Role of SOCS1 in tumor progression and therapeutic application

The Interplay Between Helicobacter pylori and Suppressors of Cytokine Signaling (SOCS) Molecules in the Development of Gastric Cancer and Induction of Immune Response

Helicobacter pylori (H. pylori) colonizes the stomach and leads to the secretion of a vast range of cytokines by infiltrated leukocytes directing immune/inflammatory response against the bacterium. To regulate immune/inflammatory responses, suppressors of cytokine signaling (SOCS) proteins bind to multiple signaling components located downstream of cytokine receptors, such as Janus kinase (JAK), signal transducers and activators of transcription (STAT). Dysfunctional SOCS proteins in immune cells may facilitate the immune evasion of H. pylori, allowing the bacteria to induce chronic inflammation. Dysregulation of SOCS expression and function can contribute to the sustained H. pylori-mediated gastric inflammation which can lead to gastric cancer (GC) development. Among SOCS molecules, dysregulated expression of SOCS1, SOCS2, SOCS3, and SOCS6 were indicated in H. pylori-infected individuals as well as in GC tissues and cells. H. pylori-induced SOCS1, SOCS2, SOCS3, and SOCS6 dysregulation can contribute to the GC development. The expression of SOCS molecules can be influenced by various factors, such as epigenetic DNA methylation, noncoding RNAs, and gene polymorphisms. Modulation of the expression of SOCS molecules in gastric epithelial cells and immune cells can be considered to control gastric carcinogenesis as well as regulate antitumor immune responses, respectively. This review aimed to explain the interplay between H. pylori and SOCS molecules in GC development and immune response induction as well as to provide insights regarding potential therapeutic strategies modulating SOCS molecules.

SOCS1 acts as a ferroptosis driver to inhibit the progression and chemotherapy resistance of triple-negative breast cancer

OBJECTIVES

Ferroptosis is involved in many types of cancers, including triple-negative breast cancer (TNBC). Suppressor of cytokine signaling 1 (SOCS1) has recently been implicated as a regulator of ferroptosis. We aim to explore whether targeting SOCS1 is a potential therapeutic strategy for TNBC therapy.

METHODS

Stable cell lines were constructed using lentivirus transfection. Cell viability was determined using CCK-8 and cell colony formation assays, respectively. Assays including lactate dehydrogenase release, lipid peroxidation and malondialdehyde assays were conducted to evaluate ferroptosis. Real-time quantitative polymerase chain reaction and western blotting were performed to evaluate mRNA and protein expression, respectively. A xenograft animal model was established by subcutaneous injection of cells into the flank.

RESULTS

Our results showed that SOCS1 overexpression inhibited cell proliferation and induced ferroptosis in TNBC cells, while SOCS1 knockdown promoted cell proliferation and reduced ferroptosis. We also found that SOCS1 regulated ferroptosis by modulating GPX4 expression. Furthermore, SOCS1 regulated cisplatin resistance in TNBC cells by promoting ferroptosis. Our in vivo data suggested that SOCS1 regulated tumor growth and cisplatin resistance in vivo.

CONCLUSIONS

SOCS1 inhibits the progression and chemotherapy resistance of TNBC by regulating GPX4 expression.

Gold nanoparticles attenuate the interferon-γ induced SOCS1 expression and activation of NF-κB p65/50 activity via modulation of microRNA-155-5p in triple-negative breast cancer cells

Objective

Triple-negative breast cancer (TNBC) is a very aggressive form of cancer that grows and spreads very fast and generally relapses. Therapeutic options of TNBC are limited and still need to be explored completely. Gold nanoparticles conjugated with citrate (citrate-AuNPs) are reported to have anticancer potential; however, their role in regulating microRNAs (miRNAs) in TNBC has never been investigated. This study investigated the potential of citrate-AuNPs against tumorigenic inflammation via modulation of miRNAs in TNBC cells.

Methods

Gold nanoparticles were chemically synthesized using the trisodium-citrate method and were characterized by UV-Vis spectrophotometry and dynamic light scattering studies. Targetscan bioinformatics was used to analyze miRNA target genes. Levels of miRNA and mRNA were quantified using TaqMan assays. The pairing of miRNA in 3'untranslated region (3'UTR) of mRNA was validated by luciferase reporter clone, containing the entire 3'UTR of mRNA, and findings were further re-validated via transfection with miRNA inhibitors.

Results

Newly synthesized citrate-AuNPs were highly stable, with a mean size was 28.3 nm. The data determined that hsa-miR155-5p is a direct regulator of SOCS1 (suppressor-of-cytokine-signaling) expression and citrate-AuNPs inhibits SOCS1 mRNA/protein expression via modulating hsa-miR155-5p expression. Transfection of TNBC MDA-MB-231 cells with anti-miR155-5p markedly increased SOCS1 expression (p<0.001), while citrate-AuNPs treatment significantly inhibited anti-miR155-5p transfection-induced SOCS1 expression (p<0.05). These findings were validated by IFN-γ-stimulated MDA-MB-231 cells. Moreover, the data also determined that citrate-AuNPs also inhibit IFN-γ-induced NF-κB p65/p50 activation in MDA-MB-231 cells transfected with anti-hsa-miR155-5p.

Conclusion

Newly generated citrate-AuNPs were stable and non-toxic to TNBC cells. Citrate-AuNPs inhibit IFN-γ-induced SOCS1 mRNA/protein expression and deactivate NF-κB p65/50 activity via negative regulation of hsa-miR155-5p. These novel pharmacological actions of citrate-AuNPs on IFN-γ-stimulated TNBC cells provide insights that AuNPs inhibit IFN-γ induced inflammation in TNBC cells by modulating the expression of microRNAs.

Identification of signature genes and drug candidates for primary plasma cell leukemia: An integrated system biology approach

BACKGROUND

Plasma cell leukemia (PCL) is one of the rare cancer which is characterized by the uncontrolled proliferation of plasma cells in peripheral blood and bone marrow. The aggressive behavior of the disease and high mortality rate among PCL patients makes it a thirst area to be explored.

METHODS

The dataset for PCL was obtained from the GEO database and was analyzed using GEO2R for differentially expressed genes. Further, the functional enrichment analysis was carried out for DEGs using DAVID. The protein-protein interactions (PPI) for DEGs were obtained using STRING 11.5 and were analyzed in Cytoscape 3.7.2. to obtain the key hub genes. These key hub genes were investigated for their interaction with suitable drug candidates using DGIdb, DrugMAP, and Schrodinger's version 2022-1.

RESULTS

Out of the total of 104 DEGs, 39 genes were up-regulated whereas 65 genes were down-regulated. A total of 11 biological processes, 2 cellular components, and 5 molecular functions were enriched along with the 7 KEGG pathways for the DEGs. Further, a total of 11 hub genes were obtained from the PPI of DEGs of which TP53, MAPK1, SOCS1, MBD3, and YES1 were the key hub genes. Oxaliplatin, mitoxantrone, and ponatinib were found to have the highest binding affinity towards the p53, MAPK1, and YES1 proteins respectively.

CONCLUSION

TP53, MAPK1, SOCS1, MBD3, and YES1 are the signature hub genes that might be responsible for the aggressive prognosis of PCL leading to poor survival rate. However, p53, MAPK1, and YES1 can be targeted with oxaliplatin, mitoxantrone, and ponatinib.

Regulatory mechanism of immune-related genes in patients with hypertension

Hypertension (HT) is among the most common cardiovascular diseases in the world and is an important risk factor for stroke, myocardial infarction, heart failure, and kidney failure. Recent studies have demonstrated that activation of the immune system plays an important role in the occurrence and maintenance of HT. Thus, this research aimed to determine the immune-related biomarkers in HT. In this study, RNA sequencing data of the gene expression profiling datasets (GSE74144) were downloaded from the Gene Expression Omnibus database. Differentially expressed genes between HT and normal samples were identified using the software limma. The immune-related genes associated with HT were screened. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed using the program "clusterProfiler" of the R package. The protein-protein interaction network of these differentially expressed immune-related genes (DEIRGs) was constructed based on the information from the STRING database. Finally, the TF-hub and miRNA-hub gene regulatory networks were predicted and constructed using the miRNet software. Fifty-nine DEIRGs were observed in HT. The Gene Ontology analysis indicated that DEIRGs were mainly enriched in the positive regulation of cytosolic calcium ions, peptide hormones, protein kinase B signaling, and lymphocyte differentiation. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis indicated that these DEIRGs were significantly involved in the intestinal immune network for IgA production, autoimmune thyroid disease, JAK-STAT signaling pathway, hepatocellular carcinoma, and Kaposi sarcoma-associated herpesvirus infection, among others. From the protein-protein interaction network, 5 hub genes (insulin-like growth factor 2, cytokine-inducible Src homology 2-containing protein, suppressor of cytokine signaling 1, cyclin-dependent kinase inhibitor 2A, and epidermal growth factor receptor) were identified. The receiver operating characteristic curve analysis was performed in GSE74144, and all genes with an area under the curve of > 0.7 were identified as the diagnostic genes. Moreover, miRNA-mRNA and TF-mRNA regulatory networks were constructed. Our study identified 5 immune-related hub genes in patients with HT and demonstrated that they were potential diagnostic biomarkers for HT.

