Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.1.1.148 (Thy1)
 1,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The CD25- and CD25+ CD4 T-lymphocyte compartments are tightly regulated. We show here that tumors break such balance, increasing the number of CD4+CD25+ T cells in draining lymph node and spleen but not contralateral node of tumor-bearing mice. Tumor injection in thymectomized and CD25-depleted mice shows that CD4+CD25+ T-cell expansion occurs even in the absence of the thymus and independently from proliferation of preexisting CD25+ T cells. These newly generated cells are bona fide regulatory T cells (T reg) in terms of Foxp3 expression and suppression of CD3-stimulated or allogeneic effector cell proliferation. Transfer of congenic Thy1.1 CD4+CD25- T cells, from mice treated or not with vinblastine, into tumor-bearing or tumor-free mice and analysis of recovered donor lymphocytes indicate that conversion is the main mechanism for acquiring the expression of CD25 and Foxp3 through a process that does not require proliferation. Although conversion of CD4+CD25- T cells for generation of T regs has been described as a natural process that maintains peripheral T-reg population, this process is used by the tumor for immune escape. The prompt recovery of T regs from monoclonal antibody-mediated CD25 depletion in tumor-bearing mice suggests attempts able to inactivate rather than deplete them when treating existing tumors.
 ...
PMID:Tumor-induced expansion of regulatory T cells by conversion of CD4+CD25- lymphocytes is thymus and proliferation independent. 1661 76

Vascular endothelial growth factor (VEGF) could play a relevant role in angiogenesis associated with chronic allograft nephropathy. Interleukin-1beta (IL-1beta) has a key role in inflammatory response. It induces prostaglandin (PG) E2, which is involved in VEGF release by some normal and tumor cells. In the present work, we studied the effect of IL-1beta on VEGF release by rat mesangial cells, the transduction signal, and whether or not PGE2 is involved in this effect. IL-1beta induced a time-dependent formation of VEGF (analyzed by enzyme-linked immunosorbent assay) and PGE2 (analyzed by enzyme immunoassay). The latter correlated with microsomal-PGE-synthase (mPGES)-1 expression rather than with cyclooxygenase (COX)-2 in terms of protein, determined by Western blotting. No effect of IL-1beta on COX-1, cytosolic PGES, or mPGES-2 expression was observed. Indomethacin exerted a nonsignificant effect on IL-1beta-induced VEGF, and exogenously added PGE2 exhibited a nonsignificant stimulatory effect on VEGF formation. SB 203580, a p38 mitogen-activated protein kinase inhibitor, weakly inhibited the induction of VEGF by IL-1beta in a concentration-dependent manner, whereas LY 294002, a phosphoinoside 3-kinase (PI3-K) inhibitor, and rapamycin, a mammalian target of rapamycin (mTOR) inhibitor, strongly inhibited both IL-1beta- and tumor necrosis factor-alpha-induced VEGF formation in a concentration-dependent manner. Rapamycin also decreased glomerular VEGF levels in the anti-Thy1.1 model of experimental glomerulonephritis. In conclusion, the PI3-K-mTOR pathway seems to be essential in cytokine-induced release of VEGF in mesangial cells.
 ...
PMID:IL-1beta induces VEGF, independently of PGE2 induction, mainly through the PI3-K/mTOR pathway in renal mesangial cells. 1703 41

Dendritic cells (DCs) have been used successfully for inducing effective anti-tumor immune responses in advanced cancer patients undergoing tumor-specific immunotherapy. Appropriate antigen pulsing is a crucial parameter for optimizing the efficacy of immunotherapy as well as anti-tumor protection therapy. Using a murine colon cancer model, we evaluated the anti-tumor efficacy of four different preparations of DC vaccines that contained either a whole tumor or its derivatives, including i) DCs pulsed with tumor lysate, ii) DCs pulsed with necrotic tumor cells, iii) DCs pulsed with apoptotic tumor cells, and iv) DC-tumor cell fusion hybrids. Our data show that DC-tumor cell fusion hybrids and DCs pulsed with irradiated apoptotic tumor cells were more potent than DCs with freeze-thawed necrotic tumor cells for the induction of protective anti-tumor responses. The vaccination of DCs pulsed with tumor lysate failed to elicit any anti-tumor effect. In animals administered with higher doses of a tumor-cell challenge, DC-tumor cell fusion hybrids elicited the most effective anti-tumor response. Among the preparations tested, mice immunized with DC-tumor cell fusion hybrids resulted in the greatest induction of cytotoxicity as measured by the cytotoxic T lymphocyte activity of both the splenocytes and the Thy1.2-positive T lymphocytes. Furthermore, the in vitro production of IFN-gamma polarized to the Th1 cytokine responses was highest in the splenocytes derived from mice vaccinated with DC-tumor cell fusion hybrids. Our results suggest that DC-tumor cell fusion hybrids are more potent inducers of protection against solid tumors, such as colon cancer, than other antigen-loading strategies using whole tumor cell materials.
 ...
PMID:Dendritic cell-tumor cell hybrids enhance the induction of cytotoxic T lymphocytes against murine colon cancer: a comparative analysis of antigen loading methods for the vaccination of immunotherapeutic dendritic cells. 1708 56

