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  • 1
    Keywords: APOPTOSIS ; CANCER ; CELLS ; EXPRESSION ; GROWTH ; carcinoma ; CELL ; Germany ; INHIBITION ; THERAPY ; HEPATOCELLULAR-CARCINOMA ; PROTEIN ; TISSUE ; LINES ; MICE ; PATIENT ; IMPACT ; INDUCTION ; CELL-LINES ; treatment ; hepatocellular carcinoma ; resistance ; AGE ; metastases ; NUDE-MICE ; CELL-LINE ; chemotherapy ; leukemia ; LINE ; MODULATION ; p53 ; CANCER-PATIENTS ; CARCINOMAS ; CISPLATIN ; CANCER PATIENTS ; cell lines ; CANCER-THERAPY ; protein expression ; P53 STATUS ; GEMCITABINE ; RE ; cancer therapy ; GENDER ; dexamethasone ; GLUCOCORTICOID-INDUCED APOPTOSIS ; NAUSEA ; HISTOLOGY ; corticosteroids ; GLUCOCORTICOIDS ; correlation ; GAMMA-IRRADIATION ; viability ; 5-FU ; xenograft
    Abstract: The glucocorticoid dexamethasone is frequently used as co-treatment in cytotoxic cancer therapy, e.g. to prevent nausea, to protect normal tissue or for other reasons. While the potent pro-apoptotic properties and the supportive effects of glucocorticoids to tumour therapy in lymphoid cells are well studied, the impact to cytotoxic treatment of colorectal and hepatocellular carcinoma is unknown. We tested apoptosis-induction, viability, tumour growth and protein expression using 8 established cell lines, 18 surgical specimen and a xenograft on nude mice. In the presence of dexamethasone we found strong inhibition of apoptosis in response to 5-FU, cisplatin, gemcitabine or gamma-irradiation, enhanced viability and tumour growth of colorectal and hepatocellular carcinomas. No correlation with age, gender, histology, TNM, the p53 status and induction of therapy resistance by dexamethasone cotreatment could be detected. These data show that glucocorticoid-induced resistance occurs not occasionally but is common in colorectal and hepatocellular carcinomas implicating that the use of glucocorticoids may be harmful for cancer patients. (c) 2005 Elsevier Ireland Ltd. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 16338063
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  • 2
    Keywords: APOPTOSIS ; CANCER ; CELLS ; EXPRESSION ; GROWTH ; IN-VITRO ; carcinoma ; Germany ; IN-VIVO ; INHIBITION ; THERAPY ; VITRO ; GENE ; GENES ; LINES ; MICE ; PATIENT ; IMPACT ; INDUCTION ; treatment ; 5-FLUOROURACIL ; prevention ; resistance ; AGE ; NUDE-MICE ; CELL-LINE ; chemotherapy ; LINE ; CARCINOMAS ; specificity ; CISPLATIN ; pancreatic cancer ; CANCER-THERAPY ; CYTOTOXICITY ; signaling ; GEMCITABINE ; RE ; PANCREATIC-CANCER ; cancer therapy ; pancreatic ; GENDER ; dexamethasone ; GLUCOCORTICOID-INDUCED APOPTOSIS ; NAUSEA ; HISTOLOGY ; in vivo ; surgical resection
    Abstract: Background: Chemotherapy for pancreatic carcinoma often has severe side effects that limit its efficacy. The glucocorticoid (GC) dexamethasone (DEX) is frequently used as co-treatment to prevent side effects of chemotherapy such as nausea, for palliative purposes and to treat allergic reactions. While the potent pro-apoptotic properties and the supportive effects of GCs to tumour therapy in lymphoid cells are well studied, the impact of GCs to cytotoxic treatment of pancreatic carcinoma is unknown. Methods: A prospective study of DEX-mediated resistance was performed using a pancreatic carcinoma xenografted to nude mice, 20 surgical resections and 10 established pancreatic carcinoma cell lines. Antiapoptotic signaling in response to DEX was examined by Western blot analysis. Results: In vitro, DEX inhibited drug-induced apoptosis and promoted the growth in all of 10 examined malignant cells. Ex