Effects of interferons in neoplastic diseases of man

Phase I study combining tumor necrosis factor with interferon-alpha and interleukin-2

We evaluated the effects of the addition of escalating doses of tumor necrosis factor (TNF) to two fixed doses and schedules of a combination of interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) to determine the maximum tolerated dose of this three-cytokine combination and its feasibility as an outpatient regimen. Eighteen patients with metastatic cancer were enrolled. Each course consisted of 3 consecutive weeks of treatment with IFN-alpha 9 x 10(6) IU/m2/day intramuscularly (i.m.) or subcutaneously (s.c.) days 1, 3, and 5 each week for 3 weeks plus IL-2 continuous infusion 1 x 10(6) IU/m2/day (group A) or 3 x 10(6) IU/m2/day (group B) days 1-5 each week for 3 weeks. TNF was administered only during the first week of each course intravenously (i.v.) for 2 h on days 1-5. The dose of TNF was escalated (40, 80, 120 micrograms/m2) in cohorts of 3 patients. The most common side effects were fever, chills, and fatigue in all patients. Grade 3-4 toxicity included anemia (3 patients), thrombocytopenia (1 patients), arrhythmia (2 patients), pulmonary edema (3 patients),- and weight loss (1 patient). Five patients withdrew from study due to toxicity. The combination of the three cytokines is feasible as an outpatient regimen in one of the following combinations: (a) TNF 80 micrograms/m2/day as 2-h infusion on days 1-5 + IL-2 1 x 10(6) IU/m2/day continuous infusion on days 1-5 for 3 weeks + IFN-alpha 9 x 10(6) IU/m2/day s.c. or i.m. on days 1, 3, and 5 for 3 weeks, or (b) TNF 40 micrograms/m2/day as a 2-h infusion on days 1-5 + IL-2 3 x 10(6) IU/m2/day continuous infusion on days 1-5 for 3 weeks + IFN-alpha 9 x 10(6) IU/m2/day s.c. or i.m. on days 1, 3, and 5 for 3 weeks.

Interferon-alpha inhibits erythropoietin-induced proliferation, but not differentiation, and restricts erythroleukemia development

The immature erythroid cell line J2E responds to erythropoietin (Epo) by proliferating and terminally differentiating into hemoglobin-synthesizing red blood cells. These cells produce a rapid, fatal erythroleukemia in mice characterized by hepatosplenomegaly and severe anemia. The aim of this study was to investigate the effects of murine interferons-alpha (MuIFN-alpha) on J2E cells in vitro and in vivo. Here we show that in culture MuIFN-alpha inhibited the Epo-induced proliferation of J2E cells but did not interfere with differentiation. When mice with J2E erythroleukemias were treated with MuIFNs in vivo, an extension of their life span was observed. Moreover, numerous necrotic lesions of infiltrating leukemic cells were detected in the spleens of these mice. Finally, ex vivo treatment of leukemic bone marrow cells with Epo and MuIFNs delayed mortality even further. It was concluded that MuIFNs (1) suppressed the proliferation of J2E cells in vitro but did not affect Epo-induced differentiation, and (2) inhibited the progress of erythroleukemias, especially in combination with Epo.

Regression of skin recurrences of breast carcinomas treated with intralesional injections of natural interferons alpha and gamma

Two groups of patients with disseminated breast carcinomas who had failed radiotherapy, chemotherapy, and hormonotherapy were treated with natural interferon alpha (nIFN-alpha) alone or in combination with nIFN-gamma delivered in cycles of 10-12 intralesional (i.l.) injections to recurrent and metastatic lesions. In group, I, 16 skin lesions in 12 patients received nIFN-alpha alone resulting in 7 complete regressions verified histologically (CR), 7 partial regressions (PR), and no regressions (NR) in 2. Group II included 4 patients in whom 7 cutaneous recurrences were treated with nIFN-alpha/nIFN-gamma (5 CR, 2 PR), 2 were injected with nIFN-alpha alone (1 CR, 1 PR), and 1 received nIFN-gamma alone (PR). Two additional patients in group II were given i.l. injections of nIFN-alpha/nIFN-gamma to lymph node metastases (1 CR, 1 PR). Clinical toxicity was experienced by 5 of 12 patients in group I and by all the patients in group II and was controlled in most instances by antipyretics. Systemic antitumor effects were not appreciable clinically. Nevertheless, noninjected lesions exposed only to systemic levels of IFNs, when studied immunohistochemically, displayed an immunological response similar to that of IFN-injected lesions, although less intense. Therefore, IFNs can be useful in controlling locoregional recurrences of breast cancer even in patients who are not responding to other forms of therapy. Furthermore, in addition to the local antitumor actions, they appear to be capable of eliciting systemic immunological effects.

