MicroRNA 520d-3p inhibits gastric cancer cell proliferation, migration, and invasion by downregulating EphA2 expression

The regulatory role of tRNA-derived small RNAs in the prognosis of gastric cancer

In recent years, tRNA-derived small RNAs (tsRNAs) including tRNA-derived stress-induced RNAs (tiRNAs) and tRNA-derived fragments (tRFs), with specific structure and enriched in body fluids, have been found to have specific biological functions. In this paper, the biogenesis, classification, subcellular localization, and biological functions of tsRNAs were summarized. It has been proved that tsRNAs affected tumor cells in proliferation, apoptosis, migration and invasion, and played roles in regulating the occurrence and development of various tumors. In gastric cancer (GC), the imbalance of tsRNAs, such as tRF-33-P4R8YP9LON4VDP, tRF-17-WS7K092, tRF-23-Q99P9P9NDD and others, was closely related to the clinicopathological characteristics of GC patients. Some tsRNAs, such as tRF-23-Q99P9P9NDD, tRF-31-U5YKFN8DYDZDD, and tRF-27-FDXXE6XRK45 promoted the proliferation, migration and invasion of GC cells. Other tsRNAs, such as tRF-41-YDLBRY73W0K5KKOVD, tRF-18-79MP9PO4, and tRF-Glu-TTC-027 inhibited the proliferation, migration and invasion of GC cells. The tsRNAs played roles in the occurrence of GC were through several signaling pathways, such as phosphoinositide 3-kinase (PI3K)-AKT serine/threonine kinase (AKT), Wnt-β-Catenin, and mitogen-activated protein kinase (MAPK) pathways. These findings may provide new strategies for the diagnosis and treatment of GC.

Erythropoietin-induced hepatocyte receptor A2 regulates effect of pyroptosis on gastrointestinal colorectal cancer occurrence and metastasis resistance

Erythropoietin-induced hepatocyte receptor A2 (EphA2) is a receptor tyrosine kinase that plays a key role in the development and progression of a variety of tumors. This article reviews the expression of EphA2 in gastrointestinal (GI) colorectal cancer (CRC) and its regulation of pyroptosis. Pyroptosis is a form of programmed cell death that plays an important role in tumor suppression. Studies have shown that EphA2 regulates pyrodeath through various signaling pathways, affecting the occurrence, development and metastasis of GI CRC. The overexpression of EphA2 is closely related to the aggressiveness and metastasis of GI CRC, and the inhibition of EphA2 can induce pyrodeath and improve the sensitivity of cancer cells to treatment. In addition, EphA2 regulates intercellular communication and the microenvironment through interactions with other cytokines and receptors, further influencing cancer progression. The role of EphA2 in GI CRC and its underlying mechanisms provide us with new perspectives and potential therapeutic targets, which have important implications for future cancer treatment.

Targeting the EphA2 pathway: could it be the way for bone sarcomas?

Bone sarcomas are malignant tumors of mesenchymal origin. Complete surgical resection is the cornerstone of multidisciplinary treatment. However, advanced, unresectable forms remain incurable. A crucial step towards addressing this challenge involves comprehending the molecular mechanisms underpinning tumor progression and metastasis, laying the groundwork for innovative precision medicine-based interventions. We previously showed that tyrosine kinase receptor Ephrin Type-A Receptor 2 (EphA2) is overexpressed in bone sarcomas. EphA2 is a key oncofetal protein implicated in metastasis, self-renewal, and chemoresistance. Molecular, genetic, biochemical, and pharmacological approaches have been developed to target EphA2 and its signaling pathway aiming to interfere with its tumor-promoting effects or as a carrier for drug delivery. This review synthesizes the main functions of EphA2 and their relevance in bone sarcomas, providing strategies devised to leverage this receptor for diagnostic and therapeutic purposes, with a focus on its applicability in the three most common bone sarcoma histotypes: osteosarcoma, chondrosarcoma, and Ewing sarcoma.

Seneca valley virus 3C protease blocks EphA2-Mediated mTOR activation to facilitate viral replication

The Seneca Valley virus (SVV) is a recently discovered porcine pathogen that causes vesicular diseases and poses a significant threat to the pig industry worldwide. Erythropoietin-producing hepatoma receptor A2 (EphA2) is involved in the activation of the AKT/mTOR signaling pathway, which is involved in autophagy. However, the regulatory relationship between SVV and EphA2 remains unclear. In this study, we demonstrated that EphA2 is proteolysed in SVV-infected BHK-21 and PK-15 cells. Overexpression of EphA2 significantly inhibited SVV replication, as evidenced by decreased viral protein expression, viral titers, and viral load, suggesting an antiviral function of EphA2. Subsequently, viral proteins involved in the proteolysis of EphA2 were screened, and the SVV 3C protease (3Cpro) was found to be responsible for this cleavage, depending on its protease activity. However, the protease activity sites of 3Cpro did not affect the interactions between 3Cpro and EphA2. We further determined that EphA2 overexpression inhibited autophagy by activating the mTOR pathway and suppressing SVV replication. Taken together, these results indicate that SVV 3Cpro targets EphA2 for cleavage to impair its EphA2-mediated antiviral activity and emphasize the potential of the molecular interactions involved in developing antiviral strategies against SVV infection.