vivo, DEX used in physiological concentrations significantly prevented the cytotoxic effect of gemcitabine and cisplatin in 18 of 20 freshly isolated cell lines from resected pancreatic tumours. No correlation with age, gender, histology, TNM and induction of therapy resistance by DEX co-treatment could be detected. In vivo, DEX totally prevented cytotoxicity of chemotherapy to pancreatic carcinoma cells xenografted to nude mice. Mechanistically, DEX upregulated pro-survival factors and anti-apoptotic genes in established pancreatic carcinoma cells. Conclusion: These data show that DEX induces therapy resistance in pancreatic carcinoma cells and raise the question whether GC-mediated protection of tumour cells from cancer therapy may be dangerous for patients
    Type of Publication: Journal article published
    PubMed ID: 16539710
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  • 3
    Keywords: brain ; APOPTOSIS ; CANCER ; CELLS ; IN-VITRO ; SURVIVAL ; AGENTS ; CELL ; Germany ; IN-VIVO ; VITRO ; DEATH ; DRUG ; SURGERY ; LINES ; TIME ; PATIENT ; LIGAND ; primary ; INDUCTION ; tumour ; treatment ; culture ; ACID ; CELL-DEATH ; PLASMA ; RATES ; RESECTION ; PHARMACOKINETICS ; CISPLATIN ; FUTURE ; TRAIL ; AGENT ; POTENT ; REGRESSION ; IV ; GRADE ; brain tumour ; betulinic acid ; CERAMIDE ; glioblastoma multiforme WHOIV
    Abstract: Background. Glioblastoma multiforme (WHO Grade IV, GBM) is the most malignant brain tumour with a mean survival time of less than one year. Betulinic acid, ceramide and TRAIL (TNF-related apoptosis inducing ligand) represent novel therapeutic agents for potential use in GBM. Method. Primary GBM cells of 21 patients with macroscopically complete tumour resection were tested in vitro for cell death induction by betulinic acid, ceramide, TRAIL and established therapeutics (BCNU, cisplatin, doxorubicin, vincristin and gamma-irradiation). Findings. At peak plasma concentrations (PPC), Betulinic acid, ceramide and TRAIL induced cell death in primary GBM cells at higher rates than established cytotoxic drugs. Specific cell death greater than or equal to75% was observed in 43% (9/21), 38% (8/21), and 19% (4/21) for betulinic acid, ceramide, and TRAIL respectively, while this was only found in 5% (1/21) of gamma-irradiated and cisplatin-treated cells, and in none of the GBM cultures, where BCNU or vincristin were applied in PPC. Conclusion. Due to a markedly improved cell death of GBM cells as compared with established therapeutics, Betulinic acid, ceramide and TRAIL might represent potent substances for future treatment of GBM
    Type of Publication: Journal article published
    PubMed ID: 15197616
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  • 4
    Keywords: RECEPTOR ; APOPTOSIS ; EXPRESSION ; IN-VITRO ; tumor ; carcinoma ; CELL ; CELL LUNG-CANCER ; Germany ; human ; IN-VIVO ; LUNG ; MODEL ; MODELS ; VITRO ; VIVO ; DEATH ; NEW-YORK ; GENE ; TUMORS ; LINES ; MICE ; FAMILY ; MEMBER ; MEMBERS ; treatment ; immunohistochemistry ; MALIGNANCIES ; ASSAY ; resistance ; CELL-DEATH ; INDUCED APOPTOSIS ; Western-blot ; NUDE-MICE ; chemotherapy ; CARCINOMAS ; STRATEGIES ; western blot ; FAILURE ; LUNG-CARCINOMA ; CASPASE 8 ; nude mice ; Bcl-2 ; CD95 ; DRUG-INDUCED APOPTOSIS ; XENOGRAFTS ; CD95/Fas/APO-1,TRAIL,gene therapy,drug reststance,cancer therapy ; IMMUNE-SYSTEM
