MicroRNA-585 suppresses tumor proliferation and migration in gastric cancer by directly targeting MAPK1

Circ_0082374 Promotes the Tumorigenesis and Suppresses Ferroptosis in Non-small Cell Lung Cancer by Up-Regulating GPX4 Through Sequestering miR-491-5p

Circular RNAs (circRNAs) have been identified to be dysregulated in non-small cell lung cancer (NSCLC) and implicated in the progression of this cancer. Here, this work aimed to investigate the role and mechanism of circ_0082374 on NSCLC progression. Levels of circ_0082374, miR-491-5p, GPX4 (glutathione peroxidase 4) and epithelial-mesenchymal transition (EMT)-related proteins were examined by quantitative real-time PCR or western blotting, respectively. Cell proliferation and metastasis were detected using cell counting kit-8, colony formation, EdU, transwell, and Scratch assays. Cell ferroptosis was evaluated by measuring cell survival after the treatment of different ferroptosis inducers or inhibitors, as well as the accumulation of intracellular reactive oxygen species (ROS), ferrous iron (Fe2+) and malondialdehyde (MDA). The binding between miR-491-5p and circ_0082374 or GPX4 was confirmed using dual-luciferase reporter and RNA pull-down assays. In vivo experiments were conducted using murine xenograft assay and immunohistochemistry. Circ_0082374 was a stable circRNA with high expression in NSCLC tissues and cells. Functionally, circ_0082374 silencing suppressed NSCLC cell proliferation and metastasis. Moreover, its down-regulation enhanced ferroptosis by decreasing iron and lipid peroxidation accumulation. Mechanistically, circ_0082374 could indirectly up-regulate GPX4 expression via miR-491-5p, indicating the circ_0082374/miR-491-5p/GPX4 competitive endogenous RNAs (ceRNA) network. Rescue experiments demonstrated that the miR-491-5p/GPX4 axis mediated the regulatory effects of circ_0082374 exerted on NSCLC cells. Moreover, knockdown of circ_0082374 impeded NSCLC growth and EMT via regulating miR-491-5p and GPX4. Circ_0082374 silencing could suppress NSCLC cell proliferation, metastasis and induce ferroptosis through miR-491-5p/GPX4 axis, suggesting a novel therapeutic approach for NSCLC patients.

MAPK1 promotes the metastasis and invasion of gastric cancer as a bidirectional transcription factor

BACKGROUND

The Mitogen-activated protein kinase 1 (MAPK1) has both independent functions of phosphorylating histones as a kinase and directly binding the promoter regions of genes to regulate gene expression as a transcription factor. Previous studies have identified elevated expression of MAPK1 in human gastric cancer, which is associated with its role as a kinase, facilitating the migration and invasion of gastric cancer cells. However, how MAPK1 binds to its target genes as a transcription factor and whether it modulates related gene expressions in gastric cancer remains unclear.

RESULTS

Here, we integrated biochemical assays (protein interactions and chromatin immunoprecipitation (ChIP)), cellular analysis assays (cell proliferation and migration), RNA sequencing, ChIP sequencing, and clinical analysis to investigate the potential genomic recognition patterns of MAPK1 in a human gastric adenocarcinoma cell-line (AGS) and to uncover its regulatory effect on gastric cancer progression. We confirmed that MAPK1 promotes AGS cells invasion and migration by regulating the target genes in different directions, up-regulating seven target genes (KRT13, KRT6A, KRT81, MYH15, STARD4, SYTL4, and TMEM267) and down-regulating one gene (FGG). Among them, five genes (FGG, MYH15, STARD4, SYTL4, and TMEM267) were first associated with cancer procession, while the other three (KRT81, KRT6A, and KRT13) have previously been confirmed to be related to cancer metastasis and migration.

CONCLUSION

Our data showed that MAPK1 can bind to the promoter regions of these target genes to control their transcription as a bidirectional transcription factor, promoting AGS cell motility and invasion. Our research has expanded the understanding of the regulatory roles of MAPK1, enriched our knowledge of transcription factors, and provided novel candidates for cancer therapeutics.

MicroRNA-592 Inhibits the Growth of Ovarian Cancer Cells by Targeting ERBB3

Objectives: Ovarian cancer is the most lethal gynecologic malignancy, and targeted therapy for different pathological types and molecular phenotypes is urgent to be studied. Studies have shown that MicroRNA-592 (miR-592) plays an important negative regulatory role in the occurrence of gastrointestinal malignancies, breast cancer, non-small cell lung cancer, and glioma, but the expression of miR-592 in ovarian cancer and the mechanism of action are still unclear. Methods: The expressions of miR-592 were examined by RT-PCR and Western Blot. Cell viability and migratory capacity were detected by CCK-8 and transwell assay. TargetScan (http://www.targetscan.org) was analyzed to predict potential targets of miR-592. Then Dual-luciferase reporter gene assay was performed to verify the targeting relationship between miR-592 and ERBB3. A mouse xenograft model was applied to confirm the effect of miR-592. Results: In our study, we found that the expression of miR-592 is reduced in epithelial ovarian cancer tissues. The exogenous expression of miR-592 inhibits the proliferation, migration, and invasion in epithelial ovarian cancer tumor cells. Furthermore, the exogenous expression of miR-592 inhibits tumor growth in the nude mouse xenograft model. Therefore, miR-592 may play a role of tumor suppressor miRNA in the occurrence and development of ovarian cancer. Further experiments demonstrated that tumor-related ERBB3 is a target gene mediated by miRNA-592. The dual-luciferase reporter system was used to identify miRNA-592 target genes; qPCR and Western Blot were used to detect the expression of ERBB3. Mechanical experiments confirmed that miRNA-592 negatively regulated ERBB3.Conclusion: Together, these findings identify a heretofore unrecognized link between miR-592 and ERBB3 and suggest that targeting on miR-592 warrants attention as a novel and potential therapeutic strategy for ovarian cancer.

