scholarly journals The tRNA-derived fragment 5026a inhibits the proliferation of gastric cancer cells by regulating the PTEN/PI3K/AKT signaling pathway

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):  
LU GE ◽  
Chang-long Hu ◽  
Zheng-hui Ge ◽  
Chun-rong Wang ◽  
Li Qian ◽  
...  

Abstract Purpose Capicua homolog protein (CIC) played a broad role in the development of cancer in humans, however, its role in the progression of gastric cancer (GC) specifically has been unclear. This study aimed to explore the expression of CIC and its potential clinical value in patients with GC. Methods The CIC levels in GC tissues and cell lines were examined by quantitative real-time polymerase chain reaction (qRT-PCR). And the in-vitro effects of CIC expression in MGC-803 cells on their proliferation, invasion, and the progression of epithelial-mesenchymal transition were assessed by CCK-8 assays, Matrigel-invasion analysis, qRT-PCR and Western blot assays, separately. In addition, the effects of downregulation of CIC on the activation of PI3K/AKT signaling pathway were measured using Western-blot analysis. Results The results showed CIC levels were lower in GC tissues and GC cell lines, and these lower CIC levels were correlated with tumor differentiation, Helicobacter pylori infection, TNM stage, and patient survival. In addition, CIC overexpression could promote cell proliferation, invasion, and progression of epithelial-mesenchymal transition in MGC-803 cells. Notably, exotic expression of CIC inactivated the phosphoinositide 3-kinase/protein kinase B signaling pathway. Conclusions In conclusion, our finding suggested CIC could serve as a potential diagnostic and prognostic biomarker and a probable therapy target for GC.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Wen-Li Liu ◽  
Hu-xia Wang ◽  
Cheng-xin Shi ◽  
Fei-yu Shi ◽  
Ling-yu Zhao ◽  
...  

Abstract Background MicroRNAs (miRNAs) play key roles in tumorigenesis and progression of gastric cancer (GC). miR-1269 has been reported to be upregulated in several cancers and plays a crucial role in carcinogenesis and cancer progression. However, the biological function of miR-1269 in human GC and its mechanism remain unclear and need to be further elucidated. Methods The expression of miR-1269 in GC tissues and cell lines was detected by quantitative real-time PCR (qRT-PCR). Target prediction programs (TargetScanHuman 7.2 and miRBase) and a dual-luciferase reporter assay were used to confirm that Ras-association domain family 9 (RASSF9) is a target gene of miR-1269. The expression of RASSF9 was measured by qRT-PCR and Western blotting in GC tissues. MTT and cell counting assays were used to explore the effect of miR-1269 on GC cell proliferation. The cell cycle and apoptosis were measured by flow cytometry. RASSF9 knockdown and overexpression were used to further verify the function of the target gene. Results We found that miR-1269 expression was upregulated in human GC tissues and cell lines. The overexpression of miR-1269 promoted GC cell proliferation and cell cycle G1-S transition and suppressed apoptosis. The inhibition of miR-1269 inhibited cell growth and G1-S transition and induced apoptosis. miR-1269 expression was inversely correlated with RASSF9 expression in GC tissues. RASSF9 was verified to be a direct target of miR-1269 by using a luciferase reporter assay. The overexpression of miR-1269 decreased RASSF9 expression at both the mRNA and protein levels, and the inhibition of miR-1269 increased RASSF9 expression. Importantly, silencing RASSF9 resulted in the same biological effects in GC cells as those induced by overexpression of miR-1269. Overexpression of RASSF9 reversed the effects of miR-1269 overexpression on GC cells. Both miR-1269 overexpression and RASSF9 silencing activated the AKT signaling pathway, which modulated cell cycle regulators (Cyclin D1 and CDK2). In contrast, inhibition of miR-1269 and RASSF9 overexpression inhibited the AKT signaling pathway. Moreover, miR-1269 and RASSF9 also regulated the Bax/Bcl-2 signaling pathway. Conclusions Our results demonstrate that miR-1269 promotes GC cell proliferation and cell cycle G1-S transition by activating the AKT signaling pathway and inhibiting cell apoptosis via regulation of the Bax/Bcl-2 signaling pathway by targeting RASSF9. Our findings indicate an oncogenic role of miR-1269 in GC pathogenesis and the potential use of miR-1269 in GC therapy.


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 ◽  
...  

2020 ◽  
Vol 19 ◽  
pp. 153303382091595 ◽  
Author(s):  
Yong Zhu ◽  
Feng Shi ◽  
Meng Wang ◽  
Jian Ding

Rabs have been reported to be involved in the carcinogenesis process and in the progression of cancer. However, it is unclear whether or not Rab9 is associated with the development of cancer. In the present study, we aimed to investigate the role of Rab9 in the biological functions of gastric cancer cells. The gastric cancer cell lines AGS and MKN45 were transfected with siRNA-Rab9 to block the expression of Rab9. The cell viability, proliferation, migration, invasion, and apoptosis were examined using Cell Count Kit-8, colony formation, wound healing, Transwell, and flow cytometry assays, respectively. Our data showed that silencing of Rab9 significantly inhibited the viability, proliferation, migration, and invasion abilities of AGS and MKN45 cells. Moreover, transfection with siRab9 promoted the rate of apoptosis in AGS and MKN45 cells through regulating the Bcl-2–Bax axis and the Caspase cascade. We also found that silencing of Rab9 inhibited activation of the Akt signaling pathway by downregulating the phosphorylation level of Akt. In conclusion, our data suggest that Rab9 plays an oncogenic role in the progression of gastric cancer, providing a potential target for the treatment of gastric cancer.


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