    Abstract: Non small cell lung carcinoma (NSCLC) is a highly lethal malignancy that often becomes resistant to chemotherapy. To determine whether alterations in apoptotic signaling might contribute to such resistance, we established in vitro and in vivo models for sensitive and resistant human NSCLC. We found that resistance is due to multiple defects found in expression of CD95-L, CD95 and members of the Bcl-2 and IAP family, as well as caspase-8, -9 and -3 as examined by immunohistochemistry, Western blot analysis, gene array analysis and functional assays. Failure to activate death receptor, as well as mitochondrial apoptosis signaling, points to a central role of caspases. To restore apoptosis signaling we transfected NSCLC xenografts on nude mice with caspase-8 and -9. This treatment strongly induced apoptosis per se and sensitized the tumors to cisplatin-induced cell death. Thus, these findings indicate that re-expression of caspases might be an effective strategy to restore sensitivity for chemotherapy in NSCLC in vivo. (C) 2003 Wiley-Liss, Inc
    Type of Publication: Journal article published
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  • 5
    Keywords: brain ; APOPTOSIS ; CANCER ; CELLS ; GROWTH ; carcinoma ; CELL ; Germany ; THERAPY ; screening ; TISSUE ; LINES ; PATIENT ; MECHANISM ; CONTRAST ; CELL-LINES ; treatment ; BREAST ; breast cancer ; BREAST-CANCER ; resistance ; INDUCED APOPTOSIS ; CERVIX ; metastases ; CELL-LINE ; chemotherapy ; LINE ; MELANOMA ; RESECTION ; CISPLATIN ; cell lines ; CANCER-THERAPY ; LUNG-CARCINOMA ; neuroblastoma ; signaling ; MALIGNANT-CELLS ; RE ; cancer therapy ; SOLID TUMORS ; dexamethasone ; NAUSEA ; corticosteroids ; GLUCOCORTICOIDS ; prospective ; BONE ; EXTENT ; clinical studies ; surgical resection ; steroids
    Abstract: Glucocorticoids (GCs) such as dexamethasone (DEX) have been widely used as co-medication in cancer therapy because they have potent proapoptotic properties in lymphoid cells, can reduce nausea, and alleviate acute toxic effects in healthy tissue. However, GCs are used in a supportive-care role, even though no prospective clinical studies have assessed the effect of these steroids on the growth of solid tumours. Data from preclinical and, to some extent, clinical studies, suggest that GCs induce treatment resistance in some solid tumours. Since it is unknown whether GC-induced resistance occurs only occasionally or is a more common phenomenon, we performed a screening study using several established cell lines from bone, brain, breast and cervix carcinoma as well as melanoma and neuroblastoma together with fresh surgical resections from patients with breast cancer. We found that DEX inhibits cisplatin and 5-fluorouracil- induced apoptosis and promotes the growth of the majority of examined malignant cells. In contrast, and as expected, DEX acted pro-apoptotically and promoted the cytotoxic effect of chemotherapy in established and primary lymphoid cells. Thus, these data demonstrate the need for detailed molecular studies to clarify the mechanism of differential glucocorticoid signaling as well as controlled, prospective clinical studies
    Type of Publication: Journal article published
    PubMed ID: 17016664
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  • 6
    Keywords: APOPTOSIS ; CELLS ; EXPRESSION ; TUMOR-CELLS ; PATHWAYS ; DRUG ; COMPONENTS ; LINES ; IMPACT ; mechanisms ; DOWN-REGULATION ; BONE-MARROW ; RECOGNITION ; leukemia ; MHC CLASS-I ; NATURAL-KILLER-CELLS ; NK cells ; allogeneic ; BONE-MARROW-TRANSPLANTATION ; CROSS-RESISTANCE ; CYTOCHROME-C RELEASE ; CYTOSOLIC DELIVERY ; CYTOTOXIC EFFECTOR-CELLS ; graft-versus-leukemia ; GRANZYME-B ; HLA class I ; INITIATES APOPTOSIS ; PERFORIN ; TARGET-CELLS
