Differential expression of miR16 in glioblastoma and glioblastoma stem cells: their correlation with proliferation, differentiation, metastasis and prognosis

Improving targeted small molecule drugs to overcome chemotherapy resistance

BACKGROUND

Conventional cancer treatments face the challenge of therapeutic resistance, which causes poor treatment outcomes. The use of combination therapies can improve treatment results in patients and is one of the solutions to overcome this challenge. Chemotherapy is one of the conventional treatments that, due to the non-targeted and lack of specificity in targeting cancer cells, can cause serious complications in the short and long-term for patients by damaging healthy cells. Also, the employment of a wide range of strategies for chemotherapy resistance by cancer cells, metastasis, and cancer recurrence create serious problems to achieve the desired results of chemotherapy. Accordingly, targeted therapies can be used as a combination treatment with chemotherapy to both cause less damage to healthy cells, which as a result, they reduce the side effects of chemotherapy, and by targeting the factors that cause therapeutic challenges, can improve the results of chemotherapy in patients.

RECENT FINDINGS

Small molecules are one of the main targeted therapies that can be used for diverse targets in cancer treatment due to their penetration ability and characteristics. However, small molecules in cancer treatment are facing obstacles that a better understanding of cancer biology, as well as the mechanisms and factors involved in chemotherapy resistance, can lead to the improvement of this type of major targeted therapy.

CONCLUSION

In this review article, at first, the challenges that lead to not achieving the desired results in chemotherapy and how cancer cells can be resistant to chemotherapy are examined, and at the end, research areas are suggested that more focusing on them, can lead to the improvement of the results of using targeted small molecules as an adjunctive treatment for chemotherapy in the conditions of chemotherapy resistance and metastasis of cancer cells.

MicroRNAs miR-16 and miR-519 control meningioma cell proliferation via overlapping transcriptomic programs shared with the RNA-binding protein HuR

Introduction

Meningiomas are the most common type of primary central nervous system tumors. In about 80% cases, these tumors are benign and grow very slowly, but the remainder 20% can unlock higher proliferation rates and become malignant. In this study we examined two miRs, miR-16 and miR-519, and evaluated their role in tumorigenesis and cell growth in human meningioma.

Methods

A cohort of 60 intracranial grade 1 and grade 2 human meningioma plus 20 healthy meningeal tissues was used to quantify miR-16 and miR-519 expressions. Cell growth and dose-response assays were performed in two human meningioma cell lines, Ben-Men-1 (benign) and IOMM-Lee (aggressive). Transcriptomes of IOMM-lee cells were measured after both miR-mimics transfection, followed by integrative bioinformatics to expand on available data.

Results

In tumoral tissues, we detected decreased levels of miR-16 and miR-519 when compared with arachnoid cells of healthy patients (miR-16: P=8.7e-04; miR-519: P=3.5e-07). When individually overexpressing these miRs in Ben-Men-1 and IOMM-Lee, we observed that each showed reduced growth (P<0.001). In IOMM-Lee cell transcriptomes, downregulated genes, among which ELAVL1/HuR (miR-16: P=6.1e-06; miR-519:P=9.38e-03), were linked to biological processes such as mitotic cell cycle regulation, pre-replicative complex, and brain development (FDR<1e-05). Additionally, we uncovered a specific transcriptomic signature of miR-16/miR-519-dysregulated genes which was highly enriched in HuR targets (>6-fold; 79.6% of target genes).

Discussion

These results were confirmed on several public transcriptomic and microRNA datasets of human meningiomas, hinting that the putative tumor suppressor effect of these miRs is mediated, at least in part, via HuR direct or indirect inhibition.

TCF12 Deficiency Impairs the Proliferation of Glioblastoma Tumor Cells and Improves Survival

Isocitrate dehydrogenase (IDH)-wild-type glioblastoma (GBM) is the most common and aggressive primary brain tumor which carries a very poor overall prognosis and is universally fatal. Understanding the transcriptional regulation of the proliferation of GBM tumor cells is critical for developing novel and effective treatments. In this study, we investigate the role of the transcription factor TCF12 in the regulation of GBM proliferation using human and murine GBM cell lines and an in vivo GBM xenograft model. Our study shows that TCF12 deficiency severely impairs proliferation of tumor cells in vitro by disrupting/blocking the G1 to S phase transition. We also discover that TCF12 loss significantly improves animal survival and that TCF12-deficient tumors grow much slower in vivo. Overexpression of TCF12, on the other hand, leads to an increase in the proliferation of tumor cells in vitro and more aggressive tumor progression in vivo. Interestingly, loss of TCF12 leads to upregulation of signature genes of the oligodendrocytic lineage in GBM stem cells, suggesting a role for TCF12 in inhibiting differentiation along the oligodendrocytic lineage. Transcriptomic data also reveals that loss of TCF12 leads to dysregulation of the expression of key genes in the cell cycle. Our work demonstrates critical roles of TCF12 in GBM tumor progression.