Tissue levels of suppressor of cytokine signaling-3 (SOCS-3) in mycosis fungoides

Mycosis fungoides (MF) is a type of cutaneous T-cell lymphoma with proposed multifactorial etiology. Suppressor of cytokine signaling-3 (SOCS-3) is one of the proteins expressed in MF. Its exact role in disease pathogenesis has not yet been thoroughly investigated. This study aimed to assess the expression of SOCS-3 in patients' skin with mycosis fungoides to elucidate their possible role in the pathogenesis in MF. 30 patients with mycosis fungoides and 30 age and sex-matched healthy controls were included. After clinical examination, tissue levels of SOCS-3 were measured by ELISA. The level of expression of SOCS-3 was significantly upregulated in the lesional tissue compared to perilesional SOCS-3 level in patients' group (P < 0.001), and both levels were higher than the SOCS-3 level in control group (P < 0.001). In addition, there was a statistically significant positive correlation between lesional SOCS-3 level and itching in patients' group (P < 0.001). Regarding lesional and perilesional SOCS-3 levels in each stage, there was a significant increase in lesional SOCS-3 levels in comparison to perilesional level whether in stage Ia, Ib, and IIa; (P < 0.001), (P < 0.001) and (P < 0.001), respectively. Increased tissue levels of SOCS-3 patients with mycosis fungoides point to a role that SOCS-3 could play in its pathogenesis. Also, high levels of SOCS-3 in MF patients with itching suggest a role in the pathogenesis of this symptom. These findings may prove helpful in formulating a new treatment modality in addition to the current treatment of MF.

Molecular pathogenesis: Connections between viral hepatitis-induced and non-alcoholic steatohepatitis-induced hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is the sixth most common cancer in the world and is usually caused by viral hepatitis (HBV and HCV), alcoholic, and non-alcoholic fatty liver disease(NAFLD). Viral hepatitis accounts for 80% of HCC cases worldwide. In addition, With the increasing incidence of metabolic diseases, NAFLD is now the most common liver disease and a major risk factor for HCC in most developed countries. This review mainly described the specificity and similarity between the pathogenesis of viral hepatitis(HBV and HCV)-induced HCC and NAFLD-induced HCC. In general, viral hepatitis promotes HCC development mainly through specific encoded viral proteins. HBV can also exert its tumor-promoting mechanism by integrating into the host chromosome, while HCV cannot. Viral hepatitis-related HCC and NASH-related HCC differ in terms of genetic factors, and epigenetic modifications (DNA methylation, histone modifications, and microRNA effects). In addition, both of them can lead to HCC progression through abnormal lipid metabolism, persistent inflammatory response, immune and intestinal microbiome dysregulation.

Interaction Between microRNAs and Myeloid-Derived Suppressor Cells in Tumor Microenvironment

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells generated during a series of pathologic conditions including cancer. MicroRNA (miRNA) has been considered as a regulator in different tumor microenvironments. Recent studies have begun to unravel the crosstalk between miRNAs and MDSCs. The knowledge of the effect of both miRNAs and MDSCs in tumor may improve our understanding of the tumor immune escape and metastasis. The miRNAs target cellular signal pathways to promote or inhibit the function of MDSCs. On the other hand, MDSCs transfer bioinformation through exosomes containing miRNAs. In this review, we summarized and discussed the bidirectional regulation between miRNAs and MDSCs in the tumor microenvironment.

SOCS3 gene silencing does not occur through methylation and mutations in gastric cancer

Gastric cancer (GC) is ranked the third leading cause of cancer-related deaths worldwide. Mutations and epigenetic alterations in several essential genes, including p53, KRAS, PIK3CA, FAT4 and ARID1A, are often reported. Furthermore, loss of SOCS3 expression was reported in GC, suggesting its tumor suppressor role. To assess the mutational and methylation status of SOCS3, we performed gene panel exome sequencing on 47 human GC samples. The SOCS3 gene was rarely mutated, suggesting alternative regulation mechanisms, such as promoter hypermethylation and/or long non-coding RNAs (lncRNAs). We first explored SOCS3 promoter methylation status in 44 human GC samples by methylation-specific PCR (MS-PCR). Thirteen out of forty-four patients (29.5%) displayed a methylation pattern. Then, to see whether SOCS3 expression is silenced by CpG methylation, we examined publicly available databases (cbioportal and The Cancer Genome Atlas (TCGA)). The analysis revealed β values lower than 0.1, indicating hypo-methylation in healthy and GC samples. Moreover, moderate methylation (β < 0.4) and high methylation (β > 0.4) did not affect the free survival, suggesting that methylation is unlikely to be the mechanism ruling SOCS3 silencing in GC. Next, to assess the regulatory effects of lncRNAs on SOCS3, we silenced the AC125807.2-lncRNA and quantified the SOCS3 gene expression in AGS and NCI-N87 gastric cancer cell line. SOCS3 was found to be downregulated following AC125807.2-lncRNA silencing in AGS cells, suggesting the potential implication of lncRNA AC125807.2 in SOCS3 regulation. However, in NCI-N87 cells, there was no significant change in SOCS3 expression. In conclusion, neither mutations nor hypermethylation was associated with the SOCS3 downregulation in GC, and alternative mechanisms, including non-coding RNAs-mediated gene silencing, may be proposed.

Nickel's Role in Pancreatic Ductal Adenocarcinoma: Potential Involvement of microRNAs

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancer types with a limited overall survival rate due to the asymptomatic progression of symptoms in metastatic stages of the malignancy and the lack of an early reliable diagnostic biomarker. MicroRNAs (miRs/miRNAs) are small (~18–24 nucleotides), endogenous, non-coding RNAs, which are closely linked to the development of numerous malignancies comprising PDAC. Recent studies have described the role of environmental pollutants such as nickel (Ni) in PDAC, but the mechanisms of Ni-mediated toxicity in cancer are still not completely understood. Specifically, Ni has been found to alter the expression and function of miRs in several malignancies, leading to changes in target gene expression. In this study, we found that levels of Ni were significantly higher in cancerous tissue, thus implicating Ni in pancreatic carcinogenesis. Hence, in vitro studies followed by using both normal and pancreatic tumor cell lines and increasing Ni concentration increased lethality. Comparing LC50 values, Ni-acetate groups demonstrated lower values needed than in NiCl₂ groups, suggesting greater Ni-acetate. Panc-10.05 cell line appeared the most sensitive to Ni compounds. Exposure to Ni-acetate resulted in an increased phospho-AKT, and decreased FOXO1 expression in Panc-10.05 cells, while NiCl₂ also increased PTEN expression in Panc-10.05 cells. Specifically, following NiCl₂ exposure to PDAC cells, the expression levels of miR-221 and miR-155 were significantly upregulated, while the expression levels of miR-126 were significantly decreased. Hence, our study has suggested pilot insights to indicate that the environmental pollutant Ni plays an important role in the progression of PDAC by promoting an association between miRs and Ni exposure during PDAC pathogenesis.

SOCS-1 1478 CA/del gene polymorphism affects survival in colorectal carcinoma

Aims and Background

Suppressor of cytokine signaling 1 (SOCS1) is a prototype molecule of the SOCS family. Alterations in the SOCS1 expression have been reported in human cancers and some studies suggest that SOCS1 might act as a tumor suppressor in carcinogenesis. In the present study, we aimed to evaluate the association of SOCS1 promoter -1478CA/del gene polymorphism detected in DNA isolated from the tissues of patients with colorectal cancer (CRC) for histopathological characteristics and survival.

Patients and Methods

For the study, we retrospectively enrolled 53 patients with resected colon due to CRC and 23 control subjects with no systemic illness. SOCS1- 1478CA/del gene polymorphism was determined using the polymerase chain reaction-restriction fragment length polymorphism methodology. These results were evaluated in relation to histopathological features and survival results and analyzed statistically. A P value equal to or less than 0.05 was considered significant.

Results

Neither control subjects nor the CRC group showed a significant association with SOCS1 -1478CA/del gene polymorphism (p = 0.248). SOCS1 -1478CA/del gene polymorphism was not significantly associated with histopathological features either. However, in the overall survival (OS) analysis, those patients with the del/del allele were found to have a 3.9-fold greater risk of mortality compared to those with CA/CA allele (p = 0.05). Progression-free survival (PFS) was also significantly different in such patients (p = 0.05).

