Antitumor effect of recombinant human interferon alpha A/D on Meth-A sarcoma in mice

Recombinant human interferon alpha A/D (IFN alpha A/D) is known to be as active on murine cells as on human cells. We studied the antitumor effect of pure IFN alpha A/D on Meth-A sarcoma subcutaneously transplanted into female syngeneic BALB/c mice. When administered systematically (intraperitoneally), IFN alpha A/D was only marginally (but significantly, P less than 0.05) effective in inhibiting tumor growth. With intralesional injection, however, IFN alpha A/D strongly suppressed the growth of Meth-A sarcoma, even leading to complete tumor regression and to subsequent immunity to Meth-A sarcoma cells in the host mice when the treatment was started early after tumor transplantation and with a high IFN alpha A/D dose. We also found that treatment of mice with IFN alpha A/D increased the level of serum alpha 1-acid glycoprotein, one of the acute-phase proteins.     

Potentiation of antitumor activity of macrophages by recombinant interferon alpha A/D contained in gelatin microspheres

Gelatin microspheres containing recombinant human interferon alpha A/D (A/D-IFN) (IFN-microspheres) potentiated the antitumor activity of mouse peritoneal macrophages (M phi) much more efficiently than free A/D-IFN. M phi acquired the inhibitory activity on tumor cell growth by the ingestion of IFN-microspheres without the aid of lipopolysaccharide (LPS), though LPS was required as a second signal for activating M phi primed with free IFN. The IFN-microspheres were much more efficient than free IFN plus LPS in respect of the IFN amount and the time required for M phi activation. Furthermore, M phi pretreated with the IFN-microspheres maintained their activated state for a much longer period than those pretreated with free A/D-IFN plus LPS. A monoclonal anti-IFN-alpha A antibody, which was capable of neutralizing A/D-IFN, did not interfere with the M phi activation by the IFN-microspheres. Even human IFN-alpha A was effective in activating murine M phi similarly to A/D-IFN, when given in the form of IFN-microspheres, though human IFN-alpha A in the free form was ineffective. These results argue that the mechanism of M phi activation by the IFN-microspheres is different from that by free IFN.     

Inhibition of human melanoma growth by prostaglandin A, D, and J analogues

The relative inhibitory potency of prostaglandin A (PGA) and prostaglandin J2 (PGJ2) analogues compared to prostaglandin A1 (PGA1) was determined in a clonogenic assay system. Three human melanoma cell strains (C8146A, C8146C, and C8161), a human melanoma cell line (M1RW5) and a human neuroblastoma cell line (IMR-32) were used. Prostaglandin analogues were screened in the clonogenic assay system and the dose effect curves were analyzed by linear regression utilizing the median effect relationship. The computer-generated 50% and 95% inhibitory doses showed that 15-deoxy-16-hydroxyl-16-vinyl-prostaglandin A2 (DHV-PGA2) was from two- to three-fold more active than PGA1 in inhibiting the clonogenic growth of human melanoma cells. Based on the 50% inhibitory dose, PGJ2 and its analogues were from two to five times more potent than PGA1. The delta 12- and delta 12,14-PGJ2 were the most potent of the prostaglandins tested. However, the 95% inhibitory dose for prostaglandin D2 (PGD2), PGJ2 and its analogues against neuroblastoma did not show any enhancement in activity in comparison to PGA1, suggesting that some tumor specificity in the activity of these analogues may be signified by the neuroblastoma data. Prostaglandins which contained a fluoride substitution at position 11 were also tested for activity. As we previously observed with other analogues which did not contain an alpha, beta-unsaturated carbonyl group in the cyclopentane ring, 9 beta, 15 alpha-dihydroxy-11 beta-fluoroprosta-5-cis-13-trans-dienoic acid and 9 alpha, 15 alpha-dihydroxy-11 beta-fluoroprosta-5-cis-13-trans-dienoic acid did not inhibit the clonogenic growth of human melanoma cells. Administration s.c. to established human melanoma tumors growing in athymic nude mice caused a significant growth inhibition. The treatment schedules ranged from 1 to 8 days. Injection s.c. of PGA1 at a dose of 40 mg/kg/day resulted in a 20% suppression in tumor growth. Higher doses (100 and 200 mg/kg/day) effected an 80% reduction in tumor growth. The higher doses were associated with reversible toxicities, diarrhea and skin inflammation. Administration of DHV-PGA2 at a dose of 20 mg/kg/day resulted in 40% reduction in tumor growth. The increased in vivo potency of DHV-PGA2 corresponds to the results obtained in the clonogenic assay system.     

