Search results for "T Cell"
showing 10 items of 2228 documents
In human retinoblastoma Y79 cells okadaic acid-parthenolide co-treatment induces synergistic apoptotic effects, with PTEN as a key player.
2013
Retinoblastoma is the most common intraocular malignancy of childhood. In developing countries, treatment is limited, long-term survival rates are low and current chemotherapy causes significant morbidity to pediatric patients and significantly limits dosing. Therefore there is an urgent need to identify new therapeutic strategies to improve the clinical outcome of patients with retinoblastoma. here, we investigated the effects of two natural compounds okadaic acid (OKa) and parthenolide (PN) on human retinoblastoma Y79 cells. For the first time we showed that OKa/PN combination at subtoxic doses induces potent synergistic apoptotic effects accompanied by lowering in p-akt levels, increasin…
The potential of acetaminophen as a prodrug in gene-directed enzyme prodrug therapy.
2000
Acetaminophen is oxidized by human CYP1A2 to the cytotoxic metabolite N-acetylbenzoquinoneimine (NABQI). Incubation of cells transfected with human CYP1A2 (H1A2 MZ cells) with 4-20 mM acetaminophen for 6 hours at 37 degrees C caused extensive cytotoxicity (cell viability10%). In contrast, nontransfected V79 MZ cells were unaffected (viability95%). By mixing H1A2 MZ cells with V79 MZ cells in various proportions and incubating with 4 mM acetaminophen, it was shown that the NABQI released from H1A2 MZ cells also caused cytotoxicity of bystander cells. Thus, in a mixture containing 5% H1A2 MZ cells, exposure to 4 mM acetaminophen for 6 hours resulted in complete cell killing by 24 hours. A sim…
The Impact of Insulin on Low-dose Metronomic Vinorelbine and Mafosfamide in Breast Cancer Cells
2021
Background/aim Breast cancer (BC) may be affected by diabetes and anti-diabetic medication, as well as its therapeutic agents. Low-dose metronomic chemotherapy (LDMC) is an available treatment option in BC. We investigated the impact of insulin on low-dose metronomic vinorelbine and mafosfamide in BC cell lines. Materials and methods Human BC cell lines T-47D, MCF-7, MDA-MB-231, BT-549 and non-tumorigenic breast cell line MCF-10A were exposed to 0.01 μg/ml and 10 μg/ml insulin in combination with low-dose metronomic vinorelbine or mafosfamide. The cell viability was determined after 24-72 hours using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Results Insulin, especi…
Heterogeneous response to differentiation induction with different polar compounds in a clonal rat rhabdomyosarcoma cell line (BA-HAN-1C)
1989
The clonal rat rhabdomyosarcoma cell line BA-HAN-1C was tested for its susceptibility to differentiation induction with different polar compounds. This cell line is composed of proliferating mononuclear tumour cells, some of which spontaneously fuse to form terminally differentiated postmitotic myotube-like giant cells. Exposure of BA-HAN-1C cells to dimethylsulphoxide (DMSO), hexamethylene bisacetamide (HMBA), sodium butyrate (NaBut) and N-monomethylformamide (NMF) resulted in a significant inhibition of proliferation (P less than 0.001) and in a simultaneous increase in differentiation. The response was most pronounced after exposure to NMF as evidenced by a marked increase in the creatin…
Clonal expansion of melan a-specific cytotoxic T lymphocytes in a melanoma patient responding to continued immunization with melanoma-associated pept…
2000
Peptides derived from human tumor antigens have been used in a number of clinical trials to induce specific immune responses against autologous tumors in cancer patients. Although favorable clinical results were observed in single patients, immune responses correlating with tumor regression were either not detected or in case of responses, the T-cell specificity was difficult to demonstrate. In this study, we analyzed antigen-specific T-cell responses induced in the skin and in peripheral blood lymphocytes (PBL) in an HLA-A2-positive melanoma patient. The patient showed major regression of metastatic melanoma under continued immunization with peptides derived from the melanocyte differentia…
Abstract LB-243: Cetuximab and Artesunate synergistically inhibit the invasion and distant metastasis of non-small cell lung cancer
2012
Abstract Cancer is a complex disease and multi step process evolving from malfunctions of molecules and their complex networks which regulate this process. The blockage of the cancer signalling network is crucial in the cancer treatment. In some cases, single drug therapy might not be comprehensive enough to inhibit the activity of secondary signals, feedback regulations and resistance to particular molecules, due to their abundant expression or activity. An understanding of these complex phenomena in cancer therapy for the benefit of patients is essential, especially since it bears the chance to establish novel concepts of combination drug therapy. In the present study, we have tried to fi…
Cytotoxic effects of chemotherapy on cancer and immune cells: how can it be modulated to generate novel therapeutic strategies?
2015
The first objective to use chemotherapy is to kill cancer cells. However, it is common knowledge that these drugs can also damage healthy host cells, especially immune cells, and thus impair the endogenous antitumor response. Here, we focus on the cytotoxic effects of chemotherapy on tumor cells and immune cells. It is not enough to simply kill cancer cells, and causing immunogenic cell death will impair the adaptive immune system's ability to fight the remaining cancer cells. On the other hand, the killing of immune cells can also enhance tumor growth. A study of the repercussions of the cytotoxic effects of chemotherapy is of great importance to evaluate the antitumor response. Strategie…
T Cells Expressing Receptor Recombination/Revision Machinery Are Detected in the Tumor Microenvironment and Expanded in Genomically Over-unstable Mod…
2021
AbstractTumors undergo dynamic immunoediting as part of a process that balances immunologic sensing of emerging neoantigens and evasion from immune responses. Tumor-infiltrating lymphocytes (TIL) comprise heterogeneous subsets of peripheral T cells characterized by diverse functional differentiation states and dependence on T-cell receptor (TCR) specificity gained through recombination events during their development. We hypothesized that within the tumor microenvironment (TME), an antigenic milieu and immunologic interface, tumor-infiltrating peripheral T cells could reexpress key elements of the TCR recombination machinery, namely, Rag1 and Rag2 recombinases and Tdt polymerase, as a poten…
Cleavage of CD95 by matrix metalloproteinase-7 induces apoptosis resistance in tumour cells
2004
The ability of tumour cells to resist apoptosis-inducing signals by cytotoxic T cells may decide the success or failure of tumour elimination. An important effector of apoptosis is the CD95/CD95 ligand system (APO-1/Fas) that mediates perforin-independent cytotoxic T-cell killing of tumour cells. We propose a new strategy by which tumour cells can resist CD95-induced apoptosis. We identified matrix metalloproteinase-7, MMP-7 (Martilysin), as the first physiologically relevant protease that can specifically cleave CD95. MMP-7 is of unique importance because it is produced by the tumour cells themselves at early stages of tumour development. Microsequencing of the positions in CD95 cleaved by…
Tumoricidal activity of endothelium-derived NO and the survival of metastatic cells with high GSH and Bcl-2 levels.
2008
Metastatic spread, not primary tumor burden, is the leading cause of cancer death. Glutathione (L-gamma-glutamyl-L-cysteinyl-glycine; GSH) is the most prevalent non-protein thiol in mammalian cells, and in cancer cells is particularly relevant in regulating mutagenic mechanisms, DNA synthesis, growth, and multidrug and radiation resistance. In malignant tumors, as compared with normal tissues, that resistance associates in most cases with higher GSH levels. Interaction of metastatic cells with the vascular endothelium activates local release of proinflammatory cytokines, which act as signals promoting cancer cell adhesion, extravasation, and proliferation. A high% of metastatic cells with h…