Conclusion

The present study examining the association of SOCS1 -1478CA/del gene polymorphism with CRC showed that CRC patients with del/del allele had both significantly shorter PFS and OS versus those with CA/CA or CA/del allele.

microRNA-21 Regulates Stemness in Pancreatic Ductal Adenocarcinoma Cells

Pancreatic ductal adenocarcinoma (PDAC) is the most common and aggressive type of pancreatic cancer (PCa) with a low survival rate. microRNAs (miRs) are endogenous, non-coding RNAs that moderate numerous biological processes. miRs have been associated with the chemoresistance and metastasis of PDAC and the presence of a subpopulation of highly plastic "stem"-like cells within the tumor, known as cancer stem cells (CSCs). In this study, we investigated the role of miR-21, which is highly expressed in Panc-1 and MiaPaCa-2 PDAC cells in association with CSCs. Following miR-21 knockouts (KO) from both MiaPaCa-2 and Panc-1 cell lines, reversed expressions of epithelial-mesenchymal transition (EMT) and CSCs markers were observed. The expression patterns of key CSC markers, including CD44, CD133, CX-C chemokine receptor type 4 (CXCR4), and aldehyde dehydrogenase-1 (ALDH1), were changed depending on miR-21 status. miR-21 (KO) suppressed cellular invasion of Panc-1 and MiaPaCa-2 cells, as well as the cellular proliferation of MiaPaCa-2 cells. Our data suggest that miR-21 is involved in the stemness of PDAC cells, may play roles in mesenchymal transition, and that miR-21 poses as a novel, functional biomarker for PDAC aggressiveness.

The Pathologic and Genetic Characteristics of Extranodal NK/T-Cell Lymphoma

Extranodal NK/T-cell lymphoma is a neoplasm of NK cells or cytotoxic T cells presenting in extranodal sites, most often in the nasal cavity. The typical immunophenotypes are cCD3+, sCD3-, CD4-, CD5-, CD8-, CD16-, and CD56+ with the expression of cytotoxic molecules. Tumor subsets express NK cell receptors, CD95/CD95L, CD30, MYC, and PDL1. Virtually all the tumor cells harbor the EBV genome, which plays a key role in lymphomagenesis as an epigenetic driver. EBV-encoded oncoproteins modulate the host-cell epigenetic machinery, reprogramming the viral and host epigenomes using host epigenetic modifiers. NGS analysis revealed the mutational landscape of ENKTL, predominantly involving the JAK-STAT pathway, epigenetic modifications, the RNA helicase family, the RAS/MAP kinase pathway, and tumor suppressors, which indicate an important role of these pathways and this group of genes in the lymphomagenesis of ENKTL. Recently, three molecular subtypes were proposed, the tumor-suppressor/immune-modulator (TSIM), MGA-BRDT (MB), and HDAC9-EP300-ARID1A (HEA) subtypes, and they are well-correlated with the cell of origin, EBV pattern, genomic alterations, and clinical outcomes. A future investigation into the function and interaction of discovered genes would be very helpful for better understanding the molecular pathogenesis of ENKTL and establishing better treatment strategies.

Identification of a genetic signature enriching for response to ibrutinib in relapsed/refractory follicular lymphoma in the DAWN phase 2 trial

Background

The single‐arm DAWN trial (NCT01779791) of ibrutinib monotherapy in patients with relapsed/refractory follicular lymphoma (FL) showed an overall response rate (ORR) of 20.9% and a median response duration of 19.4 months. This biomarker analysis of the DAWN dataset sought to determine genetic classifiers for prediction of response to ibrutinib treatment.

Methods

Whole exome sequencing was performed on baseline tumor samples. Potential germline variants were excluded; a custom set of 1216 cancer‐related genes was examined. Responder‐ versus nonresponder‐associated variants were identified using Fisher's exact test. Classifiers with increasing numbers of genes were created using a greedy algorithm that repeatedly selected genes, adding the most nonresponders to the existing “predicted nonresponders” set and were evaluated with 10‐fold cross‐validation.

Results

Exome data were generated from 88 patient samples and 13,554 somatic mutation variants were inferred. Response data were available for 83 patients (17 responders, 66 nonresponders). Each sample showed 100 to >500 mutated genes, with greater variance across nonresponders. The overall variant pattern was consistent with previous FL studies; 75 genes had mutations in >10% of patients, including genes previously reported as associated with FL. Univariate analysis yielded responder‐associated genes FANCA, HISTH1B, ANXA6, BTG1, and PARP10, highlighting the importance of functions outside of B‐cell receptor signaling, including epigenetic processes, DNA damage repair, cell cycle/proliferation, and cell motility/invasiveness. While nonresponder‐associated genes included well‐known TP53 and CARD11, genetic classifiers developed using nonresponder‐associated genes included ATP6AP1, EP400, ARID1A, SOCS1, and TBL1XR1, suggesting resistance to ibrutinib may be related to broad biological functions connected to epigenetic modification, telomere maintenance, and cancer‐associated signaling pathways (mTOR, JAK/STAT, NF‐κB).

Conclusion

The results from univariate and genetic classifier analyses provide insights into genes associated with response or resistance to ibrutinib in FL and identify a classifier developed using nonresponder‐associated genes, which warrants further investigation.

Trial registration: NCT01779791.

The Positivity of Phosphorylated STAT3 Is a Novel Marker for Favorable Prognosis in Germinal Center B-Cell Type of Diffuse Large B-Cell Lymphoma

On the basis of immunohistochemistry, diffuse large B-cell lymphoma (DLBCL) is categorized as a germinal center B-cell (GCB) or non-GCB subtype. Recent integrated genomic analyses have highlighted the importance of the JAK-STAT3 pathway in the molecular pathogenesis of DLBCL. However, its relevance to clinical outcomes remains controversial. Therefore, we evaluated the extent of the nuclear expression of phosphorylated STAT3 (pSTAT3), a surrogate marker of signal transducer and activator of transcription 3 (STAT3) activation, by immunohistochemistry. We also analyzed the potential relationship between pSTAT3 positivity (defined as ≥40% positive neoplastic cells) and clinicopathologic characteristics in 294 patients with DLBCL. pSTAT3 was detected in 122 patients (42%), with a higher rate in the non-GCB subtype than in the GCB subtype (57% vs. 28%, P<0.001). Factors potentially activating STAT3, MYD88L265P, and Epstein-Barr virus-encoded small RNA were identified in the pSTAT3-positive non-GCB subtype, whereas the pSTAT3-positive GCB subtype often showed STAT3 mutations and lacked EZH2 mutations and the rearrangements of BCL2 and MYC. Multivariate analyses revealed that the pSTAT3-positive GCB subtype showed a favorable prognosis (HR: 0.17; 95% confidence interval, 0.04-0.7; P=0.014). These findings suggest that pSTAT3 positivity may have a unique impact on the clinicopathologic characteristics of DLBCL, making it a promising novel marker for the favorable prognosis of patients with the GCB subtype.

SOCS Proteins Participate in the Regulation of Innate Immune Response Caused by Viruses

The host immune system has multiple innate immune receptors that can identify, distinguish and react to viral infections. In innate immune response, the host recognizes pathogen-associated molecular patterns (PAMP) in nucleic acids or viral proteins through pathogen recognition receptors (PRRs), especially toll-like receptors (TLRs) and induces immune cells or infected cells to produce type I Interferons (IFN-I) and pro-inflammatory cytokines, thus when the virus invades the host, innate immunity is the earliest immune mechanism. Besides, cytokine-mediated cell communication is necessary for the proper regulation of immune responses. Therefore, the appropriate activation of innate immunity is necessary for the normal life activities of cells. The suppressor of the cytokine signaling proteins (SOCS) family is one of the main regulators of the innate immune response induced by microbial pathogens. They mainly participate in the negative feedback regulation of cytokine signal transduction through Janus kinase signal transducer and transcriptional activator (JAK/STAT) and other signal pathways. Taken together, this paper reviews the SOCS proteins structures and the function of each domain, as well as the latest knowledge of the role of SOCS proteins in innate immune caused by viral infections and the mechanisms by which SOCS proteins assist viruses to escape host innate immunity. Finally, we discuss potential values of these proteins in future targeted therapies.

DNA methylation in Hepatoblastoma-a literature review

Hepatoblastoma (HB) is the most common malignant liver tumor in children. Abnormal activation of the Wnt/β-catenin signaling pathway plays an important role in the formation and development of HB. Genes in HB show a global hypomethylation change, accompanied by hypermethylation of specific tumor suppressor genes (TSGs). This article reviews the hypermethylation changes in several TSGs, such as RASSF1A, SOCS1, APC, HHIP, and P16, and analyzes the pathways and mechanisms of TSGs regulating gene expression. The role of the methylation-regulating enzymes DNA methyltransferases (DNMTs) and ten-eleven translocation (TET) family members enzymes in the methylation changes of HB was analyzed, and it was speculated that the occurrence of HB is partly due to the obstruction of liver differentiation in the early stage of differentiation. The origin cells may be incompletely differentiated hepatocytes remaining in the liver of children after birth. Therefore, further studying the role of methylation regulating enzymes in methylation changes in HB is a promising future research direction.

