Hepatoma Cell Line HepG2 Research Articles

P14.5 functions to inhibit cell migration and can be used as a prognostic marker in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy with a high mortality rate. P14.5 is a member of the highly conserved YER057c/YIL051c/YjgF subfamily and is highly expressed in the liver. However, its low expression is associated with carcinogenesis in HCC. This study aimed to investigate the role and prognostic significance of P14.5 in HCC. The clinical significance of P14.5 in HCC was examined using ONCOMINE, UALCAN, Human Protein Atlas, and Kaplan-Meier plotter. The DNA methylation profile of the P14.5 promoter was examined in 103 HCC and paired precancerous tissues; the HCC cell lines HepG2, MHCC-97L, SMMC-7721, SK-Hep-1, and Huh7; and the normal hepatic cell line HL-7702 via MALDI-TOF mass spectrometry. In addition, in vitro experiments were performed to examine the effects of P14.5 overexpression on the proliferation and migration of SMMC-7721 cells. Low expression of P14.5 was correlated with shorter overall survival (OS) and disease-free survival (DFS) in HCC. Based on the results of MALDI-TOF mass spectrometry, no difference was observed in the methylation level between HCC cells and normal human hepatic cells and between HCC and paired precancerous tissues. Additionally, P14.5overexpression promoted the proliferation and inhibited the migration of SMMC7721 cells in vitro. P14.5 may serve as a prognostic biomarker in HCC and plays a role in the migration and proliferation of HCC cells. Low expression of P14.5 during hepatocarcinogenesis is not attributed to DNA methylation.

Recombinant Humanized IgG1 Antibody Promotes Reverse Cholesterol Transport through FcRn-ERK1/2-PPARα Pathway in Hepatocytes

Hyperlipidemia-associated lipid disorders are considered the cause of atherosclerotic cardiovascular disease. Reverse cholesterol transport (RCT) is a mechanism by which excess peripheral cholesterol is transported to the liver and further converted into bile acid for excretion from the body in feces, which contributes to reducing hyperlipidemia as well as cardiovascular disease. We previously found that the recombinant humanized IgG1 antibody promotes macrophages to engulf lipids and increases cholesterol efflux to high-density lipoprotein (HDL) through ATP-binding cassette sub-family A1 (ABCA1), one of the key proteins related to RCT. In the present study, we explored other RCT related proteins expression on hepatocytes, including scavenger receptor class B type I (SR-BI), apolipoprotein A-I (ApoA-I), and apolipoprotein A-II (ApoA-II), and its modulation mechanism involved. We confirmed that the recombinant humanized IgG1 antibody selectively activated ERK1/2 to upregulate SR-BI, ApoA-I, and ApoA-II expression in mice liver and human hepatocellular carcinoma cell lines HepG2 cells. The rate-limiting enzymes of bile acid synthesis, including cholesterol 7α-hydroxylase (CYP7A1) and sterol 27-hydroxylase (CYP27A1), exhibited a significant increase when treated with the recombinant humanized IgG1 antibody, as well as increased excretion of bile acids in feces. Besides, abolishment or mutation of peroxisome proliferator-activated receptor α (PPARα)/RXR binding site on SR-BI promoter eliminated SR-BI reporter gene luciferase activity even in the presence of the recombinant humanized IgG1 antibody. Knock down the neonatal Fc receptor (FcRn) on hepatocytes impaired the effect of recombinant humanized IgG1 antibody on activation of ERK1/2, as well as upregulation of SR-BI, ApoA-I, and ApoA-II expression. In conclusion, one of the mechanisms on the recombinant humanized IgG1 antibody attenuates hyperlipidemia in ApoE-/- mice model fed with high-fat-diet might be through reinforcement of liver RCT function in an FcRn-ERK1/2-PPARα dependent manner.

MiR-9 and miR-181a Target Gab2 to Inhibit the Proliferation and Migration of Hepatocellular Carcinoma HepG2 Cells.

