Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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

The in vitro release of matrix-degrading proteinases from breast cancer cells is associated in part with shed membrane vesicles. To determine whether shed vesicles might play a similar role in ovarian cancer cells, we analyzed the shedding phenomenon in vivo and in vitro as well as the enzymatic content of their vesicles. This is the first time that an immunoelectron microscopical analysis revealed membrane vesicles carrying tumor-associated antigen alpha-Folate Receptor (alpha-FR), circulating in biological fluids (ascites and serum) of an ovarian carcinoma patient. These vesicles were trapped in a fiber network with characteristic fibrin periodicity. An ovarian cancer cell line (CABA I) established from ascitic fluid cells of this patient, grew in Matrigel and formed tubular structures suggesting invasive capability. Immunofluorescence analysis demonstrated strong cytoplasmic staining of CABA I cells with anti-matrix metalloproteinase-9 (MMP-9) and anti-urokinase-type plasminogen activator (uPA) antibodies. CABA I cells shed membrane vesicles, which were morphologically similar to those identified in vivo, as determined by electron microscopy. Gelatin zymography of vesicles isolated both in vivo and in vitro revealed major gelatinolytic bands of the MMP family, identified as the zymogen and active forms of gelatinase B (MMP-9) and gelatinase A (MMP-2). By casein-plasminogen zymography we observed high-molecular weight (HMW)-uPA and plasmin bands. Incubation of purified vesicles from CABA I cells with Matrigel led to cleavage of Matrigel components. Taken together, our results point to a possible role of shed vesicles, both in vivo and in vitro, in proteolysis that mediates invasion and spread of ovarian epithelial carcinoma cells.
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PMID:Matrix-degrading proteinases are shed in membrane vesicles by ovarian cancer cells in vivo and in vitro. 1041 Nov 5

Breast cancer is the most common cancer and second leading cause of cancer related deaths in women in the United States. Genistein is a protein tyrosine kinase inhibitor and prominent isoflavonoid in soy products and has been proposed as the agent responsible for lowering the rate of breast cancer in Asian women. We have previously shown that genistein inhibits the growth of MDA-MB-231 breast cancer cells, regulates the expression of apoptosis-related genes, and induces apoptosis through a p53-independent pathway. In this study, we investigated these effects of genistein in the breast cancer cell line MDA-MB-435 and 435.eB cells that were established by transfecting c-erbB-2 cDNA into MDA-MB-435. We also investigated the effect of genistein on matrix metalloproteinase (MMP) secretion previously shown to be effected by erbB-2 transfection. Genistein was found to inhibit MDA-MB-435 and 435.eB cell growth. Induction of apoptosis was also observed in these cell lines when treated with genistein, as measured by DNA laddering, poly(ADP-ribose) polymerase (PARP) cleavage, and flow cytometric analysis. We also found an up-regulation of Bax and p21WAF1 expression and down-regulation of Bcl-2 and c-erbB-2 in genistein-treated cells. Gelatin zymography showed that genistein inhibits the secretion of MMP in the breast cancer cells. From these results, we conclude that genistein inhibits the growth of MDA-MB-435 breast cancer cells, induces apoptosis, regulates the expression of genes, and may inhibit invasion and metastasis of breast cancer cells. These findings suggest that genistein may be a potentially effective chemopreventive or therapeutic agent against breast cancer.
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PMID:Induction of apoptosis and inhibition of c-erbB-2 in MDA-MB-435 cells by genistein. 1042 35

Human breast cancer cell line Hs578T was stably transfected with cDNA for cyclooxygenase-1 or -2. When the cells overexpressing cyclooxygenase-1 or -2 were stimulated with concanavalin A, the processing of matrix metalloproteinase-2 was observed with the aid of gelatin zymography. This processing was not seen in mock-transfected and original cells which did not express detectable cyclooxygenase activity. Furthermore, Northern blotting showed 8-13 fold induction of membrane-type 1 matrix metalloproteinase which processed matrix metalloproteinase-2 in the cells expressing cyclooxygenases. These findings suggest that both isoforms of cyclooxygenase mediate the processing of matrix metalloproteinase-2 through induction of membrane-type I metalloproteinase in breast cancer cells.
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PMID:Activation of matrix metalloproteinase-2 in human breast cancer cells overexpressing cyclooxygenase-1 or -2. 1057 Oct 77

