Phosphatidylethanolamine N-methyltransferase (PEMT) catalyzes the transfer of methyl groups to phosphatidylethanolamine to generate phosphatidylcholine (PC). PC produced de novo through this pathway is preferentially used for very-low-density lipoprotein assembly and is essential for its normal hepatic secretion as well as for bile acid detoxification. While human PEMT loss-of-function polymorphisms are linked to increased metabolic dysfunction-associated steatotic liver disease risk, the enzyme's role as a primary driver of progressive liver disease remains underexplored. We utilized PEMT knockout (PEMT KO) mice on a standard chow diet to model this deficiency. Histopathological analysis showed that while 2-month-old PEMT KO mice were protected, 6-month-old KOs of both sexes spontaneously developed extensive micro-and macrovesicular steatosis, parenchymal inflammation, and granulomatous inclusions. This severe, age-dependent pathology was confirmed by elevated hepatic triglyceride levels, bile acids, impaired methylation potential, and a cascade of secondary injuries, including increased oxidative stress, impaired proteasomal function, and the induction of cellular senescence markers. This bile acid toxicity and oxidative stress activated the central innate immune sensor, the NLRP3 inflammasome, driving pronounced macrophage infiltration and chronic inflammation. Picrosirius red staining and protein analysis confirmed the progression to severe pericellular fibrosis. Our study establishes that PEMT deficiency is sufficient to initiate and drive the complete progression from steatosis to advanced liver fibrosis, identifying PEMT as a critical metabolic checkpoint and a potent therapeutic target for mitigating progressive liver disease.

Neuroblastoma (NB) is a highly aggressive pediatric cancer that originates from immature nerve cells, presenting significant treatment challenges due to therapy resistance. Despite intensive treatment, approximately 50% of high-risk NB cases exhibit therapy resistance or experience relapse, resulting in poor outcomes often associated with tumor immune evasion. B7-H3 is an immune checkpoint protein known to inhibit immune responses. MicroRNAs (miRNAs) are small non-coding RNAs involved in post-transcriptional gene regulation. Our study aims to explore the impact of miRNAs on B7-H3 regulation, the anti-tumor immune response, and tumorigenicity in NB. Analysis of NB patients and patient-derived xenograft tumors revealed a correlation between higher B7-H3 expression and poorer patient survival. Notably, deceased patients exhibited a depletion of miR-29 family members (miR-29a, miR-29b, and miR-29c), which displayed an inverse association with B7-H3 expression in NB patients. Overexpression and knockdown experiments demonstrated that these miRNAs degrade B7-H3 mRNA, resulting in enhanced NK cell activation and cytotoxicity. In vivo, experiments provided further evidence that miR-29 family members reduce tumorigenicity, macrophage infiltration, and microvessel density, promote infiltration and activation of NK cells, and induce tumor cell apoptosis. These findings offer a rationale for developing more effective combination treatments that leverage miRNAs to target B7-H3 in NB patients.

BACKGROUND:The earliest manifestation of alcohol-associated liver disease (ALD) is steatosis characterized by deposition of fat in specialized organelles called lipid droplets (LDs). While alcohol administration causes a rise in LD numbers in the hepatocytes, little is known regarding their characteristics that allow their accumulation and size to increase. The aim of the present study is to gain insights into underlying pathophysiological mechanisms by investigating the ethanol-induced changes in hepatic LD proteome as a function of LD size. METHODS:Adult male Wistar rats (180-200 g BW) were fed with ethanol liquid diet for 6 weeks. At sacrifice, large-, medium-, and small-sized hepatic LD subpopulations (LD1, LD2, and LD3, respectively) were isolated and subjected to morphological and proteomic analyses. RESULTS:Morphological analysis of LD1-LD3 fractions of ethanol-fed rats clearly demonstrated that LD1 contained larger LDs compared with LD2 and LD3 fractions. Our preliminary results from principal component analysis showed that the proteome of different-sized hepatic LD fractions was distinctly different. Proteomic data analysis identified over 2000 proteins in each LD fraction with significant alterations in protein abundance among the three LD fractions. Among the altered proteins, several were related to fat metabolism, including synthesis, incorporation of fatty acid, and lipolysis. Ingenuity pathway analysis revealed increased fatty acid synthesis, fatty acid incorporation, LD fusion, and reduced lipolysis in LD1 compared to LD3. Overall, the proteomic findings indicate that the increased level of protein that facilitates fusion of LDs combined with an increased association of negative regulators of lipolysis dictates the generation of large-sized LDs during the development of alcohol-associated hepatic steatosis. CONCLUSION:Several significantly altered proteins were identified in different-sized LDs isolated from livers of ethanol-fed rats. Ethanol-induced increases in specific proteins that hinder LD lipid metabolism led to the accumulation and persistence of large-sized LDs in the liver.