Effect of positive pressure ventilation and bariatric surgery on extracellular vesicle microRNAs in patients with severe obesity and obstructive sleep apnea

INTRODUCTION

Obstructive sleep apnea (OSA) and severe obesity share a common pathophysiological phenomenon, systemic and tissue hypoxia. Hypoxaemia modifies microRNA expression, particularly, extracellular vesicles microRNAs which are involved in the progression of cardiovascular diseases, metabolic syndrome and cancer. We aim to evaluate extracellular vesicle miRNAs among patients with severe obesity with and without OSA and the effect of OSA and severe obesity treatment: continuous positive airway pressure (CPAP) and bariatric surgery.

METHODS

Patients were selected from the Epigenetics Modification in Morbid Obesity and Obstructive Sleep Apnea (EPIMOOSA) study (NCT03995836), a prospective observational study of patients undergoing bariatric surgery. Patients were divided into OSA (Apnea-hyponea index (AHI) > 10) and non-OSA (AHI < 10). Patients with OSA were treated with CPAP for 6 months. Then, all patients had bariatric surgery and re-evaluated 12 months later. At each visit, blood samples were obtained for biobanking. Subsequently, extracellular vesicles were extracted, and then, miRNA expression was analysed.

RESULTS

15 patients with OSA and 9 without OSA completed the protocol. At baseline, patients with OSA showed higher miR16, miR126 and miR320 (p < 0.05) and lower miR223 expression (p < 0.05) than those without OSA. In patients with severe obesity and OSA, after 6 months with CPAP, we observed a significant decrease in miR21 (p < 0.01), miR126 (p < 0.001) and miR320 (p < 0.001), with no changes in any miRNA in patients without OSA. No changes were detected in any miRNA after 6 months of bariatric surgery in patients with or without OSA.

CONCLUSION

Co-existance of OSA and severe obesity alters the profile of extracellular vesicle miRNAs. Bariatric surgery and weight loss did not reverse this effect meanwhile the treatment with CPAP in patients with severe obesity and OSA showed a recovery outcome in those extracellular vesicle miRNAs. Those facts remark the need for OSA screening in patients with severe obesity.

CLINICAL TRIAL REGISTRATION

The study has also been registered at ClinicalTrials.gov identifier: NCT03995836.

Non-coding RNAs and glioma: Focus on cancer stem cells

Glioblastoma and gliomas can have a wide range of histopathologic subtypes. These heterogeneous histologic phenotypes originate from tumor cells with the distinct functions of tumorigenesis and self-renewal, called glioma stem cells (GSCs). GSCs are characterized based on multi-layered epigenetic mechanisms, which control the expression of many genes. This epigenetic regulatory mechanism is often based on functional non-coding RNAs (ncRNAs). ncRNAs have become increasingly important in the pathogenesis of human cancer and work as oncogenes or tumor suppressors to regulate carcinogenesis and progression. These RNAs by being involved in chromatin remodeling and modification, transcriptional regulation, and alternative splicing of pre-mRNA, as well as mRNA stability and protein translation, play a key role in tumor development and progression. Numerous studies have been performed to try to understand the dysregulation pattern of these ncRNAs in tumors and cancer stem cells (CSCs), which show robust differentiation and self-regeneration capacity. This review provides recent findings on the role of ncRNAs in glioma development and progression, particularly their effects on CSCs, thus accelerating the clinical implementation of ncRNAs as promising tumor biomarkers and therapeutic targets.

Potential therapeutic applications of microRNAs in cancer diagnosis and treatment: Sharpening a double-edged sword?

Cancer is a leading cause of increased morbidity and mortality worldwide despite advancements in diagnosis and treatment. Lack of early detection and diagnosis of different cancers and adverse effects and toxicity associated with conventional cancer treatments, such as chemotherapy and radiation, remains a problem. MicroRNAs can act as oncogenes or tumour suppressors in different types of cancers. Their distinct gene expression in various stages and types of cancerous cells make them attractive targets for cancer diagnosis and therapy. The growing research and clinical interests in gene therapy and nano-drug delivery systems have led to the development of potential miRNA-targeted treatments encompassing miRNA mimics, antagonists, and their use in cancer chemotherapy sensitization. In this review, we discuss the recent advancements in understanding the role of miRNAs in cancer development and their potential use as biomarkers in clinical diagnostics and as targets in chemotherapy of cancer.

