Invasion Of AGS Cells Research Articles

Ras-related Protein in Brain 4A (Rab4A) is Downregulated by miR-496 to inhibit the Progression of Gastric Cancer.

Ras-related protein in brain 4A (Rab4A), as a member of the Rab family, is involved in the intracellular circulation of membrane receptors or endocytic substances and regulates the progression of multiple tumors. From our results, the knockdown of Rab4A inhibited the proliferation, migration and invasion in AGS cells. Importantly, the surface expression of epidermal growth factor receptor (EGFR) declined significantly in Rab4A knockdown cells. The downstream pathway of EGFR was also inhibited after the transfection of Rab4A-specific siRNA, including AKT and β-catenin pathways. In addition, miR-496 down-regulated the expression of Rab4A in AGS cells. The result of the luciferase reporter assay showed that miR-496 could bind to the 3'UTR of Rab4A. In conclusion, the expression of Rab4A is inhibited by miR-496, and the knockdown of Rab4A inhibits the proliferation, migration and invasion through down-regulating the surface expression of EGFR. Rab4A is a potential target in the treatment of gastric cancer.

The efficacy and safety of pH-responsive and photothermal-sensitive multifunctional nanoparticles loaded with cryptotanshinone for the treatment of gastric cancer.

A multifunctional polydopamine/mesoporous silica nanoparticles loaded cryptotanshinone (PDA/MSN@CTS) was synthesized and subjected to investigating its physicochemical properties and anti-gastric cancer (GC) effects. Utilizing network pharmacology and molecular docking techniques, CTS was identified as our final research target. The structural morphology and physicochemical properties of PDA/MSN@CTS were examined. Near-infrared (NIR) laser was employed to evaluate the photothermal properties of the PDA/MSN@CTS, along with pH-responsive and NIR-triggered release assessments. In vitro experiments evaluated the impact of PDA/MSN@CTS on the malignant behavior of AGS gastric cells. A subcutaneous tumor model was further established to evaluate the in vivo safety of PDA/MSN@CTS. Furthermore, the in vivo photothermal efficacy of PDA/MSN@CTS, in addition to its combined effect with photothermal therapy (PTT), was investigated. Uniform and stable PDA/MSN@CTS had been successfully synthesized and demonstrated efficient release under tumor environment and NIR irradiation. Upon increasing NIR laser conditions, in vivo cytotoxicity, apoptosis rate, reactive oxygen species scavenging ability, and suppression of migration and invasion of AGS cells by PDA/MSN@CTS were significantly enhanced. In vivo assessments revealed excellent blood compatibility and biosafety of PDA/MSN@CTS, alongside robust tumor tissue targeting. Combining nanoparticles with PTT facilitated the anti-GC effects of PDA/MSN@CTS. Compared to free drugs, PDA/MSN@CTS exhibits higher selectivity towards cancer cells, demonstrating effective anticancer activity and biocompatibility both in vitro and in vivo. Furthermore, our nanomaterial possesses excellent photothermal properties, and under NIR conditions, PDA/MSN@CTS exhibits synergistic therapeutic effects.

Lumican promotes gastric cancer progression by regulating the ERK pathway

Globally, gastric cancer (GC) remains a major cause of death. Our prior study found lumican to be an important independent predictor of GCs poor overall survival and bioinformatics analysis suggested the MAPK pathway as a signaling cascade linked to lumican function. In our study, we observed that lumican exhibited a significant elevation in GC tissues and cells, hastening tumor proliferation in vivo in comparison to control groups. We also observed that knockdown of lumican effectively inhibited the proliferation, migration and invasion of AGS cells. On the contrary, overexpression of lumican promoted the proliferation, migration and invasion of AGS cells. We clarified that lumican was upstream of ERK in the MAPK pathway. In rescue assays, TBHQ further enhanced the promoting effect of lumican overexpression on cell migration and invasion and the increased expression of ERK 1/2 or p-ERK 1/2 levels. However, the increased expression of ERK 1/2 or p-ERK 1/2, migration and invasion were completely blocked by GDC-0994 in lumicanoverexpressing AGS cells with TBHQ treated. Molecular docking prediction revealed that the amino acid sequence of lumican binding to ERK1/2 may also regulate the ERK pathway. In conclusions, lumican is highly expressed in GC and promotes the proliferation, migration and invasion of GC cells by regulating ERK pathway. Consequently, lumican emerges as pivotal indicators for both diagnosis and treatment in GC cases.

