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T Tursz

Publications and source records attributed to T Tursz.

At least 19 recordsLinked to original sources
PubMed1992

The development of human tumor-cell resistance to TNF-alpha does not confer resistance to cytokine-induced cellular cytotoxic mechanisms.

We have derived a TNF-alpha-resistant clone (RA-I) from the parental TNF-sensitive human breast-adenocarcinoma cell line (MCF-7). The acquisition of TNF-resistance was not associated with endogenous TNF production or with differential levels of TNF receptors since both MCF-7 and RA-I display comparable TNF-receptor expression. We have investigated the relationship between acquisition of resistance to TNF and susceptibility to lysis by cytokine-activated effectors. Experiments were performed using human peripheral-blood monocytes stimulated with IL-2, IFN or GM-CSF, and lymphokine-activated killer cells as effector cytotoxic cells. Our data indicate that both TNF-resistant (RA-I) and TNF-sensitive (MCF-7) cells were killed by IL-2-activated monocytes. Incubation of monocytes with IFN also resulted in the activation of their tumoricidal activity against MCF-7 and RA-I. When stimulated monocytes were pre-incubated in the presence of a TNF-specific neutralizing monoclonal antibody, prior to co-culture with target cells, no effect on their lytic capacity was observed. Thus, the monocyte killing does not appear to involve the membrane form of TNF. These observations suggest that, in our experimental system, IL-2 and IFN are able to induce non-TNF-mediated mechanisms of cytotoxicity by monocytes. Experiments performed using GM-CSF and LPS for monocyte stimulation indicate that, although both reagents were efficient in inducing the membrane form of TNF on monocytes, they did not enhance the cell-killing capacity towards MCF-7 and RA-I targets. Furthermore, using IL-2-stimulated LGL as effector cells, we show in this study that the TNF-resistant clone RA-I was as sensitive as MCF-7 to human LAK cells.

Adenocarcinoma↗
PubMed1992

Heterogeneity among human nasopharyngeal carcinoma cell lines for inflammatory cytokines mRNA expression levels.

Using polymerase chain reaction (PCR), we confirmed the expression of interleukin-1 alpha (IL-1 alpha) by the human nasopharyngeal carcinoma (NPC) cell line C15 without contribution of either human IL-1 beta or mouse IL-1 alpha in the biological activity previously found in C15. However we showed that IL-1 alpha was not expressed in all NPCs. IL-1 beta and/or tumor necrosis factor (TNF)-alpha genes could also be activated, independently from the number of Epstein Barr Virus (EBV) copies harbored by the cells. Interestingly, the primary tumor C15 showed a profile of TNF-sensitive tumor while C17, C18 and C19 which were derived from metastasis have a typical profile of TNF-resistant cells. Furthermore, the inflammatory cytokines whose genes are classically induced by IL-1 and TNF were found expressed only in C17 and C19 suggesting another level of heterogeneity among NPCs.

Animals↗
PubMed1992

Elevated expression of ICAM1 (CD54) and minimal expression of LFA3 (CD58) in Epstein-Barr-virus-positive nasopharyngeal carcinoma cells.

Undifferentiated nasopharyngeal carcinoma (NPC) is a remarkable entity among human tumors because of its constant association with the Epstein-Barr virus (EBV). Malignant epithelial cells harbor the EBV genome and often express at least 2 species of latent EBV protein (EBNA1 and LMP1). Despite the massive presence of tumor-infiltrating lymphocytes, NPC cells obviously escape immune surveillance directed to EBV antigens. Previous investigations carried out on EBV-positive Burkitt lymphoma (BL) cells have shown that this fact may be partially accounted for by a lack of expression of ICAM1 (CD54) and LFA3 (CD58). ICAM1 and LFA3 have therefore been investigated in fresh NPC biopsies and transplanted NPCs. With only 1 exception out of 9 cases, NPC cells appear to express high levels of ICAM1 and low levels of LFA3. This is a complete inversion of the pattern observed in normal epithelial cells in vivo. Additional investigations will be required to determine to what extent these characteristics affect T-cell interactions with NPC cells, specially in the process of EBV-antigen recognition.

Animals↗
PubMed1992

Does malignant small round cell tumor of the thoracopulmonary region (Askin tumor) constitute a clinicopathologic entity? An analysis of 30 cases with immunohistochemical and electron-microscopic support treated at the Institute Gustave Roussy.