MiR-585-5p impedes gastric cancer proliferation and metastasis by orchestrating the interactions among CREB1, MAPK1 and MITF

Background

Gastric cancer (GC) is one of the most malignant and lethal cancers worldwide. Multiple microRNAs (miRNAs) have been identified as key regulators in the progression of GC. However, the underlying pathogenesis that miRNAs govern GC malignancy remains uncertain. Here, we identified a novel miR-585-5p as a key regulator in GC development.

Methods

The expression of miR-585-5p in the context of GC tissue was detected by in situ hybridization for GC tissue microarray and assessed by H-scoring. The gain- and loss-of-function analyses comprised of Cell Counting Kit-8 assay and Transwell invasion and migration assay. The expression of downstream microphthalmia-associated transcription factor (MITF), cyclic AMP-responsive element-binding protein 1 (CREB1) and mitogen-activated protein kinase 1 (MAPK1) were examined by Immunohistochemistry, quantitative real-time PCR and western blot. The direct regulation between miR-585-5p and MITF/CREB1/MAPK1 were predicted by bioinformatic analysis and screened by luciferase reporter assay. The direct transcriptional activation of CREB1 on MITF was verified by luciferase reporter assay, chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assays (EMSAs). The interaction between MAPK1 and MITF was confirmed by co-immunoprecipitation (Co-IP) and immunofluorescent double-labelled staining.

Results

MiR-585-5p is progressively downregulated in GC tissues and low miR-585-5p levels were strongly associated with poor clinical outcomes. Further gain- and loss-of-function analyses showed that miR-585-5p possesses strong anti-proliferative and anti-metastatic capacities in GC. Follow-up studies indicated that miR-585-5p targets the downstream molecules CREB1 and MAPK1 to regulate the transcriptional and post-translational regulation of MITF, respectively, thus controlling its expression and cancer-promoting activity. MiR-585-5p directly and negatively regulates MITF together with CREB1 and MAPK1. According to bioinformatic analysis, promotor reporter gene assays, ChIP and EMSAs, CREB1 binds to the promotor region to enhance transcriptional expression of MITF. Co-IP and immunofluorescent double-labelled staining confirmed interaction between MAPK1 and MITF. Protein immunoprecipitation revealed that MAPK1 enhances MITF activity via phosphorylation (Ser73). MiR-585-5p can not only inhibit MITF expression directly, but also hinder MITF expression and pro-cancerous activity in a CREB1-/MAPK1-dependent manner indirectly.

Conclusions

In conclusion, this study uncovered miR-585-5p impedes gastric cancer proliferation and metastasis by orchestrating the interactions among CREB1, MAPK1 and MITF.

Integration of TE Induces Cancer Specific Alternative Splicing Events

Alternative splicing of messenger RNA (mRNA) precursors contributes to genetic diversity by generating structurally and functionally distinct transcripts. In a disease state, alternative splicing promotes incidence and development of several cancer types through regulation of cancer-related biological processes. Transposable elements (TEs), having the genetic ability to jump to other regions of the genome, can bring about alternative splicing events in cancer. TEs can integrate into the genome, mostly in the intronic regions, and induce cancer-specific alternative splicing by adjusting various mechanisms, such as exonization, providing splicing donor/acceptor sites, alternative regulatory sequences or stop codons, and driving exon disruption or epigenetic regulation. Moreover, TEs can produce microRNAs (miRNAs) that control the proportion of transcripts by repressing translation or stimulating the degradation of transcripts at the post-transcriptional level. Notably, TE insertion creates a cancer-friendly environment by controlling the overall process of gene expression before and after transcription in cancer cells. This review emphasizes the correlative interaction between alternative splicing by TE integration and cancer-associated biological processes, suggesting a macroscopic mechanism controlling alternative splicing by TE insertion in cancer.

CircRNA casein kinase 1 gamma 1 (circ-CSNK1G1) plays carcinogenic effects in thyroid cancer by acting as miR-149-5p sponge and relieving the suppression of miR-149-5p on mitogen-activated protein kinase 1 (MAPK1)

BACKGROUND

The initiation and development of thyroid cancer may be associated with the deregulation of circular RNAs (circRNAs). The purpose of this work was to explore the role of circRNA casein kinase 1 gamma 1 (circ-CSNK1G1) in thyroid cancer.

METHODS

The expression of circ-CSNK1G1, miR-149-5p, and mitogen-activated protein kinase 1 (MAPK1) was concluded using quantitative real-time PCR (qPCR), and the expression of MAPK1 protein was detected by Western blot assay. Cell viability was monitored by CCK-8 assay. Cell proliferation was determined by colony formation assay and EdU assay. Cell apoptosis and cycle were checked by flow cytometry assay. Cell invasion was determined by transwell assay. The predicted binding relationship between miR-149-5p and circ-CSNK1G1 or MAPK1 was verified by dual-luciferase reporter assay. The role of circ-CSNK1G1 in vivo was determined by establishing animal models.

RESULTS

The present work discovered the upregulation of circ-CSNK1G1 in tumor tissues of thyroid cancer. In function, circ-CSNK1G1 knockdown inhibited proliferation, survival, and invasion in cancer cells, and tumor growth in mouse models. MiR-149-5p was a target of circ-CSNK1G1, and the anti-tumor effects of circ-CSNK1G1 knockdown were abolished by miR-149-5p downregulation. In addition, miR-149-5p directly targeted MAPK1, and miR-149-5p restoration-inhibited cell proliferation and invasion were recovered by MAPK1 overexpression.