Ropivacaine inhibits the proliferation and metastasis of gastric cancer cells via the SNX10/SRC/STAT3 pathway.

Gastric cancer currently has no effective treatment due to its high metastasis and heterogeneity. It has been reported that ropivacaine (Rop) can inhibit the growth, migration, and invasion of gastric cancer. However, the therapeutic mechanism of Rop still needs to be further explored to provide insights for its clinical application. This study aimed to explore the effects of Rop on the growth, migration, and invasion of gastric cancer cells and the underlying mechanisms. The expression levels of SNX10 were assessed in gastric cancer tissues and cell line AGS by qRT-PCR. Cell Counting Kit-8 (CCK8) assay, wound-healing assay, and transwell assay were then used to examine the effects of Rop on the AGS cell viability, migration, invasion, and proliferation, respectively. Additionally, colony formation assay was used to measure cell proliferation ability, and flow cytometry was used to detect apoptosis level. Protein levels of SNX10, SRC, and STAT3 were detected by western blot. According to the experimental results, the decreased SNX10 mRNA expression was observed in gastric cancer tissue and cell line AGS. Rop inhibited the proliferation, migration, and invasion of AGS cells, but promoted apoptosis and upregulated SNX10 expression. Moreover, Rop inhibited the expression of MMP-2 and MMP-9, phosphorylation of SRC and STAT3. SNX10 knockdown could reverse Rop-induced anticancer effects. Collectively, Rop showed a potential role in preventing proliferation and metastasis of gastric cancer. The action mechanism of Rop may be related to the upregulation of SNX10 expression and further inhibition of SRC/STAT3 signaling pathway. Our findings provide new insights into the anticancer properties of Rop.

Traditional Banxia Xiexin decoction inhibits invasion, metastasis, and epithelial mesenchymal transition in gastric cancer by reducing lncRNA TUC338 expression

BackgroundBanxia Xiexin decoction (BXD) is a classic traditional Chinese medicine (TCM) formula clinically used to treat chronic gastritis, gastric ulcers, gastric cancer, and many other gastrointestinal diseases. Long noncoding RNAs (lncRNAs) have been shown to play an important role in maintaining the malignant phenotype of tumors. However, no relevant studies have shown whether Banxia Xiexin decoction regulates and controls lncRNA TUC338, and the effect of TUC338 on the regulation of gastric cancer invasion and metastasis remains unclear. PurposeTo investigate the ability of the traditional Chinese medicine (TCM) Banxia Xiexin decoction (BXD) to inhibit the migration and invasion of human gastric cancer AGS cells by regulating the long noncoding RNA (lncRNA) TUC338. MethodsUHPLC‒MS/MS was used to analyze the chemical components of BXD. MTT was performed to determine the effects of BXD on the proliferation of AGS cells. qRT‒PCR was used to determine the expression of lncRNA TUC338 in gastric cancer tissues, paracarcinoma tissues, AGS human gastric cancer cells and GES-1 normal gastric mucosa cells and to evaluate the effects of BXD on the expression of lncRNA TUC338 in AGS cells. Lentiviral transfection was used to establish human gastric cancer AGS cells with knocked down lncRNA TUC338 expression. The effects of lncRNA TUC338 knockdown on the migration and invasion of AGS cells were observed by a scratch assay and Transwell migration assay, respectively. Western blotting was performed to analyze the effects of lncRNA TUC338 knockdown on epithelial-to-mesenchymal transition (EMT) in AGS cells. We performed quality control on three batches of BXD. We used UHPLC‒MS/MS to control the quality of three random batches of BXD used throughout the study. ResultsNinety-five chemical components were identified from the water extract of BXD, some of which have anticancer effects. The expression of TUC.338 in gastric cancer tissues was higher than that in para-carcinoma tissues. BXD inhibited the invasion and migration of gastric cancer cells by inhibiting the expression of lncRNA TUC338, which reduced EMT. After knockdown of lncRNA TUC338, the migration and invasion of AGS cells were reduced; the expression of the EMT-related protein E-cadherin was increased, and the expression of N-cadherin and vimentin was reduced. ConclusionsThe present results suggest that BXD has potential as an effective treatment for gastric cancer through the inhibition of lncRNA TUC338 expression.

