MUC1的表达与乳腺癌细胞粘附的关系

背景与目的:近年研究认为,肿瘤的转移与肿瘤细胞膜上粘液型糖蛋白的大量形成有关。本实验研究糖基化抑制剂苯甲基-α-N-乙酰半乳糖胺对粘蛋白-1(mucin1,MUC1)形成的抑制作用及其对乳腺癌细胞株MDA-MB-231细胞的粘附、侵袭转移能力的影响。方法:免疫细胞化学法检测MUC1表达,噻唑蓝比色法(MTT)检测细胞对人工基底膜(Matrigel)的粘附能力,明胶酶谱法(zymography)检测MDA-MB-231细胞MMP-2、MMP-9的分泌变化。结果:经苯甲基-α-N-乙酰半乳糖胺去糖基化处理后的肿瘤细胞组与相应对照组比较,MUC1表达降低,对基底膜的粘附力明显降低(P<0.01),同时细胞中MMP-2和MMP-9的分泌量显著下降。结论:MUC1表达水平与肿瘤细胞的粘附能力相关,MUC1的抑制使乳腺癌MDA-MB-231细胞粘附能力,分泌Ⅳ型胶原酶能力明显减弱。     

Establishment of a bioluminescent MDA-MB-231 cell line for human triple-negative breast cancer research

The aim of this study was to establish a bioluminescent MDA-MB-231 cell line stably expressing luciferase and green fluorescent protein for the generation of a xenografted model of human triple-negative breast cancer (TNBC) in nude mice. Lentivirus vectors carrying eGFP, firefly luc2 and neo fusion genes were used to transduce the MDA-MB-231 human TNBC cells in vitro. After 8 weeks of G418 selection, eGFP and luc2 expression was determined using a fluorescence microscope and a Xenogen IVIS200 bioluminescent imaging system, respectively. The MTT, transwell invasion and wound healing assays were performed to confirm whether cellular proliferation, invasion and migration were altered by lentiviral infection. Cells were orthotopically implanted into female BALB/c nude mice to test the sensitivity and stability of reporter gene expression. Growth of the tumors was monitored with the in vivo imaging system once a week until they were large enough for experiments. The tumor tissues were resected for histology, and cancer cells were harvested for culture. The lentivirus-transduced MDA-MB-231 cells could stably express luc2 and eGFP, and the luciferase activity reached 9689 photons/sec/cell. Meanwhile, no significant difference in biological activities was observed between the lentivirus-transduced MDA-MB-231 cells and parental cells. An orthotopically implanted tumor model of human TNBCs was successfully established in BALB/c nude mice. Lentiviruses may be ideal carriers for luciferase genes due to their highly efficient infectivity and stable transgene expression. The modified MDA-MB-231 cell line stably expressing luciferase could be detected, allowing for immediate and sensitive detection of metastasis sites in nude mice. As the eGFP and luc2 combination are superior to single reporter genes in their ability to mark cells in vivo and in vitro, these cells may provide a visualizable, convenient and sensitive platform for research on the mechanisms of metastasis and the development of new antitumor drugs for human TNBC.     

干扰LOX表达对MDA-MB-231细胞侵袭迁移影响及其机制的探讨

目的:研究干扰赖氨酰氧化酶(LOX)基因表达对乳腺癌细胞MDA-MB-231体外侵袭迁移能力的影响,并探讨相关机制及意义。方法:设计合成特异性慢病毒干扰载体(LOX-RNAi-LV)转染MDA-MB-231细胞,实时定量PCR检测LOX mRNA和侵袭转移相关因子MMP-2、MMP-9和HIF-1α的mRNA表达,蛋白质印迹法检测LOX蛋白表达,细胞侵袭迁移实验(Transwell)检测细胞侵袭迁移能力。结果:转染LOX-RNAi-LV后,乳腺癌MDA-MB-231细胞LOXmRNA和蛋白表达水平明显降低,与空白组相比,抑制率分别为89.2%和82.97%。MMP-2(F=225.271,P=0.0000)、MMP-9(F=35.373,P=0.000 01)和低氧诱导因子HIF-1α(F=341.081,P=0.0000)的mRNA表达均明显降低。细胞侵袭迁移实验显示,干扰组穿过Transwell小室滤过膜的细胞数明显少于对照组(侵袭实验F=269.557,P=0.000 5;迁移实验F=164.321,P=0.000 3)。结论:转染LOX-RNAi-LV能有效地干扰LOX在乳腺癌细胞MDA-MB-231中表达,抑制肿瘤细胞的侵袭和迁移能力,其作用机制可能与下调MMP-2、MMP-9和HIF-1α表达有关。     