The morphology and clinical outcome of 30 patients with malignant small round cell tumors located in the thoracopulmonary region (Askin tumor) are reported. Histologically, all tumors had similar patterns, with small round-to-oval cells and a lobulated stroma. Immunohistochemical analysis always resulted in positive staining for one or several neural markers. No significant differences were found compared with the immunomarkers in 26 typical Ewing's sarcomas located outside the thoracic wall. In three specimens, electron microscopy confirmed the presence of membrane-bound neurosecretory granules. It was confirmed that there is a remarkable similarity among all malignant small round cell tumors, including Askin tumor and Ewing's sarcoma. Overall survival was poor with a 2-year rate of 38% and a 6-year rate of 14%.

Adolescent↗
PubMed1992

Phase II study of a combination of elliptinium and vinblastine in metastatic breast cancer.

Thirty nine patients with metastatic breast cancer, all previously treated with chemotherapy including anthracycline, were given Elliptinium acetate (80 mg/m2/day) and a continuous infusion of Vinblastine (2 mg/m2/day) for 3 consecutive days every 4 weeks. Twenty nine patients had measurable metastatic disease. Nine (31%) achieved a partial response. No complete response was observed. Median duration of response was 6 months. The response rate was dependent on the number of metastatic sites and independent of the number of previous chemotherapy regimes. Side effects were dry mouth (27 patients), vomiting (9), neutropenia (3 patients with grade IV, 2 with grade III), muscle cramps (5) and thrombosis (3). Xerostomia and vomiting contributed to weight loss and fatigue (8 patients). We conclude that Elliptinium-Vinblastine combination has moderate activity as second line treatment in metastatic breast cancer. This combination causes xerostomia and fatigue with moderate myelosuppression.

Adult↗
PubMed1992

Phase I-II study of vinorelbine (Navelbine) plus cisplatin in advanced non-small cell lung cancer.

32 patients with advanced non-small cell lung cancer previously untreated by chemotherapy were included in a phase I-II study in order to determine the feasibility of the combination of vinorelbine and cisplatin, each administered at its optimal dose, i.e. 30 mg/m2 weekly and 120 mg/m2 every 4-6 weeks, respectively. There were 27 males and 5 females with a mean age of 55 years and a median performance status of 80%. 13 had locally advanced disease and 19 had distant metastases at the time of inclusion. Our study demonstrated the feasibility of this protocol. Dose intensities could be maximised by adapting vinorelbine doses rather than by postponing treatment in the event of neutropenia. Both response rate (33%) and overall survival of the population (median 11 months) justify further studies.

Adult↗
PubMed1992

Human T-cell leukemia virus type I envelope protein maturation process: requirements for syncytium formation.

The human T-cell leukemia virus type I (HTLV-I) envelope protein is synthesized as a gp61 precursor product cleaved into two mature proteins, a gp45 exterior protein and a gp20 anchoring the envelope at the cell membrane. Using N-glycosylation inhibitors and site-directed mutagenesis of the potential glycosylation sites, we have studied the HTLV-I envelope intracellular maturation requirements for syncytium formation. We show here that experimental conditions resulting in the absence of precursor cleavage (tunicamycin, monensin treatments, and use of inhibitors of the reticulum steps of the N glycosylations) also result in no cell surface expression of envelope protein. The lack of syncytium formation observed in these cases is thus explained by incorrect intracellular transport. When the precursor is cleaved in the Golgi stack (no treatment or treatment with inhibitors of the Golgi steps of the N glycosylations), it is transported to the cell surface in all the cases examined. Syncytium formation is markedly reduced, however, when Golgi glycosylations are incorrect, which shows that the sugar moieties are involved in the envelope functions. Site-directed mutagenesis demonstrates that each of the five potential glycosylation sites is actually glycosylated. Glycosylation of sites 1 and 5 is required for normal maturation, whereas that of sites 2, 3, and 4 is dispensable. Glycosylation of each site, however, is required for normal syncytium formation. Altogether, the restraints exerted by the cell for the HTLV-I envelope to be transported and functional are very high, which might play a role in the observed conservation of the envelope amino acid sequence between various strains.

1-Deoxynojirimycin↗
PubMed1992

Consistent transcription of the Epstein-Barr virus LMP2 gene in nasopharyngeal carcinoma.

