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Breast Cancer Cells (breast + cancer_cell)
Kinds of Breast Cancer Cells Terms modified by Breast Cancer Cells Selected AbstractsMidregion Parathyroid Hormone-Related Protein Inhibits Growth and Invasion In Vitro and Tumorigenesis In Vivo of Human Breast Cancer CellsJOURNAL OF BONE AND MINERAL RESEARCH, Issue 12 2001Claudio Luparello Abstract Parathyroid hormone-related protein (PTHrP) is critical for normal mammary development and is overexpressed by breast cancers. PTHrP is a peptide hormone that undergoes extensive post-translational processing, and PTHrP(38,94)-amide is one of the mature secretory forms of the peptide. In this study, we explored the effect of PTHrP(38,94)-amide in a panel of six breast cancer cell lines "in vitro" and in MDA-MB231 cells "in vivo" specifically examining cell viability, proliferation, invasiveness, and growth in nude mice. PTHrP(38,94)-amide markedly inhibited proliferation and also caused striking toxicity and accelerated cell death in breast cancer cells. In addition, direct injection of PTHrP(38,94)-amide into MDA-MB231 breast cancer cells passaged in immunodeficient mice produced a marked reduction in tumor growth. These studies (i) indicate breast cancer cells are one of the few tissues in which specific effects of midregion PTHrP have been established to date, (ii) support a role for midregion secretory forms of PTHrP in modulating not only normal but also pathological mammary growth and differentiation, (iii) add further evidence for the existence of a specific midregion PTHrP receptor, and (iv) provide a novel molecule for modeling of small molecule analogues that may have anti-breast cancer effects. [source] Alcohol Stimulates Activation of Snail, Epidermal Growth Factor Receptor Signaling, and Biomarkers of Epithelial,Mesenchymal Transition in Colon and Breast Cancer CellsALCOHOLISM, Issue 1 2010Christopher B. Forsyth Background:, Alcohol consumption is associated with the risk of progressive cancers including colon and breast cancer. The mechanisms for the alcohol-induced aggressive behavior of these epithelial cancer cells have not been fully identified. Epithelial,mesenchymal transition (EMT) is a developmental program recently shown to play a role in cancer progression and metastases. We hypothesized that alcohol might promote cancer progression by inducing EMT in cancer cells and tested this hypothesis by assessing alcohol-stimulated changes in phenotypic markers of EMT as well as the EMT transcription factor Snail and its related cell signaling. Methods:, Colon and breast cancer cell lines and a normal intestinal epithelial cell line were tested as well as colonic mucosal biopsy samples from alcoholic subjects. Cells were treated with alcohol and assessed for EMT-related changes using immunofluorescent microscopy, western blotting, reporter assays, RT-PCR, and knockdown of Snail with siRNA. Results:, We show alcohol upregulated the signature EMT phenotypic marker vimentin as well as matrix metalloprotease (MMP)-2, MMP-7, and MMP-9 and cell migration in colon and breast cancer cells,all characteristics of EMT. Alcohol also stimulated nuclear localization of Snail phosphorylated at Ser246, transcription from a Snail reporter plasmid, and Snail mRNA expression by RT-PCR. Snail siRNA knockdown prevented alcohol-stimulated vimentin expression. In vivo, Snail expression was significantly elevated in colonic mucosal biopsies from alcoholics. Also, we found alcohol stimulated activation of epidermal growth factor receptor (EGFR) signaling and an EGFR inhibitor blocked alcohol-induced cell migration and Snail mRNA expression. Conclusions:, Collectively, our data support a novel mechanism for alcohol promoting cancer progression through stimulating the EMT program in cancer cells via an EGFR-Snail mediated pathway. This study reveals new pathways for alcohol-mediated promotion of cancer that could be targeted for therapy or prevention of alcohol-related cancers. [source] Eradication of Multiple Myeloma and Breast Cancer Cells by TH9402-mediated Photodynamic Therapy: Implication for Clinical Ex Vivo Purging of Autologous Stem Cell Transplants,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 6 2000N. Brasseur ABSTRACT High-dose chemotherapy combined with autologous transplantation using bone marrow or peripheral blood-derived stem cells (PBSC) is now widely used in the treatment of hematologic malignancies as well as some solid tumors like breast cancer (BC). However, some controversial results were recently obtained in the latter case. The presence of malignant cells in the autograft has been associated with the recurrence of the disease, and purging procedures are needed to eliminate this risk. The aim of this study was to evaluate the potential of the photosensitizer 4,5-dibromorhodamine methyl ester (TH9402), a dibrominated rhodamine derivative, to eradicate multiple myeloma (MM) and BC cell lines, while sparing more than 50% of normal pluripotential blood stem cells from healthy volunteers. The human BC MCF-7 and T-47D and MM RPMI 8226 and NCI-H929 cell lines were used to optimize the photodynamic purging process. Cell concentration and the cell suspension thickness as well as the dye and light doses were varied in order to eventually treat 1,2 L of apheresis. The light source consisted of two fluorescent scanning tubes emitting green light centered about 515 nm. The cellular uptake of TH9402 was measured during the incubation and washout periods and after photodynamic treatment (PDT) using spectrofluorometric analysis. The limiting dilution assay showed that an eradication rate of more than 5 logs is obtained when using a 40 min incubation with 5,10 ,M dye followed by a 90 min washout period and a light dose of 5,10 J/cm2 (2.8 mW/cm2) in all cell lines. Agitating the 2 cm thick cell suspension containing 20 × 106 cells/mL during PDT was essential for maximal photoinactivation. Experiments on mobilized PBSC obtained from healthy volunteers showed that even more drastic purging conditions than