Introduction: Sorafenib, an FDA-approved drug for advanced hepatocellular carcinoma (HCC) treatment, encounters resistance in many patients. Deciphering the mechanisms underlying sorafenib resistance is crucial for devising alternative strategies to overcome it. Aim: This study aimed to investigate sorafenib resistance mechanisms using a diverse panel of HCC cell lines. Methods: HCC cell lines were subjected to continuous sorafenib treatment, and stable cell lines (Huh 7.5 and Huh 7PX) exhibiting sustained growth in its presence were isolated. The investigation of drug resistance mechanisms involved a comparative analysis of drug-targeted signal transduction pathways (EGFR/RAF/MEK/ERK/Cyclin D), sorafenib uptake, and membrane expression of the Results: HCC cell lines (Huh 7.5 and Huh 7PX) with a higher IC50 (10 mu M) displayed a more frequent development of sorafenib resistance compared to those with a lower IC50 (2-4.8 mu M), indicating a potential impact of IC50 variation on initial treatment response. Our findings reveal that activated overexpression of Raf1 kinases and impaired sorafenib uptake, mediated by reduced membrane expression of organic cation transporter-1 (OCT1), contribute to sorafenib resistance in HCC cultures. Stable expression of the drug transporter OCT1 through cDNA transfection or adenoviral delivery of OCT1 mRNA increased sorafenib uptake and successfully overcame sorafenib resistance. Additionally, consistent with sorafenib resistance in HCC cultures, cirrhotic liverassociated human HCC tumors often exhibited impaired membrane expression of OCT1 and OCT3. Conclusion: Intrinsic differences among HCC cell clones, affecting sorafenib sensitivity at the expression level of Raf kinases, drug uptake, and OCT1 transporters, were identified. This study underscores the potential of HCC tumor targeted OCT1 expression to enhance sorafenib treatment response.

Sterile α-motif domain-14 (Samd14) protein expression increases the regenerative capacity of the erythroid system. Samd14 is transcriptionally upregulated and promotes cell signaling via the receptor tyrosine kinase Kit in a critical window of acute erythroid regeneration. We generated a hematopoietic-specific conditional Samd14 knockout mouse model (Samd14-CKO) to study the role of Samd14 in hematopoiesis. The Samd14-CKO mouse was viable and exhibited no steady-state hematopoietic phenotype. Samd14-CKO mice were hypersensitive to 5-fluorouracil, resulting in more severe anemia during recovery and impaired erythroid progenitor colony formation. Ex vivo, Samd14-CKO hematopoietic progenitors were defective in their ability to form mast cells. Samd14-CKO mast cells exhibited altered Kit/stem cell factor (SCF), IL-3/IL-3R signaling, and less granularity than Samd14-FL/FL cells. Our findings indicate that Samd14 promotes both erythroid and mast cell functions. The Samd14-CKO mouse phenotype exhibits striking similarities to the KitW/W-v mice, which carry Kit mutations resulting in reduced tyrosine kinase-dependent signaling, causing mast cell and erythroid abnormalities. The Samd14-CKO mouse model is a new tool for studying hematologic pathologies involving Kit signaling.

This review covers some important new aspects of the alcohol-induced communications between liver parenchymal and non-parenchymal cells leading to liver injury development. The information exchange between various cell types may promote end-stage liver disease progression and involves multiple mechanisms, such as direct cell-to-cell interactions, extracellular vesicles (EVs) or chemokines, cytokines, and growth factors contained in extracellular fluids/cell culture supernatants. Here, we highlighted the role of EVs derived from alcohol-exposed hepatocytes (HCs) in activation of non-parenchymal cells, liver macrophages (LM), and hepatic stellate cells (HSC). The review also concentrates on EV-mediated crosstalk between liver parenchymal and non-parenchymal cells in the settings of HIV- and alcohol co-exposure. In addition, we overviewed the literature on the crosstalk between cell death pathways and inflammasome activation in alcohol-activated HCs and macrophages. Furthermore, we covered highly clinically relevant studies on the role of non-inflammatory factors, sinusoidal pressure (SP), and hepatic arterialization in alcohol-induced hepatic fibrogenesis. We strongly believe that the review will disclose major mechanisms of cell-to-cell communications pertained to alcohol-induced liver injury progression and will identify therapeutically important targets, which can be used for alcohol-associated liver disease (ALD) prevention.

