SOCS-1, a negative regulator of cytokine signaling, is frequently silenced by methylation in multiple myeloma

Measuring the differential expression of the major hypermethylated tumor suppressor genes in tissues of primary hepatocellular carcinoma

BACKGROUND

Hepatocarcinogenesis is a multifactorial process that arises from a integration of genetic and epigenetic anomalies leading to abnormal gene expression and function. It is difficult to characterize HCC with a single biomarker. Our study aimed at detecting the expression of a panel of 8 methylated genes (SOCS1, APC, Gadd45b, CDKN1B, P15, PAX6, STAT1 and MSH2) as regulatory factors among Egyptian patients with HCC.

METHODS

This study was conducted on HCC tissue samples of 30 Egyptian patients in comparison with their non-cancerous adjacent cirrhotic tissue as a control. Tissue samples were obtained from patients who have undergone living donor liver transplantation (LDLT) or liver resection at El Sahel Teaching Hospital (Cairo, Egypt). A special Custom designed PCR Arrays was used to analyze the expression profiles of chosen methylated genes associated with HCC.

RESULTS

Expression of SOCS1, APC, Gadd45b, CDKN1B, P15, PAX6, STAT1 and MSH2 were lower in the HCC tissue compared to the cirrhotic tissue (pvalue = 0.015, 0.081, 0.004, 0.027, 0.211, 0.015, 0.025 and 0.0001 respectively). 5 genes (SOCS1, APC, GAdd45b, CDKN1B, and MSH2) showed the ability to be used as diagnostic biomarkers for HCC with high sensitivity and specificity values at cut off values: 1.05, 1.17, 0.995, 0.546, and 0.125 respectively. As for the other 3 genes (P15, PAX6, STAT1), PAX6 gene has the highest sensitivity at a cut off value of 0.3364. A significant negative correlation was shown between alpha fetoprotein (AFP) and 5 of the studied genes (SOCS1, APC, Gadd45b, STAT1, and MSH2).

CONCLUSIONS

Expression of the selected hypermethylated genes (SOCS1, APC, Gadd45b, CDKN1B, P15, PAX6, STAT1 and MSH2) in HCC tissue samples was lower than adjacent tissue. Their role should be further studied to solve the mystery that surrounds the pathogenesis of HCC.

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.

5-AZA Upregulates SOCS3 and PTPN6/SHP1, Inhibiting STAT3 and Potentiating the Effects of AG490 against Primary Effusion Lymphoma Cells

Epigenetic modifications, including aberrant DNA methylation occurring at the promoters of oncogenes and oncosuppressor genes and histone modifications, can contribute to carcinogenesis. Aberrant methylation mediated by histone methylatransferases, alongside histones, can affect methylation of proteins involved in the regulation of pro-survival pathways such as JAK/STAT and contribute to their activation. In this study, we used DNA or histone demethylating agents, 5-Azacytidine (5-AZA) or DS-3201 (valemetostat), respectively, to treat primary effusion lymphoma (PEL) cells, alone or in combination with AG490, a Signal transducer and activator of transcription 3 (STAT3) inhibitor. Cell viability was investigated by trypan blue assay and FACS analysis. The molecular changes induced by 5-AZA and/or AG490 treatments were investigated by Western blot analysis, while cytokine release by PEL cells treated by these drugs was evaluated by Luminex. Statistical analyses were performed with Graphpad Prism® software (version 9) and analyzed by Student's t test or a nonparametric one-way ANOVA test. The results obtained in this study suggest that 5-AZA upregulated molecules that inhibit STAT3 tyrosine phosphorylation, namely Suppressor of Cytokine Signaling 3 (SOCS3) and tyrosine-protein phosphatase non-receptor type (PTPN) 6/Src homology region 2 domain-containing phosphatase-1 (SHP-1), reducing STAT3 activation and downregulating several STAT3 pro-survival targets in PEL cells. As this lymphoma is highly dependent on the constitutive activation of STAT3, 5-AZA impaired PEL cell survival, and when used in combination with AG490 JAK2/STAT3 inhibitor, it potentiated its cytotoxic effect. Differently from 5-AZA, the inhibition of the EZH1/2 histone methyltransferase by DS-3201, reported to contribute to STAT3 activation in other cancers, slightly affected STAT3 phosphorylation or survival in PEL cells, either alone or in combination with AG490. This study suggests that 5-AZA, by upregulating the expression level of SOCS3 and PTPN6/SHP1, reduced STAT3 activation and improved the outcome of treatment targeting this transcription factor in PEL cells.

SOCS1 expression in cancer cells: potential roles in promoting antitumor immunity

Suppressor of cytokine signaling 1 (SOCS1) is a potent regulator immune cell responses and a proven tumor suppressor. Inhibition of SOCS1 in T cells can boost antitumor immunity, whereas its loss in tumor cells increases tumor aggressivity. Investigations into the tumor suppression mechanisms so far focused on tumor cell-intrinsic functions of SOCS1. However, it is possible that SOCS1 expression in tumor cells also regulate antitumor immune responses in a cell-extrinsic manner via direct and indirect mechanisms. Here, we discuss the evidence supporting the latter, and its implications for antitumor immunity.

SOCS1 as a Biomarker Candidate for HPV Infection and Prognosis of Head and Neck Squamous Cell Carcinomas

The pathogenesis of head and neck squamous cell carcinoma (HNSCC) is associated with human papillomavirus (HPV) infection. However, the molecular mechanisms underlying the interactions between HNSCC and HPV remain unclear. Bioinformatics was used to analyze the gene expression dataset of HPV-associated HNSCC based on the Cancer Genome Atlas (TCGA) database. Differentially expressed genes (DEGs) in HPV-positive and HPV-negative HNSCC were screened. Gene function enrichment, protein-protein interactions (PPI), survival analysis, and immune cell infiltration of DEGs were performed. Furthermore, the clinical data of HNSCC tissue samples were analyzed using immunohistochemistry. In total, 194 DEGs were identified. A PPI network was constructed and 10 hub genes (EREG, PLCG1, ERBB4, HBEGF, ZFP42, CBX6, NFKBIA, SOCS1, ATP2B2, and CEND1) were identified. Survival analysis indicated that low expression of SOCS1 was associated with worse overall survival. Immunohistochemistry demonstrated that SOCS1 expression was higher in HPV-negative HNSCC than in HPV-positive HNSCC, and there was a positive correlation between SOCS1 expression and patient survival. This study provides new information on biological targets that may be relevant to the molecular mechanisms underpinning the occurrence and development of HNSCC. SOCS1 may play an important role in the interaction between HPV and HNSCC and serve as a potential biomarker for future therapeutic targets.

