Tumor suppressor microRNA‑613 inhibits glioma cell proliferation, invasion and angiogenesis by targeting vascular endothelial growth factor A

The Significant Role of microRNAs in Gliomas Angiogenesis: A Particular Focus on Molecular Mechanisms and Opportunities for Clinical Application

MicroRNAs (miRNAs) are non-coding RNAs with only 20-22 nucleic acids that inhibit gene transcription and translation by binding to mRNA. MiRNAs have a diverse set of target genes and can alter most physiological processes, including cell cycle checkpoints, cell survival, and cell death mechanisms, affecting the growth, development, and invasion of various cancers, including gliomas. So optimum management of miRNA expression is essential for preserving a normal biological environment. Due to their small size, stability, and capability of specifically targeting oncogenes, miRNAs have emerged as a promising marker and new biopharmaceutical targeted therapy for glioma patients. This review focuses on the most common miRNAs associated with gliomagenesis and development by controlling glioma-determining markers such as angiogenesis. We also summarized the recent research about miRNA effects on signaling pathways, their mechanistic role and cellular targets in the development of gliomas angiogenesis. Strategies for miRNA-based therapeutic targets, as well as limitations in clinical applications, are also discussed.

Correlation of Diffusion Tensor Imaging Parameters with the Pathological Grade of Brain Glioma and Expression of Vascular Endothelial Growth Factor and Ki-67

Background: Most brain gliomas are high-grade and likely to spread locally. Consequently, these patients commonly have a poor prognosis. Accurate identification of the malignancy grade of brain glioma before treatment is of great clinical significance. Objectives: This study aimed to explore the correlation of diffusion tensor imaging (DTI) parameters, fractional anisotropy (FA), and apparent diffusion coefficient (ADC) with the pathological grade of brain glioma and expression of vascular endothelial growth factor (VEGF) and Ki-67. Patients and Methods: A total of 116 patients were selected for this study from January 2018 to December 2019. All the participants underwent magnetic resonance imaging (MRI) and DTI before surgery, and the FA and ADC values were measured for the regions of interest. Surgically resected tumor specimens were collected for immunohistochemical assay. Finally, the FA and ADC values and positive expression rates of VEGF and Ki-67 were compared. Results: A significantly higher FA, besides the positive expression of VEGF and Ki-67, was reported in the high-grade group, whereas a lower ADC was found in this group compared to the low-grade group (P < 0.05). Areas of normal white matter and peritumoral edema had higher FA values, whereas lower ADCs were measured in these areas compared to the cerebrospinal fluid (P < 0.05). The FA of tumor parenchymal area was positively correlated with the World Health Organization (WHO) WHO class of tumors (r = 0.588, P = 0.028), and the expression of VEGF and Ki-67 was positively correlated with the WHO grade (r = 0.843, P = 0.002 and r = 0.743, P = 0.006, respectively). The FA of tumor parenchymal area was positively correlated with the expression of VEGF and Ki-67 (r = 0.654, P = 0.008 and r = 0.567, P = 0.012, respectively). However, the ADC of tumor parenchymal area was not significantly correlated with the WHO grade, VEGF expression, or Ki-67 expression (r = 0.143, P = 0.156, r = 0.232, P = 0.116, and r = 0.054, P = 0.179, respectively). Conclusion: The FA value, as a DTI parameter, is valuable for assessing the malignancy grade of tumor cells and can provide a proper reference for formulating treatment regimens for brain gliomas.

