Hepatic Carcinoma Cells Research Articles

A multi-scale systems pharmacology approach uncovers the anti-cancer molecular mechanism of Ixabepilone

It has been realized that FDA approved drugs may have more molecular targets than is commonly thought. Thus, to find the exact drug-target interactions (DTIs) is of great significance for exploring the new molecular mechanism of drugs. Here, we developed a multi-scale system pharmacology (MSSP) method for the large-scale prediction of DTIs. We used MSSP to integrate drug-related and target-related data from multiple levels, the network structural data formed by known drug-target relationships for predicting likely unknown DTIs. Prediction results revealed that Ixabepilone, an epothilone B analog for treating breast cancer patients, may target Bcl-2, an oncogene that contributes to tumor progression and therapy resistance by inhibiting apoptosis. Furthermore, we demonstrated that Ixabepilone could bind with Bcl-2 and decrease its protein expression in breast cancer cells. The down-regulation of Bcl-2 by Ixabepilone is resulted from promoting its degradation by affecting p-Bcl-2. We further found that Ixabepilone could induce autophagy by releasing Beclin1 from Beclin1/Bcl-2 complex. Inhibition of autophagy by knockdown of Beclin1 or pharmacological inhibitor augmented apoptosis, thus enhancing the antitumor efficacy of Ixabepilone against breast cancer cells in vitro and in vivo. In addition, Ixabepilone also decreases Bcl-2 protein expression and induces cytoprotective autophagy in human hepatic carcinoma and glioma cells. In conclusion, this study not only provides a feasible and alternative way exploring new molecular mechanisms of drugs by combing computation DTI prediction, but also reveals an effective strategy to reinforce the antitumor efficacy of Ixabepilone.

Plantamajoside Inhibits Hepatic Carcinoma Cell Proliferation, Migration, Invasion and Induces Apoptosis Through Regulating Phosphatidylinositol-3-Kinase/ Protein Kinase B Pathway

Background: Plantamajoside (PMS) is the main active compound of Plantago asiatica . It is a traditional Chinese medicine and has been reported to have various biological activities. However, the function of PMS on hepatic carcinoma cells (HCC) and the potential mechanism of action still remains unevaluated. Here, we investigated the effect of PMS on HCC cells and the potential molecular mechanism. Methods: Firstly, HCC cells were treated with different dose of PMS (0, 20, 80 and 160 g/ml). Then, cell viability was determined by MTT assay. Furthermore, we investigated the cell apoptosis, migration and invasion by flow cytometry assay and Transwell assay. In addition, PI3K/AKT related proteins p-AKT and AKT were determined via Western blotting assay. Results: Our results showed that PMS dose-dependently reduced HCC cell viability. PMS also induced HCC cell apoptosis, up-regulated the expression of Bax and down-regulated expression of Bcl-2. In addition, the Bcl-2/Bax ratio was also decreased. The migration and invasion of HCC cells were also consistently suppressed by PMS treatment in a dose-dependent manner. Subsequently, the results indicated that PMS down-regulated the expression of p-AKT, suggesting the inhibition of the PI3K/AKT pathway in HCC progression. Conclusion: The results indicated that PMS could inhibit HCC progression through regulating cell viability, apoptosis, migration, invasion and PI3K/AKT pathway. Thus, PMS might be a hopeful pharmacological agent for the treatment of hepatic carcinoma.

SDC1 promotes cisplatin resistance in hepatic carcinoma cells via PI3K-AKT pathway.

This study is to analyze the potential contribution of Syndecan 1 (SDC1) to cisplatin resistance in hepatic carcinoma. Cell proliferation and viability were determined by direct counting and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, respectively. The protein levels of SDC1, p-AKT, AKT and β-actin were quantified by western blotting. The SDC1 transcript abundance was measured by real-time polymerase chain reaction. The relative expression of SDC1 in clinical liver tumor samples was analyzed with immunohistochemistry. SDC1 was up-regulated in cisplatin-resistant HepG2 cells (denoted as HepG2 CR hereafter). SDC1-knockdown re-sensitized HepG2 CR cells to cisplatin treatment. Ectopic over-expression of SDC1 conferred drug resistance to naïve HepG2 cells. PI3K/AKT pathway was over-activated in HepG2 CR cells, and simultaneous administration with PI3K inhibitor greatly surmounted the resistance. We also demonstrated that SDC1 was aberrantly up-regulated in clinical hepatocellular carcinoma samples. Our study highlighted the importance of SDC1-PI3K/AKT signaling in the cisplatin resistance in hepatocellular carcinoma.