Characterization of specific functional receptors for HuIFN-alpha on a human megakaryocytic cell line (Dami): expression related to differentiation

Interferon-alpha (IFN-alpha) treatment has been shown to be highly effective in inhibiting human megakaryocytopoiesis and controlling thrombocytosis in patients with myeloproliferative disorders. These observations suggest that IFN-alpha might play some role in the biological feature of the megakaryocytic lineage and led us to investigate the presence of specific receptors for IFN-alpha on human megakaryocytic cells, i.e. the Dami cell line, and to study the regulation of their expression. Our study demonstrates that [125I]-recombinant human IFN-alpha ([125I]rHu-IFN-alpha) binds to high-affinity specific receptor on these cells. Scatchard analysis of binding data indicates the presence of homogeneous binding sites estimated in the range of 3000-5000, with an apparent equilibrium dissociation constant, Kd, of 1-2 x 10(-9) M. Also, [125I]rHuIFN-alpha binding capacity decreased in Dami cells incubated with unlabelled rHuIFN-alpha. This down-regulation which was dose-dependent appeared to result from a reduction of IFN-alpha cell surface receptors and was observed at doses that elicited antiproliferative effects in Dami cells. Cross-linking of [125I]rHuIFN-alpha to Dami membrane proteins using a bifunctional reagent yielded to a radioactive complex of approximately 150,000 kD on SDS-PAGE. Furthermore, in response to PMA, which induces the differentiation/maturation of the Dami cells as evaluated by surface marker and ploidy analysis, a 3-fold increase of the number of specific membrane receptors for IFN-alpha was observed, without any modification of either the affinity or the M(r) value of the cross-linked complex. Such an increase appeared to be restricted to IFN-alpha receptors; actually it was not observed in [125I]IFN-gamma binding experiments. Transcript analysis indicated that down-regulation and increased expression of the IFN-alpha receptor after PMA treatment are post-transcriptional events.

Human recombinant interferon-beta SER and tamoxifen: growth suppressive effects for the human breast carcinoma MCF-7 grown in the athymic mouse

Tamoxifen is the endocrine treatment of choice for breast cancer. However, resistance to therapy and patient relapse inevitably occurs. In future treatment schedules, interferons could be administered with tamoxifen, in an attempt to prevent disease recurrence. Human recombinant interferon-beta SER (rIFN-beta SER) inhibited the growth in vitro of the estrogen receptor (ER) positive breast cancer cell line MCF-7 and the ER negative breast cancer cell line MDA-MB-231. This inhibitory effect was achieved at doses of 50 U/ml and above. The growth of MCF-7 tumors in estradiol-stimulated athymic mice was greatly inhibited by high dose rIFN-beta SER treatment (10(6)U/day). In spite of the impressive antitumor effects upon MCF-7 tumors, rIFN-beta SER had no effect upon ER levels within the tumors at either the RNA or protein level, as measured by Northern blotting and ER-EIA respectively. High dose rIFN-beta SER (10(6)U/day) did result in some inhibition in the growth in vivo of the tamoxifen-stimulated MCF-7 variant MCF-7 TAM, although not to the same extent as was observed with the estradiol-stimulated MCF-7 tumors. rIFN-beta SER was also administered to animals bearing MCF-7 tumors and treated with estradiol and tamoxifen. In the animals undergoing high dose therapy (10(6)U/day), tumor growth was completely suppressed. Furthermore, tumor growth continued to be suppressed in those animals in which the rIFN-beta SER therapy was halted and the tamoxifen capsule removed. No tumors were observed in spite of the environment of estradiol stimulation. Thus, the combination of interferon and tamoxifen was totally growth suppressive for MCF-7 xenografts in nude mice.

The use of natural interferon alpha conjugated to a monoclonal antibody anti mammary epithelial mucin (Mc5) for the treatment of human breast cancer xenografts

