Sialic acids on the plasma membrane of cultured human lymphoid cells. Chemical aspects and biosynthesis.

From 61 to 92% of the total sialic acid of a variety of human lymphoid cell lines maintained in tissue culture is present on the cell surface as measured by its susceptibility to cleavage by Clostridium perfringens neuraminidase. These cells contain from 1.22 x 10(8) to 6.99 x 10(8) molecules of surface sialic acid per cell. In synchronized cultures synthesis of surface sialic acid occurs only during a limited time in the late G(2) phase of the cell cycle. The amount and density of surface sialic acid vary considerably throughout the cell cycle.

Effect of dimethylmyleran on cell-mediated immunity to a tumor allograft.

C57BL/6 mice (H-2b) were inoculated on day 0 with killed Moloney lymphoma cells (LSTRA) of BALB/c origin (H-2d), and their spleen cells were tested for reactivity against LSTRA by the 51Cr-release cytotoxicity assay. Cytotoxic reactivity of cells from ice not treated with drug was maximal by day 6 and disappeared by day 10. Cells from mice given dimethylmyleran (DDM) (12 or 16 mg/kg) on day -1 showed higher levels of cytotoxicity, whereas DMM administered on day +1 had little effect. The effect of DMM on the secondary response was tested and compared with that of cyclophosphamide (CY), 180 mg/kg. Cytotoxicity of cells from mice immunized on days 0 and 10 was maximal on day 15 and then declined. CY administered on day 11 prevented the development of any cytotoxicity and, when given on day 14 in the presence of a detectably strong secondary cytotoxic response, abolished the established response. In contrast, DMM given on day 11 delayed the onset and moderately decreased the peaks of secondary reactivity but had no effect when administered on day 14. These results showed that DMM enhanced a primary response, interfered somewhat with the development of a secondary response, and had no effect on an established secondary cell-mediated response to a tumor allograft. DMM thus was one of the rare agents with antitumor activity and little immunosuppressive action.

Use of dimethylmyleran in adoptive chemoimmunotherapy of two murine leukemias.

Dimethylmyleran (DMM) is an antitumor agent that has minimal effects on immunity. In a study of its usefulness in adoptive chemoimmunotherapy, C57BL/6 mice inoculated on day 0 with C57BL/6 Friend virus-induced leukemia (FBL-3) were treated on day 5 with 12 mg DMM/kg [less than LD10 (lethal dose for 10% of mice)] plus C5BL/6 spleen cells. All untreated mice died, with a median survival time (MST) of 17 days. DMM alone or with nonimmune cells prolonged survival to day 20, and 3/53 mice survived beyond day 60. By contrast, 12/25 mice treated with DMM plus cells immune to FBL-3 were cured. Similar results were obtained in C57BL/6 mice with syngeneic Rauscher virus-induced leukemia (RBL-5). Untreated mice died, with an MST of 14 days. DMM alone or with nonimmune cells prolonged the MST to 21 and 26 days, respectively, and 3/26 and 6/28 mice were long-term survivors. However, 13/28 mice were cured by DMM plus cells immune to antigenically related FBL-3. Lethal irradiation of cells immune to FBL-3 abolished their efficacy. Finally, in contrast to the efficacy of sublethal DMM plus immune cells, an LD100 of DMM (20 mg/kg) plus hematopoietic reconstitution with nonimmune syngeneic cells was not effective against FBL-3 OR RBL-5. The results emphasized the critical role of immune cells in chemoimmunotherapy even when the drug used is nonimmunosuppressive.

Suppression of secondary cellular immunity to a tumor allograft by cyclophosphamide and 1,3-bis(2-chloroethyl)-1-nitrosourea.