Interleukin-34 promotes the proliferation and epithelial-mesenchymal transition of gastric cancer cells.

BACKGROUNDInterleukin (IL)-34 is a pro-inflammatory cytokine involved in tumor development. The role of IL-34 in the proliferation and epithelial-mesenchymal transition (EMT) of gastric cancer (GC) remains to be investigated.AIMTo investigate whether and how IL-34 affects the proliferation of GC cells and EMT.METHODSUsing immunohistochemical staining, the expression of IL-34 protein was detected in 60 paired GC and normal paracancerous tissues and the relationship between IL-34 and clinicopathological factors was analyzed. The expression of IL-34 mRNA and protein in normal gastric epithelial cell lines and GC was detected using quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting, respectively. Stable IL-34 knockdown and overexpression in AGS cell lines were established by lentiviral infection and validated by qRT-PCR and western blotting. The cholecystokinin-8 assay, clone formation assay, cell scratch assay, and transwell system were used to detect GC cell proliferation, clone formation, migration, and invasion capacity, respectively. The effects of IL-34 on the growth of GC transplant tumors were assessed using a subcutaneous transplant tumor assay in nude mice. The effects of IL-34 on the expression level of EMT-associated proteins in AGS cells were examined by western blotting.RESULTSExpression of IL-34 protein and mRNA was higher in GC cell lines than in GES-1 cells. Compared to matched normal paraneoplastic tissues, the expression of IL-34 protein was higher in 60 GC tissues, which was correlated with tumor size, T-stage, N-stage, tumor, node and metastasis stage, and degree of differentiation. Knockdown of IL-34 expression inhibited the proliferation, clone formation, migration, and invasion of AGS cells, while overexpression of IL-34 promoted cell proliferation, clone formation, migration, and invasion. Furthermore, the reduction of IL-34 promoted the expression of E-cadherin in AGS cells but inhibited the expression of vimentin and N-cadherin. Overexpression of IL-34 inhibited E-cadherin expression but promoted expression of vimentin and N-cadherin in AGS cells. Overexpression of IL-34 promoted the growth of subcutaneous transplanted tumors in nude mice.CONCLUSIONIL-34 expression is increased in GC tissues and cell lines compared to normal gastric tissues or cell lines. In GC cells, IL-34 promoted proliferation, clone formation, migration, and invasion by regulating EMT-related protein expression cells. Interference with IL-34 may represent a novel strategy for diagnosis and targeted therapy of GC.

Amygdalin suppresses the proliferation, migration and EMT of gastric cancer cells by inhibiting TGF-β/Smad signal pathway

Purpose: To investigate the effects of amygdalin on the proliferation, motility and epithelial mesenchymal transformation (EMT) of gastric cancer cells and to elucidate the operating mechanisms of action.Methods: Gastric cancer AGS cells were treated with amygdalin (2.5, 5 and 10 mg/L). MTT and colony formation assays were used to investigate the effect of amygdalin on gastric cancer cell proliferation, while wound healing and Transwell assays were also carried out to determine its effect on the motility of gastric cancer cells. Immunoblot assays were used to investigate the effects of amygdalin on epithelial mesenchymal transformation (EMT) process and TGF-β/Smad pathway in gastric cancer cells.Results: Treatment with amygdalin suppressed the proliferation of gastric cancer AGS cells (p < 0.05). Amygdalin suppressed the migration and invasion of AGS cells in vitro (p < 0.05). Additionally, amygdalin suppressed epithelial mesenchymal transformation (EMT) in AGS cells, and suppressed TGF-β/Smad pathway (p < 0.05), thereby suppressing growth, motility, and EMT in AGS cells.Conclusion: Amygdalin may be useful for the treatment of gastric cancer; however, further studies are required ascertain this.