TFCP2, a binding protein of ATF3, promotes the progression of glioma by activating the synthesis of serine

Glioma is one of the most common malignancies. De novo serine synthesis promotes glioma progression and therapeutic resistance. Therefore, clarifying the regulatory mechanism of serine synthesis is of great significance for glioma therapy. In this study, we found that the expression of TFCP2 was upregulated in glioma and that TFCP2 promoted glioma cell growth and sphere formation. Knockdown of TFCP2 expression inhibited glioma cell growth, sphere formation and tumorigenicity in nude mice. In terms of its molecular mechanism, TFCP2 was found to interact with ATF3 to cooperatively regulate the de novo synthesis of serine. Knockdown of TFCP2 expression significantly inhibited the binding of ATF3 to the promoter of PHGDH (a rate-limiting enzyme in the serine synthesis process). In conclusion, our studies proved that TFCP2 jointly regulates the de novo synthesis of serine through interaction with ATF3, thus promoting glioma progression. This study suggests that TFCP2 is a potential target for glioma therapy.

SOX transcription factors and glioma stem cells: Choosing between stemness and differentiation

Glioblastoma (GBM) is the most common, most aggressive and deadliest brain tumor. Recently, remarkable progress has been made towards understanding the cellular and molecular biology of gliomas. GBM tumor initiation, progression and relapse as well as resistance to treatments are associated with glioma stem cells (GSCs). GSCs exhibit a high proliferation rate and self-renewal capacity and the ability to differentiate into diverse cell types, generating a range of distinct cell types within the tumor, leading to cellular heterogeneity. GBM tumors may contain different subsets of GSCs, and some of them may adopt a quiescent state that protects them against chemotherapy and radiotherapy. GSCs enriched in recurrent gliomas acquire more aggressive and therapy-resistant properties, making them more malignant, able to rapidly spread. The impact of SOX transcription factors (TFs) on brain tumors has been extensively studied in the last decade. Almost all SOX genes are expressed in GBM, and their expression levels are associated with patient prognosis and survival. Numerous SOX TFs are involved in the maintenance of the stemness of GSCs or play a role in the initiation of GSC differentiation. The fine-tuning of SOX gene expression levels controls the balance between cell stemness and differentiation. Therefore, innovative therapies targeting SOX TFs are emerging as promising tools for combatting GBM. Combatting GBM has been a demanding and challenging goal for decades. The current therapeutic strategies have not yet provided a cure for GBM and have only resulted in a slight improvement in patient survival. Novel approaches will require the fine adjustment of multimodal therapeutic strategies that simultaneously target numerous hallmarks of cancer cells to win the battle against GBM.

Role of exosomal miRNA in chemotherapy resistance of Colorectal cancer: A systematic review

The third most common malignancy has been identified as Colorectal cancer (CRC) that conducive to death in most cases. Chemoresistance is a common obstacle to CRC treatment. Circulating exosomal microRNAs (miRNAs) have been shown to reverse chemo-resistance and are promising biomarkers for CRC. The capacity of engineered exosomes to cross biological barriers and deliver functional miRNAs could be used to achieve these proposes. The object of this review is the investigation of the role of exosomal miRNA in the chemo-resistance, diagnosis, and prognosis of CRC. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, electronic databases, PubMed, EMBASE, Web of Science, Scopus were searched from January 1990 to November 2020. Ultimately, eight articles included five in vitro (16 cell lines) and three in vivo examinations. Three studies demonstrated that increasing or decreasing mRNA expression was associated with increasing and decreasing cell proliferation in vitro. The presence of miRNA in two studies increased the sensitivity of the drug and exhibited a considerable growth inhibitory effect on cancer cell proliferation. The apoptotic rate was significantly increased in four studies by increased mRNA expression and reduced mrna expression. Tumor volume of xenograft models in three studies suppressed by antitumor miRNA activity. In contrast, anti-miRNA activity in one study decreased the tumor volume. Exosomal miRNAs can be regulators of chemo-resistance and predict adverse outcomes in CRC patients. In sum, exosomes containing miRNAs can be a promising biomarker for the prognosis and diagnosis of CRC. Subsequent research should be a focus on delineating the function of exosomal miRNA before clinical use.

miRNA signature in glioblastoma: Potential biomarkers and therapeutic targets

MicroRNAs (miRNAs) are transcripts with sizes of about 22 nucleotides, which are produced through a multistep process in the nucleus and cytoplasm. These transcripts modulate the expression of their target genes through binding with certain target regions, particularly 3' suntranslated regions. They are involved in the pathogenesis of several kinds of cancers, such as glioblastoma. Several miRNAs, including miR-10b, miR-21, miR-17-92-cluster, and miR-93, have been up-regulated in glioblastoma cell lines and clinical samples. On the other hand, expression of miR-7, miR-29b, miR-32, miR-34, miR-181 family members, and a number of other miRNAs have been decreased in this type of cancer. In the current review, we explain the role of miRNAs in the pathogenesis of glioblastoma through providing a summary of studies that reported dysregulation of these epigenetic effectors in this kind of brain cancer.

