SOCS3 Methylation Predicts a Poor Prognosis in HBV Infection-Related Hepatocellular Carcinoma

SOCS3 inhibiting JAK-STAT pathway enhances oncolytic adenovirus efficacy by potentiating viral replication and T-cell activation

Oncolytic viruses (OVs) are emerging as a potentially useful treatment for malignancies due to the capabilities of direct oncolysis and immune induction. Improving the replication of OVs is an effective approach to enhance the oncolytic effects. Here, we observed that cancer cells with deficiencies in JAK-STAT pathway showed greater sensitivity to oncolytic adenovirus (oAd), and JAK inhibitor could enhance the replication of oAd. Therefore, we constructed a novel oAd expressing SOCS3, a major negative regulator of JAK-STAT pathway, and confirmed that oAd-SOCS3 exhibited a more significant antitumor effect than oAd-Ctrl both in vitro and in vivo. Mechanistically, SOCS3 inhibited the activation of JAK-STAT pathway, resulting in stronger tumor selective replication of oAd and downregulated expression of PD-L1 on cancer cells as well. Both benefits could collectively awaken antitumor immunity. This study highlights the importance of JAK-STAT pathway in viral replication and confirms the treatment of oAd-SOCS3 in potential clinical applications.

SOCS3 protein expression predicts the responses of advanced non-small cell lung cancer patients to platinum-based chemotherapy

Background

This study sought to assess the relationship between suppressor of cytokine signaling 3 (SOCS3) expression, SOCS3 promoter methylation status, and platinum-based chemotherapy responses in advanced non-small cell lung cancer (NSCLC) patients.

Methods

A total of 400 advanced NSCLC patients with inoperable disease were enrolled in this study. All the patients underwent platinum-based chemotherapy treatment, and the clinical and prognostic outcomes of these patients were analyzed. The SOCS3 protein expression and SOCS3 promoter methylation status of the tumor tissues in these patients were also tested by immunohistochemistry and polymerase chain reaction (PCR), respectively. In addition, we knocked down SOCS3 expression via small-interfering RNA (siRNA) in the lung cancer cell lines and conducted in vitro analyses to examine cell viability and apoptosis.

Results

Patients with higher expression levels of SOCS3 were found to have a lower average tumor stage, higher average tumor differentiation, and higher rates of positive chemotherapy responses than those with lower expression levels of SOCS3. SOCS3 promoter methylation was also found to be correlated with chemotherapy responses in these patients. In the prognostic analyses, only SOCS3 expression, but not SOCS3 promoter methylation, was found to be predictive of outcomes in advanced NSCLC patients. We also found that the pro-apoptotic effects of SOCS3 were mediated by the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathways in the lung cancer cells.

Conclusions

Currently, there is a lack of reliable biomarkers for predicting the responses of NSCLC patients to chemotherapy. Our results may aid in clinical evaluations of NSCLC patients.

Dysregulation of Liver Regeneration by Hepatitis B Virus Infection: Impact on Development of Hepatocellular Carcinoma

The liver is unique in its ability to regenerate in response to damage. The complex process of liver regeneration consists of multiple interactive pathways. About 2 billion people worldwide have been infected with hepatitis B virus (HBV), and HBV causes 686,000 deaths each year due to its complications. Long-term infection with HBV, which causes chronic inflammation, leads to serious liver-related diseases, including cirrhosis and hepatocellular carcinoma. HBV infection has been reported to interfere with the critical mechanisms required for liver regeneration. In this review, the studies on liver tissue characteristics and liver regeneration mechanisms are summarized. Moreover, the inhibitory mechanisms of HBV infection in liver regeneration are investigated. Finally, the association between interrupted liver regeneration and hepatocarcinogenesis, which are both triggered by HBV infection, is outlined. Understanding the fundamental and complex liver regeneration process is expected to provide significant therapeutic advantages for HBV-associated hepatocellular carcinoma.

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.

Prognostic Significance of SOCS3 in Patients With Solid Tumors: A Meta-Analysis

Background

The identification of reliable biomarkers for predicting disease recurrence and the survival of patients with cancer is of great importance. Numerous previous studies have revealed that the abnormal expression of the suppressor of cytokine signaling 3 (SOCS3) was associated with patient outcomes. However, these results were inconsistent. The aim of the present study was to assess the prognostic value of SOCS3 in patients with solid tumors.

