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Glioblastoma (GBM) is the most prevalent primary intracranial tumor. Temozolomide (TMZ) is the first‐line chemotherapy for GBM. Nonetheless, the development of TMZ resistance has become a main cause of treatment failure in GBM patients. Evidence suggests that neuropilin‐1 (NRP‐1) silencing can attenuate GBM cell resistance to TMZ. This study aims to determine potential mechanisms by which NRP‐1 affects TMZ resistance in GBM. The parental U251 and LN229 GBM cells were exposed to increasing concentrations of TMZ to construct TMZ‐resistant GBM cells (U251/TMZ, LN229/TMZ). BALB/c nude mice were injected with U251/TMZ cells to establish the xenograft mouse model. Functional experiments were carried out to examine NRP‐1 functions. Western blotting and real‐time quantitative polymerase chain reaction were used to evaluate molecular protein and mRNA expression, respectively. Immunohistochemical staining showed NRP‐1 and STAT1 expression in mouse tumors. The results showed that NRP‐1 was highly expressed in TMZ‐resistant cells. Moreover, knocking down NRP‐1 attenuated the TMZ resistance of U251/TMZ cells, while upregulating NRP‐1 enhanced TMZ resistance of the parental cells. NRP‐1 silencing elevated GBM cell sensitivity to TMZ in tumor‐bearing mice. Depleting NRP‐1 reduced STAT1, p53, and p21 expression in U251/TMZ cells. STAT1 depletion offset NRP‐1 silencing evoked attenuation of GBM cell resistance to TMZ. Collectively, our study reveals that NRP‐1 enhances TMZ resistance in GBM possibly by regulating the STAT1/p53/p21 axis. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect of signal transducer and activator of transcription 1 (STAT1) on cell cycle of glioma U251 cells and related mechanism. Methods We transiently transfected glioma cell U251 cells with pcDNA3.1-STAT1 using LipofectamineTM2000 transfection reagent. The cells were divided into Mock group (no transfection), empty vector group (transfected with pcDNA3.1) and STAT1 group (transfected with pcDNA3.1-STAT1). The expression of STAT1 in glioma U251 cells was detected by Western blot. Cell proliferation was detected by MTT. Cell cycle was detected by flow cytometry. Wound healing assay was used to detect cell migration. The expression of P53, P21, bcl-2 and Caspase-8 in transfected cells was detected by Western blot. Results Compared with Mock group and empty vector group, the expression of STAT1 protein in STAT1 group was significantly increased (P < 0.05), cell proliferation decreased significantly (P < 0.05), the percentage of cells in phase G0/G1 increased significantly, and cell migration ability decreased significantly. The expression levels of P53, P21 and Caspase-8 increased significantly (P < 0.05) while bcl-2 decreased significantly (P < 0.05). Conclusion The high expression of STAT1 could inhibit the proliferation and promote the apoptosis of human glioma U251 cells, and STAT1 could regulate the expression of multiple signal transduction molecules. STAT1 plays a key role in the occurrence and development of glioma.

The linear axial expansion transport method avoids the negative source problem caused by transverse leakage in the traditional two-dimensional/one-dimensional (2D/1D) transport method and has better stability. However, stability is poor with the coarse-mesh finite difference (CMFD) accelerated linear axial expansion transport method. In this paper, the stability of the partial current–based coarse-mesh finite difference (p-CMFD) method, the optimally diffusive coarse-mesh finite difference (od-CMFD) method, and the linear prolongation coarse-mesh finite difference (lp-CMFD) method is studied based on Fourier analysis. The results of the Fourier analysis indicate that the problem is stable for axial coarse-mesh optical thickness less than 2 or larger than 50; the calculation diverges when the axial coarse-mesh optical thickness is between 2 and 50. The numerical results of the KUCA benchmark problem are the same as the results of the Fourier analysis. [ABSTRACT FROM AUTHOR]

The sulfonated ultrafine polystyrene fibrous membranes were fabricated by electrospinning, heat treatment and sulfonation process. The morphology, structure, properties and cationic dye adsorption of the sulfonated electrospun membranes were examined by infrared spectroscopy, scanning electron microscopy, thermogravimetry, universal testing machine and ultraviolet-visible spectrophotometry. The results show that,with the increase of sulfonation time, the fiber surfaces appeared successively the many tangential grooves and a lot of outshoots, and the water adsorption of the membranes was improved, and the gradual weight loss with temperature occurred, and that the unchange of the major degradation process of polystyrene and the mechanical properties implied no negative effect due to sulfonation. Cationic dye adsorption of sulfonated membranes demonstrated high adsorption rate and efficient removal. The dynamic adsorption with the membranes observed the Lagergren pseudo-second order kinetic. [ABSTRACT FROM AUTHOR]

The auxiliary tubular electrodes with different radii were used to modify the splitting of the electrospinning jet. The high-speed camera and scanning electron microscopy were applied to observe the process of splitting of the jet and the morphology of resultant electrospun mats, respectively. The results showed that, the auxiliary electrode postponed the splitting of the jet, and thus the area of the electrospun mat became much smaller and its density greatly increased, meanwhile, the average diameter of electrospun ultrafine fibers with good morphology slightly increased. The diameter of the tubular auxiliary electrode remarkably affected the jet splitting behaviour. The stronger the electric field was, the more obvious convergence was achieved. [ABSTRACT FROM AUTHOR]