miR-373 Inhibits Glioma Cell U251 Migration and Invasion by Down-Regulating CD44 and TGFBR2

Exploring Exosome-Based Approaches for Early Diagnosis and Treatment of Neurodegenerative Diseases

Neurodegenerative diseases (NDs), like Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and Amyotrophic Lateral Sclerosis (ALS), present an increasingly significant global health burden, primarily due to the lack of effective early diagnostic tools and treatments. Exosomes-nano-sized extracellular vesicles secreted by nearly all cell types-have emerged as promising candidates for both biomarkers and therapeutic agents in NDs. This review examines the biogenesis, molecular composition, and diverse functions of exosomes in NDs. Exosomes play a crucial role in mediating intercellular communication. They are capable of reflecting the biochemical state of their parent cells and have the ability to cross the blood-brain barrier (BBB). In doing so, they facilitate the propagation of pathological proteins, such as amyloid-beta (Aβ), tau, and alpha-synuclein (α-syn), while also enabling the targeted delivery of neuroprotective compounds. Recent advancements in exosome isolation and engineering have opened up new possibilities for diagnostic and therapeutic strategies. These range from the discovery of non-invasive biomarkers to innovative approaches in gene therapy and drug delivery systems. However, challenges related to standardization, safety, and long-term effects must be addressed before exosomes can be translated into clinical applications. This review highlights both the promising potential and the obstacles that must be overcome to leverage exosomes in the treatment of NDs and the transformation of personalized medicine.

Multipronged SMAD pathway targeting by lipophilic poly(β-amino ester) miR-590-3p nanomiRs inhibits mesenchymal glioblastoma growth and prolongs survival

ASBSTRACT

Despite aggressive therapy, glioblastoma (GBM) recurs in almost all patients and treatment options are very limited. Despite our growing understanding of how cellular transitions associate with relapse in GBM, critical gaps remain in our ability to block these molecular changes and treat recurrent disease. In this study we combine computational biology, forward-thinking understanding of miRNA biology and cutting-edge nucleic acid delivery vehicles to advance targeted therapeutics for GBM. Computational analysis of RNA sequencing from clinical GBM specimens identified TGFβ type II receptor (TGFBR2) as a key player in the mesenchymal transition associated with worse outcome in GBM. Mechanistically, we show that elevated levels of TGFBR2 is conducive to reduced temozolomide (TMZ) sensitivity. This effect is, at least partially, induced by stem-cell driving events coordinated by the reprogramming transcription factors Oct4 and Sox2 that lead to open chromatin states. We show that blocking TGFBR2 via molecular and pharmacological approaches decreases stem cell capacity and sensitivity of clinical recurrent GBM (rGBM) isolates to TMZ in vitro. Network analysis uncovered miR-590-3p as a tumor suppressor that simultaneously inhibits multiple oncogenic nodes downstream of TGFBR2. We also developed novel biodegradable lipophilic poly(β-amino ester) nanoparticles (LiPBAEs) for in vivo microRNA (miRNAs) delivery. Following direct intra-tumoral infusion, these nanomiRs efficiently distribute through the tumors. Importantly, miR-590-3p nanomiRs inhibited the growth and extended survival of mice bearing orthotopic human rGBM xenografts, with an apparent 30% cure rate. These results show that miRNA-based targeted therapeutics provide new opportunities to treat rGBM and bypass the resistance to standard of care therapy.

Enhancing Therapeutic Efficacy in Cancer Treatment: Integrating Nanomedicine with Autophagy Inhibition Strategies

The complicated stepwise lysosomal degradation process known as autophagy is in charge of destroying and eliminating damaged organelles and defective cytoplasmic components. This mechanism promotes metabolic adaptability and nutrition recycling. Autophagy functions as a quality control mechanism in cells that support homeostasis and redox balance under normal circumstances. However, the role of autophagy in cancer is controversial because, mostly depending on the stage of the tumor, it may either suppress or support the disease. While autophagy delays the onset of tumors and slows the dissemination of cancer in the early stages of tumorigenesis, numerous studies demonstrate that autophagy promotes the development and spread of tumors as well as the evolution and development of resistance to several anticancer drugs in advanced cancer stages. In this Review, we primarily emphasize the therapeutic role of autophagy inhibition in improving the treatment of multiple cancers and give a broad overview of how its inhibition modulates cancer responses. There have been various attempts to inhibit autophagy, including the use of autophagy inhibitor drugs, gene silencing therapy (RNA interference), and nanoparticles. In this Review, all these topics are thoroughly covered and illustrated by recent studies and field investigations.

