人表皮生长因子受体-2及雌激素受体与乳腺癌的关系

乳腺癌与人表皮生长因子受体-2及雌激素受体关系密切,这两种受体也是乳腺癌的分类标准和治疗靶点。在大多数乳腺癌患者中,人表皮生长因子受体-2信号途径和雌激素受体信号途径参与了细胞的增生存活过程。而且在乳腺癌病例中,人表皮生长因子受体-2和雌激素受体呈现出一定程度的负相关。这说明这两种受体活化后有一些联系。本文简要综述了人表皮生长因子受体-2和雌激素受体的联系以及这种联系在乳腺癌治疗中的意义。     

Let －7c 通过阻断雌激素激活的 Wnt 信号通路活性而抑制乳腺癌干细胞的自我更新能力

目的：探究 Let －7c 是否能通过 Wnt 信号通路调控乳腺癌干细胞自我更新能力。方法：分析乳腺癌临床样本中 Let －7家族成员的表达情况,检测 Let －7与 ERα的相关性,进一步探讨 Let －7c 与 Wnt 通路活性分子表达的相关性;在细胞试验中,通过 ALDH 流式细胞仪分选法及微成球实验分选乳腺癌干细胞;采用免疫印迹、荧光素酶报告试验及免疫荧光实验,验证 Let －7c 与 ERα－3＇UTR 是否能直接结合。结果：Let －7家族成员在乳腺癌组织中高表达,并且 Let －7b 和 Let －7c 的表达与患者临床预后显著相关;Let －7c 表达与ERα表达呈负相关,Let －7c 表达与 Wnt 信号通路活性分子呈负相关;Let －7c 能够抑制雌激素受体阳性乳腺癌干细胞自我更新能力;Let －7c 能够直接结合到 ERα－3＇UTR 上,进而抑制 ERα的表达和雌激素激活的Wnt 信号通路。结论：我们的研究首次证实了 Let －7c 通过抑制雌激素激活的 Wnt 通路活性,而对肿瘤干细胞的自我更新能力产生抑制作用。     

Effects of estrogen on breast cancer development: Role of estrogen receptor independent mechanisms

Development of breast cancer involves genetic factors as well as lifetime exposure to estrogen. The precise molecular mechanisms whereby estrogens influence breast tumor formation are poorly understood. While estrogen receptor α (ERα) is certainly involved, nonreceptor mediated effects of estradiol (E₂) may also play an important role in facilitating breast tumor development. A “reductionist” strategy allowed us to examine the role of ERα independent effects of E₂ on mammary tumor development in ERα knockout (ERKO) mice bearing the Wnt‐1 oncogene. Exogenous E₂ “clamped” at early follicular and midluteal phase levels (i.e., 80 and 240 pg/ml) accelerated tumor formation in a dose‐related fashion in ERKO/Wnt‐1 animals (p = 0.0002). Reduction of endogenous E₂ by oophorectomy (p < 0.001) or an aromatase inhibitor (AI) (p = 0.055) in intact ERKO/Wnt‐1 animals delayed tumorigenesis as further evidence for an ER‐independent effect. The effects of residual ERα or β were not involved since enhancement of tumor formation could not be blocked by the antiestrogen fulvestrant. 17α‐OH‐E₂, a metabolizable but ER‐impeded analogue of E₂ stimulated tumor development without measurable uterine stimulatory effects. Taken together, our results suggest that ER‐independent actions of E₂ can influence breast tumor development in concert with ER dependent effects. These observations suggest 1 mechanism whereby AIs, which block E₂ synthesis, would be more effective for breast cancer prevention than use of antiestrogens, which only block ER‐mediated effects.     

