Gastric Cancer Migration Research Articles

MicroRNA-135b/CAMK2D Axis Contribute to Malignant Progression of Gastric Cancer through EMT Process Remodeling.

There is a continued need for investigating the roles of microRNAs (miRNAs) and their targets on the progression of gastric cancer (GC), especially metastasis. Here, we performed an integrated study to identify dysregulated miRNAs critical for GC development and progression. miR-135b was determined as a promising biomarker for GC. The expression level of miR-135b was increased among GC cell lines, patient tumor tissues, serum samples, and correlation with aggravation of the GC patients. The in vitro functional assays demonstrated overexpression of miR-135b promoted cell proliferation, migration and invasion in GC, while miR-135b inhibition led to the opposite results. CAMK2D was found to be the direct target of miR-135b, serving as a tumor suppressor in GC cells. Based on our and public datasets, we confirmed the attenuation of CAMK2D expression in GC tissues. And, the expression levels of miR-135b and CAMK2D were closely associated with prognosis of GC patients. Ectopic expression of miR-135b resulted in the down-regulation of CAMK2D. Additionally, CAMK2D was a prerequisite for miR-135b to promote GC cells proliferation and migration by regulating the EMT process, which was confirmed by the in vivo experiments. Importantly, in vivo injection of miR-135b antagomir significantly repressed the tumor growth and metastasis of xenograft models, which suggested that the miR-135b antagomir were promising for clinical applications. Taken together, these results indicate that miR-135b/CAMK2D axis drives GC progression by EMT process remodeling, suggesting that miR-135b may be utilized as a new therapeutic target and prognostic marker for GC patients.

LncRNA MYLK-AS1 acts as an oncogene by epigenetically silencing large tumor suppressor 2 (LATS2) in gastric cancer

ABSTRACT Extensive studies showed the vital function of long noncoding RNAs (lncRNAs) in the pathological and physiological progression of tumors. Previous evidence has indicated that lncRNA MYLK Antisense RNA 1 (MYLK-AS1) acts as an oncogene to facilitate the progression of several tumors. Nevertheless, little is known about its biological role in gastric cancer (GC). Our report intended to probe the underlying mechanism and function of MYLK-AS1 in GC. Results revealed that MYLK-AS1 showed an upregulated level in GC. It was worth mentioning that upregulated MYLK-AS1 caused the unfavorable clinical outcome in GC patients. Functional assays indicated that MYLK-AS1 silencing retarded the proliferation, cell cycle, migration, and invasion in GC. Besides, in vivo assay validated that MYLK-AS1 deficiency also restrained tumor growth. Through in-depth mechanism exploration, MYLK-AS1 was uncovered to bind with wnhancer of zeste homolog 2 (EZH2), an epigenetic inhibitor, to inhibit the level of Large Tumor Suppressor 2 (LATS2), thereby exerting carcinogenicity. Conclusively, our research highlighted the importance of MYLK-AS1 in GC, indicating that MYLK-AS1 might be an effective biomarker for GC.

CDC37L1 acts as a suppressor of migration and proliferation in gastric cancer by down-regulating CDK6

The co-chaperone protein CDC37 (Cell division cycle 37) is well known to regulate multiple protein kinases and involved in tumor progression. However to date, little is known about its analogue CDC37L1 (Cell division cycle 37 like 1) in tumorigenesis. This study aimed to explore the expression and function of CDC37L1 in gastric cancer (GC). The immunohistochemical staining in a tissue microarray showed a weak expression of CDC37L1 in high grade GC tissues compared with low grade tissues. Consistently, data from online database analysis demonstrated that CDC37L1 level was decreased in stage 4 patients and low expression of CDC37L1 indicated a poor prognosis. Functional studies revealed that CDC37L1 could inhibit GC cell proliferation and migration in CCK8, EdU incorporation, colony formation and transwell assays. In the meantime, CDC37L1 also inhibited the tumorigenicity of GC cells in nude mice. Mechanistically, we found that CDC37L1 had an impact on CDK6 protein expression by western blotting. Palbociclib, a specific CDK4/6 inhibitor, was discovered to block the rapid growth phenotype of GC cells induced by CDC37L1 silencing. Taken together, these findings unveiled a tumor-suppressive role of CDC37L1 in GC, and CDK6 may act as a downstream effector in this process.

