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。     

Involvement of miR-326 in chemotherapy resistance of breast cancer through modulating expression of multidrug resistance-associated protein 1

Multidrug resistance-associated protein (MRP-1/ABCC1) transports a wide range of therapeutic agents and may play a critical role in the development of multidrug resistance (MDR) in tumor cells. However, the regulation of MRP-1 remains controversial. To explore whether miRNAs are involved in the regulation of MRP-1 expression and modulate the sensitivity of tumor cells to chemotherapeutic agents, we analyzed miRNA expression levels in VP-16-resistant MDR cell line, MCF-7/VP, in comparison with its parent cell line, MCF-7, using a miRNA microarray. MCF-7/VP overexpressed MRP-1 mRNA and protein not MDR-1 and BCRP. miR-326 was downregulated in MCF-7/VP compared to MCF-7. Additionally, miR-326 was downregulated in a panel of advanced breast cancer tissues and consistent reversely with expression levels of MRP-1. Furthermore, the elevated levels of miR-326 in the mimics-transfected VP-16-resistant cell line, MCF-7/VP, downregulated MRP-1 expression and sensitized these cells to VP-16 and doxorubicin. These findings demonstrate for the first time the involvement of miRNAs in multidrug resistance mediated by MRP-1 and suggest that miR-326 may be an efficient agent for preventing and reversing MDR in tumor cells.     

Genomic instability and mouse microRNAs

Tumor progression is the continual selection of variant subpopulations of malignant cells that have acquired increasing levels of genetic instability (Nowell Science 1976, 194, 23–28). This instability is manifested as chromosomal aneuploidy or translocations, viral integration or somatic mutations that typically affect the expression of a gene (oncogene) that is especially damaging to the proper function of a cell. With the recent discovery of non-coding RNAs such as microRNAs (miRNAs), the concept that a target of genetic instability must be a protein-encoding gene is no longer tenable. Over the years, we have conducted several studies comparing the location of miRNA genes to positions of genetic instability, principally retroviral integration sites and chromosomal translocations in the mouse as a means of identifying miRNAs of importance in carcinogenesis. In this current study, we have used the most recent annotation of the mouse miRome (miRBase, release 16.0), and several datasets reporting the sites of integration of different retroviral vectors in a variety of mouse strains and mouse models of cancer, including for the first time a model that shows a propensity to form solid tumors, as a means to further identify or define, candidate oncogenic miRNAs. Several miRNA genes and miRNA gene clusters stand out as interesting new candidate oncogenes due to their close proximity to common retroviral integration sites including miR-29a/b/c and miR106a~363. We also discussed some recently identified miRNAs including miR-1965, miR-1900, miR-1945, miR-1931, miR-1894, and miR-1936 that are close to common retroviral integration sites and are therefore likely to have some role in cell homeostasis.     

MiR-142-3p enhances chemosensitivity of breast cancer cells and inhibits autophagy by targeting HMGB1

MiR-142-3p has been reported to act as a tumor suppressor in breast cancer. However, the regulatory effect of miR-142-3p on drug resistance of breast cancer cells and its underlying mechanism remain unknown. Here, we found that miR-142-3p was significantly downregulated in the doxorubicin (DOX)-resistant MCF-7 cell line (MCF-7/DOX). MiR-142-3p overexpression increased DOX sensitivity and enhanced DOX-induced apoptosis in breast cancer cells. High-mobility group box 1 (HMGB1) is a direct functional target of miR-142-3p in breast cancer cells and miR-142-3p negatively regulated HMGB1 expression. Moreover, overexpression of HMGB1 dramatically reversed the promotion of apoptosis and inhibition of autophagy mediated by miR-142-3p up-regulation. In conclusion, miR-142-3p overexpression may inhibit autophagy and promote the drug sensitivity of breast cancer cells to DOX by targeting HMGB1. The miR-142-3p/HMGB1 axis might be a novel target to regulate the drug resistance of breast cancer patients.     

