c-Jun N-terminal kinase inhibitor favors transforming growth factor-β to antagonize hepatitis B virus X protein-induced cell growth promotion in hepatocellular carcinoma

SIAH2 suppresses c-JUN pathway by promoting the polyubiquitination and degradation of HBx in hepatocellular carcinoma

As an important protein encoded by hepatitis B virus (HBV), HBV X protein (HBx) plays an important role in the development of hepatocellular carcinoma (HCC). It has been shown that seven in absentia homologue 1 (SIAH1) could regulates the degradation of HBx through the ubiquitin-proteasome pathway. However, as a member of SIAH family, the regulatory effects of SIAH2 on HBx remain unclear. In this study, we first confirmed that SIAH2 could reduce the protein levels of HBx depending on its E3 ligase activity. Moreover, SIAH2 interacted with HBx and induced its K48-linked polyubiquitination and proteasomal degradation. Furthermore, we provided evidence that SIAH2 inhibits HBx-associated HCC cells proliferation by regulating HBx. In conclusion, our study identified a novel role for SIAH2 in promoting HBx degradation and SIAH2 exerts an inhibitory effect in the proliferation of HBx-associated HCC through inducing the degradation of HBx. Our study provides a new idea for the targeted degradation of HBx and may have great huge significance into providing novel evidence for the targeted therapy of HBV-infected HCC.

Mechanisms of Ganweikang Tablets against Chronic Hepatitis B: A Comprehensive Study of Network Analysis, Molecular Docking, and Chemical Profiling

The hepatitis B virus (HBV) is one of the major viral infection problems worldwide in public health. The exclusive proprietary Chinese medicine Ganweikang (GWK) tablet has been marketed for years in the treatment of chronic hepatitis B (CHB). However, the pharmacodynamic material basis and underlying mechanism of GWK are not completely clear. This study is aimed at investigating the pharmacological mechanism of the GWK tablet in the treatment of CHB. The chemical ingredient information was obtained from the Traditional Chinese Medicine Database and Analysis Platform (TCMSP), Traditional Chinese Medicines Integrated Database (TCMID), and Shanghai Institute of Organic Chemistry of CAS. Ingredients and disease-related targets were defined by a combination of differentially expressed genes from CHB transcriptome data and open-source databases. Target-pathway-target (TPT) network analysis, molecular docking, and chemical composition analysis were adopted to further verify the key targets and corresponding active ingredients of GWK. Eight herbs of GWK were correlated to 330 compounds with positive oral bioavailability, and 199 correlated targets were identified. The TPT network was constructed based on the 146 enriched targets by KEGG pathway analysis, significantly associated with 95 pathways. Twenty-five nonvolatile components and 25 volatile components in GWK were identified in UPLC-QTOF/MS and GC-MS chromatograms. The key active ingredients of GWK include ferulic acid, oleanolic acid, ursolic acid, tormentic acid, 11-deoxyglycyrrhetic acid, dibenzoyl methane, anisaldehyde, wogonin, protocatechuic acid, psoralen, caffeate, dimethylcaffeic acid, vanillin, β-amyrenyl acetate, formonentin, aristololactam IIIa, and 7-methoxy-2-methyl isoflavone, associated with targets CA2, NFKB1, RELA, AKT1, JUN, CA1, CA6, IKBKG, FOS, EP300, CREB1, STAT1, MMP9, CDK2, ABCB1, and ABCG2.