Cytokine-Mediated Dysregulation of Signaling Pathways in the Pathogenesis of Multiple Myeloma

Multiple myeloma (MM) is a hematologic disorder of B lymphocytes characterized by the accumulation of malignant plasma cells (PCs) in the bone marrow. The altered plasma cells overproduce abnormal monoclonal immunoglobulins and also stimulate osteoclasts. The host’s immune system and microenvironment are of paramount importance in the growth of PCs and, thus, in the pathogenesis of the disease. The interaction of MM cells with the bone marrow (BM) microenvironment through soluble factors and cell adhesion molecules causes pathogenesis of the disease through activation of multiple signaling pathways, including NF-κβ, PI3K/AKT and JAK/STAT. These activated pathways play a critical role in the inhibition of apoptosis, sustained proliferation, survival and migration of MM cells. Besides, these pathways also participate in developing resistance against the chemotherapeutic drugs in MM. The imbalance between inflammatory and anti-inflammatory cytokines in MM leads to an increased level of pro-inflammatory cytokines, which in turn play a significant role in dysregulation of signaling pathways and proliferation of MM cells; however, the association appears to be inadequate and needs more research. In this review, we are highlighting the recent findings on the roles of various cytokines and growth factors in the pathogenesis of MM and the potential therapeutic utility of aberrantly activated signaling pathways to manage the MM disease.

Cullin-RING Ligase 5: Functional characterization and its role in human cancers

Cullin-RING ligase 5 (CRL5) is a multi-protein complex and consists of a scaffold protien cullin 5, a RING protein RBX2 (also known as ROC2 or SAG), adaptor proteins Elongin B/C, and a substrate receptor protein SOCS. Through targeting a variety of substrates for proteasomal degradation or modulating various protein-protein interactions, CRL5 is involved in regulation of many biological processes, such as cytokine signal transduction, inflammation, viral infection, and oncogenesis. As many substrates of CRL5 are well-known oncoproteins or tumor suppressors, abnormal regulation of CRL5 is commonly found in human cancers. In this review, we first briefly introduce each of CRL5 components, and then discuss the biological processes regulated by four members of SOCS-box-containing substrate receptor family through substrate degradation. We next describe how CRL5 is hijacked by a variety of viral proteins to degrade host anti-viral proteins, which facilitates virus infection. We further discuss the regulation of CUL5 and its various roles in human cancers, acting as either a tumor suppressor or an oncoprotein in a context-dependent manner. Finally, we propose novel insights for future perspectives on the validation of cullin5 and other CRL5 components as potential targets, and possible targeting strategies to discover CRL5 inhibitors for anti-cancer and anti-virus therapies.

Control of viral infections by epigenetic-targeted therapy

Epigenetics is defined as the science that studies the modifications of gene expression that are not owed to mutations or changes in the genetic sequence. Recently, strong evidences are pinpointing toward a solid interplay between such epigenetic alterations and the outcome of human cytomegalovirus (HCMV) infection. Guided by the previous possibly promising experimental trials of human immunodeficiency virus (HIV) epigenetic reprogramming, the latter is paving the road toward two major approaches to control viral gene expression or latency. Reactivating HCMV from the latent phase ("shock and kill" paradigm) or alternatively repressing the virus lytic and reactivation phases ("block and lock" paradigm) by epigenetic-targeted therapy represent encouraging options to overcome latency and viral shedding or otherwise replication and infectivity, which could lead eventually to control the infection and its complications. Not limited to HIV and HCMV, this concept is similarly studied in the context of hepatitis B and C virus, herpes simplex virus, and Epstein-Barr virus. Therefore, epigenetic manipulations stand as a pioneering research area in modern biology and could constitute a curative methodology by potentially consenting the development of broad-spectrum antivirals to control viral infections in vivo.

Overexpression of SOCS3 mediated by adenovirus vector in mouse and human castration-resistant prostate cancer cells increases the sensitivity to NK cells in vitro and in vivo

Prostate cancer is one of the most common cancers in men. The overactivation of IL-6/JAK/STAT3 signaling and silencing of SOCS3 are frequently observed in prostate cancer. In the present study we undertook to develop Ad-SOCS3 gene therapy for the treatment of prostate cancer and also investigated whether Ad-SOCS3 increased sensitivity to NK cells. We demonstrated that Ad-SOCS3 could significantly inhibit growth of castration-resistant prostate cancer (CRPC) cell lines expressing pSTAT3, DU-145 (at 10, 20, and 40 MOI), and TRAMP-C2 (at 40 MOI), but not the PC-3 CRPC cell line with the STAT3 gene deleted. Ad-SOCS3 (40 MOI) could suppress IL-6 production in DU-145 cells and PD-L1 expression induced by IFN-γ in TRAMP-C2 cells, and increased the NK cell sensitivity of both TRAMP-C2 and DU-145 cells. In the DU-145 mouse xenograft tumor model, intratumoral injections (twice/week for 3 weeks) of 1 × 10⁸ pfu of Ad-SOCS3 significantly inhibited tumor growth and combining the Ad-SOCS3 treatment with intratumoral injections (once/week for 2 weeks) of 1 × 10⁷ human NK cells showed the highest tumor growth inhibitory effect. These results suggested that a combination of Ad-SOCS3 gene therapy and NK cell immunotherapy could be a powerful treatment option for advanced CRPC overexpressing pSTAT3.

Structural insights into suppressor of cytokine signaling 1 protein- identification of new leads for type 2 diabetes mellitus

The study considers the Suppressor of cytokine signaling 1 (SOCS1) protein as a novel Type 2 diabetes mellitus (T2DM) drug target. T2DM in human beings is also triggered by the over expression of SOCS proteins. The SOCS1 acts as a ubiquitin ligase (E3), degrades Insulin Receptor Substrate 1 and 2 (IRS1 and IRS2) proteins, and causes insulin resistance. Therefore, the structure of the SOCS1 protein was evaluated using homology-modeling and molecular dynamics methods and validated using standard computational protocols. The Protein-Protein docking study of SOCS1 with its natural substrates, IRS1 and IRS2, and subsequent solvent accessible surface area analysis gave insight into the binding region of the SOCS1 protein. The in silico active site prediction tools highlight the residues Val155 to Ile211 in SOCS1 being implicated in the ubiquitin mediated protein degradation of the proteins IRS1 and IRS2. Virtual screening in the active site region, using large structural databases, results in selective lead structures with 3-Pyridinol, Xanthine, and Alanine moieties as Pharmacophore. The virtual screening study shows that the residues Glu149, Gly187, Arg188, Leu191, and Ser205 of the SOCS1 are important for binding. The docking study with current anti-diabetic therapeutics shows that the drugs Glibenclamide and Glyclopyramide have a partial affinity towards SOCS1. The predicted ADMET and IC₅₀ properties for the identified ligands are within the acceptable range with drug-like properties. The structural data of SOCS1, its active site, and the identified lead structures are expedient in the development of new T2DM therapeutics.

SOCS1 is associated with clinical progression and acts as an oncogenic role in triple-negative breast cancer

Suppressors of cytokine signaling 1 (SOCS1) is a member of SOCS family and acts as negative regulators of cytokine signaling by direct inhibition of receptor-associated janus kinases. The clinical significance and biological function of SOCS1 in variant tumor tissues and at variant tumor stages is still controversial. The aim of our study is to confirm the expression status of SOCS1 in triple-negative breast cancer (TNBC) tissues and cell lines, and explore the clinical value and biological function of SOCS1 in TNBC. In microarray data sets (GDS2250 and GDS817), we observed SOCS1 was overexpressed in TNBC tissues and cell line compared with normal mammary tissues and mammary epithelial cell line, or non-TNBC tissues and cell line. Furthermore, SOCS1 mRNA and protein overexpression were confirmed in TNBC tissues and cell lines compared with normal mammary tissues and mammary epithelial cell lines or non-TNBC tissues and cell lines. SOCS1 protein overexpression was obviously associated with advanced clinical stage, large tumor size, more lymph node metastasis, present distant metastasis, and malign histological grade. Downregulation of SOCS1 expression suppressed TNBC cells proliferation and promoted cell apoptosis. In conclusion, SOCS1 is associated with clinical progression in TNBC patients and acts as an oncogenic role in regulating TNBC cells proliferation and apoptosis. © 2018 IUBMB Life, 70(4):320-327, 2018.

miR-221-5p enhances cell proliferation and metastasis through post-transcriptional regulation of SOCS1 in human prostate cancer

BACKGROUND

To investigate the effect of miR-221-5p on cell proliferaton and metastasis of human prostate cancer in vitro and vivo.

METHODS

We established PC3 cell lines with stable overexpression or silencing of miRNA-221-5p via lentivirus infection. miRNA-221-5p and its target gene SOCS1 expression levels in the stable cells were analyzed by real-time polymerase chain reaction (RT-PCR) and western blotting. Using luciferase reporter assays to study the relationship between miR-221-5p and SOCS1. Cell proliferative activity was measured using the MTT assay and colony formation assay. Migration ability was assessed using wound-healing assay and transwell assay. To further study the function of miR-221-5p in human prostate cancer we established nude mice xenograft model in vivo.

