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

E3 ligase SOCS3 regulates NOD2 expression by ubiquitin proteasome system in lung cancer progression

PURPOSE

Despite lung cancer is one of the leading causes of cancer-related deaths, it remains hard to discover effective diagnostic and therapeutic approaches. Moreover, the five-year survival rate is relatively lower than other tumors. So urgent needs for finding a new theranostic target to treat lung cancer effectively. This study aims to present SOCS3 and NOD2 proteins as novel targets for diagnosis and therapy.

METHODS

We first confirmed SOCS3 expression level in patients' tissues. Then, we applied knockdown and overexpression of SOCS3 on lung cancer cell lines and performed proliferation, migration, and invasion assay. After that, we found NOD2 is a target of SOCS3 and introduced overexpression of NOD2 to A549 for verifying reduced tumorigenicity of lung cancer cells.

RESULTS

We identified protein expression level of SOCS3 was frequently higher in tumor tissues than adjacent normal tissues. Truly, overexpression of SOCS3 promoted proliferation, migration, and invasion capacity of lung cancer cells. We found that SOCS3 interacts with NOD2 and SOCS3 ubiquitinates NOD2 directly. Furthermore, lung cancer tissues with higher SOCS3 expression showed lower NOD2 expression. We confirmed overexpression of NOD2 leads to suppressed tumorigenicity of lung cancer cells, and these effects occurred through MAPK pathway.

CONCLUSION

Collectively, our work reveals novel roles of SOCS3 in lung tumorigenesis and proposes SOCS3 as a promising biomarker candidate for therapeutic and diagnostic target for lung cancer.

Reconstruction of the regulatory hypermethylation network controlling hepatocellular carcinoma development during hepatitis C viral infection

Hepatocellular carcinoma (HCC) has been associated with hepatitis C viral (HCV) infection as a potential risk factor. Nonetheless, the precise genetic regulatory mechanisms triggered by the virus, leading to virus-induced hepatocarcinogenesis, remain unclear. We hypothesized that HCV proteins might modulate the activity of aberrantly methylated HCC genes through regulatory pathways. Virus-host regulatory pathways, interactions between proteins, gene expression, transport, and stability regulation, were reconstructed using the ANDSystem. Gene expression regulation was statistically significant. Gene network analysis identified four out of 70 HCC marker genes whose expression regulation by viral proteins may be associated with HCC: DNA-binding protein inhibitor ID - 1 (ID1), flap endonuclease 1 (FEN1), cyclin-dependent kinase inhibitor 2A (CDKN2A), and telomerase reverse transcriptase (TERT). It suggested the following viral protein effects in HCV/human protein heterocomplexes: HCV NS3(p70) protein activates human STAT3 and NOTC1; NS2-3(p23), NS5B(p68), NS1(E2), and core(p21) activate SETD2; NS5A inhibits SMYD3; and NS3 inhibits CCN2. Interestingly, NS3 and E1(gp32) activate c-Jun when it positively regulates CDKN2A and inhibit it when it represses TERT. The discovered regulatory mechanisms might be key areas of focus for creating medications and preventative therapies to decrease the likelihood of HCC development during HCV infection.

Afatinib combined with anti-PD1 enhances immunotherapy of hepatocellular carcinoma via ERBB2/STAT3/PD-L1 signaling

Background

Afatinib is mainly used to treat advanced non-small cell lung cancer, but its therapeutic effect on hepatocellular carcinoma is still unclear.

Methods

Over 800 drugs were screened by CCK8 technology and afatinib was found to have a significant inhibitory effect on liver cancer cells. The expression of PDL1 in tumor cells treated with drugs were detected by qRT-PCR and Weston Blot experiments. The effects of afatinib on the growth, migration and invasion of HCC cells were evaluated using wound healing, Transwell, and cell cloning assays. The in vivo effects of afatinib in combination with anti-PD1 were evaluated in C57/BL6J mice with subcutaneous tumorigenesis. Bioinformatics analysis was performed to explore the specific mechanism of afatinib's inhibition of ERBB2 in improving the expression level of PD-L1, which was subsequently verified through experiments.