The Hepatitis B Virus Interactome: A Comprehensive Overview

Despite the availability of a prophylactic vaccine, chronic hepatitis B (CHB) caused by the hepatitis B virus (HBV) is a major health problem affecting an estimated 292 million people globally. Current therapeutic goals are to achieve functional cure characterized by HBsAg seroclearance and the absence of HBV-DNA after treatment cessation. However, at present, functional cure is thought to be complicated due to the presence of covalently closed circular DNA (cccDNA) and integrated HBV-DNA. Even if the episomal cccDNA is silenced or eliminated, it remains unclear how important the high level of HBsAg that is expressed from integrated HBV DNA is for the pathology. To identify therapies that could bring about high rates of functional cure, in-depth knowledge of the virus' biology is imperative to pinpoint mechanisms for novel therapeutic targets. The viral proteins and the episomal cccDNA are considered integral for the control and maintenance of the HBV life cycle and through direct interaction with the host proteome they help create the most optimal environment for the virus whilst avoiding immune detection. New HBV-host protein interactions are continuously being identified. Unfortunately, a compendium of the most recent information is lacking and an interactome is unavailable. This article provides a comprehensive review of the virus-host relationship from viral entry to release, as well as an interactome of cccDNA, HBc, and HBx.

Up-regulation of S100A4 expression by HBx protein promotes proliferation of hepatocellular carcinoma cells and its correlation with clinical survival

BACKGROUND

Hepatocellular carcinoma is one of the most common cancers worldwide. HBV-related HCC has characteristics of faster progression and worse prognosis. Previous studies have confirmed that HBx protein plays numbers of important roles in development of HBV-HCC. However, the molecular mechanism of carcinogenicity of HBx is still not well documented.

METHODS

Firstly, a HCC cell line over-expressing HBx was established and its function was verified. Subsequently, the differentially expressed genes were detected by transcriptome sequencing technology and use the Western Blot technology to detect the up-regulated genes in HBx overexpressed cells, and the functional correlation of the genes was analyzed. Finally, tissue microarray was used to correlate up-regulated gene with clinical follow-up data to verify correlation with clinical prognosis.

RESULTS

Over-expression of HBx could promote cell proliferation, and over-expression of HBx could up-regulate the expression of S100A4 protein. ShRNA experiments showed that HBx promoted cell proliferation by upregulating the expression of S100A4. IFN-α2b can down-regulate the expression of S100A4 and inhibit the proliferation of HCC cells. The expression of S100A4 in cancer was significantly up-regulated compared with adjacent tissues, and was also significantly associated with tumors volume, the expression of PD-L1 and the survival time of patients with HCC.

CONCLUSION

In general, S100A4 may be an effective therapeutic target for HBV-HCC. And the connection between S100A4 and HBV are not clear yet. This study may play a guiding role in the future clinical treatment of HCC.

Comprehensive Analysis of the mRNA-lncRNA Co-expression Profile and ceRNA Networks Patterns in Chronic Hepatitis B

Background:

Long non-coding RNAs (lncRNAs) are emerging as important regulators in the modulation of virus infection by targeting mRNA transcription. However, their roles in chronic hepatitis B (CHB) remain to be elucidated.

Objective:

The study aimed to explore the lncRNAs and mRNA expression profiles in CHB and asymp-tomatic HBsAg carriers (ASC) and construct mRNA-lncRNA co-expression profile and ceRNA net-works to identify the potential targets of diagnosis and treatment in CHB.

Methods:

We determined the expression profiles of lncRNAs and mRNAs in CHB and ASC using mi-croarray analysis. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) path-way enrichment analyses were performed to explore their function. We also constructed co-expression, cis-regulatory, and competing endogenous RNA (ceRNA) networks with bioinformatics methods.

Results:

We identified 1634 mRNAs and 5550 lncRNAs that were differentially expressed between CHB and ASC. Significantly enriched GO terms and pathways were identified, many of which were linked to immune processes and inflammatory responses. Co-expression analysis showed 1196 relation-ships between the top 20 up/downregulated lncRNAs and mRNA, especially 213 lncRNAs interacted with ZFP57. The ZFP57-specific ceRNA network covered 3 lncRNAs, 5 miRNAs, and 17 edges. Cis-correlation analysis showed that lncRNA T039096 was paired with the most differentially expressed gene, ZFP57. Moreover, by expending the clinical samples size, the qRT-PCR results showed that the expression of ZFP57 and T039096 increased in CHB compared to ASC.

