miRNA-218 contributes to the regulation of D-glucuronyl C5-epimerase expression in normal and tumor breast tissues

Differential regulation of heparan sulfate biosynthesis in fibroblasts cocultured with normal vs. cancerous prostate cells

Heparan sulfate proteoglycans (HSPGs) regulate a wide range of biological activities in both physiological and pathological conditions. Altered expression or deregulated function of HSPGs and their heparan sulfate (HS) chains significantly contribute to carcinogenesis as well and crucially depends on the functioning of the complex system of HS biosynthetic/modifying enzymes termed as "GAGosome". Here, we aimed at investigating the expression profile of the system in a cell culture model of stroma-epithelial crosstalk and searching for transcription factors potentially related to the regulation of expression of the genes involved. Coculture of BjTERT-fibroblasts with normal PNT2 human prostate epithelial cells resulted in significant downregulation (2-4-fold) of transcriptional activity of HS metabolism-involved genes (EXT1/2, NDST1/2, GLCE, HS2ST1, HS3ST1/2, HS6ST1/2, SULF1/2, HPSE) in both cell types, whereas coculture with prostate cancer cells (LNCaP, PC3, DU145) demonstrated no significant interchanges. Human Transcription Factor RT2 Profiler PCR array and manual RT-PCR verification supposed FOS, MYC, E2F, SRF, NR3C1 as potential candidates for regulation and/or coordination of HS biosynthesis. Taken together, transcriptional activity of HS biosynthetic system in normal fibroblasts and prostate epithelial cells during their coculture might be controlled by their intercellular communication, reflecting of adaptation of these cells to each other. The regulation is attenuated or abrogated if normal fibroblasts interact with prostate cancer cells making the cancer cells independent of the limiting effects of fibroblasts, thus contributing to possibility of unlimited growth and progression. Overall, these data demonstrate an ability of cell-cell interactions to affect transcriptional activity of HS biosynthesis-involved genes.

Prognostic value of GLCE and infiltrating immune cells in Ewing sarcoma

Background

The prognostic value of D-glucuronyl C5-epimerase (GLCE) and mast cell infiltration in Ewing sarcoma (ES) has not been well specified and highlighted, which may facilitate survival prediction and treatment.

Methods

Several qualified datasets were downloaded from the GEO website. Common differentially expressed genes between normal subjects and ES patients in GSE17679, GSE45544, and GSE68776 were identified and screened by multiple algorithms to find hub genes with prognostic value. The prognostic value of 64 infiltrating cells was also explored. A prognostic model was established and then validated with GSE63155 and GSE63156. Finally, functional analysis was performed.

Results

GLCE and mast cell infiltration were screened as two indicators for a prognostic model. The Kaplan‒Meier analysis showed that patients in the low GLCE expression, mast cell infiltration and risk score groups had poorer outcomes than patients in the high GLCE expression, mast cell infiltration and risk score groups, both in the training and validation sets. Scatter plots and heatmaps also indicated the same results. The concordance indices and calibration analyses indicated a high prediction accuracy of the model in the training and validation sets. The time-dependent receiver operating characteristic analyses suggested high sensitivity and specificity of the model, with area under the curve values between 0.76 and 0.98. The decision curve analyses suggested a significantly higher net benefit by the model than the treat-all and treat-none strategies. Functional analyses suggested that glycosaminoglycan biosynthesis-heparan sulfate/heparin, the cell cycle and microRNAs in cancer were upregulated in ES patients.

Conclusions

GLCE and mast cell infiltration are potential prognostic indicators in ES. GLCE may affect the proliferation, angiogenesis and metastasis of ES by affecting the biosynthesis of heparan sulfate and heparin.

Anti-tumor Activity of Propofol: A Focus on MicroRNAs

BACKGROUND

MicroRNAs are endogenous, short, non-coding RNAs with the length as low as 20 to 25 nucleotides. These RNAs are able to negatively affect the gene expression at the post-transcriptional level. It has been demonstrated that microRNAs play a significant role in cell proliferation, cell migration, cell death, cell differentiation, infection, immune response, and metabolism. Besides, the dysfunction of microRNAs has been observed in a variety of cancers. So, modulation of microRNAs is of interest in the treatment of disorders.