those found optimal for maximal eradication of the malignant cell lines were compatible with a good recovery of hematopoietic progenitors cells. The absence of significant toxicity towards normal hematopoietic stem cells, combined with the 5 logs eradication of cancer cell lines induced by this procedure suggests that TH9402 offers an excellent potential as an ex vivo photodynamic purging agent for autologous transplantation in MM and BC treatment. [source] Curcumin Suppresses the Paclitaxel-Induced Nuclear Factor-,B in Breast Cancer Cells and Potentiates the Growth Inhibitory Effect of Paclitaxel in a Breast Cancer Nude Mice ModelTHE BREAST JOURNAL, Issue 3 2009Hee Joon Kang MD Abstract:, Most anticancer agents activate nuclear factor kappa B (NF-,B), which can mediate cell survival, proliferation, and metastasis. Curcumin has been shown to inhibit the growth of various cancer cells, without toxicity to normal cells. The antitumor effects of curcumin could be due in part to the inactivation of NF-,B. We hypothesize that blocking NF-,B activity may augment paclitaxel cancer chemotherapy. In this study, we investigated whether the inactivation of NF-,B by curcumin would enhance the efficacy of paclitaxel for inhibiting breast cancer growth in vitro and in vivo. We confirmed that curcumin inhibited paclitaxel-induced activation of NF-,B and potentiated the growth inhibitory effect of paclitaxel in MDA-MB-231 breast cancer cells. The combination of curcumin with paclitaxel elicited significantly greater inhibition of cell growth and more apoptosis, compared with either agent alone. In an experimental breast cancer murine model using MDA-MB-231 cells, combination therapy with paclitaxel and curcumin significantly reduced tumor size and decreased tumor cell proliferation, increased apoptosis, and decreased the expression of matrix metalloprotease 9 compared with either agent alone. These results clearly suggest that a curcumin,paclitaxel combination could be a novel strategy for the treatment of breast cancer. [source] ChemInform Abstract: Regiospecific Microwave-Assisted Synthesis and Cytotoxic Activity Against Human Breast Cancer Cells of (RS)-6-Substituted-7- or 9-(2,3-dihydro-5H-1,4-benzodioxepin-3-yl)-7H- or -9H-purines.CHEMINFORM, Issue 50 2008Ana Conejo-Garcia Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Development of multilayered cell-hydrogel composites using an acoustic focusing techniqueBIOTECHNOLOGY PROGRESS, Issue 2 2010Jason P. Mazzoccoli Abstract Multilayered composites, composed of mammalian cells arranged in a hydrogel, have been prepared using an acoustic focusing technique. Acoustic focusing is a simple, nonchemical technique that allows for the fast arrangement of cells in matrices where the control of cell geometry is beneficial. Breast cancer cells (MDA-MB231) were dispersed in a 30 wt % solution of poly(ethylene glycol) diacrylate (PEGDA) of molecular weight 400 at a density of 5 × 106 cells/mL of PEGDA solution. An ultrasonic field was used to organize the cells before polymerization of PEGDA. Disk-shaped hydrogel composites, typically 1 cm in diameter and 2-mm thick were prepared based on a PEGDA solution volume of 130 ,L. At an acoustic frequency of 2.32 MHz, composites having cells positioned within concentric cylindrical shells interspersed with zones of cell-free hydrogel were produced. The cells were located in annuli approximately 80-,m thick and about 300 ,m apart. The structure and viability of the cells within these constructs were studied using a fluorescent LIVE/DEAD assay. The viability of the cells was on the order of 50%. For the conditions used in this study, cell death was primarily attributed to exposure of cells to the PEGDA solution prior to polymerization, rather than adverse effects of polymerization or the sound field itself. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Breast cancer-derived Dickkopf1 inhibits osteoblast differentiation and osteoprotegerin expression: Implication for breast cancer osteolytic bone metastasesINTERNATIONAL JOURNAL OF CANCER, Issue 5 2008Guojun Bu Abstract Most breast cancer metastases in bone form osteolytic lesions, but the mechanisms of tumor-induced bone resorption and destruction are not fully understood. Although it is well recognized that Wnt/,-catenin signaling is important for breast cancer tumorigenesis, the role of this pathway in breast cancer bone metastasis is unclear. Dickkopf1 (Dkk1) is a secreted Wnt/,-catenin antagonist. In the present study, we demonstrated that activation of Wnt/,-catenin signaling enhanced Dkk1 expression in breast cancer cells and that Dkk1 overexpression is a frequent event in breast cancer. We also found that human breast cancer cell lines that preferentially form osteolytic bone metastases exhibited increased levels of Wnt/,-catenin signaling and Dkk1 expression. Moreover, we showed that breast cancer cell-produced Dkk1 blocked Wnt3A-induced osteoblastic differentiation and osteoprotegerin (OPG) expression of osteoblast precursor C2C12 cells and that these effects could be neutralized by a specific anti-Dkk1 antibody. In addition, we found that breast cancer cell conditioned media were able to block Wnt3A-induced NF-kappaB ligand reduction in C2C12 cells. Finally, we demonstrated that conditioned media from breast cancer cells in which Dkk1 expression had been silenced via RNAi were unable to block Wnt3A-induced C2C12 osteoblastic differentiation and OPG expression. Taken together, these results suggest that breast cancer-produced Dkk1 may be an important mechanistic link between primary breast tumors and secondary osteolytic bone metastases. © 2008 Wiley-Liss, Inc. [source] Inhibition of human breast cancer cell (MBA-MD-231) invasion by the Ea4-peptide of rainbow trout pro-IGF-IJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 5 2006Sineenat Siri Abstract It was shown previously that Ea4-peptide of trout pro-IGF-I exerted mitogenic activity in non-transformed cells and inhibited colony formation in a soft agar medium of established human cancer cells. Here we report