Galactosamine-Conjugating Zwitterionic Block Copolymer for Reduction-Responsive Release and Active Targeted Delivery of Doxorubicin to Hepatic Carcinoma Cells

Nanocarriers with integrated advantage, such as excellent stealth property, active targeting function, and rapid intracellular drug release, are significant for cancer treatment. Herein, a biodegradable zwitterionic triblock copolymer containing disulfide-linked poly-ε-caprolactone and polycarboxybetaine methacrylate (PCB-SS-PCL-SS-PCB) was first synthesized and then partly modified with galactosamine (GAL) for constructing polymeric micelle drug carrier with multifunctionality. Polymeric micelles showed ultralow protein absorption in serum and obvious reduction-responsiveness in the presence of glutathione, provided by the zwitterionic polymer shell and the disulfide bond, respectively. Furthermore, active targeting of the carrier to hepatic carcinoma cells was achieved via GAL ligands on PCB shells due to their specific binding to asialoglycoprotein receptors on the cell surface. As expected, in vivo competition studies demonstrated that doxorubicin- (DOX-) loaded GAL-modified micelles have better anticancer effect in hepatic tumor-bearing mice than free DOX and nontargetable micelles. As a result, this novel multifunctional carrier provides a valuable strategy to design promising anticancer drug delivery systems for liver cancer treatment.

LncRNA FENDRR Upregulation Promotes Hepatic Carcinoma Cells Apoptosis by Targeting miR-362-5p Via NPR3 and p38-MAPK Pathway.

Background: Abnormal long noncoding RNA FOXF1 adjacent noncoding developmental regulatory RNA (FENDRR) expression has been discovered in multiple human cancers pathogenesis, but its role in hepatocellular carcinoma (HCC) cells is rarely reported. Its effects on HCC cells are covered in this study. Materials and Methods: MiR-362-5p and NPR3 expressions in HCC tissues and cell were detected by quantitative real-time polymerase chain reaction and Western blot as needed. Cell viability and apoptosis were detected by MTT assay and flow cytometry, respectively. Target gene and potential binding sites of FENDRR, miR-362-5p, and NPR3 were predicted and confirmed by TargetScan and Starbase, and dual-luciferase reporter assay. Results: FENDRR expression was downregulated while miR-362-5p expression was upregulated in HCC tissues and cells. FENDRR upregulation inhibited HCC cells viability yet induced apoptosis, which was reversed by miR-362-5p. In addition, miR-362-5p resulted in p38-mitogen-activated protein kinase (MAPK) pathway activation and NPR3 expression decrease in HCC cells, which was reversed by FENDRR. Conclusion: FENDRR inhibited HCC cells viability yet promoted apoptosis by targeting miR-362-5p by promoting NPR3 and deactivating p38-MAPK pathway, thus exerting its anticarcinogenic effects in HCC cells.

The Effect of PEI-Mediated E1A on the Radiosensitivity of Hepatic Carcinoma Cells.

Objective:The study was undertaken to investigate the effects of polyethyleneimine (PEI)-mediated adenovirus 5 early region 1A (E1A) on radiosensitivity of human hepatic carcinoma cell in vitro and to disclosure the underlying mechanism. Materials and Methods:Human hepatic carcinoma SMMC-7721 cell line was transfected with E1A gene using PEI vector. Untransfected cells (SMMC-7721 group), cells transfected with blank-vector (SMMC-7721-vect group), and cells transfected with E1A gene (SMMC-7721-E1A group) were treated with 6 MV X-ray irradiation at doses of 0, 1, 2, 4, 8 and Gy, respectively. Radiosensitivity was determined by MTT assay and quantified by calculating the cell survival rate. Cell-cycle distribution and apotosis rate were monitored by flow cytometry. Results:The survival rate of SMMC-7721-E1A was significantly lower than that of SMMC-7721 cell. Apoptosis rate of SMMC-7721-E1A group was significantly higher than that of SMMC-7721group (P<0.01).The ratio of S stage in cell cycle of SMMC-7721-E1A was significantly lower than that in SMMC-7721 cell. The ratio of G2/M stage in cell cycle of SMMC-7721-E1A was significantly higher than that in SMMC-7721 cell (P<0.01). Conclusion:PEI could transfect E1A gene into hepatic carcinoma cells PEI-mediated E1A could effectively enhance radiosensitivity of hepatic carcinoma cells which may be related to its effects on apoptosis promoting leading to S phase suppression and G2/M phase arrest.