NKCC1 promotes proliferation, invasion and migration in human gastric cancer cells via activation of the MAPK-JNK/EMT signaling pathway.

Aims: This study aimed to explore the function of NKCC1 in the proliferation, migration and invasion of Gastric cancer (GC) cells.Materials and Methods: GC data extracted from the database was analyzed using molecular bioinformatics. The expression levels of NKCC1 in tissue samples from GC patients and GC cell lines were determined by Western blotting, qRT-PCR, and immunohistochemistry. Immunofluorescence was used to detect protein localization. The GC cell lines were transfected with NKCC1-shRNA or expression plasmid, and in vitro proliferation, invasion and migration were analyzed by the CCK8, wound healing and transwell tests.Results: The NKCC1 mRNA level was significantly increased in GC tissues than that in normal gastric tissues (P = 0.0195). This phenomenon was further confirmed by the analysis of the TCGA-GTEx database that includes 408 gastric cancer tissues and 211 normal gastric tissues (P < 0.01). Furthermore, the increased level of NKCC1 was significantly correlated with Tumor size (P = 0.039), lymphatic node metastasis (P = 0.035) and tumor stage (P = 0.034). In vitro experiments confirmed that NKCC1 expression was higher in GC cells compared to that in GES-1 cells, and was mainly localized to the cytoplasm and membrane. NKCC1 silencing inhibited GC cell proliferation, invasion, migration and EMT, whereas its overexpression had the opposite effects. Furthermore, NKCC1 overexpression upregulated and activated JNK, and the targeted inhibition of JNK by SP600125 abrogated the pro-metastatic effects of NKCC1.Conclusions: NKCC1 promotes migration and invasion of GC cells by MAPK-JNK/EMT pathway and can be a potential therapeutic target.

MiR-216b inhibits gastric cancer proliferation and migration by targeting PARK7.

Postoperative recurrence and metastasis of gastric cancer is still a difficult problem in medical field. About 60% of patients with advanced gastric cancer die from peritoneal metastasis, which has become one of the main causes of death of gastric cancer patients. To elucidate the molecular mechanism of peritoneal metastasis of gastric cancer can help us better early diagnosis and improve treatment measures. This project intends to validate the above hypothesis from three different levels of tissue, cell, and animal models by means of fluorescence quantitative PCR, Western blot, double Luciferase Report Analysis and immunohistochemical detection, and to further explore the molecular mechanism of peritoneal metastasis of gastric cancer. Our previous studies have shown that PARK7 promotes peritoneal metastasis of gastric cancer through PI3K/Akt signaling pathway, but its specific regulatory mechanism remains unclear. Our preliminary study showed that the expression of microRNA-216b in gastric cancer tissues with peritoneal metastasis was significantly lower than that in patients without peritoneal metastasis, while the expression of PARK7 was the opposite.

GPER1 Silencing Suppresses the Proliferation, Migration, and Invasion of Gastric Cancer Cells by Inhibiting PI3K/AKT-Mediated EMT.

G protein coupled estrogen receptor (GPER1) is a membrane estrogen receptor, belonging to the seven-transmembrane G protein-coupled receptors family, and has important biological functions in cancer. However, the functional role of GPER1 in gastric cancer (GC) remain incompletely understood. In the present study, we employed gene set enrichment analysis and discovered that GPER1 expression was concomitant with EMT process and was positively correlated with activation of the PI3K/AKT pathway in GC. Knockdown of GPER1 with siRNA suppressed the proliferation, migration, and invasion of AGS and MGC-803 GC cells. Knockdown of GPER1 also downregulated the mesenchymal markers N-cadherin and vimentin, upregulated E-cadherin, an epithelial marker, and suppressed expression of the Snail, Slug and Twist1 transcription factors, indicating that knockdown of GPER1 inhibited EMT. Moreover, 740Y-P, a PI3K activator, reversed the effects of GPER1 knockdown on EMT processes. Overexpression of GPER1 with plasmid can further prove these findings. In summary, these data demonstrate that GPER1 inhibition suppresses the proliferation, migration, and invasion of gastric cancer cells by inhibiting PI3K/AKT-mediated EMT. Our study elucidated the function of GPER1 in gastric cancer, and we identified PI3K/AKT-mediated EMT as a novel mechanism by which GPER1 contributes to proliferation, migration, and invasion of gastric cancer. These data suggest that combining inhibition of GPER1 and PI3K may be a potential therapeutic approach to inhibit gastric cancer metastasis.

