Effects of a particular heptapeptide on the IFN-α-sensitive CML cells

Abstract: Using the phage display biopanning technique, we have previously identified a heptapeptide KLWVIPQ which specifically bind to the surface of the IFN-α sensitive but not the IFN-α-resistant CML cells. The effects of this heptapeptide to the IFN-α-sensitive CML cells were investigated in the present study. IFN-α-sensitive KT-1/A3 and IFN-α-resistant KT-1/A3R CML cells were transfected by pEGFP KLWVIPQ expression vector and/or induced by IFN-α. WST-1 cell proliferation assay, flow cytometry and western blotting were performed to determine the effects of this heptapeptide and/or IFN-α on CML cells. The viability of the KT-1/A3 cells w as inhibited and apoptosis was induced by either expression of the heptapeptide KLWVIPQ or IFN-α treatment with concurrent up-regulation of P53 and down-regulation of P210bcr/abl. However, these effects were not observed in the IFN-α-resistant KT-1/A3R cells. These results suggest that the heptapeptide KLWVIPQ shares a similar mechanism w ith IFN-α in the regulat ion of CML cell growth and apoptosis, implying that the heptapeptide KLWVIPQ could be a novel target to go further into mechanisms of IFN-α sensitivity and/or resistance in CML

Mathematical modeling of particle deposition and distribution in indoor environments

Indoor air quality is now receiving more attention than ever before and it is known that indoor particulate matters have significant influences on indoor air quality. A few numerical models have been developed to study indoor particle dynamics by either the Lagrangian or the Eulerian approach. However, some of the important features of indoor particles, for example, the effect of turbulent dispersion for the Lagrangian simulations and the modeling of deposition for the Eulerian models, were overlooked or modeled improperly and we still do not have an effective prediction tool which is able to model both spatial and temporal profiles of indoor particle distribution and deposition quantitatively. The primary objective of the present work is to study particle deposition and distribution in indoor environments by means of both Lagrangian simulation and Eulerian modeling and to gain more understanding of the behavior of indoor particles with different sizes.DOCTOR OF PHILOSOPHY (MAE

Regulatory effects of resveratrol on antioxidant enzymes: A mechanism of growth inhibition and apoptosis induction in cancer cells

Resveratrol (RSV) is a natural polyphenol that is known as a powerful chemopreventive and chemotherapeutic anticancer molecule. This study focused on the effects of RSV on the activities and expression levels of antioxidant enzymes in the cancer cells. Prostate cancer PC-3 cells, hepatic cancer HepG2 cells, breast cancer MCF-7 cells and the non-cancerous HEK293T kidney epithelial cells were treated with a wide range of RSV concentrations (10-100 µM) for 24-72 h. Cell growth was estimated by trypan blue staining, activities of the antioxidant enzymes were measured spectrophotometrically, expression levels of the antioxidant enzymes were quantified by digitalizing the protein band intensities on Western blots, and the percentage of apoptotic cells was determined by flow cytometry. Treatment with a low concentration of RSV (25 µM) significantly increased superoxide dismutase (SOD) activity in PC-3, HepG2 and MCF-7 cells, but not in HEK293T cells. Catalase (CAT) activity was increased in HepG2 cells, but no effect was found on glutathione peroxidase (GPX) upon RSV treatment. RSV-induced SOD2 expression was observed in cancer cells, although the expression of SOD1, CAT and GPX1 was unaffected. Apoptosis increased upon RSV treatment of cancer cells, especially in PC-3 and HepG2 cells. Together, our data demonstrated that RSV inhibits cancer cell growth with minimal effects on non-cancerous cells. We postulate that the disproportional up-regulation of SOD, CAT and GPX expression and enzymatic activity in cancer cells results in the mitochondrial accumulation of H2O2, which in turn induces cancer cell apoptosis. © 2013 The Korean Society for Molecular and Cellular Biology and Springer Netherlands

Synthesis of Cucurbitacin B Derivatives as Potential Anti-Hepatocellular Carcinoma Agents

Cucurbitacin B shows potent activity against tumor cells, but its high toxicity limits its application in the clinic. A series of cucurbitacin B derivatives was synthesized and evaluated for their anti-hepatocellular carcinoma (HCC) activities against the HepG-2 cell line. These compounds were also tested for their toxicity against the L-O2 normal cell line. The compound with the most potential, 10b, exhibited potent activity against the HepG-2 cell line with an IC50 value of 0.63 μM. Moreover, compound 10b showed the highest TI value (4.71), which is a 14.7-fold improvement compared to its parent compound cucurbitacin B. A preliminary molecular mechanism study of 10b indicated that 10b could inhibit P-STAT3 to induce the activation of mitochondrial apoptotic pathways. An in vivo acute toxicity study indicated that the compound 10b has preferable safety and tolerability compared with cucurbitacin B. These findings indicate that compound 10b might be considered as a lead compound for exploring effective anti-HCC drugs

LncRNA XIST/miR-200c regulates the stemness properties and tumourigenicity of human bladder cancer stem cell-like cells