RESULTS

miR-221-5p regulates the proliferation, migration of prostate cancer cells in vitro and tumorigenesis in vivo by regulating socs1 expression through targeted its 3'UTR, and miR-221-5p regulates MAPK/ERK signaling pathway and EMT features in prostate cancer cells.

CONCLUSIONS

Up-regulation and silencing of miR-221-5p expression in prostate cancer cells are correlated with cell proliferation, migration and tumorigenesis, which suggest that miR-221-5p plays an important role in prostate cancer progression.

Phase I clinical trial of a novel autologous modified-DC vaccine in patients with resected NSCLC

BACKGROUND

The primary aim of this study was to evaluate the safety of a novel dendritic cell (DC) vaccine pulsed with survivin and MUC1, silenced with suppressor of cytokine signaling 1 (SOCS1), and immune stimulated with flagellin for patients with stage I to IIIA non-small cell lung cancer (NSCLC) in a phase I open-label, uncontrolled, and dose-escalation trial. Moreover, we evaluate the potential efficacy of this modified DC vaccine as secondary aim.

METHODS

The patients were treated with the vaccine at 1 × 106, 1 × 107and the maximum dose 8 × 107 at day 7, 14, and 21 after characterization of the vaccine phenotype by flow cytometry. The safety of the vaccine was assessed by adverse events, and the efficacy by the levels of several specific tumor markers and the patient quality of life.

RESULTS

The vaccine was well tolerated without dose-limiting toxicity even at higher doses. The most common adverse event reported was just grade 1 flu-like symptoms without unanticipated or serious adverse event. A significant decrease in CD3 + CD4 + CD25 + Foxp3+ T regulatory (Treg) cell number and increase in TNF-α and IL-6 were observed in two patients. Two patients showed 15% and 64% decrease in carcino-embryonic antigen and CYFRA21, respectively. The vaccination with the maximum dose significantly improved the patients'quality of life when administered at the highest dose. More importantly, in the long-term follow-up until February 17, 2017, 1 patient had no recurrence, 1 patients had a progressive disease (PD), and 1 patient was died in the low dose group. In the middle dose group, all 3 patients had no recurrence. In the high dose group, 1 patient was died, 1 patient had a PD, and the other 7 patients had no recurrence.

CONCLUSIONS

We provide preliminary data on the safety and efficacy profile of a novel vaccine against non-small cell lung cancer, which was reasonably well tolerated, induced modest antitumor activity without dose-limiting toxicity, and improved patients' quality of life. Further more, the vaccine maybe a very efficacious treatment for patients with resected NSCLC to prevent recurrence. Our findings on the safety and efficacy of the vaccine in this phase I trial warrant future phase II/III clinical trial.

Interleukin-6 Trans-Signaling Pathway Promotes Immunosuppressive Myeloid-Derived Suppressor Cells via Suppression of Suppressor of Cytokine Signaling 3 in Breast Cancer

Interleukin-6 (IL-6) has been reported to stimulate myeloid-derived suppressor cells (MDSCs) in multiple cancers, but the molecular events involved in this process are not completely understood. We previously found that cancer-derived IL-6 induces T cell suppression of MDSCs in vitro via the activation of STAT3/IDO signaling pathway. In this study, we aimed to elucidate the underlying mechanisms. We found that in primary breast cancer tissues, cancer-derived IL-6 was positively correlated with infiltration of MDSCs in situ, which was accompanied by more aggressive tumor phenotypes and worse clinical outcomes. In vitro IL-6 stimulated the amplification of MDSCs and promoted their T cell suppression ability, which were fully inhibited by an IL-6-specific blocking antibody. Our results demonstrate that IL-6-dependent suppressor of cytokine signaling 3 (SOCS3) suppression in MDSCs induced phosphorylation of the JAK1, JAK2, TYK2, STAT1, and STAT3 proteins, which was correlated with T cell suppression of MDSCs in vitro. Therefore, dysfunction in the SOCS feedback loop promoted long-term activation of the JAK/STAT signaling pathway and predominantly contributed to IL-6-mediated effects on MDSCs. Furthermore, IL-6-induced inhibition of SOCS3 and activation of the JAK/STAT pathway was correlated with an elevated expression of IL-6 receptor α (CD126), in which the soluble CD126-mediated IL-6 trans-signaling pathway significantly regulated IL-6-mediated effects on MDSCs. Finally, IL-6-induced SOCS3 dysfunction and sustained activation of the JAK/STAT signaling pathway promoted the amplification and immunosuppressive function of breast cancer MDSCs in vitro and in vivo, and thus blocking the IL-6 signaling pathway is a promising therapeutic strategy for eliminating and inhibiting MDSCs to improve prognosis.

SOCS Proteins as Regulators of Inflammatory Responses Induced by Bacterial Infections: A Review

Severe bacterial infections can lead to both acute and chronic inflammatory conditions. Innate immunity is the first defense mechanism employed against invading bacterial pathogens through the recognition of conserved molecular patterns on bacteria by pattern recognition receptors (PRRs), especially the toll-like receptors (TLRs). TLRs recognize distinct pathogen-associated molecular patterns (PAMPs) that play a critical role in innate immune responses by inducing the expression of several inflammatory genes. Thus, activation of immune cells is regulated by cytokines that use the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway and microbial recognition by TLRs. This system is tightly controlled by various endogenous molecules to allow for an appropriately regulated and safe host immune response to infections. Suppressor of cytokine signaling (SOCS) family of proteins is one of the central regulators of microbial pathogen-induced signaling of cytokines, principally through the inhibition of the activation of JAK/STAT signaling cascades. This review provides recent knowledge regarding the role of SOCS proteins during bacterial infections, with an emphasis on the mechanisms involved in their induction and regulation of antibacterial immune responses. Furthermore, the implication of SOCS proteins in diverse processes of bacteria to escape host defenses and in the outcome of bacterial infections are discussed, as well as the possibilities offered by these proteins for future targeted antimicrobial therapies.

The role of small adaptor proteins in the control of oncogenic signalingr driven by tyrosine kinases in human cancer

Protein phosphorylation on tyrosine (Tyr) residues has evolved as an important mechanism to coordinate cell communication in multicellular organisms. The importance of this process has been revealed by the discovery of the prominent oncogenic properties of tyrosine kinases (TK) upon deregulation of their physiological activities, often due to protein overexpression and/or somatic mutation. Recent reports suggest that TK oncogenic signaling is also under the control of small adaptor proteins. These cytosolic proteins lack intrinsic catalytic activity and signal by linking two functional members of a catalytic pathway. While most adaptors display positive regulatory functions, a small group of this family exerts negative regulatory functions by targeting several components of the TK signaling cascade. Here, we review how these less studied adaptor proteins negatively control TK activities and how their loss of function induces abnormal TK signaling, promoting tumor formation. We also discuss the therapeutic consequences of this novel regulatory mechanism in human oncology.

Inhibition of STAT3/VEGF/CDK2 axis signaling is critically involved in the antiangiogenic and apoptotic effects of arsenic herbal mixture PROS in non-small lung cancer cells

Despite the antitumor effects of asrsenic trioxide (As2O3), tetraarsenic hexoxide (As4O6 or PR) and tetraarsenic tetrasulfide (As4S4) in several cancers, their adverse poisoning, toxicity and resistance are still hot issues for effective cancer therapy. Here, antitumor mechanism of arsenic herbal mixture PROS including PR and OS (Oldenlandia diffusa and Salvia miltiorrhiza extract) was elucidated in non-small cell lung cancer cells (NSCLCs), since PR alone showed resistant cytotoxicity in NSCLCs compared to other cancers. PROS exerted significant cytotoxicity, induced sub-G1 phase and S phase arrest, increased apoptotic bodies, and attenuated the expression of pro-PARP, Bcl-2, Cyclin E, Cyclin A, CDK2, E2F1, p-Src, p-STAT3, p-ERK, p-AKT, COX-2 and SOCS-1 in A549 and H460 cells along with disrupted binding of STAT3 with CDK2 or VEGF. Notably, PROS inhibited VEGF induced proliferation, migration and tube formation in HUVECs and suppressed angiogenesis in chorioallantoic membrane (CAM) assay via reduced phosphorylation of VEGFR2, Src and STAT3. Consistently, PROS reduced the growth of H460 cells implanted in BALB/c athymic nude mice via inhibition of STAT3, and VEGF and activation of caspase 3. Overall, these findings suggest that PROS exerts antiangiogenic and apoptotic effects via inhibition of STAT3/ VEGF/ CDK2 axis signaling as a potent anticancer agent for lung cancer treatment.