In vivo effects of recombinant interferon alpha A/D incorporated in gelatin microspheres on murine tumor cell growth

Intraperitoneal (ip) injections of gelatin microspheres containing a very small amount of recombinant human interferon alpha A/D (A/D-IFN) (IFN-microspheres) plus free A/D-IFN improved the survival of mice bearing ascitic Meth A-R1 cells which we had isolated as IFN-resistant cells under in vitro conditions. The dose of free A/D-IFN in one injection was 10,000 IU, which was insufficient by itself for manifesting in vivo antitumor activity. In these mice, in vivo R1 cell growth was suppressed and macrophage recruitment was enhanced in comparison with mice receiving other control agents. Administration of IFN-microspheres alone was also effective but less than that of IFN-microspheres plus free A/D-IFN. Peritoneal macrophages obtained from normal or R1-bearing mice receiving ip injection of IFN-microspheres with or without free A/D-IFN were activated to inhibit the in vitro growth of R1 cells. The intratumoral injection of IFN-microspheres strongly inhibited the growth of solid R1 tumors. Intravenous injection of IFN-microspheres was effective in preventing the pulmonary metastasis of B16 melanoma cells. These results indicate that the IFN-microsphere is much more effective against tumors than free A/D-IFN.     

Eradication of mouse melanoma by combined treatment with recombinant human interleukin 2 and recombinant murine interferon-gamma

Successful immunotherapy of early s.c. or i.p. (B16) melanoma in syngeneic C57BL/6 (B6) mice was achieved with s.c. peri-lesional injections (for s.c. tumors) or i.p. injections (for i.p. tumors) of recombinant human interleukin 2 (rIL-2) and recombinant murine interferon-gamma (rIFN-gamma). Over a 28-day period, rIL-2 and rIFN-gamma were injected 14 times. Results with this combination were additive with s.c. tumors and synergistic with i.p. tumors. Treatment with 6,250 U-25,000 U of rIL-2 and 2 micrograms of rIFN-gamma began 1-3 days after s.c. inoculation of melanoma. On day 50, 87% (72/83) of mice thus treated were completely free of tumor. None of the 78 control mice (tumor + buffer) survived. Of mice receiving either rIL-2 or rIFN-gamma alone, 59% (47/79) and 53% (44/83), respectively, were tumor-free. I.p. tumors were also eradicated by i.p. injections of rIL-2 (50,000 U) with rIFN-gamma (5, 10, and 15 micrograms) as judged by absence of tumor in 81% (21/26) of mice autopsied between days 45 and 65. No control mice survived, and only 17% (2/12) and 20% (6/30) given either rIL-2 or rIFN-gamma separately (i.p.) were tumor-free. Doses of rIFN-gamma from 1-4 micrograms were more beneficial in eliminating 1-day s.c. melanomas than were higher doses, and local s.c. treatment was far superior to distant or systemic treatment. Non-adherent peritoneal or splenic cells from mice bearing 6-day-old i.p. melanomas and treated with one or both lymphokines on days 3 and 4 were used in cytotoxicity assays in vitro. Significant cytotoxicity against cultured melanoma cells was displayed by cells harvested from lymphokine-treated mice, but there was no evidence of the synergism observed with combination treatment of i.p. tumors in vivo. rIFN-gamma inhibited proliferation of melanoma cells in vitro, whereas rIL-2 stimulated proliferation at 1,000 U/ml. Plating efficiency was increased by at least 30% by culture with 100 U or 1,000 U of rIL-2/ml and both concentrations neutralized the inhibitory effect of 0.05 ng/ml of IFN-gamma, but not of 0.5 or 5.0 ng/ml.     