CONCLUSION

Circ-CSNK1G1 acted as miR-149-5p to relieve the inhibition of miR-149-5p on MAPK1, thus promoting the malignant development of thyroid cancer.

MiR-585-3p suppresses tumor proliferation and migration by directly targeting CAPN9 in high grade serous ovarian cancer

Background

Aberrant expression of microRNAs (miRNAs) contributes to the development of high grade serous ovarian cancer (HGSOC). However, the molecular mechanism by which miRNA-585-3p mediates high-grade serous ovarian carcinogenesis is unclear. This study aims to investigate the specific mechanism of action of miR-585-3p in HGSOC.

Methods

Expression of miR-585-3p in HGSOC tissues and cell lines was detected by qRT-PCR. Cell viability and migration were detected using MTT and transwell system. The expression of target genes and target proteins of miR-585-3p was detected by dual luciferase reporter assay and western blot.

Results

The expression of miR-585-3p was significantly lower in HGSOC tissues and cells than in normal ovarian tissues and cell lines. In HGSOC tissues, CAPN9 expression was inversely correlated with miR-585-3p expression. MiR-585-3p inhibited the proliferation and migration of HGSOC cells. MiR-585-3p bound to the 3'-untranslated region (UTR) of CAPN9 and inhibits CAPN9 expression. Overexpression of CAPN9 reduced the inhibitory effect of miR-585-3p in HGSOC cells.

Conclusions

miR-585-3p is significantly down-regulated in HGSOC tissues and cell lines. MiR-585-3p inhibits the proliferation and migration of HGSOC cells by targeting CAPN9.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00841-w.

Research on correlations of miR-585 expression with progression and prognosis of triple-negative breast cancer

Triple-negative breast cancer is a special type of breast cancer, characterized by younger onset age, shorter survival period, higher malignant degree, higher mortality, recurrence and metastasis. Triple-negative breast cancer is more harmful to women's life and health, compared with other types of breast cancer. This paper mainly studied the role of miR-585 in triple-negative breast cancer. Real-time quantitative PCR was used to detect the expression of miR-585 in triple-negative breast cancer cell lines and tissues. Kaplan-Meier curve and Cox proportional hazards model analysis were used to investigate the prognostic value of miR-585 in triple-negative breast cancer. CCK-8 and Transwell assays were used to detect cell proliferation, invasion and migration. miR-585 was significantly down-regulated in triple-negative breast cancer cells and tissues. The low expression of miR-585 has been shown to be significantly associated with poor prognosis in triple-negative breast cancer patients. Abnormally low expression of miR-585 can promote cell proliferation, migration and invasion. Overall, abnormally low expression of miR-585 is associated with prognosis and progression of triple-negative breast cancer. miR-585 may serve as a prognostic biomarker for patients with triple-negative breast cancer and it is expected to be a new method and strategy for the treatment of triple-negative breast cancer.

MicroRNA-320c inhibits articular chondrocytes proliferation and induces apoptosis by targeting mitogen-activated protein kinase 1 (MAPK1)

AIM

To clarify the interaction of microRNA-320c (miR-320c) and mitogen-activated protein kinase 1 (MAPK1), and to investigate the effects of miR-320c on articular chondroctye proliferation and apoptosis.

METHODS

Lentiviral expression vectors were constructed and dual luciferase assays containing MAPK1 3'-untranslated regions (3'-UTRs) were performed. Small hairpin RNA (shRNA) was utilized to modulate MAPK1 expression. The messenger RNA and protein expression levels were determined by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting respectively. Cell Counting Kit-8 and flow cytometry were conducted to detect the proliferation and apoptosis of Human Chondrocyte-articular (HC-a) cells. Besides that, the influences of miR-320c and MAPK1 on MAPK pathway activation were also evaluated.

RESULTS

Our data identified MAPK1 as a direct target gene of miR-320c, and miR-320c can negatively regulate MAPK1 expression by directly binding to MAPK1 3'-UTR in HC-a cells. Further functional study displayed that miR-320c overexpression and MAPK1 shRNA significantly suppressed the proliferation of HC-a cells and promoted cell apoptosis. Meanwhile, MAPK1 shRNA could attenuate miR-320c inhibitor promotive effects on HC-a cell proliferation and reverse its inhibitory effect on cell apoptosis. MAPK1 overexpression could rescue the inhibitory effect of miR-320c on HC-a cell proliferation, and weaken the accelerating effect of miR-320c on cell apoptosis. However, neither miR-320c or MAPK1 shRNA regulate the expression of c-JUN, JNK and c-Fos.

CONCLUSION

miR-320c inhibits articular chondrocyte proliferation and induces apoptosis by targeting MAPK1, suggesting that miR-320c perhaps participates in the pathogenesis of osteoarthritis and acts as a potential target for the therapeutic treatment of osteoarthritis.

Identification and validation of a miRNA-based prognostic signature for cervical cancer through an integrated bioinformatics approach

Cervical cancer is the fourth most common cancer in women worldwide. Increasing evidence has shown that miRNAs are related to the progression of cervical cancer. However, the mechanisms that affect the prognosis of cancer are still largely unknown. In the present study, we sought to identify miRNAs associated with poor prognosis of patient with cervical cancer, as well as the possible mechanisms regulated by them. The miRNA expression profiles and relevant clinical information of patients with cervical cancer were obtained from The Cancer Genome Atlas (TCGA). The selection of prognostic miRNAs was carried out through an integrated bioinformatics approach. The most effective miRNAs with synergistic and additive effects were selected for validation through in vitro experiments. Three miRNAs (miR-216b-5p, miR-585-5p, and miR-7641) were identified as exhibiting good performance in predicting poor prognosis through additive effects analysis. The functional enrichment analysis suggested that not only pathways traditionally involved in cancer but also immune system pathways might be important in regulating the outcome of the disease. Our findings demonstrated that a synergistic combination of three miRNAs may be associated, through their regulation of specific pathways, with very poor survival rates for patients with cervical cancer.

