雌激素受体与乳腺癌内分泌治疗耐药的相关性研究

目的探讨雌激素受体β(ERβ)与乳腺癌内分泌治疗耐药的相关性。方法选取2010年1月至2015年6月间广东省惠州市中心人民医院收治的行乳腺癌改良根治术且接受他莫昔芬(TAM)内分泌治疗的100例早中期绝经后乳腺癌患者。检测乳腺癌患者ERβ表达情况,计算患者无肿瘤生存时间,比较不同ERβ表达患者间临床因素和预后的差异,分析ERβ表达差异与TAM内分泌治疗耐药的关系。结果 ERβ表达与原癌基因人类表皮生长因子受体2(HER-2)的表达相关,差异有统计学意义(P<0.05),与患者年龄、肿瘤大小、淋巴结转移、化疗及放疗无关,差异无统计学意义(P>0.05)。ERβ阳性表达患者无肿瘤生存率明显低于ERβ阴性表达患者,差异有统计学意义(P<0.05)。Cox多因素分析显示,ERβ阳性表达患者中,淋巴结转移是乳腺癌内分泌治疗预后不良的独立危险因素,差异有统计学意义(P<0.05)。结论 ERβ阳性表达在乳腺癌患者内分泌治疗耐药中具有重要作用,可能是导致患者预后不佳的危险因素之一。     

GPR30在乳腺癌内分泌治疗耐受中的作用研究

G蛋白偶联受体-30(G protein-coupled receptor 30,GPR30)是一种新型膜性结合性雌激素受体(estrogen receptor,ER).他莫昔芬(tamoxifen,TAM)及其代谢产物44}他莫昔芬(4-hydroxtamoxifen,OHT)是GPR30激动剂.GPR30的激活可能导致TAM耐药性的发生,GPR30可反式激活表皮生长因子受体(epidermal growth factor receptor,EGFR),介导E2增殖效应,可能与ERα具有协同作用,参与乳腺癌细胞增殖、侵袭和转移等行为.TAM作为ERα(+)的竞争性抑制剂,在乳腺癌内分泌治疗中占据着重要的地位,但是长期应用TAM的耐药限制了其临床应用.EGFR及ER相关信号途径,在TAM耐药机制中扮演重要角色.研究证实GPR30可反转TAM变成促生长激动剂,促进肿瘤生长.本文从GPR30的作用机制和TAM的耐药性机制联系为出发点,探讨GPR30在TAM耐药性中的作用.     

5-氮杂-2’-脱氧胞苷联合曲古菌素A对乳腺癌SKBR-3细胞中性激素受体基因表达的影响

目的:探讨5-氮杂-2’-脱氧胞苷(5-aza-2’-deoxycytidine,5-aza-dC)联合曲古菌素A(trichostatin A,TSA)能否诱导性激素受体阴性的乳腺癌细胞系SKBR-3同时重新表达功能性雌激素受体α(estrogen receptor alpha,ERα)和雄激素受体(androgen receptor,AR),并进一步研究诱导前后SKBR-3细胞对乳腺癌内分泌治疗敏感性的变化.方法:分别采用RT-PCR法和免疫细胞化学法检测5-aza-dC联合TSA诱导前后SKBR-3细胞和阳性对照MCF-7细胞中ERα、AR、孕激素受体(progestone receptor,PR)、雌激素调节蛋白pS2与前列腺特异性抗原(prostate specific antigen,PSA) mRNA和蛋白的表达水平;采用CCK-8法检测各内分泌治疗药物对5-aza-dC联合TSA诱导后重新表达ERα和AR的乳腺癌SKBR-3细胞增殖能力的影响.结果:5-aza-dC联合TSA能够诱导激素受体阴性的乳腺癌SKBR-3细胞同时重新表达ERα和AR,它们的下游产物PR、pS2以及PSA也相应表达;诱导后SKBR-3细胞中ERα和AR的表达量明显低于在MCF-7细胞中的表达量(P＜0.05).5-aza-dC联合TSA能明显抑制SKBR-3细胞的增殖能力(P＜0.05),加入雌激素类药物17β-雌二醇(17β-estradiol,E2)后细胞的增殖能力略有上升,但差异无统计学意义(P＞0.05).在加入E2的基础上,分别再加入雌激素拮抗剂他莫昔芬(tamoxifen,TAM)或孕激素醋酸甲地孕酮(megestrol acetate,MA)后,二者都能使肿瘤细胞的增殖能力明显下降(P＜0.05);联合加入TAM和MA后,肿瘤细胞的增殖能力进一步明显下降(P＜0.05).结论:5-aza-dC联合TSA能够诱导乳腺癌细胞系SKBR-3同时恢复表达功能性的ERα和AR,抑制肿瘤细胞的生长,同时使SKBR-3细胞恢复了对激素的依赖性和内分泌治疗的敏感性.     

