IFN-beta Ser Research Articles

Combined effects of onconase and IFN-β on proliferation, macromolecular syntheses and expression of STAT-1 in JCA-1 cancer cells

Prostate cancer (CaP), the most common malignancy in American men, presents its greatest challenge to clinicians when the cancer progresses to the hormone-refractory state. In the present investigation, we studied the combined effects of interferon (IFN) and onconase, each of which has reported antitumor activity, on growth and specific protein expression in JCA-1 cells. Cells were treated for up to 3 days with 1 and 5 microg/ml onconase, with and without concurrent addition of IFN-beta(ser) (10(3) IU/ml). Cell count and viability, and de novo RNA and protein synthesis were determined. Expression and subcellular distribution of STAT-1 were also assessed by immunoblot analysis. JCA-1 cells treated for 3 days with IFN or onconase showed a 15-30% reduction in cell proliferation, which was increased to 42-51% with both agents. Analysis of [35S]methionine incorporation into cells confirmed a more pronounced inhibitory effect elicited by IFN-beta and onconase; IFN-beta and 1 microg/ml onconase each decreased de novo protein synthesis by 23-25%, while the combination resulted in 59% suppression. Similar studies using incorporation of [3H]uridine into RNA yielded less significant effects. Further investigation using pre-labeled cellular RNA and proteins showed that either agent or their combination did not affect the turnover of macromolecules. To test whether the antiproliferative effects of IFN-beta and onconase were correlated with one or more specific gene changes, expression of an IFN-modulated protein, STAT-1, was determined. Both phosphorylated and unphosphorylated forms of STAT-1 and its subcellular distribution in the nucleus and cytoplasm, were increased 3-fold by IFN-beta. The IFN-elicited elevation of STAT-1 was not additionally augmented by onconase but was reduced 20-25% when onconase was simultaneously present as IFN-beta. These data show that the overall changes in STAT-1 did not correlate with the reduction in cell growth and the suppression of de novo protein/RNA synthesis elicited by these two agents, and imply that other target proteins are likely to be involved in the combined effects of IFN-beta and onconase in JCA-1 cells.

Absence of biological effects of orally administered interferon-beta ser.

To assess biological effectiveness of interferon (IFN) administered orally, we measured serum IFN and several proteins and metabolites induced by IFN after oral administration of 2.5 mg or 7.5 mg of recombinant IFN-beta ser to 6 healthy volunteers. These IFN-induced metabolites, beta 2-microglobulin, and neopterin in serum, and 2',5'-oligoadenylate (2-5A) synthetase in peripheral blood mononuclear cells, are more sensitive to the presence of IFN than bioassay of IFN in serum. Up to 48 h after oral IFN was administered, serum IFN, beta 2-microglobulin, neopterin, or 2-5A synthetase were not generally increased compared to pretreatment levels, indicating that oral IFN had no significant biological effects.

Priming of human alveolar macrophages and blood monocytes for superoxide anion release by interferons and lipopolysaccharide.

Biological agents such as the interferons (IFNs) or lipopolysaccharides (LPSs) can prime phagocytic cells to generate increased amounts of oxygen metabolites upon exposure to various stimuli. The priming of human peripheral blood monocytes and alveolar macrophages (AM) by recombinant IFN-beta ser (rIFN-beta ser) and rIFN-gamma for an enhanced respiratory burst was compared. Both rIFN-beta ser and rIFN-gamma increased phorbol myristate acetate-stimulated superoxide anion generation by AM in a dose-dependent fashion. rIFN-beta ser was capable of priming AM for an enhanced superoxide anion release nearly as well as rIFN-gamma. In contrast, rIFN-beta ser was much less effective as a priming agent for monocytes when compared to either its effect on AM or to the priming effect of rIFN-gamma on monocytes. The respiratory burst of IFN-exposed AM was not inhibited by co-incubation with low concentrations of LPS. However, the ability of IFN to augment superoxide anion release by cells simultaneously exposed to LPS in comparison to superoxide anion generation by cells exposed to LPS only was attenuated.

A direct comparison of biological response modulation and clinical side effects by interferon-beta ser, interferon-gamma, or the combination of interferons beta ser and gamma in humans.

