MicroRNA-1231 exerts a tumor suppressor role through regulating the EGFR/PI3K/AKT axis in glioma

Upregulated circ_0002141 facilitates oral squamous cell carcinoma progression via the miR-1231/EGFR axis

OBJECTIVES

The dysregulation of circular RNAs (circRNAs) is implicated in the progression of various cancers. This study was aimed at expounding the role and mechanism of hsa_circ_0002141 in the OSCC progression.

MATERIALS AND METHODS

Circ_0002141 expression was examined in 52 pairs of OSCC tissues and matched adjacent tissue samples by quantitative real-time polymerase chain reaction (qRT-PCR) assay. After circ_0002141 was overexpressed or knocked down in OSCC cell lines, cell counting kit-8 (CCK-8) assay, Transwell assay, flow cytometry, and Western blotting were conducted to detect the changes in the growth, migration, invasion and apoptosis of OSCC cells. Western blot assay, qRT-PCR and dual-luciferase reporter assay were performed to clarify the interplay among circ_0002141, miR-1231, and epidermal growth factor receptor (EGFR).

RESULTS

Circ_0002141 expression was significantly upregulated in OSCC tissues and cell lines. Circ_0002141 overexpression markedly promoted the proliferation, migration, and invasion of OSCC cells whereas reduced the apoptotic of OSCC cells. Also, circ_0002141 knockdown suppressed the malignant characteristics of OSCC cells. EGFR was validated as the target of miR-1231. Besides, circ_0002141 could sponge miR-1231 and upregulate EGFR expression in OSCC cells.

CONCLUSION

Circ_0002141/miR-1231/EGFR axis is involved in the progression of OSCC.

Prognostic Potential of MicroRNAs in Glioma Patients: A Meta-Analysis

Introduction MicroRNAs are a noncoding RNA involved in affecting several transcription and translation pathways. Their use has been discussed as potential predictors of several tumors. Their use as potential biomarker in glioma patients is still controversial. The purpose of this meta-analysis is to explore the possible role of such microRNAs in glioma patients.

Methods After an extensive literature search done on PubMed and Embase, 20 studies were chosen for our analyses with the 9 discussing 11 tumor promoting microRNAs and 11 studies discussing 11 tumor suppressing microRNAs. The data needed was extracted from these studies including the hazard ratio that was used as the effect size for the purpose of our analysis. The needed analysis was performed using Stata and Excel.

Results The pooled hazard ratio for our analysis with patients having a lower microRNA expression for tumor promoting microRNAs came to be 2.63 (p < 0.001), while the hazard ratio for patients with higher expression of tumor promoting microRNA was 2.47 (p < 0.001) with both results being statistically significant. However, as significant heterogeneity was observed a random effect model for analysis was used. Subgroup analysis was further performed using grade, cutoff value (mean or median), sample type (Serum or Blood), and Karnofsky performance score, all of them showing a high hazard ratio.

Conclusion Our results showed that both tumor inhibitory and promoting microRNA can be used as prognostic tool in glioma patients with a poorer prognosis associated with a lower expression in tumor suppressive and higher expression in tumor promoting microRNA, respectively. However, to support this, future studies on a much larger scale would be needed.

Functions of non-coding RNAs in regulating cancer drug targets

With the development of precision medicine, the efficiency of tumor treatment has been significantly improved. More attention has been paid to targeted therapy and immunotherapy as the key to precision treatment of cancer. Targeting epidermal growth factor receptor (EGFR) has become one of the most important targeted treatments for various cancers. Comparing with traditional chemotherapy drugs, targeting EGFR is highly selective in killing tumor cells with better safety, tolerability and less side effect. In addition, tumor immunotherapy has become the fourth largest tumor therapy after surgery, radiotherapy and chemotherapy, especially immune checkpoint inhibitors. However, these treatments still produce a certain degree of drug resistance. Non-coding RNAs (ncRNAs) were found to play a key role in carcinogenesis, treatment and regulation of the efficacy of anticancer drugs in the past few years. Therefore, in this review, we aim to summarize the targeted treatment of cancers and the functions of ncRNAs in cancer treatment.

Screening for Prognostic microRNAs Associated with Treatment Failure in Diffuse Large B Cell Lymphoma

Simple Summary

Around 30–40% of patients with diffuse large B cell lymphoma suffer early relapse after standard chemotherapy, but today no prediction whether a patient belongs to this group is possible. MicroRNA are small nucleotide sequences that regulate cellular functions via post-transcriptional modification of gene expression and can serve as prognostic biomarkers. A novel two-step strategy first used a small patient discovery group to identify possible microRNA candidates by comparing their levels in chemosensitive and chemoresistant patients via microarray. Overexpression of these microRNA was then analyzed in a large patient cohort and, as a result, three new microRNA biomarkers with prognostic potential could be identified. Early identification of those patients being at risk of failure with standard therapy is a prerequisite to develop more efficient treatments and a step towards precision medicine.

Abstract

Diffuse large B cell lymphoma (DLBCL) treatment with R-CHOP regimen produces 5-year progression-free survival and overall survival of around 60–70%. Our objective was to discover prognostic biomarkers allowing early detection of the remaining 30–40% with poor long-term outcome. For this purpose, we applied a novel strategy: from a cohort of DLBCL patients, treated with standard therapy, a discovery group of 12 patients with poor prognosis (advanced stage III–IV, R-IPI > 2) was formed, consisting of six chemoresistant (refractory/early relapse < 12 months) and six chemosensitive (complete remission > 3 years) subjects. By using microarray assays, the most differentially expressed miRNAs were defined as an initial set of prognostic miRNA candidates. Their expression was then analyzed in a validation cohort of 68 patients and the three miRNAs with the most significant impact on event-free and overall survival were selected. In the DLBCL cell line U-2932 the transfection with miR-1244 and miR-193b-5p, but not miR-1231, blocked the effect of CHOP on cell viability. A subsequent gene set enrichment analysis in patients revealed the implication of the first two miRNAs in cell cycle control and chemoresistance-related pathways, whereas the last one was involved in immunological processes. In conclusion, this novel strategy identified three promising prognostic markers for DLBCL patients at high risk of failure with standard therapy.

