Fulvestrant,a selective estrogen receptor down-regulator,sensitizes estrogen receptor negative breast tumors to chemotherapy

Drug resistance frequently results in poor prognosis and high 5-year recurrence rate in estrogen receptor-negative (ER−) breast cancer patients. Herein, we examined the reversal effects of fulvestrant on multidrug resistance (MDR) in ER− breast cancer cells. Co-administration of fulvestrant significantly sensitized ER− MDR tumors to paclitaxel both in vitro and in vivo. Further analyses indicated that fulvestrant did not affect P-gp expression, but could inhibit P-gp function and subsequently reverse P-gp mediated drug resistance in ER− breast cancer cells. These results showed that combination of fulvestrant and chemotherapeutic agents might provide an effective treatment for ER− MDR breast cancers.     

Estrogen receptor status is the most important prognostic factor in breast cancer with ten or more positive lymph nodes

Background. In breast cancer, the prognosis worsens with increasing lymph node involvement, and aggressive therapies may prolong survival in patients with advanced breast cancer. However, there are sub-populations of patients with advanced breast cancer with ten or more diseased nodes who have long survival. Implementing appropriate treatment depends on having a realistic and well-founded view of the prognosis. Methods. Sixty-nine patients (mean follow-up, 46 months) were enrolled. All patients underwent adjuvant therapy following radical mastectomy. Thirty-seven patients relapsed after curative surgery and 40 died of their cancer. Clinicopathologic factors, tumor estrogen receptor (ER) status, progesterone receptor status, and p53 protein expression were analyzed for prognostic significance. Results. Lower lymph node stage and positive ER status reflected longer relapse-free survival (P = 0.001 and P = 0.0001, respectively). Lower tumor stage (P = 0.039), lower lymph node stage (P = 0.006), absence of distant metastasis (P = 0.006), positive ER status (P = 0.0002), and negative p53 status (P = 0.02) reflected longer overall survival. ER status was the only independent significant prognostic factor for both relapse-free and overall survival. Conclusion. ER status, an indicator of response to endocrine therapy, was the most significant factor predicting prognosis in patients with breast cancer with ten or more positive lymph nodes. Received: February 25, 1998 / Accepted: December 24, 1998     

Interactions between the estrogen receptor,its cofactors and microRNAs in breast cancer

The activity of selective estrogen receptor modulators (SERMs) is not fully explained by an estrogen receptor (ER) switch model that simply turns estrogen activity on or off. A better understanding of the mechanisms involved in estrogen signaling and the development of drug resistance could help stratify patients into more coherent treatment groups and identify novel therapeutic candidates. This review describes how interactions between two novel factors known to influence estrogenic activity: nuclear receptor cofactors—protein partners which modulate estrogen action, and microRNAs—a class of recently discovered regulatory elements, may impact hormone-sensitive breast cancer. The role of nuclear receptor cofactors in estrogen signaling and the associations between ER cofactors and breast cancer are described. We outline the activity of microRNAs (miRNAs) and their associations with breast cancer and detail recent evidence of interactions between the ER and its cofactors and miRNA and provide an overview of the emerging field of miRNA-based therapeutics. We propose that previously unrecognised interactions between these two species of regulatory molecules may underlie at least some of the heterogeneity of breast cancer in terms of its clinical course and response to treatment. The exploitation of such associations will have important implications for drug development.     