that the same peptide inhibits the invasion of human breast cancer cells (MDA-MB-231) through a matrigel membrane in a dose-dependent manner. The expression of urokinase-type plasminogen activator (uPA), tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor 1 (PAI1) genes in MDA-MB-231 cells were downregulated by treatment with rtEa4-peptide. The inhibition of expression of these genes in response to rtEa4-peptide treatment was reduced to the control level when inhibitors for c-Jun N-terminal kinase 1/2 (JNK1/2), mitogen activated protein kinase kinase 1/2 (Mek1/2), p38 mitogen activated protein kinase (p38 MAPK), phosphatidylinositol 3-kinase (PI3K), and phosphokinase C (PKC) were used. These results suggest that inhibition of invasion of MDA-MB-231 cells by rtEa4-peptide may be mediated via the suppression of uPA, tPA, and PAI1 gene activities through signal transduction pathways. J. Cell. Biochem. 99: 1363,1373, 2006. © 2006 Wiley-Liss, Inc. [source] Profilin-1 overexpression restores adherens junctions in MDA-MB-231 breast cancer cells in R-cadherin-dependent mannerCYTOSKELETON, Issue 12 2009Li Zou Abstract Profilin-1 (Pfn1), a ubiquitously expressed actin-binding protein, is downregulated in several different types of adenocarcinoma and elicits tumor-suppressive effect on breast cancer cell lines. MDA-MB-231 (MDA-231), a breast cancer cell line that displays all the characteristics of post-epithelial-to-mesenchymal transition and does not form cell,cell adhesion, can be reverted to an epithelioid phenotype by Pfn1 overexpression. This morphological transition is caused by restoration of adherens junctions (AJ) requiring Pfn1's interaction with actin. Pfn1 overexpression increases the expression level of R-cadherin (a type of cadherin that is endogenously expressed in the parental cell line) and restores AJ in MDA-231 cells in R-cadherin-dependent manner. These findings highlight important role of Pfn1 in the regulation of epithelial cell,cell adhesion. Cell Motil. Cytoskeleton 2009. © 2009 Wiley-Liss, Inc. [source] Overexpression of profilin reduces the migration of invasive breast cancer cellsCYTOSKELETON, Issue 2 2004Partha Roy Abstract The exact role profilin plays in cell migration is not clear. In this study, we have evaluated the effect of overexpression of profilin on the migration of breast cancer cells. Overexpression was carried out by stably expressing GFP-profilin in BT474 cells. It was observed that even a moderate level of overexpression of profilin significantly impaired the ability of BT474 cells to spread on fibronectin-coated substrate and migrate in response to EGF. GFP-profilin expressing cells also showed increased resistance to detachment in response to trypsin and increased tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin compared to the parental and GFP-expressing (control) cell lines. These results suggest that perturbation of profilin levels may offer a good strategy for controlling the metastatic potential of breast cancer cells. Cell Motil. Cytoskeleton 57:84,95, 2004. © 2004 Wiley-Liss, Inc. [source] Impaired lactation in mice expressing dominant-negative FADD in mammary epitheliumDEVELOPMENTAL DYNAMICS, Issue 4 2009Mark Shackleton Abstract The Fas-associated death domain (FADD/Mort1) adaptor protein was originally identified as a key mediator of apoptosis, although pleiotropic functions for FADD have also been reported. FADD-mediated tumoricidal effects have been described in breast cancer cells; however, its physiological role in normal mammary gland epithelium is not well understood. To determine the role of FADD signaling during mammary gland development, we generated transgenic mice overexpressing dominant-negative FADD (DN-FADD) in mammary epithelium, using the steroid responsive mouse mammary tumor virus promoter. Transgenic mice exhibited a perturbation in lactation resulting in impaired milk production and pup growth retardation. Reduced expansion of alveoli was evident during early lactation with extensive shedding of luminal alveolar cells. Significantly more TUNEL (terminal deoxynucleotidyl transferase,mediated deoxyuridinetriphosphate nick end-labeling)-positive cells were present at this time point and a subsequent increase in bromodeoxyuridine-positive cells was observed. These findings suggest a role for FADD in maintaining the survival of mammary secretory alveolar cells after the establishment of lactation. Developmental Dynamics 238:1010,1016, 2009. © 2009 Wiley-Liss, Inc. [source] A microfluidic device for characterizing the invasion of cancer cells in 3-D matrixELECTROPHORESIS, Issue 24 2009Tingjiao Liu Abstract A microfluidic device was developed for the study of directed invasion of cancer cells in 3-D matrix with concentration gradient. This device consists of two parallel perfusion channels connected by two cell culture chambers. To mimic extracellular matrix (ECM), gelled basement membrane extract (BME) was used to support 3-D distribution of breast cancer cells (MCF7) in cell culture chambers. A stable linear concentration gradient of epidermal growth factor (EGF) was generated across the chambers by continuous perfusion. Using the device, we investigated MCF7 cell invasion induced by different concentrations of EGF in 3-D matrix. It was found that cancer cells responded to EGF stimulation with forming cellular protrusions and migrating towards high EGF concentration. We further investigated the anti-invasion effect of GM 6001, a matrix metalloproteinase inhibitor. We identified that matrix metalloproteinase inhibition repressed both cellular protrusion formation and cell migration in 3-D matrix. These findings suggest that EGF is able to induce MCF7 cell invasion in 3-D extracellular matrix and this effect is dependent on proteolytic activity. This device is relatively simple to construct and operate. It should be a useful platform for elucidating the mechanism of cancer invasion and screening anti-invasion drugs for cancer therapy. [source] Centriole separation in DNA damage-induced centrosome amplificationENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 8 2009Chiara Saladino Abstract Altered centrosome numbers are seen in tumor cells in response to DNA damaging treatments and are hypothesised to contribute to cancer development. The mechanism by which the centrosome and chromosome cycles become disconnected after DNA damage is not yet clear. Here, we show that centrosome amplification occurs after ionising radiation (IR) in chicken DT40 cells that lack DNA-PK, Ku70, H2AX, Xpa, and Scc1, demonstrating that these activities are not required for centrosome amplification. We show that inhibition of topoisomerase II induces Chk1-dependent centrosome amplification, a similar response to that seen after IR. In the immortalised, nontransformed hTERT-RPE1 line, we observed centriole splitting, followed by dose-dependent centrosome amplification, after IR. We found that IR results in the formation of single, not multiple, daughter centrioles during centrosome amplification in U2OS osteosarcoma cells. Analysis of BRCA1 and BRCA2 mutant tumor cells showed high levels of centriole splitting in the absence of any treatment. IR caused pronounced levels of centrosome amplification in BRCA1 mutant breast cancer cells. These data show that centrosome amplification occurs after different forms of DNA damage in chicken cells, in nontransformed human cells and in human tumor cell lines, indicating that this is a general response to DNA damaging treatments. Together, our data suggest that centriole splitting is a key step in potentiation of the centrosome amplification that is a general response to DNA damage. Environ. Mol. Mutagen. 2009. © 2009 Wiley-Liss, Inc. [source] Methyl mercury influences growth-related signaling in MCF-7 breast cancer cellsENVIRONMENTAL TOXICOLOGY, Issue 1 2005Olga A. Sukocheva Abstract Environmental contaminants have been shown to alter growth-regulating signaling pathways through molecular mechanisms that are mainly unclear. Here we report that within a narrow concentration range (0.5,1 ,M) methyl mercury (MeHg) significantly stimulated growth of MCF-7 cells, induced Ca2+ mobilization, and activated extracellular signal,regulated kinase ½ (Erk1/2). MeHg modulated E2 -dependent stimulation of growth in a dose-dependent manner, although MeHg neither suppresses nor increases constitutive E2 metabolism. MeHg demonstrated weak estrogen receptor (ER),binding ability. However, long preincubation with antiestrogens LY156,758 and ICI164,384 decreased MeHg-induced foci formation, Ca2+ mobilization, and Erk1/2 activation, confirming involvement of ERs. The MeHg-induced increase in [Ca2+]i was observed to coincide with enhanced Erk1/2 phosphorylation. These data suggest that MeHg can significantly modulate the intracellular signaling environment in MCF-7 cells, resulting in a dose-dependent alteration of ER,mediated estrogenic capacity and therefore should be considered as a potential estrogen-disrupting compound. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 32,44, 2005. [source] Substances with estrogenic activity in effluents of sewage treatment plants in southwestern Germany.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2001Abstract The proliferation test with human estrogen receptor-positive MCF-7 breast cancer cells (E-Screen assay) was applied for quantitative determination of total estrogenic activity in 24-h composite effluent samples from 16 municipal and two industrial sewage treatment plants (STPs) in the state of Baden-Württemberg, southwestern Germany. The estrogenic efficacy relative to the positive control, 17,-estradiol, was between 26 and 74% (median, 48%) for the 16 municipal STPs. Estradiol equivalent concentrations (EEQs) were between 0.2 and 7.8 ng/L (median, 1.6 ng/L) and, thereby, were lower than those found in a pilot study, which revealed EEQs of greater than 10 ng/L in the effluents of two other STPs. The EEQs in 14 of the 16 effluent samples were very similar (0.9,3.3 ng/L), indicating a rather constant input of estrogenic substances via STPs into rivers. Additional activated charcoal filtration turned out to be very efficient in further eliminating estrogenic activity from effluents. The EEQs of the E-Screen assay and those calculated from the results of extensive chemical analysis using the estradiol equivalency factors determined for 13 natural and synthetic estrogenic substances were comparable for most of the effluent samples. 17,-Estradiol, 17,-ethinylestradiol, and, to a lesser extent, estrone contributed to 90% or more of the EEQ value. [source] Progestin upregulates G-protein-coupled receptor 30 in breast cancer cellsFEBS JOURNAL, Issue 10 2002Tytti M. Ahola A differential display method was used to study genes the expression of which is altered during growth inhibition induced by medroxyprogesterone acetate (MPA). A transcript of G-protein-coupled receptor 30 (GPR30) was upregulated by MPA in estrogen-treated MCF-7 breast cancer cells. Northern-blot analysis showed a progestin-specific primary target gene, which was enhanced by progesterone and different progestins, but not by dihydrotestosterone or dexamethasone, and which was abrogated by antiprogestin RU486. The dose-dependent and time-dependent increase in GPR30 mRNA expression correlated with MPA-induced growth inhibition in MCF-7 cells. Additionally, GPR30 upregulation by progestin correlated with growth inhibition when a comparison was made between different breast cancer cell lines. The ERK1/ERK2 pathway is capable of inducing progesterone receptor-dependent and ligand-dependent transcription. Thus we sought to establish whether different MAPK pathway inhibitors affect progestin-induced GPR30 mRNA regulation. The regulation of GPR30 was independent of ERK pathway activation, but the p38 pathway inhibitor induced GPR30 expression, which suggested a potential gene regulation pathway. These data demonstrate a new progestin target gene, the expression of which correlates with growth inhibition. [source] Multifunctional Mesoporous Silica Material Used for Detection and Adsorption of Cu2+ in Aqueous Solution