CD44 Modulates Cell Migration and Invasion in Ewing Sarcoma Cells

The chimeric EWSR1::FLI1 transcription factor is the main oncogenic event in Ewing sarcoma. Recently, it has been proposed that EWSR1::FLI1 levels can fluctuate in Ewing sarcoma cells, giving rise to two cell populations. EWSR1::FLI1^low cells present a migratory and invasive phenotype, while EWSR1::FLI1^high cells are more proliferative. In this work, we described how the CD44 standard isoform (CD44s), a transmembrane protein involved in cell adhesion and migration, is overexpressed in the EWSR1::FLI1^low phenotype. The functional characterization of CD44s (proliferation, clonogenicity, migration, and invasion ability) was performed in three doxycycline-inducible Ewing sarcoma cell models (A673, MHH-ES1, and CADO-ES1). As a result, CD44s expression reduced cell proliferation in all the cell lines tested without affecting clonogenicity. Additionally, CD44s increased cell migration in A673 and MHH-ES1, without effects in CADO-ES1. As hyaluronan is the main ligand of CD44s, its effect on migration ability was also assessed, showing that high molecular weight hyaluronic acid (HMW-HA) blocked cell migration while low molecular weight hyaluronic acid (LMW-HA) increased it. Invasion ability was correlated with CD44 expression in A673 and MHH-ES1 cell lines. CD44s, upregulated upon EWSR1::FLI1 knockdown, regulates cell migration and invasion in Ewing sarcoma cells.

Network of miR-373/miR-520s-CD44 Axis Significantly Inhibits the Growth and Invasion of Human Glioblastoma Cells

BACKGROUND

The expression and regulation of microRNAs (miRNAs) play an important role in glioblastoma (GBM) tumorigenesis, progression and prognosis. Little is known about the role of the miRNA regulatory network of GBM risk-related genes in GBM growth and invasiveness.

METHODS

The UALCAN and Oncomine gene expression dataset were used to explore gene expression profiles in human GBM. The Kaplan-Meier method was performed to evaluate the prognostic values of the GBM-related genes. Multiple bioinformatics databases were analysed to predict the GBM-related genes targeted by miRNAs. A luciferase reporter assay and other molecular cell function experiments were conducted to reveal the mechanisms of interaction between the identified miRNAs and their targets.

RESULTS

The CD44 expression is significantly higher in GBM tissues than that in normal tissues, and negatively correlated with survival duration in GBM patients. In normal physiological conditions, CD44 expression is lower in various parts of the central nervous system than in other organ systems. The mRNA encoding CD44 is a direct target of miR-373 and miR-520s, and this finding was verified by molecular biology experiments. We further found that miR-373 and miR-520s expression was negatively associated with CD44 expression in GBM specimens, and that the miR-373 or miR-520s-CD44 interaction network significantly affected the growth and invasiveness of GBM cells.

CONCLUSION

The miR-373 and miR-520s exert their functions by suppressing CD44 expression in GBM cells, and their expression, together with that of CD44, could thus serve as a valuable biomarker of GBM prognosis.

The Role of microRNAs in Multidrug Resistance of Glioblastoma

Glioblastoma (GBM) is an aggressive brain tumor that develops from neuroglial stem cells and represents a highly heterogeneous group of neoplasms. These tumors are predominantly correlated with a dismal prognosis and poor quality of life. In spite of major advances in developing novel and effective therapeutic strategies for patients with glioblastoma, multidrug resistance (MDR) is considered to be the major reason for treatment failure. Several mechanisms contribute to MDR in GBM, including upregulation of MDR transporters, alterations in the metabolism of drugs, dysregulation of apoptosis, defects in DNA repair, cancer stem cells, and epithelial-mesenchymal transition. MicroRNAs (miRNAs) are a large class of endogenous RNAs that participate in various cell events, including the mechanisms causing MDR in glioblastoma. In this review, we discuss the role of miRNAs in the regulation of the underlying mechanisms in MDR glioblastoma which will open up new avenues of inquiry for the treatment of glioblastoma.

miR-373 Suppresses Cell Proliferation and Apoptosis via Regulation of SIRT1/PGC-1α/NRF2 Axis in Pancreatic Cancer

Objective

Our study aimed to investigate function and mechanism of miR-373 in proliferation and apoptosis of pancreatic cancer (PC) cells by regulating NAD+-dependent histone deacetylase sirtulin 1 (SIRT1).

