The LFA-1/ICAM cell adhesion pathway is involved in tumor-cell lysis mediated by bispecific monoclonal-antibody-targeted T lymphocytes

We investigated the role of the LFA-1 /ICAM, VLA-4/VCAM-1 and CD2/LFA-3 adhesion pathways in the cytolysis of tumor cells mediated by an anti-EGF-R/anti-CD3 bispecific monoclonal antibody (biMAb). The biMAb induced efficient lysis of EGF-R+ tumor cells (A431, HT-29, IGROV-1 and MDA-MB468) by cytotoxic T lymphocytes (CTL) cultured in IL-2. Protreatment of effector cells by anti-LFA-1α (CDI 1a) and anti-LFA-1 β (CD 18) MAbs significantly inhibited cytolysis of all types of EGF-R+ tumor cells, while anti-CD2 and anti-VLA-4 MAbs were virtually ineffective. We investigated the expression of adhesion-molecule counter-receptors on tumor target cells by indirect immunofluorescence. HT-29, A431 and MDA-MB 468 tumor cells expressed an ICAM-1+2^?3^?VCAM-1^?LFA-3⁺ phenotype, while IGROV-1 was ICAM-1^?2⁺3^?VCAM-1 ^?LFA-3+. Pre-treatment of A431, HT-29 and MDA-MB468 with anti-ICAM-1 MAb inhibited cytolysis, further supporting the functional involvement of the LFA-1 /ICAM adhesion pathway in biMAb-targeted tumor-cell lysis. In addition, treatment of target cells with TNFα or IFN-γ for 24 hr increased the expression of ICAM-1 in HT-29, A431 and MDA-MB468 (ICAM-2 was induced on IGROV-1) and also enhanced the sensitivity of these target cells to biMAb-targeted cytotoxicity. These data suggest that up-regulation of ICAM-molecule expression by inflammatory cytokines may increase susceptibility of tumor cells to biMAb-targeted lysis. Anti-LFA-1 MAbs did not significantly inhibit the formation of conjugates between biMAb-coated T lymphocytes and tumor cells. Co-aggregation of LFA-1 molecules with biMAb-bound CD3 molecules resulted in a more sustained and prolonged increase in the intracellular concentration of. free Ca⁺⁺ in CD8⁺ cultured CTL lines. These findings indicate that in T cells targeted by anti-CD3/anti-TAA biMAb LFA-1 may act as a co-receptor molecule which enhances signal transduction through the CD3/TCR complex.     

Determination of platinum in plasma of patients affected by inoperable lung carcinoma treated with radiotherapy and concurrent low-dose continuous infusion ofcis-dichlorodiammine platinum(II)

Platinum microquantities were determined in plasma of patients affected by lung carcinoma during treatment with radiotherapy (RT) and concurrent low-dose continuous infusion ofcis-dichlorodiammineplatinum(II) (CDDP). RT was given at 50 Gy in continuous course; CDDP was continuously infused at 4 mg/m² daily for 100h/week for 5 weeks, and the infusions were separated by 68h of rest. The percentage of free drug versus total drug in plasma was about 3%. It did not vary with therapy duration and was not significantly different from that found in 5-day continuous infusions at much higher daily doses. Never-theless, maximal values of free Pt in plasma were very low and agreed with the low level of CDDP toxicity encountered on the present administration schedule.     

Epitope selection and development of peptide based vaccines to treat cancer

Cytotoxic T lymphocytes recognize peptides that associate with class I major histocompatibility complex molecules. Since cytotoxic T cells have the capacity to recognize and destroy tumor cells, identification of epitopes recognized by these cells in tumor-associated antigens would allow the production of compounds for the treatment of cancer. Here we review some of the approaches being explored to identify tumor-associated antigens and to develop peptide-based vaccines that induce cytotoxic T lymphocytes against specific tumors.     

