Metastatic Ability Of Gastric Cancer Cells Research Articles

EGCG-LYS Fibrils-Mediated CircMAP2K2 Silencing Decreases the Proliferation and Metastasis Ability of Gastric Cancer Cells in Vitro and in Vivo.

Aberrant expression of circular RNAs (circRNAs) has been reported to play an important biological regulatory role in gastric cancer (GC). For the purpose of silencing cancer-related genes, a new approach for cancer treatment using nanocarriers to deliver siRNA has been proposed. In this study, abundantly expressed circMAP2K2 (hsa_circRNA_102415) is identified in GC cells. CircMAP2K2 regulates the PCBP1/GPX1 axis through proteasome-mediated degradation, which further mediates the activation of the AKT/GSK3β/epithelial-to-mesenchymal transition (EMT) signaling pathway and enhances the proliferation and metastatic ability of GC cells. To establish novel GC treatment, epigallocatechin-3-gallate-lysozyme (EGCG-LYS) fibrils are synthesized, and in vitro experiments demonstrate that EGCG-LYS has a higher siRNA delivery efficiency than Lipofectamine 2000 (lipo2000), which effectively silences the expression of circMAP2K2. Further studies show that EGCG-LYS carrying siRNA can successfully achieve lysosome escape, which allows it to be located in the cytoplasm to achieve post-transcriptional gene silencing. In addition, EGCG-LYS carrying si-circMAP2K2 has good circulating stability, excellent biosafety and antitumor ability in vivo. The EGCG-LYS fibrils delivery system provides a new tool and approach for the treatment of GC.

LncRNA CASC19 promotes gastric cancer progression through preventing CREB1 protein ubiquitin/proteasome-dependent degradation.

Cancer susceptibility candidate 19 (CASC19) is a novel long non-coding RNA (lncRNA) that has been reported to implicate in the development and therapeutic resistance of various cancers. However, the biological functions and the underlying mechanisms of CASC19 in gastric cancer (GC) remain unclear. In this study, GC-related lncRNAs were screened by lnCAR-database analysis. Based on Gene Expression Profiling Interactive Analysis (GEPIA) database, GC survival analysis associated with CASC19 was carried out. Quantitative real-time PCR (qRT-PCR) and chromogenic in situ hybridization were adopted to determine the expression level of CASC19. 5-ethynyl-2'-deoxyuridine (EdU) assay, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt (MTS) assay and cell cycle assay were used to measure the proliferation capabilities of GC cells. Wound healing assay, transwell migration and invasion assay were performed to detect the metastatic ability of GC cells. Furthermore, subcellular fractionation assay, mass spectrometry, RNA pull-down, RNA immunoprecipitation, western blot and protein stability assay were conducted to investigate the mechanism of CASC19 in GC. Here, we report that CASC19 exerts an oncogenic effect on GC. CASC19 was found to be elevated in GC and overexpression of CASC19 was associated with advanced TNM (tumor node metastasis) stage and poor prognosis. Functionally, CASC19 knockdown inhibited GC cells proliferation, migration and invasion, and induced cell cycle arrest. Mechanistically, CASC19 interacted with cAMP response element-binding protein 1 (CREB1) and enhanced its stability by preventing its ubiquitin/proteasome-dependent degradation. In conclusion, these findings suggest that CASC19 may act as a cancer accelerator in GC by regulating CREB1 stability and highlight CASC19 as a potential biomarker and a valuable therapeutic target for advanced GC.

FN1 mRNA 3'-UTR supersedes traditional fibronectin 1 in facilitating the invasion and metastasis of gastric cancer through the FN1 3'-UTR-let-7i-5p-THBS1 axis.

Background: Current clinical treatments for gastric cancer (GC), particularly advanced GC, lack infallible therapeutic targets. The 3'-untranslated region (3'-UTR) has attracted increasing attention as a drug target. Methods: In vitro and in vivo experiments were conducted to determine the function of FN1 3'-UTR and FN1 protein in invasion and metastasis. RNA pull-down assay and high-throughput sequencing were used to screen the factors regulated by FN1 3'-UTR and construct the regulatory network. Western blotting and polymerase chain reaction were used to examine the correlation of intermolecular expression levels. RNA-binding protein immunoprecipitation was used to verify the correlation between FN1 3'-UTR and target mRNAs. Results: The FN1 3'-UTR may have stronger prognostic implications than the FN1 protein in GC patients. Upregulation of FN1 3'-UTR significantly promoted the invasive and metastatic abilities of GC cells to a greater extent than FN1 protein in vitro and in vivo. A novel regulatory network was constructed based on the FN1 3'-UTR-let-7i-5p-THBS1 axis, wherein FN1 3'-UTR displayed stronger oncogenic effects than the FN1 protein. Conclusions: FN1 3'-UTR may be a better therapeutic target for constructing targeted drugs in GC than the FN1 protein.