The incidence of liver cancer ranks seventh globally, with nearly half of all cases occurring in East Asia, but currently, there are very few drugs to treat it. Our previous studies demonstrated that the signal integration protein Gab2 is a potential drug target for the prevention and therapy of liver cancer. Here, we screened for and identified two miRNAs that target Gab2 to suppress the proliferation and migration of hepatocellular carcinoma (HCC) cells. First, we predicted Gab2-targeting miRNAs through biological websites, and we selected nine miRNAs that were reported in the literature as being abnormally expressed in liver cancer and fatty liver tissue. Then, we measured the expression of these miRNAs in the hepatic epithelial cell line HL-7702 and the HCC cell line HepG2. The expression levels of miR-9, miR-181a, miR-181c, miR-34a, and miR-134 were high in HL-7702 cells but low in HepG2 cells, and their expression patterns were the opposite of Gab2 in these cells. Furthermore, we transfected miR-9, miR-34a, miR-181a, and miR-181c mimics into HepG2 cells and found that only miR-9 and miR-181a reduced the level of Gab2 proteins. miR-9 also reduced the Gab2 mRNA level, but miR-181a did not affect the Gab2 mRNA levels. Using a miRNA-Gab2 3'UTR binding reporter, we confirmed that miR-9 and miR-181a bind to the Gab2 3'UTR region. Finally, we introduced miR-9 and miR-181a mimics into HepG2 cells and found that cell proliferation and migration were significantly inhibited. In conclusion, we identified two novel miRNAs targeting Gab2 and provided potential drug targets for the prevention and treatment of liver cancer.

Phytochemical investigation, molecular docking studies and DFT calculations on the antidiabetic and cytotoxic activities of Gmelina philippensis CHAM

Ethnopharmacological relevanceGmelina philippensis CHAM is an ornamental plant that is distributed in South Asia and warm regions of the Mediterranean area. The plant is traditionally applied in folk medicine for the treatment of diabetes. Aim of the studyTo evaluate the cytotoxic and the antidiabetic activities of the ethanolic extract of G. philippensis aerial parts. To isolate the metabolite(s) responsible for these activities and to elucidate the mechanism of action by molecular docking study. Materials and methodsCompounds (1–11) were isolated using various chromatographic techniques and their structures were determined by NMR spectroscopic and mass spectrometric analysis. The cytotoxic effect was tested using viability test and MTT assay. Antidiabetic activity was evaluated by measuring the inhibitory activity of the ethanolic extracts and compounds against α-glucosidase and α-amylase activities. Modeling and docking simulations were performed using Molecular Operating Environment software and the crystal structure of protein kinases CDK2, (1PYE) and AKT1 (4GV1), in addition to α-glucosidase (3TOP) and α-amylase (2QV4). ResultsCompounds 2, 3 and 8 were isolated for the first time from the plant and identified as: gmelinol (2), apigenin (3) and tyrosol (8). While β-sitosterol-3-O- β-D-glucopyranoside (4) vicenin-II (7), rhoifolin (9), isorhoifolin (11) were isolated for the first time from the genus, along with and the new iridoid 6-O-α-L-(2″-O-benzoyl-4″-O-trans-p-methoxycinnamoyl)rhamnopyranosyl-1α- β-D-glucopyranoside catalpolgenin (6). In addition, to the previously reported compounds: mixture of β -sitosterol and stigmasterol (1), and 6- O- α-L-(2″,3″,4″-tri-O -benzoyl)rhamnopyranosylcatalpol (5) and 6-O-α-L-(2″-O-trans-p-methoxycinnamoyl)rhamnopyranosylcatalpol (10). The cytotoxic activity against hepatocellular carcinoma (HepG-2) cell lines for compounds 2, 5, 7, 9 and 11 was conducted using cisplatin as a standard. Gmelinol (2) exhibited strong cytotoxic activity against HepG-2 cell lines with IC 50 value of 3.6 ± 0.1 μg/ml which is more potent than the standard cisplatin IC 50 = 8.7 ± 0.9 μg/ml. Molecular modeling of 2 against diverse targets of protein kinases suggested that CDK-2 and AKT-1 could be the dual probable kinase targets for its cytotoxic action. Compound 2 showed α-amylase inhibition activity with IC 50 value of 60.9 (μg/ml) while, compounds 5 showed strong α-glucosidase inhibition activity with IC 50 values of 41.7 (μg/ml) compared to acarbose with IC 50 value of 34.7, 30.6 (μg/ml). Molecular docking of compounds 2 and 5 on α-glucosidase (3TOP) and α-amylase (2QV4) enzymes revealed high binding affinity and active site interactions comparable to native ligand acarbose. ConclusionThe ethanolic extract of G. philippensis CHAM aerial parts is effective against HepG-2 cell lines, α-amylase and α-glucocidase activities. Biologically guided isolation indicated that compounds 2 and 5 are responsible for these activities. These results were supported by DMF calculations that detected the molecular areas responsible for protein interactions shown via docking studies.

