HOTAIR Competitively Binds MiRNA330 as a Molecular Sponge to Increase the Resistance of Gastric Cancer to Trastuzumab

2020 ◽  
Vol 20 (9) ◽  
pp. 700-709 ◽  
Author(s):  
Liangyu Bie ◽  
Suxia Luo ◽  
Dan Li ◽  
Yan Wei ◽  
Yu Mu ◽  
...  

Background: HOTAIR, one of the most widely studied long non-coding RNAs in tumors, is closely related to tumor proliferation, migration, invasion and chemoresistance. Objective: Here, we studied the mechanism behind proliferation and chemoresistance processes. Methods: A total of 75 samples were collected from patients who underwent surgical resection of their gastric cancer and received trastuzumab treatment. Primary cells were isolated and cultured. We also developed a cell line overexpressing HOTAIR by constructing a lentiviral vector. These cell lines were studied using an array of established biomolecular methods. Results: We found that HOTAIR levels were inversely associated with sensitivity to trastuzumab in gastric cancer and that overexpression of HOTAIR can promote the proliferation and invasion of gastric cancer cells. The sensitivity of cells overexpressing HOTAIR to two different types of human epidermal growth factor receptor 2 (HER2) inhibitors (trastuzumab and afatinib) showed that overexpression of HOTAIR is specific for trastuzumab resistance. Furthermore, luciferase reporter gene assay and western blot assay showed that there is a HOTAIR-miRNA330-ERBB4 competitive endogenous RNA regulatory network with miRNA330 as the core. Conclusion: HOTAIR can not only promote tumor proliferation but also enhance the resistance of tumor cells to drugs. Our experimental data not only showed strong expression of HOTAIR in gastric cancer, but also that strong expression of HOTAIR caused the sensitivity of gastric cancer cells to trastuzumab, which is a useful reference for postoperative medication.

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yingchun Zhang ◽  
Yong Zhou ◽  
Fang Wei

Objective. To investigate the role of circABCB10 in gastric cancer and the molecular mechanism of promoting malignant progression of gastric cancer cells by preventing the degradation of MYC by hsa-miR-1252-5p. Methods. The expression of circABCB10 in gastric cancer tissues and cells was detected by real-time quantitative PCR. MTT, Transwell, clone formation, and TUNEL assay were used to detect the effects of circABCB10 on the proliferation, invasion, and apoptosis of gastric cancer cells. A subcutaneous tumor-bearing model was established to study the inhibitory effect of knockdown circABCB10 on gastric cancer proliferation. The dual luciferase reporter gene assay and RNA pull-down assay were used to verify the regulatory effect of circABCB10 on miR-1252-5p and the regulatory effect of miR-1252-5p on MYC. Results. Compared with paracancerous tissues and gastric mucosal epithelial cells, the expression of circABCB10 was significantly increased in human gastric cancer tissues and gastric cancer cells. circABCB10 knockout significantly decreased cell viability and invasion ability and promoted cell apoptosis ( P < 0.01 ). Subcutaneous tumor-bearing experiments in nude mice demonstrated that circABCB10 knockdown inhibited the proliferation of gastric cancer cells. circABCB10 can act as a sponge for miR-1252-5p in gastric cancer cells. Meanwhile, MYC is the target gene of miR-1252-5p. Overexpression of miR-1252-5p and knockdown of MYC reversed the promoting effect of circABCB10 on gastric cancer. Conclusion. circABCB10 can promote the proliferation, invasion, and clonal formation of gastric cancer cells by targeting miR-1252-5p and upregulating the expression of MYC. circABCB10/miR-1252-5p/MYC constitutes the regulatory mechanism of ceRNA.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Nan Zhou ◽  
Hui Qiao ◽  
Miaomiao Zeng ◽  
Lei Yang ◽  
Yongning Zhou ◽  
...  

