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Query: UMLS:C0006142 (breast cancer)
 160,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Women at increased risk for breast cancer are at increased risk for ovarian cancer as well, reflecting common risk factors and intertwined etiology of the two diseases. We previously developed a rat model of elevated breast and ovarian cancer risk, allowing evaluation of dual-target cancer prevention strategies. Tamoxifen, a Food and Drug Administration-approved breast cancer chemoprevention drug, has been shown to promote ovarian cysts in premenopausal women; however, the effect of tamoxifen on ovarian cancer risk is still controversial. In the current experiment, Fischer 344 rats (n = 8 per treatment group) received tamoxifen (TAM) or vehicle (control) in factorial combination with combined breast and ovarian carcinogen (17beta-estradiol and 7,12 dimethylbenza[a]anthracene, respectively). Mammary and ovarian morphologies were normal in the control and TAM groups. Carcinogen (CARC) treatment induced mammary dysplasia with elevated cell proliferation and reduced estrogen receptor-alpha expression and promoted preneoplastic changes in the ovary. In the CARC + TAM group, tamoxifen reduced preneoplastic changes and proliferation rate in the mammary gland, but not in the ovary, compared with rats treated with carcinogen alone. Putative stem cell markers (Oct-4 and aldehyde dehydrogenase 1) were also elevated in the mammary tissue by carcinogen and this expansion of the stem cell population was not reversed by tamoxifen. Our study suggests that tamoxifen prevents early progression to mammary cancer but has no effect on ovarian cancer progression in this rat model.
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PMID:Tamoxifen prevents premalignant changes of breast, but not ovarian, cancer in rats at high risk for both diseases. 1913 4

Female BRCA1 mutation carriers have a nearly 80% probability of developing breast cancer during their life-time. We hypothesized that the breast epithelium at risk in BRCA1 mutation carriers harbors mammary epithelial cells (MEC) with altered proliferation and differentiation properties. Using a three-dimensional culture technique to grow MECs ex vivo, we found that the ability to form colonies, an indication of clonality, was restricted to the aldehyde dehydrogenase 1-positive fraction in MECs but not in HCC1937 BRCA1-mutant cancer cells. Primary MECs from BRCA1 mutation carriers (n = 9) had a 28% greater ability for clonal growth compared with normal controls (n = 6; P = 0.006), and their colonies were significantly larger. Colonies in controls and BRCA1 mutation carriers stained positive for BRCA1 by immunohistochemistry, and 79% of the examined single colonies from BRCA1 carriers retained heterozygosity for BRCA1 (ROH). Colonies from BRCA1 mutation carriers frequently showed high epidermal growth factor receptor (EGFR) expression (71% EGFR positive versus 44% in controls) and were negative for estrogen receptor (ERalpha; 32% ER negative, 44% mixed, 24% ER positive versus 90% ER positive in controls). Expression of CK14 and p63 were not significantly different. Microarray studies revealed that colonies from BRCA1-mutant PMECs anticipate expression profiles found in BRCA1-related tumors, and that the EGFR pathway is up-regulated. We conclude that BRCA1 haploinsufficiency leads to an increased ability for clonal growth and proliferation in the PMECs of BRCA1 mutation carriers, possibly as a result of EGFR pathway activation. These altered growth and differentiation properties may render BRCA1-mutant PMECs vulnerable to transformation and predispose to the development of ER-negative, EGFR-positive breast cancers.
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PMID:Altered proliferation and differentiation properties of primary mammary epithelial cells from BRCA1 mutation carriers. 1919 Mar 34

Since the initial discovery of leukemia stem cells nearly a decade ago, a great deal of cancer research has focused on the identification of cancer stem cells (CSCs) in many types of solid tumors, including breast cancer. Through analysis of cell surface markers and xenotransplant models, a subpopulation of putative human breast cancer stem cells (BCSCs) that is CD24-negative/CD44-positive (CD24(-)/CD44+) and bears high aldehyde dehydrogenase 1 activity has been isolated in clinical samples of breast cancer tissues. Human BCSCs are considered to be derived from basal cells that reside in the basal membranes of alveolar units in human adult mammary glands. Furthermore, BCSCs have been shown to express higher levels of oxidative stress-responsive genes, which could confer part of their ability to resist anti-cancer therapy, than non-CSCs. The emerging picture of the biological properties of BCSCs would contribute for devising innovative therapies for breast cancer, targeting the intrinsic and extrinsic factors that maintain the BCSCs.
Breast Cancer 2010 Apr
PMID:Breast cancer stem cells. 1980 28

