Invasion Ability Of Gastric Cancer Cells Research Articles

The Role of MiR-375 in Migration and Invasion of H.pylori-induced Gastric Cancer Cell Model.

This article aimed to investigate the mechanism of miR-375 in Hp-induced gastric cancer cells (GCCs) model. Human normal gastric mucosal epithelial cell (GMEC) line GES-1 and human GCCs strain MKN45 were used as research objects. The expression of miR-375 was detected after H.pylori (Hp) infection of GCCs. The cell activity was detected by, 53-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method, and the cell multiplication was determined by cell counting kit-8 (CCK-8) method. Transwell assay was used to detect the effect of cell invasion and migration ability. The expression levels of JAK1 and STAT3 proteins were determined by Western blot (WB). MiR-375 was increased in GCCs after Hp infection, and JAK1, STAT3, p-JAK1, and p-STAT3 in GCCs after Hp infection were visibly increased. In addition, the overexpressed miR-375 promoted the multiplication activity, migration, and invasion ability of GCCs. MiR-375 promotes Hp-induced migration and invasion of GCCs by targeting JAK1/STAT3. This article reveals the important role of miR-375 in Hp-induced GC, which provides new clues for further study of its mechanism and therapeutic targets.

EIF6 Promotes Gastric Cancer Proliferation and Invasion by Regulating Cell Cycle

ObjectiveTo investigate the role and function of eIF6 in gastric cancer (GC).MethodsThe expression level of eIF6 in GC tissues and normal tissues was detected in different high-throughput sequencing cohorts. Survival analysis, gene differential analysis, and enrichment analysis were performed in the TCGA cohort. Biological networks centered on eIF6 were constructed through two different databases. Immunohistochemistry (IHC) and Western blot were used to detect protein expression of eIF6, and qRT-PCR was used to detect eIF6 mRNA expression. The correlation between the expression of eIF6 in GC tissues and clinicopathological parameters of GC was analyzed. siRNA knockout of eIF6 was used to study the proliferation, migration, and invasion. The effects of eIF6 on cell cycle and Cyclin B1 were detected by flow cytometry and Western blot.ResultseIF6 was significantly overexpressed in GC tissues and predicted poor prognosis. In addition, 113 differentially expressed genes were detected in cancer-related biological pathways and functions by differential analysis. Biological networks revealed interactions of genes and proteins with eIF6. The expression intensity of eIF6 in cancer tissues was higher than that in adjacent tissues (P = 0.0001), confirming the up-regulation of eIF6 expression in GC tissues. The expression level of eIF6 was statistically significant with pTNM stage (P = 0.006). siRNA knockout of eIF6 significantly reduced the proliferation, colony formation, migration, and invasion ability of GC cells. Silencing of eIF6 also inhibited the cell cycle of GC cells in G2/M phase and decreased the expression level of CyclinB1.ConclusionOur study suggests that eIF6 is up-regulated in GC and may promote the proliferation, migration, and invasion of GC by regulating cell cycle.

Regulation of hsa_circ_0112136 by m6A demethylase FTO can enhance the malignancy of gastric cancer via the regulation of the PI3K/AKT/mTOR pathway.

