scholarly journals The RNA-Binding Protein DDX18 Promotes Gastric Cancer by Affecting the Maturation of MicroRNA-21

2021 ◽  
Vol 10 ◽  
Author(s):  
Yeqian Zhang ◽  
Fengrong Yu ◽  
Bo Ni ◽  
Qing Li ◽  
Seong-Woo Bae ◽  
...  

ObjectivesThe noncoding RNAs (ncRNAs) play important roles in gastric cancer. Most studies have focused on the functions and influence of ncRNAs, but seldom on their maturation. DEAD box genes are a family of RNA-binding proteins that may influence the development of ncRNAs, which attracted our attention. By combining a small sample for high-throughput gene microarray screening with large samples of The Cancer Genome Atlas (TCGA) data and our cohort, we aimed to find some gastric cancer-related genes. We evaluated the clinical significance and prognostic value of candidate gene DDX18, which is overexpressed in gastric cancer tissues. To provide a theoretical basis for the development of new therapeutic targets for the treatment of gastric cancer, we investigated its effect on the malignant biological behavior of gastric cancer in vitro and in vivo, and also discuss its mechanism of action.Methods(i) The differential profiling of mRNA expression in five pairs of gastric cancer and adjacent normal tissues was studied by Arraystar Human mRNA Microarray. By combining this with TCGA data and our cohort, we finally filtered out DDX18, which was upregulated in gastric cancer tissues, for further investigation. (ii) The protein expression of DDX18 was detected by immunohistochemistry staining. Then the relationship between the DDX18 expression level and the clinicopathological data and prognosis was analyzed. (iii) A CCK-8 assay and colony formation assay were used to evaluate the effect of DDX18 on cell growth and proliferation in vitro. A transwell assay was also performed to examine the migration and invasion of gastric cancer cells. Cell apoptosis was analyzed by using a fluorescein isothiocyanate–annexin V/propidium iodide double-staining assay. To identify the role of DDX18 in the tumorigenic ability of gastric cancer cells in vivo, we also established a subcutaneous gastric cancer xenograft model. Coimmunoprecipitation, small RNAseq, and western blotting were performed to explore the mechanism of action of DDX18 in gastric cancer. A patient-derived xenograft (PDX) model was used to confirm the effect of DDX18 in gastric cancer tissues.Result(i) DDX18 was upregulated in gastric cancer tumor tissues from a TCGA database and our cohort. The expression of DDX18 was also closely related to tumor volume, Borrmann classification, degree of tumor differentiation, cancer embolus, lymph node metastasis, and TNM stage. (ii) DDX18 could promote cell proliferation, migration, and invasion and inhibit cell apoptosis in vivo and in vitro. (iii) DDX18 could promote the maturation of microRNA-21 through direct interaction with Drosha, decreasing PTEN, which could upregulate the AKT signaling pathway. (iv) The PDX model showed that DDX18 could promote the proliferation of gastric cancer tissues by means of the PTEN–AKT signaling pathway.Conclusions(i) DDX18 can be treated as a molecular marker to assess the prognosis of patients with gastric cancer. (ii) DDX18 could be a potential therapeutic target in gastric cancer.

2020 ◽  
Vol 168 (2) ◽  
pp. 159-170
Author(s):  
Weiyu Liu ◽  
Yan Li ◽  
Shuting Feng ◽  
Yadi Guan ◽  
Yong Cao

