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Breast Carcinoma Cells (breast + carcinoma_cell)
Kinds of Breast Carcinoma Cells Terms modified by Breast Carcinoma Cells Selected AbstractsStochasticity of Manganese Superoxide Dismutase mRNA Expression in Breast Carcinoma Cells by Molecular Beacon ImagingCHEMBIOCHEM, Issue 11 2005Timothy J. Drake Abstract Visual and quantitative monitoring of cell-to-cell variation in the expression of manganese superoxide dismutase (MnSOD) mRNA by using novel ratiometric imaging with molecular beacons (MB) reveals a distinct change in patterns following induction of human breast-carcinoma cells with lipopolysaccharide. Interestingly, the pattern of cell-to-cell variation in a cell line stably transfected with a plasmid bearing a cDNA clone of MnSOD and overproducing the enzyme is significantly different from the pattern associated with MnSOD induction. The levels and the patterns of cell-population heterogeneity for ,-actin mRNA expression do not show distinct changes either following induction or in stably transfected cells. These results are significant in light of the reported relationship between this enzyme and malignant phenotype of breast-carcinoma cells. Use of MBs in ratiometric image analyses for cytoplasmic mRNAs represents a novel means of directly examining the stochasticity of transcription of MnSOD and other genes implicated in cellular phenotype regulation. [source] The Chemokine Receptor CXCR4 is More Frequently Expressed in Breast Compared to Other Metastatic Adenocarcinomas in EffusionsTHE BREAST JOURNAL, Issue 5 2008Ben Davidson MD Abstract:, This objective of this study was to investigate the expression of chemokine receptors in tumor cells and leukocytes in breast carcinoma effusions. The expression of leukocyte markers (CD3/4/8/14/16/19) and chemokine receptors (CXCR1/4, CCR2/5/7) was studied in 21 breast carcinoma effusions using flow cytometry. Breast carcinoma cells expressed CXCR4 in 7/21 (33%) effusions, with less frequent expression of CXCR1, CCR5, and CCR7. CXCR2 and CCR2 were absent. Lymphocytes showed frequent CXCR4, CCR5, and CCR7 expression, while CXCR1, CXCR2, CCR2 were rarely or never detected. Macrophages expressed all six receptors except for CXCR2. Comparative analysis of breast carcinoma effusions with previously studied ovarian and cervical/endometrial adenocarcinomas (ACs) showed significantly higher CXCR4 expression in breast carcinoma cells compared to the other gynecological ACs (p = 0.001). Breast and cervical/endometrial carcinoma effusions showed different expression of chemokine receptors in lymphocytes (lower CXCR1, higher CXCR4 and CCR7 levels; p = 0.012, p = 0.005, p < 0.001, respectively) and macrophages (higher CCR7 levels; p < 0.001), as well as lower CD8 counts (p < 0.001) and higher CD19 counts (p = 0.001) compared to ovarian carcinoma effusions. Higher numbers of CD8-positive lymphocytes (p = 0.080) and higher CCR7 monocyte expression (p = 0.087) were associated with a trend for shorter disease-free survival. In conclusion, breast carcinoma cells express CXCR4, a unique feature among metastatic ACs in effusions, with rare expression of other chemokine receptors. Chemokine receptor expression in leukocytes and lymphocyte counts significantly differ from those of ovarian carcinoma effusions. The prognostic role of CCR7 expression in monocytes and CD8 counts in breast carcinoma effusions merits further research. [source] Membrane type-1 matrix metalloproteinase stimulates tumour cell-induced platelet aggregation: role of receptor glycoproteinsBRITISH JOURNAL OF PHARMACOLOGY, Issue 2 2004David Alonso-Escolano Matrix metalloproteinase-2 (MMP-2) plays a role in agonist- and tumour cell-induced platelet aggregation (TCIPA). MMP-2 is synthesized as a proenzyme and is activated at the cell surface by membrane type-1 matrix metalloproteinase (MT1-MMP, MMP-14). The significance of tumour cell-associated MT1-MMP for TCIPA was investigated using human breast carcinoma MCF7 cells stably coexpressing the integrin ,v,3 with MT1-MMP, cells expressing ,v,3 alone and mock-transfected cells. Western blot and zymography confirmed that ,v,3/MT1-MMP cells expressed MT1-MMP and efficiently processed