Suppressor Of Cytokine Signaling Genes Research Articles

Abstract 5363: New targeted therapy on SOCS1-related immune-response in triple-negative breast cancer

Abstract Background: Triple-negative breast cancer (TNBC) is heterogenous, which includes basal-like, immunomodulatory, mesenchymal, mesenchymal stem cell and luminal androgen receptor subtypes. In addition to chemotherapy, PARP inhibitors and immune checkpoint inhibitors are effective for TNBC with BRCA-mutated and PD-L1-positive cases. However, overall survival of TNBC remains unfavorable. To explore new targeted therapy in TNBC, we reported previously that SOCS1 (suppressor of cytokine signaling 1), IL-13 and several genes were predicted as interactive targets of miRNA in TNBC from the microarray expression analysis (Agilent Technologies, Inc.) of small RNA extracted from 11 breast cancer specimens (AACR2020, #1709). Thus, we investigated SOCS1-related immune-response under co-culture of TNBC and monocyte cell lines with or without paclitaxel exposure. Materials and Methods: MDA-MB-231, MDA-MB-468, RAW264.7 cell lines were used with co-culture system (Falcon® Cell Culture Inserts, Corning, NY, USA). SOCS1-expression vector and siSOCS1 were transfected into TNBC cell lines with polyethylenimine (PEI Max; Polysciences, Inc., Warrington, PA). RAW264.7 was activated with lipopolysaccaride (5ug/ml) and IFNγ (10ng/ml) for 2 days before co-culture. Relative cell viability of TNBC cell lines with vehicle control (DMSO) or paclitaxel exposure was measured with WST-8 (Cell Counting Kit-8; Dojindo, Japan) using TC20 Automated cell counter (Bio-Rad Laboratories, Inc., Japan) after 2 days’ co-culture of TNBC and RAW264.7 cells under several conditions of SOCS1 overexpression and/or RAW264.7 activation. Results: First, paclitaxel inhibited cell growth of MDA-MB-231 and MDA-MB-468 in a dose-dependent manner (at 1nM~100nM). Second, at paclitaxel exposure of 10 nM and 50 nM, relative cell viability of MDA-MB-468 decreased with co-culture of activated RAW264.7. The tendency was enhanced with SOCS1 overexpression in breast cancer cell lines. Similar results were observed in MDA-MB-231 cells. Discussions: SOCS1 is well known as a negative regulator of JAK-STAT pathway. SOCS1 is also related to suppression of T cell activation and modulation of M1 macrophage. At AACR2020, we reported that SOCS1 gene amplification in cancer tissues after neoadjuvant chemotherapy was relatively lower in 6 cases with pathologically partial or complete response than in 11 cases with no pathological response. In vitro, paclitaxel-toxicity in TNBC cells was augmented by activated monocyte (M1 macrophage) and more sensitized with SOCS1 overexpression in TNBC cells. These results suggest that proinflammatory cytokines from M1 macrophage influence cell viability of TNBC. Conclusion: SOCS1 is a promising molecular target to modulate immune-response in TNBC. Citation Format: Shigeru Imoto, Tomohiro Chiba, Hirohito Seki, Yoshiharu Ishizaka, Ai Tsuchiya, Tomoko Kitaoka. New targeted therapy on SOCS1-related immune-response in triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5363.

CpG Island Methylation of Suppressor of Cytokine Signaling-1 Gene Induced by HCV Is Associated With HCV-Related Hepatocellular Carcinoma.

Suppressor of cytokine signaling 1 (SOCS-1) is implicated in both virus infection and carcinogenesis. This study investigated the role of HCV infection on SOCS-1 in normal and HCV-infected tissues and revealed a possible mechanism underlying HCV-induced hepatocellular carcinoma (HCC) genesis. In total, 10 HCV-HCC tissues, seven adjacent tissues, seven distal tissues, and 16 normal liver tissues were collected. SOCS-1 expression in tissue sections was detected by immunohistochemistry. After viral load was quantified, the correlation between SOCS-1 expression and viral load was analyzed in different tissues. Then, HCV replicon model was used to detect a relationship between HCV and SOCS-1. Subsequently, methylation-specific PCR (MSP) was applied to show the methylation status of SOCS-1 genes in normal tissues and HCV-replicating cell lines. A correlation between gene methylation, SOCS-1 expression, and HCV was analyzed. The lowest expression of SOCS-1 was observed in HCV-HCC tissues. Tissues with a higher HCV viral load showed lower SOCS-1 expression (p = 0.0282). Consistently, SOCS-1 mRNA and protein were lower in HCV-replicating cell lines than in uninfected ones. Furthermore, gene methylation was found in all examined tissues but higher in HCC tissues, and it is positively correlated with HCV viral load (r2 = 0.7309, p < 0.0001). HCV infection would upregulate methylation of the SOCS-1 gene in HCV-replicating cell lines. The downregulation of SOCS-1 in normal and HCV-replicating cell lines may result from HCV infection through epigenetic regulation, in which gene methylation in the CpG island of SOCS-1 promoters upon HCV infection suppresses its expression.

