Inhibition of hepatitis B virus and induction of hepatoma cell apoptosis by ASGPR-directed delivery of shRNAs

A comprehensive review and in silico analysis of the role of survivin (BIRC5) in hepatocellular carcinoma hallmarks: A step toward precision

Hepatocellular carcinoma (HCC) is a complex malignancy driven by the dysregulation of multiple cellular pathways. Survivin, a key member of the inhibitor of apoptosis (IAP) family, plays a central role in HCC tumorigenesis and progression. Despite significant research, a comprehensive understanding of the contributions of survivin to the hallmarks of cancer, its molecular network, and its potential as a therapeutic target remains incomplete. In this review, we integrated bioinformatics analysis with an extensive literature review to provide deeper insights into the role of survivin in HCC. Using bioinformatics tools such as the Human Protein Atlas, GEPIA, STRING, TIMER, and Metascape, we analyzed survivin expression and its functional associations and identified the top 20 coexpressed genes in HCC. These include TK1, SPC25, SGO2, PTTG1, PRR11, PLK1, NCAPH, KPNA2, KIF2C, KIF11, HJURP, GTSE1, FOXM1, CEP55, CENPA, CDCA3, CDC45, CCNB2, CCNB1 and CTD-2510F5.4. Our findings also revealed significant protein-protein interactions among these genes, which were enriched in pathways associated with the FOXM1 oncogenic signaling cascade, and biological processes such as cell cycle regulation, mitotic checkpoints, and diseases such as liver neoplasms. We also discussed the involvement of survivin in key oncogenic pathways, including the PI3K/AKT, WNT/β-catenin, Hippo, and JAK/STAT3 pathways, and its role in modulating cell cycle checkpoints, apoptosis, and autophagy. Furthermore, we explored its interactions with the tumor microenvironment, particularly its impact on immune modulation through myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages, and natural killer cell function in HCC. Additionally, we highlighted its involvement in alkylglycerone phosphate synthase (AGPS)-mediated lipid reprogramming and identified important gaps in the survivin network that warrant further investigation. This review also examined the role of survivin in cancer stemness, inflammation, and virally mediated hepatocarcinogenesis. We evaluated its potential as a diagnostic, prognostic, predictive, and pharmacodynamic biomarker in HCC, emphasizing its relevance in precision medicine. Finally, we summarized emerging survivin-targeted therapeutics and ongoing clinical trials, underscoring the need for novel strategies to effectively target survivin in HCC.

Small Extracellular Vesicles Promote HBV Replication via METTL3-IGF2BP2-Mediated m6A Modification

BACKGROUND

The roles of small extracellular vesicles (sEVs) and mRNA modifications in regulating hepatitis B virus (HBV) transmission, replication, and related disease progression have received considerable attention. However, the mechanisms through which methyltransferase-like 3 (METTL3) and insulin-like growth factor 2 (IGF2BP2), key genes that mediate m6A modifications, regulate HBV replication in sEVs remain poorly understood. Therefore, this study investigated the molecular mechanisms through which the key molecules (METTL3 and IGF2BP2) in sEVs mediate m6A epigenetic modification to regulate HBV replication.

METHODS

Small extracellular vesicles were extracted from the supernatants of HepG2.2.15 and HepG2 cells via ultracentrifugation, followed by purification with hepatitis B virus surface antigen (HepBsAg) immunomagnetic beads. The sEVs were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), and Western blotting (WB). Methylation enrichment in the two types of sEVs was analyzed by dot blotting and quantitative reverse transcription-PCR (RT-qPCR). The cells were treated with HepG2.2.15-sEVs transfected with either the METTL3 plasmid, METTL3 siRNA, the IGF2BP2 plasmid, or the IGF2BP2 siRNA. After 48 h, the expression of METTL3, IGF2BP2, and HBV DNA expressions were assessed via dot blotting, quantitative-PCR (qPCR), RT-qPCR, and WB. Co-immunoprecipitation (co-IP) was performed to investigate the interactions between METTL3 and IGF2BP2.

