Initial expression of interferon alpha receptor 2 (IFNAR2) on CD34-positive cells and its down-regulation correlate with clinical response to interferon therapy in chronic myelogenous leukemia

Long non-coding RNA prostate cancer-associated transcript 6 inhibited gefitinib sensitivity of non-small cell lung cancer by serving as a competing endogenous RNA of miR-326 to up-regulate interferon-alpha receptor 2

The critical roles of lncRNAs in drug resistance of malignancies have been widely recognized. This investigation aims to study the function of lncRNA PCAT6 in the resistance of non-small cell lung cancer (NSCLC) to gefitinib. In our study, we demonstrated that prostate cancer-associated transcript 6 (PCAT6) was upregulated in gefitinib-resistant NSCLC. PCAT6 knockdown inhibited gefitinib resistance of NSCLC, as indicated by decreased IC₅₀ value, proliferation, and metastasis, and increased cell apoptosis. Besides, PCAT6 could directly target miR-326 in gefitinib-resistant NSCLC cells and augment NSCLC resistance to gefitinib by serving as ceRNA of miR-326. Furthermore, interferon-alpha receptor 2 (IFNAR2) was validated as a downstream target of miR-326 and miR-326 reduced resistance to gefitinib by inhibiting IFNAR2 expression. Our investigation identified that PCAT6 enhanced gefitinib resistance of NSCLC via miR-326/IFNAR2 axis, which might offer a new therapeutic strategy against gefitinib resistance of NSCLC patients.

IFNAR1 expression level in Iranian multiple sclerosis patients treated with IFN-B

BACKGROUND

Multiple sclerosis (MS) as an auto-immune disease is an inflammatory, demyelinating disease of the central nervous system. Certain genes have shown to be involved in the initiation of MS but the specific role of some of them, e.g. IFNAR1 has not been identified in certain populations yet.

OBJECTIVE

The IFNAR1 as a type I membrane protein shapes one of the two chains of a receptor for interferons alpha and beta.

METHODS

To find out how IFNAR1 functions in the Iranian population, the researchers compared the expression level of this gene in relapsing-remitting MS (RR-MS) samples with normal individuals. RNA from the whole blood of 50 RR-MS patients and 50 normal controls were extracted. All patients were HLA-DRB1*15 negative and were responders to interferon-beta with a normal vitamin D level. The level of IFNAR1 gene expression was measured using quantitative RT-PCR.

RESULTS

According to the results the RR-MS patients manifested a statistically higher expression level of IFNAR1 than their normal counterparts (p= 0.012). Age-wise, females between the ages, 30 to 40 had a significant increase (p= 0.046) but males under 30 showed a statistically meaningful decrease in the expression level (p= 0.04). In terms of sex, only the female patients manifested a statistically significant increase in IFNAR1 (p= 0.004).

CONCLUSIONS

The overall results show an increase in IFNAR1 level in MS patients treated with IFN-B.

The interferon-alpha revival in CML

Interferon-alpha (IFNα) was once the standard of frontline treatment for chronic myeloid leukemia (CML). Its pleiotropic mechanism of action in CML includes immune activation and specific targeting of CML stem cells. Early studies of IFNα in CML demonstrated that patients in chronic phase could attain extremely stable remissions, which correlated with long-term survival. Some patients even sustained their remission after discontinuing therapy, but the mechanism underlying this phenomenon is not well understood. Today, BCR-ABL tyrosine kinase inhibitors (TKIs), such as imatinib, induce remarkable responses in CML patients and have become the mainstay of CML therapy. Although TKIs target the pathogenic BCR-ABL protein in CML, they cannot fully eradicate CML stem cells. Some of the clinical trials testing IFNα plus imatinib combination therapy suggest that addition of IFNα increases the speed and rate of responses with imatinib therapy. However, the undesirable side effects of IFNα can make this therapy difficult to deliver, and the optimal therapeutic window for using IFNα in combination therapy is unknown. Further studies are needed to clarify the best niche for IFNα use in CML.

Interferon (alpha, beta and omega) receptor 2 is a prognostic biomarker for lung cancer

OBJECTIVES

It has been reported that the type I interferon receptor subunit, interferon (alpha, beta and omega) receptor 2 (IFNAR2), is overexpressed in several malignancies, primarily adenocarcinomas (ADCs); however, the biological significance of IFNAR2 in human lung cancer has not yet been studied.

METHODS

Immunohistochemical analysis of 113 surgically resected lung specimens was performed, and the results were evaluated in association with clinical variables, including survival. Serum concentrations of IFNAR2 were also determined by an enzyme-linked immunosorbent assay in 157 lung cancer patients and 164 healthy volunteers.