CD44 variant expression and estrogen receptor status in breast cancer

To understand the relationship between CD44 gene expressionand an established variable associated with aggressive behaviourin human breast cancer, we have studied apanel of 6 breast cell lines and 40breast tumors selected primarily on the basis ofestrogen receptor (ER) status. CD44s (standard form) mRNAwas assessed by semi-quantitative RT-PCR, and CD44 variantsincorporating exon v7 or v10 were studied byRT-PCR and Southern blot. While CD44 expression wasnot influenced by estrogen in ER+ve MCF-7 cells,CD44s expression was slightly higher (up to 2fold) in ER–ve cells but there was amarked decrease in the range of CD44 variantsincorporating exons v7 or v10. In microdissected tumors,the levels of CD44s showed no correlation withER status but the pattern of expression oflarger forms of CD44 incorporating variant exons v7and v10 was significantly different (p=0.005and p=0.015, respectively) between ER+ve andER–ve tumors, reflecting the pattern seen in thecell lines. These findings suggest that the profileof CD44 expression in breast cancer may reflectcellular differentiation as indicated by the ER phenotype.The influence of these differences in CD44 expressionon the increased metastatic potential of ER negativebreast cancer remains to be determined.     

Immunohistochemical detection of estrogen receptor,progesterone receptor,and human epidermal growth factor receptor 2 expression in breast carcinomas

BACKGROUND:

Fine‐needle aspiration (FNA) is a rapid and accurate procedure for the detection of breast carcinomas. The evaluation of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression by immunohistochemistry (IHC) is performed routinely on formalin‐fixed, paraffin‐embedded needle‐core (NC) or excision tissue block (TB) preparations, according to the American Society of Clinical Oncology/College of American Pathologist guidelines. In this retrospective study, the authors compared expression levels of ER, PR, and HER2 in ethanol‐fixed BC FNA cell block (CB) samples with expression levels in formalin‐fixed NC and TB samples.

METHODS:

Forty‐one breast carcinoma CB samples with concurrent or subsequent NC and TB samples were identified. Patients who had received neoadjuvant or adjuvant chemotherapy were excluded. CB samples initially were fixed in 50% ethanol (4‐12 hours), and this was followed by formalin fixation (minimum, 6 hours). NC samples were placed promptly in formalin for a minimum of 6 hours. Within 4 to 8 hours, TB samples were fixed in formalin for 6 to 48 hours. Fluorescence in situ hybridization (FISH) results were also compared.

RESULTS:

IHC for ER on alcohol‐fixed CB samples had good correlation with NC and TB samples. PR results on TB samples had excellent agreement with NC samples. A higher discordance rate wais observed when PR results were compared between CB samples and NC samples. HER2 detection on ethanol‐fixed CB samples resulted in a higher rate of positive and equivocal staining than NC or TB samples. HER2 IHC on TB samples demonstrated better correlation with FISH results than CB or NC samples.

CONCLUSIONS:

Alcohol fixation did not affect ER results in breast carcinoma, but it may alter tumor cell PR antigenicity. The authors concluded that CB samples could be used to triage patients for tamoxifen therapy, but they are not reliable for the assessment of HER2 status; therefore, CB results should be correlated with results from NC or TB samples. Cancer (Cancer Cytopathol) 2009. © 2009 American Cancer Society.     

乳腺癌组织缺氧与雌激素受体-α的关系

目的:缺氧是乳腺癌常见的现象,并可能诱导肿瘤的进展。雌激素受体(ER)-α状态是乳腺癌预后和内分泌治疗疗效的重要预测指标。本研究旨在揭示乳腺癌中缺氧与ER-α表达的关系。方法:51例患者经配体结合法证实为ER阳性的乳腺癌。采用免疫组织化学染色的方法观察ER-α的异质性表达与多种缺氧标志的关系。结果:免疫组织化学染色发现本组有49例乳腺癌为ER-α阳性。无论乳腺导管内癌(n=29)还是浸润性癌(n=20),ER-α蛋白在邻近坏死灶的区域都出现了下降(P分别≤0.0001);ER-α的区域性下调还与缺氧诱导基因CA-Ⅸ和Glut-1的表达有关(P<0.0001)。结论:乳腺癌中ER-α区域性的表达下降与缺氧有关。因此缺氧可能促使乳腺癌在进展过程中向ER-α阴性的表型演变。     

65 and 47 kDa forms of estrogen receptor in human breast cancer: relation with estrogen responsiveness

Summary In breast cancer nearly 40% of estrogen receptor (ER) positive patients do not respond to hormone therapy. As several species of ER have been described, we examined 41 breast cancers for: (1) the presence of ER and progesterone receptor (PR); (2) the molecular weight (Mr) of ER; (3) estrogen responsiveness, appreciated by the ability of a piece of tumor transplanted in nude mice to show an estrogen-induced protein synthesis (PR synthesis). We found that there are: two species of ER with different Mr (65 and 47 kDa), and three species of tumors (36% containing the highest form of ER alone, 49% bearing the two components in variable amounts, and 15% bearing only the minor species). Eleven of these 41 tumors could be assayed for PR synthesis induction, showing that estrogen responsiveness is correlated with the major component. Due to the limited number of samples (11) the data are preliminary, but they strongly suggest that the different forms of ER could exist in the living cell with different functional abilities.     

