[Show abstract][Hide abstract]ABSTRACT: Arsenic trioxide (ATO) has demonstrated clinical efficacy in acute promyelocytic leukemia (APL) and in vitro activity in various solid tumors. As2O3 as single agent exhibits poor efficacy for treatment of hepatocellular carcinoma (HCC) in phase II trial, suggesting that new modalities of treatment with enhanced therapeutic effect and alleviated toxicity are needed for application of As2O3 on patients with HCC. Survivin is the strongest inhibitor of apoptosis protein over-expressed in tumors, which has been proposed as an attractive target for new anticancer interventions. Disruption of survivin by the plasmid encoding the phosphorylation-defective mouse survivin threonine 34→alanine mutant (Msurvivin T34A plasmid) has proved a promising strategy for suppressing a variety of murine cancer. In the present study, we attempted to test Msurvivin T34A and arsenic trioxide (ATO) on a cell line and mice bearing subcutaneous tumors, with regard to their effects and mechanisms. We observed that the co-treatment with surivinT34A and ATO significantly enhanced the antitumor activity by induction of apoptosis in Hepa1-6 tumor cells in vitro, compared with control groups. The synergistic apoptosis-inducing effect of combination of these two drugs resulted in elevation of reactive oxygen species (ROS) level which could be antagonized by the antioxidant N-acetyl-l-cysteine. The combination treatment induced ROS-dependent collapse of the mitochondrial membrane potential. Moreover, the tumor growth in vivo was also remarkably inhibited by combination of surivinT34A and ATO when compared with control groups. Our findings demonstrate that the combination of surivinT34A and ATO exerted synergistic antitumor effects, providing a new perspective for clinical treatment of HCC.
[Show abstract][Hide abstract]ABSTRACT: Two heterodimeric receptors consisting of either IL-20R1 or IL-22R1 in complex with a common β receptor subunit IL-20R2 are shared by three of the IL-20 family of cytokines: IL-19, IL-20, and IL-24. These proinflammatory cytokines have been implicated in the pathogenesis of some autoimmune diseases, including rheumatoid arthritis (RA), psoriasis, and atopic dermatitis. Although mAbs against IL-19 and IL-20 have each been shown to modulate disease severity of collagen-induced arthritis in animal models, and anti-IL-20 therapeutic Ab has exhibited some efficacy in the treatment of RA in clinical trials, benefits for a complete blockade of these functionally redundant cytokines remain to be explored. In this report, we show that recombinant human soluble IL-20R2-Fc fusion protein binds to IL-19, IL-20, and IL-24 with similar high affinity and blocks their signaling in vitro. In DBA/1 mouse collagen-induced arthritis model, recombinant human IL-20R2-Fc exhibits comparable efficacy as TNF blocker etanercept in the treatment of established arthritis, whereas the combined use of both biologics manifests little synergistic therapeutic effects. In situ ligand-receptor functional binding analysis shows that a large amount of immune infiltrates expressing high levels of TNFR and IL-20 subfamily cytokines congregate within the inflamed disease tissues. Colocalization experiments reveal that signals from IL-20R2 and TNF transduction pathways seem to converge in macrophages and function in tandem in orchestrating the pathogenesis of RA. Elucidation of this interaction provides a better understanding of cytokine cross-talk in RA and a rationale for more effective biologic therapies that target IL-20R2 instead of individual cytokines from IL-20 family.
[Show abstract][Hide abstract]ABSTRACT: The invention of DNA cloning over 40years ago marked the advent of molecular biology. The technique has now become a routine practice in any modern biomedical laboratory. Although positive-selection of recombinants in DNA cloning seems to be superior to blue/white selection based on the disruption of the lacZ gene, it is rarely practiced due to its high background, lack of multiple cloning sites, and inability to express the genes of interest or purify the protein products. Here we report the creation of a new positive-selection cloning vector dubbed pKILLIN, which overcomes all of the above pitfalls. The essence behind its high cloning efficiency is the extreme toxicity and small size of the toxic domain of killin, a recently discovered p53 target gene. Insertion inactivation of killin within the multiple cloning site via either blunt- or sticky-end ligation not only serves as a highly efficient cloning trap, but also may allow any cloned genes to be expressed as His-tagged fusion proteins for subsequent purification. Thus, pKILLIN is a versatile positive-selection vector ideal for cloning PCR products, making DNA libraries, as well as routine cloning and bacterial expression of genes.