Exogenous miRNAs from Moringa oleifera Lam. recover a dysregulated lipid metabolism.

A balanced diet is critical for human health, and edible plants play an important role in providing essential micronutrients as well as specific microRNAs (miRNAs) that can regulate human gene expression. Here we present the effects of Moringa oleifera (MO) miRNAs (mol-miRs) on lipid metabolism. Through in silico studies we identified the potential genes involved in lipid metabolism targeted by mol-miRs. To this end, we tested the efficacy of an aqueous extract of MO seeds (MOES), as suggested in traditional African ethnomedicine, or its purified miRNAs. The biological properties of MO preparations were investigated using a human derived hepatoma cell line (HepG2) as a model. MOES treatment decreased intracellular lipid accumulation and induced apoptosis in HepG2. In the same cell line, transfection with mol-miRs showed similar effects to MOES. Moreover, the effect of the mol-miR pool was investigated in a pre-obese mouse model, in which treatment with mol-miRs was able to prevent dysregulation of lipid metabolism.

Hepatocellular carcinoma cells loss lenvatinib efficacy in vitro through autophagy and hypoxia response-derived neuropilin-1 degradation

Despite pharmacological advances such as lenvatinib approval, therapeutic failure of hepatocellular carcinoma (HCC) remains a big challenge due to the complexity of its underlying molecular mechanisms. Neuropilin-1 (NRP1) is a co-receptor involved in several cellular processes associated to chemoresistance development. Since both the double-edged process of autophagy and hypoxia-derived response play crucial roles in the loss of therapeutic effectiveness, herein we investigated the interplay among NRP1, autophagy and hypoxia in development of lenvatinib resistance in HCC cell lines. We first analyzed NRP1 expression levels in human HCC samples from public databases, found significantly increased NRP1 expression in human HCC samples as well as its correlation with advanced tumor and metastasis stages. Among 3 HCC cell lines (HepG2, Huh-7 and Hep3B), Hep3B and Huh-7 cells showed significantly increased NRP1 expression levels and cell migration ability together with higher susceptibility to lenvatinib. We demonstrated that NRP1 gene silencing significantly enhanced the anticancer effects of lenvatinib on Hep3B and Huh-7 cells. Furthermore, lenvatinib suppressed NRP1 expression through promoting autophagy in Hep3B and Huh-7 cells; co-treatment with bafilomycin A1 attenuated the antitumor effects of lenvatinib, and NRP1 silencing prevented this loss of in vitro effectiveness of lenvatinib even in the presence of bafilomycin A1. In addition, exposure to a hypoxic microenvironment significantly decreased NRP1 expression through autophagy in Hep3B and Huh-7 cells. Under hypoxia, HIF-1α directly modulated NRP1 expression; HIF-1α silencing not only enhanced the anticancer effects of combined lenvatinib and hypoxia, but also prevented the loss of effectiveness caused by bafilomycin A1, highlighting the potential role of HIF-1α-derived hypoxia response in the adaptive cellular response to lenvatinib and promoting resistance acquisition by autophagy modulation. Overall, NRP1 may constitute a potential therapeutic target to prevent lenvatinib failure derived from a hypoxia-associated modulation of autophagy in advanced HCC.

