Potential Therapeutic Target For Gastric Cancer Research Articles

Pyrroline-5-carboxylate reductase 1 (PYCR1) upregulation contributes to gastric cancer progression and indicates poor survival outcome.

BackgroundProline levels are significantly increased in tumor specimens and urine samples from gastric cancer (GC) patients, and we previously showed that intracellular proline levels significantly differ between human GC cell lines and normal gastric epithelial cells. Pyrroline-5-carboxylate reductase 1 (PYCR1) is the key enzyme in intracellular proline synthesis, but its role in GC remains largely unknown.MethodsBioinformatic analysis and immunohistochemical (IHC) staining with a tissue microarray were conducted to assess the association between PYCR1 expression and clinical parameters. PYCR1 downregulation and overexpression were then established in two GC cell lines (AGS and MKN28 cells) to determine whether PYCR1 promotes malignant behavior in GC. Gene set enrichment analysis (GSEA) was further performed to investigate the pathway regulating PYCR1 in GC.ResultsPYCR1 expression was up-regulated in different GC cohorts. High PYCR1 protein expression was correlated with advanced tumor stage, aggressive histological type and high Ki-67 index. High PYCR1 expression in GC tissues was an indicator of poor outcome in GC patients. In vitro, PYCR1 knockdown markedly attenuated GC cells growth and promoted apoptosis, while overexpression produced the opposite effects. GSEA analysis indicated PI3K/Akt axis was strongly correlated with PYCR1 expression and that PIK3CB and AKT1 mRNA expression was positively associated with PYCR1 in GC tissues. PI3K inhibition further significantly reduced PYCR1 mRNA and protein expression. Moreover, as PYCR1 is a mitochondrial endomembrane protein, nutrient stress induced by glucose deprivation also regulated PYCR1 expression.ConclusionsPYCR1 is highly expressed in GC and acts as a mitochondrial oncogene to induce cancer progression by enhancing tumor proliferation and responding to metabolic stress. PYCR1 is a novel prognostic marker and a potential therapeutic target in GC.

PKMYT1 Promotes Gastric Cancer Cell Proliferation and Apoptosis Resistance.

BackgroundAbnormal expression of protein kinase membrane associated tyrosine/threonine 1 (PKMYT1) is closely associated with multiple types of cancers. In the present study, we examined the roles of PKMYT1 in gastric cancer (GC) progression.MethodsWe examined the expression status of PKMYT1 in GC tissues and cell lines. Meanwhile, short hairpin RNA (shRNA) was used to inhibit the endogenous expression of PKMYT1 in GC cells. Then we analyzed the effect of PKMYT1 on the malignant biological behavior of GC cells by in vitro and in vivo experiments.ResultsThe findings showed high PKMYT1 expressions in GC tissues as well as a positive correlation between PKMYT1 expression and prognosis of patients with GC. Additional findings also revealed that PKMYT1 silencing significantly enhanced apoptosis and inhibited GC cell proliferation. In vivo, the silence of PKMYT1 inhibits tumor growth. Further analysis showed that the increase in PKMYT1 expressions led to malignant biological behavior through activation of the MAPK signaling pathway.ConclusionOur data suggested that PKMYT1 promotes cell proliferation and apoptosis resistance in GC cells by activating the MAPK signaling pathway, making it a potential therapeutic target for GC.

Functional roles of E3 ubiquitin ligases in gastric cancer.

To date, >650 E3 ubiquitin ligases have been described in humans, including >600 really interesting new genes (RINGs), 28 homologous to E6-associated protein C-terminus (HECTs) and several RING-in-between-RINGs. They are considered key regulators and therapeutic targets of many types of human cancers, including gastric cancer (GC). Among them, some RING and HECT E3 ligases are closely related to the proliferation, infiltration and prognosis of GC. During the past few years, abnormal expressions and functions of many E3 ligases have been identified in GC. However, the functional roles of E3 ligases in GC have not been fully elucidated. The present article focuses on the functional roles of E3 ligases related to the proteasome in GC. In this comprehensive review, the latest research progress on E3 ligases involved in GC and elaborate their structure, classification, functional roles and therapeutic value in GC was summarized. Finally, 30 E3 ligases that serve essential roles in regulating the development of GC were described. Some of these ligases may serve as oncogenes or tumor suppressors in GC, whereas the pathological mechanism of others needs further study; for example, constitutive photomorphogenic 1. In conclusion, the present review demonstrated that E3 ligases are crucial tumor regulatory factors and potential therapeutic targets in GC. Therefore, more studies should focus on the therapeutic targeting of E3 ligases in GC.