proMMP-2 to MMP-2. Aggregometry, phase-contrast and transmission electron microscopy and flow cytometry were used to characterize TCIPA induced by MCF7 cell lines. The aggregating potency of cells was: ,v,3/MT1-MMP >,v,3=mock cells, as shown by aggregometry and phase-contrast microscopy. Electron microscopy revealed close, membrane,membrane interactions between activated platelets and ,v,3/MT1-MMP cells during TCIPA. Inhibition of MMP-2 with the neutralizing anti-MMP-2 antibody (5 ,g ml,1) and o -phenanthroline (100 ,M) reduced aggregation induced by ,v,3/MT1-MMP cells. TCIPA induced by ,v,3/MT1-MMP cells was also reduced by inhibiting the generation and actions of ADP with apyrase (250 ,g ml,1) and 2-methylthio-AMP (2-MeSAMP) (30 ,M), but not N6 -methyl-2,-deoxyadenosine-3,,5,-bisphosphate (MRS2179) (30 ,M). Flow cytometry demonstrated that TCIPA enhanced expression of glycoprotein (GP) Ib and IIb/IIIa receptors not only on platelets but also on breast cancer cells. Thus, (a) human breast carcinoma cell surface-associated MT1-MMP, via activating proMMP-2, stimulates TCIPA; (b) ADP amplifies the effects of MMPs via stimulation of P2Y12 receptors and (c) both tumour- and platelet-derived GPIb and GPIIb/IIIa are involved in the aggregatory effects of MT1-MMP. British Journal of Pharmacology (2004) 141, 241,252. doi:10.1038/sj.bjp.0705606 [source] ,3-Tubulin is induced by estradiol in human breast carcinoma cells through an estrogen-receptor dependent pathwayCYTOSKELETON, Issue 7 2009Jennifer Saussede-Aim Abstract Microtubules are involved in a variety of essential cell functions. Their role during mitosis has made them a target for anti-cancer drugs. However development of resistance has limited their use. It has been established that enhanced ,3-tubulin expression is correlated with reduced response to antimicrotubule agent-based chemotherapy or worse outcome in a variety of tumor settings. However little is known regarding the regulation of ,3-tubulin expression. We investigated the regulatory mechanisms of expression of ,3-tubulin in the MCF-7 cell line, a model of hormone-dependent breast cancer. Exposure of MCF-7 cells to estradiol was found to induce ,3-tubulin mRNA as well as ,3-tubulin protein expression. Conversely, we did not observe induction of ,3-tubulin mRNA by estradiol in MDA-MB-231 cells which are negative for the estrogen receptor (ER). In order to determine whether ,3-tubulin up-regulation is mediated through the ER pathway, MCF-7 cells were exposed to two ER modulators. Exposure to tamoxifen, a selective estrogen receptor modulator, completely abolished the ,3-tubulin mRNA induction due to estradiol in MCF-7 cells. This result was confirmed with fulvestrant, a pure antagonist of ER. These results demonstrate that the effect of estradiol on ,3-tubulin transcription is mediated through an ER dependent pathway. Cell Motil. Cytoskeleton 66:378,388, 2009. © 2009 Wiley-Liss, Inc. [source] Description and characterization of a chamber for viewing and quantifying cancer cell chemotaxisCYTOSKELETON, Issue 1 2005Lilian Soon Abstract Direct observations of cancer cell invasion underscore the importance of chemotaxis in invasion and metastasis. Yet, there is to date, no established method for real-time imaging of cancer chemotaxis towards factors clinically correlated with metastasis. A chamber has been designed and tested, called the Soon chamber, which allows the direct observation and quantification of cancer cell chemotaxis. The premise for the design of the Soon chamber is the incorporation of a dam, which creates a steep gradient while retaining stability associated with a pressure-driven system. The design is based on the characteristics of cancer cell motility such as relatively low speeds, and slower motility responses to stimuli compared to classical amoeboid cells like neutrophils and Dictyostelium. We tested MTLn3 breast carcinoma cells in the Soon chamber in the presence of an EGF gradient, obtaining hour-long time-lapses of chemotaxis. MTLn3 cells migrated further, more linearly, and at greater speeds within an EGF gradient compared to buffer controls. Computation of the degree of orientation towards the EGF/buffer source showed that MTLn3 cells were