MiR-520d-3p suppresses the proliferation and epithelial-mesenchymal transition of cervical cancer cells by targeting ZFP36L2

MiR-520d-3p has recently been reported to have anti-tumor function in several cancers, including glioma and gastric cancer. However, the biological function and its mechanism of action remain unclear in cervical cancer (CC). In this study, we observed that miR-520d-3p expression was lowly expressed in CC specimens compared with adjacent normal specimens using reverse transcription quantitative PCR. Moreover, low miR-520d-3p expression was correlated with FIGO stage and lymph node metastasis by Chi-square test. Functionally, overexpression of miR-520d-3p suppressed the proliferation and migration and invasion of two CC cell lines (HeLa and SiHa) using CCK-8 assay and wound healing assay. After target prediction, luciferase reporter assay showed that zinc finger protein 36 ring finger protein-like 2 (ZFP36L2) was a direct target of miR-520d-3p in CC cells. The expression levels of ZFP36L2 at protein and mRNA were significantly increased in CC tissues compared with adjacent tissues. The expression of ZFP36L2 was negatively correlated with miR-520d-3p in the patients with CC. Importantly, ZFP36L2 overexpression abolished the effects of miR-520d-3p on cell proliferation, migration and EMT process in CC cells. In conclusion, our findings indicate that targeting miR-520d-3p/ZFP36L2 axis might be a promising therapeutic target for CC treatment.

LncRNA PROX1 antisense RNA 1 promotes PD-L1-mediated proliferation, metastasis, and immune escape in colorectal cancer by interacting with miR-520d

It was recently found that lncRNA PROX1 antisense RNA 1 (PROX1-AS1) manifested oncogenicity in a variety of malignancies. This work intended to investigate the molecular mechanisms of PROX1-AS1 in colorectal cancer (CRC) development and immune evasion. In this study, both PROX1-AS1 and PD-L1 expressions were lifted in CRC tissues and cells. PROX1-AS1 interference restrained CRC cell proliferation, migration, invasion, as well as CD8 + T-lymphocyte apoptosis, but increased the cytotoxicity and percentage of CD8 + T lymphocytes. The inhibitory effects of PROX1-AS1 inhibition on CRC progression and immune escape were positively related to PD-L1 suppression. PROX1-AS1 absorbed miR-520d to upregulate PD-L1 expression. PROX1-AS1 facilitated CRC progression and immune escape by targeting miR-520d. Furthermore, PROX1-AS1 deletion impaired CRC tumor growth in vivo . To sum up, this study affirmed that PROX1-AS1 could absorb miR-520d to upregulate PD-L1 in CRC, thereby promoting tumor progression and immune escape.

Comparison of Oncogenes, Tumor Suppressors, and MicroRNAs Between Schizophrenia and Glioma: The Balance of Power

The risk of cancer in schizophrenia has been controversial. Confounders of the issue are cigarette smoking in schizophrenia, and antiproliferative effects of antipsychotic medications. The author has previously suggested comparison of a specific cancer like glioma to schizophrenia might help determine a more accurate relationship between cancer and schizophrenia. To accomplish this goal, the author performed three comparisons of data; the first a comparison of conventional tumor suppressors and oncogenes between schizophrenia and cancer including glioma. This comparison determined schizophrenia has both tumor-suppressive and tumor-promoting characteristics. A second, larger comparison between brain-expressed microRNAs in schizophrenia with their expression in glioma was then performed. This identified a core carcinogenic group of miRNAs in schizophrenia offset by a larger group of tumor-suppressive miRNAs. This proposed "balance of power" between oncogenes and tumor suppressors could cause neuroinflammation. This was assessed by a third comparison between schizophrenia, glioma and inflammation in asbestos-related lung cancer and mesothelioma (ALRCM). This revealed that schizophrenia shares more oncogenic similarity to ALRCM than glioma.

MicroRNA-520d-3p suppresses melanoma cells proliferation by inhibiting the anti-silencing function 1B histone chaperone

As the most common and aggressive malignant form of skin cancer, melanoma has a poor prognosis in its late stage. MicroRNA (miR)-520d-3p has been reported as a key modulator that regulates the development of different types of cancer, but its role in melanoma remains unclear. The purpose of this study was to investigate the role and mechanism of miR-520d-3p in melanoma. The expression of anti-silencing function 1B histone chaperone (ASF1B) and miR-520d-3p in melanoma tissues and cells was detected by reverse transcription-quantitative polymerase chain reaction. The interaction between ASF1B and miR-520d-3p was verified by luciferase activity detection. Cell counting kit-8, bromodeoxyuridine, fluorescein isothiocyanate, and cell adhesion assays were performed to detect cell viability, proliferation, apoptosis, and adhesion in melanoma cells. ASF1B expression was evidently increased, whereas miR-520d-3p level was downregulated in melanoma tissues and cells. Overexpression of ASF1B enhanced cell growth and adhesion and hampered cell apoptosis in melanoma cells. Furthermore, miR-520d-3p suppressed the tumorigenic effects of melanoma cells. Moreover, miR-520d-3p suppressed the expression of ASF1B to suppress melanoma tumorigenesis. In conclusion, we have found out that miR-520d-3p suppressed melanoma tumorigenesis by inhibiting ASF1B, which could be a promising target for melanoma therapy.

EphA2-YES1-ANXA2 pathway promotes gastric cancer progression and metastasis

Erythropoietin-producing hepatocellular receptor A2 (EphA2) is a key member of the receptor tyrosine kinase (RTK) family, while YES Proto-Oncogene 1 (YES1) is a non-receptor tyrosine kinase (nRTK) and annexin A2 (ANXA2) belongs to the calcium-dependent phospholipid-binding protein family annexins. Here, we show that EphA2, YES1, and ANXA2 form a signal axis, in which YES1 activated by EphA2 phosphorylates ANXA2 at Tyr24 site, leading to ANXA2 activation and increased ANXA2 nuclear distribution in gastric cancer (GC) cells. Overexpression (OE) of YES1 increases, while knockdown (KD) of YES1 or ANXA2 decreases GC cell invasion and migration in vitro and tumor growth in mouse models. Reexpression of wildtype (WT) rather than mutant ANXA2 (Tyr24F) in ANXA2 knockdown (ANXA2-KD) GC cells restores YES1-induced cell invasion and migration, while neither WT nor mutant ANXA2 (Tyr24F) can restore cell invasion and migration in YES1-KD GC cells. In addition, the activation of EphA2-YES1-ANXA2 pathway is correlated with poor prognosis. Thus, our results establish EphA2-YES1-ANXA2 axis as a novel pathway that drives GC invasion and metastasis, targeting this pathway would be an efficient way for the treatment of GC.

