scholarly journals LncRNA SNHG6 knockdown inhibits cisplatin resistance and progression of gastric cancer through miR-1297/BCL-2 axis

2021 ◽  
Author(s):  
Jiazhuan Mei ◽  
Guiju Liu ◽  
Ruijun Li ◽  
Peng Xiao ◽  
Dan Yang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cisplatin Resistance ◽  
B Cell Lymphoma ◽  
Luciferase Reporter ◽  
Related Factors ◽  
Mesenchymal Transition ◽  
Inhibition Concentration ◽  
Keywords Gastric Cancer ◽  
Resistant Cells

Cisplatin (DDP) resistance is a huge obstacle to gastric cancer (GC) treatment. Long non-coding RNAs (lncRNAs) have been manifested to exert pivotal functions in GC development. Herein, we aimed to explore the functional impact of lncRNA small nucleolar RNA host gene 6 (SNHG6) on DDP resistance and progression of GC. Quantitative real-time PCR (qRT-PCR) assay or Western blotting was performed to detect the expression of SNHG6, microRNA(miR)-1297, and epithelia-mesenchymal transition (EMT)-related factors and B-Cell Lymphoma 2 (Bcl-2) in DDP-resistant GC cells. Half inhibition concentration (IC50) to DDP, clonogenicity, apoptosis and invasion were examined via CCK-8 assay, colony formation assay, flow cytometry and Transwell assay, respectively. Target association between miR-1297 and SNHG6 or BCL-2 was demonstrated via dual-luciferase reporter assay or RIP assay. Xenograft models in nude mice were formed to investigate role of SNHG6 in vivo. We found that SNHG6 and BCL-2 were upregulated, while miR-1297 expression was declined in GC tissues and DDP-resistant cells. Moreover, depletion of SNHG6 or gain of miR-1297 could repress DDP resistance, proliferation and metastasis of DDP-resistant cells, which was weakened by miR-1297 inhibition or BCL-2 overexpression. Besides, SNHG6 positively regulated BCL-2 expression by sponging miR-1297. Furthermore, SNHG6 knockdown repressed GC tumor growth in vivo. In a word, lncRNA SNHG6 knockdown had inhibitory effects on DDP resistance and progression of GC by sponging miR-1297, highlighting its potential in GC treatment.  Keywords: Gastric cancer, cisplatin resistance, lncRNA SNHG6, miR-1297, BCL-2

scholarly journals Circular RNA CDR1as Inhibits the Metastasis of Gastric Cancer through Targeting miR-876-5p/GNG7 Axis

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jiajia Jiang ◽  
Rong Li ◽  
Junyi Wang ◽  
Jie Hou ◽  
Hui Qian ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Epithelial Mesenchymal Transition ◽  
Circular Rna ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Luciferase Reporter Gene ◽  
Mesenchymal Transition ◽  
Underlying Mechanisms

Circular RNA CDR1as has been demonstrated to participate in various cancer progressions as miRNA sponges. The exact underlying mechanisms of CDR1as on gastric cancer (GC) metastasis remain unknown. Here, we found that CDR1as knockdown facilitated GC cell migration and invasion while its overexpression inhibited the migration and invasion abilities of GC cells in vitro and in vivo. Moreover, epithelial-mesenchymal transition- (EMT-) associated proteins and MMP2 and MMP9 were downregulated by CDR1as. Bioinformatics analysis combined with dual-luciferase reporter gene assays, western blot, RT-qPCR analysis, and functional rescue experiments demonstrated that CDR1as served as a miR-876-5p sponge and upregulated the target gene GNG7 expression to suppress GC metastasis. In summary, our findings indicate that CDR1as suppresses GC metastasis through the CDR1as/miR-876-5p/GNG7 axis.

scholarly journals METTL3-mediated N6-methyladenosine modification is critical for epithelial-mesenchymal transition and metastasis of gastric cancer