Exploring Dynamic Metabolome of the HepG2 Cell Line: Rise and Fall.

Both biological and technical variations can discredit the reliability of obtained data in omics studies. In this technical note, we investigated the effect of prolonged cultivation of the HepG2 hepatoma cell line on its metabolomic profile. Using the GC × GC-MS approach, we determined the degree of metabolic variability across HepG2 cells cultured in uniform conditions for 0, 5, 10, 15, and 20 days. Post-processing of obtained data revealed substantial changes in relative abundances of 110 metabolites among HepG2 samples under investigation. Our findings have implications for interpreting metabolomic results obtained from immortal cells, especially in longitudinal studies. There are still plenty of unanswered questions regarding metabolomics variability and many potential areas for future targeted and panoramic research. However, we suggest that the metabolome of cell lines is unstable and may undergo significant transformation over time, even if the culture conditions remain the same. Considering metabolomics variability on a relatively long-term basis, careful experimentation with particular attention to control samples is required to ensure reproducibility and relevance of the research results when testing both fundamentally and practically significant hypotheses.

Covalent organic polymer induces apoptosis of liver cancer cells via photodynamic and photothermal effects.

Purp@COP is a covalent organic polymer (COP) with robust tailoring heteroatom incorporation, plentiful pore structure, and multiple functions similar to the metal-organic framework (MOF). Hepatocellular carcinoma cell line HepG2 was cultured with Purp@COP for 24 h and treated with near-infrared 808-nm laser 1 W/cm2 for 10 min. Cell Counting Kit-8 (CCK-8) assay, colony formation assay, live-dead cell fluorescence staining, and Annexin V/propidium iodide (PI) staining flow cytometry were performed to detect the viability, proliferation, and apoptosis of the HepG2 cells. The supramolecular material Purp@COP exhibited significant photothermal performance under near-infrared 808-nm laser irradiation in vitro. With the treatment of Purp@COP and near-infrared 808-nm laser irradiation on HepG2 cells, cell viability and colony formation capacity were decreased, and the number and proportion of apoptotic cells were increased. The supramolecular material Purp@COP has both photothermal and photodynamic effects and can significantly induce cancer cell death and inhibit the proliferation of cancer cells in vitro.

Novel ginsenoside derivatives induce apoptosis in HepG-2 cells via the MDM2-p53 signaling pathway

In this study, 6-aryl-5-cyanopyrimidines and quinazolinones were introduced into panaxadiol (PD) to synthesize 25 new panaxadiol derivatives. The cytotoxicity of these compounds against three cancer cells and one normal cell was examined by methylthiazoletetrazolium (MTT) cytotoxicity experiment. The findings demonstrated that PD cyanopyrimidine derivatives have superior anti-proliferative effects over quinazoline derivatives. Among them, PM14 had the strongest inhibitory activity on the proliferation of human hepatoma cell lines (HepG-2), the IC50 value was 2.13 ± 0.20 μM. 4′,6-diamidino-2-phenyl-indole (DAPI) staining showed that PM14 made HepG-2 nucleus shrink and had obvious apoptosis. Mechanistic studies confirmed that the derivative PM14 activates p53 signaling pathway by reducing the expression of MDM2 protein, and further induces an increase in the intracellular Bax/Bcl-2 ratio, down-regulated the expression of Caspase-3, up-regulated Cl-Caspase-3 expression, eventually leading to cell apoptosis. This lays the foundation for subsequent development of derivatives with stronger anti-proliferative activity.

