Suppression of triple-negative breast cancer metastasis by pan-DAC inhibitor panobinostat via inhibition of ZEB family of EMT master regulators

Triple-negative breast cancer (TNBC) is a highly aggressive breast cancer subtype that lacks effective targeted therapies. The epithelial-to-mesenchymal transition (EMT) is a key contributor in the metastatic process. We previously showed the pan-deacetylase inhibitor LBH589 induces CDH1 expression in TNBC cells, suggesting regulation of EMT. The purpose of this study was to examine the effects of LBH589 on the metastatic qualities of TNBC cells and the role of EMT in this process. A panel of breast cancer cell lines (MCF-7, MDA-MB-231, and BT-549), drugged with LBH589, was examined for changes in cell morphology, migration, and invasion in vitro. The effect on in vivo metastasis was examined using immunofluorescent staining of lung sections. EMT gene expression profiling was used to determine LBH589-induced changes in TNBC cells. ZEB overexpression studies were conducted to validate requirement of ZEB in LBH589-mediated proliferation and tumorigenesis. Our results indicate a reversal of EMT by LBH589 as demonstrated by altered morphology and altered gene expression in TNBC. LBH589 was shown to be a more potent inhibitor of EMT than other HDAC inhibitors, SAHA and TMP269. Additionally, we found that LBH589 inhibits metastasis of MDA-MB-231 cells in vivo. These effects of LBH589 were mediated in part by inhibition of ZEB, as overexpression of ZEB1 or ZEB2 mitigated the effects of LBH589 on MDA-MB-231 EMT-associated gene expression, migration, invasion, CDH1 expression, and tumorigenesis. These data indicate therapeutic potential of LBH589 in targeting EMT and metastasis of TNBC.     

αv整联蛋白拮抗剂RGD肽对乳腺癌细胞增殖侵袭能力影响的研究

目的：研究αv整联蛋白拮抗剂RGD肽对乳腺癌细胞株MDA-MB-231、MCF-7增殖侵袭能力的影响,探讨其在肿瘤靶向性治疗中的作用机制。方法：化学合成RGD肽,免疫细胞荧光技术检测RGD肽与MDA-MB-231、MCF-7细胞结合能力；MTT法检测不同浓度RGD肽对细胞增殖能力的影响；流式细胞学检测RGD肽处理对细胞周期和凋亡的影响；Boyden小室体外侵袭实验测定RGD肽处理后细胞迁移与侵袭能力的改变。结果：RGD肽与MDA-MB-231、MCF-7细胞均有特异性结合作用,15μmoI/L及更高浓度的RGD肽作用24h后细胞增殖能力显著降低(P＜0.01),细胞凋亡明显增加,细胞阻滞于G_0/G_1期,且RGD肽对细胞体外侵袭能力有不同程度的抑制作用。结论：RGD肽作为αv整联蛋白的一种拮抗剂,不仅具有药物、基因治疗载体的导向运输功能,更具有肿瘤的直接杀伤效应,是一种理想的肿瘤靶向性治疗药物。     