Conclusion:

Our study provides insights into the roles of mRNA and lncRNA networks in CHB, high-lighting potential applications of lncRNA-T039096 and mRNA-ZFP57 for diagnosis and treatment.

lncRNA RMRP knockdown suppress hepatocellular carcinoma biological activities via regulation miRNA-206/TACR1

Long noncoding RNA, RNA component of mitochondrial RNA processing endoribonuclease (RMRP) plays an important role in cancer development and is closely correlated with prognosis in cancer patients. However, whether RMRP affects prognosis in patients with hepatocellular carcinoma (HCC) remains unclear. The aim of the present study was to investigate the expression level of RMRP in HCC and its correlation with prognosis in patients with HCC and explain the effects and associated mechanisms by conducting an in vitro study. The high expression level of RMRP was correlated with poor prognosis in patients with HCC. Using in vitro analysis, RMRP knockdown suppressed HCC cell proliferation, invasion, and migration (P < .05). miRNA-206 overexpression had similar effects in HCC cell lines (Bel-7402 and Huh-7). Using Western blot analysis and cellular immunofluorescence detection, RMRP downregulation significantly suppressed TACR1/Erk1/2 pathway, while miRNA-206 was significantly upregulated (P < .05). RMRP downregulation inhibits HCC-related biological activities by the regulation of miRNA-206/TACR1.

Microbiota, Epithelium, Inflammation, and TGF-β Signaling: An Intricate Interaction in Oncogenesis

Microbiota has been widely considered to play a critical role in human carcinogenesis. Recent evidence demonstrated that microbiota, epithelial barrier and inflammation has made up a tightly interdependent triangle during the process of carcinogenesis. Hence, we discussed the triangle relationship of microbiota dysbiosis, epithelial barrier dysfunction and dysregulated immune responses to elucidate the mechanisms by which microbiota induces carcinogenesis, especially highlighting the reciprocal crosstalk between transforming growth factor-β signaling and every side of the tumorigenic triangle. This sophisticated interaction will provide insight into the basic mechanisms of carcinogenesis and may bring new hope to cancer prevention and therapeutic intervention.

The Effects of Smad3 on Adrenocorticotropic Hormone-Secreting Pituitary Adenoma Development, Cell Proliferation, Apoptosis, and Hormone Secretion

OBJECTIVE

Down-regulation of mothers against decapentaplegic homolog 3 (Smad3) results in the formation of tumors both in vivo and in vitro. However, little is known about the effect of Smad3 on adrenocorticotropic hormone-secreting pituitary adenomas (ACTH-PAs). Our objective was to study the expression and effect of Smad3 in ACTH-PAs and its possible mechanisms.

METHODS

Smad3, COOH-terminally phosphorylated mothers against decapentaplegic homolog 3 (pSmad3), and mothers against decapentaplegic homolog 2 proteins (Smad2) were detected in samples from 5 normal anterior pituitaries and 18 ACTH-PAs by Western blot and immunohistochemical analysis. Then, Smad3 expression was up-regulated by Smad3-CMV plasmid or down-regulated by small interfering RNA in ACTH tumor cells (AtT-20) in vitro. Cell proliferation, apoptosis, ACTH level, and pSmad3, B-cell lymphoma/lewkmia-2 (BCL-2), and pro-opiomelanocortin (POMC) protein expression in the AtT-20 cells were measured to investigate the antitumor effects of Smad3.

RESULTS

Reduced expression of Smad3 and pSmad3 but unchanged Smad2 levels were found in ACTH-PAs compared with normal pituitaries. In vitro, the overexpression of Smad3 inhibited cell proliferation, promoted cell apoptosis, and decreased ACTH secretion; in contrast, Smad3 knockdown increased cell proliferation and decreased cell apoptosis but had no significant effect on ACTH secretion. At the same time, overexpression of Smad3 increased pSmad3 but inhibited BCL-2 and POMC protein expression. On the contrary, underexpression of Smad3 inhibited pSmad3 but promoted BCL-2 and POMC protein expression.

