固定后乳腺癌细胞雌激素受体和孕激素受体的FCM和Western blot检测

背景与目的：雌激素受体(estrogen receptor,ER)和孕激素受体(progesterone receptor,PR)水平的定性、定量检测,对乳腺癌患者预后判断和内分泌治疗效果的评价具有重要意义。Western blot法和流式细胞术(flow cytometry,FCM)是蛋白质定性、定量分析的重要手段,但常规Western blot法要求提取新鲜样本的蛋白质。本研究拟建立固定后乳腺癌细胞ER和PR的Western blot检测方法,探索Western blot法和FCM对同批固定样本ER、PR进行同步分析的可行性。方法：取不同乳腺癌细胞株对数生长期新鲜细胞和固定细胞的蛋白提取物,分别用ERα单克隆抗体1D5和PR单克隆抗体PgR636以Western blot法对．ER、PR的表达情况进行检测,并与同期固定细胞的FCM检测结果进行比较。结果：经Westernblot法检测,T-47d、MCF-7、ZR-75-l细胞可见分子量正确的ERα清晰条带,固定T-47d和ZR-75-1细胞的ERα条带较新鲜细胞的条带浓,MM23l细胞ERα检测为阴性;T-47d和ZR-75-1细胞可见清晰且分子量正确的PR条带,固定细胞的PR条带较新鲜细胞的条带浓,MM23l和,MCF-7细胞PR检测为阴性;同期固定细胞ER、PR阳性表达的FCM检测结果与Western blot检测结果一致。结论：不同乳腺癌细胞在经0．25％多聚甲(paraformaldehyde,PFA)和75％乙醇固定后,可用于ER、PR的FCM定量检测,也可用于ER、PR的Western blot分析。     

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。     

ERβ1对乳腺癌MCF-7细胞Efp基因表达的抑制作用

目的 了解雌激素受体β1（ERβ1）对雌激素敏感性指状蛋白（Efp）基因的调节作用,为进一步探讨ERβ对Efp基因的调控机制奠定基础.方法 应用脂质体法将ERβ1真核表达质粒转染至乳腺癌MCF-7细胞中,再用Western blot检测转染细胞中Efp蛋白表达的变化.MTT比色试验观察ERβ1真核表达质粒转染后MCF-7细胞增殖活性的变化.结果 外源性ERβ1真核表达质粒组MCF-7细胞较未转染组MCF-7细胞Efp蛋白表达明显减弱.ERβ1基因转染后的MCF-7细胞的增殖活性降低.结论 ERβ1基因的表达可以抑制人乳腺癌MCF-7细胞中Efp基因的表达,并抑制MCF-7细胞的增殖能力,可能在乳腺肿瘤发生、发展机制中具有重要的作用.     

过表达CNTN1对裸鼠乳腺癌转移瘤生长的影响

目的:探讨过表达CNTN1对乳腺癌Hs578T细胞裸鼠皮下移植瘤生长的促进作用,为乳腺癌生物治疗提供实验依据.方法:脂质体法介导pEGFP-N1-CNTN1真核表达载体转染入乳腺癌Hs578T细胞,G418筛选出稳定表达CNTN1的Hs578T细胞(Hs578T-CNTN1细胞);接种Hs578T-CNTN1细胞制备裸鼠皮下移植瘤模型,观察CNTN1过表达对Hs578T细胞移植瘤生长的影响.结果:Western blot结果显,转染pEGFP-N1-CNTN1组Hs578T细胞中CNTN1蛋白表达量高于pEGFP-N1组及未转染组.Hs578T-CNTN1、Hs578T-N1和Hs578T细胞接种裸鼠的第20天,Hs578T-CNTN1组移植瘤质量较Hs578T组和Hs578T-N1组移植瘤质量显著增加[(4.62 ±0.22)g,(2.56 ±0.76)g和(2.10±0.78)g,分别P＜0.01和P＜0.05].结论:CNTN1过表达可以促进乳腺癌Hs578T细胞裸鼠移植瘤的生长.     

CNTN1基因对乳腺癌细胞株Hs578T增殖、迁移及侵袭能力的影响

目的：研究CNTN1基因对乳腺癌细胞株Hs578T细胞增殖、克隆形成、迁移及侵袭能力的影响。方法：将前期构建的稳定表达pEGFP－N1－CNTN1的Hs578T细胞系,采用MTT、流式细胞仪技术、平板克隆实验及Transwell实验检测pEGFP－N1－CNTN1对Hs578T细胞增殖、克隆形成、迁移及侵袭能力的影响。结果：与空白组及对照组相比,过表达CNTN1基因的Hs578T细胞增殖能力、克隆形成、迁移及侵袭能力增强（P＜0．05）。结论：CNTN1基因能够增强Hs578T细胞的增殖、克隆形成、迁移及侵袭能力。     