EPHA2 Promotes the Invasion and Migration of Human Tongue Squamous Cell Carcinoma Cal-27 Cells by Enhancing AKT/mTOR Signaling Pathway

EPHA2 is a member of the ephrin receptor tyrosine kinase family and is closely related to the malignant tumor progression. The effect of EPHA2 on OSCC is not clear. This study explored the role of EPHA2 and AKT/mTOR signaling pathways in Cal-27 cell invasion and migration. The expression of EPHA2 and EPHA4 in human OSCC and normal oral tissue was detected by immunohistochemistry. EPHA2-overexpressing and EPHA2-knockdown Cal-27 cells were established, and the cells were treated with an AKT inhibitor (MK2206) and mTOR inhibitor (RAD001). The expression of EPHA2 was detected by qRT-PCR, cell proliferation was evaluated by MTT assay, cell migration and invasion were examined by scratch and Transwell assay, and cell morphology and apoptosis were assessed by Hoechst 33258 staining. Western blot was performed to detect the expression of proteins related to AKT/mTOR signaling, cell cycle, and pseudopod invasion. EPHA2 and EPHA4 were highly expressed in clinical human OSCC. Overexpression of EPHA2 promoted the proliferation, migration, and invasion of Cal-27 cells, inhibited cell cycle blockage and apoptosis, and enhanced the activity of the AKT/mTOR signaling pathway. MK2206 (AKT inhibitor) and RAD001 (mTOR inhibitor) reversed the effect of EPHA2 overexpression on the biological behavior of Cal-27 cells. EPHA2 promotes the invasion and migration of Cal-27 human OSCC cells by enhancing the AKT/mTOR signaling pathway.

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.

Long Non-Coding RNA USP2-AS1 Accelerates Cell Proliferation and Migration in Ovarian Cancer by Sponging miR-520d-3p and Up-Regulating KIAA1522

Background

Ovarian cancer is one of the malignant tumors attacking the female reproductive system. Currently, increasing studies have clearly determined the importance of long non-coding RNAs (lncRNAs) in various human cancers including ovarian cancer. However, the role and in-depth mechanism of ubiquitin specific peptidase 2 antisense RNA 1 (USP2-AS1) in ovarian cancer have been not reported yet.

Purpose

We were absorbed into exploring the character of USP2-AS1 in ovarian cancer.

Methods

RT-qPCR analysis reflected gene expression. The GEPIA database provided further evidences, and bioinformatics tools analyzed the potential molecules downstream USP2-AS1 in ovarian cancer. The changes on ovarian cancer cellular functions were assessed via EdU, TUNEL, JC-1 and transwell assays. RNA pull down, RIP and luciferase reporter assays estimated molecule interactions.

Results

USP2-AS1 was obviously up-regulated in ovarian cancer tissues and cell lines. Inhibiting USP2-AS1 had anti-proliferation, pro-apoptosis, and anti-migration effects on ovarian cancer cells. Furthermore, we confirmed that USP2-AS1 sequestered miR-520d-3p to enhance KIAA1522. In addition, miR-520d-3p silence reversed the effect of depleted USP2-AS1 on ovarian cancer cellular behaviors, while such reversion was then abolished by KIAA1522 knockdown.

Conclusion

USP2-AS1 facilitated ovarian cancer progression via miR-520d-3p/KIAA1522 axis, implying USP2-AS1 as a new perspective for the treatment of ovarian cancer.

Ropivacaine Inhibits the Growth, Migration and Invasion of Gastric Cancer Through Attenuation of WEE1 and PI3K/AKT Signaling via miR-520a-3p

BACKGROUND

Metastasis remains one of the greatest challenges involved in treating gastric cancer (GC). Ropivacaine (Rop) is not only a well-documented local anesthetic medicament but also has been reported to exert an antitumor role in cancer development. This study explored the effects of ropivacaine on the growth, migration and invasion of gastric cancer and the underlying mechanisms.

METHODS

Cell Counting Kit-8 (CCK8) assay was conducted to test the effect of Rop on the proliferation of AGS and BGC-823 GC cells. Moreover, cell apoptosis, migration and invasion were examined by flow cytometry and transwell assay, respectively. The expression of miR-520a-3p was determined by qRT-PCR. miRNA targeting sites were analyzed using bioinformatics analysis and dual-luciferase reporter assay. Protein levels of WEE1 and PI3K/AKT were detected by Western blot. Furthermore, the tumor-forming experiment of nude mice was used to detect the growth of cells in vivo.

RESULTS

Rop inhibited proliferation but promoted apoptosis of GC cells. Besides, the migration and invasion of GC cells were also inhibited by Rop. Moreover, miR-520a-3p expression was enhanced by Rop, and transfection with miR-520a-3p mimic decreased cell proliferation, migration and invasion. The upregulation of miR-520a-3p was partly contributed to the inhibitory effect of ropivacaine on GC cell lines. Finally, Rop inactivated WEE1 and PI3K/AKT pathway via upregulation of miR-520a-3p.

CONCLUSION

Our results suggested that Rop decreased growth, migration and invasion of GC cells via regulating miR-520a-3p expression and further inactivated WEE1 and PI3K/AKT signaling pathways.