Phase II trial of recombinant human interferon alpha in myelodysplastic syndromes.

Twenty patients with myelodysplastic syndromes were treated with daily subcutaneous injections of interferon alpha 2a, at the initial dose of 3 x 10(6) U/m2. Hemogram, chemistry profile, natural killer (NK) cell activity and lymphokine-activated killer (LAK) cell cytotoxicity were monitored serially. Bone marrow with cytogenetic analysis was done before therapy and every three months afterwards. Normalization to the complete blood count, and wherever applicable, decrease in blast count of 5% or less were defined as a complete response. Improvement in hemoglobin level to 12 g/dl, neutrophil count to 1000/mm3 and platelets to 100,000/mm3 was considered a partial response. The median age was 71 (range 59-83) years and 16 of the patients were males. Two patients withdrew from the treatment in the first week and were considered ineligible. Among the other 18, two had refractory anemia, two refractory anemia with ringed sideroblasts, four chronic myelomonocytic leukemia, eight refractory anemia with excess blasts, and two refractory anemia with excess blasts in transformation to acute leukemia. Twelve patients were treated for six months, the other six were taken off the treatment after six to eight weeks because of disease progression. Only one patient with chronic myelomonocytic leukemia had a partial response for two months. NK cell activity remained unchanged before (18.3 +/- 4.6 lytic units) and during interferon therapy (19.6 +/- 5.3 lytic units). LAK cytotoxicity was not detected in any patient before therapy and was seen in only one patient (not the responder) during therapy (5.7 lytic units). The toxicity of the interferon therapy was substantial. Seventeen patients required a dose reduction and fifteen lost greater than 10% of body weight. Eleven patients (61%) developed infections requiring antibiotic therapy, and eight (44%) required hospitalization. Seven patients developed neurologic toxicity. Interferon alpha 2a is an ineffective but toxic therapy in these elderly patients with myelodysplastic syndromes.     

Clinical phase II trial of recombinant DNA interferon (interferon alpha 2b) in patients with metastatic malignant melanoma

Twenty-four patients with histologically proven metastatic malignant melanoma were included in a Phase II trial of human DNA recombinant interferon (rDNA IFN alpha 2). They were given 10 X 10(6) IU of IFN alpha 2 subcutaneously three times a week until progression of disease or major intolerance developed. Twenty-two patients were evaluable for toxicity and response. General manifestations of intolerance were seen in all the patients. Hematologic toxicity was seen in six patients and therapy had to be interrupted in one patient. Mild liver toxicity was seen in most patients after 2 weeks of treatment. These manifestations disappeared within 2 weeks after treatment was discontinued. A partial response was seen in four cases lasting 2, 4, 4, and 5 months, respectively. There were two complete responses (one skin, one lymph node metastasis) lasting 20 and 6 weeks, respectively. These results indicate a potential role for rDNA IFN alpha 2 in treating patients with metastatic malignant melanoma. However, further trials are required to determine the optimal dose and schedule of administration and modalities of combination.     

干扰素-α联合化疗治疗恶性黑色素瘤临床疗效观察

目的:观察干扰素-α联合化疗治疗恶性黑色素瘤的临床疗效及不良反应.方法:对25例晚期恶性黑色素瘤患者采用干扰素联合氮烯咪胺(DTIC)为主的DDAVC方案化疗(治疗组),25例晚期恶性黑色素瘤患者采用DDVAC方案化疗(对照组),比较两组的近期疗效、不良反应、免疫水平以及生存时间.结果:治疗组有效率为64%,对照组为36%,治疗组显著优于对照组(P<0.05).经干扰素-α免疫治疗的患者化疗一周后免疫水平继续提高,而单纯化疗的患者一周后明显下降,两者之间对比有显著差异(P<0.05).治疗组化疗不良反应低于对照组.两组的生存时间差异有统计学意义(P<0.05).结论:干扰素-α联合氮烯咪胺(DTIC)为主的DDAVC方案化疗可取得较满意的疗效.     