A growing body of research highlights the role that N6-methyladenosine (m6A) modification and circular RNAs (circRNAs) play in gastric cancer (GC) cases. However, studies elucidating the function and mechanism of the recently discovered circRNA hsa_circ_0112136 in GC are limited. This study aimed to examine the pathophysiology of GC progression due to fat mass and obesity-associated protein (FTO)-mediated N6-methyladenosine (m6A) modification of hsa_circ_0112136. The hsa_circ_0112136 and FTO levels in the GC samples were analyzed using qRT-PCR. The Transwell invasion assay, wound healing assay, and CCK8 assays were employed to assess alterations in GC cell invasiveness, migration, and viability due to the aberrant regulation of hsa_circ_0112136 and FTO. Phosphorylated PI3K, AKT, and mTOR (the key proteins of the PI3K/AKT/mTOR pathway) were detected via western blotting after hsa_circ_0112136 suppression. A tumor transplantation mouse model was constructed to evaluate the suppression of hsa_circ_0112136's function in vivo. The correlation among hsa_circ_0112136 and FTO was identified using the MeRIP assay. Levels of hsa_circ_0112136 and FTO were evidently elevated in GC samples. Suppression of has_circ_0112136 reduced the viability, migration, and invasive ability of GC cells in vitro, as well as delayed tumor growth in vivo via suppression of the activation of the PI3K/AKT/mTOR pathway. FTO decreased hsa_circ_0112136 m6A levels and enhanced hsa_circ_0112136 expression. Furthermore, FTO upregulation enhanced GC cell invasion, migration, and survival, which was reversed by hsa_circ_0112136 suppression. Our study proposes that hsa_circ_0112136 functions as a tumor promoter, facilitating the malignant progression of GC through m6A modification (suppressed by FTO) and activating the PI3K/AKT/mTOR pathway. This suggests that targeting FTO-m6A-hsa_circ_0112136-PI3K/AKT/mTOR may be a novel approach for GC intervention.

The potential contribution of aberrant cathepsin K expression to gastric cancer pathogenesis

The role of cathepsin K (CTSK) expression in the pathogenesis and progression of gastric cancer (GC) remains unclear. Hence, the primary objective of this study is to elucidate the precise expression and biological role of CTSK in GC by employing a combination of bioinformatics analysis and in vitro experiments. Our findings indicated a significant upregulation of CTSK in GC. The bioinformatics analysis revealed that GC patients with a high level of CTSK expression exhibited enrichment of hallmark gene sets associated with angiogenesis, epithelial–mesenchymal transition (EMT), inflammatory response, KRAS signaling up, TNFα signaling via KFκB, IL2-STAT5 signaling, and IL6-JAK-STAT3 signaling. Additionally, these patients demonstrated elevated levels of M2-macrophage infiltration, which was also correlated with a poorer prognosis. The results of in vitro experiments provided confirmation that the over-expression of CTSK leads to an increase in the proliferative and invasive abilities of GC cells. However, further evaluation was necessary to determine the impact of CTSK on the migration capability of these cells. Our findings suggested that CTSK has the potential to facilitate the initiation and progression of GC by augmenting the invasive capacity of GC cells, engaging in tumor-associated EMT, and fostering the establishment of an immunosuppressive tumor microenvironment (TME).

Clinicopathological and prognostic significance of elevated BTF3 expression in gastric cancer.

The purpose of this paper was to explore the significance of basic transcription factor 3 (BTF3) in the process and clinicopathological parameters of gastric cancer (GC) patients. GC tissues were collected in our hospital to detect the mRNA expression of BTF3 by quantitative real-time polymerase chain reaction (Q-PCR). Western blot analysis was performed to detect the protein expression of BTF3. Kaplan-Meier method and Log-rank analysis were used to analyze the progression-free survival time and overall time of GC patients, while the Chi-square test was used to investigate the association between BTF3 and clinicopathological parameters of GC patients. SiRNA was designed to suppress the expression of BTF3. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and transwell assay were conducted to determine the viability and invasion ability of GC cells. BTF3 was found abnormally up-regulated in GC tissues and cells and was related to the Grade, Lymph node metastasis and stage of GC patients, as well as the poor progression-free survival and overall survival of them. Besides, inhibition of BTF3 in GC cells could trigger the reduction of cell viability and invasion ability. Our results demonstrated that BTF3 played an important role in the process of GC and could be regarded as a new target for the diagnosis and therapy of GC.