Materials and Methods

This experimental study included two PC cell lines AsPC-1 and PANC-1 in which expression levels of miR-373 and SIRT1 were manipulated. The level of miR-373 was detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) method. Expression levels of SIRT1, BCL-2, BAX, cleaved CASPASE-8/9/3, PARP, PGC-1α, NRF2, eNOS and iNOS were examined via RT-qPCR and western blotting, respectively. The binding sites of miR-373 on the SIRT1 were examined via dual-luciferase assay. Cell proliferation and apoptosis were examined by MTT assay, colony formation assay, Annexin-V/PI staining and TUNEL assay. The oxidative metabolic changes were monitored by reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) detection.

Results

miR-373 could specifically target the 3’-UTR of SIRT1 and reduce its expression in PC cells. Either elevated expression of miR-373 or partial loss of SIRT1 inhibited cell proliferation and induced cell apoptosis. Accumulation of BAX and cleaved CASPASE-8/9/3, inhibition of PGC-1α/NRF2 pathway, increase oxidative stress and reduction of BCL-2 as well as uncleaved PARP were found in the presence of miR-373 or the absence of SIRT1. Overexpression of SIRT1 could reduce anti-proliferative and pro-apoptotic effects of miR-373.

Conclusion

Overall, this study concluded that miR-373-dependent SIRT1 inhibition displays anti-proliferative and pro- apoptotic roles in PC cells via PGC-1α/NRF2 pathway, which highlights miR-373 as a potential target for PC treatment.

Oncogenesis and Tumor Inhibition by MicroRNAs and its Potential Therapeutic Applications: A Systematic Review

MicroRNAs appear as small molecule modifiers, which improve many new findings and mechanical illustrations for critically important biological phenomena and pathologic events. The best-characterized non-coding RNA family consists of about 2600 human microRNAs. Rich evidence has revealed their crucial importance in maintaining normal development, differentiation, growth control, aging, modulation of cell survival or apoptosis, as well as migration and metastasis as microRNAs dysregulation leads to cancer incidence and progression. By far, microRNAs have recently emerged as attractive targets for therapeutic intervention. The rationale for developing microRNA therapeutics is based on the premise that aberrantly expressed microRNAs play a significant role in the emergence of a variety of human diseases ranging from cardiovascular defects to cancer, and that repairing these microRNA deficiencies by either antagonizing or restoring microRNA function may yield a therapeutic benefit. Although microRNA antagonists are conceptually similar to other inhibitory therapies, improving the performance of microRNAs by microRNA replacement or inhibition that is a less well- described attitude. In this assay, we have condensed the last global knowledge and concepts regarding the involvement of microRNAs in cancer emergence, which has been achieved from the previous studies, consisting of the regulation of key cancer-related pathways, such as cell cycle control and the DNA damage response and the disruption of profile expression in human cancer. Here, we have reviewed the special characteristics of microRNA replacement and inhibition therapies and discussed explorations linked with the delivery of microRNA mimics in turmeric cells. Besides, the achievement of biomarkers based on microRNAs in clinics is considered as novel non-invasive biomarkers in diagnostic and prognostic assessments.

CD44 polymorphisms and its variants, as an inconsistent marker in cancer investigations

Among cell surface markers, CD44 is considered the main marker for identifying and isolating the cancer stem cells (CSCs) among other cells and has attracted significant attention in a variety of research areas. Many studies have shown the essential roles of CD44 in initiation, metastasis, and tumorigenesis in different types of cancer; however, the validity of CD44 as a therapeutic or diagnostic target has not been fully confirmed in some other studies. Whereas the association of specific single nucleotide polymorphisms (SNPs) in the CD44 gene and related variants with cancer risk have been observed in clinical investigations, the significance of these findings remains controversial. Here, we aimed to provide an up-to-date overview of recent studies on the association of CD44 polymorphisms and its variants with different kinds of cancer to determine whether or not it can be used as an appropriate candidate for cancer tracking.

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.