NF-κB-mediated miR-650 plays oncogenic roles and activates AKT/ERK/NF-κB pathways by targeting RERG in glioma cells

PURPOSE

Glioma is the most common cancer in the central nervous system and has a high mortality rate. Despite advances that have been made in the treatment of glioma, its prognosis still remains poor. Dysregulation of miRNAs has been reported in many cancers, including glioma. Here, we set out to assess the role of miR-650 in glioma, including its diagnostic and therapeutic potential.

METHODS

miR-650 and RAS-like estrogen-regulated growth inhibitor (RERG) expression levels were analyzed using qRT-PCR in primary glioma tissues and cell lines. Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine, colony formation, Western blotting, scratch wound healing, Transwell, adhesion, autophagy, immunofluorescence, luciferase reporter, electrophoretic mobility shift, tumor xenograft and flow cytometry assays were employed to investigate the mechanisms underlying the effect of miR-650 and RERG on glioma development.

RESULTS

miR-650 was found to be up-regulated in glioma tissues and cell lines compared to non-cancerous brain tissues and neural progenitor cells, respectively. We also found that miR-650 promoted cell proliferation, migration and invasion in glioma cells, and enhanced glioma tumor formation and growth in vivo. We identified and validated RERG as a direct target of miR-650. RERG was shown to act as a tumor suppressor in glioma cells, and its suppressor roles were rescued by miR-650. We found that nuclear factor (NF)-κB bound to the promoter of miR-650 and enhanced its expression. PH domain and leucine rich repeat protein phosphatase 2 (PHLPP2), as a co-factor of the RERG/PHLPP2 complex, mediated miR-650-induced activation of the protein kinase B/extracellular-signal-regulated kinase/NF-κB signaling pathways.

CONCLUSIONS

Our data revealed novel functional roles for miR-650 in glioma development and may provide new avenues for future clinical applications.

Association of the Expression Level of miR-16 with Prognosis of Solid Cancer Patients: A Meta-Analysis and Bioinformatic Analysis

Objective

To assess the association between the expression level of miR-16 and prognosis of solid cancer patients by meta-analysis and bioinformatic analysis.

Methods

PubMed, Web of Science, and Embase databases were searched until October 31, 2019, to identify eligible studies reporting the association of the miR-16 status with the prognosis of solid cancer patients. Hazard ratios (HRs) with 95% confidence intervals (CIs) were pooled, and a heterogeneity test was conducted. Sensitivity analysis and a publication bias test were also carried out. Furthermore, the miRpower database was used to validate the association.

Results

Thirteen articles with 2303 solid cancer patients were included in the meta-analysis. Solid cancer patients with low expression level of miR-16 had shorter survival time (I² = 84.0%, HR = 1.47, 95% CI: 1.13-1.91, P = 0.004). In the subgroup analyses of cancer sites, low miR-16 expression level was associated with poor prognosis in the reproductive system cancers (I² = 33.3%, HR = 1.24, 95% CI: 1.06-1.45, P = 0.008). Sensitivity analysis suggested that the pooled HR was stable and omitting a single study did not change the significance of the pooled HR. Begg's test and Egger's test revealed no publication bias in the meta-analysis. In bioinformatic analysis, the significant association between miR-16 level and prognosis of patients with reproductive system cancers was further confirmed (HR = 1.21, 95% CI: 1.03-1.42, P = 0.017).

Conclusion

Low expression level of miR-16 is an indicator for poor prognosis of solid cancer patients, particularly in reproductive system cancers.

Identification of HMG-box family establishes the significance of SOX6 in the malignant progression of glioblastoma

Glioblastoma multiforme (GBM) is the most malignant neuroepithelial primary brain tumor and its mean survival time is 15 months after diagnosis. This study undertook to investigate the genome-wide and transcriptome-wide analyses of human high mobility group box (HMG-box) TF (transcript factor) families / HOX, TOX, FOX, HMG and SOX gene families, and their relationships to GBM. According to the TCGA-GBM profile analysis, differentially expressed HOX, FOX, HMG and SOX gene families (62 DEmRNA) were found in this study. We also analyzed DEmRNA (HMG-box related genes) co-expressed eight DElncRNA in GBM, and constructed a ceRNA network analysis as well. We constructed 50 DElncRNA-DEmiRNA-DEmRNA (HMG-box related genes) pairs between GBM and normal tissues. Then, risk genes SOX6 and SOX21 expression were correlated with immune infiltration levels in GBM. SOX6 also had a strong association with MAPT, GSK3B, FYN and DPYSL4, suggesting that they might be functional members in GBM.