Incidence of an estrogen receptor polymorphism in breast cancer patients

Summary We previously identified a polymorphism in the human estrogen receptor (ER) gene, within the coding region for the protein's amino terminal B-domain. In estrogen receptor-positive (ER⁺) breast tumors, the variant allele was preferentially associated with lower levels of ER, and was clinically correlated with frequent spontaneous abortions. DNA sequencing revealed a point mutation that changes codon 86 from Ala to Val and a silent mutation in codon 87. Because we initially detected the variant allele by analyzing RNA, only those tissues in which the ER gene is actively expressed were suitable for genotype analysis. We now describe an assay that uses genomic DNA as the substrate for determining the ER B genotype; DNA containing the polymorphic region of the ER gene is amplified by the polymerase chain reaction, then the amplified DNA is hybridized with radiolabeled oligonucleotide probes complementary to the wild type and variant ER alleles. This method allowed us to determine the ER B genotype of women with ER⁺ and ER^– tumors, starting with minute amounts of DNA from frozen or paraffin embedded tissues. ER B genotyping was also performed on women without breast cancer using DNA extracted from blood cells. The combined results from analyses of RNA and DNA from 300 breast cancer patients showed that 12% were heterozygotes. In the ER⁺ group (n=183), 11.5% carried the variant gene compared to 12.8% in the ER-negative group (n=117) (²=0.11; df=1; p>0.25). No link to tumor histology could be established. Preliminary data on DNA from blood of healthy women over the age of 50 (n=64) yielded a slightly lower ER B-variant frequency (9.4%); this frequency was not significantly different than that in the breast cancer groups. Thus, while the variant ER allele is associated with low ER levels in ER positive breast tumors, its frequency is not different in the ER⁺ and ER^– tumor groups and may be unrelated to breast cancer development.     

Estrogen and estrogen receptor alpha promotes malignancy and osteoblastic tumorigenesis in prostate cancer

The role of estrogen signaling in regulating prostate tumorigenesis is relatively underexplored. Although, an increasing body of evidence has linked estrogen receptor beta (ERβ) to prostate cancer, the function of estrogen receptor alpha (ERα) in prostate cancer is not very well studied. We have discovered a novel role of ERα in the pathogenesis of prostate tumors. Here, we show that prostate cancer cells express ERα and estrogen induces oncogenic properties in prostate cancer cells through ERα. Importantly, ERα knockdown in the human prostate cancer PacMetUT1 cells as well as pharmacological inhibition of ERα with ICI 182,780 inhibited osteoblastic lesion formation and lung metastasis in vivo. Co-culture of pre-osteoblasts with cancer cells showed a significant induction of osteogenic markers in the pre-osteoblasts, which was attenuated by knockdown of ERα in cancer cells suggesting that estrogen/ERα signaling promotes crosstalk between cancer and osteoblastic progenitors to stimulate osteoblastic tumorigenesis. These results suggest that ERα expression in prostate cancer cells is essential for osteoblastic lesion formation and lung metastasis. Thus, inhibition of ERα signaling in prostate cancer cells may be a novel therapeutic strategy to inhibit the osteoblastic lesion development as well as lung metastasis in patients with advanced prostate cancer.     