MicroRNA in Gastric Cancer Development: Mechanisms and Biomarkers

Gastric cancer (GC) is one of the most common and difficult diseases to treat. The study of signaling pathway regulation by microRNA provides information on the mechanisms of GC development and is the basis for biomarker creation. In this study, a circuit of microRNA interactions with signaling pathways was constructed. The microRNAs, associated with metastasis and chemoresistance, are described. In most cases, microRNAs in GC regulate the Wnt/β-catenin, PI3K/AKT/mTOR, RAS/RAF/ERK/MAPK, NF-kB, TGF-β, and JAK/STAT pathways. Part of the microRNA acts on several target genes that function in different pathways. This often leads to an intensification of the induced processes. MicroRNAs have also been described that have the opposite effect on different pathways, causing different functional consequences. By acting on several target genes, or genes associated with several pathways, microRNAs can function in a signaling network. MicroRNAs associated with metastasis most often interact with the Wnt/β-catenin pathway. MicroRNAs affecting chemoresistance, in most cases, affect the regulators of apoptosis and are associated with the PI3K/AKT/mTOR pathway. The characteristics of microRNAs proposed as candidates for GC biomarkers were analyzed. The currently developed diagnostic and prognostic panels of microRNAs are also considered.

MicroRNA-585 inhibits human glioma cell proliferation by directly targeting MDM2

Background

MicroRNAs (miRNAs) are important regulators for cancer cell proliferation. miR-585 has been shown to inhibit the proliferation of several types of cancer, however, little is known about its role in human glioma cells.

Methods

miR-585 levels in human glioma clinical samples and cell lines were examined by quantitative real-time PCR (qRT-PCR) analysis. Cell proliferation was measured by Cell Counting Kit-8 (CCK-8) and EdU incorporation assays in vitro. For in vivo investigations, U251 cells were intracranially inoculated in BALB/c nude mice and xenografted tumors were visualized by magnetic resonance imaging (MRI).

Results

miR-585 expression is downregulated in human glioma tissues and cell lines compared with non-cancerous counterparts. Additionally, miR-585 overexpression inhibits and its knockdown promotes human glioma cell proliferation in vitro. Moreover, miR-585 overexpression also inhibits the growth of glioma xenografts in vivo, suggesting that miR-585 may act as a tumor suppressor to inhibit the proliferation of human glioma. Furthermore, miR-585 directly targets and decreases the expression of oncoprotein murine double minute 2 (MDM2). More importantly, the restoration of MDM2 via enforced overexpression markedly rescues miR-585 inhibitory effect on human glioma cell proliferation, thus demonstrating that targeting MDM2 is a critical mechanism by which miR-585 inhibits human glioma cell proliferation.

Conclusions

Our study unveils the anti-proliferative role of miR-585 in human glioma cells, and also implicates its potential application in clinical therapy.

LncRNA LINC00483 promotes gastric cancer development through regulating MAPK1 expression by sponging miR-490-3p

Background

Previous studies have shown that long noncoding RNA (lncRNA) LINC00483 was aberrantly expressed in human cancers, including gastric cancer. However, the regulatory mechanism of this lncRNA in gastric cancer remains largely unknown. The present study aimed to investigate the effect of LINC00483 on gastric cancer development and explore the potential regulatory network of LINC00483/microRNA (miR)-490-3p/mitogen-activated protein kinase 1 (MAPK1).

Methods

Thirty patients with gastric cancer were recruited for tissues collection. The expression levels of LINC00483, miR-490-3p and MAPK1 were detected by quantitative real-time polymerase chain reaction or western blot. Cell viability, apoptosis, migration and invasion were determined by MTT, flow cytometry, transwell assays and western blot, respectively. The target association between miR-490-3p and LINC00483 or MAPK1 was confirmed by luciferase reporter assay. Xenograft model was established to assess the function of LINC00483 in vivo.

Results

LINC00483 and MAPK1 levels were increased in gastric cancer tissues and cells. Knockdown of LINC00483 or MAPK1 inhibited cells viability, migration and invasion but promoted apoptosis in gastric cancer cells. Moreover, MAPK1 overexpression attenuated the effect of LINC00483 knockdown on gastric cancer development. LINC00483 could increase MAPK1 expression by competitively sponging miR-490-3p. miR-490-3p overexpression suppressed gastric cancer development, which was abated by introduction of LINC00483. Besides, inhibition of LINC00483 decreased xenograft tumor growth by regulating miR-490-3p/MAPK1 axis.

Conclusion

Knockdown of LINC00483 inhibited gastric cancer development in vitro and in vivo by increasing miR-490-3p and decreasing MAPK1, elucidating a novel mechanism for understanding the development of gastric cancer.

