Long Noncoding RNA NEAT1 Promotes Tumorigenesis in H. Pylori Gastric Cancer By Sponging miR-30a To Regulate COX-2/BCL9 Pathway

Author(s):  
Xiwu Rao ◽  
Ningning Liu ◽  
Ru Jia ◽  
Yuanyuan Feng ◽  
Zhaozhou Zhang ◽  
...  

Abstract Background: Helicobacter pylori (H. pylori) is a carcinogenic factor for gastric cancer. Our previous study demonstrated that H. pylori decreased the expression of microRNA(miRNA)-30a to promote the tumorigenesis in gastric cancer. However, the upstream regulatory mechanism of miR-30a hasn’t well-elucidated. In this study, we found the long non‑coding RNA (lncRNA) NEAT1 may sponge miR-30a to regulate COX-2/BCL9 pathway. Methods: The expression of NEAT1 was detected in gastric cancer tissues and tumour adjacent tissues by fluorescence in-situ hybridization(FISH) analysis and RT-qPCR. LncRNA-miRNA interaction networks were constructed using the RNAhybird and Starbase v.2.0. and then validated using dual-luciferase assay. The effects of NEAT1 dysregulation on the proliferative, migratory and invasive abilities of H. pylori filtrate infected gastric cancer cells were observed by cell counting kit-8 (CCK-8), colony formation, wound healing test and transwell assays. Western blot and RT-qPCR were performed to detect protein and RNA expression. The Immunohistochemistry(IHC) was carried out to analyze the location and expression of COX-2 and BCL9Results: FISH and RT-qPCR demonstrated that the expression of NEAT1 was up-regulated in gastric cancer tissues, especially in H. pylori gastric cancer tissues, and the expression of NEAT1 is negatively correlated with miR-30a(miR-30a-3p, miR-30a-5p). The proliferation, migration and invasion of H. pylori filtrate infected gastric cancer cells could be largely enhanced by the up-regulation of NEAT1, while the downregulation of NEAT1 decreased these abilities, and miR-30a could reverse the effect of NEAT1 on these abilities. Dual-luciferase assay identified that NEAT1 directly targeted miR-30a(miR-30a-3p, miR-30a-5p).Due to miR-30a(miR-30a-3p, miR-30a-5p) negatively regulated the expression of downstream COX-2 and BCL9, NEAT1 was identified to indirectly upregulate the expression of COX-2 and BCL9.IHC showed that the expression of COX-2 and BCL9 were increased in H. pylori gastric cancer tissues.Conclusion: The study demonstrated that lncRNA NEAT1 may act as a promoter oftumorigenesis in H. pylori gastric cancer, by sponging miR-30a(miR-30a-3p, miR-30a-5p) to regulate COX-2/BCL9 pathway.

2020 ◽  
pp. 1-11
Author(s):  
Li-Juan Pei ◽  
Peng-Jun Sun ◽  
Kui Ma ◽  
Yan-Yan Guo ◽  
Ling-Yan Wang ◽  
...  

Gastric cancer (GC) remains poor prognosis and survival issues due to the resistance of chemotherapies, such as cisplatin. The long non-coding RNA small nucleolar RNA host gene 7 (lncRNA-SNHG7) is known as an oncogenic molecule in diverse cancers. Here, we demonstrate that SNHG7 was significantly upregulated in gastric cancer and positively correlated with cisplatin resistance of gastric cancer cells that SNHG7 was significantly upregulated in cisplatin resistant cells. Silencing SNHG7 dramatically sensitized cisplatin resistant cells. In contrast, a negative correlation between lncRNA-SNHG7 and miR-34a was found that miR-34a was downregulated in gastric cancer patient tissues and significantly sensitized cisplatin resistant gastric cancer cells. Intriguingly, bioinformatical analysis indicated miR-34a has putative biding site for SNHG7 and such negative association between SNHG7 and miR-34a was verified in gastric cancer tissues. The cisplatin resistant cells displayed increased glycolysis rate and SNHG7 promoted cellular glycolysis rate of gastric cancer cells. Luciferase assay illustrated LDHA, a glycolysis enzyme, was the direct target of miR-34a. Importantly, inhibiting SNHG7 successfully suppressed LDHA expressions and sensitized cisplatin resistant cells and such inhibitory effects could be recovered by further anti-miR-34a. These findings suggest an important regulator mechanism for the SNHG7-mediated cisplatin resistance via miR-34a/LDHA-glycolysis axis.


Author(s):  
Lei Zheng ◽  
Junli Cao ◽  
Lijie Liu ◽  
Hongmei Xu ◽  
Lanlan Chen ◽  
...  