Mesenchymal stem cell (MSC)-derived exosomes as novel vehicles for delivery of miRNAs in cancer therapy

Mesenchymal stem cells (MSCs) are known as promising sources for cancer therapy and can be utilized as vehicles in cancer gene therapy. MSC-derived exosomes are central mediators in the therapeutic functions of MSCs, known as the novel cell-free alternatives to MSC-based cell therapy. MSC-derived exosomes show advantages including higher safety as well as more stability and convenience for storage, transport and administration compared to MSCs transplant therapy. Unmodified MSC-derived exosomes can promote or inhibit tumors while modified MSC-derived exosomes are involved in the suppression of cancer development and progression via the delivery of several therapeutics molecules including chemotherapeutic drugs, miRNAs, anti-miRNAs, specific siRNAs, and suicide gene mRNAs. In most malignancies, dysregulation of miRNAs not only occurs as a consequence of cancer progression but also is directly involved during tumor initiation and development due to their roles as oncogenes (oncomiRs) or tumor suppressors (TS-miRNAs). MiRNA restoration is usually achieved by overexpression of TS-miRNAs using synthetic miRNA mimics and viral vectors or even downregulation of oncomiRs using anti-miRNAs. Similar to other therapeutic molecules, the efficacy of miRNAs restoration in cancer therapy depends on the effectiveness of the delivery system. In the present review, we first provided an overview of the properties and potentials of MSCs in cancer therapy as well as the application of MSC-derived exosomes in cancer therapy. Finally, we specifically focused on harnessing the MSC-derived exosomes for the aim of miRNA delivery in cancer therapy.

CircNPHP4 in monocyte-derived small extracellular vesicles controls heterogeneous adhesion in coronary heart atherosclerotic disease

Small extracellular vesicles (sEVs)-derived circular RNAs (circRNAs) could regulate gene expression in recipient cells, and dysregulation of sEVs-derived circRNAs has been implicated in several diseases. However, the expression and function of sEVs-derived circRNAs in coronary heart atherosclerotic disease (CAD) remain unknown. In this study, we investigated global changes in the expression patterns of circRNAs in sEVs from CAD-related monocytes and identified circNPHP4 as a significantly upregulated circRNA. Knockdown of circNPHP4 inhibited heterogeneous adhesion between monocytes and coronary artery endothelial cells and reduced ICAM-1 and VCAM-1 expression. Investigations of the underlying mechanisms revealed that circNPHP4 contains a functional miR-1231-binding site. Mutation of the circNPHP4-binding sites in miR-1231 abolished the interaction, as indicated by a luciferase reporter assay. Furthermore, circNPHP4 affected the expression of miR-1231 and its target gene EGFR. Overexpression of miR-1231 blocked the inhibitory effect of circNPHP4 on heterogeneous adhesion. Moreover, downregulation of miR-1231 restored heterogeneous adhesion upon inhibition by circNPHP4 silencing. Additionally, circNPHP4 overexpression was correlated with aggressive clinicopathological characteristics in CAD patients. A multivariate logistic regression model and bootstrapping validation showed that circNPHP4 overexpression had a good risk prediction capability for CAD. The decision curve analysis revealed that using the CAD nomogram that included circNPHP4 overexpression to predict the risk of CAD was beneficial. Our results suggest that sEVs-derived circNPHP4 can serve as a potential target for CAD treatments or as a potential diagnostic marker for CAD patients.

Identification of a miRNA-mRNA Regulatory Networks in Placental Tissue Associated With Tibetan High Altitude Adaptation

The Tibetan population has lived and successfully reproduced at high altitude for many generations. Studies have shown that Tibetans have various mechanisms for protection against high-altitude hypoxia, which are probably due, at least in part, to placental adaptation. However, comprehensive in silico analyses of placentas in Tibetans are lacking. We performed a microarray-based comparative transcriptome analysis of 10 Tibetan women from Yushu, Qinghai, CHN (∼3,780 m) and 10 European women living in Leadville, CO, United States (∼3,100 m) for less than three generations. Expression of HIF-1α, STAT3, EGFR, HSP5A, XBP1, and ATF6A mRNA was less in the Tibetan placentas as compared with European placentas. A total of 38 miRNAs were involved in regulating these genes. Differentially expressed genes were enriched for HIF1α signaling pathways, protein processing in the endoplasmic reticulum, PI3K-AKT signaling pathways, and MAPK signaling pathways. Based on the transcriptome profiles, the Tibetan population was distinct from the European population; placental tissues from the Tibetan population are lacking hypoxic responses, and “passivation” occurs in response to hypoxic stress. These results provide insights into the molecular signature of adaptation to high altitudes in these two populations.

The lncRNA-miRNA-mRNA ceRNA network in mural granulosa cells of patients with polycystic ovary syndrome: an analysis of Gene Expression Omnibus data

Background

Polycystic ovary syndrome (PCOS) is one of the most common endocrine abnormalities in women of reproductive age. In this study, we set out to construct a molecular long non-coding RNA (lncRNA)-microRNA (miRNA)-messenger RNA (mRNA) network according to the competitive endogenous RNA (ceRNA) theory and obtain insights into the related biological characteristics and pathways.

Methods

We downloaded two gene expression profile datasets of mural granulosa cells (MGCs) of women with PCOS and healthy women without PCOS (GSE84376 and GSE106724) from Gene Expression Omnibus (GEO) DataSets. Using GEO2R, we identified the mRNAs and non-coding RNAs with differential expression. The DIANA-microT-CDS algorithm was applied to predict the genes targeted by the differentially expressed miRNAs. The lncRNA-miRNA interactions were predicted using DIANA-LncBase v2. Then, we constructed the lncRNA-miRNA-mRNA network. The Database for Annotation, Visualization and Integrated Discovery (DAVID) was employed to identify the functions and enriched pathways of the genes. Subsequently, STRING was used to construct the protein-protein interaction (PPI) network. cytoHubba in Cytoscape was used to rank the hub genes, and finally, PPI modules were screened with Cytoscape MCODE.

