p对子宫内膜癌细胞增殖,凋亡以及对PTX敏感性的影响.结论 miR-338-3p通过负性调控HMGB1抑制子宫内膜癌细胞Ishikawa和HEC-1B增殖,促进凋亡和增强其对PTX敏感性.     

Contribution of nucleophosmin overexpression to multidrug resistance in breast carcinoma

Multidrug resistance (MDR) is a serious obstacle in breast cancer patients which limits chemotherapeutic drugs application. Our previous study confirmed that overexpression of nucleophosmin (NPM) was closely related to MDR in methotrexate-resistant breast cancer cells (MCF-7/MTX), and NPM could be a potential therapeutic target for chemoresistance. In this work, we aim to investigate NPM-mediated resistance mechanism in breast carcinoma. The NPM level was strongly positive in breast carcinoma tissues compared with adjacent normal samples, which was associated with lymph node metastasis. We found abnormal expression of NPM activated PI3K/Akt pathway and affected downstream apoptosis factors. Then, NPM level was attenuated by RNA interfering technology, the sensitivity of MCF-7/MTX cells to methotrexate was obviously increased, factor level of mitochondria apoptosis pathway was significantly augmented, and Akt phosphorylation was inhibited. Furthermore, examination of Akt and NPM level demonstrated that Akt inhibitor MK-2206 sensitised resistant cells to methotrexate and induced MCF-7/MTX cell apoptosis by PI3K/Akt pathway and mitochondria apoptosis pathway. These suggested NPM-induced resistance and anti-apoptosis were required for Akt activity. NPM has a crucial function in MDR of breast cancer through influencing Akt activity and resistant cell apoptosis, and it could be expected to become a therapeutic target for chemoresistance in breast cancer.     

LncRNA-MALAT1通过miR-142-3p/TEAD1分子轴调控结直肠癌细胞增殖与凋亡#br#

目的　探讨长链非编码RNA-肺腺癌转移相关转录子1（LncRNA-MALAT1）对结直肠癌细胞增殖与凋亡的影响及相关作用机制。方法　通过Real-time PCR与Western blot实验检测结直肠癌细胞株与人正常结肠上皮细胞中LncRNA-MALAT1、miR-142-3p基因以及TEA结构域转录因子1（TEAD1）蛋白的表达;使用si-MALAT1转染HCT116细胞,在此基础上共转染miR-142-3p inhibitor,利用Real-time PCR与Western blot检测细胞中LncRNA-MALAT1与miR-142-3p基因以及TEAD1、Bax、Bcl-2与Cyclin D1蛋白的表达,通过CCK-8实验检测细胞的增殖水平,通过流式细胞术检测细胞的凋亡水平,通过双荧光素酶实验检测LncRNA-MALAT1与miR-142-3p以及miR-142-3p与TEAD1的结合。结果　与人正常结肠上皮细胞相比,结直肠癌细胞株中LncRNA-MALAT1基因与TEAD1蛋白呈高表达,miR-142-3p基因呈低表达（P＜0.05）;沉默LncRNA-MALAT1能够促进miR-142-3p基因与Bax蛋白表达,抑制LncRNA-MALAT1基因以及Bcl-2、Cyclin D1与TEAD1蛋白表达,抑制细胞增殖,并促进细胞凋亡;在此基础上沉默miR-142-3p能够对上述调控作用实现部分逆转;双荧光素酶实验结果显示,LncRNA-MALAT1与miR-142-3p以及miR-142-3p与TEAD1能够结合。结论　LncRNA-MALAT1能够结合miR-142-3p,促进miR-142-3p靶基因TEAD1表达,进而促进结直肠癌细胞增殖,抑制其细胞凋亡,促进结直肠癌的病理进程。     

miR-130a-3p下调CYLD表达对乳腺癌MCF-7细胞功能的影响

目的：探讨miR-130a-3p对人乳腺癌MCF-7细胞功能的影响及其可能的靶向基因。方法：应用脂质体介导方法将miR-130a-3p模拟物（实验组）或对照模拟物（对照组）转染MCF-7细胞,分别采用MTT方法和细胞划痕实验检测细胞增殖和迁移能力变化,印迹法检测细胞中miR-130a-3p靶基因圆柱瘤基因（CYLD）的表达。结果：与对照组比较,实验组MCF-7细胞的增殖和迁移能力增强（P＜0.05）,细胞中CYLD蛋白表达水平明显下调（P＜0.05）。结论：miR-130a-3p可能通过靶向调节CYLD蛋白表达增强人乳腺癌MCF-7细胞的增殖和迁移。     