OBJECTIVE

The aim of the current review is to investigate the modulatory effect of propofol on microRNAs in cancer therapy.

METHODS

This review was performed at PubMed, SCOPUS and Web of Science data-bases using keywords "propofol', "microRNA", "cancer therapy", "propofol + microRNA" and "propofol + miR".

RESULTS

It was found that propofol dually down-regulates/upregulates microRNAs to exert its antitumor activity. In terms of oncogenesis microRNAs, propofol exert an inhibitory effect, while propofol significantly enhances the expression of oncosuppressor microRNAs.

CONCLUSION

It seems that propofol is a potential modulator of microRNAs and this capability can be used in the treatment of various cancers.

Re-expression of glucuronyl C5-epimerase in the mutant MEF cells increases heparan sulfate epimerization but has no influence on the Golgi localization and enzymatic activity of 2-O-sulfotransferase

Heparan sulfate (HS) is a linear and complex polysaccharide that modulates the biological activities through protein recognition and interaction. Evidence indicates that protein-binding properties of HS are largely dependent on distinctive sulfation and epimerization patterns that are modified by a series of Golgi-localized enzymes. In particular, the glucuronyl C5-epimerase (Hsepi) converts D-glucuronic acid residues to L-iduronic acid, and 2-O-sulfotransferase (2OST) catalyzes sulfation at C2 position of IdoA and rarely GlcA residues. Mice lacking both Hsepi and 2OST display multiple development defects, indicating the importance of IdoA in HS. Here, to gain greater insights of HS structure-function relationships, as well as a better understanding of the regulatory mechanisms of Hsepi and 2OST, the fine structure and cellular signaling functions of HS were investigated after restoration of Hsepi in the mutant mouse embryonic fibroblast cells. Introduction of Hsepi into the Hsepi mutant MEF cells led to robustly increased proportion of IdoA residues, which rescued the cell signaling in responding to FGF2. However, we found that Hsepi knockout had no influence on either cellular transportation or enzymatic activity of 2OST in the MEF cells, which is not in accord with the findings reported, suggesting that the enzymatic activity and cellular transportation of 2OST and Hsepi might be differently regulated.

Sevoflurane Limits Glioma Progression by Regulating Cell Proliferation, Apoptosis, Migration, and Invasion via miR-218-5p/DEK/β-Catenin Axis in Glioma

Purpose

Sevoflurane (SEV) is a frequently used volatile anesthetic in cancer surgery. Sevoflurane treatment has been shown to suppress the migration and invasion of several human cancer cells. However, the effect of sevoflurane on glioma remains largely unclear.

Methods

Glioma cell lines (U251 and U343) were treated by various concentrations of sevoflurane. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), flow cytometry assay, and transwell assay were performed to detect the cell viability, apoptosis, migration and invasion. Western blot assay was employed to detect the protein levels of β-catenin, c-Myc, CyclinD1, β-catenin, N-cadherin, vimentin, and DEK. Moreover, quantitative real-time polymerase chain reaction (qRT-PCR) was used to examine the expression level of miR-218-5p. The target interaction between miR-218-5p and DEK was predicted through bioinformatics analysis and verified by dual-luciferase reporter assay system.

Results

We found that sevoflurane aberrantly inhibited the abilities on viability, migration, invasion, EMT and β-catenin signaling and promoted cell apoptosis in U251 and U343 cells in a dose-dependent manner. MiR-218-5p strikingly suppressed the abilities of proliferation, migration, invasion rather than apoptosis and activation of β-catenin signaling. Sevoflurane could facilitate the miR-218-5p expression, and its suppressing effects on glioma cells were reversed by pre-treatment with miR-218-5p inhibitors or pcDNA3.1/DEK in vitro and in vivo. Silencing of miR-218-5p reverted sh-DEK and sevoflurane-induced repression on proliferation, migration, invasion, and β-catenin signaling, and promotion on apoptosis in the glioma cells.