Carbonic anhydrase IV inhibits cell proliferation in gastric cancer by regulating the cell cycle.

Carbonic anhydrase IV (CA4) is silenced in colorectal cancer. However, the effect of CA4 on the development of gastric cancer (GC) is poorly understood. The present study aimed to determine the role of CA4 in GC tumorigenesis and its underlying molecular mechanism. The levels of CA4 in GC cells and tissues were evaluated by reverse transcription-quantitative PCR and immunohistochemistry. CA4 expression was suppressed in GC cells and tissues compared with adjacent healthy tissues and normal human gastric epithelial cells, respectively. This reduced expression was significantly associated with tumor size, invasion and differentiation. Analyses with a real-time cell analyzer and clonogenic assays were conducted to validate the impact of CA4 on GC cell lines (AGS and HGC-27) and normal human gastric epithelial cell line (GES-1) proliferation. The effects of CA4 on the cell cycle in GC cells were determined by flow cytometry. The levels of CA4 and cell cycle-associated proteins were confirmed by western blotting. CA4 overexpression inhibited GC cell proliferation and reduced colony-forming ability, arrested the cell cycle in the G2/M phase, inhibited cyclin B1 and cyclin-dependent kinase 2 expression and induced p21 expression. These results indicate that CA4 may serve an important role in GC tumorigenesis by inhibiting cellular proliferation via regulating the expression of cell cycle-associated proteins. CA4 may serve as a diagnostic biomarker and a potential therapeutic target in GC.

ONECUT2 Accelerates Tumor Proliferation Through Activating ROCK1 Expression in Gastric Cancer.

BackgroundTranscription factors (TFs) are key regulators which control gene expression during cancer initiation and progression. In the current study, we aimed to explore the proliferative function and clinical significance of TFs in gastric cancer (GC).MethodsDifferential analysis was used to investigate the overall expression difference between normal and tumor tissues of each TF in TCGA-STAD cohort. The quantitative real-time polymerase chain reaction (qRT-PCR) was performed to confirm the mRNA expression of one cut homeobox 2 (ONECUT2) in GC tissues. Western blot analysis was conducted to confirm the protein knockdown efficiency. Cell counting, colony formation, and GC xenograft model assays were performed to confirm the proliferative function of ONECUT2 in GC cells. Gene set enrichment analysis (GESA) and qRT-PCR were conducted to confirm the affected signaling pathways and downstream targets of ONECUT2.ResultsOur data indicated that a TF named ONECUT2 was highly expressed in GC and correlated with patients’ poor prognosis. Importantly, knockdown of ONECUT2 dramatically decreased GC cells proliferation, whereas overexpression of ONECUT2 promoted carcinogenesis in GC. Kyoto encyclopedia of genes and genomes (KEGG) analysis revealed that the upregulating ONECUT2 induced the activation of Wnt signaling pathway and cell cycle regulation pathway. We further identified that ONECUT2 boosted gastric cancer cell proliferation through enhancing ROCK1 (Rho associated coiled-coil containing protein kinase 1) mRNA expression. High level of ROCK1 expression rescued proliferative behavior of ONECUT2-deficient GC cells.ConclusionOur findings demonstrated that ONECUT2 promoted GC cells proliferation through activating ROCK1 expression at the DNA level, suggesting that ONECUT2-ROCK1 axis might be a potential therapeutic target in GC.