Thrombospondin-2 holds prognostic value and is associated with metastasis and the mismatch repair process in gastric cancer

BackgroundThis study aims to investigate thrombospondin 2 (TSP2) expression levels in gastric cancer (GC) and determine the relationship between TSP2 and clinical characteristics and prognosis.MethodsThe online database Gene Expression Profile Interactive Analysis (GEPIA) was used to analyse TSP2 mRNA expression levels in GC. The Kaplan–Meier plotter prognostic analysis tool was used to evaluate the influence of TSP2 expression on clinical prognosis in GC patients. TSP2 expression levels were analysed in paraffin-embedded GC samples and adjacent normal tissues by immunohistochemistry. The relationship between the clinicopathological characteristics and prognosis of GC patients was assessed. Transwell experiments were used to evaluate the effect of TSP2 on HGC27 and AGS cell invasion and migration. The EdU experiment was used to detect the effect of transfection of TSP2 on cell proliferation, and the flow cytometry experiment was used to detect the effect of TSP2 on cell apoptosis and the cell growth cycle. Western blotting (Wb) technology was used to detect MMP, E-cadherin, N-cadherin, Vimentin, Snail, AKT, PI3K, and VEGF protein expression in HGC27 cells.ResultsCompared with normal tissues, TSP2 mRNA expression in GC was significantly upregulated and was closely related to the clinical stage of GC. High TSP2 expression significantly affected the OS, FP and PPS of patients with GC. Among these patients, TSP2 expression levels did not affect the prognosis of patients with GC in the N0 subgroup but significantly affected the prognosis of patients with GC in the N (1 + 2 + 3) subgroup. TSP2 protein expression levels were significantly higher in GC tissue compared with normal tissues (P < 0.01). The overall survival (OS) and relapse-free survival (RFS) of patients with high TSP2 expression were lower than those of patients with low TSP2 expression. Cells transfected with the TSP2-silencing sequence exhibited increased apoptosis and inhibition of proliferation, migration and invasion. AKT and PI3K expression in cells was significantly downregulated (P < 0.01). AKT, PI3K and VEGF expression in cells transfected with the TSP2 silencing sequence was significantly reduced. Proliferation, migration, invasion ability, and TSP2 expression levels significantly correlated with mismatch repair genes, such as PMS2, MSH6, MSH2, and MLH1 (P < 0.05).ConclusionTSP2 expression is significantly increased in GC. TSP2 expression is closely related to metastasis and the mismatch repair process in GC patients and affects GC patient prognosis. The mechanism may involve regulating gastric cancer cell proliferation and migration by modulating the VEGF/PI3K/AKT signalling pathway. TSP2 is a potential marker and therapeutic target for the prognosis of GC patients.

LncRNA LINC00342 promotes gastric cancer progression by targeting the miR-545-5p/CNPY2 axis

BackgroundThis study aimed to explore the role and underlying molecular mechanisms of long non-coding RNA (lncRNA) LINC00342 in gastric cancer (GC).MethodsThe 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.ResultsLINC00342 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.ConclusionLINC00342 plays a potential oncogenic role in GC by targeting the miR545-5p/CNPY2 axis, and might act as a novel therapeutic target for GC.

SchizandrinA induces the apoptosis and suppresses the proliferation, invasion and migration of gastric cancer cells by activating endoplasmic reticulum stress.