Methods

Studies focusing on the prognostic value of SOCS3 in solid tumors were searched for in the PubMed, Embase, Web of Science, and Scopus databases. We included studies that compared disease-free survival (DFS) and overall survival based on different levels of SOCS3. Other outcomes (e.g., Edmondson grading, tumor size, tumor vascular invasion, lymph node invasion, and distant metastasis) were also considered. The hazard ratio (HR)/risk ratio (RR) and corresponding 95% CI were determined.

Results

Twelve studies with 1,551 patients were included in this meta-analysis. The pooled analysis demonstrated that the higher expression of SOCS3 was significantly associated with better disease-free survival (HR:0.36, 95% CI:0.17–0.77, P < 0.001) and overall survival (HR:0.45, 95% CI:0.32–0.62, P < 0.001) compared with low expression. Moreover, SOCS3 expression was closely correlated with the Edmondson grading [odds ratio (OR):0.77, 95% CI:0.61–0.98, P = 0.033], vascular invasion (OR:0.63, 95% CI:0.52–0.78, P < 0.001), and distant metastasis (OR:0.73, 95% CI:0.51–1.03, P = 0.076). However, the levels of SOCS3 were not significantly associated with tumor size (OR:0.85, 95% CI:0.71–1.03, P = 0.090) and lymph node invasion (OR:0.73, 95% CI:0.51–1.03, P = 0.076).

Conclusion

Increased SOCS3 expression in tumor mass was associated with better DFS and OS, suggesting it might be a novel and reliable biomarker for predicting the risk of cancer recurrence and mortality.

Association between SOCS3 hypermethylation and HBV-related hepatocellular carcinoma and effect of sex and age: A meta-analysis

BACKGROUND

Suppressor 3 of cytokine signaling (SOCS3) hypermethylation has been reported to participate in hepatocellular carcinoma (HCC) development and progression, but conflicting results were published. This study aimed to analyze the clinical effects of SOCS3 hypermethylation in HCC and the effects of sex and age on SOCS3 hypermethylation in HCC.

METHODS

Databases were searched for relevant case-control and cohort studies on SOCS3 hypermethylation in HBV-related HCC. In vitro and in vivo studies and studies of patients with serious comorbidities were excluded. Review Manager 5.2 was used to estimate the effects of the results among the selected studies. Forest plots, sensitivity analysis, and bias analysis for the included studies were also conducted.

RESULTS

Finally, 8 relevant studies met the inclusion criteria. A significant difference in SOCS3 hypermethylation in HCC was found between tumor and nontumor groups (the odds ratio [OR] = 2.01, 95% confidence interval [CI]: 1.48-2.73, P < .00001; P for heterogeneity = .39, I2 = 5%). The meta-analysis suggested no significant difference in the effect of sex (OR = 1.00, 95% CI: 0.76-1.31, P = .76; P for heterogeneity = .44, I2 = 0%) and age on SOCS3 hypermethylation in HCC (OR = 1.11, 100% CI: 0.78-1.29, P = .03; P for heterogeneity = .14, I2 = 36%). Limited publication bias was observed in this study.

CONCLUSION

SOCS3 hypermethylation is associated with HBV-related HCC. Sex and age do not affect the association between SOCS3 hypermethylation and HCC. SOCS3 might be a treatment target for HCC.

Mechanisms of DNA Methylation in Virus-Host Interaction in Hepatitis B Infection: Pathogenesis and Oncogenetic Properties

