[AMG-102 inhibits proliferation and induces apoptosis of laryngeal squamous cell carcinoma cells by regulating c-Met/PI3K/Akt pathway].

Objective: To investigate the effects of c-Met inhibitor AMG-102 on the proliferation and apoptosis of laryngeal squamous carcinoma Hep-2 cells and the underlying mechanism. Methods: Laryngeal squamous carcinoma cell line Hep-2 cells were treated with 2.5, 5 and 10 µmol/L AMG-102, respectively. The proliferation activities of Hep-2 cells were detected by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT). The apoptotic rate of Hep-2 cells was detected by flow cytometry analysis and Hoechst staining. The mRNA expression levels of apoptosis-related genes were detected by real-time quantitative polymerase Chain reaction (RT-qPCR), and the protein expressions of c-Met/PI3K/AKT pathway were detected by western blot. Results: Compared with the control group, the proliferation rates of Hep-2 cells treated with 2.5, 5 and 10 µmol/L AMG-102 for 24 hours were (89.8±1.1)%, (79.8±1.0)% and (69.1±1.2)%, respectively; for 48 hours were (76.8±2.0)%, (60.2±1.1)% and (49.8±1.2)%, respectively; for 72 hours were (50.1±2.0)%, (41.5±1.1)% and (33.6±1.0), respectively, with significant differences (all P<0.05). The apoptotic rates of Hep-2 cells treated with 2.5, 5 and 10 µmol/L AMG-102 for 48 hours were (16.09±1.53)%, (27.51±2.02)% and (36.57±1.42)%, respectively, which were significantly higher than (3.62±0.10) % in the control group (all P<0.05). After treated with 2.5, 5 and 10 µmol/L AMG-102 for 48 hours, the relative expression levels of Bcl-2 mRNA in Hep-2 cells were 0.58±0.13, 0.38±0.12 and 0.20±0.13, respectively; the relative protein expression of p-Met were 80.0±3.8, 50.6±4.2 and 28.5±1.3, respectively; the relative protein expression of p-PI3K were 87.1±0.9, 54.2±1.2 and 21.0±1.2, respectively; the relative protein expression of p-AKT were 98.7±5.6, 56.9±3.2 and 32.2±4.3, respectively; which were significantly lower than those in the control group (all P<0.05). The relative expression levels of Bax mRNA were 1.78±0.13, 2.37±0.14 and 3.05±0.13, respectively, and the relative expression levels of caspase-3 mRNA were 1.98±0.14, 2.47±0.14 and 3.15±0.13, respectively, which were significantly higher than those in the control group (all P<0.05). Conclusion: c-Met inhibitor AMG-102 could inhibit the proliferation and induce apoptosis of laryngeal squamous carcinoma Hep-2 cells by regulating the c-Met/PI3K/Akt pathway.

[Effect of c-Met inhibitor AMG-102 on radiosensitivity in laryngeal squamous carcinoma cells].