Base-unpairing regions (BURs) contain a specialized DNA context with an exceptionally high unwinding propensity, and are typically identified within various matrix attachment regions. A BUR affinity column was used to purify a doublet of Mr 20,000 proteins from human breast carcinoma cells. These proteins were identified as the high-mobility group (HMG) protein, HMG-I, and its splicing variant, HMG-Y. We show that HMG-I(Y) specifically binds BURs. Mutating BURs so as to abrogate their unwinding property greatly reduced their binding affinity to HMG-I(Y). Numerous studies have indicated that elevated HMG-I(Y) expression is correlated with more advanced cancers and with increased metastatic potential. We studied whether the expression of HMG-I(Y) responds to signaling through the heregulin (HRG)-erbB pathway and the extracellular matrix. HMG-I(Y) expression was increased in MCF-7 cells after stable transfection with an HRG expression construct that led cells to acquire estrogen independence and metastasizing ability. A high level of HMG-I(Y) expression was detected in metastatic MDA-MB-231 cells, but the expression was virtually diminished, and the metastasizing ability was lost after cells were stably transfected with an antisense HRG cDNA construct. HMG-I(Y) was also decreased in MDA-MB-231 cells when treated with a chemical inhibitor for matrix metalloproteinase-9 that led to a reduction of invasive capability in vitro. The level of HMG-I(Y) expression, therefore, is dynamically regulated in human breast cancer cells in response to varying types of signaling that affect metastatic ability, including the HRG-erbB pathway and those from the extracellular matrix.
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PMID:HMG-I(Y) recognizes base-unpairing regions of matrix attachment sequences and its increased expression is directly linked to metastatic breast cancer phenotype. 1058 87

Elevated p21ras expression is associated with tumor aggressiveness in breast cancer including the extent of invasion into fat tissues, infiltration into lymphatic vessels and tumor recurrence. In the present study, we have examined the roles of H-ras and N-ras, members of the human ras gene family, in the pathogenesis of breast cancer. We show that H-ras, but not N-ras, induces an invasive phenotype in human breast epithelial cells (MCF10A) as determined by the Matrigel invasion assay, whereas both H-ras and N-ras induce anchorage-independent growth, as shown by soft agar assay. We examined the effects of H-ras and N-ras activation on the expression of MMP-2 and MMP-9, which can degrade type IV collagen, the major structural collagen of the basement membrane. We show that MMP-2 is efficiently induced by H-ras, whereas MMP-9 induction is more prominent in N-ras-activated MCF10A cells. We also show that H-ras-mediated invasiveness is significantly inhibited when the expression of MMP-2 is down-regulated, using an oligodeoxyribonucleotide complementary to the MMP-2 mRNA, or when MMP-2 activity is blocked by its inhibitor TIMP-2 (tissue inhibitors of matrix metalloproteinase-2). Our results show that the H-ras-induced invasive phenotype is associated more closely with the expression of MMP-2 in human breast epithelial cells, rather than the induction of MMP-9 expression, as shown previously for rat embryonic fibroblasts.
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PMID:H-ras, but not N-ras, induces an invasive phenotype in human breast epithelial cells: a role for MMP-2 in the H-ras-induced invasive phenotype. 1062 74

Tumor recurrence is a common problem in the treatment of breast cancer. In breast cancer, the expression of high protein levels of the insulin-like growth factor-1 receptor (IGF-1R) and urokinase-type plasminogen activator-1 (uPA) is strongly associated with breast cancer recurrence and decreased survival. The expression of uPA by tumors is thought to not only stimulate tumor invasion but also facilitate angiogenesis. In this study, our goal was to address whether IGF-1R could influence the expression of the extracell ular matrix proteases, matrix metalloproteinase (MMP), or uPA thus allowing a selective advantage for tumor invasion and concomitant neovascularization. Initially, we determined whether or not insulin-like growth factor (IGF)-1 regulated the production MMP or uPA in the human breast cancer MDA-MB-231 cells. There was no increase in MMP activity when the cells were treated with IGF-1 (10 ng/mL) for 24 h. In contrast, uPA mRNA and protein were induced in a time-dependent manner. Furthermore, clones expressi ng a dominant negative inhibitor of IGF-1R termed 486stop had less uPA mRNA, and the clones were less invasive through Matrigel. Taken together, these data illustrate that IGF-1R stimulates uPA production. Hence, these two prognostic indicators may be interrelated, suggesting they may function in a synergistic manner to facilitate local tumor invasion as well as angiogenesis. Our data suggest that disruption of IGF-1 signaling in breast cancer may lead to breast cancer prevention and intervention by decreasing uPA expression.
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PMID:The insulin-like growth factor-1 elevates urokinase-type plasminogen activator-1 in human breast cancer cells: a new avenue for breast cancer therapy. 1064 32