Hepatitis B virus (HBV), the well-studied oncovirus that contributes to the majority of hepatocellular carcinomas (HCC) worldwide, can cause a severe inflammatory microenvironment leading to genetic and epigenetic changes in hepatocyte clones. HBV replication contributes to the regulation of DNA methyltransferase gene expression, particularly by X protein (HBx), and subsequent methylation changes may lead to abnormal transcription activation of adjacent genes and genomic instability. Undoubtedly, the altered expression of these genes has been known to cause diverse aspects of infected hepatocytes, including apoptosis, proliferation, reactive oxygen species (ROS) accumulation, and immune responses. Additionally, pollutant-induced DNA methylation changes and aberrant methylation of imprinted genes in hepatocytes also complicate the process of tumorigenesis. Meanwhile, hepatocytes also contribute to epigenetic modification of the viral genome to affect HBV replication or viral protein production. Meanwhile, methylation levels of HBV integrants and surrounding host regions also play crucial roles in their ability to produce viral proteins in affected hepatocytes. Both host and viral changes can provide novel insights into tumorigenesis, individualized responses to therapeutic intervention, disease progress, and early diagnosis. As such, DNA methylation-mediated epigenetic silencing of cancer-related genes and viral replication is a compelling therapeutic goal to reduce morbidity and mortality from liver cancer caused by chronic HBV infection. In this review, we summarize the most recent research on aberrant DNA methylation associated with HBV infection, which is involved in HCC development, and provide an outlook on the future direction of the research.

Suppressor of cytokine signaling proteins 1 and 3 and hepatitis B virus infection

Suppressor of cytokine signaling proteins (SOCS) are cytokine pathway inhibitors that play an important role in regulating the antiviral effect of interferon (IFN). Current studies have shown that SOCS1 and SOCS3 are closely related to hepatitis B virus (HBV) infection. Inhibition or stimulation of SOCS1 and SOCS3 expression may affect the antiviral effect by regulating the production of IFN, and may also affect the pathogenicity of HBV together with other cytokines or transcription regulators. This paper mainly discusses the possible mechanisms of SOCS1 and SOCS3 in HBV infection.

The mechanistic, diagnostic and therapeutic novel nucleic acids for hepatocellular carcinoma emerging in past score years

Despite The Central Dogma states the destiny of gene as 'DNA makes RNA and RNA makes protein', the nucleic acids not only store and transmit genetic information but also, surprisingly, join in intracellular vital movement as a regulator of gene expression. Bioinformatics has contributed to knowledge for a series of emerging novel nucleic acids molecules. For typical cases, microRNA (miRNA), long noncoding RNA (lncRNA) and circular RNA (circRNA) exert crucial role in regulating vital biological processes, especially in malignant diseases. Due to extraordinarily heterogeneity among all malignancies, hepatocellular carcinoma (HCC) has emerged enormous limitation in diagnosis and therapy. Mechanistic, diagnostic and therapeutic nucleic acids for HCC emerging in past score years have been systematically reviewed. Particularly, we have organized recent advances on nucleic acids of HCC into three facets: (i) summarizing diverse nucleic acids and their modification (miRNA, lncRNA, circRNA, circulating tumor DNA and DNA methylation) acting as potential biomarkers in HCC diagnosis; (ii) concluding different patterns of three key noncoding RNAs (miRNA, lncRNA and circRNA) in gene regulation and (iii) outlining the progress of these novel nucleic acids for HCC diagnosis and therapy in clinical trials, and discuss their possibility for clinical applications. All in all, this review takes a detailed look at the advances of novel nucleic acids from potential of biomarkers and elaboration of mechanism to early clinical application in past 20 years.

MiR-30a-5p promotes cholangiocarcinoma cell proliferation through targeting SOCS3

Background: MicroRNAs (miRNAs) play important roles in the occurrence and development of cancers. In this project, we aimed to explore the role and molecular mechanism of mir-30a-5p in cholangiocarcinoma (CCA).

Materials and Methods: The expression profile and clinical significance of miR-30a-5p in CCA patients were investigated in 31 ICC and 52 ECC patients respectively. The role and mechanism of miR-30a-5p in CCA cells were investigated by up-regulating and inhibiting miR-30a-5p expression in vitro functional study.

Results: The expression of miR-30a-5p was increased in both CCA tissues and cells. The inhibition of miR-30a-5p decreased cell proliferation and induced cell apoptosis while overexpression of miR-30a-5p achieved the opposite effect. Furthermore, SOCS3 was down-regulated in ICC and ECC tissues and negatively regulated by miR-30a-5p. Dual-luciferase reporter assay revealed that co-transfection of miR-30a-5p significantly inhibited the activity of firefly luciferase reporter carrying the wild-type 3′UTR of SOCS3. The inhibition of SOCS3 could largely rescue the inhibitory effect of miR-30a-5p inhibition on CCA cells proliferation. In clinical, up-regulated miR-30a-5p expression was correlated with large tumor size in both ICC and ECC cohorts.