The cancer stem cell paradigm postulates that dysregulated tissue-specific stem cells or progenitor cells are precursors for cancer biogenesis. Consequently, identifying cancer stem cells is crucial to our understanding of cancer progression and for the development of novel therapeutic agents. In this study, we demonstrate that the overexpression of Twist in breast cells can promote the generation of a breast cancer stem cell phenotype characterized by the high expression of CD44, little or no expression of CD24, and increased aldehyde dehydrogenase 1 activity, independent of the epithelial-mesenchymal transition. In addition, Twist-overexpressing cells exhibit high efflux of Hoechst 33342 and Rhodamine 123 as a result of increased expression of ABCC1 (MRP1) transporters, a property of cancer stem cells. Moreover, we show that transient expression of Twist can induce the stem cell phenotype in multiple breast cell lines and that decreasing Twist expression by short hairpin RNA in Twist-overexpressing transgenic cell lines MCF-10A/Twist and MCF-7/Twist as well as in MDA-MB-231 partially reverses the stem cell molecular signature. Importantly, we show that inoculums of only 20 cells of the Twist-overexpressing CD44(+)/CD24(-/low) subpopulation are capable of forming tumors in the mammary fat pad of severe combined immunodeficient mice. Finally, with respect to mechanism, we provide data to indicate that Twist transcriptionally regulates CD24 expression in breast cancer cells. Taken together, our data demonstrate the direct involvement of Twist in generating a breast cancer stem cell phenotype through down-regulation of CD24 expression and independent of an epithelial-mesenchymal transition.
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PMID:Twist modulates breast cancer stem cells by transcriptional regulation of CD24 expression. 2001 40

Heterogeneity of cancer stem/progenitor cells that give rise to different forms of cancer has been well demonstrated for leukemia. However, this fundamental concept has yet to be established for solid tumors including breast cancer. In this communication, we analyzed solid tumor cancer stem cell markers in human breast cancer cell lines and primary specimens using flow cytometry. The stem/progenitor cell properties of different marker expressing-cell populations were further assessed by in vitro soft agar colony formation assay and the ability to form tumors in NOD/SCID mice. We found that the expression of stem cell markers varied greatly among breast cancer cell lines. In MDA-MB-231 cells, PROCR and ESA, instead of the widely used breast cancer stem cell markers CD44(+)/CD24(-/low) and ALDH, could be used to highly enrich cancer stem/progenitor cell populations which exhibited the ability to self renew and divide asymmetrically. Furthermore, the PROCR(+)/ESA(+) cells expressed epithelial-mesenchymal transition markers. PROCR could also be used to enrich cells with colony forming ability from MB-361 cells. Moreover, consistent with the marker profiling using cell lines, the expression of stem cell markers differed greatly among primary tumors. There was an association between metastasis status and a high prevalence of certain markers including CD44(+)/CD24(-/low), ESA(+), CD133(+), CXCR4(+) and PROCR(+) in primary tumor cells. Taken together, these results suggest that similar to leukemia, several stem/progenitor cell-like subpopulations can exist in breast cancer.
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PMID:Multiple lineages of human breast cancer stem/progenitor cells identified by profiling with stem cell markers. 2002 13

Microscopic pulmonary tumor embolism is difficult to diagnose. Herein is presented the case of a patient who suffered from acute dyspnea and breast cancer on the right side. Two weeks after the breast cancer diagnosis the patient began to experience dyspnea. After 2 weeks of dyspnea, the patient died without an accurate diagnosis of dyspnea. Autopsy indicated massive microscopic pulmonary emboli of the breast cancer. Immunohistochemistry showed that most of the cancer cells in the primary site were negative for estrogen receptors, progesterone receptors Her2/neu oncogene (triple negative), and stem cell-like markers (OCT3/4, NANOG2, CD44, CD24, aldehyde dehydrogenase 1 (ALDH1)). The breast cancer cells in the lung (the metastasized site), however, were triple negative, but were enriched in stem cell-like markers (OCT3/4(+), NANOG2(+), CD44(+)/CD24(-/low), ALDH1(+)). This is a significant case report indicating that vascular emboli themselves contain the essential molecular signature of 'stemness' independent of the origin.
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PMID:Aggressive progression of breast cancer with microscopic pulmonary emboli possessing a stem cell-like phenotype independent of its origin. 2040 50