Flavopiridol is a flavone that inhibits several cyclin-dependent kinases and exhibits potent growth-inhibitory activity against a number of human tumor cell lines, both in vitro and when grown as xenografts in mice. It is presently being investigated as a novel antineoplastic agent in the primary screen conducted by the Developmental Therapeutics Program, National Cancer Institute. Because breast cancer is the most common cancer and second leading cause of cancer-related deaths in women in the United States, we investigated whether flavopiridol could be an effective agent against a series of isogenic breast- cancer cell lines having different levels of erbB-2 expression and differential invasion and metastatic characteristics. Flavopiridol was found to inhibit the growth of MDA-MB-435 (parental) and 435.eB (stable transfectants) cells that were established by transfecting c-erbB-2 cDNA into MDA-MB-435. Induction of apoptosis was also observed in these cell lines when treated with flavopiridol, as measured by DNA laddering, PARP, and CPP32 cleavages. We also found modest up-regulation of Bax and down-regulation of Bcl-2, but there was a significant down-regulation of c-erbB-2 in flavopiridol-treated cells. Gelatin zymography showed that flavopiridol inhibits the secretion of matrix metalloproteinase (MMP; MMPs 2 and 9) in the breast cancer cells and that the inhibition of c-erbB-2 and MMPs may be responsible for the inhibition of cell invasion observed in flavopiridol-treated cells. Collectively, these molecular effects of flavopiridol, however, were found to be independent of c-erbB-2 overexpression, suggesting that flavopiridol may be effective in all breast cancer. From these results, we conclude that flavopiridol inhibits the growth of MDA-MB-435 breast cancer cells, induces apoptosis, regulates the expression of genes, and inhibits invasion and, thus, may inhibit metastasis of breast cancer cells. These findings suggest that flavopiridol may be an effective chemotherapeutic or preventive agent against breast cancer.
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PMID:Induction of apoptosis and inhibition of c-erbB-2 in breast cancer cells by flavopiridol. 1065 53

Invasive breast cancer varies widely in biologic aggressiveness, from fairly indolent tumors to rapidly disseminating carcinomas. Matrix metalloproteinases have enzymatic activity and assist in tumor invasion by degrading basement membranes and extracellular matrix. The extracellular matrix metalloproteinase inducer EMMPRIN is thought to stimulate fibroblasts to produce the zymogen pro-gelatinase A. The membrane type 1-matrix metalloproteinase (MT1-MMP) is thought to assist in tumor invasion and metastasis by activating pro-gelatinase A, which shows enhanced expression in various tumors. Overexpression of gelatinase A has shown to correlate with a malignant phenotype in many tumor forms. The aim of the study was to investigate the mRNA expression pattern of MT1-MMP, gelatinase A, and EMMPRIN in breast tumors. Formalin-fixed paraffin-embedded breast tissue samples from 18 patients operated on with breast-conserving surgery for invasive breast carcinoma <20 mm between 1977 and 1985 were analyzed using the mRNA in situ hybridization technique. Most of the patients were node-negative (15/18) and underwent postoperative irradiation to the breast (16/18). The median age at diagnosis was 52 years (21-83 years). At the time of the study 11 patients were alive, 4 without recurrence; 7 patients had been operated for ipsilateral breast tumor recurrences, and 2 had distant metastases. The median follow-up was 112 months (102-193 months). Seven patients died of disseminated breast cancer; their median follow-up was 43 months (22-116 months). (35)S-labeled antisense and sense mRNA probes transcribed from linearized plasmids containing cDNA for the matrix metalloproteinases gelatinase A and MT1-MMP and the glycoprotein EMMPRIN were hybridized to 5 microm paraffin-embedded tissue sections. Several invasive carcinomas were surrounded by normal tissue and carcinoma in situ lesions. Gelatinase A, MT1-MMP, and EMMPRIN mRNA expression were detected in all of the carcinomas. The gelatinase A mRNA expression was mainly localized to stromal cells at moderate to high levels surrounding the invading carcinoma cells but was also seen in single cells at low levels in in situ lesions and in some normal glandular cells. MT1-MMP and EMMPRIN were expressed in all of the carcinomas and were mainly localized to tumor cells; but they were also seen to some extent in single cells at low levels in in situ lesions and in normal glandular cells. No differences in levels of expression for gelatinase A, MT1-MMP, or EMMPRIN were seen in patients who survived compared to patients who died from metastatic disease. The co-expression of gelatinase A, MT1-MMP, and EMMPRIN mRNA in invasive breast carcinoma supports the theory that these proteins interact and are important for the invasive phenotype in breast carcinoma. Hence EMMPRIN may be a central factor for stimulation of gelatinase A activation. Specific inhibition for individual MMP members could in the future be target-specific events in breast tumor progression. Inhibition of EMMPRIN could be such a target.
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PMID:Gelatinase A, membrane type 1 matrix metalloproteinase, and extracellular matrix metalloproteinase inducer mRNA expression: correlation with invasive growth of breast cancer. 1065 69