Hypomethylation of the cyclin D1 promoter in hepatitis B virus-associated hepatocellular carcinoma

The hypomethylation of the Cyclin D1 (CCND1) promoter induced by excess oxidative stress likely promotes the development of hepatitis B virus-associated hepatocellular carcinoma (HBV-HCC). We aimed to evaluate methylation status of the CCND1 promoter as a new plasma marker for the detection of HBV-HCC.We consecutively recruited 191 participants, including 105 patients with HBV-HCC, 54 patients with chronic hepatitis B (CHB), and 32 healthy controls (HCs). Using methylation-specific polymerase chain reaction, we identified the methylation status of the CCND1 promoter in plasma samples. We analyzed the expression levels of the CCND1 mRNA in peripheral blood mononuclear cells by using quantitative real-time PCR. We assessed the plasma levels of superoxide dismutase, 8-hydroxydeoxyguanosine and malondialdehyde by using enzyme-linked immunosorbent assays.Patients with HBV-HCC (23.81%) presented a reduced methylation frequency compared with patients with CHB (64.81%) or HCs (78.13%) (P < .001). When receiver operating characteristic curves were plotted for patients with HBV-HCC versus CHB, the methylation status of the CCND1 promoter yielded diagnostic parameter values for the area under the curve of 0.705, sensitivity of 76.19%, and specificity of 64.81%, thus outperforming serum alpha-fetoprotein (AFP), which had an area under the curve of 0.531, sensitivity of 36.19%, and specificity of 90.74%. Methylation of the CCND1 promoter represents a prospective diagnostic marker for patients with AFP-negative HBV-HCC and AFP-positive CHB. The expression levels of CCND1 mRNA was increased in patients with HBV-HCC compared with patients with CHB (Z = -4.946, P < .001) and HCs (Z = -6.819, P < .001). Both the extent of oxidative injury and antioxidant capacity indicated by the superoxide dismutase, 8-hydroxydeoxyguanosine and malondialdehyde levels were increased in patients with HBV-HCC. Clinical follow up of patients with HBV-HCC revealed a worse overall survival (P = .012, log-rank test) and a decreased progression-free survival (HR = 0.109, 95%CI: 0.031-0.384) for the unmethylated CCND1 group than methylated CCND1 group.Our study confirms that oxidative stress appears to correlate with plasma levels of CCND1 promoter methylation, and the methylation status of the CCND1 promoter represents a prospective biomarker with better diagnostic performance than serum AFP levels.

Exosomal miRNAs in tumor microenvironment

Tumor microenvironment (TME) is the internal environment in which tumor cells survive, consisting of tumor cells, fibroblasts, endothelial cells, and immune cells, as well as non-cellular components, such as exosomes and cytokines. Exosomes are tiny extracellular vesicles (40-160nm) containing active substances, such as proteins, lipids and nucleic acids. Exosomes carry biologically active miRNAs to shuttle between tumor cells and TME, thereby affecting tumor development. Tumor-derived exosomal miRNAs induce matrix reprogramming in TME, creating a microenvironment that is conducive to tumor growth, metastasis, immune escape and chemotherapy resistance. In this review, we updated the role of exosomal miRNAs in the process of TME reshaping.

CyclinD1 Is a New Target Gene of Tumor Suppressor MiR-520e in Breast Cancer

Objective

To investigate the involvement of miR-520e in the modulation of cancer-promoting cyclinD1 in breast cancer.

Methods

A reverse transcription-polymerase chain reaction (RT-PCR) was applied to test the regulation of miR-520e on cyclinD1. The binding of miR-520e to 3'-untranslated region (3'UTR) of cyclinD1 mRNA was predicted by an online bioinformatics website. The effect of miR-520e on the luciferase reporters with binding sites of miR-520e and 3'UTR of cyclinD1 mRNA was revealed using a luciferase reporter gene assay. The correlation between miR-520e and cyclinD1 in clinical breast cancer samples was detected through quantitative real-time PCR.

Results

The expression of cyclinD1 was gradually reduced as the dose of miR-520e increased. Anti-miR-520e obviously induced cyclinD1 in breast cancer cells. After anti-miR-520e was introduced into the cells, the inhibition of cyclinD1 expression mediated by miR-520e was reversed. The binding of miR-520e with cyclinD1 was revealed via bioinformatics. Under the treatment of dose-increasing miR-520e or anti-miR-520e, the luciferase activities of cyclinD1 3'UTR vector were lower or higher by degrees. However, the activity of the mutant vector was not affected at all. Finally, in clinical breast cancer tissues the negative correlation of miR-520e with cyclinD1 was revealed.