Identification of chromosomal rearrangements in the human myeloid leukemia cell line GF-D8 by dual-colour fluorescence in situ hybridization

Fluorescence In Situ Hybridization (FISH) studies with chromosome-specific libraries and repetitive probes were performed on the human acute myeloid leukemia cell line GF-D8 in order to define the complex chromosomal rearrangements observed by conventional cytogenetic analysis. Two-colour FISH with whole chromosome painting probes 8 and 11 showed that the add(8) chromosome had an 11-derived region inserted at q24, whereas the add(11) chromosome had an 8-derived region translocated onto q23. It also demonstrated that no normal chromosome 11 is present in GF-D8 cells, since a translocation involving chromosomes 11 and 17q was detected in addition to the add(11). The der(7) chromosome with extra material in its long arm, identified by QFQ and GTG banding, turned out to have a chromosome 15-derived segment translocated to q22. The deletion of 7q was proved to be interstitial, as the 7q-specific telomere as well as a tiny 7-specific band were observed on an unknown chromosome. Fine mapping of the breakpoints involved in the multiple chromosomal rearrangements of the GF-D8 cell line might provide insights into the mechanisms of myeloid leukaemogenesis.     

Expression of protectin (CD59) in human melanoma and its functional role in cell- and complement-mediated cytotoxicity

Immunohistochemical and/or indirect immunofluorescence analysis with monoclonal antibody (MAb) H19 demonstrated the expression of protectin (CD59) in 54 surgically removed metastatic melanoma lesions and on 8 out of 12 melanoma cell lines. CD59 expression had a low degree of intra- and intertumor heterogeneity. SDS-PAGE analysis showed that the molecular weight of CD59 expressed on melanoma cells is about 20 kDa. Treatment of melanoma cells with 5 U/ml of phosphatidylinositol-specific phospholipase C completely abolished cell-surface expression of CD59. Interferon-γ and/or tumor necrosis factor-α or phorbol 12-myristate 13-acetate neither modulated the expression of CD59 by melanoma cells nor influenced the amounts of CD59-specific mRNA. F(ab')₂ fragments of anti-CD59 MAb YTH53.1 did not inhibit the lysis of melanoma cells by allogeneic natural killer (NK) cells or lymphokine-activated killer (LAK) cells. In contrast, the whole lg molecule of MAb H19 or YTH53. I significantly (p < 0.05) enhanced NK-cell-mediated lysis of melanoma cells, suggesting the induction of antibody-dependent cell-mediated cytotoxicity. Lastly, masking of CD59 by MAb YTH53. I or its F(ab')₂ fragments significantly (p < 0.05) enhanced, in a dose-dependent fashion, the lysis of anti-GD3-sensitized melanoma cells by homologous complement. These data demonstrate that CD59 expressed by human melanoma cells might regulate host-tumor interaction by protecting neoplastic cells from complement-mediated lysis. © 1995 Wiley-Liss, Inc.     

Expression of the mage gene family in primary and metastatic human breast cancer: Implications for tumor antigen-specific immunotherapy

Some human tumors express known antigens that can be utilized as targets for specific immunotherapy. An absolute requirement for the efficacy of this therapeutic strategy is an adequate expression of the candidate antigen by all cells of the primary and metastatic tumor. To examine the presence and distribution of tumor-associated antigens in metastatic breast cancer, we used PCR analysis and ethidium bromide staining to test the expression of genes of the MAGE family in 28 primary tumors and related metastatic samples. Overall, samples obtained from 7 of 28 patients revealed positive. However, 2 of 3 primary tumors positive for MAGE-1 and/or MAGE-3 had corresponding negative metastatic lesions. On the contrary, 4 of the 25 MAGE-negative primary tumors gave rise to positive metastatic nodes. Our results confirm in vivo, at the molecular level, the tumor-antigen heterogeneity previously observed at the cellular level by in vitro analysis. Our data strongly suggest that, at least in patients with breast cancer, multiple different antigens would be required to optimize the recognition of neoplastic cells in immunotherapeutic protocols using MAGE products as target antigens. © 1995 Wiley-Liss, Inc.     