DDX24 promotes tumor progression by mediating hexokinase-1 induced glycolysis in gastric cancer

Metabolic reprogramming allows tumor cells to meet high demand of biogenesis and increased energy for rapid proliferation. Gastric cancer (GC) ranks among the most prevalent malignancies globally. Exploring the underlying mechanisms of glycolytic reprogramming in GC could provide new therapeutic target for GC treatment. Here, we showed that DEAD-box helicase 24 (DDX24) played a critical role in hexokinase-1 (HK1) induced glycolysis. DDX24 expression was significantly elevated in GC tissues and was closely associated with worse survival in GC patients. In addition, DDX24 promoted glucose uptake and lactate production in GC cells. Mechanistically, DDX24 could bind the HK1 mRNA and positively regulated HK1 level at the transcriptional level. Moreover, DDX24 promoted the proliferation, migration, and invasion ability of GC cells by upregulating HK1. Collectively, these results suggested that DDX24 was a critical player in the regulation of glycolytic reprogramming and also implicated DDX24 as a valuable therapeutic target for GC.

Xiaotan Sanjie recipe, a compound Chinese herbal medicine, inhibits gastric cancer metastasis by regulating GnT-V-mediated E-cadherin glycosylation

ObjectiveXiaotan Sanjie recipe (XTSJ), a Chinese herbal compound medicine, exerts a significant inhibitory effect on gastric cancer (GC) metastasis. This work investigated the mechanism underlying the XTSJ-mediated inhibition of GC metastasis. MethodsThe effect of XTSJ on GC metastasis and the associated mechanism were investigated in vitro, using GC cell lines, and in vivo, using a GC mouse model, by focusing on the expression of Glc-N-Ac-transferase V (GnT-V; encoded by MGAT5). ResultsThe migration and invasion ability of GC cells decreased significantly after XTSJ administration, which confirmed the efficacy of XTSJ in treating GC in vitro. XTSJ increased the accumulation of E-cadherin at junctions between GC cells, which was reversed by MGAT5 overexpression. XTSJ administration and MGAT5 knockdown alleviated the structural abnormality of the cell–cell junctions, while MGAT5 overexpression had the opposite effect. MGAT5 knockdown and XTSJ treatment also significantly increased the accumulation of proteins associated with the E-cadherin-mediated adherens junction complex. Furthermore, the expression of MGAT5 was significantly lower in the lungs of BGC-823-MGAT5 + XTSJ mice than in those of BGC-823-MGAT5 + solvent mice, indicating that the ability of gastric tumors to metastasize to the lung was decreased in vivo following XTSJ treatment. ConclusionXTSJ prevented GC metastasis by inhibiting the GnT-V-mediated E-cadherin glycosylation and promoting the E-cadherin accumulation at cell–cell junctions.

High expression of serine protease 2 (PRSS2) associated with invasion, metastasis, and proliferation in gastric cancer.

Accumulating evidence indicates that the occurrence and development of tumors are related to the activation of oncogenes and the inactivation of tumor suppressor genes caused by epigenetic mechanisms. However, the function of serine protease 2 (PRSS2) in gastric cancer (GC) is still unknown. Our study aimed to find a regulation network involved in GC. The mRNA data (GSE158662 and GSE194261) of GC and normal tissues were downloaded from the Gene Expression Omnibus (GEO) dataset. Differential expression analysis was performed using R software, and Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was conducted by using Xiantao software. Besides, we used Quantitative Real-time PCR (qPCR) to verify our conclusions. After gene knockdown, cell migration and CCK-8 experiment were carried out to detect the effect of gene on cell proliferation and invasion. Totally, 412 differentially expressed genes (DEGs) were identified from GSE158662 and 94 DEGs were identified from GSE196261. Km-plot database results indicated that PRSS2 exhibited high diagnosis worth for GC. Gene functional annotation enrichment analysis revealed that these hub mRNAs were mainly taken part in the process of tumorigenesis and development. Besides, vitro experiments showed that down-regulation of PRSS2 gene reduced the proliferation and invasion ability of GC cells. Our results indicated that PRSS2 may play vital roles in the carcinogenesis and progression of GC and can be potential biomarkers for patients with GC.