Vascular transcriptome landscape of Trail-/- mice: Implications and therapeutic strategies for diabetic vascular disease

Circulating plasma TRAIL levels are suppressed in patients with cardiovascular and diabetic diseases. To identify novel targets in vascular metabolic diseases, genome-wide transcriptome of aortic tissue from Trail^-/- versus Trail^+/+ mice were interrogated. We found 861 genes differentially expressed with TRAIL deletion. Gene enrichment analyses showed many of these genes were related to inflammation, cell-to-cell cytoskeletal interactions, and transcriptional modulation. We identified vascular protective and pathological gene clusters, with Ifi205 as the most significantly reduced vascular protective gene, whereas Glut1, the most significantly increased pathological gene with TRAIL deletion. We hypothesized that therapeutic targets could be devised from such integrated analysis and validated our findings from vascular tissues of diabetic mice. From the differentially expressed gene targets, enriched transcription factor (TF) and microRNA binding motifs were identified. The top two TFs were Elk1 and Sp1, with enrichment to eight gene targets common to both. miR-520d-3p and miR-377-3p were the top enriched microRNAs with TRAIL deletion; with four overlapping genes enriched for both microRNAs. Our findings offer an alternate in silico approach for therapeutic target identification and present a deeper understanding of gene signatures and pathways altered with TRAIL suppression in the vasculature.

To construct a ceRNA regulatory network as prognostic biomarkers for bladder cancer

Emerging evidence demonstrates that competing endogenous RNA (ceRNA) hypothesis has played a role in molecular biological mechanisms of cancer occurrence and development. But the effect of ceRNA network in bladder cancer (BC), especially lncRNA‐miRNA‐mRNA regulatory network of BC, was not completely expounded. By means of The Cancer Genome Atlas (TCGA) database, we compared the expression of RNA sequencing (RNA‐Seq) data between 19 normal bladder tissue and 414 primary bladder tumours. Then, weighted gene co‐expression network analysis (WGCNA) was conducted to analyse the correlation between two sets of genes with traits. Interactions between miRNAs, lncRNAs and target mRNAs were predicted by MiRcode, miRDB, starBase, miRTarBase and TargetScan. Next, by univariate Cox regression and LASSO regression analysis, the 86 mRNAs obtained by prediction were used to construct a prognostic model which contained 4 mRNAs (ACTC1 + FAM129A + OSBPL10 + EPHA2). Then, by the 4 mRNAs in the prognostic model, a ceRNA regulatory network with 48 lncRNAs, 14 miRNAs and 4 mRNAs was constructed. To sum up, the ceRNA network can further explore gene regulation and predict the prognosis of BC patients.

The Complex Network between MYC Oncogene and microRNAs in Gastric Cancer: An Overview

Despite the advancements in cancer treatments, gastric cancer is still one of the leading causes of death worldwide. In this context, it is of great interest to discover new and more effective ways of treating this disease. Accumulated evidences have demonstrated the amplification of 8q24.21 region in gastric tumors. Furthermore, this is the region where the widely known MYC oncogene and different microRNAs are located. MYC deregulation is key in tumorigenesis in various types of tissues, once it is associated with cell proliferation, survival, and drug resistance. microRNAs are a class of noncoding RNAs that negatively regulate the protein translation, and which deregulation is related with gastric cancer development. However, little is understood about the interactions between microRNAs and MYC. Here, we overview the MYC role and its relationship with the microRNAs network in gastric cancer aiming to identify potential targets useful to be used in clinic, not only as biomarkers, but also as molecules for development of promising therapies.

Upregulation of microRNA-520a-3p inhibits the proliferation, migration and invasion via spindle and kinetochore associated 2 in gastric cancer

MicroRNAs (miR) serve important roles in the development and progression of tumors by targeting different genes. miR-520a-3p reported in lung and breast cancers as a tumor suppressor gene. However, the expression and functional significance of miR-520a-3p is not completely understood in gastric cancer (GC). In the present study, it was demonstrated that the expression levels of miR-520a-3p were significantly downregulated in GC tissues and cells using RT-qPCR. In addition, downregulated expression of miR-520a-3p was associated with the clinical stage of the tumor and invasion in patients with GC. Furthermore, overexpression of miR-520a-3p significantly inhibited cell proliferation, invasion and migration in SGC-7901 and MGC-803 GC cell lines using proliferation, wound healing and cell invasion assays. Spindle and kinetochore associated 2 (SKA2) was upregulated in GC cells using western blot analysis and a target gene of miR-520a-3p; miR-520a-3p mimics significantly reduced SKA2 expression. In addition, upregulation of SKA2 protein expression SKA2 reversed the miR-520a-3p-mediated inhibition of SGC-7901 cell proliferation, migration and invasion. In conclusion, miR-520a-3p functioned as a tumor suppressor gene by targeting SKA2 in GC cell lines, and may serve as a novel prognostic and potential therapeutic marker.

Lidocaine inhibits the progression of retinoblastoma in vitro and in vivo by modulating the miR‑520a‑3p/EGFR axis

