Hepatoma Carcinoma Cell HepG2 Research Articles

Study of a water-soluble supramolecular complex of curcumin and β-cyclodextrin polymer with electrochemical property and potential anti-cancer activity

As a member of the curcuminoid compound family, curcumin (Cur) has many interesting therapeutic properties. However, its low aqueous solubility and stability have resulted in poor bioavailability and restricted clinical efficacy. Based on size matching, β-cyclodextrin polymer (β-CDP), with its hydrophilic polymer chains and hydrophobic cavities, can form an inclusion complex with Cur. To improve the water solubility and stability of Cur, a simple and eco-friendly grinding method was designed to form β-CDP inclusion complexes. According to the Boltzmann–Hamel's method and Job's method, the molar ratio of the β-CD unit in β-CDP to Cur was determined to be 1:1. The diffusion coefficient and diffusion activation energy of Cur-β-CDP were calculated in an electrochemical study. This supramolecular complex worked well in vitro to inhibit the proliferation of hepatoma carcinoma cells HepG2. Remarkably, this method visibly reduced the undesirable side effects on normal cells, without weakening the anti-cancer activity of the drugs. We expect that the obtained host–guest complex will provide a new approach for delivering natural drug molecules, having low water solubility.

A supramolecular complex of hydrazide-pillar[5]arene and bisdemethoxycurcumin with potential anti-cancer activity

Pillar[5]arene complexes of the naturally occurring compound bisdemethoxycurcumin (BDMC) were acquired for improving the water solubility and stability of BDMC. As a family member of curcuminoid compounds, BDMC has many interesting therapeutic properties. However, its low aqueous solubility and stability resulted in poor availability and restricted the clinical efficacy. Pillar[5]arenes with hydrophilic ends and a hydrophobic cavity could include with BDMC based on size matching. The synthesized hydrazide-pillar[5]arene (HP5A) and BDMC had a strong host–guest interaction with a 1:1 binding stoichiometry. Furthermore, the HP5A ⊃ BDMC complex could self-assemble into well-defined fibers in water/ethanol solution. This supramolecular complex worked well in vitro for inhibiting the proliferation of hepatoma carcinoma cells HepG2. Remarkably, this method of complexation with pillar[5]arenes visibly reduced the undesirable side effects on normal cells without weakening the anti-cancer activity of the drugs. We expected that the obtained host–guest complex and fibrous assembly would provide a promising platform for delivering drugs with low water solubility.

Strepantibins A-C: Hexokinase II Inhibitors from a Mud Dauber Wasp Associated Streptomyces sp.

Two new p-terphenyls, strepantibins A and B (1 and 2), along with the first representative of a naturally occurring bisphenyltropone, strepantibin C (3), were characterized from a Streptomyces sp. associated with the larvae of the mud dauber wasp Sceliphron madraspatanum. Their structures were determined by high-resolution electrospray ionization mass spectrometry, NMR, and X-ray crystallography data interpretation. Strepantibins A-C inhibited hexokinase II (HK2) activity and displayed antiproliferative activity against hepatoma carcinoma cells HepG-2, SMMC-7721and plc-prf-5. In SMMC-7721 cells treated with strepantibin A, the morphological characteristics of apoptosis were observed.

Angucycline Glycosides from an Intertidal Sediments Strain Streptomyces sp. and Their Cytotoxic Activity against Hepatoma Carcinoma Cells.

Four angucycline glycosides including three new compounds landomycin N (1), galtamycin C (2) and vineomycin D (3), and a known homologue saquayamycin B (4), along with two alkaloids 1-acetyl-β-carboline (5) and indole-3-acetic acid (6), were isolated from the fermentation broth of an intertidal sediments-derived Streptomyces sp. Their structures were established by IR, HR-ESI-MS, 1D and 2D NMR techniques. Among the isolated angucyclines, saquayamycin B (4) displayed potent cytotoxic activity against hepatoma carcinoma cells HepG-2, SMMC-7721 and plc-prf-5, with IC50 values 0.135, 0.033 and 0.244 μM respectively, superior to doxorubicin. Saquayamycin B (4) also induced apoptosis in SMMC-7721 cells as detected by its morphological characteristics in 4′,6-diamidino-2-phenylindole (DAPI) staining experiment.

Design and screening of a chimeric survivin-specific nanobody and its anticancer activities in vitro.

Survivin is a strong inhibitor of apoptosis protein and a promising target for cancer prevention and treatment. Here, we report the design and preparation of novel chimeric nanobodies (Nbs) that could specifically bind to survivin. We screened the peptides from phage-displayed libraries (7-mer, 12-mer) for nonconserved sequences of complementarity-determining regions (CDRs) in the scaffold of the Nb. By a combination of the nonconserved sequences for CDRs, the corresponding chimeric Nbs (10 Nbs) were prepared with genetic operations. The antisurvivin Nb TAT-Nb4A (a fusion with cellular transduction peptide TAT) was found to be the most efficient antibody on the basis of the results from enzyme-linked immunosorbent assay, MTT, and flow cytometry when these nanobodies were tested with hepatoma carcinoma cell HepG2. TAT-Nb4A could inhibit the growth of HepG2 and promote cancer cell apoptosis significantly in a dose-dependent and time-dependent manner: the apoptosis rate reached 52.5% when the concentration of TAT-Nb4A was 120 μg/ml. Western blotting with cells expressing survivin showed that the prepared nanobody could efficiently bind to expressed survivin and blocked the signaling pathway in which survivin played a role. This study provided a convenient and feasible method of obtaining a novel specific Nb with the case of survivin as a good example.

A type of novel fluorescent magnetic carbon quantum dots for cells imaging and detection.

A new type of multifunctional fluorescent magnetic carbon quantum dots SPIO@CQDs(n) ([superparamagnetic iron oxide nanoparticles (SPIO), carbon quantum dots, (CQDs)]) with magnetic and fluorescence properties was designed and prepared through layer-by-layer self-assembly method. The as-synthesized SPIO@CQDs(n) exhibited different emission colors including blue, green, and red when they were excited at different excitation wavelengths, and its fluorescent intensity increased as the increase of CQD layer (n). SPIO@CQDs(n) with quite low toxicity could mark cytoplasm with fluorescence by means of nonimmune markers. The mixture sample of liver cells L02 and hepatoma carcinoma cells HepG2 was taken as an example, and HepG2 cells were successfully separated and detected effectively by SPIO@CQDs(n), with a separation rate of 90.31%. Importantly, the designed and prepared SPIO@CQDs( n ) are certified to be wonderful biological imaging and magnetic separation regents.

Effect of rhDCN on the expression of HLA molecules on HepG2 cell lines.

Objective To observe the regulatory effect of recombinant human DCN on the expression of HLA class Ⅰ, Ⅱ molecule on hepatoma carcinoma cell HepG2 and investigate the relatively immune mechanism of human DCN on enhancing anti-tumor effect. Methods After transfected HepG2 cells with pcDNA3.1 (+)-DCN by liposome transfection, the expression of HLA class Ⅰ , Ⅱ molecule and the apoptotic indexes were analyzed by the flow cytometer. Results The expression of HLA class Ⅰ , Ⅱ molecule on the HepG2 cells transfected with pcDNA3.1 (+)-DCN was up-regulated with the apoptosis indexes being significantly higher than that of other control groups. Conclusion The human DCN can induce HepG2 apoptosis and up-regulate the expressions of HLA class Ⅰ , Ⅱ molecule which may contribute to its antitumor effect. Key words: Proteoglycans; HepG2; Genes, MHC class Ⅰ; Genes, MHC class Ⅱ(2007011107)