Results

There were 462 mRNAs, 2,464 lncRNAs, and 55 miRNAs which showed differential expression between the MGCs of patients with PCOS and those of healthy controls. Based on the PPI analysis, differentially expressed genes (DEGs) were significantly enriched in retinol metabolism, drug metabolism—cytochrome P450, malaria, the Hippo signaling pathway, and glycine, serine, and threonine metabolism. The ceRNA network contained 71 lncRNA nodes, 14 miRNA nodes, and 69 mRNA nodes, as well as 167 edges. We identified some novel genes and non-coding RNAs that might be involved in PCOS, including CD163, MRC1, VSIG4, CCL2, CCR2, SPP1, hsa-miR-3135b, hsa-miR-4649-3p, hsa-miR-1231, hsa-miR-3609, and hsa-miR-4433b-3p.

Conclusions

This study identified a novel lncRNA-miRNA-mRNA network based on the ceRNA mechanism in PCOS. Some novel genes and non-coding RNAs that may be involved in the occurrence and development of PCOS were excavated, including CD163, MRC1, VSIG4, CCL2, CCR2, SPP1, hsa-miR-3135b, hsa-miR-4649-3p, hsa-miR-1231, hsa-miR-3609, and hsa-miR-4433b-3p. However, our findings need to be validated by in vivo and in vitro experiments.

Low miR-1231 expression predicts poor prognosis in non-small-cell lung cancer and accelerates cell proliferation, migration and invasion

Aim: miRNAs have been found to be involved in the tumor progression. This study aimed to assess the prognostic significance and biological function of miRNA-1231 (miR-1231) in non-small-cell lung cancer (NSCLC). Materials & methods: Expression of miR-1231 was measured by using quantitative real-time PCR. The prognosis value of miR-1231 was evaluated by Kaplan-Meier survival curves and Cox regression analysis. The biological function of miR-1231 was further studied. Results: Expression of miR-1231 in NSCLC patients and NSCLC cell lines were decreased. MiR-1231 was an independent prognostic biomarker. Overexpression of miR-1231 inhibited NSCLC cell proliferation, migration and invasion. Conclusion: Downregulated expression of miR-1231 serves as a prognostic biomarker of NSCLC and may be a potential therapeutic target.

Differences in expression of genes related to drug resistance and miRNAs regulating their expression in skin fibroblasts exposed to adalimumab and cyclosporine A

Introduction

Adalimumab and cyclosporine A are drugs used in moderate to severe forms of psoriasis. Despite the molecular orientation of the drugs, there is a loss of adequate cell sensitivity to the anti-cytokine therapy.

Aim

To determine the changes in the gene expression profile associated with drug resistance in the culture of normal human dermal fibroblasts (NHDF) exposed to adalimumab or cyclosporine A compared to the controls.

Material and methods

NHDF was exposed to adalimumab/cyclosporine A for 2, 8, 24 h compared to the control culture. Molecular analysis was performed using mRNA and miRNA microarray techniques. The obtained results were analysed using PL - Grid infrastructure (p < 0.05).

Results

Of the 22277 ID mRNA, 47 are associated with drug resistance, of which the change in expression of 17 mRNA ID is statistically significant (p < 0.05). The greatest change in transcriptional activity (FC ≥ 1.3) was observed for GLO1, SLC10A3, TUFT1, STATH, ABCB1, AGTR1. Expression of these genes can be regulated by miR-199a-5p, miR-1231, miR-34a, miR-3188, and miR-106a (except AGTR1).

Conclusions

The analysis of changes in the expression of mRNA and miRNA related to drug resistance gives the possibility of monitoring the effectiveness of anti-cytokine therapy.

MicroRNA signatures associated with lymph node metastasis in intramucosal gastric cancer

Although a certain proportion of intramucosal carcinomas (IMCs) of the stomach does metastasize, the majority of patients are currently treated with endoscopic resection without lymph node dissection, and this potentially veils any existing metastasis and may put some patients in danger. In this regard, biological markers from the resected IMC that can predict metastasis are warranted. Here, we discovered unique miRNA expression profiles that consist of 21 distinct miRNAs that are specifically upregulated (miR-628-5p, miR-1587, miR-3175, miR-3620-5p, miR-4459, miR-4505, miR-4507, miR-4720-5p, miR-4742-5p, and miR-6779-5p) or downregulated (miR-106b-3p, miR-125a-5p, miR-151b, miR-181d-5p, miR-486-5p, miR-500a-3p, miR-502-3p, miR-1231, miR-3609, and miR-6831-5p) in metastatic (M)-IMC compared to nonmetastatic (N)-IMC, or nonneoplastic gastric mucosa. Intriguingly, most of these selected miRNAs showed stepwise increased or decreased expression from nonneoplastic tissue to N-IMC to M-IMC. This suggests that common oncogenic mechanisms are gradually intensified during the metastatic process. Using a machine-learning algorithm, we demonstrated that such miRNA signatures could distinguish M-IMC from N-IMC. Gene ontology and pathway analysis revealed that TGF-β signaling was enriched from upregulated miRNAs, whereas E2F targets, apoptosis-related, hypoxia-related, and PI3K/AKT/mTOR signaling pathways, were enriched from downregulated miRNAs. Immunohistochemical staining of samples from multiple institutions indicated that PI3K/AKT/mTOR pathway components, MAPK1, phospho-p44/42 MAPK, and pS6 were highly expressed and the expression of SMAD7, a TGF-β pathway component, was decreased in M-IMC, which could aid in distinguishing M-IMC from N-IMC. The miRNA signature discovered in this study is a valuable biological marker for identifying metastatic potential of IMCs, and provides novel insights regarding the metastatic progression of IMC.