Two species of the Epstein-Barr virus-encoded latent membrane protein 2, LMP2A and LMP2B, are generated by alternative splicing, each species having a distinct first exon. LMP2 transcription in undifferentiated nasopharyngeal carcinoma (NPC), which is consistently associated with the Epstein-Barr virus, was investigated. Fifteen NPC specimens were analyzed by Northern (RNA) blot and RNA-based polymerase chain reaction; the LMP2A transcript was present in all specimens except one. In some specimens the LMP2B transcript was also detected. Sequence analysis of LMP2 cDNAs obtained from two NPC specimens revealed four mutations in exon 1 of the LMP2A transcript, which were present in both tumors and which resulted in nonconservative amino acid changes. These data suggest that the LMP2 expressed in NPC is distinct from that which is expressed in lymphoid cells.

Amino Acid Sequence↗
PubMed1992

Alterations of the p53 gene in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a malignancy which is consistently associated with the Epstein-Barr virus (EBV). The structure of the EBV genome in NPC suggests that NPC is a clonal proliferation of epithelial cells which emerges after EBV infection. The disease develops with high incidence in specific populations in discrete geographic locations, implicating possible genetic or environmental cofactors. Mutations of the p53 gene are among the most frequent genetic changes found in a large variety of human tumors. Mutations in p53 have been shown to abrogate the suppressor function of wild-type p53 and thus contribute to the transformed phenotype. To determine if mutation in p53 participates in the development of the malignant clone in NPC, the structure and sequence of p53 in 42 primary, metastatic, and nude mouse-passaged NPC specimens was analyzed. A high frequency (6 of 9) of mutations was detected in the nude mouse-passaged tumors, while only 2 of 15 metastatic and 0 of the 18 primary tumors harbored mutant p53. The p53 mutations included single-point mutations and more extensive changes such as frame shifts, deletion, duplication, or complete loss of coding sequences. These data indicate that alterations of the p53 gene are unlikely to be involved in the initial genetic events leading to the clonal outgrowth in NPC. However, although it is a rare NPC which can be established in nude mice, this growth advantage appears to be conferred on tumors bearing a mutant p53.

Animals↗
PubMed1992

IL-2 phase II trial in metastatic melanoma: analysis of clinical and immunological parameters.

Twenty-four patients with histologically proven metastatic malignant melanoma were included in a phase II trial of recombinant IL-2 (rIL-2, RU 49637). Twenty million international units (IU)/m2/day were given by continuous intravenous infusion on days 1 to 5, 15 to 18, and 29 to 31, and then monthly for 5 days until disease progression or major intolerance developed. All patients were evaluable for response and toxicity. Toxicity was consistent with one case of myocardial ischemia, 13 cases of grade III and IV hypotension, and 15 cases of proven sepsis. There were 8 objective responses: 4 of them were of short duration as they were observed on day 31 only. An activation of the immune system was detected in all patients. It was demonstrated by an increase in lymphocyte populations, especially in activated NK cells. A tendency for higher numbers of cytotoxic cells was found in patients with objective tumor responses. These results indicate a role for rIL-2 RU 49637 in treating patients with metastatic malignant melanoma. However, further trials are required to determine its optimal dosage and schedule of administration.

Adolescent↗
PubMed1992

[Immunotherapy: current problems and outlook].

Cytokines are soluble mediators involved in cell-cell regulations in the immunological and the hematopoietic systems-genetic engineering now allows the characterization and the availability of recombinant molecules, some of them being recently introduced in clinical trials. Interleukin-2 (IL-2) is the first factor having demonstrated a reproducible therapeutic effect on human metastatic solid tumors, mainly chemo-resistant. High-dose IL-2 alone could achieve about 25% objective responses in metastatic renal cancers, with a low but significant number of complete, relatively long-lasting complete responses. Similar data are obtained in metastatic melanoma. IL-2 is probably acting through the activation of cytotoxic lymphocytes (LAK: lymphokine activated killers). The interest for simultaneous administration of autologous LAK cells generated through in vitro culture with IL-2 is discussed. Cytokine therapy is currently limited by important systemic toxicities, including mainly general symptoms with fever, and a capillary leak syndrome with weight gain, edema and functional renal failure-cardiac are respiratory troubles can be life-threatening. Future trends for cytokine therapy will be: The discovery of new cytokines, and a better knowledge of their synergies, allowing the design of rational associations. A letter understanding of the mechanisms of toxicities, allowing specific prevention of adverse effects not needed for efficient anti-tumor action. Gene therapy, which will lead to important and prolonged release of cytokines by the tumor cells themselves, or by infiltrating peri-tumoral cells, in order to achieve local efficacy and to circumvent systemic toxicities.

Forecasting↗
PubMed1991

A phase II study of the combination of carboplatin and ifosfamide in previously untreated metastatic small cell lung carcinoma.