    Abstract: Background and Objectives. Drug-resistant leukemia cells may exhibit cross-resistance towards immunological, effector mechanisms by alterations of apoptosis pathways. This is particularly relevant in allogeneic bone m, arrow transplantation for leukemia, where the graft-versus-leukemia effect acts on cells pretreated with cytostatic drugs. Here, we clarify the mechanism underlying cross-resistance of drug- resistant variants of the T-leukemia cell, line CEM towards natural killer cells. Design and Methods. We determined the sensitivity of. different CEM sublines to natural killer (NK) cytotoxicity, and separately analyzed the components of the killing machinery by detection of granzyme B-induced caspase, cleavage and HLA class I-dependent recognition mechanisms. Furthermore, We studied regulation of HLA class I expression comparing CEM with other cell lines. Results. We found that CEM cells resistant to cytostatic drugs or CD95 were cross- resistant towards NK cells from a variety of donors. Granzyme B-induced caspase and PARP cleavage in the sensitive and resistant cells were comparable, indicating that downstream apoptosis pathways were not altered in the drug-resistant cells, HLA class I molecules were upregulation in the resistant cells, inhibiting NK cells at the level of killer/target recognition. HLA class I upregulation was not found in other leukemia cell lines. Interpretation and Conclusions., This is the first description of HLA class I-mediated, NK cross- resistance, in drug-resistant cells. This finding may have a,clinical impact since it may be considered as a possible reason for resistance to a graft-versus-leukemia approach in allogeneic bone marrow transplantation
    Type of Publication: Journal article published
    PubMed ID: 12745270
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  • 7
    Keywords: APOPTOSIS ; CANCER ; CANCER CELLS ; CELLS ; INHIBITOR ; CELL ; Germany ; human ; INHIBITION ; KINASE ; PATHWAY ; THERAPY ; EXPOSURE ; NEW-YORK ; RELEASE ; TIME ; STRESS-INDUCED APOPTOSIS ; ACTIVATION ; DNA ; INDUCTION ; T cell ; T-CELL ; CLEAVAGE ; PROGRESSION ; resistance ; MEMBRANE ; STRESS ; ALKYLATING-AGENTS ; fragmentation ; LINE ; CANCER-CELLS ; SURFACE ; PROTEIN-KINASES ; CYTOCHROME-C ; doxorubicin ; CISPLATIN ; CELL-SURFACE ; FAS LIGAND EXPRESSION ; stable transfection ; apoptosis,JNK,cancer therapy,caspases ; FACTOR C-JUN ; INITIATION ; JNK/SAPK ACTIVITY ; JUN NH2-TERMINAL KINASE ; MAP KINASES ; N-TERMINAL KINASE ; THERAPY-INDUCED APOPTOSIS ; TNF-ALPHA
    Abstract: The human leukemic T-cell line Jurkat was used to define the role of the cellular stress pathway with its key player kinase JNK in cancer therapy-induced apoptosis. JNK activity was inhibited by stable transfection with a dominant negative mutant of the upstream kinase JNKK/MKK4 or with the novel, potent and selective JNKI, -2 and -3 inhibitor SP600125. Inhibition of JNK activity delayed the onset of apoptosis induced by cisplatin, doxorubicin, gamma-irradiation and CD95-L but did not prevent apoptosis per se. Early events during apoptosis such as induction of CD95-L, activation of caspase-8 and exposure of phosphatidylserine on the cell surface were strongly inhibited. Also, at early time points of apoptosis, loss of the mitochondrial membrane potential and release of cytochrome c were markedly impaired. However, late signaling events during apoptosis such as cleavage of PARP and DNA fragmentation apoptosis were only marginally affected. These findings are in accordance with the activity of initiator and effector caspases. Whereas activity of the initiator caspase-8 was strongly inhibited early and late after induction, an inhibition of caspase-3 activity was only observed early after induction of apoptosis. We therefore suggest that cellular stress signaling contributes to the initiation of apoptosis, whereas it might be dispensable for the progression of apoptosis. Dysfunction of this pathway under pathological conditions might contribute to therapy resistance of cancer cells. (C) 2003 Wiley-Liss, Inc