The tumor microenvironment of human non-small cell lung cancer (NSCLC) is composed largely of stromal cells, including fibroblasts, yet these cells have been the focus of few studies. In this study, we established stromal cell cultures from primary NSCLC through isolation of adherent cells. Characterization of these cells by flow cytometry demonstrated a population which expressed a human fibroblast-specific 112-kDa surface molecule, Thy1, alpha-smooth muscle actin, and fibroblast activation protein, but failed to express CD45 and CD11b, a phenotype consistent with that of an activated myofibroblast. A subset of the tumor-associated fibroblasts (TAF) was found to express B7H1 (PD-L1) and B7DC (PD-L2) constitutively, and this expression was up-regulated by IFN-gamma. Production of cytokines and chemokines, including IFN-gamma, monokine induced by IFN-gamma, IFN-gamma-inducible protein-10, RANTES, and TGF-beta1 was also demonstrated in these cells. Together, these characteristics provide multiple opportunities for the TAF to influence cellular interactions within the tumor microenvironment. To evaluate the ability of TAF to modulate tumor-associated T cell (TAT) activation, we conducted coculture experiments between autologous TAF and TAT. In five of eight tumors, TAF elicited a contact-dependent enhancement of TAT activation, even in the presence of a TGF-beta1-mediated suppressive effect. In the three other tumors, TAF had a net suppressive effect upon TAT activation, and, in one of these cases, blockade of B7H1 or B7DC was able to completely abrogate the TAF-mediated suppression. We conclude that TAF in human NSCLC are functionally and phenotypically heterogeneous and provide multiple complex regulatory signals that have the potential to enhance or suppress TAT function in the tumor microenvironment.
 ...
PMID:Characterization of human lung tumor-associated fibroblasts and their ability to modulate the activation of tumor-associated T cells. 1761 59

Neuroblastoma (NBL) is the most common solid tumor in children. Tumors in advanced stage or with positive risk factors still have a poor prognosis. Thy1 (CD90) is a membrane glycoprotein expressed in thymus, retinal ganglionic cells, and several types of stem cells. The aim of this study was to assess Thy1 expression in NBL and analyze the correlation with clinical outcome. Sixty-three specimens of NBL were stained for Thy1 on a tissue microarray by immunohistochemistry. Fresh frozen tumor tissues were used for RNA isolation, and RT-PCR analysis for Thy1-mRNA expression was performed. Patients' survival data were correlated with Thy1 status using a log rank test and a Cox regression multivariate analysis. Thy1 was expressed on 51 (81%) of the tumors. Kaplan-Meier survival analysis showed a significantly impaired survival in patients with NBL missing Thy1 (P < 0.005 by log-rank test). A multivariate Cox regression showed an independent prognostic value of Thy1 status for overall survival (P < 0.05). In addition, the frequency of events and deaths was significantly higher in the group of patients with Thy1 negative tumors, as assessed by ANOVA analysis (P < 0.05 by F-test). The data showed that Thy1-negative NBL patients have a significantly impaired overall survival compared with Thy1-positive NBL patients. Thus, Thy1 seemed to be a marker with a specific prognostic value in NBL patients. Future studies are aiming at the biological role of this marker in the tumor cell differentiation.
 ...
PMID:Lack of Thy1 (CD90) expression in neuroblastomas is correlated with impaired survival. 1795 44