Retinoblastoma (RB) is a common malignant tumor in children. Lidocaine is a local anesthetic and anti-arrhythmic drug, and has been reported to possess anti-tumor properties. MicroRNAs (miRs) are a group of endogenous small noncoding RNAs that have important roles in various biological processes via actions on target genes. The aim of the present study was to investigate the effect of lidocaine on retinoblastoma in vitro and in vivo. CCK-8 assay and flow cytometry assay were used to measure cell viability and apoptosis. The relationship between miR-520a-3p and EGFR was predicted and confirmed by TargetScan and dual-luciferase reporter assay. For in vivo study, tumor xenograft was performed. In addition, gene and protein expression was detected using reverse transcription-quantitative polymerase chain reaction and western blotting respectively. In the present study, it was observed that lidocaine inhibited the proliferation and induced the apoptosis of RB cells. miR-520a-3p was reported to be downregulated in RB tissues and cell lines; treatment with lidocaine increased the expression of miR-520a-3p in RB cells. The human epidermal growth factor receptor (EGFR) was identified as a direct target of miR-520a-3p, and its expression was negatively associated with that of miR-520a-3p. Additionally, EGFR was upregulated in RB tissues and cell lines; treatment with lidocaine decreased the expression of EGFR in RB cells. Furthermore, compared with treatment with lidocaine alone, the combination of transfection with miR-520a-3p inhibitor and lidocaine treatment significantly decreased the expression of miR-520a-3p, increased EGFR expression, promoted RB cell proliferation and reduced the apoptosis of cells in vitro, and increased tumor volume and weight in vivo. The results indicated that lidocaine reduced the proliferation and induced the apoptosis of RB cells by decreasing EGFR expression via the upregulation of miR-520a-3p, suggesting that the miR-520a-3p/EGFR axis may be a novel therapeutic target in the treatment of RB.

Influence of miR-520e-mediated MAPK signalling pathway on HBV replication and regulation of hepatocellular carcinoma cells via targeting EphA2

We determined the role of miR-520e in the replication of hepatitis B virus (HBV) and the growth of hepatocellular carcinoma (HCC) cells. MiR-520e and EPH receptor A2 (EphA2) in HBV-positive HCC tissues and cells were detected, and we studied the impact of miR-520e and the EphA2 receptor in cellular and murine HBV replication models. We find that MiR-520e was upregulated and EphA2 was downregulated in HBV-positive HCC tissues and cells. MiR-520e was decreased in Huh7-X and HepG2-X cells in which HBx was stably expressed, but was dose-dependently elevated after interfering with HBx. Additionally, miR-520e mimic and si-EphA2 groups were reduced in association with increases in HBV DNA content, HBsAg and HBeAg levels, cell proliferation and were enhanced in the expressions of EphA2, p-p38MAPK/p38MAPK, phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2)/ERK1/2 and cell apoptosis. Furthermore, si-EphA2 reversed the promotion effect of miR-520e inhibitor on HBV replication and tumour cell growth. Upregulating miR-520e in rAAV8-1.3HBV-infected mouse resulted in reduced EphA2 in liver tissues and HBV DNA content in serum. We find that MiR-520e was decreased in HBV-positive HCC, while overexpression of miR-520e blocked p38MAPK and ERK1/2 signalling pathways by an inhibitory effect on EphA2 and ultimately reduced HBV replication and inhibited tumour cell growth. These data indicate a role for miR-520e in the regulation of HBV replication.

Deregulation of miR-520d-3p promotes hepatocellular carcinoma development via lncRNA MIAT regulation and EPHA2 signaling activation

MicroRNA-520d-3p (miR-520d-3p) is a novel cancer-related miRNA and functions as a tumor suppressor in human cancers. However, the expression patterns and mechanisms of miR-520d-3p involved in hepatocellular carcinoma (HCC) remain rarely known. Here, we found that the expression levels of miR-520d-3p in HCC tissues and cells were significantly lower than in tumor-adjacent tissues and L02 cells. Decreased level of miR-520d-3p was relevant to poor overall survival, whereas miR-520d-3p up-regulation resulted in a marked inhibition of cell growth, migration and invasion. In addition, the long non-coding RNA, myocardial infarction associated transcript (MIAT) was up-regulated in both HCC tissues and cell lines. MIAT suppressed the expression and function of miR-520d-3p. Moreover, erythropoietin-producing hepatocellular A2 (EPHA2) was speculated and confirmed as a direct target of miR-520d-3p. We also demonstrated that MIAT may function as a sponge competitive endogenous RNA for miR-520d-3p, and thus regulate the molecular expression of EPHA2. In summary, our study has identified a novel signaling pathway through which miR-520d-3p exerts its anticarcinogenic roles and suggested that the MIAT/miR-520d-3p/EPHA2 may be a new target for HCC therapy.

MiR-708-5p inhibits proliferation, migration and invasion of gastric cancer cells by targeting GAGE12I

AIM

To explore the effect of miR-708-5p on the proliferation, migration and invasion of gastric cancer (GC) cells and the possible mechanism involved.

METHODS

qRT-PCR was used to detect the expression of miR-708-5p in GC cell lines AGS and BGC-823. MTT, colony formation and Transwell chamber assays were performed to detect the effect of overexpression of miR-708-5p and silencing of GAGE12I on the proliferation, migration and invasion of AGS and BGC-823 cells. The double luciferase reporter gene experiment was performed to confirm the relationship between miR-708-5p and GAGE12I. Western blot analysis was used to detect the effect of miR-708-5p on the expression of GAGE12I. Target response assay was used to confirm the effect of GAGE12I on the inhibition of proliferation, migration and invasion of AGS and BGC-823 cells by miR-708-5p.

RESULTS

MiR-708-5p was downregulated in GC tissues and GC cell lines AGS and BGC-823. Upregulation of miR-708-5p and silencing of GAGE12I inhibited the proliferation, migration and invasion of AGS cells. GAGE12I was a target gene of miR-708-5p, and miR-708-5p negatively regulated GAGE12I expression. Overexpression of GAGE12I partly reversed the inhibitory effect of miR-708-5p on proliferation, migration and invasion of AGS and BGC-823 cells.

CONCLUSION

MiR-708-5p inhibits the proliferation, migration and invasion of GC cells by targeting GAGE12I.

