Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0085110 (SCID)
 11,041 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endoglin (CD105), which is a component of the TGF-beta receptor complex, is highly expressed at the surface of proliferating human endothelial cells such as those of tumor vessels. In the present study, we tested the antitumor efficacy of (125)I-labeled anti-endoglin monoclonal antibodies (MAbs), SN6f and SN6j, against s. c. tumors of MCF-7 human breast cancer cells in SCID mice by i.v. administration. SN6f and SN6j cross-react weakly with mouse endothelial cells, but show no significant reactivity with MCF-7 tumor cells. These MAbs are effectively internalized into the cells after binding to the cell surface antigen of endothelial cells. Four groups of SCID mice (n = 10 or 9 in each group) inoculated s.c. with 8 x 10(6) MCF-7 cells were treated with (125)I-SN6f (10 microCi), (125)I-SN6j (10 microCi), a (125)I-labeled isotype-matched control IgG (10 microCi) or PBS. The systemic therapy was performed in 2 series, i.e., on days 3, 5, 7 and days 58, 60, 62. Both (125)I-SN6f and (125)I-SN6j showed significant growth suppression of the tumors, whereas the (125)I-labeled control IgG did not show any significant antitumor efficacy. No significant toxicity or weight loss was observed in mice treated with either (125)I-SN6f or (125)I-SN6j. After 100 days of observation, autopsies revealed no significant organ damage. Our results show the possible usefulness of antiangiogenic radioimmunotherapy using (125)I-labeled anti-endoglin MAbs.
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PMID:Antiangiogenic radioimmunotherapy of human solid tumors in SCID mice using (125)I-labeled anti-endoglin monoclonal antibodies. 1041 73

The progression of breast cancer depends on the establishment of a neovasculature, by a process called angiogenesis. Angiogenesis is an invasive cellular event that requires the co-ordination of numerous molecules including growth factors and their receptors, extracellular proteins, adhesion molecules, and proteolytic enzymes. TGFbeta has emerged to be a major modulator of angiogenesis by regulating endothelial cell proliferation, migration, extracellular matrix (ECM) metabolism, and the expression of adhesion molecules. It is a potent growth inhibitor of normal mammary epithelial cells and a number of breast cancer cell lines. It seems that TGFbeta exerts pleiotropic effects in the oncogenesis of breast cancers in a contextual manner, i.e., it suppresses tumourigenesis at an early stage by direct inhibition of angiogenesis and tumour cell growth. However, over-production of TGFbeta by an advanced tumour may accelerate disease progression through indirect stimulation of angiogenesis and immune suppression. The cell membrane antigen CD105 (endoglin) binds TGFbeta1 and TGFbeta3 and is preferentially expressed in angiogenic vascular endothelial cells. The reduction of CD105 levels in HUVEC leads to in vitro angiogenesis inhibition and massive cell mortality in the presence of TGFbeta1. CD105 null mice die in utero with impaired vasculature, indicating the pivotal role of CD105 in vascular development. The administration of an immunotoxin-conjugate, mab to CD105, induces long-term and complete regression of breast cancer growth in SCID mice. Therefore, CD105 is a promising vascular target for antiangiogenic therapy.
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PMID:Angiogenesis in breast cancer: the role of transforming growth factor beta and CD105. 1117 Mar 3