Quantification of Mesenchymal Stem Cells (MSCs) at Sites of Human Prostate Cancer

Circulating bone marrow-derived Mesenchymal Stem Cells (BM-MSCs) have an innate tropism for tumor tissue in response to the inflammatory microenvironment present in malignant lesions. The prostate is bombarded by numerous infectious & inflammatory insults over a lifetime. Chronic inflammation is associated with CXCL12, CCL5, and CCL2, which are highly overexpressed in prostate cancer. Among other cell types, these chemoattractant stimuli recruit BM-MSCs to the tumor. MSCs are minimally defined as plastic-adhering cells characterized by the expression of CD90, CD73, and CD105 in the absence of hematopoietic markers, which can differentiate into osteoblasts, chondrocytes, and adipocytes. MSCs are immunoprivileged and have been implicated in tumorigenesis through multiple mechanisms, including promoting proliferation, angiogenesis, and metastasis, in addition to the generation of an immunosuppressive microenvironment. We have demonstrated that MSCs represent 0.01-1.1% of the total cells present in core biopsies from primary human prostatectomies. Importantly, these analyses were performed on samples prior to expansion in tissue culture. MSCs in these prostatectomy samples are FAP-, CD90-, CD73-, and CD105-positive, and CD14-, CD20-, CD34-, CD45-, and HLA-DR-negative. Additionally, like BM-MSCs, these prostate cancer-derived stromal cells (PrCSCs) were shown to differentiate into osteoblasts, adipocytes, & chondrocytes. In contrast to primary prostate cancer-derived epithelial cells, fluorescently-labeled PrCSCs & BM-MSCs were both shown to home to CWR22RH prostate cancer xenografts following IV injection. These studies demonstrate that not only are MSCs present in sites of prostate cancer where they may contribute to carcinogenesis, but these cells may also potentially be used to deliver cytotoxic or imaging agents for therapeutic and/or diagnostic purposes.     

Estrogen receptor negative/progesterone receptor positive breast cancer is not a reproducible subtype

Introduction

Estrogen receptor (ER) and progesterone receptor (PR) testing are performed in the evaluation of breast cancer. While the clinical utility of ER as a predictive biomarker to identify patients likely to benefit from hormonal therapy is well-established, the added value of PR is less well-defined. The primary goals of our study were to assess the distribution, inter-assay reproducibility, and prognostic significance of breast cancer subtypes defined by patterns of ER and PR expression.

Methods

We integrated gene expression microarray (GEM) and clinico-pathologic data from 20 published studies to determine the frequency (n = 4,111) and inter-assay reproducibility (n = 1,752) of ER/PR subtypes (ER+/PR+, ER+/PR-, ER-/PR-, ER-/PR+). To extend our findings, we utilized a cohort of patients from the Nurses’ Health Study (NHS) with ER/PR data recorded in the medical record and assessed on tissue microarrays (n = 2,011). In both datasets, we assessed the association of ER and PR expression with survival.

Results

In a genome-wide analysis, progesterone receptor was among the least variable genes in ER- breast cancer. The ER-/PR+ subtype was rare (approximately 1 to 4%) and showed no significant reproducibility (Kappa = 0.02 and 0.06, in the GEM and NHS datasets, respectively). The vast majority of patients classified as ER-/PR+ in the medical record (97% and 94%, in the GEM and NHS datasets) were re-classified by a second method. In the GEM dataset (n = 2,731), progesterone receptor mRNA expression was associated with prognosis in ER+ breast cancer (adjusted P <0.001), but not in ER- breast cancer (adjusted P = 0.21). PR protein expression did not contribute significant prognostic information to multivariate models considering ER and other standard clinico-pathologic features in the GEM or NHS datasets.

Conclusion

ER-/PR+ breast cancer is not a reproducible subtype. PR expression is not associated with prognosis in ER- breast cancer, and PR does not contribute significant independent prognostic information to multivariate models considering ER and other standard clinico-pathologic factors. Given that PR provides no clinically actionable information in ER+ breast cancer, these findings question the utility of routine PR testing in breast cancer.     