Abstract 1709: New targeted therapy on SOCS1-related immune-response in triple-negative breast cancer

Abstract Background: Triple-negative breast cancer (TNBC) includes heterogenous molecular subtypes, e.g., basal-like, immunomodulatory, mesenchymal, mesenchymal stem cell and luminal androgen receptor subtypes. Chemotherapy is the standard care for patients with early TNBC, but advanced or metastatic disease has unfavorable prognosis. PARP inhibitors and immune checkpoint inhibitors are effective for patients with BRCA gene mutation and PD-L1-positive TNBC, respectively. However, their clinical benefits seem to be limited. Thus, we are investigating new therapy targeted on immune modulation in TNBC. Materials and methods: First, we performed microarray expression analysis (Agilent Technologies, Inc.) of small RNA extracted from 11 breast cancer specimens. Second, miRNA subset was compared in TNBC and non-TNBC, and several genes were identified as predicted targets for interaction of miRNA in TNBC. Third, we examined a targeted gene and protein expressions in cancer tissues by real-time qPCR and immunohistochemical staining. Tissues samples were obtained from breast cancer patients with TNBC and non-TNBC, who were scheduled to receive neoadjuvant chemotherapy (NAC). Statistical significance is evaluated by chi-squared test. This study is approved at IRB in Kyorin University School of Medicine and also supported by Grant-in-Aid for Scientific Research C of Japan Society for the Promotion of Science. Results: From comprehensive analysis, SOCS1 (suppressor of cytokine signaling 1), IL-13 and several genes were predicted as interactive targets of miRNA in TNBC. We focused on SOCS1 gene amplification and its protein overexpression in breast cancer. Most patients were treated with NAC of anthracycline- and/or taxane-based regimens. Their pathological response was graded in surgical specimens according to classification of the Japanese Breast Cancer Society. From 55 tissue specimens stained by anti-SOCS1 antibody, there was no difference among staining intensity graded at score 0-3 and pathological response of chemotherapy. However, gene amplification of SOCS1 was not statistically different but relatively lower in 6 cases with pathologically partial or complete response (grade 2 or 3) than in 11 cases with no pathological response (grade 1a or 1b). Discussions: SOCS1 is well known as a negative regulator of JAK-STAT pathway. SOCS1 is also related to suppression of T cell activation and modulation of M1 macrophage. Our data suggest that down regulation of SOCS1 gene influences clinical benefit of chemotherapy as well as host immune response like tumor-infiltrating lymphocytes (TIL). We will examine relationship between SOCS1 protein expression and TIL in breast cancer and also examine cell proliferation and T cell activation in TNBC and non-TNBC cell lines under presence and absence of SOCS1 gene expression. Conclusion: SOCS1 is a promising molecular target to modulate immune editing in TNBC. Citation Format: Shigeru Imoto, Tomohiro Chiba, Sota Asaga, Hirotsugu Isaka, Shigehiro Yokoi, Yoshiharu Ishizaka, Ai Tsuchiya, Hiroshi Kamma. New targeted therapy on SOCS1-related immune-response in triple-negative breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1709.

The Effect of 5-Aza-2′-Deoxycytidine in Combination to and in Comparison with Vorinostat on DNA Methyltransferases, Histone Deacetylase 1, Glutathione S-Transferase 1 and Suppressor of Cytokine Signaling 1 Genes Expression, Cell Growth Inhibition and Apop