Apart from its basic antioxidant and anti-inflammatory properties, schizandrin A (SchA), which is isolated from Fructus schisandra, can exert anticancer effects on multiple cancer types. However, to the best of our knowledge, there has been no study identifying the impacts of SchA on gastric cancer (GC). Therefore, the aim of the present study was to identify how SchA functioned to affect the progression of GC. To investigate the role of SchA in GC development, Cell Counting Kit-8, colony formation, wound healing and Transwell assays were conducted to assess the viability, proliferation, migration and invasion of AGS cells, respectively. Then, the apoptosis rate and apoptosis- and endoplasmic reticulum (ER) stress-related protein expression levels in AGS cells exposed to SchA were detected via TUNEL assays and western blotting, respectively. Subsequently, the aforementioned functional assays were performed again in AGS cells exposed to both SchA and the ER stress inhibitor 4-phenylbutyric acid (4-PBA) for the confirmation of the effect of SchA on ER stress in GC. It was found that SchA markedly decreased the viability, proliferation, migration and invasion, while it induced the apoptosis of AGS cells. Moreover, the markers of ER stress were elevated by SchA treatment in AGS cells. Nevertheless, 4-PBA reversed the effects of SchA on the viability, proliferation, migration, invasion and apoptosis of AGS cells, accompanied by decreased expression of ER stress markers. In conclusion, the present study demonstrated that SchA induced the apoptosis and suppressed the proliferation, invasion and migration of GC cells by activating ER stress, which provides a theoretical basis for the use of SchA in the treatment of GC.

Melittin suppresses epithelial-mesenchymal transition and metastasis in human gastric cancer AGS cells via regulating Wnt/BMP associated pathway.

Gastric cancer has a poor prognosis; once cancer has metastasized, it can easily lead to patient death. Melittin is one of the major components extracted from the bee venom. It has been shown that melittin emerges antitumor activities against many human cancer cell lines. Our results indicated that melittin at 0.2-0.5 µm significantly reduced total cell viability in human gastric cancer AGS cells. At low concentrations (0.05-0.15 µm), melittin displayed antimetastasis effects and inhibited cell adhesion and colony formation. Besides, it inhibited cell motility and suppressed cell migration and invasion. Melittin inhibited the activities of MMP-2 and MMP-9 and the integrity of cell membrane in AGS cells. Furthermore, Western blotting results showed that melittin decreased the protein expressions of Wnt/BMP and MMP-2 signaling pathways. Based on these observations, melittin inhibited cell migration and invasion of AGS cells through multiple signaling pathways. It may be used to treat metastasized gastric cancers in the future.

MiR-496 inhibits proliferation via LYN and AKT pathway in gastric cancer.

MicroRNAs (miRNAs) operate as tumor suppressor or carcinogen to regulate cell proliferation, metastasis, invasion, differentiation, apoptosis, and metabolic process. In the present research, we investigated the effect and mechanism of miR-496 in human gastric cancer cells. miR-496 was downregulated in two gastric cancer cell lines, AGS and MKN45, compared with normal gastric epithelial cell line GES-1. miR-496 mimics inhibited the proliferation of AGS cells after the transfection for 48 and 72 h. The migration and invasion of AGS cells were also inhibited by the transfection of miR-496 mimics. miR-496 mimics induced the apoptosis through upregulating the levels of Bax and Active Caspase 3 and downregulating the levels of Bcl-2 and Total Caspase 3. Bioinformatics analysis showed that there was a binding site between miR-496 and Lyn kinase (LYN). miR-496 mimics could inhibit the expression of LYN in AGS cells. LYN overexpression blocked the inhibition of tumor cell growth, as well as the inhibition of AKT/mTOR signaling pathway induced by miR-496. In conclusion, miR-496 inhibited the proliferation through the AKT/mTOR signaling pathway via targeting LYN in gastric cancer cells. Our research provides a new potential target for clinical diagnosis and targeted treatment for gastric cancer.

Metformin is a Novel Suppressor for Vimentin in Human Gastric Cancer Cell Line.

Vimentin, an intermediate filament of mesenchymal cells, is upregulated in epithelial-mesenchymal transition (EMT) and has a main role in cancer metastasis. As a new strategy to control metastatic outgrowth, EMT markers are generally inhibited using some drugs or specific siRNA. In this study, AGS gastric cancer cells were treated with metformin and vimentin-specific siRNA (vim-siRNA) for 48 h. The impact of metformin and vim-siRNA on vimentin downregulation in AGS cells were analyzed by quantitative PCR and Western blot. Following treatment with metformin and vim-siRNA, cell motility, migration and invasion abilities of AGS cells were also analyzed. The results showed that inhibition of vimentin due to metformin was comparable with the vim-siRNA. Furthermore, wound-healing and invasion assays showed a significant decrease in migration and invasion of AGS cells following metformin and vim-siRNA treatment. Our finding for the first time indicated that metformin can be an alternative to specific siRNA for inhibition of vimentin expression and migration of AGS cell line. Taken together, our data indicates that the use of metformin might have a priority to siRNA for inhibition of gastric cancer cell behaviors siRNA is more unstable and expensive than metformin, and needs special vehicles and delivery strategies for efficient transfection of cells. Further in vivo studies can reveal metformin's potential in inhibition of EMT and metastasis of cancer cells.