Conclusion

Our data showed that sevoflurane inhibited the proliferation, migration, invasion, and enhanced the apoptosis in glioma cells through regulating miR-218-5p/DEK/β-catenin axis.

Sweet Control: MicroRNA Regulation of the Glycome

Glycosylation is a sophisticated informational system that controls specific biological functions at the cellular and organismal level. Dysregulation of glycosylation may underlie some of the most complex and common diseases of the modern era. In the past 5 years, microRNAs have come to the forefront as a critical regulator of the glycome. Herein, we review the current literature on miRNA regulation of glycosylation and how this work may point to a new way to identify the biological importance of glycosylation enzymes.

Glycosaminoglycanomics: where we are

Glycosaminoglycans regulate numerous physiopathological processes such as development, angiogenesis, innate immunity, cancer and neurodegenerative diseases. Cell surface GAGs are involved in cell-cell and cell-matrix interactions, cell adhesion and signaling, and host-pathogen interactions. GAGs contribute to the assembly of the extracellular matrix and heparan sulfate chains are able to sequester growth factors in the ECM. Their biological activities are regulated by their interactions with proteins. The structural heterogeneity of GAGs, mostly due to chemical modifications occurring during and after their synthesis, makes the development of analytical techniques for their profiling in cells, tissues, and biological fluids, and of computational tools for mining GAG-protein interaction data very challenging. We give here an overview of the experimental approaches used in glycosaminoglycomics, of the major GAG-protein interactomes characterized so far, and of the computational tools and databases available to analyze and store GAG structures and interactions.

miR-218 is essential to establish motor neuron fate as a downstream effector of Isl1-Lhx3

While microRNAs have emerged as an important component of gene regulatory networks, it remains unclear how microRNAs collaborate with transcription factors in the gene networks that determines neuronal cell fate. Here, we show that in the developing spinal cord, the expression of miR-218 is directly upregulated by the Isl1-Lhx3 complex, which drives motor neuron fate. Inhibition of miR-218 suppresses the generation of motor neurons in both chick neural tube and mouse embryonic stem cells, suggesting that miR-218 plays a crucial role in motor neuron differentiation. Results from unbiased RISC-trap screens, in vivo reporter assays, and overexpression studies indicated that miR-218 directly represses transcripts that promote developmental programs for interneurons. Additionally, we found that miR-218 activity is required for Isl1-Lhx3 to effectively induce motor neurons and suppress interneuron fates. Together, our results reveal an essential role of miR-218 as a downstream effector of the Isl1-Lhx3 complex in establishing motor neuron identity.

Propofol suppresses proliferation and invasion of glioma cells by upregulating microRNA-218 expression

Propofol (2,6-diisopropylphenol) is a commonly used intravenous anesthetic agent. The present study aimed to assess the effect of propofol on the proliferation and invasion of human glioma cells, and to determine the potential underlying molecular mechanisms. The effects of propofol on U373 glioblastoma cell proliferation, apoptosis and invasion were detected by an MTT assay, caspase‑3 activity measurement and a Matrigel™ invasion assay, respectively. MicroRNA (miR)‑218 expression and matrix metalloproteinase (MMP)‑2 protein expression levels were analyzed by quantitative polymerase chain reaction and western blot analysis, respectively. In addition, miR‑218 precursor was transfected into the cells to assess whether overexpression of miR‑218 could affect MMP‑2 expression. Anti‑miR‑218 was transfected into the cells to evaluate the role of miR‑218 in the effects of propofol on the biological behavior of glioma cells. The results of the present study demonstrated that propofol significantly increased the expression levels of miR‑218, inhibited U373 cell proliferation and invasion, and facilitated apoptosis. In addition, treatment with propofol efficiently reduced MMP‑2 protein expression levels, and overexpression of miR‑218 also decreased MMP‑2 protein expression levels. Whereas, neutralization of miR‑218 using the anti‑miR-218 antibody reversed the effects of propofol on the biological behavior of U373 cells, and on the inhibition of MMP-2 protein expression. In conclusion, propofol may effectively suppress proliferation and invasion, and induce the apoptosis of glioma cells, at least partially through upregulation of miR-218 expression.