The suppressor of cytokine signaling-1 (SOCS1) gene polymorphism and promoter methylation correlate with the course of COVID-19

The suppressor of the cytokine signaling-1 (SOCS1) gene is a short sequence located on chromosome 16 that functions to induce an appropriate immune response and is an essential physiological regulator of interferon (IFN) signaling. In addition to comparing the global DNA and SOCS1 gene promoter methylation status between our patients with coronavirus disease 2019 (COVID-19) and healthy controls, this study demonstrates the effect of the SOCS1 rs33989964 polymorphism on patients with COVID-19. The study group included 139 patients diagnosed with COVID-19 in our hospital's clinics between June and December 2020, and the control group included 78 healthy individuals. After comparing the initial gene polymorphisms of the patients with the healthy control group, three separate clinical subgroups were formed. The gene polymorphism distribution and the methylation status of SOCS1 were examined in these clinical subgroups. Hypomethylation of the SOCS1 gene was observed in the COVID-19 patient group compared to the healthy control group (p = 0.001). Between the patients divided into two separate clinical subgroups, those with severe and mild infections, the Del/Del genotype of the SOCS1 gene was more common in patients with severe infection than in patients with mild infection (p = 0.018). Patients with the CA/CA and CA/Del genotypes were 0.201 times more likely to have a severe infection (95% CI: 0.057-0.716, p = 0.007). Having a non-Del/Del genotype was a protective factor against severe infection. The effect of the SOCS1 rs33989964 polymorphism and methylation status of the SOCS1 gene throughout the COVID-19 pandemic could be significant contributions to the literature.

Cisplatin or Doxorubicin Reduces Cell Viability via the PTPIVA3-JAK2-STAT3 Cascade in Hepatocellular Carcinoma

Introduction

Hepatocellular carcinoma (HCC) accounts for 80% of all liver cancers and is the 2nd leading cause of cancer-related death in Taiwan. Various factors, including rapid cell growth, a high recurrence rate and drug resistance, make HCC difficult to cure. Moreover, the survival rate of advanced HCC patients treated with systemic chemotherapy remains unsatisfactory. Hence, the identification of novel molecular targets and the underlying mechanisms of chemoresistance in HCC and the development more effective therapeutic regimens are desperately needed.

Methods

An MTT assay was used to determine the cell viability after cisplatin or doxorubicin treatment. Western blotting, qRT‒PCR and immunohistochemistry were utilized to examine the protein tyrosine phosphatase IVA3 (PTP4A3) level and associated signaling pathways. ELISA was utilized to analyze the levels of the inflammatory cytokine IL-6 influenced by cisplatin, doxorubicin and PTP4A3 silencing.

Results

In this study, we found that PTP4A3 in the cisplatin/doxorubicin-resistant microarray was closely associated with the overall and recurrence-free survival rates of HCC patients. Cisplatin or doxorubicin significantly reduced cell viability and decreased PTP4A3 expression in hepatoma cells. IL-6 secretion increased with cisplatin or doxorubicin treatment and after PTP4A3 silencing. Furthermore, PTP4A3 was highly expressed in tumor tissues versus adjacent normal tissues from HCC patients. In addition, we evaluated the IL-6-associated signaling pathway involving STAT3 and JAK2, and the levels of p-STAT3, p-JAK2, STAT3 and JAK2 were obviously reduced with cisplatin or doxorubicin treatment in HCC cells using Western blotting and were also decreased after silencing PTP4A3. Collectively, we suggest that cisplatin or doxorubicin decreases HCC cell viability via downregulation of PTP4A3 expression through the IL-6R-JAK2-STAT3 cascade.

Discussion

Therefore, emerging evidence provides a deep understanding of the roles of PTP4A3 in HCC cisplatin/doxorubicin chemoresistance, which can be applied to develop early diagnosis strategies and reveal prognostic factors to establish novel targeted therapeutics to specifically treat HCC.

Alterations of SOCS1 and SOCS3 transcript levels, but not promoter methylation levels in subcutaneous adipose tissues in obese women

BACKGROUND

Animal model studies suggest that change in the members of the suppressor of the cytokine signaling (SOCS) family (mainly SOCS1 and SOCS3) is linked to the pathogenesis of obesity-related metabolic disorders. Moreover, epigenetic modification is involved in the transcriptional regulation of the SOCS gene family. Here, we aimed to evaluate the mRNA expression as well as gene promoter methylation of SOCS1 and SOCS3 in subcutaneous adipose tissue (SAT) from obese women compared to normal-weight subjects. We also intend to identify the possible association of SOCS1 and SOCS3 transcript levels with metabolic parameters in the context of obesity.

METHODS

This study was conducted on women with obesity (n = 24) [body mass index (BMI) ≥ 30 kg/m ²] and women with normal-weight (n = 22) (BMI < 25 kg/m ²). Transcript levels of SOCS1 and SOCS3 were evaluated by real-time PCR in SAT from all participants. After bisulfite treatment of DNA, methylation-specific PCR was used to assess the putative methylation of 10 CpG sites in the promoter of SOCS1 and 13 CpG sites in SOCS3 in SAT from women with obesity and normal weight.

RESULTS

It was found that unlike SOCS3, which disclosed an elevating expression pattern, the expression level of SOCS1 was lower in the women with obesity as compared with their non-obese counterparts (P-value = 0.03 for SOCS1 transcript level and P-value = 0.011 for SOCS3 transcript level). As for the analysis of promoter methylation, it was found that SOCS1 and SOCS3 methylation were not significantly different between the individuals with obesity and normal weight (P-value = 0.45 and P-value = 0.89). Correlation analysis indicated that the transcript level of SOCS1 mRNA expression had an inverse correlation with BMI, hs-CRP levels, HOMA-IR, and insulin levels. However, the SOCS3 transcript level showed a positive correlation with BMI, waist-to-height ratio, waist circumference, hip circumference, hs-CRP, HOMA-IR, insulin, fasting blood glucose, and total cholesterol. Interestingly, HOMA-IR is the predictor of the transcript level of SOCS1 (β =  - 0.448, P-value = 0.003) and SOCS3 (β = 0.465, P-value = 0.002) in SAT of all participants.

CONCLUSIONS

Our findings point to alterations of SOCS1 and SOCS3 transcript levels, but not promoter methylation levels in subcutaneous adipose tissues from women with obesity. Moreover, mRNA expression of SOCS1 and SOCS3 in SAT was associated with known obesity indices, insulin resistance, and hs-CRP, suggesting the contribution of SOCS1 and SOCS3 in the pathogenesis of obesity-related metabolic abnormalities. However, further studies are required to establish this concept.

Epigenetic and genetic investigation of SOCS-1 gene in patients with multiple myeloma

Background

The suppressor of cytokine signaling-1 (SOCS-1) functions to induce an appropriate immune response and is an essential physiological regulator of interferon signaling. DNA methylation involves adding a methyl group to the carbon 5 position of cytosine. Besides comparing SOCS-1 gene methylation status between patients with multiple myeloma (MM) and healthy controls, this study also aimed to demonstrate the effect of SOCS-1 gene distribution and the effect of methylation of SOCS-1 on progression-free survival (PFS) and overall survival (OS).

Methods

This study included 120 patients diagnosed with MM between January 2018 and 2020 and 80 healthy individuals. The distribution of the SOCS-1 genotypes was statistically compared between MM patients and healthy controls. Additionally, the statistically significant effects of these genotypes on survival were examined.