LncRNA FAM230B Promotes Gastric Cancer Growth and Metastasis by Regulating the miR-27a-5p/TOP2A Axis.

Long non-coding RNAs serve as key components of competing endogenous RNA (ceRNA) networks that underlie tumorigenesis. We investigated the pathogenic roles of lncRNA FAM230B and its molecular mechanism in gastric cancer (GC). The levels of FAM230B expression in five gastric cancer cell lines and in human gastric mucosal cells were compared by quantitative RT-PCR. To analyze the function of FAM230B in GC, we overexpressed FAM230B in AGS cells, silenced FAM230B in MGC-803 cells, and tested the effect of FAM230B on tumor growth in nude mice. The interaction between miR-27a-5p and FAM230B was predicted by a bioinformatics analysis and then verified with a dual-luciferase reporter assay. We also further investigated the role and mechanism of FAM230B by forcing overexpression of miR-27a-5p in MGC-803 gastric cancer cells. We found that FAM230B was highly expressed in gastric cancer cell lines and mainly located in the cytoplasm. FAM230B overexpression promoted the proliferation, migration, and invasion of AGS cells and repressed their apoptosis; it also facilitated tumor growth in vivo. In contrast, FAM230B knockdown suppressed the proliferation, migration, and invasion of MGC0803 cells, but enhanced their apoptosis and inhibited tumor growth in vivo. MiR-27a-5p expression was suppressed by FAM230B overexpression in AGS cells. MiR-27a-5p inhibited the proliferation, migration, and invasion of gastric cancer cells, and promoted the apoptosis of gastric cancer cells by reducing TOP2A (topoisomerase 2 alpha) expression. Our study showed that lncRNA FAM230B might function to promote GC. FAM230B functioned as a ceRNA by sponging miR-27a-5p and enhancing TOP2A expression.

Oncogenic role of LYN in human gastric cancer via the Wnt/β-catenin and AKT/mTOR pathways.

LYN kinase (LYN) is a member of the Src tyrosine kinase family, which plays an important role in multiple tumor-related functions. The current study demonstrated that LYN functions as a pro-oncogene in AGS gastric cancer cells. It was found that LYN expression levels were significantly raised in gastric cancer tissue and were significantly associated with the pathological grades of patients with gastric cancer. This was accomplished by knocking down LYN in AGS cells using short hairpin RNA (shRNA) plasmid transfection, with reverse transcription-quantitative PCR detection verifying the effectiveness of RNA interference. It was found that the cell proliferation and colony formation abilities of AGS cells were significantly inhibited, using CCK-8 and clone formation assays, respectively. Furthermore, LYN knockdown was found to induce apoptosis and inhibit both migration and invasion in AGS cells, using flow cytometry and Transwell assays, respectively. A mechanical investigation further suggested that LYN knockdown resulted in the activation of the mitochondrial apoptotic pathway. Likewise, the Wnt/β-catenin pathway was inactivated by LYN knockdown, including decreased levels of Wnt3a, β-catenin, snail family transcriptional repressor (Snail)1 and Snail2. Epithelial-mesenchymal transition mesenchymal markers (including N-cadherin and vimentin) were also found to be downregulated, and E-cadherin was upregulated in LYN-silenced AGS cells. Finally, the AKT/mTOR pathway was found to be downregulated by LYN knockdown in AGS cells, including decreased levels of phosphorylated (p)-AKT (Ser473), p-mTOR (Ser2448), and the down-stream effector p70S6 kinase (p70S6K). Furthermore, the AKT pathway activator, insulin like growth factor-1 (IGF-1), was found to reverse the inhibitory effects of LYN knockdown on the proliferation, migration and invasion of AGS cells. In conclusion, the current study demonstrated that LYN plays an oncogenic role in the proliferation, survival and movement of human gastric cancer cells by activating the mitochondrial apoptotic pathway, and downregulating the Wnt/β-catenin and AKT/mTOR pathways. The current research provides a comprehensive insight into the regulation of LYN in gastric cancer and may help with the development of new tumor treatment strategies.