This Phase II study evaluated the combination of two active agents in small cell lung carcinoma (SCLC): carboplatin and ifosfamide. Thirty previously untreated patients (27 men and 3 women) with a median age of 59 years were included in this study. Twelve patients had one metastatic site and 18 had two or more metastatic sites. The median performance status was 80%. The chemotherapy (CT) regimen administered during the course of this study consisted of carboplatin (300 mg/m2) and ifosfamide (4 g/m2) plus mesna every 4 weeks. All 30 patients were evaluable: 1 achieved a complete remission (CR) and 18 achieved a partial remission (PR) (objective response rate, 63%). The median response time was 3 months and the median survival time was 8 months (range, 1 to 25+ months). Bone marrow toxicity was Grade III in three patients and Grade IV in four patients. The carboplatin and ifosfamide combination was well tolerated. No cross-resistance with the doxorubicin and etoposide regimen was established because 4 of 11 patients responded to this combination (+/- cisplatin) after failing to respond to the ifosfamide and carboplatin regimen. The ifosfamide and carboplatin combination may be considered for inclusion in non-cross-resistant alternating CT schedules.

Adult↗
PubMed1991

[Phase I trial of a recombinant human interleukin 2. Results in patients with disseminated solid tumors].

A phase I trial of Roussel-Uclaf recombinant human interleukin 2 (IL 2) was performed on 31 cancer bearing patients of the Institut Gustave-Roussy, Villejuif, and the Institut Curie, Paris. This study allowed to define a schedule for administration of IL 2 in continuous infusion over 5 day cycles. This schedule is manageable in patients without major visceral failure. It is reproducibly feasible in conventional medical oncology units, without specialized intensive care facilities. Toxicities, although numerous, are acceptable for IL 2 doses below 24,000,000 IU/m2/day. There is a close relationship between secondary effect severity and IL 2 doses received. Main toxicities were: fever with chills, fatigue and general discomfort in 23 patients, nauseas and vomiting in 12, diarrhea in 10 and cutaneous rashes with erythema and dermal vascularitis in 13. One peculiar feature of this study was the minimal occurrence of manifestation related to leaky capillary syndrome prominant in other studies. Oliguria, functional renal failure and edema were observed in only 4 patients with functionally unique kidney. Five patients had severe anemia, 2 grade III thrombocytopenia, 1 grade IV hepatic cytolysis, 4 severe confusion episodes and 2 hypothyroidism with anti-thyroid microsome auto-antibodies. All these toxicities were reversible after withdrawal of IL 2 treatment. During this phase I trial, 3 therapeutic objective responses were observed, all 3 occurring in patients with metastatic melanoma treated with IL 2 doses equal to, or above 16,000,00 IU/m2/d. Recombinant IL 2 Roussel-Uclaf thus can be administered through a simple, manageable and efficient regimen.

Adolescent↗
PubMed1991

Cytotoxic potential despite impaired activation pathways in T lymphocytes infiltrating nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is an epithelial tumor consistently associated with EBV. The histological picture is characterized by a strikingly abundant lymphocytic infiltrate. Furthermore, the epithelial tumor cells present several immunological characteristics which suggest an important role for tumor-infiltrating lymphocytes (TIL) in the biology of this tumor. The present study reports the phenotypic and functional characterization of TIL from NPC obtained after enzymatic digestion of 15 NPC biopsies. Flow cytometric analysis of TIL suspensions indicated that most TIL were mature CD3+ T lymphocytes (mean = 60%) with a variable CD4/CD8 ratio. Most TIL were TCR alpha/beta-positive (mean = 55%) and only a few TCR gamma-delta-positive cells could be identified. A small percentage (mean = 9%) displayed an activated phenotype (CD25+, HLA class II+). Using limiting dilution analysis, we found that the average frequency of proliferative T-lymphocyte precursors (PTL-P) is lower among TIL (1/40) than in autologous (1/7) or normal PBL (1/1.4). Moreover, sorting experiments have shown that this defect is significantly more pronounced in the CD8+ than in the CD4+ TIL subset. Accordingly, the TCR and the CD2-mediated antigen-independent pathways of activation were impaired. Different types of cytotoxic precursor could be detected. These included lectin-dependent cell cytotoxicity (LDCC) and NK-like or lymphokine-activated killer (LAK) activity. Interestingly, some TIL from NPC were able to lyse an NPC tumor (C15) maintained in nude mice. Thus, despite impaired activation pathways, the cytolytic potential of proliferating TIL in NPC is preserved.

Adolescent↗