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

In vivo experiments were performed on breast cancer xenografts to examine whether the combination therapy with S-1, an oral dihydrouracil dehydrogenase (DPD) inhibitory fluoropyrimidine, plus docetaxel functions as an additive/synergistic modulator in tumor growth. The human breast cancer xenograft, MDA-MB-435SHM, was inoculated into SCID female mice. The tumor growth and thymidylate synthase (TS)/DPD activity of tumors treated with the agents were investigated. The T/C value (relative mean tumor weight of the treated group/relative tumor weight of the control group) of the group treated with docetaxel, S-1 and combination therapy were 45.3, 63.1 and 29.8%, respectively; suggesting the positive antitumor effects of the combination therapy in particular. In addition, significant down-regulation of DPD activity was also observed in the tumors treated with S-1, docetaxel and their combination. Down-regulation of the DPD activity of the tumors is also considered to be correlated with the antitumor effect of the treated groups, suggesting its influence on the synergistic effect of the combination therapy.
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PMID:Antitumor effect of combination of S-1 and docetaxel on the human breast cancer xenograft transplanted into SCID mice. 1668 89

Research into the interaction between the E. coli heat-stable enterotoxin (STh) and the guanylin receptor guanylate cyclase C (GC-C) has generated >100 synthetic analogs of the peptide, several of which have been investigated as imaging or therapeutic agents for colorectal cancers. The evidence presented here suggests that in addition to STh binding to GC-C expressing cell lines derived from human colon, STh also specifically binds to an as yet unidentified receptor expressed in high densities on the surface of cell lines derived from human breast cancers. In vitro whole-cell crosslinking studies using 125I-labeled F19-STh(1-19) demonstrate that the putative STh binding protein migrates as an approximately 120-125 kDa species by SDS-PAGE, significantly smaller than the glycosylated GC-C molecule found in the T84 human colon cancer cell line. RT-PCR using total RNA isolated from breast and colon cancer cell lines indicates that GC-C transcripts are undetectable in human breast cancer cell lines and abundant in human colon cancer cell lines. In vitro competitive binding studies using STh analogs and the estrogen receptor positive (ER+) T-47D cell line demonstrated IC50 values between 2.6 and 8.5 nM. Similar studies on the estrogen receptor negative (ER-) cell line MDA-MB-231 showed IC50's between 5.6 and 9.9 nM. Saturation binding analysis revealed receptor expression to fall between 40,000 and 120,000 sites per cell in these cell lines, receptor abundances equal to or greater than the abundance of GC-C in colorectal cancer cell lines. STh binding to these cells, although of similar affinity to STh binding to GC-C, is distinguishable from it on the basis of its ligand specificity. The characteristics of STh analogs as radiopharmaceutical agents were tested in an in vivo model utilizing T-47D human breast cancer cell xenografts in SCID mice. Clearance of STh analogs was rapid, primarily via renal excretion into the urine, with >85% ID excreted into the urine at 1 h p.i. Tumor uptake at 1 h p.i. in T-47D tumor cell xenografts was 0.67+/-0.23% ID/g, and was significantly decreased (p<0.05) upon co-administration of 4 mg/kg unlabeled STh. These results suggest that STh may find application for the imaging and treatment of breast cancer.
Breast Cancer Res Treat 2006 Jul
PMID:In vitro and in vivo evaluation of 111In-labeled E. coli heat-stable enterotoxin analogs for specific targeting of human breast cancers. 1672 66