LncRNA PCAT18 inhibits proliferation, migration and invasion of gastric cancer cells through miR-135b suppression to promote CLDN11 expression

BackgroundGastric cancer is a severe disease with a high occurrence rate worldwide. And lncRNAs are demonstrated to be responsible for cancer growth and metastasis. So, it is of great importance to explore the lncRNAs involved mechanism of gastric cancer occurrence and development deeply. MethodsTransfection was conducted to build over-expression and down-expression models. Moreover, RT-qPCR and western blot were used to detect the transcriptional and translational levels. The biological functions such as proliferation, migration and invasion of AGS cells were evaluated by MTT analysis, colony formation assay, scarification detection and transwell assay, respectively. The potential binding of miR-135b and its downstream and upstream molecules was validated by dual luciferase reporter gene assay or RIP. Also, the in-vivo mice model was further used to demonstrate the role of lncRNA PCAT18 in gastric cancer. ResultsPCAT18 down-expression promoted proliferation, migration and invasion of gastric cancer cells. Furtherly, over-expression of miR-135b also promoted these biological characteristics of AGS cells. Importantly, we found that PCAT18 could bind miR-135b which also was bound with CLDN11. We found that miR-135b is negatively correlated with CLDN11; PCAT18 and CLDN11 are positively correlated. Moreover, miR-135b mimics could down-regulate protein level of CLDN11, whereas CLDN11 could reverse this effect. In in-vivo experiment, PCAT18 over-expression restrained tumor growth and metastasis. ConclusionsOver-expressed lncRNA PCAT18 inhibits proliferation, migration and invasion of gastric cancer cells through regulation of miR-135b/CLDN11.

Rhus verniciflua Stokes extract suppresses migration and invasion in human gastric adenocarcinoma AGS cells.

BACKGROUND/OBJECTIVESMany studies have suggested that Rhus verniciflua Stokes (RVS) and its extract are anticancer agents. However, RVS had limited use because it contains urushiol, an allergenic toxin. By improving an existing allergen-removal extraction method, we developed a new allergen-free Rhus verniciflua Stokes extract (RVSE) with higher flavonoid content. In this study, we examined whether RVSE inhibits the ability of AGS gastric cancer cells to migrate and invade.MATERIALS/METHODSThe flavonoids content of RVSE was analyzed by HPLC. The effects of RVSE on migration and invasion in AGS cells were analyzed by each assay kit. Matrix metalloproteinase (MMP)-9, plasminogen activator inhibitor-1 (PAI-1) and urokinase-type plasminogen activator (uPA) protein expression was analyzed by protein antibody array. The Phosphorylation of signal transducer and activator of transcription (STAT) 3 were assayed by Western blot analysis.RESULTSRVSE treatment with 0–100 μg/mL dose-dependently reduced the ability of AGS cells to migrate and invade. Notably, treatment with RVSE strongly inhibited the expression of MMP-9 and uPA and the phosphorylation of STAT3. In contrast, RVSE treatment dramatically increased the expression of PAI-1. These results indicate that the inhibition of MMP-9 and uPA expression and STAT3 phosphorylation and the stimulation of PAI-1 expression contributed to the decreased migration and invasion of AGS cells treated with RVSE.CONCLUSIONSThese results suggest that RVSE may be used as a natural herbal agent to reduce gastric cancer metastasis.