SOCS1 function in BCR-ABL mediated myeloproliferative disease is dependent on the cytokine environment

Treatment with tyrosine kinase inhibitors is the standard of care for Philadelphia chromosome positive leukemias. However the eradication of leukemia initiating cells remains a challenge. Circumstantial evidence suggests that the cytokine microenvironment may play a role in BCR-ABL mediated leukemogenesis and in imatinib resistance. Gene expression analyses of BCR-ABL positive ALL long-term cultured cells revealed strong reduction of SOCS mRNA expression after imatinib treatment, thereby demonstrating a strong inhibition of cytokine signaling. In this study we employed SOCS1—a strong inhibitor of cytokine signaling—as a tool to terminate external cytokine signals in BCR-ABL transformed cells in vitro and in vivo. In colony formation assays with primary bone marrow cells, expression of SOCS1 decreased colony numbers under pro-proliferative cytokines, while it conferred growth resistance to anti-proliferative cytokines. Importantly, co-expression of SOCS1 with BCR-ABL led to the development of a MPD phenotype with a prolonged disease latency compared to BCR-ABL alone in a murine bone marrow transplantation model. Interestingly, SOCS1 co-expression protected 20% of mice from MPD development. In summary, we conclude that under pro-proliferative cytokine stimulation at the onset of myeloproliferative diseases SOCS1 acts as a tumor suppressor, while under anti-proliferative conditions it exerts oncogenic function. Therefore SOCS1 can promote opposing functions depending on the cytokine environment.

Clinico-biological significance of suppressor of cytokine signaling 1 expression in acute myeloid leukemia

Suppressor of cytokine signaling 1 (SOCS1) protein, which encodes a member of signal transducers and activators of transcription-induced inhibitors, takes part in a negative regulation of cytokine signaling. The mechanism of SOCS1 in tumor carcinogenesis is complex and there have been no studies concerning the clinic-biologic implication of SOCS1 expression in acute myeloid leukemia (AML). Here, we first identified that higher bone marrow (BM) SOCS1 expression was closely associated with older age, FLT3-ITD, NPM1 and DNMT3A mutations, but negatively correlated with CEBPA mutation in patients with de novo AML. Compared to patients with lower SOCS1 expression, those with higher expression had lower complete remission rates and shorter overall survival. Further, higher expression of SOCS1 in the BM was an independent unfavorable prognostic factor irrespective of age, white blood cell, cytogenetics and gene mutations. Next, we generated zebrafish model overexpressing SOCS1 by spi1 promoter, which showed kidney marrow from adult SOCS1 zebrafish had increased myelopoiesis, myeloid progenitors and the kidney or spleen structure were effaced and distorted, mimicking leukemia phenotype. The SOCS1/FLT3-ITD double transgenic fish could further facilitate the leukemic process. The results indicate SOCS1 plays an important role in AML and its higher expression serves as a new biomarker to risk-stratify AML patients.

Effect of SOCS1 silencing on proliferation and apoptosis of melanoma cells: An in vivo and in vitro study

This study aimed to investigate the effect of SOCS1 silencing on the proliferation and apoptosis of melanoma cells by in vivo and in vitro studies. Immunohistochemical staining was used to detect SOCS1 expression in melanoma tissues and pigmented nevi. Quantitative real-time polymerase chain reaction and western blotting were applied to detect the messenger RNA and protein expressions of SOCS1 in primary human melanocytes and malignant melanoma cell lines (A375, SK-MEL-5, M14, and MV3). Melanoma cells were assigned into mock, negative small interfering RNA, and SOCS1-small interfering RNA groups. The proliferation, cell cycle and apoptosis, and messenger RNA expression of SOCS1 in MV3 and A375 cells were detected using MTT assay, flow cytometry, and quantitative real-time polymerase chain reaction, respectively. The expressions of SOCS1 protein, extracellular signal-regulated kinase, and janus kinase signal transduction and activators of transcription signaling pathways-related proteins were detected using western blotting. After the establishment of subcutaneous xenograft tumor models in nude mice, the latent period, size, volume and growth speed of xenograft tumors in the mock, negative small interfering RNA, and SOCS1-small interfering RNA groups were examined and compared. The results indicated that positive expression rate of SOCS1 was higher in malignant melanoma tissues than in pigmented nevi. MV3 cells had the highest messenger RNA and protein expressions of SOCS1, followed by A357 cells. Compared with the mock and negative small interfering RNA groups, SOCS1-small interfering RNA group showed lower cell viability, elevated cell apoptosis, more cells in G0/G1 phase and less cells in S and G2/M phases, and decreased messenger RNA and protein expressions of SOCS1, p-ERK1/2, p-JAK2, p-STAT1, and p-STAT3. Compared with the mock and negative small interfering RNA groups, the SOCS1-small interfering RNA group showed longer latent period of tumor, smaller tumor size and volume, and smoother tumor growth curve. To conclude, SOCS1 silencing can inhibit proliferation and induce apoptosis of MV3 and A357 melanoma cells in vivo and in vitro by inhibiting extracellular signal-regulated kinase and janus kinase signal transduction and activators of transcription signaling pathways.

Suppressor of cytokine signaling-1 gene therapy induces potent antitumor effect in patient-derived esophageal squamous cell carcinoma xenograft mice

Chronic inflammation is involved in cancer growth in esophageal squamous cell carcinoma (ESCC), which is a highly refractory cancer with poor prognosis. This study investigated the antitumor effect and mechanisms of SOCS1 gene therapy for ESCC. Patients with ESCC showed epigenetics silencing of SOCS1 gene by methylation in the CpG islands. We infected 10 ESCC cells with an adenovirus-expressing SOCS1 (AdSOCS1) to examine the antitumor effect and mechanism of SOCS1 overexpression. SOCS1 overexpression markedly decreased the proliferation of all ESCC cell lines and induced apoptosis. Also, SOCS1 inhibited the proliferation of ESCC cells via multiple signaling pathways including Janus kinase (JAK)/signal transducer and activator of transcription (STAT) and focal adhesion kinase (FAK)/p44/42 mitogen-activated protein kinase (p44/42 MAPK). Additionally, we established two xenograft mouse models in which TE14 ESCC cells or ESCC patient-derived tissues (PDX) were subcutaneously implanted. Mice were intra-tumorally injected with AdSOCS1 or control adenovirus vector (AdLacZ). In mice, tumor volumes and tumor weights were significantly lower in mice treated with AdSOCS1 than that with AdLacZ as similar mechanism to the in vitro findings. The Ki-67 index of tumors treated with AdSOCS1 was significantly lower than that with AdLacZ, and SOCS1 gene therapy induced apoptosis. These findings demonstrated that overexpression of SOCS1 has a potent antitumor effect against ESCC both in vitro and in vivo including PDX mice. SOCS1 gene therapy may be a promising approach for the treatment of ESCC.

SOCS1 Regulates Apoptosis and Inflammation by Inhibiting IL-4 Signaling in IL-1β-Stimulated Human Osteoarthritic Chondrocytes

Recently, Suppressor of Cytokine Signaling 1 (SOCS1) was identified as a potential therapeutic target for osteoarthritis (OA) treatment. However, the mechanisms and signaling pathways of SOCS1 in the regulation of OA development are unclear. The purpose of the current study was to investigate whether interleukin- (IL-) 4 was involved in regulatory mechanism of SOCS1 in human osteoarthritic chondrocytes. First, IL-1β was used to stimulate human osteoarthritic chondrocytes isolated from the articular cartilage of OA patients undergoing total knee replacement. The protein and mRNA expression levels of SOCS1 were upregulated in IL-1β-stimulated human osteoarthritic chondrocytes compared with control cells. The knockdown of SOCS1 increased cell viability and inhibited cell apoptosis. It was also found that IL-4 expression was increased by SOCS1 silencing. Additionally, knockdown of IL-4 reduced cell viability and increased cell apoptosis of osteoarthritic chondrocytes transfected with SOCS1 siRNA. Moreover, the decreased expression of inflammatory factors induced by SOCS1 was enhanced by IL-4 knockdown. In conclusion, IL-4 signaling plays a crucial role in the regulatory functions of SOCS1 in apoptosis and inflammation in human osteoarthritic chondrocytes. These findings provide a potential therapeutic target for the clinical treatment of OA.

Dysregulation of SOCS-Mediated Negative Feedback of Cytokine Signaling in Carcinogenesis and Its Significance in Cancer Treatment

Suppressor of cytokine signaling (SOCS) proteins are major negative feedback regulators of cytokine signaling mediated by the Janus kinase (JAK)-signal transducer and activator of transcription signaling pathway. In particular, SOCS1 and SOCS3 are strong inhibitors of JAKs and can play pivotal roles in the development and progression of cancers. The abnormal expression of SOCS1 and SOCS3 in cancer cells is associated with the dysregulation of cell growth, migration, and death induced by multiple cytokines and hormones in human carcinomas. In addition, the mechanisms involved in SOCS1- and SOCS3-regulated abnormal development and activation of immune cells in carcinogenesis, including T cells, macrophages, dendritic cells, and myeloid-derived suppressor cells, are still unclear. Therefore, this study aims to further discuss the molecules and signal pathways regulating the expression and function of SOCS1 and SOCS3 in various types of cancers and elucidate the feasibility and efficiency of SOCS-based target therapeutic strategy in anticancer treatment.