CRISPR-Cas9-mediated gene therapy in lung cancer

As the largest cause of cancer-related deaths worldwide, pulmonary cancer is the most common form of the disease. Several genetic, epigenetic, and environmental factors come into play during the multi-step mechanism of tumorigenesis. The heterogeneity that makes discovering successful therapeutics for pulmonary cancer problematic is significantly influenced by the epigenetic landscape, including DNA methylation, chromatin architecture, histone modifications, and noncoding RNA control. Clinical activity of epigenetic-targeted medicines has been reported in hematological tumors, and these compounds may also have therapeutic effects in solid tumors. Over the course of the past few years, some researchers have successfully modified the expression of genes in cells using the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas (CRISPR-associated proteins) technique. The utilization of this technology allows for the induction of site-specific mutagenesis, epigenetic alterations, and the regulation of gene expression. This study will present an overview of the primary epigenetic alterations seen in pulmonary cancer, as well as a summary of therapeutic implications for targeting epigenetics in the management of pulmonary cancer, with a particular emphasis on the technique known as CRISPR/Cas9.

Long non-coding RNA NUT family member 2A-antisense RNA 1 sponges microRNA-613 to increase the resistance of gastric cancer cells to matrine through regulating oxidative stress and vascular endothelial growth factor A

Matrine has been shown to play a role in the suppression of gastric cancer (GC) tumorigenesis. However, whether long non-coding RNA NUT family member 2A-antisense RNA 1 (NUTM2A-AS1) is involved in matrine-induced inhibition of GC remains unknown. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, cell colony formation, and terminal deoxynucleotidyl transferase dUTP nick-end labeling assays were employed to determine the proliferation, viability, and apoptosis of GC cells, respectively. The Cancer Genome Atlas database suggested an association between NUTM2A-AS1 and GC. The reverse transcription-quantitative polymerase chain reaction was used to quantify relative levels of NUTM2A-AS1, miR-613, and vascular endothelial growth factor A (VEGFA). Reactive oxygen species generation, glutathione content, and superoxide dismutase activity were determined by corresponding reagents or assay kits. NUTM2A-AS1 knockdown led to attenuated cell viability and proliferation, as well as to enhanced apoptosis of N87 and AGS cells treated with matrine. These changes were prevented by an inhibitor of microRNA (miR)-613. Importantly, NUTM2A-AS1 expression was positively associated with tumor progression in patients with GC. NUTM2A-AS1 and miR-613 regulated the generation of reactive oxygen species, the content of glutathione, and the activity of superoxide dismutase. VEGFA served as an important effector for the NUTM2A-AS1/miR-613-regulated resistance of GC cells to matrine. These results reveal a novel mechanism of matrine resistance in GC.

Angioregulatory role of miRNAs and exosomal miRNAs in glioblastoma pathogenesis

Glioblastoma (GB) is a highly aggressive cancer of the central nervous system, occurring in the brain or spinal cord. Many factors such as angiogenesis are associated with GB development. Angiogenesis is a procedure by which the pre-existing blood vessels create new vessels that play an essential role in health and disease, including tumors. Also, angiogenesis is one of the significant factors thought to be responsible for treatment resistance in many tumors, including GB. Hence, an improved understanding of the molecular processes underlying GB angiogenesis will pave the way for developing potential new treatments. Recently, it has been found that microRNAs (miRNAs) and exosomal miRNAs have a crucial role in inducing or inhibiting the angiogenesis process in GB development. A better knowledge of the miRNA's regulation pathway in the angiogenesis process in cancer offers unique mechanistic insight into the mechanism of tumor-associated neovascularization. Because of advancements in miRNA characterization and delivery methods, miRNAs can also be employed in clinical settings as potential biomarkers for anti-angiogenic treatment response as well as therapies targeting tumor angiogenesis. The recent finding and insights about miRNAs' angioregulatory role and exosomal miRNAs in GB are provided throughout the review. Also, we discuss the new concept of miRNAs-based therapies for GB in the future.