[Show abstract][Hide abstract]ABSTRACT: Aurora A plays an essential role in centrosome maturation, separation and in the formation of the mitotic bipolar spindle. Overexpression or amplication of Aurora A gene has been detected in many cancer cell lines and various tumor tissues, including breast cancer, suggesting that Aurora A might be drug target for breast cancer treatment. In the current study, short hairpin RNA targeting Aurora A was cloned into pGenesil-2 plasmid vector and then transfected into MDA-MB-435S and ZR-75-30 human breast cancer cells using cationic liposome. Reduced expression of Aurora A was detected by RT-PCR and Western blot. The effect of pGenesil-2-shAURKA plasmid on tumor growth in MDA-MB-435S xenogenic implantation model was studied. pGenesil-2-shAURKA plasmid inhibited tumor growth significantly by systemantic administration. To further study the underlying mechanisms, cell apoptosis and proliferation were investigated by flow cytometric analysis, propidium iodide staining, TUNEL and Ki-67 immunostaining respectively. Increased apoptosis and reduced cell proliferation were detected in vitro and in vivo studies. In summary, our results suggested that specific knockdown of Aurora A expression by vector based shRNA may be a potential therapy for human breast cancer.
Article · May 2010 · International Journal of Oncology
[Show abstract][Hide abstract]ABSTRACT: Hydrolytic degradable PBT/PEG copolymer was synthesized by macromolecular transesterification method from PBT and PEG macromonomers. The resultant copolymers were characterized by (1)H-NMR and GPC. The non-isothermal crystallization behavior of these copolymers was studied by differential scanning calorimetry (DSC). The water absorption and hydrolytic degradation behavior of PBT/PEG copolymers were also studied in detail.
Article · Apr 2007 · Journal of Materials Science Materials in Medicine
[Show abstract][Hide abstract]ABSTRACT: In this work, a kind of aliphatic biodegradable polyesteramide (PEA) copolymer based on 6-aminocaproic acid, adipic acid,
and 1,6-hexane diol was synthesized by melt polycondensation method, and was characterized by 1H-NMR, FTIR and DSC. The PEA fiber was prepared by melt-spinning method. Tensile properties of the as-spun and hot-drawn fibers
were also investigated. Hydrolytic degradation behavior of PEA copolymer chips and fibers were evaluated by weight loss in
PBS solution with different pH value. The alkaline degradation behavior of fiber was also studied on change of diameter and
surface morphology. During alkaline degradation, the PEA fiber underwent surface erosion.
[Show abstract][Hide abstract]ABSTRACT: In this paper, a new kind of biodegradable polyetheresteramide-based polyurethane (PEEA-U) copolymers were prepared by melt polymerization from ε-caprolactone, 6-aminocaproic acid, poly(ethylene glycol), and toluene diisocyanate. The obtained polymers were characterized by 1H NMR, FTIR, DSC, WAXD, and TGA/DTG. The water absorption, hydrolytic degradation, and alkaline degradation behavior of these copolymers were also studied in detail.
[Show abstract][Hide abstract]ABSTRACT: In this article, a pH sensitive semi-interpenetrating network (SIPN) hydrogel based on methacrylic acid, BSA, and PEG was
prepared by UV initiated free radical polymerization. The swelling behavior and pH sensitivity of these hydrogels were studied
in detail. With the increase in pH of the aqueous solution from 1.7 to 9.23, the swelling ratio of these hydrogels increased
accordingly. The effect of BSA and crosslinker (BIS) content on the swelling behavior was more complicated, and the results
were shown in the text.