Targeting ER stress/PKA/GSK-3β/β-catenin pathway as a potential novel strategy for hepatitis C virus-infected patients

Elucidation of the role of XBP1 in the progression of complete hydatidiform mole to invasive mole through RNA-seq

OBJECTIVE

A complete hydatidiform mole (CHM) is a common disease and is known to develop post-molar gestational trophoblast neoplasia (GTN). However, the molecular mechanisms underlying the progression of CHM to post-molar GTN remain largely unknown. In this study, we investigated the molecular factors associated with the progression using RNA-seq.

METHODS

We included 13 patients with CHM and performed RNA-seq using freshly frozen samples. We identified differentially expressed genes between patients who developed GTN (GTN group) and those who achieved spontaneous remission after uterine evacuation (SR group), and performed pathway analysis. Then, functional analyses were performed on choriocarcinoma (JAR and JEG-3) and CHM (Hmol1-3B and Hmol1-2C) cells. Moreover, we evaluated the in vivo tumorigenicity of XBP1-overexpressed Hmol1-3B cells.

RESULTS

The gene expression profiles were separated into two groups, and an upstream regulator analysis was performed using 281 differentially expressed genes. We focused on transcription factors and identified that 33 transcription factors were activated in the GTN group. Then, excluding those with low expression levels in clinical samples and cell lines, XBP1 was selected for further analysis. Additionally, XBP1 downregulation significantly decreased the migration and invasive abilities of choriocarcinoma cells, whereas XBP1 overexpression significantly increased the migration and invasive abilities of CHM cells. Furthermore, animal experiments showed that tumor weight and blood human chorionic gonadotropin (hCG) levels were significantly higher in the XBP1-overexpressing Hmol1-3B-bearing mice than those in the control mice.

CONCLUSION

RNA-seq identified XBP1 as a key factor in post-molar GTN, suggesting it contributes to the development of post-molar GTN.

Glycogen synthase kinase 3 inhibition controls Mycobacterium tuberculosis infection

Compounds targeting host control of infectious diseases provide an attractive alternative to antimicrobials. A phenotypic screen of a kinase library identified compounds targeting glycogen synthase kinase 3 as potent inhibitors of Mycobacterium tuberculosis (Mtb) intracellular growth in the human THP-1 cell line and primary human monocytes-derived macrophages (hMDM). CRISPR knockouts and siRNA silencing showed that GSK3 isoforms are needed for the growth of Mtb and that a selected compound, P-4423632 targets GSK3β. GSK3 inhibition was associated with macrophage apoptosis governed by the Mtb secreted protein tyrosine phosphatase A (PtpA). Phospho-proteome analysis of macrophages response to infection revealed a wide array of host signaling and apoptosis pathways controlled by GSK3 and targeted by P-4423632. P-4423632 was additionally found to be active against other intracellular pathogens. Our findings strengthen the notion that targeting host signaling to promote the infected cell's innate antimicrobial capacity is a feasible and attractive host-directed therapy approach.

Hepatitis C virus and hepatocellular carcinoma: carcinogenesis in the era of direct-acting antivirals

Chronic hepatitis C virus (HCV) infection is a major cause of hepatic fibrosis and cirrhosis, with a risk for the development of hepatocellular carcinoma (HCC). Although highly effective direct-acting antivirals (DAAs) are available, the incidence, morbidity, and mortality of HCV-associated HCC are still high. This article reviews the current knowledge of the mechanisms of HCV-induced carcinogenesis with a special focus on those processes that continue after virus clearance and outlines implications for patient surveillance after DAA treatment.