雄激素受体与乳腺癌内分泌耐药的研究进展

乳腺癌是女性最常见的恶性肿瘤。其中雌激素受体（ER）阳性乳腺癌对内分泌治疗敏感,通过规范的内分泌治疗,患者复发及死亡风险显著降低。但是,内分泌耐药的出现成为临床治疗中最大的障碍。雄激素受体（AR）在ER阳性乳腺癌中广泛表达,与ER之间存在串扰,影响乳腺癌发展、内分泌耐药及预后。本文就AR在ER阳性乳腺癌中的作用机制、预后及内分泌治疗影响,尤其是内分泌耐药的相关研究进展进行综述。     

AR在乳腺导管原位癌中的表达及其与ER、PR表达的关系

目的:研究导管原位癌中雄激素受体(androgen receptor,AR)的表达情况,探讨AR表达与组织分级及与雌激素受体(estrogen receptor,ER)、孕激素受体(progesterone receptor,PR)表达的关系.方法:用免疫组织化学方法研究51例不同级别导管原位癌(breast ductal carcinoma in situ,DCIS)中AR的表达及与ER、PR表达状态的相关性.结果:AR阳性表达于18例DCIS中,33例DCIS中没有表达.13例低级别导管内癌中有3例AR阳性表达,15例中级导管内癌中有7例AR阳性表达,23例高级导管内癌中有8例AR阳性表达(P=0.4270).导管内癌的分化程度与ER(P =0.0036)及PR(P=0.0398)的表达密切相关.在导管内癌的不同组织学亚型间AR的表达差异有统计学意义(P=0.0156),但ER(P =0.0695)与PR(P=0.4672)的表达无差异.绝经前与绝经后患者导管内癌的AR表达无差异(P =0.6510),但ER(P=0.0074)与PR(P=0.0259)的表达有差异.结论:有一部分乳腺导管内癌表达AR,导管内癌的AR表达与组织分化程度无关,与DCIS中ER、PR表达也没有相关性.     

激素受体ER与PR及AR在男性乳腺癌与良性病变组织中的表达

目的:探讨激素受体(ER、PR和AR)在男性乳腺癌的表达及三种受体之间表达的相关关系。方法:采用免疫组化方法对ER、PR、AR三种受体进行检测,并用SPSS软件分析各组差异。结果:ER、PR在23例男性乳腺癌患者组织中表达阳性率较良性病变低,分别为82.6%、56.5%与良性疾病相比有明显的统计学差异(OR分别为:4.32和5.25,P<0.05),AR表达与ER、PR之间表达不相关。结论:男性乳腺癌患者中ER、PR表达阳性率较良性病变低,AR表达与ER、PR之间表达不相关。     

HER-2阳性乳腺癌中肿瘤浸润淋巴细胞与雄激素受体的相关性研究

  目的  探讨人表皮生长因子受体-2（human epidermal growth factor receptor-2，HER-2）阳性乳腺癌中肿瘤浸润淋巴细胞（tumor-infiltrating lymphocytes，TILs）浸润水平与雄激素受体（androgen receptor，AR）表达的关系。  方法  收集2018年3月至2018年11月天津医科大学肿瘤医院收治的448例HER-2阳性乳腺癌患者的临床资料。病理评估TILs浸润水平，免疫组织化学方法检测AR表达情况，分析TILs浸润水平和AR表达与临床病理学参数的关系以及TILs和AR的相关性。  结果  448例HER-2阳性乳腺癌患者中TILs无浸润或低浸润的患者占38.2%（171/448）、中等浸润者占42.2%（189/448）、高浸润者占19.6%（88/448），AR阳性率为62.7%（281/448）。Spearman等级相关分析显示TILs浸润水平与AR表达呈负相关（r=-0.140，P=0.003）。在雌激素受体（estrogen receptor，ER）阳性乳腺癌中，TILs浸润水平和AR表达密切相关（P=0.009）。  结论  HER-2阳性乳腺中TILs浸润水平和AR表达呈负相关，提示HER-2阳性乳腺癌患者可根据TILs的不同浸润水平与AR的表达行精准治疗。      