Novel anthracene-9-sulfonyl derivatives as anticancer agents: synthesis and in vitro biological evaluation

In this study, a new series of anthracene-9-sulfonyl derivatives incorporated with different heterocyclic moieties were synthesized and screened for their in vitro anticancer activity against colon carcinoma cell lines (HCT-116), hepatic carcinoma cell lines (HepG 2) and breast carcinoma cell lines (MCF-7). Among them, compound 4-acetylphenyl anthracene-9-sulfonate (8) showed selective high cytotoxic activity over colon carcinoma cell lines (HCT-116), also compounds 2-(anthracen-9-ylsulfonyl)malononitrile (7), N-(4-fluorophenyl)anthracene-9-sulfonamide (5b) and N-((1H-benzo[d]imidazol-2-yl)methyl)anthracene-9-sulfonamide (10) showed the significant selective cytotoxic effect over breast carcinoma cell lines (MCF-7). All the compounds are subjected to explore their safety on normal human skin cell lines (BJ-1), the results revealed that all the compounds are safe and have insignificant weak cytotoxicity over normal human cells.

Reused palm oil from frying pork or potato induced expression of cytochrome P450s and the SLCO1B1 transporter in HepG2 cells.

Deep frying degrades the oil and generates harmful products. This study evaluated effects of reused palm oil (from frying pork or potato) on expression of cytochrome P450s (CYPs), the transporter (SLCO1B1), and lipid metabolism regulators; proliferator-activated receptors (PPAR) and sterol regulatory element binding protein (SREBP). Human hepatic carcinoma cell line (HepG2) cells were incubated with oleic acid (OA), new palm oil, or reused palm oils for 24hr. Fatty acid accumulation was examined by Nile red staining. Total RNA was extracted, followed by RT/qPCR of the target genes. Fatty acid accumulation was significantly different between the new and the reused oils. Expression of CYP1A2, CYP2C19, CYP2E1, CYP3A4, CYP4A11, and SLCO1B1 was induced by reused oils. Expression of PPAR-α was strongly increased in all treatments while SREBP-1a and SREBP-1c were suppressed. Modification of CYPs, PPAR-α, and SLCO1B1 by palm oil might increase the risk of fatty acid accumulation with associated oxidative stress. Therefore, consumption of palm oil or reused oil should be limited. PRACTICAL APPLICATIONS: Deep frying degrades the oil and generates harmful products. This study evaluated effects of reused palm oil (from frying pork or potato) on expression of cytochrome P450s (CYPs), the transporter (SLCO1B1), and lipid metabolism regulators; PPAR and SREBP in HepG2 cells. Both of the reused oils-induced profiles of all CYP and SLCO1B1, but the new oil upregulated CYP2E1, CYP3A4, and CYP4A11. PPAR-α was induced while SREBP-1a and SREBP-1c were suppressed by all treatments. Inductions of CYPs with suppression of SREBP-1a and SREBP-1c might contribute to an increased risk of fatty acid accumulation. These findings revealed the impacts of reused palm oil on metabolism via CYPs which related to oxidative stress for further study. Hence, consumption of palm oil or reused cooking oil should be of concern.

Targeted Therapy for Hepatocellular Carcinoma: Co-Delivery of Sorafenib and Curcumin Using Lactosylated pH-Responsive Nanoparticles.

PurposeHepatocellular carcinoma (HCC) is a leading cancer worldwide. In the present investigation, sorafenib (SFN) and curcumin (CCM) were co-delivered using pH-sensitive lactosylated nanoparticles (LAC-NPs) for targeted HCC treatment.MethodspH-responsive lactosylated materials were synthesized. SFN and CCM co-delivered, pH-responsive lactosylated nanoparticles (LAC-SFN/CCM-NPs) were self-assembled by using the nanoprecipitation technique. The nanoparticles were characterized in terms of particle size, charge and drug release profile. The anti-cancer effects of the nanoparticles were evaluated in human hepatic carcinoma cells (HepG2) cells and HCC tumor xenograft models.ResultsLAC-SFN/CCM-NPs are spherical particles with light coats on the surface. The size and zeta potential of LAC-SFN/CCM-NPs were 115.5 ± 3.6 nm and −34.6 ± 2.4, respectively. The drug release of LAC-SFN/CCM-NPs in pH 5.5 was more efficient than in pH 7.4. LAC-SFN/CCM-NPs group exhibited the smallest tumor volume (239 ± 14 mm3), and the inhibition rate of LAC-SFN/CCM-NPs was 77.4%.ConclusionIn summary, LAC-SFN/CCM-NPs was proved to be a promising system for targeted HCC therapy.