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。     

The effects of MYC on exosomes derived from cancer cells in the context of breast cancer

MYC amplification and overexpression in breast cancer occur 16% and 22%, respectively, and MYC has a linchpin role in breast carcinogenesis. Emerging evidence has started to shed light on central role of MYC in breast cancer progression. On the contrary, tumor-derived exosomes and their cargo molecules are required for the modulation of the tumor environment and to promote carcinogenesis. Still, how MYC regulates tumor-derived exosomes is still a matter of investigation in the context of breast cancer. Here, we investigated for the first time how MYC affects the biological functions of normal breast cells cocultured with exosomes derived from MYC-expression manipulated breast cancer cells. Accordingly, exosomes were isolated from MCF-7 and MDA-MB-231 cells that MYC expression was manipulated through siRNAs or lentiviral vectors by using exosome isolation reagent. Then, normal breast epithelial MCF-10A cells were treated with breast cancer cell-derived exosomes. The cellular activity of MCF-10A was investigated by cell growth assay, wound healing assay, and transwell assay. Our results suggested that MCF-10A cells treated with exosomes derived from MYC-overexpressing breast cancer cells demonstrated higher proliferation and migration capability compared with nontreated cells. Likewise, MCF-10A cells treated with exosomes derived from MYC-silenced cancer cells did not show high proliferation and invasive capacity. Overall, MYC can drive the functions of exosomes secreted from breast cancer cells. This may allow exploring a new mechanism how tumor cells regulate cancer progression and modulate tumor environment. The present study clears the way for further researches as in vivo studies and multi-omics that clarify exosomal content in an MYC-dependent manner.     

Breast cancer resistance protein BCRP/ABCG2 regulatory microRNAs (hsa-miR-328, -519c and -520h) and their differential expression in stem-like ABCG2+ cancer cells

Recent studies have shown that a number of microRNAs (miRNA or miR) may regulate human breast cancer resistance protein (BCRP/ABCG2), an important efflux transporter responsible for cellular drug disposition, whereas their effects on ABCG2 protein expression are not compared. In this study, we first identified a new proximal miRNA response element (MRE) for hsa-miR-519c within ABCG2 3′-untranslated region (3′UTR) through computational analyses. This miR-519c MRE site was confirmed using dual luciferase reporter assay and site-directed mutagenesis. Immunoblot analyses indicated that ABCG2 protein expression was significantly down-regulated in MCF-7/MX100 cells after transfection with hsa-miR-328- or -519c expression plasmids, and was markedly up-regulated in MCF-7 cells after transfection with miR-328 or -519c antagomir. However, ABCG2 protein expression was unchanged in MCF-7/MX100 cells after transfection with hsa-miR-520h expression plasmids, which was associated with undetectable miR-520h expression. Furthermore, ABCG2 mRNA degradation was accelerated dramatically in cells transfected with miR-519c expression plasmid, suggesting the involvement of mRNA degradation mechanism. Intervention of miR-328 or -519c signaling led to significant change in intracellular mitoxantrone accumulation, as determined by flow cytometry analyses. In addition, we separated RB143 human retinoblastoma cells into stem-like (ABCG2+) and non-stem-like (ABCG2−) populations through immunomagnetic selection, and found that miR-328, -519c and -520h levels were 9-, 15- and 3-fold lower in the ABCG2+ cells, respectively. Our data suggest that miR-519c and -328 have greater impact on ABCG2 expression than miR-520h in MCF-7 human breast cancer cells, and the presence of proximal miR-519c MRE explains the action of miR-519c on shortened ABCG2 3′UTR.     