The emerging role of non-coding RNAs in the regulation of PI3K/AKT pathway in the carcinogenesis process

The PI3K/AKT pathway is an intracellular signaling pathway with an indispensable impact on cell cycle control. This pathway is functionally related with cell proliferation, cell survival, metabolism, and quiescence. The crucial role of this pathway in the development of cancer has offered this pathway as a target of novel anti-cancer treatments. Recent researches have demonstrated the role of microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) in controlling the PI3K/AKT pathway. Some miRNAs such as miR-155-5p, miR-328-3p, miR-125b-5p, miR-126, miR-331-3p and miR-16 inactivate this pathway, while miR-182, miR-106a, miR-193, miR-214, miR-106b, miR-93, miR-21 and miR-103/107 enhance activity of this pathway. Expression levels of PI3K/AKT-associated miRNAs could be used to envisage the survival of cancer patients. Numerous lncRNAs such as GAS5, FER1L4, LINC00628, PICART1, LOC101928316, ADAMTS9-AS2, SLC25A5-AS1, MEG3, AB073614 and SNHG6 interplay with this pathway. Identification of the impact of miRNAs and lncRNAs in the control of the activity of PI3K/AKT pathway would enhance the efficacy of targeted therapies against this pathway. Moreover, each of the mentioned miRNAs and lncRNAs could be used as a putative therapeutic candidate for the interfering with the carcinogenesis. In the current study, we review the role of miRNAs and lncRNAs in controlling the PI3K/AKT pathway and their contribution to carcinogenesis.

Circular RNA hsa_Circ_0005795 mediates cell proliferation of cutaneous basal cell carcinoma via sponging miR-1231

Growing evidence has revealed that circular RNAs (circRNA) play critical roles in cancer progression. Here, we examined the function of a novel circRNA, Circ_0005795, in basal cell carcinoma (BCC) and explored the possible molecular mechanism. Nodular BCC and adjacent non-tumor tissues derived from 30 patients and 2 BCC cell lines were applied to analyze gene expression. Circ_0005795 loss- and gain-of-function were constructed to investigate BCC progression. Nuclear and cytoplasmic fractionation and luciferase assay were carried out to determine cellular localization and molecular interaction of Circ_0005795. Circ_0005795 expression was significantly elevated in BCC tissues and cells. Knockdown of Circ_0005795 dramatically reduced cell viability, colony formation, and anti-apoptotic protein levels, while increased caspase-3 activity. Circ_0005795 located in cytoplasm, which exerted its tumor-promoting effect through targeting and sponging miR-1231 in BCC cells. In summary, Circ_0005795 works as an oncogene in BCC, which might be used as a promising biomarker and a potential therapeutic target for BCC diagnosis and treatment.

MicroRNAs involved in the EGFR pathway in glioblastoma

Glioblastoma (GBM) is the most common primary malignant tumor in adults, and its morbidity and mortality are very high. Although progress has been achieved in the treatment of GBM, such as surgery, chemotherapy and radiotherapy, in recent years, the prognosis of patients with GBM has not improved significantly. MicroRNAs (miRNAs) are endogenous noncoding single-stranded RNAs consisting of approximately 20-22 nucleotides that regulate gene expression at the posttranscriptional level by binding to target protein-encoding mRNAs. Notably, miRNAs regulate various carcinogenic pathways, one of which is the epidermal growth factor receptor (EGFR) signaling pathway, which controls cell proliferation, invasion, migration, angiogenesis and apoptosis. In this review, we summarize the novel discoveries of roles for miRNAs targeting the factors in the EGFR signaling pathway in the occurrence and development of GBM. In addition, we describe their potential roles as biomarkers for the diagnosis and prognosis of GBM and for determining the treatment resistance of GBM and the efficacy of therapeutic drugs.

The miR-30a-5p/CLCF1 axis regulates sorafenib resistance and aerobic glycolysis in hepatocellular carcinoma

HCC (hepatocellular carcinoma) is a major health threat for the Chinese population and has poor prognosis because of strong resistance to chemotherapy in patients. For instance, a considerable challenge for the treatment of HCC is sorafenib resistance. The aberrant glucose metabolism in cancer cells aerobic glycolysis is associated with resistance to chemotherapeutic agents. Drug-resistance cells and tumors were exposed to sorafenib to establish sorafenib-resistance cell lines and tumors. Western blotting and real-time PCR or IHC staining were used to analyze the level of CLCF1 in the sorafenib resistance cell lines or tumors. The aerobic glycolysis was analyzed by ECAR assay. The mechanism mediating the high expression of CLCF1 in sorafenib-resistant cells and its relationships with miR-130-5p was determined by bioinformatic analysis, dual luciferase reporter assays, real-time PCR, and western blotting. The in vivo effect was evaluated by xenografted with nude mice. The relation of CLCF1 and miR-30a-5p was determined in patients' samples. In this study, we report the relationship between sorafenib resistance and increased glycolysis in HCC cells. We also show the vital role of CLCF1 in promoting glycolysis by activating PI3K/AKT signaling and its downstream genes, thus participating in glycolysis in sorafenib-resistant HCC cells. Furthermore, we also show that miR-30a-5p directly targets CLCF1 and that sorafenib-mediated suppression of miR-30a-5p results in the upregulation of CLCF1 in HCC cells resistant to sorafenib. We also found that when a cholesterol modified agomiR-30a-5p was delivered systemically to mice harboring sorafenib-resistant HCC tumors, tumor growth decreased significantly. There is an uncharacterized mechanism of biochemical resistance to hormone therapies orchestrated by the miR-30a-5p/CLCF1 axis to mediate sorafenib resistance and aerobic glycolysis in HCC. Therefore, this study indicates that targeting the miR-30a-5p/CLCF1 axis may hold promise for therapeutic intervention in HCC sorafenib resistance patients.

MiR-1231 decrease the risk of cancer-related mortality in patients combined with non-small cell lung cancer and diabetes mellitus

Background

Non-small cell lung cancer (NSCLC) is a deadly human malignancy, and previous studies support the contribution of microRNAs (miRNAs) to cancer assessment. It has been reported that miR-1231 can be used as a biomarker to assess prognosis in different cancers. However, the prognostic value of miR-1231 in NSCLC patients with comorbid diabetes mellitus (DM) remains unclear. The present study evaluated the risk factors for NSCLC with DM and developed a predictive model for it.