Electroanalytical Method for Quantification of Hepatocellular Carcinoma Cells as Charge Transport Barriers in Culture Media

AbstractHere we report a strategy in which electroanalytical method was used to quantify human hepatic carcinoma cell (HepG2) density in culture media and their interaction with biomolecules. The cyclic voltammogram response of vitamin and amino acids redox mediators containing culture media had shown distinct oxidation peak at −0.63 V along with a low intensity peak at +0.67 V. Both oxidation and reduction peak current of culture media were gradually decreased with an increase in cell number indicating their role as charge transport barrier at electrode surface. The difference between cathodic and anodic peak potential was also decreased with the addition of cells. The oxidation peak disappeared in CV response, with the addition of optimum cell number in culture media, indicating the adsorption of redox mediators at cell surface. CV response of fetal bovine serum (FBS) containing cell suspension showed presence of reduction and oxidation peaks of culture media in CV. This indicates stronger possibility of binding of serum proteins with cells and release of redox mediators in culture media. The chemical interactions of cells with FBS was further confirmed by the FTIR and UV‐Vis spectroscopy. The viability, adhesion and proliferation responses of the cells were found to be normal. The reported electroanalytical method may be applied in the future for rapid quantification of cell density and confirmation of interactions among cells and biomolecules.

Synthesis and biological evaluations of N'-substituted methylene-4-(quinoline-4-amino) benzoylhydrazides as potential anti-hepatoma agents.

In the effort to develop novel quinoline derivatives for the treatment of liver cancer, we synthesized a series of N'-Substituted methylene-4-(quinoline-4-amino) benzoylhydrazides and evaluated their biological activities as anticancer agents. Compounds 5h and 5j were found to be the potent antiproliferative agents against HepG2 cell line with an IC50 value of 12.6±0.1μM and 27.3±1.7μM, respectively. The most effective compound 5h also exhibited potent cytotoxicity against SMMC-7721 and Huh7 cells with IC50 values of 9.6±0.7μM and 6.3±0.2μM, respectively. Inspiringly, both 5h and 5j exhibited lower cytotoxic property in normal cells than hepatic carcinoma cells. Compounds 5h and 5j could down-regulate mRNA level of c-Myc and expression level of c-Myc. Meanwhile, they decreased expression level of anti-apoptotic protein Bcl-2 and increased expression levels of pro-apoptotic protein Bax and cleaved PARP with reference to tubulin. So various assays including cell colony formation, cell cycle distribution, as well as cell apoptosis and migration were performed to understand their antitumor role. It was confirmed that 5h and 5j inhibited the growth of HepG2 cells due to their anti-survival effect, induction of cell cycle arrest and cell apoptosis, and inhibition of cell migration. These results demonstrated that 5h might be as potential lead compounds to develop anticancer agents for the treatment of hepatocellular carcinoma.

Mitofusin-2 (Mfn-2) Might Have Anti-Cancer Effect through Interaction with Transcriptional Factor SP1 and Consequent Regulation on Phosphatidylinositol Transfer Protein 3 (PITPNM3) Expression

