TGF-ß1-Induced SOX18 Elevation Promotes Hepatocellular Carcinoma Progression and Metastasis Through Transcriptionally Upregulating PD-L1 and CXCL12.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is characterized by an immune-suppressive microenvironment, which contributes to tumor progression, metastasis, and immunotherapy resistance. Identification of HCC-intrinsic factors regulating the immunosuppressive microenvironment is urgently needed. Here, we aimed to elucidate the role of SYR-Related High-Mobility Group Box 18 (SOX18) in inducing immunosuppression and to validate novel combination strategies for SOX18-mediated HCC progression and metastasis. METHODS: The role of SOX18 in HCC was investigated in orthotopic allografts and diethylinitrosamine/carbon tetrachloride-induced spontaneous models by using murine cell lines, adeno-associated virus 8, and hepatocyte-specific knockin and knockout mice. The immune cellular composition in the HCC microenvironment was evaluated by flow cytometry and immunofluorescence. RESULTS: SOX18 overexpression promoted the infiltration of tumor-associated macrophages (TAMs) and regulatory T cells (Tregs) while diminishing cytotoxic T cells to facilitate HCC progression and metastasis in cell-derived allografts and chemically induced HCC models. Mechanistically, transforming growth factor-beta 1 (TGF-ß1) upregulated SOX18 expression by activating the Smad2/3 complex. SOX18 transactivated chemokine (C-X-C motif) ligand 12 (CXCL12) and programmed death ligand 1 (PD-L1) to induce the immunosuppressive microenvironment. CXCL12 knockdown significantly attenuated SOX18-induced TAMs and Tregs accumulation and HCC dissemination. Antagonism of chemokine receptor 4 (CXCR4), the cognate receptor of CXCL12, or selective knockout of CXCR4 in TAMs or Tregs likewise abolished SOX18-mediated effects. TGFßR1 inhibitor Vactosertib or CXCR4 inhibitor AMD3100 in combination with anti-PD-L1 dramatically inhibited SOX18-mediated HCC progression and metastasis. CONCLUSIONS: SOX18 promoted the accumulation of immunosuppressive TAMs and Tregs in the microenvironment by transactivating CXCL12 and PD-L1. CXCR4 inhibitor or TGFßR1 inhibitor in synergy with anti-PD-L1 represented a promising combination strategy to suppress HCC progression and metastasis.

Linagliptin, a DPP-4 inhibitor, activates AMPK/FOXO3a and suppresses NFκB to mitigate the debilitating effects of diethylnitrosamine exposure in rat liver: Novel mechanistic insights.

Accumulating evidence suggests that dysregulation of FOXO3a plays a significant role in the progression of various malignancies, including hepatocellular carcinoma (HCC). FOXO3a inactivation, driven by oncogenic stimuli, can lead to abnormal cell growth, suppression of apoptosis, and resistance to anticancer drugs. Therefore, FOXO3a emerges as a potential molecular target for the development of innovative treatments in the era of oncology. Linagliptin (LNGTN), a DPP-4 inhibitor known for its safe profile, has exhibited noteworthy anti-inflammatory and anti-oxidative properties in previous in vivo studies. Several potential molecular mechanisms have been proposed to explain these effects. However, the capacity of LNGTN to activate FOXO3a through AMPK activation has not been investigated. In our investigation, we examined the potential repurposing of LNGTN as a hepatoprotective agent against diethylnitrosamine (DENA) intoxication. Additionally, we assessed LNGTN's impact on apoptosis and autophagy. Following a 10-week administration of DENA, the liver underwent damage marked by inflammation and early neoplastic alterations. Our study presents the first experimental evidence demonstrating that LNGTN can reinstate the aberrantly regulated FOXO3a activity by elevating the nuclear fraction of FOXO3a in comparison to the cytosolic fraction, subsequent to AMPK activation. Moreover, noteworthy inactivation of NFκB induced by LNGTN was observed. These effects culminated in the initiation of apoptosis, the activation of autophagy, and the manifestation of anti-inflammatory, antiproliferative, and antiangiogenic outcomes. These effects were concomitant with improved liver function and microstructure. In conclusion, our findings open new avenues for the development of novel therapeutic strategies targeting the AMPK/FOXO3a signaling pathway in the management of chronic liver damage.