Roles of Non-coding RNAs and Angiogenesis in Glioblastoma

One of the significant hallmarks of cancer is angiogenesis. It has a crucial function in tumor development and metastasis. Thus, angiogenesis has become one of the most exciting targets for drug development in cancer treatment. Here we discuss the regulatory effects on angiogenesis in glioblastoma (GBM) of non-coding RNAs (ncRNAs), including long ncRNA (lncRNA), microRNA (miRNA), and circular RNA (circRNA). These ncRNAs may function in trans or cis forms and modify gene transcription by various mechanisms, including epigenetics. NcRNAs may also serve as crucial regulators of angiogenesis-inducing molecules. These molecules include, metalloproteinases, cytokines, several growth factors (platelet-derived growth factor, vascular endothelial growth factor, fibroblast growth factor, hypoxia-inducible factor-1, and epidermal growth factor), phosphoinositide 3-kinase, mitogen-activated protein kinase, and transforming growth factor signaling pathways.

Co-Deregulated miRNA Signatures in Childhood Central Nervous System Tumors: In Search for Common Tumor miRNA-Related Mechanics

Simple Summary

Childhood tumors of the central nervous system (CNS) constitute a grave disease and their diagnosis is difficult to be handled. To gain better knowledge of the tumor’s biology, it is essential to understand the underlying mechanisms of the disease. MicroRNAs (miRNAs) are small noncoding RNAs that are dysregulated in many types of CNS tumors and regulate their occurrence and development through specific signal pathways. However, different types of CNS tumors’ area are characterized by different deregulated miRNAs. Here, we hypothesized that CNS tumors could have commonly deregulated miRNAs, i.e., miRNAs that are simultaneously either upregulated or downregulated in all tumor types compared to the normal brain tissue, irrespectively of the tumor sub-type and/or diagnosis. The only criterion is that they are present in brain tumors. This approach could lead us to the discovery of miRNAs that could be used as pan-CNS tumoral therapeutic targets, if successful.

Abstract

Despite extensive experimentation on pediatric tumors of the central nervous system (CNS), related to both prognosis, diagnosis and treatment, the understanding of pathogenesis and etiology of the disease remains scarce. MicroRNAs are known to be involved in CNS tumor oncogenesis. We hypothesized that CNS tumors possess commonly deregulated miRNAs across different CNS tumor types. Aim: The current study aims to reveal the co-deregulated miRNAs across different types of pediatric CNS tumors. Materials: A total of 439 CNS tumor samples were collected from both in-house microarray experiments as well as data available in public databases. Diagnoses included medulloblastoma, astrocytoma, ependydoma, cortical dysplasia, glioblastoma, ATRT, germinoma, teratoma, yoc sac tumors, ocular tumors and retinoblastoma. Results: We found miRNAs that were globally up- or down-regulated in the majority of the CNS tumor samples. MiR-376B and miR-372 were co-upregulated, whereas miR-149, miR-214, miR-574, miR-595 and miR-765 among others, were co-downregulated across all CNS tumors. Receiver-operator curve analysis showed that miR-149, miR-214, miR-574, miR-595 and miR765 could distinguish between CNS tumors and normal brain tissue. Conclusions: Our approach could prove significant in the search for global miRNA targets for tumor diagnosis and therapy. To the best of our knowledge, there are no previous reports concerning the present approach.

Interplay between SOX9 transcription factor and microRNAs in cancer

SOX transcription factors are critical regulators of development, homeostasis and disease progression and their dysregulation is a common finding in various cancers. SOX9 belongs to SOXE family located on chromosome 17. MicroRNAs (miRNAs) possess the capacity of regulating different transcription factors in cancer cells by binding to 3'-UTR. Since miRNAs can affect differentiation, migration, proliferation and other physiological mechanisms, disturbances in their expression have been associated with cancer development. In this review, we evaluate the relationship between miRNAs and SOX9 in different cancers to reveal how this interaction can affect proliferation, metastasis and therapy response of cancer cells. The tumor-suppressor miRNAs can decrease the expression of SOX9 by binding to the 3'-UTR of mRNAs. Furthermore, the expression of downstream targets of SOX9, such as c-Myc, Wnt, PI3K/Akt can be affected by miRNAs. It is noteworthy that other non-coding RNAs including lncRNAs and circRNAs regulate miRNA/SOX9 expression to promote/inhibit cancer progression and malignancy. The pre-clinical findings can be applied as biomarkers for diagnosis and prognosis of cancer patients.