C57BL/6 mice (H-2b) were immunized with lethally x-irradiated Moloney virus-induced lymphoma cells of BALB/c origin (H-2d) on Days 0 and 10 and received rug on Days 11 and 14. Their spleen cells were then tested for reactivity against Moloney virus-induced lymphoma of BALB/c origin by the 51Cr-release cytotoxicity assay. In non-drug-treated mice the secondary cytotoxic response was maximal on Days 14 to 15, declined rapidley, and recurred after Day 21. The cytotoxic effector cells were shown to be theta-bearing T-lymphocytes. Cyclophosphamide (CY), 180 mg/kg, given on Day 11, totally prevented the development of a cytotoxic response and when given on Day 14 abolished the response already established. CY, 48 mg/kg, as well as 1,3-bis(2-chloroethyl)-1-nitrosourea 33 mg/kg, were almost as suppressive. Immune mice given CY on Day 14 and reimmunized on Day 36 exhibited a normal tertiary response. Mice similarly immunized on Days 1 and 10 and given drugs on Day 14 were challenged on Day 15 with up to 3.5 x 10-8 viable Moloney virus-induced lymphoma cells of BALB/c origin. Despite H-2 incompatibility, all nonimmune control mice developed ascites and died, whereas all mice immunized but not given drug failed to develop ascites. By contrast, 17 of 34 immunized mice given CY, 180 mg/kg, and 7 of 34 given 1,3-bis(2-chloroethyl)-1-nitrosourea developed ascites. The ascites eventually regressed. THE RESULTS SHOW THAT CY and 1,3-bis(2-chloroethyl)-1-nitrosourea can suppress a secondary cellular immune response as measured by the T-cell-mediated 51Cr-release cytotoxicity assay in vitro and by viable tumor challenge in vivo.

Phase II trial of chlorozotocin and fluorouracil in islet cell carcinoma: a Southwest Oncology Group study.

PURPOSE: A phase II trial that used fluorouracil (5-FU) and chlorozotocin (CTZ) was performed in patients with metastatic islet cell carcinoma to determine the response rate and toxicity. PATIENTS AND METHODS: Patients received four cycles of induction chemotherapy. Good-risk patients received 5-FU 800 mg/m2/d days 1 to 4 as a continuous intravenous (IV) infusion (CIV) and CTZ 175 mg/m2 IV on day 1. Poor-risk patients (previous radiation to > or = 25% bone marrow-bearing areas; serum bilirubin > or = 5 mg/dL; creatinine > 1.0 mg/dL) received 5-FU 600 mg/m2/d and CTZ 75 mg/m2 in a similar manner. In responding or stable patients, reduced doses of 5-FU and CTZ were continued as maintenance therapy (maximum, 18 months). RESULTS: Forty-seven of 51 patients were eligible, and 44 received chemotherapy. Fourteen of 44 patients had partial responses, with 13 of 36 (36%; 95% confidence interval [CI], 21.0% to 54.0%) good-risk patients and one of eight (12%; 95% CI, 0.3 to 52.6%) poor-risk patients responding. Median survival of all patients was 25 months, and the median response duration was 11 months. Side effects were moderate to severe and included myelosuppression and gastrointestinal toxicity. Thirteen patients developed renal toxicity, which was severe or life-threatening in five. This seemed to be related to the administration of cumulative doses of CTZ > or = 1,500 mg. CONCLUSION: These results demonstrate that the combination of 5-FU and CTZ has activity in islet cell carcinoma, but the occurrence of renal toxicity secondary to CTZ may limit the use of this agent.

Induction of increased graft-versus-host disease by mouse spleen cells sensitized in vitro to allogeneic tumor.

The aim of our study was to sensitize cells in vitro, follow their proliferative and cytotoxic responses, and determine their ability to cause lethal graft-versus-host disease (GVHD). C57BL/6 (H2b) spleen cells were incubated with irradiated BALB/C (H2d) Moloney lymphoma cells (LSTRA) in mixed leukocyte culture conditions for 2, 4, or 6 days and then tested. The maximal proliferative response occurred after 4 days. In vitro cytotoxic reactivity against 51Cr-labeled LSTRA was generated by 4 days (76.3+/-3.1% 51Cr released) and 6 days (133.0+/-4.8%) of sensitization but not by 2 days (-0.2+/-1.1%). Induction of fatal GVHD was assayed by injecting graded doses of the C57BL/6 spleen cells i.v. into adult BALB/c mice pretreated with cyclophosphamide, 180 mg/kg. Cells sensitized for 2 days were effective but no more so than were (control) cells cultured with irradiated C57BL/6 spleen cells. However, cells sensitized longer were far more active than the control cells. Cells sensitized for 4 days killed 70 of 88 mice (80%), and those sensitized for 6 days killed 37 of 48 mice (77%), whereas control cells killed only 42 of 90 mice (47%) (P less than 0.005). Thus, cells sensitized in vitro exhibited an increased ability to induce GVHD in vivo, which was temporally associated with the development of cytotoxicity in vitro.

