scholarly journals Long noncoding RNA STXBP5-AS1 inhibits cell proliferation, migration, and invasion through inhibiting the PI3K/AKT signaling pathway in gastric cancer cells

2019 ◽  
Vol Volume 12 ◽  
pp. 1929-1936 ◽  
Author(s):  
Dongzhi Cen ◽  
Hu Huang ◽  
Liu Yang ◽  
Kai Guo ◽  
Jinshan Zhang
Open Medicine ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Sen Lin ◽  
Jianing Liu ◽  
Wen Jiang ◽  
Peng Wang ◽  
Chao Sun ◽  
...  

AbstractMethyltransferase-like 3 (METTL3) was originally known to be responsible for N6-methyladenosine (m6A) modification of mRNA. Recent studies have found that METTL3 plays important roles in a variety of tumors by regulating the translation of oncogenes. However, the functional and regulating mechanisms of METTL3 in human gastric cancer have not yet been understood. Here we knocked down METTL3 in human gastric cancer cell lines, AGS and MKN45, by using shRNA transfection. RT-qPCR assay and western blotting verified the effectiveness of RNA interference on mRNA and protein levels, respectively. Then we found that METTL3 knockdown inhibited cell proliferation, migration and invasion in AGS and MKN45 cells. Moreover, METTL3 knockdown decreased Bcl2 and increased Bax and active Caspase-3 in gastric cancer cells, which suggested the apoptotic pathway was activated. Mechanistic investigation suggested that METTL3 led to inactivation of the AKT signaling pathway in human gastric cancer cells, including decreased phosphorylation levels of AKT and expression of down-stream effectors p70S6K and Cyclin D1. In conclusion, our study reveals that down-regulation of METTL3 inhibits the proliferation and mobility of human gastric cancer cells and leads to inactivation of the AKT signaling pathway, suggesting that METTL3 may be a potential target for the treatment of human gastric cancer.


Author(s):  
Jianjun Shen ◽  
Weina Niu ◽  
Hongbo Zhang ◽  
Ma Jun ◽  
Hongyan Zhang

Gastric cancer is the fourth most common malignancy and the third leading cause of cancer-related deaths worldwide. This study aimed to investigate the expression patterns, biological roles, and underlying mechanisms of microRNA-147 (miR-147) in gastric cancer. The present study demonstrated that miR-147 was significantly upregulated in gastric cancer tissues and cell lines. Downregulation of miR-147 decreased cell proliferation and enhanced the chemosensitivity of gastric cancer cells to 5-fluorouracil (5-FU) through the cell apoptosis pathway. In addition, phosphatase and tensin homolog (PTEN) was mechanically identified as the direct target of miR-147 in gastric cancer. PTEN knockdown reversed the effects of miR-147 downregulation on the proliferation, chemosensitivity, and 5-FU-induced apoptosis of gastric cancer cells. Moreover, miR-147 regulated the PI3K/AKT signaling pathway in gastric cancer by targeting PTEN. In conclusion, miR-147 suppressed the proliferation and enhanced the chemosensitivity of gastric cancer cells to 5-FU by promoting cell apoptosis through directly targeting PTEN and regulating the PI3K/AKT signaling pathway. This study provides important insight into the molecular mechanism that underlies the chemoresistance of gastric cancer cells. The results of this study could aid the development of a novel therapeutic strategy for gastric cancer.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Linwen Zhu ◽  
Zhe Li ◽  
Xiuchong Yu ◽  
Yao Ruan ◽  
Yijing Shen ◽  
...  