Comprehensive analysis of circular RNA-associated competing endogenous RNA networks and immune infiltration in gastric cancer

BackgroundCircular RNA (circRNA) has been proved to be an important regulator of gastric cancer (GC). However, the role and regulatory mechanism of circrna related competitive endogenous RNA (ceRNA) in GC have not been established. MethodsCircRNA data and clinical data were obtained from the GEO and TCGA databases. The ceRNA networks were constructed and a function enrichment analysis was completed. Additionally, correlations between hub genes expression, immune cell infiltration, and clinical phenotypes were determined. The differentially expressed circRNAs and their downstream microRNAs (miRNAs) were validated by quantitative real-time polymerase chain reaction, and the hub genes were validated by western blot analysis. The migration and invasion ability of overexpressed hsa_circ_0002504 was determined by a transwell assay. ResultsThe ceRNA network contained 2 circRNAs, 3 miRNAs, and 55 messenger RNAs (mRNAs). 323 biological processes terms, 53 cellular components terms, 51 molecular functions terms, and 4 signaling pathways were revealed by the function enrichment analysis. The GSEA analysis revealed that the hub genes were positively correlated with the axon guidance and adhesion molecules pathways. The correlation analysis revealed that overexpressed EPHA4 and KCNA1 indicated poor tissue differentiation and were associated with clinically advanced stages of GC. The in vitro experiments showed that hsa_circ_0002504 was significantly down-regulated in GC cell lines. In addition, the overexpression of hsa_circ_0002504 led to a significant downregulation of hsa-miR-615-5p and hsa-miR-767-5p, as well as an upregulation of EPHA4, KCNA1, and NCAM1. Furthermore, it suppressed the migration and invasion ability of GC cells. ConclusionsHsa_circ_0002504 is a potential diagnostic biomarker for GC. High expression of EPHA4 and KCNA1 may indicate poor prognosis.

Circular RNA circ_0006089 regulates the IGF1R expression by targeting miR-143-3p to promote gastric cancer proliferation, migration and invasion

ABSTRACT Circular RNAs (circRNAs) figure prominently in regulating the progression of a variety of human malignancies. This study was performed to probe how circ_0006089 functioned in gastric cancer (GC). CircRNA expression profile GSE83521 was downloaded from Gene Expression Omnibus (GEO) database, and circRNAs and analyzed. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure circ_0006089, microRNA-143-3p (miR-143-3p) and insulin-like growth factor 1 receptor (IGF1R) mRNA expressions in GC tissues and cell lines. Kaplan-Meier curves were used to detect the relationship between circ_0006089 expression and overall survival time of GC patients. Cell counting kit-8 (CCK-8) and 5-bromo-2-deoxyuridine (BrdU) assays were employed to detect the proliferative ability of GC cells after circ_0006089 was overexpressed or knocked down. Wound healing assay and Transwell assay were executed to examine the migration and invasion ability of GC cells. Western blot was adopted to detect IGF1R protein expressions. Circ_0006089 expression was up-regulated in GC samples and cell lines. And high circ_0006089 expression was associated with shorter survival time in GC patients. Circ_0006089 overexpression in GC cells significantly accelerated GC cell proliferation, migration and invasion, whereas circ_0006089 knockdown resulted in the opposite effects. Additionally, miR-143-3p was validated as a downstream target of circ_0006089, and circ_0006089 could positively regulate IGF1R expression via repressing miR-143-3p. Circ_0006089 is highly expressed in GC, and it promotes the malignancy of GC cells via modulating miR-143-3p/IGF1R axis, suggesting that circ_0006089 may serve as a promising therapeutic target for GC.

MiR-139-3p/Kinesin family member 18B axis suppresses malignant progression of gastric cancer

ABSTRACT miR-139-3p exerts tumor-suppressing functions in various cancers. We analyzed and identified that miR-139-3p expression was notably low in gastric cancer (GC) via edgeR differential analysis based on The Cancer Genome Atlas database and quantitative real-time polymerase chain reaction (qRT-PCR) assay. The binding relationship between Kinesin Family Member 18B (KIF18B) and miR-139-3p was predicted by bioinformatics databases, and verified through dual-luciferase assay. Western blot and qRT-PCR results also indicated that miR-139-3p restrained KIF18 expression at mRNA and protein levels. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, wound healing, transwell, flow cytometry assays were introduced to evaluate cell proliferation, migration, invasion, and cell cycle, respectively, where the results indicated that upregulating miR-139-3p inhibited proliferative, migratory, and invasive abilities of GC cells, while caused cell-cycle arrest. Moreover, the results of rescue experiments illustrated that miR-139-3p hampered the progression of GC cells by targeting and suppressing KIF18B. To sum up, we concluded that miR-139-3p suppressed GC progression by targeting KIF18B.