Stromal cell-derived factor-1 (SDF-1)/CXCR4 interaction is critical for the trafficking of lymphocytes, homing and retention of hematopoietic stem cells within the bone marrow and is essential in fetal hematopoiesis. Binding of SDF-1 to CXCR4 activates a variety of intracellular signal transduction pathways and effector molecules that regulate cell survival, proliferation, chemotaxis, migration and adhesion. Recently, intensive research has demonstrated that SDF-1/CXCR4 interaction also regulates several key events in wide variety of cancers. Serum-depleted media in the presence of SDF-1 protected the breast cancer cells from apoptosis. CXCR4-low-expressing MCF-7 formed small tumor at inoculated site in SCID mice 8-9 weeks after inoculation while completely failed to metastasis into various organs. In contrast, CXCR4-high-expressing MDA-231 cells were most efficient in the formation of a large tumor and organ-metastasis within 3 weeks in SCID mice. This review briefly focuses on the role of SDF-1/CXCR4 interaction in tumor growth and metastasis of breast cancer cell both in vitro and in vivo.
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PMID:Stromal cell-derived factor-1 and CXCR4 receptor interaction in tumor growth and metastasis of breast cancer. 1682 53

We investigated anti-angiogenic/vascular targeting therapy of established tumors in immunocompetent mice using an anti-human endoglin (EDG; CD105) monoclonal antibody (mAb) SN6j. SN6j weakly cross-reacted with murine endothelial cells but reacted neither with colon-26 murine colon carcinoma cells nor with 4T1 murine mammary carcinoma cells. Systemic administration of naked (unconjugated) SN6j showed significant growth suppression of established tumors of colon-26 and 4T1 cells in immunocompetent BALB/c mice (P<0.05). Moreover, the overall survival rate of SN6j-treated mice was significantly higher than that of control IgG-treated mice (P<0.01). During these studies, we found that two different types of tumor formed in BALB/c and immunodeficient SCID mice when three different types of tumor cells (colon-26, 4T1 and MCF-7 human breast cancer cells) were inoculated subcutaneously. One type of tumor grew in the skin-side tissue (i.e., epidermis, corium, or subcutis), and mainly invaded into the corium and epidermis. The other type grew in the muscle-side tissue (i.e., fascia, muscle, or peritoneum/pleura). We termed the former SS tumors and the latter MS tumors. MS tumors grew faster than SS tumors. This differential growth of MS and SS tumors was observed in three different animal models, i.e., colon-26 tumors and 4T1 tumors in BALB/c mice, and MCF-7 tumors in SCID mice. In the therapeutic study of colon-26 and 4T1 tumors with SN6j, MS tumors were less responsive to therapy than SS tumors although SN6j showed significant antitumor efficacy against both tumors (P<0.05). The results show that antitumor therapy can yield different therapeutic outcomes depending on the tumor growth sites even for the same tumor. A differential survival between mice with the two types of tumor was also observed when mice were untreated (P<0.01).
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PMID:Effective anti-angiogenic therapy of established tumors in mice by naked anti-human endoglin (CD105) antibody: differences in growth rate and therapeutic response between tumors growing at different sites. 1701 38

Natural killer (NK) cells play a central role in host defense against tumor and virus-infected cells. Direct role of NK cells in tumor growth and metastasis remains to be elucidated. We here demonstrated that NOD/SCID/gammac(null) (NOG) mice lacking T, B and NK cells inoculated with breast cancer cells were efficient in the formation of a large tumor and spontaneous organ-metastasis. In contrast, breast cancer cells produced a small tumor at inoculated site in T and B cell knock-out NOD/SCID mice with NK cells while completely failed to metastasize into various organs. Immunosupression of NOD/SCID by treatment with an anti-murine TM-beta1 antibody, which transiently abrogates NK cell activity in vivo, resulted in enhancing tumor formation and organ-metastasis in comparison with non-treated NOD/SCID mice. Activated NK cells inhibited tumor growth in vivo. The rapid and efficient engraftment of the breast cancer cells in NOG mice suggests that this new animal model could provide a unique opportunity to understand and investigate the mechanism of tumor cell growth and metastasis. Our results suggest that NK cells play an important role in cancer growth and metastasis and could be a promising immunotherapeutic strategy against cancer either alone or in combination with conventional therapy.
Breast Cancer Res Treat 2007 Sep
PMID:Role of natural killer cells in hormone-independent rapid tumor formation and spontaneous metastasis of breast cancer cells in vivo. 1706 21