RNA干扰对MDA-MB-231乳腺癌细胞株骨保护素基因表达的抑制作用

目的 构建针对骨保护素（OPG）基因的一个载体编码三条短发夹RNA（shRNA）的真核表达质粒,观察其对MDA—MB-231乳腺癌细胞株OPG表达的抑制作用。方法选择3个针对OPG基因的RNA干扰（RNAi）位点,分别设计合成3对编码相应shRNA的DNA单链,每对单链连接形成双链后分别与线性化载体pGenesil-1．1、pGenesil-1．2、pGenesil-1．3连接形成pGenesil-1．1-shRNAl、pGenesil-1．2-shRNA2、pGenesil-1．3-shRNA3,对以上重组载体反复酶切连接,构建成重组质pGenesil—1．1—1．2-1．3-shRNA1-shRNA2-shRNA3,酶切鉴定和测序无误后,将该质粒转染MDA—MB一231细胞,以G418加压筛选,对转染细胞行单克隆化,稳定转染细胞行RT—PCR和Westernblot检测,确定其对OPG基因表达抑制作用。统计分析采用单因素方差分析和SLD分析法。结果成功构建了pGenesil-1．1—1．2-1．3-shRNA1-shRNA2-shRNA3重组质粒;以该质粒稳定转染MDA—MB-231细胞后其OPGmRNA和蛋白表达均较对照差异有统计学意义（P〈0．05）,RNAi对OPGmRNA和蛋白的表达抑制率分别为91％和73％。结论本研究构建了针对OPG的一个载体编码3条shRNA的真核表达质粒,通过RNAi抑制了MDA—MB-231细胞OPG基因表达,为进一步深入探讨肿瘤细胞自身OPG表达在乳腺癌骨转移发生发展中的作用提供了相关实验基础。     

Ghrelin促进乳腺癌细胞MDA-MB-231增殖的分子机制

目的:探讨生长激素释放肽（Ghrelin）促进乳腺癌细胞MDA-MB-231增殖的分子机制。方法:乳腺癌细胞MDA-MB-231经Ghrelin、Ghrelin受体（growth hormone secretagogue receptor,GHSR)抑制剂［D-Lys3］-GHRP-6或哺乳动物雷帕霉素靶蛋白(mammalian target of Rapamycin,mTOR)抑制剂雷帕霉素（Rapamycin）处理后,MTT或BrdU实验检测MDA-MB-231细胞的增殖能力;Western blot检测MDA-MB-231细胞GHSR表达及mTOR、p70S6K和S6磷酸化水平。结果:增殖实验结果表明Ghrelin增强MDA-MB-231细胞增殖能力;Western blot检测发现Ghrelin激活MDA-MB-231细胞mTOR、p70S6K和S6磷酸化,［D-Lys3］-GHRP-6或Rapamycin消除Ghrelin促进MDA-MB-231细胞增殖效应,同时抑制Ghrelin诱导的mTOR、p70S6K和S6磷酸化。结论:Ghrelin通过与GHSR结合激活MDA-MB-231细胞mTOR/p70S6K/S6信号途径促进MDA-MB-231细胞增殖。     