乙醛脱氢酶1与乳腺癌耐药蛋白在乳腺癌中的表达及相关性研究

背景与目的：乳腺癌患者对化疗药物耐药是导致化疗失败的主要原因。有研究证实,肿瘤干细胞标志物乙醛脱氢酶1(aldehyde dehydrogenase 1,ALDH1)与某些抗癌药物(如环磷酰胺、顺铂等)的耐药有关,并发现经这些药物治疗后的患者癌灶细胞中ALDH1的含量较治疗前高。乳腺癌耐药蛋白(breast cancerresistance protein,BCRP)不仅在正常组织中表达,更高表达于治疗后的乳腺癌中,提示这可能与肿瘤耐药机制相关。关于在乳腺癌患者中两者是否存在共表达的研究很少,本研究主要探讨ALDH1、BCRP与临床病理特征的关系及两种蛋白表达之间的相关性。方法：采用免疫组化法检测乳腺浸润性导管癌组织石蜡切片中ALDH1与BCRP的表达,研究并探讨它们与临床病理特征的关系以及两者表达之间是否有相关性。结果：ALDH1、BCRP在乳腺癌及癌旁乳腺组织中表达差异有统计学意义(χ²=14.685,P=0.000;χ²=12.243,P=0.000)。ALDH1的表达与患者年龄、病理分期、腋窝淋巴结转移、组织学分级及雌激素受体(estrogen receptor,ER)、孕激素受体(progesterone receptor,PR)、人类表皮生长因子受体(human epidermal growth factor receptor,HER-2)状态均无关(P>0.05);BCRP的表达与HER-2高表达有关,HER-2高表达组的癌组织中BCRP阳性表达率较高,差异有统计学意义(χ²＝5.289,P＝0.021)。BCRP的表达与患者年龄、肿瘤分化程度、腋窝淋巴结转移、病理分期及ER、PR状态无关(P>0.05);乳腺癌肿瘤干细胞标志物ALDH1与BCRP无相关性(r=-0.039,P=0.786)。结论：ALDH1可能是区别于其他耐药蛋白的一种独立的生物学因子,参与乳腺癌的化疗耐药或肿瘤的侵袭、转移等恶性生物学行为。     

HER-2过表达与乳腺癌内分泌治疗临床疗效的关系

内分泌耐药在乳腺癌治疗中是一个严峻的临床问题,其耐药的机制非常复杂且涉及多种基因的参与和调控.研究表明,在乳腺癌中HER-2的表达与雌激素受体ER呈负相关,但HER-2过表达的乳腺癌患者中仍有将近一半ER为阳性.现综述HER-2过表达、ER阳性乳腺癌患者内分泌治疗的疗效.     

POR overexpression induces tamoxifen-resistance in breast cancer through the STAT1/c-Myc pathway

Breast cancer is the most common cancer in women worldwide. Although tamoxifen (TAM), a selective estrogen receptor (ER) modulator, is widely used to treat ER-positive breast cancers, resistance to TAM remains a major clinical problem. NADPH-dependent cytochrome P450 reductase (POR) is known to participate in drug metabolism and steroid metabolism. Recent studies showed that high POR expression was correlated with poor outcomes in triple-negative breast cancer (TNBC), and POR might be a prognostic biomarker in TNBC. However, the role of POR in TAM resistance is still elusive. In this study, we found that high POR expression was associated with poor prognosis of ER-positive and TAM-treated breast cancer patients. In addition, COX analysis showed that POR expression was an independent prognostic biomarker for ER-positive as well as TAM-treated breast cancer patients. Furthermore, our results suggested that POR overexpression promoted TAM resistance by activating the STAT1/c-Myc pathway in ER-positive breast cancer cells. Immunohistochemical analysis showed that high POR/STAT1 expression was correlated with poor prognosis in TAM-treated breast cancer patients. Notably, combined treatment with TAM and a specific STAT1 inhibitor Fludarabine was more effective for inhibiting TAM-resistant breast cancer cells. Altogether, our findings suggested that POR overexpression induced TAM resistance through STAT1/c-Myc pathway and might serve as an independent prognostic biomarker in TAM-treated breast cancer patients. Combining TAM and STAT1 inhibitors might be an effective strategy for treating POR-induced TAM-resistant breast cancer.     

