Mefloquine effectively targets gastric cancer cells through phosphatase-dependent inhibition of PI3K/Akt/mTOR signaling pathway

2016 ◽  
Vol 470 (2) ◽  
pp. 350-355 ◽  
Author(s):  
Yanwei Liu ◽  
Sen Chen ◽  
Rui Xue ◽  
Juan Zhao ◽  
Maojun Di
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.


2019 ◽  
Vol 19 (14) ◽  
pp. 1754-1761 ◽  
Author(s):  
Yayun Qian ◽  
Yan Yan ◽  
Hongmei Lu ◽  
Tingting Zhou ◽  
Mengying Lv ◽  
...  

Background: Rapamycin receptor inhibitors have been applied in the clinic and achieved satisfactory therapeutic effect recently. The mechanisms did not clearly show how the Celastrus orbiculatus Extracts (COE) inhibited the expression of the mammalian Target of Rapamycin (mTOR) in human gastric cancer cells. The aim of this study was to investigate whether the COE inhibited the metastasis through the mTOR signaling pathway in human gastric cancer MGC-803 cells. Methods: The abnormal expression level of mTOR protein was detected by immunohistochemistry in human gastric cancer tissue. The MGC-803/mTOR- cells were constructed by knockdown of mTOR using lentivirus infection technique. The human gastric cancer MGC-803/mTOR- cells were treated with different concentrations (20, 40, 80 μg/ml) of COE for 24 hours. The ability of cell metastasis was analyzed by the cell invasion and migration assay. The expression levels of PI3K/Akt/mTOR signaling pathway were detected by Western Blotting. Results: COE inhibited the proliferation, invasion and migration of MGC-803/mTOR- cells in a concentrationdependent manner. The expression of E-cadherin protein increased, and the expression of N-cadherin and Vimentin decreased simultaneously in the MGC-803/mTOR- cells. 4EBP1, p-4EBP1, P70S6k, p-P70S6k, mTOR, p-mTOR, PI3K and Akt proteins in MGC-803/mTOR- cells were reduced in a dose-dependent manner. Conclusion: COE could not only inhibit cell growth, invasion and migration, but also inhibit the epithelialmesenchymal transition of gastric cancer cells. The molecular mechanism of COE inhibited the metastasis which may be related to the PI3K/Akt/mTOR signal pathway. This study provides ideas for the development of new anti-gastric cancer drugs.


2019 ◽  
Vol 18 ◽  
pp. 153303381986431 ◽  
Author(s):  
Ruiqi Lu ◽  
Gang Zhao ◽  
Yulong Yang ◽  
Zhaoyan Jiang ◽  
Jingli Cai ◽  
...  

Cisplatin is widely used as the standard gastric cancer treatment, but the relapse and metastasis are common as intrinsic or acquired drug resistance. CD133 has been widely known to be associated with chemoresistance in various cancer cells. In this study, we focused on investigating the function and mechanism of CD133 underlying cisplatin resistance in gastric cancer cell line KATO-III. We detected CD133 expression by using quantitative real-time polymerase chain reaction and Western blot and found that expression of CD133 was upregulated in cisplatin resistance of KATO-III cells (Cis-KATO-III) compared with KATO-III cells, indicating the role of CD133 in regulating cisplatin resistance of KATO-III cells. Then we sorted the Cis-KATO-III cells into CD133-positive (CD133+) pools and measured the proliferation and apoptosis after the cell is transfected with pc-CD133 and sh-CD133 by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay and flow cytometry. The results showed that the inhibition of CD133 inhibited the cell viability and promoted the cell apoptosis after cisplatin treatment. Furthermore, we found that inhibition of CD133 downregulated the expression of PI3K/AKT and promoted the expression of mammalian target of rapamycin, thus inhibited the autophagic activity in the Cis-KATO-III cells after cisplatin treatment. Besides, we also verified the effects of CD133 in vivo. The results indicated that inhibition of CD133 enhanced the Cis-KATO-III cell sensitivity to cisplatin by regulating PI3K/AKT/mTOR signaling pathway. In summary, our data provide new insight that CD133 activates the PI3K/AKT/mTOR signaling transduction pathway, resulting in activation of autophagy and cisplatin resistance of Cis-KATO-III cells. These results may offer a novel therapeutic target in cisplatin-resistant gastric cancer.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuqin Li ◽  
Xiaolan Lu ◽  
Peiying Tian ◽  
Kai Wang ◽  
Jianping Shi