Upregulating the expression of long non-coding RNA LINC00982 controlled cell proliferation in gastric cancer, but the regulatory molecular mechanisms are yet to be expounded. We here aimed to elaborate how LINC00982 regulated the malignancy of gastric cancer cells. RT-qPCR and Western blot analysis were used to detect the expression of LINC00982 and CTSF in gastric cancer tissues and cells. Modulatory effect of LINC00982 on gastric cancer cells was assessed by CCK-8, colony formation, Transwell migration and invasion assays. The relationship between LINC00982, HEY1 and CTSF was examined by RIP, luciferase assay, and ChIP, and their interaction in the regulation of gastric cancer cellular functions was analyzed by performing gain-of-function and rescue assays. The nude mouse model of tumor formation was developed to examine the effects of LINC00982 on tumorigenesis. LINC00982 was lowly expressed in gastric cancer tissues, while its overexpression impaired the proliferative, migratory and invasive properties of gastric cancer cells. Furthermore, LINC00982 could bind to transcription factor HEY1 and inhibited its expression. Through blocking the binding of HEY1 to CTSF promoter. LINC00982 promoted the expression of CTSF. Overexpression of HEY1 or inhibition of CTSF could reverse the anti-tumor effects of LINC00982 on gastric cancer, which were further demonstrated in vivo. Taken together, LINC00982 acted as a tumor suppressor in gastric cancer, which is therefore suggested to be a potential anti-tumor target for gastric cancer.


Author(s):  
Qiong Luo ◽  
Suyun Zhang ◽  
Donghuan Zhang ◽  
Rui Feng ◽  
Nan Li ◽  
...  

Background: Gastric cancer(GC) is currently one of the major malignancies that threatens human lives and health. Anlotinib is a novel small-molecule that inhibits angiogenesis to exert anti-tumor effects. However, the function in gastric cancer is incompletely understood. Objective: The aim of the present study was to investigate the anti-tumor effects and molecular mechanisms of anlotinib combined with dihydroartemisinin (DHA) in SGC7901 gastric cancer cells. Method: Different concentrations of anlotinib and DHA were used to treat SGC7901 gastric cancer cells, after which cell proliferation was measured. Drug interactions of anlotinib and DHA were analyzed by the Chou-Talalay method with CompuSyn software. proliferation, apoptosis, invasion, migration, and angiogenesis were measured using the cell counting kit-8 (CCK8) assay, flow cytometry, Transwell invasion assays, scratch assays, and chicken chorioallantoic membrane (CAM) assays. proliferation-associated protein (Ki67), apoptosis-related protein (Bcl-2), and vascular endothelial growth factor A (VEGF-A) were quantified by Western bloting. Results: The combination of 2.5 μmol/L of anlotinib and 5 of μmol/L DHA was highly synergistic in inhibiting cell growth, significantly increased the apoptosis rate and suppressed obviously the invasion and migration capability and angiogenesis of gastric cancer cells. In addition, the expression levels of Ki67, Bcl-2, and VEGF-A, as well as angiogenesis, were significantly decreased in the Combination of drugs compared with in control and either drug alone. Conclusion: The combination of anlotinib and DHA showed synergistic antitumor activity, suggesting their potential in treating patients with gastric cancer.


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.


2009 ◽  
Vol 20 (24) ◽  
pp. 5127-5137 ◽  
Author(s):  
Kai-Wen Hsu ◽  
Rong-Hong Hsieh ◽  
Chew-Wun Wu ◽  
Chin-Wen Chi ◽  
Yan-Hwa Wu Lee ◽  
...  

The c-Myc promoter binding protein 1 (MBP-1) is a transcriptional suppressor of c-myc expression and involved in control of tumorigenesis. Gastric cancer is one of the most frequent neoplasms and lethal malignancies worldwide. So far, the regulatory mechanism of its aggressiveness has not been clearly characterized. Here we studied roles of MBP-1 in gastric cancer progression. We found that cell proliferation was inhibited by MBP-1 overexpression in human stomach adenocarcinoma SC-M1 cells. Colony formation, migration, and invasion abilities of SC-M1 cells were suppressed by MBP-1 overexpression but promoted by MBP-1 knockdown. Furthermore, the xenografted tumor growth of SC-M1 cells was suppressed by MBP-1 overexpression. Metastasis in lungs of mice was inhibited by MBP-1 after tail vein injection with SC-M1 cells. MBP-1 also suppressed epithelial-mesenchymal transition in SC-M1 cells. Additionally, MBP-1 bound on cyclooxygenase 2 (COX-2) promoter and downregulated COX-2 expression. The MBP-1-suppressed tumor progression in SC-M1 cells were through inhibition of COX-2 expression. MBP-1 also exerted a suppressive effect on tumor progression of other gastric cancer cells such as AGS and NUGC-3 cells. Taken together, these results suggest that MBP-1–suppressed COX-2 expression plays an important role in the inhibition of growth and progression of gastric cancer.