BackgroundThe aim of this study was to explore the influence of mitofusin-2 (Mfn-2) on phosphatidylinositol transfer protein 3 (PITPNM3) and tumor growth and the potential mechanism behind the regulation of Mfn-2 on PITPNM3 in hepatic carcinoma cell line SMMC-7721.Material/MethodsWe obtained promoter sequence of PITPNM3 gene from University of Santa Cruz (UCSC) genomic database, and we predict transcriptional factor of PITPNM3 genes by JASPAR database. Target transcription factor was determined by comparison of binding sites number for promoter. SMMC-7721 cells were transfected with expression plasmid containing Mfn-2, transcription factor gene and PITPNM3. The cells transfected with empty vector were used as control. Real-time polymerase chain reaction was used to determine the mRNA level of target genes. Co-immunoprecipitation (Co-IP) assay was used to determine the interaction between Mfn-2 and target transcription factor. Chromatin immunoprecipitation assay (ChIP) assay was used to determine the binding of transcription factor with PITPNM3 promoter. Tumorigenicity assay was used to compare the effect of Mfn-2, SP1, and PITPNM3 on tumor development.ResultsSP1 was selected as the target transcriptional factor. In the Co-IP assay, Mfn-2 was shown to interact with SP1. In the ChIP assay Mfn-2 transfection resulted in decreased binding number of SP1 with PITPNM3 promoter. Furthermore, PITPNM3 mRNA levels were significantly increased in SMMC-7721 cells transfected with SP1 but were decreased after transfection with Mfn-2. In nude mice, PITPNM3 and SP1 upregulation lead to larger tumor lump and conversely Mfn-2 upregulation lead to smaller tumor lump.ConclusionsMfn-2 could suppress expression of PITPNM3 through interaction with transcription factor SP1; Mfn-2 may have anti-tumor activity; SP1 and PITPNM3 may promote tumor development.

Determination of Volatile Constituents of Cucumis melo L. var. aegyptiacus cv. Ismailawi Fruits and Evaluation of Its Cytotoxic Activity

Objectives: Cucumis melo L. var. aegyptiacus cv. Ismailawi plant is a member of family Cucurbitaceae. This study aimed to identify volatile components of the pulp of the fruit and also to evaluate its cytotoxic activity. Methods: Automated rapid headspace solid phase micro extraction (SPME) was applied for extraction of the volatile components combined with gas chromatography coupled to mass spectrometry GC/MS for identification of the compounds responsible for the specific aroma of the fruits, MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay) was used for the evaluation of the cytotoxic activity of both petroleum ether and defatted methanol extracts of the fruits’ pulp against 3 different tumor cell lines; colon (Caco-2), hepatic (HepG2) and cervix (HeLa) carcinoma cells. Results: Twenty volatile components were identified in the pulp of the fruits which were dominated by esters as the major class of components, with hexyl acetate representing the major constituent (23.07%). Petroleum ether extract of the pulp displayed mild cytotoxic activity against HepG2 cell line with IC50 of (31.6) µg/ml, all results were standardized against doxorubicinpositive control. Conclusion: This is the first report for the evaluation of the volatile constituents of Cucumis melo L. var. aegyptiacus cv. Ismailawi fruits which can serve as a base for its differentiation from other similar varieties in the same family.

Phosphoinositide specific phospholipase Cγ1 inhibition-driven autophagy caused cell death in human lung adenocarcinoma A549 cells in vivo and in vitro.

Our previous studies indicated that phosphoinositide specific phospholipase Cγ1 (PLCγ1) was involved in autophagy induction in colon and hepatic carcinoma cells. However, whether and how PLCγ1 regulation in human lung adenocarcinoma is linked to autophagy remains unclear. Here, we assessed the protein expression of PLCγ1 in human lung adenocarcinoma tissue using immunohistochemistry assay and the relationship between PLCG1 and autophagy in The Cancer Genome Atlas Network (TCGA) using Spearman correlation analysis and GSEA software. Furthermore, the interaction between PLCγ1 and autophagy-related signal molecules was investigated in human lung adenocarcinoma A549 cells treated with different inhibitors or transduction with lentivirus-mediated PLCγ1 gene short-hairpin RNA (shRNA) vectors using MTT, clonogenicity, Transwell migration, RT-PCR, Caspase-3, mitochondrial transmembrane potential, and western blotting assays, as well as transmission electron microscope technique. Additionally, the effect of shRNA/PLCγ1 alone or combined with autophagic activator Lithium Chloride (LiCl) on tumor growth and metastasis was measured using immunohistochemistry and assays in A549 xenograft nude mouse model. The results showed that increased PLCγ1 expression occurred frequently in human lung adenocarcinoma tissue with higher grades of T in TNM staging classification. PLCγ1 significantly enriched in autophagic process and regulation, which negatively regulating autophagy was enriched in higher expression of PLCγ1. PLCγ1 inhibition partially reduced cell proliferation and migration of A549 cells, with an increased autophagic flux involving alterations of AMPKα, mTOR, and ERK levels. However, PLCγ1 inhibition-driven autophagy led to cell death without depending on Caspase-3 and RIP1. Additionally, the abrogation of PLCγ1 signaling by shRNA and combination with autophagic activator LiCl could efficaciously suppress tumor growth and metastasis in A549 xenograft nude mice, in combination with a decrease in P62 level. These findings collectively suggest that reduction of cell proliferation and migration by PLCγ1 inhibition could be partially attributed to PLCγ1 inhibition-driven autophagic cell death (ACD). It highlights the potential role of a combination between targeting PLCγ1 and autophagy pathway in anti-tumor therapy, which may be an efficacious new strategy to overcome the autophagy addition of tumor and acquired resistance to current therapy.