Results

Afatinib was found to have a significant inhibitory effect on liver cancer cells, as confirmed by in vitro experiments, which demonstrated that it could significantly suppress the growth, invasion and migration of HCC cells. qRT PCR and Weston Blot experiments also showed that Afatinib can enhance the expression of PD-L1 in tumor cells. In addition, in vitro experiments confirmed that afatinib can significantly enhance the immunotherapeutic effect of hepatocellular carcinoma. Afatinib's ability to increase PD-L1 expression is mediated by STAT3 activation following its action on HCC cells.

Conclusion

Afatinib enhances PD-L1 expression in tumor cells through the STAT3/PD-L1 pathway. The combination of afatinib and anti-PD1 treatment significantly increases the immunotherapeutic effect of HCC.

Prognostic Value of Erythroblastic Leukemia Viral Oncogene Homolog 2 and Neuregulin 4 in Hepatocellular Carcinoma

Although the roles of erythroblastic leukemia viral oncogene homolog 2 (ERBB2), neuregulin 4 (NRG4), and mitogen-inducible gene 6 (MIG6) in epidermal growth factor receptor signaling in hepatocellular carcinoma (HCC) and other malignancies have been previously investigated, the prognostic value of their serum levels in HCC remains undetermined. In the present study, correlations between serum levels and tumor characteristics, overall survival, and tumor recurrence were analyzed. Furthermore, the prognostic potential of the serum levels of these biomarkers was evaluated relative to that of alpha-fetoprotein. Both ERBB2 and NRG4 correlated with the Barcelona Clinic Liver Cancer stage, ERBB2 correlated with the tumor-maximal diameter, and NRG4 correlated with a tumor number. Cox proportional hazards regression analysis revealed that ERBB2 (hazard ratio [HR], 2.719; p = 0.007) was an independent prognostic factor for overall survival. Furthermore, ERBB2 (HR, 2.338; p = 0.002) and NRG4 (HR, 431.763; p = 0.001) were independent prognostic factors for tumor recurrence. The products of ERBB2 and NRG4 had a better area under the curve than alpha-fetoprotein for predicting 6-month, 1-year, 3-year, and 5-year mortality. Therefore, these factors could be used to evaluate prognosis and monitor treatment response in patients with HCC.

Computer analysis of regulation of hepatocarcinoma marker genes hypermethylated by HCV proteins

Hepatitis C virus (HCV) is a risk factor that leads to hepatocellular carcinoma (HCC) development. Epigenetic changes are known to play an important role in the molecular genetic mechanisms of virus-induced oncogenesis. Aberrant DNA methylation is a mediator of epigenetic changes that are closely associated with the HCC pathogenesis and considered a biomarker for its early diagnosis. The ANDSystem software package was used to reconstruct and evaluate the statistical significance of the pathways HCV could potentially use to regulate 32 hypermethylated genes in HCC, including both oncosuppressor and protumorigenic ones identified by genome-wide analysis of DNA methylation. The reconstructed pathways included those affecting protein-protein interactions (PPI), gene expression, protein activity, stability, and transport regulations, the expression regulation pathways being statistically significant. It has been shown that 8 out of 10 HCV proteins were involved in these pathways, the HCV NS3 protein being implicated in the largest number of regulatory pathways. NS3 was associated with the regulation of 5 tumor-suppressor genes, which may be the evidence of its central role in HCC pathogenesis. Analysis of the reconstructed pathways has demonstrated that following the transcription factor inhibition caused by binding to viral proteins, the expression of a number of oncosuppressors (WT1, MGMT, SOCS1, P53) was suppressed, while the expression of others (RASF1, RUNX3, WIF1, DAPK1) was activated. Thus, the performed gene-network reconstruction has shown that HCV proteins can influence not only the methylation status of oncosuppressor genes, but also their transcriptional regulation. The results obtained can be used in the search for pharmacological targets to develop new drugs against HCV-induced HCC.