Quercetin Effects on Cell Cycle Arrest and Apoptosis and Doxorubicin Activity in T47D Cancer Stem Cells

Backgrounds: Targeting breast cancer stem cells with the CD44+/CD24- phenotype is critical for complete eradication of cancer cells due to its Self-renewal, differentiation, and therapeutic resistance ability. Quercetin is a popular flavonoid with lower adverse effects and has anti-tumor properties. Therefore, we assessed the anticancer activity of Quercetin and Doxorubicin alone and in combination in the T47D cells of human breast cancer and their isolated Cancer stem cells (CSCs). Materials and Methods: The human breast cancer cell line T47D was used for this experiment. T47D CSCs were isolated by magnetic bead sorting using the MACS system. The anticancer activity of Quercetin and Doxorubicin alone and in combination were evaluated using MTT cytotoxicity assay and cell cycle distribution and apoptosis induction by flow cytometry analysis. Results: We have shown that almost 1% of T47D cell populations are made up of CD44+/CD24- cells, which considered as cancer stem cells. Quercetin and Doxorubicin alone or in combination inhibited cell proliferation and induced apoptosis in breast cancer T47D cells and in lower extent in CD44+/CD24- cells. Quercetin significantly strengthened Doxorubicin’s cytotoxicity and apoptosis induction in both cell populations. Quercetin and Doxorubicin and their combination induced G2/M arrest in the T47D cells and to a lesser extent in isolated CSCs. A value of p < 0.05 was considered as indicating a statistically significant difference. Conclusion: These outcomes suggested that CSCs are a minor population of cancer cells, which play a significant role in drug resistance by being quiescent, slow cycling and resistance to apoptosis. Furthermore, our data showed that adding Quercetin to Doxorubicin is an effective approach for the treatment of both CSCs and bulk tumor cells.     

肿瘤坏死因子α在乳腺癌中的表达及其与雌激素受体的相关性

目的研究肿瘤坏死因子α（TNF—d）在乳腺癌中的表达及其与雌激素受体（ER）的相关性研究。方法采用免疫组织化学SABC法检测112例原发性乳腺癌患者肿瘤组织中TNF—α的表达,分析TNF—α在乳腺癌中的表达、与乳腺癌组织学分级的关系以及和ER的相关性。结果正常乳腺组织、乳腺小叶增生标本中TNF—α的阳性表达率分别为6．67％（1／15）、12．00％（3／25）。乳腺癌中TNF—α的阳性表达率为33．93％（38／112）。乳腺癌中TNF-α阳性表达率显著高于正常组织和乳腺小叶增生组织（X^2=8．573,P=0．014）。乳腺癌组织学分级为Ⅰ、Ⅱ、Ⅲ级时,TNF—α阳性表达率逐渐升高,分别为27．77％（15／54）、37．83％（14／37）、38．10％（8／21）,但差异无统计学意义（X^2=1．304,P=0．521）。ER阴性时TNF—α的阳性率为25．00％（21／84）,ER阳性时TNF-α的阳性率为60．70％（17／28）。ER和TNF-α在乳腺癌中的表达呈正相关（X^2=11．949,P=0．001）。结论TNF—α在乳腺癌组织中的阳性表达率高于正常组织和小叶增生组织,与ER在乳腺癌中的表达呈正相关,机制尚不明确．有待更多研究。     

乳腺癌干细胞上皮-间质转化标志物表达变化及意义

目的 探讨乳腺癌干细胞上皮．间质转化标志物表达变化及其临床意义。方法采用无血清悬浮培养法,从MCF-7细胞培养乳腺癌微球体细胞,应用流式细胞仪检测微球体细胞中CD44和CD24的表达,采用Westernblot方法检测微球体细胞中E-钙黏素、N-钙黏素、纤维连接蛋白、波形蛋白的表达水平,体外穿膜实验检测肿瘤细胞的迁移、侵袭能力。结果乳腺微球体富集了CD44＋CD24-的乳腺癌干细胞,并能在含血清培养基中增殖分化。该微球体细胞的上皮标志物E-钙黏素表达水平下调,而间质标志物N-钙黏素、纤维连接蛋白、波形蛋白的表达水平上调,同时乳腺癌干细胞的迁移、侵袭能力显著增强。结论乳腺癌干细胞具有上皮-间质转化的特征,具有显著增强的迁移、侵袭能力。     