他莫昔芬对转染ERβ1基因的MCF-7细胞生长特性的影响

目的研究在不同处理因子作用下,外源基因ERβ1的表达对MCF-7乳腺癌细胞系生长特性的影响。方法利用脂质体转染方法将ERβ1真核表达载体pcDNA3.1-EGFPERβ1导入MCF-7乳腺癌细胞系。采用Western blot方法检测转染细胞中ERβ1的蛋白表达水平,筛选阳性克隆。以亲本细胞MCF-7为对照,分别在雌激素和雌激素受体拮抗剂他莫昔芬作用下观察细胞的生长特点。结果在转染ERβ1基因的MCF-7细胞系中,Western blot检测证实ERβ1的蛋白表达水平显著增高。在无处理因子的情况下,外源基因ERβ1在MCF-7细胞系中的表达能抑制细胞生长。与亲本细胞MCF-7细胞相比,转染ERβ1的MCF-7细胞对雌激素的敏感性下降,但对他莫昔芬的敏感性无明显变化。结论外源性ERβ1基因在MCF-7乳腺癌细胞中的稳定表达不增加对他莫昔芬的耐药性,但使之对雌激素的敏感性下降。     

Caveolin-1对乳腺癌细胞Hs578T耐药株生长、增殖的影响

目的：探讨caveolin-1基因对乳腺癌细胞系Hs578T耐药株（Hs578T／Dox）生长、增殖的影响。方法：在乳腺癌细胞系Hs578T耐药株中转染caveolin-1基因，构建高表达caveolin-1蛋白的细胞系（Hs578T／Dox—cav），Western Blot方法证实转染成功。MTT法绘制转染前后细胞生长曲线，比较生长速度的差别；将两种细胞接种于软琼脂中，比较转染前后集落形成的区别，接种于裸鼠体内，比较成瘤情况。结果：转染caveolin-1后Hs578T耐药株的生长速度明显加快（P〈0．01），集落形成明显增多（P〈0．01），裸鼠成瘤率明显增加（P〈0．01）。x结论：caveolin-1可促进乳腺癌细胞系Hs578T耐药株的生长和增殖。     

LRRK2在乳腺癌细胞增殖和耐药中的作用及其机制研究

目的:探讨LRRK2在乳腺癌组织中的表达及其对乳腺癌细胞增殖、凋亡及耐药的作用和分子机制.方法:采用实时荧光定量PCR(qRT-PCR)和Western blot检测了48例乳腺癌组织及其配对正常组织中LRRK2表达;并检测人正常乳腺上皮细胞MCF-10A、乳腺癌细胞株MCF-7、MDA-MB-231、BT-483及阿...     

稳定转染ERβ基因对MCF-7乳腺癌细胞系生长特性的影响

目的研究在不同处理因子作用下,外源基因ERβ的表达对MCF-7乳腺癌细胞系生长特性的影响。方法利用lipofectamine 2000将ERβ真核表达载体pCDNA3,ERβ导入MCF-7乳腺癌细胞系。采用含雌激素应答元件（ERE）的荧光素酶报告基因及Western blot方法,检测转染细胞中ERβ的转录活性和蛋白表达水平,筛选阳性克隆。以亲本细胞MCF-7及转染空载体质粒pCDNA3的MCF-7细胞为对照,在雌激素E2和雌激素受体拮抗剂4-OHT作用下观察细胞的生长特点。结果在转染ERβ基因的MCF3细胞系中,ERβ的转录激活活性明显升高;Western blot检测证实,ERβ的蛋白表达水平显著增高。在无处理因子情况下,外源基因ERβ在MCF-7细胞系中的表达对细胞的形态及生长速度无明显影响。与亲本细胞MCF-7及转染空载体质粒的MCF-7细胞相比,稳定转染ERβ的MCF-7细胞对雌激素的敏感性下降,但对4-OHT处理的敏感性无明显减少。结论外源性ERβ基因在MCF-7乳腺癌细胞中的稳定表达不增加对4-OHT的耐药性,但使之对雌激素的敏感性下降。     

细胞周期蛋白E小干扰RNA靶向调控乳腺癌细胞的生长

目的 研究乳腺癌细胞中细胞周期蛋白E(cyelin E)对乳腺癌细胞肿瘤生物学特征的影响.方法 用带有cyclin E小干扰RNA(siRNA)的真核表达载体pEGFP/CCNE2转染乳腺痛细胞系MCF-7.采用逆转录聚合酶链反应(RT-PCR)和Western blot方法分别在RNA水平和蛋白水平检测siRNA对细胞内cyclin E表达水平的影响,CCK-8方法检测转染后细胞株生长增殖能力以及对化疗药物的敏感性,流式细胞仪检测细胞周期的变化,裸鼠移植瘤成瘤实验检测转染后细胞成瘤能力的变化.结果 pEGFP/CCNE2转染后,MCF-7细胞内cyclin E的表达受到抑制,cyclin E mRNA相对表达水平为0.23±0.05,蛋白相对表达水平为0.24±0.05;细胞的生长增殖能力下降,抑制率为68.56%±0.08%,对化疗药物的敏感性增加;细胞被大量阻滞在G1期,G1期细胞占77.38%.细胞的成瘤能力降低,移植瘤体积缩小.结论 抑制乳腺癌细胞中cyclin E的表达能够抑制乳腺癌细胞的生长、分化和增殖,提高肿瘤对化疗药物的敏感性.     