The m6A methyltransferase METTL14 inhibits the proliferation, migration, and invasion of gastric cancer by regulating the PI3K/AKT/mTOR signaling pathway.

Background N6‐methyladenosine (m6A) modification may participate in the regulation of occurrence and development of tumors. However, the m6A level and the potential regulatory mechanism of m6A in gastric cancer (GC) remain uncertain.MethodsRNA m6A quantification assay was conducted to detect the m6A level in GC tissues and cell lines. Methyltransferase‐like 14 (METTL14) expression in GC tissues was explored by bioinformatics and immunohistochemistry. Then, the function of METTL14 in GC cells was examined by CCK‐8, colony formation assay, wound healing assay, and Transwell assay. Besides, Western blotting was conducted to probe the PI3K/AKT/mTOR pathway and the epithelial‐mesenchymal transformation (EMT) pathway‐related gene expression.ResultsThe m6A modification level was decreased in GC and METTL14 was a key regulator resulting in m6A disorder in GC. METTL14 was downregulated in GC by analyzing both clinical samples and bioinformatics. METTL14 overexpression suppressed GC cell proliferation and aggression by deactivating the PI3K/AKT/mTOR pathway and the EMT pathway, respectively.ConclusionsOur findings indicate that METTL14 partakes in the biological process of GC as a tumor suppressor and may be an emerging biomarker in GC.

VSNL1 Promotes Gastric Cancer Cell Proliferation and Migration by Regulating P2X3/P2Y2 Receptors and Is a Clinical Indicator of Poor Prognosis in Gastric Cancer Patients.

Purpose The aim of this study was to investigate the role of Visinin Like 1 (VSNL1) in the proliferation and migration of gastric cancer (GC) cells as well as its clinical prognostic significance. Methods To this end, we evaluated VSNL1 expression in GC tissues and cell lines by real-time PCR and immunohistochemistry. To further explore the effects of VSNL1, a lentiviral vector expressing a short hairpin RNA (shRNA) against VSNL1 was constructed and transduced into the GC cell lines BGC-823 and SGC-7901. The interference efficiency of VSNL1-shRNA was determined by western blot. The effects of VSNL1 on the migration and invasion of GC cells as well as the expression of P2X3/P2Y2 were explored using MTS, colony formation, migration, and western blot assays. Results VSNL1 mRNA and protein levels were increased in GC tissues and cell lines. Furthermore, VSNL1 expression was positively correlated with Lauren's classification, lymph node metastasis, distant metastasis, TNM stage, and prognosis. VSNL1 expression was inversely correlated with the 5-year survival rate of GC patients. VSNL1 expression was markedly reduced in cells transduced with lentivirus expressing shRNA against VSNL1, and inhibiting VSNL1 expression significantly suppressed cell growth, migration, and colony formation and reduced the expression of P2X3/P2Y2. Conclusion VSNL1 may promote the proliferation and migration of GC cells by regulating P2X3 and P2Y2 expression. VSNL1 plays important roles in GC development and metastasis and may be correlated with patient prognosis.

LncRNA SUMO1P3 regulates the invasion, migration and cell cycle of gastric cancer cells through Wnt/β-catenin signaling pathway

