Trends in nano-platforms for the treatment of viral infectious diseases.

Viral diseases have always been a major health issue, from the currently eradicated poliovirus to the still unresolved human immunodeficiency virus, and have since become a recent global threat brought about by the COVID-19 pandemic. Pathogenic viruses easily spread through various means such as contaminated food and water intake, exchange of bodily fluids, or even inhalation of airborne particles mainly due to their miniscule size. Furthermore, viral coats contain virulent proteins which trigger assimilation into target cells on contact through either direct penetration or induction of endocytosis. In some viruses their outer envelope contains masking ligands that create a means of escape from detection of immune cells. To deal with the nanometer size range and biomolecular-based invasion mechanism, nanoparticles are highly suitable for the treatment. The review highlights the progress in nanoparticle technology, particularly viral therapeutics, including therapeutic strategies and existing clinical applications.

Nanosome-Mediated Delivery Of Hdac Inhibitors and Oxygen Molecules for the Transcriptional Reactivation of Latent Hiv-Infected Cd4+ T Cells.

The treatment of human immunodeficiency virus (HIV) infection is notoriously difficult due to the ability of this virus to remain latent in the host's CD4+ T cells. Histone deacetylases (HDACs) interfere with DNA transcription in HIV-infected hosts, resulting in viral latency. Therefore, HDAC inhibitors can be used to activate viral transcription in latently infected cells, after which the virus can be eliminated through a shock-and-kill strategy. Here, a drug delivery system is developed to effectively deliver HDAC inhibitors to latent HIV-infected cells. Given that the efficacy of HDAC inhibitors is reduced under hypoxic conditions, oxygen-containing nanosomes are used as drug carriers. Oxygen-containing nanosomes can improve the efficiency of chemotherapy by delivering essential oxygen to cells. Additionally, their phospholipid bilayer structure makes them uniquely well-suited for drug delivery. In this study, a novel drug delivery system is developed by taking advantage of the oxygen carriers in these oxygen nanosomes, incorporating a multi-drug strategy consisting of HDAC inhibitors and PKA activators, and introducing CXCR4 binding peptides to specifically target CD4+ T cells. Oxygen nanosomes with enhanced targeting capability through the introduction of the CXCR4 binding peptide mitigate drug toxicity and slow down drug release. The observed changes in the expression of p24, a capsid protein of HIV, indirectly confirm that the proposed drug delivery system can effectively induce transcriptional reactivation of HIV in latent HIV-infected cells.

Gene expression profiling of glioblastoma cell lines depending on TP53 status after tumor-treating fields (TTFields) treatment.

Glioblastoma is frequently associated with TP53 mutation, which is linked to a worse prognosis and response to conventional treatments (chemoradiotherapy). Therefore, targeting TP53 is a promising strategy to overcome this poor therapeutic response. Tumor-treating fields (TTFields) are a recently approved treatment for newly diagnosed glioblastoma, which involves direct application of low-intensity, intermediate-frequency alternating electric fields to the tumor, thereby offering a local tumor-killing effect. However, the influence of TP53 mutation status on the effectiveness of TTFields is controversial. Here, we identified the key gene signatures and pathways associated with TTFields in four glioblastoma cell lines varying in TP53 mutation status using gene profiling and functional annotation. Overall, genes associated with the cell cycle, cell death, and immune response were significantly altered by TTFields regardless of TP53 status. TTFields appeared to exert enhanced anti-cancer effects by altering the immune system in the inflammatory environment and regulating cell cycle- and cell death-related genes, but the precise genes influenced vary according to TP53 status. These results should facilitate detailed mechanistic studies on the molecular basis of TTFields to further develop this modality as combination therapy, which can improve the therapeutic effect and minimize side effects of chemoradiotherapy.

Cetylpyridinium chloride interaction with the hepatitis B virus core protein inhibits capsid assembly.

Hepatitis B virus (HBV) infection is a major risk factor for chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC) worldwide. While multiple hepatitis B drugs have been developed, build up of drug resistance during treatment or weak efficacies observed in some cases have limited their application. Therefore, there is an urgent need to develop substitutional pharmacological agents for HBV-infected individuals. Here, we identified cetylpyridinium chloride (CPC) as a novel inhibitor of HBV. Using computational docking of CPC to core protein, microscale thermophoresis analysis of CPC binding to viral nucleocapsids, and in vitro nucleocapsid formation assays, we found that CPC interacts with dimeric viral nucleocapsid protein (known as core protein or HBcAg) specifically. Compared with other HBV inhibitors, such as benzenesulfonamide (BS) and sulfanilamide (SA), CPC achieved significantly better reduction of HBV particle number in HepG2.2.15 cell line, a derivative of human HCC cells that stably expresses HBV. CPC also inhibited HBV replication in mouse hydrodynamic model system. Taken together, our results show that CPC inhibits capsid assembly and leads to reduced HBV biogenesis. Thus, CPC is an effective pharmacological agent that can reduce HBV particles.