LncRNA MIR4435-2HG potentiates the proliferation and invasion of glioblastoma cells via modulating miR-1224-5p/TGFBR2 axis

Glioblastoma (GBM) belongs to the high-grade (IV) gliomas with extremely poor prognosis. Accumulating evidence uncovered the key roles of long non-coding RNAs (lncRNAs) in GBM development. This study aimed to determine the biological actions and the clinical relevance of lncRNA MIR4435-2 Host Gene (MIR4435-2HG) in GBM. Data from GEPIA database showed that MIR4435-2HG was up-regulated in GBM tissues and high expression of MIR4435-2HG correlated with shorter overall survival of GBM patients. Further experimental assays verified the up-regulation of MIR4435-2HG in GBM tissues and cell lines. In vitro cell studies and in vivo animal studies showed that knockdown of MIR4435-2HG resulted in the inhibition of GBM cell proliferation and invasion and in vivo tumour growth, while MIR4435-2HG overexpression driven GBM progression. Furthermore, MIR44435-2HG was found to sponge miR-1224-5p and suppress miR-1224-5p expression; overexpression of miR-1224-5p attenuated the enhancement in GBM cell proliferation and invasion induced by MIR4435-2HG overexpression. In a subsequent study, miR-1224-5p was found to target transforming growth factor-beta receptor type 2 (TGFBR2) and repressed TGFBR2 expression, and in vitro assays showed that miR-1224-5p exerted tumour-suppressive effects via targeting TGFBR2. More importantly, TGFRB2 knockdown antagonized hyper-proliferation and invasion of GBM cells with MIR4435-2HG overexpression. Clinically, the down-regulation of miR-1224-5p and up-regulation of TGFBR2 were verified in the GBM clinical samples. Taken together, the present study suggests the oncogenic role of MIR4435-2HG in GBM and underlies the key function of MIR4435-2HG-driven GBM progression via targeting miR-1224-5p/TGFBR2 axis.

Abuhamad A, Syahir A. Understanding Glioblastoma Biomarkers: Knocking a Mountain with a Hammer

Gliomas are the most frequent and deadly form of human primary brain tumors. Among them, the most common and aggressive type is the high-grade glioblastoma multiforme (GBM), which rapidly grows and renders patients a very poor prognosis. Meanwhile, cancer stem cells (CSCs) have been determined in gliomas and play vital roles in driving tumor growth due to their competency in self-renewal and proliferation. Studies of gliomas have recognized CSCs via specific markers. This review comprehensively examines the current knowledge of the most significant CSCs markers in gliomas in general and in glioblastoma in particular and specifically focuses on their outlook and importance in gliomas CSCs research. We suggest that CSCs should be the superior therapeutic approach by directly targeting the markers. In addition, we highlight the association of these markers with each other in relation to their cascading pathways, and interactions with functional miRNAs, providing the role of the networks axes in glioblastoma signaling pathways.

Propofol Inhibits Cell Proliferation, Migration, and Invasion via mir-410-3p/Transforming Growth Factor-β Receptor Type 2 (TGFBR2) Axis in Glioma

BACKGROUND Propofol is a common intravenous anesthetic used to induce and maintain anesthesia. Numerous studies have reported that propofol plays an anti-tumor role in diverse human cancers, including glioma. In this research, we explored the roles of propofol and its related molecular mechanisms in glioma. MATERIAL AND METHODS U251 and A172 cells were exposed to different doses of propofol for 24 h. Cell proliferation, migration, and invasion in glioma were evaluated using MTT assay and Transwell assay, respectively. The levels of microRNA-410-3p (miR-410-3p) and transforming growth factor-ß receptor type 2 (TGFBR2) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) assay and Western blot assay, respectively. The association between miR-410-3p and TGFBR2 was predicted by TargetScan and confirmed by dual-luciferase reporter assay. RESULTS Propofol inhibited the proliferation, migration, and invasion of glioma cells in a concentration-dependent way. miR-410-3p was induced and TGFBR2 was inhibited by different concentrations of propofol treatment. Moreover, TGFBR2 was confirmed to be a target gene of miR-410-3p and TGFBR2 was inversely modulated by miR-410-3p in glioma cells. Depletion of miR-410-3p reversed the inhibition of propofol treatment on U251 and A172 cell growth and metastasis, but the effects were further abolished by knocking down the expression of TGFBR2. CONCLUSIONS Propofol can suppress cell growth and metastasis by regulating the miR-410-3p/TGFBR2 axis in glioma.