An immunoconjugate composed of natural interferon alpha (nIFN alpha) bound in a noncleavable fashion to a monoclonal antibody (MoAb) recognizing a breast epithelial membrane mucin (Mc5) was used to to treat xenografts of a human mammary carcinoma cell line (MCF-7) growing in nude mice. The immunoconjugate (nIFN alpha/Mc5) was administered as 20 intralesional (i.l.) injections to 1 of 2 xenografts in each animal. It was found that nIFN alpha/Mc5 produced a significant enhancement of the growth inhibitory actions of nIFN alpha on the injected tumors. Further enhancement was obtained when nIFN gamma or nIFN gamma together with Mc5 (at a dose 10 times larger than that present in nIFN alpha/Mc5) were added to the immunoconjugate. Biodistribution experiments showed that the uptake of 125I-nIFN alpha/Mc5 by the tumors was greater and its elimination slower than for 125I-nIFN alpha alone or conjugated to irrelevant mouse IgG1. In addition, the immunoconjugate up-regulated the antigenic expression of a breast epithelial membrane mucin by the carcinoma cells, an up-regulation which was not significantly different from that produced by nIFN alpha alone. The contralateral noninjected tumors exposed to systemic levels of the immunoconjugate showed an enhancement of antitumor effects, but to a lesser extent than the injected tumors. These findings suggest that the enhancement of the growth inhibitory action of the immunoconjugate was related to the specific binding of Mc5 which targeted the IFN to the carcinoma cells and impeded its elimination. It is likely that the targeting was favored by the IFN-mediated up-regulation of antigenic expression by the carcinoma cells, thereby producing a cascade of interrelated effects. The results of this study point out the feasibility and potential usefulness of IFN treatment by means of immunoconjugates as well as the worth of pursuing and improving this form of therapy.

21-day intravenous toxicity study with feline interferon in rats

The toxicity of recombinant feline interferon, a prospective antiviral drug for cats, was examined in a subacute study. Groups of five male and five female Wistar rats were given iv feline interferon in 20 mM-NaCl at doses of 0, 5, 15 and 50 MU/kg body weight/day for 21 consecutive days. Criteria to assess toxicity included clinical observations, ophthalmoscopy, growth, food and water intake, haematology, clinical chemistry, urinalysis, organ weights, gross examination at autopsy and microscopic examination of the liver, kidneys, spleen, adrenals, heart, mesenteric lymph nodes and thymus. No treatment-related were observed even at the highest dose level. The no-observed-adverse-effect level for feline interferon in this study was therefore 50 MU/kg body weight/day.

Interferons: Pleiotropic cellular modulators

Interferons play a key role in host response as pleiotropic modulators of cell function. As induced proteins, interferons contrast with other physiologic regulators such as glucocorticoids which are produced relatively continuously. Antitumor effects have been suggested to be principally the result of two mechanisms: a direct effect on the functional capacity or antigenic composition of tumor cells or an indirect effect on modulation of immunological effector cell populations with tumor specificities. Over the past decade, interferons have been established as therapeutically useful molecules for malignant and viral diseases.

A dual anti-tumor effect of a combination of interferon-α or interleukin-2 and 5-fluorouracil on natural killer (NK) cell-mediated cytotoxicity

Previous in vitro and in vivo studies have shown a synergism between interferon (IFN) and 5-fluorouracil (5-FU) against different tumor cell lines. In the present study we report that the combination of IFN-alpha and 5-FU has a significant effect not only on the inhibition of tumor cell growth but also on the regulation of natural killer cell-mediated cytotoxicity (NK-CMC). The addition of 5-FU to effector cell population neither affects NK cell activity nor activation of NK cells by IFN or by interleukin (IL)-2. However, pretreatment of target cells with 5-FU increased their susceptibility to NK activity and abolished the protective effect induced by IFN against NK-CMC. This dual effect of IFN-alpha and 5-FU was found to be applicable to target cells of different origins including a cervical carcinoma cell line (ME-180), a hairy cell leukemia-like cell line (Eskol), a CML cell line (K-562) and a primary culture of AIDS-related Kaposi's sarcoma cells. Similar results were found with IL-2 treatment of Eskol cells but not other cells. Combination of IL-2 with 5-FU resulted in enhancement of the sensitivity of the cells to NK activity and abolished the protection against NK-CMC. Based on these results we propose that the combination of IFN-alpha and 5-FU not only has a direct growth inhibitory effect on tumor cells but also has a regulatory role on the immunological arm of the NK-CMC. Moreover, since the combination gave the same pattern of response in different tumor cells, both NK-sensitive and NK-resistant, this combination treatment may be a candidate for clinical trials in various types of tumors.

Cardiotoxicity of interferon. A review of 44 cases

Cardiovascular complications have occurred in clinical trials of interferon. We review herein experience to date of cardiotoxicity with all types of interferons in cancer patients. The most common presentations of cardiotoxicity were cardiac arrhythmia, dilated cardiomyopathy, and symptoms of ischemic heart disease, including myocardial infarction and sudden death. The cardiac effects were not related to the daily dose, cumulative total dose, or period of therapy. Some of the patients in whom interferon has caused cardiovascular sequelae have had a history of coronary heart disease or have previously been given chemotherapy with drugs known to be cardiotoxic. In most of the patients, cardiac toxicity was reversible following the cessation of the drug therapy.