Specific inhibition of DNMT1 by antisense oligonucleotides induces re-expression of estrogen receptor-alpha (ER) in ER-negative human breast cancer cell lines

Recent studies have shown that changes in epigenetic regulation, such as DNA methylation and histone acetylation, are associated with silencing of the estrogen receptor a (ER) gene in ER-negative human breast cancer cells. Treatment of these cells with the general DNMT inhibitor, 5-aza-2'deoxycytidine, led to reactivation of functional ER protein. This study addresses the hypothesis that specific inhibition of the maintenance DNA methyltransferase, DNMT1, by antisense oligonucleotides (DNMT1 ASO) is sufficient to re-express the ER gene in ER-negative human breast cancer cell lines. MDA-MB-231 and Hs578t cells were transfected with 100 nM and 150 nM DNMT1 ASO respectively for three consecutive days and evidence of DNMT1 downregulation and functional ER re-expression was sought. Significant growth reduction was observed within 48 hr and persisted after 96 hr. DNMT1 expression was blocked after exposure to DNMT1 ASO as detected by RT-PCR, Western blot and enzymatic assay whereas a mutant DNMT1 ASO had little effect. This was associated with enhanced ER mRNA and protein expression and restoration of estrogen responsiveness in MDA-MB-231 cells as demonstrated by the ability of the induced ER protein to elicit ERE-regulated reporter activity from a luciferase reporter construct. Methylation specific PCR showed that the ER CpG island was minimally demethylated, suggesting that other epigenetic events, introduced by specific DNMT1 inhibition, might also be involved in ER re-expression. Our results suggest that specific inhibition of DNMT1 expression alone is sufficient to re-express ERa in human breast cancer cell lines.     

Effect of transient expression of the oestrogen receptor on constitutive and inducible CYP1A1 in Hs578T human breast cancer cells.

Hs578T human breast cancer cells are an oestrogen receptor (ER)-negative cell line. Treatment of these cells with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) resulted in formation of a 6.9 S nuclear aryl hydrocarbon (Ah) receptor complex, which bound to a [32P]dioxin-responsive element in a gel electrophoretic mobility shift assay. However, TCDD does not induce CYP1A1 gene expression or chloramphenicol acetyl transferase (CAT) activity in cells transiently transfected with pRNH11c or pMCAT5.12, which are Ah-responsive plasmids derived from the 5''-flanking region of the human and murine CYP1A1 genes respectively. Restoration of Ah responsiveness was investigated by co-transfecting Hs578T cells with pRNH11c or pMCAT5.12 and plasmids that express the ER (hER), Ah receptor (AhR) and AhR nuclear translocator (Arnt) proteins. ER expression resulted in significantly increased basal CAT activity; however, TCDD did not induce CAT activity in the transiently transfected cells. Expression of the AhR or Arnt proteins did not alter basal or inducible CAT activity. Expression of N- or C-terminal truncated ER in Hs578T resulted in differential regulation of Ah responsiveness. In Hs578T cells transiently expressing the ER, which contains C-terminal deletions (amino acids 282-595), basal CAT activity was also increased; however, Ah responsiveness was not restored. In contrast, transient expression of N-terminal-deleted (amino acids 1-178) ER resulted in a marked decrease in basal CAT activity but a restoration of Ah responsiveness. These results suggest that basal and inducible CAT activity in Hs578T cells transiently transfected with pRNH11c is modulated differentially by ER domains that are present in the N- and C-terminal regions of the ER.     

