A phase II trial of homoharringtonine and caracemide in the treatment of patients with advanced large bowel cancer.

Twenty-four previously untreated, ambulatory patients with advanced colorectal carcinoma were treated with either caracemide (11 patients) or homoharringtonine (13 patients). No objective responses were observed in any of the treatment cohorts. Caracemide was well tolerated with the exception of one death due to sepsis. On the homoharringtonine arm one patient died of pulmonary sepsis, one patient experienced grade 4 leukopenia requiring more than 4 weeks of recovery, and an additional patient developed grade 4 renal failure. These severe and unexpected complications caused early termination of accrual to the homoharringtonine arm of the study. These agents have no activity in the treatment of advanced colorectal carcinoma.

High-dose carboplatin, etoposide and cyclophosphamide with autologous bone marrow transplantation for the treatment of advanced malignancies: a phase I study.

Carboplatin is a platinum-derivative widely used in conditioning regimens with ABMT, particularly in combination with cyclophosphamide and etoposide, drugs which co-express synergism in vitro. The objective of this study was to determine the maximum tolerated dose (MTD) of this combination. Thirty-four patients with refractory lymphoid or solid tumors were treated in a dose-escalation study with continuous infusion carboplatin (1.2-2 g/m2) on days -7 to -4, etoposide (1.2-2.4 g/m2) on days -7 to -5 and cyclophosphamide (120 mg/kg) given in two dose schedules: (1) day -3, -2; (2) day -9, -8. Autologous bone marrow or peripheral blood stem cells were infused on day 0. Mucositis/enterocolitis was dose limiting. In addition, severe cardiac dysfunction occurred in schedule 1 but not in schedule 2. Renal dysfunction occurred in the setting of fungemia, respiratory failure and congestive heart failure, and did not correlate with carboplatin dose. Hepatic and pulmonary dysfunction were minimal. The MTD was etoposide 2.1 g/m2 and carboplatin 2.0 g/m2, in combination with cyclophosphamide (120 mg/kg) on schedule 2. Responses were seen in 16 of 19 patients with measurable disease. Seven patients are disease-free survivors 50-60+ months post-ABMT. This study defines the MTD of carboplatin when combined with etoposide and cyclophosphamide in patients with adequate renal function and suggests significant anti-tumor activity.

Long-term survival after autologous bone marrow transplantation for metastatic breast carcinoma.

A phase II study of doxorubicin (Adriamycin)-based induction chemotherapy followed by cyclophosphamide/BCNU (CyBCNU) intensification and autologous bone marrow transplantation (ABMT) was conducted in 20 consecutive women with hormone-resistant metastatic breast cancer referred to our center. Of these 20 women, aged 24 to 56 (median age, 41), 9 had complete remission and 11 had partial remission after induction chemotherapy. Predominant sites of metastases included liver (5), lung (4), bone/bone marrow (5), and soft tissue (6). The dose of cyclophosphamide was 160 mg/kg and the dose of BCNU, 600 mg/m2, followed by infusion of a mean 2.30 x 10(8) nucleated marrow cells per kilogram of body weight. All patients achieved durable engraftment. Three patients remain disease-free at 62+, 67+, and 73+ months; two of these were in complete remission before ABMT. Actual relapse-free survival at 5 years is 15% and median survival from ABMT is 17 months. Induction chemotherapy followed by CyBCNU intensification in metastatic breast cancer can achieve prolonged relapse-free survival in 15% of patients, some of whom may be cured.

Peritoneal carcinomatosis of unknown primary site in women. A distinctive subset of adenocarcinoma.

STUDY OBJECTIVE: To define the clinical features and results of systemic treatment in women with adenocarcinoma of unknown primary site involving predominantly the peritoneal surfaces. DESIGN: Retrospective analysis of 18 patients treated at a single institution between 1978 and 1984. PATIENTS: All 18 women had abdominal carcinomatosis and had no primary site identified at laparotomy. Nine patients had limited residual tumor (maximal tumor diameter, 3 cm or less) after initial cytoreductive surgery, and 9 patients had extensive residual disease. INTERVENTIONS: In general, patients were treated according to standard guidelines for treatment of advanced ovarian carcinoma. All patients had initial laparotomy with attempted cytoreduction; of these 18 patients, 16 subsequently received cisplatin-based chemotherapy. Patients were restaged either clinically (10 patients) or with second-look surgery (8 patients). RESULTS: The median survival for all patients was 23 months. Five patients had complete response to chemotherapy, and three patients remain disease-free 41, 59, and 77 months after diagnosis. Patients with limited residual disease had longer median survival than did those with extensive residual disease (31 months compared with 11 months). CONCLUSIONS: Women with adenocarcinoma of unknown primary site involving predominantly the peritoneal surface should be distinguished from other patients with adenocarcinoma of unknown primary site because they have a more indolent disease course, a higher response rate to systemic therapy, and a chance for long-term, disease-free survival after therapy. Although optimal treatment is undefined, we recommend that these patients be treated using the guidelines established for therapy of advanced ovarian carcinoma, including initial surgical cytoreduction followed by cisplatin-based combination chemotherapy.

Interactive effects of pertussis toxin and the phorbol ester tumour promotor, phorbol dibutyrate, on T-lymphocyte mitogenesis and the expression of phenotypic determinants.