    Type of Publication: Journal article published
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  • 8
    Keywords: APOPTOSIS ; CELLS ; EXPRESSION ; GROWTH ; IN-VITRO ; CELL ; Germany ; human ; IN-VIVO ; THERAPY ; VITRO ; VIVO ; SYSTEM ; DEATH ; GENE ; PROTEIN ; DRUG ; LINES ; MICE ; gene transfer ; GENE-TRANSFER ; LIGAND ; INDUCTION ; tumour ; T cell ; T cells ; T-CELL ; T-CELLS ; ANTITUMOR-ACTIVITY ; TARGET ; LYMPHOMA ; resistance ; CELL-DEATH ; chemotherapy ; LINE ; CANCER-CELLS ; PRODUCT ; SURFACE ; sensitization ; SELECTION ; CELL-SURFACE ; TRAIL ; HUMAN HEPATOCYTES ; APOPTOSIS-INDUCING LIGAND ; DRINKING ; DRUG-INDUCED APOPTOSIS ; INDUCE APOPTOSIS ; TRAIL,gene therapy,Tet system,apoptosis,B cell lymphoma
    Abstract: In the present study, we demonstrate the utility of a non-tumour-forming T-cell line for the inducible gene transfer of tumour necrosis factor (TNF)-related apoptosis-inducing ligand (Apo2L/TRAIL), which has been shown to selectively induce apoptosis in malignant but not in normal cells. To generate T cells inducible for TRAIL expression, we stably transfected Jurkat cells with TRAIL in the context of the Tet-On system. The switched on cells strongly expressed TRAIL mRNA, whose protein product was expressed on the cell surface. Paracrine induction of apoptosis in human target tumour cells was solely found for membrane-bound TRAIL. The Jurkat-TRAIL cells itself survived due to clonal selection of TRAIL-resistant cells. Jurkat-TRAIL cells had an additive effect with cytotoxic drugs in vitro, since cell death was enhanced. To elucidate the antitumoral activity of these Jurkat-TRAIL cells in vivo, we injected them intratumorally in xenografts of human Burkitt lymphomas. Switching on expression of TRAIL by adding tetracycline to the drinking water of the mice strongly reduced tumour growth by apoptosis in a caspase-dependent manner. Thus, non-tumour-forming T-cell lines offer a novel method for gene transfer and inducible expression of TRAIL in tumour therapy
    Type of Publication: Journal article published
    PubMed ID: 14647152
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  • 9
    Keywords: APOPTOSIS ; CANCER ; CANCER CELLS ; CELLS ; EXPRESSION ; GROWTH ; IN-VITRO ; SURVIVAL ; carcinoma ; CELL ; Germany ; IN-VIVO ; INHIBITION ; THERAPY ; VITRO ; VIVO ; DENSITY ; GENE ; GENES ; PROTEIN ; TISSUE ; LINES ; MICE ; PATIENT ; IMPACT ; INDUCTION ; CELL-LINES ; treatment ; BREAST-CANCER ; prevention ; resistance ; PLASMA ; ovarian cancer ; OVARIAN-CANCER ; NUDE-MICE ; CELL-LINE ; chemotherapy ; LINE ; CANCER-CELLS ; CANCER-PATIENTS ; CARCINOMAS ; ovarian carcinoma ; CANCER PATIENTS ; cell lines ; CANCER-THERAPY ; protein expression ; ONCOLOGY ; RE ; TUMOR-GROWTH ; cancer therapy ; EX-VIVO ; LEVEL ; PLASMA-LEVELS ; dexamethasone ; NAUSEA ; OVARIAN CARCINOMAS ; corticosteroids ; GLUCOCORTICOIDS ; in vivo ; OVARIAN ; viability ; xenograft