Author(s):  
Jifu Song ◽  
Zhibin Guan ◽  
Maojiang Li ◽  
Sha Sha ◽  
Chao Song ◽  
...  

MicroRNAs (miRNAs) have emerged as pivotal regulators of the development and progression of gastric cancer. Studies have shown that miR-154 is a novel cancer-associated miRNA involved in various cancers. However, the role of miR-154 in gastric cancer remains unknown. Here we aimed to investigate the biological function and the potential molecular mechanism of miR-154 in gastric cancer. We found that miR-154 was significantly downregulated in gastric cancer tissues and cell lines. The overexpression of miR-154 significantly repressed the growth and invasion of gastric cancer cells. Bioinformatics analysis and Dual-Luciferase Reporter Assay data showed that miR-154 directly targeted the 3′-untranslated region of Dishevelled‐Axin domain containing 1 (DIXDC1). Real-time quantitative polymerase chain reaction and Western blot analyses showed that miR-154 overexpression inhibited DIXDC1 expression. An inverse correlation of miR-154 and DIXDC1 was also demonstrated in gastric cancer specimens. Overexpression of miR-154 also significantly suppressed the activation of WNT signaling. Moreover, restoration of DIXDC1 expression significantly reversed the inhibitory effect of miR-154 overexpression on the cell proliferation, invasion, and WNT signaling in gastric cancer cells. Overall, these results suggest that miR-154 inhibits gastric cancer cell growth and invasion by targeting DIXDC1 and could serve as a potential therapeutic target for the treatment of gastric cancer.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Dan Li ◽  
Yunqing Zhang ◽  
Yulong Li ◽  
Xiaofei Wang ◽  
Fenghui Wang ◽  
...  

Purpose. Gastric cancer is one of the most common cancers in the world. miRNAs play an important role in regulating gene expression by binding with 3 ′ -UTR of the target gene. The aim of this study was to investigate the function of miRNA-149 and FOXC1 in gastric cancer. Patients and Methods. qRT-PCR was used to detect the expression of miRNA-149 and FOXC1 in gastric cancer tissues and cells. Human gastric cancer cell lines AGS and MKN28 were cultured and transfected with miR-149 overexpression plasmid and its control or FOXC1 siRNA and its control. The MTT, colony formation, flow cytometry, wound healing, transwell, and western blotting were performed to examine the function of miRNA-149 and FOXC1 in the development of gastric cancer. What is more, dual-luciferase assay and western blotting were used to demonstrated the relationship between miRNA-149 and FOXC1. Results. miRNA-149 was underexpressed in gastric cancer tissues and cells, while overexpression of miRNA-149 promoted cell apoptosis, retarded cell cycle, and inhibited proliferation and migration in AGS and MKN28 cells. In addition, we showed that miRNA-149 targeted FOXC1. What is more, FOXC1 was highly expressed in gastric cancer tissues and cells; the silencing of FOXC1 inhibited the biological function of AGS and MKN28 cells. Conclusion. miRNA-149 inhibits the biological behavior of gastric cancer by targeting FOXC1, providing a promising target in the treatment of human gastric cancer.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Qing Li ◽  
Dachuan Zhang ◽  
Hui Wang ◽  
Jun Xie ◽  
Lei Peng ◽  
...  

Solute carrier organic anion transporter family member 4A1 (SLCO4A1-AS1), a newly discovered lncRNA, may exert effects in tumors. Since its role in gastric cancer remains obscure, we sought to explore the mechanism of SLCO4A1-AS1 in gastric cancer. The relationship among SLCO4A1-AS1, miR-149-5p, and STAT3 was detected by bioinformatics, dual luciferase analysis, and Pearson’s test, and the expressions of these genes were determined by quantitative real-time PCR and Western blot. Moreover, CCK-8, flow cytometry, wound healing assay, and Transwell analysis were performed to verify the function of SLCO4A1-AS1 in gastric cancer. Rescue experiments were used to detect the role of miR-149-5p. The expressions of SLCO4A1-AS1 and STAT3 were increased, while the expression of miR-149-5p was suppressed in gastric cancer tissues and cell lines. In addition, STAT3 expression was negatively correlated with miR-149-5p expression but was positively correlated with SLCO4A1-AS1 expression. Overexpression of SLCO4A1-AS1 promoted cell viability, migration, invasion, and STAT3 expression but suppressed apoptosis, while knockdown of SLCO4A1-AS1 had the opposite effect. SLCO4A1-AS1 bound to miR-149-5p and targeted STAT3. Moreover, miR-149-5p mimic inhibited the malignant development of gastric cancer cells and obviously reversed the function of SLCO4A1-AS1 overexpression. Our research reveals that abnormally increased SLCO4A1-AS1 expression may be an important molecular mechanism in the development of gastric cancer.


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