PI3Kδ Is a Therapeutic Target in Hepatocellular Carcinoma.

Class I phosphoinositide 3-kinase (PI3K) signaling is a major pathway in human cancer development and progression. Among the four PI3K isoforms, PI3Kα and PI3Kß are ubiquitously expressed, whereas PI3Kγ and PI3Kδ are found primarily in leukocytes. Until now, PI3K targeting in solid tumors has focused on inhibiting PI3Kα-mediated and PI3Kß-mediated cancer cell-intrinsic PI3K activity. The role of PI3Kδ in solid tumors is unknown. Here, we evaluated the effects of PI3Kδ using established hepatocellular carcinoma (HCC) cells, malignant hepatocytes derived from patients with advanced HCC, murine models, and HCC tissues using RNA sequencing, quantitative PCR, immunoblotting, immunofluorescence, microarray, liquid chromatography-tandem mass spectrometry, and kinase assay. We established a chemical carcinogenesis model of liver malignancy that reflects the malignant phenotype and the in vivo environment of advanced HCC. In this in vivo advanced HCC-mimic system using HCC cells treated with hydrogen peroxide (H2 O2 ), we showed that H2 O2 selectively increases PI3Kδ activity while decreasing that of other class I PI3Ks. Blocking PI3Kδ activity with a PI3Kδ inhibitor or small interfering RNA-mediated PI3Kδ gene silencing inhibited HCC-cell proliferation and dampened key features of malignant HCC, including the up-regulation of telomerase reverse transcriptase (TERT). Mechanistically, H2 O2 induced oxidative modification of the serpin peptidase inhibitor, serpin peptidase inhibitor (SERPINA3), blocking its ubiquitin-dependent degradation and enhancing its activity as a transcriptional activator of PI3Kδ and TERT. High PI3Kδ levels in HCC were found to correlate with poor survival rates, with human advanced HCC showing positive correlations between the protein levels of oxidized SERPINA3, PI3Kδ, and TERT. Thus, PI3Kδ plays significant roles in malignant liver tumors. Conclusion: Our data identify PI3Kδ inhibition, recently approved for the treatment of human B-cell malignancies, as a potential treatment for HCC.

Heat shock protein 70 and heat shock protein 90 synergistically increase hepatitis B viral capsid assembly.

Hepatitis B virus (HBV) infection can cause chronic liver diseases, cirrhosis, and hepatocellular carcinoma (HCC). Heat shock proteins (Hsps) are important factors in the formation of the HBV capsid and in genome replication during the viral life cycle. Hsp90 is known to promote capsid assembly. However, the functional roles of Hsp70 in HBV capsid assembly with Hsp90 have not been studied so far. Using microscale thermophoresis analyses and in vitro nucleocapsid formation assays, we found that Hsp70 bound to a HBV core protein dimer and facilitated HBV capsid assembly. Inhibition of Hsp70 by methylene blue (MB) led to a decrease in capsid assembly. Moreover, Hsp70 inhibition reduced intracellular capsid formation and HBV virus particle number in HepG2.2.15 cells. Furthermore, we examined synergism between Hsp70 and Hsp90 on HBV capsid formation in vitro. Our results clarify the role of Hsp70 in HBV capsid formation via an interaction with core dimers and in synergistically promoting capsid assembly with Hsp90.

Oxidatively Modified Protein-Disulfide Isomerase-Associated 3 Promotes Dyskerin Pseudouridine Synthase 1-Mediated Malignancy and Survival of Hepatocellular Carcinoma Cells.

Dyskerin pseudouridine synthase 1 (DKC1) is a conserved gene encoding the RNA-binding protein dyskerin, which is an essential component of the telomerase holoenzyme. DKC1 up-regulation is frequently observed in many different human cancers including hepatocellular carcinoma (HCC); however, its regulatory mechanisms remain unclear. Thus, we investigated the regulatory mechanism of DKC1 in HCC progression. We found that protein-disulfide isomerase-associated 3 (PDIA3) interacted with the DKC1 regulatory DNA in HCC cells but not in HCC cells with elevated reactive oxygen species (ROS) levels, using liquid chromatographic-tandem mass spectrometric analysis after isolating the DKC1 regulatory region binding proteins. PDIA3 repressed DKC1 expression in HCC cells by recognizing the G-quadruplex DNA at the DKC1 location. However, oxidative modification of PDIA3 induced by ROS redistributed this protein into the cytosolic regions, which stimulated DKC1 expression. We also identified Met338 in PDIA3 as the oxidatively modified residue and validated the effect of oxidative modification using an ectopic expression system, a clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 knock-in system, and a xenograft mouse model. We observed that oxidatively modified PDIA3 promoted DKC1-mediated malignancy and survival of HCC cells in vitro and in vivo. HCC tissues showed a positive association with ROS, cytoplasmic PDIA3, and nuclear DKC1 levels. HCC patients with high PDIA3 protein and DKC1 mRNA levels also displayed reduced recurrence-free survival rates. Cumulatively, the results showed that cytoplasmic PDIA3 activity could be essential in raising DKC1 expression in HCC progression and predicting poor prognoses in HCC patients. Conclusion: Our study indicates that the elevated ROS levels in HCC modulate cytoplasmic PDIA3 levels, resulting in HCC cell survival through DKC1 up-regulation.