Exosomal miRNAs in central nervous system diseases: biomarkers, pathological mediators, protective factors and therapeutic agents

Exosomes are small bilipid layer-enclosed extracellular vesicles that can be found in tissues and biological fluids. As a key cell-to-cell and distant communication mediator, exosomes are involved in various central nervous system (CNS) diseases, potentially through transferring their contents such as proteins, lipids and nucleic acids to the target cells. Exosomal miRNAs, which are small non-coding RNAs in the exosomes, are known to be more stable than free miRNAs and therefore have lasting effects on disease-related gene expressions. There are distinct profiles of exosomal miRNAs in different types of CNS diseases even before the onset of irreversible neurological damages, indicating that exosomal miRNAs within tissues and biological fluids could serve as promising biomarkers. Emerging evidence has also demonstrated the pathological effects of several exosomal miRNAs in CNS diseases via specific modulation of disease-related factors. Moreover, exosomes carry therapeutically beneficial miRNAs across the blood-brain-barrier, which can be exploited as a powerful drug delivery tool to help alleviating multiple CNS diseases. In this review, we summarize the recent progress made in understanding the biological roles of exosomal miRNAs as potential diagnostic biomarkers, pathological regulators, and therapeutic targets/drugs for CNS diseases. A comprehensive discussion of the main concerns and challenges for the applications of exosomal miRNAs in the clinical setting is also provided.

Characterizing CD44 regulatory microRNAs as putative therapeutic agents in human melanoma

The multistructural and multifunctional transmembrane glycoprotein CD44 is overexpressed in many tumors of distinct origin including malignant melanoma and contributes to a poor prognosis by affecting cell proliferation, cell migration, and also the sensitivity for apoptosis induction. Previous studies reported so far 15 CD44 regulatory microRNAs (miRs) in different cell systems. Using a novel method for miR affinity purification miR-143-3p was identified as most potent binder to the 3' untranslated region (UTR) of CD44. Overexpression of miR-143-3p in melanoma cells inhibits CD44 translation, which is accompanied by a reduced proliferation, migration and enhanced daunorubicin induced apoptosis of melanoma cells in vitro. Analyses of discordant CD44 and miR-143-3p expression levels in human melanocytic nevi and dermal melanoma samples demonstrated medium to high CD44 levels with no association to tumor grading or staging. The CD44 expression correlated to PD-L1, but not to MART-1 expression in malignant melanoma. Interestingly, the CD44 expression was inversely correlated to the infiltration of pro-inflammatory immune effector cells. In conclusion, the tumor suppressive miR-143-3p was identified as the most potent CD44 inhibitory miR, which affects growth characteristics of melanoma cells suggesting the implementation of miR-143-3p as as a potential anti-CD44 therapy of malignant melanoma.

Mechanism of microRNA-431-5p-EPB41L1 interaction in glioblastoma multiforme cells

INTRODUCTION

Glioblastoma multiforme (GBM) is a kind of malignant brain tumor prevalent in adults, with the characteristics well adapted to poorly immunogenic and hypoxic conditions. Effective treatment of GBM is impeded due to the high proliferation, migration and invasion of GBM cells. GBM cells migrate by degrading the extracellular matrix, so it is difficult to have GBM cells eradicated completely by surgery. This study aims to confirm that miR-431-5p could influence the proliferation, invasion and migration of human glioblastoma multiforme cells by targeting EPB41L1 (erythrocyte membrane protein band 4.1).

MATERIAL AND METHODS

The expression levels of miR-431-5p and EPB41L1 were detected in GBM cells and tissues using qRT-PCR. Dual luciferase reporter gene assay and western blot were applied to confirm the targeting relationship between miR-431-5p and EPB41L1. GBM cell line U87 was used in MTT, flow cytometry, Transwell, and wound healing assays to determine cell proliferation, migration and invasion.

RESULTS

MiR-431-5p was overexpressed in GBM tissues while EPB41L1 was under-expressed. The results of dual luciferase reporter gene assay and western blot demonstrated that miR-431-5p could target EPB41L1 and suppress its expression. Down-regulating the expression of miR-431-5p or up-regulating the expression of EPB41L1 could inhibit the proliferation, invasion and migration but promote the apoptosis of GBM cells.

CONCLUSIONS

MiR-431-5p facilitated the progression of GBM by inhibiting EPB41L1 expression.