Conclusion

In conclusion, cyclinD1 is a new target of miR-520e in breast cancer.

Downregulation of miR‑16 protects H9c2(2‑1) cells against hypoxia/reoxygenation damage by targeting CIAPIN1 and regulating the NF‑κB pathway

The aim of the present study was to determine the function of microRNA‑16 (miR‑16) in myocardial hypoxia/reoxygenation (H/R)‑induced cardiomyocyte injury and the possible mechanism underlying its involvement. An H/R model was constructed using H9c2(2‑1) cells in vitro. The results of reverse transcription‑quantitative PCR demonstrated that the expression levels of miR‑16 were significantly upregulated in H9c2(2‑1) cells in the H/R group compared with the sham group (1.53±0.09 vs. 1.0±0.08; P=0.0019). Cell Counting Kit‑8 assays revealed that the relative proliferative ability of H9c2(2‑1) cells was significantly decreased in the H/R + negative control (NC) group compared with the sham group (0.53±0.05 vs. 1.0±0.08; P=0.00005). Upregulation of miR‑16 using miR‑16 mimics further decreased the proliferative ability of cells (0.31±0.03 vs. 0.53±0.05; P=0.0097), whereas downregulation of miR‑16 using an miR‑16 inhibitor increased the proliferative ability of cells compared with the H/R+NC group (0.89±0.08 vs. 0.53±0.05; P=0.000385). Flow cytometric analysis found that the apoptotic rate of H9c2(2‑1) cells was increased significantly following H/R compared with the sham group (25.86±2.62% vs. 9.29±0.82%, P=0.000014). Upregulation of miR‑16 further increased the apoptotic rate (38.62±2.04% vs. 25.86±2.62%; P=0.000099), whereas downregulation of miR‑16 decreased the apoptotic rate compared with the H/R+NC group (15.14±0.92% vs. 25.86±2.62%; P=0.000343). miR‑16 directly bound to the 3'‑untranslated region of cytokine‑induced apoptosis inhibitor 1 (CIAPIN1) and negatively modulated CIAPIN1 expression. Overexpression of CIAPIN1 reversed the changes in the expression of apoptosis‑associated proteins caused by H/R. Western blot analysis revealed that the levels of phospho‑(p‑)nuclear factor‑κB (NF‑κB) and p‑NF‑κB inhibitor α (IκBα) were upregulated following H/R (1.82±0.11 vs. 1.0±0.08; P=0.000152; and 1.77±0.07 vs. 1.0±0.00; P=0.000024, respectively), and these changes were further enhanced when miR‑16 expression levels were increased (3.10±0.14 vs. 1.82±0.11; P=0.000006; and 2.19±0.10 vs. 1.77±0.07; P=0.0017, respectively). Downregulation of miR‑16 exhibited the opposite effect on p‑NF‑κB and p‑IκBα expression levels. The present study illustrates that downregulation of miR‑16 may protect against H/R‑induced injury partially by targeting CIAPIN1 and the NF‑κB signaling pathway.

Delivery luteolin with folacin-modified nanoparticle for glioma therapy

Background

Glioblastoma mutliforme is the most common and has the poorest prognosis of any malignant tumor of the central nervous system. Luteolin, the most abundant xanthone extracted from vegetables and medicinal plants, has been shown to have treatment effects in various cancer cell types. Luteolin is however, hydrophobic and has poor biocompatibility, which leads to low bioavailability.

Patients and methods

In this study, folic acid modifiedpoly(ethylene glycol)-poly(e-caprolactone) (Fa-PEG-PCL) nano-micelles was used to encapsulate the luteolin, creating luteolin loaded PEG-PCL (Lut/Fa-PEG-PCL) micelles to treat glioma both in vitro and in vivo.

Results

When compared with the free luteolin and Lut/MPEG-PCL, Lut/Fa-PEG-PCL induced a significant cell growth inhibition and more apoptosis of GL261 cells both in vitro and in vivo. The safety assessment also showed no obvious side effects were observed in mice which were administrated with free luteolin or Lut/MPEG-PCL and Lut/Fa-PEG-PCL.

Conclusion

These results suggested Lut/Fa-PEG-PCL may be used as an excellent intravenously injectable formulation for the treatment and chemoprevention.

Exosome-mediated uptake of mast cell tryptase into the nucleus of melanoma cells: a novel axis for regulating tumor cell proliferation and gene expression

It is well established that mast cell accumulation accompanies most malignancies. However, the knowledge of how mast cells functionally impact on tumors is still rudimentary. Here we addressed this issue and show that mast cells have anti-proliferative activity on melanoma cells and that this effect is dependent on tryptase, a tetrameric protease stored in mast cell granules. Mechanistically, tryptase was found to be endocytosed by melanoma cells as cargo of DNA-coated exosomes released from melanoma cells, followed by transport to the nucleus. In the nucleus, tryptase executed clipping of histone 3 and degradation of Lamin B1, accompanied by extensive nuclear remodeling. Moreover, tryptase degraded hnRNP A2/B1, a protein involved in mRNA stabilization and interaction with non-coding RNAs. This was followed by downregulated expression of the oncogene EGR1 and of multiple non-coding RNAs, including oncogenic species. Altogether, these findings establish a new principle for regulation of tumor cell proliferation.