Objective To investigate the regulatory effect of long non-coding RNA (lncRNA) SUMO1P3 on invasion, migration and cell cycle of gastric cancer (GC) cells through Wnt/β-catenin signaling pathway. Methods Tumor tissues and adjacent normal tissues from the GC patients were collected, and human normal gastric epithelial cells GES1 and GC cells SGC-7901, MKN45, HGC-27 and AGS were selected for study. The expression of SUMO1P3 in GC tissues and cells were detected by RT-qPCR. The effects of SUMO1P3 on the proliferation, invasion and migration of SGC-7901 and MKN45 cells were detected by CCK-8, transwell and wound healing assay respectively, and the effects of SUMO1P3 on apoptosis and cycle progression of SGC-7901 and MKN45 cells were detected by flow cytometry. The expressions of Wnt/β-catenin pathway-related and cell cycle-related proteins were detected by Western blot. Results The expression of SUMO1P3 was significantly upregulated in GC tissues and cell lines. Downregulation of SUMO1P3 significantly inhibited the SGC-7901 and MKN45 cell proliferation, invasion, migration, and cycle progression and promoted the cell apoptosis, while overexpression of SUMO1P3 showed the opposite effect. Further study showed that downregulation of SUMO1P3 significantly reduced the expressions of Wnt1, β-catenin, c-myc, and Cyclin D1 in SGC-7901 and MKN45 cells. Conclusion SUMO1P3 may promote invasion, migration, and cycle progression of SGC-7901 and MKN45 cells by enhancing the Wnt/β-catenin pathway.

CircRNA_100876 Is Upregulated in Gastric Cancer (GC) and Promotes the GC Cells' Growth, Migration and Invasion via miR-665/YAP1 Signaling.

The present study aimed to investigate the biological function and relative mechanisms of circRNA_100876 in gastric cancer (GC). To this end, quantitative real-time polymerase chain reaction (RT-qPCR) was performed to examine the expression of circRNA_100876 and miR-665 in GC tissues and cells, and circRNA_100876 expression was depleted by the transfection of circ_100876-targeting siRNAs. CCK-8, flow cytometry, and Transwell assays were applied to examine GC cell cycle distribution, proliferation, apoptosis, migration, and invasion abilities. Proteins related to apoptosis and epithelial-mesenchymal transition (EMT) were detected by western blotting. Luciferase reporter assays were conducted to verify the direct target site between circRNA_100876 and miR-665. Our study confirmed that circRNA_100876 was highly expressed in GC lesions compared with the adjacent normal tissues (P < 0.001). High circRNA_100876 expression was negatively associated with survival outcome (P = 0.000). Furthermore, the down-regulation of circRNA_100876 could inhibit GC cell proliferation, invasion, and migration by suppressing the EMT pathway. Further study suggested that circRNA_100876 could act as a competing endogenous RNA by sequestering miR-665, and luciferase activity assay indicated that circRNA_100876 could bind directly with miR-665. Moreover, we found that Yes-associated protein 1 (YAP1) was the downstream target gene of miR-665, miR-665 knockdown could up-regulate YAP1 expression in MKN45 cells, and YAP1 knockdown could inhibit MKN45 cell proliferation, migration and invasion. Therefore, we demonstrated that circRNA_100876 over-expression in GC could promote GC tumor growth, migration and invasion and exert its effects through miR-665/YAP1 signaling.

The Regulatory Mechanism and Biological Significance of Mitochondrial Calcium Uniporter in the Migration, Invasion, Angiogenesis and Growth of Gastric Cancer.

ObjectiveIncreasing evidences suggest that mitochondrial calcium uniporter (MCU), a selective channel responsible for mitochondrial Ca2+ uptake, is involved in the progression of several cancers. In this study, we aimed to observe the clinical implications and biological functions of MCU in gastric cancer.MethodsThe expression of MCU in 90 pairs of gastric cancer tissues and adjacent normal tissues was examined using immunohistochemistry and correlation between MCU expression and clinical features was analyzed. After construction of stable MCU knockdown or overexpression gastric cancer cells, mitochondrial membrane potential (MMP), wound healing and transwell assays were performed to examine MMP levels, migration and invasion. Subcutaneous xenograft tumors induced by gastric cancer cells transfected with MCU siRNAs or controls were constructed. Immunofluorescence was used to detect CD34 expression. Western blot was used to detect the expression of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), epithelial-mesenchymal transition (EMT)-related proteins.ResultsMCU had a higher expression in gastric cancer tissues than normal tissues. Compared to gastric cancer tissues, its expression was significantly higher after omental metastasis. MCU expression was significantly correlated with depth of invasion (p=0.048), lymph metastasis (p=0.027), TNM stage (p=0.036) and distant metastasis (p=0.029). Patients with high MCU expression indicated a worse prognosis than those with its low expression (p=0.0098). MCU significantly increased the MMP levels of gastric cancer cells. Wound healing and transwell assay results showed that MCU promoted migration and invasion of gastric cancer cells. In vivo, MCU knockdown significantly inhibited tumor growth and angiogenesis. Both in vitro and in vivo, silencing MCU suppressed the expression of HIF-1α and VEGF as well as activity of EMT processes.ConclusionOur findings suggested that highly expressed MCU could promote migration, invasion, angiogenesis and growth of gastric cancer, which could become a potential therapeutic marker for gastric cancer.