Neuroblastoma (NB) is an enigmatic and deadliest pediatric cancer to treat. The major obstacles to the effective immunotherapy treatments in NB are defective immune cells and the immune evasion tactics deployed by the tumor cells and the stromal microenvironment. Nervous system development during embryonic and pediatric stages is critically mediated by non-coding RNAs such as micro RNAs (miR). Hence, we explored the role of miRs in anti-tumor immune response via a range of data-driven workflows and in vitro & in vivo experiments. Using the TARGET, NB patient dataset (n=249), we applied the robust bioinformatic workflows incorporating differential expression, co-expression, survival, heatmaps, and box plots. We initially demonstrated the role of miR-15a-5p (miR-15a) and miR-15b-5p (miR-15b) as tumor suppressors, followed by their negative association with stromal cell percentages and a statistically significant negative regulation of T and natural killer (NK) cell signature genes, especially CD274 (PD-L1) in stromal-low patient subsets. The NB phase-specific expression of the miR-15a/miR-15b-PD-L1 axis was further corroborated using the PDX (n=24) dataset. We demonstrated miR-15a/miR-15b mediated degradation of PD-L1 mRNA through its interaction with the 3'-untranslated region and the RNA-induced silencing complex using sequence-specific luciferase activity and Ago2 RNA immunoprecipitation assays. In addition, we established miR-15a/miR-15b induced CD8+T and NK cell activation and cytotoxicity against NB in vitro. Moreover, injection of murine cells expressing miR-15a reduced tumor size, tumor vasculature and enhanced the activation and infiltration of CD8+T and NK cells into the tumors in vivo. We further established that blocking the surface PD-L1 using an anti-PD-L1 antibody rescued miR-15a/miR-15b induced CD8+T and NK cell-mediated anti-tumor responses. These findings demonstrate that miR-15a and miR-15b induce an anti-tumor immune response by targeting PD-L1 in NB.

Background Neuroblastoma (NB) is an enigmatic and deadliest pediatric cancer to treat. The major obstacles to effective immuno- therapy treatments in NB are defective immune cells and the immune evasion tactics deployed by the tumor cells and the stromal microenvironment. Nervous system development during embryonic and pediatric stages is critically mediated by non-coding RNAs such as micro RNAs (miR). However, how miRs influence T and NK cell function and anti-tumor immune response in NB remains poorly understood.1-3 Methods We explored the role of miRs in anti-tumor immune response via a range of data-driven workflows and in vitro & in vivo experiments. Using the TARGET, NB patient dataset (n=249), we applied the robust bioinformatic workflows incorporating differential expression, co-expression, survival, heatmaps, and box plots. We performed PD-L1 mRNA 3'-untranslated region sequence-specific luciferase activity and Ago2 RNA immunoprecipitation assays. NB cells expressing miR-15a/miR-15b were cocultured with CD8+T and NK cells and analyzed the activation and cytotoxicity against NB in vitro. Murine stable NB cells expressing miR-15a were subcutaneously injected into C57/BL6 mice and analyzed tumor size, tumor vasculature, and the activation and infiltration of tumoral CD8+T and NK cells. Further, surface PD- L1 was blocked using an anti-PD-L1 antibody and CD8+T, and NK cell-mediated anti-tumor responses were studied. Results We initially demonstrated the role of miR-15a-5p (miR-15a) and miR-15b-5p (miR-15b) as tumor suppressors, followed by their negative association with stromal cell percentages and a statistically significant negative regulation of T and natural killer (NK) cell signature genes, especially CD274 (PD-L1) in stromal-low patient subsets. The NB phase-specific expression of the miR-15a/miR-15b-PD-L1 axis was further corroborated using the PDX (n=24) dataset. We demonstrated miR-15a/ miR-15b mediated degradation of PD-L1 mRNA through its interaction with the 3'-untranslated region and the RNA- induced silencing complex using sequence-specific luciferase activity and Ago2 RNA immunoprecipitation assays. In addition, we established miR-15a/miR-15b induced CD8+T and NK cell activation and cytotoxicity against NB in vitro. Moreover, the injection of murine cells expressing miR-15a reduced tumor size and tumor vasculature and enhanced the activation and infiltration of CD8+T and NK cells into the tumors in vivo. We further established that blocking the surface PD- L1 using an anti-PD-L1 antibody rescued miR-15a/miR-15b induced CD8+T and NK cell-mediated anti-tumor responses. Conclusions These findings demonstrate that miR-15a and miR-15b induce an anti-tumor immune response by targeting PD-L1 in NB. Acknowledgements Financial support: NIH/NCI grant CA197074; the Buffett Cancer Center/Child Health Research Institute/ Pediatric Cancer Research Group & the Department of Biochemistry & Molecular Biology at UNMC. Dataset: Therapeutically Applicable Research to Generate Effective Treatments (TARGET) (https://ocg.cancer.gov/programs/target) initiative, phs000218. PDXs: Childhood Cancer Repository of the COG and Solid Tumor Network of St. Jude Children9s Research Hospital References Challagundla KB, Wise PM, Neviani P, Chava H, Murtadha M, Xu T, Kennedy R, Ivan C, Zhang X, Vannini I, Fanini F, Amadori D, Calin GA, Hadjidaniel M, Shimada H, Jong A, Seeger RC, Asgharzadeh S, Goldkorn A, Fabbri M. Exosome-mediated transfer of microRNAs within the tumor microenvironment and neuroblastoma resistance to chemotherapy. Journal of the National Cancer Institute. 2015;107(7). Pathania AS, Prathipati P, Olwenyi OA, Chava S, Smith OV, Gupta SC, Chaturvedi NK, Byrareddy SN, Coulter DW, Challagundla KB. miR-15a and miR-15b modulate natural killer and CD8(+)T-cell activation and anti-tumor immune response by targeting PD-L1 in neuroblastoma. Mol Ther Oncolytics. 2022;25:308–29. Pathania AS, Prathipati P, Pandey MK, Byrareddy SN, Coulter DW, Gupta SC, Challagundla KB. The emerging role of non-coding RNAs in the epigenetic regulation of pediatric cancers. Seminars in Cancer Biology. 2021. Epub 2021/04/29.