The relationship between miR-302b and EphA2 and their clinical significance in gastric cancer

Introduction: EphA2 is a crucial oncogene in gastric cancer (GC) development and metastasis, and miR-302b can target EphA2 in gastric cancer. This study plans to investigate their relationship and clinical significance in clinical samples. Materials and Methods: We explored the correlation of the expression of EphA2 and miR-302b, and their clinical significance in the training (n=226) cohort of GC patients, and then validated the results in the validation (n=128) cohort. Results: miR-302b was remarkably downregulated in GC tissues, while high EphA2 expression were detected, and they were inversely correlated both in mRNA and protein, (r=-0.4209, P<0.0001; r=-0.336, P <0.001, respectively). Furthermore, the pattern of high EphA2 and low miR-302b expression were found to be associated with poor overall survival in stage IV GC patients in both training and validation cohort. Conclusions: The expression of miR-302b and EphA2 was inversely correlated, and had prognostic significance on GC in clinic.

Molecular alterations of cancer cell and tumour microenvironment in metastatic gastric cancer

The term metastasis is widely used to describe the endpoint of the process by which tumour cells spread from the primary location to an anatomically distant site. Achieving successful dissemination is dependent not only on the molecular alterations of the cancer cells themselves, but also on the microenvironment through which they encounter. Here, we reviewed the molecular alterations of metastatic gastric cancer (GC) as it reflects a large proportion of GC patients currently seen in clinic. We hope that further exploration and understanding of the multistep metastatic cascade will yield novel therapeutic targets that will lead to better patient outcomes.

Aberrant expression of LncRNA-MIR31HG regulates cell migration and proliferation by affecting miR-31 and miR-31* in Hirschsprung's disease

Hirschsprung's disease (HSCR) is a birth defect that causes a failure of the enteric nervous system to cover the distal gut during early embryonic development. Evidence shows that long non-coding RNAs (lncRNA) play important roles in HSCR. The MIR31 host gene (MIR31HG), also known as Loc554202, is a long non-coding RNA (lncRNA), which acts as the host gene of (microRNA) miR-31 and miR-31*. There have been no studies regarding its function in early developmental defects during pregnancy, and its downstream genetic receptors. We report that downregulation of MIR31HG inhibited migration and proliferation in 293T and SH-SY5Y cell lines, by suppressing miR-31 and miR-31*. Moreover, the downregulation of miR-31 and miR-31* enhanced inter-α-trypsin inhibitor heavy chain 5 (ITIH5) and the phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic gamma subunit (PIK3CG), respectively with reductions of cell migration and proliferation in 293T and SH-SY5Y cell lines. In addition, synergistic actions were observed between miR-31 and miR-31* in cell migration and proliferation. Our results demonstrated that the MIR31HG-miR-31/31*-ITIH5/PIK3CG pathway plays a role in the pathogenesis of HSCR.

miR-302b inhibits tumorigenesis by targeting EphA2 via Wnt/ β-catenin/EMT signaling cascade in gastric cancer

Background

EphA2 is a crucial oncogene in gastric cancer (GC) development and metastasis, this study aims to identify microRNAs that target it and serve as key regulators of gastric carcinogenesis.

Methods

We identified several potential microRNAs targeting EphA2 by bioinformatics websites and then analyzed the role of miR-302b in modulating EphA2 in vitro and in vivo of GC, and it’s mechanism.

Results

Our analysis identified miR-302b, a novel regulator of EphA2, as one of the most significantly downregulated microRNA (miRNA) in GC tissues. Overexpression of miR-302b impaired GC cell migratory and invasive properties robustly and suppressed cell proliferation by arresting cells at G0–G1 phase in vitro. miR-302b exhibited anti-tumor activity by reversing EphA2 regulation, which relayed a signaling transduction cascade that attenuated the functions of N-cadherin, β-catenin, and Snail (markers of Wnt/β-catenin and epithelial-mesenchymal transition, EMT). This modulation of EphA2 also had distinct effects on cell proliferation and migration in GC in vivo.

Conclusions

miR-302b serves as a critical suppressor of GC cell tumorigenesis and metastasis by targeting the EphA2/Wnt/β-catenin/EMT pathway.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3875-3) contains supplementary material, which is available to authorized users.

Prognostic value of microRNAs in gastric cancer: a meta-analysis

BACKGROUND

Previous articles have reported that expression levels of microRNAs (miRNAs) are associated with survival time of patients with gastric cancer (GC). A systematic review and meta-analysis was performed to study the outcome of it.

DESIGN

Meta-analysis.

METHODS

English studies estimating expression levels of miRNAs with any of survival curves in GC were identified up till March 19, 2017 through performing online searches in PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews by two authors independently. The pooled hazard ratios (HR) with 95% confidence intervals (CI) were used to estimate the correlation between miRNA expression and overall survival (OS).

RESULTS

Sixty-nine relevant articles about 26 miRNAs with 6148 patients were ultimately included. GC patients with high expression of miR-20b (HR=2.38, 95%CI=1.16-4.87), 21 (HR=1.77, 95%CI=1.01-3.08), 106b (HR=1.84, 95%CI=1.15-2.94), 196a (HR=2.66, 95%CI=1.94-3.63), 196b (HR=1.67, 95%CI=1.38-2.02), 214 (HR=1.84, 95%CI=1.27-2.67) or low expression of miR-125a (HR=2.06, 95%CI=1.26-3.37), 137 (HR=3.21, 95%CI=1.68-6.13), 141 (HR=2.47, 95%CI=1.34-4.56), 145 (HR=1.62, 95%CI=1.07-2.46), 146a (HR=2.60, 95%CI=1.63-4.13), 206 (HR=2.85, 95%CI=1.73-4.70), 218 (HR=2.61, 95%CI=1.74-3.92), 451 (HR=1.73, 95%CI=1.19-2.52), 486-5p (HR=2.45, 95%CI=1.65-3.65), 506 (HR=2.07, 95%CI=1.33-3.23) have significantly poor OS (P<0.05).