Suppressor of cytokine signaling 1 gene mutation status as a prognostic biomarker in classical Hodgkin lymphoma

Suppressor of cytokine signaling 1 (SOCS1) mutations are among the most frequent somatic mutations in classical Hodgkin lymphoma (cHL), yet their prognostic relevance in cHL is unexplored. Here, we performed laser-capture microdissection of Hodgkin/Reed-Sternberg (HRS) cells from tumor samples in a cohort of 105 cHL patients. Full-length SOCS1 gene sequencing showed mutations in 61% of all cases (n = 64/105). Affected DNA-motifs and mutation pattern suggest that many of these SOCS1 mutations are the result of aberrant somatic hypermutation and we confirmed expression of mutant alleles at the RNA level. Contingency analysis showed no significant differences of patient-characteristics with HRS-cells containing mutant vs. wild-type SOCS1. By predicted mutational consequence, mutations can be separated into those with non-truncating point mutations (‘minor’ n = 49/64 = 77%) and those with length alteration (‘major’; n = 15/64 = 23%). Subgroups did not differ in clinicopathological characteristics; however, patients with HRS-cells that contained SOCS1 major mutations suffered from early relapse and significantly shorter overall survival (P = 0.03). The SOCS1 major status retained prognostic significance in uni-(P = 0.016) and multivariate analyses (P = 0.005). Together, our data indicate that the SOCS1 mutation type qualifies as a single-gene prognostic biomarker in cHL.

Resveratrol inhibits STAT3 signaling pathway through the induction of SOCS-1: Role in apoptosis induction and radiosensitization in head and neck tumor cells

BACKGROUND

Signal transducer and activator of transcription 3 (STAT3) is persistently activated in squamous cell carcinoma of the head and neck (SCCHN) and can cause uncontrolled cellular proliferation and division.

HYPOTHESIS

Thus, its targeted abrogation could be an effective strategy to reduce the risk of SCCHN. Resveratrol is known for its anti-cancer efficacy in a variety of cancer models.

STUDY DESIGN

The effect resveratrol on STAT3 activation, associated protein kinases, phosphatases, cellular proliferation and apoptosis was investigated.

METHODS

We evaluated the effect of resveratrol on STAT3 signaling cascade and its regulated functional responses in SCCHN cells.

RESULTS

We found that HN3 and FaDu cells expressed strongly phosphorylated STAT3 on both tyrosine 705 and serine 727 residues as compared to other SCCHN cells. The phosphorylation was completely suppressed by resveratrol in FaDu cells, but not substantially in HN3 cells. STAT3 suppression was mediated through the inhibition of activation of upstream JAK2, but not of JAK1 and Src kinases. Treatment with the protein tyrosine phosphatase (PTP) inhibitor pervanadate reversed the resveratrol-induced down-regulation of STAT3, thereby indicating a critical role for a PTP. We also found that resveratrol induced the expression of the SOCS-1 protein and mRNA. Further, deletion of SOCS-1 gene by siRNA suppressed the induction of SOCS-1, and reversed the inhibition of STAT3 activation. Resveratrol down-regulated various STAT3-regulated gene products, inhibited proliferation, invasion, as well as induced the cell accumulation in the sub-G1 phase and caused apoptosis. Beside, this phytoalexin also exhibited the enhancement of apoptosis when combined with ionizing radiation treatment.

CONCLUSION

Our results suggest that resveratrol blocks STAT3 signaling pathway through induction of SOCS-1, thus attenuating STAT3 phosphorylation and proliferation in SCCHN cells.

Upregulation of miR-572 transcriptionally suppresses SOCS1 and p21 and contributes to human ovarian cancer progression

Ovarian cancer is a gynecological malignancy with high mortality rates worldwide and novel diagnostic and prognostic markers and therapeutic targets are urgently required. The suppressor of cytokine signaling 1 (SOCS1) and cyclin-dependent kinase inhibitor 1A (p21^KIP) are known to regulate tumor cell proliferation. However, the mechanisms that regulate these genes have not yet been completely elucidated. In the present study, analysis of a published microarray-based high-throughput assessment (NCBI/E-MTAB-1067) and real-time PCR demonstrated that miR-572 was upregulated in human ovarian cancer tissues and cell lines. Kaplan-Meir analysis indicated that high level expression of miR-572 was associated with poorer overall survival. Ectopic miR-572 promoted ovarian cancer cell proliferation and cell cycle progression in vitro and tumorigenicity in vivo. SOCS1 and p21 were identified as direct targets of miR-572 and suppression of SOCS1 or p21 reversed the inhibiting-function of miR-572-silenced cell on proliferation and tumorigenicity in ovarian cancer cells. Additionally, the expression of miR-572 correlated inversely with the protein expression levels of SOCS1, p21 and positively with Cyclin D1 in ovarian carcinoma specimens. This study demonstrates that miR-572 post-transcriptionally regulates SOCS1 and p21 and may play an important role in ovarian cancer progression; miR-572 may represent a potential therapeutic target for ovarian cancer therapy.

Expression of SOCS1 and CXCL12 Proteins in Primary Breast Cancer Are Associated with Presence of Circulating Tumor Cells in Peripheral Blood

Circulating tumor cells (CTCs) are independent prognostic factors in the primary and metastatic breast cancer patients and play crucial role in hematogenous tumor dissemination. The aim of this study was to correlate the presence of CTCs in peripheral blood with the expression of proteins in tumor tissue that have a putative role in regulation of cell growth and metastatic potential. This prospective study included 203 primary breast cancer patients treated by definitive surgery. CTCs were detected by quantitative real-time PCR for the expression of epithelial (CK19) or epithelial-to-mesenchymal transition–inducing transcription factor genes (TWIST1, SNAIL1, SLUG, and ZEB1). Expression of APC, ADAM23, CXCL12, E-cadherin, RASSF1, SYK, TIMP3, BRMS1, and SOCS1 proteins in primary breast tumor tissue was evaluated by immunohistochemistry. CTCs with epithelial markers were found in 17 (9.2%) patients. Their occurrence was associated with inhibition of SOCS1 expression (odds ratio [OR] = 0.07; 95% confidence interval [CI], 0.03-0.13; P < .001). CTCs with positive epithelial-to-mesenchymal transition markers were detected in 30 (15.8%) patients; however, no association with analyzed protein expressions was found. Overall, CTCs were detected in 44 (22.9%) patients. Presence of any CTC marker was significantly associated with positive CXCL12 expression (OR = 3.08; 95% CI, 1.15-8.26; P = .025) and lack of SOCS1 expression (OR = 0.10; 95% CI, 0.04-0.25; P < .001) in patient’s tumor tissues. As both CXCL12 and SOCS1 proteins are involved in cytokine signaling, our results provide support for the hypothesis that aberrant signaling cross talk between cytokine and chemokine responses could have an important role in hematogenous dissemination of tumor cells in breast cancer.

Tumor suppression by MEG3 lncRNA in a human pituitary tumor derived cell line

Human clinically non-functioning pituitary adenomas (NFAs) account for approximately 40% of diagnosed pituitary tumors. Epigenetic mutations in tumor suppressive genes play an important role in NFA development. Maternally expressed gene 3 (MEG3) is a long non-coding RNA (lncRNA) and we hypothesized that it is a candidate tumor suppressor whose epigenetic silencing is specifically linked to NFA development. In this study, we introduced MEG3 expression into PDFS cells, derived from a human NFA, using both inducible and constitutively active expression systems. MEG3 expression significantly suppressed xenograft tumor growth in vivo in nude mice. When induced in culture, MEG3 caused cell cycle arrest at the G1 phase. In addition, inactivation of p53 completely abolished tumor suppression by MEG3, indicating that MEG3 tumor suppression is mediated by p53. In conclusion, our data support the hypothesis that MEG3 is a lncRNA tumor suppressor in the pituitary and its inactivation contributes to NFA development.

[SOCSJ gene mutations in patients with diffuse large B-cell lymphoma]

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous group of diseases, which accounts for 30% of all non-Hodgkin lymphomas. Current molecular studies have confirmed that there are several DLBCL subtypes characterized by different cellular origin, cytogenetic profile, molecular genetic disorders, and different pathogenesis. Impaired JAK-STAT signaling is a part of the pathogenesis of various cancers, including DLBCL. The review deals with the molecular genetic aspects of the occurrence of DLBCL and the function of the SOCSI gene that has been proven to be responsible for the development of several cancers. Mutations of this gene result from spontaneously impaired B-cell somatic hypermutation and they are frequently inactivating. The presence of point mutations in the functionally significant region of this gene in DLBCL could identify a group of patients with poor prognosis during standard chemotherapy.