Randomized Multicentric Italian Study on two Treatment Regimens for Marrow Relapse in Childhood Acute Lymphoblastic Leukemia

This paper reports the results of a multicentric randomized clinical trial on the treatment of first hematological relapse in childhood ALL. Induction treatment consisted of vincristine, adriamycin, L-asparaginase, and prednisone. Patients achieving complete remission were randomized to two maintenance regimens (A and B). Regimen A consisted of five different drug associations including VM26 and IDMTX in a sequential schedule; Regimen B was essentially classical Spiers schedule for the first year, followed by a milder treatment. Eighty-four of 102 evaluahle patients (82%) achieved second complete remission. The two maintenance regimens were similar as regards duration of second complete remission (median duration A, 32 weeks; B, 37 weeks) and toxicity. Better results were obtained in patients relapsing after 12 months from suspension of treatment in first complete remission than in those relapsing within the first year off therapy (82.8% vs. 31.4%). In group A fewer CNS relapses were reported. The two regimens produced results similar to those reported by other authors. The good prognosis in patients relapsing at least 1 year after treatment suspension in first complete remission must be emphasized.     

Selecting patients for home treatment of deep vein thrombosis: the problem of cancer

BACKGROUND AND OBJECTIVES. Patients with deep vein thrombosis are selected for home treatment on the basis of their clinical and social condition. Cancer is frequently associated with venous thromboembolism and is often considered an exclusion criterion for outpatient treatment. We investigated the impact of cancer on the outpatient management of venous thrombosis. DESIGN AND METHODS. We performed a prospective, cohort study on consecutive patients with objectively documented deep vein thrombosis. All were assessed for home treatment. Hospital admission was recommended in the presence of common exclusion criteria. All patients were treated with low molecular weight heparin and warfarin. Information on previous, active, or suspected cancer was collected. Recurrent thrombosis, bleeding and mortality were documented at a 3-month follow-up. RESULTS. One hundred patients were included; 72 were entirely treated at home (mean age: 61.2 years). There were 22 patients with known cancer: 12 (55%) were managed as outpatients (16.5% of the outpatient population) and 10 were hospitalized (36% of the inpatient population), 6 because of a poor clinical condition, 4 because further investigation of their malignancy was required. The presence of cancer and the likelihood of poor compliance were the most frequent reasons cited for in-hospital treatment. Overall, event rates at 3 months were comparable to those reported in previous studies in the outpatient population and slightly higher in the inpatient population (recurrent thrombosis 1.5% and 7%; bleeding 5.5% and 10.7%; mortality 4% and 18%, respectively). INTERPRETATION AND CONCLUSIONS. Cancer was the most common reason cited for in-hospital treatment. Nevertheless, more than half of the patients with known cancer were safely and effectively treated at home.     

Long-term clinical significance of frequent and complex ventricular tachyarrhythmias in trained athletes

OBJECTIVES: The aim of this study was to clarify the clinical relevance of ventricular tachyarrhythmias assessed by 24-h ambulatory electrocardiograms (ECG) in a large, unique, and prospectively evaluated athletic population. BACKGROUND: For athletes with ventricular tachyarrhythmias, the risk of sudden cardiac death associated with participation in competitive sports is unresolved. METHODS; We assessed 355 competitive athletes with ventricular arrhythmias (VAs) on a 24-h ambulatory (Holter) ECG that was obtained because of either palpitations, the presence of > or = 3 premature ventricular depolarizations (PVDs) on resting 12-lead ECG, or both. RESULTS: Athletes were segregated into three groups: Group A with > or = 2,000 PVDs/24 h (n = 71); Group B with > or = 100 <2,000 PVDs/24 h (n = 153); and Group C with only <100 PVDs/24 h (n = 131). Cardiac abnormalities were detected in 26 of the 355 study subjects (7%) and were significantly more common in Group A (21/71, 30%) than in Group B (5/153, 3%) or Group C athletes (0/131, 0% p < 0.001). Only the 71 athletes in Group A were excluded from competition. During follow-up (mean, 8 years), 70 of 71 athletes in Group A and each of the 284 athletes in Groups B and C have survived without cardiovascular events. The remaining Group A athlete died suddenly of arrhythmogenic right ventricular cardiomyopathy while participating in a field hockey game against medical advice.Frequent and complex ventricular tachyarrhythmias are common in trained athletes and are usually unassociated with underlying cardiovascular abnormalities. Such VAs (when unassociated with cardiovascular abnormalities) do not convey adverse clinical significance, appear to be an expression of "athlete's heart syndrome," and probably do not per se justify a disqualification from competitive sports.