CONCLUSIONS

In summary, miR-20b, 21, 106b, 125a, 137, 141, 145, 146a, 196a, 196b, 206, 214, 218, 451, 486-5p and 506 demonstrate significantly prognostic value. Among them, miR-20b, 125a, 137, 141, 146a, 196a, 206, 218, 486-5p and 506 are strong biomarkers of prognosis in GC.

A multidimensional integration analysis reveals potential bridging targets in the process of colorectal cancer liver metastasis

Approximately 9% of cancer-related deaths are caused by colorectal cancer. Liver metastasis is a major factor for the high colorectal cancer mortality rate. However, the molecular mechanism underlying colorectal cancer liver metastasis remains unclear. Using a global and multidimensional integration approach, we studied sequencing data, protein-protein interactions, and regulation of transcription factor and non-coding RNAs in primary tumor samples and liver metastasis samples to unveil the potential bridging molecules and the regulators that functionally link different stages of colorectal cancer liver metastasis. Primary tumor samples and liver metastasis samples had modules with significant overlap and crosstalk from which we identified several bridging genes (e.g. KNG1 and COX5B), transcription factors (e.g. E2F4 and CDX2), microRNAs (e.g. miR-590-3p and miR-203) and lncRNAs (e.g. lincIRX5 and lincFOXF1) that may play an important role in the process of colorectal cancer liver metastasis. This study enhances our understanding of the genetic alterations and transcriptional regulation that drive the metastatic process, but also provides the methodology to guide the studies on other metastatic cancers.

SIRP Alpha Protein Downregulates in Human Astrocytoma: Presumptive Involvement of Hsa-miR-520d-5p and Hsa-miR-520d-3p

Astrocytomas are the most common brain tumors with poor survival in malignant forms. Signal regulatory protein alpha (SIRP alpha) is a transmembrane protein expressed on immune cells and macrophages and is reported to modulate tumor cell phagocytosis. In the present study, we investigated the involvement of miR-520d-5p and miR-520d-3p in regulation of SIRP alpha expression. Here, we report mRNA and protein expression profile of SIRP alpha in 39 surgically resected human astrocytoma tissue samples and 14 control brain tissue samples. Transcript expression pattern was studied by real-time PCR while Western blotting and immunohistochemistry were used to evaluate protein expression. Expression profile of miR-520d-5p and miR-520d-3p was studied by real-time PCR. Computational prediction was employed to analyze the binding of miR-520d-5p and miR-520d-3p for SIRP alpha mRNA. It is evident from preliminary investigation that SIRP alpha transcripts are expressed in control brain tissues, increased in low-grade (grade II) tumor tissues, and decreased with further grade progression (P < 0.05). SIRP alpha protein was moderately expressed in control brain tissues but under-expressed in low- and high-grade tissue samples (P < 0.05). Immunohistochemistry results further confirmed Western blot outcomes. Computational prediction supplemented with 3' and 5'UTR targeting analysis and correlation studies reveals that hsa-miR-520d-5p (P = 0.028, R ² = 0.94) (95 % CI 0.15 to 0.99) and hsa-miR-520d-3p (P = 0.027, R ² = 0.94) (95% CI 0.17 to 0.99) may be the putative microRNAs involved in regulation of SIRP alpha protein expression. Real-time PCR expression profile depicts that mature form of both miRNAs is significantly overexpressed in low-grade (GII) tumor tissue samples compared to control and high-grade (GIII and GIV) tissue samples. MiR-520d-5p and miR-520d-3p were found with expression pattern similar to SIRP alpha transcripts. We show that SIRP alpha protein is under-expressed in low and high grades of astrocytoma patients' tissue samples. Control brain tissues were found to be positive with SIRP alpha protein expression. Real-time PCR expression analysis confirms that miR-520d-5p and miR-520d-3p expression levels were significantly correlated with SIRP alpha transcripts in control, low-grade, and high-grade tissue samples. Computational prediction further evidenced for binding sites of these miRNAs on 3' and 5'UTR of SIRP alpha transcripts. Taken together, we predict that miR-520d-5p and miR-520d-3p may be having role in the regulation of under-expressed SIRP alpha protein expression.

MicroRNAs May Serve as Emerging Molecular Biomarkers for Diagnosis and Prognostic Assessment or as Targets for Therapy in Gastric Cancer

Gastric cancer (GC) is one of the most common cancers, with high incidences in East Asia countries. Most GC patients have been reported with low early diagnosis rate and show extremely poor prognosis. Therefore, it is necessary to develop novel and more sensitive biomarkers to improve early diagnosis and therapy in order to provide longer survival and better quality of life for gastric cancer patients. MicroRNAs (miRNAs) play crucial roles in GC development and progression. miRNAs have emerged as a novel molecular biomarker for cancer diagnosis, prognosis and therapy with surprising stability in tissues, serum or other body fluids. This review summarizes major advances in our current knowledge about potential miRNA biomarkers for GC that have been reported in the past two years.

miR-488 acts as a tumor suppressor gene in gastric cancer

MicroRNAs (miRNAs) are small, non-coding RNAs that modulate development, cell proliferation, and apoptosis. The deregulated expression of microRNAs is found in carcinogenesis including gastric cancer (GC). In this study, we showed that the expression levels of miR-488 were downregulated in GC tissues compared to in non-tumor tissues. In addition, the expression of miR-488 was also lower in GC cell lines in contrast with the gastric epithelial cell line (GES). In addition, the expression level of miR-488 was negatively correlated with the TNM stage in GC patients, and lower miR-488 expression was found in tumors with advanced TNM stage. The ectopic expression of miR-488 suppressed the GC cell proliferation, cell cycle, colony information, and migration. PAX6 was identified as a direct target gene of miR-488 in HGC-27. Moreover, we found that the expression level of PAX6 was upregulated in the GC tissues compared with the non-tumor tissues. The PAX6 expression level was correlated with the cancer TNM stage, and higher PAX6 expression was found in tumors with advanced TNM stage. Furthermore, there was an inverse correlation between PAX6 and miR-488 expression levels in GC tissues. Therefore, these studies demonstrated that miR-488 might act as a tumor suppressor miRNA in the development of GC.