CONCLUSIONS

Smad3 is underexpressed in ACTH-PAs. Reversing the expression of Smad3 in AtT-20 cells could suppress cell growth, promote tumor apoptosis, and decrease ACTH secretion. Tumor suppression was possibly mediated by the promotion of pSmad3 and the reduction of BCL-2 and POMC expression.

Viruses as key modulators of the TGF-β pathway; a double-edged sword involved in cancer

Transforming growth factor-β (TGF-β) signaling pathway is a key network in cell signaling that controls vital processes such as proliferation, differentiation, apoptosis, epithelial-mesenchymal transition, and migration, thus acting as a double-edged sword in normal development and diseases, in particular organ fibrosis, vascular disorders, and cancer. Early in tumorigenesis, the pathway exerts anti-tumor effects through suppressing cell cycle and inducing apoptosis, while during late stages, it functions as a tumor promoter by enhancing tumor invasiveness and metastasis. This signaling pathway can be perturbed by environmental and genetic factors such as microbial interference and mutation, respectively. In this way, the present review describes the modulation of the TGF-β pathway by oncogenic human viral pathogens and other viruses. The main mechanisms by which viruses interferes with TGF-β signaling seems to be through (1) the alteration of either TGF-β protein expression or activation, (2) the modulation of the TGF-β receptors or SMADs factors (by interfering with their levels and functions), (3) the alteration of none-SMAD pathways, and (4) indirect interaction with the pathway by the modulation of transcriptional co-activator/repressor and regulators of the pathway. Given the axial role of this pathway in tumorigenesis, it can be regarded as an attractive target for cancer therapy. Hence, further investigations on this subject may represent molecular targets among either TGF-β signaling molecules or viral factors for the treatment and management of viral infection consequences such as cancer.

Long non-coding RNA linc-ITGB1 promotes cell proliferation and migration in human hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) represents a major endpoint of chronic liver diseases and is the third leading cause of cancer-related mortality. Long intergenic non-coding RNA-integrin subunit β1 ITGB1 (linc-ITGB1) is a novel long non-coding RNA, which is implicated in the development and progression of human tumors. However, its involvement in hepatocarcinogenesis remains to be elucidated. In the present study, the specific roles of linc-ITGB1 on cell proliferation and metastasis in HCC were investigated. It was initially observed that the expression of linc-ITGB1 was significantly elevated in 30 cases of clinical HCC tissues relative to their adjacent non-cancerous tissues. Expression of linc-ITGB1 was particularly elevated in the highly invasive cell line, HCCLM3. Knockdown of linc-ITGB1 in HCCLM3 cells using a specific short hairpin RNA decreased cell viability and colony formation in vitro. In addition, cell cycle analysis demonstrated that linc-ITGB1-depleted cells accumulated in the G0/G1 phase. HCCLM3 cells with linc-ITGB1 depletion exhibited significantly decreased migration and invasion abilities, when compared with control cells (P<0.05). These data suggest that linc-ITGB1 promotes HCC progression by inducing cell-cycle arrest. Therefore, targeted therapy against linc-ITGB1 may be a novel strategy to treat HCC.

Hepatitis B virus X protein in liver tumor microenvironment

Encoded by the hepatitis B virus, hepatitis B virus X protein (HBx) is a multifunctional, potentially oncogenic protein that acts primarily during the progression from chronic hepatitis B to cirrhosis and hepatocellular carcinoma (HCC). In recent decades, it has been established that chronic inflammation generates a tumor-supporting microenvironment. HCC is a typical chronic inflammation-related cancer, and inflammation is the main risk factor for HCC progression. The viral transactivator HBx plays a pivotal role in the initiation and maintenance of hepatic inflammatory processes through interactions with components of the tumor microenvironment including tumor cells and the surrounding peritumoral stroma. The complex interactions between HBx and this microenvironment are thought to regulate tumor growth, progression, invasion, metastasis, and angiogenesis. In this review, we have summarized the current evidence evaluating the function of HBx and its contribution to the inflammatory liver tumor microenvironment.