and Biological Applications in vitro and in vivoADVANCED FUNCTIONAL MATERIALS, Issue 12 2010Qingtao Meng Abstract An inorganic,organic silica material (SBA,P2), prepared by immobilization of the 1,8-naphthalimide-based receptor P2 within the channels of the mesoporous silica material SBA-15, is characterized by transmission electron microscopy and several spectroscopic methods. SBA,P2 features a high affinity Cu2+ -specific fluorescence response in aqueous solution with a detection limit for Cu2+ of ca. 0.65,ppb (10,×,10,9,M) under optimized conditions. It can extract Cu2+ from the solution with only trace amounts remaining. Through isolating of the toxic ions within the mesopores of the silica, SBA,P2 has the potential to work as a toxicide for Cu2+ in living systems. The fluorogenical responses are reversible and do not vary over a broad (4.0 to 9.0) pH range suitable for application under physiological conditions. The fluorescence responses of Cu2+ in vitro (human breast cancer cells) and in vivo (five-day-old zebrafish) demonstrate the possibility of further application in biology. [source] Generic Strategy of Preparing Fluorescent Conjugated-Polymer-Loaded Poly(DL -lactide- co -Glycolide) Nanoparticles for Targeted Cell ImagingADVANCED FUNCTIONAL MATERIALS, Issue 22 2009Kai Li Abstract A general strategy for the preparation of highly fluorescent poly(DL-lactide- co -glycolide) (PLGA) nanoparticles (NPs) loaded with conjugated polymers (CPs) is reported. The process involves encapsulation of organic-soluble CPs with PLGA using a modified solvent extraction/evaporation technique. The obtained NPs are stable in aqueous media with biocompatible and functionalizable surfaces. In addition, fluorescent properties of the CP-loaded PLGA NPs (CPL NPs) could be fine-tuned by loading different types of CPs into the PLGA matrix. Four types of CPL NPs are prepared with a volume-average hydrodynamic diameter ranging from 243 to 272,nm. The application of CPL NPs for bio-imaging is demonstrated through incubation with MCF-7 breast cancer cells. Confocal laser scanning microscopy studies reveal that the CPL NPs are internalized in cytoplasm around the nuclei with intense fluorescence. After conjugation with folic acid, cellular uptake of the surface-functionalized CPL NPs is greatly enhanced via receptor-mediated endocytosis by MCF-7 breast cancer cells, as compared to that for NIH/3T3 fibroblast cells, which indicates a selective targeting effect of the folate-functionalized CPL NPs in cellular imaging. The merits of CPL NPs, such as low cytotoxicity, high fluorescence, good photostability, and feasible surface functionalization, will inspire extensive study of CPL NPs as a new generation of probes for specific biological imaging and detection. [source] Ginkgo biloba extracts and cancer: a research area in its infancyFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 4 2003Francis V. DeFeudis Abstract Recent studies conducted with various molecular, cellular and whole animal models have revealed that leaf extracts of Ginkgo biloba may have anticancer (chemopreventive) properties that are related to their antioxidant, anti-angiogenic and gene-regulatory actions. The antioxidant and associated anti-lipoperoxidative effects of Ginkgo extracts appear to involve both their flavonoid and terpenoid constituents. The anti-angiogenic activity of the extracts may involve their antioxidant activity and their ability to inhibit both inducible and endothelial forms of nitric oxide synthase. With regard to gene expression, a Ginkgo extract and one of its terpenoid constituents, ginkgolide B, inhibited the proliferation of a highly aggressive human breast cancer cell line and xenografts of this cell line in nude mice. cDNA microarray analyses have shown that exposure of human breast cancer cells to a Ginkgo extract altered the expression of genes that are involved in the regulation of cell proliferation, cell differentiation or apoptosis, and that exposure of human bladder cancer cells to a Ginkgo extract produced an adaptive transcriptional response that augments antioxidant status and inhibits DNA damage. In humans, Ginkgo extracts inhibit the formation of radiation-induced (chromosome-damaging) clastogenic factors and ultraviolet light-induced oxidative stress , effects that may also be associated with anticancer activity. Flavonoid and terpenoid constituents of Ginkgo extracts may act in a complementary manner to inhibit several carcinogenesis-related processes, and therefore the total extracts may be required for producing optimal effects. [source] Anti-apoptotic effect of the basic helix-loop-helix (bHLH) transcription factor DEC2 in human breast cancer cellsGENES TO CELLS, Issue 4 2010Yang Liu DEC1 (BHLHB2/Stra13/Sharp2) and DEC2 (BHLHB3/Sharp1) are basic helix-loop-helix (bHLH) transcription factors that are involved in circadian rhythms, differentiation and the responses to hypoxia. We examined whether DEC1 and DEC2 are involved in apoptosis regulation, in human breast cancer MCF-7 cells. We found that siRNA-mediated knockdown of DEC2 resulted in marked enhancement of apoptosis compared with that in control cells transfected with nonspecific siRNA. However, knockdown of DEC1 by siRNA did not affect cell survival. Knockdown of DEC2 affected the expression of mRNA or proteins related to apoptosis, such as Fas, c-Myc, caspase-8, poly (ADP-ribose) polymerase (PARP) and Bax. We also showed that tumor necrosis factor-, (TNF-,) up-regulates the expression of DEC1 and DEC2. DEC2 over-expression caused by the transfection of an expression vector reduced the amounts of cleaved PARP and caspase-8 induced by TNF-, treatment, whereas DEC1 over-expression increased it. Finally, we revealed that treatment with double knockdown against both DEC1 and DEC2 decreased the amounts of cleaved PARP and caspase-8 induced by DEC2 siRNA with or without TNF-,. These data indicate that DEC2 has an anti-apoptotic effect, whereas DEC1 has a pro-apoptotic effect, which are involved in the balance of survival of human breast cancer MCF-7 