PPAPDC1A在体内外对乳腺癌细胞增殖、侵袭和转移能力的影响

目的:通过构建稳定过表达和干扰PPAPDC1A的乳腺癌细胞株,探讨PPAPDC1A对乳腺癌细胞增殖、侵袭和转移能力的影响。方法:利用CCK-8和Transwell实验检测PPAPDC1A稳定过表达和干扰后对乳腺癌细胞体外增殖和侵袭能力的影响。采用裸鼠皮下成瘤实验检测PPAPDC1A对乳腺癌细胞体内增殖和裸鼠致瘤性的作用。利用免疫组织化学染色法检测各组肿瘤组织中Ki-67的表达。通过裸鼠尾静脉注射实验检测PPAPDC1A对乳腺癌MCF-7细胞和MDA-MB-231细胞体内转移能力的影响。结果:成功建立稳定过表达PPAPDC1A的乳腺癌MCF-7细胞株和稳定干扰PPAPDC1A的乳腺癌MDA-MB-231细胞株;CCK-8和Transwell实验结果显示,与MCF-7和MCF-7-Vector细胞株相比,MCF-7-PPAPDC1A细胞株的生长速度显著增快,穿膜细胞数量多（P＜0.05）;与此相反,MDA-MB-231-shPPAPDC1A组细胞的生长速度和穿膜细胞数明显少于MDA-MB-231-shNC和MDA-MB-231 细胞株（P＜0.05）。动物实验结果显示,与MCF-7-Vector组相比,MCF-7-PPAPDC1A组的肿瘤生长速度较快,肿瘤的体积较大,Ki-67的阳性率高,肺转移灶的数目增多（P＜0.05）;与此相反,与MDA-MB-231-shNC组相比MDA-MB-231-shPPAPDC1A组的肿瘤生长速度较慢,肿瘤的体积较小,Ki-67的阳性率低,肺转移灶的数目减少（P＜0.05）。结论:PPAPDC1A对乳腺癌细胞的增殖、侵袭和转移有促进作用。     

LINC02163靶向miR-338-3p影响乳腺癌细胞增殖、侵袭及迁移

背景与目的： 长链非编码RNA（long non-coding RNA,lncRNA）已被发现在乳腺癌中失调,与肿瘤恶性行为密切相关。本研究旨在探究LINC02163靶向miR-338-3p对乳腺癌细胞增殖、侵袭及迁移的影响。方法： 收集郑州人民医院2020年1月—2021年9月收治的9例乳腺癌患者的乳腺癌组织及距其2 cm外的癌旁组织样本,通过实时荧光定量聚合酶链反应（real-time fluorescence quantitative polymerase chain reaction,RTFQ-PCR）检测组织样本、人正常乳腺上皮细胞系（MCF-10A）和乳腺癌细胞系（MCF-7、BT-20、MDA-MB-231、T47D）中LINC02163的表达。将MDA-MB-231分为control组、sh-NC组、sh-LINC02163组、sh-LINC02163+inhibitor-NC组和sh-LINC02163+miR-338-3p inhibitor组。采用MTT法、transwell实验及划痕实验分别检测MDA-MB-231细胞活力、侵袭及迁移能力。采用蛋白质印迹法（Western blot）检测MDA-MB-231细胞c-Myc、基质金属蛋白酶（matrix metalloproteinase,MMP）2、MMP9、E-钙粘素（E-cadherin）及N-钙粘素（N-cadherin）蛋白的表达。通过双荧光素酶报告基因实验分析LINC02163与miR-338-3p的靶向关系。采用体内成瘤实验检测BALB/c裸鼠肿瘤体积及重量。采用免疫组织化学法检测裸小鼠移植瘤组织的Ki-67增殖指数。结果： 与癌旁组织相比,LINC02163在乳腺癌组织中的表达显著升高（P<0.05）。与MCF-10A细胞相比,LINC02163在MCF-7、BT-20、MDA-MB-231及T47D细胞中的表达均显著升高,并且其在MDA-MB-231细胞中升高最为显著（P<0.05）。与control组比,sh-LINC02163组LINC02163表达、细胞存活率、侵袭细胞数及迁移率、c-Myc、MMP2、MMP9、N-cadherin表达、肿瘤体积及重量、Ki-67增殖指数显著降低,miR-338-3p、E-cadherin表达显著升高（P<0.05）。与sh-LINC02163组相比,sh-LINC02163+miR-338-3p inhibitor组LINC02163表达无显著变化（P>0.05）,细胞存活率、侵袭细胞数及迁移率、c-Myc、MMP2、MMP9、N-cadherin表达、肿瘤体积及重量、Ki-67增殖指数显著增加,miR-338-3p、E-cadherin表达显著降低（P<0.05）。在乳腺癌中LINC02163与miR-338-3p存在潜在的靶向关系。结论： 沉默LINC02163表达通过促进miR-338-3p表达来抑制乳腺癌细胞增殖、侵袭及迁 移。     