Effectiveness of cannabidiol (CBD) on histopathological changes and gene expression in hepatocellular carcinoma (HCC) model in male rats: the role of Hedgehog (Hh) signaling pathway.

The third most prevalent malignancy to cause mortality is hepatocellular carcinoma (HCC). The Hedgehog (Hh) signaling pathway is activated by binding to the transmembrane receptor Patched-1 (PTCH-1), which depresses the transmembrane G protein-coupled receptor Smoothened (SMO). This study was performed to examine the preventative and therapeutic effects of cannabidiol in adult rats exposed to diethyl nitrosamine (DENA)-induced HCC.A total of 50 male rats were divided into five groups of 10 rats each. Group I was the control group. Group II received intraperitoneal (IP) injections of DENA for 14 weeks. Group III included rats that received cannabidiol (CBD) orally (3-30 mg/kg) for 2 weeks and DENA injections for 14 weeks. Group IV rats received oral CBD for 2 weeks before 14 weeks of DENA injections. Group V included rats that received CBD orally for 2 weeks after their last injection of DENA. Measurements were made for alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyl transferase (GGT), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and alpha fetoprotein (AFP). Following total RNA extraction, Smo, Hhip, Ptch-1, and Gli-1 expressions were measured using quantitative real-time polymerase chain reaction (qRT-PCR). A histopathological analysis of liver tissues was performed.The liver enzymes, oxidant-antioxidant state, morphological, and molecular parameters of the adult male rat model of DENA-induced HCC showed a beneficial improvement after CBD administration. In conclusion, by focusing on the Hh signaling system, administration of CBD showed a beneficial improvement in the liver enzymes, oxidant-antioxidant status, morphological, and molecular parameters in the DENA-induced HCC in adult male rats.

Targeting the SphK1/S1P/PFKFB3 axis suppresses hepatocellular carcinoma progression by disrupting glycolytic energy supply that drives tumor angiogenesis.

BACKGROUND: Hepatocellular carcinoma (HCC) remains a leading life-threatening health challenge worldwide, with pressing needs for novel therapeutic strategies. Sphingosine kinase 1 (SphK1), a well-established pro-cancer enzyme, is aberrantly overexpressed in a multitude of malignancies, including HCC. Our previous research has shown that genetic ablation of Sphk1 mitigates HCC progression in mice. Therefore, the development of PF-543, a highly selective SphK1 inhibitor, opens a new avenue for HCC treatment. However, the anti-cancer efficacy of PF-543 has not yet been investigated in primary cancer models in vivo, thereby limiting its further translation. METHODS: Building upon the identification of the active form of SphK1 as a viable therapeutic target in human HCC specimens, we assessed the capacity of PF-543 in suppressing tumor progression using a diethylnitrosamine-induced mouse model of primary HCC. We further delineated its underlying mechanisms in both HCC and endothelial cells. Key findings were validated in Sphk1 knockout mice and lentiviral-mediated SphK1 knockdown cells. RESULTS: SphK1 activity was found to be elevated in human HCC tissues. Administration of PF-543 effectively abrogated hepatic SphK1 activity and significantly suppressed HCC progression in diethylnitrosamine-treated mice. The primary mechanism of action was through the inhibition of tumor neovascularization, as PF-543 disrupted endothelial cell angiogenesis even in a pro-angiogenic milieu. Mechanistically, PF-543 induced proteasomal degradation of the critical glycolytic enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3, thus restricting the energy supply essential for tumor angiogenesis. These effects of PF-543 could be reversed upon S1P supplementation in an S1P receptor-dependent manner. CONCLUSIONS: This study provides the first in vivo evidence supporting the potential of PF-543 as an effective anti-HCC agent. It also uncovers previously undescribed links between the pro-cancer, pro-angiogenic and pro-glycolytic roles of the SphK1/S1P/S1P receptor axis. Importantly, unlike conventional anti-HCC drugs that target individual pro-angiogenic drivers, PF-543 impairs the PFKFB3-dictated glycolytic energy engine that fuels tumor angiogenesis, representing a novel and potentially safer therapeutic strategy for HCC.

Ames test study designs for nitrosamine mutagenicity testing: qualitative and quantitative analysis of key assay parameters.