To directly compare clinical side effects and biological response modification, IFN-beta ser, IFN-gamma, or the combination of IFN-beta ser plus IFN-gamma was administered to 21 cancer patients. Each IFN or the combination was given intravenously on days 1, 8, and 15 in varied order. Each IFN and the combination resulted in significant (P less than 0.05) modulation of IFN-induced proteins. IFN-beta ser was more effective than IFN-gamma in enhancing 2-5A synthetase activity (P = 0.001). IFN-gamma was more effective than IFN-beta ser in enhancing serum beta 2 microglobulin expression (P = 0.05) and indoleamine dioxygenase activity, as assessed by decreased serum tryptophan (P = 0.03). The combination enhanced tryptophan catabolism more effectively than IFN-beta ser in a dose-dependent manner (P less than 0.03). IFN-beta ser/IFN-gamma did not potentiate natural killer cells or antibody-dependent cellular toxicity (ADCC). IFN-beta ser/IFN-gamma enhanced monocyte guanylate cyclase activity, as assessed by serum neopterin, more effectively than IFN-gamma alone (P = 0.005). Both IFNs and the combination resulted in increases in HLA class II expression on monocytes. However, no significant difference in the level of induction of HLA DQ and HLA DR expression between IFN-beta ser/IFN-gamma and either IFN-beta ser or IFN-gamma was noted. Although frequency and servity of side effects of IFN-beta ser, IFN-gamma, or the combination were dose related, induction of induced proteins (with exception of influences on tryptophan catabolism) were not a function of dose administered over the 10-fold range. Continued treatment with the combination intravenously three times a week for 4 wk sustained but did not further potentiate, most of the changes in interferon-induced proteins. Thus, IFN-beta ser and IFN-gamma each resulted in effective and essentially equivalent patterns of induction of induced proteins. When combined, however, these IFNs did not result in potentiation of biological response modification in vivo.

A pilot study of recombinant interferon beta (IFN-βser) in patients with recurrent glioma

Recombinant interferon beta (IFN-beta ser) has been administered by intravenous bolus injection three times weekly at a dose of 90 x 10(6) IU to 14 patients with recurrent malignant glioma in an ongoing study. The treatment period has ranged from 1 to 40 weeks. The most common adverse experiences were fever, chills, malaise, and headache. Fever, chills and headache were worse with the first two doses and were usually relieved with acetaminophen. All patients tolerated subsequent treatments without any difficulties. No neurologic or hematologic toxicities were observed. Of ten evaluable patients, five had progressive disease in 4 to 8 weeks; three had stable disease for 12 to 21 weeks; one has had a minor response for 13 weeks; and one has had a complete resolution of tumor for 150 + weeks. IFN-beta ser appears to have activity in human glioma and is well tolerated at this dosage and schedule.

Growth Inhibitory Effects of Interferon-β but Not Interferon-α on Human Glioma Cells: Correlation of Receptor Binding, 2′,5′-O1igoadenylate Synthetase and Protein Kinase Activity

The antiproliferative effects of human recombinant interferon-alpha (rIFN-alpha A) and interferon-beta (rIFN-beta ser) were assessed in vitro against seven human glioma cell lines. Further analysis of one of these lines (EFC-2) in response to rIFN-alpha A demonstrated a minimum growth inhibition by day 6 of treatment, whereas a 50% inhibition of cell growth was observed with a dose of 50 U/ml of IFN-beta ser. No significant growth inhibition was seen by rIFN-alpha A at doses up to 500 U/ml. Addition of rIFN-alpha A to rIFN-beta ser-treated EFC-2 cells neither suppressed nor augmented the antiproliferative response to IFN-beta ser. The binding of 125I-labeled rIFN-alpha A or 125I-labeled rIFN-beta ser to EFC-2 cells was inhibited competitively by increasing concentrations of either unlabeled rIFN-alpha A or rIFN-beta ser. This suggests that the cellular receptors for both rIFN-alpha A and rIFN-beta ser appear to be intact and appear to bind both agents equally. Furthermore, incubation of EFC-2 cells for 72 h with either rIFN-alpha A or rIFN-beta ser resulted in an increase in 2',5'-oligoadenylate (2-5A) synthetase activity 5-fold with rIFN-alpha A and 50-fold with rIFN-beta ser. Similarly, the 68-kD IFN-induced protein kinase was induced substantially with rIFN-beta ser but only slightly induced with rIFN-alpha A treatment. These results suggest that EFC-2 human glioma cells demonstrate a differential sensitivity in terms of growth inhibition to rIFN-beta ser and to rIFN-alpha A which appears to correlate with a differential induction of both intracellular 2-5A synthetase and protein kinase activity. These results cannot be explained solely on the basis of surface receptor binding of rIFN-alpha A and rIFN-beta ser. These data do suggest that, for human glioma cells in culture, type I IFN receptors may display a subtle architectural variation that allows equivalent binding of both IFN-alpha and IFN-beta ser, but allows an enhanced signal transduction and biological effect only after binding a specific IFN subtype.