SP1-activated LINC01638 promotes proliferation and migration of gastric cancer cells by regulating epithelial-mesenchymal transition.

The aim of this study was to detect the expression of long intergenic non-protein coding ribonucleic acid 01638 (LINC01638) in gastric cancer (GC), and to explore its role and molecular mechanism in regulating the proliferation and metastasis of GC cells. The relative expression level of LINC01638 in 50 cases of GC tissues and paracancerous tissues and GC cells was determined using quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). After interference with the expression of LINC01638, the interference efficiency was detected via qRT-PCR, and the changes in GC cell proliferation ability, cell cycle distribution, and migration and invasion abilities were examined using colony formation assay, flow cytometry, and transwell assay, respectively. The possible transcription factors binding to the promoter region of LINC01638 were predicted using bioinformatics methods. After interference with specificity protein 1 (SP1), qRT-PCR was performed to detect the interference efficiency and the change in LINC01638 expression. Besides, the changes in the molecular markers for epithelial-mesenchymal transition (EMT) were detected using Western blotting assay after interfering with LINC01638 expression and using Western blotting after interfering with SP1. The expression of LINC01638 was upregulated in 40 cases of GC tissues, and its expression level in GC cells was higher than that in normal gastric mucosal cells. After interfering with the expression of LINC01638, the colony formation assay results showed that the proliferation of GC cells was suppressed, it was found through flow cytometry that the cell cycle was arrested in G1/G0 phase, and transwell assay results manifested that the cell migration and invasion abilities declined. According to the bioinformatics and qRT-PCR results, the transcription factor SP1 contributed to the expression of LINC01638, and the expressions of molecular markers in the EMT signaling pathway were changed after interfering with LINC0168 and SP1. In this study, it was verified through the in vitro experiments that LINC01638 promotes the migration and invasion of GC by regulating EMT.

DNA methyltransferase 3 beta regulates ras related domain family 1 methylation leading to enhanced proliferation and migration in gastric cancer cells

Silencing expression of RASSF1A, which is induced by DNA hypermethylation, contributes to proliferation and migration in gastric cancer. However, the molecular mechanisms of this process remain unclear. In order to investigate the effect and mechanisms of RASSF1A methylation on proliferation and migration of gastric cancer, DNA methyltransferase inhibitors (5-AZA-CdR) were used to interfere with expression of DNMT3B and RASSF1A in gastric cancer AGS cells. Fe3O4–SiO2 nanoparticles were used to extract mRNA for RT-qPCR, and RT-qPCR and western blotting were used to measure the effect of RASSF1A expression on the expression of Caspase 3, Bcl-2, and Bax in AGS cells. MTT and cell scratch assays were used to assess the proliferation and migration of AGS cells. Our findings show that DNA methyltransferase inhibitors inhibit expression of DNMT3B, which leads to an increase in the expression of RASSF1A, Caspase3, and Bax at both the mRNA and protein levels, and inhibits the expression of Bcl-2. Thus, inhibiting the expression of DNMT3B and altering levels of DNA methylation can promote the expression of RASSF1A, regulate the expression of apoptosis-related genes, and inhibit proliferation and migration of gastric cancer cells. It is helpful to explore the pathological mechanism of endometrial cancer and provide theoretical basis for RASSF1A as a potential therapeutic target of gastric cancer.

Loganetin and 5-fluorouracil synergistically inhibit the carcinogenesis of gastric cancer cells via down-regulation of the Wnt/β-catenin pathway.