Expression of c-erbB2, cyclin D1 and estrogen receptor and their clinical implications in the invasive ductal carcinoma of the breast

BACKGROUND: C-erbB2 and estrogen receptors (ER) are well known for their cell proliferative capacity. Cyclin D1 is a major downstream target of both c-erbB2 and ER. This study was designed to analyze the expression of c-erbB2, cyclin D1 and ER and their prognostic implications in invasive ductal carcinoma of the breast. METHODS: The c-erbB2 status was evaluated by fluorescence in situ hybridization and immunohistochemistry (IHC) and cyclin D1 and ER were evaluated by IHC in 333 invasive breast cancer specimens. RESULTS: The results of FISH and IHC for c-erbB2 showed 86.7% concordance. The overexpression of c-erbB2 was associated with the high expression of cyclin D1 and the negative expression of ER (P < 0.01 for both). The high expression of cyclin D1 was associated with the positive expression of ER (P < 0.01). When the group of patients who overexpressed c-erbB2 were analyzed, the patients with the low expression of cyclin D1 showed a significantly higher mortality than those with the high expression of cyclin D1 (RR = 3.2; 95% CI, 1.6-6.6). When the group of the high cyclin D1 expression was analyzed, the patients with negative expression of ER showed a significantly higher mortality than those with the positive expression of ER (RR = 2.1; 95% CI, 1.1-3.8). CONCLUSIONS: Higher expression of cyclin D1 was associated with better prognosis in patients with c-erbB2 overexpression, and positive expression of ER was associated with better prognosis in patients with high cyclin D1 expression.     

ERβ、C-erbB-2及bcl-2蛋白在乳腺癌组织的表达及意义

目的：检测乳腺癌组织中雌激素受体p（ERp）、C—erbB-2和bcl-2蛋白的表达情况，并分析ERB蛋白的表达与组织学分级、C—erbB-2及bcl-2蛋白表达的关系。方法：采用免疫组化S—P法检测96例乳腺癌组织标本中ERB、C—erbB-2及bcl-2蛋白的表达情况，并作统计学分析。结果：96例乳腺癌组织标本中，ERp、C—erbB-2及bcl-2蛋白阳性表达率分别为64．6％、36．5％和51．0％；ERB蛋白的表达与组织学分级、C—erbB-2蛋白的表达呈负相关（P〈0．05），与bcl-2蛋白的表达呈正相关，与腋淋巴结状态无关（P〉0．05）。结论：ERB蛋白表达可能是乳腺癌患者预后良好的指标。     

Anticancer effects of wogonin in both estrogen receptor-positive and -negative human breast cancer cell lines in vitro and in nude mice xenografts

Wogonin is a plant monoflavonoid which has been reported to inhibit cell growth and/or induce apoptosis in various tumors. Herein, we investigated the in vitro and in vivo anticancer effects and associated mechanisms of wogonin in human breast cancer. Effects of wogonin were examined in estrogen receptor (ER)-positive and -negative human breast cancer cells in culture for proliferation, cell cycle progression, and apoptosis. The in vivo effect of oral wogonin was examined on tumor xenograft growth in athymic nude mice. The molecular changes associated with the biological effects of wogonin were analyzed by immunoblotting. Cell growth was attenuated by wogonin (50-200 microM), independently of its ER status, in a time- and concentration-dependent manner. Apoptosis was enhanced and accompanied by upregulation of PARP and Caspase 3 cleavages as well as proapoptotic Bax protein. Akt activity was suppressed and reduced phosphorylation of its substrates, GSK-3beta and p27, was observed. Suppression of Cyclin D1 expression suggested the downregulation of the Akt-mediated canonical Wnt signaling pathway. ER expression was downregulated in ER-positive cells, while c-ErbB2 expression and its activity were suppressed in ER-negative SK-BR-3 cells. Wogonin feeding to mice showed inhibition of tumor growth of T47D and MDA-MB-231 xenografts by up to 88% without any toxicity after 4 weeks of treatment. As wogonin was effective both in vitro and in vivo, our novel findings open the possibility of wogonin as an effective therapeutic and/or chemopreventive agent against both ER-positive and -negative breast cancers, particularly against the more aggressive and hormonal therapy-resistant ER-negative types.     