significantly more directional toward the EGF gradient compared to buffer controls. Analysis of the time-lapse data obtained during chemotaxis demonstrated that two populations of cancer cells were present. One population exhibited oscillations in directionality occurring at average intervals of 12 min while the second population exhibited sustained high levels of directionality toward the source of EGF. This result suggests that polarized cancer cells can avoid the need for oscillatory path corrections during chemotaxis. Cell Motil. Cytoskeleton 62:27,34, 2005. © 2005 Wiley-Liss, Inc. [source] CNTO 859, a humanized anti-tissue factor monoclonal antibody, is a potent inhibitor of breast cancer metastasis and tumor growth in xenograft modelsINTERNATIONAL JOURNAL OF CANCER, Issue 6 2007Cam V. Ngo Abstract Thromboembolic complications are frequently associated with advanced cancer. Interestingly, one of the major initiators of blood coagulation, tissue factor (TF), is reported to be overexpressed in several tumor types and can be found on both tumor cells and tumor vasculature. Although the exact mechanisms have yet to be elucidated, TF expressed on tumor cells can trigger intracellular signaling events through various pathways that can lead to tumor angiogenesis, proliferation, and metastasis. There exists preclinical evidence that disruption of TF dependent signaling can effectively inhibit tumor cell migration, metastasis, and angiogenesis. Here, we report for the first time that an antibody to tissue factor can also prevent tumor growth in vivo. Prophylactic administration of CNTO 859, a humanized anti-human TF antibody, was shown to inhibit experimental lung metastasis of MDA-MB-231 human breast carcinoma cells by over 99% compared to a control antibody. Furthermore, therapeutic doses of CNTO 859 were shown to reduce tumor incidence and growth of orthotopically implanted MDA-MB-231 cells. © 2006 Wiley-Liss, Inc. [source] Early Detection of Bone Metastases in a Murine Model Using Fluorescent Human Breast Cancer Cells: Application to the Use of the Bisphosphonate Zoledronic Acid in the Treatment of Osteolytic LesionsJOURNAL OF BONE AND MINERAL RESEARCH, Issue 11 2001Olivier Peyruchaud Abstract A very common metastatic site for human breast cancer is bone. The traditional bone metastasis model requires human MDA-MB-231 breast carcinoma cell inoculation into the left heart ventricle of nude mice. MDA-MB-231 cells usually develop osteolytic lesions 3,4 weeks after intracardiac inoculation in these animals. Here, we report a new approach to study the formation of bone metastasis in animals using breast carcinoma cells expressing the bioluminescent jellyfish protein (green fluorescent protein [GFP]). We first established a subclone of MDA-MB-231 cells by repeated in vivo passages in bone using the heart injection model. On stable transfection of this subclone with an expression vector for GFP and subsequent inoculation of GFP-expressing tumor cells (B02/GFP.2) in the mouse tail vein, B02/GFP.2 cells displayed a unique predilection for dissemination to bone. Externally fluorescence imaging of live animals allowed the detection of fluorescent bone metastases approximately 1 week before the occurrence of radiologically distinctive osteolytic lesions. The number, size, and intensity of fluorescent bone metastases increased progressively with time and was indicative of breast cancer cell progression within bone. Histological examination of fluorescent long bones from B02/GFP.2-bearing mice revealed the occurrence of profound bone destruction. Treatment of B02/GFP.2-bearing mice with the bisphosphonate zoledronic acid markedly inhibited the progression of established osteolytic lesions and the expansion of breast cancer cells within bone. Overall, this new bone metastasis model of breast cancer combining both fluorescence imaging and radiography should provide an invaluable tool to study the effectiveness of pharmaceutical agents that could suppress cancer colonization in bone. [source] A novel technique to monitor carboxypeptidase G2 expression in suicide gene therapy using 19F magnetic resonance spectroscopyNMR IN BIOMEDICINE, Issue 5 2009Laura Mancini Abstract Development and evaluation