Long non-coding RNA GAS6-AS1 acts as a ceRNA for microRNA-585, thereby increasing EIF5A2 expression and facilitating hepatocellular carcinoma oncogenicity

Long non-coding RNA termed GAS6 antisense RNA 1 (GAS6-AS1) plays an essential role in gastric and non-small cell lung cancers. Nonetheless, the function of GAS6-AS1 in hepatocellular carcinoma (HCC) has not been so far studied in detail. In this study, reverse-transcription quantitative PCR was performed to measure GAS6-AS1 expression in HCC samples. A series of functional experiments, including MTT assay, colony formation assay, flow-cytometric analysis, and transwell migration and invasion assays, was performed to determine the influence of GAS6-AS1 knockdown on the malignant phenotype of HCC. The results showed that GAS6-AS1 was significantly upregulated in HCC tissue samples and cell lines. Increased GAS6-AS1 expression was associated with tumor size, Edmondson grade, and Tumor-Node-Metastasis (TNM) stage among patients with HCC. The overall survival of patients with HCC characterized with high expression of GAS6-AS1 was significantly shorter in comparison to that of patients with low level of GAS6-AS1. Functional experiments indicated that knockdown of GAS6-AS1 suppressed HCC cell proliferation, colony formation, migration, and invasion in vitro; promoted apoptosis in vitro; and decreased tumor growth in vivo. Of note, GAS6-AS1 was validated as a competing endogenous RNA (ceRNA) for microRNA-585 (miR-585) and consequently increased the expression of eukaryotic translation initiation factor 5A2 (EIF5A2). Finally, rescue experiments confirmed the association among GAS6-AS1, miR-585, and EIF5A2 in HCC cells. Our study provides substantial evidence that the GAS6-AS1/miR-585/EIF5A2 pathway plays an important role in HCC progression and that might be considered as a potential target for therapeutic approaches in HCC.

Circular RNA circ_0006282 Contributes to the Progression of Gastric Cancer by Sponging miR-155 to Upregulate the Expression of FBXO22

Background

There is increasing evidence that circular RNAs (circRNAs) play an important role in human cancers. As a newly identified human circular RNA, circ_0006282 is abnormally expressed in several types of cancers and promotes the development of cancers. However, the expression and function of circ_0006282 in gastric cancer (GC) remain unclear.

Methods

The expression of circ_0006282 in cancer tissues and adjacent non-cancer tissues was detected by quantitative real-time polymerase chain reaction (qRT-PCR) method, and the relationship between circ_0006282 expression and clinicopathological parameters was analyzed. After knockdown of circ_0006282 by RNA interference in GC cells, CCK-8 assay, colony formation and transwell assays were conducted to examine the effects of circ_0006282 on GC cells. The influence of circ_0006282 on tumor growth in vivo was assessed in a xenograft model. Furthermore, regulatory relationship between circ_0006282, miR-155 and FBXO22 was detected by luciferase assay, qRT-PCR and Western blot.

Results

The expression of circ_0006282 in GC tissues was significantly higher than its adjacent non-cancer tissues and over-expression of circ_0006282 was associated with tumor size, lymph nodes metastasis and TNM stage, but no obvious links with other pathological parameters. Knockdown of circ_0006282 inhibited the proliferation and metastasis ability of GC cells in vitro and suppressed the tumor growth in vivo. Furthermore, mechanistic investigations suggested that circ_0006282 served as a competing endogenous RNA (ceRNA) of miR-155. Moreover, FBXO22 was identified as the functional target of miR-155 and down-expression of circ_0006282 inhibited FBXO22 expression. Rescue assays also demonstrated that the oncogenic function of circ_0006282 is partly attributed to its regulation on miR-155/FBXO22 axis.

Conclusion

Our findings indicated that over-expression of circ_0006282 down‑regulated miR-155 to activate the expression of FBXO22, thus promoting proliferation and metastasis of GC cells, which provides a promising therapeutic target for GC treatment.

LINC01436, regulating miR-585 and FBXO11, is an oncogenic lncRNA in the progression of gastric cancer

Accumulating studies have indicated that long non-coding RNAs (lncRNAs) are crucial modulators in cancer biology. In this work, we investigated the function and related mechanisms of LINC01436 in the progression of gastric cancer (GC). We demonstrated that LINC01436 was significantly up-regulated in cancerous tissues of GC samples, and its overexpression was correlated with a worse prognosis for the patients. In the GC cell line BGC823 cells, LINC01436 knockdown repressed the proliferation and metastasis of cancer cells; conversely, in GC cell line AGS cells, overexpression of LINC01436 showed the opposite effects. We then demonstrated that miR-585, a tumor suppressor, could bind to both LINC01436 and the 3'-UTR of F-box protein 11 (FBOX11), and LINC01436 was proved to sponge miR-585 and repress it, and indirectly promoted the expression of FBOX11. Collectively, these results suggested that LINC01436 was an oncogenic lncRNA in GC and promoted proliferation and metastasis of GC cell via regulating miR-585 and FBOX11.

Identification of the lncRNA-miRNA-mRNA network associated with gastric cancer via integrated bioinformatics analysis

The aim of the present study was to investigate the long non-coding RNA (lncRNA)-microRNA (miRNA)-mRNA regulatory network in gastric cancer (GC) using bioinformatics analysis. Two mRNA gene expression profiles, GSE79973 and GSE54129, and two miRNA expression profiles, GSE93415 and GSE78091, were downloaded from the Gene Expression Omnibus database. The differentially expressed mRNAs (DEMs) and the differentially expressed miRNAs (DEMis) were merged separately. Gene ontology and pathway enrichment analysis were conducted using the Database for Annotation, Visualization and Integrated Discovery. A protein-protein interaction (PPI) network was then constructed and the 10 top hub genes in the network were analyzed using the Search Tool for the Retrieval of Interacting Genes. The lncRNA-miRNA-mRNA networks were visualized using Cytoscape software. As a result, 158 shared DEMs (40 upregulated and 118 downregulated) were identified from two mRNA datasets. A total of 30 upregulated miRNAs and 1 downregulated miRNA functioned as DEMis. The PPI network consisted of 129 nodes and 572 interactions. The 10 top hub genes were selected by degree using Cytohubba, including Jun proto-oncogene, mitogen-activated protein kinase (MAPK)3, transforming growth factor-β1, Fos proto-oncogene, AP-1 transcription factor subunit, interleukin (IL)-8, MAPK1, RELA proto-oncogene nuclear factor-κB subunit, interferon regulatory factor 7, ubiquitin like modifier and vascular endothelial growth factor A. In the lncRNA-miRNA-mRNA network, a total of 1,215 regulatory associations were constructed using Cytoscape. In conclusion, the present study provides a novel perspective of the molecular mechanisms underlying GC by identifying the lncRNA-miRNA-mRNA regulatory network via bioinformatics analysis.