Conclusions: miR-30a-5p promoted CCA cells proliferation through targeting SOCS3. These findings suggested that miR-30a-5p could be a potential therapeutic target.

DNA methylation of SOCS1/2/3 predicts hepatocellular carcinoma recurrence after liver transplantation

DNA methylation status of SOCS1/SOCS2/SOCS3 is intensely involved in the development and progression of hepatocellular carcinoma (HCC). This study explored its prognostic value for HCC recurrence after liver transplantation (LT). Clinical data from 62 HCC patients who underwent LT at our centre were retrospectively collected. The SOCS1/2/3 methylation level were determined using next generation sequencing. Overall, 244 methylated sites at the SOCS1/2/3 promoter were identified. Multivariate analysis yielded the methylated sites SOCS2-1-90 (Chromosome 12, Position 93963982; HR 0.386, 95% CI 0.149-0.998) and SOCS1-1-68 (Chromosome 16, Position 11350699; HR 4.376, 95% CI 1.324-14.459) as independent predictors of post-LT HCC recurrence. Patients were divided into highly- and lowly methylated groups according to the median SOCS1-1-68 (0.95%) and SOCS2-1-90 (1.05%) methylation levels. Highly methylated SOCS2-1-90 was associated with significantly lower AFP levels (P = 0.008), decreased proportion of maximal tumour size > 8 cm (P = 0.02), and better pathological grading (P = 0.06). Conversely, patients in the highly methylated SOCS1-1-68 group had higher AFP levels (P = 0.043). Kaplan-Meier analyses revealed that patients with highly methylated SOCS2-1-90 had increased recurrence free survival (RFS) and overall survival (OS) rates when compared with those with lowly methylated SOCS2-1-90 (P = 0.0041 and 0.012, respectively). Nevertheless, the correlation between methylated SOCS1-1-68 and cumulative recurrence rates was less pronounced (P = 0.098). Subgroup analyses demonstrated that patients meeting the Milan criteria, UCSF criteria, Metroticket 2.0 Model or Hangzhou criteria with highly methylated SOCS2-1-90 had the best RFS rates. DNA methylation of SOCS2-1-90 is a novel biomarker for predicting post-transplant HCC recurrence.

Knockdown of CTCF reduces the binding of EZH2 and affects the methylation of the SOCS3 promoter in hepatocellular carcinoma

The epigenetic silencing mechanism of suppressor 3 of cytokine signaling (SOCS3) in cancers has not been fully elucidated. Polycomb repressive complexes 2 (PRC2), an important epigenetic regulatory factors, exerts a critical role in repressing the initial phase of gene transcription. Whether PRC2 participates the down- regulation of SOCS3 in Hepatocellular carcinoma (HCC) remains unclear and how does PRC2 be recruited target gene still needs to explore. In this study, Using TCGA HCC dataset, and detecting HCC tissue specimens and cell lines, we found that SOCS3 expression in HCC was inversely related to that of EZH2, and depended on its promoter methylation status. CTCF, vigilin, EZH2 and H3K27me3 were enriched at CTCF and EZH2 binding sites on the methylated SOCS3 gene promoter. The depletion of CTCF did not affect expression of EZH2 and DNMT1, but decrease recruitment of CTCF, vigilin, EZH2 and H3K27me3. Further, knockdown of CTCF led to a loss of methylation of the methylated SOCS3 promoter, which sequentially increased the expression of SOCS3 and decreased the expression of pSTAT3, the downstream effector. These findings suggest that the CTCF dependent recruitment of EZH2 to the SOCS3 gene promoter is likely to participate in the epigenetic silencing of SOCS3 and in regulating its gene expression.