of new anticancer drugs are expedited when minimally invasive biomarkers of pharmacokinetic and pharmacodynamic behaviour are available. Gene-directed enzyme prodrug therapy (GDEPT) is a suicide gene therapy in which the anticancer drug is activated in the tumor by an exogenous enzyme previously targeted by a vector carrying the gene. GDEPT has been evaluated in various clinical trials using several enzyme/prodrug combinations. The key processes to be monitored in GDEPT are gene delivery and expression, as well as prodrug delivery and activation. {4-[bis(2-chloroethyl)amino]-3,5-difluorobenzoyl}-L-glutamic acid, a prodrug for the GDEPT enzyme carboxypeptidase-G2 (CPG2; Km,=,1.71,µM; kcat,=,732,s,1), was measured with 19F magnetic resonance spectroscopy (MRS). The 1,ppm chemical shift separation found between the signals of prodrug and activated drug (4-[bis(2-chloroethyl)amino]-3,5-difluorobenzoic acid) is sufficient for the detection of prodrug activation in vivo. However, these compounds hydrolyze rapidly, and protein binding broadens the MR signals. A new CPG2 substrate was designed with hydroxyethyl instead of chloroethyl groups (Km,=,3.5,µM, kcat,=,747,s,1). This substrate is nontoxic and stable in solution, has a narrow MRS resonance in the presence of bovine and foetal bovine albumin, and exhibits a 1.1,ppm change in chemical shift upon cleavage by CPG2. In cells transfected to express CPG2 in the cytoplasm (MDA MB 361 breast carcinoma cells and WiDr colon cancer cells), well-resolved 19F MRS signals were observed from clinically relevant concentrations of the new substrate and its nontoxic product. The MRS conversion half-life (470,min) agreed with that measured by HPLC (500,min). This substrate is, therefore, suitable for evaluating gene delivery and expression prior to administration of the therapeutic agent. Copyright © 2009 John Wiley & Sons, Ltd. [source] The Chemokine Receptor CXCR4 is More Frequently Expressed in Breast Compared to Other Metastatic Adenocarcinomas in EffusionsTHE BREAST JOURNAL, Issue 5 2008Ben Davidson MD Abstract:, This objective of this study was to investigate the expression of chemokine receptors in tumor cells and leukocytes in breast carcinoma effusions. The expression of leukocyte markers (CD3/4/8/14/16/19) and chemokine receptors (CXCR1/4, CCR2/5/7) was studied in 21 breast carcinoma effusions using flow cytometry. Breast carcinoma cells expressed CXCR4 in 7/21 (33%) effusions, with less frequent expression of CXCR1, CCR5, and CCR7. CXCR2 and CCR2 were absent. Lymphocytes showed frequent CXCR4, CCR5, and CCR7 expression, while CXCR1, CXCR2, CCR2 were rarely or never detected. Macrophages expressed all six receptors except for CXCR2. Comparative analysis of breast carcinoma effusions with previously studied ovarian and cervical/endometrial adenocarcinomas (ACs) showed significantly higher CXCR4 expression in breast carcinoma cells compared to the other gynecological ACs (p = 0.001). Breast and cervical/endometrial carcinoma effusions showed different expression of chemokine receptors in lymphocytes (lower CXCR1, higher CXCR4 and CCR7 levels; p = 0.012, p = 0.005, p < 0.001, respectively) and macrophages (higher CCR7 levels; p < 0.001), as well as lower CD8 counts (p < 0.001) and higher CD19 counts (p = 0.001) compared to ovarian carcinoma effusions. Higher numbers of CD8-positive lymphocytes (p = 0.080) and higher CCR7 monocyte expression (p = 0.087) were associated with a trend for shorter disease-free survival. In conclusion, breast carcinoma cells express CXCR4, a unique feature among metastatic ACs in effusions, with rare expression of other chemokine receptors. Chemokine receptor expression in leukocytes and lymphocyte counts significantly differ from those of ovarian carcinoma effusions. The prognostic role of CCR7 expression in monocytes and CD8 counts in breast carcinoma effusions merits further research. [source] Tight control of transgene expression by lentivirus vectors containing second-generation tetracycline-responsive promotersTHE JOURNAL OF GENE MEDICINE, Issue 6 2005Krzysztof Pluta Abstract Background The goal of this study was to design improved regulatable lentivirus vector systems. The aim was to design tetracycline (tet)-regulatable lentivirus vectors based on the Tet-on system displaying low background expression in the absence of the doxycycline (DOX) inducer and high transgene expression levels in the presence of DOX. Methods We constructed a binary lentivirus vector system that is composed of a self-inactivating (SIN) lentivirus vector bearing inducible first- or second-generation tet-responsive promoter elements (TREs) driving expression of a transgene and a second lentivirus vector encoding a reverse tetracycline-controlled transactivator (rtTA) that activates transgene expression from the TRE in the presence of DOX. Results We evaluated a number of different rtTAs and found rtTA2S -M2 to induce the highest levels of transgene expression. Regulated transgene expression was stable in human breast carcinoma cells implanted into nude mice for up to 11 weeks. In an attempt to minimize background expression levels, the chicken ,-globin cHS4 insulator element was cloned into the 3, long terminal repeat (LTR) of the transgene transfer vector. The cHS4 insulator element reduced background expression but expression levels following DOX addition were lower than those observed with vectors lacking an insulator sequence. In a second strategy, vectors bearing second-generation TREs harboring repositioned tetracycline operator elements were used. Such vectors displayed greatly reduced leakiness in the absence of DOX and induced transgene expression levels were up to 522-fold above those seen in the absence of DOX. Conclusions Inducible lentivirus vectors bearing insulators or second-generation TREs will likely prove useful for applications demanding the lowest levels of background expression. Copyright © 2005 John Wiley & Sons, Ltd. [source] Serum HER-2/neu conversion to positive at the time of disease progression in patients with breast carcinoma on hormone therapyCANCER, Issue 2 2005Allan Lipton M.D. Abstract BACKGROUND Prolonged exposure of breast carcinoma cells in vitro to tamoxifen results in tamoxifen resistance. Tamoxifen-resistant cells express increased HER-2/neu mRNA and protein. The objective of this study was to determine whether patients with metastatic or locally advanced breast carcinoma who have negative serum HER-2/neu status at the initiation of first-line hormone therapy with letrozole or tamoxifen convert to positive serum HER-2/neu status at the time of disease progression and to determine whether serum HER-2/neu conversion to positive status is associated with response to therapy and overall survival. METHODS Serum samples were obtained at baseline and at the time of disease progression from 240 patients who initially had negative serum HER-2/neu status (< 15 ng/mL). A manual microtiter, enzyme-linked immunosorbent assay that was specific for the extracellular domain of the HER-2/neu (c- erbB-2) oncoprotein product was used to quantitate serum levels. RESULTS Among 240 patients, 61 patients (26%) converted from serum HER-2/neu negative to positive (> 15 ng/mL) at the time of disease progression. Thirty-two of 129 patients (25%) who were treated with tamoxifen and 29 of 111 patients (26%) who were treated with letrozole became converted to positive serum HER-2/neu status at the time of disease progression. The response rate and the time to disease progression on first-line hormone therapy were not affected by serum HER-2/neu conversion. The survival of patients who converted to positive serum HER-2/neu status was significantly shorter compared with the survival of patients who remained negative for serum HER-2/neu. A multivariate analysis revealed that conversion to positive serum HER-2/neu status was an independent prognostic variable for survival. CONCLUSIONS Conversion to positive serum HER-2/neu status occurred in approximately 25% of patients who received first-line hormone therapy. Conversion to serum HER-2/neu -positive status occurred with equal frequency in antiestrogen and aromatase-inhibitor therapy. The current results showed that serum conversion to HER-2/neu -positive status was an independent risk factor for decreased survival in patients with breast carcinoma. Cancer 2005. © 2005 American Cancer Society. [source] Modulation of tamoxifen sensitivity