Methods

A real-world study was conducted, including data from 108 patients with NSCLC combined with DM from April 1, 2010, to June 1, 2015. MiR-1231 was recorded during hospital admission. Cox-proportional hazards model was applied for survival analysis of risk factors for cancer-related mortality and to create nomograms for prediction. The accuracy of the model was evaluated by C-index and calibration curves.

Results

The mortality rate in the high miR-1231 level (≥ 1.775) group was 57.4%. On the basis of univariate analysis, we put factors (P < 0.05) into multivariate regression models, and high miR-1231 levels (P < 0.001, HR = 0.57), surgery (P < 0.001, HR = 0.37) and KPS score > 80 (P = 0.01, HR = 0.47) had a better prognosis and were considered as independent protective factors. These independently relevant factors were used to create nomograms to predict long-term patient survival. Nomogram showed good accuracy in risk estimation with a guide-corrected C-index of 0.691.

Conclusion

MiR-1231 reduced the risk of cancer-related death in patients with combined NSCLC and DM. Nomogram based on multivariate analysis showed good accuracy in estimating the overall risk of death.

Proteomics identifies EGF-like domain multiple 7 as a potential therapeutic target for epidermal growth factor receptor-positive glioma

Background

Glioma, the most frequent primary tumor of the central nervous system, has poor prognosis. The epidermal growth factor receptor (EGFR) pathway and angiogenesis play important roles in glioma growth, invasion, and recurrence. The present study aimed to use proteomic methods to probe into the role of the EGF‐EGFR‐angiogenesis axis in the tumorigenesis of glioma and access the therapeutic efficacy of selumetinib on glioma.

Methods

Proteomic profiling was used to characterize 200 paired EGFR‐positive and EGFR‐negative glioma tissues of all pathological types. The quantitative mass spectrometry data were used for systematic analysis of the proteomic profiles of 10 EGFR‐positive and 10 EGFR‐negative glioma cases. Consensus‐clustering analysis was used to screen target proteins. Immunofluorescence analysis, cell growth assay, and intracranial xenograft experiments were used to verify and test the therapeutic effect of selumetinib on glioma.

Results

Advanced proteomic screening demonstrated that the expression of EGF‐like domain multiple 7 (EGFL7) was higher in EGFR‐positive tumor tissues than in EGFR‐negative tumor tissues. In addition, EGFL7 could act as an activator in vitro and in vivo to promote glioma cell proliferation. EGFL7 was associated strongly with EGFR and prognosis. EGFL7 knockdown effectively suppressed glioma cell proliferation. Selumetinib treatment showed tumor reduction effect in EGFR‐positive glioblastoma xenograft mouse model.

Conclusions

EGFL7 is a potential diagnostic biomarker and therapeutic target of glioma. Selumetinib could target the EGFR pathway and possibly improve the prognosis of EGFR‐positive glioma.

MicroRNA-505-3p inhibits development of glioma by targeting HMGB1 and regulating AKT expression

Previous studies have reported that microRNA (miR)-505 exhibits important effect in human cancers. However, the regulatory mechanism of miR-505-3p/high-mobility group box 1 (HMGB1) axis is still unclear in glioma. Therefore, the regulatory mechanism of miR-505-3p/HMGB1 axis in glioma was illuminated. Expression of miR-505-3p and HMGB1 was observed by RT-qPCR. Protein expression was measured by western blot analysis. Dual luciferase assay was performed to confirm the relationship between miR-505-3p and HMGB1. The function of miR-505-3p was investigated by MTT and Transwell assays. Expression of miR-505-3p was reduced in glioma, which was related to poor clinical outcomes and prognosis in glioma patients. Moreover, overexpression of miR-505-3p suppressed proliferation, migration and invasion of glioma cells. In addition, HMGB1 was confirmed as a direct target of miR-505-3p, and miR-505-3p inhibited the development of glioma by targeting HMGB1. Furthermore, miR-505-3p blocked EMT suppressing p-AKT expression in glioma cells. In conclusion, miR-505-3p inhibited the development of glioma by targeting HMGB1 and regulating AKT expression.

How microRNAs affect the PD-L1 and its synthetic pathway in cancer

Programmed cell death-ligand 1 (PD-L1) is a glycoprotein that is expressed on the cell surface of both hematopoietic and nonhematopoietic cells. PD-L1 play a role in the immune tolerance and protect self-tissues from immune system attack. Dysfunction of this molecule has been highlighted in the pathogenesis of tumors, autoimmunity, and infectious disorders. MicroRNAs (miRNAs) are endogenous molecules that are classified as small non-coding RNA with approximately 20-22 nucleotides (nt) length. The function of miRNAs is based on complementary interactions with target mRNA via matching completely or incompletely. The result of this function is decay of the target mRNA or preventing mRNA translation. In the past decades, several miRNAs have been discovered which play an important role in the regulation of PD-L1 in various malignancies. In this review, we discuss the effect of miRNAs on PD-L1 expression and consider the effect of miRNAs on the synthetic pathway of PD-L1, especially during cancers.

A putative competing endogenous RNA network in cisplatin-resistant lung adenocarcinoma cells identifying potentially rewarding research targets

Lung adenocarcinoma (LUAD) is the most common type of non-small cell lung cancer and has a poor 5 year survival rate (<10%). Cisplatin is one of the most effective chemotherapeutic treatments for LUAD, even though it is of limited overall utility due to acquired drug resistance. To identify possible genetic targets for the mitigation of cisplatin resistance, gene expression data from cisplatin-resistant cell lines were integrated with patient information. Expression data for cisplatin-resistant and cisplatin-sensitive A549 cell lines were obtained from the Gene Expression Omnibus database, while LUAD patient data was obtained from The Cancer Genome Atlas (TCGA) database. Differentially expressed mRNAs (DEmRNAs), microRNAs (DEmiRNAs) and long non-coding RNAs (DElncRNAs) were identified between the cisplatin-sensitive and cisplatin-resistant cells. Using the TCGA patient data, 33 DEmRNAs associated with survival were identified. A total of 74 DElncRNAs co-expressed with the survival-associated DEmRNAs, and 11 DEmiRNAs that regulated the survival-associated DEmRNAs, were also identified. A competing endogenous RNA (ceRNA) network was constructed based on the aforementioned results, which included 17 survival-associated DEmRNAs, 9 DEmiRNAs and 16 DElncRNAs. This network revealed 8 ceRNA pathway axes possibly associated with cisplatin resistance in A549 cells. Specifically, the network suggested that the lncRNAs HOXD-AS2, LINC01123 and FIRRE may act as ceRNAs to increase cisplatin resistance in human LUAD cells. Therefore, it was speculated that these lncRNAs represent potentially rewarding research targets.