miR-96在人乳腺癌中表达及其对乳腺癌细胞侵袭和迁移活性的影响

目的研究miR-96在人乳腺上皮细胞株和乳腺病变组织中表达状况及其对人乳腺癌细胞增殖、侵袭和迁移的影响。方法抽提4株人乳腺上皮细胞系和28例人乳腺病变新鲜组织总miRNA,实时定量PCR方法检测它们miR-96的表达状况;脂质体介导的转染方法将miR-96抑制物转染人乳腺癌MCF-7细胞株;通过MTS试剂盒检测细胞增殖能力,Transwell侵袭和迁移实验检测细胞侵袭及迁移能力。结果miR-96在高侵袭乳腺癌细胞株中表达较低侵袭乳腺细胞明显下调(P<0.01);人乳腺癌组织中miR-96表达较乳腺良性病变组织明显下调(P<0.01);miR-96抑制物转染乳腺癌MCF-7后,乳腺癌细胞侵袭和迁移活力较阴性对照组细胞明显增强(P<0.05),而细胞增殖活力改变无统计学意义(P>0.05)。结论 miR-96在人乳腺癌细胞株和乳腺癌组织中存在表达下调,并对人乳腺癌细胞的侵袭及迁移能力可能存在一定负性调控作用。     

MicroRNA-137 is downregulated in human osteosarcoma and regulates cell proliferation and migration through targeting FXYD6

Background: In this work, we investigated the functional role of microRNA 137 (miR-137) in regulating osteosarcoma both in vitro and in vivo.

Methods: Quantitative RT-PCR was used to examine the gene expressions of miR-137 in osteosarcoma cell lines and osteosarcoma tumors. 143B and Saos-2 cells were infected with lentivirus expressing miR-137 mimics (miR-137-mimic) to ectopically upregulate miR-137. In vitro cancer proliferation and migration were examined by MTT assay and transwell assay, respectively. Viral infected Saos-2 cells were also subcutaneously inoculated into null mice to evaluate the effect of miR-137 upregulation on in vivo tumor growth. The interaction between miR-137 and its downstream target, FXYD6, was evaluated by dual-luciferase reporter assay and quantitative real-time PCR. FXYD6 was then subsequently upregulated in osteosarcoma cells to evaluate its effect on miR-137 regulation in osteosarcoma.

Results: We found that miR-137 was significantly downregulated in both osteosarcoma cell lines and osteosarcoma tumors. Lentiviral infection of miR-137-mimic upregulated miR-137 gene expression, reduced in vitro proliferation and migration and inhibited in vivo osteosarcoma tumor growth. FXYD6 was verified to be directly interacting with miR-137, and its subsequent upregulation reversed the inhibitory effect of miR-137 upregulation in osteosarcoma.

Conclusion: We revealed novel functional role of miR-137 in osteosarcoma regulation, likely through FXYD6 binding.     

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。     

姜黄素通过调控miR-7641/PTPN14分子轴抑制乳腺癌发展进程的分子机制研究

目的 探讨姜黄素通过调控miR-7641/PTPN14分子轴抑制乳腺癌发展进程的分子机制。方法 采用实时荧光定量PCR（qRT-PCR）检测乳腺癌患者癌组织及细胞系中miR-7641表达情况;使用Kaplan-Meier方法作乳腺癌患者生存曲线;采用不同浓度的姜黄素处理细胞,或转染miR-7641 mimic、Anti-miR-7641及pcDNA-PTPN14载体,采用qRT-PCR检测miR-7641表达情况,MTT实验及克隆形成实验检测细胞增殖能力,Transwell小室法检测细胞迁移及侵袭,western blotting检测Ki67、pcDNA、CyclinD1、Bax、Bcl-2、caspase-3、caspase-8蛋白表达水平,采用双荧光素酶报告基因系统检测miR-7641与PTPN14靶向调控关系。结果 与癌旁组织或乳腺正常上皮细胞比较,miR-7641在乳腺癌患者癌组织及乳腺癌细胞系中高表达（P<0.01、0.001）,且miR-7641能够明显促进乳腺癌细胞的增殖、迁移及侵袭（P<0.05、0.01、0.001）,并促进Ki67、pcDNA、CyclinD1、Bcl-2蛋白表达,抑制Bax、caspase-3、caspase-8蛋白表达;miR-7641与PTPN14 3''-UTR靶向结合,姜黄素通过miR-7641/PTPN14分子轴抑制乳腺癌细胞的增殖、迁移及侵袭（P<0.01、0.001）,并抑制Ki67、pcDNA、CyclinD1、Bax蛋白表达,促进Bcl-2、caspase-3、caspase-8蛋白表达。结论 姜黄素可通过下调miR-7641促进PTPN14表达,进而抑制乳腺癌细胞的增殖、迁移及侵袭。     