Although most gastrointestinal tumours are sensitive to 5‐fluorouracil (5FU), drug resistance is commonly occurred after 5FU therapy in gastric cancer (GC). Loganetin is the primary active compound in Cornus officinali. However, the synergetic effects of loganetin and 5FU on GC remain unknown. Here, we investigated the synergetic effects and the underlying mechanism of loganetin and 5FU on proliferation, stem‐like properties, migration, and invasion of GC both in vitro and in vivo. We found that loganetin alone inhibited the proliferation, stem‐like properties, migration and invasion of GC cells in vitro. Importantly, the loganetin remarkably enhanced the anti‐cancer effect of 5FU on GC cells and the Wnt/β‐catenin pathway might be involved in this process. Animal experiments further confirmed the synergistic effects of 5FU and loganetin on inhibiting cell growth and metastasis of GC. These results suggested that loganetin could synergistically increase the effect of 5FU against GC, which sheds light on effective combinational drug strategies for GC treatment.

The regulatory role of exosomal CagA and microRNAs derived from H. pylori-related gastric cancer cells on signaling pathways related to cancer development: a bioinformatics aspect

Exosomes are small vesicles outside the membrane, which are secreted by healthy, cancerous, and bacterial infected cells. These worthy vesicles carry shared information between adjacent cells and cause cell-cell communication. Bacteria can also secrete vesicles similar to exosomes called outer membrane vesicles (OMVs). The OMVs, also called quasi-exosomes due to its similarity to exosomes, are bacterial extracellular membrane vesicles that are secreted to enhance the pathogenicity of the bacteria. The continued secretion of exosome by cells and quasi-exosome by bacteria in gastric cancer played a vital role in cancer progression to metastasis and acute cancer state. In gastric cancer associated with Helicobacter pylori infection, both cancerous and immune cells secretion are involved. Exosomes and quasi-exosomes interact with each other to overcome cancer or worsen it. Cancer cells, through the involvement of T lymphocytes and macrophages, make these cells to secrete. Exosomes stimulate the immune system and improve gastric cancer. Exosomes containing CagA, miR155, MET, and GGT factors play an important role in gastric cancer. The regulatory role of some of these factors such as microRNAs and CagA are evaluated by enrichment analysis. KEGG pathway analysis illustrated the most significant pathway of upregulated gene in gastric cancer patient with inflammation history of H. pylori. Functional annotation analysis of H. pylori-related gastric sample highlighted the cluster of genes which regulated signal transduction and cellular respond to stimulus mechanism. Also, the protein-protein interaction (PPI) network of upregulated genes manifest CXCL8, CDC42, and BDKRB2 genes as a core network. Regarding the augmentation role of candidate genes in metastasis, migration, and angiogenesis in gastric cancer and also their regulatory role in pathogenesis and expansion of H. pylori, these genes offer the therapeutic opportunity against H. pylori and gastric cancer parallelly. Our final analysis was based on microRNAs related database underline mir-499, mir-208a-3p, and mir-208b which are the most downregulated microRNAs in H. pylori-related gastric cancer and could serve as an anti-cancer therapeutic agent.

Cir-ITCH inhibits gastric cancer migration, invasion and proliferation by regulating the Wnt/\u03b2-catenin pathway

Circular RNAs (circRNAs) are differentially expressed in various tumours, but the expression and regulatory mechanisms of circular RNA ITCH (cir-ITCH) in gastric cancer remain unclear. For this reason, in the present study, we assessed the expression of cir-ITCH and the associated regulatory mechanism of cir-ITCH in gastric cancer. Through RTq-PCR assays, we observed that cir-ITCH expression was attenuated in gastric cancer cell lines and tissues, with cir-ITCH expression in gastric cancer tissues with lymph node metastasis being considerably lower than that observed in gastric cancer tissues without lymph node metastasis. In addition, we demonstrated that cir-ITCH or linear ITCH may be a useful marker for gastric cancer prognosis by Kaplan–Meier survival analysis. We also showed that cir-ITCH overexpression could increase linear ITCH expression through miR-17 via RNA immunoprecipitation (RIP) and luciferase reporter assays. Moreover, in vivo and in vitro experimental results showed that cir-ITCH can act as a tumour suppressor to prevent gastric cancer tumourgenesis by sponging miR-17. The Wnt/β-catenin pathway plays a crucial role during the carcinogenesis of cancers, and we observed that cir-ITCH could negatively regulate Wnt/β-catenin signalling, which could be restored by miR-17. In summary, cir-ITCH was shown to prevent gastric cancer tumourgenesis through the Wnt/β-catenin signalling pathway by sequestering miR-17.