Endoglin (EDG; CD105) is a proliferation-associated cell membrane antigen of endothelial cells and is strongly expressed on the tumor-associated angiogenic vascular endothelium. Furthermore, EDG is essential for angiogenesis and a component of the transforming growth factor (TGF)-beta receptor complex. The present three anti-EDG monoclonal antibodies (mAbs), SN6f, SN6j, and SN6k, react strongly with proliferating human endothelial cells but cross-react very weakly with murine endothelial cells. Analysis of Scatchard plot of direct binding of these mAbs to proliferating human umbilical vein endothelial cells showed equilibrium constants of 8.3 x 10(9), 3.1 x 10(9), and 1.0 x 10(9) liter/mol, respectively, for SN6f, SN6j, and SN6k. These mAbs did not react with MCF-7 human breast cancer cells. To facilitate antiangiogenic tumor therapy by these mAbs in animal models, we used human skin/severe combined immunodeficiency (SCID) mouse chimeras bearing tumors of MCF-7. Blood vessels in the chimeras were analyzed by immunostaining with species (human or mouse)-specific anti-CD31 and anti-EDG mAbs including an antihuman EDG mAb termed SN6h. Blood vessels in the completely healed grafted human skins consisted of a mixture of human (43.5%) and murine (56.5%) vessels, whereas only murine vessels were detected in the adjacent murine skins and s.c. tissues. Therefore, murine vessels infiltrate into the human skin grafts from the adjacent murine tissues, whereas the growth of human vessels is limited within the boundary of human skins. Growth of human MCF-7 tumors in the human skin grafts increased the ratio of human:murine vessels. Analyses of the grafted skins before and after tumor transplantation showed that SN6h reacted with tumor-induced angiogenic blood vessels but not with nonangiogenic vessels, whereas antihuman CD31 mAb reacted with both angiogenic and nonangiogenic vessels. The results show that SN6h is capable of distinguishing the tumor-induced angiogenic vasculature from the nonangiogenic vasculature in the present model. Antiangiogenic therapy of the chimeras bearing established MCF-7 tumors was carried out by i.v. administration of a mAb(s) via the tail vein of mice. SN6j and SN6k were effective for suppressing the established tumors, whereas tumor suppression was weaker with SN6f. The results indicate an absence of a direct correlation between antigen-binding avidity and in vivo antitumor efficacy of anti-EDG mAbs and suggest the importance of other factors (e.g., epitopes) in antitumor efficacy. No significant toxicity of the mAbs was detected. Combination of SN6f and SN6k that define mutually nonoverlapping epitopes showed an additive antitumor effect. Combination of SN6j and cyclophosphamide using an antiangiogenic schedule of drug dosing showed synergistic antitumor efficacy. The combination therapy induced lasting complete regression of the established tumors in two of the eight treated chimeras. We examined human and murine blood vessels in large human tumors from the chimeras at the end of therapeutic experiment. The test showed that SN6j therapy resulted in complete suppression of human vessels in the tumors but resulted in only weak suppression of murine vessels. Cyclophosphamide was not effective for suppressing human vessels and only weakly suppressive against murine vessels. Combination of SN6j and cyclophosphamide was effective for completely suppressing human vessels and also effective for partial (i.e., 35%) suppression of murine vessels. The results show that systemic administration of naked antihuman EDG mAbs can suppress established tumors, and the efficacy is markedly enhanced by combining a chemotherapeutic drug using an antiangiogenic schedule of drug dosing. These mAbs should show stronger antitumor efficacy in patients whose tumors depend entirely on human blood vessels.
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PMID:Antiangiogenic therapy of established tumors in human skin/severe combined immunodeficiency mouse chimeras by anti-endoglin (CD105) monoclonal antibodies, and synergy between anti-endoglin antibody and cyclophosphamide. 1169 2

Human mesenchymal stem cells (hMSCs) are excellent candidates for ex vivo gene transfer and cell therapy in various systems. However, hMSCs are mortal somatic cells, and thus invariably enter an irreversible growth arrest after a finite number of cell divisions in culture. It has been proposed that this is due to telomere shortening. In this study, pGRN145 plasmid containing human telomerase reverse transcriptase (hTRT) was introduced into fetal dermis-derived hMSCs. Single-cell clones positive for telomerase activity and hTRT mRNA were selected and expanded. Single-cell-derived hTRT(+) cells could be expanded rapidly in vitro and passaged up to 70 doublings without showing senescence. FACScan flow cytometer showed that hTRT(+) cells were positive for CD29, CD44, CD105, and CD166, while CD31, CD45, CD34, vWF, and HLA-DR were negative. Under suitable conditions, hTRT(+) cells have the ability of multiple lineage differentiation, including bone, fat, and nerve. Furthermore, transplantation of hTRT(+) cells could protect NOD/SCID mice from lethal irradiation. Thus, these cells may be an ideal cell source for promoting hematopoietic recovery after radiotherapy.
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PMID:Establishment and properties of fetal dermis-derived mesenchymal stem cell lines: plasticity in vitro and hematopoietic protection in vivo. 1596 79