人参皂苷Rg3对乳腺癌MCF-7细胞增殖和侵袭的影响

目的 观察人参皂苷Rg3对雌激素受体阳性的乳腺癌细胞MCF-7增殖和侵袭的影响,并探讨其可能的作用机制。方法 采用MTT法检测细胞的增殖能力,流式细胞仪分析细胞周期分布以及凋亡比率,通过Transwell小室观察细胞侵袭力,RT-PCR法检测细胞中的MMP-9 mRNA的表达。结果 与对照组相比,人参皂苷Rg3能显著抑制MCF-7细胞的增殖;G₀/G₁期及S期细胞比例减少,而G₂/M期细胞比例显著增加;同时细胞凋亡比率亦明显提升,而细胞侵袭指数降低,且呈现良好的剂量、时间依赖性。同时人参皂苷Rg3还能显著抑制细胞中MMP-9 mRNA的表达水平(P<0.05)。结论 人参皂苷Rg3能抑制MCF-7细胞的增殖和侵袭,其作用机制可能与其能降低MMP-9基因的表达有关。     

MicroRNA-302 Replacement Therapy Sensitizes Breast Cancer Cells to Ionizing Radiation

Purpose

Solid tumors can be resistant or develop resistance to radiotherapy. The purpose of this study is to explore whether microRNA-302 is involved in radioresistance and can be exploited as a sensitizer to enhance sensitivity of breast cancer cells to radiation therapy.

Methods

MiR-302 expression levels in radioresistant cell lines were analyzed in comparison with their parent cell lines. Furthermore, we investigated whether enforced expression of miR-302 sensitized radioresistant breast cancer cells to ionizing radiation in vitro and in vivo.

Results

MiR-302 was downregulated in irradiated breast cancer cells. Additionally, the expression levels of miR-302a were inversely correlated with those of AKT1 and RAD52, two critical regulators of radioresistance. More promisingly, miR-302a sensitized radioresistant breast cancer cells to radiation therapy in vitro and in vivo and reduced the expression of AKT1 and RAD52.

Conclusion

Our findings demonstrated that decreased expression of miR-302 confers radioresistance and restoration of miR-302 baseline expression sensitizes breast cancer cells to radiotherapy. These data suggest that miR-302 is a potential sensitizer to radiotherapy.     

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。     

Effect of low dose metronomic therapy on MCF-7 tumor cells growth and angiogenesis. Role of muscarinic acetylcholine receptors

The non-neuronal cholinergic system refers to the presence of acetylcholine, choline acetyltransferase, acetylcholinesterase and cholinergic receptors, nicotinic and muscarinic (mAChRs) expressed in non-neuronal cells. The presence of mAChRs has been detected in different type of tumor cells and they are linked with tumorigenesis. We had previously documented the expression of mAChRs in murine and human mammary adenocarcinomas and the absence of these receptors in normal mammary cells of the same origins. We also demonstrated that mAChRs are involved in breast cancer progression, pointing to a main role for mAChRs as oncogenic proteins. Since the long term treatment of breast cancer cells with the muscarinic agonist carbachol promoted cell death, here we investigated the ability of low doses of this agonist combined with paclitaxel (PX), a taxane usually administered to treat breast cancer, to inhibit the progression of human MCF-7 tumor cells. We demonstrated that PX plus carbachol reduced cell viability and tumor growth in vitro probably due to a down-regulation in cancer stem cells population and in the expression of ATP “binding cassette” G2 drug extrusion pump; also a reduction in malignant-induced angiogenesis was produced by the in vivo administration of the mentioned combination in a metronomic schedule to MCF-7 tumor-bearing NUDE mice. Our results confirm that mAChRs could be considered as therapeutic targets for metronomic therapy in breast cancer as well as the usefulness of a muscarinic agonist as repositioning drug in the treatment of this type of tumors.     