MicroRNA in Brain pathology: Neurodegeneration the Other Side of the Brain Cancer

The mammalian brain is made up of billions of neurons and supporting cells (glial cells), intricately connected. Molecular perturbations often lead to neurodegeneration by progressive loss of structure and malfunction of neurons, including their death. On the other side, a combination of genetic and cellular factors in glial cells, and less frequently in neurons, drive oncogenic transformation. In both situations, microenvironmental niches influence the progression of diseases and therapeutic responses. Dynamic changes that occur in cellular transcriptomes during the progression of developmental lineages and pathogenesis are controlled through a variety of regulatory networks. These include epigenetic modifications, signaling pathways, and transcriptional and post-transcriptional mechanisms. One prominent component of the latter is small non-coding RNAs, including microRNAs, that control the vast majority of these networks including genes regulating neural stemness, differentiation, apoptosis, projection fates, migration and many others. These cellular processes are also profoundly dependent on the microenvironment, stemness niche, hypoxic microenvironment, and interactions with associated cells including endothelial and immune cells. Significantly, the brain of all other mammalian organs expresses the highest number of microRNAs, with an additional gain in expression in the early stage of neurodegeneration and loss in expression in oncogenesis. However, a mechanistic explanation of the concept of an apparent inverse correlation between the odds of cancer and neurodegenerative diseases is only weakly developed. In this review, we thus will discuss widespread de-regulation of microRNAome observed in these two major groups of brain pathologies. The deciphering of these intricacies is of importance, as therapeutic restoration of pre-pathological microRNA landscape in neurodegeneration must not lead to oncogenesis and vice versa. We thus focus on microRNAs engaged in cellular processes that are inversely regulated in these diseases. We also aim to define the difference in microRNA networks between pro-survival and pro-apoptotic signaling in the brain.

Potential Epigenetic-Based Therapeutic Targets for Glioma

Glioma is characterized by a high recurrence rate, short survival times, high rates of mortality and treatment difficulties. Surgery, chemotherapy and radiation (RT) are the standard treatments, but outcomes rarely improve even after treatment. With the advancement of molecular pathology, recent studies have found that the development of glioma is closely related to various epigenetic phenomena, including DNA methylation, abnormal microRNA (miRNA), chromatin remodeling and histone modifications. Owing to the reversibility of epigenetic modifications, the proteins and genes that regulate these changes have become new targets in the treatment of glioma. In this review, we present a summary of the potential therapeutic targets of glioma and related effective treating drugs from the four aspects mentioned above. We further illustrate how epigenetic mechanisms dynamically regulate the pathogenesis and discuss the challenges of glioma treatment. Currently, among the epigenetic treatments, DNA methyltransferase (DNMT) inhibitors and histone deacetylase inhibitors (HDACIs) can be used for the treatment of tumors, either individually or in combination. In the treatment of glioma, only HDACIs remain a good option and they provide new directions for the treatment. Due to the complicated pathogenesis of glioma, epigenetic applications to glioma clinical treatment are still limited.

MicroRNA-373 promotes cell migration via targeting salt-inducible kinase 1 expression in melanoma

It is well established that altered expression of microRNAs (miRs) is critical in numerous human cancer types. Nevertheless, the molecular mechanisms of many miRs are yet to be elucidated. In the present study, reverse transcription-quantitative polymerase chain reaction and western blot analyses, and cell migration assays were performed to verify dysregulation of miR-373 in melanoma and its biological function. The transcriptional level of miR-373 was identified to be upregulated in melanoma tissues and cell lines compared with nevus and normal melanocytes. miR-373 was identified to function as an oncomiR, promoting melanoma cell migration. Notably, miR-373 was observed to suppress its downstream gene salt-inducible kinase 1 (SIK1) through directly binding the 3'-untranslated region of SIK1 expression. Furthermore, reduced SIK1 expression was identified to be responsible for the oncogenic effect of miR-373. In conclusion, the present study indicates that miR-373 functions as an oncomiR to promote melanoma progression through targeting SIK1 expression. This may provide a new therapeutic approach for melanoma.

Aberrant miRNAs Regulate the Biological Hallmarks of Glioblastoma

GBM is the highest incidence in primary intracranial malignancy, and it remains poor prognosis even though the patient is gave standard treatment. Despite decades of intense research, the complex biology of GBM remains elusive. In view of eight hallmarks of cancer which were proposed in 2011, studies related to the eight biological capabilities in GBM have made great progress. From these studies, it can be inferred that miRs, as a mode of post-transcriptional regulation, are involved in regulating these malignant biological hallmarks of GBM. Herein, we discuss state-of-the-art research on how aberrant miRs modulate the eight hallmarks of GBM. The upregulation of 'oncomiRs' or the genetic loss of tumor suppressor miRs is associated with these eight biological capabilities acquired during GBM formation. Furthermore, we also discuss the applicable clinical potential of these research results. MiRs may aid in the diagnosis and prognosis of GBM. Moreover, miRs are also therapeutic targets of GBM. These studies will develop and improve precision medicine for GBM in the future.