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).

ELK4-mediated lncRNA SNHG22 promotes gastric cancer progression through interacting with EZH2 and regulating miR-200c-3p/Notch1 axis

Long non-coding RNAs (lncRNAs) play important regulatory roles in the initiation and progression of various cancers. However, the biological roles and the potential mechanisms of lncRNAs in gastric cancers remain unclear. Here, we report that the expression of lncRNA SNHG22 (small nucleolar RNA host gene 22) was significantly increased in GC (Gastric Cancer) tissues and cells, which confers poor prognosis of patients. Knockdown of SNHG22 inhibited the proliferation and invasion ability of GC cells. Moreover, we identified that the transcriptional factor, ELK4 (ETS transcription factor ELK4), could promote SNHG22 expression in GC cells. In addition, using RNA pull-down followed MS assay, we found that SNHG22 directly bound to EZH2 (enhancer of zeste 2 polycomb repressive complex 2 subunit) to suppress the expression of tumor suppressor genes. At the same time, SNHG22 sponged miR-200c-3p to increase Notch1 (notch receptor 1) expression. Taken together, our findings demonstrated the role of SNHG22 on promoting proliferation and invasion of GC cells. And we revealed a new regulatory mechanism of SNHG22 in GC cells. SNHG22 is a promising lncRNA biomarker for diagnosis and prognosis and a potential target for GC treatment.

RETRACTED ARTICLE: CircHAS2 promotes the proliferation, migration, and invasion of gastric cancer cells by regulating PPM1E mediated by hsa-miR-944

Gastric cancer (GC) is considered one of the most common gastrointestinal malignancies worldwide. Circular RNAs (circRNAs) are a new class of endogenous noncoding RNAs, which can be used as biomarkers and therapeutic targets for many tumors. However, the role and potential regulatory mechanisms of circRNAs in GC remain unclear. In this study, we demonstrated that a specific circRNA, circHAS2, was upregulated in GC tissues and cells and was positively correlated with tumor metastasis. In vitro experiments demonstrated that circHAS2 knockdown or the addition of hsa-miR-944 mimics inhibited the proliferation, migration, and invasion ability of GC cells and affected the epithelial-mesenchymal transition. In addition, hsa-miR-944 interacted with protein phosphatase, Mg2+/Mn2+-dependent 1E (PPM1E), and was found to be a target gene of circHAS2. The upregulation of PPM1E reversed the effects of circHAS2 knockout on GC cells. The circHAS2/hsa-miR-944/PPM1E axis may be involved in the progression of GC; thus, circHAS2 may be a potential biomarker and therapeutic target for GC.

Silencing of Long Non-coding RNA LINC01106 Represses Malignant Behaviors of Gastric Cancer Cells by Targeting miR-34a-5p/MYCN Axis.