Stable transfection and overexpression of metallothionein isoform 3 inhibits the growth of MCF-7 and Hs578T cells but not that of T-47D or MDA-MB-231 cells

The third isoform of metallothionein (MT-3) is overexpressed in some breast cancers and its expression is associated with a poor disease outcome. In the PC-3 prostate cancer cell line, MT-3 expression has been shown to inhibit cell growth and increase drug resistance. The goal of the present study was to determine if MT-3 overexpression would influence the growth of human breast cancer cell lines. To determine this, the coding sequence of the MT-3 gene was stably transfected into two estrogen receptor positive (MCF-7 and T-47D) and two estrogen receptor negative cell lines (Hs578T and MDA-MB-231) having no basal expression of MT-3. Cell growth was determined by counting DAPI-stained nuclei, cadmium resistance by the colony formation assay, MT mRNA expression by RT-PCR, and MT protein by immuno-blot. It was demonstrated that MCF-7 and Hs578T cells that overexpress the MT-3 gene were growth inhibited compared to untransfected cells. In contrast, T-47D and MDA-MB-231 cells that overexpress MT-3 were not growth inhibited. Stable transfection of the MT-1E gene had no effect on the growth of any of the four cell lines. It was also demonstrated that the overexpression of both MT-3 and MT-1E only increased the resistance of MCF-7 cells to Cd⁺². In all instances, stable transfection of the MT-3 or MT-1E gene had no effect on the expression of the other MT isoforms. The study shows that MT-3 can influence the growth of some breast cancer cell lines.     

Evaluation of ER,PgR, HER-2, Ki-67, cyclin D1, and nm23-H1 as predictors of pathological complete response to neoadjuvant chemotherapy for locally advanced breast cancer

To investigate the expression and significance of proteasomes reactivator REG gamma (γ) in breast cancer. First, we showed the expression of REGγ in breast cancer, metastatic lymph nodes and normal breast tissues. Meanwhile, we also analyzed the relationship between REGγ and estrogen receptor (ER), CerBb-2, lymph nodes metastasis and clinical stage of breast cancer. REGγ expression was determined by immunohistochemical staining and western blot. Secondly, we detected the expression of REGγ and REGγ-mRNA in human breast cancer cell lines (MDA-MB-231, MCF-7) and human breast ductal epithelial cell line (HBL-100) by western blot and real-time PCR. Finally, in order to identify effect of REGγ on breast cancer cell cycle and proliferation, we constructed recombinant plasmid of PcDNA3.1-REGγ and designed siRNA for REGγ in vitro. Cell cycle was assayed by flow cytometer (FCM), proliferation was measured by methyl thiazolyl tetrazolium (MTT). The results demonstrated abnormal high expression of REGγ in breast cancer and its metastatic lymph nodes. REGγ expression was related to breast cancer and its status of ER, CerBb-2 and lymph nodes metastasis. REGγ is one of the potential markers in breast cancer. REGγ could facilitate the growth of breast cancer cells.     

Growth regulation of estrogen receptor-negative breast cancer cells transfected with complementary DNAs for estrogen receptor.

BACKGROUND: The growth of estrogen receptor (ER)-positive breast cancer cells is hormonally regulated, but the majority of breast cancers are ER negative and unresponsive to hormonal therapy. PURPOSE AND METHODS: To test whether hormonal control over replication can be re-established in ER-negative cells, we transfected ER-negative MDA-MB-231 (clone 10A) cells with sense and antisense constitutive ER expression vectors containing the gene for either wild-type or mutant ER linked to the gene for neomycin resistance aminoglycoside phosphotransferase (neo). A Northern blot analysis was done on total RNA from eight of the 10 transfectant clones produced to detect messenger RNA coding for ER and neo, and a Western blot analysis was done on protein extracted from the cells of one mutant and two wild-type ER sense transfectant clones to determine the molecular weight of the ER in transfectants. Levels of ER in transfectants were measured both by enzyme immunoassay and by ligand-binding methods. To ascertain whether the ER in wild-type and mutant sense transfectants was functional, we tested the effects of 17 beta-estradiol (E2) and/or an antiestrogen, ICI 164,384, on 1) ER-activated gene regulation (by transient transfection of these cells a second time with a reporter plasmid containing an estrogen response element linked to the chloramphenicol acetyl transferase [CAT] gene), 2) induction of progesterone receptor, 3) DNA replication, and 4) cell cycle kinetics. RESULTS: Messenger RNA coding for ER and for neo was detectable in both sense and antisense transfectant clones. Sense transfectants (both mutant and wild-type) expressed ER protein with a molecular weight similar to that found in ER-positive control cells. By the ligand-binding method high levels of ER were detected in both wild-type and mutant transfectants, although by the enzyme immunoassay method lower levels were detected in mutant transfectants. ER from both wild-type and mutant sense transfectants appeared functional, since E2 stimulated the expression of reporter-linked CAT and of progesterone receptor in these transfectants. E2 inhibited DNA replication in wild-type sense transfectants at a concentration of 10(-10) M and mutant sense transfectants at a concentration of 10(-8) M, and ICI 164,384 blocked this effect. CONCLUSION: ER-negative breast cancer cells stably transfected with either a mutant or wild-type ER gene regain hormonal responsiveness; however, E2 inhibits rather than stimulates cell growth. IMPLICATION: Reactivation of quiescent ER may provide a novel therapeutic approach for controlling ER-negative breast cancers.