华蟾素对人乳腺癌细胞株MDA-MB-231生物学特性的影响

目的:探讨华蟾素(cinobufacini)对人乳腺癌细胞株MDA-MB-231增殖、细胞周期和体外侵袭的影响及其可能机制.方法:用CCK-8试剂盒测定并绘制华蟾素作用后MDA-MB-231细胞的生长曲线,FCM法分析细胞周期分布,Transwell小室检测MDA-MB-231细胞的体外侵袭能力, RT-PCR检测细胞周期素(cyclin)及p21 mRNA的表达变化.结果:华蟾素可抑制MDA-MB-231细胞的增殖能力,其半数抑制浓度(half inhibition concentration, IC50)为 0.31 mg/mL,抑制作用随着华蟾素作用时间的延长而增强,与对照组相比差异有统计学意义(P<0.05);Transwell小室检测表明,华蟾素作用后细胞的侵袭能力比对照组明显下降(P<0.05);FCM分析可见,随着华蟾素浓度的增加,停滞于S期的细胞比率比对照组明显增加(P<0.000 1);华蟾素作用后,MDA-MB-231细胞cyclin A1、cyclin D1和cyclin E1 mRNA的表达水平下降, p21 mRNA的表达水平上升,但cyclin B1 mRNA的表达无明显改变.结论:华蟾素通过调控cyclin A1、cyclin D1、cyclin E1和p21的表达而抑制乳腺癌细胞的增殖和侵袭,并影响其细胞周期的分布.     

Influence of mitoxantrone on nucleolar function in MDA-MB-231 human breast tumor cell line

The effect of mitoxantrone (DHAQ) on [3H]thymidine and [3H]uridine incorporation by exponentially growing MDA-MB-231, a human breast tumor cell line has been studied. The results have indicated that DHAQ was more effective in inhibiting [3H]thymidine than [3H]uridine incorporation in a concentration dependent manner. Following drug treatment at 20 ng/ml concentration, 50% inhibition of growth and [3H]thymidine incorporation were noted, whereas [3H]uridine incorporation was only inhibited by about 12%. At 2000 ng/ml of DHAQ the inhibition of cell growth, [3H]thymidine and [3H]uridine incorporations were 78%, 95% and 62%, respectively. Nuclear-associated radioactivity detected at light and electron microscope autoradiographic levels after [3H]thymidine and [3H]uridine incorporations, into DHAQ treated cells indicated that DHAQ prevented the accumulation of radioactivity into the nuclei in a concentration dependent manner. These results gave further indication that mitoxantrone induced a definitive alteration of nuclear template activities, correlated with nuclear functional-structural relation and suggested that the nucleoli were the primary site of DHAQ action.     

5-氮杂脱氧胞苷对乳腺癌细胞MDA-MB-231雌激素受体α表达和增殖侵袭的影响

目的：检测5-氮杂脱氧胞苷（5-aza-2’-deoxycytidine,5-Aza-CdR）对乳腺癌细胞MDA-MB-231雌激素受体α（estrogen receptor alpha,ERα）的表达和增殖侵袭的影响。方法：利用细胞生长曲线、MTT法及FCM法检测使用去甲基化药物5-Aza-CdR处理MDA-MB-231细胞后,对MDA-MB-231细胞增殖和周期的影响。通过RT-PCR和免疫细胞化学检测5-Aza-CdR对ERα阴性的乳腺癌细胞MDA-MB-231ERα及基质金属蛋白酶-2（matrix metalloproteinase-2,MMP-2）表达的影响。通过Boyden小室侵袭实验检测该细胞的浸润能力。结果：5-Aza-CdR能使MDA-MB-231细胞的生长速度明显减慢,细胞周期被阻滞在G0/G1期。5-Aza-CdR能部分恢复ERα阴性乳腺癌细胞MDA-MB-231的ERα表达,并能使MDA-MB-231细胞中MMP-2基因表达下降,细胞的侵袭能力降低。结论：5-Aza-CdR可有效抑制乳腺癌细胞生长并导致细胞周期的阻滞,明显降低乳腺癌细胞的侵袭能力。利用5-Aza-CdR可部分恢复ERα的表达及降低MMP-2的表达,这可能是其引起乳腺癌细胞MDA-MB-231生物学行为改变的机制之一。     