Background: Aberrant methylation and histone deacetylation of tumor suppressor genes (TSGs) are the most epigenetic alterations involving in tumorigenesis. Overexpression of DNA methyltransferases (DNMTs) and histone deacetylase 1 (HDAC1) have been reported in several cancers. The reversion of hypermethylation and deacetylation by epi-drugs such as 5-aza-2′-deoxycytidine (5-AZA-CdR) and vorinostat (SAHA) can restore normal expression of TSGs. Previously, we reported that 5-AZA-CdR and valproic acid (VPA) can inhibit DNMT1 in hepatocellular carcinoma (HCC). The aim of this study was to investigate the effect of 5-AZA-CdR in combination to and in comparison with SAHA on DNMT1, DNMT3a, DNMT3b, histone deacetylase 1 (HDAC1), glutathione S-transferase 1 (GSTP1) and suppressor of cytokine signaling 1 (SOCS1) genes expression, cell growth inhibition and apoptotic induction in hepatocellular LCL-PI 11 cell line. Materials and Methods: The cells were treated with 5-AZA-CdR and SAHA and then MTT assay, cell apoptosis assay and Real-time quantitative RT-PCR (qRT-PCR) were done. Results: Both agents indicated significant inhibitory and apoptotic effect (P&lt; 0.001). The apoptotic effect of SAHA was more than that of 5-Aza-CdR. The result of qRT-PCR indicated that 5-Aza-CdR decreased DNMT1, DNMT3a, DNMT3b and increased GSTP1and SOCS1 genes expression and SAHA decreased HDAC1 and increased GSTP1 and SOCS1 genes expression significantly. Maximal apoptosis and genes expression were seen with combined treatment. Conclusion: 5-AZA-CdR and SAHA down-regulated DNMT1, DNMT3a, DNMT3b, and HDAC1 and up-regulated GSTP1 and SOCS1 gene expression by which inhibited cell viability and induced apoptosis, suggesting that they could be used in the treatment of HCC.

Bromodomain and Extraterminal Inhibition by JQ1 Produces Divergent Transcriptional Regulation of Suppressors of Cytokine Signaling Genes in Adipocytes.

The Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway has cell-specific functions. Suppressors of cytokine signaling (SOCS) proteins are negative-feedback regulators of JAK-STAT signaling. STAT5 plays a significant role in adipocyte development and function, and bromodomain and extraterminal (BET) proteins may be involved in STAT5 transcriptional activity. We treated 3T3-L1 adipocytes with the BET inhibitor JQ1 and observed that growth hormone (GH)-induced expression of 2 STAT5 target genes from the SOCS family, Socs3 and Cish, were inversely regulated (increased and decreased, respectively) by BET inhibition. Chromatin immunoprecipitation analyses revealed that changes in STAT5 binding did not correlate with gene expression changes. GH promoted the recruitment of the BET protein BRD2 to the Cish, but not Socs3, promoter. JQ1 treatment ablated this effect as well as the GH-induced binding of ribonucleic acid polymerase II (RNA Pol II) to the Cish transcription start site. BRD2 knockdown also suppressed GH induction of Cish, further supporting the role of BRD2 in Cish transcriptional activation. In contrast, JQ1 increased the binding of activated Pol II to the Socs3 coding region, suggesting enhanced messenger RNA (mRNA) elongation. Our finding that JQ1 transiently reduced the interaction between the positive transcription elongation factor (P-TEFb) and its inhibitor hexamethylene bis-acetamide inducible 1 (HEXIM1) is consistent with a previously described off-target effect of JQ1, whereby P-TEFb becomes more available to be recruited by genes that do not depend on BET proteins for activating transcription. These results demonstrate substantially different transcriptional regulation of Socs3 and Cish and suggest distinct roles in adipocytes for these 2 closely related proteins.

Sexual dimorphism in up-regulation of suppressors of cytokine signaling genes in patients with bipolar disorder

BackgroundProteins encoded by Suppressors of cytokine signaling (SOCS) genes have critical roles in the regulation of immune responses. Meanwhile, several lines of evidence support the presence of immune dysfunction in bipolar disorder (BD) patients.MethodsIn the present study, we assessed expression levels of SOCS1–3 and SOCS5 genes in peripheral blood of patients with BD and healthy subjects.ResultsAll SOCS genes were up-regulated in patients compared with healthy subjects. However, when comparing patients with sex-matched controls, the significant differences were observed only in the male subjects except for SOCS5 which was up-regulated in both male and female patients compared with the corresponding control subjects. Significant pairwise correlations were found between expression levels of genes in both patients and controls. Based on the area under curve values, SOCS5 had the best performance in the differentiation of disease status in study participants (AUC = 0.92). Combination of four genes increased the specificity of tests and resulted in diagnostic power of 0.93.ConclusionTaken together, these data suggest a role for SOCS genes in the pathogenesis of BD especially in the male subjects. Moreover, peripheral expression levels of SOCS genes might be used as a subsection of a panel of diagnostic biomarkers in BD.

