Low concentrations of 4-ABP promote liver carcinogenesis in human liver cells and a zebrafish model

Hepatocellular carcinoma and lipid metabolism: Novel targets and therapeutic strategies

Hepatocellular carcinoma (HCC) is an increasingly prevalent disease that is associated with high and continually rising mortality rates. Lipid metabolism holds a crucial role in the pathogenesis of HCC, in which abnormalities pertaining to the delicate balance of lipid synthesis, breakdown, and storage, predispose for the pathogenesis of the nonalcoholic fatty liver disease (NAFLD), a disease precursor to HCC. If caught early enough, HCC treatment may be curative. In later stages, treatment is only halting the inevitable outcome of death, boldly prompting for novel drug discovery to provide a fighting chance for this patient population. In this review, we begin by providing a summary of current local and systemic treatments against HCC. From such we discuss hepatic lipid metabolism and highlight novel targets that are ripe for anti-cancer drug discovery. Lastly, we provide a targeted summary of current known risk factors for HCC pathogenesis, providing key insights that will be essential for rationalizing future development of anti-HCC therapeutics.

The role of miRNA-26a-5p and target gene socs1a in flutolanil induced hepatotoxicity of zebrafish at environmental relevant levels

Flutolanil has been detected worldwide in aquatic environment and fish, which has become an undeniable stressor on ecosystem and human health. Flutolanil has been reported to be toxic to aquatic organisms. However, the pathophysiological and molecular mechanism behind the detrimental effects remains obscure. Here we reported hepatotoxicity induced by flutolanil in HepG2 cells and zebrafish, as revealed by toxicokinetic, HE staining, miRNAs-mRNAs sequencing, molecular dynamic simulations and dual luciferase reporter assays. Collectively, our results indicated that flutolanil could be absorbed by and accumulated in the liver of zebrafish, causing hepatic vacuolar degeneration, steatosis and nuclear condensation and abnormal liver function, where its exposure at environmental levels disrupted the expressions of miRNA-26a-5p and its target gene socs1a by mediating JAK-STAT signaling pathway, which was partially responsible for hepatotoxicity, correlated with oxidative stress, cell apoptosis, inflammation, cell cycle disorder and mitochondrial dysfunction. These findings suggest that miRNA-26a-5p/socs1a can serve as potential biomarkers of hepatotoxicity in zebrafish following exposure to flutolanil. This uncovered route will provide a new tool for the risk assessment of flutolanil and a guide to proper use of flutolanil and environmental remedy, and open up a new horizon for liver disease assessment.

HBV-associated DLBCL of poor prognosis: advance in pathogenesis, immunity and therapy

Advanced studies have shown a biological correlation between hepatitis B virus (HBV) and B-cell lymphoma, especially diffuse large B-cell lymphoma (DLBCL). Patients with DLBCL infected with HBV (HBV-associated DLBCL) are clinically characterized by an advanced clinical stage, poor response to front-line immunochemotherapy regimens, and worse clinical prognosis. HBV-associated DLBCL often exhibits abnormal activation of the nuclear factor kappa B pathway as well as mutations in oncogenes, including Myc and BCL-6. Currently, there is no consensus on any specific and effective treatment for HBV-associated DLBCL. Therefore, in this review, we comprehensively and mechanistically analyzed the natural history of HBV infection and immunity, including HBV-mediated oncogenes, immune escape, epigenetic alterations, dysregulated signaling pathways, and potential therapeutic approaches for HBV-associated DLBCL. We hope that an improved understanding of the biology of HBV-associated DLBCL would lead to the development of novel therapeutic approaches, enhance the number of effective clinical trials, and improve the prognosis of this disease.

In Vitro Approaches to Determine the Potential Carcinogenic Risk of Environmental Pollutants