Abstract Background Mounting evidence implicates circular RNAs (circRNAs) in various biological processes during cancer progression. Gastric cancer is a main cause of cancer-related deaths worldwide. Herein, we aimed at investigating whether circ_002117 mediates gastric cancer progression through endoplasmic reticulum (ER) stress. Methods Bioinformatics analysis detected differentially expressed circRNAs and their target miRNA candidates, and RT-qPCR was performed to detect expression of circ_002117, microRNA (miRNA)-370 and HERPUD1 in gastric cancer tissues and cells. Gastric cancer cells were transfected with plasmids and their proliferative ability and apoptosis were detected with gain- and loss-of-function assay. The ER of treated cells was observed under a transmission electron microscope. Dual-luciferase reporter gene assay and RIP were performed to detect the interaction between HEPRUD1, miR-370 and circ_002117-treated cells were injected into mice to establish xenograft tumor model. Results Circ_002117 and HEPRUD1 were poorly expressed whereas miR-370 was highly expressed in clinical cancer tissues and cells. Circ_002117 was indicated to target and suppress miR-370 expression, while HERPUD1 was directly targeted by miR-370. Circ_002117 overexpression or miR-370 deficiency promoted ER stress-induced apoptosis and decreased proliferation of gastric cancer cells, which was reversed by silencing of HEPRUD1. Circ_002117 overexpression or miR-370 depletion significantly suppressed gastric cancer tumorigenesis in vivo. Conclusions Taken altogether, circ_002117 facilitated ER stress-induced apoptosis in gastric cancer by upregulating HERPUD1 through miR-370 inhibition.


2021 ◽  
Author(s):  
Chuanliang Liu ◽  
Dan Wang ◽  
Lei Li ◽  
Ruihua Zhang

Abstract Background: Ferroptosis is a newly described form of regulated cell death, targeting nuclear factor erythroid-2-related factor 2 (Nrf2) -mediated ferroptosis may be an attractive option to counteract malignant tumor. Whether miR-144-5p sensitize erastin-induced ferroptosis in gastric cancer via regulation of Nrf2 pathway is unclear. Methods: To speculate the function of miR-144-5p in cancers, bioinformatic analysis was performed. Dual-luciferase reporter gene assay was used to predict effect of miR-144-5p on the expression of Nrf2. The expressions of miR-144-5p and Nrf2 in human gastric cancer cell lines and tissues were detected by qPCR, Immunohistochemistry or western blot. Results: miR-144-5p, identified to wreck Nrf2 mRNA, was selected and overexpressed in gastric cancer cells to sensitize erastin-induced ferroptosis. Ectopic expression of miR-144-5p in AGS and BGC-823 cells downregulated the mRNA and protein expression of Nrf2. In addition, AGS and BGC-823 cell lines with exogenous expression of miR-144-5p were more sensitive to erastin-induced ferroptosis with overgeneration of lipid reactive oxygen species and depletion of glutathione. Conclusions: miR-144-5p sensitizes erastin-induced ferroptosis via abrogating expression of Nrf2 to eliminate cancer cells selectively with high Nrf2 pathway activation.


2020 ◽  
Vol 15 (1) ◽  
pp. 159-172
Author(s):  
Guoning Su ◽  
Zhibing Yan ◽  
Min Deng

AbstractSevoflurane was frequently used as a volatile anesthetic in cancer surgery. However, the potential mechanism of sevoflurane on lung cancer remains largely unclear. In this study, lung cancer cell lines (H446 and H1975) were treated by various concentrations of sevoflurane. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assessment and colony formation assay were performed to detect the cell viability and proliferation, separately. Also, transwell assay or flow cytometry assay was applied as well to evaluate the invasive ability or apoptosis in lung cancer cells, respectively. Western blot assay was employed to detect the protein levels of β-catenin and Wnt5a. Moreover, quantitative real-time polymerase chain reaction (qRT-PCR) was used to examine the expression level of prostate cancer-associated transcript 6 (PCAT6) and miR-326 in lung cancer tissues and cells. The target interaction between miR-326 and PCAT6 or Wnt5a was predicted by bioinformatics analysis and verified by the dual-luciferase reporter gene assay. Sevoflurane inhibited the abilities on viability, proliferation, invasion, and activation of Wnt/β-catenin signaling, but promoted apoptosis of H446 and H1975 cells in a dose-dependent manner. The expression of PCAT6 was increased in lung cancer tissues and cells, except for that of miR-326. Besides, sevoflurane could lead to expressed limitation of PCAT6 or improvement of miR-326. This process presented a stepwise manner. Up-regulation of PCAT6 restored the suppression of sevoflurane on abilities of proliferation, invasion, rather than apoptosis, and re-activated the Wnt5a/β-catenin signaling in cells. Moreover, the putative binding sites between miR-326 and PCTA6 or Wnt5a were predicted by starBase v2.0 software online. PCAT6 suppressing effects on cells could be reversed by pre-treatment with miR-326 vector. The promotion of Wnt5a inverted effects led from miR-326 or sevoflurane. Our study indicated that sevoflurane inhibited the proliferation, and invasion, but enhanced the apoptosis in lung cancer cells by regulating the lncRNA PCAT6/miR-326/Wnt5a/β-catenin axis.