基质硬度对乳腺癌MDA-MB-231细胞增殖能力的影响

目的研究乳腺癌MDA-MB-231细胞在不同硬度基质上黏附率、增殖能力及整合素(intergrin)β1表达变化的差异,探讨肿瘤细胞的生物学性状和细胞外基质硬度的相关性。方法将乳腺癌MDA-MB-231细胞分别种植到不同硬度的人工模拟基质上(硬度分别为1、20、40kPa),3d后观察比较MDA-MB-231细胞克隆形成差异。用四唑盐(MTT)比色试验观察MDA-MB-231细胞增殖活性的变化。Westernblot检测细胞Intergrinβ1蛋白表达的变化。结果在硬度40kPa的人工基质上,乳腺癌细胞增殖能力、克隆形成能力及Intergrinβ1蛋白表达均高于其它两组,且差异有统计学意义。结论MDA-MB-231细胞更容易在硬性较高的基质上增殖,其机制需进一步探讨。     

塞来昔布对人三阴性乳腺癌细胞MDA-MB-231迁移、侵袭及黏附性的影响

背景与目的:三阴性乳腺癌(triple-negative breast cancer,TNBC)由于其高侵袭和高转移特性,是目前乳腺癌中预后最差的一种亚型.大量研究表明塞来昔布(celecoxib)具有很好的抗肿瘤活性,可以抑制肿瘤生长、减少肿瘤血管发生,防止肿瘤的早期转移.为了进一步明确塞来昔布与TNBC细胞侵袭活性之间的关系,本实验研究塞来昔布作用下人TNBC细胞MDA-MB-231黏附、迁移及体外侵袭能力的变化,并初步探讨其可能的机制.方法:以不同浓度的塞来昔布(0、40、80、120 μmol/L)作用MDA-MB-231细胞24 h后,采用细胞基质黏附实验检测塞来昔布对MDA-MB-231细胞黏附能力的影响;采用细胞划痕实验检测塞来昔布对MDA-MB-231细胞平面迁移能力的影响;采用Transwell侵袭小室实验检测塞来昔布对MDA-MB-231细胞体外侵袭能力的影响;RT-PCR检测塞来昔布作用前后基质金属蛋白酶(matrix metalloproteinases,MMPs)MMP-2和MMP-9 mRNA的表达情况.结果:经80、120 μmol/L塞来昔布作用24 h后,MDA-MB-231细胞与基质的黏附能力分别为(50.2±7.3)%和(31.5±2.2)%,与对照组(96.8±10.9)%相比显著下降,差异具有统计学意义(P<0.05).Transwell侵袭小室实验结果显示,经80、120 μmol/L塞来昔布作用后MDA-MB-231细胞趋化运动明显减少,穿过人工基底膜的细胞较对照组显著降低(P<0.05).划痕实验结果显示,经塞来昔布作用后MDA-MB-231细胞平面迁移到损伤区的细胞数明显减少(P<0.05).RT-PCR结果显示,经塞来昔布作用MDA-MB-231细胞后,MMP-2和MMP-9 mRNA的表达水平显著降低(P<0.05).结论:塞来昔布能显著地抑制MDA-MB-231细胞黏附、细胞体外的迁移和侵袭能力,该作用可能与抑制MMP-2和MMP-9 mRNA的表达有关.     

Growth Inhibiton of Human Breast Cancer Cell Line MDAMB-231 by Rosiglitazone through Activation of PPARγ

Objective  To investigate the anti-proliferative effect of rosiglitazone and its relationship to peroxisome proliferator-activated receptor γ (PPARγ) in human breast cancer cell line MDA-MB-231 and evaluate the potential application value of rosiglitazone for breast cancer therapy. Methods  The cytostatic effect of rosiglitazone on MDA-MB-231 cells was measured by the MTT assay. Cell-cycle kinetics was assessed by flow cytometry. Apoptotic cells were determined by the TUNEL assay. MDA-MB-231 cells were treated with rosiglitazone or in combination with the PPARγ antagonist GW9662 to investigate the effect of rosiglitazone on cell proliferation and its relationship to PPARγ. Results  The results showed that rosiglitazone could inhibit growth of MDA-MB-231 cells in a dose- and time-dependent manner with an IC₅₀ value of 5.2 μmol/L at 24 h after the drug was added into the culture. Cell cycle analysis showed that the percentage of G₀/G₁ phase cells increased, S phase cells decreased, and cells were arrested in G1 phase with increasing concentrations of rosiglitazone. Detectable signs of apoptotic cell death caused by rosiglitazone occurred at a concentration of 100 μmol/L and the apoptotic rate was (18 ± 3)%. PPARγ selective antagonist GW9662 could partially reverse the inhibitory effect of rosiglitazone on proliferation of MDA-MB-231 cells. Conclusion  It was concluded that rosiglitazone can inhibit growth of MDA-MB-231 cells via PPARγ activation and a high concentration of rosiglitazone can also induce MDA-MB-231 cell apoptosis. These results suggest that PPARγ represents a putative molecular target for chemopreventive therapy and rosiglitazone may be effective in the treatment of breast cancer.     