Cathepsin L promotes angiogenesis by regulating the CDP/Cux/VEGF-D pathway in human gastric cancer

BackgroundIncreasing evidence indicates that angiogenesis plays an important role in tumor progression. The function of cathepsin L (CTSL), an endosomal proteolytic enzyme, in promoting tumor metastasis is well recognized. The mechanisms by which CTSL has promoted the angiogenesis of gastric cancer (GC), however, remains unclear.MethodsThe nuclear expression levels of CTSL were assessed in GC samples. The effects of CTSL on GC angiogenesis were determined by endothelial tube formation analysis, HUVEC migration assay, and chick embryo chorioallantoic membrane (CAM) assay. The involvement of the CDP/Cux/VEGF-D pathway was analyzed by angiogenesis antibody array, Western blot, co-immunoprecipitation (Co-IP) and dual-luciferase reporter assay.ResultsIn this study, we found that the nuclear CTSL expression level in GC was significantly higher than that in adjacent nontumor gastric tissues and was a potential important clinical prognostic factor. Loss- and gain-of-function assays indicated that CTSL promotes the tubular formation and migration of HUVEC cells in vitro. The CAM assay also showed that CTSL promotes angiogenesis of GC in vivo. Mechanistic analysis demonstrated that CTSL can proteolytically process CDP/Cux and produce the physiologically relevant p110 isoform, which stably binds to VEGF-D and promotes the transcription of VEGF-D, thus contributing to the angiogenesis of GC.ConclusionThe findings of the present study suggested that CTSL plays a constructive role in the regulation of angiogenesis in human GC and could be a potential therapeutic target for GC.

The CCDC43-ADRM1 axis regulated by YY1, promotes proliferation and metastasis of gastric cancer.

Previous studies have shown an association between coiled-coil domain-containing (CCDC) genes and different cancers. Our previous studies revealed that CCDC43 is highly expressed in colorectal cancer, but the expression and molecular mechanisms of CCDC43 in gastric cancer (GC) are yet to be determined. Here, we show that CCDC43 is overexpressed in gastric tissues. CCDC43 expression is closely related to tumor differentiation, lymph-node-metastasis, and prognosis of gastric cancer. Overexpression of CCDC43 promotes the proliferation, invasion, and metastasis of GC cells. CCDC43 may upregulate and stabilize ADRM1, resulting in the construction of the ubiquitin-mediated proteasome. In contrast, inhibition of ADRM1 could reverse the function of CCDC43 in GC both in vitro and in vivo. Our data demonstrate that transcription factor YY1 directly binds to CCDC43 and ADRM1 gene promoters, leading to over-expression of CCDC43 and ADRM1. Furthermore, in vitro experiments demonstrate that knock down of CCDC43 or ADRM1 attenuates the YY1-mediated malignant phenotypes. Finally, the association among YY1, CCDC43 and ADRM1 is validated in clinical samples. Our findings suggest that the CCDC43-ADRM1 axis regulated by YY1, promotes proliferation and metastasis of GC, and the axis may be a potential therapeutic target for GC.

Effects of miR-330-3p on Invasion, Migration and EMT of Gastric Cancer Cells by Targeting PRRX1-Mediated Wnt/β-Catenin Signaling Pathway.

BackgroundmiRNA, as a biological marker, had more and more attention in recent years due to the important role it plays in cancer. Currently, there are extensive studies on miRNAs, among which miR-330-3p is reported to be implicated in the pathophysiological processes of various cancers. However, little progress has been made in the mechanism of miR-330-3p in gastric cancer.ObjectiveTo explore the expression and relevant mechanism of miR-330-3p and PRRX1 in gastric cancer (GC).MethodsForty-five GC patients (study group), from whom paired GC and paracancerous tissues were collected, and another 45 healthy subjects (control group) who underwent physical examination during the same period were enrolled. In addition, GC cells and human gastric mucosa cells were purchased, and miR-330-3p-mimics, miR-330-3p-inhibitor, miR-NC, si-PRRX1, and sh-PRRX1 were transfected into MKN45, SGC7901 cell. QRT-PCR was employed to assess the miR-330-3p and PRRX1 expressions in the samples, and the cell expressions of PRRX1, GSK-3β, p-GSK-3β, β-catenin, p-β-catenin, cyclin D1, N-cadherin, E-cadherin and vimentin were evaluated by Western blot (WB). MTT, Transwell and wound-healing experiments were adopted to detect cell proliferation, invasion and migration.ResultsMiR-330-3p was under-expressed, while PRRX1 was highly expressed in the serum of patients, both of which had an area under the curve (AUC) of more than 0.9. MiR-330-3p and PRRX1 were associated with tumor diameter, TNM staging, lymph node metastasis and differentiation of GC patients. Overexpression of miR-330-3p and inhibition of PRRX1 expression could suppress epithelial–mesenchymal transition (EMT), proliferation, invasion and apoptosis of cells. What is more, WB assay showed that overexpressed miR-330-3p and inhibited PRRX1 could inhibit the expression levels of p-GSK-3β, β-catenin, cyclin D1, N-cadherin and vimentin proteins, while elevating GSK-3β, p-β-catenin and E-cadherin protein expressions. Dual-luciferase reporter assay confirmed that there was a targeting relation between miR-330-3p and PRRX1. Furthermore, rescue experiments revealed that the cell proliferation, invasion, migration did not differ significantly between co-transfected miR-330-3p-mimics+sh-PRRX1, miR-330-3p-inhibitor+si-PRRX1 groups of MKN45 and SGC7901 and the miR-NC group (without transfected sequences).ConclusionOverexpressed miR-330-3p can promote cell EMT, proliferation, invasion and apoptosis through inhibiting PRRX1-mediated Wnt/β-catenin signaling pathway, which is expected to be a potential therapeutic target for GC.