Results

The CA/CA genotype of SOCS-1 was significantly higher in healthy controls (P=0.001), while the Del/Del genotype was significantly higher in patients with MM (P=0.034). The percent methylated reference (PMR) value of the SOCS-1 gene was significantly higher in the healthy controls (median, 43.48; range, 2.76‒247.75; P=0.001). Patients with a PMR value of ≥43.48 were 3.125 times more likely to develop progression than those with a PMR value of ＜43.48.

Conclusion

The effects of SOCS-1 polymorphisms on the pathogenesis of.

DNA methylation changes and inflammaging in aging-associated diseases

Aging as an inevitable phenomenon is associated with pervasive changes in physiological functions. There is a relationship between aging and the increase of several chronic diseases. Most age-related disorders are accompanied by an underlying chronic inflammatory state, as demonstrated by local infiltration of inflammatory cells and greater levels of proinflammatory cytokines in the bloodstream. Within inflammaging, many epigenetic events, especially DNA methylation, change. During the aging process, due to aberrations of DNA methylation, biological processes are disrupted, leading to the emergence or progression of a variety of human diseases, including cancer, neurodegenerative disorders, cardiovascular disease and diabetes. The focus of this review is on DNA methylation, which is involved in inflammaging-related activities, and how its dysregulation leads to human disorders.

Aberrant DNA methylation in multiple myeloma: A major obstacle or an opportunity?

Drug resistance (DR) of cancer cells leading to relapse is a huge problem nowadays to achieve long-lasting cures for cancer patients. This also holds true for the incurable hematological malignancy multiple myeloma (MM), which is characterized by the accumulation of malignant plasma cells in the bone marrow (BM). Although new treatment approaches combining immunomodulatory drugs, corticosteroids, proteasome inhibitors, alkylating agents, and monoclonal antibodies have significantly improved median life expectancy, MM remains incurable due to the development of DR, with the underlying mechanisms remaining largely ill-defined. It is well-known that MM is a heterogeneous disease, encompassing both genetic and epigenetic aberrations. In normal circumstances, epigenetic modifications, including DNA methylation and posttranslational histone modifications, play an important role in proper chromatin structure and transcriptional regulation. However, in MM, numerous epigenetic defects or so-called ‘epimutations’ have been observed and this especially at the level of DNA methylation. These include genome-wide DNA hypomethylation, locus specific hypermethylation and somatic mutations, copy number variations and/or deregulated expression patterns in DNA methylation modifiers and regulators. The aberrant DNA methylation patterns lead to reduced gene expression of tumor suppressor genes, genomic instability, DR, disease progression, and high-risk disease. In addition, the frequency of somatic mutations in the DNA methylation modifiers seems increased in relapsed patients, again suggesting a role in DR and relapse. In this review, we discuss the recent advances in understanding the involvement of aberrant DNA methylation patterns and/or DNA methylation modifiers in MM development, progression, and relapse. In addition, we discuss their involvement in MM cell plasticity, driving myeloma cells to a cancer stem cell state characterized by a more immature and drug-resistant phenotype. Finally, we briefly touch upon the potential of DNA methyltransferase inhibitors to prevent relapse after treatment with the current standard of care agents and/or new, promising (immuno) therapies.

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 &lt; 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.

Suppressors of Cytokine Signaling and Hepatocellular Carcinoma

Simple Summary

Hepatocellular carcinoma (HCC) is a common malignancy worldwide. The HCC generally develops in the liver of patients already suffering from chronic liver disease. There have been significant advances in both the curative and palliative treatment of HCC. Although liver resection is a curative treatment for HCC, its indication is often limited due to an impaired liver function reservoir. There is still a need to understand how to control liver regeneration after resection and find better cancer immunotherapy and anticancer drugs for advanced HCC. Suppressors of cytokine signaling (SOCS) negatively regulate cytokine signaling related to cell proliferation, differentiation, and immune response; therefore, SOCS are thought to play an important role in HCC development and liver regeneration.

Abstract

Cytokines are secreted soluble glycoproteins that regulate cellular growth, proliferation, and differentiation. Suppressors of cytokine signaling (SOCS) proteins negatively regulate cytokine signaling and form a classical negative feedback loop in the signaling pathways. There are eight members of the SOCS family. The SOCS proteins are all comprised of a loosely conserved N-terminal domain, a central Src homology 2 (SH2) domain, and a highly conserved SOCS box at the C-terminus. The role of SOCS proteins has been implicated in the regulation of cytokines and growth factors in liver diseases. The SOCS1 and SOCS3 proteins are involved in immune response and inhibit protective interferon signaling in viral hepatitis. A decreased expression of SOCS3 is associated with advanced stage and poor prognosis of patients with hepatocellular carcinoma (HCC). DNA methylations of SOCS1 and SOCS3 are found in HCC. Precise regulation of liver regeneration is influenced by stimulatory and inhibitory factors after partial hepatectomy (PH), in particular, SOCS2 and SOCS3 are induced at an early time point after PH. Evidence supporting the important role of SOCS signaling during liver regeneration also supports a role of SOCS signaling in HCC. Immuno-oncology drugs are now the first-line therapy for advanced HCC. The SOCS can be potential targets for HCC in terms of cell proliferation, cell differentiation, and immune response. In this literature review, we summarize recent findings of the SOCS family proteins related to HCC and liver diseases.

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.

Pathogenic signaling in multiple myeloma

Multiple myeloma is a common hematological malignancy of plasma cells, the terminally differentiated B cells that secrete antibodies as part of the adaptive immune response. Significant progress has been made in treating multiple myeloma, but this disease remains largely incurable, and most patients will eventually suffer a relapse of disease that becomes refractory to further therapies. Moreover, a portion of patients with multiple myeloma present with disease that is refractory to all treatments from the initial diagnosis, and no current therapeutic approaches can help. Therefore, the task remains to advance new therapeutic strategies to help these vulnerable patients. One strategy to meet this challenge is to unravel the complex web of pathogenic signaling pathways in malignant plasma cells and use this information to design novel precision medicine strategies to assist these patients most at risk.

The Relevance of SOCS1 Methylation and Epigenetic Therapy in Diverse Cell Populations of Hepatocellular Carcinoma

The suppressor of cytokine signaling 1 (SOCS1) is a tumor suppressor gene found to be hypermethylated in cancers. It is involved in the oncogenic transformation of cirrhotic liver tissues. Here, we investigated the clinical relevance of SOCS1 methylation and modulation upon epigenetic therapy in diverse cellular populations of hepatocellular carcinoma (HCC). HCC clinical specimens were evaluated for SOCS1 methylation and mRNA expression. The effect of 5-Azacytidine (5-AZA), a demethylation agent, was assessed in different subtypes of HCC cells. We demonstrated that the presence of SOCS1 methylation was significantly higher in HCC compared to peri-HCC and non-tumoral tissues (52% vs. 13% vs. 14%, respectively, p < 0.001). In vitro treatment with a non-toxic concentration of 5-AZA significantly reduced DNMT1 protein expression for stromal subtype lines (83%, 73%, and 79%, for HLE, HLF, and JHH6, respectively, p < 0.01) compared to cancer stem cell (CSC) lines (17% and 10%, for HepG2 and Huh7, respectively), with the strongest reduction in non-tumoral IHH cells (93%, p < 0.001). 5-AZA modulated the SOCS1 expression in different extents among the cells. It was restored in CSC HCC HepG2 and Huh7 more efficiently than sorafenib. This study indicated the relevance of SOCS1 methylation in HCC and how cellular heterogeneity influences the response to epigenetic therapy.