The robust control of genotoxic N-nitrosamine (NA) impurities is an important safety consideration for the pharmaceutical industry, especially considering recent drug product withdrawals. NAs belong to the 'cohort of concern' list of genotoxic impurities (ICH M7) because of the mutagenic and carcinogenic potency of this chemical class. In addition, regulatory concerns exist regarding the capacity of the Ames test to predict the carcinogenic potential of NAs because of historically discordant results. The reasons postulated to explain these discordant data generally point to aspects of Ames test study design. These include vehicle solvent choice, liver S9 species, bacterial strain, compound concentration, and use of pre-incubation versus plate incorporation methods. Many of these concerns have their roots in historical data generated prior to the harmonization of Ames test guidelines. Therefore, we investigated various Ames test assay parameters and used qualitative analysis and quantitative benchmark dose modelling to identify which combinations provided the most sensitive conditions in terms of mutagenic potency. Two alkyl-nitrosamines, N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) were studied. NDMA and NDEA mutagenicity was readily detected in the Ames test and key assay parameters were identified that contributed to assay sensitivity rankings. The pre-incubation method (30-min incubation), appropriate vehicle (water or methanol), and hamster-induced liver S9, alongside Salmonella typhimurium strains TA100 and TA1535 and Escherichia coli strain WP2uvrA(pKM101) provide the most sensitive combination of assay parameters in terms of NDMA and NDEA mutagenic potency in the Ames test. Using these parameters and further quantitative benchmark dose modelling, we show that N-nitrosomethylethylamine (NMEA) is positive in Ames test and therefore should no longer be considered a historically discordant NA. The results presented herein define a sensitive Ames test design that can be deployed for the assessment of NAs to support robust impurity qualifications.

Novel method for monitoring of carcinogenic impurity of N-nitrosamine in nizatidine pharmaceutical products using ultra high-pressure liquid chromatography triple quadrupole mass spectrometry.

Nitrosamine compounds pose a significant concern as potential carcinogens, prompting heightened scrutiny from regulatory bodies, particularly regarding their presence in pharmaceuticals. The detection of unacceptable levels of N-nitrosodiethylamine (NDMA) in ranitidine has led to widespread recalls, driving interest in alternative medications such as nizatidine, which shares a similar pharmacological class and is used to treat various gastrointestinal conditions. Despite fewer reports on NDMA levels in nizatidine, its structural similarity to ranitidine, characterized by a tertiary amine, underscores the potential for NDMA formation. Addressing the analytical challenges associated with nitrosamine detection, this study focuses on developing and validating an ultra-high pressure liquid chromatography triple quadrupole mass spectrometry (UHPLC-MS/MS) method for quantifying NDMA in both nizatidine active pharmaceutical ingredients and tablet formulations. Method validation adheres to International Council for Harmonisation recommendations, with a demonstrated linear range of 0.25-100 ng/mL for NDMA, exhibiting excellent linearity (regression coefficient >0.999) and efficient recovery rates ranging from 95.98% to 109.57%. The method shows high sensitivity, with limits of detection and quantification of 0.25 and 0.5 ng/mL, respectively. The developed UHPLC-MS/MS method offers a simple, precise, accurate, and selective approach for monitoring NDMA levels in nizatidine formulations available in Australia, promising enhanced sensitivity and specificity with limits of quantification in the ppb and sub-ppb ranges.

A systematic review on multipotent carcinogenic agent, N-nitrosodiethylamine (NDEA), its major risk assessment, and precautions.

The International Agency for Research on Cancer has classified N-nitrosodiethylamine (NDEA) as a possible carcinogen and mutagenic substances, placing it in category 2A of compounds that are probably harmful to humans. It is found in nature and tobacco smoke, along with its precursors, and is also synthesized endogenously in the human body. The oral or parenteral administration of a minimal quantity of NDEA results in severe liver and kidney organ damage. The NDEA required bioactivation by CYP450 enzyme to form DNA adduct in the alkylation mechanism. Thus, this bioactivation directs oxidative stress and injury to cells due to the higher formation of reactive oxygen species and alters antioxidant system in tissues, whereas free radical scavengers guard the membranes from NDEA-directed injury in many enzymes. This might be one of the reasons in the etiology of cancer that is not limited to a certain target organ but can affect various organs and organ systems. Although there are various possible approaches for the treatment of NDEA-induced cancer, their therapeutic outcomes are still very dismal. However, several precautions were considered to be taken during handling or working with NDEA, as it considered being the best way to lower down the occurrence of NDEA-directed cancers. The present review was designed to enlighten the general guidelines for working with NDEA, possible mechanism, to alter the antioxidant line to cause malignancy in different parts of animal body along with its protective agents. Thus, revelation to constant, unpredictable stress situations even in common life may remarkably augment the toxic potential through the rise in the oxidative stress and damage of DNA.