miRNA-34a抑制乳腺癌细胞MCF-7、MDA-MB-231的增殖与侵袭

目的:研究miRNA-34a(miR-34a)对乳腺癌细胞MCF-7、MDA-MB-231的生物调控作用。方法:采用定量PCR检测人乳腺上皮细胞MCF-10A,乳腺癌细胞株MCF-7、T47D、MDA-MB-231、MDA-MB-453、Hs578T中miR-34a的表达水平。通过miR-34a mimics分别上调MCF-7、MDA-MB-231细胞中miR-34a的表达水平,MTT和Transwell检测肿瘤细胞增殖能力、侵袭力等生物学行为的变化。结果:乳腺癌细胞MCF-7、T47D、MDA-MB-231、MDA-MB-453、Hs578T中miR-34a处于低表达水平。通过miR-34a mimics上调MCF-7、MDA-MB-231细胞中miR-34a的表达后,细胞的增殖能力被miR-34a抑制（P＜0.05）,miR-34a对细胞侵袭有显著抑制作用（P＜0.05）。结论:miR－34a在乳腺癌细胞MCF-7、T47D、MDA-MB-231、MDA-MB-453及Hs578T中低表达,miR-34a抑制乳腺癌细胞MCF-7、MDA-MB-231的细胞增殖和侵袭能力。     

Dehydroepiandrosterone inhibits events related with the metastatic process in breast tumor cell lines

Dehydroepiandrosterone (DHEA), an adrenal hormone, has a protective role against cancer. We previously shown that DHEA inhibits the proliferation and migration of cell lines derived from breast cancer; however, the role of DHEA in others events related with these effects are unknown. We hypothesized that DHEA inhibits the expression of proteins and some events related with cell migration and metastasis. We determined the migration in Boyden chambers, the invasion in matrigel, anchorage-independent growth and the formation of spheroids in 3 cell lines (MCF-7, MDA-MB-231, ZR-75-30) derived from breast cancer exposed to DHEA. The secretion of metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), and several pro-inflammatory molecules in the secretome of these cells was also evaluated. DHEA inhibited the migration in transwells and the invasion in matrigel of MCF-7 and MDA-MB-231 cells. Besides, DHEA inhibited the anchorage-independent growth on agar and decreased the size of spheroids, and also reduced the secretion of IL-1α, IL-6, IL-8, and TNF-α in all cell lines. Metalloproteinase-1 (MMP-1) secretion was slightly decreased by DHEA treatment in MDA-MB-231 cells. Our results also showed that inhibition of migration and invasion induced by DHEA in breast cancer cells is correlated with the decrease of cytokine/chemokine secretion and the diminution of tumor cells growth. MCF-7 cells were the most responsive to the exposure to DHEA, whereas ZR-75-30 cells responded less to this hormone, suggesting that DHEA could be used in the treatment of breast cancer in early stages.     

FSIP1促进乳腺癌细胞迁移和侵袭并导致患者不良预后

目的 探讨乳腺癌组织中纤维鞘相互作用蛋白1(FSIP1)表达对乳腺癌细胞侵袭和迁移能力的影响及其与乳腺癌患者预后的关系,从而为乳腺癌的诊断和治疗提供一定的理论参考。方法 收集2004年1月—2018年12月于哈尔滨医科大学附属肿瘤医院确诊的404例乳腺癌患者的乳腺组织样本和病例资料,对收集的乳腺癌患者资料进行回顾性分析并采用Kaplan-Meier方法绘制生存曲线,采用免疫组织化学方法分析FSIP1在乳腺癌和癌旁组织中的表达情况,取乳腺癌细胞系MCF-7、MDA-MB-231、MDA-MB-435、SK-BR-3、T-47D及正常乳腺上皮细胞(HMECs)MCF-10A进行细胞培养,采用CRISPR/CAS9技术敲除乳腺癌细胞系MDA-MB-231和SK-BR-3中的FSIP1基因,通过Western blot实验检测各乳腺癌细胞系中FSIP1蛋白的表达情况并对FSIP1基因敲除结果进行检测,通过细胞迁移和侵袭实验评估FSIP1蛋白敲除对乳腺癌细胞迁移和侵袭能力的影响。结果 与正常乳腺上皮细胞(MCF-10A)相比,乳腺癌细胞系MCF-7、MDA-MB-231、MDA-MB-435、S...     