Abstract Gastric cancer is one of the most common types of carcinoma with a threat to global health. MicroRNA-760 (miR-760) was significantly down-regulated in the primary tumour of patients with advanced gastric cancer. However, the role of miR-760 in gastric cancer is still unclear. Herein, miR-760 was down-regulated in gastric cancer tissues. Moreover, miR-760 overexpression and knockdown were conducted in gastric cancer cells (MGC-803 and SGC-7901) in vitro. The in vitro functional assays proved that miR-760 overexpression reduced cell viability, cell cycle, migration and invasion, promoted apoptosis and suppressed MMP activity in MGC-803 cells. Conversely, miR-760 knockdown led to the opposite in SGC-7901 cells. Notably, bone marrow stromal antigen 2 (BST2) was verified as a target gene of miR-760. MiR-760 mimics down-regulated BST2 level in gastric cancer tissues and in MGC-803 cells, whereas miR-760 inhibitor up-regulated its level in SGC-7901 cells. MiR-760-regulated cell properties through reduction of BST2. In addition, miR-760 inhibited tumourigenesis in a nude mouse xenograft model in vivo. In conclusion, our results demonstrated that miR-760 exhibited a suppressive role in gastric cancer via inhibiting BST2, indicating that miR-760/BST2 axis may provide promising therapeutic target for gastric cancer.


2021 ◽  
Author(s):  
Shenshuo Gao ◽  
Zhikai Zhang ◽  
Xubin Wang ◽  
Yan Ma ◽  
Chensheng Li ◽  
...  

Abstract Background: Gastric cancer (GC) is one of the most common malignancies, and more and more evdiences show that the pathogenesis is regulated by various miRNAs.In this study, we investigated the role of miR-875 in GC. Methods:The expression of miR-875-5p was detected in human GC specimens and cell lines by miRNA RT-PCR. The effect of miR-875-5p on GC proliferation was determined by CCK-8 proliferation assay and EDU assay. Migration and invasion were examined by transwell migration and invasion assay and wound healing assay. The interaction between miR-875-5p and its target gene USF2 was verified by a dual luciferase reporter assay. The effects of miR-875-5p in vivo were studied in xenograft nude mice models.Related proteins were detected by Western blot.Results:The results showed that miR-875-5p inhibited the proliferation, migration and invasion of gastric cancer cells in vitro, and inhibited tumorigenesis in vivo. USF2 proved to be a direct target of miR-875-5p. Knockdown of USF2 partially counteracts the effects of miR-875-5p inhibitors.Overexpression of miR-875-5p can inhibit proliferation, migration, and invasion through the TGF-β signaling pathway by down-regulation of USF2 in GC, providing a new research direction for the diagnosis and targeted therapy of GC.Conclusions: MiR-875-5pcan inhibited the progression of GC by directly targeting USF2 and negatively regulating TGF-β signaling pathway.In the future, miR-875-5p is expected to be used as a potential therapeutic target for GC therapy.


2022 ◽  
Vol 22 ◽  
Author(s):  
Meng Li ◽  
Jiang Chang ◽  
Honglin Ren ◽  
Defeng Song ◽  
Jian Guo ◽  
...  

Background Increased CCKBR expression density or frequency has been reported in many neoplasms. Objective We aimed to investigate whether CCKBR drives the growth of gastric cancer (GC) and its potential as a therapeutic target of immunotoxins. Methods A lentiviral interference system was used to generate CCKBR-knockdown gastric cancer cells. Cell Counting Kit-8 and clonogenic assays were used to evaluate cell proliferation. Wound-healing and cell invasion assays were performed to evaluate cell mobility. Cell cycle was analyzed by flow cytometry. Tumor growth in vivo was investigated using a heterologous tumor transplantation model in nude mice. In addition, we generated the immunotoxin FQ17P and evaluated the combining capacity and tumor cytotoxicity of FQ17P in vitro. Results Stable downregulation of CCKBR expression resulted in reduced proliferation, migration and invasion of BGC-823 and SGC-7901 cells. The impact of CCKBR on gastric cancer cells was further verified through CCKBR overexpression studies. Downregulation of CCKBR expression also inhibited the growth of gastric tumors in vivo. Furthermore, FQ17P killed CCKBR-overexpressing GC cells by specifically binding to CCKBR on the tumor cell surface. Conclusion The CCKBR protein drives the growth, migration, and invasion of gastric cancer cells, and it might be a promising target for immunotoxin therapy based on its aberrant expression, functional binding interactions with gastrin, and subsequent internalization.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yunfeng Hu ◽  
Yani Su ◽  
Xia Lei ◽  
Hong Zhao ◽  
Lelin Wang ◽  
...  