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Ben Yue ◽  
Chenlong Song ◽  
Linxi Yang ◽  
Ran Cui ◽  
Xingwang Cheng ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Epithelial Mesenchymal Transition ◽  
Luciferase Reporter ◽  
Mesenchymal Transition ◽  
Qrt Pcr ◽  
Rna Immunoprecipitation ◽  
E Cadherin

Abstract Background As one of the most frequent chemical modifications in eukaryotic mRNAs, N6-methyladenosine (m6A) modification exerts important effects on mRNA stability, splicing, and translation. Recently, the regulatory role of m6A in tumorigenesis has been increasingly recognized. However, dysregulation of m6A and its functions in tumor epithelial-mesenchymal transition (EMT) and metastasis remain obscure. Methods qRT-PCR and immunohistochemistry were used to evaluate the expression of methyltransferase-like 3 (METTL3) in gastric cancer (GC). The effects of METTL3 on GC metastasis were investigated through in vitro and in vivo assays. The mechanism of METTL3 action was explored through transcriptome-sequencing, m6A-sequencing, m6A methylated RNA immunoprecipitation quantitative reverse transcription polymerase chain reaction (MeRIP qRT-PCR), confocal immunofluorescent assay, luciferase reporter assay, co-immunoprecipitation, RNA immunoprecipitation and chromatin immunoprecipitation assay. Results Here, we show that METTL3, a major RNA N6-adenosine methyltransferase, was upregulated in GC. Clinically, elevated METTL3 level was predictive of poor prognosis. Functionally, we found that METTL3 was required for the EMT process in vitro and for metastasis in vivo. Mechanistically, we unveiled the METTL3-mediated m6A modification profile in GC cells for the first time and identified zinc finger MYM-type containing 1 (ZMYM1) as a bona fide m6A target of METTL3. The m6A modification of ZMYM1 mRNA by METTL3 enhanced its stability relying on the “reader” protein HuR (also known as ELAVL1) dependent pathway. In addition, ZMYM1 bound to and mediated the repression of E-cadherin promoter by recruiting the CtBP/LSD1/CoREST complex, thus facilitating the EMT program and metastasis. Conclusions Collectively, our findings indicate the critical role of m6A modification in GC and uncover METTL3/ZMYM1/E-cadherin signaling as a potential therapeutic target in anti-metastatic strategy against GC.

scholarly journals Circular RNA circFGD4 suppresses gastric cancer progression via modulating miR-532-3p/APC/β-catenin signalling pathway

2020 ◽  
Author(s):  
Xinglong Dai ◽  
Jianjun Liu ◽  
Xiong Guo ◽  
Anqi Cheng ◽  
Xiaoya Deng ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Viability ◽  
Cancer Progression ◽  
Epithelial Mesenchymal Transition ◽  
Luciferase Reporter ◽  
Circular Rnas ◽  
Mesenchymal Transition ◽  
Potential Biomarker

Background: Mounting evidence has displayed critical roles of circular RNAs (circRNAs) in multiple cancers. The underlying mechanisms by which circFGD4 contributed to gastric cancer (GC) are still unclear. Methods: The levels and clinical values of circFGD4 in GC patients were detected and analysed by quantitative real-time PCR. The biological roles of circFGD4 in GC were assessed in vitro and in vivo experiments. Dual-luciferase reporter, fluorescence in situ hybridization, RNA immunoprecipitation, biotin-coupled RNA pull-down, and TOP/Flash and FOP/Flash reporter gene assays were employed to evaluate the effects of circFGD4 on miR-532-3p-mediated adenomatous polyposis coli (APC)/β-catenin signalling in GC cells. Results: circFGD4 expression was down-regulated the most in human GC tissues and cell lines. Low expression of circFGD4 was correlated with poor tumour differentiation, lymphatic metastasis, and poor prognosis of GC patients. circFGD4 suppressed GC cell viability, colony formation, migration, induced epithelial-mesenchymal transition (EMT) and tumorigenesis and metastasis in vivo. Next, we validated that circFGD4 acted as a sponge of miR-532-3p to relieve the tumour-promoting effects of miR-532-3p on its target APC. The mechanistic analysis demonstrated that the circFGD4 suppressed GC cell viability, migration, and EMT by modulating the miR-532-3p/APC axis to inactivate the β-catenin signalling. Conclusion: circFGD4 suppressed GC progression through sponging miR-532-3p and enhancing APC expression to inactivate the β-catenin signalling. Thus circFGD4 provides a novel potential biomarker and valuable therapeutic strategy for GC.