Delivery of LINC00589 via mesoporous silica nanoparticles inhibits peritoneal metastasis in gastric cancer

Peritoneal metastasis is one of the common forms of metastasis in gastric cancer (GC). In this study, we identified the expression pattern of LINC00589 in GC patients and investigate the biological function in GC cells. RNA-pulldown assay was performed to explore the underlying molecular mechanism. Further, we utilize polyethyleneimine-modified mesoporous silica nanoparticles (PMSNs) as the nanocarriers for delivery of LINC00589 encoding plasmid and tested its therapeutic potential for GC with peritoneal dissemination. We revealed that LINC00589 was downregulated in GC tissues and suppressed the metastatic ability of GC cells. Mechanistically, LINC00589 exerted tumor suppressive function by promoting hnRNPA1 protein ubiquitination and proteasomal degradation, thus blocking alternative splicing of PKM to PKM2. Furthermore, LINC00589 delivered by PMSNs could suppress the peritoneal metastasis of GC in vivo and in vitro. This work may provide a new treatment option in GC peritoneal metastasis.

Essential meiotic structure-specific endonuclease1 (EME1) promotes malignant features in gastric cancer cells via the Akt/GSK3B/CCND1 pathway

ABSTRACT DNA damage plays a key role in various biological processes involved in malignant disease, the role of the DNA damage repair gene EME1 (essential meiotic structure-specific endonuclease 1) in gastric cancer (GC) development is unknown. This work aimed to investigate expression and role of EME1 in tumorigenesis. Quantitative real-time polymerase chain reaction (qRT-PCR), immunoblot, cell viability and dual-luciferase reporter assays, RNAi and gene transfection, and immunofluorescent staining were performed to assess EME1 regulation in GC tumorigenesis. Further, mouse xenografts were established for in vivo mechanistic studies. EME1 was found to be upregulated in both gastric cancer cells and clinically obtained tumors. Additionally, EME1 levels were strongly associated with the differentiation level of GC and lymph node metastasis. In vivo and in vitro knockdown of EME1 markedly suppressed the proliferative, migratory, and invasive abilities of GC cells and enhanced apoptotic cell death and cell cycle arrest rates. Mechanistically, EME1 modulated Akt/GSK3B/CCND1 signaling. MYB may also have contributed to EME1-dependent gastric carcinogenesis. Elevated EME1 expressions may enhance the proliferative and metastatic abilities of GC cells, thereby acting as a tumor-promoting factor via Akt. These findings reveal that EME1 is an important biomarker for GC prognosis and treatment in humans. Abbreviations: Essential meiotic structure-specific endonuclease 1 (EME1); MYB proto-oncogene (MYB); Cell counting kit-8 (CCK-8); 4,6-diamimo-2-phenyl indole (DAPI); Quantitative real-time PCR (qRT-PCR); Gastric cancer (GC); Immunofluorescence (IF); Small interfering RNA (siRNA); Small hairpin RNA (shRNA); Alpha serine threonine-protein kinase (Akt); Glycogen synthase kinase 3 beta (GSK3B); Cyclin D1 (CCND1); Glyceraldehyde-3-phosphate dehydrogenase (GAPDH); Disease-free survival (DFS); Overall survival (OS); Negative controls (NC); American Joint Committee on Cancer (AJCC); Coding sequence (CDS); Lymph node metastasis (LNM); Tris-Buffered Saline-Tween-20 (TBST); Horseradish Peroxidase (HRP); Electrochemiluminescence (ECL); Polyvinylidene Fluoride (PVDF); Excision repair cross complementation group 1 (ERCC1).

Long Intergenic Non-Protein Coding RNA 1089 Suppresses Cell Proliferation and Metastasis in Gastric Cancer by Regulating miRNA-27a-3p/Epithelial-Mesenchymal Transition (EMT) Axis.

AimTo explore the expression and biological function of long intergenic non-protein coding RNA 1089 (LINC01089) in gastric cancer (GC) progression and its underlying mechanism.MethodsLINC01089 and microRNA-27a-3p (miR-27a-3p) expressions were detected with the quantitative real-time polymerase chain reaction (RT-qPCR). Cell proliferation, migration and invasion were evaluated by Cell Counting Kit-8 (CCK-8) and Transwell assay. Epithelial–mesenchymal transition (EMT)-related proteins were also measured by Western blot. The relationship between LINC01089 and miR-27a-3p was revealed by a bioinformatics analysis and dual-luciferase reporter assay.ResultsLINC01089 was significantly down-regulated in GC tissues, as well as GC cell lines. GC patients with lower LINC01089 expression were more likely to have poor outcomes. Overexpression of LINC01089 significantly suppressed GC cells growth, migration and invasion and forbade the EMT process. LINC01089 was directly targeted at miR-27a-3p. The transfection of miR-27a-3p mimics reversed the inhibitory effects on proliferative and metastatic abilities of GC cells with LINC01089 overexpression.ConclusionLINC01089 inhibits cell proliferation and metastasis in GC by targeting miR-27a-3p/EMT axis, which should be considered as a promising therapeutic target.