KLF5 promotes proliferation in gastric cancer via regulating p21 and CDK4.

This study aims to investigate the expression characteristics of Krüppel-like factor 5 (KLF5) in gastric cancer (GC) and its potential correlation to pathological indexes in GC patients. Molecular mechanisms underlying the regulatory effect of KLF5 on GC progression are explored. KLF5 expressions in GC tissues were analyzed through GEPIA dataset and those collected in our hospital. By analyzing the clinical data of GC patients, the correlation between KLF5 level and pathological characteristics of GC was determined. The regulatory effects of KLF5 on proliferative ability and cell cycle progression of SGC7901 and MGC803 cells were assessed by Cell Counting Kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU) assay, and flow cytometry. The regulation of KLF5 on expression levels of p21 and CDK4 in GC cells was determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) and Western blot. KLF5 was markedly upregulated in GC tissues. KLF5 level was positively correlated to TNM staging, tumor size, and metastasis of GC. Meanwhile, high level of KLF5 predicted poor prognosis in GC patients. The knockdown of KLF5 in SGC7901 and MGC803 cells attenuated proliferative ability and arrested cell cycle in G0/G1 phase. Both mRNA and the protein levels of p21 were upregulated, and CDK4 levels were downregulated in SGC7901 and MGC803 cells transfected with si-KLF5. KLF5 is upregulated in GC and closely linked to pathological characteristics of GC patients. High level of KLF5 indicates poor prognosis of GC. It is believed that KLF5 may be a potential therapeutic target for GC.

MiR-26a-5p Inhibit Gastric Cancer Cell Proliferation and Invasion Through Mediated Wnt5a.

PurposeGastric cancer (GC) is a malignant disease of digestive tract. Clinically, radiation therapy is widely applied in treating GC, while with undesirable outcome due to tumor re-proliferation and recurrence and metastasis after radiation. Therefore, it is crucial to explore potential molecular mechanisms to develop therapeutic strategies. The present study found that miR-26a-5p has low expression in GC patients and could regulate Wnt5a to inhibit tumor growth, which was a potential therapeutic target for GC. To explore the expression and related mechanism of miR-26a-5p and Wnt5a in GC.Patients and MethodsMiR-26a-5p and Wnt5a were extracted from the transcriptome data of GC downloaded from TCGA database for analysis. The expression levels of miR-26a-5p and Wnt5a in patients’ tissues and serum were detected by qRT-PCR, and their correlation with patients’ pathological data and survival was analyzed. In addition, miR-26a-5p and Wnt5a overexpression and inhibition vectors were transfected into cells to observe the effects on the proliferation, invasion and apoptosis of GC cells. The relationship between miR-26a-5p and Wnt5a was analyzed by dual luciferase report.ResultsThe database and clinical samples showed that miR-26a-5p level was low while Wnt5a was high in GC. MiR-26a-5p level decreased in patients with stage III+IV, lymphatic metastasis and tumor ≥3cm, and Wnt5a was contrary to that of the miR-26a-5p, with diagnostic value. Overexpressed miR-26a-5p and inhibited Wnt5a enhanced apoptosis, decreased proliferation and invasion, reduced Bcl-2 and β-catenin proteins, and elevated Caspase 3, E-cadherin and Bax proteins, while inhibited miR-26a-5p and over-expressed Wnt5a showed the opposite results. Dual luciferase report confirmed that miR-26a-5p targeted to regulate Wnt5a, and rescue experiments found that these effects could be counteracted by reducing miR-26a-5p level.ConclusionOverexpressed miR-26a-5p can inhibit Wnt5a expression, promote cell apoptosis, and suppress cell proliferation and invasion in GC.