Reduction of fatal graft-versus-host disease by 3H-thymidine suicide of donor cells cultured with host cells.

The effect of the tritiated thymidine (3H-TdR) suicide technique on the ability of donor cells to induce fatal graft-versus-host disease (GVHD) was studied. C57BL/6 (H-2b) spleen cells were stimulated in vitro with irradiated BALB/c (H-2d) Moloney lymphoma cells in mixed culture and 3H-TdR of high-specific activity added to eliminate proliferating cells. The ability of such cells to induce fatal GVHD was assayed by injecting them i.v. into adult BALB/c mice immunosuppressed with cyclophosphamide (180 mg/kg). These cells induced fatal GVHD in fewer mice (52 per cent) than did C57BL/6 cells cultures with BALB/C lymphoma cells but without 3H-TdR (87%) and C57BL/L cells cultured with irradiated C57BL/6 cells with (95 per cent) or without 3H-TdR (86 per cent). Thus, the 3H-TdR suicide technique greatly diminished the ability of cells to induce lethal GVHD.

Combination transurethral resection, systemic chemotherapy, and pelvic radiotherapy for invasive (T2-T4) bladder cancer unsuitable for cystectomy: a phase I/II Southwestern Oncology Group study.

OBJECTIVES: Primarily to evaluate the toxicity and, secondarily, the tumor response and patient survival associated with a three-phase combined modality treatment plan for patients with invasive transitional cell carcinoma (TCC) of the bladder (T2-T4,NX-N2, MO) who are medically unsuitable for or who refuse cystectomy. METHODS: Eligible patients initially underwent extensive transurethral resection (TUR) of the primary tumor with the attempt to resect disease totally. Subsequently, they received systemic combination chemotherapy consisting of two cycles of methotrexate, cisplatin, and vinblastine (MCV), followed by cystoscopic re-evaluation of the bladder tumor. Patients then received 6480 cGy radiotherapy to the bladder with concurrent systemic cisplatin. Toxicity, primary tumor response, and overall survival were evaluated. RESULTS: Of 34 eligible patients, 27 patients completed the treatment series. Twenty-two received 80% to 100% of the prescribed doses of MCV and only 2 patients experienced grade 4 hematologic toxicities. The most common toxicities were gastrointestinal (23), hematologic (21), and renal (8). The complete response (CR) rate after all treatment phases was 56% (19 of 34), 10 patients achieving a complete tumor resection of visible tumor at the initial TUR of the bladder (TURB); 3, a CR after MCV; and 6, after radiotherapy and concomitant cisplatin. The median overall survival was 21 months with 6 of 34 (18%) alive at 57 months (range, 36 to 75). Complete resection of tumor by TURB was associated with prolonged overall survival. The bladder was the initial site of recurrence in 85% of patients who had achieved a CR status. CONCLUSIONS: This older age patient group tolerated this combined modality therapy with acceptable toxicities, but the overall survival rate was not improved compared with those reported with radiotherapy alone.

Phase II trial of CHIP for the treatment of advanced, hormonally refractory carcinoma of the prostate. A Southwest Oncology Group Study.

CHIP, a second generation analogue of cisplatin, was subjected to a Phase II trial for the treatment of advanced, hormonally refractory carcinoma of the prostate. Forty-six patients were treated with CHIP 300 mg/m2 intravenously every 4 weeks. Evaluations for tumor response were done after three cycles of therapy. Among 40 evaluable patients there were no complete responses, but there were 6 partial responses for an overall response rate of 15% (95% confidence interval of 5.7 to 29.8%). The median time to response was 2.4 months and the median progression-free survival was 4.1 months. Median survival was 8.4 months. The most common toxicities were hematologic and gastrointestinal. While CHIP can be administered on an outpatient basis, its response rate for prostatic carcinoma appears to be similar to that of cisplatin.

