scholarly journals Transcriptomic analysis reveals that bromodomain containing 9 controls signaling pathways in gastric cancer

2020 ◽  
Author(s):  
Yuan Wang ◽  
Chen Wang ◽  
Yu-Ting Mo ◽  
Wen Yi Tan ◽  
Xi-Yong Yu

Abstract Background According to the Cancer Genome Atlas, gastric cancers involve 30% BRD9 changes. Studying the signaling net controlled by BRD9 is important and provides useful information for the treatment of patients with gastric cancer and BRD9 alteration. Objective We performed this study to find the signaling pathways controlled by BRD9 in gastric cancer cells. Methods MGC-803 and AGS cells were selected as BRD9 overexpression and normal expression models, respectively, and added with BRD9 inhibitors BI9564 and BI7273, respectively. RNA-seq and limma R language were used to obtain differentially expressed genes (DEGs), and heatmap R language was employed for cluster analysis. Database for Annotation, Visualization and Integrated Discovery (DAVID) was applied to identify the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichments, and STRING database was utilized to construct the protein–protein interaction (PPI) networks. Analysis was performed through Cytoscape software to determine the possible signaling pathway and target genes. Results Group MGC-803: 1204 and 1338 DEGs were found in MGC-803 cells added with BI9564 and BI7273, respectively, and 425 DEGs were found in the intersection of these two sets. AGS group: 974 and 1006 DEGs were found in AGS cells added with BI9564 and BI7273, respectively, and 382 DEGs were found in the intersection of these two sets. The DEG number in the intersection of groups MGC-803 and AGS was only 12, and only 3 of which showed the same regulation direction. Hence, these two types of gastric cancers are greatly altered in the signaling network. GO enrichment and KEGG signaling pathway analyses showed that in group MGC-803, BRD9 mainly controls cell adhesion molecule (CAM) pathway, and genes SPP1 and GNAO1 may play important an important role in the BRD9 controlling network. In group AGS, BRD9 mainly controls protein digestion and absorption pathway, and genes AR and GNGT2 have an important function in the BRD9 controlling network. Conclusion Comprehensive bioinformatics analyses were conducted to screen the DEGs and signaling pathways controlled by BRD9 in different gastric cancer cells. The findings provide a theoretical basis in curing patients with clinical gastric cancer.

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.


2020 ◽  
Author(s):  
Haile Zhao ◽  
Gezi Gezi ◽  
Xiaoxia Tian ◽  
Peijun Jia ◽  
Morigen Morigen ◽  
...  

Abstract BackgroundLysophosphatidic acid (LPA) is one of the simplest active phospholipid molecules. Binding to its receptors on the cell surface, LPA initiates various intracellular signal cascades, involving in numerous biological processes, such as cell proliferation, migration, and apoptosis. If abnormalities occur in the processes of LPA production, receptor expression or signal transduction, it may induce certain diseases and even contribute to the occurrence, development and metastasis of cancer. However, whether the initiation of DNA replication is regulated by LPA has not yet been investigated.MethodsFirst, diverse public databases were analyzed to explore the genetic abnormalities affecting geminin. Next, an LPA gradient treatment was performed on gastric cancer cells, followed by detecting geminin expression variation using western blot analysis. Finally, RNAi technology or inhibitors were used to block the biological activity of related factors in the GPCR induced EGFR transactivation signaling pathway to verify whether the effect of LPA evoked gastric cancer DNA replication is dependent on geminin upregulation.ResultsWe found that LPA specifically up-regulated expression of an essential replication negative regulator geminin in early S phase in gastric cancer cell lines, and that the deletion of geminin selectively induced DNA re-replication. Neither of these phenomena has been observed in normal gastric epithelial cells, indicating LPA-induced geminin up-regulation is restricted to tumor cells. Using RNAi or specific inhibitors to block the activity of related factors in the signaling pathway, we found that LPA acts through LPAR3 and downstream coupled MMPs signaling to trans-activate EGFR, increasing the expression level of geminin in S phase. On the other hand, LPA stimulation induced the up-regulation of de-ubiquitinating enzyme 3 (DUB3) in a short time and inhibited the ubiquitination degradation of geminin to enhance geminin stability and positively regulate the DNA replication initiation in gastric cancer cells. Taken together, our results suggested that LPA mediated DNA replication and S-phase cell-cycle progression through a LPAR3/MMPs/EGFR/PI3K/mTOR signaling axis in gastric cancer. ConclusionsOur research is for the first time to study the regulatory effect of LPA-induced EGFR transactivation in DNA replication of tumor cells, and to uncover a novel mechanism for regulating the stability of geminin through LPA and related downstream signaling pathways. All of which will provide potential targets for the development of signaling pathways and tumor cell-specific EGFR transactivation inhibitor for the treatment of 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.


2018 ◽  
Vol Volume 11 ◽  
pp. 4177-4187 ◽  
Author(s):  
Hua Ge ◽  
Chaojie Liang ◽  
Zhixia Li ◽  
Dali An ◽  
Shulin Ren ◽  
...  

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.


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