HOXD9 Activates the TGF-β/Smad Signaling Pathway to Promote Gastric Cancer.

BackgroundGastric cancer (GC) is the most common malignant tumor of the digestive tract and its molecular mechanism is not clear. HOXD9 plays an important role in tumor progression as transcription factor. In the current study, we explored the role of HOXD9 in GC.MethodsWe predicted the expression and potential mechanism of HOXD9 in GC through an online database. The expression of HOXD9 was detected in GC and adjacent tissues, and then we analyzed the relationship between HOXD9 and the prognosis of patients with GC. In vitro, we investigated the effects of HOXD9 on malignant biological behaviors such as proliferation, migration, and invasion of the GC cell line MCG-803. In addition, we have initially studied the underlying mechanism by Western blot.ResultsHigh expression of HOXD9 in GC was predicted by online database prediction and implied poor prognosis. In the clinical sample, we confirmed the above predictions. In vitro, we found that knockdown of HOXD9 could effectively inhibit the proliferation, migration, and invasion of GC cells. In terms of mechanism, HOXD9 may activate the TGF-β/Smad signaling pathway.ConclusionHOXD9 promotes the malignant biological process of GC, which may be a potential therapeutic target for GC.

MicroRNA-4316 inhibits gastric cancer proliferation and migration via directly targeting VEGF-A

Background and aimsmicroRNAs (miRNAs) have been reported to regulate proliferation and migration by down-regulating the expression of target genes. The aims of this study were to investigate whether miR-4316 inhibited proliferation and migration by downregulating vascular endothelial growth factor A (VEGF-A) and its clinical significance in gastric cancer (GC).MethodsThe clinical tissues of the GC patients for miR-4316 and VEGF-A were detected by qRT-PCR. The protein levels of VEGF-A and c-Met were determined by western blotting. Cell Proliferation, migration, and colony forming assays were conducted to show whether miR-4316 affects proliferation by CCK-8, migration by transwell, wound healing and colony formation assays. The bioinformatic methods and luciferase reporter assay were applied to detect the relationship between miRNA and VEGF-A on its targeting 3-untranslated regions (3-UTRs). CCK-8, colony formation, wound healing, and transwell assay were performed to explore the function of miR-4316.ResultsThe results of qRT-PCR indicated that miR-4316 expression level was significantly downregulated in human GC tissues and GC cell lines compared with their control. miR-4316 inhibited proliferation, migration and colony formation in GC cell lines by reducing VEGF-A. And western blot results indicated that miR-4316 significantly inhibited GC through repressing VEGF-A and c-Met. The investigation of Luciferase assay indicated that VEGF-A is a direct target gene of miR-4316.ConclusionsmiR-4316 suppressed proliferation and migration of GC through the VEGF-A gene. MiR-4316 acts as a tumor suppressor by targeting VEGF-A and this indicated that MiR-4316 might be a potential therapeutic target for GC.

Identification of potential key genes in gastric cancer using bioinformatics analysis.