Transforming growth factor beta 1 (TGF-beta1) is a potent tumor suppressor but, paradoxically, TGF-beta1 enhances tumor growth and metastasis in the late stages of cancer progression. This study investigated the role of TGF-beta type I receptor, ALK5, and three mitogen-activated protein kinases (MAPKs) in metastasis by breast cancer cell line MDA-MB-231. We show that autocrine TGF-beta signaling in MDA-MB-231 cells is required for tumor cell invasion and tumor angiogenesis. Expression of kinase-inactive ALK5 reduces tumor invasion and formation of new blood vessels within the tumor orthotopic xenografts in severe combined immunodeficiency (SCID) mice. In contrast, constitutively active ALK5-T204D enhances tumor invasion and angiogenesis by stimulating expression of matrix metalloproteinase MMP-9/gelatinase-B. Ablation of MMP-9 in ALK5-T204D cells by RNA interference (RNAi) reduces tumor invasion and tumor growth. Importantly, RNAi-MMP-9 reduces tumor neovasculature and increases tumor cell death. Induction of MMP-9 by TGF-beta-ALK5 signaling requires MEK-ERK but not JNK, p38 MAPK or Smad4. Dominant-negative MEK blocks and constitutively active MEK1 enhances MMP-9 expression. However, all three MAPK cascades (ERK, JNK and p38 MAPK) are required for TGF-beta-mediated cell migration. Collectively, our results show that TGF-beta-ALK5-MAPK signaling in tumor cells promotes tumor angiogenesis and MMP-9 is an important component of this program.
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PMID:ALK5 promotes tumor angiogenesis by upregulating matrix metalloproteinase-9 in tumor cells. 1707 48

The cellular function of electroneutral K-Cl cotransport (KCC) is to regulate epithelial ion transport and osmotic homeostasis. Here we investigate the mechanisms by which insulin-like growth factor 1 (IGF-1) cooperates with KCC to modulate breast cancer biology. IGF-1 stimulates KCC activity of MCF-7 breast cancer cells in a dose- and time-dependent manner. Increased KCC3 and KCC4 abundances contribute to IGF-1-enhanced KCC activity. Endogenous cellular invasiveness was modestly attenuated by KCC4-specific siRNA and the residual invasiveness was much less sensitive to IGF-1 stimulation. KCC3 knockdown significantly reduced basal growth rate and almost abolished IGF-1-stimulated cell proliferation. Consistently, MCF-7 cells obtained advantage in cell proliferation and invasiveness by overexpression of KCC3 and KCC4, respectively. Blockade of gene transcription by actinomycin D abolished IGF-1-mediated increase in KCC3 and KCC4 mRNA, indicating that IGF-1 increases KCC abundance through the regulation of KCC genes. IGF-1 treatment triggered phosphatidylinositol 3-kinase and mitogen-activated protein kinase (MAPK) cascades which were differentially required for IGF-1-stimulated biosynthesis of KCC3 and KCC4. Loss-of-function mutations in KCC significantly inhibited the development and progression of xenograft tumor in SCID mice. The expression level of IGF-1 and KCC polypeptides in the surgical specimens showed a good linear correlation, suggesting autocrine or paracrine IGF-1 stimulation of KCC production in vivo. Among patients with early-stage node-negative breast cancer, disease-free survival (DFS) and overall survival (OS) curves were significantly different based on IGF-1 and KCC expression. Thus, we conclude that KCC activation by IGF-1 plays an important role in IGF-1 receptor signaling to promote growth and spread of breast cancer cells.
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PMID:IGF-1 upregulates electroneutral K-Cl cotransporter KCC3 and KCC4 which are differentially required for breast cancer cell proliferation and invasiveness. 1713 54