Long noncoding RNA CA3-AS1 suppresses gastric cancer migration and invasion by sponging miR-93-5p and targeting BTG3.

The long noncoding RNAs (lncRNAs) are a class of noncoding RNAs that are broadly expressed in various biological cells and function in regulating gene expression. However, the function of lncRNAs and the role of lncRNAs in gastric cancer remain to be determined. Herein, the function of lncRNA CA3-AS1 was investigated in gastric cancer. Firstly, we found that the expression level of CA3-AS1 was decreased in gastric cancer cell lines and tissues. Then, CA3-AS1 overexpression inhibited the gastric cancer cells migration and invasion and knockdown of CA3-AS1 enhanced the gastric cancer cells migration and invasion. Moreover, FISH assays and qPCR results revealed that CA3-AS1 was mainly expressed in the cytoplasm of gastric cancer cells. Then, the relationship between CA3-AS1 and miR-93-5p was explored. Luciferase reporter assays results showed that miR-93-5p was a direct target of CA3-AS1 in SGC-7901 and BCG-823. Furthermore, BTG3 was identified as a direct target gene of miR-93-5p. Restore experiments showed that CA3-AS1 upregulated the expression level of BTG3 and inhibited the gastric cancer cells invasion by sponging miR-93-5p. Finally, we found that CA3-AS1 inhibited the metastasis ability of gastric cancer cells in vivo. Above results suggested that CA3-AS1 acted as anti-oncogene in gastric cancer and might become a vital target for clinical treatment.

LINC00675 Suppresses Cell Proliferation and Migration via Downregulating the H3K4me2 Level at the SPRY4 Promoter in Gastric Cancer

Accumulating evidence indicates that long noncoding RNAs (lncRNAs) are dysregulated in diverse tumors and take a pivotal role in modulating biological processes. In our study, a decreased expression level of LINC00675 in gastric cancer (GC) was first determined by data from The Cancer Genome Atlas (TCGA) and was identified using specimens from GC patients. Then, in vitro and in vivo functional experiments elaborated that LINC00675 could suppress cell proliferation and migration in GC. Multiple differentially expressed genes (DEGs) in LINC00675-overexpressing cells were identified through RNA sequencing analysis. An RNA-binding protein immunoprecipitation (RIP) assay was conducted to reveal that LINC00675 competitively bound with lysine-specific demethylase 1 (LSD1). A coimmunoprecipitation (coIP) assay indicated that LINC00675 overexpression may strengthen the binding of LSD1 and H3K4me2, whereas the chromatin immunoprecipitation (ChIP) assay results verified lower expression of H3K4me2 at the sprouty homolog 4 (SPRY4) promoter region. Together, our research identified that LINC00675 was remarkably downregulated in GC tissues and cells relative to nontumor tissues and cells. LINC00675 could repress GC tumorigenesis and metastasis via competitively binding with LSD1 and intensifying the binding of LSD1 and its target H3K4me2. Importantly, this contributed to attenuated binding of H3K4me2 at the promoter region of oncogene SPRY4 and suppressed SPRY4 transcription, thus suppressing GC cell proliferation and migration.

Retraction of: lncRNA IGF2-AS Promotes Cell Proliferation, Migration, and Invasion of Gastric Cancer by Modulating miR-937/EZH2 Axis by Li et al., Cancer Biother Radiopharm epub 25 May 2020; DOI: 10.1089/cbr.2019.3275.