scholarly journals Circular RNA circ-PVT1 contributes to paclitaxel resistance of gastric cancer cells through the regulation of ZEB1 expression by sponging miR-124-3p

2019 ◽  
Vol 39 (12) ◽  
Author(s):  
Yan-yan Liu ◽  
Li-ying Zhang ◽  
Wen-zhen Du
Keyword(s):  
Gastric Cancer ◽  
Tumor Model ◽  
Circular Rna ◽  
Luciferase Reporter ◽  
Gastric Cancer Cells ◽  
Western Blot Assay ◽  
Protein Levels ◽  
Zeb1 Expression ◽  
Resistant Cells

Abstract Gastric cancer (GC) is the fifth most commonly diagnosed malignancy. Paclitaxel (PTX) is an effective first-line chemotherapy drug in GC treatment, but the resistance of PTX attenuates the therapeutic effect. Circular RNA circ-PVT1 can exert the oncogenic effect in GC. But the function of circ-PVT1 involved in PTX resistance of GC is still unknown. In the present study, the expression levels of circ-PVT1, miR-124-3p and ZEB1 in PTX-resistant GC tissues and cells were detected by quantitative real-time polymerase chain reaction (RT-qPCR). PTX resistance in PTX-resistant cells was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The protein levels of Zinc finger E-box binding homeobox 1 (ZEB1), P-glycoprotein (P-gp) and glutathione S-transferase (GST-π) were detected by Western blot assay. Cell apoptosis and invasion were measured in PTX-resistant cells by flow cytometry and transwell invasion assays, severally. The interaction between miR-124-3p and circ-PVT1 or ZEB1 was predicted by starBase software, and then verified by the dual-luciferase reporter assay. The role of circ-PVT1 in PTX resistance of GC in vivo was measured by xenograft tumor model. Our results showed that circ-PVT1 expression was up-regulated in PTX-resistant GC tissues and cells. Circ-PVT1 down-regulation enhanced PTX sensitivity in PTX-resistant GC cells by negatively regulating miR-124-3p. ZEB1 served as a direct target of miR-124-3p. Circ-PVT1 enhanced ZEB1 expression by sponging miR-124-3p. Circ-PVT1 knockdown increased PTX sensitivity of GC in vivo. Taken together, our studies disclosed that circ-PVT1 facilitated PTX resistance by up-regulating ZEB1 mediated via miR-124-3p, suggesting an underlying therapeutic strategy for GC.

scholarly journals The POU2F1/miR-4490/USP22 axis regulates cell proliferation and metastasis in gastric cancer

2020 ◽  
Vol 43 (6) ◽  
pp. 1017-1033 ◽  
Author(s):  
Yizhi Xiao ◽  
Side Liu ◽  
Jiaying Li ◽  
Weiyu Dai ◽  
Weimei Tang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Proliferation ◽  
Cell Cycle Progression ◽  
Epithelial Mesenchymal Transition ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Aberrant Expression ◽  
Mesenchymal Transition