Modulatory mechanisms of copperII-albumin complex toward N-nitrosodiethylamine-induced neurotoxicity in mice via regulating oxidative damage, inflammatory, and apoptotic signaling pathways.

N-nitrosodiethylamine (ND) is an extremely toxic unavoidable environmental contaminant. CopperII-albumin (CuAB) complex, a newly developed Cu complex, showed antioxidant and anti-inflammatory potential. Hereby, we explored the plausible neuroprotective role of CuAB complex toward ND-evoked neurotoxicity in mice. Twenty-four male mice were sorted into 4 groups (6 mice each). Control group, mice were administered oral distilled water; and CuAB group, mice received CuAB complex at a dose of 817 µg/kg orally, three times weekly. In ND group, ND was given intraperitoneally (50 mg/kg body weight, once weekly for 6 w). CuAB+ND group, mice were administered a combination of CuAB and ND. The brain was quickly extracted upon completion of the experimental protocol for the evaluation of the oxidative/antioxidative markers, inflammatory cytokines, and histopathological examination. Oxidative stress was induced after ND exposure indicated by a reduction in GSH and SOD1 level, with increased MDA level. In addition, decreased expression of SOD1 proteins, Nrf2, and 5-HT mRNA expression levels were noticed. An apoptotic cascade has also been elicited, evidenced by overexpression of Cyt c, Cl. Casp 3. In addition, increased regulation of proinflammatory genes (TNF-α, IL-6, iNOS, Casp1, and NF-κB (p65/p50); besides, increment of protein expression of P-IKBα and reduced expression of IKBα. Pretreatment with CuAB complex significantly ameliorated ND neuronal damage. Our results recommend CuAB complex supplementation because it exerts neuroprotective effects against ND-induced toxicity.

Phyto-Fabrication of Moringa Oleifera Peel-Sourced Silver Nanoparticles: A Promising Approach for Combating Hepatic Cancer by Targeting Proinflammatory Cytokines and Mitigating Cytokine Storms.

Hepatocellular carcinoma (HCC) arises from precancerous nodules, leading to liver damage and inflammation, which triggers the release of proinflammatory cytokines. Dysregulation of these cytokines can escalate into a cytokine storm, causing severe organ damage. Interestingly, Moringa oleifera (M. oleifera) fruit peel, previously discarded as waste, contains an abundance of essential biomolecules and high nutritional value. This study focuses on the eco-friendly synthesis of silver nanoparticles infused with M. oleifera peel extract biomolecules and their impact on regulating proinflammatory cytokines, as well as their potential anticancer effects against Wistar rats. The freshly synthesized nanoformulation underwent comprehensive characterization, followed by antihepatic cancer evaluation using a diethyl nitrosamine-induced model (at a dose of 200 mg kg-1 BW). The study demonstrates a significant reduction in proinflammatory cytokines such as tumor necrosis factor-α, interleukin-6, interleukin-1ß, and nuclear factor kappa beta (NF-κB). Furthermore, it confirms that the newly biosynthesized silver nanoparticles exhibit additional potential against hepatic cancer due to their capped biomolecules.

Targeting the PI3K/pAKT/mTOR/NF-κB/FOXO3a signaling pathway for suppressing the development of hepatocellular carcinoma in rats: Role of the natural remedic Suaeda vermiculata forssk.

