scholarly journals Downregulation of MicroRNA-147 Inhibits Cell Proliferation and Increases the Chemosensitivity of Gastric Cancer Cells to 5-Fluorouracil by Directly Targeting PTEN

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.


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.


2020 ◽  
Vol Volume 13 ◽  
pp. 10995-11006
Author(s):  
Ya-Nan Sheng ◽  
Ying-Hua Luo ◽  
Shao-Bin Liu ◽  
Wan-Ting Xu ◽  
Yu Zhang ◽  
...  

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