    Abstract: The glucocorticoid dexamethasone is frequently used as a co-treatment in cytotoxic cancer therapy, e.g. to prevent nausea, to protect normal tissue or for other reasons. While the potent pro-apoptotic properties and supportive effects of glucocorticoids to tumour therapy in lymphoid cells are well studied, the impact on the cytotoxic treatment of ovarian carcinoma is unknown. We tested apoptosis-induction, viability, tumour growth and protein expression using established cell lines, primary cell lines freshly isolated from patient material and a xenograft on nude mice. We found a general induction of resistance toward cytotoxic therapy by DEX-co-treatment in most of the examined ovarian cancer cells treated in vitro, ex vivo or in vivo. Resistance occured independently of cell density and was found at peak plasma levels of dexamethasone and below. Mechanistically, the dexamethasone-induced expression of survival genes may be involved in the resistance. These data show that glucocorticoid-induced resistance is common in ovarian carcinomas implicating that the use of glucocorticoids may be harmful for cancer patients
    Type of Publication: Journal article published
    PubMed ID: 16391812
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  • 10
    Keywords: RECEPTOR ; APOPTOSIS ; INHIBITOR ; tumor ; CELL ; COMBINATION ; Germany ; THERAPY ; SUPPORT ; DEATH ; DISEASE ; GENE ; GENES ; SAMPLE ; SAMPLES ; cell line ; LINES ; PATIENT ; ACTIVATION ; LIGAND ; prognosis ; CELL-LINES ; FORM ; DELETION ; resistance ; MUTATION ; CELL-LINE ; leukemia ; STRATEGIES ; CHILDREN ; cell lines ; TRAIL ; TP53 ; TRAIL-INDUCED APOPTOSIS ; APOPTOSIS-INDUCING LIGAND ; INHIBITORS ; signaling ; FEATURES ; THERAPIES ; CLL ; regulation ; CD95-MEDIATED APOPTOSIS ; interaction ; development ; X-LINKED INHIBITOR ; LEVEL ; B-CELL ; NECROSIS ; caspase-3 ; XIAP ; STRATEGY ; death-receptor ; TP53 mutation ; FORMS ; 17p deletion ; UNFAVORABLE PROGNOSIS
    Abstract: Evasion of apoptosis is a hallmark of chronic lymphocytic leukemia (CLL), calling for new strategies to bypass resistance. Here, we provide first evidence that small-molecule X-linked inhibitor of apoptosis (XIAP) inhibitors in combination with the death receptor ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) present a novel approach to trigger apoptosis in CLL, including subgroups with resistant disease or unfavorable prognosis. XIAP, cellular IAP (cIAP) 1, and cIAP2 are expressed at high levels in primary CLL samples. Proof-of-concept studies in CLL cell lines show that subtoxic concentrations of XIAP inhibitors significantly enhance TRAIL-induced apoptosis and also sensitize for CD95-mediated apoptosis. Importantly also in primary CLL samples, XIAP inhibitor acts in concert with TRAIL to trigger apoptosis in 18 of 27 (67%) cases. This XIAP inhibitor-induced and TRAIL-induced apoptosis involves caspase-3 activation and is blocked by the caspase inhibitor zVAD.fmk. The cooperative interaction of XIAP inhibitor and TRAIL is even evident in distinct subgroups of patients with poor prognostic features (i.e., with 17p deletion, TP53 mutation, chemotherapy-refractory disease, or unmutated V(H) genes). Interestingly, cases with unmutated V(H) genes were significantly more sensitive to XIAP inhibitor-induced and TRAIL-induced apoptosis compared with V(H) gene-mutated samples, pointing to a role of B-cell receptor signaling in apoptosis regulation. By showing that XIAP inhibitors in combination with TRAIL present a new strategy to trigger apoptosis even in resistant forms and poor prognostic subgroups of CLL, our findings have important implications for the development of apoptosis-based therapies in CLL.
    Type of Publication: Journal article published
    PubMed ID: 19920200
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