The Impact of EGCG and RG108 on SOCS1 Promoter DNA Methylation and Expression in U937 Leukemia Cells

BACKGROUND

The available evidence has increasingly demonstrated that a combination of genetic and epigenetic factors, such as DNA methylation, could be considered as causing leukemia. Epigenetic changes and methylation of the suppressor of the cytokine signaling 1 promoter (SOCS1) CpG region silence SOCS1 expression in cancer. In the current study, we evaluated the impact of epigallocatechin gallate (EGCG) and RG108 on SOCS1 promoter methylation and expression in U937 cells.

METHODS

In the current study, U937 leukemic cells were treated with EGCG and RG108 for 12, 24, 48, and 72 h and SOCS1 promoter methylation and its expression were measured by methylation-specific PCR (MSP) and quantitative real-time PCR, respectively.

RESULTS

The outcomes indicated that the SOCS1 promoter is methylated in U937 cells, and treatment of these cells with either EGCG or RG108 reduced its methylation. Moreover, we observed that SOCS1 expression was significantly upregulated in a time-dependent manner by both EGCG and RG108 in U937 cells compared with control cells. In the RG108-treated group at 12, 24, 48, and 72 h, SOCS1 expression was upregulated by 1, 4.2, 16.6, and 32.6 -fold respectively, and in the EGCG-treated group, by 0.5, 3.2, 10.8, and 22.3 -fold, respectively.

CONCLUSION

Treatment with either EGCG or RG108 reduced SOCS1 promoter methylation and increased SOCS1 expression in U937 cells in a time-dependent manner, which may play a role in leukemia therapy.

PRMT5 regulates cell pyroptosis by silencing CASP1 in multiple myeloma

Protein arginine methyltransferase 5 (PRMT5), a histone methyltransferase responsible for the symmetric dimethylation of histone H4 on Arg 3 (H4R3me2s), is an enzyme that participates in tumor cell progression in a variety of hematological malignancies. However, the biological functions of PRMT5 in multiple myeloma (MM) and the underlying molecular mechanisms remain unclear. In this study, we conducted a bioinformatics analysis and found that PRMT5 expression was significantly upregulated in MM. In vitro and in vivo phenotypic experiments revealed that knockdown of PRMT5 expression enhanced cell pyroptosis in MM. Moreover, we found that CASP1 expression was negatively correlated with PRMT5 expression, and repressing PRMT5 expression rescued both the phenotype and expression markers (N-GSDMD, IL-1b, and IL-18). Inhibition of PRMT5 activity increased CASP1 expression and promoted MM cell pyroptosis. Finally, high expression of PRMT5 or low expression of CASP1 was correlated with poor overall survival in MM. Collectively, our results provide a mechanism by which PRMT5 regulates cell pyroptosis by silencing CASP1 in MM.

Investigating the Interplay between Myeloma Cells and Bone Marrow Stromal Cells in the Development of Drug Resistance: Dissecting the Role of Epigenetic Modifications

Simple Summary

Despite advances made in the last two decades, multiple myeloma (MM) is still an incurable disease. The genetic complexity of MM and the presence of intra-clonal heterogeneity are major contributors to disease relapse and the development of treatment resistance. Additionally, the bone marrow microenvironment is known to play a pivotal role in MM disease progression. Together with genetic modifications, epigenetic changes have been shown to influence MM development and progression. However, epigenetic treatments for MM are still lacking. This is mainly due to the high rate of adverse events of epigenetic drugs in clinical practice. In this review, we will focus on the role of epigenetic modifications in MM disease progression and the development of drug resistance, as well as their role in shaping the interplay between bone marrow stromal cells and MM cells. The current and future treatment strategies involving epigenetic drugs will also be addressed.

Abstract

Multiple Myeloma (MM) is a malignancy of plasma cells infiltrating the bone marrow (BM). Many studies have demonstrated the crucial involvement of bone marrow stromal cells in MM progression and drug resistance. Together with the BM microenvironment (BMME), epigenetics also plays a crucial role in MM development. A variety of epigenetic regulators, including histone acetyltransferases (HATs), histone methyltransferases (HMTs) and lysine demethylases (KDMs), are altered in MM, contributing to the disease progression and prognosis. In addition to histone modifications, DNA methylation also plays a crucial role. Among others, aberrant epigenetics involves processes associated with the BMME, like bone homeostasis, ECM remodeling or the development of treatment resistance. In this review, we will highlight the importance of the interplay of MM cells with the BMME in the development of treatment resistance. Additionally, we will focus on the epigenetic aberrations in MM and their role in disease evolution, interaction with the BMME, disease progression and development of drug resistance. We will also briefly touch on the epigenetic treatments currently available or currently under investigation to overcome BMME-driven treatment resistance.

The Emerging Role of Suppressors of Cytokine Signaling (SOCS) in the Development and Progression of Leukemia

Cytokines are pleiotropic signaling molecules that execute an essential role in cell-to-cell communication through binding to cell surface receptors. Receptor binding activates intracellular signaling cascades in the target cell that bring about a wide range of cellular responses, including induction of cell proliferation, migration, differentiation, and apoptosis. The Janus kinase and transducers and activators of transcription (JAK/STAT) signaling pathways are activated upon cytokines and growth factors binding with their corresponding receptors. The SOCS family of proteins has emerged as a key regulator of cytokine signaling, and SOCS insufficiency leads to constitutive activation of JAK/STAT signaling and oncogenic transformation. Dysregulation of SOCS expression is linked to various solid tumors with invasive properties. However, the roles of SOCS in hematological malignancies, such as leukemia, are less clear. In this review, we discuss the recent advances pertaining to SOCS dysregulation in leukemia development and progression. We also highlight the roles of specific SOCS in immune cells within the tumor microenvironment and their possible involvement in anti-tumor immunity. Finally, we discuss the epigenetic, genetic, and post-transcriptional modifications of SOCS genes during tumorigenesis, with an emphasis on leukemia.

Bioactive Compounds from Herbal Medicine Targeting Multiple Myeloma

Multiple myeloma (MM) is one of the most widespread hematological cancers. It is characterized by a clonal proliferation of malignant plasma cells in the bone marrow and by the overproduction of monoclonal proteins. In recent years, the survival rate of patients with multiple myeloma has increased significantly due to the use of transplanted stem cells and of the new therapeutic agents that have significantly increased the survival rate, but it still cannot be completely cured and therefore the development of new therapeutic products is needed. Moreover, many patients have various side effects and face the development of drug resistance to current therapies. The purpose of this review is to highlight the bioactive active compounds (flavonoids) and herbal extracts which target dysregulated signaling pathway in MM, assessed by in vitro and in vivo experiments or clinical studies, in order to explore their healing potential targeting multiple myeloma. Mechanistically, they demonstrated the ability to promote cell cycle blockage and apoptosis or autophagy in cancer cells, as well as inhibition of proliferation/migration/tumor progression, inhibition of angiogenesis in the tumor vascular network. Current research provides valuable new information about the ability of flavonoids to enhance the apoptotic effects of antineoplastic drugs, thus providing viable therapeutic options based on combining conventional and non-conventional therapies in MM therapeutic protocols.