MircoRNA-129-5p suppresses the development of glioma by targeting HOXC10

BACKGROUND

miR-129-5p has been reported to be abnormally expressed and plays an important role in the progression of various malignancies. However, its role in gliomas and its exact molecular mechanism need further research.

METHODS AND MATERIALS

RT-qPCR was performed to evaluate miR-129-5p and HOXC10 mRNA expression levels in tissues and cell lines. Cell proliferation was detected via Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU) and clone formation assays. Luciferase assays were used to validate the binding of seeds between miR-129-5p and HOXC10. A tumor xenograft model was developed to study the effect of miR-129-5p on glioma growth in vivo.

RESULTS

miR-129-5p was expressed at low levels in glioma tissues and cell lines. miR-129-5p overexpression inhibited glioma proliferation, migration and invasion. miR-129-5p negatively and directly targeted HOXC10. At the same time, HOXC10 was upregulated in glioma cancer, and HOXC10 knockdown inhibited cell proliferation, migration and invasion.

CONCLUSION

miR-129-5p inhibits glioma development by altering HOXC10 expression and may therefore serve as a new diagnostic marker and therapeutic target for glioma in the future.

EGFRvIII: An Oncogene with Ambiguous Role

Epidermal growth factor receptor variant III (EGFRvIII) seems to constitute the perfect therapeutic target for glioblastoma (GB), as it is specifically present on up to 28-30% of GB cells. In case of other tumor types, expression and possible role of this oncogene still remain controversial. In spite of EGFRvIII mechanism of action being crucial for the design of small active anticancer molecules and immunotherapies, i.e., CAR-T technology, it is yet to be precisely defined. EGFRvIII is known to be resistant to degradation, but it is still unclear whether it heterodimerizes with EGF-activated wild-type EGFR (EGFRWT) or homodimerizes (including covalent homodimerization). Constitutive kinase activity of this mutated receptor is relatively low, and some researchers even claim that a nuclear, but not a membrane function, is crucial for its activity. Based on the analyses of recurrent tumors that are often lacking EGFRvIII expression despite its initial presence in corresponding primary foci, this oncogene is suggested to play a marginal role during later stages of carcinogenesis, while even in primary tumors EGFRvIII expression is detected only in a small percentage of tumor cells, undermining the rationality of EGFRvIII-targeting therapies. On the other hand, EGFRvIII-positive cells are resistant to apoptosis, more invasive, and characterized with enhanced proliferation rate. Moreover, expression of this oncogenic receptor was also postulated to be a marker of cancer stem cells. Opinions regarding the role that EGFRvIII plays in tumorigenesis and for tumor aggressiveness are clearly contradictory and, therefore, it is crucial not only to determine its mechanism of action, but also to unambiguously define its role at early and advanced cancer stages.

miR-1231 Is Downregulated in Prostate Cancer with Prognostic and Functional Implications

BACKGROUND

Our study investigated the expression levels of miR-1231 in prostate cancer tissues and cell lines and explored its potential prognostic significance as well as its functional effects on prostate cancer cells.

METHODS

miR-1231 expression levels were detected in prostate cancer tissues and prostate cancer cell lines using qRT-PCR. The prognostic significance of miR-1231 in prostate cancer was assessed using the Kaplan-Meier curve and Cox regression analyses. Evaluation of the impact of ectopic expression or inhibition of miR-1231 on aggressive tumor behavior (cellular proliferation, migration, and invasion) of prostate cancer cell lines involved the CCK-8 and Transwell assays.

RESULTS

miR-1231 expression was downregulated in both prostate cancer tissues and cell lines. Downregulation of miR-1231 was significantly associated with lymph node metastasis, higher TNM stage, higher clinical stage, and shorter overall survival. The expression of miR-1231 was predicted as a prognostic factor for prostate cancer patients. Additionally, we found overexpression of miR-1231 suppressed proliferation, migration, and invasion of prostate cancer cell linesin vitro. EGFR was a direct target of miR-1231.

CONCLUSION

Taken together, our results indicate that miR-1231 expression plays a tumor-suppressive role in prostate cancer. It is downregulated in prostate cancer and may suppress prostate cancer cell proliferation, migration, and invasion by targeting EGFR, and it may be a prognostic biomarker and potential therapeutic strategy for prostate cancer treatment in the future.

Exosomal miRNA-1231 derived from bone marrow mesenchymal stem cells inhibits the activity of pancreatic cancer

Pancreatic cancer (PC) is a highly malignant tumor with increased morbidity and mortality, which is difficult to diagnose and cure in the clinic. Through secreting exosomes containing biological molecules, including diverse RNAs and proteins, bone marrow mesenchymal stem cells (BM-MSCs) influence the immunity, inflammation, tumor environment, and cancer metastasis. In this study, low expression of miRNA-1231 (miR-1231) in exosomes derived from the peripheral blood was significantly correlated with the TNM stage of PC, suggesting the potential inhibitory effect of exosomal miR-1231 on PC occurrence and development. The proliferation, migration, invasion, and adhesion to the matrix of PC cells BxPC-3 and PANC-1 were negatively regulated by exosomes derived from the supernatants of BM-MSCs that transfected with miR-1231 oligonucleotides. Simultaneously, tumor growth in vivo was seriously restrained in BALB/C nude mice by tail vein injection with exosomes originated from BM-MSCs that transfected with miR-1231 mimics. The exosomes extracted from BM-MSCs with high level of miR-1231 inhibit the activity of PC, providing the potential application for developing new and efficient medicine for cancer therapy, especially for PC treatment. The exosomal miR-1231 of peripheral blood may also be a potential indicator for PC diagnosis in the future.