Chalcone-thiosemicarbazone Hybrids as Inhibitors of Human Hepatocellular Carcinoma HepG2 Cells Viability and Oxygen Consumption

Background: Chalcones are open-chain flavonoids especially attractive to medicinal chemistry due to their easy synthesis and the possibility of structural modifications. Objective: This study aims to evaluate the in vitro anticancer activity of a series of hybrids chalcones- thiosemicarbazones against the human hepatocellular carcinoma cell line HepG2. Methods: Seven hybrid chalcones-thiosemicarbazones (CTs), 3-(4’-X-phenyl)-1-phenylprop- 2-en-1-one thiosemicarbazone, where X=H (CT-H), CH3 (CT-CH3), NO2 (CT-NO2), Cl (CTCl), CN (CT-CN), F (CT-F), and Br (CT-Br), were synthesized and their effects on cells’ viability and mitochondrial oxygen consumption were assessed. Results: Incubation with CTs caused a decrease in HepG2 cells viability in a time-concentration-dependent manner. The most effective compounds in inhibiting cell viability, after 24 hours of treatment, were CT-Cl and CT-CH3 (IC50 20.9 and 23.63 μM, respectively). In addition, using 10 μM and only 1 hour of pre-incubation, CT-CH3 caused a reduction in basal respiration (-37 %), oxygen consumption coupled with ATP synthesis (-60 %), and maximum oxygen consumption (-54 %). These alterations in respiratory parameters may be involved with the inhibitory effects of CT-CH3 since significant changes in oxygen consumption rates were observed in a condition that anticipates more significant losses of cell viability. The ADME parameters and the no violation of Lipinski Rule of Five showed that all compounds are safe. Conclusion: These results may contribute to the knowledge about the effects of CTs on these cells and the development of new treatments against HCCs.

Alizarin as a New Activator of the Aryl Hydrocarbon Receptor Signaling Pathway

Alizarin (1,2-dihydroxyanthraquinone) is a natural red dye extracted from the roots of Rubia cordifolia L. (family Rubiaceae). Alizarin has been used as a biological red stain for calcium. The aryl hydrocarbon receptor (AhR) has critical roles in multiple physiological pathways. This study aimed to determine whether alizarin is an unreported ligand of AhR. In the present study, we investigated the effects on cytochrome P450 (CYP) 1A1 mRNA, protein expression, AhR nuclear translocation, aryl hydrocarbon response element (AHRE) reporter activity, and AhR-specific antagonist following alizarin treatment of cells of the human hepatoma cell line, HepG2, and murine hepatoma cell line, Hepa-1c1c7. Alizarin induced CYP1A1 mRNA and protein expression in HepG2 and Hep-1c1c7 cells. Such induction was not present in C4 (B13NBii1) cells, which are AhR signal deficient, C12 (B15ECiii2) cells, which reduce AhR protein levels. The alizarin-induced responses were blocked by CH-223191, which is an AhR antagonist. Alizarin, the same as with the AhR ligand, induced the nuclear localization of AhR, as well as stimulated the transcriptional activity of AHRE. The results of this study suggest that alizarin is an AhR agonist.

The effect of natural polyphenols Resveratrol, Gallic acid, and Kuromanin chloride on human telomerase reverse transcriptase (hTERT) expression in HepG2 hepatocellular carcinoma: role of SIRT1/Nrf2 signaling pathway and oxidative stress.