Continuous-infusion 5-fluorouracil and cisplatin for advanced/recurrent transitional cell cancer of the bladder: a Southwest Oncology Group trial.

Significant toxicities result from the use of MVAC (methotrexate, vinblastine, adriamycin, cisplatin) for advanced/ recurrent transitional cell carcinoma of the bladder (ARTCCB). An alternative regimen of 5-fluorouracil (5-FU) and cisplatin was evaluated by Southwest Oncology Group (SWOG). Thirty-eight patients with ARTCCB were treated with continuous infusion 5-FU 1,000 mg/m2/days 1-5 and cisplatin 100 mg/day 1, on a every-21-days schedule. There were two complete responses (CR) and eight partial responses (PR) among 36 eligible patients, for an overall response rate of 28% [95% confidence interval (CI) 14-45%]. Median duration of response was 6 months, and median duration of survival was 9 months. No toxic deaths occurred. Grade 4 leukopenia occurred in 5 patients. Other toxicities were mild. Only two documented infections occurred in 5 patients with neutropenia. The response rate of 28% is better than that achieved with cisplatin alone and not dissimilar to the range of response for MVAC. Toxicities were less and tolerable. This regimen will need further evaluation.

Hormonal therapy for locally advanced prostate cancer.

A patient with locally advanced prostate cancer (stages C and D1) has a poor prognosis with a high risk of developing and dying of distant metastases. Hormonal therapy is the major form of systemic therapy for metastatic (stage D2) prostate cancer. The most commonly used forms of hormonal therapy are orchiectomy, diethylstilbestrol, and luteinizing hormone releasing hormone, agonists that prevent the stimulation of tumor cells by testosterone. They produce a 60%-80% symptomatic or objective response rate, but their ability to prolong overall survival remains uncertain. Surgical adrenalectomy, hypophysectomy, and pharmacologic adrenal suppression prevent the clinically less significant adrenal androgen stimulation of tumor cells. Antiandrogens competitively inhibit the interaction between androgens and cytosolic androgen receptors. Complete androgen blockade (luteinizing hormone releasing hormone agonist and antiandrogen) was initially espoused to be superior to single-agent hormonal therapy, but preliminary results from a multigroup randomized trial suggest that it has only a minimal advantage. The benefit of hormonal therapy in stages C and D1 prostate cancer at the time of diagnosis has not been clearly established. Available studies are few, and most often they are uncontrolled or include only small numbers of patients. However, they suggest that the early use of hormonal therapy prolongs disease-free survival but does not prevent ultimate disease progression or prolong overall survival. Hormone receptor assays may be helpful in the selection of patients who would benefit from early hormonal therapy.

Cisplatin bolus and 5-FU infusion chemotherapy for non-small cell lung cancer.

Patients with unresectable non-small cell lung cancer were treated with combination chemotherapy: cisplatin (100 mg/m2) on Day 1 and 5-FU (1 g/m2 continuous infusion) on Days 1-5, initially every third week, then every 4-6 weeks. Group 1 consisted of 19 patients without prior therapy and Group 2 consisted of 15 patients with prior therapy. Using standard criteria, seven patients (37%) in Group 1 achieved partial remissions lasting 2 to greater than 31 months (median, 10). Patients with squamous cell carcinoma or good performance status were somewhat more likely to respond. Three patients (20%) in Group 2 achieved partial remissions lasting 5-7 months. Mucositis (grade II in six patients, grade III-IV in seven patients) was the dose-limiting toxicity, especially in Group 2. These responses to cisplatin bolus and 5-FU infusion in patients with non-small cell lung cancer were not greater than those achieved with other cisplatin-containing regimens. However, this combination does have activity and might be effectively combined with radiation therapy as has been done for carcinomas of other sites.