Comprehensive circular RNA profiling reveals the regulatory role of the hsa_circ_0137606/miR‑1231 pathway in bladder cancer progression

Bladder cancer (BC) is one of the most common malignant tumors in males globally. Its progression imposes a heavy burden on patients; however, the expression profile of circular (circ)RNAs in BC progression remains unclear. This study explored changes in circRNA expression during BC progression by sequencing different grade BC samples and normal controls to reveal the circRNA expression profiles of different BC grades. Gene Ontology (GO) and Kyoto Encyclopedia of Gens and Genomes (KEGG) pathway analyses, and protein-protein interaction network construction were used to predict pathways that the differentially expressed circRNAs may participate in. circRNA expression levels were detected using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and dual-luciferase reporter assays were used to investigate the interactions between circRNA and microRNA (miR). Cell Counting Kit-8 and Transwell assays were also performed to detect cell proliferation, migration, and invasion. In total, 244 circRNAs were found to be differentially expressed in high-grade BC compared to low-grade BC, whilst 316 dysregulated circRNAs were detected in high-grade BC compared with normal urothelium. Furthermore, 42 circRNAs overlapped between the two groups, seven of which were randomly selected and detected by RT-qPCR to validate the sequencing results. GO analysis and KEGG pathway analyses revealed that the differentially expressed circRNAs may participate in BC via 'GTPase activity regulation', 'cell junction', and 'focal adhesion' pathways. Of note, we proposed that a novel circRNA in BC progression, hsa_circ_0137606, could suppress BC proliferation and metastasis by sponging miR-1231. Through bioinformatics analysis, we predicted that PH domain and leucine rich repeat protein phosphatase 2 could be a target of the hsa_circ_0137606/miR-1231 axis in BC progression. Using high-throughput sequencing, this study revealed the circRNA expression profiles of different grades of BC and proposed that the novel circRNA, hsa_circ_0137606, suppresses BC proliferation and metastasis by sponging miR-1231. Our findings may provide novel insight into potential therapeutic targets for treating BC.

miR-423-5p inhibits the proliferation and metastasis of glioblastoma cells by targeting phospholipase C beta 1

Glioma is a common brain tumor which is highly invasive, responds poorly to therapy, and has a poor prognosis. There is growing evidence that an abnormal expression of many genes is related to glioma and leads to glioma cell growth and metastasis. Phospholipase C beta 1 (PLCB1) plays critical roles in intracellular transduction and regulating signal activation, which are important to tumorigenesis. Therefore, it could bind to miRNA as a target gene. The purpose of our study was to confirm that PLCB1 plays a critical role in suppressing glioma progression. We found that the expression of miR-423-5p was reduced, but the expression of PLCB1 was increased, in glioma tissues and cells. To explore whether miR-423-5p affects PLCB1, a bioinformatics approach suggested that miR-423-5p can directly target PLCB1. Moreover, we observed, using luciferase reporter assays, that miR-423-5p could target PLCB1 3'-UTR. Functionally, the overexpression of miR-423-5p could attenuate the proliferation, invasion, and migration and promote the apoptosis of glioma cells. Furthermore, we found that miR-423-5p could enhance p-ERK expression in glioma cells. Taken together, we deduced that miR-423-5p inhibited proliferation and metastasis by targeting PLCB1, and it also promotes apoptosis in glioma cells. These results suggest that miR-423-5p directly targets PLCB1 3'-UTR and could inhibit cell invasion and migration through the ERK-dependent pathway in glioma, and the miR-423-5p/PLCB1 axis may be a potential target for new potential therapeutic strategies to treat glioma.

Enhanced expression of circular RNA circ-DCAF6 predicts adverse prognosis and promotes cell progression via sponging miR-1231 and miR-1256 in gastric cancer

Circular RNAs (circRNAs) have been reported as essential regulators in various malignancies, including gastric cancer (GC). Previously, circ-DCAF6 was screened as an elevated circRNA in GC patients' tissue samples compared with the normal tissues. To our knowledge, the role of circ-DCAF6 in human cancers is still needed to reveal. The present project is to evaluate the functions and mechanisms of circ-DCAF6 in GC progression. Upregulation of circ-DCAF6 was determined in GC tissue samples and cells by qRT-PCR. Enhanced level of circ-DCAF6 was linked to deeper tumor invasion, positive lymph node metastasis, and higher TNM stages in GC patients. Multivariate analysis further indicated circ-DCAF6 as an independent prognostic indicator. Functionally, CCK-8, clone forming, flow cytometry and transwell assays verified that circ-DCAF6 played as an oncogene in GC cells. Mechanistically, we found the negative correlation between circ-DCAF6 and miR-1231/-1256 in GC specimens. Moreover, luciferase reporter gene assay illustrated that miR-1231 and miR-1256 could be bound to circ-DCAF6. Rescue experiments revealed that circ-DCAF6 facilitated cell growth and invasion via suppressing the levels of miR-1231 and miR-1256. To sum up, circ-DCAF6 acts as an important role in GC tumor progression, and high circ-DCAF6 level may be a useful biomarker for GC.