Biological and Clinical Effects of Interferon-βserat Two Doses

To assess biological response, therapeutic activity, and side effects, a randomized, double-blind trial of two doses of interferon-beta ser (IFN-beta ser), differing by 20-fold 4.5 and 90 x 10(6) units), was undertaken in 64 patients with metastatic renal carcinoma. Patients were treated intravenously with injections daily for 10 days with an 11-day rest before treatment was reinitiated. The trial confirmed the relatively good toleration of IFN-beta ser; in the first cycle only 4/63 patients had anorexia of moderate or greater severity. Median weight change over the duration on study was -1.5 kg; in the first cycle only 7% of patients had performance status decline greater than 1 level. Statistically significant changes (p less than 0.05) occurred in granulocytes, lymphocytes, calcium, cholesterol, alkaline phosphatase, and aspartate transferase (AST); however, except for AST, overall clinical differences in the two doses were not great. Of 60 patients evaluated, 1 developed neutralizing antibody. When assessed 24 h after IFN-beta ser at 4.5 x 10(6) units, significant (p less than 0.05) augmentation had occurred in beta 2-microglobulin, HLA-DR, and HLA-DQ expression on monocytes, 2',5'-oligoadenylate (2-5A) synthetase in peripheral mononuclear cells, and natural killer (NK) and K cells functional activity. Although the 90 x 10(6) unit dose also resulted in stimulation of these responses, little additional augmentation of biological response occurred at the higher dose. Except for a decline in monocyte HLA-DR expression, biological responses remained increased at both doses over the 10-day period of treatment. However, no objective regressions of metastatic disease occurred. In view of objective responses in metastatic renal carcinoma in other trials with IFN-beta ser, consideration should be given to alternative schedules.

Human Biologic Response Modification by Interferon in the Absence of Measurable Serum Concentrations: A Comparative Trial of Subcutaneous and Intravenous Interferon-beta serine

The effect on a range of biologic responses of interferon-beta serine (IFN-beta ser), administered by either the sc or the iv route, was examined in 16 patients. Despite the absence of IFN in the serum of 13 of 16 patients after sc administration, biologic changes associated with IFN administration occurred. Significant increases in peripheral mononuclear cell surface proteins were evident. Monocyte human leukocyte antigen-DR (HLA-DR) showed a 23% increase in mean fluorescent intensity (P = .04) and a 9% increase in percentage of positive cells (P = .02); lymphocyte OKT10 had an 11% increase in percentage of positive cells (P less than .0001) and a 26% increase in mean fluorescent intensity (P = .002). Natural killer cell activity against the Change target increased by 125% (P = .004). Intracellular activity of 2',5'-oligoadenylate synthetase increased 297% at 24 hours and 226% at 48 hours (P less than .0001). Significant increases in serum concentrations of beta 2 microglobulin (24% at 24 hr and 27% at 48 hr, P less than .0001) and neopterin (85%, P = .0001 and 165%, P = .00001) were observed. These alterations after sc administration were similar quantitatively to those resulting from the same dose of IFN-beta ser given iv. Thus, serum IFN concentrations did not have to be measurable for IFN-beta ser to exert biologic activity. The different effects of two dose levels, 45 X 10(6) IU and 180 X 10(6) IU, also were compared independent of route. The higher dose resulted in greater increases over baseline of 2',5'-oligoadenylate synthetase activity (344% vs. 145% at 24 hr; 231% vs. 83% at 48 hr) and serum neopterin concentrations (185% vs. 99% at 24 hr; 271% vs. 153% at 48 hr). For all the other parameters, there was no significant difference between the two doses.