RESULTS

IFNAR2 overexpression was observed in all histological types of lung cancer examined. Furthermore, strong IFNAR2 expression was associated with shorter progression-free survival (PFS) and overall survival (OS) (p < 0.0001 and p = 0.0110, respectively) in non-small cell lung cancer patients. Multivariate analyses confirmed its independent prognostic value for PFS and OS (p < 0.0001 and p = 0.0222, respectively). IFNAR2 serum levels were also significantly higher in lung cancer patients than in healthy volunteers (p < 0.0001).

CONCLUSIONS

IFNAR2 overexpression was observed in various histological types of lung cancer, and appears to be associated with lung cancers that behave aggressively. The results of this study strongly support the potential of IFNAR2 to be a prognostic biomarker for lung cancer.

Bcr-abl signals to desensitize chronic myeloid leukemia cells to IFNα via accelerating the degradation of its receptor

Constitutive activity of Bcr-abl fusion protein kinase causes chronic myeloid leukemia (CML). Inhibitors of Bcr-abl such as imatinib mesylate have replaced the cytokine IFNα as the primary treatment for the management of patients with this malignancy. We found that pretreatment of CML cells with imatinib mesylate augments the antigrowth effects of IFNα. Furthermore, introduction of Bcr-abl into non-CML cells inhibits the cellular responses to IFNα. This inhibition is mediated via a mechanism that involves activation of protein kinase D2. The latter promotes an accelerated phosphorylation-dependent degradation of the interferon-α/β receptor 1 chain of the type I interferon receptor, leading to attenuation of IFNα signaling. We discuss the relationship between Bcr-abl activity and IFNα signaling as a molecular basis of the combination of inhibitors of Bcr-abl and IFNα for CML treatment.

Stochastic receptor expression determines cell fate upon interferon treatment

Type I interferons trigger diverse biological effects by binding a common receptor, composed of IFNAR1 and IFNAR2. Intriguingly, while the activation of an antiviral state is common to all cells, antiproliferative activity and apoptosis affect only part of the population, even when cells are stimulated with saturating interferon concentrations. Manipulating receptor expression by different small interfering RNA (siRNA) concentrations reduced the fraction of responsive cells independent of the interferon used, including a newly generated, extremely tight-binding variant. Reduced receptor numbers increased 50% effective concentrations (EC(50)s) for alpha interferon 2 (IFN-α2) but not for the tight-binding variant. A correlation between receptor numbers, STAT activation, and gene induction is observed. Our data suggest that for a given cell, the response is binary (+/-) and dependent on the stochastic expression levels of the receptors on an individual cell. A low number of receptors suffices for antiviral response and is thus a robust feature common to all cells. Conversely, a high number of receptors is required for antiproliferative activity, which allows for fine-tuning on a single-cell level.

Role of differential expression of interferon receptor isoforms on the response of multiple sclerosis patients to therapy with interferon beta

The cytokine interferon (IFN)-β is successfully used in the treatment of multiple sclerosis. However, some patients fail to respond to therapy, probably due to different biological patterns that are of importance in influencing clinical response. A common mechanism involved in the modulation of responsiveness to cytokine is represented by regulation of their receptor expression through autocrine-ligand-mediated loops. Mechanistically, IFN-β exerts its biological effects through interaction with the IFN-α/-β-receptor (IFNAR), which then activates several transcription factors. IFNAR is composed of 2 chains, IFNAR-1 and IFNAR-2, which associate with IFN-β to form a ternary complex. The major ligand-binding subunit is IFNAR-2 and it exists in 3 mRNA splice variants, resulting in 2 transmembrane (IFNAR-2b and IFNAR-2c) isoforms and a soluble (IFNAR-2a) one. On the contrary, from normal cells only one IFNAR-1 isoform, with transcriptional capacity, was identified. In the past decades, considerable information has accumulated pertaining to the downregulation of the IFNAR complex in IFN-treated patients, but only a few studies have investigated the molecular events involved in this phenomenon. The intent of the present review is to place this receptor downregulation in the context of IFN-β therapy and of its clinical and biological outcomes in IFN-β-treated patients.

