Synergistic Flame Retardant Effect between Ionic Liquid Functionalized Imogolite Nanotubes and Ammonium Polyphosphate in Epoxy Resin.

Ionic liquid functionalized imogolite nanotubes (INTs-PF-ILs) were introduced into the epoxy resin (EP)/ammonium polyphosphate (APP) system to investigate the flame retardant performance and thermal properties using the limiting oxygen index (LOI) test, the UL-94 test, and the cone calorimeter test (CCT). The results suggested that a synergistic effect exists between INTs-PF-ILs and APP on the char formation and anti-dripping behavior of EP composites. For the EP/APP, an UL-94 V-1 rating was obtained for the loading of 4 wt% APP.

Synergistic Flame Retardant Effect between Ionic Liquid-Functionalized Imogolite Nanotubes and Ammonium Polyphosphate in Unsaturated Polyester Resin.

Imogolite nanotubes (INTs) were synthesized from tetraethoxysilane, aluminum nitrate nonahydrate, and ammonia solution by the method of Arancibia-Miranda, and their dispersion was modified by 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF) to obtain ionic liquid (IL)-functionalized INTs (INTs-PF-ILs). Then, the flame retardant INTs-PF-ILs was complexed with ammonium polyphosphate (APP) and applied to unsaturated polyester resin (UPR). The limiting oxygen index value and the UL-94 level of the UPR/APP/INTs-PF-ILs composites reached 28 and V-0, respectively.

HIF-1-mediated metabolic reprogramming reduces ROS levels and facilitates the metastatic colonization of cancers in lungs.

Hypoxia-inducible factor 1 (HIF-1) has been associated with distant tumor metastasis; however, its function in multiple metastatic processes has not yet been fully elucidated. In the present study, we demonstrated that cancer cells transiently upregulated HIF-1 activity during their metastatic colonization after extravasation in the lungs in hypoxia-independent and reactive oxygen species (ROS)-dependent manners. Transient activation induced the expression of lactate dehydrogenase A and phosphorylation of the E1α subunit of pyruvate dehydrogenase, which indicated the reprogramming of glucose metabolic pathways from mitochondrial oxidative phosphorylation to anaerobic glycolysis and lactic acid fermentation.

siRNA-mediated MDM2 inhibition sensitizes human lung cancer A549 cells to radiation.

MDM2 (murine double minute 2) is well-documented to play a key role in radiation response and tumor radiosensitivity, thus offering an attractive clinic drug target to enhance tumor sensitivity to anti-cancer radiotherapy. In this study, we designed and tested two siRNA fragments against human MDM2 in non-small cell human lung cancer A549 cells. Transfection of mammalian expression vector pUR/U6 containing either MDM2 siRNA1 or siRNA2 fragment was shown to reduce MDM2 mRNA levels by 72% and 31%, respectively.

Identification of differentially expressed genes contributing to radioresistance in lung cancer cells using microarray analysis.

Radiotherapy has played a key role in the control of tumor growth in many cancer patients. It is usually difficult to determine what fraction of the tumor cell population is radioresistant after a course of radiotherapy. The response of tumor cells to radiation is believed to be accompanied by complex changes in the gene expression pattern.

Expression of ErbB2 enhances radiation-induced NF-kappaB activation.

Her-2/neu (ErbB2) oncogene, the second member of the epidermal growth factor receptor (EGFR) family, encodes a transmembrane tyrosine kinase receptor in Her-2-positive tumors. Accumulating evidences demonstrate that signaling networks activated by EGFR and transcription factor NF-kappaB are associated with cell response to ionizing radiation (IR). The present study shows that overexpression of ErbB2 enhanced NF-kappaB activation induced by IR in human breast carcinoma MCF-7 cells transfected with ErbB2 genes (MCF-7/ErbB2).

Manganese superoxide dismutase-mediated gene expression in radiation-induced adaptive responses.

Antioxidant enzymes are critical in oxidative stress responses. Radioresistant variants isolated from MCF-7 human carcinoma cells following fractionated ionizing radiation (MCF+FIR cells) or overexpression of manganese superoxide dismutase (MCF+SOD cells) demonstrated dose-modifying factors at 10% isosurvival of 1.8 and 2.