Selective Interferon-Induced Enhancement of Tumor-Associated Antigens on a Spectrum of Freshly Isolated Human Adenocarcinoma Cells

Freshly isolated cells from patients with pleural or peritoneal effusions cytologically diagnosed as adenocarcinoma (n = 43), malignant nonepithelial neoplasms (n = 10), and benign (n = 8) were analyzed for expression of constitutive levels of the tumor antigens TAG-72 [recognized by monoclonal antibody (MAb) B72.3] and carcinoembryonic antigen (CEA) (recognized by MAb COL-4) as well as the class I and class II major histocompatibility (MHC) antigens, and the ability of human interferons (Hu-IFNs) to enhance cell surface expression of those antigens as measured by MAb binding. Both type I and type II IFNs enhanced the expression of TAG-72 and CEA and altered the level of expression of the MHC antigens. Comparative studies of three different Hu-IFNs (IFN-alpha A, IFN-beta ser, and IFN-gamma) revealed that IFN-gamma was the most potent in augmenting either B72.3 or COL-4 binding. Unlike the IFN-gamma -mediated induction of the class II human leukocyte antigens, the change in tumor antigen expression consisted of enhanced constitutive antigen expression; de novo induction of either TAG-72 or CEA could not be achieved by either type I or type II IFN. Of 43 effusions isolated from different adenocarcinoma patients, 42 (97.7%) expressed either CEA or TAG-72, and treatment with Hu-IFN increased the level of expression of either antigen in 36 of 42 samples (85.7%). These studies demonstrate the augmentation of tumor-associated antigens on human carcinoma cells isolated from serous effusions by Hu-IFNs which may be used to enhance the targeting of conjugated MAbs to human carcinoma lesions.

Effect of recombinant interferon-beta ser on primary human tumor colony-forming units.

A capillary cloning system for primary human tumor colony-forming units was applied to a total of 286 tumors, and 226 (79%) provided satisfactory cultures. These were used to study the in vitro anti-proliferative effects of a recombinant DNA human interferon-beta (rIFN-beta ser). Growth inhibition was somewhat greater when relatively high IFN concentrations were used, but continuous exposure to the IFN was not more effective than exposure for only 1 h. The tumors inhibited included breast, kidney, lung (non-small-cell), head and neck cancers, melanoma, and, especially, mesothelioma. This spectrum of activity differs from that of the IFNs-alpha so far examined. The IFN-beta ser did not differ significantly in activity from native IFN-beta. When tested in combination with five cytotoxic anticancer agents, it did not increase their effects. Future correlation of these in vitro data with clinical results will show whether this capillary cell cloning method is a useful predictor of antitumor activity in patients.

Clinical and Biological Effects of Recombinant Interferon-β Administered Intravenously Daily in Phase I Trial

Interferon-beta serine (IFN-beta ser) was administered intravenously (i.v.) daily for 14 days at doses of 3, 10, 30 X 10(6) units to 19 patients. In this Phase I trial, IFN-beta ser was tolerated without limiting fever or subjective toxicities. At 30 X 10(6) units, 3 patients developed hematologic toxicity and dose escalation was thus terminated. No patient developed detectable binding or neutralizing antibody to IFN-beta. A significant (p less than 0.006) increase in serum beta 2-microglobulin and a significant (less than 0.005) increase in 2',5'-oligoadenylate synthetase (2-5A) in peripheral mononuclear cells were identified. Increase in these proteins did not correlate with dose or with the disappearance of serum IFN over the first 5 h after injection. Two patients, one with renal carcinoma and one with melanoma, had objective responses. This trial further confirms safety and biological potency of this synthetic mutant of IFN-beta.

Binding of recombinant-produced interferon beta ser to human lymphoblastoid cells. Evidence for two binding domains.

Human interferon beta (IFN beta ser), produced by recombinant DNA technology, was radiolabeled to approximately one atom of iodine-125/molecule of interferon without detectable loss of antiviral activity. At 37 degrees C, binding of 125I IFN beta ser occurred rapidly (t1/2max less than or equal to 15 min) followed by internalization and degradation of bound ligand. Kinetic analysis at 4 degrees C indicated diffusion-limited association kinetics independent of 125I IFN beta ser concentration. Dissociation of bound 125I IFN beta ser from Daudi cells was slow (t1/2 = 1.2 h) of bound radiolabeled ligand was observed in the presence of unlabeled IFN beta ser, naturally produced IFN beta, and IFN alpha 6, but was not observed with unlabeled IFN gamma or nonspecific proteins. Concomitantly, equilibrium analysis indicated heterogeneous binding of 125I IFN beta ser to six cell lines of lymphoid origin consistent with either negative cooperativity or two populations of receptors. Analysis of binding of 125I IFN beta ser to Daudi cell receptors in the presence of unlabeled IFN alpha 6 suggested that one receptor served both ligands. The latter conclusion was supported by results of chemical cross-linking experiments in which an 125I IFN beta ser/receptor complex (Mr 120,000-130,000) was observed following sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This complex was absent when binding occurred in the presence of either excess unlabeled IFN beta ser or IFN alpha 6.