There is evidence that low doses or physiological concentrations of certain natural polyphenols enhance the activity of telomerase. However, the precise mechanism by which natural polyphenols regulate telomerase activity remains unclear. Recent research indicates that NF-E2 related factor 2 (Nrf2) and silent information regulator 1 (SIRT1) are involved in human telomerase reverse transcriptase (hTERT) regulation. Thus, in order to better comprehend the mechanism by which polyphenols regulate hTERT, the present study investigated the effects of the natural polyphenols Resveratrol, Gallic acid, and Kuromanin chloride on hTERT, Nrf2, and SIRT1 expression as well as oxidative stress in HepG2 hepatocellular carcinoma. The trypan blue dye exclusion assay was used to assess cell viability. The level of mRNA for hTERT, Nrf2, and SIRT1 was then determined using real-time PCR. A spectrophotometric analysis was conducted to quantify oxidative stress markers. The results demonstrated that Resveratrol induces the expression of hTERT and the SIRT1/Nrf2 pathway in a dose-dependent manner. Gallic acid at concentrations of 10 and 20μM also increased the expression of the hTERT and SIRT1/Nrf2 pathway. Furthermore, dose-dependent overexpression of hTERT and Nrf2 was induced by Kuromanin chloride at 10 and 20µM. Moreover, we found that Resveratrol and Kuromanin chloride ameliorated oxidative stress, whereas Gallic acid exacerbated it. This study demonstrates that low doses of polyphenols (Resveratrol, Gallic acid, and Kuromanin chloride) upregulate the expression of the hTERT gene in the HepG2 hepatocellular carcinoma cell line, possibly via induction of the SIRT1/Nrf2 signaling pathway. Therefore, by targeting this pathway or hTERT, the anti-cancer effect of polyphenols can be enhanced.

New Schiff base ligand and its novel Cr(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II) complexes: spectral investigation, biological applications, and semiconducting properties

New Schiff base ligand, derived from antiviral valacyclovir, and its novel Cr(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II) complexes have been synthesized. By using a variety of analytical and spectroscopic techniques, the type of bonding between the ligand and the metal ions in the recently formed complexes was clarified. The Schiff base ligand act as a bidentate and coordinated with the metal ions through the azomethine-N and the phenolic-O centers, in a mono-deprotonated form. Except for the Zn(II) complex, which displayed a tetrahedral geometry, all complexes displayed octahedral geometry. The TGA findings supported that the stability and decomposition properties of the metal complexes were entirely distinct from one another. The thermogram showed decomposition of all investigated metal complexes above 200 °C in three, four or five steps, and indicated the high thermal stability of these complexes. According to XRD patterns, the particles of these complexes were located at the nanoscale. Moreover, for all the samples analyzed, the TEM images showed uniform and homogeneous surface morphology. The biological activity revealing the high efficiencies of the screened complexes as antibacterial and antitumor agents. The antimicrobial activity of the ligand and its complexes was examined against a variety of pathogenic bacteria and fungi including Escherichia coli, Staphylococcus aureus and Candida albicans. The data obtained revealed that the metal ion in the complexes enhanced the antimicrobial activity compared to the free ligand. The high efficiencies toward S. aureus, E. coli, and C. albicans appeared by Cu(II) complex 23, Ni(II) complex 20, and Ni(II) complex 19, respectively. The antitumor activity of the ligand and its complexes was tested against Hepatocellular carcinoma cell line (HepG-2 cells), the residue 28 which produced after heating the Cu(II) complex 25 at 200 °C for 1 h, exhibited strong inhibition of HepG-2 cell growth. The results of the DNA cleavage investigation demonstrated the ability of investigated Cu(II) complex to degrade DNA. The docking findings showed strong interactions of both the ligand and its examined Cu(II) complex, revealing their ability to cleavage DNA and their potent inhibitory effects on tumor cells. The electrical conductivity study confirmed that the ligand and its investigated complexes had semiconducting properties.

Syntheses of heterocyclic derivatives as potential cytotoxic compounds evaluated toward hepatocellular and cervical carcinoma cell lines

ABSTRACT. Through the present work the 3-oxo-N,3-diphenylpropamide derivatives 5a,b were used to synthesize pridine, pyrazole and thiophene derivatives. 3-Phenylisoxazol-5(4H)-one produced from the reaction of ethyl benzoylacetate was used as the key starting compound for different multi-component reactions. The synthesized compounds were evaluated toward Hepatocellular carcinoma HepG2 and cervical carcinoma HeLa cell lines. Compounds 3b, 5b, 7b, 7d, 9c, 9d, 15e, 15f, 16b, 18b, 18e, 18f, 19e and 19f were the most cytotoxic compounds against the tested cell lines. The results obtained in this work encourage further work in the future to produce new cytotoxic compounds.
 