Estrogen receptor alpha expression in normal human breast epithelium is consistent over time

If increased expression of estrogen receptor alpha (ER) in benign breast epithelium increases susceptibility to breast cancer, such overexpression should be stable over time. There are no published data regarding this important aspect of ER expression in breast epithelium. We examined the temporal consistency of ER expression in the normal breast tissue of 28 women who had 2 separate breast surgical procedures, at least 6 months apart (mean interval, 2.8 years). Paraffin embedded breast tissue blocks containing an adequate sample of normal breast epithelium and no cancer, were sectioned and processed using the 6F11 antibody and standard immunohistochemical techniques. The ER labelling index (ER LI) was calculated by counting a mean of 2,000 epithelial cells. The median ER LI at first sampling was 13.6 and at second sample 15.5, with R(2) = 0.34 and p = 0.001. The ER LI was categorized into high and low values, using a threshold of 10. Twenty-four women (85.7%) showed concordance of high and low expression between the 2 samples (p = 0.002). There were 11 women who were premenopausal at both time points. Among them, much of the variation in ER LI was explained by differences in the menstrual cycle day at the time of sampling and adding the day of cycle to the regression model substantially improved the correlation between first and second labeling indices. These data suggest that ER expression of normal breast tissue is fairly consistent over time and support the notion that overexpression of ER in normal epithelium is a constant feature of the high risk breast.     

Survivin与乳腺癌雌激素受体信号通路相关基因的相关性

目的:探讨乳腺癌中Survivin与雌激素受体（estrogen receptor,ER）信号通路相关基因的相关性。方法:采用Real-time PCR技术检测10例乳腺癌组织中Survivin的含量,选择含量最高的3例作为高表达组,含量最低的3例作为低表达组;采用人乳腺癌雌激素受体信号通路PCR芯片检测两组标本中相关基因表达的差异。结果:两组标本中Survivin的含量差异有统计学意义（P<0.05）。雌激素受体信号通路相关基因PCR芯片检测结果表明,Survivin低表达组的ER含量较高表达组降低,但差异无统计学意义（P>0.05）;Survivin低表达组的CDKN1B、NME1、ERBB2、TOP2A含量较高表达组显著降低,差异有统计学意义（P<0.05）。结论:在乳腺癌中,Survivin与CDKN1B、NME1、ERBB2、TOP2A的表达在mRNA水平上呈正相关,与ER的表达存在着正相关的趋势,表明Survivin与雌激素受体信号通路之间存在着一定的相关性。Survivin在乳腺癌的内分泌治疗中可能具有潜在的重要意义。     

雌激素受体表达与癌家族史阳性乳腺癌的关系

目的　为了探讨癌家族史阳性乳腺癌妇女ER水平是否高于非癌家族性乳腺癌者。方法　采用莹光组织化学法检测了本院 1985～ 1998年间 430例妇女可手术乳腺癌的新鲜组织ER水平 ,对其中癌家族史阳性乳腺癌ER与非癌家族性乳腺癌ER水平进行比较分析。结果　在 430例乳腺癌组织总的ER阳性率为 5 0 .2 % (2 16 / 430 ) ,其中绝经期前、后ER阳性率分别为 46 .3 % (6 8/ 14 7)和 5 0 .7% (10 7/ 2 11)。癌家族史阳性乳腺癌ER阳性率为 5 5 .1% (2 7/ 49) ;家族性乳腺癌ER阳性率为 72 .2 % (8/ 11) ;非癌家族性乳腺癌ER阳性率为 49.6 % (189/ 381)。结论　癌家族史阳性乳腺癌ER和家族性乳腺癌ER水平分别与非癌家族性乳腺癌ER相比 ,各呈明显增高倾向 ,但经统计学处理P >0 .0 5 ,认为无显著差异。本组乳腺癌病人中至少半数病例属于雌激素受体依赖性肿瘤 ,而且绝经期后水平略高于绝经期前者。     

Impact of low estrogen/progesterone receptor expression on survival outcomes in breast cancers previously classified as triple negative breast cancers

PURPOSE:

To evaluate the impact of low estrogen/progesterone receptor (ER/PR) expression and effect of endocrine therapy on survival outcomes in human epidermal growth factor receptor 2 (HER2)‐negative tumors with ER/PR <10%, previously labeled as triple negative.

METHODS:

In a retrospective review, 1257 patients were categorized according their ER/PR percentages into 3 groups, ER/PR <1% (group A), ER/PR 1% to 5% (group B), and ER/PR 6% to 10% (group C). Kaplan‐Meier product limit method was used to estimate survival outcomes. Cox proportional hazards models was used to adjust for patient and tumor characteristics.