Abstract Background Recently, tRNA-derived fragments (tRFs) have been shown to serve important biological functions. However, the role of tRFs in gastric cancer has not been fully elucidated. This study aimed to identify the tumor suppressor role of tRF-5026a (tRF-18-79MP9P04) in gastric cancer. Methods Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was first used to detect tRF-5026a expression levels in gastric cancer tissues and patient plasma. Next, the relationship between tRF-5026a levels and clinicopathological features in gastric cancer patients was assessed. Cell lines with varying tRF-5026a levels were assessed by measuring tRF-5026a using qRT-PCR. After transfecting cell lines with a tRF-5026a mimic or inhibitor, cell proliferation, colony formation, migration, apoptosis, and cell cycle were evaluated. The expression levels of related proteins in the PTEN/PI3K/AKT pathway were also analyzed by Western blotting. Finally, the effect of tRF-5026a on tumor growth was tested using subcutaneous tumor models in nude mice. Results tRF-5026a was downregulated in gastric cancer patient tissues and plasma samples. tRF-5026a levels were closely related to tumor size, had a certain diagnostic value, and could be used to predict overall survival. tRF-5026a was also downregulated in gastric cancer cell lines. tRF-5026a inhibited the proliferation, migration, and cell cycle progression of gastric cancer cells by regulating the PTEN/PI3K/AKT signaling pathway. Animal experiments showed that upregulation of tRF-5026a effectively inhibited tumor growth. Conclusions tRF-5026a (tRF-18-79MP9P04) is a promising biomarker for gastric cancer diagnostics and has tumor suppressor effects mediated through the PTEN/PI3K/AKT signaling pathway.


2020 ◽  
Author(s):  
Rui Su ◽  
Enhong Zhao ◽  
Jun Zhang

Abstract MiRNA operates as a tumor suppressor or carcinogen to regulate cell proliferation, metastasis, invasion, differentiation, apoptosis and metabolic process. In the present research, we investigated the effect and mechanism of miR496 in human gastric cancer cells. Cell proliferation was measured by CCK8 and clonogenic assay. Transwell test was performed to detect cell migration and invasion. Flow cytometry analysis was used to evaluate cell apoptosis. Bioinformatics software targetscan was used for the screening of miR-496’s target gene. MiR-496 was down regulated in three gastric cancer cell lines, SGC-790, AGS and MKN45 compared with normal gastric epithelial cell line GES-1. MiR-496 mimics inhibited the proliferation of AGS cells after the transfection for 48 h and 72 h. The migration and invasion of AGS cells were also inhibited by the transfection of miR-496 mimics. In addition, miR-496 mimics induced the apoptosis through up regulating the levels of Bax and Active Caspase3 and down regulating the levels of Bcl-2 and Total Caspase3. Bioinformatics analysis showed that there was a binding site between miR-496 and LYN kinase (LYN). MiR-496 mimics could inhibit the expression of LYN in AGS cells. The overexpression of LYN blocked the inhibition of tumor cell growth, as well as the inhibition of AKT/mTOR signaling pathway induced by miR-496 in gastric cancer cells. In conclusion, miR-496 inhibited the proliferation through the AKT/mTOR signaling pathway via targeting LYN in gastric cancer cells. Our research provides a new potential target for clinical diagnosis and targeted treatment of gastric cancer.


Author(s):  
Yizhuo LU ◽  
Lianghui LI ◽  
Guoyang WU ◽  
Huiqin ZHUO ◽  
Guoyan LIU ◽  
...  

Background: We aimed to investigate the effect of PI3K/Akt signaling pathway on PRAS40Thr246 phosphorylation in gastric cancer cells. Methods: The study was conducted from April 2017 to January 2018 in Zhongshan Hospital, Xiamen University, Xiamen, China. Gastric cancer cells were divided into three groups: gastric cancer cell group, LY294002 group and MK-2206 group. Specific tests were conducted accordingly. Results: Inhibition of PI3K/Akt signaling pathway activation and PRAS40Thr246 phosphorylation could inhibit proliferation and invasion and promote apoptosis of gastric cancer cells, and PRAS40Thr246 phosphorylation could activate PI3K/Akt signaling pathway. Conclusion: The levels of PI3K/Akt signaling pathway related proteins and p-PRAS40Thr246 were significantly increased in gastric cancer cells. p-PRAS40-Thr246 was able to reflect the activation of the PI3K/Akt signaling pathway, reflecting the sensitivity of the PI3K/AKT signaling pathway to inhibitors.


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