miRNA-613在乳腺癌中的表达及作用机制

  目的  探讨乳腺癌中微小RNA (microRNA,miRNA)-613表达及作用机制。  方法  收集2017年5月至2018年5月91例于南充市中心医院手术切除的乳腺癌患者的组织标本,实时荧光定量PCR检测乳腺癌组织及癌旁组织标本、乳腺癌细胞系(MDAMB-231、MDA-MB-468、MCF-7)和正常乳腺上皮细胞系HBL-100中miRNA-613的表达水平,分析其与乳腺癌患者临床病理特征的关系。TCGA数据库分析miRNA-613与乳腺癌患者预后的关系。双荧光素酶报告实验检测miRNA-613与SOX9的3'UTR区的结合情况。将miRNA-613模拟物转染至MDA-MB-231细胞,CCK-8法和Transwell侵袭及迁移实验分别检测细胞增殖活性、侵袭和迁移能力的变化,Western blot检测细胞中SOX9、β-catenin、E-Cadherin和Vimentin蛋白的表达变化。  结果  miRNA-613在乳腺癌组织中表达明显低于癌旁组织(P < 0.05),并且miRNA-613表达与TNM分期和淋巴结转移密切相关(P < 0.05),TCGA生存数据显示miRNA-613表达与乳腺癌患者的总生存率无关(P>0.05)。乳腺癌细胞系中miRNA-613的表达明显低于正常乳腺上皮细胞系(P < 0.05),并且高侵袭转移性乳腺癌细胞系MDA-MB-231、MDA-MB-468中miRNA-613的表达明显低于低侵袭转移性乳腺癌细胞系MCF-7(P < 0.05)。双荧光素酶报告实验显示miRNA-613可与SOX9的3'UTR特异性结合。上调miRNA-613的表达能抑制MDA-MB-231细胞的增殖和侵袭迁移能力(P < 0.05),同时下调SOX9、β-catenin和Vimentin蛋白的表达(P < 0.05),并上调ECadherin蛋白的表达(P < 0.05)。  结论  在乳腺癌组织和细胞中miRNA-613异常低表达,miRNA-613可能通过调控SOX9、Wnt/β-catenin信号通路抑制乳腺癌细胞的增殖、侵袭转移及上皮间质转化。      

三阴性乳腺癌组织中AIF1L低表达及其抑制癌细胞增殖、迁移、侵袭的机制探讨

目的:探究三阴性乳腺癌（triple negative breast cancer,TNBC）组织中同种异体移植炎症因子 1 样（allograft inflammatory factor-1 like,AIF1L）的表达及其对癌细胞增殖、迁移、侵袭的影响和分子机制。方法:分别选取132例乳腺癌组织和39例癌旁组织标本以及TNBC细胞系MDAMB231进行研究。采用免疫组化染色法验证乳腺癌不同分子分型中AIF1L表达情况。通过构建过表达AIF1L腺病毒载体转染MDAMB231细胞系,采用MTT实验、细胞划痕愈合实验、Transwell实验、细胞伸展实验分别检测AIF1L对TNBC细胞增殖、迁移、侵袭及伸展能力的影响;采用Western blot 法检测AIF1L对FAK-RhoA 信号通路及上皮间质转化（epithelial mesenchymal transition,EMT）的影响,探究其分子作用机制。结果:乳腺癌组织中AIF1L阳性表达率低于癌旁组织,TNBC组织中AIF1L阳性表达率最低。AIF1L抑制MDAMB231细胞的增殖、迁移、侵袭及伸展能力。AIF1L抑制FAK-RhoA信号通路相关蛋白表达及活性,逆转癌细胞EMT表型。结论:AIF1L在TNBC组织中极低表达,对TNBC细胞生物学功能具有抑制作用,其可能是通过抑制FAK-RhoA信号通路和（或）EMT相关通路进而抑制肿瘤细胞的迁移、侵袭。     