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.


2020 ◽  
Author(s):  
Yi Gao ◽  
Yanfeng Wang ◽  
Xiaofei Wang ◽  
Changan Zhao ◽  
Fenghui Wang ◽  
...  

Abstract Background: In recent years, many microRNAs(miRNAs) involved in cancer progression. The aberrant expression of miR-335-5p in tumorigenesis has been demonstrated. The present study aimed to investigate the molecular mechanisms underlying miR-335-5p- regulated MAPK10 expression in human gastric cancer(GC).Methods: The quantitative real-time PCR was used to study the level of miR-335-5p expression in gastric cancer cell lines and tissues. Subsequently, the MTT and cloning formation assays were used to detect cell proliferation, while transwell and wound-healing assays were used to identify invasion and migration of the gastric cancer cells. The correlation between the miR-335-5p and the cell cycle-related target gene mitogen‑activated protein kinase 10 (MAPK10) in gastric cancer was analyzed based on the website. In addition, the target gene of miR-335-5p was detected by luciferase reporter assay, qRT-PCR, and western blotting.Results: The miR-335-5p level was down-regulated in GC tissues and cell lines. Furthermore, miR-335-5p inhibited proliferation, migration of gastric cancer cells, and induced apoptosis. During the G1/S phase, miR-335-5p arrested the cycle of gastric cancer cells in vitro. The correlation between the miR-335-5p and the cell cycle-related target gene MAPK10 in GC was analyzed, MAPK10 was directly targeted by the miR-335-5p.Conclusion: These data suggested that miR-335-5p acts as a tumor suppressor, and go through the MAPK10 to inhibit the GC progression.


2021 ◽  
Author(s):  
Yaping Liu ◽  
Xu Zhao ◽  
Yinnan Chen ◽  
Gang Guo ◽  
Jiansheng Wang ◽  
...  

Abstract To evaluate the expression of PITPNA-AS1 and miR-98-5p in gastric cancer tissues as well as their association with progression of gastric cancer, and investigate the role of PITPNA-AS1 and miR-98-5p in developing platinum resistance. RNA sequencing was used to identify candidate lncRNAs and microRNAs related to local recurrence of gastric cancer. qRT-PCR was used to investigate the expression of PITPNA-AS1 and miR-98-5p. CCK-8 and caspase3/7 activity were used to evaluate the cell proliferation and apoptosis rate. Dual luciferase reporter gene assay and RNA pull down were used to evaluate the cross talk between PITPNA-AS1 and miR-98-5p. PITPNA-AS1 and miR-98-5p could regulate cell proliferation and inhibit apoptosis in gastric cancer cell lines. Cisplatin and lobaplatin could significantly suppress the expression of PITPNA-AS1, which interacted with negatively regulated miR-98-5p expression. PITPNA-AS1 overexpression impaired the effect of platinum, which was partially reversed by downregulation of miR-98-5p knock down. In gastric cancer, PITPNA-AS1 and miR-98-5p could regulat cell growth, apoptosis and platinum resistance. They have the potential to be biomarkers and curative therapeutic targets. However, further research on molecular mechanisms are needed.


2021 ◽  
Vol 11 ◽  
Author(s):  
Ling Gao ◽  
Tingting Xia ◽  
Mingde Qin ◽  
Xiaofeng Xue ◽  
Linhua Jiang ◽  
...  

BackgroundGastric cancer is a type of malignant tumor with high morbidity and mortality. It has been shown that circular RNAs (circRNAs) exert critical roles in gastric cancer progression via working as microRNA (miRNA) sponges to regulate gene expression. However, the role and potential molecular mechanism of circRNAs in gastric cancer remain largely unknown.MethodsCircPTK2 (hsa_circ_0005273) was identified by bioinformatics analysis and validated by RT-qPCR assay. Bioinformatics prediction, dual-luciferase reporter, and RNA pull-down assays were used to determine the interaction between circPTK2, miR-196a-3p, and apoptosis-associated tyrosine kinase 1 (AATK).ResultsThe level of circPTK2 was markedly downregulated in gastric cancer tissues and gastric cancer cells. Upregulation of circPTK2 significantly suppressed the proliferation, migration, and invasion of gastric cancer cells, while circPTK2 knockdown exhibited opposite effects. Mechanically, circPTK2 could competitively bind to miR-196a-3p and prevent miR-196a-3p to reduce the expression of AATK. In addition, overexpression of circPTK2 inhibited tumorigenesis in a xenograft mouse model of gastric cancer.ConclusionCollectively, circPTK2 functions as a tumor suppressor to suppress gastric cancer cell proliferation, migration, and invasion through regulating the miR-196a-3p/AATK axis, suggesting that circPTK2 may serve as a novel therapeutic target for gastric cancer.