Abstract The poor prognosis of gastric adenocarcinoma is partly due to chemotherapy failure, especially the oxaliplatin-based chemotherapy. However, the specific mechanism of oxaliplatin resistance is unclear. We aim to find the roles that LINC00641 and miR-582-5p play in regulating oxaliplatin resistance. Quantitative reverse transcriptase-PCR was used to evaluate the expression of LINC00641 and microRNA-582-5p (miR-582-5p) in gastric cancer both in vivo and in vitro. Transwell and CCK-8 assays were performed; and LC3 I/II and p62 were detected by western blot to evaluate the activation of autophagy. LINC00641 expression was associated with prognosis and oxaliplatin resistance in patients with gastric adenocarcinoma. The expression of LINC00641 was higher in gastric cancer tissues; whereas miR-582-5p was down-regulated in gastric cancer tissues. Moreover, LINC00641 was highly expressed in oxaliplatin-resistant cell lines and miR-582-5p was down-regulated. In addition, LINC00641 negatively regulated the expression of miR-582-5p. With regard to biological functions, down-regulation of LINC00641 suppressed cell migration and proliferation. Further experiments indicated that down-regulation of LINC00641 inhibited the autophagy process, making gastric cancer cells more sensitive to oxaliplatin. LINC00641 and miR-582-5p are biomarkers for predicting overall survival, as they were involved in regulating oxaliplatin resistance by altering autophagy in gastric adenocarcinoma.


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.


Tumor Biology ◽  
2017 ◽  
Vol 39 (5) ◽  
pp. 101042831769839 ◽  
Author(s):  
Bi-bo Tan ◽  
Yong Li ◽  
Li-qiao Fan ◽  
Qun Zhao ◽  
Qing-wei Liu ◽  
...  

Several studies have proved that Vav2 gene is associated with the carcinogenesis of some tumors, but the relationship between Vav2 gene and gastric cancer remains unclear. Purpose of this study is to detect the expression of Vav2 protein in gastric cancer tissues and to evaluate the clinical value of Vav2. Furthermore, both effect of Vav2 gene on invasion and metastasis of gastric cancer cells and its mechanism are investigated in vitro. Results showed that positive rate of Vav2 protein was significantly higher in gastric cancer tissues than in adjacent tissues and notably higher in metastatic lymph nodes than in gastric cancer tissues. Results of western blot were consistent with immunohistochemistry. Expression of Vav2 protein in gastric cancer tissues was related to degree of tumor differentiation, lymph node metastasis, and clinical stages. Inhibition of endogenous Vav2 in BGC823 cells led to significantly decreased cell activity, migration, and invasion ability in vitro, and expression of Rac1, MMP-2, and MMP-9 decreased, whereas expression of TIMP-1 increased. We concluded that Vav2 might promote invasion and metastasis of gastric cancer by regulating some invasion and metastasis-related genes.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yixun Lu ◽  
Benlong Zhang ◽  
Baohua Wang ◽  
Di Wu ◽  
Chuang Wang ◽  
...  