基因芯片技术筛查并鉴定乳腺癌细胞中MAGE-A11的相关基因

目的：应用高通量基因芯片技术筛查乳腺癌细胞中黑色素瘤相关抗原（melanoma antigen,MAGE）-A11 的相关基因,并从数量和功能两方面加以验证。方法：采用基因芯片技术筛选乳腺癌MCF-7、MDA-MB-231 和BT-549 中MAGE-A11 下游靶基因的mRNA的差异表达,对有代表性的基因进行了聚类分析,并利用qRT-PCR进行验证。以CCK-8 法、细胞划痕实验和Transwell实验检测MAGE-A11 对乳腺癌细胞中增殖、迁移和侵袭功能的影响。结果：3 种乳腺癌细胞过表达MAGE-A11 导致1 608个下游基因差异表达,主要涉及蛋白泛素化、细胞增殖和凋亡、肿瘤侵袭和转移。基因芯片中典型高表达的ZNF-451、CENPTJ、CDK13、API5 和LMO7 在qRT-PCR 在验证结果中也显著高于对照组（P<0.01）,低表达的SHPRH、PML、MARK2、LIMA1 和ANGPTL4也显著低于对照组（P<0.01）。转染MAGE-A11 组的乳腺癌细胞MCF-7、MDA-MB-231 和BT-549 72 h 的增殖能力较对照组明显增强（均P<0.01）,培养48 h 后与对照组相比,转染MAGE-A11 的3 种细胞划痕出现明显愈合（P<0.05 或P<0.01）,穿膜数较对照组明显增多（均P<0.01）。结论：在MCF-7、MDA-MB-231 和BT-549 三种乳腺癌细胞中筛查到涉及蛋白泛素化、细胞增殖和凋亡、肿瘤侵袭和迁移等生物功能众多的表达差异基因,对其中10 种典型差异基因从数量和功能两方面进行验证,并得到初步确认。     

沉默CD44表达对乳腺癌细胞MDA-MB-231增殖与侵袭的影响

目的:探索乳腺癌细胞MDA-MB-231及MCF-7中CD44分子的表达水平差异及沉默CD44对乳腺癌细胞MDA-MB-231增殖、侵袭和迁移的影响。方法:利用qRT-PCR及Western blot技术检测细胞中CD44基因表达水平;设计并合成CD44的siRNA片段(CD44-siRNA)转染乳腺癌细胞,利用qRT-PCR、Western blot技术检测细胞中CD44基因表达水平的变化;MTT检测MDA-MB-231细胞增殖;Transwell侵袭实验检测MDA-MB-231细胞的迁移与侵袭能力变化。结果:CD44在侵袭性乳腺癌细胞MDA-MB-231中的表达高于非侵袭性乳腺癌细胞MCF-7,CD44-siRNA下调了 MDA-MB-231细胞中CD44 mRNA与蛋白水平的表达,并抑制了细胞的增殖和侵袭转移能力。结论:CD44-siRNA能够下调CD44的表达,并有效抑制乳腺癌细胞MDA-MB-231的增殖及其侵袭迁移力。     