Suppressor of cytokine signaling genes in renal transplant receivers: Association with transplant fate

Suppressor of cytokine signaling (SOCS) proteins have acknowledged roles in regulation of immune responses. Moreover, their role in the evolution of allograft rejection is being elucidated. In the current investigation, we measured transcript levels of SOCS1-4 in the peripheral blood of a group of renal transplant recipients including both rejected and non-rejected allografts. Expression analyses showed that relative expression of SOCS2 was significantly higher in transplant-rejected male patients compared to non-rejected group. However, such significant difference was not detected between female subjects. Expression of SOCS2 was significantly higher in T-cell-mediated rejection group compared with non-rejected individuals with creatinine rise (Relative expression difference [95% CrI] =6.74 [0.94, 12.65], P = 0.043). Conversely, SOCS4 expression was significantly lower in T-cell-mediated rejection group compared with non-rejected individuals with creatinine rise (Relative expression difference [95% CrI] = −0.35 [−0.63, −0.1], P = 0.008). Patterns of correlations between expression levels of SOCS genes were different in non-rejected group. The obtained results indicate the role SOCS genes in development of allograft rejection.

Role of SOCS1 Gene in Chronic Hepatitis C Virus Patients: A Mini-Review.

Hepatitis C virus (HCV) is a global health problem, with an estimated bioburden of >180 million. Every year about 350,000 people die from HCV-associated liver complications such as cirrhosis and cancer (e.g., hepatocellular carcinoma). Pakistan has the second highest prevalence of HCV. Treatment of this life-threatening disease has been a challenge, but recent developments in direct-acting antivirals have offered hope to many. Although direct-acting antivirals have dramatically improved viral clearance, their exorbitant costs put them out of reach for patients in developing countries. Thus, interferon therapy is still being used in Pakistan. Specifically, interferon-stimulating genes can alter treatment response. For example, interferons induce expression of many antiviral genes through signal transducer and activator of transcription/Janus kinase signaling. Suppressor of cytokine signaling genes play an eminent role in the inhibition of cytokine signaling pathways and regulation of both adaptive and innate immunity. The present review examines expression of suppressor of cytokine signaling-1 in HCV-treated patients.

SOCS1 and pattern recognition receptors: TLR9 and RIG-I; novel haplotype associations in Egyptian fibrotic/cirrhotic patients with HCV genotype 4.

In this paper we explore the role of suppressor of cytokine signaling 1 (SOCS1) (rs243327), the regulator of toll-like receptor-9 (TLR9) (rs352140), retinoic acid inducible gene-I (RIG-I) (rs669260), and cluster of differentiation 152 (CD152) (rs231776) in fibrotic/cirrhotic patients. Single nucleotide polymorphisms (SNPs) within these genes as well as haplotype analyses were performed on a cohort of 120 Egyptian fibrotic patients. Fibrosis had progressed from HCV genotype 4 infections. Using RT-PCR, SNPs were evaluated in the DNA collected from each patient using TaqMan® genotyping assays. A regression model was used to evaluate allelic and haplotypic associations with a fibrosis/cirrhotic scale. The necroinflammatory A score was adjusted for non-genetic covariates. The genotype distributions for SOCS1 (rs243327) and TLR-9 (rs352140) differed significantly between the F1-F3 and F3-F4 groups. On the other hand, the genotype distributions for RIG-I (rs669260) and CD152 (rs231776) genes did not significantly differ. The allele frequency was calculated using Hardy-Weinberg Equilibrium (HWE) for the SOCS1 (rs243327), RIG-I (rs669260), and CD152 (rs231776) genes. These calculated frequency values indicated the need to compare them to another population for that locus. However, TLR9 (rs352140) did not show similar results. The A allele in SOCS1, TLR9, and RIG-I SNPs was an adverse prognostic factor forliver fibrosis and liver activity. Haplotype analysis revealed a significant association between SOCS1 and TLR9 in fibrotic/cirrhotic patients. This indicated the presence of the A allele in either gene, which is considered a risk factor for the progression of liver disease to cirrhosis. SOCS1 rs243327, TLR9 rs352140, and RIG-I rs669260 polymorphisms might affect liver pathophysiology and the cirrhotic outcome following genotype 4 HCV infection. Therefore, performing this specific SNP testing may be of value for the stratification of the population at risk.

Functional polymorphisms affecting Th1 differentiation are associated with the severity of autoimmune thyroid diseases.