Gastric cancer (GC) is one of the most common types of cancer worldwide. Patients must be identified at an early stage of tumor progression for treatment to be effective. The aim of the present study was to identify potential biomarkers with diagnostic value in patients with GC. To examine potential therapeutic targets for GC, four Gene Expression Omnibus (GEO) datasets were downloaded and screened for differentially expressed genes (DEGs). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were subsequently performed to study the function and pathway enrichment of the identified DEGs. A protein-protein interaction (PPI) network was constructed. The CytoHubba plugin of Cytoscape was used to calculate the degree of connectivity of proteins in the PPI network, and the two genes with the highest degree of connectivity were selected for further analysis. Additionally, the two DEGs with the largest and smallest log Fold Change values were selected. These six key genes were further examined using Oncomine and the Kaplan-Meier plotter platform. A total of 99 upregulated and 172 downregulated genes common to all four GEO datasets were screened. The DEGs were primarily enriched in the Biological Process terms: ‘extracellular matrix organization’, ‘collagen catabolic process’ and ‘cell adhesion’. These three KEGG pathways were significantly enriched in the categories: ‘ECM-receptor interaction’, ‘protein digestion and absorption’, and ‘focal adhesion’. Based on Oncomine, expression of ATP4A and ATP4B were downregulated in GC, whereas expression of the other genes were all upregulated. The Kaplan-Meier plotter platform confirmed that upregulated expression of the identified key genes was significantly associated with worse overall survival of patients with GC. The results of the present study suggest that FN1, COL1A1, INHBA and CST1 may be potential biomarkers and therapeutic targets for GC. Additional studies are required to explore the potential value of ATP4A and ATP4B in the treatment of GC.

Anthrax toxin receptor 1/tumor endothelial marker 8 promotes gastric cancer progression through activation of the PI3K/AKT/mTOR signaling pathway.

Anthrax toxin receptor 1 (ANTXR1), a type I transmembrane protein, is one of the receptors that facilitates the entrance of anthrax toxin into cells. Previous studies have confirmed the pivotal role of ANTXR1 in progression and tumorigenesis of diverse cancer types. However, the biological function of ANTXR1 in gastric cancer (GC) is still unknown. The present study aimed to investigate the role of ANTXR1 in GC and illuminate the potential molecular mechanisms. Bioinformatics analysis found that ANTXR1 expression was significantly upregulated in GC tissue and its overexpression was associated with poor prognosis of GC patients. Moreover, we confirmed the upregulation of ANTXR1 in GC cell lines and GC tissue by quantitative PCR, western blot analysis, and immunohistochemical analysis. Additionally, high protein expression level of ANTXR1 was positively associated with several clinicopathological parameters in GC patients. In our study, a series of in vitro and in vivo assays were undertaken through strategies of loss/gain‐of‐function and rescue assays. Consequently, our results indicated that ANTXR1 induced proliferation, cell cycle progression, invasion and migration, and tumorigenicity and induced suppressed apoptosis in GC. Mechanistic investigation indicated that ANTXR1 exerted its promoting effects on GC through activation of the PI3K/AKT/mTOR signaling pathway. In conclusion, our findings suggested that ANTXR1 plays a crucial role in the development and progression of GC and could serve as a novel prognostic biomarker and potential therapeutic target for GC.

Overexpression of the human cytomegalovirus UL111A is correlated with favorable survival of patients with gastric cancer and changes T-cell infiltration and suppresses carcinogenesis

PurposeWe previously found that human cytomegalovirus (HCMV) infection is associated with gastric cancer (GC) development. UL111A plays a role during HCMV productive or latent infection. However, UL111A expression profiles in GC tissues and their relationship with this disease are unknown.MethodsPCR and nested RT-PCR were performed to verify UL111A expression in 71 GC tissues and its transcripts in 16 UL111A-positive GC samples. UL111A expression levels in GC patients were evaluated by immunohistochemistry on a tissue microarray for 620 GC patients. The correlations among UL111A expression levels, clinicopathological characteristics, and prognosis were analyzed. Further, the effects of overexpression of latency-associated viral interleukin-10 (LAcmvIL-10) and cmvIL-10 on GC cell proliferation, colony formation, migration, and invasion were assessed.ResultsThe UL111A detection rate in GC tissues was 32.4% (23/71) and that of its mRNA expression was 68.75% (11/16). High expression of UL111A was also related to better overall and disease-free survival in GC patients. GC patients with TNM II/III stage expressing higher UL111A levels might benefit from adjuvant chemotherapy (ACT) after surgery. Moreover, high UL111A expression was also associated with increased CD4+ , CD8+ T-lymphocyte and Foxp3+ T-cell infiltration. In vitro assays further demonstrated that LAcmvIL-10 and cmvIL-10 overexpression inhibits GC cell line proliferation, colony formation, migration, and invasion.ConclusionsHigh UL111A expression changes the number of infiltrating T cells and is associated with favorable survival. Therefore, UL111A could be used as an independent prognostic biomarker and might be a potential therapeutic target for GC.