lncBRM对乳腺癌细胞生长的影响及作用机制

目的  探讨Brahma相关长链非编码RNA （long non-coding RNA for association with Brahma,lncBRM）对人乳腺癌细胞系（MCF-7、MDA-MB-453）生长、迁移和侵袭的影响及可能的作用机制。方法 采用RT-PCR实验检测lncBRM在不同乳腺癌细胞（MCF-7、 ZR-75-30、BT474、MDA-MB-231和MDA-MB-453）和正常人乳腺上皮细胞株MCF 10A中的表达;利用siRNA在MCF-7、MDA-MB-453细胞中敲低lncBRM,分别转染si-lncBRM质粒（si-lncBRM组）和空载质粒（si-Ctrl组）,采用CCK-8实验检测细胞增殖情况,流式细胞术检测细胞凋亡情况,Transwell小室实验检测细胞侵袭和迁移能力,采用Western blot检测迁移相关蛋白E-cadherin和N-cadherin的表达水平,并采用miRDB数据库预测lncBRM靶点。结果 lncBRM在不同乳腺癌细胞中的表达水平均高于正常人乳腺上皮细胞株MCF 10A （P<0.01）。si-Ctrl组比较,敲低lncBRM可抑制MCF-7、MDA-MB-453细胞增殖能力（P<0.05）,提高细胞凋亡率（P<0.01）,细胞侵袭和迁移细胞数目较少（均P<0.01）;同时E-cadherin表达明显上调,而N-cadherin表达下调（均P<0.01）。miRDB数据库预测发现lncBRM和68个miRNAs存在结合位点,敲低lncBRM导致评分最高的前5个miRNA中的4个（miR-4646-5p、miR-204-3p、miR-204-5p和miR-6832-3p）表达上调。结论 lncBRM可能通过调控miRNAs的表达而抑制乳腺癌细胞的增殖、侵袭和迁移并诱导其凋亡。     

FRZB is Regulated by the Transcription Factor EGR1 and Inhibits the Growth and Invasion of Triple-Negative Breast Cancer Cells by Regulating the JAK/STAT3 Pathway

BackgroundTo explore the expression of frizzled related protein (FRZB) in triple-negative breast cancer (TNBC) and role of FRZB in TNBC cell growth and invasion.MethodsBreast cancer clinical data were downloaded from the Cancer Genome Atlas. FRZB and early growth response 1 (EGR1) mRNA levels in TNBC were measured by quantitative real-time polymerase chain reaction. FRZB protein level was measured by immunohistochemistry and western blot. Proliferation, migration, and invasion of TNBC cells were detected by colony formation, wound healing, and transwell assay, respectively. The protein levels of EGR1, E-cadherin, N-cadherin, Snail, p-JAK1/JAK1, p-JAK2/JAK2, and p-STAT3/STAT3 were measured by western blot. JASPAR was used to predict the binding site of FRZB and EGR1. The binding ability of FRZB and EGR1 was verified by dual-luciferase reporter gene assay and chromatin immunoprecipitation assay.ResultsFRZB was low expressed in TNBC tissues and cells. Silencing FRZB promoted cell proliferation, migration, invasion, and EMT and activated JAK/STAT pathway in MDA-MB-468 and MDA-MB-231 cells, but overexpression of FRZB acted opposite effects in MDA-MB-468 and MDA-MB-231 cells. EGR1 was low expressed in TNBC samples and positively correlated with FRZB. Moreover, EGR1 could recover the promotion of silencing FRZB on cell proliferation, migration, invasion, and JAK/STAT pathway in MDA-MB-468 cells, but silencing EGR1 led to the opposite results in MDA-MB-231 cells.ConclusionFRZB was low expressed in TNBC and was regulated by EGR1, and FRZB inhibited TNBC cell growth and invasion by regulating the JAK/STAT3 pathway.     

Positive regulation of migration and invasion by vasodilator-stimulated phosphoprotein via Rac1 pathway in human breast cancer cells

This study aimed to investigate the role of the cytoskeleton-associated protein vasodilator-stimulated phosphoprotein (VASP) on the migration and invasion of human breast cancer cells and its relationship to Rac1 which is a member of the Rho family and has been found to be implicated in tumorigenesis, invasion and metastasis. We detected the mRNA and protein expression levels of VASP and Rac1 of the non-invasive breast cancer cell line MCF-7 as well as the invasive cell line MDA-MB-231 by RT-PCR and Western blotting. GST pull-down assay was used to examine the activitiy of Rac1. Accordingly, the cell invasive migration ability was analyzed in a wound-healing assay (2D) and transwell assays (3D migration and invasion). We then used VASP-siRNA to inhibit the expression of VASP in breast cancer cells in order to study the relationship between the VASP expression level and the invasive migration ability of breast cancer cells. Rac1-siRNA was used to decrease the expression of Rac1, and observe its effect on the VASP expression level together with the migration and invasion ability of MCF-7 and MDA-MB-231 cells. Our results revealed that the invasive breast cancer cell line MDA-MB-231 showed a higher Rac1 activity and VASP expression level compared with the non-invasive MCF-7. Inhibition of Rac1 or VASP by siRNA, respectively, decreased the migration and invasion ability of breast cancer cells and the transfection of Rac1 siRNA-mediated reduction of VASP expression at mRNA and protein levels. Collectively, our data showed that the higher expression level of VASP contributed to a higher invasive migration capacity of human breast cancer cells which was controlled by the Rac1 pathway.     