The present review is based on the research presented at the symposium dedicated to the legacy of the two scientists that made important discoveries in the field of alcohol-induced liver damage: Professors C.S. Lieber and S.W. French. The invited speakers described pharmacological, toxicological and patho-physiological effects of alcohol misuse. Moreover, genetic biomarkers determining adverse drug reactions due to interactions between therapeutics used for chronic or infectious diseases and alcohol exposure were discussed. The researchers presented their work in areas of alcohol-induced impairment in lipid protein trafficking and endocytosis, as well as the role of lipids in the development of fatty liver. The researchers showed that alcohol leads to covalent modifications that promote hepatic dysfunction and injury. We concluded that using new advanced techniques and research ideas leads to important discoveries in science.

Binge drinking is the most common form of excessive alcohol use. Repeated episodes of binge drinking cause multiple organ injuries, including liver damage. We previously demonstrated that chronic ethanol administration causes a decline in the intrahepatic ratio of S-adenosylmethionine (SAM) to S-adenosylhomocysteine (SAH). This decline causes impairments in essential methylation reactions that result in alcohol-induced fatty liver (steatosis) and other features of alcohol-associated liver disease (ALD). Co-treatment with betaine during chronic ethanol feeding, normalizes hepatocellular SAM:SAH ratio and alleviates many features of liver damage including steatosis. Here, we sought to examine whether betaine treatment similarly protects against liver injury in an alcohol binge-drinking model. We hypothesized that ethanol binge with prior or simultaneous betaine administration would prevent or attenuate acute alcohol-induced liver damage. Male C57Bl/6 mice were gavaged twice, 12 h apart, with either 6 g ethanol/kg BW or with an equal volume/kg BW of 0.9% NaCl. Two separate groups of mice (n = 5/group) were gavaged with 4 g betaine/kg BW, either 2 h before or simultaneously with the ethanol or saline gavages. All mice were sacrificed 8 h after the last gavage and serum and liver parameters were quantified. Ethanol binges caused a 50% decrease in hepatic SAM:SAH ratio and a >3-fold rise in liver triglycerides (p ≤ 0.05). These latter changes were accompanied by elevated serum AST and ALT activities and blood alcohol concentrations (BAC) that were ∼three-times higher than the legal limit of intoxication in humans. Mice that were treated with betaine 2 h before or simultaneously with the ethanol binges exhibited similar BAC as in mice given ethanol-alone. Both betaine treatments significantly elevated hepatic SAM levels thereby normalizing the SAM:SAH ratio and attenuating hepatic steatosis and other injury parameters, compared with mice given ethanol alone. Simultaneous betaine co-administration with ethanol was more effective in preventing or attenuating liver injury than betaine given before ethanol gavage. Our findings confirm the potential therapeutic value of betaine administration in preventing liver injury after binge drinking in an animal model.