Transcriptomic Profiles of MV4-11 and Kasumi 1 Acute Myeloid Leukemia Cell Lines Modulated by Epigenetic Modifiers Trichostatin A and 5-Azacytidine

Background: Acute myeloid leukemia (AML) is the most common form of acute leukemias in adults which is clinically and molecularly heterogeneous. Several risk and genetic factors have been widely investigated to characterize AML. However, the concomitant epigenetic factors in controlling the gene expression lead to AML transformation was not fully understood. This study was aimed to identify epigenetically regulated genes in AML cell lines induced by epigenetic modulating agents, Trichostatin A (TSA) and 5-Azacytidine (5-Aza). Materials and Methods: MV4-11 and Kasumi 1 were treated with TSA and/or 5-Aza at IC₅₀ concentration. Gene expression profiling by microarray was utilized using SurePrint G3 Human Gene Expression v3. Gene ontology and KEGG pathway annotations were analyzed by DAVID bioinformatics software using EASE enrichment score. mRNA expression of the differentially expressed genes were verified by quantitative real time PCR. Results: Gene expression analysis revealed a significant changes in the expression of 24,822, 15,720, 15,654 genes in MV4-11 and 12,598, 8828, 18,026 genes in Kasumi 1, in response to TSA, 5-Aza and combination treatments, respectively, compared to non-treated (p<0.05). 7 genes (SOCS3, TUBA1C, CCNA1, MAP3K6, PTPRC, STAT6 and RUNX1) and 4 genes (ANGPTL4, TUBB2A, ADAM12 and PTPN6) shown to be predominantly expressed in MV4-11 and Kasumi 1, respectively (EASE<0.1). The analysis also revealed phagosome pathway commonly activated in both cell lines. Conclusion: Our data showed a distinct optimal biological characteristic and pathway in different types of leukemic cell lines. These finding may help in the identification of cell-specific epigenetic biomarker in the pathogenesis of AML.

Jak-Stat Signaling Induced by Interleukin-6 Family Cytokines in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. It can be caused by chronic liver cell injury with resulting sustained inflammation, e.g., triggered by infections with hepatitis viruses B (HBV) and C (HCV). Death of hepatocytes leads to the activation of compensatory mechanisms, which can ultimately result in liver fibrosis and cirrhosis. Another common feature is the infiltration of the liver with inflammatory cells, which secrete cytokines and chemokines that act directly on the hepatocytes. Among several secreted proteins, members of the interleukin-6 (IL-6) family of cytokines have emerged as important regulatory proteins that might constitute an attractive target for therapeutic intervention. The IL-6-type cytokines activate multiple intracellular signaling pathways, and especially the Jak/STAT cascade has been shown to be crucial for HCC development. In this review, we give an overview about HCC pathogenesis with respect to IL-6-type cytokines and the Jak/STAT pathway. We highlight the role of mutations in genes encoding several proteins involved in the cytokine/Jak/STAT axis and summarize current knowledge about IL-6 family cytokines in this context. We further discuss possible anti-cytokine therapies for HCC patients in comparison to already established therapies.

Expression and prognostic value of HER-2/neu, STAT3 and SOCS3 in hepatocellular carcinoma

BACKGROUND AND AIMS

Hepatocellular carcinoma (HCC) is a complex and heterogeneous tumor with several genomic alterations, while the viral-chemical etiology along with molecular mechanisms of HCC pathogenesis remains largely unknown. This study aimed to determine expression profile and prognostic value of HER-2/neu, STAT3 and SOCS3 in HCC.

METHODS

Immunohistochemistry and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were performed to evaluate the expression of HER-2/neu, STAT3 and SOCS3 in HCC tissues and adjacent normal tissues collected from 176 HCC patients.

RESULTS

HER-2/neu and STAT3 levels were higher and SOCS3 expression was lower in HCC tissues than in adjacent normal tissues. HER-2/neu, STAT3 and SOCS3 levels were associated with histological grade, tumor diameter, TNM stage, vascular invasion, lymph node metastasis and distant metastasis in HCC. SOCS3 expression was negatively associated with HER-2/neu and STAT3 expression. HCC patients with higher HER-2/neu and STAT3 levels had shorter overall, disease-free and disease-specific survival, whereas the opposite was found in patients with higher SOCS3 expression. In Cox regression analysis, tumor size, TNM stage, and STAT3 expression were identified as independent prognostic factors of HCC.

CONCLUSION

Taken together, these observations suggest that HER-2/neu, STAT3 and, SOCS3 are related to the aggressive tumor behavior and STAT3 has potential value as a prognostic factor for HCC.