A phase I-II trial of the combination of recombinant leukocyte A interferon and recombinant human interferon-gamma in patients with metastatic malignant melanoma

Twenty patients with advanced malignant melanoma received daily intramuscular recombinant leukocyte A interferon (rIFN-alpha A, Roferon-A, Hoffmann-Laroche, Nutley, NJ) concomitant with recombinant human interferon-gamma (rIFN-gamma Genentech, South San Francisco, CA). During the first week alpha dose was 2 X 10(6) U/m2 and the gamma dose was 0.01 mg/m2 with escalations, if clinically tolerable, during the second week to 5 X 10(6) U/m2 and 0.025 mg/m2, respectively. Twelve patients received the escalated doses; subsequent granulocytopenia and a flu-type illness were severe in four of the 12. We observed one partial response of MRI-documented and biopsy-confirmed osseous metastases for 7+ months. For all study participants, the median time to progression was 1 month with a median survival of 6 months. From the dose and schedule which we utilized, concurrent rIFN-alpha A and rIFN-gamma provided little impact on advanced malignant melanoma.     

Inhibition of growth of B16 murine malignant melanoma by exogenous interferon

We previously reported that polyinosinic-polycytidylic acid, a potent interferon inducer, inhibits the growth of B16 malignant melanoma in the C57BL/6 mouse. Two experiments were done to evaluate the effectiveness of interferon in tumor inhibition in vivo. In the first, mice were implanted with melanoma and divided into four groups, according to treatment: interferon preparation; interferon control preparation ("breakthrough fraction"); phosphate-buffered saline control; and murine serum albumin control. Daily, each mouse was given i.p. injections of 200,000 NIH reference units (hereafter called units) of interferon or of one of the control substances. The second experiment was similar to the first, except that bovine serum albumin was an additional control. In both experiments, the average tumor volume in interferon-treated mice was statistically significantly smaller than that of each control group. Mouse interferon preparations also inhibited the multiplication of B16 malignant melanoma cells in culture. This inhibition was statistically significant from interferon levels as low as 5 to as high as 5000 units/ml. The degree of inhibition markedly increased from 5 up to 500 units, the inhibition reaching its maximum at this concentration. The inhibitory effect of interferon was abrogated by anti-murine interferon serum produced in a rabbit. These findings suggest that the in vivo inhibition of the growth of B16 melanoma demonstrated with polyinosinicpolycytidylic acid and with exogenous interferon probably results, at least in part, from a direct effect of interferon on the tumor cells themselves.     

Inhibition of mouse alpha/beta-interferon of the multiplication of alpha/beta-interferon-resistant Friend erythroleukemia cells cocultured with mouse hepatocytes

Administration of alpha/beta-interferon (IFN) exerts a marked antitumor effect in DBA/2 mice given injections i.v. of large numbers of IFN-alpha/beta-resistant erythroleukemia cells (FLC). To investigate the possible mechanisms of FLC tumor inhibition in the liver of interferon-treated mice, we developed an in vitro model consisting of a coculture of IFN-alpha/beta-resistant 3Cl8 FLC and syngeneic mouse hepatocytes. Whereas IFN-alpha/beta did not inhibit the multiplication of 3Cl8 FLC cultivated alone, it effectively inhibited the multiplication of 3Cl8 FLC in coculture with hepatocytes. The inhibitory effect was directly proportional to the amount of IFN-alpha/beta added to the cocultures, and more than 90% inhibition of FLC multiplication was noted with 1.6 x 10(5) IU/ml of IFN-alpha/beta on Day 3 of coculture. When FLC were separated from the monolayer of hepatocytes by a pored membrane (0.4 microns), the inhibitory effect on FLC proliferation was unchanged, indicating that a soluble factor(s) released from IFN-treated hepatocytes was most important in the inhibition of FLC multiplication. An inhibitory activity of FLC multiplication was detected only in the conditioned medium of IFN-treated hepatocytes but not in the conditioned medium of control hepatocytes nor in extracts of IFN-treated or control hepatocytes. The inhibitory factor(s) in the conditioned medium of IFN-treated hepatocytes was retained by an ultrafiltration membrane (Mr cut off 10,000), and its activity was completely abrogated by trypsin digestion. Its stability to treatment with 1 M acetic acid as well as lack of correlation between the antiproliferative effect and the amount of L-arginine in the medium distinguished this factor(s) from liver arginase which was also found to be a potent inhibitor of FLC multiplication in vitro. The inhibitory factor(s) was also distinguishable in its biological activity from IFN gamma, interleukin 1 alpha and beta, and transforming growth factor beta 1 and beta 2. These results suggest the possibility that the inhibitory effect of IFN-alpha/beta on the development of 3Cl8 FLC in the livers of IFN-treated mice may be mediated by an IFN-induced inhibitor of FLC multiplication.     