Oxidative Stress and Redox-Dependent Signaling in Prostate Cancer

Tumor emergence and progression is complicated by the dual role of reactive oxygen species (ROS). Low concentrations of ROS are essential for many intracellular metabolic processes and cell proliferation, while excessive ROS generation disrupts the mechanisms of cancer suppression, leading to the cell damage and death. A long-term imbalance in the ROS/antioxidant ratio and upregulation of the ROS generation due to the reduced efficacy of the antioxidant defense system cause chronic oxidative stress resulting in the damage of proteins, lipid, and DNA molecules and cancer development. Numerous data demonstrate that prostate cancer (the most common cancer in males) is associated with the development of oxidative stress. However, the reasons for the emergence of prostate cancer, as well as changes in the redox signaling and cellular redox homeostasis in this disease, are still poorly understood. The review examines the role of prooxidant and antioxidant enzyme systems, the imbalance in their activity leading to the oxidative stress development, changes in the key components of redox signaling, and the role of microRNAs in the modulation of redox status of cancer cells in prostate cancer.

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.

NT157 Inhibits HCC Migration via Downregulating the STAT3/Jab1 Signaling Pathway

Purpose:

The high fatality-to-case ratio of hepatocellular carcinoma is directly related to metastasis. The signal transducer and activator of transcription-3 is a key mediator of the cytokine and growth factor signaling pathways and drives the transcription of genes responsible for cancer-associated phenotypes. However, so far, no specific inhibitor for signal transducer and activator of transcription-3 has been used in clinical practice. Therefore, targeting the signal transducer and activator of transcription-3 for cancer therapy is highly desired to improve outcomes in patients with hepatocellular carcinoma.

Experimental Design:

Using the small-molecule inhibitor NT157, the effect of signal transducer and activator of transcription-3 inhibition on cell migration was tested in hepatocellular carcinoma cell lines and a lung metastasis model of the disease.

Results:

NT157 significantly inhibited the migration of hepatocellular carcinoma cell lines in vitro and lung metastasis of hepatocellular carcinoma in vivo. Mechanistically, it inhibited the phospho-signal transducer and activator of transcription-3 in a dose- and time-dependent manner. Furthermore, NT157 treatment suppressed the c-Jun activation domain-binding protein-1 levels in the nucleus but no significant decrease was observed in its expression in the cytoplasm. Finally, high mRNA expression levels of signal transducer and activator of transcription-3 and c-Jun activation domain-binding protein-1 in hepatocellular carcinoma were associated with significantly low survival rates.

Conclusion:

NT157 inhibits hepatocellular carcinoma migration and metastasis by downregulating the signal transducer and activator of transcription-3/c-Jun activation domain-binding protein-1 signaling pathway and targeting it may serve as a novel therapeutic strategy for the clinical management of hepatocellular carcinoma in the future.

Hepatoma Cell-Derived Extracellular Vesicles Promote Liver Cancer Metastasis by Inducing the Differentiation of Bone Marrow Stem Cells Through microRNA-181d-5p and the FAK/Src Pathway