cells. [source] Critical roles of LGN/GPSM2 phosphorylation by PBK/TOPK in cell division of breast cancer cellsGENES, CHROMOSOMES AND CANCER, Issue 10 2010Chikako Fukukawa To investigate the molecular mechanism of mammary carcinogenesis and identify novel molecular targets for breast cancer therapy, we analyzed genome-wide gene expression profiles of 81 clinical breast cancer samples. Here, we report the critical role of LGN/GPSM2 (Leu-Gly-Asn repeat-enriched protein/G-protein signaling modulator 2) in the growth of breast cancer cells. Semiquantitative RT-PCR and Northern blot analyses confirmed upregulation of LGN/GPSM2 in a large proportion of breast cancers. Immunocytochemical staining identified LGN/GPSM2 at the spindle in cells at metaphase, and at midzone and midbody in cytokinetic cells. Western blot analysis indicated the highest expression and the phosphorylated form of LGN/GPSM2 protein in G2/M phase. Treatment with small-interfering RNAs (siRNAs) targeting LGN/GPSM2 caused incompletion of cell division and resulted in significant growth suppression of breast cancer cells. We found that the 450th threonine (Thr450) of LGN/GPSM2 was phosphorylated by the serine/threonine kinase PBK/TOPK during mitosis. Overexpression of LGN/GPSM2-T450A in which Thr450 was substituted with alanine induced growth suppression and aberrant chromosomal segregation. These findings imply an important role of LGN/GPSM2 in cell division of breast cancer cells and suggest that the PBK/TOPK-LGN/GPSM2 pathway might be a promising molecular target for treatment of breast cancer. © 2010 Wiley-Liss, Inc. [source] Anticancer Drug Delivery: Doxorubicin-Conjugated Immuno-Nanoparticles for Intracellular Anticancer Drug Delivery (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 11 2009Mater. Self-assembled polymeric nanoparticles of the amphiphilic copolymer poly(TMCC-co-LA)-g-PEG-furan can couple both anti-HER2 antibodies and chemotherapeutic doxorubicin (DOX) on their surfaces, report Molly Shoichet and co-workers on page 1689. This novel strategy selectively delivers DOX to the cell nucleus of HER2-overexpressing breast cancer cells while maintaining the pharmaceutical toxicity of DOX, paving the way to targeted drug delivery in breast cancer treatment. [source] Experimental design comparison of studies evaluating doxorubicin nanoparticles in breast cancer therapyHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 3 2008Farman A. Moayed Background The unique properties of nanoparticles (NP) qualify these colloidal systems for a wide range of medical applications, including diagnosis and treatment. Particularly in cancer therapy, NP have significantly enhanced the potential of conventional imaging, radiotherapy, and chemotherapy and, consequently, offered new avenues for early interventions. So far, breast cancer has been one of the most studied cancer types with NP research, which can benefit the occupational breast cancer for the increasing number of women in the labor force in industry. Objectives The objective of this study is to compare the experimental designs of preclinical studies that assessed the effect of doxorubicin NP (DOX-NP) on the estrogen-dependent MCF-7 breast cancer cell line using a recently established quantitative Experimental Appraisal Instrument (ExpAI). Methods A systematic review of research articles published between August 2004 and August 2005 on NP and breast cancer treatment with doxorubicin was performed using various online databases and indexes available through the University of Cincinnati. Restrictive inclusion and exclusion criteria were defined leading to selection of four relevant articles that used comparable experimental designs. Critical appraisal of those studies was performed by five independent assessors using the ExpAI version 2.0 and the results were summarized in a table of evidence. Results The study design in the selected articles was either between groups or mixed, with sample sizes varying from n = 3,6, and the evaluation of the effect of DOX-NP either in vitro or in vivo. The cytotoxic drug doxorubicin was the input variable in all studies, whereas different end points such as pharmacokinetic parameters, cytotoxicity surrogates (e.g., growth inhibition, mitochondrial activity), and quantitative analysis of messenger RNA were used as output variables. Conclusions Although the articles assessed in this article were preclinical experimental studies, the results showed that doxorubicin NP drugs can be used effectively to enhance the delivery process in MCF-7 breast cancer cells by increasing the circulation time and targeting the tumor tissues. Considering the rising number of women in the labor force and the risk of occupational breast cancer, it can be concluded that DOX-NP may potentially be used as an effective anticancer drug on humans, but further research and studies are required to understand how DOX-NP drugs might react in the human body before using it on breast cancer patients. © 2008 Wiley Periodicals, Inc. [source] Expression of estrogen receptor alpha increases leptin-induced STAT3 activity in breast cancer cellsINTERNATIONAL JOURNAL OF CANCER, Issue 1 2010Nadine A. Binai Abstract Adipositas correlates with an enhanced risk of developing malignant diseases such as breast cancer, endometrial tumor or prostate carcinoma, but the molecular basis for this is not well understood. Potential mechanisms include increased bioavailability of adipocytokines (e.g. leptin) and steroid hormones. Here, we investigated cross-talk between ER, (estrogen receptor alpha) and leptin-induced activation of signal transducer and activator of transcription 3 (STAT3), a transactivator of important oncogenes. Upon leptin binding to its receptor Ob-RL (obesity receptor), STAT3 tyrosine phosphorylation and transactivation activity were enhanced by simultaneously expressing ER,. Downregulation of ER, using small interfering RNA abolished leptin-induced STAT3 phosphorylation. Interestingly, leptin-mediated STAT3 activation was unaffected by co-stimulation with the ER, ligands estradiol (E2) or estrogen antagonists ICI182,780 and tamoxifen, implying that enhancement of leptin-mediated STAT3 activity is independent of ER, ligands. We also detected ER, binding to STAT3 and JAK2 (Janus kinase 2), resulting in enhanced JAK2 activity upstream of STAT3 in response to leptin that might lead to an increased ER,-dependent cell viability. Altogether, our results indicate that leptin-induced STAT3 activation acts as a key event in ER,-dependent development of malignant diseases. [source] BEX2 regulates mitochondrial apoptosis and G1 cell cycle in breast cancerINTERNATIONAL JOURNAL OF CANCER, Issue 7 2010Ali Naderi Abstract We have recently demonstrated that BEX2 is differentially expressed in primary breast tumors and BEX2 expression is required for the Nerve Growth factor inhibition of ceramide-induced apoptosis in breast cancer. In this study we investigate the functional role of BEX2 in the survival and growth of breast cancer cells. We demonstrate that BEX2 downregulation induces mitochondrial apoptosis and sensitizes breast cancer cells to the pro-apoptotic effects of ceramide, doxorubicin and staurosporine. In addition, BEX2 overexpression protects the breast cancer cells against mitochondrial apoptosis. We show that this effect of BEX2 is mediated through the modulation of Bcl-2 protein family, which involves the positive regulation of anti-apoptotic member Bcl-2 and the negative regulation of pro-apoptotic members BAD, BAK1 and PUMA. Moreover, our data suggests that BEX2 expression is required for the normal cell cycle progression during G1 in breast cancer cells through the regulation of cyclin D1 and p21. To further support the significance of BEX2 in the pathogenesis of breast cancer we demonstrate that BEX2 overexpression is associated with a higher activation of the Bcl-2/NF-,B pathway in primary breast tumors. Furthermore, we show that BEX2 downregulation results in a higher expression and activity of protein phosphatase 2A. The modulation of protein phosphatase 2A, which is also known to mediate the cellular response to ceramide, provides a possible mechanism to explain the BEX2-mediated cellular effects. This study demonstrates that BEX2 has a significant role in the regulation of mitochondrial apoptosis and G1 cell cycle in breast cancer. [source] Sustained delivery and efficacy of polymeric nanoparticles containing osteopontin and bone sialoprotein antisenses in rats with breast cancer bone metastasisINTERNATIONAL JOURNAL OF CANCER, Issue 7 2010Victoria Elazar Abstract Poor prognosis in mammary carcinoma is associated with a certain expression profile of a defined set of genes including osteopontin and bone sialoprotein. Efficient and specific delivery of antisenses (AS) and a protection of the sequences from degradation are the crucial conditions for AS therapeutic efficiency. We hypothesized that effective and safe AS delivery direceted against these genes could be achieved by polymeric nanoparticles (NP) fabricated from a biocompatible polymer. Due to their nano-size range and small negative charge, AS-NP can overcome the absorption barrier offering increased resistance to nuclease degradation, sustained duration of AS administration, and consequently, prolonged antisense action. The ASs designed against OPN and BSP-II were successfully encapsulated in NP composed of the biodegradable and biocompatible polylactide- co -glycolide polymer (PLGA), exhibiting sustained release and stability of the ASs. The therapeutic efficacy of the AS-NP delivery system was examined in vitro, and in a breast cancer bone metastasis animal model of MDA-MB-231 human breast cancer cells in nude rats. Treatment with OPN-AS or BSP-AS loaded NP in comparison with osmotic mini-pumps (locoregional injection and SC implants, respectively) resulted in a significant decrease in both, tumor bone metastasis incidence and in the size of the lesions in rats with metastases. Despite its smaller dose, AS-NP exhibited a better therapeutic efficacy than osmotic mini-pumps in terms of lesion ratio at later time periods (8,12 weeks). It may be concluded that AS delivery by NP is a promising therapeutic modality providing stability of the encapsulated AS and a sustained release. [source] BRCA1 modulates malignant cell behavior, the expression of survivin and chemosensitivity in human breast cancer cells,INTERNATIONAL JOURNAL OF CANCER, Issue 12 2009Moltira Promkan Abstract BRCA1 is a multifunctional tumor-suppressive protein. Many functional aspects of BRCA1 are not fully understood. We used a shRNA approach to probe the function of BRCA1 in human breast cancer cells. Knocking down BRCA1 expression by shRNA in the wild-type BRCA1 human breast cancer MCF-7 and MDA-MB-231 cells resulted in an increase in cell proliferation, anchorage-independent growth, cell migration, invasion and a loss of p21/Waf1 and p27Kip1 expression. In BRCA1 knocked-down cells, the expression of survivin was significantly up regulated with a concurrent decrease in cellular sensitivity to paclitaxel. We also found that cells harboring endogenous mutant or defective BRCA1 (MDA-MB-436 and HCC1937) were highly proliferative and expressed a relatively low level of p21/Waf1 and p27Kip1 by comparison to wild-type BRCA1 cells. Cells harboring mutated BRCA1 also expressed a high level of survivin and were relatively resistant to paclitaxel by comparison to wild-type cells. Increase resistance to paclitaxel was due to an increase in the expression of survivin in both the BRCA1 knocked-down and mutant BRCA1 cells because knocking down survivin expression by siRNA restored sensitivity to paclitaxel. We conclude that BRCA1 down-modulates the malignant behavior of breast cancer cells, promotes the expression of p21/Waf1, p27Kip1 and inhibits the expression of survivin. Moreover, loss of BRCA1 expression or function leads to an increase in survivin expression and a reduction in chemosensitivity to paclitaxel. © 2009 UICC [source] Stromal MCP-1 in mammary tumors induces tumor-associated macrophage infiltration and contributes to tumor progressionINTERNATIONAL