Delivery of genome-editing biomacromolecules for treatment of lung genetic disorders

Genome-editing systems based on clustered, regularly interspaced, short palindromic repeat (CRISPR)/associated protein (CRISPR/Cas), are emerging as a revolutionary technology for the treatment of various genetic diseases. To date, the delivery of genome-editing biomacromolecules by viral or non-viral vectors have been proposed as new therapeutic options for lung genetic disorders, such as cystic fibrosis (CF) and α-1 antitrypsin deficiency (AATD), and it has been accepted that these delivery vectors can introduce CRISPR/Cas9 machineries into target cells or tissues in vitro, ex vivo and in vivo. However, the efficient local or systemic delivery of CRISPR/Cas9 elements to the lung, enabled by either viral or by non-viral carriers, still remains elusive. Herein, we first introduce lung genetic disorders and their current treatment options, and then summarize CRISPR/Cas9-based strategies for the therapeutic genome editing of these disorders. We further summarize the pros and cons of different routes of administration for lung genetic disorders. In particular, the potentials of aerosol delivery for therapeutic CRISPR/Cas9 biomacromolecules for lung genome editing are discussed and highlighted. Finally, current challenges and future outlooks in this emerging area are briefly discussed.

miR-613 Suppresses Chemoresistance and Stemness in Triple-Negative Breast Cancer by Targeting FAM83A

Introduction

Triple-negative breast cancer (TNBC) is the most aggressive malignancy of breast cancer, which represents about 20% of all cases. The prognosis of TNBC remains unfavorable due to the lack of targeted therapy and chemoresistance. The aim of this study is to investigate the role of miR-613 in TNBC.

Material and Methods

Quantitative RT-PCT was used to explore the expression of miR-613 in breast cancer clinical samples and cell lines. MTT, colony formation assay, spheroid formation assay and xenograft tumor growth assay were used to investigate the role of miR-613 in vitro and in vivo. Cell apoptosis and surface marker expression were measured by flow cytometry. Dual-luciferase reporter assay was used to explore the function of miR-613 in regulating FAM83A 3ʹUTR. Immunohistochemical staining was used to investigate the expression of FAM83A in TNBC tissues.

Results

We found that miR-613 expression was significantly downregulated in breast cancer tissues and was even lower in TNBC compared with that in other types of breast cancer. A similar result was found in breast cancer cell lines. Further analysis indicated that miR-613 could suppress TNBC cell growth, chemoresistance and stem-cell-like phenotype. Moreover, we also demonstrated that miR-613 suppressed tumorigenesis in vivo. Mechanically, we explored the downstream target of miR-613 and identified that miR-613 could directly bind to the 3ʹUTR of FAM83A, which contributed to the miR-613 mediated tumor suppression. The expression of miR-613 and FAM83A was negatively correlated. Restoring the expression of FAM83A attributed to the chemoresistance and stemness of TNBC cells.

Conclusion

We demonstrated that loss of miR-613 was critical for TNBC malignancy and restoring its expression could be served as a potential approach for TNBC treatment.

The Long Intergenic Noncoding RNA 00707 Sponges MicroRNA-613 (miR-613) to Promote Proliferation and Invasion of Gliomas

Background:

Glioma is one of the most deadly malignant tumors in humans. Long non-coding RNA (lncRNA) plays a key role in the occurrence, development and invasion of tumors by regulating oncogenic and tumor suppressor pathways. However, the role and action mechanism of long intergenic non-coding RNA 00707 (LINC00707) in gliomas have not been elucidated. This study aimed to investigate the interaction between LINC00707 and miR-613 as well as its role in gliomas.