Abstract Background Gastric cancer (GC) is the fifth most commonly diagnosed cancer worldwide. Due to the dismal prognosis, identifying novel therapeutic targets in GC is urgently needed. Evidences have shown that miRNAs played critical roles in the regulation of tumor initiation and progression. GLI family zinc finger 2 (GLI2) has been reported to be up-regulated and facilitate cancer progression in multiple malignancies. In this study, we focused on identifying GLI2-targeted miRNAs and clarifying the underlying mechanism in GC. Methods Paired fresh gastric cancer tissues were collected from gastrectomy patients. GLI2 and miRNAs expression were detected in gastric cancer tissues and cell lines. Bioinformatics analysis was used to predict GLI2-targeted miRNAs and dual-luciferase reporter assay was applied for target verification. CCK-8, clone formation, transwell and flow cytometry were carried out to determine the proliferation, migration, invasion and cell cycle of gastric cancer cells. Tumorsphere formation assay and flow cytometry were performed to detail the stemness of gastric cancer stem cells (GCSCs). Xenograft models in nude mice were established to investigate the role of the miR-144-3p in vivo. Results GLI2 was frequently upregulated in GC and indicated a poor survival. Meanwhile, miR-144-3p was downregulated and negatively correlated with GLI2 in GC. GLI2 was a direct target gene of miR-144-3p. MiR-144-3p overexpression inhibited proliferation, migration and invasion of gastric cancer cells. Enhanced miR-144-3p expression inhibited tumorsphere formation and CD44 expression of GCSCs. Restoration of GLI2 expression partly reversed the suppressive effect of miR-144-3p. Xenograft assay showed that miR-144-3p could inhibit the tumorigenesis of GC in vivo. Conclusions MiR-144-3p was downregulated and served as an essential tumor suppressor in GC. Mechanistically, miR-144-3p inhibited gastric cancer progression and stemness by, at least in part, regulating GLI2 expression.


2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 53-53
Author(s):  
Mitsuro Kanda ◽  
Haruyoshi Tanaka ◽  
Takashi Miwa ◽  
Daisuke Kobayashi ◽  
Chie Tanaka ◽  
...  

53 Background: Hepatic metastasis of gastric cancer has become a growing issue, because effective treatment and specific biomarkers are not available. The aim of this study was to identify a molecule mediating hepatic metastasis, which serves as a diagnostic marker, and to determine its potential as a therapeutic target. Methods: Stable knockdown gastric cancer cells were established using genome editing technique and cell activities were compared to control cells in vitro and in vivo. Tissue expression levels of the candidate molecule were evaluated in 300 patients with gastric cancer and correlated to clinicopathological parameters including patterns of metastasis and recurrences. Results: Global expression analysis revealed that synaptotagmin VII (SYT7) was overexpressed in gastric cancer tissues with hepatic metastasis. Gastric cancer cell lines differentially expressed high levels of SYT7 that positively correlated with those of SNAI1 and TGFB3, and inversely with RGS2. Stable knockout of SYT7 inhibited the proliferation of gastric cancer cells, indicated by increased apoptosis, and decreased cell migration, invasion, and adhesion abilities. The tumorigenicity of SYT7 knockout cells was moderately reduced in a mouse subcutaneous model and more strikingly decreased in a hepatic metastasis model. The protein expression levels of BCL2 and HIF1A were decreased in tumors formed by SYT7 knockout cells, and SYT7 levels in primary gastric cancer tissues were significantly associated with hepatic recurrence, metastasis, and adverse prognosis. Conclusions: SYT7 serves as a target for treating hepatic metastasis of gastric cancer as well as a diagnostic tool.


2020 ◽  
Vol 19 ◽  
pp. 153303382091595 ◽  
Author(s):  
Yong Zhu ◽  
Feng Shi ◽  
Meng Wang ◽  
Jian Ding

Rabs have been reported to be involved in the carcinogenesis process and in the progression of cancer. However, it is unclear whether or not Rab9 is associated with the development of cancer. In the present study, we aimed to investigate the role of Rab9 in the biological functions of gastric cancer cells. The gastric cancer cell lines AGS and MKN45 were transfected with siRNA-Rab9 to block the expression of Rab9. The cell viability, proliferation, migration, invasion, and apoptosis were examined using Cell Count Kit-8, colony formation, wound healing, Transwell, and flow cytometry assays, respectively. Our data showed that silencing of Rab9 significantly inhibited the viability, proliferation, migration, and invasion abilities of AGS and MKN45 cells. Moreover, transfection with siRab9 promoted the rate of apoptosis in AGS and MKN45 cells through regulating the Bcl-2–Bax axis and the Caspase cascade. We also found that silencing of Rab9 inhibited activation of the Akt signaling pathway by downregulating the phosphorylation level of Akt. In conclusion, our data suggest that Rab9 plays an oncogenic role in the progression of gastric cancer, providing a potential target for the treatment of gastric cancer.


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