Objective: To investigate the effect of c-Met inhibitor AMG-102 on proliferation and radiosensitivity in laryngeal squamous carcinoma cells. Methods: The effects of AMG-102 on proliferation and radiosensitivity of laryngeal squamous carcinoma cell lines Hep-2 and KBV200 were detected by 3-(4, 5-dimethy-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) assay and colony formation assay, respectively. The apoptosis of Hep-2 and KBV200 cells was detected by flow cytometry. The expression levels of c-Met, phospho-Met (p-Met), cleaved caspase-3 and Akt/p-Akt, Erk/p-Erk were detected by Western blot. Specific small interfering RNA targeting c-Met or plasmid of c-Met were transfected into Hep-2 and KBV200 cells to investigate the cell sensitivity to AMG-102. Results: Compared with KBV200 cells, Hep-2 cells were more sensitive to AMG-102 with IC(50) of 14 and 9 µmol/L, respectively. The relative expression levels of c-Met and p-Met proteins in Hep-2 cells were 194.48±0.57 and 177.76±1.53, respectively, which were significantly higher than those in KBV200 cells (171.24±1.00 and 115.37±0.56, respectively, P<0.001 for both). Exogenous hepatocyte growth factor (HGF) was added to increase the expression level of p-Met protein in KBV200 cells. The results showed that AMG-102 significantly reduced the expression of p-Met in KBV200 cells treated with HGF (P<0.001). Compared with the dimethyl sulfoxide (DMSO) group, AMG-102 treatment combined with radiotherapy significantly increased the radiosensitivity of Hep-2 cells (SER=1.28, P<0.001). However, AMG-102 had little effect on the radiosensitivity of KBV200 cells (SER=1.18, P=0.002). Compared with the 4 Gy radiotherapy alone group and the 5 µmol/L of AMG-102 alone treatment group, the apoptosis rate of Hep-2 cells in the combined treatment group was significantly increased. Meanwhile, the expression level of cleaved caspase-3 protein was also markedly increased. However, there were no significant changes in the apoptotic rate and cleaved caspase-3 expression in each treatment group of KBV200 cells. Compared with DMSO treatment group, the expression levels of p-Met, p-Akt and p-Erk were significantly decreased in the 4 Gy radiotherapy group, 5 µmol/L of AMG-102 treatment group and combined treatment group of Hep-2 cells. And the levels of p-Met, p-Akt and p-Erk in the combined treatment group were significantly lower than those in the 4 Gy radiotherapy alone group and 5 µmol/L of AMG-102 treatment alone group. By contrast, in KBV200 cells, the expression of p-Met, p-Akt and p-Erk in each group was not changed. The relative expression of p-Met in Hep-2 cells before and after radiotherapy at 30 min, 1 h, 4 h, 8 h, 24 h were 99.89±0.61, 138.62±1.00, 163.07±5.00, 87.80±1.85, 90.67±0.65 and 94.09±1.41, respectively. The level of p-Met was slightly increased after radiotherapy at 30 min and 1 h (P<0.001 for all), whereas it was significantly decreased from 4 h to 24 h after radiotherapy (P<0.05 for all). By contrast, the expression of p-Met in KBV200 cells did not change with time after radiotherapy (P>0.05). The sensitivity of Hep-2 cells to AMG-102 was decreased after silencing of c-Met, while the sensitivity of KBV200 cells to AMG-102 was not significantly changed (P>0.05). Moreover, the radiosensitivity of Hep-2 cells in c-Met knockdown group had a slightly increasing trend (SER=1.07, P=0.068). After the treatment with 10 µmol/L of AMG-102, the proliferation rate of c-Met ectopically expressed KBV200 cells was 60.05%±3.23%, It was significantly lower than that of the blank control 90.08%±1.04% and siRNA negative control (90.12%±1.01%, P<0.001). The results suggested that the overexpression of c-Met in KBV200 cells increased the radiosensitivity to AMG-102, whereas depletion of c-Met resulted in resistance to AMG-102 in Hep-2 cells. Furthermore, the radiosensitivity of KBV200 cells that overexpressed c-Met showed a decreased trend (SER=0.7, P=0.005). Conclusions: c-Met inhibitor AMG-102 has a significant inhibitory effect on the proliferation of c-Met overexpressing laryngeal squamous carcinoma cells, leading to increased radiosensitivity. It suggests that molecular targeted therapy against c-Met receptor is more effective in c-Met overexpressed subtype of laryngeal squamous cell carcinoma.

Giant Magneto-Impedance (GMI) Effect in Single-Layer Soft Magnetic Film Under Stress.

The stress-induced magnetic anisotropy can significantly affect giant magneto-impedance (GMI) effect of the soft magnetic film. This paper is devoted to the GMI effect of the single layer soft magnetic film implied without and with a stress. By simulating a physical model with MATLAB and COMSOL software, the impedance expression of the single layer soft magnetic film and the relation between external magnetic field and magnetic permeability are deduced. We observed that, without a stress, the sensitive region increased firstly and then decreased with the increasing of the excitation current frequency from 1 MHz to 200 MHz. While the film was subjected to the stress in the direction of the current with one end stressed, the stress on the film was gradually reduced from stressed end to free end. Also, the impedance change rate of the film changed when the stress was added, which is similar to the effect of adding a bias magnetic field on the film. More importantly, the addition of stress σ can induce the bias of the GMI measurement range and improve its sensitivity near zero magnetic fields. This may provide a new way for designing a GMI sensor with higher sensitivity and adjustable measurement range.

Resistive Switching Mechanism of HfO2 Based Resistance Random Access Memory Devices with Different Electrode Materials.

