Search results for "tumor cells"
showing 10 items of 663 documents
p95HER-2 Predicts Worse Outcome in Patients with HER-2-Positive Breast Cancer
2006
AbstractBackground: The HER-2 receptor undergoes a proteolytic cleavage generating an NH2-terminally truncated fragment, p95HER-2, that is membrane-associated and tyrosine-phosphorylated. We have reported that p95HER-2, but not the full-length receptor, p185HER-2, correlated with the extent of lymph node involvement in patients with breast cancer and its expression was significantly enhanced in nodal metastatic tissue. These facts suggested an important role for p95HER-2 either as a marker or cause of metastasis and poor outcome in breast cancer. In this work, we have studied the prognostic value of p95HER-2 in breast cancer.Methods: Primary breast tumor tissues (n = 483) were from surgical…
The response of autologous T cells to a human melanoma is dominated by mutated neoantigens
2005
Our understanding of pathways leading to antitumor immunity may depend on an undistorted knowledge of the primary antigenic targets of patients' autologous T cell responses. In the melanoma model derived from patient DT, we applied cryopreserved short-term autologous mixed lymphocyte–tumor cell cultures (MLTCs) in combination with an IFN-γ enzyme-linked immunospot (ELISPOT) assay to cDNA expression screening. We identified three previously unknown peptides processed from melanosomal proteins tyrosinase (presented by HLA-A*2601 and -B*3801) and gp100 (presented by HLA-B*07021) and five neoantigens generated by somatic point mutations in the patient's melanoma. The mutations were found in the…
Evaluation of the antiproliferative, proapoptotic, and antiangiogenic effects of a double-stranded RNA mimic complexed with polycations in an experim…
2015
Objective To assess the antiproliferative, proapoptotic, and antiangiogenic effects of the double-stranded RNA mimic polyinosine-polycytidylic acid (pIC) complexed with polyethylenimine [pIC PEI ] in xenografted human leiomyomas. Design Heterologous leiomyoma mouse model. Setting University-affiliated infertility center. Animal(s) Ovariectomized and hormone-replaced nude mice (n = 16) who received human leiomyoma fragment transplantation. Intervention(s) Leiomyoma fragments placed in the peritoneum of 5-week-old nude female mice and treated with the vehicle (n = 8) or 0.6 mg/kg [pIC PEI ] (n = 8) for 4 weeks. Main Outcome Measure(s) The size of the leiomyoma implants, and cellular prolifera…
Induction of apoptosis in human retinoblastoma cells by topoisomerase inhibitors
1998
PURPOSE:To examine the apoptotic effect induced in human retinoblastoma Y79 cells by camptothecin, etoposide, and amsacrine, to examine the effect of these drugs on the expression of many apoptosis-related modulators, and to test the antiapoptotic effect exerted by insulin-like growth factor-I (IGF-I). METHODS:Morphologic features of apoptosis were demonstrated using acridine orange- ethidium bromide staining and electron microscopy. DNA fragmentation was determined by means of an in situ cell detection procedure (TdT-dUTP terminal nick-end labeling [TUNEL]) or by electrophoresis on agarose gels and was quantified by enzyme-linked immunosorbent assay. The expression of apoptosis-related mod…
Apoptotic effects of different drugs on cultured retinoblastoma Y79 cells
1998
This paper deals with the apoptotic effect exerted in human retinoblastoma Y79 cells by a number of compounds. A remarkable effect was observed after treatment with DNA-damaging agents, such as camptothecin, etoposide, cisplatin and carboplatin; camptothecin was found to be the most efficacious. Treatment with these compounds induced the appearance of morphological features of apoptosis in the cells together with the distinct fragmentation of DNA, as shown by agarose gel electrophoresis. These effects were also accompanied by a remarkable increase in the level of p53. Many other compounds, which are not DNA-damaging agents, induced the morphological features of apoptosis but none of them we…
Factors influencing the interaction of herpes simplex virus glycoprotein C with the third component of complement.
1992
The factors influencing the interaction of herpes simplex virus (HSV) glycoprotein C (gC) with the third component of complement (C3) were investigated in this study. The ability of gC of HSV type 1 (gC-1) to bind to the C3b fragment of C3 was found to be influenced by cell specific processing of gC-1 in a different manner, binding being remarkably enhanced in some cell lines following removal of sialic acid residues. Testing several intertypic recombinants of HSV we found that only strains expressing gC-1 exhibited binding to C3b, even though their genome consisted mainly of HSV-2 sequences in some recombinants. Expression of type-2 glycoproteins gB, gD, gE, gG, gH, and gI did not alter th…
TAP off - tumors on
1997
Abstract The molecular characterization of T-cell-defined tumor-associated antigens has provided targets for cell-mediated immunotherapy for malignant diseases. The success of this strategy is negatively influenced by structural and functional abnormalities of major histocompatibility complex (MHC) class I molecules, which provide tumor cells with resistance to T-cell-mediated immune recognition. This article reviews the physiology of the MHC class I processing machinery and describes the deficiencies of this pathway in malignant cells.
Enzymatic Activity of CD26 (Dipeptidylpeptidase IV) is not Required for Its Signalling Function in T Cells
1993
Abstract CD26 is a proteolytic enzyme (dipeptidylpeptidase IV) expressed on the T cell surface that defines an alternative activation signal for human T lymphocytes. Crosslinking of CD26 via monoclonal antibodies triggers proliferation and cytotoxicity in preactivated T cells. In this study, we used highly specific competitive and irreversible inhibitors of dipeptidylpeptidase IV to study the role of the enzymatic activity in activation of CD26- transfected T cells as well as of CD26-expressing normal human T cell clones. These inhibitors at concentrations that blocked up to 95% of the enzymatic activity, did not specifically inhibit T cell activation neither via TCR/CD3 nor via CD26 itself…
Function of Dipeptidyl Peptidase IV (CD26, Tp103) in Transfected Human T Cells
1993
CD26 (Tp103) is a proteolytic enzyme (dipeptidyl peptidase IV) expressed on the T cell surface that defines an alternative activation signal for human T lymphocytes. It is absent from or present in only low amounts on resting T cells but it is expressed strongly after activation. Crosslinking of CD26/Tp103 via the monoclonal antibody CB.1 triggers functional activities in preactivated T cells. To study the molecular requirements for T cell activation via CD26 we transfected a cDNA encoding CD26 into several CD26-negative cells. In Jurkat T cell leukemia cells that normally do not express the CD26 antigen, the transfected CD26 molecule is functional because the monoclonal antibody CB.1 induc…
T cell activation defect in hemodialysis patients: Evidence for a role of the B7/CD28 pathway
1993
T cell activation defect in hemodialysis patients: Evidence for a role of the B7/CD28 pathway. The immunosuppressive effect of chronic renal failure is correlated with an impaired proliferation of peripheral blood leukocytes in vitro . This is mainly due to an impaired function of the accessory cells rather than the T cells. Here we tried to define a missing accessory signal for T cell activation in hemodialysis patients. We substituted cell surface bound molecules by adding tumor cell lines to the in vitro assays that express different patterns of accessory molecules. Cell lines that express the costimulatory B7 molecule reconstituted the activation of patients' cells whereas B7 negative c…