BACKGROUND AND AIMS:Hepatocellular carcinoma (HCC) developing in the context of preexisting cirrhosis is characterized by impaired autophagy that results in increased exosome release. This study was conducted to determine whether circulating exosomes expressing glypican 3 (GPC3) could be utilized as a biomarker for HCC detection and treatment response in patients with cirrhosis.METHODS:Immunohistochemistry was performed to assess p62 and GPC3 expression in the lesion and adjacent tissue from cirrhosis with HCC. GPC3-enriched exosomes were captured by an enzyme-linked immunosorbent assay (ELISA). The diagnostic specificity of serum exosome-derived GPC3 (eGPC3) was determined using samples obtained from malignancy-free controls, malignancy-free cirrhotics, cirrhotics with confirmed HCC, and patients with a non-HCC malignancy. The performance of eGPC3 was validated using serum samples of HCC patients received chemotherapy.RESULTS:We found that the expression of p62 and GPC3 was significantly increased in HCC tissues compared to adjacent cirrhotic liver. Impaired autophagy and exosome shedding were confirmed in HCC cell lines. Mass spectroscopic analysis revealed that GPC3 was enriched in exosomes isolated from HCC cell lines. An affinity ELISA assay was developed that specifically captures GPC3 positive exosomes in the serum. Total exosome concentration and eGPC3 were significantly elevated in cirrhotic patients with HCC as compared to the reference control groups. Furthermore, decreases in post-treatment exosome concentration and eGPC3 levels were more closely correlated with response to locoregional chemotherapy compared to change in serum AFP in HCC patients awaiting liver transplantation.CONCLUSION:We developed an affinity exosome capture assay to detect GPC3 enriched exosomes. Our preliminary assessment shows that GPC3 positive exosomes can be used for HCC detection and prediction of treatment outcomes.

It has been previously shown that chronic ethanol administration-induced increase in adipose tissue lipolysis and reduction in the secretion of protective adipokines collectively contribute to alcohol-associated liver disease (ALD) pathogenesis. Further studies have revealed that increased adipose S-adenosylhomocysteine (SAH) levels generate methylation defects that promote lipolysis. Here, we hypothesized that increased intracellular SAH alone causes additional related pathological changes in adipose tissue as seen with alcohol administration. To test this, we used 3-deazaadenosine (DZA), which selectively elevates intracellular SAH levels by blocking its hydrolysis. Fully differentiated 3T3-L1 adipocytes were treated in vitro for 48 h with DZA and analysed for lipolysis, adipokine release and differentiation status. DZA treatment enhanced adipocyte lipolysis, as judged by lower levels of intracellular triglycerides, reduced lipid droplet sizes and higher levels of glycerol and free fatty acids released into the culture medium. These findings coincided with activation of both adipose triglyceride lipase and hormone sensitive lipase. DZA treatment also significantly reduced adipocyte differentiation factors, impaired adiponectin and leptin secretion but increased release of pro-inflammatory cytokines, IL-6, TNF and MCP-1. Together, our results demonstrate that elevation of intracellular SAH alone by DZA treatment of 3T3-L1 adipocytes induces lipolysis and dysregulates adipokine secretion. Selective elevation of intracellular SAH by DZA treatment mimics ethanol's effects and induces adipose dysfunction. We conclude that alcohol-induced elevations in adipose SAH levels contribute to the pathogenesis and progression of ALD.

The coronavirus disease 2019 (COVID-19) is a viral disease caused by a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that affects the respiratory system of infected individuals. COVID-19 spreads between humans through respiratory droplets produced when an infected person coughs or sneezes. The COVID-19 outbreak originated in Wuhan, China at the end of 2019. As of 29 Sept 2020, over 235 countries, areas or territories across the globe reported a total of 33,441,919 confirmed cases, and 1,003,497 confirmed deaths due to COVID-19. Individuals of all ages are at risk for infection, but in most cases disease severity is associated with age and pre- existing diseases that compromise immunity, like cancer. Numerous reports suggest that people with cancer can be at higher risk of severe illness and related deaths from COVID-19. Therefore, managing cancer care under this pandemic is challenging and requires a collaborative multidisciplinary approach for optimal care of cancer patients in hospital settings. In this comprehensive review, we discuss the impact of the COVID-19 pandemic on cancer patients, their care, and treatment. Further, this review covers the SARS-CoV-2 pandemic, genome characterization, COVID-19 pathophysiology, and associated signaling pathways in cancer, and the choice of anticancer agents as repurposed drugs for treating COVID-19. Original article: Pathania AS, Prathipati P, Abdul BAA, et al. COVID-19 and Cancer Comorbidity: Therapeutic Opportunities and Challenges. Theranostics. 2021;11(2):731-753. DOI: 10.7150/thno.51471. The article was translated into Russian and published under the terms of the Creative Commons Attribution 4.0 license.