Endothelial precursor cells (EPCs) cultured from adult bone marrow (BM) have been shown to mediate neovasculogenesis in murine models of vascular injury. We sought to directly compare umbilical cord blood (UCB)- and BM-derived EPC surface phenotypes and in vivo functional capacity. UCB and BM EPCs derived from mononuclear cells (MNC) were phenotyped by surface staining for expression of stromal (Stro-1, CXCR4, CD105, and CD73), endothelial (CD31, CD146, and vascular endothelial [VE]-cadherin), stem cell (CD34 and CD133), and monocyte (CD14) surface markers and analyzed by flow cytometry. The nonobese diabetic/severe combined immunodeficiency murine model of hind-limb ischemia was used to analyze the potential of MNCs and culture-derived EPCs from UCB and BM to mediate neovasculogenesis. Histologic evaluation of the in vivo studies included capillary density as a measure of neovascularization. Surface CXCR4 expression was notably higher on UCB-derived EPCs (64.29%+/-7.41%) compared with BM (19.69%+/-5.49%; P=.021). Although the 2 sources of EPCs were comparable in expression of endothelial and monocyte markers, BM-derived EPCs contained higher proportions of cells expressing stromal cell markers (CD105 and CD73). Injection of UCB- or BM-derived EPCs resulted in significantly improved perfusion as measured by laser Doppler imaging at days 7 and 14 after femoral artery ligation in nonobese diabetic/severe combined immunodeficiency mice compared with controls (P<.05). Injection of uncultured MNCs from BM or UCB showed no significant difference from control mice (P=.119; P=.177). Tissue samples harvested from the lower calf muscle at day 28 demonstrated increased capillary densities in mice receiving BM- or UCB-derived EPCs. In conclusion, we found that UCB and BM-derived EPCs differ in CXCR4 expression and stromal surface markers but mediate equivalent neovasculogenesis in vivo as measured by Doppler flow and histologic analyses.
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PMID:Direct comparison of umbilical cord blood versus bone marrow-derived endothelial precursor cells in mediating neovascularization in response to vascular ischemia. 1663 94

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

Mesenchymal stem-like cells identified in different tissues reside in a perivascular niche. In the present study, we investigated the putative niche of adipose-derived stromal/stem cells (ASCs) using markers, associated with mesenchymal and perivascular cells, including STRO-1, CD146, and 3G5. Immunofluorescence staining of human adipose tissue sections, revealed that STRO-1 and 3G5 co-localized with CD146 to the perivascular regions of blood vessels. FACS was used to determine the capacity of the CD146, 3G5, and STRO-1 specific monoclonal antibodies to isolate clonogenic ASCs from disassociated human adipose tissue. Clonogenic fibroblastic colonies (CFU-F) were found to be enriched in those cell fractions selected with either STRO-1, CD146, or 3G5. Flow cytometric analysis revealed that cultured ASCs exhibited similar phenotypic profiles in relation to their expression of cell surface markers associated with stromal cells (CD44, CD90, CD105, CD106, CD146, CD166, STRO-1, alkaline phosphatase), endothelial cells (CD31, CD105, CD106, CD146, CD166), haematopoietic cells (CD14, CD31, CD45), and perivascular cells (3G5, STRO-1, CD146). The immunoselected ASCs populations maintained their characteristic multipotential properties as shown by their capacity to form Alizarin Red positive mineralized deposits, Oil Red O positive lipid droplets, and Alcian Blue positive proteoglycan-rich matrix in vitro. Furthermore, ASCs cultures established from either STRO-1, 3G5, or CD146 selected cell populations, were all capable of forming ectopic bone when transplanted subcutaneously into NOD/SCID mice. The findings presented here, describe a multipotential stem cell population within adult human adipose tissue, which appear to be intimately associated with perivascular cells surrounding the blood vessels.
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PMID:Multipotential human adipose-derived stromal stem cells exhibit a perivascular phenotype in vitro and in vivo. 1765 79

