scholarly journals LncRNA FEZF1-AS1 Promotes Multi-Drug Resistance of Gastric Cancer Cells via Upregulating ATG5

Author(s):  
Zhifu Gui ◽  
Zhenguo Zhao ◽  
Qi Sun ◽  
Guoyi Shao ◽  
Jianming Huang ◽  
...  

Long non-coding RNAs (lncRNAs) play important roles in human cancers including gastric cancer (GC). Dysregulation of lncRNAs is involved in a variety of pathological activities associated with gastric cancer progression and chemo-resistance. However, the role and molecular mechanisms of FEZF1-AS1 in chemoresistance of GC remain unknown. In this study, we aimed to determine the role of FEZF1-AS1 in chemoresistance of GC. The level of FEZF1-AS1 in GC tissues and GC cell lines was assessed by qRT-PCR. Our results showed that the expression of FEZF1-AS1 was higher in gastric cancer tissues than in adjacent normal tissues. Multivariate analysis identified that high level of FEZF1-AS1 is an independent predictor for poor overall survival. Increased FEZF1-AS1 expression promoted gastric cancer cell proliferation in vitro. Additionally, FEZF1-AS1 was upregulated in chemo-resistant GC tissues. The regulatory effect of FEZF1-AS1 on multi-drug resistance (MDR) in GC cells and the underlying mechanism was investigated. It was found that increased FEZF1-AS1 expression promoted chemo-resistance of GC cells. Molecular interactions were determined by RNA immunoprecipitation (RIP) and the results showed that FEZF1-AS1 regulated chemo-resistance of GC cells through modulating autophagy by directly targeting ATG5. The proliferation and autophagy of GC cells promoted by overexpression of LncFEZF1-AS1 was suppressed when ATG5 was knocked down. Moreover, knockdown of FEZF1-AS1 inhibited tumor growth and increased 5-FU sensitivity in GC cells in vivo. Taken together, this study revealed that the FEZF1-AS1/ATG5 axis regulates MDR of GC cells via modulating autophagy.

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Shihua Wu ◽  
Feng Liu ◽  
Liming Xie ◽  
Yaling Peng ◽  
Xiaoyuan Lv ◽  
...  

Understanding the molecular mechanisms underlying gastric cancer progression contributes to the development of novel targeted therapies. In this study, we found that the expression levels of miR-125b were strongly downregulated in gastric cancer and associated with clinical stage and the presence of lymph node metastases. Additionally, miR-125b could independently predict OS and DFS in gastric cancer. We further found that upregulation of miR-125b inhibited the proliferation and metastasis of gastric cancer cells in vitro and in vivo. miR-125b elicits these responses by directly targeting MCL1 (myeloid cell leukemia 1), which results in a marked reduction in MCL1 expression. Transfection of miR-125b sensitizes gastric cancer cells to 5-FU-induced apoptosis. By understanding the function and molecular mechanisms of miR-125b in gastric cancer, we may learn that miR-125b has the therapeutic potential to suppress gastric cancer progression and increase drug sensitivity to gastric cancer.


2016 ◽  
Vol 0 (0) ◽  
Author(s):  
Min Yang ◽  
Nan Jiang ◽  
Qi-wei Cao ◽  
Qing Sun

Abstract Gastric cancer is the most common digestive malignant tumor worldwild. EDD1 was reported to be frequently amplified in several tumors and played an important role in the tumorigenesis process. However, the biological role and potential mechanism of EDD1 in gastric cancer remains poorly understood. In this study, we are aim to investigate the effect of EDD1 on gastric cancer progression and to explore the underlying mechanism. The results showed the significant up-regulation of EDD1 in -gastric cancer cell tissues and lines. The expression level of EDD1 was also positively associated with advanced clinical stages and predicted poor overall patient survival and poor disease-free patient survival. Besides, EDD1 knockdown markedly inhibited cell viability, colony formation, and suppressed tumor growth. Opposite results were obtained in gastric cancer cells with EDD1 overexpression. EDD1 knockdown was also found to induce gastric cancer cells apoptosis. Further investigation indicated that the oncogenic role of EDD1 in regulating gastric cancer cells growth and apoptosis was related to its PABC domain and directly through targeting miR-22, which was significantly down-regulated in gastric cancer tissues. Totally, our study suggests that EDD1 plays an oncogenic role in gastric cancer and may be a potential therapeutic target for gastric cancer.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Meng-Yao Sun ◽  
Jian Sun ◽  
Jie Tao ◽  
Yu-Xia Yuan ◽  
Zhen-Hua Ni ◽  
...  

