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Hao Y.,Xian Jiaotong University | Gao R.,Xian Jiaotong University | Liu D.,First Hospital Of Xian Jiaotong University | Tang Y.,Xian Jiaotong University | Guo Z.,Xian Jiaotong University
Analytical and Bioanalytical Chemistry | Year: 2015

A novel surface imprinting polymer based on magnetic carbon nanotubes was prepared using dendritic polyethyleneimine as functional monomer to amplify the number of imprinted cavities. The characteristics of resulting polymers were evaluated by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM). Results suggest that magnetic nanoparticles are deposited onto the surface of multiwalled carbon nanotubes and the imprinted shell is coated on the surface of magnetic carbon nanotubes with a thickness of approximately 8 nm. Magnetic imprinted polymers are sensitive to magnetic fields and can be easily separated within 3 s using an external magnet. The adsorption results indicate that the obtained imprinted polymers have fast kinetics, an ultrahigh adsorption capacity of 479.9 mg g−1, and satisfactory selectivity towards the template molecule. The prepared materials have excellent stability with no obvious deterioration after six adsorption–regeneration cycles. In addition, a method for determination of gallic acid (GA) in pomegranate rind was developed, using a combination of the prepared polymers used as solid-phase extraction (SPE) sorbents and high-performance liquid chromatography (HPLC) for rapid isolation and determination of GA. The limit of detection of the proposed method is 0.001 μg mL−1, and the intra and inter-day relative standard deviations (RSDs) are lower than 3.8 % and 5.3 %, respectively. The recoveries of GA from pomegranate rind extract are in the range 98.2–103.6 % with RSDs lower than 4.3 %. [Figure not available: see fulltext.] © 2015 Springer-Verlag Berlin Heidelberg

Wang T.,First Hospital Of Xian Jiaotong University | Liu Z.,First Hospital Of Xian Jiaotong University | Shi F.,First Hospital Of Xian Jiaotong University | Wang J.,First Hospital Of Xian Jiaotong University
Molecular and Cellular Biochemistry | Year: 2016

The prolyl isomerase Pin1, which is frequently highly expressed in many different cancers, can directly regulate cell proliferation and the cell cycle. However, the role of Pin1 in chemo-resistance remains to be elucidated in cervical cancer. The purpose of the present study was to investigate the role of Pin1 in the chemo-resistance of cervical cancer. The cisplatin resistance was assessed using the MTT assay. Pin1, FoxM1, β-catenin, Cyclin D1, and c-myc expression levels were detected by RT-qPCR or Western blot. The results showed that Pin1 expression displayed a similar expression pattern with the resistance to cisplatin in five cervical cell lines. Knockdown of Pin1 significantly increased the sensitivity to cisplatin in HeLa cells, while Pin1 overexpression decreased the sensitivity to cisplatin in Me180 cells. Knockdown of Pin1 significantly down-regulated FoxM1 expression in HeLa cells, while Pin1 overexpression showed a contrary effect in Me180 cells. Besides, overexpression of Pin1 markedly increased the protein expression of β-catenin and its target genes cyclin D1 and c-myc. FoxM1 siRNA remarkably reversed the promotory effect of pcDNA-Pin1(+) on β-catenin and its target genes cyclin D1 and c-myc in Me180 cells. Furthermore, we also found that FoxM1 siRNA and IWP-2 markedly decreased cell viability, and IWP-2 decreased cell viability to the maximum extent in the Me180 cells co-transfected with pcDNA-Pin1(+) and FoxM1 siRNA. Taken together, these data suggest that Pin1 contributes to cisplatin resistance, partly by up-regulating FoxM1 and Wnt/β-catenin signaling pathway involved in cervical cancer. © 2016, Springer Science+Business Media New York.

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