Liver malignancy is well recognized as a prominent health concern, with numerous treatment options available. Natural products are considered a renewable source, providing inspiring chemical moieties that could be used for cancer treatment. Suaeda vermiculata Forssk has traditionally been employed for management of hepatic conditions, including liver inflammation, and liver cirrhosis, as well as to improve general liver function. The findings of our earlier study demonstrated encouraging in vivo hepatoprotective benefits against liver injury generated by paracetamol and carbon tetrachloride. Additionally, Suaeda vermiculata Forssk exhibited cytotoxic activities in vitro against Hep-G2 cell lines and cell lines resistant to doxorubicin. The present investigation aimed to examine the potential in vivo hepatoprotective efficacy of Suaeda vermiculata Forssk extract (SVE) against hepatocellular carcinoma induced by diethylnitrosamine (DENA) in rats. The potential involvement of the PI3K/AKT/mTOR/NF-κB pathway was addressed. Sixty adult male albino rats were allocated into five groups randomly (n = 10). First group received a buffer, whereas second group received SVE only, third group received DENA only, and fourth and fifth groups received high and low doses of SVE, respectively, in the presence of DENA. Liver toxicity and tumor markers (HGFR, p-AKT, PI3K, mTOR, NF-κB, FOXO3a), apoptosis markers, and histopathological changes were analyzed. The current results demonstrated that SVE inhibited PI3K/AKT/mTOR/NF-κB pathway as well as increased expression of apoptotic parameters and FOXO3a levels, which were deteriorated by DENA treatment. Furthermore, SVE improved liver toxicity markers and histopathological changes induced by DENA administration. This study provided evidence for the conventional hepatoprotective properties attributed to SV and investigated the underlying mechanism by which its extract, SVE, could potentially serve as a novel option for hepatocellular carcinoma (HCC) treatment derived from a natural source.

Advanced Techniques for Liver Fibrosis Detection: Spectral Photoacoustic Imaging and Superpixel Photoacoustic Unmixing Analysis for Collagen Tracking.

Liver fibrosis, a major global health issue, is marked by excessive collagen deposition that impairs liver function. Noninvasive methods for the direct visualization of collagen content are crucial for the early detection and monitoring of fibrosis progression. This study investigates the potential of spectral photoacoustic imaging (sPAI) to monitor collagen development in liver fibrosis. Utilizing a novel data-driven superpixel photoacoustic unmixing (SPAX) framework, we aimed to distinguish collagen presence and evaluate its correlation with fibrosis progression. We employed an established diethylnitrosamine (DEN) model in rats to study liver fibrosis over various time points. Our results revealed a significant correlation between increased collagen photoacoustic signal intensity and advanced fibrosis stages. Collagen abundance maps displayed dynamic changes throughout fibrosis progression. These findings underscore the potential of sPAI for the noninvasive monitoring of collagen dynamics and fibrosis severity assessment. This research advances the development of noninvasive diagnostic tools and personalized management strategies for liver fibrosis.

Pantoprazole suppresses carcinogenesis and growth of hepatocellular carcinoma by inhibiting glycolysis and Na+/H+ exchange.

Hepatocellular carcinoma (HCC) is one of the deadliest cancers. The prevention and therapy for this deadly disease remain a global medical challenge. In this study, we investigated the effect of pantoprazole (PPZ) on the carcinogenesis and growth of HCC. Both diethylnitrosamine (DEN) plus CCl4-induced and DEN plus high fat diet (HFD)-induced HCC models in mice were established. Cytokines and cell proliferation-associated gene in the liver tissues of mice and HCC cells were analyzed. Cellular glycolysis and Na+/H+ exchange activity were measured. The preventive administration of pantoprazole (PPZ) at a clinically relevant low dose markedly suppressed HCC carcinogenesis in both DEN plus CCl4-induced and HFD-induced murine HCC models, whereas the therapeutic administration of PPZ at the dose suppressed the growth of HCC. In the liver tissues of PPZ-treated mice, inflammatory cytokines, IL1, CXCL1, CXCL5, CXCL9, CXCL10, CCL2, CCL5, CCL6, CCL7, CCL20, and CCL22, were reduced. The administration of CXCL1, CXCL5, CCL2, or CCL20 all reversed PPZ-suppressed DEN plus CCL4-induced HCC carcinogenesis in mice. PPZ inhibited the expressions of CCNA2, CCNB2, CCNE2, CDC25C, CDCA5, CDK1, CDK2, TOP2A, TTK, AURKA, and BIRC5 in HCC cells. Further results showed that PPZ reduced the production of these inflammatory cytokines and the expression of these cell proliferation-associated genes through the inhibition of glycolysis and Na+/H+ exchange. In conclusion, PPZ suppresses the carcinogenesis and growth of HCC, which is related to inhibiting the production of inflammatory cytokines and the expression of cell proliferation-associated genes in the liver through the inhibition of glycolysis and Na+/H+ exchange.