IL-24-TRAIL基因载体的构建及其对乳腺癌干细胞迁移和凋亡的影响

目的 构建真核表达载体pIRES-IL-24-TRAIL,探讨其对乳腺癌干细胞迁移和凋亡的影响。方法 以人胎盘组织总RNA为模板,采用RT-PCR二步法,扩增TRAIL的cDNA序列,将其克隆入pIRES载体,扩增IL-24的cDNA序列,将其克隆入pIRES- TRAIL载体,构建重组真核表达载体pIRESIL-24- TRAIL,以Lipofectamine2000转染技术,将质粒pIRES- IL-24-TRAIL导入乳腺癌干细胞MCF-7和MDA-MB-231,流式细胞仪检测各组细胞凋亡情况,划痕实验比较不同组间细胞迁移情况。结果（1）克隆到TRAIL、IL-24基因的cDNA序列,成功构建其真核表达载体。（2）流式细胞仪发现,实验组比对照组细胞凋亡率高(P<0.05)。（3）细胞划痕实验显示实验组细胞迁移能力明显低于对照组（P＜0.05）。结论 pIRES-IL-24-TRAIL构建成功,并能诱导乳腺癌干细胞凋亡、降低其迁移能力。     

Estrogen receptor genotype is associated with risk of venous thromboembolism during tamoxifen therapy

Thromboembolism is a serious complication of tamoxifen therapy in women with breast cancer. Banked DNA from tamoxifen-treated individuals with breast cancer from the Marshfield Clinic Personalized Medicine Research Project, a population-based DNA repository, was tested for association between incidence of tamoxifen-associated thromboembolic events (TTE) and single nucleotide polymorphisms encoding the estrogen receptors 1,2 (ESR1, ESR2) or drug metabolism enzymes cytochrome P450 2D6 (CYP2D6) and aromatase (CYP19). TTE were experienced by 16/220 subjects with risk association noted for XbaI (rs9340799) genotype and ESR1 Xbal/PvuII diplotype (rs9340799 and rs2234693) (hazard ratio 3.47, 95% CI 0.97–12.44, P = 0.035). Association persisted after adjusting for classical risk factors including age at diagnosis and body mass index at enrollment. Initial evidence of association between increased risk for TTE and ESR1 genotype and ESR1 diplotype is presented. Determination of estrogen receptor genotype may identify a subset of women at increased risk for thromboembolism with tamoxifen exposure.     

Estrogen receptor alpha haplotypes and breast cancer risk in older Caucasian women

Life-long exposure to estrogen is an established risk factor for breast cancer development. The underlying mechanism has been suggested to be the binding of estrogen-to-estrogen receptors in mammary tissue, which in turn promotes the proliferation and differentiation of breast tissue. Polymorphisms and haplotypes in estrogen receptor alpha (ESR1) have been reportedly associated with breast cancer risk; however, the results are not fully consistent. In this study, we investigated breast cancer risk associated with genotypes and haplotypes resulting from four ESR1 single nucleotide polymorphisms (SNPs), rs746432, rs2234693, rs9340799, and rs1801132. Genotyping has been performed on 393 breast cancer cases and 790 randomly selected controls in 1,183 Caucasian women over age 65 from the Study of Osteoporotic Fractures (SOF). We observed an allelic protective effect for SNP rs9340799 with an estimated odds ratio (OR) of 0.82 (95% CI = 0.68–1.00; P = 0.04) after adjustment for age, BMI and hip BMD. A protective effect of this SNP has been reported before in several different studies. We did not replicate the previously reported C–C–A–G haplotype association to breast cancer—the C–C–A–G haplotype from these SNPs was rare in this study (estimated frequency below 0.001% in cases and controls). No other statistically significant associations were observed between ESR1 haplotypes from the same four SNPs and the risk of breast cancer in older Caucasian women.     