JOURNAL OF CANCER, Issue 6 2009Hiroshi Fujimoto Abstract There is growing evidence that tumor-associated macrophages (TAMs) promote tumor growth and dissemination. Many individual reports have focused on the protumor function of molecules linked to the recruitment of macrophages, but little is known about which factor has the strongest impact on recruitment of macrophages in breast cancer. To elucidate this question, we performed RT-PCR using species-specific primers and evaluated tumoral and stromal mRNA expression of macrophage chemoattractants separately in human breast tumor xenografts. The correlation between the tumoral or stromal chemoattractant mRNA expression including monocyte chemoattractant protein-1 (MCP-1) (CCL2), MIP-1, (CCL3), RANTES (CCL5), colony-stimulating factor 1, tumor necrosis factor ,, platelet-derived growth factor (PDGF)-BB and macrophage infiltration were compared. There was significant positive correlation between stromal MCP-1 expression and macrophage number (r = 0.63), and negative correlation between tumoral RANTES expression and macrophage number (r = ,0.75). However, no significant correlation was found for the other tumoral and stromal factors. The interaction between the tumor cells and macrophages was also investigated. Tumor cell,macrophage interactions augmented macrophage-derived MCP-1 mRNA expression and macrophage chemotactic activity in vitro. Treatment of immunodeficient mice bearing human breast cancer cells with a neutralizing antibody to MCP-1 resulted in significant decrease of macrophage infiltration, angiogenetic activity and tumor growth. Furthermore, immunohistochemical analysis of human breast cancer tissue showed stromal MCP-1 had a significant correlation with relapse free survival (p = 0.029), but tumoral MCP-1 did not (p = 0.105). These findings indicate that stromal MCP-1 produced as a result of tumor,stromal interactions may be important for the progression of human breast cancer and macrophages may play an important role in this tumor,stroma interaction. © 2009 UICC. [source] Nicotine induces cell proliferation, invasion and epithelial-mesenchymal transition in a variety of human cancer cell linesINTERNATIONAL JOURNAL OF CANCER, Issue 1 2009Piyali Dasgupta Abstract Cigarette smoking is strongly correlated with the onset of nonsmall cell lung cancer (NSCLC). Nicotine, an active component of cigarettes, has been found to induce proliferation of lung cancer cell lines. In addition, nicotine can induce angiogenesis and confer resistance to apoptosis. All these events are mediated through the nicotinic acetylcholine receptors (nAChRs) on lung cancer cells. In this study, we demonstrate that nicotine can promote anchorage-independent growth in NSCLCs. In addition, nicotine also induces morphological changes characteristic of a migratory, invasive phenotype in NSCLCs on collagen gel. These morphological changes were similar to those induced by the promigratory growth factor VEGF. The proinvasive effects of nicotine were mediated by ,7-nAChRs on NSCLCs. RT-PCR analysis showed that the ,7-nAChRs were also expressed on human breast cancer and pancreatic cancer cell lines. Nicotine was found to promote proliferation and invasion in human breast cancer. The proinvasive effects of nicotine were mediated via a nAChR, Src and calcium-dependent signaling pathway in breast cancer cells. In a similar fashion, nicotine could also induce proliferation and invasion of Aspc1 pancreatic cancer cells. Most importantly, nicotine could induce changes in gene expression consistent with epithelial to mesenchymal transition (EMT), characterized by reduction of epithelial markers like E-cadherin expression, ZO-1 staining and concomitant increase in levels of mesenchymal proteins like vimentin and fibronectin in human breast and lung cancer cells. Therefore, it is probable that the ability of nicotine to induce invasion and EMT may contribute to the progression of breast and lung cancers. © 2008 Wiley-Liss, Inc. [source] Imatinib mesylate suppresses bone metastases of breast cancer by inhibiting osteoclasts through the blockade of c-Fms signalsINTERNATIONAL JOURNAL OF CANCER, Issue 1 2009Toru Hiraga Abstract Imatinib mesylate (imatinib) is a potent and selective inhibitor of the tyrosine kinases, Bcr-Abl, c-Kit and platelet-derived growth factor receptors (PDGFRs). Recently, it has been reported that imatinib also targets the macrophage colony-stimulating factor (M-CSF) receptor c-Fms. M-CSF signals are essential for the differentiation of osteoclasts. Bone metastases of breast cancer are frequently associated with osteoclastic bone destruction. Furthermore, several lines of evidence suggest that osteoclasts play central roles in the development and progression of bone metastases. Thus, in the present study, we examined the effects of imatinib on bone metastases of breast cancer. Coimmunoprecipitation assays showed that imatinib inhibited the M-CSF-induced phosphorylation of c-Fms in osteoclast precursor cells as well as the PDGF-induced PDGFR phosphorylation in MDA-MB-231 human breast cancer cells. Imatinib also markedly reduced osteoclast formation in vitro. In contrast, those concentrations of imatinib did not affect osteoblast differentiation. We then examined the effects of imatinib on bone metastases of MDA-MB-231 cells in a nude mouse model. Radiographic and histomorphometric analyses demonstrated that imatinib significantly decreased bone metastases associated with the reduced number of osteoclasts. In support of the notion that the inhibition of c-Fms acts to suppress the development of bone metastases, we found that a specific inhibitor of c-Fms Ki20227 also decreased bone metastases. In conclusion, these results collectively suggest that imatinib reduced bone metastases, at least in part, by inhibiting osteoclastic bone destruction through the blockade of c-Fms signals. Our results also suggest that imatinib may have a protective effect against cancer treatment-induced bone loss. © 2008 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||||||||