RESULTS

By conducting TEM, DLS, and WB analyses, we confirmed that the isolated sEVs exhibited typical characteristics. HepG2.2.15-derived sEVs presented elevated levels of m6A modifications, with increased METTL3 and IGF2BP2 mRNA and protein expression levels, respectively (p < 0.05). In the overexpression (OE)-METTL3 group, the expression levels of HBV pregenomic RNA (HBV pgRNA), HBV DNA, HBV relaxed circular DNA (HBV rcDNA), HBV covalently closed circular DNA (HBV cccDNA), HBsAg, hepatitis B virus core antigen (HBcAg), and hepatitis B virus e antigen (HBeAg) were significantly elevated compared to those in the control group (p < 0.01). In contrast, results for the small interfering (SI)-METTL3 group were the opposite. Similarly, in the OE-IGF2BP2 group, HBV pgRNA, HBV DNA, HBV rcDNA, HBV cccDNA, HBsAg, HBcAg, and HBeAg expression were greater than in the control group (p < 0.05), whereas the opposite results were recorded in the SI-IGF2BP2 group. Co-immunoprecipitation confirmed that METTL3 and IGF2BP2 interact synergistically.

CONCLUSION

Small extracellular vesicles increase METTL3 and IGF2BP2 expression, synergistically promoting HBV replication by regulating m6A modification levels.

Interaction of a Triantennary Quinoline Glycoconjugate with the Asialoglycoprotein Receptor

Targeted intracellular delivery is an efficient strategy for developing therapeutics against cancer and other intracellular infections. Nonspecific drug delivery shows limited clinical applications owing to high dosage, cytotoxicity, nonspecific action, high cost, etc. Therefore, targeted delivery of less cytotoxic drug candidates to hepatocytes through ASGPR-mediated endocytosis could be an efficient strategy to surmount the prevailing shortcomings. In the present work, the gene encoding ASGPR-H1-CRD was amplified from Huh7 cells, cloned into pET 11a vector, and the ASGPR-H1-CRD protein was expressed and purified from E. coli. A novel triantennary galactose-conjugated quinoline derivative 4 was synthesized that demonstrates 17-fold higher binding affinity to isolated ASGPR-H1-CRD protein receptor (K_d ∼54 μM) in comparison to D-galactose (K_d ∼900 μM). Moreover, micro-calorimetric studies for the interaction of glycoconjugate 4 with ASGPR protein on live hepatocytes showed notable thermal response in case of ASGPR-containing Huh7 cells, in comparison to non-ASGPR Chang cells. These results might serve as an approach towards targeted delivery of small glycoconjugates to hepatocytes.

Variable asialoglycoprotein receptor 1 expression in liver disease: Implications for therapeutic intervention

AIM

One of the most promising strategies for the treatment of liver diseases is targeted drug delivery via the asialoglycoprotein receptor (ASGPR). The success of this approach heavily depends on the ASGPR expression level on parenchymal liver cells. In this study, we assessed the mRNA and protein expression levels of the major receptor subunit, ASGR1, in hepatocytes both in vitro and in vivo.

METHODS

In vitro, various liver cancer-derived cell lines were evaluated. In vivo, we screened the ASGR1 mRNA on 59 hepatocellular carcinoma and matched non-neoplastic tissue using RNA microarray. In addition, 350 human liver specimens of patients with hepatocellular carcinoma or non-neoplastic liver diseases were screened for ASGR1 protein level using tissue microarray analysis.

RESULTS

Our data reveal that the ASGR1 mRNA expression directly correlates with the protein level. We demonstrate that the ASGR1 expression is upregulated in cirrhotic specimens and is significantly decreased with increasing hepatocellular carcinoma grade.

CONCLUSION

Because the ASGR1 expression levels are variable between patients, our findings suggest that ASGPR-based targeting strategies should be combined with ASGPR-companion diagnostics to maximize clinical benefit.

Liver-targeted gene therapy: Approaches and challenges

The liver plays a major role in many inherited and acquired genetic disorders. It is also the site for the treatment of certain inborn errors of metabolism that do not directly cause injury to the liver. The advancement of nucleic acid-based therapies for liver maladies has been severely limited because of the myriad untoward side effects and methodological limitations. To address these issues, research efforts in recent years have been intensified toward the development of targeted gene approaches using novel genetic tools, such as zinc-finger nucleases, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeats as well as various nonviral vectors such as Sleeping Beauty transposons, PiggyBac transposons, and PhiC31 integrase. Although each of these methods uses a distinct mechanism of gene modification, all of them are dependent on the efficient delivery of DNA and RNA molecules into the cell. This review provides an overview of current and emerging therapeutic strategies for liver-targeted gene therapy and gene repair.