The B oligomer of pertussis toxin serves as a weak mitogen in the T lymphocyte, an effect which is associated with an early rise in cytosolic free calcium concentrations, as monitored by Fura-2 fluorescence. Upon co-administration of phorbol dibutyrate, a phorbol ester tumour promotor which activates protein kinase C, pertussis toxin-induced proliferation was synergistically enhanced, as measured by the increased uptake of [3H]thymidine, into cellular DNA. Although phorbol ester co-administration has often been associated with an inhibition of Ca2+-mobilizing pathways, phorbol dibutyrate pretreatment had no inhibitory effect on the pertussis toxin-induced calcium flux and may actually have enhanced this response slightly. Flow cytometric analysis of cell populations expanded by the combined regimen did not provide evidence for the preferential expansion of cells bearing either CD4 or CD8, the T-cell determinants representative of the helper-inducer and cytotoxic-suppressor subsets, respectively. Pertussis toxin and phorbol dibutyrate appear, therefore, to elicit polyclonal stimulation, rather than the selective activation of a given lymphocyte subset. Expression of the transferrin receptor, a marker for nutrient uptake, and CD25, the Tac component of the interleukin-2 (IL-2) receptor, was, however, synergistically enhanced in cells activated by the co-treatment procedure.

Human T lymphocyte mitogenesis in response to the B oligomer of pertussis toxin is associated with an early elevation in cytosolic calcium concentrations.

Pertussis toxin was found to serve as a mitogen in the human T lymphocyte, an effect which could be mimicked by its resolved binding component, the B oligomer. The mechanism of action of this component appeared to involve a rapid and sustained elevation of cytosolic calcium levels, as monitored by fura-2 fluorescence. The source of mobilized calcium was predominantly extracellular, suggesting that the binding of the B oligomer to the T cell plasma membrane in some way elicited calcium channel activation. Notably, the influx of calcium was not observed with cholera toxin, an AB toxin lacking mitogenic effects on the human T lymphocyte.

Dual regulation of neutrophil adenylate cyclase by fluoride and its relationship to cellular activation.

1 Fluoride stimulated (1-10 mM) and inhibited (10-100 mM) adenylate cyclase of neutrophil membranes in a GTP-independent manner. The latter fluoride concentration range corresponded to that shown previously to induce cellular responses. 2 Dual regulation of cyclase activity was also exhibited by a nonhydrolysable GTP analogue, guanosine 5'[gamma-thio]triphosphate (GTP gamma S). Inhibition was observed at 0.1-10 nM GTP gamma S while stimulation occurred at greater than 10 nM GTP gamma S. 3 Relatively high levels (greater than microM) of formylmethionyl-leucyl-phenylalanine inhibited adenylate cyclase in the presence of GTP (10 microM). 4 Pertussis toxin pretreatment abolished adenylate cyclase inhibition mediated by GTP gamma S and formylmethionyl-leucyl-phenylalanine but did not influence fluoride-induced inhibition.

Use of fluoride ion as a probe for the guanine nucleotide-binding protein involved in the phosphoinositide-dependent neutrophil transduction pathway.

Fluoride activation of neutrophils was found to be associated with phosphoinositide turnover, as monitored by the time-dependent accumulation of inositol phosphates. Unlike phosphoinositide turnover induced by the chemotactic peptide, formylmethionylleucylphenylalanine, that induced by fluoride was not inhibited by pretreatment with pertussis toxin. The translocation of protein kinase C activity from the cytosolic to the membrane compartment was also observed in fluoride-stimulated cells. We have proposed that the mode of action of this halide ion involves interaction with a GTP-binding protein which serves as an intermediary unit between the receptors for inflammatory stimuli and the phosphoinositide-specific phosphodiesterase.

Effect of the calcium ionophore A23187 on superoxide generation in phorbol ester stimulated human neutrophils.

The calcium ionophore, A23187, and the tumor-promoting phorbol ester, phorbol 12-myristate 13-acetate (PMA), interacted synergistically to elicit an accelerated superoxide production response in human neutrophils. The lag period preceding PMA-induced superoxide generation was decreased in a dose-dependent manner by A23187 at a concentration range from 1.0 X 10(-8) to 1.0 X 10(-5) M. Superoxide production rate, however, was subject to biphasic effects. While the rate was potentiated in a dose-dependent manner at A23187 concentrations below 1.0 X 10(-6) M, inhibitory influences became manifest at higher concentrations. Total superoxide production was subject to inhibitory effects, characterized by a mean inhibitory dose of 1.3 X 10(-6) M. The synergistic interaction of A23187 with PMA is consistent with a role for protein kinase C in neutrophil activation. Inhibition at high A23187 concentrations appeared to result from the effects of elevated intracellular Ca2+ levels on either NADPH oxidase itself, or some step in the transduction process linking protein kinase C to the oxidase complex.

Calcium mobilization in fluoride activated human neutrophils.

Fluoride ion, at concentrations above 10 mM, was found to elicit a rise in intracellular calcium levels in neutrophils, as monitored by changes in Quin 2 fluorescence intensity. The calcium mobilization response was characterized by a lag period of 4 to 10 min. and a prolonged duration of action (greater than 20 min.). In contrast, the chemotactic peptide, formylmethionyl-leucyl-phenylalanine, induced a rise in intracellular calcium concentrations which peaked within 1 min. Preincubation of the cells with 1 microgram/ml pertussis toxin resulted in inhibition of the formylmethionyl-leucyl-phenylalanine induced response, but not that mediated by fluoride. Recent evidence suggests that the formylmethionyl-leucyl-phenylalanine receptor is coupled to phospholipase C and phosphoinositide degradation through a guanine nucleotide binding protein susceptible to inhibition by pertussis toxin. Present results suggest that fluoride ion may serve to activate this protein in a manner resistant to inhibition by pertussis toxin.