Tumour-promoting role of SOCS1 in colorectal cancer cells

The SOCS1 (Suppressor Of Cytokine Signalling 1) protein is considered a tumour suppressor. Notably, the SOCS1 gene is frequently silenced in cancer by hypermethylation of its promoter. Besides blocking inflammation, SOCS1 tumour suppressor activity involves Met receptor inhibition and enhancement of p53 tumour suppressor activity. However, the role of SOCS1 in colorectal cancer (CRC) remains understudied and controversial. Here, we investigated SOCS1 relevance for CRC by querying gene expression datasets of human CRC specimens from The Cancer Genome Atlas (TCGA), and by SOCS1 gain/loss-of-function analyses in murine and human colon carcinoma cells. Our results show that SOCS1 mRNA levels in tumours were more often elevated than reduced with respect to matched adjacent normal tissue of CRC specimens (n = 41). The analysis of TCGA dataset of 431 CRC patients revealed no correlation between SOCS1 expression and overall survival. Overexpression of SOCS1 in CRC cells triggered cell growth enhancement, anchorage-independent growth and resistance to death stimuli, whereas knockdown of SOCS1 reduced these oncogenic features. Moreover, SOCS1 overexpression in mouse CT26 cells increased tumourigenesis in vivo. Biochemical analyses showed that SOCS1 pro-oncogenic activity correlated with the down-modulation of STAT1 expression. Collectively, these results suggest that SOCS1 may work as an oncogene in CRC.

The Cancer Genomics Resource List 2014

CONTEXT

Genomic sequencing for cancer is offered by commercial for-profit laboratories, independent laboratory networks, and laboratories in academic medical centers and integrated health networks. The variability among the tests has created a complex, confusing environment.

OBJECTIVE

To address the complexity, the Personalized Health Care (PHC) Committee of the College of American Pathologists proposed the development of a cancer genomics resource list (CGRL). The goal of this resource was to assist the laboratory pathology and clinical oncology communities.

DESIGN

The PHC Committee established a working group in 2012 to address this goal. The group consisted of site-specific experts in cancer genetic sequencing. The group identified current next-generation sequencing (NGS)-based cancer tests and compiled them into a usable resource. The genes were annotated by the working group. The annotation process drew on published knowledge, including public databases and the medical literature.

RESULTS

The compiled list includes NGS panels offered by 19 laboratories or vendors, accompanied by annotations. The list has 611 different genes for which NGS-based mutation testing is offered. Surprisingly, of these 611 genes, 0 genes were listed in every panel, 43 genes were listed in 4 panels, and 54 genes were listed in 3 panels. In addition, tests for 393 genes were offered by only 1 or 2 institutions. Table 1 provides an example of gene mutations offered for breast cancer genomic testing with the annotation as it appears in the CGRL 2014.

CONCLUSIONS

The final product, referred to as the Cancer Genomics Resource List 2014, is available as supplemental digital content.

Methylation of suppressor of cytokine signalling 1 gene promoter is associated with acute-on-chronic hepatitis B liver failure

Suppressor of cytokine signalling 1 (SOCS1) was demonstrated to play an important negative role in fulminant hepatitis and might be involved in acute-on-chronic hepatitis B liver failure (ACHBLF). This study was therefore to identify the potential role of SOCS1 and its promoter methylation pattern in ACHBLF patients. Sixty ACHBLF patients, 60 chronic hepatitis B (CHB) patients and 30 healthy controls were investigated in this study. We found that expression of SOCS1 mRNA in CHB and ACHBLF patients was significantly higher than that in healthy controls. The serum level of IL-6, IFN-γ and TNF-α was significantly higher in ACHBLF than CHB. Increased serum level of IL-6, IFN-γ and TNF-α was correlated with total bilirubin, ALT, PTA and MELD scores in ACHBLF. The degree of methylation of the SOCS1 in ACHBLF patients (35.0%, 21/60) was significantly higher than that in CHB patients (16.7%, 10/60). Furthermore, methylated group showed lower level of SOCS1, and higher MELD scores and mortality rate when compared with unmethylated group of ACHBLF. These results suggested that SOCS1 might contribute to immune-related liver damage in ACHBLF, and its aberrant methylation may be a key event for the prognosis of ACHBLF.

MicroRNA-19a functions as an oncogenic microRNA in non-small cell lung cancer by targeting the suppressor of cytokine signaling 1 and mediating STAT3 activation

MicroRNA‑19a (miR‑19a) has been found to be overexpressed in lung cancers. However, the underlying molecular mechanisms of miR‑19a in tumorigenesis and the development of lung cancer remain poorly understood. In the present study, we aimed to delineate the role and mechanisms of action of miR‑19a in non‑small cell lung cancer (NSCLC). miR‑19a was found to be overexpressed in both NSCLC tumor tissues and cell lines, as shown by RT-PCR. The enforced expression of miR‑19a by transfection with miR-19a mimics significantly enhanced cell growth and viability, cell invasion and the migration of NSCLC cells, as shown by cell invasion and migration assays, and promoted the growth of xenograft tumors in a mouse xenograft tumor model. Conversely, the inhibition of miR‑19a by transfection of the cells with miR‑19a inhibitor displayed the opposite effects. More importantly, we found that miR‑19a directly interacted with the 3'‑untranslated region (3'‑UTR) of the suppressor of cytokine signaling 1 (SOCS1) by dual‑luciferase reporter assay. miR‑19a was found to be capable of regulating the expression of SOCS1 in NSCLC cells. Thus, by modulating SOCS1 expression, miR‑19a regulated the expression of the signal transducer and activator of transcription 3 (STAT3). Taken together, our data provide a possible underlying mechanism of action of miR‑19a in the development of NSCLC and suggest that miR‑19a may be a novel and promising target for therapeutic intervention in NSCLC.

Low expression of SOCS-1 and SOCS-3 is a poor prognostic indicator for gastric cancer patients

BACKGROUND AND OBJECTIVES

Inflammation plays an important role in gastric cancer (GC) development and progression. Suppressor of cytokine signaling (SOCS)-1 and SOCS-3 negatively regulate proinflammatory cytokine signaling; however, their prognostic significance in GC remains unknown. We evaluated the clinicopathological correlation and prognostic significance of SOCS-1 and SOCS-3 in GC.

METHODS

SOCS-1 and SOCS-3 mRNA levels were analyzed in 80 paired gastric tumor and adjacent normal mucosal tissues using a microarray dataset from the Gene Expression Omnibus. Univariate and multivariate analyses were performed to investigate the prognostic impact of SOCS-1 and SOCS-3 immunohistochemical expression on overall survival (OS) and relapse-free survival (RFS) in 186 consecutive GC patients who underwent curative surgery.

RESULTS

SOCS-1 and SOCS-3 mRNA expression levels were lower in gastric tumor tissues than in matched normal mucosa. OS and RFS were significantly longer in the high SOCS-1 and SOCS-3 expression groups than in their corresponding low expression groups (p < 0.05). High simultaneous SOCS-1 and SOCS-3 expression were associated with longer OS compared with low simultaneous SOCS-1 and SOCS-3 expression (68.8 vs. 22.2 months; p < 0.001). SOCS-1 [hazards ratio (HR) 0.54, 95 % confidence interval (CI) 0.33-0.87, p = 0.011] and SOCS-3 (HR 0.46, 95 % CI 0.26-0.80, p = 0.006) were independent prognostic factors for OS. Only SOCS-1 (HR 0.20, 95 % CI 0.11-0.38, p = 0.006) was an independent prognostic factor for RFS.

CONCLUSION

Low SOCS-1 and SOCS-3 expression are poor prognostic indicators in GC. GC patients with low SOCS-1 and SOCS-3 expression need close follow-up.

The SOCS-1 -1478CA/del polymorphism is not associated with colorectal cancer or age at onset in Turkish subjects

BACKGROUND

Suppressor of cytokine signaling (SOCS)-1 acts as a key regulator of many cytokine signaling pathways and its abnormal expression has been identified in several human malignancies, suggesting potential roles in carcinogenesis. The aim of this study was to investigate any association between the functional SOCS- 1 -1478CA>del polymorphism and colorectal cancer (CC) as well as age at onset in a Turkish clinical sample.

MATERIALS AND METHODS

A total of 122 subjects were enrolled in this case-control study (70 CC cases and 52 controls). The SOCS-1 -1478CA>del polymorphism was genotyped using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

The odds ratio of the del allele for CC relative to the CA allele was not significantly different between the groups (OR=0.71, 95% CI=0.41-1.22, p=0.27). This result did not change after adjustment for age and sex on multivariable regression analysis (OR=0.84, 95% CI=0.59-1.34, p=0.53). When the SOCS-1 -1478CA>del polymorphism was analyzed among CC patients in relation to the age at disease onset, we found no significant differences between subjects with the del/del, CA/del, and CA/CA genotypes.

CONCLUSIONS

The results of our study did not point towards a major role of the SOCS-1 -1478CA>del polymorphism in the pathogenesis of CC in Turkish subjects.