MicroRNA‑4712‑5p promotes proliferation of the vulvar squamous cell carcinoma cell line A431 by targeting PTEN through the AKT/cyclin D1 signaling pathways

The aim of the present study was to screen differentially expressed miRNAs in vulvar squamous cell carcinoma (VSCC), observe the role of microRNA-4712-5p in VSCC and investigate its targets and regulatory mechanism. Differentially expressed miRNAs in human VSCC tissues were screened. microRNA-4712-5p was selected and its expression level was verified in clinical tissue samples and the VSCC cell line A431 by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis. The overexpression vector of microRNA-4712-5p was prepared and transfected into A431 cells; subsequently, cell invasion and metastasis were examined by Cell Counting Kit-8 and Transwell migration assays. Furthermore, the target gene of miRNA-4712-5p was predicted by bioinformatics and verified by The Dual-Luciferase^® Reporter (DLR™) Assay System. The expression of phosphatase and tensin homologue (PTEN) and its downstream proteins, such as protein kinase B (PKB; AKT), glycogen synthase kinase (GSK)3β and cyclin D1, were detected by western blot assays. The expression level of microRNA-4712-5p in VSCC tissues and the A431 cell line was found to be significantly increased, promoting proliferation and invasion of VSCC. The DLR™ assay indicated that PTEN was a target of miR-4712-5p. RT-qPCR revealed that PTEN expression was markedly lower in VSCC tissues compared with that in adjacent tissues. After A431 cells were transfected with the miRNA-4712-5p overexpression vector, phospho-AKT (p-AKT) and cyclin D1 expression were notably increased, but miRNA-4712-5p-targeted PTEN and phospho-GSK3β (p-GSK3β) protein markedly decreased. Therefore, microRNA-4712-5p can reduce the expression of PTEN, further affecting its downstream p-AKT, p-GSK3β and cyclin D1 signaling pathways, promoting the proliferation and invasion of VSCC.

MicroRNA-125a-3p affects smooth muscle cell function in vascular stenosis

AIMS

Many studies have indicated that microRNAs are closely related to the process of peripheral arterial disease (PAD). Previously, we found that microRNA-125a-3p (miR-125a-3p) in restenotic arteries after interventional therapy of lower extremity vessels was notably decreased compared with that of normal control arteries. However, its role in the development of vascular stenosis is not yet clearly understood. The purpose of this study was to investigate the expression, regulatory mechanism and function of miR-125a-3p in the process of vascular stenosis.

METHODS AND RESULTS

Quantitative reverse-transcription polymerase chain reaction assays indicated that miR-125a-3p in restenotic arteries after interventional therapy was significantly lower than that in normal control arteries. Immunofluorescence and in situ hybridization co-staining assays in arterial sections demonstrated that miR-125a-3p was mainly expressed in the medial smooth muscle layer. Transfection of miR-125a-3p mimics into cultured vascular smooth muscle cells (VSMCs) effectively inhibited cell proliferation and migration. Then, western blot and luciferase activity assays showed that recombinant human mitogen-activated protein kinase 1 (MAPK1) was a functional target of miR-125a-3p and was involved in miR-125a-3p-mediated cell effects. Finally, the lentiviral infection of miR-125a-3p in balloon-injured rat carotid vascular walls showed that miR-125a-3p overexpression significantly reduced the probability of neointimal membrane production.

CONCLUSIONS

miR-125a-3p can effectively inhibit the function of VSMCs and the occurrence of vascular stenosis by targeting MAPK1. This study introduces a new molecular mechanism of PAD. We show that regulation of the miR-125a-3p level has the potential to provide a new treatment for PAD and other proliferative vascular diseases.

miR-217 inhibits the migration and invasion of HeLa cells through modulating MAPK1

MicroRNA (miR)-217 serves a pivotal role in the progression of colorectal cancer, renal cell carcinoma and glioma, however, the role of miR-217 in cervical cancer (CC) remains unclear. In the present study, the mechanism of miR-217 in cervical cancer was explored. The mRNA expression of miR-217 and mitogen-activated protein kinase 1 (MAPK1) were assessed using reverse transcription-quantitative polymerase chain reaction analysis. Cell Counting-Kit 8, wound-healing and Transwell assays were performed to detect cell viability, migration and invasion, respectively. Apoptosis and cell cycle were determined by flow cytometry. TargetScan 7.2 and dual-luciferase reporter assays were respectively used to determine miR-217 target genes and their binding capacities. The protein expression levels of MAPK1, phosphorylated (p)-extracellular signal-regulated kinase 1/2 (ERK1/2)/ERK1/2, Bcl-2, Bax and cleaved caspase-3 were quantified by western blotting. It was found that miR-217 was downregulated in patients with CC and in CC cells. The viability, migration and invasion of cells were suppressed by a miR-217 mimic. It was also found that apoptosis was increased and cell cycle was inhibited by the miR-217mimic, which was supported by changes in Bcl-2, Bax and cleaved caspase-3. MAPK1 was upregulated in patients with CC and was a target gene of miR-217. MAPK1 reversed the inhibition of miR-217 on cell viability, migration, invasion and apoptosis. The protein levels of MAPK1 and p-ERK1/2, which were higher in the mimic MAPK1 group than those in the control or mimic groups, were ameliorated by PD98059. The results of the present study demonstrated that miR-217 had an anti-CC effect and may be effectively used in the treatment of CC.