by antisense Bcl-2 and trastuzumab in breast carcinoma cellsCANCER, Issue 10 2005Ph.D., Ryungsa Kim M.D. Abstract BACKGROUND Because the overexpression of HER-2 and Bcl-2 is associated with resistance to tamoxifen (TAM), the authors examined the effect of antisense (AS) Bcl-2 on sensitivity to TAM compared with the effect of trastuzumab on sensitivity to TAM in breast carcinoma cell lines. METHODS Drug sensitivity was assessed in vitro using a [3-4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay with the breast carcinoma cell lines ZR-75-1, MDA-MB-453, and BT-474. AS Bcl-2 18-mer phosphorothioate oligonucleotide was applied. Apoptotic cell death was assessed with the terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick-end labeling method, and gene expression was evaluated with Western blot analysis. RESULTS The expression of Bcl-2 was identified in ZR-75-1 and BT-474 cells and, to a lesser extent, in MDA-MB-453 cells. Overexpression of HER-2 was identified in BT-474 cells, and moderate expression was identified in MDA-MB-453 and ZR-75-1 cells. Combination treatment with trastuzumab or AS Bcl-2 enhanced TAM sensitivity in ZR-75-1 cells, which showed 50% inhibitory concentration (IC50) values of 0.9 ,M (7.2-fold increase) and 0.5 ,M (13.0-fold), respectively. Combination treatment with trastuzumab or AS Bcl-2 slightly enhanced TAM sensitivity of BT-474 cells, with IC50 values of 3.0 ,M (1.3-fold) and 1.5 ,M (2.6-fold), respectively. The sensitivity of MDA-MB-453 cells to TAM was not enhanced by combination with trastuzumab or AS Bcl-2. Modulation of TAM sensitivity by AS Bcl-2 was superior to modulation by trastuzumab in HER-2-expressing and Bcl-2 -expressing breast carcinoma cells. Enhanced sensitivity in combination with AS Bcl-2 was associated with down-regulation of Bcl-2 and pAkt, which was correlated with the induction of Bax and caspase-3, leading to apoptosis. CONCLUSIONS AS Bcl-2 appeared to be superior to trastuzumab with respect to regulating the signal-transduction pathways involved in breast carcinoma cells. Cancer 2005. © 2005 American Cancer Society. [source] Role of the aging vasculature and Erb B-2 signaling in epidermal growth factor-dependent intravasion of breast carcinoma cells,CANCER, Issue 1 2004Daniel J. Price Ph.D. Abstract BACKGROUND The risks for developing breast carcinoma and dying from the disease increase with age. Mortality from breast carcinoma usually is due to metastatic disease. Metastatic cells are able to invade into the vascular tissue in a growth factor-dependent manner. Because breast carcinoma mortality increases with age, examination of breast carcinoma interactions with young and aged endothelial cells is essential. METHODS We studied a series of breast epithelial cells (HMT-3522 cells) that exhibited either noninvasive characteristics (S-1 cells) or epidermal growth factor (EGF)-dependent invasive characteristics (T4-2 cells). RESULTS Increased invasion of HMT-3522 cells was observed across an aged rat brain microvascular endothelial cell (BMEC) monolayer that was isolated from aged rats (24 months) compared with young rats (age 1 month). This increased invasion was inhibited by the specific EGF receptor inhibitor, AG1478, and by the Erb B-2-specific inhibitor, AG825. To analyze further the contribution of Erb B-2 to the EGF-dependent invasion of HMT-3522 cells, T4-2 cells were treated with the Erb B-2-specific therapeutic antibody trastuzumab and with the specific inhibitor AG825 and were then assayed for invasion. Both inhibitors led to a significant decrease in EGF-dependent invasion. Erb B-2 expression was found to be elevated in T4-2 cells (, 5-fold higher) compared with S-1 cells. However, treatment of T4-2 cells with the specific Erb B-2 inhibitor, AG825, failed to inhibit EGF-mediated signaling to phosphatidylinositol 3-kinase or extracellular-regulated kinases 1 and 2. CONCLUSIONS The current study findings indicate that aging of endothelium may contribute to the invasive phenotype of breast carcinoma cells and that "cross-talk" between Erb B-2 and EGF receptor is required for the intravasion of these cells into the surrounding vasculature. Cancer 2004. © 2004 American Cancer Society. [source] | |||||||||||||