Abstract. In previous years, three-dimensional (3D) cell culture technology has become a focus of research in tumor cell biology, using a variety of methods and materials to mimic the in vivo microenvironment of cultured tumor cells ex vivo. These 3D tumor cells have demonstrated numerous different characteristics compared with traditional two-dimensional (2D) culture. 3D cell culture provides a useful platform for further identifying the biological characteristics of tumor cells, particularly in the drug sensitivity area of the key points of translational medicine. It promises to be a bridge between traditional 2D culture and animal experiments, and is of great importance for further research in the field of tumor biology. In the present review, previous 3D cell culture applications, focusing on anti-tumor drug susceptibility testing, are summarized.
Purpose To investigate the expression of endoplasmic reticulum (ER) stress-related genes, glucose-regulated protein 78 (GRP78) and growth arrest DNA damage-inducible gene 153 (GADD153)/CPEBP homologous protein (CHOP), in rat retinal detachment (RD) model. Materials and methods At various time points after RD, the apoptosis of retinal cells was detected by TdT-mediated fluorescein-16-dUTP nick-end labelling (TUNEL) assay; GRP78 and GADD153 mRNA levels were detected by reverse transcription (RT)-PCR; proteins were detected by western blotting analysis; protein distributions in the retinal cells were observed by immunofluorescence using laser-scanning confocal microscope. Results After RD, the apoptosis was peaked on 2-4 d and then dropped down. The GRP78 mRNA and GADD153 mRNA levels in RD groups on 0.5, 1, 2, and 4 d were all significantly higher than those in the control group (Po0.05). The expression of GRP78 mRNA peaked on 1-2 d after RD. Expression of GRP78 protein was significantly higher than that in the normal control group on 0.5, 1, 2, 4, 8, 16, and 32 d after RD (Po0.05). The expression of GRP78 protein was observed in all the layers of retina in the RD groups, and peaked on 8, 16, and 32 d. The expression of GADD153 protein, mostly in photoreceptor layers, was significantly higher than that in the control group on 0.5, 1, 2, and 4 d after RD (Po0.05). Conclusions ER stress-related markers, GRP78 and GADD153, are elevated after RD.The elevation of GADD153 is in parallel with the post-RD apoptosis of retinal cells, suggesting that ER stress-mediated death is likely to be activated after RD and involved in post-RD vision loss.
miRNAs are short, noncoding RNAs that regulate expression of target genes at post-transcriptional levels and function in many important cellular processes, including differentiation, proliferation, etc. In this study, we observed down-regulation of miR-199a-5p during monocyte/macrophage differentiation of HL-60 and THP-1 cells, as well as human CD34(+) HSPCs. This down-regulation of miR-199a-5p resulted from the up-regulation of PU.1 that was demonstrated to regulate transcription of the miR-199a-2 gene negatively. Overexpression of miR-199a-5p by miR-199a-5p mimic transfection or lentivirus-mediated gene transfer significantly inhibited monocyte/macrophage differentiation of the cell lines or HSPCs. The mRNA encoding an ACVR1B was identified as a direct target of miR-199a-5p. Gradually increased ACVR1B expression level was detected during monocyte/macrophage differentiation of the leukemic cell lines and HSPCs, and knockdown of ACVR1B resulted in inhibition of monocyte/macrophage differentiation of HL-60 and THP-1 cells, which suggested that ACVR1B functions as a positive regulator of monocyte/macrophage differentiation. We demonstrated that miR-199a-5p overexpression or ACVR1B knockdown promoted proliferation of THP-1 cells through increasing phosphorylation of Rb. We also demonstrated that the down-regulation of ACVR1B reduced p-Smad2/3, which resulted in decreased expression of C/EBPα, a key regulator of monocyte/macrophage differentiation, and finally, inhibited monocyte/macrophage differentiation.
SnO2/Al2O3 supports with different SnO2 loadings were prepared by using a deposition–precipitation method and characterized by using N2 and CO adsorption–desorption, XRD, H2 temperature‐programmed reduction, and X‐ray photoelectron spectroscopy techniques. SnO2 dispersed finely on the Al2O3 surface with a capacity of 0.172 mmol 100 m−2, which equals 6.4 % SnO2 loading. Below this loading, no crystalline SnO2 can be detected owing to the formation of the sub‐monolayer‐ or monolayer‐dispersed SnO2 phase. Crystalline SnO2 can be observed only if the SnO2 loading reaches 9 %. With use of these SnO2/Al2O3 supports, all prepared Pd/SnO2/Al2O3 catalysts demonstrate increased activity compared to Pd/SnO2 and Pd/Al2O3 owing to the presence of more active oxygen species on SnO2/Al2O3 supports as well as their higher surface areas, which improve Pd dispersion. This result indicates that with SnO2/Al2O3 supports, less amount of Pd can be used to obtain catalysts with competitive performance.
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