In vivo and in vitro effects of microRNA-221 on hepatocellular carcinoma development and progression through the JAK-STAT3 signaling pathway by targeting SOCS3

Hepatocellular carcinoma (HCC), as the third leading cancer-caused deaths, prevails with high mortality, and affects more than half a million individuals per year worldwide. A former study revealed that microRNA-221 (miR-221) was involved in cell proliferation of liver cancer and HCC development. The current study aims to evaluate whether miR-221 targeting SOCS3 affects HCC through JAK-STAT3 signaling pathway. A series of miR-221 mimic, miR-221 inhibitor, siRNA against SOCS3, and SOCS3 plasmids were introduced to SMMC7721 cells with the highest miR-221 expression assessed. The expression of JAK-STAT3 signaling pathway-related genes and proteins was determined by Western blot analysis. Cell apoptosis, viability, migration, and invasion were evaluated by means of flow cytometry, 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide, and transwell assays, respectively. HCC xenograft in nude mice was performed to measure HCC tumor growth. miR-221 was found to be highly expressed but SOCS3 was poorly expressed in HCC tissues. miR-221 expression was correlated with lymph node metastasis (LNM) and tumor node metastasis (TNM) of HCC, and SOCS3 expression was correlated with LNM, differentiation and TNM of HCC. SOCS3 is a target gene of miR-221. MiR-221 mimic or si-SOCS3 exposure was found to induce cell viability, migration, and invasion, and reduce apoptosis. MiR-221 inhibitor was observed to have inhibitory effects on HCC cell proliferation, migration, and invasion. Moreover, the expression of JAK-STAT3 signaling pathway was suppressed by miR-221 inhibitor. Downregulated miR-221 expression could promote its target gene SOCS3 to inhibit the proliferation, invasion and migration of HCC cells by repressing JAK-STAT3 signaling pathway.

Tumor SOCS3 methylation status predicts the treatment response to TACE and prognosis in HCC patients

BACKGROUND

Suppressor of cytokine signaling (SOCS) 1 and 3 methylation have been associated with clinical features and outcomes of cancer patients. However, their roles in determining the treatment response to transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC) remain unknown.

RESULTS

We found that presence of SOCS3 methylation is significantly associated with the major clinical features of HCC patients, including tumor stage, lymph node and vascular invasion. Of note, we observed that the presence of SOCS3 methylation is closely related to TACE response. In prognosis analyses, HCC patients with SOCS3 methylation presence have a poorer prognosis indicated by lower 3-, and 5-year survival rates and shorter mean survival period, than those without. Multivariate COX analysis confirms the prognostic role of the presence of SOCS3 methylation in HCC patients receiving TACE treatment.

MATERIALS AND METHODS

A total of 246 HCC patients receiving TACE were enrolled in this study. Tumor samples was obtained from echo-guided fine needle aspiration and genomic DNA from tumor samples was purified. SOCS1 and SOCS3 methylation status were detected using methylation-specific polymerase chain reaction. The treatment responses to TACE of patients were evaluated after procedure and all patients were followed for prognosis analysis.

CONCLUSIONS

This finding suggests that the presence of SOCS3 methylation is a marker to predict treatment response and prognosis in HCC patients receiving TACE therapy.

Epigenetic Changes of the Immune System with Role in Tumor Development

Tumor development is closely related to chronic inflammation and to evasion of immune defense mechanisms by neoplastic cells. The mediators of the inflammatory process as well as proteins involved in immune response or immune response evasion can be subject to various epigenetic changes such as methylation, acetylation, or phosphorylation. Some of these, such as cytokine suppressors, are undergoing repression through epigenetic changes, and others such as cytokines or chemokines are undergoing activation through epigenetic changes, both modifications having as a result tumor progression. The activating changes can affect the receptor molecules involved in immune response and these promote inflammation and subsequently tumor development while the inactivating changes seem to be related to the tumor regression process. The proteins involved in antigen presentation, and, therefore in immune response escape, such as classical HLA proteins and related APM (antigen presentation machinery) with their epigenetic changes contribute to the tumor development process, either to tumor progression or regression, depending on the immune effector cells that are in play.