Investigation of the effects of Theranekron and Sorafenib treatments on carcinogenesis, apoptosis and biochemical profile in hepatocellular carcinoma in rats.

This study aimed to investigate the effects of Tarantula cubensis alcohol extract (TCAE, Theranekron) and Sorafenib (S) treatments on carcinogenesis, apoptosis and biochemical profile of rats with experimentally induced hepatocellular carcinoma (HCC). In the presented study, 58 male rats were divided into 7 groups; Negative Control (NC, n = 6), NC + TCAE (NCT, n = 6), NC + Sorafenib (NCS, n = 6), Positive Control (PC, n = 10), Positive Control + TCAE (PCT, n = 10), Positive Control + Sorafenib (PCS, n = 10), Positive Control + TCAE + Sorafenib (PCTS, n = 10). The active ingredients Diethylnitrosamine (DEN, 120 mg/kg, single dose) and Nitrosomorpholine (NMOR, 50 ppm, 21 weeks orally) were used to induce HCC in rats. At the end of the experiment, the animals were euthanized under appropriate conditions and samples were collected for biochemical and pathological investigations. In the PC group, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT) levels were higher (p < 0.001) and urea levels were lower (p < 0.001) compared to all other groups. Treatment groups reorganized the relevant markers (ALT, AST, GGT, and urea). A significant increase was detected in Caspase-10, Caspase-3 and Granzyme-B (GrzB) (p < 0.001) in blood and Caspase-10 and GrzB (p < 0.05) in liver tissue in PCT, PCS and PCTS groups compared to the PC group. Histopathological examination revealed that the PC group showed cancer morphology, and the treatment groups caused a decrease in tumor incidence and size. Our current findings suggest that the mechanism of action of TCAE in HCC is through the NKs/CTLs-GrzB-Casp10-Casp3 signaling pathway and can be used in combination with chemotherapy drugs for the development of future drug designs.

OMA1 and YME1L as a Diagnostic Panel in Hepatocellular Carcinoma.

Identifying new hepatocellular carcinoma (HCC)-driven signaling molecules and discovering their molecular mechanisms are crucial for efficient and better outcomes. Recently, OMA1 and YME1L, the inner mitochondrial proteases, were displayed to be associated with tumor progression in various cancers; however, their role in HCC has not yet been studied. Therefore, we evaluated the possible role of OMA1/YME1L in HCC staging and discussed their potential role in cellular apoptosis and proliferation. Our study was performed using four groups of male albino rats: a normal control and three diethyl nitrosamine-treated groups for 8, 16, and 24 weeks. The OMA1 and YME1L, matrix-metalloproteinase-9 (MMP-9), and cyclin D1 content were measured in liver tissues, while alpha-fetoprotein (AFP) level was assessed in serum. Additionally, Ki-67 expression was evaluated by immunohistochemistry. The relative hepatic expression of Bax, and tissue inhibitor matrix metalloproteinase (TIMP-3) was measured. Herein, we confirmed for the first time that OMA1 is down-regulated while YME1L is up-regulated in HCC in the three studied stages with subsequent inhibition of apoptosis and cell cycle progression. Furthermore, these proteases have a possible role in metastasis. These newly recognized results suggested OMA1 and YME1L as possible diagnostic tools and therapeutic targets for HCC management.

Compromised very-low density lipoprotein induced polyunsaturated triglyceride accumulation in N-nitrosodiethylamine-induced hepatic steatosis.