Incorporating molecular biomarkers into clinical practice for gastric cancer

Introduction: Gastric cancer is one of the most common causes of cancer-related mortality worldwide. To improve clinical outcomes, it is critical to develop appropriate approaches to diagnosis and treatment. Biomarkers have numerous potential clinical applications, including screening, assessing risk, determining prognosis, monitoring recurrence, and predicting response to treatment. Furthermore, biomarkers may contribute to the development of effective therapies. Areas covered: Here we review recent progress in exploiting GC-specific biomarkers such as protein-coding genes, microRNAs, long noncoding RNAs, and methylated gene promoters. Expert opinion: The development of biomarkers for diagnosing and monitoring gastric cancer and for individualizing therapeutic targets shows great promise for improving gastric cancer management.

Downregulated miR-585-3p promotes cell growth and proliferation in colon cancer by upregulating PSME3

Background

Upregulation of PSME3 and its oncogenic roles have been reported in colon cancer recently. However, the underlying mechanism of PSME3 upregulation remains unknown. Here, we explored the expression of PSME3 and subsequently uncovered its mechanism in colon cancer.

Materials and methods

The expression of PSME3 was analyzed by using online databases, Oncomine and UALCAN. qPCR was carried out to detect the expression of PSME3 in collected colon cancer tissues and cell lines. Moreover, the promoter methylation and the hnRNA level of PSME3 were also analyzed by online database and qPCR, respectively. The candidate miRNAs targeting PSME3 were predicted by Starbase 3.0 and validated by luciferase reporter system. CCK-8, plate colon formation, and Edu incorporation were applied to study the functions of miRNA in colon cancer. The expression of miRNA and its correlation with PSME3 were detected in colon cancer tissues.

Results

Oncomine and UALCAN data indicate PSME3 is obviously upregulated in colon cancer tissue samples which is further confirmed in collected colon cancer tissues and cells by qPCR. No significant difference in methylation status promoter of PSME3 was observed between colon and colon cancer tissues. The hnRNA level of PSME3 was comparable between colon epithelial cell and colon cancer cells. miR-585-3p is predicted to directly target PSME3 and is validated by luciferase reporter assay. Then, miR-585-3p downregulation is confirmed and miR-585-3p restoration can suppress cell growth and proliferation by inhibiting PSME3 in colon cancer indicating by CCK-8, plate colon formation, and Edu incorporation. Moreover, negative correlation in expression between miR-585-3p and PSME3 was observed in our collected tissues samples.

Conclusion

We reveal for the first time that miR-585-3p downregulation accounts for the overexpression of PSME3 in colon cancer. Moreover, miR-585-3p, serving as a tumor suppressor, can inhibit cell growth and proliferation in colon cancer by targeting PSME3.

Circular RNA hsa_circRNA_102958 promotes tumorigenesis of colorectal cancer via miR-585/CDC25B axis

Purpose: Circular RNAs (circRNAs) are recently identified new noncoding RNAs and play an important role in tumorigenesis. Previous studies have indicated that hsa_circRNA_102958 is a potential diagnostic indicator in gastric cancer. However, its role in colorectal cancer (CRC) is poorly understood.

Methods: qRT-PCR and ISH were used to test gene expression in tissues. Survival rate was analzyed by Kaplan-Meier curve. Luciferase reporter assay was used to determine the interaction between circRNA and miRNA or between miRNA and mRNA. Western blotting was used to test protein expression. CCK8 and colony formation assay was used to analyze proliferation. Transwell assay was used for migration and invasion determination.

Results: In our research, we found that hsa_circRNA_102958 expression was significantly increased in CRC tissues, compared to adjacent normal controls. Increased hsa_circRNA_102958 levels in CRC patients indicated a poor prognosis. The effects of hsa_circRNA_102958 on CRC cell proliferation, migration and invasion were then determined by CCK8, colony formation and Transwell assays. We showed that hsa_circRNA_102958 silencing markedly suppressed CRC growth, migration and invasion. Furthermore, hsa_circRNA_102958 was identified as a sponge for miR-585. We demonstrated that hsa_circRNA_102958 promoted CDC25B expression through inhibiting miR-585 in CRC. Rescue assays illustrated that CDC25B overexpression reversed the suppressive effects of hsa_circRNA_102958 silencing on CRC.

Conclusion: Taken together, our findings revealed the novel oncogenic roles of hsa_circRNA_102958 in CRC through miR-585/CDC25B axis.

Identification of driver genes and key pathways of prolactinoma predicts the therapeutic effect of genipin

The purpose of the present study was to identify the potential targets and markers for diagnosis, therapy and prognosis in patients with prolactinoma at the molecular level and to determine the therapeutic effects of genipin in prolactinoma. The gene expression profiles of GSE2175, GSE26966 and GSE36314 were obtained from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) were identified after comparing between gene expression profiles of the prolactinoma tissues and normal tissues. Then, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and protein‑protein interaction (PPI) network analysis were conducted. In addition, in vitro, scratch assay, colony‑forming assay, Cell Counting Kit 8 (CCK8) assay and flow cytometry were performed to verify the functional effects of genipin. An aggregate of 12,695, 3,847 and 5,310 DEGs were identified from GSE2175, GSE26966 and GSE36314, respectively. The results of GO and KEGG analysis showed that the DEGs significant and important for prolactinoma were mostly involved with 'spindle pole' and 'oocyte meiosis'. A total of 20 genes were selected as hub genes with high degrees after PPI network analysis, including mitogen‑activated protein kinase 1 (MAPK1), MYC, early growth response 1 (EGR1), Bcl2 and calmodulin 1 (CALM1). CCK8 assay, colony‑forming assay and scratch assay were performed to verify the anti‑prolactinoma effect of genipin. The results of flow cytometry showed that apoptosis was increased by genipin. MAPK1, MYC, EGR1, Bcl2 and CALM1 were screened as main hub genes. Genipin upregulated the expression level of EGR1 and p21 (downstream mediator of EGR1) and EGR1, inhibited the proliferation and migration of prolactinoma cells. Genipin is a promising drug for treatment of patients with prolactinoma.