 KEY WORDS: Diphenylpropamide, 3-Phenylisoxazole, Pyran, Pyridine, Cytotoxicity
 Bull. Chem. Soc. Ethiop. 2023, 37(1), 141-158. 
 DOI:https://dx.doi.org/10.4314/bcse.v37i1.12

The Biological Relevance of Papaverine in Cancer Cells.

Papaverine (PPV), a benzylisoquinoline alkaloid, extracted from the Papaverine somniferum plant, is currently in clinical use as a vasodilator. Research has shown that PPV inhibits phosphodiesterase 10A (PDE10A,) resulting in the accumulation of cyclic adenosine 3', 5'-monophosphate (cAMP) that affects multiple downstream pathways, including phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt), a mammalian target of rapamycin (mTOR) and vascular endothelial growth factor (VEGF). The accumulation of cAMP can further affect mitochondrial metabolism through the activation of protein kinase A (PKA), which activates the mitochondrial complex I. Literature has shown that PPV exerts anti-proliferative affects in several tumorigenic cell lines including adenocarcinoma alveolar cancer (A549) and human hepatoma (HepG-2) cell lines. Cell cycle investigations have shown varying results with the effects dependent on concentration and cell type with data suggesting an increase in cells occupying the sub-G1 phase, which is indicative of cell death. These results suggest that PPV may be a beneficial compound to explore for the use in anticancer studies. More insight into the effects of the compound on cellular and molecular mechanisms is needed. Understanding the effects PPV may exert on tumorigenic cells may better researchers' understanding of phytomedicines and the effects of PPV and PPV-derived compounds in cancer.

Transcription factor SP1 regulates haptoglobin fucosylation via induction of GDP-fucose transporter 1 in the hepatoma cell line HepG2

Fucosylation is involved in cancer and inflammation, and several fucosylated proteins, such as AFP-L3 for hepatocellular carcinoma, are used as cancer biomarkers. We previously reported an increase in serum fucosylated haptoglobin (Fuc-Hp) as a biomarker for several cancers, including pancreatic and colon cancer and hepatocellular carcinoma. The regulation of fucosylated protein production is a complex cellular process involving various fucosylation regulatory genes. In this report, we investigated the molecular mechanisms regulating Fuc-Hp production in cytokine-treated hepatoma cells using a partial least squares (PLS) regression model. We found that SLC35C1, which encodes GDP-fucose transporter 1 (GFT1), is the most responsible factor for Fuc-Hp production among various fucosylation regulatory genes. Furthermore, the transcription factor SP1 was essential in regulating SLC35C1 expression. We also found that an SP1 inhibitor was able to suppress Fuc-Hp production without affecting total Hp levels. Taken together, Fuc-Hp production was regulated by SP1 via induction of GFT1 in the hepatoma cell line HepG2.

Smp24, a Scorpion-Venom Peptide, Exhibits Potent Antitumor Effects against Hepatoma HepG2 Cells via Multi-Mechanisms In Vivo and In Vitro.

Scorpion-venom-derived peptides have become a promising anticancer agent due to their cytotoxicity against tumor cells via multiple mechanisms. The suppressive effect of the cationic antimicrobial peptide Smp24, which is derived from the venom of Scorpio Maurus palmatus, on the proliferation of the hepatoma cell line HepG2 has been reported earlier. However, its mode of action against HepG2 hepatoma cells remains unclear. In the current research, Smp24 was discovered to suppress the viability of HepG2 cells while having a minor effect on normal LO2 cells. Moreover, endocytosis and pore formation were demonstrated to be involved in the uptake of Smp24 into HepG2 cells, which subsequently interacted with the mitochondrial membrane and caused the decrease in its potential, cytoskeleton reorganization, ROS accumulation, mitochondrial dysfunction, and alteration of apoptosis- and autophagy-related signaling pathways. The protecting activity of Smp24 in the HepG2 xenograft mice model was also demonstrated. Therefore, our data suggest that the antitumor effect of Smp24 is closely related to the induction of cell apoptosis, cycle arrest, and autophagy via cell membrane disruption and mitochondrial dysfunction, suggesting a potential alternative in hepatocellular carcinoma treatment.