N-Nitrosodiethylamine (NDEA), a carcinogen in some foods and medications, is linked to liver damage similar to non-alcoholic fatty liver disease (NAFLD). This study explores how NDEA disrupts liver lipid metabolism. Sprague-Dawley rats were given two doses of NDEA (100 mg/kg) orally, 24 h apart. Liver response was assessed through tissue staining, blood tests, and biochemical markers, including fatty acids, lipid peroxidation, and serum very-low density lipoprotein (VLDL) levels. Additionally, lipidomic analysis of liver tissues and serum was performed. The results indicated significant hepatic steatosis (fat accumulation in the liver) following NDEA exposure. Blood analysis showed signs of inflammation and liver damage. Biochemical tests revealed decreased liver protein synthesis and specific enzyme alterations, suggesting liver cell injury but maintaining mitochondrial function. Increased fatty acid levels without a rise in lipid peroxidation were observed, indicating fat accumulation. Lipidomic analysis showed increased polyunsaturated triglycerides in the liver and decreased serum VLDL, implicating impaired VLDL transport in liver dysfunction. In conclusion, NDEA exposure disrupts liver lipid metabolism, primarily through the accumulation of polyunsaturated triglycerides and impaired fat transport. These findings provide insight into the mechanisms of NDEA-induced liver injury and its progression to hepatic steatosis.

Structural abnormality of hepatic glycogen in rat liver with diethylnitrosamine-induced carcinogenic injury.

Growing evidence confirms associations between glycogen metabolic re-wiring and the development of liver cancer. Previous studies showed that glycogen structure changes abnormally in liver diseases such as cystic fibrosis, diabetes, etc. However, few studies focus on glycogen molecular structural characteristics during liver cancer development, which is worthy of further exploration. In this study, a rat model with carcinogenic liver injury induced by diethylnitrosamine (DEN) was successfully constructed, and hepatic glycogen structure was characterized. Compared with glycogen structure in the healthy rat liver, glycogen chain length distribution (CLD) shifts towards a short region. In contrast, glycogen particles were mainly present in small-sized ß particles in DEN-damaged carcinogenic rat liver. Comparative transcriptomic analysis revealed significant expression changes of genes and pathways involved in carcinogenic liver injury. A combination of transcriptomic analysis, RT-qPCR, and western blot showed that the two genes, Gsy1 encoding glycogen synthase and Gbe1 encoding glycogen branching enzyme, were significantly altered and might be responsible for the structural abnormality of hepatic glycogen in carcinogenic liver injury. Taken together, this study confirmed that carcinogenic liver injury led to structural abnormality of hepatic glycogen, which provided clues to the future development of novel drug targets for potential therapeutics of carcinogenic liver injury.

Genotoxicity assessments of N-nitrosoethylisopropylamine (NEIPA) and N-nitrosodiisopropylamine (NDIPA) in the C57BL/6J mouse.

N-Nitrosamines, known as drug impurities and suspected carcinogens, have drawn significant public concern. In response to drug regulatory needs, the European Medicines Agency (EMA) has previously proposed a carcinogenic potency categorization approach based on the N-nitrosamine α-hydroxylation hypothesis, i.e., that N-nitrosamine mutagenicity increases with the number of α-hydrogen atoms. However, this structure-activity relationship has not been fully tested in vivo. NEIPA (N-nitrosoethylisopropylamine) and NDIPA (N-nitrosodiisopropylamine) are small N-Nitrosamines with similar structures, differing in that the former compound has an additional α-hydrogen atom. In this study, NEIPA and NEIPA doses, 25-100 mg/kg, were administered orally to C57BL/6 J mice for seven consecutive days, and their mutation and DNA damage effects were compared. Compared with NDIPA, the mutagenicity and DNA damage potencies of NEIPA (which contains one more α-hydrogen) were much greater. These differences may be related to their distinct metabolic pathways and target organs. This case study confirms the role of α-hydroxyl modification in the mutagenicity of nitrosamines, with oxidation at the α-hydrogen being a crucial step in the formation of mutagens from N-Nitrosamines, and can inform mutagenicity risk assessment and the formulation of regulatory standards for N-nitrosamine impurities.