KCNQ1OT1 affects the progression of diabetic retinopathy by regulating miR-1470 and epidermal growth factor receptor

Long noncoding RNAs have been reported to play important roles in the pathogenesis of diabetic retinopathy (DR), which has been considered as the most common disease leading to vision loss. However, it is still unclear whether KCNQ1 overlapping transcript 1 (KCNQ1OT1) could affect DR. In this study, regarding quantitative reverse transcription polymerase chain reaction assay, KCNQ1OT1 level was upregulated while microRNA-1470 (miR-1470) was decreased in DR patients and human retinal endothelial cells. High KCNQ1OT1 expression was correlated with DR stage and low visual function. Using miR-1470 mimic or knockdown of KCNQ1OT1 could lead to the similar phenomenon; phospho-AKT, Bax, B-cell lymphoma 2, and cleaved poly-ADP ribose polymerase (PARP) were regulated, while vascularization was inhibited and apoptosis was promoted. Regarding bioinformatics analysis and in vitro dual luciferase reporter assay, there should be a negative correlation between KCNQ1OT1 and miR-1470. Additionally, mRNA of epidermal growth factor receptor (EGFR) was proved as the target of miR-1470 and EGFR targeting by miR-1470 initiated KCNQ1OT1 deficiency-induced apoptosis and promoted proliferation. KCNQ1OT1 and miR-1470 were proved to be the promoter and repressor of EGFR, respectively. The results suggested that KCNQ1OT1 could sponge miR-1470 and further regulate EGFR in DR.

Upregulated circular RNA circ_0025033 promotes papillary thyroid cancer cell proliferation and invasion via sponging miR-1231 and miR-1304

Recent evidence revealed that circular RNAs (circRNAs) are key regulators for tumorigenesis. However, their roles in papillary thyroid cancer (PTC) is not fully understood. In the current work, the differentially expressed circRNAs between PTC tissues and adjacent noncancerous tissue samples were screened by circRNA microarray. We further selected the highest expressed circRNA (circ_0025033) in tumorous tissues for the study. qRT-PCR was used to measure the level of circ_0025033 in PTC tissue samples and cell lines. Gain/loss of function assays were carried out to determine the effect of circ_0025033 on cell viability, clone-forming, apoptosis, migration and invasion. Dual-luciferase reporter assays were conducted to investigate the mechanisms of circ_0025033 in PTC. The data showed that circ_0025033 aggravated cell proliferation, migration and invasion and inhibited cell apoptosis. Additionally, circ_0025033 could directly sponge miR-1231 and miR-1304 in PTC cells. Furthermore, the oncogenic role of circ_0025033 is dependent on its suppression of miR-1231 and miR-1304. Collectively, this work uncovers a novel signal of circ_0025033/miR-1231/miR-1304 involved in PTC initiation and progression.

Identification of miR-375 as a potential prognostic biomarker for esophageal squamous cell cancer: A bioinformatics analysis based on TCGA and meta-analysis

Accumulating evidence has demonstrated that aberrantly expressed miRNAs in cancer tissues regulated various cellular processes related to carcinogenesis. The present study aimed to identify the differentially expressed miRNAs between esophageal squamous cell cancer (ESCC) and adjacent normal esophageal tissue (ANET). In our present study, we identified 129 differentially expressed miRNAs between ESCC and ANET by analyzing high-throughput miRNA data downloaded from TCGA database. After investigating the prognostic value of the 129 differential expressed miRNAs, eight miRNAs were found to be associated with prognosis of patients with ESCC. The clinical significance and bio-function of miR-375 was further examined. We performed Gene Set Enrichment Analysis (GSEA) to identify the top three gene sets that significantly altered between the patients with miR-375 low expression and high expression. In order to explore the mechanism of the development and progression of ESCC, the role of miR-375 in ESCC and its four candidate target genes was examined. At last, we performed a meta-analysis to verify the prognostic value of miR-375 in ESCC. In conclusion, our findings suggest that miR-375 serves as a promising independent prognostic factor for ESCC and function as a tumor suppressor.

MicroRNA-562 negatively regulated c-MET/AKT pathway in the growth of glioblastoma cells

Background

MicroRNA-562 (miR-562) has been found to possess anti-cancer function in certain tumors. However, the function of miR-562 in glioblastoma (GBM) is still not fully understood.

Purpose

The aim at present study is to analyze the function of miR-562 and its possible target in GBM cells.

Patients and methods

In the present study, a total of 80 GBM samples and 16 adjacent noncancerous tissues were used to examine the expression of miR-562 and c-MET. In order to gain a deep insight into the molecular network of miR-562 and c-MET in GBM, the miR-562 mimic and inhibitor were transfected into two GBM cell lines (U251 and U87), respectively. Meanwhile, lentiviral vector was used to mediate overexpression of c-MET. Cell proliferation was examined via Cell Counting Kit-8 (CCK-8) assays. Meanwhile, cell apoptosis was analyzed by Annexin V-FTTC/PI staining assay.

Results

Our results indicated that the level of miR-562 was downregulated in GBM tissues and the expression of c-MET was upregulated in tumors. Cell proliferation analysis indicated that miR-562 was an anti-proliferation effector in GBM cells. Moreover, cell apoptosis analysis suggested the pro-apoptosis function of miR-562 in GBM cells.

Conclusion

Our results demonstrated that miR-562 negatively regulated the c-MET/AKT signal pathway. In addition, caspase-3 might also serve as another target for miR-562 in GBM cells. This research not only obtained a deep understanding of miR-562 but also provided evidence in terms of developing new prognostic biomarker for GBM.

MiRNA-139-3p inhibits the proliferation, invasion, and migration of human glioma cells by targeting MDA-9/syntenin

Gliomas are the most common primary malignant brain tumor in adults. Although these tumors are aggressive and frequently lethal, there are currently few therapeutic approaches available to prolong patient survival. MicroRNAs play important roles in regulating the expression of genes that control diverse cellular processes. Here, we investigated the expression and function of miR-139-3p in gliomas using clinical specimens, cultured cells, and a mouse xenograft tumor model. We found that miR-139-3p expression is markedly lower in human glioma tissues than in normal brain tissues. We identified melanoma differentiation-associated gene-9 (MDA-9)/syntenin, an adaptor protein implicated in tumor metastasis, as a novel direct target of miR-139-3p and showed that syntenin mRNA and miR-139-3p levels were inversely correlated in clinical specimens (r = -0.6817, P = 0.0002). Overexpression of miR-139-3p in human glioma cell lines inhibited cell proliferation, migration, and invasion, and these effects were rescued by co-transfection with syntenin. Our results indicate that miR-139-3p plays a significant role in controlling behaviors associated with the malignant progression of gliomas, and we identify the miR-139-3p-syntenin axis as a potential therapeutic target for glioma.