The prognosis for autoimmune thyroid diseases (AITDs), such as Hashimoto's disease (HD) and Graves' disease (GD), varies among patients. Interleukin (IL)-12 and IL-18 also induce Th1 differentiation, and SOCS1 (Suppressor of cytokine signaling 1) and TIM-3 (T cell immunoglobulin and mucin domain-3) are known to be negative regulators of Th1 cells. To clarify the association of functional polymorphisms in the IL12, IL12Rβ1, IL18, SOCS1 and TIM3 genes with the intractability and severity of autoimmune thyroid disease (AITD), we genotyped these polymorphisms in 151 GD patients, including 61 patients with intractable GD and 51 patients with GD in remission, in 140 HD patients, including 59 patients with severe HD and 55 patients with mild HD, and in 74 healthy controls. The frequency of the IL18 -607CC genotype which correlates with a high production of IL-18, was significantly higher in patients with GD in remission than in those with intractable GD (p=0.0178). The -607C allele was significantly higher in patients with severe HD than in those with mild HD (p=0.0050). The -607CC genotype in IL18 gene may be protective against the intractability of GD, and the -607C allele may enhance the severity of HD.

Methylation and mRNA expression levels of P15, death-associated protein kinase, and suppressor of cytokine signaling-1 genes in multiple myeloma.

The aim of this study was to investigate the methylation status and mRNA expression levels of P15, death-associated protein kinase (DAPK), and suppressor of cytokine signaling-1 (SOCS1) genes in multiple myeloma (MM). The bone marrow samples of 54 MM patients were collected and the methylation status of the P15, DAPK, and SOCS1 gene promoter regions was determined by methylation-specific polymerase chain reaction. Automated sequencing technology was used to sequence the amplified products in order to analyze the base methylation sites. mRNA expression levels were determined using real-time fluorescent quantitative polymerase chain reaction. Among the 54 MM patients, the positive methylation rates of the P15, DAPK, and SOCS1 genes were 27.78%, 18.52%, and 16.67%, respectively. The methylation results were confirmed by sequencing. The positive methylation rates of the P15, DAPK, and SOCS1 genes showed no correlation with patient gender, age, typing, staging, and grouping (P>0.05). There was no significant difference in the mRNA expression levels of the P15, DAPK, and SOCS1 genes between the MM patient group and the control group (P>0.05). Aberrant methylation of the P15, DAPK, and SOCS1 genes exists in MM, and these genes may play certain roles in pathogenesis of MM. There was no significant difference in mRNA expression levels between the methylated group and the non-methylated group, suggesting that these genes are regulated by other mechanisms during their transcription.

Evaporative cooling in late-gestation Murrah buffaloes potentiates immunity around transition period and overcomes reproductive disorders

The objective of the study was to observe the effect of evaporative cooling during late gestation on immunity around the transition period and the probable outcome on reproductive disorders in Murrah buffaloes. Sixteen pregnant dry Murrah buffaloes at 60 days prepartum were selected and divided into two groups of eight animals each. Group 1 buffaloes remained without the provision of cooling, whereas the second group of buffaloes was managed under fans and mist cooling during the dry period. After parturition, all the animals were managed under evaporative cooling. Dry matter intake was significantly (P < 0.05) higher in cooled relative to noncooled animals at −15, 0, and +20 days of parturition. Cortisol and prolactin levels were significantly (P < 0.05) higher in noncooled relative to cooled animals at −15 and 0 days of parturition. However, prolactin was significantly (P < 0.05) higher in cooled animals at +20 days. Messenger RNA expression of prolactin receptor gene (PRL-R) was upregulated and suppressor of cytokine signaling gene 1 (SOCS-1) was downregulated in cooled animals at −20, 0, and +20 days of parturition. Tumor necrosis factor α and interleukin 4 levels remained significantly (P < 0.05) higher in cooled animals at −20, 0, and +20 days of parturition. Interleukin 6 was significantly (P < 0.05) lower in cooled animals at −20 and 0 days. Interferon γ levels were significantly higher at −20 and +20 days of parturition in cooled relative to noncooled animals. The reproductive disorders such as retention of placenta, metritis, and endometritis occurred at the rate of 37.25%, 25%, and 12.25% in the noncooled group, whereas only retention of placenta was observed in the cooled (12.5%) group.