RESULTS

Groups A, B, and C had 897 (71.4%), 241 (19.2%), and 119 (9.4%) patients, respectively. After a median follow‐up of 40 months there was no significant difference in 3‐year recurrence‐free survival (RFS): 64%, 67%, and 77% (P = .34) or overall survival (OS): 79%, 81%, and 88% (P = .33) for groups A, B, and C, respectively. ER/PR expression was not an independent predictor for RFS (hazard ratio [HR], 1.10; 95% confidence interval [CI], 0.86‐1.39; P = .46 for group B, and HR, 0.96; 95% CI, 0.66‐1.38; P = .81 for group C, compared with group A), or OS (HR, 1.11; 95% CI, 0.84‐1.46; P = .46 for group B, and HR, 0.94; 95% CI, 0.63‐1.42; P = .78 for group C, compared with group A). Endocrine therapy had no impact on survival outcomes (RFS: P = .10; OS: P = .45) among groups.

CONCLUSIONS:

In this cohort, a low ER/PR level (1%‐5%) does not appear to have any significant impact on survival outcomes. There was a tendency for survival advantages in the ER/PR 6% to 10% is seen. Benefit of endocrine therapy in these patients is unclear. Cancer 2011;. © 2011 American Cancer Society.     

Genomic DNA analysis of the estrogen receptor gene in breast cancer

Summary A human estrogen receptor (ER) cDNA probe was used to examine genomic DNA extracted from 59 primary invasive breast cancers. The tumors were also studied histopathologically, and their ER status was assessed by hormone-binding assay and immunohistochemical analysis. Southern blots of genomic DNA samples digested with restriction endonucleases (BamHI, EcoRI, HindIII, PvuII, XbaI) revealed identical restriction fragments for each tumor, indicating preservation of gross ER gene integrity regardless of ER status, clinical stage, or histopathologic appearance. Digestion with PvuII identified a single, two-allele polymorphism with band(s) at 1.6 and/or 0.7 kb. The homozygous 1.6 kb pattern was present in 14 (24%) patients, the heterozygous 1.6/0.7 kb pattern in 29 (49%) patients and the homozygous 0.7 kb pattern in 16 (27%) patients. The PvuII restriction fragment length polymorphism (RFLP) within the ER gene showed no correlation with the results of the ER binding assay, the immunohistochemical analysis, clinical stage, or histopathologic appearance. A significant correlation was found between the genotypes and patient age at the time of tumor diagnosis. Tumors with the homozygous 1.6 kb and the heterozygous 1.6/0.7 kb patterns were observed in older women with mean ages of 64.6 and 64.4 years, respectively. In contrast, patients with tumors containing the homozygous 0.7 kb pattern were significantly younger, with a mean age of 50.4 years (p-value = 0.0024). The mechanism by which the homozygous 0.7 kb genotype is associated with breast cancer in the premenopausal age group is unknown.     

Prognostic effect of estrogen receptor status across age in primary breast cancer

Estrogen receptor (ER) status is considered as an important prognostic factor as well as a predictive factor for endocrine responsiveness in breast cancer. We analyzed the distribution of ER status across age and estimated variations in the prognostic impact of ER status related to patients' age and time since diagnosis. Overall, 26,944 patients with primary breast cancer diagnosed from 1989 to 2004 were included. The proportion of ER positive tumors increased over age from 51 to 82%. In multivariate analysis of overall survival, ER positive status was found to be a significantly positive prognostic factor over all age groups. This effect was limited to the first 5 years after diagnosis, RR: 2.08 (95% CI: 1.95-2.22, p < 0.0001). Overall survival during the following 5 years was slightly superior for women with ER negative tumors, RR of death: 0.89 (95% CI: 0.79-1.00, p = 0.049). Results were unchanged in patients who did not receive adjuvant systemic therapy (n = 6,272). Thus, positive ER status does not confer a negative impact on survival in young women as has been previously reported. The inferior prognosis for ER negative patients during the first 5 years after diagnosis changes into a slightly superior residual prognosis compared to ER positive patients independent of use of adjuvant systemic therapy. This may have an impact on future designing of guidelines for adjuvant endocrine therapy beyond 5 years.