In human breast cancers, a phenotypically distinct minority population of tumorigenic (TG) cancer cells (sometimes referred to as cancer stem cells) drives tumor growth when transplanted into immunodeficient mice. Our objective was to identify a mouse model of breast cancer stem cells that could have relevance to the study of human breast cancer. To do so, we used breast tumors of the mouse mammary tumor virus (MMTV)-Wnt-1 mice. MMTV-Wnt-1 breast tumors were harvested, dissociated into single-cell suspensions, and sorted by flow cytometry on Thy1, CD24, and CD45. Sorted cells were then injected into recipient background FVB/NJ female syngeneic mice. In six of seven tumors examined, Thy1+CD24+ cancer cells, which constituted approximately 1%-4% of tumor cells, were highly enriched for cells capable of regenerating new tumors compared with cells of the tumor that did not fit this profile ("not-Thy1+CD24+"). Resultant tumors had a phenotypic diversity similar to that of the original tumor and behaved in a similar manner when passaged. Microarray analysis comparing Thy1+CD24+ tumor cells to not-Thy1+CD24+ cells identified a list of differentially expressed genes. Orthologs of these differentially expressed genes predicted survival of human breast cancer patients from two different study groups. These studies suggest that there is a cancer stem cell compartment in the MMTV-Wnt-1 murine breast tumor and that there is a clinical utility of this model for the study of cancer stem cells.
 ...
PMID:Isolation and molecular characterization of cancer stem cells in MMTV-Wnt-1 murine breast tumors. 1797 24

Antigen specific T cell migration to sites of infection or cancer is critical for an effective immune response. In mouse models of cancer, the number of lymphocytes reaching the tumor is typically only a few hundred, yet technology capable of imaging these cells using bioluminescence has yet to be achieved. A combination of codon optimization, removal of cryptic splice sites and retroviral modification was used to engineer an enhanced firefly luciferase (ffLuc) vector. Compared with ffLuc, T cells expressing our construct generated >100 times more light, permitting detection of as few as three cells implanted s.c. while maintaining long term coexpression of a reporter gene (Thy1.1). Expression of enhanced ffLuc in mouse T cells permitted the tracking of <3 x 10(4) adoptively transferred T cells infiltrating sites of vaccination and preestablished tumors. Penetration of light through deep tissues, including the liver and spleen, was also observed. Finally, we were able to enumerate infiltrating mouse lymphocytes constituting <0.3% of total tumor cellularity, representing a significant improvement over standard methods of quantitation including flow cytometry.
 ...
PMID:Visualizing fewer than 10 mouse T cells with an enhanced firefly luciferase in immunocompetent mouse models of cancer. 1879 21

That benzo alpha)pyrene (Balpha P) decreases both humoral and cell-mediated immunity, and leads to increases in progeny tumor development after in utero insult, suggests that T- and B-lymphocytes are made defective in exposed offspring. In the study here, C3H mice were injected once with Balpha P (150 microg/g BW) at day 12 of pregnancy and progeny lymphoid tissues were excised during gestation (day 18; GD18) or at 1 or 6 weeks post-partum. The isolated lymphoid cells were analyzed by flow cytometry/immunofluorescence or assessed for function. In Balpha P-exposed fetuses, thymic Thy1(+) cell levels were decreased (relative to levels in organs of corn oil-exposed dam progeny). In addition, for up to 6 weeks post-birth, CD4(+)CD8(+) (double positive; DP) cells were virtually absent and levels of CD4(-)CD8(-) (double negative; DN) cells were consistently at epsilon 90%. With regard to single positive (SP) cells, CD4(+) cell levels were also decreased in tissues at GD18 up through 6 weeks post-birth; CD8(+) cell levels were increased, but only in pups at 1-week and 6-weeks post-birth. In 1-week-old progeny, spleen CD8(+) cell levels were quantitatively unchanged, though CD4(+) levels were reduced 2-4-fold and CD4(-)CD8(-) DN levels significantly increased. With respect to TCRs, fetal levels of thymic CD3Vgamma(3)(+) and CD3Vgamma delta(+) cells were decreased; levels of CD3Valphabeta cells were only slightly depressed. The latter results contrast sharply with a strong reduction in CD3Valphabeta cells in the fetal livers of Balpha P-exposed progeny. Interestingly, these livers also strongly evidenced a presence of BalphaP-7,8-dihydrodiol-9,10-epoxide metabolite. When assessed for any change in function, the CD4(+), Thy1(+) cells isolated from Balpha P-exposed progeny tissues responded weakly (relative to controls) to ConA and in an allogeneic MLR. Taken in totality, the results here strengthen our original hypothesis that BalphaP can create a favorable milieu for tumor growth progression in progeny of exposed mothers by affecting development of sufficient numbers of functional lymphocytes in the offspring.
 ...
PMID:Alterations in CD4+, CD8+, Vgamma3, Vgammadelta, and/or Valpha betaT-lymphocyte expression in lymphoid tissues of progeny after in utero exposure to benzo(alpha)pyrene. 1883 Aug 90