Low serum miR-373 predicts poor prognosis in patients with pancreatic cancer

BACKGROUND

Circulating microRNAs (miRNAs) are emerging as novel biomarkers for various types of cancer including pancreatic cancer (PC).

OBJECTIVE

We aimed to explore the diagnostic and prognostic significance of serum miR-373 in PC.

METHODS

In the current study, we recruited a total of 103 PC patients, 30 patients with benign pancreatic tumor, 20 patients with chronic pancreatitis and 50 healthy volunteers. Total RNA was isolated from all the blood samples, and relative miR-373 expression levels were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR).

RESULTS

Our findings demonstrated that serum miR-373 expression was greatly down-regulated in PC patients. The area under the receiver-operating characteristic (ROC) curve (AUC) for serum miR-373 was 0.852 for discriminating PC patients from normal control subjects. In addition, a positive correlation was observed between reduced serum miR-373 level and several clinical parameters, including TNM stage, lymph node metastasis and distant metastasis. Moreover, PC patients with lower serum miR-373 level had shorter 5 year overall survival. Finally, serum miR-373 was proved to be an independent predictor for PC.

CONCLUSIONS

Taken together, serum miR-373 might serve as a promising biomarker for the early detection and prognosis prediction of PC.

Expression and role of microRNA-1271 in the pathogenesis of osteosarcoma

The aim of the current study was to investigate the expression and role of microRNA (miR)-1271 in the pathogenesis of osteosarcoma, and the associated underlying mechanisms. Tissue samples from 45 patients with osteosarcoma were collected, while the 143B, MG-63 and U-2 OS osteosarcoma cell lines were also cultured. The expression levels of miR-1271 in the tissues and cells were detected with reverse transcription-quantitative polymerase chain reaction, and 143B osteosarcoma cells were subjected to miR-1271 manipulation. In addition, the cell proliferation, cell cycle progression, and migration and invasion abilities were assessed by Cell Counting Kit-8 assay, flow cytometry and Transwell chamber assay, respectively. Tissue inhibitor of metalloproteinases 2 (TIMP2) expression level was also detected with western blot analysis. Dual-luciferase reporter assay was performed to investigate the interaction between miR-1271 and TIMP2. The results revealed that miR-1271 expression was significantly elevated in the osteosarcoma tissue and was closely correlated with the clinical TNM staging. The expression levels of miR-1271 were also upregulated in the osteosarcoma cells, with the highest expression observed in 143B cells. Inhibition of miR-1271 significantly inhibited the cell proliferation, G1/S phase transition, and the migration and invasion abilities of 143B cells, while it also resulted in upregulated TIMP2 expression in these cells. Furthermore, overexpression of TIMP2 significantly inhibited the cell proliferation, G1/S phase transition, and migration and invasion abilities of 143B cells. Dual-luciferase reporter assay demonstrated that miR-1271 targeted on the 3′-untranslated region of TIMP2 mRNA. In conclusion, the expression levels of miR-1271 were significantly elevated in osteosarcoma tissues and cells. miR-1271 downregulated the expression of TIMP2 to promote the proliferation and enhance the migration and invasion abilities of 143B osteosarcoma cells, functioning as an oncogene.

MicroRNA-98 Attenuates Cell Migration and Invasion in Glioma by Directly Targeting Pre-B Cell Leukemia Homeobox 3

Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults. The extraordinary invasion of human GBM into adjacent normal brain tissues contributes to treatment failure. However, the mechanisms that control this process remain poorly understood. Increasing evidence has demonstrated that microRNAs are strongly implicated in the migration and invasion of GBM. In this study, we found that microRNA-98 (miR-98) was markedly downregulated in human glioma tissues and cell lines. Functional experiments indicated that restored expression of miR-98 attenuated glioma cell invasion and migration, whereas depletion of miR-98 promoted glioma cell invasion and migration. Subsequent investigation showed that pre-B-cell leukemia homeobox 3 (PBX3), an important transcription factor that controls tumor invasion, was a direct and functional target of miR-98 in GBM cells. Consistently, an orthotopic mouse model also demonstrated the suppressive effects of miR-98 overexpression on tumor invasion and PBX3 expression. Silencing of PBX3 using small interfering RNA inhibited the migratory and invasive capacities of glioma cells, whereas reintroduction of PBX3 into glioma cells reversed the anti-invasive function of miR-98. Furthermore, depletion of PBX3 phenocopied the effects of miR-98 overexpression in vivo. Finally, quantitative real-time polymerase chain reaction results showed that miR-98 was negatively correlated with PBX3 expression in 24 glioma tissues. Thus, we propose that PBX3 modulation by miR-98 has an important role in regulating GBM invasion and may serve as therapeutic target for GBM.