Long non-coding RNA LINC01106 is an lncRNA aberrantly expressed in gastric cancer (GC). However, the accurate function remains unclear. The objective of this investigation is to explore detailed regulatory mechanism of lncRNA LINC01106 in GC. The expression of lncRNA LINC01106, MYCN, and miR-34a-5p was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability was examined using MTT assay. Migratory and invasive abilities of GC cells were evaluated by transwell assay. The targeting relation among lncRNA LINC01106, MYCN, and miR-34a-5p was tested by dual-luciferase reporter (DLR) assay. Relative protein expression of MYCN was assessed via western blot. Besides, a xenograft mouse model was established to assess the role of LINC01106 in GC in vivo. LncRNA LINC01106 and MYCN expression were boosted and miR-34a-5p expression was reduced in GC cells and tissues compared to their controls. Functionally, decreased lncRNA LINC01106 or increased miR-34a-5p restrained GC cells in viability, invasion, and migration in vitro. LINC01106 down-regulation suppressed tumor growth of mice in vivo. In terms of mechanism, lncRNA LINC01106 directly targeted miR-34a-5p and was inversely correlated with miR-34a-5p. MYCN was targeted by miR-34a-5p and was inversely correlated with miR-34a-5p. There was a positive correlation between LINC01106 and MYCN. LINC01106 knockdown led to the suppression of cell invasion, migration, and viability, whereas these effects caused by LINC01106 knockdown were reversed by miR-34a-5p down-regulation or MYCN up-regulation in GC cells. Silencing of lncRNA LINC01106 attenuated cell viability, invasion, and migration by sponging miR-34a-5p to target MYCN in GC.

FHOD1 is upregulated in gastric cancer and promotes the proliferation and invasion of gastric cancer cells.

Gastric cancer (GC) is one of the main causes of cancer-associated morbidity and mortality worldwide. The present study aimed to investigate the role of the gene encoding formin homology 2 domain containing 1 (FHOD1) protein in GC development. Data from The Cancer Genome Atlas were firstly analyzed, and immunohistochemistry was conducted on GC tissues. The results demonstrated that FHOD1 expression in GC tissues was significantly increased compared with adjacent non-tumor tissues. Furthermore, the expression level of FHOD1 was negatively associated with the overall survival of patients with GC. For the functional studies, lentivirus-mediated short hairpin RNA against FHOD1 and FHOD1-overexpression vectors were constructed to knockdown and overexpress the expression level of FHOD1 in human GC cell lines, respectively. The results indicated that FHOD1 knockdown inhibited the proliferation, colony formation and migratory and invasive abilities of GC cells. Conversely, overexpression of FHOD1 in GC cells promoted soft-agar colony formation and migratory and invasive abilities. In addition, it was demonstrated that genes of which expression levels were correlated with FHOD1 were enriched in the Gene Ontology term of 'extracellular matrix (ECM) structural constituent', suggesting that FHOD1 may serve an important role in the regulation of ECM. In conclusion, the present study demonstrated that FHOD1 may exert an oncogenic role in cultured GC cells and be inversely associated with the overall survival of patients with GC.

Upregulation of ECT2 Predicts Adverse Clinical Outcomes and Increases 5-Fluorouracil Resistance in Gastric Cancer Patients.

Background The abnormal expression and prognosis prediction of epithelial cell transforming sequence 2 (ECT2) in gastric cancer (GC) has been reported. However, the effect of ECT2 on 5-fluorouracil (5-Fu) resistance in GC is unclear. This research aims to solve the abovementioned problems. Methods Gene expression was detected by RT-qPCR and Western blot analysis. Cell viability was evaluated by the colony formation assay, MTT assay, and flow cytometric analysis. Transwell and wound healing assays were used to detect cell metastasis. Results Upregulation of ECT2 was found in stomach adenocarcinoma (STAD) and GC tissues. In addition, high ECT2 expression can predict adverse clinical outcomes in GC patients. More importantly, ECT2 knockdown weakened the resistance of 5-FU in GC cells. ECT2 silencing reduced the cell migratory and invasive abilities of GC cells treated with 5-FU. We also found that downregulation of ECT2 increased 5-FU sensitivity in GC cells by downregulating P-gp, MRP1, and Bcl-2. Conclusion Upregulation of ECT2 can predict adverse clinical outcomes and increase 5-FU resistance in GC patients.

Methylation of microRNA-338-5p by EED promotes METTL3-mediated translation of oncogene CDCP1 in gastric cancer.