miR-218 suppresses tumor growth and enhances the chemosensitivity of esophageal squamous cell carcinoma to cisplatin

A growing body of evidence suggests that microRNA-218 (miR-218) acts as a tumor suppressor and is involved in tumor progression, development and metastasis and confers sensitivity to certain chemotherapeutic drugs in several types of cancer. However, our knowledge concerning the exact roles played by miR-218 in esophageal squamous cell carcinoma (ESCC) and the underlying molecular mechanisms remain relatively unclear. Thus, the aims of this study were to detect the expression of miR-218 in human ESCC tissues and explore its effects on the biological features and chemosensitivity to cisplatin (CDDP) in an ESCC cell line (Eca109), so as to provide new insights for ESCC treatment. Here, we found increased expression of miR-218 in the ESCC tissues compared with that in the matched non-tumor tissues, and its expression level was correlated with key pathological characteristics including clinical stage, tumor depth and metastasis. We also found that enforced expression of miR-218 significantly decreased cell proliferation, colony formation, migration and invasion, induced cell apoptosis and arrested the cell cycle in the G0/G1 phase, as well as suppressed tumor growth in a nude mouse model. In addition, our results showed that miR-218 mimics increased the sensitivity to the antitumor effect of CDDP in the human Eca109 cells. Importantly, this study also showed that miR-218 regulated the expression of phosphorylated PI3K, AKT and mTOR, which may contribute to suppressed tumor growth of ESCC and enhanced sensitivity of ESCC cells. These findings suggest that miR-218 is a potential therapeutic agent for the treatment of ESCC.

Andrographolide antagonizes cigarette smoke extract-induced inflammatory response and oxidative stress in human alveolar epithelial A549 cells through induction of microRNA-218

Andrographolide is a major bioactive labdane diterpenoid isolated from Andrographis paniculata and has protective effects against cigarette smoke (CS)-induced lung injury. This study was done to determine whether such protective effects were mediated through modulation of microRNA (miR)-218 expression. Therefore, we exposed human alveolar epithelial A549 cells to cigarette smoke extract (CSE) with or without andrographolide pretreatment and measured the level of glutathione, nuclear factor-kappaB (NF-κB) activation, proinflammatory cytokine production, and miR-218 expression. We found that andrographolide pretreatment significantly restored the glutathione level in CSE-exposed A549 cells, coupled with reduced inhibitor κB (IκB)-α phosphorylation and p65 nuclear translocation and interleukin (IL)-8 and IL-6 secretion. The miR-218 expression was significantly upregulated by andrographolide pretreatment. To determine the biological role of miR-218, we overexpressed and downregulated its expression using miR-218 mimic and anti-miR-218 inhibitor, respectively. We observed that miR-218 overexpression led to a marked reduction in IκB-α phosphorylation, p65 nuclear accumulation, and NF-κB-dependent transcriptional activity in CSE-treated A549 cells. In contrast, miR-218 silencing enhanced IκB-α phosphorylation and p65 nuclear accumulation in cells with andrographolide pretreatment and reversed andrographolide-mediated reduction of IL-6 and IL-8 production. In addition, depletion of miR-218 significantly reversed the upregulation of glutathione levels in A549 cells by andrographolide. Taken together, our results demonstrate that andrographolide mitigates CSE-induced inflammatory response in A549 cells, largely through inhibition of NF-κB activation via upregulation of miR-218, and thus has preventive benefits in CS-induced inflammatory lung diseases.