Gastric cancer (GC) is the third leading cause of cancer-related death. Chemotherapy resistance remains the major reason for GC treatment failure and poor overall survival of patients. Our previous studies have proved that Zuo Jin Wan (ZJW), a traditional Chinese medicine (TCM) formula, could significantly enhance the sensitivity of cisplatin (DDP)-resistant gastric cancer cells to DDP by inducing apoptosis via mitochondrial translocation of cofilin-1. However, the underlying mechanism remains poorly understood. This study aimed to evaluate the effects of ROCK/PTEN/PI3K on ZJW-induced apoptosis in vitro and in vivo. We found that ZJW could significantly activate the ROCK/PTEN pathway, inhibit PI3K/Akt, and promote the apoptosis of SGC-7901/DDP cells. Inhibition of ROCK obviously attenuated ZJW-induced apoptosis as well as cofilin-1 mitochondrial translocation, while inhibition of PI3K had the opposite effects. In vivo, combination treatment of DDP and ZJW (2000 mg/kg) significantly reduced tumor growth compared with DDP alone. Moreover, the combined administration of ZJW and DDP increased the expression of cleaved ROCK and p-PTEN while it decreased p-PI3K and p-cofilin-1, which was consistent with our in vitro results. These findings indicated that ZJW could effectively inhibit DDP resistance in GC by regulating ROCK/PTEN/PI3K signaling and provide a promising treatment strategy for gastric cancer.


2020 ◽  
Vol 11 ◽  
Author(s):  
Yingying Kou ◽  
Bending Tong ◽  
Weiqing Wu ◽  
Xiangqing Liao ◽  
Min Zhao

Gastric cancer is one of the most common malignancies ranks as the second leading cause of cancer-related mortality in the world. Cisplatin (DDP) is commonly used for gastric cancer treatment, whereas recurrence and metastasis are common because of intrinsic and acquired DDP-resistance. The aim of this study is to examine the effects of berberine on the DDP-resistance in gastric cancer and explore the underling mechanisms. In this study, we established the DDP-resistant gastric cancer cells, where the IC50 values of DDP in the BGC-823/DDP and SGC-7901/DDP were significantly higher than that in the corresponding parental cells. Berberine could concentration-dependently inhibited the cell viability of BGC-823 and SGC-7901 cells; while the inhibitory effects of berberine on the cell viability were largely attenuated in the DDP-resistant cells. Berberine pre-treatment significantly sensitized BGC-823/DDP and SGC-7901/DDP cells to DDP. Furthermore, berberine treatment concentration-dependently down-regulated the multidrug resistance-associated protein 1 and multi-drug resistance-1 protein levels in the BGC-823/DDP and SGC7901/DDP cells. Interestingly, the cell apoptosis of BGC-823/DDP and SGC-7901/DDP cells was significantly enhanced by co-treatment with berberine and DDP. The results from animals also showed that berberine treatment sensitized SGC-7901/DDP cells to DDP in vivo. Mechanistically, berberine significantly suppressed the PI3K/AKT/mTOR in the BGC-823/DDP and SGC-7901/DDP cells treated with DDP. In conclusion, we observed that berberine sensitizes gastric cancer cells to DDP. Further mechanistic findings suggested that berberine-mediated DDP-sensitivity may be associated with reduced expression of drug transporters (multi-drug resistance-1 and multidrug resistance-associated protein 1), enhanced apoptosis and repressed PI3K/AKT/mTOR signaling.


Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1088 ◽  
Author(s):  
I-Han Wang ◽  
Tzu-Ting Huang ◽  
Ji-Lin Chen ◽  
Li-Wei Chu ◽  
Yueh-Hsin Ping ◽  
...  

The 3-hydroxy-3-methylglutaryl-CoA synthase 1 (HMGCS1) is a potential regulatory node in the mevalonate pathway that is frequently dysregulated in tumors. This study found that HMGCS1 expression is upregulated in stomach adenocarcinoma samples of patients and tumorspheres of gastric cancer cells. HMGCS1 elevates the expression levels of the pluripotency genes Oct4 and SOX-2 and contributes to tumorsphere formation ability in gastric cancer cells. HMGCS1 also promotes in vitro cell growth and progression and the in vivo tumor growth and lung metastasis of gastric cancer cells. After blocking the mevalonate pathway by statin and dipyridamole, HMGCS1 exerts nonmetabolic functions in enhancing gastric cancer progression. Furthermore, the level and nuclear translocation of HMGCS1 in gastric cancer cells are induced by serum deprivation. HMGCS1 binds to and activates Oct4 and SOX-2 promoters. HMGCS1 also enhances the integrated stress response (ISR) and interacts with the endoplasmic reticulum (ER) stress transducer protein kinase RNA-like endoplasmic reticulum kinase (PERK). Our results reveal that HMGCS1 contributes to gastric cancer progression in both metabolic and nonmetabolic manners.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e15581-e15581
Author(s):  
Yuhao Luo ◽  
Rui Zhou ◽  
Na Huang ◽  
Li Sun ◽  
Wangjun Liao