Unmasking the complex regulatory pathways that mediate the malignant phenotypes of cancer cells can provide novel targets for therapies that could limit the recurrence and metastasis of gastric cancer (GC). Herein, we intended to clarify the role of embryonic ectoderm development protein (EED), microRNA-228-5p (miR-338-5p), methyltransferase like 3 (METTL3) and CUB domain containing protein 1 (CDCP1) in GC. Differentially expressed miRNAs and their target genes were extracted by in silico analysis. The studies revealed high expression of EED in GC tissues and cell lines and it high expression in GC patients was shown to be associated with poor prognosis. The chromatin immunoprecipitation assay identified that EED methylated miR-338-5p to inhibit its expression. EED knockdown could restrain the proliferative and invasive abilities of GC cells by inducing miR-338-5p. Furthermore, miR-338-5p targeted m6A methylase METTL3, while METTL3 amplified the translation of CDCP1 via m6A activity which led to accelerated proliferation and invasion of GC cells. Moreover, in vivo experiments validated that EED promoted the progression of GC through mediating the miR-338-5p/METTL3/CDCP1 axis. Collectively, EED downregulated miR-338-5p through histone methylation, which in turn impaired miR-338-5p-dependent METTL3 inhibition and enhanced CDCP1 translation, therefore contributing to the development of GC.

Visfatin facilitates gastric cancer malignancy by targeting snai1 via the NF-κB signaling.

Visfatin acts as an oncogenic factor in numerous tumors through a variety of cellular processes. Visfatin has been revealed to promote cell migration and invasion in gastric cancer (GC). Snai1 is a well-known regulator of EMT process in cancers. However, the relationship between visfatin and snai1 in GC remains unclear. The current study aimed to explore the role of visfatin in GC. The RT-qPCR and western blot analysis were used to measure RNA and protein levels, respectively. The cell migration and invasion were tested by Trans-well assays and western blot analysis. Visfatin showed upregulation in GC cells. Additionally, Visfatin with increasing concentration facilitated epithelial-mesenchymal transition (EMT) process by increasing E-cadherin and reducing N-cadherin and Vimentin protein levels in GC cells. Moreover, endogenous overexpression and knockdown of visfatin promoted and inhibited migratory and invasive abilities of GC cells, respectively. Then, we found that snai1 protein level was positively regulated by visfatin in GC cells. In addition, visfatin activated the NF-κB signaling to modulate snai1 protein expression. Furthermore, the silencing of snai1 counteracted the promotive impact of visfatin on cell migration, invasion and EMT process in GC. Visfatin facilitates cell migration, invasion and EMT process by targeting snai1 via the NF-κB signaling, which provides a potential insight for the treatment of GC.

Ghrelin Affects Gastric Cancer Progression by Activating AMPK Signaling Pathway.

As the endogenous ligand for the GH secretagogue receptor (GHSR), Ghrelin is aberrant expressed in multiple malignant carcinoma, and involved in regulating a number of progression of cancer, especially in metastasis and proliferation. However, the precise role of Ghrelin in tumorigenesis of gastric cancer (GC) is still poorly understood. In this study, we extensively investigated the roles and mechanisms of Ghrelin in human gastric cancer. Ghrelin levels in cancer tissues and cell lines were analyzed by immunohistochemistry, qRT-PCR, and Western blot. Functional studies were performed after Ghrelin overexpressed or knockdown in AGS cell line. Cell proliferation was evaluated in by MTT and clone formation assays. The wound healing and Transwell system were used to assess the cell migration and invasive ability of GC cells. Cell apoptosis was detected by flow cytometry, and metabolic assays were performed to reveal the function of Warburg effect in the process. Ghrelin was lowly expressed in gastric cancer tissues and cell lines. Overexpression of Ghrelin inhibited gastric cancer cell proliferation, migration, invasion, and promoted apoptosis by activating the AMPK pathway, while D-[lys3]-GHRP-6 (a GHSR agonist) treatment relieved the effect, promoting tumorigenesis. Ghrelin knockdown increased the glucose uptake and lactic acid release, suggesting that Ghrelin elicited an anti-Warburg effect via AMPK pathway to inhibit gastric tumorigenesis. Ghrelin inhibits cell proliferation, migration, and invasion by eliciting an anti-Warburg effect via AMPK signaling pathway in gastric cancer cells.