D-glucuronyl C5-epimerase cell type specifically affects angiogenesis pathway in different prostate cancer cells

D-glucuronyl C5-epimerase (GLCE) is involved in breast and lung carcinogenesis as a potential tumor suppressor gene, acting through inhibition of tumor angiogenesis and invasion/metastasis pathways. However, in prostate tumors, increased GLCE expression is associated with advanced disease, suggesting versatile effects of GLCE in different cancers. To investigate further the potential cancer-promoting effect of GLCE in prostate cancer, GLCE was ectopically re-expressed in morphologically different LNCaP and PC3 prostate cancer cells. Transcriptional profiles of normal PNT2 prostate cells, LNCaP, PC3 and DU145 prostate cancer cells, and GLCE-expressing LNCaP and PC3 cells were determined. Comparative analysis revealed the genes whose expression was changed in prostate cancer cells compared with normal PNT2 cells, and those differently expressed between the cancer cell lines (ACTA2, IL6, SERPINE1, TAGLN, SEMA3A, and CDH2). GLCE re-expression influenced mainly angiogenesis-involved genes (ANGPT1, SERPINE1, IGF1, PDGFB, TNF, IL8, TEK, IFNA1, and IFNB1) but in a cell type-specific manner (from basic deregulation of angiogenesis in LNCaP cells to significant activation in PC3 cells). Invasion/metastasis pathway was also affected (MMP1, MMP2, MMP9, S100A4, ITGA1, ITGB3, ERBB2, and FAS). The obtained results suggest activation of angiogenesis as a main molecular mechanism of pro-oncogenic effect of GLCE in prostate cancer. GLCE up-regulation plus expression pattern of a panel of six genes, discriminating morphologically different prostate cancer cell sub-types, is suggested as a potential marker of aggressive prostate cancer.

Heterogeneity of d-glucuronyl C5-epimerase expression and epigenetic regulation in prostate cancer

Heparansulfate proteoglycans (HSPG) play an important role in cell–cell and cell–matrix interactions and signaling, and one of the key enzymes in heparansulfate biosynthesis is d-glucuronyl C5-epimerase (GLCE). A tumor suppressor function has been demonstrated for GLCE in breast and lung carcinogenesis; however, no data are available as to the expression and regulation of the gene in prostate cancer. In this study, decreased GLCE expression was observed in 10% of benign prostate hyperplasia (BPH) tissues and 53% of prostate tumors, and increased GLCE mRNA levels were detected in 49% of BPH tissues and 21% of tumors. Statistical analysis showed a positive correlation between increased GLCE expression and Gleason score, TNM staging, and prostate-specific antigen (PSA) level in the prostate tumors (Pearson correlation coefficients GLCE/Gleason = 0.56, P < 0.05; GLCE/TNM = 0.62, P < 0.05; and GLCE/PSA = 0.88, P < 0.01), suggesting GLCE as a candidate molecular marker for advanced prostate cancer. Immunohistochemical analysis revealed an intratumoral heterogeneity of GLCE protein levels both in BPH and prostate cancer cells, resulting in a mixed population of GLCE-expressing and nonexpressing epithelial cells in vivo. A model experiment on normal (PNT2) and prostate cancer (LNCaP, PC3, DU145) cell lines in vitro showed a 1.5- to 2.5-fold difference in GLCE expression levels between the cancer cell lines and an overall decrease in GLCE expression in cancer cells. Methyl-specific polymerase chain reaction (PCR), bisulfite sequencing, and deoxy-azacytidin (aza-dC) treatment identified differential GLCE promoter methylation (LNCaP 70–72%, PC3 32–35%, DU145, and PNT2 no methylation), which seems to contribute to heterogeneous GLCE expression in prostate tumors. The obtained results reveal the complex deregulation of GLCE expression in prostatic diseases compared with normal prostate tissue and suggest that GLCE may be used as a potential model to study the functional role of intratumor cell heterogeneity in prostate cancer progression.

The molecular mechanisms of intratumour heterogeneity of cancer cells, contributing to tissue malignisation, remain unclear. This study reveals the complex deregulation of d-glucuronyl C5-epimerase (GLCE) expression in benign prostatic hyperplasia and prostate tumours, and the high intratumour heterogeneity of prostate cancer cells in terms of GLCE expression and promoter methylation. The results suggest that GLCE may be used as a potential target gene to study the functional role of cancer cell heterogeneity in disease progression and treatment.