Although there is experimental evidence supporting the involvement of angiogenesis in the pathogenesis of breast cancer, the exact nature and effects of interaction between human breast epithelial cells (HBECs) and endothelial cells (ECs) have not been described thus far. This approach requires an assay system that permits growth and differentiation of both epithelial and endothelial cells. Here, we report the development of a three-dimensional in vitro culture system that supports growth and functional differentiation of preneoplastic HBECs and ECs and recapitulates estrogen-induced in vivo effects on angiogenesis and the proliferative potential of MCF10AT xenografts. MCF10A and MCF10AT1-EIII8 (referred to as EIII8) cell lines used in this study are normal or produce preneoplastic lesions, respectively. When MCF10A or EIII8 cells are seeded on reconstituted basement membrane (Matrigel), both lines organize into a three-dimensional tubular network of cells; however, tubes produced by EIII8 cells appear multicellular in contrast to unicellular structures formed by MCF10A cells. However, when MCF10A or EIII8 cells are cocultured with human umbilical vein endothelial cells (HUVECs) on Matrigel, rather than interacting with extracellular matrix, the ECs exhibit preferential adherence to epithelial cells. Although both MCF10A and EIII8 cells provide preferential substrate for EC attachment, only EIII8 cells facilitate sustained proliferation of ECs for prolonged periods that are visualized as "endothelial cell enriched spots," which express factor VIII-related antigen. At regions of endothelial-enriched spots, preneoplastic HBECs undergo branching ductal-alveolar morphogenesis that produce mucin, express cytokeratins, and proliferating cell nuclear antigen. The presence of actively proliferating and functional endothelial cells is essential for ductal-alveolar morphogenesis of preneoplastic HBECs because without ECs, the epithelial cells formed only tubular structures. This ability to establish functional ECs and ductal-alveolar morphogenesis is facilitated only by preneoplastic HBECs because normal MCF10A cells fail to elicit similar effects. Thus, a cause-effect relationship that is mutually beneficial exists between EC and preneoplastic HBECs that is critical for generation of functional vascular networks and local proliferative ductal alveolar outgrowths with invasive potential. Both these processes are augmented by estrogen, whereas antiestrogens inhibit these processes. Induction and maintenance of angiogenic phenotype is associated with up-regulation in expression of interleukin 8 and matrix metalloproteinase-2 and estrogen-induced increases in vascular endothelial growth factor and vascular endothelial growth factor receptor 2. This three-dimensional culture model offers a unique opportunity to study endothelial- and epithelial cell-specific factors that are important for ductal-alveolar morphogenesis, angiogenesis, and progression to malignant phenotype.
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PMID:Interaction with endothelial cells is a prerequisite for branching ductal-alveolar morphogenesis and hyperplasia of preneoplastic human breast epithelial cells: regulation by estrogen. 1066 99

E- and N-cadherin are calcium-dependent cell adhesion molecules that mediate cell-cell adhesion and also modulate cell migration and tumor invasiveness. The loss of E-cadherin-mediated adhesion has been shown to play an important role in the transition of epithelial tumors from a benign to an invasive state. However, recent evidence indicates that another member of the cadherin family, N-cadherin, is expressed in highly invasive tumor cell lines that lacked E-cadherin expression. These findings have raised the possibility that N-cadherin contributes to the invasive phenotype. To determine whether N-cadherin promotes invasion and metastasis, we transfected a weakly metastatic and E-cadherin-expressing breast cancer cell line, MCF-7, with N-cadherin and analyzed the effects on cell migration, invasion, and metastasis. Transfected cells expressed both E- and N-cadherin and exhibited homotypic cell adhesion from both molecules. In vitro, N-cadherin-expressing cells migrated more efficiently, showed an increased invasion of Matrigel, and adhered more efficiently to monolayers of endothelial cells. All cells produced low levels of the matrix metalloproteinase MMP-9, which was dramatically upregulated by treatment with FGF-2 only in N-cadherin-expressing cells. Migration and invasion of Matrigel were also greatly enhanced by this treatment. When injected into the mammary fat pad of nude mice, N-cadherin-expressing cells, but not control MCF-7 cells, metastasized widely to the liver, pancreas, salivary gland, omentum, lung, lymph nodes, and lumbar spinal muscle. The expression of both E- and N-cadherin was maintained both in the primary tumors and metastatic lesions. These results demonstrate that N-cadherin promotes motility, invasion, and metastasis even in the presence of the normally suppressive E-cadherin. The increase in MMP-9 production by N-cadherin-expressing cells in response to a growth factor may endow them with a greater ability to penetrate matrix protein barriers, while the increase in their adherence to endothelium may improve their ability to enter and exit the vasculature, two properties that may be responsible for metastasis of N-cadherin-expressing cells.
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PMID:Exogenous expression of N-cadherin in breast cancer cells induces cell migration, invasion, and metastasis. 1068 58


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