Abstract Purpose Growing evidence indicates that aberrant expression of microRNAs contributes to tumor development. However, the biological role of microRNA-4490 (miR-4490) in gastric cancer (GC) remains to be clarified. Methods To explore the function of miR-4490 in GC, we performed colony formation, EdU incorporation, qRT-PCR, Western blotting, in situ hybridization (ISH), immunohistochemistry (IHC), flow cytometry, ChIP and dual-luciferase reporter assays. In addition, the growth, migration and invasion capacities of GC cells were evaluated. Results We found that miR-4490 was significantly downregulated in primary GC samples and in GC-derived cell lines compared with normal controls, and that this expression level was negatively correlated with GC malignancy. Exogenous miR-4490 expression not only reduced cell cycle progression and proliferation, but also significantly inhibited GC cell migration, invasion and epithelial-mesenchymal transition (EMT) in vitro. Mechanistically, we found that miR-4490 directly targets USP22, which mediates inhibition of GC cell proliferation and EMT-induced metastasis in vitro and in vivo. Moreover, we found through luciferase and ChIP assays that transcription factor POU2F1 can directly bind to POU2F1 binding sites within the miR-4490 and USP22 promoters and, by doing so, modulate their transcription. Spearman’s correlation analysis revealed a positive correlation between USP22 and POU2F1 expression and negative correlations between miR-4490 and USP22 as well as miR-4490 and POU2F1 expression in primary GC tissues. Conclusion Based on our results we conclude that miR-4490 acts as a tumor suppressor, and that the POU2F1/miR-4490/USP22 axis plays an important role in the regulation of growth, invasion and EMT of GC cells.

scholarly journals MiR-199b-5p Promotes Gastric Cancer Progression by Regulating HHIP Expression

2021 ◽  
Vol 11 ◽  
Author(s):  
Songda Chen ◽  
Huijie Wu ◽  
Lingyu Zhu ◽  
Mengjie Jiang ◽  
Shuli Wei ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Western Blot ◽  
Cancer Progression ◽  
Bioinformatics Analysis ◽  
Luciferase Reporter ◽  
Rt Pcr ◽  
Mesenchymal Transition

ObjectivesGastric cancer (GC) is one of the most common malignant tumors. More and more evidences support the role of microRNAs (miRNAs) in tumor progression. However, the role of miRNAs in human GC remains largely unknown.MethodsBased on the published gastric cancer expression profile data, combined with bioinformatics analysis, potential miRNAs in the process of GC were screened. The expression of miR-199b-5p in GC cells and patients’ plasma was detected by RT-PCR. The effects of miR-199b-5p on GC in vitro were detected by EdU proliferation assay, colony formation assay, Transwell assay and wound healing assay. Western blot was used to detect epithelial-mesenchymal transition (EMT) related proteins. The subcutaneous tumorigenesis model and metastatic tumor model of mice were used to study its effect in vivo. Bioinformatics and Dual luciferase reporter assay were used to verify the effect of miR-199b-5p and its target gene.ResultsThrough bioinformatics analysis, we screened a novel miRNA miR-199b-5p that was significantly up-regulated in GC tissue and associated with poor prognosis of GC patients. RT-PCR results showed that its expression was also up-regulated in GC cell lines and patients’ plasma. MiR-199b-5p can significantly promote GC cell proliferation and migration in vitro and in vivo. Western blot showed that miR-199b-5p could promote the EMT process of GC. HHIP has been proved to be a target of miR-199b-5p, and the recovery of HHIP can weaken the effect of miR-199b-5p.ConclusionMiR-199b-5p may play an oncogene role in GC by targeting HHIP, suggesting that miR-199b-5p may be a potential therapeutic target for GC.

scholarly journals Exosomal Transfer of MiR-500a-3p Confers Cisplatin Resistance and Stemness via Targeting FBXW7 in Gastric Cancer

2020 ◽  
Author(s):  
Hao Lin ◽  
Caihua Zhang ◽  
Liang Zhang ◽  
pengpeng liu
Keyword(s):  
Gastric Cancer ◽  
Cisplatin Resistance ◽  
Luciferase Reporter ◽  
In Vivo Experiments ◽  
Bioinformatics Software ◽  
Alternative Modality ◽  
Cisplatin Sensitivity