cAMP-PKA/EPAC signaling and cancer: the interplay in tumor microenvironment

Cancer is a complex disease resulting from abnormal cell growth that is induced by a number of genetic and environmental factors. The tumor microenvironment (TME), which involves extracellular matrix, cancer-associated fibroblasts (CAF), tumor-infiltrating immune cells and angiogenesis, plays a critical role in tumor progression. Cyclic adenosine monophosphate (cAMP) is a second messenger that has pleiotropic effects on the TME. The downstream effectors of cAMP include cAMP-dependent protein kinase (PKA), exchange protein activated by cAMP (EPAC) and ion channels. While cAMP can activate PKA or EPAC and promote cancer cell growth, it can also inhibit cell proliferation and survival in context- and cancer type-dependent manner. Tumor-associated stromal cells, such as CAF and immune cells, can release cytokines and growth factors that either stimulate or inhibit cAMP production within the TME. Recent studies have shown that targeting cAMP signaling in the TME has therapeutic benefits in cancer. Small-molecule agents that inhibit adenylate cyclase and PKA have been shown to inhibit tumor growth. In addition, cAMP-elevating agents, such as forskolin, can not only induce cancer cell death, but also directly inhibit cell proliferation in some cancer types. In this review, we summarize current understanding of cAMP signaling in cancer biology and immunology and discuss the basis for its context-dependent dual role in oncogenesis. Understanding the precise mechanisms by which cAMP and the TME interact in cancer will be critical for the development of effective therapies. Future studies aimed at investigating the cAMP-cancer axis and its regulation in the TME may provide new insights into the underlying mechanisms of tumorigenesis and lead to the development of novel therapeutic strategies.

Prognostic significance of CTNNB1 mutation in hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUNDS

Hepatocellular Carcinoma (HCC) is one of the most common malignant cancers in humans and has a high fatality rate. In recent years, researchers have verified that the Wnt/β-catenin signaling pathway affects the clinicopathological features and prognosis of patients with HCC. Although many studies have investigated the relationship between Wnt/β-catenin signaling pathway and HCC, the prognostic value of β-catenin in HCC remains inconclusive. CTNNB1 (Catenin Beta-1) is an important factor in the Wnt/β-catenin signaling pathway. However, no consensus has been reached on the clinical and prognostic significance of CTNNB1 mutations in HCCs.

METHODS

Eligible studies and relevant data were obtained from PubMed, Web of Science, Elsevier, Cochrane Library, Ovid, and Embase databases. The correlation between CTNNB1 mutations and clinical/prognosis of patients were evaluated. A fixed- or random-effects model was used to calculate pooled odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Seventeen studies matched the selection criteria, and 1828 patients were included. This meta-analysis demonstrated that patients with HCC with CTNNB1 mutations had favorable clinicopathological features and survival. The combined ORs of 1-, 3- and 5-year overall survival were0.52 (n = 6 studies, 95% CI: 0.34-0.81, Z = 2.89, P =0.004, 0.28 (n =6 studies, 95% CI: 0.18-0.42, Z = 6.03, P<0.00001), -0.22 (n = 6 studies, 95% CI: 0.37-0.06, Z = 2.78, P = 0.005), respectively. Additionally, CTNNB1 mutation might be significantly associated with differentiation (OR = 0.54, 95% CI:0.36-0.81, Z = 2.98, P = 0.003), TMN stages (Tumor, Node, Metastasis staging classification) (OR = -0.25, 95% CI:-0.33--0.18, Z = 6.60, P<0.00001), liver cirrhosis (OR = 0.21, 95% CI:0.11-0.39, Z = 4.94, P< = 0.00001), and HBV (Hepatitis B Virus) infection (OR = 0.44, 95% CI:0.31-0.64, Z = 4.37, P<0.0001), but not with tumor size, metastasis, vascular invasion, and HCV infection.

CONCLUSIONS

CTNNB1 mutation can serve as an indicator of favorable prognosis as well as a novel target for treatment in HCC.

Infectious Agents Induce Wnt/β-Catenin Pathway Deregulation in Primary Liver Cancers

Interaction between infectious agents and liver tissue, as well as repeated and extreme biological events beyond adaptive capacities, may result in pathological conditions predisposing people to development of primary liver cancers (PLCs). In adults, PLCs mainly comprise hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA). Various infectious agents in the hepatic microenvironment can destabilize normal liver cell functions by modulating the Wnt/β-catenin pathway components. Among them, hepatotropic viruses B, C, and D are involved in Wnt/β-catenin signaling dysregulation. Other microbial agents, including oncogenic viruses such as Epstein-Barr virus (EBV) and human papilloma virus (HPV), bacteria, e.g., Mycoplasma hyorhinis and Salmonella Typhi, the protozoan parasite Toxoplasma gondii, the fungus Aspergillus flavus, and liver flukes such as Clonorchissinensis or Opisthorchis viverrini, may induce malignant transformation in hepatocytes or in target cells of the biliary tract through aberrant Wnt signaling activation. This review focuses on new insights into infectious agents implicated in the deregulation of Wnt signaling and PLC development. Since the Wnt/β-catenin pathway is a driver of cancer following viral and bacterial infections, molecules inhibiting the complex axis of Wnt signaling could represent novel therapeutic approaches in PLC treatment.