Anticancer effect of propranolol on diethylnitrosamine-induced hepatocellular carcinoma rat model.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most widespread type of primary liver cancer. Diethylnitrosamine (DEN), a hepatotoxic hepatocarcinogenic compound, is used to induce HCC in animal models. The non-selective ß-blocker propranolol demonstrated antiproliferative activity in many cancer types. OBJECTIVE: This investigation aimed to evaluate the anticancer effect of propranolol against DEN-induced HCC in rats. METHODS: Thirty adult male rats were divided into the following groups: Group I (C, control), Group II (HCC); received DEN, 70 mg/kg body weight (b.wt.) once a week for 10 weeks, to induce HCC, and Group III (HCC/Prop); received DEN for 10 weeks for HCC induction, then received 20 mg/kg b.wt. propranolol, intraperitoneally for four successive weeks. RESULTS: HCC was developed in rats' livers and confirmed via significant liver architecture changes, significantly elevated activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), α-fetoprotein (AFP), total- and direct-bilirubin (Bil), and a decline in albumin (ALB) level in serum. HCC group demonstrated elevated levels of malondialdehyde (MDA), nitric oxide (NO), HIF-1α, IL-8, NF-κB, PGE2, TGF-ß1, VEGF, and CD8, but significant decline of GSH, and IL-10 level, with suppression of the antioxidant enzymes' activities. In addition, the gene expression of the hepatic inducible nitric oxide synthase (iNOS), and LAG-3 were up-regulated. Moreover, the protein expression of p-PKC was up-regulated, while that of PD-1 and PD-L1 were down-regulated in the liver tissues of the HCC group. However, propranolol ameliorated the investigated parameters in the HCC/Prop group. CONCLUSION: Propranolol exhibited an anticancer effect and thus can be considered as a promising treatment for HCC. Blocking of PD-1/PD-L1 and LAG-3 signals participated in the anti-tumor effect of propranolol on HCC.

Loss of hepatic Sirt7 accelerates diethylnitrosamine (DEN)-induced formation of hepatocellular carcinoma by impairing DNA damage repair.

The mammalian sirtuin family (SIRT1-SIRT7) has shown diverse biological roles in the regulation and maintenance of genome stability under genotoxic stress. SIRT7, one of the least studied sirtuin, has been demonstrated to be a key factor for DNA damage response (DDR). However, conflicting results have proposed that Sirt7 is an oncogenic factor to promote transformation in cancer cells. To address this inconsistency, we investigated properties of SIRT7 in hepatocellular carcinoma (HCC) regulation under DNA damage and found that loss of hepatic Sirt7 accelerated HCC progression. Specifically, the number, size, and volume of hepatic tumor colonies in diethylnitrosamine (DEN) injected Sirt7-deficient liver were markedly enhanced. Further, levels of HCC progression markers and pro-inflammatory cytokines were significantly elevated in the absence of hepatic Sirt7, unlike those in the control. In chromatin, SIRT7 was stabilized and colocalized to damage site by inhibiting the induction of γH2AX under DNA damage. Together, our findings suggest that SIRT7 is a crucial factor for DNA damage repair and that hepatic loss-of-Sirt7 can promote genomic instability and accelerate HCC development, unlike early studies describing that Sirt7 is an oncogenic factor [BMB Reports 2024; 57(2): 98-103].

Obesity phenotype induced by high-fat diet promotes diethylnitrosamine (DEN)-induced precancerous lesions by M1 macrophage polarization in mice liver.

Liver precancerous lesions are the key to improving the efficacy of cancer treatment because of the extremely poor prognosis of HCC patients in moderate and late stages. Obesity-related HCC progression is closely related to the inflammatory microenvironment, in which macrophages are one of the major constituents. In the present study, we ask whether obesity promotes diethylnitrosamine (DEN)-induced precancerous lesions by M1 macrophage polarization. First, an association between obesity and liver precancerous lesions was determined by histopathological observations, immunochemistry and immunoblotting. The characteristics of early precancerous lesions (trabecular thickening) appeared earlier eight weeks in obese mice than in normal diet mice after DEN induction. The glutathione S-transferase placental-1 (Gstp 1) and alpha-fetoprotein (AFP) expression in obese mice after DEN induction was higher than that in the same period after DEN injection in normal diet mice. Furthermore, there was a significant increase in the total macrophage number (F4/80+) of DEN and M1 macrophage number (CD86+F4/80+) in obese mice compared with that in normal diet mice. Besides, the expressions of four pro-inflammatory factors in DEN-induced obese mice were significantly higher compared with that in normal diet mice. Additionally, angiogenesis was revealed by immunostaining assay to be associated with the inflammatory response. All the results demonstrate that obesity promotes DEN-induced precancerous lesions by inducing M1 macrophage polarization and angiogenesis.