Photoacoustic-Guided Surgery with Indocyanine Green-Coated Superparamagnetic Iron Oxide Nanoparticle Clusters

A common cause of local tumor recurrence in brain tumor surgery results from incomplete surgical resection. Adjunctive technologies meant to facilitate gross total resection have had limited efficacy to date. Contrast agents used to delineate tumors preoperatively cannot be easily or accurately used in the real-time operative setting. Although multimodal imaging contrast agents are developed to help the surgeon discern tumor from normal tissue in the operating room, these contrast agents are not readily translatable. This study has developed a novel contrast agent comprised solely of two Food and Drug Administration approved components, indocyanine green (ICG) and superparamagnetic iron oxide (SPIO) nanoparticles-with no additional amphiphiles or carrier materials, to enable preoperative detection by magnetic resonance (MR) imaging and intraoperative photoacoustic (PA) imaging. The encapsulation efficiency of both ICG and SPIO within the formulated clusters is ≈100%, and the total ICG payload is 20-30% of the total weight (ICG + SPIO). The ICG-SPIO clusters are stable in physiologic conditions; can be taken up within tumors by enhanced permeability and retention; and are detectable by MR. In a preclinical surgical resection model in mice, following injection of ICG-SPIO clusters, animals undergoing PA-guided surgery demonstrate increased progression-free survival compared to animals undergoing microscopic surgery.

Following MicroRNAs Through the Cancer Metastatic Cascade

Approximately a decade ago the first MicroRNAs (MiRNAs) participating in cancer metastasis were identified and metastmiRs were initially only a handful. Since those first reports, MiRNA research has explosively thrived, mainly due to their revolutionary mechanism of action and the hope of having at hand a novel tool to control cancer aggressiveness. This has ultimately led to delineate an almost impenetrable regulatory network: hundreds of MiRNAs transversally dominating every aspect of normal and cancer biology, each MiRNA having hundreds of targets and context-dependent activity. Providing a comprehensive description of MiRNA roles in cancer metastasis is a daunting task; nevertheless, we still believe that grasping the big picture of MiRNAs in cancer metastasis can give a different perspective on the potential insights and approaches that MiRNAs can offer to understand cancer complexity (e.g., as predictive and prognostic markers) and to tackle cancer metastasis (e.g., as therapeutic targets or tools). This chapter presents a schematic overview of the role of MiRNAs in governing cancer metastasis, describing step by step the cellular and molecular processes whereby cancer cells conquer distant organs and can grow as secondary tumors at different distant sites, and for each step, we will introduce how MiRNAs impinge on each one of them. We deeply apologize with our colleagues for any of their research work that, for clarity, for our effort to streamline and due to space limitations, we did not cite.

miRNA-520f Reverses Epithelial-to-Mesenchymal Transition by Targeting ADAM9 and TGFBR2

Reversing epithelial-to-mesenchymal transition (EMT) in cancer cells has been widely considered as an approach to combat cancer progression and therapeutic resistance, but a limited number of broadly comprehensive investigations of miRNAs involved in this process have been conducted. In this study, we screened a library of 1120 miRNA for their ability to transcriptionally activate the E-cadherin gene CDH1 in a promoter reporter assay as a measure of EMT reversal. By this approach, we defined miR-520f as a novel EMT-reversing miRNA. miR-520f expression was sufficient to restore endogenous levels of E-cadherin in cancer cell lines exhibiting strong or intermediate mesenchymal phenotypes. In parallel, miR-520f inhibited invasive behavior in multiple cancer cell systems and reduced metastasis in an experimental mouse model of lung metastasis. Mechanistically, miR-520f inhibited tumor cell invasion by directly targeting ADAM9, the TGFβ receptor TGFBR2 and the EMT inducers ZEB1, ZEB2, and the snail transcriptional repressor SNAI2, each crucial factors in mediating EMT. Collectively, our results show that miR-520f exerts anti-invasive and antimetastatic effects in vitro and in vivo, warranting further study in clinical settings. Cancer Res; 77(8); 2008-17. ©2017 AACR.