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。     

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,     

LincRNA-P21通过靶向miR-17-3p对三阴性乳腺癌细胞迁移和侵袭能力的影响

目的　探讨LincRNA-P21通过靶向miR-17-3p对三阴性乳腺癌（TNBC）细胞迁移和侵袭作用的影响。方法　qPCR检测30例TNBC患者肿瘤组织、癌旁正常组织以及6种乳腺细胞（乳腺正常细胞MCF-10A,乳腺癌细胞MDA-MB-231、MDA-MB-435、MDA-MB-468、BT549、T47D）LincRNA-P21和miR-17-3p的表达。取MDA-MB-231细胞,单独过表达LincRNA-P21（实验设对照组、pcDNA3.1空白组、pcDNA-LincRNA-P21组）,抑制miR-17-3p表达（实验设对照组、miR-17-3p空白组、miR-17-3p抑制剂组）,过表达LincRNA-P21+抑制miR-17-3p表达（实验设对照组、miR-17-3p抑制剂组和pcDNA-LincRNA-P21+miR-17-3p inhibitor组）。CCK-8法检测MDA-MB-231细胞增殖,集落形成实验检测细胞的集落数量,细胞划痕实验检测细胞的迁移能力,Transwell实验检测细胞侵袭能力。Western blot检测E-cadherin和Vimentin蛋白表达。结果　TNBC患者组织中LincRNA-P21的表达明显低于癌旁组织（0.48±0.03 vs. 1.03±0.06,t=11.714,P＜0.01）,miR-17-3p的表达显著高于癌旁组织（2.93±0.17 vs. 1.02±0.04,t=15.593,P＜0.01）。乳腺癌细胞系中LincRNA-P21表达量明显低于MCF-10A,miR-17-3p表达量高于MCF-10A（P＜0.01）。单独过表达LincRNA-P21或抑制miR-17-3p后,MDA-MB-231细胞增殖能力、集落形成数量、迁移和侵袭能力均明显下降。过表达LincRNA-P21的同时抑制miR-17-3p,MDA-MB-231细胞增殖能力、集落形成数量、迁移和侵袭能力出现进一步下降,且上调E-cadherin的表达,抑制Vimentin的表达（P＜0.05）。结论　LincRNA-P21通过竞争性结合miR-17-3p来抑制MDA-MB-231细胞增殖、集落形成、迁移和侵袭。     

月腺大戟素A通过干扰PKD1介导的MEK/ERK和PI3K/AKT信号通路抑制乳腺癌细胞增殖的研究

目的乳腺癌是世界上最致命的恶性肿瘤之一。月腺大戟素A(EA)是从中药月腺大戟中提取的乙酰间苯三酚类化合物。探讨EA抑制乳腺癌细胞MCF-7增殖的具体机制,以期为乳腺癌的临床治疗提供新的思路。方法在乳腺癌细胞MCF-7中添加不同浓度的EA药物,检测PKD1蛋白表达水平的变化。构建PKD1的过表达质粒体并转染至细胞,用实时荧光定量PCR技术和Western Blot实验检测PKD1的mRNA和蛋白表达水平。CCK-8实验用于检测细胞增殖能力的变化。Western Blot实验用于检测PKD1介导的相关信号通路中关键蛋白的表达水平。结果EA以剂量依赖的方式抑制乳腺癌细胞中PKD1蛋白的表达(P<0.05)。当转染过表达质粒后,PKD1在mRNA和蛋白水平上显著升高(P<0.001)。同时过表达PKD1显著逆转EA对MCF-7的增殖抑制作用(P<0.001)。信号通路分析证实EA通过抑制PKD1介导的MEK/ERK和PI3K/AKT信号通路活性影响乳腺癌细胞的增殖能力(P<0.05)。结论EA通过调控PKD1介导MEK/ERK和PI3K/AKT信号通路,能够抑制乳腺癌细胞的增殖。     

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。