Investigation of the roles of interleukin 6 and transforming growth factor β signaling in Th17/Treg imbalance of Hashimoto's thyroiditis

Objective To investigate the role of interleukin(IL)-6/transforming growth factor β(TGF-β)signaling in T helper cell 17(Th17)/regulatory T cells(Treg)imbalance of Hashimoto's thyroiditis(HT). Methods Thirty-eight patients with HT and thirty-two healthy controls were studied. Plasma concentration of IL-6 and TGF-β was measured by enzyme-linked immunosorbent assay. Expression levels of retinoid related orphan receptor γt(RORγt), forkhead box P3(FOXP3), Smad3, Smad4, transforming growth factor β inducible early response gene 1(TIEG1), itchy E3 ubiquitin protein ligase(Itch), suppressor of cytokine signaling 1(SOCS1), and SOCS3 mRNA were determined by realtime PCR. The proportions of CD4+ IL-17A+ T cells(Th17), CD4+ CD25+ FOXP3+ regulatory T cells(Treg)and mean fluorescence intensity for transforming growth factor β receptor type Ⅱ(TGF-βRⅡ)and phosphated signal transducer and activator of transcription 3(pSTAT3)protein in CD4+ T cells were analyzed by flow cytometry. Quantitative methylation specific PCR was used to evaluate methylation status of CpG islands in SOCS1 exon2, and three potential bind sites for signal transducer and activator of transcription 3(STAT3)in 5'-untraslated region(5'-UTR)of SOCS3 in CD4+ T cells. In-vitro culture of CD4+ T cells isolated from healthy donors was used to identify the effects of IL-6/TGF-β signaling on differentiation of Th17/Treg and methylation status of SOCS1 and SOCS3 genes after being stimulated for 72 hours. Results (1)In patients with HT, the proportion of Th17 cells and expression levels of RORγt mRNA were significantly elevated(P 0.05). (4)Compared with blank controls, Treg increased remarkably while Th17 and the ration of Th17/Treg decreased significantly after TGF-β stimulation for 72 h(P 0.05). Conclusions Aberrant IL-6/TGF-β signaling may be one of the important factors that contribute to imbalance of Th17/Treg in HT. (Chin J Endocrinol Metab, 2015, 31: 320-326) Key words: Interleukin 6; STAT3; Hashimoto's thyroiditis; Th17; Regulatory T cells

Molecular characterization of two suppressor of cytokine signaling 1 genes (SOCS1a and SOCS1b) in chickens

Suppressor of cytokine signaling 1 (SOCS1) protein can inhibit the signal transduction triggered by some cytokines or hormones and thus are important in many physiological/pathological processes, including innate and adaptive immunity, inflammation, and deve- lopment in mammals. However, there is sparse informa- tion about their structure, tissue expression, in birds, where their biological functions remain unknown. In this study, we cloned and characterized two SOCS1 genes (named cSOCS1a and cSOCS1b) from chickens. SOCS1a is predicted to encode a 207-amino acid protein, which shares high amino acid sequence identity (64%-67%) with human and mouse SOCS1. Besides SOCS1a, a novel SOCS1b gene was also identified in chickens and other non-mammalian vertebrates including Xenopus tropicalis. Chicken SOCS1b is predicted to encode a 212-amino acid protein, which shares only 30%-32% amino acid sequence identity with human SOCS1 and cSOCS1a. RT-PCR assay revealed that both cSOCS1a and cSOCS1b are widely expressed in all chicken tissues. Using a luciferase reporter assay system, we further demonstrated that transient expression of cSOCS1a and cSOCS1b can significantly inhibit chicken growth hormone (GH)- or prolactin (PRL)- induced luciferase activities of Hep G2 cells expressing cGH receptor (or cPRL receptor), indicating that SOCS1a and SOCS1b proteins can negatively regulate GH/PRL signaling. Taken together, these data suggest that both cSOCS1a and cSOCS1b may function as negative regulators of cytokine/hormone actions, such as modula- tion of GH/PRL actions in chickens.

Expression of suppressor of cytokine signaling genes in human elderly and Alzheimer’s disease brains and human microglia

Multiple cellular systems exist to prevent uncontrolled inflammation in brain tissues; the suppressor of cytokine signaling (SOCS) proteins have key roles in these processes. SOCS proteins are involved in restricting cellular signaling pathways by enhancing the degradation of activated receptors and removing the stimuli for continued activation. There are eight separate SOCS genes that code for proteins with similar structures and properties. All SOCS proteins can reduce signaling of activated transcription factors Janus kinase (JAK) and signal transducer and activator of transcription (STAT), but they also regulate many other signaling pathways. SOCS-1 and SOCS-3 have particular roles in regulating inflammatory processes. Chronic inflammation is a key feature of the pathology present in Alzheimer’s disease (AD)-affected brains resulting from responses to amyloid plaques or neurofibrillary tangles, the pathological hallmarks of AD. The goal of this study was to examine SOCS gene expression in human non-demented (ND) and AD brains and in human brain-derived microglia to determine if AD-related pathology resulted in a deficit of these critical molecules. We demonstrated that SOCS-1, SOCS-2, SOCS-3 and cytokine-inducible SH2 containing protein (CIS) mRNA expression was increased in amyloid beta peptide (Aβ)- and inflammatory-stimulated microglia, while SOCS-6 mRNA expression was decreased by both types of treatments. Using human brain samples from the temporal cortex from ND and AD cases, SOCS-1 through SOCS-7 and CIS mRNA and SOCS-1 through SOCS-7 protein could be detected constitutively in ND and AD human brain samples. Although, the expression of key SOCS genes did not change to a large extent as a result of AD pathology, there were significantly increased levels of SOCS-2, SOCS-3 and CIS mRNA and increased protein levels of SOCS-4 and SOCS-7 in AD brains. In summary, there was no evidence of a deficit of these key inflammatory regulating proteins in aged or AD brains.