Abstract Background Chemoresistance has become a major obstacle for gastric cancer (GC) therapy in clinical practice. MiRNAs have been reported to play critical roles in the development of chemoresistance in various tumors, including GC. However, the role of MiR-500a-3p within exosomes in cisplatin-resistant GC cells remains largely unknown. Materials and methods Cell proliferation and exosome delivery assays were performed using CCK-8 and transwell assays, respectively. CD63, CD81, β-tubulin, FBXW7, GAPDH, CD133, CD44 and SOX2 were detected by western blot and immunofluorescence assays. The expression levels of miR-500a-3p and FBXW7 mRNA were measured by real-time qRT-PCR. The interaction between miR-500a-3p and FBXW7 was predicted by bioinformatics software and confirmed by the dual-luciferase reporter. The mechanism of exosomal miR-500a-3p for cisplatin resistance was investigated in vitro and in vivo experiments. Results MiR-500a-3p level was upregulated in cisplatin-resistant GC cells and its downregulation enhanced cisplatin sensitivity. Moreover, extracellular miR-500a-3p could be incorporated into exosomes and transmitted to sensitive cells, thus disseminating cisplatin resistance. Additionally, exosomal miR-500a-3p promoted cisplatin resistance via targeting FBXW7 in vitro and in vivo . Clinically, higher expression of miR-500a-3p in the plasma exosomes of GC patients is correlated with DDP resistance and thereby results in poor progression-free prognosis. Conclusion Our finding highlights the potential of exosomal miR-500a-3p as an alternative modality for the prediction and treatment of GC with chemoresistance, providing a novel avenue for the treatment of GC.

scholarly journals FOXF2-Mediated lncRNA LINC02532 Promotes Gastric Cancer Cell Migration and Invasion By Decreasing SOX7 mRNA Stability

2021 ◽  
Author(s):  
Cheng Zhang ◽  
Chun-Dong Zhang ◽  
Jun-Peng Pei ◽  
Yong-Zhi Li ◽  
Maimaititusun Yusupu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Transcriptional Regulation ◽  
Cell Migration ◽  
Mrna Stability ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Mesenchymal Transition ◽  
Cell Migration And Invasion

Abstract Background LncRNAs are known to play a crucial role in the initiation and progression of human diseases, especially cancers. Our previous study demonstrated that dysregulation of LINC02532 facilitated the malignant phenotype of gastric cancer (GC). However, the potential molecular mechanisms regarding the upstream and downstream regulation of LINC02532 in GC progression remain unclear. Methods RNA-Seq and clinical data from public databases were used for gene expression and clinical analyses. The subcellular location of LINC02532 was predicted by the bioinformatics tools and further validated by the RNA-Fluorescence in situ hybridization (FISH) assay. The effect of FOXF2/LINC02532/SOX7 axis in GC cell migration and invasion was evaluated using in vitro and in vivo assays. The transcriptional regulation role of FOXF2 and the mRNA stability of SOX7 were explored by dual-luciferase reporter assay and Actinomycin-D drug assay. Results We found that high LINC02532 expression was associated with poor prognosis of GC. Furthermore, a Cox regression model indicated that LINC02532 was an independent prognostic factor for GC patients. Using in vitro and in vivo assays, we found that LINC02532 promoted GC cell migration and invasion, as well as tumour growth and metastasis in nude mice. Mechanistically, LINC02532 decreased SOX7 mRNA stability by binding to its 3’UTR, resulting in reduced SOX7 expression. In addition, FOXF2 was identified as a transcriptional factor of LINC02532 and was shown to repress LINC02532 expression by negative transcriptional regulation. Conclusions Together, these findings show that LINC02532 promotes GC progression through epithelial–mesenchymal transition (EMT). Cross-talk between the FOXF2/LINC02532/SOX7 axis may provide a novel target for the treatment and prognostic prediction of GC.

scholarly journals LncRNA DHRS4-AS1 Inhibits the Stemness of NSCLC Cells by Sponging miR-224-3p and Upregulating TP53 and TET1