Comparison of Prognostic MicroRNA Biomarkers in Blood and Tissues for Gastric Cancer

Gastric cancer (GC) still keeps up high mortality worldwide with poor prognosis. Efficient and non-invasive prognostic biomarkers are urgently needed. MicroRNAs are non-coding RNAs playing roles in post-transcriptional gene regulation, which contribute to various biological processes such as development, differentiation and carcinogenesis. MicroRNA expression profiles have been associated with the prognosis and outcome in GC. MicroRNA prognostic biomarkers have been identified from blood or tissues samples, but with different prognostic features. Understanding the various roles of microRNAs in different sample sources of GC will provide deep insights into GC progression. In this review, we highlight the distinct prognostic roles of microRNAs biomarkers in blood and tissue according to their relationships with prognostic parameters, survival rates and target pathways. This will be useful for non-invasive biomarker development and selection in prognosis of GC.

MicroRNAs and Cancer Drug Resistance

The discovery of small regulatory noncoding RNAs revolutionized our thinking on gene regulation. The class of microRNAs (miRs), a group of small noncoding RNAs (20-22 nt in length) that bind imperfectly to the 3'-untranslated region of target mRNA, has been insistently implicated in several pathological conditions including cancer. Indeed, major hallmarks of cancer, such as cell differentiation, cell proliferation, cell cycle, cell survival, and cell invasion, has been described as being regulated by miRs. Recent studies have also implicated miRs in cancer drug resistance. Regardless of the several studies done until now, drug resistance still is a burden for cancer therapy and patients' outcome, often resulting in more aggressive tumors that tend to metastasize to distant organs. Hence, with this review, we aim to summarize the miRs that influence molecular pathways that are involved in cancer drug resistance, such as drug metabolism, drug influx/efflux, DNA damage response (DDR), epithelial-to-mesenchymal transition (EMT), and cancer stem cells.

Oxidative stress response and Nrf2 signaling in aging

Increasing oxidative stress, a major characteristic of aging, has been implicated in a variety of age-related pathologies. In aging, oxidant production from several sources is increased, whereas antioxidant enzymes, the primary lines of defense, are decreased. Repair systems, including the proteasomal degradation of damaged proteins, also decline. Importantly, the adaptive response to oxidative stress declines with aging. Nrf2/EpRE signaling regulates the basal and inducible expression of many antioxidant enzymes and the proteasome. Nrf2/EpRE activity is regulated at several levels, including transcription, posttranslation, and interactions with other proteins. This review summarizes current studies on age-related impairment of Nrf2/EpRE function and discusses the changes in Nrf2 regulatory mechanisms with aging.

Dysregulation of non-coding RNAs in gastric cancer

Gastric cancer (GC) is one of the most common cancers in the world and a significant threat to the health of patients, especially those from China and Japan. The prognosis for patients with late stage GC receiving the standard of care treatment, including surgery, chemotherapy and radiotherapy, remains poor. Developing novel treatment strategies, identifying new molecules for targeted therapy, and devising screening techniques to detect this cancer in its early stages are needed for GC patients. The discovery of non-coding RNAs (ncRNAs), primarily microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), helped to elucidate the mechanisms of tumorigenesis, diagnosis and treatment of GC. Recently, significant research has been conducted on non-coding RNAs and how the regulatory dysfunction of these RNAs impacts the tumorigenesis of GC. In this study, we review papers published in the last five years concerning the dysregulation of non-coding RNAs, especially miRNAs and lncRNAs, in GC. We summarize instances of aberrant expression of the ncRNAs in GC and their effect on survival-related events, including cell cycle regulation, AKT signaling, apoptosis and drug resistance. Additionally, we evaluate how ncRNA dysregulation affects the metastatic process, including the epithelial-mesenchymal transition, stem cells, transcription factor activity, and oncogene and tumor suppressor expression. Lastly, we determine how ncRNAs affect angiogenesis in the microenvironment of GC. We further discuss the use of ncRNAs as potential biomarkers for use in clinical screening, early diagnosis and prognosis of GC. At present, no ideal ncRNAs have been identified as targets for the treatment of GC.

Screening of differential microRNA expression in gastric signet ring cell carcinoma and gastric adenocarcinoma and target gene prediction

Gastric signet ring cell carcinoma (GSRCC) is a unique pathological type of gastric carcinoma that is extremely invasive and has a poor prognosis after diagnosis. The expression of microRNAs has been closely linked to the carcinogenesis of gastric cancer and has been considered as a powerful prognostic marker. Distinctive expression of miRNAs in GSRCC was investigated in the present study. Samples of GSRCC were compared to that of intestinal gastric adenocarcinoma using Agilent microarray technique, and two differentially expressed miRNAs were identified, hsa-miR-665 and hsa-miR‑95. qRT-PCR verification showed downregulation of both miRNAs in signet ring cell carcinoma and upregulation in gastric adenocarcinoma, which was not consistent with the results obtained by the microarray. Target gene prediction using online databases conferred two strong candidate genes, GLI2 and PLCG1. GO/KO analysis of these two genes showed close correlations with carcinogenesis and chemoresistance. It was concluded that hsa-miR-665 and hsa-miR-95 were downregulated in GSRCC but upregulated in intestinal gastric adenocarcinoma, and the relatively differential expression of the miRNAs negatively controlling their target genes could be closely related to the high invasive metastasis and chemoresistance of GSRCC.