SOCS3 genetic variants and promoter hypermethylation in patients with chronic hepatitis B

The clinical manifestations of hepatitis B viral infection (HBV) include chronic hepatitis B (CHB), liver cirrhosis (LC) and hepatocellular carcinoma (HCC). The contribution of negative regulator suppressor of cytokine signaling-3 (SOCS3) promoter variants in HBV disease and SOCS3 hypermethylation in tumor tissues were investigated The SOCS3 promoter region was screened for polymorphisms in 878 HBV patients and in 272 healthy individuals. SOCS3 promoter methylation was examined by bisulfite sequencing. SOCS3 mRNA expression was quantified in 37 tumor and adjacent non-tumor liver tissue specimens. The minor allele rs12953258A was associated with increased susceptibility to HBV infection (OR=1.3, 95%CI=1.1-1.6, adjusted P=0.03). The minor allele rs111033850C and rs12953258A were observed in increased frequencies in HCC and LC patients compared to CHB patients (HCC: OR=1.7, 95%CI=1.1-2.9, adjusted P=0.046; LC: OR=1.4, 95%CI=1.1-1.9, adjusted P=0.017, respectively). HBV patients with rs111033850CC major genotype had decreased viral load (P=0.034), whereas the rs12953258AA major genotype contributed towards increased viral load (P=0.029). Tumor tissues revealed increased hypermethylation compared to adjacent non-tumor tissues (OR=5.4; 95%CI= 1.9-17.1; P=0.001). Increased SOCS3 expression was observed in HBV infested tumor tissues than non-HBV related tumor tissues (P=0.0048). SOCS3 promoter hypermethylation was associated with relatively low mRNA expression in tumor tissues (P=0.0023). In conclusion, SOCS3 promoter variants are associated with HBV susceptibility and SOCS3 hypermethylation stimulates HCC development.

Exosomes derived from gemcitabine-resistant cells transfer malignant phenotypic traits via delivery of miRNA-222-3p

BACKGROUND

Although gemcitabine-based chemotherapy has been established as a core multimodal therapy for non-small cell lung cancer (NSCLC) treatment, its clinical efficacy remains limited by the development of acquired resistance following tumor metastasis and relapse. In this study, we investigated how gemcitabine-resistant (GR) cells contribute to the development of NSCLC tumor malignancy via exosome-mediated transfer of microRNAs.

METHODS

We first studied the mechanism of exosome internalization via PKH-67 staining and an immunofluorescence assay, then confirmed our finding by transmission electron microscopy and western blot analysis. Candidate miRNAs were identified through microarray analysis. Thereafter, RT-PCR, MTS, Transwell and soft agar assays were performed to assess the role of exosomic miR-222-3p in vitro. A 3' untranslated region reporter assay was applied to identify the target of miR-222-3p. A lung metastasis mouse model was constructed to evaluate tumor growth and metastasis in vivo. Finally, clinical samples were used for correlation analysis between exosomic miR-222-3p levels and patients' response to gemcitabine.

RESULTS

A549-GR-derived exosomes were internalized by receipt cells via caveolin- and lipid raft-dependent endocytosis, which allowed the transfer of miR-222-3p. Exosomic miR-222-3p enhanced the proliferation, gemcitabine resistance, migration, invasion, and anti-anoikis of parental sensitive cells by directly targeting the promoter of SOCS3. In addition, a higher level of exosomic miR-222-3p in sera usually predicted worse prognosis in NSCLC patients.

CONCLUSION

Our data demonstrate that exosomic-miR-222-3p functions as a principal regulator of gemcitabine resistance and malignant characteristics by targeting SOCS3. The exosomic miR-222-3p level in sera may be a potential prognostic biomarker for predicting gemcitabine sensitivity in NSCLC patients.

Multiple correlation analyses revealed complex relationship between DNA methylation and mRNA expression in human peripheral blood mononuclear cells