Hsa_circ_0101432 promotes the development of hepatocellular carcinoma (HCC) by adsorbing miR-1258 and miR-622

The present research was major in investigating the regulation association among hsa_circ_0101432 (has_circ_RPPH1), miR-1258, miR-622 and MAPK1 in hepatocellular carcinoma (HCC), and we explored the mechanism underlying pathogenesis of HCC. Microarray analysis was employed to detect hsa_circ_0101432 expression in HCC. Hsa_circ_0101432 was verified as a circRNA by testing divergent primers and RNase R. And qRT-PCR was performed to determine the expression of hsa_circ_0101432, miR-1258, miR-622 and MAPK1 mRNA. Furthermore, miRanda predicted that mRNAs targeted miR-1258 and miR-622. CCK-8 assay, colony formation assay, flow cytometry as well as transwell assay were performed to detect cell viability, proliferation, apoptosis and invasive ability, respectively. Xenograft in nude mice was applied to observe tumor growth in vivo. Up-regulated hsa_circ_0101432 and down-regulated miR-1258 and miR-622 were detected in HCC while Hsa_circ_0101432 enhanced expression of MAPK1 mRNA by targeting miR-1258 and miR-622. Knocking down hsa_circ_0101432 or overexpressing miR-1258 and miR-622 inhibited proliferation and invasive ability of HCC cell and promoted cell apoptosis. Hsa_circ_0101432 was confirmed to promote tumor growth via inhibiting miR-1258 and miR-622 expression and promoting MAPK1 mRNA expression by in vivo experiment. Hsa_circ_0101432 inhibited HCC cell apoptosis, promoted cell proliferation, invasive ability and HCC tumor growth by targeting miR-1258 and miR-622 and upregulating MAPK1 mRNA expression.

miR‑3664‑5P suppresses the proliferation and metastasis of gastric cancer by attenuating the NF‑κB signaling pathway through targeting MTDH

Gastric cancer (GC) is one of the most common and fatal types of cancers worldwide and the specific mechanism has not been completely elucidated. microRNA (miR)‑3664‑5P has rarely been studied and the aim of the present study was to assess an association between miR‑3664‑5P and GC. Differences in miR‑3664‑5P expression in 100 GC (0.1846±0.08276) and paired normal tissues (0.4382±0.1595) were detected using reverse transcription‑quantitative polymerase chain reaction assays (P<0.001). 5‑Ethynyl‑2‑deoxyuridine, Cell Counting Kit‑8, transwell and flow cytometry assays were performed in vitro and the results were further verified using a mouse xenotransplantation and a lung metastasis model in vivo. miR‑3664‑5P was significantly downregulated in GC tissues when compared with normal tissues and positively associated with the prognosis of patients with GC (P<0.001). Overexpression of miR‑3664‑5P suppressed and miR‑3664‑5P knockdown promoted the proliferation and metastasis of GC cells in vitro and in vivo. Following the application of bioinformatic algorithms and luciferase reporter assays, metadherin (MTDH) was confirmed as the target gene of miR‑3664‑5P. miR‑3664‑5P reduced MTDH expression and downregulated the nuclear factor (NF)‑κB signaling pathway. Rescue experiments demonstrated that suppression of MTDH restored the effect of miR‑3664‑5P inhibitors on GC cell lines. The results suggested that miR‑3664‑5P suppressed the proliferation and metastasis of GC cells by attenuating the NF‑κB signaling pathway via MTDH targeting. Consequently, miR‑3664‑5P may have potential to be an independent prognostic factor and biomarker in GC.

MiR-324-5p reduces viability and induces apoptosis in gastric cancer cells through modulating TSPAN8

OBJECTIVES

The purpose of this study was to further clarify the role and underlying mechanism of miR-324-5p in gastric cancer.

METHODS

The expressions of miR-324-5p and TSPAN8 as determined by qRT-PCR or Western blot were compared between the gastric cancer tissues and normal tissues. Human gastric cancer cell line SGC-7901 was cultured and transfected with miR-324-5p mimic/inhibitor or pcDNA-TSPAN8. The cell survival was assessed by the cell viability and apoptosis. Luciferase reporter gene assays were performed to explore the interaction between miR-324-5p and TSPAN8 in SGC-7901 cells.

KEY FINDINGS

MiR-324-5p was decreased in human gastric carcinoma tissues (n = 33), but TSPAN8 protein expression was increased in the gastric carcinoma tissues (n = 33). Moreover, miR-324-5p inhibited the viability and induced the apoptosis of gastric cancer cells in vitro. TSPAN8 is a functional target of miR-324-5p in gastric cancer. MiR-324-5p was further confirmed to reduce gastric cancer cell viability and induce apoptosis via downregulating TSPAN8 in SGC-7901 cells in vitro. Additionally, miR-324-5p overexpression markedly inhibited the tumorigenesis of gastric cancer cells in vivo, as shown by the smaller tumour volume compared with the control.

CONCLUSIONS

This study suggested a novel, probable mechanism of miR-324-5p in gastric cancer context and revealed that miR-324-5p inhibited gastric cancer cell survival by targeting TSPAN8.