Recently, substantial progress has been made in the identification and characterization of stem and progenitor cells in the mouse and human mammary gland. Furthermore, there is increasing evidence that a variety of neoplasms, including breast cancer, may result from transformation of normal stem and progenitor cells. Consistent with this model of carcinogenesis, a breast cancer stem cell population, with the phenotype CD24-CD44+ lineage, was recently identified utilizing flow-cytometry based cell sorting and nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice xenografts. As few as 200 cells of this cancer stem cell population were capable of generating tumors in animals, whereas the bulk of the tumor population was tumorigenic only when implanted in high numbers. Like their normal counterparts, the cancer stem cells have the ability to self-renew, driving tumorigenicity and possibly recurrence and metastasis, and have the ability to differentiate, generating the heterogeneity of the tumors. This stem cell model of carcinogenesis has important implications for understanding the basic biology of breast cancer, as well as other cancers. Furthermore, the concept of cancer as a disease of stem and progenitor cells has profound implications for the development of new strategies for cancer prevention and therapy.
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PMID:Stem cells in mammary development and carcinogenesis: implications for prevention and treatment. 1714 57

This mini-review summarizes our recent experimental and clinical studies on neutrophil elastase (NE) and cancer based on our original view point. Neoplasms metastasize as a result of a complex series of events. This process requires various degradative enzymes including proteases. NE has broad substrate specificity under physiological conditions, and excessive NE results in digestion of not only elastin, but also other extracellular matrix proteins. Several cell lines from human breast cancer and human lung cancer produce immunoreactive NE. The amount of immunoreactive NE in tumor tissue is an independent prognostic indicator of patients with breast cancer and lung cancer. Furthermore, a specific NE inhibitor completely suppressed growth of cancer cells transplanted into severe combined immunodeficiency mice. The use of NE inhibitor would seem to be a promising way to prevent the invasion and metastasis of cancer.
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PMID:Neutrophil elastase and cancer. 1732 Mar 78

Deregulated signaling by the epidermal growth factor receptor family of proteins is encountered in human malignancies including breast cancer. Cell cycle and apoptosis-regulatory protein-1 (CARP-1), a novel, perinuclear phosphoprotein, is a regulator of apoptosis signaling by epidermal growth factor receptors. CARP-1 expression is diminished in human breast cancers, and correlates inversely with human breast cancer grades which could be attributed to increased methylation. The expression of CARP-1, on the other hand, interferes with the ability of human breast cancer cells to invade through the matrigel-coated membranes, to form colonies in the soft agar, and to grow as s.c. tumors in severe combined immunodeficiency (SCID) mice. To test whether CARP-1 is a suppressor of human breast cancer growth, we generated transactivator of transcription (TAT)-tagged CARP-1 peptides. Treatment of human breast cancer cells with affinity purified, TAT-CARP-1 1-198, 197-454, and 896-1150 peptides caused inhibition of human breast cancer cell proliferation and elevated apoptosis. In contrast, TAT-tagged enhanced green fluorescent protein or CARP-1 (1-198(Y192/F)) peptide failed to inhibit cell proliferation or induce apoptosis. Apoptosis by CARP-1 peptides, with the exception of CARP-1 (1-198(Y192/F)), involves the activation of p38 stress-activated protein kinase and caspase-9. Moreover, administration of TAT-CARP-1 (1-198), but not TAT-tagged enhanced green fluorescent protein or TAT-CARP-1 (1-198(Y192/F)), inhibits growth of human breast cancer cell-derived tumor xenografts in SCID mice. We conclude that CARP-1 is a suppressor of human breast cancer growth, and its expression is diminished in tumors, in part, by methylation-dependent silencing.
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PMID:Transactivator of transcription-tagged cell cycle and apoptosis regulatory protein-1 peptides suppress the growth of human breast cancer cells in vitro and in vivo. 1751 14


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