Rat small hepatocytes (SHs) are committed progenitor cells that can differentiate into mature hepatocytes and can selectively proliferate in serum-free medium when they are cultured on hyaluronic acid (HA)-coated dishes. In this study we examined the separation of human SHs from adult human livers. We obtained liver tissues from the resected liver of 16 patients who underwent hepatic resections. Extracted liver specimens were clearly separate from the tumor regions with sufficient margins. Hepatic cells were isolated using the modified method of two-step collagenase perfusion. A low-speed centrifugation was performed and cells in the supernatant were finally cultured on HA-coated dishes in serum-free DMEM/F12 medium including nicotinamide, EGF, and HGF. Small-sized hepatocytes selectively proliferated to form colonies and many colonies continued growing for more than 3 weeks. The average number of cells in a colony was 38.6 +/- 18.0, 79.0 +/- 54.0, and 101.5 +/- 115.7 at day 7, 14, and 21, respectively. About 0.04% of plated cells could form an SH colony. Immunocytochemistry showed that the cells forming a colony were positive for albumin, transferrin, keratin 8, and CD44. The results of RT-PCR showed that colony-forming cells expressed albumin, transferrin, alpha1-antitrypsin, fibrinogen, glutamine synthetase, many cytochrome P450s, and liver-enriched transcription factors (HNF3alpha, HNF4alpha, C/EBPalpha, and C/EBPbeta). Furthermore, the cells expressed not only the genes of hepatic differentiated functions but also those of both hepatic stem cell marker (Thy1.1, EpCAM, AFP) and SH marker (CD44, D6.1A, BRI3). Albumin secretion into culture medium was also observed. Our results demonstrate the existence of hepatocyte progenitor cells in human adult livers, and the cells can grow in a serum-free medium on HA-coated dishes. Human SHs may be a useful source for cell transplantation as well as pharmaceutical and toxicological investigations.
 ...
PMID:Proliferation of hepatocyte progenitor cells isolated from adult human livers in serum-free medium. 1918 Dec 16

Tumor cells have the capability to trans- and to dedifferentiate, for example by reactivating embryonic development genes and stem cell characteristics. The aim of our study was to show the differential expression of stem- and progenitor cell markers in human hepatocellular carcinoma cell lines (HCC). Different human HCC cell lines (HUH7, HUH7 5-15, HUH7 pcDNA3.1, Hep3B and HepG2) were cultured under standard conditions in vitro or implanted subcutaneously (5x10(6) cells) in male NMRI mice. Specimens were characterized by quantitative real-time PCR, Western blotting, methylation-specific PCR and immunohistochemistry for markers of differentiation (cytokeratins, vimentin), embryonic development or stem cells (PTC, PDX-1, SHH, Thy1, c-kit, CD34, beta-catenin, Ki-67). The investigated HCC cell lines showed different patterns of marker expression allowing to distinguish four distinct groups: the classical cholangiocellular type (Huh-7, Huh-7 pcDNA3.1, Hep3B) with expression of CK7/19, beta-catenin and CD34; a dedifferentiated mesenchymal-proliferative type (Huh-7 5-15) characterized by CK19, Vimentin and Ki-67; a dedifferentiated embryonic-development type (Hep3B implanted in matrigel) with expression of CK19, beta-catenin and PTC and a classical HCC type (HepG2) showing CK18/19 and beta-catenin expression. HCC cell lines showed significantly different expression patterns of differentiation markers in a xenograft model. Furthermore, direct association of some markers was observed. The groups differ from each other in expression patterns, but also show that environmental factors play an important role in the behaviour of cells.
 ...
PMID:Cellular plasticity of trans- and dedifferentiation markers in human hepatoma cells in vitro and in vivo. 1951 53


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>