WITHDRAWN: Cetylpyridinium chloride as a novel inhibitor of hepatitis B viral capsid assembly.

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Telomere length and reactive oxygen species levels are positively associated with a high risk of mortality and recurrence in hepatocellular carcinoma.

Telomeres protect chromosomal ends from deterioration and have been shown to be susceptible to shortening by reactive oxygen species (ROS)-induced damage. ROS levels increase during the progression from early to advanced hepatocellular carcinoma (HCC). An independent study found that the telomeres in most HCC tissues lengthened during carcinogenic advancement. Activated telomerase has been hypothesized to elongate telomeres during the progression of malignant HCC, but it remains unclear which signaling pathway is necessary for telomerase activation in HCC. Here, we showed using cell lines derived from human HCC that H2 O2 , which is a major component of ROS in living organisms, elongates telomeres by increasing telomerase activity through protein kinase B (AKT) activation. The AKT inhibitor, perifosine, decreased telomere length, cellular viability, and H2 O2 -mediated migration and invasion capacity in HCC cells while also inhibiting AKT activation, telomere maintenance, and tumor growth in nude mice. Advanced HCC tissues showed a positive correlation among ROS levels, phosphorylated AKT (pAKT) levels, and telomere length. Furthermore, patients with HCC tumors that have high ROS levels and long telomeres displayed poorer survival rates. These data demonstrate the significant utilities of ROS levels, pAKT levels, and telomere length for predicting a poor prognosis in patients with HCC. Taken together, AKT activation could be essential for telomere maintenance in advanced HCC tumors as well as being an important contributor to malignant HCC progression. CONCLUSION: We showed that H2 O2 contributes to telomere elongation through AKT activation in advanced HCC, suggesting that an AKT inhibitor such as perifosine may be useful for treating patients with malignant HCC. (Hepatology 2018;67:1378-1391).

The TERT promoter SNP rs2853669 decreases E2F1 transcription factor binding and increases mortality and recurrence risks in liver cancer.

A common single-nucleotide polymorphism in the telomerase reverse transcriptase (TERT) promoter, rs2853669 influences patient survival rates and the risk of developing cancer. Recently, several lines of evidence suggest that the rs2853669 suppresses TERT promoter mutation-mediated TERT expression levels and cancer mortality as well as recurrence rates. However, no reports are available on the impact of rs2853669 on TERT expression in hepatocellular carcinoma (HCC) and its association with patient survival. Here, we found that HCC-related overall and recurrence-free survival rates were not associated with TERT promoter mutation individually, but rs2853669 and the TERT promoter mutation in combination were associated with poor survival rates. TERT mRNA expression and telomere fluorescence levels were greater in patients with HCC who had both the combination. The combination caused TERT promoter methylation through regulating the binding of DNA methyltransferase 1 and histone deacetylase 1 to the TERT promoter in HCC cell lines. The TERT expression level was significantly higher in HCC tumor with a methylated promoter than in that with an unmethylated promoter. In conclusion, we demonstrate a substantial role for the rs2853669 in HCC with TERT promoter mutation, which suggests that the combination of the rs2853669 and the mutation indicate poor prognoses in liver cancer.

Reactive oxygen species promote heat shock protein 90-mediated HBV capsid assembly.

Hepatitis B virus (HBV) infection induces reactive oxygen species (ROS) production and has been associated with the development of hepatocellular carcinoma (HCC). ROS are also an important factor in HCC because the accumulated ROS leads to abnormal cell proliferation and chromosome mutation. In oxidative stress, heat shock protein 90 (Hsp90) and glutathione (GSH) function as part of the defense mechanism. Hsp90 prevents cellular component from oxidative stress, and GSH acts as antioxidants scavenging ROS in the cell. However, it is not known whether molecules regulated by oxidative stress are involved in HBV capsid assembly. Based on the previous study that Hsp90 facilitates HBV capsid assembly, which is an important step for the packing of viral particles, here, we show that ROS enrich Hsp90-driven HBV capsid formation. In cell-free system, HBV capsid assembly was facilitated by ROS with Hsp90, whereas it was decreased without Hsp90. In addition, GSH inhibited the function of Hsp90 to decrease HBV capsid assembly. Consistent with the result of cell-free system, ROS and buthionine sulfoximine (BS), an inhibitor of GSH synthesis, increased HBV capsid formation in HepG2.2.15 cells. Thus, our study uncovers the interplay between ROS and Hsp90 during HBV capsid assembly.