Estrogen receptor alpha gene amplification in breast cancer: 25 years of debate

Twenty-five years ago, Nembrot and colleagues reported amplification of the estrogen receptor alpha gene (ESR1) in breast cancer, initiating a broad and still ongoing scientific debate on the prevalence and clinical significance of this genetic aberration, which affects one of the most important genes in breast cancer. Since then, a multitude of studies on this topic has been published, covering a wide range of divergent results and arguments. The reported prevalence of this alteration in breast cancer ranges from 0% to 75%, suggesting that ESR1 copy number analysis is hampered by technical and interpreter issues. To date, two major issues related to ESR1 amplification remain to be conclusively addressed: (1) The extent to which abundant amounts of messenger RNA can mimic amplification in standard fluorescence in situ hybridization assays in the analysis of strongly expressed genes like ESR1, and (2) the clinical relevance of ESR1 amplification: Such relevance is strongly disputed, with data showing predictive value for response as well as for resistance of the cancer to anti-estrogen therapies, or for subsequent development of cancers in the case of precursor lesions that display amplification of ESR1. This review provides a comprehensive summary of the various views on ESR1 amplification, and highlights explanations for the contradictions and conflicting data that could inform future ESR1 research.     

Candida albicans Beta-Glucan Induce Anti- Cancer Activity of Mesenchymal Stem Cells against Lung Cancer Cell Line: An In-Vitro Experimental Study

Objective: β-glucan, glucopyranosyl polymers of fungi cell wall, represent an immune stimulating effects with potential anti-cancer activity. Mesenchymal stem cells (MSC) have immunomodulating properties in cancer microenvironment. The aim of this study was to investigate the anti-cancer effect of Candida albicans (C. albicans) beta-glucan on MSCs supernatant for apoptosis assay of lung cancer cells in vitro. Methods: Beta-glucan was extracted from cell wall of C.albicans. MSC isolated from adipose tissue of patients and confirmed using specific surface markers expression which examined by flow cytometry. MSCs treated with various concentrations of β-glucans for 48 hours. Cytotoxic effect of β-glucans was evaluated using MTT assay. MSC and lung cancer line cocultured and treated with β-glucans and apoptosis assay was done by flow cytometry. Results: Cytotoxicity findings showed a significant decrease in MSC viability during 48h, however it was dose-dependent (P<0.05). According to the obtained findings, supernatant of mesenchymal stem cells treated with β-glucans increased cancer cells apoptosis (P<0.05). Conclusion: Beta glucan may highlight a potential and novel promising candidate in future strategies to cause apoptosis of cancer cells and consider as therapeutic  agent against tumor growth as well. Definitely, more in vitro and in vivo studies are required to understand its functions.     

雌激素受体共调节因子在乳腺癌内分泌治疗抵抗中的作用

雌激素受体(ER)共调节因子通过调节ER的转录活性,影响由ER介导的靶基因的转录及翻译.除在乳腺癌的发生、进展和转移中发挥重要作用外,ER共调节因子通过其基因组和非基因组功能也与乳腺癌的内分泌治疗反应密切相关.     

Estrogen receptor positive breast cancer identified by 95-gene classifier as at high risk for relapse shows better response to neoadjuvant chemotherapy

A 95-gene classifier (95-GC) recently developed by us can predict the risk of relapse for ER-positive and node-negative breast cancer patients with high accuracy. This study investigated association of risk classification by 95-GC with response to neoadjuvant chemotherapy (NAC). Tumor biopsy samples obtained preoperatively from 72 patients with ER-positive breast cancer were classified by 95-GC into high-risk and low-risk for relapse. Pathological complete response (pCR) rate was numerically higher for high-risk (15.8%) than low-risk patients (8.8%) although the difference was not statistically significant. Pathological response evaluated in terms of the pathological partial response (pPR) rate (loss of tumor cells in more than two-thirds of the primary tumor) showed a significant association (P=0.005) between the high-risk patients and a high pPR rate. Besides, external validation study using the public data base (GSE25066) showed that the pCR rate (16.4%) for high-risk patients (n=128) was significantly (P=0.003) higher than for low-risk patients (5.7%) (n=159). These results demonstrate that the high-risk patients for relapse show a higher sensitivity to chemotherapy and thus are likely to benefit more from adjuvant chemotherapy.     