Disruption of estrogen receptor DNA-binding domain and related intramolecular communication restores tamoxifen sensitivity in resistant breast cancer

A serious obstacle to successful treatment of estrogen receptor (ER)-positive human breast cancer is cell resistance to tamoxifen (TAM) therapy. Here we show that the electrophile disulfide benzamide (DIBA), an ER zinc finger inhibitor, blocks ligand-dependent and -independent cell growth of TAM-resistant breast cancer in vitro and in vivo. Such inhibition depends on targeting disruption of the ER DNA-binding domain and its communication with neighboring functional domains, facilitating ERalpha dissociation from its coactivator AIB1 and concomitant association with its corepressor NCoR bound to chromatin. DIBA does not affect phosphorylation of HER2, MAPK, AKT, and AIB1, suggesting that DIBA-modified ERalpha may induce a switch from agonistic to antagonistic effects of TAM on resistant breast cancer cells.     

Investigation of elemene-induced reversal of tamoxifen resistance in MCF-7 cells through oestrogen receptor α (ERα) re-expression

Endocrine therapy is an important therapeutic approach for the treatment of oestrogen receptor (ER)-positive breast cancer. However, a number of these endocrine therapies can fail when the tumour loses its ER expression during treatment. To date, few studies have explored the potential clinical significance of traditional Chinese medicine in inducing the reversal of resistance to endocrine therapy in breast cancers. We used the ER??-negative MCF7 breast cancer cell line to create a tamoxifen (TAM)-resistant cell line, MCF7/TAM cells. After treating MCF7/TAM cells with ELE to induce the re-expression of ER??, we investigated the role and molecular mechanisms by which elemene (ELE) promotes the reversal of resistance to endocrine therapy. We discovered that treatment with 10???g/ml ELE restored the sensitivity of MCF7/TAM cells to TAM. RT-PCR analysis revealed that ELE treatment upregulated ER?? mRNA levels in MCF7/TAM cells, and immunohistochemistry confirmed the upregulation of ER?? expression. Western blot analysis revealed that ELE treatment decreased the protein expression levels of Ras, MEK1/2 and p-ERK1/2 in MCF7/TAM cells. The loss of ER?? expression was the primary reason for TAM resistance in MCF7 cells. The ELE-induced reversal of TAM resistance was mediated by the upregulation of ER?? mRNA and the re-expression of ER?? through the MAPK pathway.     

三苯氧胺抑制实验的建立及临床意义

应用三苯氧胺（ＴＡＭ）抑制实验对３９例乳腺癌ＥＲ（＋）病人进行了检测。其中２４例ＴＡＭ抑制实验有不同程度的抑制阻断，抑制率从１０％～１００％。其余１５例ＥＲ（＋）者，而ＴＡＭ抑制率为零。不同组织学类型ＴＡＭ抑制率实验似有差异，髓样癌的阳性检出率较浸润性导管癌高。从理论上讲，ＴＡＭ在部分ＥＲ（＋）病人体内，并不能阻断Ｅ２与受体结合，因而对ＴＡＭ抑制实验阴性的病人，ＴＡＭ不能起到治疗效果。因此建议进行激素受体测定时，加测ＴＡＭ抑制实验，以指导临床用药。     

三苯氧胺诱导人乳腺癌MCF-7细胞株耐药及自噬的关系研究

背景与目的:三苯氧胺(tamoxifen)作为第一代选择性雌激素受体调节剂(selective estrogen receptor modulator,SERM)被广泛地应用于激素敏感型乳腺癌的内分泌一线治疗。三苯氧胺耐药的发生严重限制了临床治疗,是乳腺癌患者用药面临的重大难题,明确其耐药机制对乳腺癌的治疗有重要临床意义。本研究通过体外诱导人乳腺癌细胞MCF-7三苯氧胺耐药,探讨细胞产生三苯氧胺耐药时自噬水平的变化与MAPK家族蛋白细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)蛋白表达量及磷酸化水平的变化。方法:浓度递增筛选法诱导MCF-7细胞耐药,透射电镜观察MCF-7细胞与耐药细胞内的自噬泡数量,CCK8法检测细胞增殖状态,应用Western blot检测LC3Ⅱ、ERK1/2、Phospho-ERK1/2蛋白的表达情况。结果:诱导的三苯氧胺耐药细胞株TR5达到5μmol/L的耐药浓度。TR5细胞内的自噬泡数量与LC3Ⅱ表达量明显高于MCF-7细胞。ERK蛋白在两种细胞中的表达量差异无统计学意义,但其在TR5中的磷酸化水平比MCF-7细胞高。结论:...     

Antitumor action of physiological estradiol on tamoxifen-stimulated breast tumors grown in athymic mice.