The renaissance of interferon therapy for the treatment of myeloid malignancies

IFNα has been used to treat malignant and viral disorders for more than 25 years. Its efficacy is likely the consequence of its broad range of biologic activities, including direct effects on malignant cells, enhancement of anti-tumor immune responses, induction of proapoptotic genes, inhibition of angiogenesis, and promotion of the cycling of dormant malignant stem cells. Because of the recent development of "targeted" therapies, the use of IFN has been dramatically reduced over the last decade. The increasing awareness of the multistep pathogenesis of many malignancies has suggested, however, that such an approach using target-specific agents is not universally effective. These observations have resulted in a number of recent clinical trials utilizing IFNα in patients with chronic myeloid leukemia (CML), systemic mast cell disease, hypereosinophilic syndrome and the Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) with promising outcomes. These reports provide evidence that IFNα, alone or in combination with other agents, can induce surprisingly robust molecular response rates and possibly improve survival. Although IFNα at present remains an experimental form of therapy for patients with myeloid malignancies, these promising results suggest that it may become again an important component of the therapeutic arsenal for this group of hematologic malignancies.

Cyclic changes in gene expression induced by Peg-interferon alfa-2b plus ribavirin in peripheral blood monocytes (PBMC) of hepatitis C patients during the first 10 weeks of treatment

Background and Aims

This study determined the kinetics of gene expression during the first 10 weeks of therapy with Pegylated-interferon-alfa2b (PegIntron™) and ribavirin (administered by weight) in HCV patients and compared it with the recently completed Virahep C study [1,2] in which Peginterferon-alfa2a (Pegasys™) and ribavirin were administered.

Methods

RNA was isolated from peripheral blood monocytes (PBMC) from twenty treatment-naïve patients just before treatment (day 1) and at days 3, 6, 10, 13, 27, 42 and 70 days after treatment. Gene expression at each time was measured using Affymetrix microarrays and compared to that of day 1.

Results

The expression of many genes differed significantly (p ≤ 0.001 and changed at least 1.5-fold) at days 3 (290 probes) and 10 (255 probes), but the number dropped at days 6 (165) and 13 (142). Most genes continued to be up regulated throughout the trial period. A second group of genes, including CXCL10, CMKLR1 (chemokine receptor 1), TRAIL, IL1Rα and genes associated with complement and lipid metabolism, was transiently induced early in treatment. CDKN1C (cyclin kinase inhibitor 1) was induced early but repressed at later times. Genes induced at later times were mostly related to blood chemistry and oxygen transport. By week 10, 11 of the patients demonstrated a positive response to therapy, and the final sustained viral response (SVR) was 35%. The levels of gene induction or decrease was very similar to that previously reported with Pegasys/ribavirin treatment.

Conclusion

The response to Pegintron/ribavirin was similar to that reported for Pegasys/ribavirin despite some differences in the amount administered. We did not detect major differences at the genomic level between patients responding to treatment or non-responders, perhaps because of limited power. Gene induction occurred in a cyclic fashion, peaking right after administration of interferon and declining between administrations of the drug. Our data suggest that more than once a week dosing might be desirable early during treatment to maintain high levels of response as measured by gene expression.

Decreased type I interferon receptor-soluble isoform in antiretroviral-treated HIV-positive children

We developed a real-time PCR assay to simultaneously measure the mRNA level of type I interferon (IFN) receptor (IFNAR) components in peripheral blood cells of children with chronic immune stimulation due to HIV infection. All patients were undergoing antiretroviral therapy and were divided into two groups on the basis of the induction of MxA mRNA, a marker of type I IFN bioactivity. We found that IFNAR-2 subunit mRNA was higher than that of the IFNAR-1 subunit, that the mRNA for the IFNAR-2.2 functional isoform was more expressed than that for the truncated IFNAR-2.1 isoform, and both were much more represented than that of the IFNAR-2.3 soluble isoform. We also demonstrated that soluble isoform mRNA was significantly diminished in the subgroup of patients with MxA mRNA below the cutoff value (determined as the 99th percentile of MxA measured in healthy controls). These results suggest that downregulation of the soluble receptor isoform, which would not compete with the functional isoform for binding to the target cytokine, would give type I IFN, eventually induced in these patients in the case of viral reactivation, the opportunity to promptly exert its antiviral activity.

Modulation of IFNAR1 mRNA expression in multiple sclerosis patients

Interferon-beta receptor (IFNAR) is composed of 2 subunits, IFNAR1 and IFNAR2, the latter of which is expressed as functional (IFNAR2.2), non-functional (IFNAR2.1) and soluble (IFNAR2.3) isoform. Real-Time PCR analysis of mRNA for all IFNAR components in multiple sclerosis patients naïve for therapy and undergoing long-term treatment with interferon-beta shows that IFNAR1 mRNA level is lower than in healthy controls. If long-term treated patients are divided according to the production of mRNA for Myxovirus protein-A, a marker of interferon-beta bioactivity, IFNAR1 mRNA reaches the values observed in controls only in Myxovirus protein-A-induced patients. Since chronic cell stimulation by interferon-beta induces IFNAR protein down-regulation, we suggest that the increase of IFNAR1 mRNA might serve as a mechanism for counterbalancing the loss of protein receptor, enhancing, at least in this sub-group of patients, cell responsiveness to interferon-beta.