沉默环状RNA hsa_circ_0001785表达对乳腺癌MDA-MB-231细胞增殖、迁移及侵袭能力的影响

目的:探究环状RNA（circRNA）hsa_circ_0001785在乳腺癌组织和细胞中的表达变化及其对乳腺癌细胞增殖、迁移和侵袭能力的影响。方法:qRT-PCR实验检测hsa_circ_0001785在乳腺癌组织和乳腺癌细胞（MDA-MB-231和SK-BP-3）中的相对表达水平；CCK-8和克隆形成实验检测沉默或上调表达hsa_circ_0001785对MDA-MB-231细胞活性和克隆形成能力的影响；划痕愈合实验和Transwell侵袭实验检测沉默或上调表达hsa_circ_0001785对MDA-MB-231细胞迁移及侵袭能力的影响。结果:hsa_circ_0001785在乳腺癌组织中的相对表达水平明显高于癌旁组织，hsa_circ_0001785在MDA-MB-231和SK-BP-3细胞中的相对表达水平明显高于人乳腺上皮细胞MCF10A。在MDA-MB-231细胞沉默hsa_circ_0001785，MDA-MB-231细胞的活性和克隆形成能力明显降低，迁移距离显著减少，侵袭能力也明显下降。而在MDA-MB-231细胞中上调表达hsa_circ_0001785，MDA-MB-231细胞的活性和克隆形成能力显著升高，迁移距离明显升高，侵袭能力也明显升高。结论:hsa_circ_0001785在乳腺癌组织和乳腺癌细胞（MDA-MB-231和SK-BP-3）中的表达水平明显升高；沉默hsa_circ_0001785显著抑制乳腺癌MDA-MB-231细胞的增殖、迁移和侵袭能力，而上调表达hsa_circ_0001785明显促进乳腺癌MDA-MB-231细胞的增殖、迁移和侵袭能力。     

外泌体介导的Let-7a 通过下调MYC表达抑制三阴性乳腺癌细胞的恶性生物学行为

[摘要] 目的：探讨外泌体(EXO)传输Let-7a 调控MYC基因在三阴性乳腺癌（TNBC）细胞恶性生物学行为中的作用及其机制。方法：TNBC细胞MDA-MB-231 培养完成后,qPCR实验检测TNBC组织和细胞中MYC与Let-7a mRNA的表达水平,WB实验检测MYC与Let-7a 蛋白的表达水平。携Let-7a 重组慢病毒和敲除MYC的Crisper/Cas-9 系统分别转染MDA-MB-231 细胞,MTT、Transwell、划痕愈合实验检测MDA-MB-231 细胞增殖、侵袭和迁移能力。荧光素酶活性实验验证MYC和Let-7a 的作用靶点。分别在野生型和过表达Let-7a 的MDA-MB-231 细胞中分离EXO,并以透射电镜和WB实验鉴定。qPCR、WB、MTT、Transwell等实验检测两种EXO分别和MDA-MB-231 细胞共孵育后Let-7a 通过EXO影响MDA-MB-231 细胞的生物学功能。结果：Let-7a 与MYC在TNBC组织和细胞系中表达呈负相关（P<0.05）;MYC促进MDA-MB-231 细胞的增殖、迁移与侵袭,Let-7a 可以抑制MDA-MB-231 细胞的增殖、迁移与侵袭（均P<0.01）。Let-7a 通过作用于MYC基因的3''UTR 使其沉默,从而减少MYC蛋白的表达（P＜0.05）。Let-7a 由EXO包裹运输至肿瘤细胞,进而抑制MDA-MB-231 细胞的增殖、迁移与侵袭能力（P<0.05）。结论：EXO介导的Let-7a通过作用于MYC基因3’UTR区使得MYC基因沉默,从而抑制MDA-MB-231 细胞的增殖、迁移与侵袭。     