Active radar guides missile to its target: receptor-based targeted treatment of hepatocellular carcinoma by nanoparticulate systems

Patients with hepatocellular carcinoma (HCC) usually present at advanced stages and do not benefit from surgical resection, so drug therapy should deserve a prominent place in unresectable HCC treatment. But chemotherapy agents, such as doxorubicin, cisplatin, and paclitaxel, frequently encounter important problems such as low specificity and non-selective biodistribution. Recently, the development of nanotechnology led to significant breakthroughs to overcome these problems. Decorating the surfaces of nanoparticulate-based drug carriers with homing devices has demonstrated its potential in concentrating chemotherapy agents specifically to HCC cells. In this paper, we reviewed the current status of active targeting strategies for nanoparticulate systems based on various receptors such as asialoglycoprotein receptor, transferrin receptor, epidermal growth factor receptor, folate receptor, integrin, and CD44, which are abundantly expressed on the surfaces of hepatocytes or liver cancer cells. Furthermore, we pointed out their merits and defects and provided theoretical references for further research.

Diagnosis of abnormal biliary copper excretion by positron emission tomography with targeting of (64)Copper-asialofetuin complex in LEC rat model of Wilson's disease

Identification by molecular imaging of key processes in handling of transition state metals, such as copper (Cu), will be of considerable clinical value. For instance, the ability to diagnose Wilson's disease with molecular imaging by identifying copper excretion in an ATP7B-dependent manner will be very significant. To develop highly effective diagnostic approaches, we hypothesized that targeting of radiocopper via the asialoglycoprotein receptor will be appropriate for positron emission tomography, and examined this approach in a rat model of Wilson's disease. After complexing (64)Cu to asialofetuin we studied handling of this complex compared with (64)Cu in healthy LEA rats and diseased homozygous LEC rats lacking ATP7B and exhibiting hepatic copper toxicosis. We analyzed radiotracer clearance from blood, organ uptake, and biliary excretion, including sixty minute dynamic positron emission tomography recordings. In LEA rats, (64)Cu-asialofetuin was better cleared from blood followed by liver uptake and greater biliary excretion than (64)Cu. In LEC rats, (64)Cu-asialofetuin activity cleared even more rapidly from blood followed by greater uptake in liver, but neither (64)Cu-asialofetuin nor (64)Cu appeared in bile. Image analysis demonstrated rapid visualization of liver after (64)Cu-asialofetuin administration followed by decreased liver activity in LEA rats while liver activity progressively increased in LEC rats. Image analysis resolved this difference in hepatic activity within one hour. We concluded that (64)Cu-asialofetuin complex was successfully targeted to the liver and radiocopper was then excreted into bile in an ATP7B-dependent manner. Therefore, hepatic targeting of radiocopper will be appropriate for improving molecular diagnosis and for developing drug/cell/gene therapies in Wilson's disease.

Expression of cytokines in mouse hepatitis B virus X gene-transfected model

The expression profile in the mouse hepatitis B virus X (HBx)-transfected model was investigated in order to lay a foundation for further study on the implication of cytokines expression in hepatitis B virus (HBV) infection. Hydrodynamic injection method via the tail vein was used to establish the animal HBx-transfected model. By using microassay, the differential expression of gene in each group was analyzed, which was further confirmed by using real-time PCR and semi-quantitative PCR. Most of chemokine genes such as Ccl2, Ccl5, Ccl9, MIG and IP-10 were up-regulated in the HBx-transfected mouse model versus the control mice, which was coincided with the microarray results. Western blotting and immunohistochemistry were applied to detect the expression of MIG and IP-10 in the liver tissues. Simultaneously, ELISA was adopted to measure the content of IFN-γ in the liver tissues. DNA microassay revealed that the expression of 611 genes changed in HBx-transfected mice as compared with that in pCMV-tag2B-transfected mice, and most of the screened chemokines were up-regulated (including MIG and IP-10). Additionally, IFN-γ protein levels were increased by 20.7% (P<0.05) in pCMV-tag2B-HBx-transfected mice as compared with the untreated mice. IFN-γ protein levels were reduced by 53.9% (P<0.05) in pCMV-tag2B-transfected mice as compared with the untreated mice, which was consistent with the up-regulation of MIG and IP-10. It was suggested HBx transfection could induce the expression of MIG and IP-10 in the liver tissues, which might play the roles in HBV-related liver immunity and cytokines-mediated antiviral effect.