Polymer nanoparticles for enhanced immune response: Combined delivery of tumor antigen and small interference RNA for immunosuppressive gene to dendritic cells

In this study, we report on polymer nanoparticles (NPs) that can induce an enhanced immune response in dendritic cell (DC)-based cancer immunotherapy by the combined delivery of tumor antigen and small interference RNA (siRNA) for the immunosuppressive gene to DCs. DCs are specialized antigen-presenting cells (APCs) that capture, process and present antigens and induce an antigen-specific cytotoxic T lymphocyte response. Because the suppressor of cytokine signaling 1 (SOCS1) is a negative regulator of the APC-based immune response, the inhibition of SOCS1 gene expression is essential for DCs to enhance antigen-specific anti-tumor immunity. Multifunctional poly(lactide-co-glycolic acid) (PLGA) NPs that can deliver tumor antigen and siRNA for immunosuppressive SOCS1 genes to DCs simultaneously were fabricated by the emulsion solvent evaporation method. We have found that the encapsulation efficiency of small-sized and hydrophilic SOCS1 siRNA into hydrophobic PLGA matrix is drastically enhanced by the help of a tumor model antigen such as ovalbumin (OVA), and the encapsulation efficiency of siRNA in PLGA (SOCS1 siRNA only) NPs and PLGA (OVA/SOCS1 siRNA) NPs was ∼2% and 57.6%, respectively. PLGA (OVA/SOCS1 siRNA) NPs were efficiently taken up by bone-marrow-derived dendritic cells (BMDCs) and showed no detectable toxic effect. The knockdown of SOCS1 in BMDCs by PLGA (OVA/SOCS1 siRNA) NPs enhanced pro-inflammatory cytokine (tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), IL-12 and IL-2) expression. Additionally, PLGA (OVA/SOCS1 siRNA) NP-treated BMDCs could elicit an immune response through cross-presentation in OVA-specific CD8 T cells that express IL-2 cytokine. Taken together, the combined delivery of NPs that can deliver both tumor antigen and immunosuppressive gene siRNA to BMDCs simultaneously could be a potent strategy to enhance immunotherapeutic effects in BMDC-based cancer therapy.

Enhanced cancer immunotherapy using nanoparticle-based modulation of SOCS1 genes in dendritic cells (P4242)

Abstract Although dendritic cells have important roles in cancer immunotherapy, their therapeutic efficiencies were limited due to the presence of immunosuppressive factors. Here, we report the fabrication and use of polymer nanoparticles for the simultaneous delivery of antigens and small interference RNA (siRNA) of immune suppressor genes into dendritic cells. The polymer nanoparticles containing ovalbumin (OVA, as a model antigen) and siRNA of suppressor of cytokine signaling 1 (SOCS1) were fabricated by double emulsion solvent evaporation method. The encapsulation of siRNA was about 57.6 % when OVA was present during the preparation, while that was only 2 % without the OVA. The polymer nanoparticles containing OVA and siRNA of SOCS1 were efficiently taken up by the dendritic cells and showed no detectable toxicity. The knockdown of SOCS1 genes in dendritic cells induced pro-inflammatory and anti-inflammatory cytokine expression. The polymer nanoparticles are expected to be potent nanotechnology platform for targeted delivery of siRNA and antigens into dendritic cells, and use as CD8+ T cells-based cancer immunotherapy.