保护性自噬对顺铂诱导人乳腺癌 MCF-7细胞凋亡的抑制作用探讨

目的：探讨顺铂对乳腺癌 MCF-7细胞自噬的影响及自噬在顺铂诱导凋亡中的作用。方法顺铂处理乳腺癌 MCF-7细胞,MTT 检测细胞增殖的能力,Hoechst 33342染分析细胞的凋亡,吖啶橙染色分析细胞的自噬,Western blot 分析自噬蛋白 LC3Ⅰ／Ⅱ和 p62的表达和凋亡蛋白多聚 ADP-核糖聚合酶 PARP 表达。结果顺铂呈时间和剂量依赖性抑制乳腺癌 MCF-7细胞的增殖,并且凋亡细胞数量随顺铂浓度的递增而增加;同时顺铂能诱导微管相关蛋白轻链3-Ⅱ（LC3Ⅱ）蛋白的增加,p62蛋白的减少以及酸性自噬溶酶体的增加,顺铂联合氯喹明显增加了 LC3Ⅱ和 p62的蛋白的表达;与单药顺铂相比,自噬抑制剂氯喹明显降低细胞存活率（89．17％±2．56％）vs （74．63％±1．51％）,（P ＜0．05）,而且 PARP 蛋白发生了明显的裂解（P ＜0．05）。结论顺铂诱导乳腺癌 MCF-7细胞保护性自噬,抑制自噬可以增加顺铂诱导乳腺癌 MCF-7细胞凋亡,自噬抑制剂联合顺铂为乳腺癌提供了新的治疗策略。     

两种新型西地那非同系物对MCF-7/ADR细胞对阿霉素耐药的影响

目的探讨两种新型西地那非同系物对人乳腺癌MCF-7/ADR细胞耐阿霉素的逆转作用。方法采用GENMED磷酸二酯酶5（PDE5）活性酶测定试剂盒检测两种同系物对5型磷酸二酯酶（PDE5）的抑制作用,用MTT法检测西地那非、西地那非同系物、阿霉素以及西地那非同系物与阿霉素联合作用对人乳腺癌耐药细胞MCF-7/ADR和敏感株MCF-7的抑制率及IC50值,运用Western blot检测P-gp蛋白的表达。结果两种同系物与西地那非相比具有较低的PDE5抑制活性;10μmol·L^-1两种西地那非同系物对MCF-7/ADR细胞耐药性的逆转倍数分别是6.36和5.58,20μmol·L^-1两种西地那非同系物对MCF-7/ADR细胞耐药性的逆转倍数分别是11.83和13.47;两种同系物作用对P-gp蛋白的表达无明显影响。结论两种新型西地那非同系物具有较低的PDE5抑制活性,一定浓度的西地那非同系物可显著逆转MCF-7/ADR细胞对阿霉素的耐药。     

miR-17-5p down-regulation contributes to erlotinib resistance in non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) is the major cause of lung cancer-related deaths. Erlotinib is an effective drug for NSCLC patients, but its effect in advanced NSCLC is compromised because of the drug resistance. The mechanism of erlotinib resistance in NSCLC is largely unknown. In the current study, we found that erlotinib treatment down-regulated miR-17-5p level in A549 cells and miR-17-5p was lower in acquired erlotinib-resistant A549 cells (A549-ER) compared with erlotinib-sensitive A549 cells. Consistently, miR-17-5p was down-regulated in the tumor tissues and the plasma of erlotinib-resistant NSCLC patients in comparison to those who are sensitive to erlotinib. Moreover, miR-17-5p mimic increased the sensitivity of A549 and A549-ER to erlotinib. In contrast, miR-17-5p inhibitor decreased the cell death of A549 and A549-ER induced by erlotinib. In addition, we also demonstrated that miR-17-5p could inhibit the mRNA and protein levels of enhancer of zeste homolog (EZH) 1, a member of the EZH family that contributes to drug resistance in several types of cancer. The luciferase assay of 3′-untranslated region (UTR) demonstrates that EZH1 is a direct target of miR-17-5p and EZH1 RNAi recapitulates the effect of miR-17-5p overexpression on erlotinib resistance. Further, mutation in seed sequence of miR-17-5p could totally abolish the sensitization of A549-ER to erlotinib induced by miR-17-5p overexpression. Our results indicate that miR-17-5p down-regulation contributes to erlotinib resistance of NSCLC by modulating its target genes such as EZH1 and plasma miR-17-5p might be a potential biomarker of erlotinib response in NSCLC patients.     