Gonadotropin-releasing hormone analogues inhibit cell proliferation and activate signal transduction pathways in MDA-MB-231 human breast cancer cell line

A novel gonadotropin-releasing hormone (GnRH) agonist (folligen) which stimulates follicular maturation has been developed in our laboratory. The direct effect of folligen and a well-known superactive GnRH analogue, buserelin, on the MDA-MB-231 human breast cancer cell line was investigated. Folligen was found to be slightly more active in inhibiting cell proliferation than buserelin, and significant differences were found in the signal transduction pathways activated by these analogues. These results demonstrate for the first time that tyrosine kinases and/or phospholipid turnover together with protein kinase C activation can be directly involved in the antitumor activity of GnRH analogues. The results also suggest that folligen and buserelin might have a different mechanism of action on this human breast cancer cell line.     

Glycosphingolipid composition of MDA-MB-231 and MCF-7 human breast cancer cell lines

Much evidence has shown that glycosphingolipids are involved in cellular recognition, regulation of cell growth, and metastasis. In the present study, the major glycosphingolipids of two widely studied human breast cancer cell lines were examined. The MCF-7 cell line has functional estrogen and EGF receptors, is dependent on estrogen and EGF for growth, and is uninvasive, while MDA-MB-231 cells are a model for more aggressive, hormone-independent breast cancer. There was twice as much neutral glycolipid in MCF-7 cells as in MDA-MB-231 cells. The major neutral glycolipids in MDA-MB-231 cells were identified as CTH and globoside. MCF-7 cells also contained as the major neutral glycolipids CTH as well as globoside and two other glycolipids which were tentatively identified as galactosylgloboside and fucosylgalactosylgloboside by exoglycosidase treatments. Conversely, the ganglioside content was four fold higher in MDA-MB-231 cells compared to MCF-7 cells. The abundant gangliosides in both cell lines were GM3, GM2, GM1, and GD1a. A minor monosialoganglioside was detected in MDA-MB-231 cells. The striking 18 fold greater amount of GM3 in MDA-MB-231 cells may have important implications because GM3 has been suggested to be involved in regulation of growth factor functions. In agreement, insertion of ganglioside GM3 into the plasma membrane of MCF-7 cells blocked the growth stimulatory effect of EGF.     

黄芪注射液对basal-like型乳腺癌MDA-MB-231细胞株增殖和凋亡的影响

目的 探讨黄芪注射液作用于basal-like型乳腺癌MDA-MB-231细胞株后对其增殖和凋亡的影响.方法 将实验细胞分为对照组和5种不同剂量的黄芪注射液作用组.用MTT法检测细胞增殖,流式细胞仪分析细胞周期,碘化丙啶染色检测细胞凋亡率.黄芪注射液作用于MDA-MB-231细胞48 h和72 h的OD值采用多个均数比较的方差分析;48 h时细胞周期各阶段细胞比率的比较用χ2检验.结果 作用48 h时,各剂量组均可抑制MDA-MB-231细胞增殖(P<0.01),其效应呈质量浓度依赖性.作用48 h时,高剂量组(2×10-1～2×10-2 g/ml)黄芪注射液还可促进细胞凋亡(χ2＝8.01,P=0.00);作用72 h时,高剂量组仍呈抑制作用,但随质量浓度的降低,抑制作用减少,低剂量黄芪组(2×10-4 ～2×10-5 g/ml)有促进增殖作用(P<0.01);中高剂量组(2×10-3 g/ml)可改变细胞周期的分布.结论 黄芪注射液可抑制MDA-MB-231细胞增殖,并诱导其凋亡,可能为basal-like乳腺癌的治疗带来益处..     