Expression ofSOCS1andSOCS3genes in human graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

BackgroundSuppressor of cytokine signaling genes (SOCS) are regarded as pivotal negative feedback regulators of cytokine signals, including the interferon-gamma (IFN-γ), granulocyte-colony stimulating factor, and interleukin families, released by T cells. A detailed understanding of the involvement of SOCS genes in graft-versus-host disease (GVHD) is critical to effectively manage GVHD, yet their expression patterns among recipients remain largely unexplored.MethodsExpression levels of SOCS1 and SOCS3 were determined by real-time quantitative reverse transcription PCR (qRT-PCR) in patients with acute GVHD (aGVHD) and chronic GVHD (cGVHD), in a severity-dependent manner, after allogeneic hematopoietic stem cell transplantation (HSCT). A total of 71 recipients with AML (N=40), ALL (N=12), myelodysplastic syndromes (MDS; N=10), chronic myelogenous leukemia (CML; N=2), severe aplastic anemia (SAA; N=5), or others (N=2), who received allogeneic HSCT from human leukocyte antigen-identical siblings or unrelated donors between 2009 and 2011, were included in the present study.ResultsOverall, the expression levels of SOCS1 decreased in recipients with grade II to IV aGVHD and cGVHD when compared to normal donors and non-GVHD recipients. Interestingly, the expressions of SOCS1 decreased significantly more in cGVHD than in aGVHD recipients (P=0.0091). In contrast, SOCS3 expressions were similarly reduced in all the recipients.ConclusionThis is the first study to show that SOCS1 and SOCS3 are differentially expressed in recipients following allogeneic HSCT, suggesting a prognostic correlation between SOCS genes and the development of GVHD. This result provides a new platform to study GVHD immunobiology and potential diagnostic and therapeutic targets for GVHD.

Association of primary biliary cirrhosis with variants in the CLEC16A, SOCS1, SPIB and SIAE immunomodulatory genes

We fine mapped two primary biliary cirrhosis (PBC) risk loci, CLEC16A (C-type lectin domain family 16 member A)-suppressor of cytokine signaling 1 (SOCS1) and Spi-B protein (SPIB) and sequenced a locus, sialic acid acetylesterase (SIAE), proposed to harbor autoimmunity-associated mutations. In all, 1450 PBC cases and 2957 healthy controls were genotyped for 84 single-nucleotide polymorphisms (SNPs) across the CLEC16A-SOCS1 and SPIB loci. All 10 exons of the SIAE gene were resequenced in 381 cases and point substitutions of unknown significance assayed for activity and secretion. Fine mapping identified 26 SNPs across the CLEC16A-SOCS1 and 11 SNPs across the SPIB locus with significant association to PBC, the strongest signals at the CLEC16A-SOCS1 locus emanating from a SOCS1 intergenic SNP (rs243325; P=9.91 × 10(-9)) and at the SPIB locus from a SPIB intronic SNP (rs34944112; P=3.65 × 10(-9)). Among the associated SNPs at the CLEC16A-SOCS1 locus, two within the CLEC16A gene as well as one SOCS1 SNP (rs243325) remained significant after conditional logistic regression and contributed independently to risk. Sequencing of the SIAE gene and functional assays of newly identified variants revealed six patients with functional non-synonymous SIAE mutations (Fisher's P=9 × 10(-4) vs controls) We demonstrate independent effects on risk of PBC for CLEC16A, SOCS1 and SPIB variants, while identifying functionally defective SIAE variants as potential factors in risk for PBC.

Identification and characterization of suppressor of cytokine signaling 1 (SOCS-1) homologues in teleost fish

The suppressor of cytokine signaling 1 (SOCS-1), as the name implies, is a member of proteins that regulate cytokine signaling pathways by inhibiting the events of key tyrosine phosphorylation on cytokine receptors and signaling molecules such as Janus kinase family members. Although mammalian SOCS-1 homologues were characterized in several species, no similar research work has been reported in fish yet. In this paper, we initially cloned the SOCS-1 genes from Tetraodon nigroviridis and Danio rerio, and identified other two SOCS-1 genes from Fugu rubripes and Gasterosteus aculeatus. The results showed that the fish SOCS-1-encoding genes consist of two exons and a single intron, a typical characteristic of SOCS family in gene organization. Moreover, two alternatively spliced transcripts that encoded 220 and 196 amino acids were obtained in T. nigroviridis, proving the distinct existence of alternative splicing in fish SOCS-1 different from higher vertebrates. By reverse transcriptase polymerase chain reaction (PCR) and real-time quantitative PCR, gene expression studies indicated that both two alternatively spliced transcripts of Tetraodon SOCS-1 were expressed extensively in major tissues as we examined and their corresponding expression levels could be strikingly raised at 3 h postinjection with lipopolysaccharide, which strongly suggested that SOCS-1 proteins in fish might be involved in inflammatory responses. This is the first report of cloning and characterization of SOCS-1 complementary deoxyribonucleic acids and genes in fish.