One important environmental/health challenge is to determine, in a feasible way, the potential carcinogenic risk associated with environmental agents/exposures. Since a significant proportion of tumors have an environmental origin, detecting the potential carcinogenic risk of environmental agents is mandatory, as regulated by national and international agencies. The challenge mainly implies finding a way of how to overcome the inefficiencies of long-term trials with rodents when thousands of agents/exposures need to be tested. To such an end, the use of in vitro cell transformation assays (CTAs) was proposed, but the existing prevalidated CTAs do not cover the complexity associated with carcinogenesis processes and present serious limitations. To overcome such limitations, we propose to use a battery of assays covering most of the hallmarks of the carcinogenesis process. For the first time, we grouped such assays as early, intermediate, or advanced biomarkers which allow for the identification of the cells in the initiation, promotion or aggressive stages of tumorigenesis. Our proposal, as a novelty, points out that using a battery containing assays from all three groups can identify if a certain agent/exposure can pose a carcinogenic risk; furthermore, it can gather mechanistic insights into the mode of the action of a specific carcinogen. This structured battery could be very useful for any type of in vitro study, containing human cell lines aiming to detect the potential carcinogenic risks of environmental agents/exposures. In fact, here, we include examples in which these approaches were successfully applied. Finally, we provide a series of advantages that, we believe, contribute to the suitability of our proposed approach for the evaluation of exposure-induced carcinogenic effects and for the development of an alternative strategy for conducting an exposure risk assessment.

An unconventional cancer-promoting function of methamphetamine in hepatocellular carcinoma

For the past decade, the prevalence and mortality of methamphetamine (METH) use have doubled, suggesting that METH use could be the next substance use crisis worldwide. Ingested METH is transformed into other products in the liver, a major metabolic organ. Studies have revealed that METH causes deleterious inflammatory response, oxidative stress, and extensive DNA damage. These pathological damages are driving factors of hepatocellular carcinoma (HCC). Nonetheless, the potential role of METH in HCC and the underlying mechanisms remain unknown. Herein, we found a higher HCC incidence in METH abusers. METH promoted cellular proliferation, migration, and invasion in two human-derived HCC cells. Consistently, METH uptake promoted HCC progression in a xenograft mouse model. Mechanistically, METH exposure induced ROS production, which activated the Ras/MEK/ERK signaling pathway. Clearance of ROS by NAC suppressed METH-induced activation of Ras/ERK1/2 pathways, leading to arrest of HCC xenograft formation in nude mice. To the best of our knowledge, this is the first study to substantiate that METH promotes HCC progression and inhibition of ROS may reverse this process.

Zebrafish as a Mainstream Model for In Vivo Systems Pharmacology and Toxicology

Pharmacology and toxicology are part of a much broader effort to understand the relationship between chemistry and biology. While biomedicine has necessarily focused on specific cases, typically of direct human relevance, there are real advantages in pursuing more systematic approaches to characterizing how health and disease are influenced by small molecules and other interventions. In this context, the zebrafish is now established as the representative screenable vertebrate and, through ongoing advances in the available scale of genome editing and automated phenotyping, is beginning to address systems-level solutions to some biomedical problems. The addition of broader efforts to integrate information content across preclinical model organisms and the incorporation of rigorous analytics, including closed-loop deep learning, will facilitate efforts to create systems pharmacology and toxicology with the ability to continuously optimize chemical biological interactions around societal needs. In this review, we outline progress toward this goal.

N-acetyltransferase 2 acetylator genotype-dependent N-acetylation and toxicity of the arylamine carcinogen β-naphthylamine in cryopreserved human hepatocytes

We used cryopreserved human hepatocytes that express rapid, intermediate, and slow acetylator N-acetyltransferase 2 (NAT2) genotypes to measure the N-acetylation of β-naphthylamine (BNA) which is one of the aromatic amines found in cigarette smoke including E-cigarettes. We investigated the role of NAT2 genetic polymorphism in genotoxicity and oxidative stress induced by BNA. In vitro BNA NAT2 activities in rapid acetylators was 1.6 and 3.5-fold higher than intermediate (p < 0.01) and slow acetylators (p < 0.0001). BNA N-acetylation in situ was 3 to 4- fold higher in rapid acetylators than slow acetylators, following incubation with 10 and 100 µM BNA (p < 0.01). DNA damage was two to threefold higher in the rapid versus slow acetylators (p < 0.0001) and 2.5-fold higher in intermediate versus slow acetylators following BNA treatment at 100 and 1000 μM, ROS/RNS level was the highest in rapid acetylators followed by intermediate and then slow acetylators (p < 0.0001). Our findings show that the N-acetylation of BNA is NAT2 genotype dependent in cryopreserved human hepatocytes and our data further document an important role for NAT2 genetic polymorphism in modifying BNA-induced genotoxicity and oxidative damage.