Abstract Background Procyanidin B2 (PB2), a unique component of the grape seed and other medicinal plants. PB2 has shown wide anticancer activity in various human cancer cells. However, it remains unclear about the biological effects and associated mechanisms of PB2 on gastric cancer cells. Methods Cell proliferation was measured by CCK8 assay, and cellular lactate dehydrogenase (LDH) release was measured in the culture medium. Cellular apoptosis was observed via TUNEL staining assay and measured by caspase-3 and -9 activities. Autophagy was observed by LC3 staining. Western blot analysis was performed to verify autophagy-associated proteins (Beclin1 and Atg5) and Akt-mTOR pathway. Results PB2 reduced the viability of BGC-823 and SGC-7901 cells in a concentration-dependent manner. Furthermore, PB2 induced increased apoptosis rate of gastric cancer cells and enhanced caspase-3 and -9 activities. Simultaneously, PB2 triggered autophagy in gastric cancer cells, with enhanced LC3 staining and increased expression of Beclin1 and Atg5, while the inhibition of autophagy by 3-MA reversed the PB2-induced suppression on cell viability. In addition, PB2 significantly decreased p-Akt and p-mTOR protein expression of gastric cancer cells. Conclusion PB2 exerts anti-proliferative and apoptotic effects and induces autophagy by modulating Akt/mTOR signaling pathway. PB2 may be developed as a potential therapeutic drug for gastric cancer.


Open Medicine ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 1206-1214
Author(s):  
Rui Su ◽  
Enhong Zhao ◽  
Jun Zhang

Abstract MicroRNAs (miRNAs) operate as 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 miR-496 in human gastric cancer cells. miR-496 was downregulated in two gastric cancer cell lines, 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 and 72 h. The migration and invasion of AGS cells were also inhibited by the transfection of miR-496 mimics. miR-496 mimics induced the apoptosis through upregulating the levels of Bax and Active Caspase 3 and downregulating the levels of Bcl-2 and Total Caspase 3. 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. LYN overexpression blocked the inhibition of tumor cell growth, as well as the inhibition of AKT/mTOR signaling pathway induced by miR-496. 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 for gastric cancer.


2020 ◽  
Vol 10 (12) ◽  
pp. 1843-1850
Author(s):  
M. M. Jiashu Lu ◽  
M. M. Lei Yu ◽  
M. M. Ying Ma ◽  
M. M. Jie Li

Gastric cancer (GC) is a kind of digestive tract malignancy that has very high morbidity and mortality, making it crucial to find new drug treatments. Vitexin is a kind of flavonoid compound, which has anti-tumor, anti-inflammatory, analgesic and antiviral effects, etc. However, the specific role of vitexin in GC is still unclear. In this study, the expression of the survival rate and apoptosis was detected by CCK-8 and flow cytometry after vitexin acted on cells. Plasmid transfection technique was used to overexpress PI3K. Expression of PI3K/AKT/mTOR pathway-related proteins, autophagic-related proteins (Atg14, beclin-1, P62) and apoptotic-related proteins (bcl-2, Bax, cleaved caspase3) were detected by Western blot. We found that the cell survival rate decreased with the increasing time and dosage of vitexin. When vitexin acted on cells, the expression of p-PI3K, p-AKT and p-mTOR was significantly decreased, the degree of autophagy was increased, and the apoptosis rate was obviously increased. However, the overexpression of PI3K, the level of autophagy and apoptosis rate of cells which were given vitexin significantly decreased. In conclusion, Vitexin induces autophagy by inhibiting PI3K/AKT/mTOR signaling pathway, thereby inhibiting proliferation and promoting apoptosis of GC cells.


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