Treatment with IFNalpha in vivo up-regulates serum-soluble TNF-related apoptosis inducing ligand (sTRAIL) levels and TRAIL mRNA expressions in neutrophils in chronic myelogenous leukemia patients

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an interferon alpha (IFNalpha)-induced, apoptosis-inducing molecule. TRAIL could be one of the reagents for therapeutic use in combination with imatinib in chronic myeloid leukemia (CML). Here we examined serum-soluble TRAIL (sTRAIL) levels in CML patients either before or during therapies with IFNalpha or imatinib. In untreated CML patients, serum sTRAIL was detectable and the levels were substantially comparable with those in healthy donors. sTRAIL levels significantly increased in patients during IFNalpha therapy, but not at all in patients during imatinib therapy. TRAIL mRNA expressions in neutrophils in CML patients undergoing IFNalpha therapy was significantly elevated when compared with those in patients prior to therapy. TRAIL mRNA expressions were also detectable in CD34-positive cells in bone marrow, and the levels increased in patients during IFNalpha therapy. In vitro IFNalpha stimulation of CML neutrophils increased intracellular TRAIL rather than cell-surface TRAIL, and the secretion of sTRAIL in the culture supernatant was observed. This sTRAIL secretion was augmented with lipopolysaccharide (LPS) stimulation only in IFNalpha-primed neutrophils, whereas LPS alone had no effect. Taken together, in vivo IFNalpha treatment provokes the release of sTRAIL when administered systematically in CML patients. The main source of the IFNalpha-induced serum sTRAIL may be neutrophils in CML, and sTRAIL may be one of the mechanisms of the anti-proliferative action of IFNalpha on CML. These findings give another rationale for the use of IFNalpha or recombinant sTRAIL in CML, and also implicate the potential importance of neutrophils in tumor immunosurveillance.

Interferon receptor expression in multiple sclerosis patients

To determine the gene expression of IFNAR1, IFNAR2 and MxA protein and the association with IFNbeta treatment response in MS patients. MS patients treated with IFNbeta had a significant decrease in IFNAR1 and IFNAR2 expression, and a significant increase in MxA compared to non-treated patients and healthy controls. Also, those patients who had a good response to treatment had a significant decrease in IFNAR1 and IFNAR2 expression compared to non-responders, non-treated patients and healthy controls. IFNbeta influences the expression of its receptors, and is greater in patients who respond to IFNbeta treatment. This down-regulation could be indicative of the response to IFNbeta.

Functional expression of human type I interferon receptors in the mouse liver

We expressed human type I interferon (IFN) receptors (IFNAR) in mice and investigated their signaling. Using a hydrodynamics-based delivery method, vectors containing the genes for IFNAR1 and IFNAR2 were transferred into mice. Six hours after gene-transfer, mice were intravenously injected with human IFN-alpha at 10,000 IU. IFNAR1 and IFNAR2 were both expressed in the liver, but not spleen or lung. The receptors were coexpressed in single liver cells. One hour after IFN-alpha injection, the phosphorylation status of signal transducer and activator of transcription factor 1 (STAT1), a key molecule of IFN signaling, was determined. Phosphotyrosine-STAT1 (p-STAT1), localized to the nucleus of IFNAR-expressing cells, was increased in the livers of IFNAR gene-transferred mice but not in control vector-transferred animals. In conclusion, functional human IFNAR can be delivered to the mouse liver, resulting in an increase in p-STAT1 levels following human IFN-alpha stimulation.

Type I interferons act directly on CD8 T cells to allow clonal expansion and memory formation in response to viral infection

T cell expansion and memory formation are generally more effective when elicited by live organisms than by inactivated vaccines. Elucidation of the underlying mechanisms is important for vaccination and therapeutic strategies. We show that the massive expansion of antigen-specific CD8 T cells that occurs in response to viral infection is critically dependent on the direct action of type I interferons (IFN-Is) on CD8 T cells. By examining the response to infection with lymphocytic choriomeningitis virus using IFN-I receptor–deficient (IFN-IR⁰) and –sufficient CD8 T cells adoptively transferred into normal IFN-IR wild-type hosts, we show that the lack of direct CD8 T cell contact with IFN-I causes >99% reduction in their capacity to expand and generate memory cells. The diminished expansion of IFN-IR⁰ CD8 T cells was not caused by a defect in proliferation but by poor survival during the antigen-driven proliferation phase. Thus, IFN-IR signaling in CD8 T cells is critical for the generation of effector and memory cells in response to viral infection.