PLXNC1 Enhances Carcinogenesis Through Transcriptional Activation of IL6ST in Gastric Cancer.

Background: Transcriptional factors (TFs) are responsible for orchestrating gene transcription during cancer progression. However, their roles in gastric cancer (GC) remain unclear.Methods: We analyzed the differential expressions of TFs and, using GC cells and tissues, investigated plexin C1 (PLXNC1) RNA levels, as well as PLXNC1's clinical relevance and functional mechanisms. The molecular function of PLXNC1 was evaluated in vitro and in vivo. Kaplan-Meier curves and the log-rank test were used to analyze overall survival (OS) and disease-free survival (DFS).Results: PLXNC1 was frequently up-regulated in GC and associated with poor prognosis. The expression level of PLXNC1 could serve as an independent biomarker to predict a patient's overall survival. Notably, knockdown of PLXNC1 significantly abolished GC cell proliferation, and migration, and overexpression of PLXNC1 accelerated carcinogenesis in GC. The gene set enrichment analysis (GSEA) indicated that high-expression of PLXNC1 was positively correlated with the activation of epithelial-mesenchymal transition (EMT), TNF-α, and IL-6/STAT3 signaling pathways. PLXNC1 promoted proliferation and migration of GC cells through transcriptional activation of the interleukin 6 signal transducer (IL6ST), which could rescue the malignant behavior of PLXNC1-deficient GC cells.Conclusions: Our study demonstrated that the PLXNC1 plays an oncogenic role in GC patients. The PLXNC1-IL6ST axis represents a novel potential therapeutic target for GC.

Long Noncoding RNA AFAP1-AS1 Promotes Cell Proliferation and Metastasis via the miR-155-5p/FGF7 Axis and Predicts Poor Prognosis in Gastric Cancer.

Background Actin filament-associated protein 1-antisense RNA 1 (AFAP1-AS1) plays an important role in the development and progression of several human cancers. However, its biological function in gastric cancer (GC) progression is still unknown. Methods We used qRT-PCR to detect the relative expression of AFAP1-AS1 in GC tissues and cell lines. The loss-of-function assays were conducted to detect the effect of AFAP1-AS1 on GC development. Bioinformatics analysis, luciferase reporter gene analysis, and RIP analysis were used to identify and validate target genes of AFAP1-AS1. Finally, rescue tests were performed to confirm the influence of the AFAP1-AS1-miR-155-5p-FGF7 axis on GC development. Results AFAP1-AS1 was upregulated in GC tissues and cell lines and was closely correlated with poor prognosis of GC patients. AFAP1-AS1 knockdown inhibited proliferation, migration, and invasion of GC cells, indicating that AFAP1-AS1 acts as an oncogene in GC. Bioinformatics analysis, dual-luciferase reporter gene detection, and RIP assays validated that AFAP1-AS1 directly interacts to miR-155-5p and could positively affect cell proliferation, migration, and invasion by regulation of the expression of miR-155-5p and FGF7. Further rescue assays revealed that AFAP1-AS1 promotes cell proliferation and metastasis through the miR-155-5p/FGF7 axis in GC. Conclusions AFAP1-AS1 might be an oncogenic lncRNA that promoted GC progression by acting as a competing endogenous RNA (ceRNA) that regulates the expression of FGF7 through sponging miR-155-5p, suggesting that AFAP1-AS1 may be a novel potential therapeutic target for GC.

Prognostic significance of artemin in gastric cancer and its role in tumorigenesis.

BackgroundAbundant evidence suggests that a neurotrophic factor, artemin (ARTN), is involved in the tumorigenesis and progression in several malignancies. However, the biological functions of ARTN in gastric cancer (GC) remain poorly elucidated.MethodsARTN expression was evaluated by immunohistochemistry in GC tissue, and its clinical and prognosis significance was analyzed. Cell counting kit-8 (CCK-8), transwell chamber assay, and western blot were used to detect the effects of ARTN knockdown on GC cell behavior in vitro.ResultsARTN was highly expressed in GC tissue, and its positive expression predicted poor prognosis of GC. In vitro studies showed that ARTN knockdown inhibited the STAT3 phosphorylation, thus impeding cell proliferation and DNA synthesis in GC. Furthermore, the promotion of ARTN on the migration and invasion of GC cells was achieved by regulating the expression of MMP9 and E-cadherin.ConclusionsARTN might be a promising prognostic marker and a potential therapeutic target for GC.