CD44+/CD24-/low tumor cells or aldehyde dehydrogenase 1 (ALDH1) positive tumor cells are considered cancer stem cells (CSCs) that possess the properties of self-renewal and tumorigenicity. However, their clinical value and significance in breast cancer remain controversial. A meta-analysis based on published studies was performed with the aim of obtaining an accurate evaluation of the association between the presence of CSCs in clinical samples and clinical outcome. A total of 12 eligible studies with 898 cases and 1,853 controls were included. CSC positive breast cancers, in particular those positive for ALDH1, were significantly associated with high histological grade, estrogen receptor (ER) negativity, progesterone receptor (PR) negativity, and human epidermal growth factor receptor type 2 (HER2) positivity. However, the presence of cancer stem cells was not associated with tumor size or nodal status. ALDH1 positive (RR = 2.83, 95% CI: 2.16-3.67, P < 0.001) and CD44+/CD24-/low tumor cells (RR = 2.32, 95% CI: 1.51-3.60, P < 0.001) were significantly associated with poor overall survival (OS). The stem cell markers are prognostic factors in breast cancer. Larger clinical studies are required to further evaluate the role of these markers in clinical practice.
Breast Cancer Res Treat 2010 Aug
PMID:The prognostic role of cancer stem cells in breast cancer: a meta-analysis of published literatures. 2057 67

Here we show that a subpopulation of MCF-7 breast cancer cells which stains pale to Toluidine Blue (Light Cells- LCs), is endowed with features of CSCs. LCs give rise to self-renewing mammospheres and express typical CSC markers; moreover this subpopulation is chemoresistant and highly tumorigenic in vivo. LCs can be identified in several other breast cancer cell lines, irrespectively of their histological origin (luminal vs. mesenchymal vs. basal) and represent an heterogeneous cell population composed mainly of CSC-like and early progenitor cells. By a limited in vitro drug screening assay, we identify compounds which can specifically interfere with the viability of LCs from multiple breast cancer cell lines. Analysis of the Sphere-Forming Efficiency (SFE) and of the distribution of ALDH(bright) cells within the treated cell lines suggest that one of the identified compounds acts in vitro by modulating the CSC phenotype. Interestingly, a subset of the identified compounds is known to affect directly or indirectly the NFkappaB pathway which is emerging as an important modulator of CSC proliferation and chemoresistance.
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PMID:Mammosphere-forming cells from breast cancer cell lines as a tool for the identification of CSC-like- and early progenitor-targeting drugs. 2058 42

Elevated aldehyde dehydrogenase 1 (ALDH1) has been proposed as one of the possible candidates for a stem cell maker that can be used for the isolation of cancer stem cells from cancers such as leukemia and breast cancer. In the current study, we found that subpopulations with elevated ALDH1 were present in the human sarcoma cell lines, MG63 (osteosarcoma) and HT1080 (fibrosarcoma), using Aldefluor assay. Both ALDH1 positive and negative cell populations were isolated from the MG63 cell line, by cell-sorting using FACSAria. Both subpopulations had a comparable ability to differentiate similarly to the parental MG63, under normal monolayer culture condition. Subpopulations with the ability to form spheres in anchorage-independent, serum-starved conditions showed increased ALDH1 mRNA expression in addition to strong mRNA expression of the stem cell-related genes, such as Nanog, Oct3/4, Stat3 and Sox2, and possessed ability for self-renewal with secondary sphere formation. Sarcosphere cells from the MG63 cell line showed strong chemo-resistance against both doxorubicin and cisplatin compared with monolayer, adherent cells. In conclusion, sphere-forming cells with elevated ALDH1 are a possible candidate for sarcoma stem cells, possessing strong chemo-resistant capacities. Although ALDH1 elevation was not sufficient for representing sarcoma stem cells, the efficient detoxification could contribute to the chemo-resistant properties of the stem-like sphere cells form human sarcoma.
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PMID:Possible involvement of stem-like populations with elevated ALDH1 in sarcomas for chemotherapeutic drug resistance. 2059 39

Lung cancer is a leading cause of death in human. Cancer stem cells have been regarded as basis for failure of current therapeutic options. Salinomycin was shown to kill these cancer stem cells in some types of cancer such as breast cancer and leukemia. The in vitro anticancer activities of salinomycin have been validated against the lung cancer cell line A549 via sulforhodamine B and colony formation assay. Salinomycin has been demonstrated to significantly rupture the in vitro lung cancer tumorospheres from ALDH positive A549 lung cells using flow cytometry. Expression of stem cell markers OCT-4, NANOG and SOX2 in ALDH positive A549 lung cells was decreased significantly by real-time RT-PCR analysis after 24 hour salinomycin treatment. Taken together, salinomycin may provide a promising approach for lung cancer chemotherapy.
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PMID:Effects of salinomycin on cancer stem cell in human lung adenocarcinoma A549 cells. 2122 17


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