LETM1 Promotes Gastric Cancer Cell Proliferation, Migration, and Invasion via the PI3K/Akt Signaling Pathway

Yunfeng Zhang,Lele Chen,Yifan Cao,Si Chen,Chao Xu,Jun Xing,Kaiguang Zhang 대한위암학회 2020 Journal of gastric cancer Vol.20 No.2

Purpose: Globally, there is a high incidence of gastric cancer (GC). Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is reported to play a vital role in several human malignancies. However, there is limited understanding of the role of LETM1 in GC. This study aims to investigate the effects of LETM1 on proliferation, migration, and invasion of GC cells. Materials and Methods: The expression levels of LETM1 in the normal gastric mucosal epithelial cells (GES-1) and GC cells were analyzed by quantitative real-time polymerase chain reaction and western blotting. CCK-8, wound healing, and Transwell invasion assays were performed to evaluate the effect of LETM1 knockdown or overexpression on the proliferation, migration, and invasion of the GC cells, respectively. Additionally, the effect of LETM1 knockdown or overexpression on GC cell apoptosis was determined by flow cytometry. Furthermore, the effect of LETM1 knockdown or overexpression on the expression levels of PI3K/Akt signaling pathway-related proteins was evaluated by western blotting. Results: The GC cells exhibited markedly higher mRNA and protein expression levels of LETM1 than the GES-1 cells. Additionally, the knockdown of LETM1 remarkably suppressed the GC cell proliferation, migration, and invasion, and promoted the apoptosis of GC cells, which were reversed upon LETM1 overexpression. Furthermore, the western blotting analysis indicated that LETM1 facilitates GC progression via the PI3K/Akt signaling pathway. Conclusions: LETM1 acts as an oncogenic gene to promote GC cell proliferation, migration, and invasion via the PI3K/Akt signaling pathway. Therefore, LETM1 may be a potential target for GC diagnosis and treatment.

LETM1 Promotes Gastric Cancer Cell Proliferation, Migration, and Invasion via the PI3K/Akt Signaling Pathway

Zhang, Yunfeng,Chen, Lele,Cao, Yifan,Chen, Si,Xu, Chao,Xing, Jun,Zhang, Kaiguang The Korean Gastric Cancer Association 2020 Journal of gastric cancer Vol.20 No.2

Purpose: Globally, there is a high incidence of gastric cancer (GC). Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is reported to play a vital role in several human malignancies. However, there is limited understanding of the role of LETM1 in GC. This study aims to investigate the effects of LETM1 on proliferation, migration, and invasion of GC cells. Materials and Methods: The expression levels of LETM1 in the normal gastric mucosal epithelial cells (GES-1) and GC cells were analyzed by quantitative real-time polymerase chain reaction and western blotting. CCK-8, wound healing, and Transwell invasion assays were performed to evaluate the effect of LETM1 knockdown or overexpression on the proliferation, migration, and invasion of the GC cells, respectively. Additionally, the effect of LETM1 knockdown or overexpression on GC cell apoptosis was determined by flow cytometry. Furthermore, the effect of LETM1 knockdown or overexpression on the expression levels of PI3K/Akt signaling pathway-related proteins was evaluated by western blotting. Results: The GC cells exhibited markedly higher mRNA and protein expression levels of LETM1 than the GES-1 cells. Additionally, the knockdown of LETM1 remarkably suppressed the GC cell proliferation, migration, and invasion, and promoted the apoptosis of GC cells, which were reversed upon LETM1 overexpression. Furthermore, the western blotting analysis indicated that LETM1 facilitates GC progression via the PI3K/Akt signaling pathway. Conclusions: LETM1 acts as an oncogenic gene to promote GC cell proliferation, migration, and invasion via the PI3K/Akt signaling pathway. Therefore, LETM1 may be a potential target for GC diagnosis and treatment.

Chemical Bonds-Conjugated Ag2SO3/NaNbO3 Hybrids as Efficient Photocatalysts: In-situ Fabrication, Characterization and Degradation of Rhodamine B and Methyl Orange

Yanmei Feng,Zhiqiang Wang,Yunfeng Yang,Xiang-Feng Wu,Xiaodong Gong,Yajian Liu,Yufei Li,Zuo-Lin Cao,Chao Wang,Xin Tong 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.7

The Ag2SO3/NaNbO3 hybrids have been fabricated via a facile method at room temperature. Several methods such as X-ray diffraction, UV-Vis diffuse reflectance spectroscopy, scanning electron microscopy, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy were used to characterize the samples. Moreover, the photocatalytic activity of the samples was assessed by degradation of rhodamine B and methyl orange under the visible light illumination. Experimental results indicated the photocatalytic degradation efficiency of the as-fabricated hybrids was first increased and then decreased with increasing the dosage of NaNbO3. When the molar ratio of Ag2SO3 to NaNbO3 was 1:0.7, the as-fabricated composites had the best photodegradation efficiency of 96.4% in 30 min for rhodamine B and 97.1% in 60 min for methyl orange, respectively. These were obviously higher than that of pure samples. Furthermore, Ag2SO3 was conjugated with NaNbO3 via chemical-bonds rather than physical contact. In addition, the possible photocatalytic degradation mechanism was also provided and the main roles during the process of photocatalytic degradation were played by holes.

Experimental and Numerical Investigation on the Cyclic Behavior of SRC Columns considering Unsymmetrical Confinement Effect

Xianpan Liu,Lei Zeng,Yunfeng Xiao,Yanhua Liu,Heng Zhang,Yun Cao 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.4

Experimental and numerical studies were conducted on the cyclic behavior of steel reinforced concrete (SRC) columns with T-shaped and L-shaped steel section. A total of 8 SRC columns were tested under axial compression and lateral cyclic loading. The design details, loading procedure and main results, including the failure modes, hysteretic characteristics and ductility were reported. Four failure modes as flexural failure, shear bond failure, shear compression failure and shear compound failure were observed. By considering various unsymmetrical confinement and plastic hinge region, the experimental study was supplemented by numerical analysis to study the influence of axial compression ratio, shear-span ratio and concrete strength. The results revealed that the FEA is in good agreement with the experimental results. The ultimate loading of specimen with confinement effect has been improved by 21.4% − 33.8%. The failure modes is dominated by the shear-span ratio and type of cross section. The specimens with smaller shear-span ratio are prone to shear failure, while the unsymmetrical steel arrangement causes shear compound failure which is combined with shear bond failure and shear compression failure. Moreover, the specimens with larger shear-span ratio and stirrup ratio present greater deformation capacity and ductility. In practical engineering, the confinement degree of SRC columns with unsymmetrical steel section can be enhanced by increasing the stirrup ratio and arranging the cross ties.

Modeling and Evaluation of Inertia Emulation Control for DFIG Wind Turbine

Haoshu SHAO,Xu CAI,Jianwen Zhang,Yunfeng Cao,Fangquan RAO,Dapeng ZHENG,Dangsheng ZHOU,Yan WANG 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

With the increasing penetration of renewable energy generators in power grid, many inertia emulation control strategies have been raised to solve the problem of reduced power system inertia. A co-simulation research platform is built based on RTDS and GH Bladed, detailed comparisons are made in terms of inertia response performance, weak grid operation stability, secondary frequency drop and wind tower load analysis. Research results point out that different control schemes are similar in inertia response while virtual synchronous generator control (VSG) and inertial synchronization control (ISynC) can improve weak grid operation stability, VSG strategy is also effective in reducing frequency secondary drop and wind tower fatigue load, the combination of VSG and ISynC can get the best control results.