Bone marrow mesenchymal stem cells (BMSCs) are beneficial to repair the damaged liver. Tumor-derived extracellular vesicles (EV) are notorious in tumor metastasis. But the mechanism underlying hepatoma cell-derived EVs in BMSCs and liver cancer remains unclear. We hypothesize that hepatoma cell-derived EVs compromise the effects of BMSCs on the metastasis of liver cancer. The differentially expressed microRNAs (miRNAs) were screened. HepG2 cells were transfected with miR-181d-5p mimic or inhibitor, and the EVs were isolated and incubated with BMSCs to evaluate the differentiation of BMSCs into fibroblasts. Hepatoma cells were cultured with BMSCs conditioned medium (CM) treated with HepG2-EVs to assess the malignant behaviors of hepatoma cells. The downstream genes and pathways of miR-181d-5p were analyzed and their involvement in the effect of EVs on BMSC differentiation was verified through functional rescue experiments. The nude mice were transplanted with BMSCs-CM or BMSCs-CM treated with HepG2-EVs, and then tumor growth and metastasis in vivo were assessed. HepG2-EVs promoted fibroblastic differentiation of BMSCs, and elevated levels of α-SMA, vimentin, and collagen in BMSCs. BMSCs-CM treated with HepG2-EVs stimulated the proliferation, migration, invasion and epithelial-mesenchymal-transition (EMT) of hepatoma cells. miR-181d-5p was the most upregulated in HepG2-EVs-treated BMSCs. miR-181d-5p targeted SOCS3 to activate the FAK/Src pathway and SOCS3 overexpression inactivated the FAK/Src pathway. Reduction of miR-181d-5p in HepG2-EVs or SOCS3 overexpression reduced the differentiation of BMSCs into fibroblasts, and compromised the promoting effect of HepG2-EVs-treated BMSCs-CM on hepatoma cells. In vivo, HepG2-EVs-treated BMSCs facilitated liver cancer growth and metastasis. In conclusion, HepG2-EVs promote the differentiation of BMSCs, and promote liver cancer metastasis through the delivery of miR-181d-5p and the SOCS3/FAK/Src pathway.

EYA2 suppresses the progression of hepatocellular carcinoma via SOCS3-mediated blockade of JAK/STAT signaling

BACKGROUND

Somatic mutations are involved in hepatocellular carcinoma (HCC) progression, but the genetic mechanism associated to hepatocarcinogenesis remains poorly understood. We report that Eyes absent homolog 2 (EYA2) suppresses the HCC progression, while EYA2(A510E) mutation identified by exome sequencing attenuates the tumor-inhibiting effect of EYA2.

METHODS

Whole-exome sequencing was performed on six pairs of human HCC primary tumors and matched adjacent tissues. Focusing on EYA2, expression level of EYA2 in human HCC samples was evaluated by quantitative real-time PCR, western blot and immunohistochemistry. Loss- and gain-of-function studies, hepatocyte-specific deletion of EYA2 (Eya2-/-) in mice and RNA sequencing analysis were used to explore the functional effect and mechanism of EYA2 on HCC cell growth and metastasis. EYA2 methylation status was evaluated using Sequenom MassARRAY and publicly available data analysis.

RESULTS

A new somatic mutation p.Ala510Glu of EYA2 was identified in HCC tissues. The expression of EYA2 was down-regulated in HCC and associated with tumor size (P = 0.001), Barcelona Clinic Liver Cancer stage (P = 0.016) and tumor differentiation (P = 0.048). High level of EYA2 was correlated with a favorable prognosis in HCC patients (P = 0.003). Results from loss-of-function and gain-of-function experiments suggested that knockdown of EYA2 enhanced, while overexpression of EYA2 attenuated, the proliferation, clone formation, invasion, and migration of HCC cells in vitro. Delivery of EYA2 gene had a therapeutic effect on inhibition of orthotopic liver tumor in nude mice. However, EYA2(A510E) mutation led to protein degradation by unfolded protein response, thus weakening the inhibitory function of EYA2. Hepatocyte-specific deletion of EYA2 in mice dramatically promoted diethylnitrosamine-induced HCC development. EYA2 was also down-regulated in HCC by aberrant CpG methylation. Mechanically, EYA2 combined with DACH1 to transcriptionally regulate SOCS3 expression, thus suppressing the progression of HCC via SOCS3-mediated blockade of the JAK/STAT signaling pathway.

CONCLUSIONS

In our study, we identified and validated EYA2 as a tumor suppressor gene in HCC, providing a new insight into HCC pathogenesis.

