scholarly journals Glycogen synthase kinase 3 beta inhibits microRNA-183-96-182 cluster via the β-Catenin/TCF/LEF-1 pathway in gastric cancer cells

2013 ◽  
Vol 42 (5) ◽  
pp. 2988-2998 ◽  
Author(s):  
Xiaoli Tang ◽  
Dong Zheng ◽  
Ping Hu ◽  
Zongyue Zeng ◽  
Ming Li ◽  
...  

Abstract Glycogen synthase kinase 3 beta (GSK3β) is a critical protein kinase that phosphorylates numerous proteins in cells and thereby impacts multiple pathways including the β-Catenin/TCF/LEF-1 pathway. MicroRNAs (miRs) are a class of noncoding small RNAs of ∼22 nucleotides in length. Both GSK3β and miR play myriad roles in cell functions including stem cell development, apoptosis, embryogenesis and tumorigenesis. Here we show that GSK3β inhibits the expression of miR-96, miR-182 and miR-183 through the β-Catenin/TCF/LEF-1 pathway. Knockout of GSK3β in mouse embryonic fibroblast cells increases expression of miR-96, miR-182 and miR-183, coinciding with increases in the protein level and nuclear translocation of β-Catenin. In addition, overexpression of β-Catenin enhances the expression of miR-96, miR-182 and miR-183 in human gastric cancer AGS cells. GSK3β protein levels are decreased in human gastric cancer tissue compared with surrounding normal gastric tissue, coinciding with increases of β-Catenin protein, miR-96, miR-182, miR-183 and primary miR-183-96-182 cluster (pri-miR-183). Furthermore, suppression of miR-183-96-182 cluster with miRCURY LNA miR inhibitors decreases the proliferation and migration of AGS cells. Knockdown of GSK3β with siRNA increases the proliferation of AGS cells. Mechanistically, we show that β-Catenin/TCF/LEF-1 binds to the promoter of miR-183-96-182 cluster gene and thereby activates the transcription of the cluster. In summary, our findings identify a novel role for GSK3β in the regulation of miR-183-96-182 biogenesis through β-Catenin/TCF/LEF-1 pathway in gastric cancer cells.

2005 ◽  
Vol 281 (8) ◽  
pp. 4564-4569 ◽  
Author(s):  
Alexandra Thiel ◽  
Mira Heinonen ◽  
Johanna Rintahaka ◽  
Tuija Hallikainen ◽  
Annabrita Hemmes ◽  
...  

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):  
Sahar Sadat Sedighzadeh ◽  
Hamid Galehdari ◽  
Mohammad Reza Tabandeh ◽  
Ali Roohbakhsh ◽  
Mehdi Shamsara

Background: Cannabinoid receptor 1 (CB1R) located throughout the central, peripheral, and enteric nervous system can be found all over the gastrointestinal tract. Cannabinoid receptors (CBRs) play important roles in pathophysiological processes and have been identified as a therapeutic target for developing novel anticancer agents. Objectives: The purposes of this study were to evaluate the CB1R expression in human gastric cancer, mRNA and protein expression of CB1R under lipopolysaccharide (LPS)-mediated inflammation condition in human gastric cancer cells (AGS) cells, and the effects of inflammation on cell proliferation in LPS-stimulated AGS cells. Methods: CB1R mRNA expression in human gastric cancer samples and AGS cells were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). The expression level of CB1R, after inflammation induction using LPS, was evaluated by qRT-PCR and western blot. Cell proliferation was evaluated using 5-bromo-2-deoxyuridine (BrdU) labeling assay. Results: CB1R mRNA was significantly higher in human gastric cancer samples compared to adjacent tissues. LPS induced CB1R mRNA and protein expression in stimulated cells and promoted the proliferation of AGS cells. Conclusions: Our results show the increased expression of CB1R in gastric cancer samples and reveal that LPS induction increases the expression of CB1R and promotes cell proliferation in AGS cells. Accordingly, CB1R may be suggested as a potential molecular target for diagnostic and therapeutic aims in patients with 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.


2016 ◽  
Vol 40 (6) ◽  
pp. 1401-1409 ◽  
Author(s):  
Jin-fang Liu ◽  
Xiao-cui Nie ◽  
You-cheng Shao ◽  
Wen-hui Su ◽  
Hai-ying Ma ◽  
...  

Background/Aims: Extensive studies have demonstrated that Bleomycin (BLM) is a glycopeptide antibiotic that has been used as an anticancer chemotherapeutic reagent. It can induce both single- and double-strand DNA damage, inhibit synthesis of DNA, suppress proliferation, and induce apoptosis in cancer cells. Smad signaling transducers are considered as important molecules in tumor development and progression, and may closely be related to the biological behaviors of some malignant carcinomas, including gastric cancer. Methods: The effects of different concentrations of BLM on the proliferation, cell cycle, apoptosis, migration, and invasion on gastric cancer cell lines MKN45 and AGS were assayed by using CCK-8 assay, Annexin V/PI double staining, PI staining, and transwell assay. Western blot and Immunohistochemistry were applied to analyze the potential mechanism(s). Results: BLM treatment resulted in a low proliferation, high apoptosis, low migration and invasion in MKN45 and AGS cells. Furthermore, the possible mechanisms underlying that Smad3 activity could be changed after binding with BLM, and subsequently the Smad signaling pathway had a cascade response. Conclusion: These results highlight BLM as an exciting theme for gastric cancer treatment, which may represent an effective clinical therapeutic reagent for gastric cancer patients.


2020 ◽  
Vol 20 ◽  
Author(s):  
En Xu ◽  
Hao Zhu ◽  
Feng Wang ◽  
Ji Miao ◽  
Shangce Du ◽  
...  

: Gastric cancer is one of the most common malignancies worldwide and the third leading cause of cancer-related death. In the present study, we investigated the potential activity of OSI-027, a potent and selective mammalian target of rapamycin complex 1/2 (mTOR1/2) dual inhibitor, alone or in combination with oxaliplatin against gastric cancer cells in vitro. Cell counting kit-8 assays and EdU staining were performed to examine the proliferation of cancer cells. Cell cycle and apoptosis were detected by flow cytometry. Western blot was used to detect the elements of the mTOR pathway and Pgp in gastric cancer cell lines. OSI-027 inhibited the proliferation of MKN-45 and AGS cells by arresting the cell cycle in the G0/G1 phase. At the molecular level, OSI-027 simultaneously blocked mTORC1 and mTORC2 activation, and resulted in the downregulation of phosphor-Akt, phpspho-p70S6k, phosphor-4EBP1, cyclin D1, and cyclin-dependent kinase4 (CDK4). Additionally, OSI-027 also downregulated P-gp, which enhanced oxaliplatin-induced apoptosis and suppressed multidrug resistance. Moreover, OSI-027 exhibited synergistic cytotoxic effects with oxaliplatin in vitro, while a P-gp siRNA knockdown significantly inhibited the synergistic effect. In summary, our results suggest that dual mTORC1/mTORC2 inhibitors (e.g., OSI-027) should be further investigated as a potential valuable treatment for gastric cancer.


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