Abstract Background The abnormal expression of non-coding RNAs (ncRNAs), such as microRNAs and long ncRNAs, often contribute to the development of cancers. miR-200c functions as a tumour suppressor that impacts the growth of bladder cancer cells and the epithelial-to-mesenchymal transition (EMT). LncRNA X inactive specific transcript (XIST) is highly expressed in tumour tissues, promotes cancer progression and might act as an miRNA molecular sponge. This study aimed to examine the relationship between lncRNA XIST and miR-200c and to assess their functions in the regulation of the stemness properties and tumourigenicity of human bladder cancer stem cell (BCSC)-like cells. Methods Biological effects including cell clone formation, sphere formation, self-renewal properties and mouse tumourigenesis were examined in BCSC-like cells with miR-200c overexpression or XIST knockdown. Real-time PCR and western blotting were used to detect the expression changing of related factors in BCSC-like cells gene models. Dual luciferase reporter assay was used to examine the changes of XIST and miR-200c expression levels. Results The results indicated that miR-200c overexpression and XIST knockdown could inhibit cell clone formation, self-renewal ability and EMT in BCSC-like cells. miR-200c knockdown could restore the tumour growth inhibition caused by XIST knockdown. Conclusion LncRNA XIST may act as an inhibitor of miR-200c to regulate the stemness properties and tumourigenicity of bladder cancer cells, and our findings might reveal a potential strategy of targeting XIST for bladder cancer therapy

Hydrophobic Janus Foam Motors: Self-Propulsion and On-The-Fly Oil Absorption

In this work, we for the first time have proposed and fabricated a self-propelled Janus foam motor for on-the-fly oil absorption on water by simply loading camphor/stearic acid (SA) mixture as fuels into one end of the SA-modified polyvinyl alcohol (PVA) foam. The as-fabricated Janus foam motors show an efficient Marangoni effect-based self-propulsion on water for a long lifetime due to the effective inhibition of the rapid release of camphor by the hydrophobic SA in the fuel mixture. Furthermore, they can automatically search, capture, and absorb oil droplets on the fly, and then be spontaneously self-assembled after oil absorption due to the self-propulsion of the motors as well as the attractive capillary interactions between the motors and oil droplets. This facilitates the subsequent collection of the motors from water after the treatment. Since the as-developed Janus foam motors can effectively integrate intriguing behaviors of the self-propulsion, efficient oil capture, and spontaneous self-assembly, they hold great promise for practical applications in water treatment

Transient Micromotors That Disappear When No Longer Needed.

Transient self-destroyed micromotors that autonomously disappear in biological media at controlled rates upon completing their task, without leaving a toxic residue, are presented. The propulsion and degradation characteristics of the self-destroyed Mg/ZnO, Mg/Si, and Zn/Fe Janus micromotors and single-component Zn micromotors are described. The degradation of the Janus micromotors relies on the different corrosion rates of their core-shell components. Inductively coupled plasma optical emission spectrometry measurements are used to probe the time-dependent degradation of the different constituents of the micromotors. The toxicity of the transient micromotors is discussed toward their potential use in biomedical applications. This concept of transient micromotors offers considerable potential for diverse practical applications in the near future

Rationally Designed Bi₂M₂O₉ (M = Mo/W) Photocatalysts with Significantly Enhanced Photocatalytic Activity

Novel Bi2W2O9 and Bi2Mo2O9 with irregular polyhedron structure were successfully synthesized by a hydrothermal method. Compared to ordinary Bi2WO6 and Bi2MoO6, the modified structure of Bi2W2O9 and Bi2Mo2O9 were observed, which led to an enhancement of photocatalytic performance. To investigate the possible mechanism of enhancing photocatalytic efficiency, the crystal structure, morphology, elemental composition, and optical properties of Bi2WO6, Bi2MO6, Bi2W2O9, and Bi2Mo2O9 were examined. UV-Vis diffuse reflectance spectroscopy revealed the visible-light absorption ability of Bi2WO6, Bi2MO6, Bi2W2O9, and Bi2Mo2O9. Photoluminescence (PL) and photocurrent indicated that Bi2W2O9 and Bi2Mo2O9 pose an enhanced ability of photogenerated electron–hole pairs separation. Radical trapping experiments revealed that photogenerated holes and superoxide radicals were the main active species. It can be conjectured that the promoted photocatalytic performance related to the modified structure, and a possible mechanism was discussed in detail

Autonomous Motion and Temperature-Controlled Drug Delivery of Mg/Pt-Poly(<i>N</i>‑isopropylacrylamide) Janus Micromotors Driven by Simulated Body Fluid and Blood Plasma

In this work, we have demonstrated the autonomous motion of biologically-friendly Mg/Pt-Poly­(<i>N</i>-isopropylacrylamide) (PNIPAM) Janus micromotors in simulated body fluids (SBF) or blood plasma without any other additives. The pit corrosion of chloride anions and the buffering effect of SBF or blood plasma in removing the Mg­(OH)₂ passivation layer play major roles for accelerating Mg–H₂O reaction to produce hydrogen propulsion for the micromotors. Furthermore, the Mg/Pt-PNIPAM Janus micromotors can effectively uptake, transport, and temperature-control-release drug molecules by taking advantage of the partial surface-attached thermoresponsive PNIPAM hydrogel layers. The PNIPAM hydrogel layers on the micromotors can be easily replaced with other responsive polymers or antibodies by the surface modification strategy, suggesting that the as-proposed micromotors also hold a promising potential for separation and detection of heavy metal ions, toxicants, or proteins