Role of the lung resistance-related protein (LRP) in the drug sensitivity of cultured tumor cells.

Drug resistance, one of the major obstacle in the successful anticancer therapy, can be observed at the outset of therapy (intrinsic resistance) or after exposure to the antitumor agent (acquired resistance). To gain a better insight into the mechanisms of intrinsic resistance we have analyzed two human cell types derived from untreated tumors: MCF-7 breast cancer and A549 non small cell lung cancer (NSCLC). We have examined: the cytotoxic effect induced by doxorubicin (DOX); the time course of drug accumulation by flow cytometry and intracellular drug distribution by confocal microscopy; the expression and distribution of proteins related to anthracycline resistance, such as P-gp (P-glycoprotein), MRP1 (multidrug resistance-associated protein) and LRP (lung resistance-related protein). The cytotoxicity assays showed that A549 cells were less sensitive than MCF-7 cells to the DOX treatment in agreement with the different DOX uptake. Moreover, while in A549 cells DOX was mostly located in well defined intracytoplasmic vesicles, in MCF-7 cells it was mainly revealed inside the nuclei. The analysis of P-gp and MRP expression did not show significant differences between the two cell lines while a high expression of LRP was detected at the nuclear envelope and cytoplasmic levels in A549 cells. These findings suggest that the lower sensitivity to DOX treatment showed by lung carcinoma cells could be ascribed to drug sequestration by LRP inside the cytoplasmic compartments.     

Erk信号传导通路在雷公藤甲素诱导人乳腺癌MCF-7细胞自噬与凋亡中的影响

目的：探讨雷公藤甲素通过Erk信号传导通路对人乳腺癌细胞MCF-7增殖、自噬和凋亡的影响。方法：培养MCF-7细胞,MTT法检测细胞存活率,Western-blot方法分析凋亡相关蛋白Bax、Bcl-2和Caspase-3,自噬相关蛋白LC3B、p62和Beclin-1和有关MAPK信号通路p38和Erk1/2蛋白水平的变化。结果：10 nmol·L^-1雷公藤甲素显著抑制人乳腺癌细胞MCF-7的增殖,促进凋亡,且呈剂量-时间依赖性;TPI能够增加LC3BⅡ和Beclin-1的表达,降低p62的蛋白水平,诱导MCF-7细胞自噬。雷公藤甲素促进p38和Erk1/2磷酸化,当联用自噬抑制剂时,磷酸化水平下降。结论：雷公藤甲素能够显著抑制人乳腺癌细胞MCF-7增殖,促进凋亡,通过诱导细胞自噬及促进p38及Erk1/2磷酸化等多途径发挥抗肿瘤作用,并首次证明其自噬的发生可能与Erk1/2的激活有关。     

Reversal activity of nanostructured lipid carriers loading cytotoxic drug in multi-drug resistant cancer cells

To overcome multi-drug resistance (MDR) of cancer cells, paclitaxel (PTX) and doxorubicin (DOX)-loaded nanostructured lipid carriers (NLC) were prepared by solvent diffusion method using monostearin as solid lipid and oleic acid as liquid lipid matrix. The cytotoxicities and reversal activity of drug-loaded NLC were tested against human breast cancer (MCF-7) cells, human ovarian cancer (SKOV3) cells and their multi-drug resistant (MCF-7/ADR and SKOV3-TR30) cells. The chemical conjugant of folic acid and stearic acid (FA-SA) was further synthesized to prepare folated NLC. Comparing with taxol and doxorubicin solution, the NLC loading PTX exhibited high cytotoxicities in MCF-7 and MCF-7/ADR cells, while the NLC loading DOX only indicated high cytotoxicity in MCF-7/ADR cells. The reversal powers of the NLC loading PTX and DOX were 34.3 and 6.4 folds, respectively. The NLC loading PTX and DOX showed the same trends of enhanced cytotoxicity against SKOV3 and SKOV3-TR30 cells. The reversal powers were 31.3 and 2.2 folds for the NLC loading PTX and DOX, respectively. The modification of NLC with FA-SA could further enhance the cytotoxicities of drug in drug sensitive and drug resistant cells.