Anti-Cancer Activity of Curcumin on Multiple Myeloma

Multiple Myeloma (MM) is the third most common and deadly hematological malignancy, which is characterized by a progressive monoclonal proliferation within the bone marrow. MM is cytogenetically heterogeneous with numerous genetic and epigenetic alterations, which lead to a wide spectrum of signaling pathways and cell cycle checkpoint aberrations. MM symptoms can be attributed to CRAB features (hyperCalcemia, Renal failure, Anemia, and Bone lesion), which profoundly affect both the Health-Related Quality of Life (HRQoL) and the life expectancy of patients. Despite all enhancement and improvement in therapeutic strategies, MM is almost incurable, and patients suffering from this disease eventually relapse. Curcumin is an active and non-toxic phenolic compound, isolated from the rhizome of Curcuma longa L. It has been widely studied and has a confirmed broad range of therapeutic properties, especially anti-cancer activity, and others, including anti-proliferation, anti-angiogenesis, antioxidant and anti-mutation activities. Curcumin induces apoptosis in cancerous cells and prevents Multidrug Resistance (MDR). Growing evidence concerning the therapeutic properties of curcumin caused a pharmacological impact on MM. It is confirmed that curcumin interferes with various signaling pathways and cell cycle checkpoints, and with oncogenes. In this paper, we summarized the anti- MM effects of curcumin.

TGF-β-induced epigenetic deregulation of SOCS3 facilitates STAT3 signaling to promote fibrosis

Fibroblasts are key effector cells in tissue remodeling. They remain persistently activated in fibrotic diseases, resulting in progressive deposition of extracellular matrix. Although fibroblast activation may be initiated by external factors, prolonged activation can induce an "autonomous," self-maintaining profibrotic phenotype in fibroblasts. Accumulating evidence suggests that epigenetic alterations play a central role in establishing this persistently activated pathologic phenotype of fibroblasts. We demonstrated that in fibrotic skin of patients with systemic sclerosis (SSc), a prototypical idiopathic fibrotic disease, TGF-β induced the expression of DNA methyltransferase 3A (DNMT3A) and DNMT1 in fibroblasts in a SMAD-dependent manner to silence the expression of suppressor of cytokine signaling 3 (SOCS3) by promoter hypermethylation. Downregulation of SOCS3 facilitated activation of STAT3 to promote fibroblast-to-myofibroblast transition, collagen release, and fibrosis in vitro and in vivo. Reestablishment of the epigenetic control of STAT3 signaling by genetic or pharmacological inactivation of DNMT3A reversed the activated phenotype of SSc fibroblasts in tissue culture, inhibited TGF-β-dependent fibroblast activation, and ameliorated experimental fibrosis in murine models. These findings identify a pathway of epigenetic imprinting of fibroblasts in fibrotic disease with translational implications for the development of targeted therapies in fibrotic diseases.

Phosphorylated STAT3 expression linked to SOCS3 methylation is associated with proliferative ability of gastric mucosa in patients with early gastric cancer

Gastric cancers (GCs) may develop in the gastric mucosa after elimination of Helicobacter pylori (H. pylori) using eradication therapy. Cytokine signaling is a key mechanism underlying GC development and progression, and STAT3 signaling may serve a central role in gastritis-associated tumorigenesis. In the present study, suppressor of cytokine signaling 3 (SOCS3) methylation was examined, as an activator of phosphorylated (p-)STAT3 expression in the non-neoplastic gastric mucosa (non-NGM) of patients with early GC. The methylation status of the SOCS3 gene promoter was analyzed using methylation-specific PCR in the non-NGM of patients with or without early GC. Expression levels of p-STAT3 and Ki67 were investigated immunohistochemically in non-NGM with early GC before and after H. pylori eradication. In non-NGM, SOCS3 promoter methylation was detected in 17/51 patients (33.3%) with early GC. In those patients, the non-NGM labeling indices of both Ki67 and p-STAT3 were significantly higher compared with that in patients with early GC without SOCS3 methylation. A significant correlation between Ki67 and p-STAT3 expression levels was demonstrated in the non-NGM of patients with early GC. In patients with early GC without SOCS3 methylation, the labeling indices of both Ki67 and p-STAT3 in non-NGM were significantly reduced after H. pylori eradication, whereas no such change was observed in patients with early GC with SOCS3 methylation. SOCS3 methylation is associated with continuous p-STAT3 overexpression and enhanced epithelial cell proliferation in non-NGM of patients with early GC.

MicroRNA-1 Negatively Regulates Peripheral NK Cell Function via Tumor Necrosis Factor-Like Weak Inducer of Apoptosis (TWEAK) Signaling Pathways During PPRV Infection

Peste des petits ruminants virus (PPRV) has emerged as a significant threat to the productivity of small ruminants worldwide. PPRV is lymphotropic in nature and induces in the hosts a transient but severe immunosuppression, especially innate immunity. However, it remains largely unknown how NK cells respond and are regulated at the earliest time points after an acute viral PPRV infection in goats. In this study, we revealed that multiple immune responses of goat peripheral NK cells were compromised during PPRV infection, including the cytolytic effector molecule expression and cytokine production. Importantly, we demonstrated that PPRV infection stimulated the expression of TWEAK, a negative regulator of cytotoxic function of NK cells, which may be involved in the suppression of cytotoxicity as well as cytokine production in infected goat NK cells. Furthermore, we found that PPRV infection induced TWEAK expression in goat NK cells involving post-transcription by suppressing miR-1, a novel negative miRNA directly targeting the TWEAK gene. Moreover, replication of virus is required for inhibition of miR-1 expression during PPRV infection, and the non-structural V protein of PPRV plays an important role in miR-1 mediated TWEAK upregulation. Additionally, we revealed that the regulation of NK cell immune responses by TWEAK is mediated by MyD88, SOCS1, and STAT3. Taken together, our results demonstrated that TWEAK may play a key role in regulating goat peripheral NK cell cytotoxicity and cytokine expression levels during PPRV infection.

MicroRNA-106a-3p Induces Apatinib Resistance and Activates Janus-Activated Kinase 2 (JAK2)/Signal Transducer and Activator of Transcription 3 (STAT3) by Targeting the SOCS System in Gastric Cancer

Background

MicroRNA (miR)-106a was involved in the tumorigenesis and highly expressed in gastric cancer. Required apatinib resistance greatly limits its efficacy in patients. Thus, the aim of the present study was to investigate the potential role of miR-106a-3p in gastric cancer cells with apatinib-resistance.

