DNA can be used to nanofabricate three-dimensional (3D) polyhedra. A variety of applications of 3D DNA assemblies have been proposed. Drug encasulation and intracellular delivery using DNA nanoparticles, however, have remained a challenge. Here, we create a distinct five-point-star motif and aptamer-conjugated six-point-star motif using well-used primer sequences to intermolecularly construct DNA icosahedra as a nanocarrier for doxorubicin. Aptamer-conjugated doxorubicin-intercalated DNA icosahedra (Doxo@Apt-DNA-icosa) show an efficient and specific internalization for killing epithelial cancer cells.

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There are about 200 -600 million betel quid (BQ) chewers in the world. BQ chewing is one of the major risk factor of hepatocarcinoma, oropharyngeal, and esophagus cancers in Taiwan, India, and Southeast Asian countries. Thus, the precise molecular mechanisms deserve investigation. We used cultured primary keratinocytes and KB

There are 600 million betel quid (BQ) chewers in the world. BQ chewing is a major etiologic factor of oral cancer. Areca nut (AN) and arecoline may inhibit the growth of oral mucosal fibroblasts (OMF) and keratinocytes. In this study, AN extract (100-800 microg/ml) and arecoline (20-120 microM) inhibited the growth of oral KB cells by 36-90 and 15-75%, respectively. Exposure to arecoline (> 0.2 mM) for 24 h induced G(2)/M cell cycle arrest of OMF and KB cells. Areca nut extract (> 400 microg/ml) also induced G(2)/M arrest of KB cells, being preceded by S-phase arrest at 7-h of exposure. No evident sub-G(0)/G(1) peak was noted. Marked retraction and intracellular vacuoles formation of OMF and KB cells were observed. Glutathione (GSH) level, mitochondrial membrane potential (Deltabetam) and H(2)O(2) production of KB cells were measured by flow cytometry. GSH level [indicated by 5-chloromethyl-fluorescein (CMF) fluorescence] was depleted by 24-h exposure of KB cells to arecoline (0.4-1.2 mM) and AN extract (800-1200 microg/ml), with increasing the percentage of cells in low CMF fluorescence. By contrast, arecoline (0.1-1.2 mM) and AN extract (800-1200 microg/ml) induced decreasing and increasing H(2)O(2) production (by 2',7'-dichloro- fluorescein fluorescence), respectively. Hyperpolarization of Deltabetam (increasing of rhodamine uptake) was noted by 24-h exposure of KB cells to arecoline (0.4-1.2 mM) and AN extract (800-1200 microg/ml). AN extract (100- 1200 microg/ml) and arecoline (0.1-1.2 mM) induced little DNA fragmentation on KB cells within 24 h. These results indicate that AN ingredients are crucial in the pathogenesis of oral submucous fibrosis (OSF) and oral cancer by differentially inducing the dysregulation of cell cycle control, Deltabetam, GSH level and intracellular H(2)O(2) production, these events being not coupled with cellular apoptosis.

The protein delivery across cellular membranes or compartments is limited by low biomembrane permeability because of the hydrophobic characteristics of cell membranes. Usually the delivery processes utilize passive protein channels or active transporters to overcome the membrane impediment. In this report, we demonstrate that arginine-rich intracellular delivery (AID) peptide is capable of efficiently delivering fused fluorescent proteins unpreferentially into different plant tissues of both tomato (a dicot plant) and onion (a monocot plant) in a fully bioactive form. Thus, cellular internalization via AID peptide can be a powerful tool characterized by its simplicity, non-invasion and high efficiency to express those bioactive proteins in planta or in plant cells in vivo. This novel method may alternatively provide broader applications of AID chimera in plants without the time-consuming transgenic approaches.

Research Summary• Protein delivery across cellular membranes or compartments is primarily limited by low biomembrane permeability.• Many protein transduction domains (PTDs) have previously been generated, and covalently cross-linked with cargoes for cellular internalization.• An arginine-rich intracellular delivery (AID) peptide could rapidly deliver fluorescent proteins or β -galactosidase enzyme into plant and animal cells in a noncovalent fashion. The possible mechanism of this noncovalent protein transduction (NPT) may involve macropinocytosis.• The NPT via a nontoxic AID peptide provides a powerful tool characterized by its simplicity and quickness to have active proteins function in living cells in vivo . This should be of broad utility for functional enzyme assays and protein therapies in both plant biology research as well as biomedical applications.

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1 Hydroxychavicol (HC; 10 ± 50 mM), a betel leaf component, was found to suppress the 2% H 2 O 2 -induced lucigenin chemiluminescence for 53 ± 75%. HC (0.02 ± 2 mM) was also able to trap superoxide radicals generated by a xanthine/xanthine oxidase system with 38 ± 94% of inhibition. Hydroxyl radicals-induced PUC18 plasmid DNA breaks was prevented by HC (1.6 ± 16 mM). 2 A 24-h exposure of KB cells to HC (0.5, 1 mM) resulted in 54 ± 74% cell death as analysed by a 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. HC (10, 50 mM) further suppressed the growth of KB cells (15 and 76%, respectively). Long-term colony formation of KB cells was inhibited by 51% with 10 mM HC. 3 Pretreatment of KB cells with 100 mM HC inhibited the attachment of KB cells to type I collagen and ®bronectin by 59 and 29%, respectively. 4 Exposure of KB cells to 0.1 mM HC for 24 h resulted in cell cycle arrest at late S and G2/M phase. Increasing the HC concentration to 0.25 and 0.5 mM led to apoptosis as revealed by detection of sub-G 0 /G 1 peaks with a concomitant decrease in the number of cells residing in late S and G 2 /M phase. 5 Inducing the apoptosis of KB cells by HC was accompanied by marked depletion in reduced form of GSH (40.2 mM) and the increasing of reactive oxygen species production (40.1 mM) as analysed by CMF-and DCF-single cell¯uorescence¯ow cytometry. 6 These results indicate that HC exerts antioxidant property at low concentration. HC also inhibits the growth, adhesion and cell cycle progression of KB cells, whereas its induction of KB cell apoptosis (HC40.1 mM) was accompanied by cellular redox changes.