The estrogen receptor (ER)-positive MCF-7 breast cancer cell line can be transplanted into athymic mice and grown into tumors with estradiol (E2) support. Tamoxifen (TAM) blocks E2-stimulated tumor growth; however, continuous TAM treatment results in transplantable tumors within a year that will grow with either E2 or TAM (M. M. Gottardis and V. C. Jordan, Cancer Res., 48: 5183-5187, 1988). Although this model may represent the development of TAM resistance for the treatment of advanced breast cancer, no laboratory model exists to study the exposure of breast cancer to 5 years of adjuvant TAM therapy. We have addressed this issue and report the development and characterization of two tumor lines, MCF-7TAM and MT2, which have been serially transplanted into TAM-treated athymic mice for >5 years. The MCF-7TAM tumor rapidly regresses in response to E2 and then about 50% of tumors regrow in response to E2. Interestingly, tumor regression does not occur if TAM treatment is stopped, probably because E2 levels are too low in ovariectomized athymic mice. The development of the antitumor effect of E2 was documented for MT2 tumors over a 1-year period; TAM-stimulated tumor growth was retained, but E2 caused progressively less of a stimulatory effect. Most importantly, E2-stimulated tumors that regrew after initial tumor regression in both MCF-7TAM and MT2 lines were again responsive to TAM to block E2-stimulated growth. Unlike MCF-7 tumors, the MT2 tumor line contains a single point mutation, Asp351Tyr, in the ER, which was retained after the development of E2-stimulated regrowth. The mutation is associated with increased estrogen-like actions for the TAM-ER complex (A. S. Levenson et al., Br. J. Cancer, 77: 1812-1819, 1998), but we conclude that the mutant ER is not required for TAM resistance. On the basis of the new breast cancer models presented, we propose a cyclic sensitivity to TAM that may have important clinical implications: (a) it is possible that a woman's own estrogen may produce an antitumor effect on the presensitized micrometastatic disease after 5 years of TAM. Long-term antitumor action occurs because the drug is stopped, but resistance accumulates and tumors start to grow if adjuvant therapy is continued; and (b) although in the clinic TAM-resistant tumors respond to second-line therapies that cause estrogen withdrawal, e.g., pure antiestrogens or aromatase inhibitors, estrogen therapy may also be effective and return the tumor to TAM responsiveness. In this way, a hormone-responsive tumor may be controlled longer in the patient with advanced disease.     

乳腺癌他莫昔芬耐药机制的研究进展

他莫昔芬(Tamoxifen,TAM)对于治疗雌激素受体(ER)阳性的乳腺癌是一种重要的治疗策略.然而TAM耐药是内分泌治疗失败的一个主要原因.TAM耐药的潜在机制是多因素的,其中大部分仍是未知的.本文介绍了近年来有关乳腺癌TAM耐药机制的研究进展,为阐明TAM耐药机理及克服耐药性提供有价值的信息和思路.     

Resistance to tamoxifen-induced apoptosis is associated with direct interaction between Her2/neu and cell membrane estrogen receptor in breast cancer.

Overexpression of Her2/neu is implicated in the development of resistance to the antiestrogen tamoxifen (TAM) that exerts its inhibitory effect through interaction with estrogen receptor (ER). Whereas Her2/neu and ER are believed to be important cell survival/death factors in human breast cancer cells, if and how they interact to confer resistance to hormone therapy is not known. This prompted us to investigate whether modulation of the effect of TAM occurs via the Her2/neu pathway and whether targeting the interaction between the Her2/neu pathway and the ER pathway is beneficial. There are 2 forms of ER that are localized to the cell membrane and to the nucleus. For the first time, we found that Her2/neu directly interacts with ER at the cell membrane. We then investigated the role of Her2/neu overexpression in the regulation of the cell membrane ER pathway in TAM-resistant breast cancer cells and the nature of this interaction in apoptotic signaling. Relief of TAM resistance was associated with Her2/neu downregulation and ER upregulation. TAM-induced apoptosis occurred immediately after dissociation of Her2/neu from cell membrane ER. These results demonstrate a novel mechanism by which Her2/neu regulates the cell membrane ER-coupled apoptosis and the possible involvement of the Her2/neu in TAM resistance of breast cancer cells. Moreover, the antiproliferative activity of TAM should rely on the integration between the signal transduction from the cell membrane ER and the gene regulation by the nuclear ER. Coordinated modulation on the cell membrane ER/Her2/neu pathway and the nuclear ER/RAR pathway may provide a new approach for treatment of ER-positive, Her2/neu overexpressing breast cancer.