Material/Methods

The expression of miR-106a-3p was quantified by real-time quantitative polymerase chain reaction (RT-qPCR). Cell Counting Kit-8 (CCK-8) assay was performed to analyze the sensitivity of gastric cancer cells to apatinib. The expression of relevant drug-resistant proteins was detected by western blot. We searched Targetscan6.2 to find out the target gene of miR-106a-3p. Luciferase reporter assay was used to analyze whether miR-106a-3p bound to relevant gene of SOCS family. The SOCS2, SOCS4, and SOCS5 were qualified by western blot, and their mRNA levels were detected by RT-qPCR. Further, JAK2, STAT3, and their phosphorylation levels were detected by western blot.

Results

The results showed that the expression of miR-106a-3p was increased in apatinib-resistant gastric cancer, while miR-106a-3p inhibitor reduced the drug-resistance of SGC-7901-AP cells to apatinib. Dual luciferase reporter gene assay suggested that SOCS2, SOCS4, and SOCS5 were target genes of miR-106a-3p. The relevant SOCS genes silencing reversed the effects of miR-106a-3p inhibitor on decreasing the apatinib resistance of SGC-7901-AP cells, while the phosphorylation level of JAK and STAT reduced by miR-106a-3p inhibitor were increased.

Conclusions

miR-106a-3p induces apatinib resistance and activates JAK2/STAT3 by targeting SOCS system in gastric cancer. miR-106a-3p/SOCS plays a potent role in gastric cancer cell resistance to apatinib.

STAT3 Activation and Oncogenesis in Lymphoma

Signal transducer and activator of transcription 3 (STAT3) is an important and the most studied transcription factor in the Janus kinase (JAK)/STAT signaling pathway. STAT3 mediates the expression of various genes that play a critical role in many cellular and biological processes, such as cell proliferation, survival, differentiation, migration, angiogenesis, and inflammation. STAT3 and associated JAKs are activated and tightly regulated by a variety of cytokines and growth factors and their receptors in normal immune responses. However, abnormal expression of STAT3 leads to its constitutive activation, which promotes malignant transformation and tumor progression through oncogenic gene expression in numerous human cancers. Human lymphoma is a heterogeneous malignancy of T and B lymphocytes. Constitutive signaling by STAT3 is an oncogenic driver in several types of B-cell lymphoma and most of T-cell lymphomas. Aberrant STAT3 activation can also induce inappropriate expression of genes involved in tumor immune evasion such as PD-L1. In this review, we focus on the oncogenic role of STAT3 in human lymphoma and highlight potential therapeutic intervention by targeting JAK/STAT3 signaling.

Demethylation of SOCS1 mediates its abnormally high expression in ovarian cancer

The present study aimed to investigate the association between methylation and the high expression of the suppressor of cytokine signaling 1 (SOCS1) in ovarian cancer by detecting the methylation rate and the degree of expression. The present study investigated the expression of SOCS1 mRNA and SOCS1 protein in ovarian cancer and normal ovary tissues using reverse transcription-quantitative polymerase chain reaction (PCR) and immunohistochemistry, and the methylation status of the CpG islands of SOCS1 mRNA in ovarian cancer tissue were examined using a methylation-specific PCR. The expression levels of SOCS1 mRNA in ovarian cancer specimens were significantly increased compared with that in the normal ovary tissues (P=0.0215). Consistent with this, the expression levels of SOCS1 protein in ovarian cancer specimens were significantly increased, while the methylation rate of SOCS1 mRNA was significantly decreased compared with that in the normal ovary tissues. Therefore, it may be concluded that the low methylation rate of SOCS1 mRNA in ovarian cancer increased the expression of SOCS1 mRNA, which may serve a role in the development of ovarian cancer.

MiR-19b and miR-20a suppress apoptosis, promote proliferation and induce tumorigenicity of multiple myeloma cells by targeting PTEN

Multiple myeloma (MM) is a common hematological malignancy that is often associated with osteolytic lesions, anemia and renal impairment. Deregulation of miRNA has been implicated in the pathogenesis of MM. It was found in our study that miR-19b and miR-20a as members of crucial oncogene miR-17-92 cluster were differentially expressed between patients with MM and normal controls by genechip microarray, and this result was further confirmed in sera of patients with MM by qRT-PCR. The functional effect of miR-19b/20a was analyzed and results showed that miR-19b/20a promoted cell proliferation and migration, inhibited cell apoptosis and altered cell cycle in MM cells. PTEN protein expression was reduced after transfection of miR-19b/20a, suggesting that PTEN was a direct target of miR-19b/20a. In addition, over-expression of miR-19b/20a reversed the anti-proliferation and pro-apoptosis effect of PTEN in MM cells. Finally, our in vivo experiment demonstrated that lentivirus-mediated delivery of miR-20a promoted tumor growth in murine xenograft model of MM, which provide evidence that miR-20a inhibitor exerts therapeutic activity in preclinical models and supports a framework for the development of miR-19b/20a-based treatment strategies for MM patients.

STAT3: A Promising Therapeutic Target in Multiple Myeloma

Multiple myeloma (MM) is an incurable plasma cell malignancy for which novel treatment options are required. Signal Transducer and Activator of Transcription 3 (STAT3) overexpression in MM appears to be mediated by a variety of factors including interleukin-6 signaling and downregulation of Src homology phosphatase-1 (SHP-1). STAT3 overexpression in MM is associated with an adverse prognosis and may play a role in microenvironment-dependent treatment resistance. In addition to its pro-proliferative role, STAT3 upregulates anti-apoptotic proteins and leads to microRNA dysregulation in MM. Phosphatase of regenerating liver 3 (PRL-3) is an oncogenic phosphatase which is upregulated by STAT3. PRL-3 itself promotes STAT-3 phosphorylation resulting in a positive feedback loop. PRL-3 is overexpressed in a subset of MM patients and may cooperate with STAT3 to promote survival of MM cells. Indirectly targeting STAT3 via JAK (janus associated kinase) inhibition has shown promise in early clinical trials. Specific inhibitors of STAT3 showed in vitro efficacy but have failed in clinical trials while several STAT3 inhibitors derived from herbs have been shown to induce apoptosis of MM cells in vitro. Optimising the pharmacokinetic profiles of novel STAT3 inhibitors and identifying how best to combine these agents with existing anti-myeloma therapy are key questions to be addressed in future clinical trials.

Cell of Origin and Genetic Alterations in the Pathogenesis of Multiple Myeloma

B cell activation and differentiation yields plasma cells with high affinity antibodies to a given antigen in a time-frame that allows for host protection. Although the end product is most commonly humoral immunity, the rapid proliferation and somatic mutation of the B cell receptor also results in oncogenic mutations that cause B cell malignancies including plasma cell neoplasms such as multiple myeloma. Myeloma is the second most common hematological malignancy and results in over 100,000 deaths per year worldwide. The genetic alterations that occur in the germinal center, however, are not sufficient to cause myeloma, but rather impart cell proliferation potential on plasma cells, which are normally non-dividing. This pre-malignant state, referred to as monoclonal gammopathy of undetermined significance or MGUS, provides the opportunity for further genetic and epigenetic alterations eventually resulting in a progressive disease that becomes symptomatic. In this review, we will provide a brief history of clonal gammopathies and detail how some of the key discoveries were interwoven with the study of plasma cells. We will also review the genetic and epigenetic alterations discovered over the past 25 years, how these are instrumental to myeloma pathogenesis, and what these events teach us about myeloma and plasma cell biology. These data will be placed in the context of normal B cell development and differentiation and we will discuss how understanding the biology of plasma cells can lead to more effective therapies targeting multiple myeloma.