e15581 Background: Gastric cancer (GC) is a leading cause of cancer mortality worldwide, oxaliplatin and epirubicin based chemotherapy are one of the most important treatment options for GC patients. However, drug resistance, especially multi-drug resistance remains a major obstacle for successful chemotherapy. Recently, long non-coding RNAs (lncRNAs) have been widely identified to play emerging roles in diverse physiological and pathophysiological processes including drug resistance. Our previous bioinformatics analysis showed long non-coding RNA EIF3J-AS1 was a potential multi-drug resistance gene, but the underlying mechanism is still unknown. Methods: We generated oxaliplatin resistance cells (MGC803/OXA) and epirubicin resistance cells(MGC803/EPI) based on parental gastric cancer cells MGC803. Relative expression levels of EIF3J-AS1 were measured by qRT-PCR. Transmission electron microscopy was used to measure autophagosomes. Rapamycin was applied to inducing autophagy while chloroquine and 3-methyladenine were used to block autophagy. Protein level of autophagy related genes were examined by Western Blot. Coexpression genes of EIF3J-AS1 from TCGA RNA-seq datas were analyzed by cBiportal. RNA immunoprecipitation was used to analyze endogenous microRNAs and mRNAs. Results: EIF3J-AS1 was significantly upregulated in MGC803/OXA and MGC803/EPI cells compared with parental cells MGC803. EIF3J-AS1 inhibition increased chemosensitivity to both oxaliplatin and epirubicin. Moreover, EIF3J-AS1 silence lead to the decrease of autophagy. Autophagy related gene ATG14 was identified as a downstream target gene. EIF3J-AS1 promoted ATG14 expression by directly interacting with and increasing stability of ATG14 mRNA, On the other hand, EIF3J-AS1 competitively sponged miR-188-3p and promoted ATG14 expression in a ceRNA-dependent way. Conclusions: LncRNA EIF3J-AS1 is a crucial regulator of multi-drug resistance by inducing autophagy in gastric cancer. Targeting EIF3J-AS1/ATG14 axis might be a new paradigm for cancer therapeutics.


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Run Liu ◽  
Xianwu Yang

Abstract Background This study aimed to explore the role and underlying molecular mechanisms of long non-coding RNA (lncRNA) LINC00342 in gastric cancer (GC). Methods The expression of LINC00342 in GC tissues was evaluated by Quantitative reverse transcription polymerase chain reaction (qRT-PCR). Silencing of LINC00342 was conducted to investigate the effect of LINC00342 in vitro and in vivo. The underlying molecular mechanisms of LINC00342 were determined by dual luciferase reporter assay, Western blotting analysis and rescue experiments. Biological functions of LINC00342 were evaluated by cell counting kit-8 (CCK-8) assay, colony formation assay, wound healing assay and Transwell assays. In addition, a tumor model was used to verify the effect of LINC00342 in tumorigenesis in vivo. Results LINC00342 was significantly upregulated in GC tissues and cell lines. Silencing of LINC00342 efficiently inhibited proliferation, migration and invasion of AGS cells in vitro, and also suppressed the tumorigenesis of GC in vivo. Functional experiments showed that LINC00342 regulated the expression of canopy fibroblast growth factor signaling regulator 2 (CNPY2) by competitively sponging miR-545-5p. Rescue experiments showed that inhibition of miR-545-5p and overexpression of CNPY2 significantly reversed cell phenotypes caused by silencing of LINC00342. Conclusion LINC00342 plays a potential oncogenic role in GC by targeting the miR545-5p/CNPY2 axis, and might act as a novel therapeutic target for GC.


2020 ◽  
Author(s):  
Lu Jin ◽  
Zhiwei He ◽  
Changhao Zhu ◽  
Guoliang Xiao ◽  
Xianjin Yang ◽  
...  