FOXM1 functions collaboratively with PLAU to promote gastric cancer progression.

Background: Gastric cancer (GC) is one of the main mortality cause worldwide. Previously, we found Forkhead box protein (FOXM1) or Urokinase-type plasminogen activator (PLAU) are independent prognostic markers of GC. This study aims to explore the combining prognostic efficacy and the potential insights underlying additive effect of FOXM1 to PLAU in GC progression through in-silico analyses.Method: The expression of FOXM1 and PLAU were profiled in 33 cancer types using public data. A merged GC expression dataset containing 598 samples was used for evaluating prognostic significance of FOXM1/PLAU. Gene Set Enrichment Analysis (GSEA) was performed to elucidate the mechanisms underlying FOXM1/PLAU promoted GC progression. The Cancer Genome Atlas (TCGA) was used for analyzing the association between FOXM1/PLAU and tumor immune infiltration. Genomic and proteomic differences between FOXM1+PLAU+ and FOXM1-PLAU- groups were also computed using TCGA GC data. Drugs targeting FOXM1/PLAU associated gene expression pattern was analyzed using LINCs database.Results: FOXM1 and PLAU are overexpressed in 17/33 cancer types including GC. Kaplan-Meier analyses indicate that the FOXM1+PLAU+ subgroup have the worst prognosis, while FOXM1-PLAU- subgroup have the best survival. Bioinformatics analysis indicated that FOXM1+PLAU+ associated genes are enriched in TGF-beta, DNA repair and drug resistance signaling pathways; FOXM1 and PLAU expression are negatively correlated with tumor immune infiltration. Genomic and proteomic differences between FOXM1+PLAU+ and FOXM1-PLAU- groups were presented. Data mining from LINCs suggested several chemicals or drugs that could target the gene expression pattern of FOXM1+PLAU+ patients.Conclusion: FOXM1+PLAU+ can serve as effective prognostic biomarkers and potential therapeutic targets for GC. Due to the additive effect of these two genes, screening for drugs or chemicals that targeting the expression patterns PLAU+FOXM1+ subgroup may exert important clinical impact on GC management.

LncRNA FEZF1-AS1 Modulates Cancer Stem Cell Properties of Human Gastric Cancer Through miR-363-3p/HMGA2

Gastric cancer (GC) is a leading cause of cancer-related death with poor prognosis. Growing evidence has shown that long noncoding ribonucleic acid (lncRNA) FEZ family zinc finger 1 antisense RNA 1(FEZF1-AS1), an “oncogene,” regulates tumor progression and supports cancer stem cell. However, the tumorigenic mechanism of FEZF1-AS1 on gastric cancer stem cell (GCSC) is yet to be investigated. Here, we discovered that FEZF1-AS1 was upregulated in GC tissues and cell lines. Knockdown of FEZF1-AS1 inhibited sphere formation and decreased expression of stem factors and markers. Moreover, FEZF1-AS1 silence also suppressed cell proliferation, viability, invasion, and migration of GCSCs. MiR-363-3p is used as a target of FEZF1-AS1, because its expression was suppressed by FEZF1-AS1 in GCSCs. FEZF1-AS1 could sponge miR-363-3p and increased the expression of high-mobility group AT-hook 2 (HMGA2). The expression of FEZF1-AS1 and miR-363-3p, as well as that of miR-363-3p and HMGA2, was negatively correlated in GC tissues. Finally, FEZF1-AS1 contributed to promotion of GCSCs progression partially through inhibition of miR-363-3p. Subcutaneous xenotransplanted tumor model revealed that silence of FEZF1-AS1 suppressed in vivo tumorigenic ability of GSCS via downregulation of HMGA2. In general, our findings clarified the critical regulatory role of FEZF1-AS1/miR-363-3p/HMGA2 axis in GCSC progression, providing a potential therapeutic target for GC.