Active immunotherapy of metastatic melanoma with allogeneic melanoma lysates and interferon alpha.

PURPOSE: A therapeutic lyophilized melanoma vaccine consisting of two mechanically disrupted allogeneic melanoma cell lines and the immunological adjuvant Detox-PC (Melacine) has demonstrated encouraging activity in metastatic malignant melanoma, often in regimens containing pretreatment with low-dose cyclophosphamide. In addition, IFN-alpha2b (INTRON A; Schering-Plough Corporation, Kenilworth, NJ) has shown efficacy in melanoma refractory to Melacine. In this Phase II trial, the combination of cyclophosphamide, Melacine, and IFNalpha was tested in metastatic malignant melanoma. EXPERIMENTAL DESIGN: Eligibility criteria included measurable disease, no prior systemic therapy for a minimum of 4 weeks, and adequate marrow, renal, and hepatic function. Cyclophosphamide was administered once at a dose of 300 mg/m(2) i.v. on day -3 before the first dose of Melacine. Melacine was administered at a dose of 2 x 10(7) tumor cell equivalents per dose admixed with 0.25 ml of Detox-PC s.c. once a week on weeks 1-4 and week 6. Melacine maintenance was then given monthly from the 8th week, until progression or intolerable toxicity. IFN was started in the evening after the fourth dose of Melacine at a dose of 5,000,000 units/m(2) 3 times a week, and continued until progression. RESULTS: Forty-seven patients were enrolled, of whom 39 completed the full course and were considered evaluable. The toxicity of the regimen was minimal and consisted mainly of pain at injection sites and granulomas caused by Detox-PC, and constitutional symptoms attributable to IFN. In 39 evaluable patients, the overall objective response rate was 10.2%, but 64% of patients had stabilization of their disease for at least 16 weeks. The median time to disease progression in evaluable patients was 8 months [95% confidence interval (CI), 6-13 months]. Median survival time for all of the 47 patients enrolled was 12.5 months (95% CI, 8-15 months) with a median time to disease progression of 4 months (95% CI, 3-7 months). CONCLUSION: Despite a low objective response rate, this combination holds great promise because of its tolerability and the high proportion of prolonged durations of remission or disease stabilization that it elicited.     

Recombinant interferon alpha and gamma modulate the invasive potential of human melanoma in vitro.

We have studied the effects of interferons (IFNs) on the attachment, collagenase IV activity, chemotactic migration and in vitro invasion of human melanoma (A2058) cells treated for various time periods with human recombinant interferon alpha (hrIFN-alpha) or gamma (hrIFN-gamma). The cells treated with hrIFN alpha for a short time period attached more readily to purified basement membrane components, type IV collagen and laminin, than control cells. The stimulating effect of hrIFN gamma on the attachment was seen, however, when the cells were treated for a longer period of time (3 days) with this drug. The short-term treatment with hrIFN alpha also enhanced the in vitro invasion of cells through a reconstituted basement membrane compared to findings with untreated control cells. Pre-treatment of 3 days or more was, however, needed for hrIFN gamma to promote the invasion of A2058 cells. Both IFNs increased the secretion of basement membrane (type IV) collagen degrading metalloproteinase (collagenase IV) activity from human melanoma cells. Further, chemotaxis, i.e., directed migration of A2058 cells to laminin, was enhanced by both IFNs. In contrast, the attachment, collagenase IV activity, chemotaxis, and in vitro invasion were markedly inhibited when the cells were treated for an extended time period (7 days) with the IFNs. Interferons also inhibited cell proliferation after 4 days of exposure. These results suggest that time of treatment with interferons modulates the invasive capacity of human melanoma cells in vitro, causing initially a transient enhancement of invasion followed by an inhibition of invasive propensity after extended exposure to these drugs, and that different biochemical steps required for successful invasion are regulated in parallel by interferons alpha and gamma.     