Therapeutic Implication of SOCS1 Modulation in the Treatment of Autoimmunity and Cancer

The suppressor of cytokine signaling (SOCS) family of intracellular proteins has a vital role in the regulation of the immune system and resolution of inflammatory cascades. SOCS1, also called STAT-induced STAT inhibitor (SSI) or JAK-binding protein (JAB), is a member of the SOCS family with actions ranging from immune modulation to cell cycle regulation. Knockout of SOCS1 leads to perinatal lethality in mice and increased vulnerability to cancer, while several SNPs associated with the SOCS1 gene have been implicated in human inflammation-mediated diseases. In this review, we describe the mechanism of action of SOCS1 and its potential therapeutic role in the prevention and treatment of autoimmunity and cancer. We also provide a brief outline of the other JAK inhibitors, both FDA-approved and under investigation.

Identification and characterization of differentially expressed genes in hepatopancreas of oriental river prawn Macrobrachium nipponense under nitrite stress

The oriental river prawn Macrobrachium nipponense is a highly adaptable, tolerant, and fecund freshwater prawn that inhabits a wide range of aquatic environments. The hepatopancreas of crustaceans is not only a site for secretion of digestive enzymes, and also plays important roles in several metabolic processes, such as lipid and carbohydrate metabolism. It is the main organ for the detoxification and immunity. In this study, high-throughput sequencing techniques were used to detect the effect of nitrite stress (10 mg/L nitrite-N for 48 h) on gene expression in the hepatopancreas of M. nipponense. A total of 13,769 million reads were harvested, and 94,534 transcripts were de novo assembled using Trinity software and produced 56,054 non-redundant transcripts. A total of 825 differentially expressed genes were obtained comparing 48 h nitrite stress with control group. In the analysis of GO and KEGG database, significant differences were found in 49 pathways. Immune-related pathways under nitrite stress included arginine and proline metabolism, glutamate metabolism, Jak-Stat signaling pathway, endocytosis, wnt signaling pathway, RIG-I-like receptor signaling pathway, TGF-beta signaling pathway, GnRH signaling pathway and phagosome. Apoptosis-related pathway was also significantly altered, such as lysosome and apoptosis. Remarkably, nitrite stress altered the expression patterns of key apoptosis genes (tetraspanins-like protein, LAMP, CD63, caspase 3C and Caspase 1) and immune genes (Serine proteinase-like protein, C-type lectin, daf-36, SOCS-2, alpha-2-macroglobulin), confirmed that nitrite-stress induce immune response and eventually even apoptosis. This study provided a new insight into the role of hepatopancreas in crustaceans, and further investigation will continue.

Genomic analysis reveals recurrent deletion of JAK-STAT signaling inhibitors HNRNPK and SOCS1 in mycosis fungoides

Mycosis fungoides (MF) is the most common cutaneous T-cell lymphoma (CTCL). Causative genetic alterations in MF are unknown. The low recurrence of pathogenic small-scale mutations (ie, nucleotide substitutions, indels) in the disease, calls for the study of additional aspects of MF genetics. Here, we investigated structural genomic alterations in tumor-stage MF by integrating whole-genome sequencing and RNA-sequencing. Multiple genes with roles in cell physiology (n = 113) and metabolism (n = 92) were found to be impacted by genomic rearrangements, including 47 genes currently implicated in cancer. Fusion transcripts involving genes of interest such as DOT1L, KDM6A, LIFR, TP53, and TP63 were also observed. Additionally, we identified recurrent deletions of genes involved in cell cycle control, chromatin regulation, the JAK-STAT pathway, and the PI-3-K pathway. Remarkably, many of these deletions result from genomic rearrangements. Deletion of tumor suppressors HNRNPK and SOCS1 were the most frequent genetic alterations in MF after deletion of CDKN2A. Notably, SOCS1 deletion could be detected in early-stage MF. In agreement with the observed genomic alterations, transcriptome analysis revealed up-regulation of the cell cycle, JAK-STAT, PI-3-K and developmental pathways. Our results position inactivation of HNRNPK and SOCS1 as potential driver events in MF development.

Evaluation of SOCS1 methylation in patients with Behcet's disease

INTRODUCTION

Epigenetic discusses to inherited changes in mitosis and meiosis in the gene expression pattern which is independent of primary DNA sequence. Since, SOCS1 hyper-methylation can activate JAK / STAT signaling pathway and activation of this pathway can directly affect the impact of different cytokines on cell function and subsequently lead to pathophysiology of diseases, in particular autoimmune diseases that interact directly with the amount of cytokines and due to the fact that the cause and pathology of Behcet's disease (BD) have not ever been completely determined. So, the purpose of this study was to evaluate the methylation pattern of SOCS1 gene in patients with BD and compare them with healthy group.

METHODOLOGY

This study was a case-control study in which 50 patients with BD and 60 subjects as healthy group participated. Blood samples were collected from all participants and then Peripheral Blood Mononuclear Cells (PBMCs) were isolated through Ficoll method. After extraction of DNA by Salting out method and its analysis with Nano-drop, the methylation level of SOCS1 was examined using qMS-PCR technique.

RESULTS

Findings about methylation and gene expression in SOCS1 gene showed that the level of SOCS1 methylation was increased in patient groups compared with healthy subjects (control group) which the increase was statistically significant (p-value<0.05). Also, the results of gene expression revealed that the fold change of SOCS1 gene expression was decreased in patient group compared with healthy subjects which the decrease was statistically significant (p-value<0.05).

DISCUSSION AND CONCLUSION

According to the results of this study, it can be suggested that the DNA methylation of SOCS1 gene is likely to affect the gene expression and thereby contribute to the pathogenesis of Behcet's disease.

Anti-myeloma Effects of Icariin Are Mediated Through the Attenuation of JAK/STAT3-Dependent Signaling Cascade

Because of the essential role of signal transducer and activator of transcription 3 (STAT3) in proliferation, anti-apoptosis, and chemoresistance of multiple myeloma (MM), we investigated whether icariin, a prenylated flavonol glycoside, inhibits both constitutive and inducible STAT3 activation in human myeloma cell lines. We noted that icariin could block constitutive STAT3 phosphorylation as well as its nuclear translocation and DNA binding ability in U266 cells. Icariin also suppressed IL-6-induced STAT3 activation through the inhibition of upstream kinases (Janus activated kinase-1 and -2, and c-Src). We found that icariin downregulated the protein expression of STAT3 downstream target gene products such as Bcl-2, Bcl-xl, survivin, IAP-1/2, COX-2, VEGF, and matrix metallopeptidase 9 (MMP-9) in a concentration-dependent manner. Moreover, this flavonoid also exhibited the capacity to significantly induce apoptosis and suppress proliferation of MM cells. Interestingly, this agent also significantly potentiated the apoptotic effects of bortezomib through the suppression of STAT3 activation in MM cells. Altogether, our data indicates that the potential application of icariin as a STAT3 blocker in myeloma therapy.