Human embryonic stem cells (hESC) face ethical sensitivities and the problem of teratoma formation. Although Wharton's jelly stem cells (WJSC), also of embryonic origin, may not face such ethical concerns, it is not definitely known whether under hESC culture conditions they would be as pluripotent as hESC. WJSC grown on plastic showed two types of morphology (epithelioid and short fibroblastic) in primary culture depending on the culture medium used, and only fibroblastic morphology when passaged. When grown in the presence of hESC medium on mouse feeder cells, they produced atypical colonies containing hESC-like cells with high-nuclear cytoplasmic ratios and prominent nucleoli. They were positive for the hESC markers Tra-1-60, Tra-1-81, SSEA-1, SSEA-4, Oct-4 and alkaline phosphatase, negative for SSEA-3, showed normal karyotypes, developed embryoid body (EB)-like structures, did not produce teratomas in SCID mice and differentiated into neuronal derivatives. They were also positive for the mesenchymal CD markers (CD105, CD90, CD44), negative for CD34 and HLA, and although nine out of 10 embryonic stem cell genomic markers were detectable, these were expressed at low levels. WJSC are thus not as pluripotent as hESC but widely multipotent, and have the advantages of being able to be scaled up easily and not inducing teratomas.
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PMID:Comparative growth behaviour and characterization of stem cells from human Wharton's jelly. 1806 71

In the present study, we investigated the mechanisms by which anti-endoglin (EDG; CD105) monoclonal antibodies (mAbs) suppress angiogenesis and tumor growth. Antihuman EDG mAb SN6j specifically bound to murine endothelial cells and was internalized into the cells in vitro. SN6j effectively suppressed angiogenesis in mice in the Matrigel plug assay. We found that SN6j is more effective for tumor suppression in immunocompetent mice than in SCID mice. We hypothesized that T cell immunity is important for effective antitumor efficacy of SN6j in vivo. To test this hypothesis, we investigated effects of CpG oligodeoxynucleotides (ODN) and depletion of CD4(+) T cells and/or CD8(+) T cells on antitumor efficacy of SN6j in mice. Systemic (i.v.) administration of a relatively small dose (0.6 mug/g body weight/dose) of SN6j suppressed growth of established s.c. tumors of colon-26 in BALB/c mice and improved survival of the tumor-bearing mice. Addition of CpG ODN to SN6j synergistically enhanced antitumor efficacy of SN6j. In contrast, such enhancing effects of CpG ODN were not detected in SCID mice. Antitumor efficacy of SN6j in BALB/c mice was abrogated when CD4(+) T cells and/or CD8(+) T cells were depleted; effect of CD8(+) T cell depletion was stronger. Interestingly, CD4-depletion decreased tumor growth while CD8-depletion enhanced tumor growth in the absence of SN6j. SN6j induced apoptosis in human umbilical vein endothelial cells in a dose-dependent manner which indicates an additional mechanism of antiangiogenesis by SN6j. (c) 2008 Wiley-Liss, Inc.
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PMID:Anti-tumor activity of an anti-endoglin monoclonal antibody is enhanced in immunocompetent mice. 1822 82

This study was carried out to determine whether mesenchymal stem cells (MSCs) derived from teratoma of human embryonic stem cells (hESCs) function as feeder cells to support hESCs growth. Approximately 5x10(6) hESCs were injected into the hind limb muscle of each SCID-beige mouse to form teratoma. After 8 weeks, the MSCs were isolated from the teratoma and cultured in Mesencult medium. Purified MSCs were then used as the feeder cells for hESCs culture. High purity MSCs derived from teratoma were isolated. The cells were morphologically similar to bone marrow MSCs (bMSCs). The teratoma-derived MSCs were negative for CD34 and CD45 but positive for CD29, CD49b, CD105, CD73, and CD90, which resembled those expressed by bMSCs. After passaged on MSCs feeder cells more than 10 passages, hESCs maintained hESC characteristics in morphology. Reverse PCR showed the expression of Oct4 and Nanog. SSEA-1 was negative and SSEA-4, TRA-1-60, and TRA-1-81 were positive. Alkaline phosphatase staining showed positive results.The karyotype remained normal. Moreover, the hECSs cultured on teratoma-derived MSCs formed teratoma in vivo and embryoid body in vitro confirmed their pluripotency. Accordingly, MSCs derived from hESCs by in vivo differentiation can be used as the feeder cells for hESCs culture.
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PMID:[Growing of human embryonic stem cells on feeders derived from themselves]. 1907 71


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