CXCL5 promotes gastric cancer metastasis by inducing epithelial-mesenchymal transition and activating neutrophils

Deregulated expression of chemokines in tumor microenvironment contributes to tumor metastasis by targeting distinct cells. Epithelial-derived neutrophil-activating peptide-78 (ENA78/CXCL5) is upregulated in many cancers and involved in tumor progression. The role and underlying mechanism of CXCL5 in gastric cancer (GC) metastasis remain unclear. In this study, we reported that the expression of CXCL5 was elevated in tumor tissues and positively associated with lymphatic metastasis and tumor differentiation. Stimulation by recombinant human CXCL5 (rhCXCL5) induced epithelial-mesenchymal transition (EMT) in GC cells through the activation of ERK pathway, which enhanced their migration and invasion abilities. The culture supernatant from tumor tissues also enhanced the migration and invasion abilities of GC cells, however, this effect was reversed by pre-treatment with CXCL5 neutralizing antibody. Further studies showed that rhCXCL5 could induce the expression of IL-6 and IL-23 in neutrophils through the activation of ERK and p38 signaling pathways, which in turn facilitated GC cell migration and invasion. The culture supernatant from tumor tissues showed similar effects on neutrophils in a CXCL5-dependent manner. Blockade of IL-6 and IL-23 with neutralizing antibodies reversed the induction of EMT and the increased migration and invasion abilities in GC cells by CXCL5-activated neutrophils. Moreover, CXCL5 activated neutrophils could promote gastric cancer metastasis in vivo. Taken together, our results indicate that CXCL5 acts on gastric cancer cells to induce EMT and mediates pro-tumor activation of neutrophils, which synergistically promotes the metastatic ability of GC cells.

LINC01857 promotes the development of gastric cancer by regulating microRNA-200b.

The aim of this study was to investigate the expression characteristics of LINC01857 in gastric cancer (GCa), and to further study whether it could promote GCa development by modulating microRNA-200b. Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to examine LINC01857 expression in 60 pairs of GCa tissues and adjacent tissues. The interplay between LINC01857 level and clinical indexes and the prognosis of GCa patients was analyzed. Meanwhile, qRT-PCR was used to verify the expression level of LINC01857 in GCa cell lines. LINC01857 knockdown model was constructed by lentivirus transfection in GCa cell lines. Subsequently, the effect of LINC01857 on the biological function of GCa cells was analyzed by Cell Counting Kit 8 (CCK8), wound healing, and transwell assays. Furthermore, the in-depth relationship between LINC01857 and microRNA-200b was explored. QRT-PCR results showed that LINC01857 level in GCa tissues was remarkably higher than that of adjacent tissues, and the difference was statistically significant (p<0.05). Compared with patients with a low level of LINC01857, the rate of lymph node and distant metastasis in patients with a high level of LINC01857 was remarkably higher, while the overall survival rate was lower (p<0.05). In vitro experiments showed that LINC01857 knockdown remarkably decreased the invasion, migration, and crawling ability of GCa cells (p<0.05). Subsequent qRT-PCR results demonstrated that the level of microRNA-200b was remarkably upregulated after the silence of LINC01857. In addition, the silence of microRNA-200b could reverse the biological function of GCa cells induced by the knockout of LINC01857. LINC01857 was highly expressed in GCa, and was associated with lymph node metastasis, distant metastasis, and poor prognosis of patients with GCa. In addition, LINC01857 enhanced the metastatic ability of GCa cells by regulating microRNA-200b.

RETRACTED ARTICLE: A positive feedback loop consisting of C12orf59/NF-\u03baB/CDH11 promotes gastric cancer invasion and metastasis

BackgroundMetastasis remains the main cause of cancer-related death for gastric cancer (GC) patients, but the mechanisms are poorly understood. Using The Cancer Genome Atlas (TCGA) data base and bioinformatics analyses, we identified C12orf59 might act as a potential oncogenic protein in GC.MethodsWe investigate the expression pattern and clinical significance of C12orf59 in two independent cohorts of GC samples. In the training cohort, we used the X-tile program software to generate the optimal cutoff value for C12orf59 expression in order to classify patients accurately according to clinical outcome. In the validation cohort, this derived cutoff score was applied to exam the association of C12orf59 expression with survival outcome. A series of in vivo and in vitro assays were then performed to investigate the function of C12orf59 in GC.ResultsC12orf59 was significantly upregulated, and associated with poor survival outcome in two cohorts of GC samples. Gain- and loss of- function studies demonstrated C12orf59 promotes GC cell invasive and metastatic capacity both in vitro and in vivo, and induces epithelial–mesenchymal transition and angiogenesis. Mechanically, C12orf59 exerts oncogenic functions by up-regulating CDH11 expression via NF-κB signaling. Interesting, CDH11 could in turn promote NF-κB bind to C12orf59’s promoter and form a positive feedback loop to sustain the metastatic ability of GC cells. Additionally, downregulation of miR-654-5p is another important mechanism for C12orf59 overexpression in GC.ConclusionOur finding suggested the newly identified C12orf59/NF-κB/CDH11 feedback loop may represent a new strategy for GC treatment.