耐药基因及雌孕激素受体在乳腺癌中的表达及意义

本文用免疫组化法对15例乳腺癌做了多药耐药基因产物P17。及谷航计肽S一转移酶（GST。）以及雌孕激素受体（ER，PR）的检测。浸润性导管瘤14例，粘液腺癌1例。检测结果雌孕激素受体共同表达率为667％（IO门5），巳？。过度表达为“7（10／15）．GSTx过度表达为553％（8／15）。ER、PR表达与肿瘤的分化程度有关，即分化好的乳腺癌标记率较高，提示预后较好。结果表明多数乳腺癌表达雌孕激素受体，提示对内分泌治疗有效。P；0，GST，不仅为乳腺癌标记物，而且也提示了多数乳腺癌对亲脂类及烷化剂类化疗药可能具有耐药性。因此时过度表达的乳腺癌临床上应慎用此类化疗药。     

Androgen receptor in estrogen receptor positive breast cancer: Beyond expression

In recent years, new therapeutic approaches have reshaped the overall strategy of breast cancer (BC) treatment and have markedly improved patient survival. This is, in part, due to novel therapies for estrogen receptor (ER)-positive BC. Unfortunately, many patients present de novo resistance to these therapies or develop an acquired resistance over time. Therefore, research is now focused on discovering new molecular targets to overcome these resistances. Interestingly, preclinical and clinical studies have shown a critical role for the cross-talk between androgen receptor (AR) and ER in luminal-like BC. AR is expressed in >60% of BC and in up to 90% of ERα-positive tumors. Multiple studies suggest that AR is associated with a favorable prognosis. However, AR overexpression and, in particular, the high AR:ER ratio, seem to be involved in resistance to hormonal treatment. In this setting, a group of BCs could benefit from AR-inhibitors; nevertheless, some ER-positive BC patients do not seem to benefit from this strategy. Therefore, it is crucial to identify biomarkers that would enable the selection of patients who might benefit from combination treatment with ER and AR inhibitors.     

金属硫蛋白ⅡA 过表达对乳腺癌细胞耐药性的影响

 目的　研究金属硫蛋白 ( Metallothionein,MT)基因过表达对乳腺癌细胞耐药性的影响。方法　表达质粒 p BAc Neo MT A转染 MCF- 7/Adr细胞 ,用 SRB方法检测了 MT过表达细胞对顺铂的耐药性的变化。结果　与对照细胞相比 ,p BAc Neo MT A转染的细胞对顺铂的耐受性提高 ,其 LD50 由约 1 2 u M增加到大约 30 u M。结论　 MT过表达可提高乳腺癌细胞对顺铂的耐药性.     

Estrogen receptors outside the nucleus in breast cancer

The estrogen receptor (ER) is the single most powerful predictor of breast cancer prognosis as well as an important contributor to the biology of carcinogenesis. In addition, endocrine therapy targeting ER directly (SERMS) or indirectly (aromatase inhibitors) forms the mainstay of adjuant therapy. Traditionally, human tumors are scored for the amount and presence of ER. However, this has centered on the population of ER found in the transformed epithelial cell nucleus. Over the last 40 years, it has been appreciated that additional cellular ER pools exist, in cytoplasm and at the plasma membrane. In this review, we discuss the important functions of extra-nuclear ER in breast cancer, including integration of function with nuclear ER.     

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.