Cancer Biotherapy & RadiopharmaceuticalsVol. 35, No. 8 RetractionsOpen AccessRetraction of: lncRNA IGF2-AS Promotes Cell Proliferation, Migration, and Invasion of Gastric Cancer by Modulating miR-937/EZH2 Axis by Li et al., Cancer Biother Radiopharm epub 25 May 2020; DOI: 10.1089/cbr.2019.3275This article retracts the following:Retracted: lncRNA IGF2-AS Promotes Cell Proliferation, Migration, and Invasion of Gastric Cancer by Modulating miR-937/EZH2 AxisPublished Online:13 Oct 2020https://doi.org/10.1089/cbr.2019.3275.retractAboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail The article entitled, “lncRNA IGF2-AS Promotes Cell Proliferation, Migration, and Invasion of Gastric Cancer by Modulating miR-937/EZH2 Axis,” by Zizi Li, Zhanyu Li, Zhijuan Zhong, Jianhui Zhou, Shenhao Huang, Wenying Zhou, and Jianfeng Xu (Cancer Biother Radiopharm epub 25 May 2020; Doi: 10.1089/cbr.2019.3275) is being officially retracted from the literature.The Editor-in-Chief of Cancer Biotherapy and Radiopharmaceuticals (CBR) received an email from the corresponding author of the article, Wenying Zhou, on September 7, 2020, indicating:“…this manuscript should no longer be published [because of] information from our superior and also after discussion with my research team, we want to repeat our experiment and then revise the [manuscript]…Our team has a lot of controversy about these results. In order to ensure the quality of the data and not to mislead readers, we decided to [retract] the manuscript. We will be more rigorous in our further study.”The editor requested further information about precisely which data could not be reproduced, to which Dr. Wenying Zhou responded:“…we found that the results of Figure 4B and 4C, Figure 5A and 5B could not be repeated. Our repeated results of Figure 4B and 4C were as follow[s]: compared with miR-NC group, there was no significant decrease of the luciferase activity in miR-937 group when cells co-transfected with EZH2 3′-UTR-WT.Our repeated results of Figure 5A and 5B were as follow[s]: miR-937 inhibited the proliferation of MNK-28 and SGC-7901 cells, but the cell proliferation had no significant change in miR-937+EZH2 group compared with miR-937+pcDNA group.These findings resulted in the uncertainty of the targeted relationship between miR-937 and EZH2. We also repeated these experiments in different environments, but they all contradict the results in the original data. So, the conclusion is very controversial. In a responsible attitude to the readers, we decide to [retract] the manuscript.”The authors have extended their apologies to the Editor and to the readers of CBR.Though in the author's original email, the request was made to “withdraw” the paper, CBR has decided to fully retract it due to irreproducible data, as the journal is committed to preserving the scientific literature and the community it serves.FiguresReferencesRelatedDetailsCited ByLINC00514 promotes gastric cancer cell growth and EMT progression via miR-204-3p/KRAS22 April 2021 | Aging, Vol. 13, No. 8Related articlesRetracted: lncRNA IGF2-AS Promotes Cell Proliferation, Migration, and Invasion of Gastric Cancer by Modulating miR-937/EZH2 Axis23 May 2020Cancer Biotherapy & Radiopharmaceuticals Volume 35Issue 8Oct 2020 InformationCopyright 2020, Mary Ann Liebert, Inc., publishersTo cite this article:Cancer Biotherapy and Radiopharmaceuticals.Oct 2020.628-628.http://doi.org/10.1089/cbr.2019.3275.retractPublished in Volume: 35 Issue 8: October 13, 2020PDF download

E2F1-induced upregulation of lncRNA HCG18 stimulates proliferation and migration in gastric cancer by binding to miR-197-3p.

LncRNA HCG18 is considered to be an oncogene in many types of tumors. The aim of this study was to explore the role of lncRNA HCG18 in gastric cancer (GC). HCG18 levels in GC tissues were detected. Potential biological influences of HCG18 on GC cell phenotypes were examined by Cell Counting Kit-8 (CCK-8), wound healing and transwell assay. Subsequently, bioinformatics analysis, Chromatin immunoprecipitation (ChIP), Luciferase assay and rescue experiments were conducted to identify the regulatory network of HCG18 in GC. It was found that HCG18 was upregulated in GC samples, and the knockdown of HCG18 inhibited proliferative and migratory abilities in GC. The transcription factor E2F1 could directly bind to the promoter region of HCG18 and thus activate its transcription. In addition, HCG18 sponged miR-197-3p to stimulate the malignant development of GC. HCG18 is upregulated in GC samples by E2F1 induction, which stimulates proliferative and migratory abilities in GC by binding to miR-197-3p.