Isolation and partial characterization of surface components of cell line MDA-MB-231 derived from a human metastatic breast carcinoma

Neuraminidase (Vibrio cholerae) treatment of human metastatic mammary carcinoma MDA-MB-231 cells grown in culture released 0.60-0.63 mg of N-acetylneuraminic acid from 10(9) cells. Incubation of intact cells with a modified trypsin and fractionation by gel filtration gave mainly O-glycopeptides. The presence of O-glycosyl-linked chains having one or two carbohydrate residues was confirmed by treatment of the glycopeptide fractions with galactose oxidase, followed by reduction with alkaline sodium borotritide and fractionation. The major glycopeptide fraction, which consisted of 53% carbohydrate and 47% protein, and a minor glycopeptide fraction each inhibited hemagglutination by peanut lectin. These results suggest the presence of O-beta-D-galactopyranosyl-(1 leads to 3)-O-(2-acetamido-2-deoxy-alpha-D-galactopyranosyl)-(1 leads to 3)-L-serine (threonine) residues. The absorptive capacities for anti-HLA-A2 and anti-HLA-B8 antisera were slightly greater for intact than for lyophilized cells, which suggested that masking of these major histocompatibility antigens did not occur in intact cells.     

乳腺癌细胞株MDA-MB-231获得性放疗抵抗机制探讨

目的探讨乳腺癌细胞株MDA-MB-231产生获得性放疗抵抗的可能机制。方法采用CCK8及流式细胞术检测产生乳腺癌细胞株MDA-MB-231获得放疗抵抗能力后细胞增殖及细胞周期的变化,采用蛋白质印迹法检测放疗抵抗后相关信号通路蛋白的变化,初步探讨乳腺癌细胞产生放疗抵抗的可能机制。结果 CCK8法检测结果显示,第1天实验组吸光度值为0.305 7±0.013 1,明显高于对照组的0.277 8±0.011 8,差异无统计学意义,F=7.571,P=0.051;第2天实验组为0.401 7±0.048 0,明显高于对照组的0.289 0±0.020 9,差异有统计学意义,F=13.907,P=0.020;第4天实验组为0.635 7±0.026 1,明显高于对照组的0.434 2±0.080 6,差异有统计学意义,F=16.994,P=0.015;第6天实验组为1.5347±0.0391,显著高于对照组的1.075 7±0.036 8,差异有统计学意义,F=218.953,P〈0.001。提示231/RR10细胞株在获得放疗抵抗能力的同时,增殖能力也增强,差异有统计学意义,P〈0.05。流式细胞术检测结果显示,放疗抵抗细胞株中,G0-G1及S期的细胞比例减少,但差异无统计学意义,P值分别为0.083和0.165;G2-M期的细胞比例明显增加,差异有统计学意义,P值分别为0.002和〈0.01。蛋白质印迹法检测结果显示,抑癌基因PTEN的表达明显减少,表皮生长因子的活化状态pEGFR的表达明显增加,AKT蛋白的表达水平无变化,而AKT磷酸化蛋白的表达明显增加。结论乳腺癌细胞株MDA-MB-231中EGFR/AKT信号通路激活,促进细胞生长和生存,从而导致放疗抵抗的产生。这一信号通路可能由抑癌基因PTEN负性调控。     