Nanozyme-assisted sensitive profiling of exosomal proteins for rapid cancer diagnosis.

The proteins expressed on exosomes have emerged as promising liquid-biopsy biomarkers for cancer diagnosis. However, molecular profiling of exosomal proteins remains technically challenging. Herein, we report a nanozyme-assisted immunosorbent assay (NAISA) that enables sensitive and rapid multiplex profiling of exosomal proteins. This NAISA system is based on the installation of peroxidase-like nanozymes onto the phospholipid membranes of exosomes, thus avoiding the need for post-labelling detection antibodies. The exosomal proteins are determined by a sensitive nanozyme-catalyzed colorimetric assay less than 3 h, without the need for multi-step incubation and washing operations. Using NAISA to profile exosomal proteins from different cell lines and clinical samples, we reveal that tumor-associated exosomal proteins can serve as promising biomarkers for accurate cancer diagnosis in a cooperative detection pattern.Methods: Exosomes were engineered with DSPE-PEG-SH through hydrophobic interaction, and then were assembled with gold nanoparticles (2 nm) to produce Exo@Au nanozyme. The proteins on Exo@Au could be selectively captured by their specific antibodies seeded into a 96-well plate. The immobilized Exo@Au shows peroxidase-like activity to perform colorimetric assays by reaction with 3,3′,5,5′-tetramethylbenzidine (TMB) and H2O2. The protein levels of exosomes were recorded on a microplate reader.Results: The NAISA platform is capable of profiling multiple exosomal proteins from both cancer cell lines and clinical samples. The expression levels of exosomal proteins, such as CD63, CEA, GPC-3, PD-L1 and HER2, were used to classify different cancer cell lines. Moreover, the protein profiles have been applied to differentiate healthy donors, hepatitis B patients, and hepatic cell carcinoma (HCC) patients with high accuracy.Conclusion: The NAISA nanozyme was allowed to rapidly profile multiple exosomal proteins and could have great promise for early HCC diagnosis and identification of other cancer types.

Classification of hyperspectral images for detection of hepatic carcinoma cells based on spectral–spatial features of nucleus

A distinguishing characteristic of normal and cancer cells is the difference in their nuclear chromatin content and distribution. This difference can be revealed by the transmission spectra of nuclei stained with a pH-sensitive stain. Here, we used hematoxylin–eosin (HE) to stain hepatic carcinoma tissues and obtained spectral–spatial data from their nuclei using hyperspectral microscopy. The transmission spectra of the nuclei were then used to train a support vector machine (SVM) model for cell classification. Especially, we found that the chromatin distribution in cancer cells is more uniform, because of which the correlation coefficients for the spectra at different points in their nuclei are higher. Consequently, we exploited this feature to improve the SVM model. The sensitivity and specificity for the identification of cancer cells could be increased to 99% and 98%, respectively. We also designed an image-processing method for the extraction of information from cell nuclei to automate the identification process.

Rapanone, a naturally occurring benzoquinone, inhibits mitochondrial respiration and induces HepG2 cell death