The potential function of microRNAs as biomarkers and therapeutic targets in multiple myeloma

Multiple myeloma (MM), accounting for ~1% of all types of human cancer and 13% of all hematological malignancies, is characterized by the malignant proliferation of monoclonal plasma cells (PCs) in the bone marrow. MM leads to end stage organ impairment, including bone lesions, renal dysfunction, hypercalcemia and anemia. So far, the specific pathogenesis of MM remains unclear and no early-stage sensitive biomarker of MM has been well characterized. Furthermore, treating MM is difficult, as the majority of patients eventually relapse or become refractory following treatment using presently available methods. To date, a number of studies have demonstrated that microRNAs (miRNAs) may serve crucial functions in the progression of numerous cancers, including MM. During the tumorigenesis and pathogenesis of MM, there are multiple carcinogenic events that involve the pernicious transformation from normal to malignant PCs. miRNAs, as oncogenes or tumor suppressors, regulate MM progression-related signaling pathways. In the present review, the up-to-date preliminary basic studies and associated clinical works on the underlying mechanisms of aberrant miRNA profiling in MM have been summarized, including an evaluation of its value as a potential biomarker and a novel therapeutic strategy for MM.

The molecular basis of JAK/STAT inhibition by SOCS1

The SOCS family of proteins are negative-feedback inhibitors of signalling induced by cytokines that act via the JAK/STAT pathway. SOCS proteins can act as ubiquitin ligases by recruiting Cullin5 to ubiquitinate signalling components; however, SOCS1, the most potent member of the family, can also inhibit JAK directly. Here we determine the structural basis of both these modes of inhibition. Due to alterations within the SOCS box domain, SOCS1 has a compromised ability to recruit Cullin5; however, it is a direct, potent and selective inhibitor of JAK catalytic activity. The kinase inhibitory region of SOCS1 targets the substrate binding groove of JAK with high specificity and thereby blocks any subsequent phosphorylation. SOCS1 is a potent inhibitor of the interferon gamma (IFNγ) pathway, however, it does not bind the IFNγ receptor, making its mode-of-action distinct from SOCS3. These findings reveal the mechanism used by SOCS1 to inhibit signalling by inflammatory cytokines.

The molecular basis of JAK/STAT inhibition by SOCS1

The SOCS family of proteins are negative-feedback inhibitors of signalling induced by cytokines that act via the JAK/STAT pathway. SOCS proteins can act as ubiquitin ligases by recruiting Cullin5 to ubiquitinate signalling components; however, SOCS1, the most potent member of the family, can also inhibit JAK directly. Here we determine the structural basis of both these modes of inhibition. Due to alterations within the SOCS box domain, SOCS1 has a compromised ability to recruit Cullin5; however, it is a direct, potent and selective inhibitor of JAK catalytic activity. The kinase inhibitory region of SOCS1 targets the substrate binding groove of JAK with high specificity and thereby blocks any subsequent phosphorylation. SOCS1 is a potent inhibitor of the interferon gamma (IFNγ) pathway, however, it does not bind the IFNγ receptor, making its mode-of-action distinct from SOCS3. These findings reveal the mechanism used by SOCS1 to inhibit signalling by inflammatory cytokines.

Cytokines are key molecules in controlling haematopoiesis that signal via the JAK/STAT pathway. Here the authors present the structures of SOCS1 bound to its JAK1 target as well as in complex with elonginB and elonginC, providing a molecular explanation for the potent JAK- inhibitory activity of SOCS1.

Microenvironment drug resistance in multiple myeloma: emerging new players

Multiple myeloma (MM) drug resistance (DR) is a multistep transformation process based on a powerful interplay between bone marrow stromal cells and MM cells that allows the latter to escape anti-myeloma therapies. Here we present an overview of the role of the bone marrow microenvironment in both soluble factors-mediated drug resistance (SFM-DR) and cell adhesion-mediated drug resistance (CAM-DR), focusing on the role of new players, namely miRNAs, exosomes and cancer-associated fibroblasts.

Physiological and pathological implications of 5-hydroxymethylcytosine in diseases

Gene expression is the prerequisite of proteins. Diverse stimuli result in alteration of gene expression profile by base substitution for quite a long time. However, during the past decades, accumulating studies proved that bases modification is involved in this process. CpG islands (CGIs) are DNA fragments enriched in CpG repeats which mostly locate in promoters. They are frequently modified, methylated in most conditions, thereby suggesting a role of methylation in profiling gene expression. DNA methylation occurs in many conditions, such as cancer, embryogenesis, nervous system diseases etc. Recently, 5-hydroxymethylcytosine (5hmC), the product of 5-methylcytosine (5mC) demethylation, is emerging as a novel demethylation marker in many disorders. Consistently, conversion of 5mC to 5hmC has been proved in many studies. Here, we reviewed recent studies concerning demethylation via 5hmC conversion in several conditions and progress of therapeutics-associated with it in clinic. We aimed to unveil its physiological and pathological significance in diseases and to provide insight into its clinical application potential.

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.

Epigenetic regulatory mutations and epigenetic therapy for multiple myeloma

PURPOSE OF REVIEW

Next generation sequencing and large-scale analysis of patient specimens has created a more complete picture of multiple myeloma (MM) revealing that epigenetic deregulation is a prominent factor in MM pathogenesis.

RECENT FINDINGS

Over half of MM patients have mutations in genes encoding epigenetic modifier enzymes. The DNA methylation profile of MM is related to the stage of the disease and certain classes of mutations in epigenetic modifiers are more prevalent upon disease relapse, suggesting a role in disease progression. Many small molecules targeting regulators of epigenetic machinery have been developed and clinical trials are underway for some of these in MM.

SUMMARY

Recent findings suggest that epigenetic targeting drugs could be an important strategy to cure MM. Combining these agents along with other strategies to affect the MM cell such as immunomodulatory drugs and proteasome inhibitors may enhance efficacy of combination regimens in MM.

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.

Multiple myeloma

Multiple myeloma is a malignancy of terminally differentiated plasma cells, and patients typically present with bone marrow infiltration of clonal plasma cells and monoclonal protein in the serum and/or urine. The diagnosis of multiple myeloma is made when clear end-organ damage attributable to the plasma cell proliferative disorder or when findings that suggest a high likelihood of their development are present. Distinguishing symptomatic multiple myeloma that requires treatment from the precursor stages of monoclonal gammopathy of undetermined significance and smouldering multiple myeloma is important, as observation is the standard for those conditions. Much progress has been made over the past decade in the understanding of disease biology and individualized treatment approaches. Several new classes of drugs, such as proteasome inhibitors and immunomodulatory drugs, have joined the traditional armamentarium (corticosteroids, alkylating agents and anthracyclines) and, along with high-dose therapy and autologous haemopoietic stem cell transplantation, have led to deeper and durable clinical responses. Indeed, an increasing proportion of patients are achieving lasting remissions, raising the possibility of cure for this disease. Success will probably depend on using combinations of effective agents and treating patients in the early stages of disease, such as patients with smouldering multiple myeloma.