西妥昔单抗对乳腺癌MDA-MB-231细胞放射敏感性影响的研究

目的:探讨西妥昔单抗(C225)对乳腺癌MDA-MB-231细胞株的放射增敏作用及其机制。方法:体外培养人乳腺癌MDA-MB-231细胞。使用活细胞计数试剂盒(CCK-8)检测浓度分别为1、5、25、125和625nmol/L C225对乳腺癌MDA-MB-231细胞株的增殖抑制率,计算C225的半数抑制浓度(IC50),并将20%IC50作为后续实验的浓度;观察C225联合X射线照射对MDA-MB-231细胞株增殖抑制的影响,并评价两者的联合效应。采用克隆形成实验检测MDA-MB-231细胞存活率,观察C225对细胞放射增敏性的影响,按多靶单击模型拟合细胞存活曲线,计算反映放射敏感性指标的细胞存活分数(SF2)、平均致死剂量(D0)、准阈剂量(Dq)和放射增敏比(SER)。流式细胞仪检测细胞凋亡及细胞周期情况。结果:1)1、5、25、125、625nmol/L C225对细胞的增殖抑制率分别为(3.66±0.26)%、(16.48±1.78)%、(35.41±2.46)%、(47.84±1.67)%和(62.49±2.94)%,C225作用于细胞48h的IC50为(151±2.98)nmol/L。2、4、6和8Gy的照射对细胞的增殖抑制率分别为31.12%、47.95%、59.12%和68.54%;当30nmol/L的C225与上述剂量的照射联合使用,细胞增殖抑制率分别为66.27%、82.03%、89.86%和93.03%,两者表现出协同作用,P<0.05。2)克隆形成实验显示,C225+照射组与单纯照射组相比,克隆形成能力下降,SF2、D0及Dq均下降(P<0.05),放射增敏比(SERD0)为1.41。3)细胞凋亡实验结果显示,C225+0、2、4、6、8Gy照射组凋亡率分别为(11.76±0.81)%、(21.46±1.40)%、(38.23±1.76)%、(44.01±1.23)%和(50.41±1.87)%,均高于单独照射组相应剂量点的凋亡率,分别为(2.94±0.58)%、(10.72±0.34)%、(21.14±1.08)%、(24.12±0.98)%和(30.05±2.64)%,P<0.05。C225联合照射明显增强了照射诱导的细胞凋亡。4)细胞周期分布显示,单独使用C225使细胞阻滞于G0/G1期,并减少S期细胞比例,C225作用后G0/G1期及S期细胞比例分别为(58.35±1.66)%和(31.12±0.23)%,P<0.05;单独照射使细胞阻滞于G2/M期,G2/M期细胞比例为(28.25±1.55)%,P<0.05;C225与照射联合作用后,G0/G1期细胞比例进一步升高,为(59.90±2.21)%,S期细胞比例进一步降低,为(13.67±1.34)%,P<0.05。结论:C225对MDA-MB-231细胞具有放射增敏作用,其机制可能与C225增强放射线对细胞的生长抑制作用、抑制肿瘤细胞亚致死性损伤的修复、增加细胞凋亡和诱导细胞G0/G1期阻滞有关。     

洛伐他汀对人乳腺癌细胞MDA-MB-231的生长抑制作用及相关机制

目的：探讨洛伐他汀对人乳腺癌细胞MDA-MB-231的作用及相关机制。方法：选用人乳腺癌MDA-MB-231细胞进行体外培养，采用MTT比色法俭测细胞增殖，测定其吸光度（OD）值。流式细胞仪测定细胞周期和凋亡率，光学显微镜和荧光显做镜进行形态学观察，流式细咆仪间接免疫荧光技术分析细胞内bcl-2蛋白、cdk2蛋白的表达。结果：不同浓度洛伐他汀处理不同时间后，MDA-MB-231细胞增殖明显受到抑制，抑制率最高可达77％，且同一处理时相点各组间比较差异均有显著性。洛伐他汀作用MDA-MB-231后，出现细胞凋亡峰和凋亡率的升高。细胞期分析显示，各组处理72小时，G0／G1期细胞增多，S期细胞减少，G2／M期细胞增加，而H细胞周期分布特点与药物浓度有关。用流式细胞仪间接分析细胞内bcl-2、cdk2蛋白的表达率显示：洛伐他汀处理组bcl-2、cdk2蛋白表达低于对照组，差异有显著性。结论：洛伐他汀对人乳腺癌MDA-MB-231细咆有明显的抑制增殖和诱导凋亡作用，bcl-2蛋白、cdk2蛋白表达下降可能为其分子机制之一。