Rapanone is a natural occurring benzoquinone with several biological effects including unclear cytotoxic mechanisms. Here we addressed if mitochondria are involved in the cytotoxicity of rapanone towards cancer cells by employing hepatic carcinoma (HepG2) cells and isolated rat liver mitochondria. In the HepG2, rapanone (20–40 μM) induced a concentration-dependent mitochondrial membrane potential dissipation, ATP depletion, hydrogen peroxide generation and, phosphatidyl serine externalization; the latter being indicative of apoptosis induction. Rapanone toxicity towards primary rats hepatocytes (IC50 = 35.58 ± 1.50 μM) was lower than that found for HepG2 cells (IC50 = 27.89 ± 0.75 μM). Loading of isolated mitochondria with rapanone (5–20 μM) caused a concentration-dependent inhibition of phosphorylating and uncoupled respirations supported by complex I (glutamate and malate) or the complex II (succinate) substrates, being the latter eliminated by complex IV substrate (TMPD/ascorbate). Rapanone also dissipated mitochondrial membrane potential, depleted ATP content, released Ca2+ from Ca2+-loaded mitochondria, increased ROS generation, cytochrome c release and membrane fluidity. Further analysis demonstrated that rapanone prevented the cytochrome c reduction in the presence of decylbenzilquinol, identifying complex III as the site of its inhibitory action. Computational docking results of rapanone to cytochrome bc1 (Cyt bc1) complex from the human sources found spontaneous thermodynamic processes for the quinone-Qo and Qi binding interactions, supporting the experimental in vitro assays. Collectively, these observations suggest that rapanone impairs mitochondrial respiration by inhibiting electron transport chain at Complex III and promotes mitochondrial dysfunction. This property is potentially involved in rapanone toxicity on cancer cells.

TCF19 Promotes Cell Proliferation through Binding to the Histone H3K4me3 Mark.

Transcription factor 19 (TCF19) plays critical roles in type 1 diabetes and the maintenance of pancreatic β cells. Recent studies have also implicated TCF19 in cell proliferation of hepatic carcinoma and non-small cell lung carcinoma; however, the mechanism underlying this regulation remains elusive. At the molecular level, TCF19 contains two modules, the plant homeodomain (PHD) finger and the forkhead-associated (FHA) domain, of unclear function. Here, we show that TCF19 mediates hepatocellular carcinoma HepG2 cell proliferation through its PHD finger that recognizes trimethylated lysine 4 of histone 3 (H3K4me3). W316 of the PHD finger of TCF19 is one of the critical residues eliciting this function. Whole genome microarray analysis and orthogonal cell-based assays identified a large subset of genes involved in cell survival and proliferation that depend on TCF19. Our data suggest that TCF19 acts as a pro-oncogene in hepatocellular carcinoma cells and that its functional PHD finger is critical in cell proliferation.

A hybridization chain reaction based assay for fluorometric determination of exosomes using magnetic nanoparticles and both aptamers and antibody as recognition elements.

Exosomes represent a new generation of biomarkers for the early diagnosis of hepatic carcinoma. A fluorometric assay is presented that is based on the hybridization chain reaction and magnetic nanoparticles for the highly sensitive determination of exosome (from HepG2 cells). Antibody as the recognition element was modified on the surface of magnetic nanoparticles. Antibody was used to capture the exosome. The Probe 1 was consisted of aptamer sequence and trigger sequence. Aptamer sequence will bind with the surface protein of exosome. The trigger sequence will hybridize with the probe2 (FAM-labeled) and the probe3 (FAM-labeled). So the product of the hybridization chain reaction will present a strong fluorescence signal. The fluorescence product of hybridization chain reaction will link with magnetic nanoparticles through the 'magnetic nanoparticles-antibody-exosome-aptamer' structure. The product can be separated from the matrix due to the present of the magnetic nanoparticles. The excitation was set at 490nm. The fluorescence value of the emission spectra at 519nm was set as the signal response. The linear range of this assay is from 1000 to 107 particles·mL-1. The detection limit is 100 particles·mL-1. This assay was applied to the determination of exosome from the hepatic carcinoma cells. Graphical abstractIn the presence of exosmes, the hybridization chain reaction was triggered and strong greenfluorescence will be produced. Moreover, the magnetic particles can separate the products from the matrix.

Five new 5,6-β-epoxywithanolides from Physalis minima

Five new 5,6-β-epoxywithanolides (1–5) were isolated from the whole plants of Physalis minima L. Their structural elucidations were achieved by the extensive spectroscopic analysis (IR, UV, HR-ESI-MS, 1D-NMR, and 2D-NMR). The isolates were evaluated for their anti-inflammatory activities on lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells and cytotoxic activities against three cancer cell lines, viz. A549 lung adenocarcinoma cells, SMMC-7721 hepatic carcinoma cells and MCF-7 breast cancer cells by using the MTT-based assay. All of them possessed moderate inhibition to the production of nitric oxide with IC50 values from 42.18 to 73.26 μM, and the IC50 values of the cytotoxic activities were in the range of 31.25 to 80.14 μM.