2020 ◽  
Author(s):  
Hanshu Ji ◽  
Xiaoyu Zhang

Abstract Purpose: lncRNA NEAT1 has been reported as a tumor-promoting gene in a variety of tumors, but few studies have explored its role and mechanism in gastric cancer. In the face of increasing incidence of gastric cancer, how to improve the diagnostic accuracy and therapeutic effect of gastric cancer is a major clinical problem. Therefore, we studied the effect and mechanism of lncRNA NEAT1 on the proliferation, invasion and epithelial-mesenchymal transition of gastric cancer cells. To inquiry into the effect of lncRNA NEAT1 on the proliferation, invasion and epithelial-mesenchymal transition (EMT) of gastric cancer (GC) cells by regulating miR-129-5p/PBX3 axis. Methods: Totally 63 GC diagnosed and treated in our hospital were selected as the study subjects, whose paired GC tissues and pericarcinomatous tissues were collected as the study specimens after obtaining their consent. QRT-PCR was employed to detect the NEAT1 expression in tissues and cells to analyze the relationship between NEAT1 and clinicopathological data of GC patients. In addition, stable and transient overexpression and inhibition vectors were established and transfected into GC cells HCG-27 and MKN-45. CCK-8, traswell, and flow cytometry were employed to evaluate the proliferation, invasion, and apoptosis of transfected cells. The correlation of miR-129-5p between PBX3 and NEAT1 was assessed using dual luciferase reporter assay, while that between NEAT1 and miR-129-5p was assessed by RNA-binding protein immunoprecipitation (RIP) . Western blot was applied for the detection of apoptosis and EMT related proteins.Results: NEAT1 was overexpressed in GC patients and had a high diagnostic value. The expression of NEAT1 was related to the pathological stage, differentiation degree, tumor size and lymph node metastasis of patients with GC. Down-regulated NEAT1 brought decreased cell proliferation, invasion and EMT, and increased apoptosis. According to dual luciferase reporter assay, NEAT1 could target miR-129-5p, while in turn miR-129-5p could target PBX3. Functional analysis exhibited that miR-129-5p overexpression inhibited PBX3 in GC cells, affecting cell proliferation, invasion, EMT and apoptosis, and rescue experiments demonstrated that these effects were eliminated by up-regulating NEAT1 expression.Conclusion: Inhibition of NEAT1 could mediate miR-129-5p/PBX3 axis to promote apoptosis of GC cells, and reduce cell proliferation, invasion and EMT.


Author(s):  
Chunsheng Li ◽  
Jingrong Dong ◽  
Zhenqi Han ◽  
Kai Zhang

MicroRNAs (miRNAs) are reportedly involved in gastric cancer development and progression. In particular, miR-219-5p has been reported to be a tumor-associated miRNA in human cancer. However, the role of miR-219-5p in gastric cancer remains unclear. In this study, we investigated for the first time the potential role and underlying mechanism of miR-219-5p in the proliferation, migration, and invasion of human gastric cancer cells. miR-219-5p was found to be markedly decreased in gastric cancer tissues and cell lines compared with adjacent tissues and normal gastric epithelial cells. miR-219-5p mimics or anti-miR-219-5p was transfected into gastric cancer cell lines to overexpress or suppress miR-219-5p expression, respectively. Results showed that miR-219-5p overexpression significantly decreased the proliferation, migration, and invasion of gastric cancer cells. Conversely, miR-219-5p suppression demonstrated a completely opposite effect. Bioinformatics and luciferase reporter assays indicated that miR-219-5p targeted the 3′-untranslated region of the liver receptor homolog-1 (LRH-1), a well-characterized oncogene. Furthermore, miR-219-5p inhibited the mRNA and protein levels of LRH-1. LRH-1 mRNA expression was inversely correlated with miR-219-5p expression in gastric cancer tissues. miR-219-5p overexpression significantly decreased the Wnt/β-catenin signaling pathway in gastric cancer cells. Additionally, LRH-1 restoration can markedly reverse miR-219-5p-mediated tumor suppressive effects. Our study suggests that miR-219-5p regulated the proliferation, migration, and invasion of human gastric cancer cells by suppressing LRH-1. miR-219-5p may be a potential target for gastric cancer therapy.


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