Growth Inhibitory Effects of Dipotassium Glycyrrhizinate in Glioblastoma Cell Lines by Targeting MicroRNAs Through the NF-κB Signaling Pathway

It has been shown that nuclear factor kappa-B (NF-κB) is constitutively activated in glioblastoma (GBM), suggesting that the pathway could be a therapeutic target. Glycyrrhetic acid (GA), a compound isolated from licorice (Glycyrrhiza glabra), has been shown to decrease cell viability and increases apoptosis in human cancer cell lines by NF-κB signaling pathway suppression. Dipotassium glycyrrhizinate (DPG), a dipotassium salt of GA, has anti-inflammatory properties without toxicity. The current study examined the effectiveness of DPG as an anti-tumor in U87MG and T98G GBM cell lines. Additionally, we assessed DPG as a candidate for combinational therapy in GBM with temozolomide (TMZ). Our results demonstrated that the viability of U87MG and T98G cells significantly decreased in a time- and dose-dependent manner after DPG treatment, and the apoptotic ratio of DPG-treated groups was significantly higher than that of control groups. In addition, DPG in combination with TMZ revealed synergistic effects. Furthermore, the expression of NF-κB-luciferase-reporter in transfected GBM cell lines was remarkably reduced after DPG exposure by up-regulating miR16 and miR146a, which down-regulate its target genes, IRAK2 and TRAF6. A reduced neuro-sphere formation was also observed after DPG in both GBM cells. In conclusion, DPG presented anti-tumoral effect on GBM cell lines through a decrease on proliferation and an increase on apoptosis. In addition, our data also suggest that DPG anti-tumoral effect is related to NF-κB suppression, where IRAK2- and TRAF6-mediating miR16 and miR146a, respectively, might be a potential therapeutic target of DPG.

PITX2 Expression in Non-functional Pituitary Neuroendocrine Tumor with Cavernous Sinus Invasion

Although most pituitary neuroendocrine tumors (PitNETs) show benign behavior, a significant number of PitNETs exhibit an aggressive course including cavernous sinus (CS) invasion. To date, the cause of CS invasion has not been fully elucidated. In this study, we analyzed the relationship between CS invasion in PitNETs and the expression of PITX2 and SNAIL1, which are the transcription factors associated with the morphogenesis of pituitary gland. Sixty cases with non-functional PitNETs were classified into four types: type 1a, none of CS invasion and suprasellar expansion; type 1b, suprasellar expansion without CS invasion; type 2a, CS invasion without suprasellar expansion; and type 2b, CS invasion with suprasellar expansion. We analyzed the expression of PITX2 and SNAIL1 employing quantitative real-time polymerase chain reaction (qPCR) and immunohistochemistry. Other parameters such as mitotic count, Ki-67 index, and p53 expression were also analyzed, which were previously reported as potential tumor proliferative markers in PitNETs. PITX2 expression was significantly higher in PitNETs with CS invasion than PitNETs without CS invasion (P = 0.019). Expression of SNAIL1 was significantly elevated in PitNETs with suprasellar expansion compared with PitNETs without suprasellar expansion (P = 0.02). There was no apparent relationship between CS invasion and mitotic count, Ki-67 index, and p53 expression (mitotic count, P = 0.11; Ki-67 index, P = 0.61; p53, P = 0.66). High PITX2 expression was observed in non-functional PitNETs with CS invasion, suggesting that PITX2 may be involved in CS invasion of PitNETs.

Downregulations of circulating miR-31 and miR-21 are associated with preeclampsia