Insulin Downregulates the Expression of ATP-binding Cassette Transporter A-I in Human Hepatoma Cell Line HepG2 in a FOXO1 and LXR Dependent Manner.

ATP-binding cassette transporter A-I (ABCA1) is an ubiquitously expressed protein whose main function is the transmembrane transport of cholesterol and phospholipids. Synthesis of ABCA1 protein in liver is necessary for high-density lipoprotein (HDL) formation in mammals. Thus, the mechanism of ABCA1 gene expression regulation in hepatocytes are of critical importance. Recently, we have found the insulin-dependent downregulation of other key player in the HDL formation-apolipoprotein A-I gene (J. Cell. Biochem., 2017, 118:382-396). Nothing is known about the role of insulin in the regulation of ABCA1 gene. Here we show for the first time that insulin decreases the mRNA and protein levels of ABCA1 in human hepatoma cell line HepG2. PI3K, p38, MEK1/2, JNK and mTORC1 signaling pathways are involved in the insulin-mediated downregulation of human ABCA1 gene. Transcription factors LXRα, LXRβ, FOXO1 and NF-κB are important contributors to this process, while FOXA2 does not regulate ABCA1 gene expression. Insulin causes the decrease in FOXO1, LXRα and LXRβ binding to ABCA1 promoter, which is likely the cause of the decrease in the gene expression. Interestingly, the murine ABCA1 gene seems to be not regulated by insulin in hepatocytes (in vitro and in vivo). We suggest that the reason for this discrepancy is the difference in the 5'-regulatory regions of human and murine ABCA1 genes.

Highly Oxidized Germacranolides from Elephantopus tomentosus and the Configurational Revision of Some Previously Reported Analogues.

Highly oxidized germacranolides are mainly found in the genus Elephantopus, contain a characteristic ten-membered molecular core that is highly flexible, and exhibit potential cytotoxic properties. However, their configurations were assigned ambiguously in previous reports due to spectroscopic observation of macrocyclic systems. Herein, 17 highly oxidized germacranolides, including 12 new germacranolides (1-12), were isolated from Elephantopus tomentosus. Their structures were characterized by spectroscopic data analysis combined with X-ray crystallography and ECD calculations, and it was possible to propose configurational revisions of five previously reported analogues (13-17). Cytotoxic activities for 1-17 against two hepatocellular carcinoma cell lines (HepG2 and Hep3B) were tested, and compounds 1-10 and 13-16 generated IC50 values of 2.2-9.8 μM. Furthermore, the observed cytotoxic activity of 1 was determined as being mediated by inducing the apoptosis of HepG2 and Hep3B cells via mitochondrial dysfunction.

New derivative of trans-dehydrocrotonin isolated from Croton cajucara shows reduced cytotoxic and genotoxic effects in hepatocellular carcinoma (HepG2) cell line

The Croton cajucara (Euphorbiales, Euphorbiaceae) plant occurs widely in the Amazon region, where its leaves and stem bark are consumed by the population to treat several diseases. The secondary metabolite trans-dehydrocrotonin (DCTN) is mainly accountable for the biological activities of this plant. However, prolonged consumption is associated with hepatotoxic effects due to the furan ring present in the molecule. This group is responsible for toxicity reactions in other drugs. In this work, we inserted a COOH group into the molecule to prevent the formation of toxic intermediates. We assessed the cytotoxicity and genotoxicity of both molecules on HepG2 cells. Results showed that the new derivative (CCTN) is less cytotoxic and did not reduce cell viability at any concentration tested. Genotoxicity was also reduced as assessed by the comet and micronucleus assay. Therefore, the new derivative appears to be promising and additional tests should be performed to evaluate its therapeutic activities.