Combined recombinant human interferon alpha 2 and cytotoxic agents studied in a clonogenic assay

A human tumor clonogenic assay has been used to test the antiproliferative effect of recombinant human leukocyte interferon alpha 2 alone and in combination with each of 8 cytotoxic agents. Cell lines derived from 6 human tumors and primary tumor cells from 13 patients have been used in these clonogenic assay studies. Results show that interferon as a single agent causes insignificant reduction in tumor cell colony survival if the short-term 1-hr cell exposure method is used; only high concentrations of interferon used in continuous cell exposure in the clonogenic assay can demonstrate a reduction in colony survival to below 50% of control values. Combinations of interferon with either doxorubicin or cisplatin frequently show additive and occasionally synergistic antiproliferative effects on tumor cell colony formation. Variations in drug concentrations and sequencing of drugs have been tested, showing that optimal antiproliferative effects of combined interferon and doxorubicin are realized when maximal concentrations of interferon and prolonged cell exposure time of both interferon and doxorubicin are employed. Combinations of interferon and doxorubicin tested in the clonogenic assay demonstrate cytotoxicity superior to that of either agent tested alone.     

Inhibition of experimentally-induced murine metastases by recombinant alpha interferon: correlation between the modulatory effect of interferon treatment on natural killer cell activity and inhibition of metastases

The effect of a human recombinant hybrid alpha interferon (referred to as rHuIFN-alphaA/D) on pulmonary metastases induced by intravenous injection of B16 F10 melanoma cells in C57BL/6 mice was examined; rHuIFN-alphaA/D has been previously shown to have anti-viral, anti-proliferative and immunomodulatory activities in murine cells. Pretreatment of mice with 4 daily intraperitoneal injections of rHuIFN-alphaA/D resulted in a marked decrease in the number of pulmonary metastases. This inhibition was dose-dependent but was not seen when mice were similarly treated with rHuIFN-alphaA, a human recombinant alpha interferon subtype which is inactive on murine cells. Treatment of mice with rHuIFN-alphaA/D following B16 F10 injection resulted in no significant inhibition of pulmonary metastases. Mice given a similar treatment regimen of rHuIFN-alphaA/D had elevated natural killer (NK) cell activity as measured by in vitro cytotoxicity against YAC-I or in vivo pulmonary clearance of B16 F10 cells. Pretreatment of mice with 10 daily injections of rHuIFN-alphaA/D resulted in decreased NK activity and less inhibition of metastases. Therefore, in this model system, rHuIFN-alphaA/D inhibits metastases when given in the appropriate treatment schedule. Furthermore, the data are consistent with the hypothesis that rHuIFN-alphaA/D-induced inhibition is a consequence of the immunomodulation of NK cells, which prevent the establishment of pulmonary metastases.     

Treatment of plasma cell neoplasm with recombinant leukocyte A interferon and human lymphoblastoid interferon

Summary Thisty cases of plasma cell neoplasms (24 multiple myeloma, one plasma cell leukemia, and three primary macroglobulinemia) were treated with two kinds of highly purified -interferons, recombinant human leukocyte interferon (rIFN-A) (16 cases) and human lymphoblastoid interferon (HLBI) (14 cases). Partial remission (PR) was obtained in two of 16 evaluable cases treated with rIFN-A and in two of 12 evaluable cases treated with HLBI. If minor response (MR) was included, responses were observed in seven (31.3%) and six (50%), respectively. Response (PR+MR) was noted in 38% of 21 previously treated patients and 71% of seven previously untreated patients. Side-effects were noted in more than two-thirds of the patients. They included fever, malaise, nausea/anorexia and myelosuppression. Thus, these two kinds of highly purified -interferon were effective in plama cell neoplasm, producing unequivocal response in 14.3% of the cases without unacceptable side-effects.