MicroRNAs (miRNAs/miRs) are highly stable in circulating, which suppress target gene expression by base-pairing to the 3'-untranslated region. We compared the expressions of 3 circulating miRs (miR-31, miR-21, and miR-16), which are related to the control of cell apoptosis, invasion, angiogenesis and immune tolerance in non-pregnancy (n = 10), 20-34 gestational weeks normal pregnancy (20-34 GW NP, n = 20), early onset preeclampsia (EOPE, n = 20), 34-41 gestational weeks normal pregnancy (34-41 GW NP, n = 20) and late onset preeclampsia (LOPE, n = 20). Using quantitative RT-PCR, we found the levels of miR-31, miR-21 and miR-16 changed throughout different stages of pregnancy with the non-pregnancy as the calibrator. The plasma miR-31 levels were significantly down-regulated in EOPE rather than in LOPE when compared to gestational age matched normal pregnancy (P < 0.001). MiR-21 levels were significantly lower in LOPE compared to healthy controls (P < 0.001), while no significant difference was found between EOPE and 20-34 gestational weeks normal pregnancy (P = 0.376). The miR-16 expressions were at similar levels between preeclampsia (PE) and normal pregnancy. Receiver operating characteristic (ROC) curve analyses indicated the miR-31 differentiated EOPE patients from healthy controls with an area under the curve (AUC) of 0.875 with 95.0% sensitivity and 70.0% specificity. ROC curves also discriminated the LOPE patients from healthy pregnancy with an AUC of 0.793, 65.1% sensitivity and 90.3% specificity for plasma miR-21 levels. This study is the first to demonstrate the difference, and circulating miR-31 may serve as a diagnostic biomarker for early onset preeclampsia meanwhile miR-21 might be a diagnostic biomarker for late onset preeclampsia.

The role of SOX family members in solid tumours and metastasis

Cancer is a heavy burden for humans across the world with high morbidity and mortality. Transcription factors including sex determining region Y (SRY)-related high-mobility group (HMG) box (SOX) proteins are thought to be involved in the regulation of specific biological processes. The deregulation of gene expression programs can lead to cancer development. Here, we review the role of the SOX family in breast cancer, prostate cancer, renal cell carcinoma, thyroid cancer, brain tumours, gastrointestinal and lung tumours as well as the entailing therapeutic implications. The SOX family consists of more than 20 members that mediate DNA binding by the HMG domain and have regulatory functions in development, cell-fate decision, and differentiation. SOX2, SOX4, SOX5, SOX8, SOX9, and SOX18 are up-regulated in different cancer types and have been found to be associated with poor prognosis, while the up-regulation of SOX11 and SOX30 appears to be favourable for the outcome in other cancer types. SOX2, SOX4, SOX5 and other SOX members are involved in tumorigenesis, e.g. SOX2 is markedly up-regulated in chemotherapy resistant cells. The SoxF family (SOX7, SOX17, SOX18) plays an important role in angio- and lymphangiogenesis, with SOX18 seemingly being an attractive target for anti-angiogenic therapy and the treatment of metastatic disease in cancer. In summary, SOX transcription factors play an important role in cancer progression, including tumorigenesis, changes in the tumour microenvironment, and metastasis. Certain SOX proteins are potential molecular markers for cancer prognosis and putative potential therapeutic targets, but further investigations are required to understand their physiological functions.

MiR-9 promotes tumorigenesis and angiogenesis and is activated by MYC and OCT4 in human glioma

BACKGROUND

Glioma, characterized by its undesirable prognosis and poor survival rate, is a serious threat to human health and lives. MicroRNA-9 (miR-9) is implicated in the regulation of multiple tumors, while the mechanisms underlying its aberrant expression and functional alterations in human glioma are still controversial.

METHODS

Expressions of miR-9 were measured in GEO database, patient specimens and glioma cell lines. Gain- and loss-of-function assays were applied to identify the effects of miR-9 on glioma cells and HUVECs in vitro and in vivo. Potential targets of miR-9 were predicted by bioinformatics and further verified via in vitro experiments. Transcriptional regulation of miR-9 by MYC and OCT4 was determined in glioma cells.

RESULTS

MiR-9 was frequently up-regulated in glioma specimens and cells, and could significantly enhance proliferation, migration and invasion of glioma cells. In addition, miR-9 could be secreted from glioma cells via exosomes and was then absorbed by vascular endothelial cells, leading to an increase in angiogenesis. COL18A1, THBS2, PTCH1 and PHD3 were verified as the direct targets of miR-9, which could elucidate the miR-9-induced malignant phenotypes in glioma cells. MYC and OCT4 were able to bind to the promoter region of miR-9 to trigger its transcription.

CONCLUSIONS

Our results highlight that miR-9 is pivotal for glioma pathogenesis and can be treated as a potential therapeutic target for glioma.

MicroRNA-Based Drugs for Brain Tumors

MicroRNAs (miRNAs) are key regulatory elements encoded by the genome. A single miRNA can downregulate the expression of multiple genes involved in diverse functions. Because cancer is a disease with multiple gene aberrations, developing novel approaches to identify and modulate miRNA pathways may result in a breakthrough for cancer treatment. With a special focus on glioblastoma (GBM), this review provides an up-to-date summary of miRNA biogenesis, the role of miRNA in cancer resistance, and essential tools for modulating miRNA expression, as well as of clinically promising RNAi delivery systems and how they can be adapted for therapy.