ROS‑mediated hypomethylation of PRDX5 promotes STAT3 binding and activates the Nrf2 signaling pathway in NSCLC

Deoxyribonucleic acid (DNA) epigenetic modification has been linked to specific sequences of CpG islands and plays roles in the progression of lung cancer. In this study, it was found that peroxiredoxin‑5 (PRDX5) was highly expressed in non‑small cell lung cancer (NSCLC) tissues; however, its specific regulatory mechanisms and functions in NSCLC remain unknown. The present study therefore explored the regulatory mechanism of PRDX5 under conditions of oxidative stress (OS) in NSCLC. The results revealed that 79 of 121 NSCLC patients exhibited demethylation in the PRDX5 promoter region, which was related to the tumor, node and metastasis (TNM) stage (P=0.027). PRDX5 messenger ribonucleic acid (mRNA) expression positively correlated with the demethylation status of the promoter region. The results of bisulfite sequencing polymerase chain reaction (BSP) revealed lower demethylation frequencies in H1299 cells treated with 0 µM H2O2, but maximum demethylation following treatment with 100 µM H2O2. Using chromatin immunoprecipitation (ChIP) and luciferase detection assays, the effective binding of STAT3 to the transcriptional binding sites of the PRDX5 promoter region was confirmed (2 sites confirmed: Site 1, ‑444 to ‑434 bp; and site 4, ‑1,417 to ‑1,407 bp). STAT3 knockdown significantly decreased the protein expression of PRDX5, while the overexpression of STAT3 significantly increased the protein levels of PRDX5. When PRDX5 was overexpressed in lung cancer cells under conditions of OS, the levels of the epithelial‑mesenchymal transition (EMT) biomarkers, E‑cadherin and vimentin, were significantly decreased and increased, respectively. By contrast, PRDX5 knockdown resulted in significantly increased E‑cadherin and decreased vimentin protein expression levels. Ultimately, when PRDX5‑small interfering RNA (siRNA) or pcDNA3.1‑PRDX5 expression vector were constructed and transfected into H1299 cells pre‑treated with 100 µM H2O2, the nuclear factor (erythroid‑derived 2)‑like 2 (Nrf2) signaling pathway was inhibited or activated. All these results suggested that the reactive oxygen species (ROS)‑mediated hypomethylation of PRDX5 enhanced STAT3 binding affinity with the promoter region, and resulted in the promotion of cell migration and invasion, as well as in the activation of the Nrf2 signaling pathway in NSCLC. The demethylation status of the PRDX5 promoter may thus be used as an epigenetic biomarker in NSCLC. STAT3/PRDX5 signaling may also prove to be a potential strategy for the treatment of this type of cancer.

Dynamics of Axl Receptor Shedding in Hepatocellular Carcinoma and Its Implication for Theranostics

Signaling of the receptor tyrosine kinase Axl and its ligand Gas6 is crucially involved in the development of liver fibrosis and hepatocellular carcinoma (HCC) by activation of hepatic stellate cells and modulation of hepatocyte differentiation. Shedding of Axl’s ectodomain leads to the release of soluble Axl (sAxl), which is increased in advanced fibrosis and in early-to-late stage HCC in the presence and absence of cirrhosis. Here, we focus on the dynamics of Axl receptor shedding and delineate possible scenarios how Axl signaling might act as driver of fibrosis progression and HCC development. Based on experimental and clinical data, we discuss the consequences of modifying Axl signaling by sAxl cleavage, as well as cellular strategies to escape from antagonizing effects of Axl shedding by the involvement of the hepatic microenvironment. We emphasize a correlation between free Gas6 and free sAxl levels favoring abundant Gas6/Axl signaling in advanced fibrosis and HCC. The raised scenario provides a solid basis for theranostics allowing the use of sAxl as an accurate diagnostic biomarker of liver cirrhosis and HCC, as well as Axl receptor signaling for therapeutic intervention in stratified HCC patients.