Abstract Background: CircRNA is a new type of non-coding RNA that has attracted much attention for involvement in the development and progression of various human diseases, especially cancer. The most reported role of circRNA in many tumors is ‘MiRNA sponge’. We aimed to investigate the role of circBVES in the proliferation and glycolysis of gastric cancer cells and its molecular mechanisms.Methods: In this study, higher CircBVES expression in gastric cancer tissues was detected by RNA sequencing. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression of CircBVES in gastric cancer tissues, and the relationship between the expression of CircBVES and prognosis was further analyzed. Then, the effects of CircBVES on the growth and glycolysis of gastric cancer cells were investigated through in vitro and in vivo functional experiments. The interaction between CircBVES and miR-145-5p was detected by bioinformatics analysis, luciferase activity assay and RNA immunoprecipitation.Results: We found that the expression of CircBVES in gastric cancer tissues was evidently up-regulated, and its level was closely correlated with the prognosis of patients with gastric cancer. Inhibition of CircBVES decreased cell proliferation and glycolysis in vitro. Low expression of CircBVES inhibited tumor growth in vivo. Mechanism analysis showed that CircBVES may serve as a competitive endogenous RNA of miR-145-5p to reduce the expression of miR-145-5p in gastric cancer cells, and relieve the repressive effect of miR-145-5p on target genes HMGB3 and cycle-related proteins CCNE1 and CDK2.Conclusions: Our results suggest that CircAGFG1 may promote the progress of gastric cancer through the CircBVES / miR-145-5p / HMGB3 axis, providing a new target for the treatment of gastric cancer cells.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ying Jiang ◽  
Shan Jin ◽  
Shisheng Tan ◽  
Yingbo Xue ◽  
Xue Cao

Abstract Background Long noncoding RNA nuclear-enriched abundant transcript 1 (NEAT1) exhibits an oncogenic role in multiple cancers, including gastric cancer (GC). But, the functions of NEAT1 in modulating radio-sensitivity of GC and its potential molecular mechanisms have not been totally elucidated. Methods qRT-PCR was performed to detect the expressions of NEAT1 and microRNA-27b-3p (miR-27b-3p). Kaplan–Meier survival curves for NEAT1 expression in GC created using KM Plotter. Colony formation assay was used to determine the survival fraction. Cell apoptosis was evaluated by flow cytometry. Luciferase reporter assay was used to verify the relationship between miR-27b-3p and NEAT1. Results NEAT1 was highly expressed while miR-27b-3p was downregulated in GC tissues and cells. NEAT1 was negatively correlated with that of miR-27b-3p and associated with poor overall survival. Moreover, NEAT1 and miR-27b-3p varied inversely after radiation in GC tissues and cells. Loss of NEAT1 or upregulation of miR-27b-3p increased the effect of radiation on cell survival fraction inhibition and apoptosis promotion. In addition, NEAT1 negatively regulated the expression of miR-27b-3p in GC cells. Interestingly, the depletion of miR-27b-3p dramatically attenuated the NEAT1 knockdown-mediated function in AGS and MKN-45 cells treated with radiation in vitro. Similarly, downregulation of NEAT1 enhanced the radiation-mediated inhibition of tumor growth, which was mitigated by decrease of miR-27b-3p. Conclusion NEAT1 depletion enhanced radio-sensitivity of GC by negatively regulating miR-27b-3p in vitro and in vivo.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Feng Yang ◽  
Anpei Hu ◽  
Dan Li ◽  
Jianqun Wang ◽  
Yanhua Guo ◽  
...  

Abstract Background Circular RNAs (circRNAs), a subclass of non-coding RNAs, play essential roles in tumorigenesis and aggressiveness. Our previous study has identified that circAGO2 drives gastric cancer progression through activating human antigen R (HuR), a protein stabilizing AU-rich element-containing mRNAs. However, the functions and underlying mechanisms of circRNAs derived from HuR in gastric cancer progression remain elusive. Methods CircRNAs derived from HuR were detected by real-time quantitative RT-PCR and validated by Sanger sequencing. Biotin-labeled RNA pull-down, mass spectrometry, RNA immunoprecipitation, RNA electrophoretic mobility shift, and in vitro binding assays were applied to identify proteins interacting with circRNA. Gene expression regulation was observed by chromatin immunoprecipitation, dual-luciferase assay, real-time quantitative RT-PCR, and western blot assays. Gain- and loss-of-function studies were performed to observe the impacts of circRNA and its protein partner on the growth, invasion, and metastasis of gastric cancer cells in vitro and in vivo. Results Circ-HuR (hsa_circ_0049027) was predominantly detected in the nucleus, and was down-regulated in gastric cancer tissues and cell lines. Ectopic expression of circ-HuR suppressed the growth, invasion, and metastasis of gastric cancer cells in vitro and in vivo. Mechanistically, circ-HuR interacted with CCHC-type zinc finger nucleic acid binding protein (CNBP), and subsequently restrained its binding to HuR promoter, resulting in down-regulation of HuR and repression of tumor progression. Conclusions Circ-HuR serves as a tumor suppressor to inhibit CNBP-facilitated HuR expression and gastric cancer progression, indicating a potential therapeutic target for gastric cancer.


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