2020 ◽  
Vol 8 ◽  
Author(s):  
Fei Yan ◽  
Wei Zhao ◽  
Xiaoyue Xu ◽  
Chenchen Li ◽  
Xiaoyou Li ◽  
...  
Keyword(s):  
Real Time ◽  
Cancer Cell ◽  
Real Time Pcr ◽  
Colony Formation ◽  
Epithelial Mesenchymal Transition ◽  
Luciferase Reporter ◽  
Pcr Analysis ◽  
Related Factors ◽  
Mesenchymal Transition

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death. This study aimed to examine the roles of DHRS4-AS1/miR-224-3p signaling in the cancer cell stemness of NSCLC. Real-time PCR showed that DHRS4-AS1 was downregulated in cancerous tissues, and bioinformatics analysis revealed that high DHRS4-AS1 expression indicated a good prognosis for NSCLC patients. Sphere and colony formation assays showed that DHRS4-AS1 overexpression significantly suppressed NSCLC cell colony formation and stem cell-like properties. DHRS4-AS1 also abrogated the expression of OCT4, SOX2, CD34, and CD133, markedly inhibited the expression of epithelial-mesenchymal transition (EMT)-related factors, N-cadherin, ZEB1, and Vimentin, and increased E-cadherin expression in spheres. Furthermore, luciferase reporter assays and real-time PCR analysis demonstrated that DHRS4-AS1 and miR-224-3p were antagonistically repressed in NSCLC cells. RNA immunoprecipitation (RIP) analysis revealed that DHRS4-AS1 interacted with miR-224-3p. DHRS4-AS1 partially reversed the miR-224-3p-decreased TP53 and TET1, resulting in the inhibition of tumor growth in vivo. Finally, TP53 and TET1 were antagonistically regulated by DHRS4-AS1 and miR-224-3p in NSCLC cells. In conclusion, TP53- and TET1-associated DHRS4-AS1/miR-224-3p axis is an essential mechanism by which NSCLC modulates cancer cell stemness.

scholarly journals MiR-592 Promotes Gastric Cancer Proliferation, Migration, and Invasion Through the PI3K/AKT and MAPK/ERK Signaling Pathways by Targeting Spry2

2018 ◽  
Vol 47 (4) ◽  
pp. 1465-1481 ◽  
Author(s):  
Yu He ◽  
Yugang Ge ◽  
Mingkun Jiang ◽  
Jundong Zhou ◽  
Dakui Luo ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Signaling Pathways ◽  
Cell Counting ◽  
Erk Signaling ◽  
Luciferase Reporter ◽  
Population Doubling ◽  
Migration And Invasion ◽  
Mesenchymal Transition

Background/Aims: Gastric cancer (GC) is one of the most prevalent digestive malignancies. MicroRNAs (miRNAs) are involved in multiple cellular processes, including oncogenesis, and miR-592 itself participates in many malignancies; however, its role in GC remains unknown. In this study, we investigated the expression and molecular mechanisms of miR-592 in GC. Methods: Quantitative real-time PCR and immunohistochemistry were performed to determine the expression of miR-592 and its putative targets in human tissues and cell lines. Proliferation, migration, and invasion were evaluated by Cell Counting Kit-8, population doubling time, colony formation, Transwell, and wound-healing assays in transfected GC cells in vitro. A dual-luciferase reporter assay was used to determine whether miR-592 could directly bind its target. A tumorigenesis assay was used to study whether miR-592 affected GC growth in vivo. Proteins involved in signaling pathways and the epithelial–mesenchymal transition (EMT) were detected with western blot. Results: The ectopic expression of miR-592 promoted GC proliferation, migration, and invasion in vitro and facilitated tumorigenesis in vivo. Spry2 was a direct target of miR-592 and Spry2 overexpression partially counteracted the effects of miR-592. miR-592 induced the EMT and promoted its progression in GC via the PI3K/AKT and MAPK/ERK signaling pathways by inhibiting Spry2. Conclusions: Overexpression of miR-592 promotes GC proliferation, migration, and invasion and induces the EMT via the PI3K/AKT and MAPK/ERK signaling pathways by inhibiting Spry2, suggesting a potential therapeutic target for GC.

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