Materials and Methods:

The expression levels of LINC00707 and miR-613 were detected by qRT-PCR. The chi-square test was used to analyze the correlation between LINC00707 expression and clinicopathological parameters. CCK-8 and colony formation assays were used to detect glioma cell proliferation; and wound healing and transwell assays were used to detect glioma cell migration and invasion. The relationship between LINC00707 and miR-613 was predicted by Starbase, and verified by qRT-PCR and dual luciferase reporter gene assay.

Results:

LINC00707 was up-regulated in gliomas. Up-regulated LINC00707 increased the proliferation, migration and invasion of glioma cells, and silenced LINC00707 reduced these abilities. The increase of the expression level of LINC00707 down-regulated miR-613 in glioma cells, while the inhibition of the expression level of LINC00707 up-regulated miR-613 in glioma cells. The high expression of LINC00707 was related to the Karnofsky performance status (KPS) score and WHO staging. LINC00707 could offset the ability of miR-613 to inhibit glioma proliferation and invasion.

Conclusion:

LINC00707 promotes proliferation and invasion of glioma cells by sponging miR-613. The regulatory axis of LINC00707/miR-613 provides new insights into the mechanism and treatment of gliomas.

Molecular and Cellular Complexity of Glioma. Focus on Tumour Microenvironment and the Use of Molecular and Imaging Biomarkers to Overcome Treatment Resistance

This review highlights the importance and the complexity of tumour biology and microenvironment in the progression and therapy resistance of glioma. Specific gene mutations, the possible functions of several non-coding microRNAs and the intra-tumour and inter-tumour heterogeneity of cell types contribute to limit the efficacy of the actual therapeutic options. In this scenario, identification of molecular biomarkers of response and the use of multimodal in vivo imaging and in particular the Positron Emission Tomography (PET) based molecular approach, can help identifying glioma features and the modifications occurring during therapy at a regional level. Indeed, a better understanding of tumor heterogeneity and the development of diagnostic procedures can favor the identification of a cluster of patients for personalized medicine in order to improve the survival and their quality of life.

The Caspase-3/PKCδ/Akt/VEGF-A Signaling Pathway Mediates Tumor Repopulation during Radiotherapy

PURPOSE

Tumor repopulation is known as a major cause of treatment failure and/or tumor recurrence after radiotherapy. The underlying mechanism remains unclear. Our previous study demonstrated that irradiated apoptotic cells mediated tumor repopulation, in which caspase-3 played an important role. Herein, we investigated downstream effectors of caspase-3 involved in this process.

EXPERIMENTAL DESIGN

A dominant-negative protein kinase Cδ (DN_PKCδ) mutant that could not be cleaved by caspase-3 and therefore could not be activated by irradiation-induced apoptosis was constructed. DN_PKCδ stably transduced tumor cells were compared with wild-type tumor cells for their growth stimulation effects in in vitro and in vivo tumor repopulation models. Downstream effectors of caspase-3 and PKCδ were investigated. The role of PKCδ was further verified in human colorectal tumor specimens.

RESULTS

Inactivation of caspase-3 or caspase-7 attenuated tumor repopulation and weakened PKCδ cleavage. Both DN_PKCδ and PKCδ inhibitors restrained tumor repopulation both in vitro and in vivo. Phosphorylated Akt was attenuated in caspase-3-, caspase-7-, or PKCδ-inactivated tumor cells. Furthermore, expression of vascular endothelial growth factor (VEGF)-A but not hypoxia-inducible factor 1α (HIF1α) was decreased in PKCδ- or Akt-inactivated tumor cells. In addition, inhibition of p-Akt, HIF1α, VEGF-A, or VEGF-A receptor reduced tumor repopulation significantly. Finally, increased nuclear translocation of PKCδ in colorectal tumor specimens was associated with worse patient prognosis.

CONCLUSIONS

The caspase-3/PKCδ/Akt/VEGF-A axis is involved in tumor repopulation and could be exploited as a potential target to enhance the efficacy of radiotherapy.