The effects of RKIP gene expression on the biological characteristics of human triple-negative breast cancer cells in vitro

The purpose of this study was to investigate the effect of Raf kinase inhibitor protein (RKIP) on the growth, proliferation, invasion and metastasis of triple-negative breast cancer (TNBC) cells to provide experimental evidence for developing future therapies against human TNBC. The pcDNA3.1-RKIP eukaryotic expression vector was constructed and transfected into the TNBC cell line MDA-MB-231. The alterations of the biological characteristics of RKIP-transfected MDA-MB-231 cells were analyzed using the following approaches: a growth curve, a 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) assay, bromodeoxyuridine (BrdU) staining and a cell migration assay. The effects of the RKIP gene on MMP-1 and MMP-2 expression were also examined. The pcDNA3.1 empty vector-transfected and mock-transfected MDA-MB-231 cells were used as control groups. Compared with the empty vector-transfected and mock-transfected cells, the cell growth of RKIP-transfected MDA-MB-231 cells was significantly reduced. The empty vector-transfected group was not significantly different compared with the mock-transfected MDA-MB-231 cells. The results of the MTT and BrdU assays demonstrated that the proliferation of pcDNA3.1-RKIP-transfected cells was significantly reduced compared to the control cells (P < 0.05). The result of the cell migration assay suggested that the cross-membrane migration rate of the pcDNA3.1-RKIP-transfected cells was significantly lower than that of the control MDA-MB-231 cells (P < 0.05). We also demonstrated that RKIP may inhibit MMP-1 and MMP-2 expression in MDA-MB-231 cells. The RKIP gene may play a role in inhibiting cellular proliferation. The RKIP gene may also have some inhibitory effects on the invasiveness and metastatic capability of human TNBC cells.     

circRNA_001569通过miR-145/HBXIP轴影响乳腺癌细胞的恶性生物学行为

目的：探讨 circRNA_001569 通过 miR-145/HBXIP 轴在乳腺癌细胞增殖、侵袭、迁移中发挥的作用。方法:收集2016年1月至2019年1月期间衡水市人民医院收治的30例乳腺癌患者的癌组织和癌旁组织。qPCR检测circRNA_001569在乳腺癌组织、癌旁组织以及细胞系中的表达。生物信息学工具预测miR-145的靶基因,RNA免疫沉淀（RNA immunoprecipitation,RIP）和双荧光素酶报告基因实验检测 miR-145 或靶基因之间的相互作用 ;向乳 腺 癌 MDA-MB-231 和 MCF-7细胞中转染si-circRNA_001569、miR-145 mimics或miR-145 inhibitor,建立基因过表达或沉默的细胞模型,qPCR和Western blotting分别检测转染对相关基因和蛋白表达的影响,CCK-8法、Transwell实验检测转染对细胞增殖、侵袭和迁移的影响。结果:在乳腺癌组织和乳腺癌细胞中,circRNA_001569 和 HBXIP 均呈高表达、miR-145 呈低表达。RIP 分析和双荧光素酶实验证实了 miR-145 与circRNA_001569和HBXIP之间的靶向关系;circRNA_001569或HBXIP过表达促进MDA-MB-231和MCF-7细胞的增殖、侵袭和迁移（均 P<0.01）,而 miR-145 过表达起相反的作用（均 P<0.01）。结论:circRNA_001569 可能通过下调 miR-145 的表达、上调HBXIP的表达从而促进乳腺癌细胞的增殖、侵袭和迁移。