LncRNA DLEU2 accelerates gastric cancer growth by downregulating miR-30a-5p

Introduction: lncRNA DLEU2 has been indicated to act a crucial role in the bioprocess of cancer. But, the role and molecular mechanisms of lncRNA DLEU2 in gastric cancer (GC) remain unknown. Methods: The correlation of DLEU2 or miR-30a-5p with the clinical parameters and outcomes of GC patents was implemented by TCGA cohort. Cell viability and invasion were estimated by MTT and Transwell assays. The interplay between DLEU2 and miR-30a-5p was confirmed by a luciferase report assay. The effects of DLEU2 on miR-30a-5p or MMP2/9 were detected by qRT-PCR and Western blot. Results: We found that the enhanced expression of DLEU2 was linked to the pathological stage and poor survival in GC patients. Overexpressing DLEU2 prompted the cell proliferation and invasion of AGS cells, but silencing DLEU2 weakened these effects in MKN-28 cells. In addition, DLEU2 could negatively modulate and be bound with miR-30a-5p, which could counteract DLEU2-caused cell proliferation. High expression of miR-30a-5p was linked to a favorable survival in patients with GC. Conclusion: Our findings suggested that lncRNA DLEU2 could favor the growth of GC by downregulating miR-30a-5p.

CRISPR/Cas9-mediated knockout of the PDEF gene inhibits migration and invasion of human gastric cancer AGS cells

Gastric cancer is one of the most common malignant tumors worldwide and has the second highest incidence and mortality rate among malignant tumors in China. Prostate-derived Ets factor (PDEF) is a member of the Ets family of transcription factors. Although PDEF plays an important role in tumorigenesis, its biological function in gastric cancer is still unclear. Here, we evaluated PDEF expression in 30 cases of human gastric carcinoma and the corresponding peritumoral tissues, using immunohistochemistry and immunofluorescence. Significantly higher levels of PDEF were detected in tumors compared to peritumoral tissues. We then investigated PDEF expression in the gastric cancer cell lines SGC and AGS and the normal gastric epithelial cell line GES; The CRISPR/Cas9 genome-editing system was used to knockout PDEF in AGS cells as a model for gastric cancer. Cell proliferation, apoptosis, migration, and invasion of PDEF-knockout AGS cells were evaluated using CCK-8, flow cytometry, scratch wound, and transwell assays, respectively. The results illustrated that PDEF-knockout inhibited AGS cell proliferation, migration, and invasion. Taken together, the results imply that PDEF plays important roles in the proliferation, migration, and invasion of AGS cells and may serve as a new treatment target in gastric cancer.

MicroRNA-30a-5p inhibits the proliferation and invasion of gastric cancer cells by targeting insulin-like growth factor 1 receptor.

MicroRNAs (miRs) are a class of small non-coding RNAs of 18–25 nucleotides in length that serve as key regulators in the development and progression of human cancers. Recently, miR-30b-5p, as a member of the miR-30 family, has been reported to act as a tumor suppressor in gastric cancer. However, the expression and function of miR-30a-5p in gastric cancer, as well as the corresponding underlying mechanism, remain unknown. In the present study, it was demonstrated that the expression of miR-30a-5p was significantly reduced in gastric cancer tissues (n=43) compared with normal gastric tissues (n=10; P<0.01). Similarly, miR-30a-5p was significantly downregulated in the gastric cancer cell lines AGS, HGC27, BGC823 and SGC7901, when compared with the normal gastric mucosa epithelial cell line GES-1 (P<0.01). In addition, overexpression of miR-30a-5p significantly inhibited the proliferation and invasion of AGS cells (P<0.01). Insulin-like growth factor 1 receptor (IGF-1R) was identified as a novel target of miR-30a-5p, and the protein expression of IGF-1R was negatively regulated by miR-30a-5p in AGS cells (P<0.01). Furthermore, overexpression of IGF-1R significantly reversed the inhibitory effect of miR-30a-5p on the proliferation and invasion of AGS cells (P<0.01), indicating that IGF-1R was involved in miR-30a-5p-mediated proliferation and invasion of AGS cells. It was also observed that the expression of IGF-1R mRNA was upregulated in gastric cancer tissues compared with normal gastric tissues (P<0.01), and its levels of expression were reversely correlated with that of miR-30a-5p in gastric cancer tissues (R2=0.3892; P<0.01). Collectively, these data suggest that miR-30a-5p inhibits the growth and metastasis of gastric cancer by directly targeting IGF-1R. Therefore, the miR-30a-5p/IGF-1R axis may be a potential therapeutic target in the treatment of gastric cancer.