DNA methylation is an important regulator on the mRNA expression. However, a genome-wide correlation pattern between DNA methylation and mRNA expression in human peripheral blood mononuclear cells (PBMCs) is largely unknown. The comprehensive relationship between mRNA and DNA methylation was explored by using four types of correlation analyses and a genome-wide methylation-mRNA expression quantitative trait locus (eQTL) analysis in PBMCs in 46 unrelated female subjects. An enrichment analysis was performed to detect biological function for the detected genes. Single pair correlation coefficient (r _T1) between methylation level and mRNA is moderate (-0.63-0.62) in intensity, and the negative and positive correlations are nearly equal in quantity. Correlation analysis on each gene (T4) found 60.1% genes showed correlations between mRNA and gene-based methylation at P < 0.05 and more than 5.96% genes presented very strong correlation (R _T4 > 0.8). Methylation sites have regulation effects on mRNA expression in eQTL analysis, with more often observations in region of transcription start site (TSS). The genes under significant methylation regulation both in correlation analysis and eQTL analysis tend to cluster to the categories (e.g., transcription, translation, regulation of transcription) that are essential for maintaining the basic life activities of cells. Our findings indicated that DNA methylation has predictive regulation effect on mRNA with a very complex pattern in PBMCs. The results increased our understanding on correlation of methylation and mRNA and also provided useful clues for future epigenetic studies in exploring biological and disease-related regulatory mechanisms in PBMC.

Aberrant promoter methylation profiles and association with survival in patients with hepatocellular carcinoma

The aim of this study was to investigate the prognostic and diagnostic value of genes with promoter methylation in hepatocellular carcinoma (HCC) patients. On the basis of The Cancer Genome Atlas data, we identified genes with differentially methylated promoters in HCC tissues and adjacent non-tumor tissues, using the linear models for microarray data approach. Cox proportional hazard regression analysis was applied to access the prognostic value of identified differentially methylated genes. The diagnostic value of the genes was evaluated through receiver operating characteristic. Pathway analyses were performed to illustrate biological functions of the identified genes. Compared to adjacent tissues, 77 genes with hypermethylated promoters and 2,412 genes with hypomethylated promoters were identified in HCC. The promoter hypomethylations of RNA5SP38, IL21, SDC4P, and MIR4439 were found to be associated with HCC patient survival (P=0.035, 0.040, 0.004, and 0.024, respectively). Hypomethylated SDC4P was associated with a better prognosis (hazard ratio, 0.482; 95% confidence interval [CI], −0.147–1.110; P=0.007). The combination of the promoter hypomethylations with RNA5SP38, IL21, and SDC4P showed an area under receiver operating characteristic curves of 0.975 (95% CI, 0.962–0.989; P=4.811E-25). Several pathways, including olfactory transduction, cytokine–cytokine receptor interaction, natural killer cell–mediated cytotoxicity, as well as inflammation mediated by chemokine and cytokine signaling pathway, were annotated with the hypomethylated promoter genes. SDC4P promoter hypomethylation may be a potential prognosis biomarker. A panel of promoter methylations in RNA5SP38, IL21, and SDC4P was proven a novel approach to diagnosis HCC. The pathway analysis defined the extensive functional role of DNA hypomethylation in cancer.

The prognostic role of BORIS and SOCS3 in human hepatocellular carcinoma

Brother of regulator of imprinted sites (BORIS) is a DNA-binding protein that is normally expressed in the testes. However, aberrant expression of BORIS is observed in various carcinomas, indicating a malignant role for this protein. Furthermore, abolishment or reduction of suppressor of cytokine signaling 3 (SOCS3) expression directed by promoter methylation is considered significant in hepatocellular carcinoma (HCC) carcinogenesis. This study aims to investigate BORIS and SOCS3 expression in HCC specimens and assess the prognostic significance of these proteins.BORIS and SOCS3 expression was examined using immunohistochemistry in HCC tissues, along with corresponding paracarcinomatous, cirrhosis, hepatitis, and normal liver tissues. The expression levels of these 2 proteins in HCC were evaluated for their association with clinicopathological parameters. Survival analysis was performed using Kaplan-Meier curves, the log-rank test, and multivariate Cox regression analysis.BORIS expression was significantly higher in HCC tissues than in normal liver tissues. In contrast, SOCS3 expression was dramatically lower in HCC tissues. BORIS expression was associated with tumor size, differentiation grade, satellite lesions, and recurrence while SOCS3 expression correlated with differentiation grade, vascular invasion, and recurrence. A significant negative correlation between BORIS and SOCS3 was observed. Patients with high BORIS expression and/or low SOCS3 expression had poorer postoperative survival. Patients with both these characteristics had the poorest prognostic outcome.BORIS and SOCS3 are promising as valuable indicators for predicting HCC prognosis.