Antiproliferative effects of natural interferon beta alone and in combination with natural interferon gamma on human breast carcinomas in nude mice

Nude mice bearing bilateral xenografts of human breast carcinoma cells (MCF-7 and BT20) were treated with 2 or 45-day cycles of intralesional (i.l.) injections of human natural interferon beta (nIFN-beta) alone or in combination with human natural interferon gamma (nIFN-gamma). The injections were administered to only 1 of the 2 tumors in each animal, thus making it possible to assess at the same time local therapeutic effects in the injected tumors and systemic effects in the contralateral ones. When n-IFN-beta was used as a single agent only mild local antitumor effects and virtually no systemic effects were observed. In contrast, the combined administration of nIFN-beta/nIFN-gamma produced marked antiproliferative effects, presumably as a result of the synergistic action of type I and type II IFNs. These effects ranged from complete regression documented histologically in 2 MCF-7 tumors to varying degrees of growth inhibition with persistence of residual microscopic or grossly detectable tumor. Local effects were more pronounced than systemic effects. The therapeutic efficacy of nIFN-beta proved to be greater than that of recombinant interferon beta (rIFN-beta). In MCF-7 tumors nIFN-beta appeared to be less effective than nIFN-alpha, whereas the opposite was true for BT20 tumors.

Biologic response modifiers: the future of cancer therapy?

The major shift today has been away from nonspecific compounds acting on immune mechanisms to using biologics which have specific, defined roles in acting on the immune response. The field of biologic response modification is progressing very rapidly. New peptides are being identified, as are receptors for these peptides, autocrines, lymphokines, cytokines, growth factors, differentiation factors, hormones, and so on-all of which will control body function, cell populations, and cell to cell interactions. This rapidly advancing area of research in cancer biology and cancer therapy may hold the key to the future of successful therapy.

Effects of subchronic treatment with natural human interferons on antipyrine clearance and liver function in patients with chronic hepatitis

To determine whether natural human interferon administered under the usual therapeutic dosing scheme would inhibit the hepatic drug metabolism, we performed an antipyrine test in eight patients with chronic B or non-A, non-B hepatitis before and after a subchronic interferon therapy (6 megaunits/day for 17 +/- 4 days, mean +/- SD). Six patients received interferon-beta and 2 received interferon-alpha. To circumvent a possible influence of interferon-induced fever on the hepatic drug metabolism, the antipyrine test during the interferon therapy was performed at least 14 days after the interferon-induced fever disappeared. The kinetic parameters of antipyrine were obtained from seven saliva samples over 32 hours postdose. There were no significant differences in any kinetic parameters of antipyrine observed before and during the interferon therapy. With the sample size of the study, there was only a 20% chance (i.e., beta-power = 0.8 at alpha = 0.05) that we might have missed a 17% reduction in antipyrine clearance by the interferon therapy (type II error). On the other hand, the subchronic interferon therapy lowered serum aminotransferases and DNA polymerase activity significantly (P less than .05) compared with the respective baseline values. Our results suggest that the subchronic therapeutic dosing scheme of interferon as conducted in the present study does not cause the inhibitory effect on the oxidative drug metabolism to a statistically significant or clinically relevant degree in patients with chronic hepatitis, while it improves their liver function. Further studies are required for determining if different types of interferons administered under the different dosing schemes would alter the hepatic drug metabolism and the inhibitory effect would be time-dependent.

Lymphokines and cytokines as cancer treatment. Immunotherapy realized

Human proteins with identified effects on host responses to malignant cells have been established as effective therapeutic techniques in cancer. Lymphokines, products of activated cells of the immune system, have pleiotropic biochemical and cellular effects. These include stimulation of immune effector cell proliferation, augmentation of cytotoxicity of immune effector cells for tumor cell targets, enhancement in antigen-recognition potential by monocytes, and modulation of tumor-associated antigen expression on neoplastic cells. Interferons (IFN) and interleukin-2 (IL-2), purified to homogeneity, can induce regression of metastatic malignancy. Recombinant DNA technology has facilitated large-scale production of these and other lymphokines and cytokines. It has also made possible analyses of physical structures of the molecules themselves and has enabled creation of mutated molecules with specific, desired substitutions in their amino acid sequence. Monoclonal antibodies, directed at tumor-associated antigens, can augment antibody-dependent cell-mediated cytotoxicity and can selectively deliver cytotoxic techniques to malignant cells. Molecules that modify the host resistance to malignant disease also have potential to augment effectiveness of other cancer treatment techniques. Lymphokines, cytokines, and monoclonal antibodies, all products of biotechnology, have resulted in fulfillment of the promise of the immune system for inhibition of growth of human malignancy.