This study investigated the impact of electrode materials on HfO2-based RRAM devices. The research includes three types of electrode materials: (1) the electrodes with strong ability of oxygen reservoirs; (2) the electrode with poor ability of oxygen reservoirs; (3) the active electrode with injection ability. Through implementing different combinations of electrodes, three types of switching modes were obtained and the relative conduction mechanism was analyzed, as well as conduction model. Those studies may offer ways of using electrodes to control the resistive switching processes and fabricating the RRAM devices with good performance.

[Multimodal analgesic analgesia in patients with obstructive sleep apnea hypopnea syndrome with multiple planar surgery].

Objective:To observe the value of multimodal analgesia in patients with OSAHS undergoing multiplanar surgery.Method: A total number of 90 patients with obstructive sleep apnea hypopnea syndrome with tongue hypertrophy or hyperplasia of the root lymphoid tissue were collected. All patients underwent improved uvulatopharyngeal angioplasty (H-UPPP) and tongue root partial resection, or simultaneous tongue ablation at the same time, and they were randomly divided into two groups,45 patients in each group.In multi-modal analgesic group, the parrixibub sodium 40 mg were given intravenously 0.5 h before surgery, and oxygen budesonide aerosol inhalation therapy was given after surgery.Besides,sodium aescinate 10 mg was given intravenously 24, 48, 72 h after surgery,respectively.The control group did not do the above treatment. Both groups received 40 mg paradoxes sodium hydrostatic Bid for 4 days.To perform VAS on two groups of patients, uvula swelling time and first time to eat were recorded，and the symptoms of postoperative nausea and vomiting were observed.Result: The general conditions of the two groups of patients, including age, sex, body mass index, intraoperative blood loss, and operative time, were not statistically significant(all of the P>0.05). The scores of 24, 48, 72, 96 h VAS in multi-mode analgesic group were lower than those in control group after the operation of multi-mode analgesia, and the difference was statistically significant（P<0.05）.The duration of the swelling time of the uvula in the multi-mode analgesic group was significantly shorter than that in the control group, and the difference was statistically significant (5.44±0.88) d compared with (7.68±0.89) d (t=12.01, P<0.01);(30.1±7.3)h compared with (36.5±7.0) h,(t=4.25, P<0.01). Conclusion: Multi-mode analgesia is effective for OSAHS patients after multi-planar surgery. It effectively reduces postoperative pain, shortened postoperative swelling time, and improves the surgical compliance and safety.

Columnar structured FePt films epitaxially grown on large lattice mismatched intermediate layer.

The microstructure and magnetic properties of the FePt films grown on large mismatched ZrN (15.7%) intermediate layer were investigated. With using ZrN intermediate layer, FePt 10 nm films exhibited (001) texture except for some weaker FePt (110) texture. Good epitaxial relationships of FePt (001) <100>//ZrN (001) <100>//TiN (001) <100> among FePt and ZrN/TiN were revealed from the transmission electron microscopy (TEM) results. As compared with TiN intermediate layer, although FePt-SiO2-C films grown on ZrN/TiN intermediate layer showed isotropic magnetic properties, the large interfacial energy and lattice mismatch between FePt and ZrN would lead to form columnar structural FePt films with smaller grain size and improved isolation. By doping ZrN into the TiN layer, solid solution of ZrTiN was formed and the lattice constant is increased comparing with TiN and decreased comparing with ZrN. Moreover, FePt-SiO2-C films grown on TiN 2 nm-20 vol.% ZrN/TiN 3 nm intermediate layer showed an improved perpendicular magnetic anisotropy. Simultaneously, columnar structure with smaller grain size retained.

Nanogranular TiN-ZrO2 intermediate layer induced improvement of isolation and grain size of FePt thin films.

The effects of TiN-ZrO2 intermediate layer on the microstructures and magnetic properties of FePt films were investigated. The TiN-ZrO2 intermediate layer was granular consisting of grains of solid solution of Ti(Zr)ON segregated by amorphous ZrO2. By doping ZrO2 into TiN intermediate layer, the FePt grains became better isolated from each other and the FePt grain size was reduced. For 20 vol. % ZrO2 doping into TiN, the grain size decreased dramatically from 11. 2 nm to 6. 4 nm, and good perpendicular anisotropy was achieved simultaneously. For the FePt 4nm-SiO2 35 vol. % -C 20 vol. % films grown on top of the TiN-ZrO2 20 vol. % intermediate layer, well isolated FePt (001) granular films with coercivity higher than 18. 1 kOe and an average size as small as 6. 4 nm were achieved.